| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Rafael J. Wysocki | 2500 | 11.85% | 57 | 11.56% |
| Alex Williamson | 2327 | 11.03% | 25 | 5.07% |
| Rajat Jain | 1165 | 5.52% | 2 | 0.41% |
| Björn Helgaas | 1035 | 4.90% | 50 | 10.14% |
| Mika Westerberg | 751 | 3.56% | 10 | 2.03% |
| Logan Gunthorpe | 733 | 3.47% | 8 | 1.62% |
| Tejun Heo | 525 | 2.49% | 7 | 1.42% |
| Patrick Mochel | 508 | 2.41% | 1 | 0.20% |
| Tal Gilboa | 471 | 2.23% | 5 | 1.01% |
| Christian König | 466 | 2.21% | 3 | 0.61% |
| Yinghai Lu | 373 | 1.77% | 9 | 1.83% |
| Yu Zhao | 373 | 1.77% | 10 | 2.03% |
| Peter Oruba | 364 | 1.72% | 1 | 0.20% |
| Lorenzo Pieralisi | 351 | 1.66% | 2 | 0.41% |
| Michael Ellerman | 328 | 1.55% | 2 | 0.41% |
| Sean O. Stalley | 326 | 1.54% | 2 | 0.41% |
| Huang Ying | 300 | 1.42% | 5 | 1.01% |
| Keith Busch | 294 | 1.39% | 7 | 1.42% |
| Benjamin Herrenschmidt | 289 | 1.37% | 5 | 1.01% |
| Yuji Shimada | 270 | 1.28% | 2 | 0.41% |
| Christoph Hellwig | 263 | 1.25% | 5 | 1.01% |
| Linus Torvalds | 253 | 1.20% | 4 | 0.81% |
| Hidetoshi Seto | 250 | 1.18% | 3 | 0.61% |
| Matthew Garrett | 249 | 1.18% | 2 | 0.41% |
| Michael S. Tsirkin | 242 | 1.15% | 2 | 0.41% |
| Stephen Hemminger | 239 | 1.13% | 2 | 0.41% |
| Sheng Yang | 230 | 1.09% | 4 | 0.81% |
| Jan Kiszka | 219 | 1.04% | 2 | 0.41% |
| Ryan Desfosses | 198 | 0.94% | 3 | 0.61% |
| Jay Cornwall | 193 | 0.91% | 1 | 0.20% |
| Tomasz Nowicki | 184 | 0.87% | 4 | 0.81% |
| Jon Mason | 180 | 0.85% | 4 | 0.81% |
| Sinan Kaya | 157 | 0.74% | 13 | 2.64% |
| Vidya Sagar | 144 | 0.68% | 2 | 0.41% |
| Arjan van de Ven | 143 | 0.68% | 2 | 0.41% |
| Liviu Dudau | 136 | 0.64% | 2 | 0.41% |
| Heiner Kallweit | 130 | 0.62% | 2 | 0.41% |
| Jens Axboe | 127 | 0.60% | 1 | 0.20% |
| Linus Torvalds (pre-git) | 127 | 0.60% | 15 | 3.04% |
| Sergei Shtylyov | 126 | 0.60% | 1 | 0.20% |
| Lukas Wunner | 124 | 0.59% | 11 | 2.23% |
| Brice Goglin | 117 | 0.55% | 2 | 0.41% |
| Yongji Xie | 110 | 0.52% | 5 | 1.01% |
| Oza Pawandeep | 100 | 0.47% | 1 | 0.20% |
| Matthew Wilcox | 100 | 0.47% | 4 | 0.81% |
| Eric W. Biedermann | 98 | 0.46% | 2 | 0.41% |
| Roland Dreier | 98 | 0.46% | 1 | 0.20% |
| Myron Stowe | 97 | 0.46% | 3 | 0.61% |
| John W. Linville | 91 | 0.43% | 3 | 0.61% |
| Jacob E Keller | 90 | 0.43% | 1 | 0.20% |
| Kai-Heng Feng | 82 | 0.39% | 2 | 0.41% |
| Jacek Lawrynowicz | 81 | 0.38% | 1 | 0.20% |
| Mike Travis | 79 | 0.37% | 1 | 0.20% |
| James Sewart | 78 | 0.37% | 2 | 0.41% |
| Pavel Machek | 75 | 0.36% | 6 | 1.22% |
| Atsushi Nemoto | 75 | 0.36% | 1 | 0.20% |
| Luis R. Rodriguez | 72 | 0.34% | 1 | 0.20% |
| Daniel Drake | 70 | 0.33% | 1 | 0.20% |
| Ben Hutchings | 70 | 0.33% | 1 | 0.20% |
| Nicholas Johnson | 69 | 0.33% | 1 | 0.20% |
| Kristen Carlson Accardi | 66 | 0.31% | 3 | 0.61% |
| Jesse Barnes | 65 | 0.31% | 4 | 0.81% |
| Andrew Morton | 64 | 0.30% | 5 | 1.01% |
| Brett M Russ | 62 | 0.29% | 2 | 0.41% |
| Ivan Kokshaysky | 58 | 0.27% | 2 | 0.41% |
| David Daney | 58 | 0.27% | 2 | 0.41% |
| Konrad Rzeszutek Wilk | 56 | 0.27% | 3 | 0.61% |
| Shaohua Li | 53 | 0.25% | 8 | 1.62% |
| Denis Efremov | 50 | 0.24% | 2 | 0.41% |
| Alan Stern | 50 | 0.24% | 3 | 0.61% |
| Dean Nelson | 49 | 0.23% | 3 | 0.61% |
| Jiang Liu | 48 | 0.23% | 1 | 0.20% |
| Jeff Garzik | 46 | 0.22% | 2 | 0.41% |
| Zhichang Yuan | 45 | 0.21% | 1 | 0.20% |
| Marc Zyngier | 43 | 0.20% | 1 | 0.20% |
| Felipe Balbi | 43 | 0.20% | 1 | 0.20% |
| Scott Murray | 41 | 0.19% | 1 | 0.20% |
| Gavin Shan | 39 | 0.18% | 4 | 0.81% |
| Gil Kupfer | 39 | 0.18% | 1 | 0.20% |
| Randy Dunlap | 36 | 0.17% | 6 | 1.22% |
| Brian King | 34 | 0.16% | 1 | 0.20% |
| Andrew Patterson | 32 | 0.15% | 2 | 0.41% |
| Alexandru Gagniuc | 32 | 0.15% | 1 | 0.20% |
| Allen M Kay | 31 | 0.15% | 2 | 0.41% |
| Jon Derrick | 31 | 0.15% | 1 | 0.20% |
| Yijing Wang | 30 | 0.14% | 6 | 1.22% |
| Dave Airlie | 27 | 0.13% | 2 | 0.41% |
| Mathias Koehrer | 27 | 0.13% | 1 | 0.20% |
| Yan Zheng | 26 | 0.12% | 1 | 0.20% |
| FUJITA Tomonori | 24 | 0.11% | 2 | 0.41% |
| Jan Glauber | 23 | 0.11% | 1 | 0.20% |
| Iñaky Pérez-González | 23 | 0.11% | 1 | 0.20% |
| Bolarinwa Olayemi Saheed | 22 | 0.10% | 1 | 0.20% |
| Frederick Lawler | 21 | 0.10% | 1 | 0.20% |
| Chen Yu | 20 | 0.09% | 1 | 0.20% |
| Greg Kroah-Hartman | 20 | 0.09% | 6 | 1.22% |
| Konstantin Khlebnikov | 20 | 0.09% | 1 | 0.20% |
| Kenji Kaneshige | 17 | 0.08% | 5 | 1.01% |
| Casey Leedom | 17 | 0.08% | 1 | 0.20% |
| Ram Pai | 17 | 0.08% | 2 | 0.41% |
| Alan Cox | 16 | 0.08% | 1 | 0.20% |
| CQ Tang | 13 | 0.06% | 1 | 0.20% |
| Sasha Neftin | 13 | 0.06% | 1 | 0.20% |
| Hanjun Guo | 12 | 0.06% | 1 | 0.20% |
| David Brownell | 11 | 0.05% | 2 | 0.41% |
| Dave Jones | 11 | 0.05% | 1 | 0.20% |
| Vignesh Babu | 11 | 0.05% | 1 | 0.20% |
| Shawn Lin | 11 | 0.05% | 1 | 0.20% |
| Krzysztof Hałasa | 10 | 0.05% | 1 | 0.20% |
| Sebastian Ott | 10 | 0.05% | 1 | 0.20% |
| Mayurkumar Patel | 10 | 0.05% | 1 | 0.20% |
| Alex Deucher | 10 | 0.05% | 1 | 0.20% |
| Brian Norris | 10 | 0.05% | 1 | 0.20% |
| Quentin Lambert | 9 | 0.04% | 2 | 0.41% |
| Mikulas Patocka | 9 | 0.04% | 1 | 0.20% |
| Taku Izumi | 9 | 0.04% | 2 | 0.41% |
| Dennis Dalessandro | 8 | 0.04% | 2 | 0.41% |
| Gustavo A. R. Silva | 6 | 0.03% | 2 | 0.41% |
| Alexander Duyck | 6 | 0.03% | 1 | 0.20% |
| Andi Kleen | 5 | 0.02% | 1 | 0.20% |
| Thomas Gleixner | 5 | 0.02% | 1 | 0.20% |
| Gabriele Paoloni | 5 | 0.02% | 1 | 0.20% |
| Will Deacon | 5 | 0.02% | 1 | 0.20% |
| Ray Jui | 5 | 0.02% | 1 | 0.20% |
| Ben Dooks | 4 | 0.02% | 2 | 0.41% |
| Adrian Hunter | 4 | 0.02% | 1 | 0.20% |
| Mohan Kumar | 4 | 0.02% | 2 | 0.41% |
| Krzysztof Wilczynski | 4 | 0.02% | 2 | 0.41% |
| Dexuan Cui | 4 | 0.02% | 1 | 0.20% |
| Roger Luethi | 3 | 0.01% | 1 | 0.20% |
| Xudong Hao | 3 | 0.01% | 1 | 0.20% |
| Andy Shevchenko | 3 | 0.01% | 2 | 0.41% |
| Alek Du | 3 | 0.01% | 1 | 0.20% |
| Yicong Yang | 3 | 0.01% | 1 | 0.20% |
| Tim Schmielau | 3 | 0.01% | 1 | 0.20% |
| Stephen Rothwell | 3 | 0.01% | 1 | 0.20% |
| Harvey Harrison | 2 | 0.01% | 1 | 0.20% |
| Sumit Saxena | 2 | 0.01% | 1 | 0.20% |
| Al Viro | 2 | 0.01% | 2 | 0.41% |
| Jakub Kiciński | 2 | 0.01% | 1 | 0.20% |
| Wei Yang | 2 | 0.01% | 1 | 0.20% |
| Yu Luming | 2 | 0.01% | 1 | 0.20% |
| Gustavo Pimentel | 2 | 0.01% | 1 | 0.20% |
| Jan H. Schönherr | 2 | 0.01% | 1 | 0.20% |
| Roman Fietze | 1 | 0.00% | 1 | 0.20% |
| Kuppuswamy Sathyanarayanan | 1 | 0.00% | 1 | 0.20% |
| John Crispin | 1 | 0.00% | 1 | 0.20% |
| Julia Lawall | 1 | 0.00% | 1 | 0.20% |
| Piotr Gregor | 1 | 0.00% | 1 | 0.20% |
| Frans Pop | 1 | 0.00% | 1 | 0.20% |
| Wang Sheng-Hui | 1 | 0.00% | 1 | 0.20% |
| Geliang Tang | 1 | 0.00% | 1 | 0.20% |
| Total | 21105 | 493 |
// SPDX-License-Identifier: GPL-2.0 /* * PCI Bus Services, see include/linux/pci.h for further explanation. * * Copyright 1993 -- 1997 Drew Eckhardt, Frederic Potter, * David Mosberger-Tang * * Copyright 1997 -- 2000 Martin Mares <mj@ucw.cz> */ #include <linux/acpi.h> #include <linux/kernel.h> #include <linux/delay.h> #include <linux/dmi.h> #include <linux/init.h> #include <linux/msi.h> #include <linux/of.h> #include <linux/of_pci.h> #include <linux/pci.h> #include <linux/pm.h> #include <linux/slab.h> #include <linux/module.h> #include <linux/spinlock.h> #include <linux/string.h> #include <linux/log2.h> #include <linux/logic_pio.h> #include <linux/pm_wakeup.h> #include <linux/interrupt.h> #include <linux/device.h> #include <linux/pm_runtime.h> #include <linux/pci_hotplug.h> #include <linux/vmalloc.h> #include <linux/pci-ats.h> #include <asm/setup.h> #include <asm/dma.h> #include <linux/aer.h> #include "pci.h" DEFINE_MUTEX(pci_slot_mutex); const char *pci_power_names[] = { "error", "D0", "D1", "D2", "D3hot", "D3cold", "unknown", }; EXPORT_SYMBOL_GPL(pci_power_names); int isa_dma_bridge_buggy; EXPORT_SYMBOL(isa_dma_bridge_buggy); int pci_pci_problems; EXPORT_SYMBOL(pci_pci_problems); unsigned int pci_pm_d3_delay; static void pci_pme_list_scan(struct work_struct *work); static LIST_HEAD(pci_pme_list); static DEFINE_MUTEX(pci_pme_list_mutex); static DECLARE_DELAYED_WORK(pci_pme_work, pci_pme_list_scan); struct pci_pme_device { struct list_head list; struct pci_dev *dev; }; #define PME_TIMEOUT 1000 /* How long between PME checks */ static void pci_dev_d3_sleep(struct pci_dev *dev) { unsigned int delay = dev->d3_delay; if (delay < pci_pm_d3_delay) delay = pci_pm_d3_delay; if (delay) msleep(delay); } #ifdef CONFIG_PCI_DOMAINS int pci_domains_supported = 1; #endif #define DEFAULT_CARDBUS_IO_SIZE (256) #define DEFAULT_CARDBUS_MEM_SIZE (64*1024*1024) /* pci=cbmemsize=nnM,cbiosize=nn can override this */ unsigned long pci_cardbus_io_size = DEFAULT_CARDBUS_IO_SIZE; unsigned long pci_cardbus_mem_size = DEFAULT_CARDBUS_MEM_SIZE; #define DEFAULT_HOTPLUG_IO_SIZE (256) #define DEFAULT_HOTPLUG_MMIO_SIZE (2*1024*1024) #define DEFAULT_HOTPLUG_MMIO_PREF_SIZE (2*1024*1024) /* hpiosize=nn can override this */ unsigned long pci_hotplug_io_size = DEFAULT_HOTPLUG_IO_SIZE; /* * pci=hpmmiosize=nnM overrides non-prefetchable MMIO size, * pci=hpmmioprefsize=nnM overrides prefetchable MMIO size; * pci=hpmemsize=nnM overrides both */ unsigned long pci_hotplug_mmio_size = DEFAULT_HOTPLUG_MMIO_SIZE; unsigned long pci_hotplug_mmio_pref_size = DEFAULT_HOTPLUG_MMIO_PREF_SIZE; #define DEFAULT_HOTPLUG_BUS_SIZE 1 unsigned long pci_hotplug_bus_size = DEFAULT_HOTPLUG_BUS_SIZE; enum pcie_bus_config_types pcie_bus_config = PCIE_BUS_DEFAULT; /* * The default CLS is used if arch didn't set CLS explicitly and not * all pci devices agree on the same value. Arch can override either * the dfl or actual value as it sees fit. Don't forget this is * measured in 32-bit words, not bytes. */ u8 pci_dfl_cache_line_size = L1_CACHE_BYTES >> 2; u8 pci_cache_line_size; /* * If we set up a device for bus mastering, we need to check the latency * timer as certain BIOSes forget to set it properly. */ unsigned int pcibios_max_latency = 255; /* If set, the PCIe ARI capability will not be used. */ static bool pcie_ari_disabled; /* If set, the PCIe ATS capability will not be used. */ static bool pcie_ats_disabled; /* If set, the PCI config space of each device is printed during boot. */ bool pci_early_dump; bool pci_ats_disabled(void) { return pcie_ats_disabled; } EXPORT_SYMBOL_GPL(pci_ats_disabled); /* Disable bridge_d3 for all PCIe ports */ static bool pci_bridge_d3_disable; /* Force bridge_d3 for all PCIe ports */ static bool pci_bridge_d3_force; static int __init pcie_port_pm_setup(char *str) { if (!strcmp(str, "off")) pci_bridge_d3_disable = true; else if (!strcmp(str, "force")) pci_bridge_d3_force = true; return 1; } __setup("pcie_port_pm=", pcie_port_pm_setup); /* Time to wait after a reset for device to become responsive */ #define PCIE_RESET_READY_POLL_MS 60000 /** * pci_bus_max_busnr - returns maximum PCI bus number of given bus' children * @bus: pointer to PCI bus structure to search * * Given a PCI bus, returns the highest PCI bus number present in the set * including the given PCI bus and its list of child PCI buses. */ unsigned char pci_bus_max_busnr(struct pci_bus *bus) { struct pci_bus *tmp; unsigned char max, n; max = bus->busn_res.end; list_for_each_entry(tmp, &bus->children, node) { n = pci_bus_max_busnr(tmp); if (n > max) max = n; } return max; } EXPORT_SYMBOL_GPL(pci_bus_max_busnr); /** * pci_status_get_and_clear_errors - return and clear error bits in PCI_STATUS * @pdev: the PCI device * * Returns error bits set in PCI_STATUS and clears them. */ int pci_status_get_and_clear_errors(struct pci_dev *pdev) { u16 status; int ret; ret = pci_read_config_word(pdev, PCI_STATUS, &status); if (ret != PCIBIOS_SUCCESSFUL) return -EIO; status &= PCI_STATUS_ERROR_BITS; if (status) pci_write_config_word(pdev, PCI_STATUS, status); return status; } EXPORT_SYMBOL_GPL(pci_status_get_and_clear_errors); #ifdef CONFIG_HAS_IOMEM void __iomem *pci_ioremap_bar(struct pci_dev *pdev, int bar) { struct resource *res = &pdev->resource[bar]; /* * Make sure the BAR is actually a memory resource, not an IO resource */ if (res->flags & IORESOURCE_UNSET || !(res->flags & IORESOURCE_MEM)) { pci_warn(pdev, "can't ioremap BAR %d: %pR\n", bar, res); return NULL; } return ioremap(res->start, resource_size(res)); } EXPORT_SYMBOL_GPL(pci_ioremap_bar); void __iomem *pci_ioremap_wc_bar(struct pci_dev *pdev, int bar) { /* * Make sure the BAR is actually a memory resource, not an IO resource */ if (!(pci_resource_flags(pdev, bar) & IORESOURCE_MEM)) { WARN_ON(1); return NULL; } return ioremap_wc(pci_resource_start(pdev, bar), pci_resource_len(pdev, bar)); } EXPORT_SYMBOL_GPL(pci_ioremap_wc_bar); #endif /** * pci_dev_str_match_path - test if a path string matches a device * @dev: the PCI device to test * @path: string to match the device against * @endptr: pointer to the string after the match * * Test if a string (typically from a kernel parameter) formatted as a * path of device/function addresses matches a PCI device. The string must * be of the form: * * [<domain>:]<bus>:<device>.<func>[/<device>.<func>]* * * A path for a device can be obtained using 'lspci -t'. Using a path * is more robust against bus renumbering than using only a single bus, * device and function address. * * Returns 1 if the string matches the device, 0 if it does not and * a negative error code if it fails to parse the string. */ static int pci_dev_str_match_path(struct pci_dev *dev, const char *path, const char **endptr) { int ret; int seg, bus, slot, func; char *wpath, *p; char end; *endptr = strchrnul(path, ';'); wpath = kmemdup_nul(path, *endptr - path, GFP_KERNEL); if (!wpath) return -ENOMEM; while (1) { p = strrchr(wpath, '/'); if (!p) break; ret = sscanf(p, "/%x.%x%c", &slot, &func, &end); if (ret != 2) { ret = -EINVAL; goto free_and_exit; } if (dev->devfn != PCI_DEVFN(slot, func)) { ret = 0; goto free_and_exit; } /* * Note: we don't need to get a reference to the upstream * bridge because we hold a reference to the top level * device which should hold a reference to the bridge, * and so on. */ dev = pci_upstream_bridge(dev); if (!dev) { ret = 0; goto free_and_exit; } *p = 0; } ret = sscanf(wpath, "%x:%x:%x.%x%c", &seg, &bus, &slot, &func, &end); if (ret != 4) { seg = 0; ret = sscanf(wpath, "%x:%x.%x%c", &bus, &slot, &func, &end); if (ret != 3) { ret = -EINVAL; goto free_and_exit; } } ret = (seg == pci_domain_nr(dev->bus) && bus == dev->bus->number && dev->devfn == PCI_DEVFN(slot, func)); free_and_exit: kfree(wpath); return ret; } /** * pci_dev_str_match - test if a string matches a device * @dev: the PCI device to test * @p: string to match the device against * @endptr: pointer to the string after the match * * Test if a string (typically from a kernel parameter) matches a specified * PCI device. The string may be of one of the following formats: * * [<domain>:]<bus>:<device>.<func>[/<device>.<func>]* * pci:<vendor>:<device>[:<subvendor>:<subdevice>] * * The first format specifies a PCI bus/device/function address which * may change if new hardware is inserted, if motherboard firmware changes, * or due to changes caused in kernel parameters. If the domain is * left unspecified, it is taken to be 0. In order to be robust against * bus renumbering issues, a path of PCI device/function numbers may be used * to address the specific device. The path for a device can be determined * through the use of 'lspci -t'. * * The second format matches devices using IDs in the configuration * space which may match multiple devices in the system. A value of 0 * for any field will match all devices. (Note: this differs from * in-kernel code that uses PCI_ANY_ID which is ~0; this is for * legacy reasons and convenience so users don't have to specify * FFFFFFFFs on the command line.) * * Returns 1 if the string matches the device, 0 if it does not and * a negative error code if the string cannot be parsed. */ static int pci_dev_str_match(struct pci_dev *dev, const char *p, const char **endptr) { int ret; int count; unsigned short vendor, device, subsystem_vendor, subsystem_device; if (strncmp(p, "pci:", 4) == 0) { /* PCI vendor/device (subvendor/subdevice) IDs are specified */ p += 4; ret = sscanf(p, "%hx:%hx:%hx:%hx%n", &vendor, &device, &subsystem_vendor, &subsystem_device, &count); if (ret != 4) { ret = sscanf(p, "%hx:%hx%n", &vendor, &device, &count); if (ret != 2) return -EINVAL; subsystem_vendor = 0; subsystem_device = 0; } p += count; if ((!vendor || vendor == dev->vendor) && (!device || device == dev->device) && (!subsystem_vendor || subsystem_vendor == dev->subsystem_vendor) && (!subsystem_device || subsystem_device == dev->subsystem_device)) goto found; } else { /* * PCI Bus, Device, Function IDs are specified * (optionally, may include a path of devfns following it) */ ret = pci_dev_str_match_path(dev, p, &p); if (ret < 0) return ret; else if (ret) goto found; } *endptr = p; return 0; found: *endptr = p; return 1; } static int __pci_find_next_cap_ttl(struct pci_bus *bus, unsigned int devfn, u8 pos, int cap, int *ttl) { u8 id; u16 ent; pci_bus_read_config_byte(bus, devfn, pos, &pos); while ((*ttl)--) { if (pos < 0x40) break; pos &= ~3; pci_bus_read_config_word(bus, devfn, pos, &ent); id = ent & 0xff; if (id == 0xff) break; if (id == cap) return pos; pos = (ent >> 8); } return 0; } static int __pci_find_next_cap(struct pci_bus *bus, unsigned int devfn, u8 pos, int cap) { int ttl = PCI_FIND_CAP_TTL; return __pci_find_next_cap_ttl(bus, devfn, pos, cap, &ttl); } int pci_find_next_capability(struct pci_dev *dev, u8 pos, int cap) { return __pci_find_next_cap(dev->bus, dev->devfn, pos + PCI_CAP_LIST_NEXT, cap); } EXPORT_SYMBOL_GPL(pci_find_next_capability); static int __pci_bus_find_cap_start(struct pci_bus *bus, unsigned int devfn, u8 hdr_type) { u16 status; pci_bus_read_config_word(bus, devfn, PCI_STATUS, &status); if (!(status & PCI_STATUS_CAP_LIST)) return 0; switch (hdr_type) { case PCI_HEADER_TYPE_NORMAL: case PCI_HEADER_TYPE_BRIDGE: return PCI_CAPABILITY_LIST; case PCI_HEADER_TYPE_CARDBUS: return PCI_CB_CAPABILITY_LIST; } return 0; } /** * pci_find_capability - query for devices' capabilities * @dev: PCI device to query * @cap: capability code * * Tell if a device supports a given PCI capability. * Returns the address of the requested capability structure within the * device's PCI configuration space or 0 in case the device does not * support it. Possible values for @cap include: * * %PCI_CAP_ID_PM Power Management * %PCI_CAP_ID_AGP Accelerated Graphics Port * %PCI_CAP_ID_VPD Vital Product Data * %PCI_CAP_ID_SLOTID Slot Identification * %PCI_CAP_ID_MSI Message Signalled Interrupts * %PCI_CAP_ID_CHSWP CompactPCI HotSwap * %PCI_CAP_ID_PCIX PCI-X * %PCI_CAP_ID_EXP PCI Express */ int pci_find_capability(struct pci_dev *dev, int cap) { int pos; pos = __pci_bus_find_cap_start(dev->bus, dev->devfn, dev->hdr_type); if (pos) pos = __pci_find_next_cap(dev->bus, dev->devfn, pos, cap); return pos; } EXPORT_SYMBOL(pci_find_capability); /** * pci_bus_find_capability - query for devices' capabilities * @bus: the PCI bus to query * @devfn: PCI device to query * @cap: capability code * * Like pci_find_capability() but works for PCI devices that do not have a * pci_dev structure set up yet. * * Returns the address of the requested capability structure within the * device's PCI configuration space or 0 in case the device does not * support it. */ int pci_bus_find_capability(struct pci_bus *bus, unsigned int devfn, int cap) { int pos; u8 hdr_type; pci_bus_read_config_byte(bus, devfn, PCI_HEADER_TYPE, &hdr_type); pos = __pci_bus_find_cap_start(bus, devfn, hdr_type & 0x7f); if (pos) pos = __pci_find_next_cap(bus, devfn, pos, cap); return pos; } EXPORT_SYMBOL(pci_bus_find_capability); /** * pci_find_next_ext_capability - Find an extended capability * @dev: PCI device to query * @start: address at which to start looking (0 to start at beginning of list) * @cap: capability code * * Returns the address of the next matching extended capability structure * within the device's PCI configuration space or 0 if the device does * not support it. Some capabilities can occur several times, e.g., the * vendor-specific capability, and this provides a way to find them all. */ int pci_find_next_ext_capability(struct pci_dev *dev, int start, int cap) { u32 header; int ttl; int pos = PCI_CFG_SPACE_SIZE; /* minimum 8 bytes per capability */ ttl = (PCI_CFG_SPACE_EXP_SIZE - PCI_CFG_SPACE_SIZE) / 8; if (dev->cfg_size <= PCI_CFG_SPACE_SIZE) return 0; if (start) pos = start; if (pci_read_config_dword(dev, pos, &header) != PCIBIOS_SUCCESSFUL) return 0; /* * If we have no capabilities, this is indicated by cap ID, * cap version and next pointer all being 0. */ if (header == 0) return 0; while (ttl-- > 0) { if (PCI_EXT_CAP_ID(header) == cap && pos != start) return pos; pos = PCI_EXT_CAP_NEXT(header); if (pos < PCI_CFG_SPACE_SIZE) break; if (pci_read_config_dword(dev, pos, &header) != PCIBIOS_SUCCESSFUL) break; } return 0; } EXPORT_SYMBOL_GPL(pci_find_next_ext_capability); /** * pci_find_ext_capability - Find an extended capability * @dev: PCI device to query * @cap: capability code * * Returns the address of the requested extended capability structure * within the device's PCI configuration space or 0 if the device does * not support it. Possible values for @cap include: * * %PCI_EXT_CAP_ID_ERR Advanced Error Reporting * %PCI_EXT_CAP_ID_VC Virtual Channel * %PCI_EXT_CAP_ID_DSN Device Serial Number * %PCI_EXT_CAP_ID_PWR Power Budgeting */ int pci_find_ext_capability(struct pci_dev *dev, int cap) { return pci_find_next_ext_capability(dev, 0, cap); } EXPORT_SYMBOL_GPL(pci_find_ext_capability); /** * pci_get_dsn - Read and return the 8-byte Device Serial Number * @dev: PCI device to query * * Looks up the PCI_EXT_CAP_ID_DSN and reads the 8 bytes of the Device Serial * Number. * * Returns the DSN, or zero if the capability does not exist. */ u64 pci_get_dsn(struct pci_dev *dev) { u32 dword; u64 dsn; int pos; pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DSN); if (!pos) return 0; /* * The Device Serial Number is two dwords offset 4 bytes from the * capability position. The specification says that the first dword is * the lower half, and the second dword is the upper half. */ pos += 4; pci_read_config_dword(dev, pos, &dword); dsn = (u64)dword; pci_read_config_dword(dev, pos + 4, &dword); dsn |= ((u64)dword) << 32; return dsn; } EXPORT_SYMBOL_GPL(pci_get_dsn); static int __pci_find_next_ht_cap(struct pci_dev *dev, int pos, int ht_cap) { int rc, ttl = PCI_FIND_CAP_TTL; u8 cap, mask; if (ht_cap == HT_CAPTYPE_SLAVE || ht_cap == HT_CAPTYPE_HOST) mask = HT_3BIT_CAP_MASK; else mask = HT_5BIT_CAP_MASK; pos = __pci_find_next_cap_ttl(dev->bus, dev->devfn, pos, PCI_CAP_ID_HT, &ttl); while (pos) { rc = pci_read_config_byte(dev, pos + 3, &cap); if (rc != PCIBIOS_SUCCESSFUL) return 0; if ((cap & mask) == ht_cap) return pos; pos = __pci_find_next_cap_ttl(dev->bus, dev->devfn, pos + PCI_CAP_LIST_NEXT, PCI_CAP_ID_HT, &ttl); } return 0; } /** * pci_find_next_ht_capability - query a device's Hypertransport capabilities * @dev: PCI device to query * @pos: Position from which to continue searching * @ht_cap: Hypertransport capability code * * To be used in conjunction with pci_find_ht_capability() to search for * all capabilities matching @ht_cap. @pos should always be a value returned * from pci_find_ht_capability(). * * NB. To be 100% safe against broken PCI devices, the caller should take * steps to avoid an infinite loop. */ int pci_find_next_ht_capability(struct pci_dev *dev, int pos, int ht_cap) { return __pci_find_next_ht_cap(dev, pos + PCI_CAP_LIST_NEXT, ht_cap); } EXPORT_SYMBOL_GPL(pci_find_next_ht_capability); /** * pci_find_ht_capability - query a device's Hypertransport capabilities * @dev: PCI device to query * @ht_cap: Hypertransport capability code * * Tell if a device supports a given Hypertransport capability. * Returns an address within the device's PCI configuration space * or 0 in case the device does not support the request capability. * The address points to the PCI capability, of type PCI_CAP_ID_HT, * which has a Hypertransport capability matching @ht_cap. */ int pci_find_ht_capability(struct pci_dev *dev, int ht_cap) { int pos; pos = __pci_bus_find_cap_start(dev->bus, dev->devfn, dev->hdr_type); if (pos) pos = __pci_find_next_ht_cap(dev, pos, ht_cap); return pos; } EXPORT_SYMBOL_GPL(pci_find_ht_capability); /** * pci_find_parent_resource - return resource region of parent bus of given * region * @dev: PCI device structure contains resources to be searched * @res: child resource record for which parent is sought * * For given resource region of given device, return the resource region of * parent bus the given region is contained in. */ struct resource *pci_find_parent_resource(const struct pci_dev *dev, struct resource *res) { const struct pci_bus *bus = dev->bus; struct resource *r; int i; pci_bus_for_each_resource(bus, r, i) { if (!r) continue; if (resource_contains(r, res)) { /* * If the window is prefetchable but the BAR is * not, the allocator made a mistake. */ if (r->flags & IORESOURCE_PREFETCH && !(res->flags & IORESOURCE_PREFETCH)) return NULL; /* * If we're below a transparent bridge, there may * be both a positively-decoded aperture and a * subtractively-decoded region that contain the BAR. * We want the positively-decoded one, so this depends * on pci_bus_for_each_resource() giving us those * first. */ return r; } } return NULL; } EXPORT_SYMBOL(pci_find_parent_resource); /** * pci_find_resource - Return matching PCI device resource * @dev: PCI device to query * @res: Resource to look for * * Goes over standard PCI resources (BARs) and checks if the given resource * is partially or fully contained in any of them. In that case the * matching resource is returned, %NULL otherwise. */ struct resource *pci_find_resource(struct pci_dev *dev, struct resource *res) { int i; for (i = 0; i < PCI_STD_NUM_BARS; i++) { struct resource *r = &dev->resource[i]; if (r->start && resource_contains(r, res)) return r; } return NULL; } EXPORT_SYMBOL(pci_find_resource); /** * pci_wait_for_pending - wait for @mask bit(s) to clear in status word @pos * @dev: the PCI device to operate on * @pos: config space offset of status word * @mask: mask of bit(s) to care about in status word * * Return 1 when mask bit(s) in status word clear, 0 otherwise. */ int pci_wait_for_pending(struct pci_dev *dev, int pos, u16 mask) { int i; /* Wait for Transaction Pending bit clean */ for (i = 0; i < 4; i++) { u16 status; if (i) msleep((1 << (i - 1)) * 100); pci_read_config_word(dev, pos, &status); if (!(status & mask)) return 1; } return 0; } static int pci_acs_enable; /** * pci_request_acs - ask for ACS to be enabled if supported */ void pci_request_acs(void) { pci_acs_enable = 1; } static const char *disable_acs_redir_param; /** * pci_disable_acs_redir - disable ACS redirect capabilities * @dev: the PCI device * * For only devices specified in the disable_acs_redir parameter. */ static void pci_disable_acs_redir(struct pci_dev *dev) { int ret = 0; const char *p; int pos; u16 ctrl; if (!disable_acs_redir_param) return; p = disable_acs_redir_param; while (*p) { ret = pci_dev_str_match(dev, p, &p); if (ret < 0) { pr_info_once("PCI: Can't parse disable_acs_redir parameter: %s\n", disable_acs_redir_param); break; } else if (ret == 1) { /* Found a match */ break; } if (*p != ';' && *p != ',') { /* End of param or invalid format */ break; } p++; } if (ret != 1) return; if (!pci_dev_specific_disable_acs_redir(dev)) return; pos = dev->acs_cap; if (!pos) { pci_warn(dev, "cannot disable ACS redirect for this hardware as it does not have ACS capabilities\n"); return; } pci_read_config_word(dev, pos + PCI_ACS_CTRL, &ctrl); /* P2P Request & Completion Redirect */ ctrl &= ~(PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_EC); pci_write_config_word(dev, pos + PCI_ACS_CTRL, ctrl); pci_info(dev, "disabled ACS redirect\n"); } /** * pci_std_enable_acs - enable ACS on devices using standard ACS capabilities * @dev: the PCI device */ static void pci_std_enable_acs(struct pci_dev *dev) { int pos; u16 cap; u16 ctrl; pos = dev->acs_cap; if (!pos) return; pci_read_config_word(dev, pos + PCI_ACS_CAP, &cap); pci_read_config_word(dev, pos + PCI_ACS_CTRL, &ctrl); /* Source Validation */ ctrl |= (cap & PCI_ACS_SV); /* P2P Request Redirect */ ctrl |= (cap & PCI_ACS_RR); /* P2P Completion Redirect */ ctrl |= (cap & PCI_ACS_CR); /* Upstream Forwarding */ ctrl |= (cap & PCI_ACS_UF); pci_write_config_word(dev, pos + PCI_ACS_CTRL, ctrl); } /** * pci_enable_acs - enable ACS if hardware support it * @dev: the PCI device */ static void pci_enable_acs(struct pci_dev *dev) { if (!pci_acs_enable) goto disable_acs_redir; if (!pci_dev_specific_enable_acs(dev)) goto disable_acs_redir; pci_std_enable_acs(dev); disable_acs_redir: /* * Note: pci_disable_acs_redir() must be called even if ACS was not * enabled by the kernel because it may have been enabled by * platform firmware. So if we are told to disable it, we should * always disable it after setting the kernel's default * preferences. */ pci_disable_acs_redir(dev); } /** * pci_restore_bars - restore a device's BAR values (e.g. after wake-up) * @dev: PCI device to have its BARs restored * * Restore the BAR values for a given device, so as to make it * accessible by its driver. */ static void pci_restore_bars(struct pci_dev *dev) { int i; for (i = 0; i < PCI_BRIDGE_RESOURCES; i++) pci_update_resource(dev, i); } static const struct pci_platform_pm_ops *pci_platform_pm; int pci_set_platform_pm(const struct pci_platform_pm_ops *ops) { if (!ops->is_manageable || !ops->set_state || !ops->get_state || !ops->choose_state || !ops->set_wakeup || !ops->need_resume) return -EINVAL; pci_platform_pm = ops; return 0; } static inline bool platform_pci_power_manageable(struct pci_dev *dev) { return pci_platform_pm ? pci_platform_pm->is_manageable(dev) : false; } static inline int platform_pci_set_power_state(struct pci_dev *dev, pci_power_t t) { return pci_platform_pm ? pci_platform_pm->set_state(dev, t) : -ENOSYS; } static inline pci_power_t platform_pci_get_power_state(struct pci_dev *dev) { return pci_platform_pm ? pci_platform_pm->get_state(dev) : PCI_UNKNOWN; } static inline void platform_pci_refresh_power_state(struct pci_dev *dev) { if (pci_platform_pm && pci_platform_pm->refresh_state) pci_platform_pm->refresh_state(dev); } static inline pci_power_t platform_pci_choose_state(struct pci_dev *dev) { return pci_platform_pm ? pci_platform_pm->choose_state(dev) : PCI_POWER_ERROR; } static inline int platform_pci_set_wakeup(struct pci_dev *dev, bool enable) { return pci_platform_pm ? pci_platform_pm->set_wakeup(dev, enable) : -ENODEV; } static inline bool platform_pci_need_resume(struct pci_dev *dev) { return pci_platform_pm ? pci_platform_pm->need_resume(dev) : false; } static inline bool platform_pci_bridge_d3(struct pci_dev *dev) { if (pci_platform_pm && pci_platform_pm->bridge_d3) return pci_platform_pm->bridge_d3(dev); return false; } /** * pci_raw_set_power_state - Use PCI PM registers to set the power state of * given PCI device * @dev: PCI device to handle. * @state: PCI power state (D0, D1, D2, D3hot) to put the device into. * * RETURN VALUE: * -EINVAL if the requested state is invalid. * -EIO if device does not support PCI PM or its PM capabilities register has a * wrong version, or device doesn't support the requested state. * 0 if device already is in the requested state. * 0 if device's power state has been successfully changed. */ static int pci_raw_set_power_state(struct pci_dev *dev, pci_power_t state) { u16 pmcsr; bool need_restore = false; /* Check if we're already there */ if (dev->current_state == state) return 0; if (!dev->pm_cap) return -EIO; if (state < PCI_D0 || state > PCI_D3hot) return -EINVAL; /* * Validate transition: We can enter D0 from any state, but if * we're already in a low-power state, we can only go deeper. E.g., * we can go from D1 to D3, but we can't go directly from D3 to D1; * we'd have to go from D3 to D0, then to D1. */ if (state != PCI_D0 && dev->current_state <= PCI_D3cold && dev->current_state > state) { pci_err(dev, "invalid power transition (from %s to %s)\n", pci_power_name(dev->current_state), pci_power_name(state)); return -EINVAL; } /* Check if this device supports the desired state */ if ((state == PCI_D1 && !dev->d1_support) || (state == PCI_D2 && !dev->d2_support)) return -EIO; pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr); if (pmcsr == (u16) ~0) { pci_err(dev, "can't change power state from %s to %s (config space inaccessible)\n", pci_power_name(dev->current_state), pci_power_name(state)); return -EIO; } /* * If we're (effectively) in D3, force entire word to 0. * This doesn't affect PME_Status, disables PME_En, and * sets PowerState to 0. */ switch (dev->current_state) { case PCI_D0: case PCI_D1: case PCI_D2: pmcsr &= ~PCI_PM_CTRL_STATE_MASK; pmcsr |= state; break; case PCI_D3hot: case PCI_D3cold: case PCI_UNKNOWN: /* Boot-up */ if ((pmcsr & PCI_PM_CTRL_STATE_MASK) == PCI_D3hot && !(pmcsr & PCI_PM_CTRL_NO_SOFT_RESET)) need_restore = true; fallthrough; /* force to D0 */ default: pmcsr = 0; break; } /* Enter specified state */ pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, pmcsr); /* * Mandatory power management transition delays; see PCI PM 1.1 * 5.6.1 table 18 */ if (state == PCI_D3hot || dev->current_state == PCI_D3hot) pci_dev_d3_sleep(dev); else if (state == PCI_D2 || dev->current_state == PCI_D2) msleep(PCI_PM_D2_DELAY); pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr); dev->current_state = (pmcsr & PCI_PM_CTRL_STATE_MASK); if (dev->current_state != state) pci_info_ratelimited(dev, "refused to change power state from %s to %s\n", pci_power_name(dev->current_state), pci_power_name(state)); /* * According to section 5.4.1 of the "PCI BUS POWER MANAGEMENT * INTERFACE SPECIFICATION, REV. 1.2", a device transitioning * from D3hot to D0 _may_ perform an internal reset, thereby * going to "D0 Uninitialized" rather than "D0 Initialized". * For example, at least some versions of the 3c905B and the * 3c556B exhibit this behaviour. * * At least some laptop BIOSen (e.g. the Thinkpad T21) leave * devices in a D3hot state at boot. Consequently, we need to * restore at least the BARs so that the device will be * accessible to its driver. */ if (need_restore) pci_restore_bars(dev); if (dev->bus->self) pcie_aspm_pm_state_change(dev->bus->self); return 0; } /** * pci_update_current_state - Read power state of given device and cache it * @dev: PCI device to handle. * @state: State to cache in case the device doesn't have the PM capability * * The power state is read from the PMCSR register, which however is * inaccessible in D3cold. The platform firmware is therefore queried first * to detect accessibility of the register. In case the platform firmware * reports an incorrect state or the device isn't power manageable by the * platform at all, we try to detect D3cold by testing accessibility of the * vendor ID in config space. */ void pci_update_current_state(struct pci_dev *dev, pci_power_t state) { if (platform_pci_get_power_state(dev) == PCI_D3cold || !pci_device_is_present(dev)) { dev->current_state = PCI_D3cold; } else if (dev->pm_cap) { u16 pmcsr; pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr); dev->current_state = (pmcsr & PCI_PM_CTRL_STATE_MASK); } else { dev->current_state = state; } } /** * pci_refresh_power_state - Refresh the given device's power state data * @dev: Target PCI device. * * Ask the platform to refresh the devices power state information and invoke * pci_update_current_state() to update its current PCI power state. */ void pci_refresh_power_state(struct pci_dev *dev) { if (platform_pci_power_manageable(dev)) platform_pci_refresh_power_state(dev); pci_update_current_state(dev, dev->current_state); } /** * pci_platform_power_transition - Use platform to change device power state * @dev: PCI device to handle. * @state: State to put the device into. */ int pci_platform_power_transition(struct pci_dev *dev, pci_power_t state) { int error; if (platform_pci_power_manageable(dev)) { error = platform_pci_set_power_state(dev, state); if (!error) pci_update_current_state(dev, state); } else error = -ENODEV; if (error && !dev->pm_cap) /* Fall back to PCI_D0 */ dev->current_state = PCI_D0; return error; } EXPORT_SYMBOL_GPL(pci_platform_power_transition); /** * pci_wakeup - Wake up a PCI device * @pci_dev: Device to handle. * @ign: ignored parameter */ static int pci_wakeup(struct pci_dev *pci_dev, void *ign) { pci_wakeup_event(pci_dev); pm_request_resume(&pci_dev->dev); return 0; } /** * pci_wakeup_bus - Walk given bus and wake up devices on it * @bus: Top bus of the subtree to walk. */ void pci_wakeup_bus(struct pci_bus *bus) { if (bus) pci_walk_bus(bus, pci_wakeup, NULL); } static int pci_dev_wait(struct pci_dev *dev, char *reset_type, int timeout) { int delay = 1; u32 id; /* * After reset, the device should not silently discard config * requests, but it may still indicate that it needs more time by * responding to them with CRS completions. The Root Port will * generally synthesize ~0 data to complete the read (except when * CRS SV is enabled and the read was for the Vendor ID; in that * case it synthesizes 0x0001 data). * * Wait for the device to return a non-CRS completion. Read the * Command register instead of Vendor ID so we don't have to * contend with the CRS SV value. */ pci_read_config_dword(dev, PCI_COMMAND, &id); while (id == ~0) { if (delay > timeout) { pci_warn(dev, "not ready %dms after %s; giving up\n", delay - 1, reset_type); return -ENOTTY; } if (delay > 1000) pci_info(dev, "not ready %dms after %s; waiting\n", delay - 1, reset_type); msleep(delay); delay *= 2; pci_read_config_dword(dev, PCI_COMMAND, &id); } if (delay > 1000) pci_info(dev, "ready %dms after %s\n", delay - 1, reset_type); return 0; } /** * pci_power_up - Put the given device into D0 * @dev: PCI device to power up */ int pci_power_up(struct pci_dev *dev) { pci_platform_power_transition(dev, PCI_D0); /* * Mandatory power management transition delays are handled in * pci_pm_resume_noirq() and pci_pm_runtime_resume() of the * corresponding bridge. */ if (dev->runtime_d3cold) { /* * When powering on a bridge from D3cold, the whole hierarchy * may be powered on into D0uninitialized state, resume them to * give them a chance to suspend again */ pci_wakeup_bus(dev->subordinate); } return pci_raw_set_power_state(dev, PCI_D0); } /** * __pci_dev_set_current_state - Set current state of a PCI device * @dev: Device to handle * @data: pointer to state to be set */ static int __pci_dev_set_current_state(struct pci_dev *dev, void *data) { pci_power_t state = *(pci_power_t *)data; dev->current_state = state; return 0; } /** * pci_bus_set_current_state - Walk given bus and set current state of devices * @bus: Top bus of the subtree to walk. * @state: state to be set */ void pci_bus_set_current_state(struct pci_bus *bus, pci_power_t state) { if (bus) pci_walk_bus(bus, __pci_dev_set_current_state, &state); } /** * pci_set_power_state - Set the power state of a PCI device * @dev: PCI device to handle. * @state: PCI power state (D0, D1, D2, D3hot) to put the device into. * * Transition a device to a new power state, using the platform firmware and/or * the device's PCI PM registers. * * RETURN VALUE: * -EINVAL if the requested state is invalid. * -EIO if device does not support PCI PM or its PM capabilities register has a * wrong version, or device doesn't support the requested state. * 0 if the transition is to D1 or D2 but D1 and D2 are not supported. * 0 if device already is in the requested state. * 0 if the transition is to D3 but D3 is not supported. * 0 if device's power state has been successfully changed. */ int pci_set_power_state(struct pci_dev *dev, pci_power_t state) { int error; /* Bound the state we're entering */ if (state > PCI_D3cold) state = PCI_D3cold; else if (state < PCI_D0) state = PCI_D0; else if ((state == PCI_D1 || state == PCI_D2) && pci_no_d1d2(dev)) /* * If the device or the parent bridge do not support PCI * PM, ignore the request if we're doing anything other * than putting it into D0 (which would only happen on * boot). */ return 0; /* Check if we're already there */ if (dev->current_state == state) return 0; if (state == PCI_D0) return pci_power_up(dev); /* * This device is quirked not to be put into D3, so don't put it in * D3 */ if (state >= PCI_D3hot && (dev->dev_flags & PCI_DEV_FLAGS_NO_D3)) return 0; /* * To put device in D3cold, we put device into D3hot in native * way, then put device into D3cold with platform ops */ error = pci_raw_set_power_state(dev, state > PCI_D3hot ? PCI_D3hot : state); if (pci_platform_power_transition(dev, state)) return error; /* Powering off a bridge may power off the whole hierarchy */ if (state == PCI_D3cold) pci_bus_set_current_state(dev->subordinate, PCI_D3cold); return 0; } EXPORT_SYMBOL(pci_set_power_state); /** * pci_choose_state - Choose the power state of a PCI device * @dev: PCI device to be suspended * @state: target sleep state for the whole system. This is the value * that is passed to suspend() function. * * Returns PCI power state suitable for given device and given system * message. */ pci_power_t pci_choose_state(struct pci_dev *dev, pm_message_t state) { pci_power_t ret; if (!dev->pm_cap) return PCI_D0; ret = platform_pci_choose_state(dev); if (ret != PCI_POWER_ERROR) return ret; switch (state.event) { case PM_EVENT_ON: return PCI_D0; case PM_EVENT_FREEZE: case PM_EVENT_PRETHAW: /* REVISIT both freeze and pre-thaw "should" use D0 */ case PM_EVENT_SUSPEND: case PM_EVENT_HIBERNATE: return PCI_D3hot; default: pci_info(dev, "unrecognized suspend event %d\n", state.event); BUG(); } return PCI_D0; } EXPORT_SYMBOL(pci_choose_state); #define PCI_EXP_SAVE_REGS 7 static struct pci_cap_saved_state *_pci_find_saved_cap(struct pci_dev *pci_dev, u16 cap, bool extended) { struct pci_cap_saved_state *tmp; hlist_for_each_entry(tmp, &pci_dev->saved_cap_space, next) { if (tmp->cap.cap_extended == extended && tmp->cap.cap_nr == cap) return tmp; } return NULL; } struct pci_cap_saved_state *pci_find_saved_cap(struct pci_dev *dev, char cap) { return _pci_find_saved_cap(dev, cap, false); } struct pci_cap_saved_state *pci_find_saved_ext_cap(struct pci_dev *dev, u16 cap) { return _pci_find_saved_cap(dev, cap, true); } static int pci_save_pcie_state(struct pci_dev *dev) { int i = 0; struct pci_cap_saved_state *save_state; u16 *cap; if (!pci_is_pcie(dev)) return 0; save_state = pci_find_saved_cap(dev, PCI_CAP_ID_EXP); if (!save_state) { pci_err(dev, "buffer not found in %s\n", __func__); return -ENOMEM; } cap = (u16 *)&save_state->cap.data[0]; pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &cap[i++]); pcie_capability_read_word(dev, PCI_EXP_LNKCTL, &cap[i++]); pcie_capability_read_word(dev, PCI_EXP_SLTCTL, &cap[i++]); pcie_capability_read_word(dev, PCI_EXP_RTCTL, &cap[i++]); pcie_capability_read_word(dev, PCI_EXP_DEVCTL2, &cap[i++]); pcie_capability_read_word(dev, PCI_EXP_LNKCTL2, &cap[i++]); pcie_capability_read_word(dev, PCI_EXP_SLTCTL2, &cap[i++]); return 0; } static void pci_restore_pcie_state(struct pci_dev *dev) { int i = 0; struct pci_cap_saved_state *save_state; u16 *cap; save_state = pci_find_saved_cap(dev, PCI_CAP_ID_EXP); if (!save_state) return; cap = (u16 *)&save_state->cap.data[0]; pcie_capability_write_word(dev, PCI_EXP_DEVCTL, cap[i++]); pcie_capability_write_word(dev, PCI_EXP_LNKCTL, cap[i++]); pcie_capability_write_word(dev, PCI_EXP_SLTCTL, cap[i++]); pcie_capability_write_word(dev, PCI_EXP_RTCTL, cap[i++]); pcie_capability_write_word(dev, PCI_EXP_DEVCTL2, cap[i++]); pcie_capability_write_word(dev, PCI_EXP_LNKCTL2, cap[i++]); pcie_capability_write_word(dev, PCI_EXP_SLTCTL2, cap[i++]); } static int pci_save_pcix_state(struct pci_dev *dev) { int pos; struct pci_cap_saved_state *save_state; pos = pci_find_capability(dev, PCI_CAP_ID_PCIX); if (!pos) return 0; save_state = pci_find_saved_cap(dev, PCI_CAP_ID_PCIX); if (!save_state) { pci_err(dev, "buffer not found in %s\n", __func__); return -ENOMEM; } pci_read_config_word(dev, pos + PCI_X_CMD, (u16 *)save_state->cap.data); return 0; } static void pci_restore_pcix_state(struct pci_dev *dev) { int i = 0, pos; struct pci_cap_saved_state *save_state; u16 *cap; save_state = pci_find_saved_cap(dev, PCI_CAP_ID_PCIX); pos = pci_find_capability(dev, PCI_CAP_ID_PCIX); if (!save_state || !pos) return; cap = (u16 *)&save_state->cap.data[0]; pci_write_config_word(dev, pos + PCI_X_CMD, cap[i++]); } static void pci_save_ltr_state(struct pci_dev *dev) { int ltr; struct pci_cap_saved_state *save_state; u16 *cap; if (!pci_is_pcie(dev)) return; ltr = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_LTR); if (!ltr) return; save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_LTR); if (!save_state) { pci_err(dev, "no suspend buffer for LTR; ASPM issues possible after resume\n"); return; } cap = (u16 *)&save_state->cap.data[0]; pci_read_config_word(dev, ltr + PCI_LTR_MAX_SNOOP_LAT, cap++); pci_read_config_word(dev, ltr + PCI_LTR_MAX_NOSNOOP_LAT, cap++); } static void pci_restore_ltr_state(struct pci_dev *dev) { struct pci_cap_saved_state *save_state; int ltr; u16 *cap; save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_LTR); ltr = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_LTR); if (!save_state || !ltr) return; cap = (u16 *)&save_state->cap.data[0]; pci_write_config_word(dev, ltr + PCI_LTR_MAX_SNOOP_LAT, *cap++); pci_write_config_word(dev, ltr + PCI_LTR_MAX_NOSNOOP_LAT, *cap++); } /** * pci_save_state - save the PCI configuration space of a device before * suspending * @dev: PCI device that we're dealing with */ int pci_save_state(struct pci_dev *dev) { int i; /* XXX: 100% dword access ok here? */ for (i = 0; i < 16; i++) { pci_read_config_dword(dev, i * 4, &dev->saved_config_space[i]); pci_dbg(dev, "saving config space at offset %#x (reading %#x)\n", i * 4, dev->saved_config_space[i]); } dev->state_saved = true; i = pci_save_pcie_state(dev); if (i != 0) return i; i = pci_save_pcix_state(dev); if (i != 0) return i; pci_save_ltr_state(dev); pci_save_dpc_state(dev); pci_save_aer_state(dev); return pci_save_vc_state(dev); } EXPORT_SYMBOL(pci_save_state); static void pci_restore_config_dword(struct pci_dev *pdev, int offset, u32 saved_val, int retry, bool force) { u32 val; pci_read_config_dword(pdev, offset, &val); if (!force && val == saved_val) return; for (;;) { pci_dbg(pdev, "restoring config space at offset %#x (was %#x, writing %#x)\n", offset, val, saved_val); pci_write_config_dword(pdev, offset, saved_val); if (retry-- <= 0) return; pci_read_config_dword(pdev, offset, &val); if (val == saved_val) return; mdelay(1); } } static void pci_restore_config_space_range(struct pci_dev *pdev, int start, int end, int retry, bool force) { int index; for (index = end; index >= start; index--) pci_restore_config_dword(pdev, 4 * index, pdev->saved_config_space[index], retry, force); } static void pci_restore_config_space(struct pci_dev *pdev) { if (pdev->hdr_type == PCI_HEADER_TYPE_NORMAL) { pci_restore_config_space_range(pdev, 10, 15, 0, false); /* Restore BARs before the command register. */ pci_restore_config_space_range(pdev, 4, 9, 10, false); pci_restore_config_space_range(pdev, 0, 3, 0, false); } else if (pdev->hdr_type == PCI_HEADER_TYPE_BRIDGE) { pci_restore_config_space_range(pdev, 12, 15, 0, false); /* * Force rewriting of prefetch registers to avoid S3 resume * issues on Intel PCI bridges that occur when these * registers are not explicitly written. */ pci_restore_config_space_range(pdev, 9, 11, 0, true); pci_restore_config_space_range(pdev, 0, 8, 0, false); } else { pci_restore_config_space_range(pdev, 0, 15, 0, false); } } static void pci_restore_rebar_state(struct pci_dev *pdev) { unsigned int pos, nbars, i; u32 ctrl; pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_REBAR); if (!pos) return; pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl); nbars = (ctrl & PCI_REBAR_CTRL_NBAR_MASK) >> PCI_REBAR_CTRL_NBAR_SHIFT; for (i = 0; i < nbars; i++, pos += 8) { struct resource *res; int bar_idx, size; pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl); bar_idx = ctrl & PCI_REBAR_CTRL_BAR_IDX; res = pdev->resource + bar_idx; size = ilog2(resource_size(res)) - 20; ctrl &= ~PCI_REBAR_CTRL_BAR_SIZE; ctrl |= size << PCI_REBAR_CTRL_BAR_SHIFT; pci_write_config_dword(pdev, pos + PCI_REBAR_CTRL, ctrl); } } /** * pci_restore_state - Restore the saved state of a PCI device * @dev: PCI device that we're dealing with */ void pci_restore_state(struct pci_dev *dev) { if (!dev->state_saved) return; /* * Restore max latencies (in the LTR capability) before enabling * LTR itself (in the PCIe capability). */ pci_restore_ltr_state(dev); pci_restore_pcie_state(dev); pci_restore_pasid_state(dev); pci_restore_pri_state(dev); pci_restore_ats_state(dev); pci_restore_vc_state(dev); pci_restore_rebar_state(dev); pci_restore_dpc_state(dev); pci_aer_clear_status(dev); pci_restore_aer_state(dev); pci_restore_config_space(dev); pci_restore_pcix_state(dev); pci_restore_msi_state(dev); /* Restore ACS and IOV configuration state */ pci_enable_acs(dev); pci_restore_iov_state(dev); dev->state_saved = false; } EXPORT_SYMBOL(pci_restore_state); struct pci_saved_state { u32 config_space[16]; struct pci_cap_saved_data cap[]; }; /** * pci_store_saved_state - Allocate and return an opaque struct containing * the device saved state. * @dev: PCI device that we're dealing with * * Return NULL if no state or error. */ struct pci_saved_state *pci_store_saved_state(struct pci_dev *dev) { struct pci_saved_state *state; struct pci_cap_saved_state *tmp; struct pci_cap_saved_data *cap; size_t size; if (!dev->state_saved) return NULL; size = sizeof(*state) + sizeof(struct pci_cap_saved_data); hlist_for_each_entry(tmp, &dev->saved_cap_space, next) size += sizeof(struct pci_cap_saved_data) + tmp->cap.size; state = kzalloc(size, GFP_KERNEL); if (!state) return NULL; memcpy(state->config_space, dev->saved_config_space, sizeof(state->config_space)); cap = state->cap; hlist_for_each_entry(tmp, &dev->saved_cap_space, next) { size_t len = sizeof(struct pci_cap_saved_data) + tmp->cap.size; memcpy(cap, &tmp->cap, len); cap = (struct pci_cap_saved_data *)((u8 *)cap + len); } /* Empty cap_save terminates list */ return state; } EXPORT_SYMBOL_GPL(pci_store_saved_state); /** * pci_load_saved_state - Reload the provided save state into struct pci_dev. * @dev: PCI device that we're dealing with * @state: Saved state returned from pci_store_saved_state() */ int pci_load_saved_state(struct pci_dev *dev, struct pci_saved_state *state) { struct pci_cap_saved_data *cap; dev->state_saved = false; if (!state) return 0; memcpy(dev->saved_config_space, state->config_space, sizeof(state->config_space)); cap = state->cap; while (cap->size) { struct pci_cap_saved_state *tmp; tmp = _pci_find_saved_cap(dev, cap->cap_nr, cap->cap_extended); if (!tmp || tmp->cap.size != cap->size) return -EINVAL; memcpy(tmp->cap.data, cap->data, tmp->cap.size); cap = (struct pci_cap_saved_data *)((u8 *)cap + sizeof(struct pci_cap_saved_data) + cap->size); } dev->state_saved = true; return 0; } EXPORT_SYMBOL_GPL(pci_load_saved_state); /** * pci_load_and_free_saved_state - Reload the save state pointed to by state, * and free the memory allocated for it. * @dev: PCI device that we're dealing with * @state: Pointer to saved state returned from pci_store_saved_state() */ int pci_load_and_free_saved_state(struct pci_dev *dev, struct pci_saved_state **state) { int ret = pci_load_saved_state(dev, *state); kfree(*state); *state = NULL; return ret; } EXPORT_SYMBOL_GPL(pci_load_and_free_saved_state); int __weak pcibios_enable_device(struct pci_dev *dev, int bars) { return pci_enable_resources(dev, bars); } static int do_pci_enable_device(struct pci_dev *dev, int bars) { int err; struct pci_dev *bridge; u16 cmd; u8 pin; err = pci_set_power_state(dev, PCI_D0); if (err < 0 && err != -EIO) return err; bridge = pci_upstream_bridge(dev); if (bridge) pcie_aspm_powersave_config_link(bridge); err = pcibios_enable_device(dev, bars); if (err < 0) return err; pci_fixup_device(pci_fixup_enable, dev); if (dev->msi_enabled || dev->msix_enabled) return 0; pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin); if (pin) { pci_read_config_word(dev, PCI_COMMAND, &cmd); if (cmd & PCI_COMMAND_INTX_DISABLE) pci_write_config_word(dev, PCI_COMMAND, cmd & ~PCI_COMMAND_INTX_DISABLE); } return 0; } /** * pci_reenable_device - Resume abandoned device * @dev: PCI device to be resumed * * NOTE: This function is a backend of pci_default_resume() and is not supposed * to be called by normal code, write proper resume handler and use it instead. */ int pci_reenable_device(struct pci_dev *dev) { if (pci_is_enabled(dev)) return do_pci_enable_device(dev, (1 << PCI_NUM_RESOURCES) - 1); return 0; } EXPORT_SYMBOL(pci_reenable_device); static void pci_enable_bridge(struct pci_dev *dev) { struct pci_dev *bridge; int retval; bridge = pci_upstream_bridge(dev); if (bridge) pci_enable_bridge(bridge); if (pci_is_enabled(dev)) { if (!dev->is_busmaster) pci_set_master(dev); return; } retval = pci_enable_device(dev); if (retval) pci_err(dev, "Error enabling bridge (%d), continuing\n", retval); pci_set_master(dev); } static int pci_enable_device_flags(struct pci_dev *dev, unsigned long flags) { struct pci_dev *bridge; int err; int i, bars = 0; /* * Power state could be unknown at this point, either due to a fresh * boot or a device removal call. So get the current power state * so that things like MSI message writing will behave as expected * (e.g. if the device really is in D0 at enable time). */ if (dev->pm_cap) { u16 pmcsr; pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr); dev->current_state = (pmcsr & PCI_PM_CTRL_STATE_MASK); } if (atomic_inc_return(&dev->enable_cnt) > 1) return 0; /* already enabled */ bridge = pci_upstream_bridge(dev); if (bridge) pci_enable_bridge(bridge); /* only skip sriov related */ for (i = 0; i <= PCI_ROM_RESOURCE; i++) if (dev->resource[i].flags & flags) bars |= (1 << i); for (i = PCI_BRIDGE_RESOURCES; i < DEVICE_COUNT_RESOURCE; i++) if (dev->resource[i].flags & flags) bars |= (1 << i); err = do_pci_enable_device(dev, bars); if (err < 0) atomic_dec(&dev->enable_cnt); return err; } /** * pci_enable_device_io - Initialize a device for use with IO space * @dev: PCI device to be initialized * * Initialize device before it's used by a driver. Ask low-level code * to enable I/O resources. Wake up the device if it was suspended. * Beware, this function can fail. */ int pci_enable_device_io(struct pci_dev *dev) { return pci_enable_device_flags(dev, IORESOURCE_IO); } EXPORT_SYMBOL(pci_enable_device_io); /** * pci_enable_device_mem - Initialize a device for use with Memory space * @dev: PCI device to be initialized * * Initialize device before it's used by a driver. Ask low-level code * to enable Memory resources. Wake up the device if it was suspended. * Beware, this function can fail. */ int pci_enable_device_mem(struct pci_dev *dev) { return pci_enable_device_flags(dev, IORESOURCE_MEM); } EXPORT_SYMBOL(pci_enable_device_mem); /** * pci_enable_device - Initialize device before it's used by a driver. * @dev: PCI device to be initialized * * Initialize device before it's used by a driver. Ask low-level code * to enable I/O and memory. Wake up the device if it was suspended. * Beware, this function can fail. * * Note we don't actually enable the device many times if we call * this function repeatedly (we just increment the count). */ int pci_enable_device(struct pci_dev *dev) { return pci_enable_device_flags(dev, IORESOURCE_MEM | IORESOURCE_IO); } EXPORT_SYMBOL(pci_enable_device); /* * Managed PCI resources. This manages device on/off, INTx/MSI/MSI-X * on/off and BAR regions. pci_dev itself records MSI/MSI-X status, so * there's no need to track it separately. pci_devres is initialized * when a device is enabled using managed PCI device enable interface. */ struct pci_devres { unsigned int enabled:1; unsigned int pinned:1; unsigned int orig_intx:1; unsigned int restore_intx:1; unsigned int mwi:1; u32 region_mask; }; static void pcim_release(struct device *gendev, void *res) { struct pci_dev *dev = to_pci_dev(gendev); struct pci_devres *this = res; int i; if (dev->msi_enabled) pci_disable_msi(dev); if (dev->msix_enabled) pci_disable_msix(dev); for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) if (this->region_mask & (1 << i)) pci_release_region(dev, i); if (this->mwi) pci_clear_mwi(dev); if (this->restore_intx) pci_intx(dev, this->orig_intx); if (this->enabled && !this->pinned) pci_disable_device(dev); } static struct pci_devres *get_pci_dr(struct pci_dev *pdev) { struct pci_devres *dr, *new_dr; dr = devres_find(&pdev->dev, pcim_release, NULL, NULL); if (dr) return dr; new_dr = devres_alloc(pcim_release, sizeof(*new_dr), GFP_KERNEL); if (!new_dr) return NULL; return devres_get(&pdev->dev, new_dr, NULL, NULL); } static struct pci_devres *find_pci_dr(struct pci_dev *pdev) { if (pci_is_managed(pdev)) return devres_find(&pdev->dev, pcim_release, NULL, NULL); return NULL; } /** * pcim_enable_device - Managed pci_enable_device() * @pdev: PCI device to be initialized * * Managed pci_enable_device(). */ int pcim_enable_device(struct pci_dev *pdev) { struct pci_devres *dr; int rc; dr = get_pci_dr(pdev); if (unlikely(!dr)) return -ENOMEM; if (dr->enabled) return 0; rc = pci_enable_device(pdev); if (!rc) { pdev->is_managed = 1; dr->enabled = 1; } return rc; } EXPORT_SYMBOL(pcim_enable_device); /** * pcim_pin_device - Pin managed PCI device * @pdev: PCI device to pin * * Pin managed PCI device @pdev. Pinned device won't be disabled on * driver detach. @pdev must have been enabled with * pcim_enable_device(). */ void pcim_pin_device(struct pci_dev *pdev) { struct pci_devres *dr; dr = find_pci_dr(pdev); WARN_ON(!dr || !dr->enabled); if (dr) dr->pinned = 1; } EXPORT_SYMBOL(pcim_pin_device); /* * pcibios_add_device - provide arch specific hooks when adding device dev * @dev: the PCI device being added * * Permits the platform to provide architecture specific functionality when * devices are added. This is the default implementation. Architecture * implementations can override this. */ int __weak pcibios_add_device(struct pci_dev *dev) { return 0; } /** * pcibios_release_device - provide arch specific hooks when releasing * device dev * @dev: the PCI device being released * * Permits the platform to provide architecture specific functionality when * devices are released. This is the default implementation. Architecture * implementations can override this. */ void __weak pcibios_release_device(struct pci_dev *dev) {} /** * pcibios_disable_device - disable arch specific PCI resources for device dev * @dev: the PCI device to disable * * Disables architecture specific PCI resources for the device. This * is the default implementation. Architecture implementations can * override this. */ void __weak pcibios_disable_device(struct pci_dev *dev) {} /** * pcibios_penalize_isa_irq - penalize an ISA IRQ * @irq: ISA IRQ to penalize * @active: IRQ active or not * * Permits the platform to provide architecture-specific functionality when * penalizing ISA IRQs. This is the default implementation. Architecture * implementations can override this. */ void __weak pcibios_penalize_isa_irq(int irq, int active) {} static void do_pci_disable_device(struct pci_dev *dev) { u16 pci_command; pci_read_config_word(dev, PCI_COMMAND, &pci_command); if (pci_command & PCI_COMMAND_MASTER) { pci_command &= ~PCI_COMMAND_MASTER; pci_write_config_word(dev, PCI_COMMAND, pci_command); } pcibios_disable_device(dev); } /** * pci_disable_enabled_device - Disable device without updating enable_cnt * @dev: PCI device to disable * * NOTE: This function is a backend of PCI power management routines and is * not supposed to be called drivers. */ void pci_disable_enabled_device(struct pci_dev *dev) { if (pci_is_enabled(dev)) do_pci_disable_device(dev); } /** * pci_disable_device - Disable PCI device after use * @dev: PCI device to be disabled * * Signal to the system that the PCI device is not in use by the system * anymore. This only involves disabling PCI bus-mastering, if active. * * Note we don't actually disable the device until all callers of * pci_enable_device() have called pci_disable_device(). */ void pci_disable_device(struct pci_dev *dev) { struct pci_devres *dr; dr = find_pci_dr(dev); if (dr) dr->enabled = 0; dev_WARN_ONCE(&dev->dev, atomic_read(&dev->enable_cnt) <= 0, "disabling already-disabled device"); if (atomic_dec_return(&dev->enable_cnt) != 0) return; do_pci_disable_device(dev); dev->is_busmaster = 0; } EXPORT_SYMBOL(pci_disable_device); /** * pcibios_set_pcie_reset_state - set reset state for device dev * @dev: the PCIe device reset * @state: Reset state to enter into * * Set the PCIe reset state for the device. This is the default * implementation. Architecture implementations can override this. */ int __weak pcibios_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state) { return -EINVAL; } /** * pci_set_pcie_reset_state - set reset state for device dev * @dev: the PCIe device reset * @state: Reset state to enter into * * Sets the PCI reset state for the device. */ int pci_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state) { return pcibios_set_pcie_reset_state(dev, state); } EXPORT_SYMBOL_GPL(pci_set_pcie_reset_state); void pcie_clear_device_status(struct pci_dev *dev) { u16 sta; pcie_capability_read_word(dev, PCI_EXP_DEVSTA, &sta); pcie_capability_write_word(dev, PCI_EXP_DEVSTA, sta); } /** * pcie_clear_root_pme_status - Clear root port PME interrupt status. * @dev: PCIe root port or event collector. */ void pcie_clear_root_pme_status(struct pci_dev *dev) { pcie_capability_set_dword(dev, PCI_EXP_RTSTA, PCI_EXP_RTSTA_PME); } /** * pci_check_pme_status - Check if given device has generated PME. * @dev: Device to check. * * Check the PME status of the device and if set, clear it and clear PME enable * (if set). Return 'true' if PME status and PME enable were both set or * 'false' otherwise. */ bool pci_check_pme_status(struct pci_dev *dev) { int pmcsr_pos; u16 pmcsr; bool ret = false; if (!dev->pm_cap) return false; pmcsr_pos = dev->pm_cap + PCI_PM_CTRL; pci_read_config_word(dev, pmcsr_pos, &pmcsr); if (!(pmcsr & PCI_PM_CTRL_PME_STATUS)) return false; /* Clear PME status. */ pmcsr |= PCI_PM_CTRL_PME_STATUS; if (pmcsr & PCI_PM_CTRL_PME_ENABLE) { /* Disable PME to avoid interrupt flood. */ pmcsr &= ~PCI_PM_CTRL_PME_ENABLE; ret = true; } pci_write_config_word(dev, pmcsr_pos, pmcsr); return ret; } /** * pci_pme_wakeup - Wake up a PCI device if its PME Status bit is set. * @dev: Device to handle. * @pme_poll_reset: Whether or not to reset the device's pme_poll flag. * * Check if @dev has generated PME and queue a resume request for it in that * case. */ static int pci_pme_wakeup(struct pci_dev *dev, void *pme_poll_reset) { if (pme_poll_reset && dev->pme_poll) dev->pme_poll = false; if (pci_check_pme_status(dev)) { pci_wakeup_event(dev); pm_request_resume(&dev->dev); } return 0; } /** * pci_pme_wakeup_bus - Walk given bus and wake up devices on it, if necessary. * @bus: Top bus of the subtree to walk. */ void pci_pme_wakeup_bus(struct pci_bus *bus) { if (bus) pci_walk_bus(bus, pci_pme_wakeup, (void *)true); } /** * pci_pme_capable - check the capability of PCI device to generate PME# * @dev: PCI device to handle. * @state: PCI state from which device will issue PME#. */ bool pci_pme_capable(struct pci_dev *dev, pci_power_t state) { if (!dev->pm_cap) return false; return !!(dev->pme_support & (1 << state)); } EXPORT_SYMBOL(pci_pme_capable); static void pci_pme_list_scan(struct work_struct *work) { struct pci_pme_device *pme_dev, *n; mutex_lock(&pci_pme_list_mutex); list_for_each_entry_safe(pme_dev, n, &pci_pme_list, list) { if (pme_dev->dev->pme_poll) { struct pci_dev *bridge; bridge = pme_dev->dev->bus->self; /* * If bridge is in low power state, the * configuration space of subordinate devices * may be not accessible */ if (bridge && bridge->current_state != PCI_D0) continue; /* * If the device is in D3cold it should not be * polled either. */ if (pme_dev->dev->current_state == PCI_D3cold) continue; pci_pme_wakeup(pme_dev->dev, NULL); } else { list_del(&pme_dev->list); kfree(pme_dev); } } if (!list_empty(&pci_pme_list)) queue_delayed_work(system_freezable_wq, &pci_pme_work, msecs_to_jiffies(PME_TIMEOUT)); mutex_unlock(&pci_pme_list_mutex); } static void __pci_pme_active(struct pci_dev *dev, bool enable) { u16 pmcsr; if (!dev->pme_support) return; pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr); /* Clear PME_Status by writing 1 to it and enable PME# */ pmcsr |= PCI_PM_CTRL_PME_STATUS | PCI_PM_CTRL_PME_ENABLE; if (!enable) pmcsr &= ~PCI_PM_CTRL_PME_ENABLE; pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, pmcsr); } /** * pci_pme_restore - Restore PME configuration after config space restore. * @dev: PCI device to update. */ void pci_pme_restore(struct pci_dev *dev) { u16 pmcsr; if (!dev->pme_support) return; pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr); if (dev->wakeup_prepared) { pmcsr |= PCI_PM_CTRL_PME_ENABLE; pmcsr &= ~PCI_PM_CTRL_PME_STATUS; } else { pmcsr &= ~PCI_PM_CTRL_PME_ENABLE; pmcsr |= PCI_PM_CTRL_PME_STATUS; } pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, pmcsr); } /** * pci_pme_active - enable or disable PCI device's PME# function * @dev: PCI device to handle. * @enable: 'true' to enable PME# generation; 'false' to disable it. * * The caller must verify that the device is capable of generating PME# before * calling this function with @enable equal to 'true'. */ void pci_pme_active(struct pci_dev *dev, bool enable) { __pci_pme_active(dev, enable); /* * PCI (as opposed to PCIe) PME requires that the device have * its PME# line hooked up correctly. Not all hardware vendors * do this, so the PME never gets delivered and the device * remains asleep. The easiest way around this is to * periodically walk the list of suspended devices and check * whether any have their PME flag set. The assumption is that * we'll wake up often enough anyway that this won't be a huge * hit, and the power savings from the devices will still be a * win. * * Although PCIe uses in-band PME message instead of PME# line * to report PME, PME does not work for some PCIe devices in * reality. For example, there are devices that set their PME * status bits, but don't really bother to send a PME message; * there are PCI Express Root Ports that don't bother to * trigger interrupts when they receive PME messages from the * devices below. So PME poll is used for PCIe devices too. */ if (dev->pme_poll) { struct pci_pme_device *pme_dev; if (enable) { pme_dev = kmalloc(sizeof(struct pci_pme_device), GFP_KERNEL); if (!pme_dev) { pci_warn(dev, "can't enable PME#\n"); return; } pme_dev->dev = dev; mutex_lock(&pci_pme_list_mutex); list_add(&pme_dev->list, &pci_pme_list); if (list_is_singular(&pci_pme_list)) queue_delayed_work(system_freezable_wq, &pci_pme_work, msecs_to_jiffies(PME_TIMEOUT)); mutex_unlock(&pci_pme_list_mutex); } else { mutex_lock(&pci_pme_list_mutex); list_for_each_entry(pme_dev, &pci_pme_list, list) { if (pme_dev->dev == dev) { list_del(&pme_dev->list); kfree(pme_dev); break; } } mutex_unlock(&pci_pme_list_mutex); } } pci_dbg(dev, "PME# %s\n", enable ? "enabled" : "disabled"); } EXPORT_SYMBOL(pci_pme_active); /** * __pci_enable_wake - enable PCI device as wakeup event source * @dev: PCI device affected * @state: PCI state from which device will issue wakeup events * @enable: True to enable event generation; false to disable * * This enables the device as a wakeup event source, or disables it. * When such events involves platform-specific hooks, those hooks are * called automatically by this routine. * * Devices with legacy power management (no standard PCI PM capabilities) * always require such platform hooks. * * RETURN VALUE: * 0 is returned on success * -EINVAL is returned if device is not supposed to wake up the system * Error code depending on the platform is returned if both the platform and * the native mechanism fail to enable the generation of wake-up events */ static int __pci_enable_wake(struct pci_dev *dev, pci_power_t state, bool enable) { int ret = 0; /* * Bridges that are not power-manageable directly only signal * wakeup on behalf of subordinate devices which is set up * elsewhere, so skip them. However, bridges that are * power-manageable may signal wakeup for themselves (for example, * on a hotplug event) and they need to be covered here. */ if (!pci_power_manageable(dev)) return 0; /* Don't do the same thing twice in a row for one device. */ if (!!enable == !!dev->wakeup_prepared) return 0; /* * According to "PCI System Architecture" 4th ed. by Tom Shanley & Don * Anderson we should be doing PME# wake enable followed by ACPI wake * enable. To disable wake-up we call the platform first, for symmetry. */ if (enable) { int error; if (pci_pme_capable(dev, state)) pci_pme_active(dev, true); else ret = 1; error = platform_pci_set_wakeup(dev, true); if (ret) ret = error; if (!ret) dev->wakeup_prepared = true; } else { platform_pci_set_wakeup(dev, false); pci_pme_active(dev, false); dev->wakeup_prepared = false; } return ret; } /** * pci_enable_wake - change wakeup settings for a PCI device * @pci_dev: Target device * @state: PCI state from which device will issue wakeup events * @enable: Whether or not to enable event generation * * If @enable is set, check device_may_wakeup() for the device before calling * __pci_enable_wake() for it. */ int pci_enable_wake(struct pci_dev *pci_dev, pci_power_t state, bool enable) { if (enable && !device_may_wakeup(&pci_dev->dev)) return -EINVAL; return __pci_enable_wake(pci_dev, state, enable); } EXPORT_SYMBOL(pci_enable_wake); /** * pci_wake_from_d3 - enable/disable device to wake up from D3_hot or D3_cold * @dev: PCI device to prepare * @enable: True to enable wake-up event generation; false to disable * * Many drivers want the device to wake up the system from D3_hot or D3_cold * and this function allows them to set that up cleanly - pci_enable_wake() * should not be called twice in a row to enable wake-up due to PCI PM vs ACPI * ordering constraints. * * This function only returns error code if the device is not allowed to wake * up the system from sleep or it is not capable of generating PME# from both * D3_hot and D3_cold and the platform is unable to enable wake-up power for it. */ int pci_wake_from_d3(struct pci_dev *dev, bool enable) { return pci_pme_capable(dev, PCI_D3cold) ? pci_enable_wake(dev, PCI_D3cold, enable) : pci_enable_wake(dev, PCI_D3hot, enable); } EXPORT_SYMBOL(pci_wake_from_d3); /** * pci_target_state - find an appropriate low power state for a given PCI dev * @dev: PCI device * @wakeup: Whether or not wakeup functionality will be enabled for the device. * * Use underlying platform code to find a supported low power state for @dev. * If the platform can't manage @dev, return the deepest state from which it * can generate wake events, based on any available PME info. */ static pci_power_t pci_target_state(struct pci_dev *dev, bool wakeup) { pci_power_t target_state = PCI_D3hot; if (platform_pci_power_manageable(dev)) { /* * Call the platform to find the target state for the device. */ pci_power_t state = platform_pci_choose_state(dev); switch (state) { case PCI_POWER_ERROR: case PCI_UNKNOWN: break; case PCI_D1: case PCI_D2: if (pci_no_d1d2(dev)) break; fallthrough; default: target_state = state; } return target_state; } if (!dev->pm_cap) target_state = PCI_D0; /* * If the device is in D3cold even though it's not power-manageable by * the platform, it may have been powered down by non-standard means. * Best to let it slumber. */ if (dev->current_state == PCI_D3cold) target_state = PCI_D3cold; if (wakeup) { /* * Find the deepest state from which the device can generate * PME#. */ if (dev->pme_support) { while (target_state && !(dev->pme_support & (1 << target_state))) target_state--; } } return target_state; } /** * pci_prepare_to_sleep - prepare PCI device for system-wide transition * into a sleep state * @dev: Device to handle. * * Choose the power state appropriate for the device depending on whether * it can wake up the system and/or is power manageable by the platform * (PCI_D3hot is the default) and put the device into that state. */ int pci_prepare_to_sleep(struct pci_dev *dev) { bool wakeup = device_may_wakeup(&dev->dev); pci_power_t target_state = pci_target_state(dev, wakeup); int error; if (target_state == PCI_POWER_ERROR) return -EIO; pci_enable_wake(dev, target_state, wakeup); error = pci_set_power_state(dev, target_state); if (error) pci_enable_wake(dev, target_state, false); return error; } EXPORT_SYMBOL(pci_prepare_to_sleep); /** * pci_back_from_sleep - turn PCI device on during system-wide transition * into working state * @dev: Device to handle. * * Disable device's system wake-up capability and put it into D0. */ int pci_back_from_sleep(struct pci_dev *dev) { pci_enable_wake(dev, PCI_D0, false); return pci_set_power_state(dev, PCI_D0); } EXPORT_SYMBOL(pci_back_from_sleep); /** * pci_finish_runtime_suspend - Carry out PCI-specific part of runtime suspend. * @dev: PCI device being suspended. * * Prepare @dev to generate wake-up events at run time and put it into a low * power state. */ int pci_finish_runtime_suspend(struct pci_dev *dev) { pci_power_t target_state; int error; target_state = pci_target_state(dev, device_can_wakeup(&dev->dev)); if (target_state == PCI_POWER_ERROR) return -EIO; dev->runtime_d3cold = target_state == PCI_D3cold; __pci_enable_wake(dev, target_state, pci_dev_run_wake(dev)); error = pci_set_power_state(dev, target_state); if (error) { pci_enable_wake(dev, target_state, false); dev->runtime_d3cold = false; } return error; } /** * pci_dev_run_wake - Check if device can generate run-time wake-up events. * @dev: Device to check. * * Return true if the device itself is capable of generating wake-up events * (through the platform or using the native PCIe PME) or if the device supports * PME and one of its upstream bridges can generate wake-up events. */ bool pci_dev_run_wake(struct pci_dev *dev) { struct pci_bus *bus = dev->bus; if (!dev->pme_support) return false; /* PME-capable in principle, but not from the target power state */ if (!pci_pme_capable(dev, pci_target_state(dev, true))) return false; if (device_can_wakeup(&dev->dev)) return true; while (bus->parent) { struct pci_dev *bridge = bus->self; if (device_can_wakeup(&bridge->dev)) return true; bus = bus->parent; } /* We have reached the root bus. */ if (bus->bridge) return device_can_wakeup(bus->bridge); return false; } EXPORT_SYMBOL_GPL(pci_dev_run_wake); /** * pci_dev_need_resume - Check if it is necessary to resume the device. * @pci_dev: Device to check. * * Return 'true' if the device is not runtime-suspended or it has to be * reconfigured due to wakeup settings difference between system and runtime * suspend, or the current power state of it is not suitable for the upcoming * (system-wide) transition. */ bool pci_dev_need_resume(struct pci_dev *pci_dev) { struct device *dev = &pci_dev->dev; pci_power_t target_state; if (!pm_runtime_suspended(dev) || platform_pci_need_resume(pci_dev)) return true; target_state = pci_target_state(pci_dev, device_may_wakeup(dev)); /* * If the earlier platform check has not triggered, D3cold is just power * removal on top of D3hot, so no need to resume the device in that * case. */ return target_state != pci_dev->current_state && target_state != PCI_D3cold && pci_dev->current_state != PCI_D3hot; } /** * pci_dev_adjust_pme - Adjust PME setting for a suspended device. * @pci_dev: Device to check. * * If the device is suspended and it is not configured for system wakeup, * disable PME for it to prevent it from waking up the system unnecessarily. * * Note that if the device's power state is D3cold and the platform check in * pci_dev_need_resume() has not triggered, the device's configuration need not * be changed. */ void pci_dev_adjust_pme(struct pci_dev *pci_dev) { struct device *dev = &pci_dev->dev; spin_lock_irq(&dev->power.lock); if (pm_runtime_suspended(dev) && !device_may_wakeup(dev) && pci_dev->current_state < PCI_D3cold) __pci_pme_active(pci_dev, false); spin_unlock_irq(&dev->power.lock); } /** * pci_dev_complete_resume - Finalize resume from system sleep for a device. * @pci_dev: Device to handle. * * If the device is runtime suspended and wakeup-capable, enable PME for it as * it might have been disabled during the prepare phase of system suspend if * the device was not configured for system wakeup. */ void pci_dev_complete_resume(struct pci_dev *pci_dev) { struct device *dev = &pci_dev->dev; if (!pci_dev_run_wake(pci_dev)) return; spin_lock_irq(&dev->power.lock); if (pm_runtime_suspended(dev) && pci_dev->current_state < PCI_D3cold) __pci_pme_active(pci_dev, true); spin_unlock_irq(&dev->power.lock); } void pci_config_pm_runtime_get(struct pci_dev *pdev) { struct device *dev = &pdev->dev; struct device *parent = dev->parent; if (parent) pm_runtime_get_sync(parent); pm_runtime_get_noresume(dev); /* * pdev->current_state is set to PCI_D3cold during suspending, * so wait until suspending completes */ pm_runtime_barrier(dev); /* * Only need to resume devices in D3cold, because config * registers are still accessible for devices suspended but * not in D3cold. */ if (pdev->current_state == PCI_D3cold) pm_runtime_resume(dev); } void pci_config_pm_runtime_put(struct pci_dev *pdev) { struct device *dev = &pdev->dev; struct device *parent = dev->parent; pm_runtime_put(dev); if (parent) pm_runtime_put_sync(parent); } static const struct dmi_system_id bridge_d3_blacklist[] = { #ifdef CONFIG_X86 { /* * Gigabyte X299 root port is not marked as hotplug capable * which allows Linux to power manage it. However, this * confuses the BIOS SMI handler so don't power manage root * ports on that system. */ .ident = "X299 DESIGNARE EX-CF", .matches = { DMI_MATCH(DMI_BOARD_VENDOR, "Gigabyte Technology Co., Ltd."), DMI_MATCH(DMI_BOARD_NAME, "X299 DESIGNARE EX-CF"), }, }, #endif { } }; /** * pci_bridge_d3_possible - Is it possible to put the bridge into D3 * @bridge: Bridge to check * * This function checks if it is possible to move the bridge to D3. * Currently we only allow D3 for recent enough PCIe ports and Thunderbolt. */ bool pci_bridge_d3_possible(struct pci_dev *bridge) { if (!pci_is_pcie(bridge)) return false; switch (pci_pcie_type(bridge)) { case PCI_EXP_TYPE_ROOT_PORT: case PCI_EXP_TYPE_UPSTREAM: case PCI_EXP_TYPE_DOWNSTREAM: if (pci_bridge_d3_disable) return false; /* * Hotplug ports handled by firmware in System Management Mode * may not be put into D3 by the OS (Thunderbolt on non-Macs). */ if (bridge->is_hotplug_bridge && !pciehp_is_native(bridge)) return false; if (pci_bridge_d3_force) return true; /* Even the oldest 2010 Thunderbolt controller supports D3. */ if (bridge->is_thunderbolt) return true; /* Platform might know better if the bridge supports D3 */ if (platform_pci_bridge_d3(bridge)) return true; /* * Hotplug ports handled natively by the OS were not validated * by vendors for runtime D3 at least until 2018 because there * was no OS support. */ if (bridge->is_hotplug_bridge) return false; if (dmi_check_system(bridge_d3_blacklist)) return false; /* * It should be safe to put PCIe ports from 2015 or newer * to D3. */ if (dmi_get_bios_year() >= 2015) return true; break; } return false; } static int pci_dev_check_d3cold(struct pci_dev *dev, void *data) { bool *d3cold_ok = data; if (/* The device needs to be allowed to go D3cold ... */ dev->no_d3cold || !dev->d3cold_allowed || /* ... and if it is wakeup capable to do so from D3cold. */ (device_may_wakeup(&dev->dev) && !pci_pme_capable(dev, PCI_D3cold)) || /* If it is a bridge it must be allowed to go to D3. */ !pci_power_manageable(dev)) *d3cold_ok = false; return !*d3cold_ok; } /* * pci_bridge_d3_update - Update bridge D3 capabilities * @dev: PCI device which is changed * * Update upstream bridge PM capabilities accordingly depending on if the * device PM configuration was changed or the device is being removed. The * change is also propagated upstream. */ void pci_bridge_d3_update(struct pci_dev *dev) { bool remove = !device_is_registered(&dev->dev); struct pci_dev *bridge; bool d3cold_ok = true; bridge = pci_upstream_bridge(dev); if (!bridge || !pci_bridge_d3_possible(bridge)) return; /* * If D3 is currently allowed for the bridge, removing one of its * children won't change that. */ if (remove && bridge->bridge_d3) return; /* * If D3 is currently allowed for the bridge and a child is added or * changed, disallowance of D3 can only be caused by that child, so * we only need to check that single device, not any of its siblings. * * If D3 is currently not allowed for the bridge, checking the device * first may allow us to skip checking its siblings. */ if (!remove) pci_dev_check_d3cold(dev, &d3cold_ok); /* * If D3 is currently not allowed for the bridge, this may be caused * either by the device being changed/removed or any of its siblings, * so we need to go through all children to find out if one of them * continues to block D3. */ if (d3cold_ok && !bridge->bridge_d3) pci_walk_bus(bridge->subordinate, pci_dev_check_d3cold, &d3cold_ok); if (bridge->bridge_d3 != d3cold_ok) { bridge->bridge_d3 = d3cold_ok; /* Propagate change to upstream bridges */ pci_bridge_d3_update(bridge); } } /** * pci_d3cold_enable - Enable D3cold for device * @dev: PCI device to handle * * This function can be used in drivers to enable D3cold from the device * they handle. It also updates upstream PCI bridge PM capabilities * accordingly. */ void pci_d3cold_enable(struct pci_dev *dev) { if (dev->no_d3cold) { dev->no_d3cold = false; pci_bridge_d3_update(dev); } } EXPORT_SYMBOL_GPL(pci_d3cold_enable); /** * pci_d3cold_disable - Disable D3cold for device * @dev: PCI device to handle * * This function can be used in drivers to disable D3cold from the device * they handle. It also updates upstream PCI bridge PM capabilities * accordingly. */ void pci_d3cold_disable(struct pci_dev *dev) { if (!dev->no_d3cold) { dev->no_d3cold = true; pci_bridge_d3_update(dev); } } EXPORT_SYMBOL_GPL(pci_d3cold_disable); /** * pci_pm_init - Initialize PM functions of given PCI device * @dev: PCI device to handle. */ void pci_pm_init(struct pci_dev *dev) { int pm; u16 status; u16 pmc; pm_runtime_forbid(&dev->dev); pm_runtime_set_active(&dev->dev); pm_runtime_enable(&dev->dev); device_enable_async_suspend(&dev->dev); dev->wakeup_prepared = false; dev->pm_cap = 0; dev->pme_support = 0; /* find PCI PM capability in list */ pm = pci_find_capability(dev, PCI_CAP_ID_PM); if (!pm) return; /* Check device's ability to generate PME# */ pci_read_config_word(dev, pm + PCI_PM_PMC, &pmc); if ((pmc & PCI_PM_CAP_VER_MASK) > 3) { pci_err(dev, "unsupported PM cap regs version (%u)\n", pmc & PCI_PM_CAP_VER_MASK); return; } dev->pm_cap = pm; dev->d3_delay = PCI_PM_D3_WAIT; dev->d3cold_delay = PCI_PM_D3COLD_WAIT; dev->bridge_d3 = pci_bridge_d3_possible(dev); dev->d3cold_allowed = true; dev->d1_support = false; dev->d2_support = false; if (!pci_no_d1d2(dev)) { if (pmc & PCI_PM_CAP_D1) dev->d1_support = true; if (pmc & PCI_PM_CAP_D2) dev->d2_support = true; if (dev->d1_support || dev->d2_support) pci_info(dev, "supports%s%s\n", dev->d1_support ? " D1" : "", dev->d2_support ? " D2" : ""); } pmc &= PCI_PM_CAP_PME_MASK; if (pmc) { pci_info(dev, "PME# supported from%s%s%s%s%s\n", (pmc & PCI_PM_CAP_PME_D0) ? " D0" : "", (pmc & PCI_PM_CAP_PME_D1) ? " D1" : "", (pmc & PCI_PM_CAP_PME_D2) ? " D2" : "", (pmc & PCI_PM_CAP_PME_D3) ? " D3hot" : "", (pmc & PCI_PM_CAP_PME_D3cold) ? " D3cold" : ""); dev->pme_support = pmc >> PCI_PM_CAP_PME_SHIFT; dev->pme_poll = true; /* * Make device's PM flags reflect the wake-up capability, but * let the user space enable it to wake up the system as needed. */ device_set_wakeup_capable(&dev->dev, true); /* Disable the PME# generation functionality */ pci_pme_active(dev, false); } pci_read_config_word(dev, PCI_STATUS, &status); if (status & PCI_STATUS_IMM_READY) dev->imm_ready = 1; } static unsigned long pci_ea_flags(struct pci_dev *dev, u8 prop) { unsigned long flags = IORESOURCE_PCI_FIXED | IORESOURCE_PCI_EA_BEI; switch (prop) { case PCI_EA_P_MEM: case PCI_EA_P_VF_MEM: flags |= IORESOURCE_MEM; break; case PCI_EA_P_MEM_PREFETCH: case PCI_EA_P_VF_MEM_PREFETCH: flags |= IORESOURCE_MEM | IORESOURCE_PREFETCH; break; case PCI_EA_P_IO: flags |= IORESOURCE_IO; break; default: return 0; } return flags; } static struct resource *pci_ea_get_resource(struct pci_dev *dev, u8 bei, u8 prop) { if (bei <= PCI_EA_BEI_BAR5 && prop <= PCI_EA_P_IO) return &dev->resource[bei]; #ifdef CONFIG_PCI_IOV else if (bei >= PCI_EA_BEI_VF_BAR0 && bei <= PCI_EA_BEI_VF_BAR5 && (prop == PCI_EA_P_VF_MEM || prop == PCI_EA_P_VF_MEM_PREFETCH)) return &dev->resource[PCI_IOV_RESOURCES + bei - PCI_EA_BEI_VF_BAR0]; #endif else if (bei == PCI_EA_BEI_ROM) return &dev->resource[PCI_ROM_RESOURCE]; else return NULL; } /* Read an Enhanced Allocation (EA) entry */ static int pci_ea_read(struct pci_dev *dev, int offset) { struct resource *res; int ent_size, ent_offset = offset; resource_size_t start, end; unsigned long flags; u32 dw0, bei, base, max_offset; u8 prop; bool support_64 = (sizeof(resource_size_t) >= 8); pci_read_config_dword(dev, ent_offset, &dw0); ent_offset += 4; /* Entry size field indicates DWORDs after 1st */ ent_size = ((dw0 & PCI_EA_ES) + 1) << 2; if (!(dw0 & PCI_EA_ENABLE)) /* Entry not enabled */ goto out; bei = (dw0 & PCI_EA_BEI) >> 4; prop = (dw0 & PCI_EA_PP) >> 8; /* * If the Property is in the reserved range, try the Secondary * Property instead. */ if (prop > PCI_EA_P_BRIDGE_IO && prop < PCI_EA_P_MEM_RESERVED) prop = (dw0 & PCI_EA_SP) >> 16; if (prop > PCI_EA_P_BRIDGE_IO) goto out; res = pci_ea_get_resource(dev, bei, prop); if (!res) { pci_err(dev, "Unsupported EA entry BEI: %u\n", bei); goto out; } flags = pci_ea_flags(dev, prop); if (!flags) { pci_err(dev, "Unsupported EA properties: %#x\n", prop); goto out; } /* Read Base */ pci_read_config_dword(dev, ent_offset, &base); start = (base & PCI_EA_FIELD_MASK); ent_offset += 4; /* Read MaxOffset */ pci_read_config_dword(dev, ent_offset, &max_offset); ent_offset += 4; /* Read Base MSBs (if 64-bit entry) */ if (base & PCI_EA_IS_64) { u32 base_upper; pci_read_config_dword(dev, ent_offset, &base_upper); ent_offset += 4; flags |= IORESOURCE_MEM_64; /* entry starts above 32-bit boundary, can't use */ if (!support_64 && base_upper) goto out; if (support_64) start |= ((u64)base_upper << 32); } end = start + (max_offset | 0x03); /* Read MaxOffset MSBs (if 64-bit entry) */ if (max_offset & PCI_EA_IS_64) { u32 max_offset_upper; pci_read_config_dword(dev, ent_offset, &max_offset_upper); ent_offset += 4; flags |= IORESOURCE_MEM_64; /* entry too big, can't use */ if (!support_64 && max_offset_upper) goto out; if (support_64) end += ((u64)max_offset_upper << 32); } if (end < start) { pci_err(dev, "EA Entry crosses address boundary\n"); goto out; } if (ent_size != ent_offset - offset) { pci_err(dev, "EA Entry Size (%d) does not match length read (%d)\n", ent_size, ent_offset - offset); goto out; } res->name = pci_name(dev); res->start = start; res->end = end; res->flags = flags; if (bei <= PCI_EA_BEI_BAR5) pci_info(dev, "BAR %d: %pR (from Enhanced Allocation, properties %#02x)\n", bei, res, prop); else if (bei == PCI_EA_BEI_ROM) pci_info(dev, "ROM: %pR (from Enhanced Allocation, properties %#02x)\n", res, prop); else if (bei >= PCI_EA_BEI_VF_BAR0 && bei <= PCI_EA_BEI_VF_BAR5) pci_info(dev, "VF BAR %d: %pR (from Enhanced Allocation, properties %#02x)\n", bei - PCI_EA_BEI_VF_BAR0, res, prop); else pci_info(dev, "BEI %d res: %pR (from Enhanced Allocation, properties %#02x)\n", bei, res, prop); out: return offset + ent_size; } /* Enhanced Allocation Initialization */ void pci_ea_init(struct pci_dev *dev) { int ea; u8 num_ent; int offset; int i; /* find PCI EA capability in list */ ea = pci_find_capability(dev, PCI_CAP_ID_EA); if (!ea) return; /* determine the number of entries */ pci_bus_read_config_byte(dev->bus, dev->devfn, ea + PCI_EA_NUM_ENT, &num_ent); num_ent &= PCI_EA_NUM_ENT_MASK; offset = ea + PCI_EA_FIRST_ENT; /* Skip DWORD 2 for type 1 functions */ if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) offset += 4; /* parse each EA entry */ for (i = 0; i < num_ent; ++i) offset = pci_ea_read(dev, offset); } static void pci_add_saved_cap(struct pci_dev *pci_dev, struct pci_cap_saved_state *new_cap) { hlist_add_head(&new_cap->next, &pci_dev->saved_cap_space); } /** * _pci_add_cap_save_buffer - allocate buffer for saving given * capability registers * @dev: the PCI device * @cap: the capability to allocate the buffer for * @extended: Standard or Extended capability ID * @size: requested size of the buffer */ static int _pci_add_cap_save_buffer(struct pci_dev *dev, u16 cap, bool extended, unsigned int size) { int pos; struct pci_cap_saved_state *save_state; if (extended) pos = pci_find_ext_capability(dev, cap); else pos = pci_find_capability(dev, cap); if (!pos) return 0; save_state = kzalloc(sizeof(*save_state) + size, GFP_KERNEL); if (!save_state) return -ENOMEM; save_state->cap.cap_nr = cap; save_state->cap.cap_extended = extended; save_state->cap.size = size; pci_add_saved_cap(dev, save_state); return 0; } int pci_add_cap_save_buffer(struct pci_dev *dev, char cap, unsigned int size) { return _pci_add_cap_save_buffer(dev, cap, false, size); } int pci_add_ext_cap_save_buffer(struct pci_dev *dev, u16 cap, unsigned int size) { return _pci_add_cap_save_buffer(dev, cap, true, size); } /** * pci_allocate_cap_save_buffers - allocate buffers for saving capabilities * @dev: the PCI device */ void pci_allocate_cap_save_buffers(struct pci_dev *dev) { int error; error = pci_add_cap_save_buffer(dev, PCI_CAP_ID_EXP, PCI_EXP_SAVE_REGS * sizeof(u16)); if (error) pci_err(dev, "unable to preallocate PCI Express save buffer\n"); error = pci_add_cap_save_buffer(dev, PCI_CAP_ID_PCIX, sizeof(u16)); if (error) pci_err(dev, "unable to preallocate PCI-X save buffer\n"); error = pci_add_ext_cap_save_buffer(dev, PCI_EXT_CAP_ID_LTR, 2 * sizeof(u16)); if (error) pci_err(dev, "unable to allocate suspend buffer for LTR\n"); pci_allocate_vc_save_buffers(dev); } void pci_free_cap_save_buffers(struct pci_dev *dev) { struct pci_cap_saved_state *tmp; struct hlist_node *n; hlist_for_each_entry_safe(tmp, n, &dev->saved_cap_space, next) kfree(tmp); } /** * pci_configure_ari - enable or disable ARI forwarding * @dev: the PCI device * * If @dev and its upstream bridge both support ARI, enable ARI in the * bridge. Otherwise, disable ARI in the bridge. */ void pci_configure_ari(struct pci_dev *dev) { u32 cap; struct pci_dev *bridge; if (pcie_ari_disabled || !pci_is_pcie(dev) || dev->devfn) return; bridge = dev->bus->self; if (!bridge) return; pcie_capability_read_dword(bridge, PCI_EXP_DEVCAP2, &cap); if (!(cap & PCI_EXP_DEVCAP2_ARI)) return; if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ARI)) { pcie_capability_set_word(bridge, PCI_EXP_DEVCTL2, PCI_EXP_DEVCTL2_ARI); bridge->ari_enabled = 1; } else { pcie_capability_clear_word(bridge, PCI_EXP_DEVCTL2, PCI_EXP_DEVCTL2_ARI); bridge->ari_enabled = 0; } } static bool pci_acs_flags_enabled(struct pci_dev *pdev, u16 acs_flags) { int pos; u16 cap, ctrl; pos = pdev->acs_cap; if (!pos) return false; /* * Except for egress control, capabilities are either required * or only required if controllable. Features missing from the * capability field can therefore be assumed as hard-wired enabled. */ pci_read_config_word(pdev, pos + PCI_ACS_CAP, &cap); acs_flags &= (cap | PCI_ACS_EC); pci_read_config_word(pdev, pos + PCI_ACS_CTRL, &ctrl); return (ctrl & acs_flags) == acs_flags; } /** * pci_acs_enabled - test ACS against required flags for a given device * @pdev: device to test * @acs_flags: required PCI ACS flags * * Return true if the device supports the provided flags. Automatically * filters out flags that are not implemented on multifunction devices. * * Note that this interface checks the effective ACS capabilities of the * device rather than the actual capabilities. For instance, most single * function endpoints are not required to support ACS because they have no * opportunity for peer-to-peer access. We therefore return 'true' * regardless of whether the device exposes an ACS capability. This makes * it much easier for callers of this function to ignore the actual type * or topology of the device when testing ACS support. */ bool pci_acs_enabled(struct pci_dev *pdev, u16 acs_flags) { int ret; ret = pci_dev_specific_acs_enabled(pdev, acs_flags); if (ret >= 0) return ret > 0; /* * Conventional PCI and PCI-X devices never support ACS, either * effectively or actually. The shared bus topology implies that * any device on the bus can receive or snoop DMA. */ if (!pci_is_pcie(pdev)) return false; switch (pci_pcie_type(pdev)) { /* * PCI/X-to-PCIe bridges are not specifically mentioned by the spec, * but since their primary interface is PCI/X, we conservatively * handle them as we would a non-PCIe device. */ case PCI_EXP_TYPE_PCIE_BRIDGE: /* * PCIe 3.0, 6.12.1 excludes ACS on these devices. "ACS is never * applicable... must never implement an ACS Extended Capability...". * This seems arbitrary, but we take a conservative interpretation * of this statement. */ case PCI_EXP_TYPE_PCI_BRIDGE: case PCI_EXP_TYPE_RC_EC: return false; /* * PCIe 3.0, 6.12.1.1 specifies that downstream and root ports should * implement ACS in order to indicate their peer-to-peer capabilities, * regardless of whether they are single- or multi-function devices. */ case PCI_EXP_TYPE_DOWNSTREAM: case PCI_EXP_TYPE_ROOT_PORT: return pci_acs_flags_enabled(pdev, acs_flags); /* * PCIe 3.0, 6.12.1.2 specifies ACS capabilities that should be * implemented by the remaining PCIe types to indicate peer-to-peer * capabilities, but only when they are part of a multifunction * device. The footnote for section 6.12 indicates the specific * PCIe types included here. */ case PCI_EXP_TYPE_ENDPOINT: case PCI_EXP_TYPE_UPSTREAM: case PCI_EXP_TYPE_LEG_END: case PCI_EXP_TYPE_RC_END: if (!pdev->multifunction) break; return pci_acs_flags_enabled(pdev, acs_flags); } /* * PCIe 3.0, 6.12.1.3 specifies no ACS capabilities are applicable * to single function devices with the exception of downstream ports. */ return true; } /** * pci_acs_path_enable - test ACS flags from start to end in a hierarchy * @start: starting downstream device * @end: ending upstream device or NULL to search to the root bus * @acs_flags: required flags * * Walk up a device tree from start to end testing PCI ACS support. If * any step along the way does not support the required flags, return false. */ bool pci_acs_path_enabled(struct pci_dev *start, struct pci_dev *end, u16 acs_flags) { struct pci_dev *pdev, *parent = start; do { pdev = parent; if (!pci_acs_enabled(pdev, acs_flags)) return false; if (pci_is_root_bus(pdev->bus)) return (end == NULL); parent = pdev->bus->self; } while (pdev != end); return true; } /** * pci_acs_init - Initialize ACS if hardware supports it * @dev: the PCI device */ void pci_acs_init(struct pci_dev *dev) { dev->acs_cap = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ACS); if (dev->acs_cap) pci_enable_acs(dev); } /** * pci_rebar_find_pos - find position of resize ctrl reg for BAR * @pdev: PCI device * @bar: BAR to find * * Helper to find the position of the ctrl register for a BAR. * Returns -ENOTSUPP if resizable BARs are not supported at all. * Returns -ENOENT if no ctrl register for the BAR could be found. */ static int pci_rebar_find_pos(struct pci_dev *pdev, int bar) { unsigned int pos, nbars, i; u32 ctrl; pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_REBAR); if (!pos) return -ENOTSUPP; pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl); nbars = (ctrl & PCI_REBAR_CTRL_NBAR_MASK) >> PCI_REBAR_CTRL_NBAR_SHIFT; for (i = 0; i < nbars; i++, pos += 8) { int bar_idx; pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl); bar_idx = ctrl & PCI_REBAR_CTRL_BAR_IDX; if (bar_idx == bar) return pos; } return -ENOENT; } /** * pci_rebar_get_possible_sizes - get possible sizes for BAR * @pdev: PCI device * @bar: BAR to query * * Get the possible sizes of a resizable BAR as bitmask defined in the spec * (bit 0=1MB, bit 19=512GB). Returns 0 if BAR isn't resizable. */ u32 pci_rebar_get_possible_sizes(struct pci_dev *pdev, int bar) { int pos; u32 cap; pos = pci_rebar_find_pos(pdev, bar); if (pos < 0) return 0; pci_read_config_dword(pdev, pos + PCI_REBAR_CAP, &cap); return (cap & PCI_REBAR_CAP_SIZES) >> 4; } /** * pci_rebar_get_current_size - get the current size of a BAR * @pdev: PCI device * @bar: BAR to set size to * * Read the size of a BAR from the resizable BAR config. * Returns size if found or negative error code. */ int pci_rebar_get_current_size(struct pci_dev *pdev, int bar) { int pos; u32 ctrl; pos = pci_rebar_find_pos(pdev, bar); if (pos < 0) return pos; pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl); return (ctrl & PCI_REBAR_CTRL_BAR_SIZE) >> PCI_REBAR_CTRL_BAR_SHIFT; } /** * pci_rebar_set_size - set a new size for a BAR * @pdev: PCI device * @bar: BAR to set size to * @size: new size as defined in the spec (0=1MB, 19=512GB) * * Set the new size of a BAR as defined in the spec. * Returns zero if resizing was successful, error code otherwise. */ int pci_rebar_set_size(struct pci_dev *pdev, int bar, int size) { int pos; u32 ctrl; pos = pci_rebar_find_pos(pdev, bar); if (pos < 0) return pos; pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl); ctrl &= ~PCI_REBAR_CTRL_BAR_SIZE; ctrl |= size << PCI_REBAR_CTRL_BAR_SHIFT; pci_write_config_dword(pdev, pos + PCI_REBAR_CTRL, ctrl); return 0; } /** * pci_enable_atomic_ops_to_root - enable AtomicOp requests to root port * @dev: the PCI device * @cap_mask: mask of desired AtomicOp sizes, including one or more of: * PCI_EXP_DEVCAP2_ATOMIC_COMP32 * PCI_EXP_DEVCAP2_ATOMIC_COMP64 * PCI_EXP_DEVCAP2_ATOMIC_COMP128 * * Return 0 if all upstream bridges support AtomicOp routing, egress * blocking is disabled on all upstream ports, and the root port supports * the requested completion capabilities (32-bit, 64-bit and/or 128-bit * AtomicOp completion), or negative otherwise. */ int pci_enable_atomic_ops_to_root(struct pci_dev *dev, u32 cap_mask) { struct pci_bus *bus = dev->bus; struct pci_dev *bridge; u32 cap, ctl2; if (!pci_is_pcie(dev)) return -EINVAL; /* * Per PCIe r4.0, sec 6.15, endpoints and root ports may be * AtomicOp requesters. For now, we only support endpoints as * requesters and root ports as completers. No endpoints as * completers, and no peer-to-peer. */ switch (pci_pcie_type(dev)) { case PCI_EXP_TYPE_ENDPOINT: case PCI_EXP_TYPE_LEG_END: case PCI_EXP_TYPE_RC_END: break; default: return -EINVAL; } while (bus->parent) { bridge = bus->self; pcie_capability_read_dword(bridge, PCI_EXP_DEVCAP2, &cap); switch (pci_pcie_type(bridge)) { /* Ensure switch ports support AtomicOp routing */ case PCI_EXP_TYPE_UPSTREAM: case PCI_EXP_TYPE_DOWNSTREAM: if (!(cap & PCI_EXP_DEVCAP2_ATOMIC_ROUTE)) return -EINVAL; break; /* Ensure root port supports all the sizes we care about */ case PCI_EXP_TYPE_ROOT_PORT: if ((cap & cap_mask) != cap_mask) return -EINVAL; break; } /* Ensure upstream ports don't block AtomicOps on egress */ if (pci_pcie_type(bridge) == PCI_EXP_TYPE_UPSTREAM) { pcie_capability_read_dword(bridge, PCI_EXP_DEVCTL2, &ctl2); if (ctl2 & PCI_EXP_DEVCTL2_ATOMIC_EGRESS_BLOCK) return -EINVAL; } bus = bus->parent; } pcie_capability_set_word(dev, PCI_EXP_DEVCTL2, PCI_EXP_DEVCTL2_ATOMIC_REQ); return 0; } EXPORT_SYMBOL(pci_enable_atomic_ops_to_root); /** * pci_swizzle_interrupt_pin - swizzle INTx for device behind bridge * @dev: the PCI device * @pin: the INTx pin (1=INTA, 2=INTB, 3=INTC, 4=INTD) * * Perform INTx swizzling for a device behind one level of bridge. This is * required by section 9.1 of the PCI-to-PCI bridge specification for devices * behind bridges on add-in cards. For devices with ARI enabled, the slot * number is always 0 (see the Implementation Note in section 2.2.8.1 of * the PCI Express Base Specification, Revision 2.1) */ u8 pci_swizzle_interrupt_pin(const struct pci_dev *dev, u8 pin) { int slot; if (pci_ari_enabled(dev->bus)) slot = 0; else slot = PCI_SLOT(dev->devfn); return (((pin - 1) + slot) % 4) + 1; } int pci_get_interrupt_pin(struct pci_dev *dev, struct pci_dev **bridge) { u8 pin; pin = dev->pin; if (!pin) return -1; while (!pci_is_root_bus(dev->bus)) { pin = pci_swizzle_interrupt_pin(dev, pin); dev = dev->bus->self; } *bridge = dev; return pin; } /** * pci_common_swizzle - swizzle INTx all the way to root bridge * @dev: the PCI device * @pinp: pointer to the INTx pin value (1=INTA, 2=INTB, 3=INTD, 4=INTD) * * Perform INTx swizzling for a device. This traverses through all PCI-to-PCI * bridges all the way up to a PCI root bus. */ u8 pci_common_swizzle(struct pci_dev *dev, u8 *pinp) { u8 pin = *pinp; while (!pci_is_root_bus(dev->bus)) { pin = pci_swizzle_interrupt_pin(dev, pin); dev = dev->bus->self; } *pinp = pin; return PCI_SLOT(dev->devfn); } EXPORT_SYMBOL_GPL(pci_common_swizzle); /** * pci_release_region - Release a PCI bar * @pdev: PCI device whose resources were previously reserved by * pci_request_region() * @bar: BAR to release * * Releases the PCI I/O and memory resources previously reserved by a * successful call to pci_request_region(). Call this function only * after all use of the PCI regions has ceased. */ void pci_release_region(struct pci_dev *pdev, int bar) { struct pci_devres *dr; if (pci_resource_len(pdev, bar) == 0) return; if (pci_resource_flags(pdev, bar) & IORESOURCE_IO) release_region(pci_resource_start(pdev, bar), pci_resource_len(pdev, bar)); else if (pci_resource_flags(pdev, bar) & IORESOURCE_MEM) release_mem_region(pci_resource_start(pdev, bar), pci_resource_len(pdev, bar)); dr = find_pci_dr(pdev); if (dr) dr->region_mask &= ~(1 << bar); } EXPORT_SYMBOL(pci_release_region); /** * __pci_request_region - Reserved PCI I/O and memory resource * @pdev: PCI device whose resources are to be reserved * @bar: BAR to be reserved * @res_name: Name to be associated with resource. * @exclusive: whether the region access is exclusive or not * * Mark the PCI region associated with PCI device @pdev BAR @bar as * being reserved by owner @res_name. Do not access any * address inside the PCI regions unless this call returns * successfully. * * If @exclusive is set, then the region is marked so that userspace * is explicitly not allowed to map the resource via /dev/mem or * sysfs MMIO access. * * Returns 0 on success, or %EBUSY on error. A warning * message is also printed on failure. */ static int __pci_request_region(struct pci_dev *pdev, int bar, const char *res_name, int exclusive) { struct pci_devres *dr; if (pci_resource_len(pdev, bar) == 0) return 0; if (pci_resource_flags(pdev, bar) & IORESOURCE_IO) { if (!request_region(pci_resource_start(pdev, bar), pci_resource_len(pdev, bar), res_name)) goto err_out; } else if (pci_resource_flags(pdev, bar) & IORESOURCE_MEM) { if (!__request_mem_region(pci_resource_start(pdev, bar), pci_resource_len(pdev, bar), res_name, exclusive)) goto err_out; } dr = find_pci_dr(pdev); if (dr) dr->region_mask |= 1 << bar; return 0; err_out: pci_warn(pdev, "BAR %d: can't reserve %pR\n", bar, &pdev->resource[bar]); return -EBUSY; } /** * pci_request_region - Reserve PCI I/O and memory resource * @pdev: PCI device whose resources are to be reserved * @bar: BAR to be reserved * @res_name: Name to be associated with resource * * Mark the PCI region associated with PCI device @pdev BAR @bar as * being reserved by owner @res_name. Do not access any * address inside the PCI regions unless this call returns * successfully. * * Returns 0 on success, or %EBUSY on error. A warning * message is also printed on failure. */ int pci_request_region(struct pci_dev *pdev, int bar, const char *res_name) { return __pci_request_region(pdev, bar, res_name, 0); } EXPORT_SYMBOL(pci_request_region); /** * pci_release_selected_regions - Release selected PCI I/O and memory resources * @pdev: PCI device whose resources were previously reserved * @bars: Bitmask of BARs to be released * * Release selected PCI I/O and memory resources previously reserved. * Call this function only after all use of the PCI regions has ceased. */ void pci_release_selected_regions(struct pci_dev *pdev, int bars) { int i; for (i = 0; i < PCI_STD_NUM_BARS; i++) if (bars & (1 << i)) pci_release_region(pdev, i); } EXPORT_SYMBOL(pci_release_selected_regions); static int __pci_request_selected_regions(struct pci_dev *pdev, int bars, const char *res_name, int excl) { int i; for (i = 0; i < PCI_STD_NUM_BARS; i++) if (bars & (1 << i)) if (__pci_request_region(pdev, i, res_name, excl)) goto err_out; return 0; err_out: while (--i >= 0) if (bars & (1 << i)) pci_release_region(pdev, i); return -EBUSY; } /** * pci_request_selected_regions - Reserve selected PCI I/O and memory resources * @pdev: PCI device whose resources are to be reserved * @bars: Bitmask of BARs to be requested * @res_name: Name to be associated with resource */ int pci_request_selected_regions(struct pci_dev *pdev, int bars, const char *res_name) { return __pci_request_selected_regions(pdev, bars, res_name, 0); } EXPORT_SYMBOL(pci_request_selected_regions); int pci_request_selected_regions_exclusive(struct pci_dev *pdev, int bars, const char *res_name) { return __pci_request_selected_regions(pdev, bars, res_name, IORESOURCE_EXCLUSIVE); } EXPORT_SYMBOL(pci_request_selected_regions_exclusive); /** * pci_release_regions - Release reserved PCI I/O and memory resources * @pdev: PCI device whose resources were previously reserved by * pci_request_regions() * * Releases all PCI I/O and memory resources previously reserved by a * successful call to pci_request_regions(). Call this function only * after all use of the PCI regions has ceased. */ void pci_release_regions(struct pci_dev *pdev) { pci_release_selected_regions(pdev, (1 << PCI_STD_NUM_BARS) - 1); } EXPORT_SYMBOL(pci_release_regions); /** * pci_request_regions - Reserve PCI I/O and memory resources * @pdev: PCI device whose resources are to be reserved * @res_name: Name to be associated with resource. * * Mark all PCI regions associated with PCI device @pdev as * being reserved by owner @res_name. Do not access any * address inside the PCI regions unless this call returns * successfully. * * Returns 0 on success, or %EBUSY on error. A warning * message is also printed on failure. */ int pci_request_regions(struct pci_dev *pdev, const char *res_name) { return pci_request_selected_regions(pdev, ((1 << PCI_STD_NUM_BARS) - 1), res_name); } EXPORT_SYMBOL(pci_request_regions); /** * pci_request_regions_exclusive - Reserve PCI I/O and memory resources * @pdev: PCI device whose resources are to be reserved * @res_name: Name to be associated with resource. * * Mark all PCI regions associated with PCI device @pdev as being reserved * by owner @res_name. Do not access any address inside the PCI regions * unless this call returns successfully. * * pci_request_regions_exclusive() will mark the region so that /dev/mem * and the sysfs MMIO access will not be allowed. * * Returns 0 on success, or %EBUSY on error. A warning message is also * printed on failure. */ int pci_request_regions_exclusive(struct pci_dev *pdev, const char *res_name) { return pci_request_selected_regions_exclusive(pdev, ((1 << PCI_STD_NUM_BARS) - 1), res_name); } EXPORT_SYMBOL(pci_request_regions_exclusive); /* * Record the PCI IO range (expressed as CPU physical address + size). * Return a negative value if an error has occurred, zero otherwise */ int pci_register_io_range(struct fwnode_handle *fwnode, phys_addr_t addr, resource_size_t size) { int ret = 0; #ifdef PCI_IOBASE struct logic_pio_hwaddr *range; if (!size || addr + size < addr) return -EINVAL; range = kzalloc(sizeof(*range), GFP_ATOMIC); if (!range) return -ENOMEM; range->fwnode = fwnode; range->size = size; range->hw_start = addr; range->flags = LOGIC_PIO_CPU_MMIO; ret = logic_pio_register_range(range); if (ret) kfree(range); #endif return ret; } phys_addr_t pci_pio_to_address(unsigned long pio) { phys_addr_t address = (phys_addr_t)OF_BAD_ADDR; #ifdef PCI_IOBASE if (pio >= MMIO_UPPER_LIMIT) return address; address = logic_pio_to_hwaddr(pio); #endif return address; } unsigned long __weak pci_address_to_pio(phys_addr_t address) { #ifdef PCI_IOBASE return logic_pio_trans_cpuaddr(address); #else if (address > IO_SPACE_LIMIT) return (unsigned long)-1; return (unsigned long) address; #endif } /** * pci_remap_iospace - Remap the memory mapped I/O space * @res: Resource describing the I/O space * @phys_addr: physical address of range to be mapped * * Remap the memory mapped I/O space described by the @res and the CPU * physical address @phys_addr into virtual address space. Only * architectures that have memory mapped IO functions defined (and the * PCI_IOBASE value defined) should call this function. */ int pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr) { #if defined(PCI_IOBASE) && defined(CONFIG_MMU) unsigned long vaddr = (unsigned long)PCI_IOBASE + res->start; if (!(res->flags & IORESOURCE_IO)) return -EINVAL; if (res->end > IO_SPACE_LIMIT) return -EINVAL; return ioremap_page_range(vaddr, vaddr + resource_size(res), phys_addr, pgprot_device(PAGE_KERNEL)); #else /* * This architecture does not have memory mapped I/O space, * so this function should never be called */ WARN_ONCE(1, "This architecture does not support memory mapped I/O\n"); return -ENODEV; #endif } EXPORT_SYMBOL(pci_remap_iospace); /** * pci_unmap_iospace - Unmap the memory mapped I/O space * @res: resource to be unmapped * * Unmap the CPU virtual address @res from virtual address space. Only * architectures that have memory mapped IO functions defined (and the * PCI_IOBASE value defined) should call this function. */ void pci_unmap_iospace(struct resource *res) { #if defined(PCI_IOBASE) && defined(CONFIG_MMU) unsigned long vaddr = (unsigned long)PCI_IOBASE + res->start; unmap_kernel_range(vaddr, resource_size(res)); #endif } EXPORT_SYMBOL(pci_unmap_iospace); static void devm_pci_unmap_iospace(struct device *dev, void *ptr) { struct resource **res = ptr; pci_unmap_iospace(*res); } /** * devm_pci_remap_iospace - Managed pci_remap_iospace() * @dev: Generic device to remap IO address for * @res: Resource describing the I/O space * @phys_addr: physical address of range to be mapped * * Managed pci_remap_iospace(). Map is automatically unmapped on driver * detach. */ int devm_pci_remap_iospace(struct device *dev, const struct resource *res, phys_addr_t phys_addr) { const struct resource **ptr; int error; ptr = devres_alloc(devm_pci_unmap_iospace, sizeof(*ptr), GFP_KERNEL); if (!ptr) return -ENOMEM; error = pci_remap_iospace(res, phys_addr); if (error) { devres_free(ptr); } else { *ptr = res; devres_add(dev, ptr); } return error; } EXPORT_SYMBOL(devm_pci_remap_iospace); /** * devm_pci_remap_cfgspace - Managed pci_remap_cfgspace() * @dev: Generic device to remap IO address for * @offset: Resource address to map * @size: Size of map * * Managed pci_remap_cfgspace(). Map is automatically unmapped on driver * detach. */ void __iomem *devm_pci_remap_cfgspace(struct device *dev, resource_size_t offset, resource_size_t size) { void __iomem **ptr, *addr; ptr = devres_alloc(devm_ioremap_release, sizeof(*ptr), GFP_KERNEL); if (!ptr) return NULL; addr = pci_remap_cfgspace(offset, size); if (addr) { *ptr = addr; devres_add(dev, ptr); } else devres_free(ptr); return addr; } EXPORT_SYMBOL(devm_pci_remap_cfgspace); /** * devm_pci_remap_cfg_resource - check, request region and ioremap cfg resource * @dev: generic device to handle the resource for * @res: configuration space resource to be handled * * Checks that a resource is a valid memory region, requests the memory * region and ioremaps with pci_remap_cfgspace() API that ensures the * proper PCI configuration space memory attributes are guaranteed. * * All operations are managed and will be undone on driver detach. * * Returns a pointer to the remapped memory or an ERR_PTR() encoded error code * on failure. Usage example:: * * res = platform_get_resource(pdev, IORESOURCE_MEM, 0); * base = devm_pci_remap_cfg_resource(&pdev->dev, res); * if (IS_ERR(base)) * return PTR_ERR(base); */ void __iomem *devm_pci_remap_cfg_resource(struct device *dev, struct resource *res) { resource_size_t size; const char *name; void __iomem *dest_ptr; BUG_ON(!dev); if (!res || resource_type(res) != IORESOURCE_MEM) { dev_err(dev, "invalid resource\n"); return IOMEM_ERR_PTR(-EINVAL); } size = resource_size(res); name = res->name ?: dev_name(dev); if (!devm_request_mem_region(dev, res->start, size, name)) { dev_err(dev, "can't request region for resource %pR\n", res); return IOMEM_ERR_PTR(-EBUSY); } dest_ptr = devm_pci_remap_cfgspace(dev, res->start, size); if (!dest_ptr) { dev_err(dev, "ioremap failed for resource %pR\n", res); devm_release_mem_region(dev, res->start, size); dest_ptr = IOMEM_ERR_PTR(-ENOMEM); } return dest_ptr; } EXPORT_SYMBOL(devm_pci_remap_cfg_resource); static void __pci_set_master(struct pci_dev *dev, bool enable) { u16 old_cmd, cmd; pci_read_config_word(dev, PCI_COMMAND, &old_cmd); if (enable) cmd = old_cmd | PCI_COMMAND_MASTER; else cmd = old_cmd & ~PCI_COMMAND_MASTER; if (cmd != old_cmd) { pci_dbg(dev, "%s bus mastering\n", enable ? "enabling" : "disabling"); pci_write_config_word(dev, PCI_COMMAND, cmd); } dev->is_busmaster = enable; } /** * pcibios_setup - process "pci=" kernel boot arguments * @str: string used to pass in "pci=" kernel boot arguments * * Process kernel boot arguments. This is the default implementation. * Architecture specific implementations can override this as necessary. */ char * __weak __init pcibios_setup(char *str) { return str; } /** * pcibios_set_master - enable PCI bus-mastering for device dev * @dev: the PCI device to enable * * Enables PCI bus-mastering for the device. This is the default * implementation. Architecture specific implementations can override * this if necessary. */ void __weak pcibios_set_master(struct pci_dev *dev) { u8 lat; /* The latency timer doesn't apply to PCIe (either Type 0 or Type 1) */ if (pci_is_pcie(dev)) return; pci_read_config_byte(dev, PCI_LATENCY_TIMER, &lat); if (lat < 16) lat = (64 <= pcibios_max_latency) ? 64 : pcibios_max_latency; else if (lat > pcibios_max_latency) lat = pcibios_max_latency; else return; pci_write_config_byte(dev, PCI_LATENCY_TIMER, lat); } /** * pci_set_master - enables bus-mastering for device dev * @dev: the PCI device to enable * * Enables bus-mastering on the device and calls pcibios_set_master() * to do the needed arch specific settings. */ void pci_set_master(struct pci_dev *dev) { __pci_set_master(dev, true); pcibios_set_master(dev); } EXPORT_SYMBOL(pci_set_master); /** * pci_clear_master - disables bus-mastering for device dev * @dev: the PCI device to disable */ void pci_clear_master(struct pci_dev *dev) { __pci_set_master(dev, false); } EXPORT_SYMBOL(pci_clear_master); /** * pci_set_cacheline_size - ensure the CACHE_LINE_SIZE register is programmed * @dev: the PCI device for which MWI is to be enabled * * Helper function for pci_set_mwi. * Originally copied from drivers/net/acenic.c. * Copyright 1998-2001 by Jes Sorensen, <jes@trained-monkey.org>. * * RETURNS: An appropriate -ERRNO error value on error, or zero for success. */ int pci_set_cacheline_size(struct pci_dev *dev) { u8 cacheline_size; if (!pci_cache_line_size) return -EINVAL; /* Validate current setting: the PCI_CACHE_LINE_SIZE must be equal to or multiple of the right value. */ pci_read_config_byte(dev, PCI_CACHE_LINE_SIZE, &cacheline_size); if (cacheline_size >= pci_cache_line_size && (cacheline_size % pci_cache_line_size) == 0) return 0; /* Write the correct value. */ pci_write_config_byte(dev, PCI_CACHE_LINE_SIZE, pci_cache_line_size); /* Read it back. */ pci_read_config_byte(dev, PCI_CACHE_LINE_SIZE, &cacheline_size); if (cacheline_size == pci_cache_line_size) return 0; pci_info(dev, "cache line size of %d is not supported\n", pci_cache_line_size << 2); return -EINVAL; } EXPORT_SYMBOL_GPL(pci_set_cacheline_size); /** * pci_set_mwi - enables memory-write-invalidate PCI transaction * @dev: the PCI device for which MWI is enabled * * Enables the Memory-Write-Invalidate transaction in %PCI_COMMAND. * * RETURNS: An appropriate -ERRNO error value on error, or zero for success. */ int pci_set_mwi(struct pci_dev *dev) { #ifdef PCI_DISABLE_MWI return 0; #else int rc; u16 cmd; rc = pci_set_cacheline_size(dev); if (rc) return rc; pci_read_config_word(dev, PCI_COMMAND, &cmd); if (!(cmd & PCI_COMMAND_INVALIDATE)) { pci_dbg(dev, "enabling Mem-Wr-Inval\n"); cmd |= PCI_COMMAND_INVALIDATE; pci_write_config_word(dev, PCI_COMMAND, cmd); } return 0; #endif } EXPORT_SYMBOL(pci_set_mwi); /** * pcim_set_mwi - a device-managed pci_set_mwi() * @dev: the PCI device for which MWI is enabled * * Managed pci_set_mwi(). * * RETURNS: An appropriate -ERRNO error value on error, or zero for success. */ int pcim_set_mwi(struct pci_dev *dev) { struct pci_devres *dr; dr = find_pci_dr(dev); if (!dr) return -ENOMEM; dr->mwi = 1; return pci_set_mwi(dev); } EXPORT_SYMBOL(pcim_set_mwi); /** * pci_try_set_mwi - enables memory-write-invalidate PCI transaction * @dev: the PCI device for which MWI is enabled * * Enables the Memory-Write-Invalidate transaction in %PCI_COMMAND. * Callers are not required to check the return value. * * RETURNS: An appropriate -ERRNO error value on error, or zero for success. */ int pci_try_set_mwi(struct pci_dev *dev) { #ifdef PCI_DISABLE_MWI return 0; #else return pci_set_mwi(dev); #endif } EXPORT_SYMBOL(pci_try_set_mwi); /** * pci_clear_mwi - disables Memory-Write-Invalidate for device dev * @dev: the PCI device to disable * * Disables PCI Memory-Write-Invalidate transaction on the device */ void pci_clear_mwi(struct pci_dev *dev) { #ifndef PCI_DISABLE_MWI u16 cmd; pci_read_config_word(dev, PCI_COMMAND, &cmd); if (cmd & PCI_COMMAND_INVALIDATE) { cmd &= ~PCI_COMMAND_INVALIDATE; pci_write_config_word(dev, PCI_COMMAND, cmd); } #endif } EXPORT_SYMBOL(pci_clear_mwi); /** * pci_intx - enables/disables PCI INTx for device dev * @pdev: the PCI device to operate on * @enable: boolean: whether to enable or disable PCI INTx * * Enables/disables PCI INTx for device @pdev */ void pci_intx(struct pci_dev *pdev, int enable) { u16 pci_command, new; pci_read_config_word(pdev, PCI_COMMAND, &pci_command); if (enable) new = pci_command & ~PCI_COMMAND_INTX_DISABLE; else new = pci_command | PCI_COMMAND_INTX_DISABLE; if (new != pci_command) { struct pci_devres *dr; pci_write_config_word(pdev, PCI_COMMAND, new); dr = find_pci_dr(pdev); if (dr && !dr->restore_intx) { dr->restore_intx = 1; dr->orig_intx = !enable; } } } EXPORT_SYMBOL_GPL(pci_intx); static bool pci_check_and_set_intx_mask(struct pci_dev *dev, bool mask) { struct pci_bus *bus = dev->bus; bool mask_updated = true; u32 cmd_status_dword; u16 origcmd, newcmd; unsigned long flags; bool irq_pending; /* * We do a single dword read to retrieve both command and status. * Document assumptions that make this possible. */ BUILD_BUG_ON(PCI_COMMAND % 4); BUILD_BUG_ON(PCI_COMMAND + 2 != PCI_STATUS); raw_spin_lock_irqsave(&pci_lock, flags); bus->ops->read(bus, dev->devfn, PCI_COMMAND, 4, &cmd_status_dword); irq_pending = (cmd_status_dword >> 16) & PCI_STATUS_INTERRUPT; /* * Check interrupt status register to see whether our device * triggered the interrupt (when masking) or the next IRQ is * already pending (when unmasking). */ if (mask != irq_pending) { mask_updated = false; goto done; } origcmd = cmd_status_dword; newcmd = origcmd & ~PCI_COMMAND_INTX_DISABLE; if (mask) newcmd |= PCI_COMMAND_INTX_DISABLE; if (newcmd != origcmd) bus->ops->write(bus, dev->devfn, PCI_COMMAND, 2, newcmd); done: raw_spin_unlock_irqrestore(&pci_lock, flags); return mask_updated; } /** * pci_check_and_mask_intx - mask INTx on pending interrupt * @dev: the PCI device to operate on * * Check if the device dev has its INTx line asserted, mask it and return * true in that case. False is returned if no interrupt was pending. */ bool pci_check_and_mask_intx(struct pci_dev *dev) { return pci_check_and_set_intx_mask(dev, true); } EXPORT_SYMBOL_GPL(pci_check_and_mask_intx); /** * pci_check_and_unmask_intx - unmask INTx if no interrupt is pending * @dev: the PCI device to operate on * * Check if the device dev has its INTx line asserted, unmask it if not and * return true. False is returned and the mask remains active if there was * still an interrupt pending. */ bool pci_check_and_unmask_intx(struct pci_dev *dev) { return pci_check_and_set_intx_mask(dev, false); } EXPORT_SYMBOL_GPL(pci_check_and_unmask_intx); /** * pci_wait_for_pending_transaction - wait for pending transaction * @dev: the PCI device to operate on * * Return 0 if transaction is pending 1 otherwise. */ int pci_wait_for_pending_transaction(struct pci_dev *dev) { if (!pci_is_pcie(dev)) return 1; return pci_wait_for_pending(dev, pci_pcie_cap(dev) + PCI_EXP_DEVSTA, PCI_EXP_DEVSTA_TRPND); } EXPORT_SYMBOL(pci_wait_for_pending_transaction); /** * pcie_has_flr - check if a device supports function level resets * @dev: device to check * * Returns true if the device advertises support for PCIe function level * resets. */ bool pcie_has_flr(struct pci_dev *dev) { u32 cap; if (dev->dev_flags & PCI_DEV_FLAGS_NO_FLR_RESET) return false; pcie_capability_read_dword(dev, PCI_EXP_DEVCAP, &cap); return cap & PCI_EXP_DEVCAP_FLR; } EXPORT_SYMBOL_GPL(pcie_has_flr); /** * pcie_flr - initiate a PCIe function level reset * @dev: device to reset * * Initiate a function level reset on @dev. The caller should ensure the * device supports FLR before calling this function, e.g. by using the * pcie_has_flr() helper. */ int pcie_flr(struct pci_dev *dev) { if (!pci_wait_for_pending_transaction(dev)) pci_err(dev, "timed out waiting for pending transaction; performing function level reset anyway\n"); pcie_capability_set_word(dev, PCI_EXP_DEVCTL, PCI_EXP_DEVCTL_BCR_FLR); if (dev->imm_ready) return 0; /* * Per PCIe r4.0, sec 6.6.2, a device must complete an FLR within * 100ms, but may silently discard requests while the FLR is in * progress. Wait 100ms before trying to access the device. */ msleep(100); return pci_dev_wait(dev, "FLR", PCIE_RESET_READY_POLL_MS); } EXPORT_SYMBOL_GPL(pcie_flr); static int pci_af_flr(struct pci_dev *dev, int probe) { int pos; u8 cap; pos = pci_find_capability(dev, PCI_CAP_ID_AF); if (!pos) return -ENOTTY; if (dev->dev_flags & PCI_DEV_FLAGS_NO_FLR_RESET) return -ENOTTY; pci_read_config_byte(dev, pos + PCI_AF_CAP, &cap); if (!(cap & PCI_AF_CAP_TP) || !(cap & PCI_AF_CAP_FLR)) return -ENOTTY; if (probe) return 0; /* * Wait for Transaction Pending bit to clear. A word-aligned test * is used, so we use the control offset rather than status and shift * the test bit to match. */ if (!pci_wait_for_pending(dev, pos + PCI_AF_CTRL, PCI_AF_STATUS_TP << 8)) pci_err(dev, "timed out waiting for pending transaction; performing AF function level reset anyway\n"); pci_write_config_byte(dev, pos + PCI_AF_CTRL, PCI_AF_CTRL_FLR); if (dev->imm_ready) return 0; /* * Per Advanced Capabilities for Conventional PCI ECN, 13 April 2006, * updated 27 July 2006; a device must complete an FLR within * 100ms, but may silently discard requests while the FLR is in * progress. Wait 100ms before trying to access the device. */ msleep(100); return pci_dev_wait(dev, "AF_FLR", PCIE_RESET_READY_POLL_MS); } /** * pci_pm_reset - Put device into PCI_D3 and back into PCI_D0. * @dev: Device to reset. * @probe: If set, only check if the device can be reset this way. * * If @dev supports native PCI PM and its PCI_PM_CTRL_NO_SOFT_RESET flag is * unset, it will be reinitialized internally when going from PCI_D3hot to * PCI_D0. If that's the case and the device is not in a low-power state * already, force it into PCI_D3hot and back to PCI_D0, causing it to be reset. * * NOTE: This causes the caller to sleep for twice the device power transition * cooldown period, which for the D0->D3hot and D3hot->D0 transitions is 10 ms * by default (i.e. unless the @dev's d3_delay field has a different value). * Moreover, only devices in D0 can be reset by this function. */ static int pci_pm_reset(struct pci_dev *dev, int probe) { u16 csr; if (!dev->pm_cap || dev->dev_flags & PCI_DEV_FLAGS_NO_PM_RESET) return -ENOTTY; pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &csr); if (csr & PCI_PM_CTRL_NO_SOFT_RESET) return -ENOTTY; if (probe) return 0; if (dev->current_state != PCI_D0) return -EINVAL; csr &= ~PCI_PM_CTRL_STATE_MASK; csr |= PCI_D3hot; pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, csr); pci_dev_d3_sleep(dev); csr &= ~PCI_PM_CTRL_STATE_MASK; csr |= PCI_D0; pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, csr); pci_dev_d3_sleep(dev); return pci_dev_wait(dev, "PM D3hot->D0", PCIE_RESET_READY_POLL_MS); } /** * pcie_wait_for_link_delay - Wait until link is active or inactive * @pdev: Bridge device * @active: waiting for active or inactive? * @delay: Delay to wait after link has become active (in ms) * * Use this to wait till link becomes active or inactive. */ static bool pcie_wait_for_link_delay(struct pci_dev *pdev, bool active, int delay) { int timeout = 1000; bool ret; u16 lnk_status; /* * Some controllers might not implement link active reporting. In this * case, we wait for 1000 ms + any delay requested by the caller. */ if (!pdev->link_active_reporting) { msleep(timeout + delay); return true; } /* * PCIe r4.0 sec 6.6.1, a component must enter LTSSM Detect within 20ms, * after which we should expect an link active if the reset was * successful. If so, software must wait a minimum 100ms before sending * configuration requests to devices downstream this port. * * If the link fails to activate, either the device was physically * removed or the link is permanently failed. */ if (active) msleep(20); for (;;) { pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status); ret = !!(lnk_status & PCI_EXP_LNKSTA_DLLLA); if (ret == active) break; if (timeout <= 0) break; msleep(10); timeout -= 10; } if (active && ret) msleep(delay); else if (ret != active) pci_info(pdev, "Data Link Layer Link Active not %s in 1000 msec\n", active ? "set" : "cleared"); return ret == active; } /** * pcie_wait_for_link - Wait until link is active or inactive * @pdev: Bridge device * @active: waiting for active or inactive? * * Use this to wait till link becomes active or inactive. */ bool pcie_wait_for_link(struct pci_dev *pdev, bool active) { return pcie_wait_for_link_delay(pdev, active, 100); } /* * Find maximum D3cold delay required by all the devices on the bus. The * spec says 100 ms, but firmware can lower it and we allow drivers to * increase it as well. * * Called with @pci_bus_sem locked for reading. */ static int pci_bus_max_d3cold_delay(const struct pci_bus *bus) { const struct pci_dev *pdev; int min_delay = 100; int max_delay = 0; list_for_each_entry(pdev, &bus->devices, bus_list) { if (pdev->d3cold_delay < min_delay) min_delay = pdev->d3cold_delay; if (pdev->d3cold_delay > max_delay) max_delay = pdev->d3cold_delay; } return max(min_delay, max_delay); } /** * pci_bridge_wait_for_secondary_bus - Wait for secondary bus to be accessible * @dev: PCI bridge * * Handle necessary delays before access to the devices on the secondary * side of the bridge are permitted after D3cold to D0 transition. * * For PCIe this means the delays in PCIe 5.0 section 6.6.1. For * conventional PCI it means Tpvrh + Trhfa specified in PCI 3.0 section * 4.3.2. */ void pci_bridge_wait_for_secondary_bus(struct pci_dev *dev) { struct pci_dev *child; int delay; if (pci_dev_is_disconnected(dev)) return; if (!pci_is_bridge(dev) || !dev->bridge_d3) return; down_read(&pci_bus_sem); /* * We only deal with devices that are present currently on the bus. * For any hot-added devices the access delay is handled in pciehp * board_added(). In case of ACPI hotplug the firmware is expected * to configure the devices before OS is notified. */ if (!dev->subordinate || list_empty(&dev->subordinate->devices)) { up_read(&pci_bus_sem); return; } /* Take d3cold_delay requirements into account */ delay = pci_bus_max_d3cold_delay(dev->subordinate); if (!delay) { up_read(&pci_bus_sem); return; } child = list_first_entry(&dev->subordinate->devices, struct pci_dev, bus_list); up_read(&pci_bus_sem); /* * Conventional PCI and PCI-X we need to wait Tpvrh + Trhfa before * accessing the device after reset (that is 1000 ms + 100 ms). In * practice this should not be needed because we don't do power * management for them (see pci_bridge_d3_possible()). */ if (!pci_is_pcie(dev)) { pci_dbg(dev, "waiting %d ms for secondary bus\n", 1000 + delay); msleep(1000 + delay); return; } /* * For PCIe downstream and root ports that do not support speeds * greater than 5 GT/s need to wait minimum 100 ms. For higher * speeds (gen3) we need to wait first for the data link layer to * become active. * * However, 100 ms is the minimum and the PCIe spec says the * software must allow at least 1s before it can determine that the * device that did not respond is a broken device. There is * evidence that 100 ms is not always enough, for example certain * Titan Ridge xHCI controller does not always respond to * configuration requests if we only wait for 100 ms (see * https://bugzilla.kernel.org/show_bug.cgi?id=203885). * * Therefore we wait for 100 ms and check for the device presence. * If it is still not present give it an additional 100 ms. */ if (!pcie_downstream_port(dev)) return; if (pcie_get_speed_cap(dev) <= PCIE_SPEED_5_0GT) { pci_dbg(dev, "waiting %d ms for downstream link\n", delay); msleep(delay); } else { pci_dbg(dev, "waiting %d ms for downstream link, after activation\n", delay); if (!pcie_wait_for_link_delay(dev, true, delay)) { /* Did not train, no need to wait any further */ return; } } if (!pci_device_is_present(child)) { pci_dbg(child, "waiting additional %d ms to become accessible\n", delay); msleep(delay); } } void pci_reset_secondary_bus(struct pci_dev *dev) { u16 ctrl; pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &ctrl); ctrl |= PCI_BRIDGE_CTL_BUS_RESET; pci_write_config_word(dev, PCI_BRIDGE_CONTROL, ctrl); /* * PCI spec v3.0 7.6.4.2 requires minimum Trst of 1ms. Double * this to 2ms to ensure that we meet the minimum requirement. */ msleep(2); ctrl &= ~PCI_BRIDGE_CTL_BUS_RESET; pci_write_config_word(dev, PCI_BRIDGE_CONTROL, ctrl); /* * Trhfa for conventional PCI is 2^25 clock cycles. * Assuming a minimum 33MHz clock this results in a 1s * delay before we can consider subordinate devices to * be re-initialized. PCIe has some ways to shorten this, * but we don't make use of them yet. */ ssleep(1); } void __weak pcibios_reset_secondary_bus(struct pci_dev *dev) { pci_reset_secondary_bus(dev); } /** * pci_bridge_secondary_bus_reset - Reset the secondary bus on a PCI bridge. * @dev: Bridge device * * Use the bridge control register to assert reset on the secondary bus. * Devices on the secondary bus are left in power-on state. */ int pci_bridge_secondary_bus_reset(struct pci_dev *dev) { pcibios_reset_secondary_bus(dev); return pci_dev_wait(dev, "bus reset", PCIE_RESET_READY_POLL_MS); } EXPORT_SYMBOL_GPL(pci_bridge_secondary_bus_reset); static int pci_parent_bus_reset(struct pci_dev *dev, int probe) { struct pci_dev *pdev; if (pci_is_root_bus(dev->bus) || dev->subordinate || !dev->bus->self || dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET) return -ENOTTY; list_for_each_entry(pdev, &dev->bus->devices, bus_list) if (pdev != dev) return -ENOTTY; if (probe) return 0; return pci_bridge_secondary_bus_reset(dev->bus->self); } static int pci_reset_hotplug_slot(struct hotplug_slot *hotplug, int probe) { int rc = -ENOTTY; if (!hotplug || !try_module_get(hotplug->owner)) return rc; if (hotplug->ops->reset_slot) rc = hotplug->ops->reset_slot(hotplug, probe); module_put(hotplug->owner); return rc; } static int pci_dev_reset_slot_function(struct pci_dev *dev, int probe) { struct pci_dev *pdev; if (dev->subordinate || !dev->slot || dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET) return -ENOTTY; list_for_each_entry(pdev, &dev->bus->devices, bus_list) if (pdev != dev && pdev->slot == dev->slot) return -ENOTTY; return pci_reset_hotplug_slot(dev->slot->hotplug, probe); } static void pci_dev_lock(struct pci_dev *dev) { pci_cfg_access_lock(dev); /* block PM suspend, driver probe, etc. */ device_lock(&dev->dev); } /* Return 1 on successful lock, 0 on contention */ static int pci_dev_trylock(struct pci_dev *dev) { if (pci_cfg_access_trylock(dev)) { if (device_trylock(&dev->dev)) return 1; pci_cfg_access_unlock(dev); } return 0; } static void pci_dev_unlock(struct pci_dev *dev) { device_unlock(&dev->dev); pci_cfg_access_unlock(dev); } static void pci_dev_save_and_disable(struct pci_dev *dev) { const struct pci_error_handlers *err_handler = dev->driver ? dev->driver->err_handler : NULL; /* * dev->driver->err_handler->reset_prepare() is protected against * races with ->remove() by the device lock, which must be held by * the caller. */ if (err_handler && err_handler->reset_prepare) err_handler->reset_prepare(dev); /* * Wake-up device prior to save. PM registers default to D0 after * reset and a simple register restore doesn't reliably return * to a non-D0 state anyway. */ pci_set_power_state(dev, PCI_D0); pci_save_state(dev); /* * Disable the device by clearing the Command register, except for * INTx-disable which is set. This not only disables MMIO and I/O port * BARs, but also prevents the device from being Bus Master, preventing * DMA from the device including MSI/MSI-X interrupts. For PCI 2.3 * compliant devices, INTx-disable prevents legacy interrupts. */ pci_write_config_word(dev, PCI_COMMAND, PCI_COMMAND_INTX_DISABLE); } static void pci_dev_restore(struct pci_dev *dev) { const struct pci_error_handlers *err_handler = dev->driver ? dev->driver->err_handler : NULL; pci_restore_state(dev); /* * dev->driver->err_handler->reset_done() is protected against * races with ->remove() by the device lock, which must be held by * the caller. */ if (err_handler && err_handler->reset_done) err_handler->reset_done(dev); } /** * __pci_reset_function_locked - reset a PCI device function while holding * the @dev mutex lock. * @dev: PCI device to reset * * Some devices allow an individual function to be reset without affecting * other functions in the same device. The PCI device must be responsive * to PCI config space in order to use this function. * * The device function is presumed to be unused and the caller is holding * the device mutex lock when this function is called. * * Resetting the device will make the contents of PCI configuration space * random, so any caller of this must be prepared to reinitialise the * device including MSI, bus mastering, BARs, decoding IO and memory spaces, * etc. * * Returns 0 if the device function was successfully reset or negative if the * device doesn't support resetting a single function. */ int __pci_reset_function_locked(struct pci_dev *dev) { int rc; might_sleep(); /* * A reset method returns -ENOTTY if it doesn't support this device * and we should try the next method. * * If it returns 0 (success), we're finished. If it returns any * other error, we're also finished: this indicates that further * reset mechanisms might be broken on the device. */ rc = pci_dev_specific_reset(dev, 0); if (rc != -ENOTTY) return rc; if (pcie_has_flr(dev)) { rc = pcie_flr(dev); if (rc != -ENOTTY) return rc; } rc = pci_af_flr(dev, 0); if (rc != -ENOTTY) return rc; rc = pci_pm_reset(dev, 0); if (rc != -ENOTTY) return rc; rc = pci_dev_reset_slot_function(dev, 0); if (rc != -ENOTTY) return rc; return pci_parent_bus_reset(dev, 0); } EXPORT_SYMBOL_GPL(__pci_reset_function_locked); /** * pci_probe_reset_function - check whether the device can be safely reset * @dev: PCI device to reset * * Some devices allow an individual function to be reset without affecting * other functions in the same device. The PCI device must be responsive * to PCI config space in order to use this function. * * Returns 0 if the device function can be reset or negative if the * device doesn't support resetting a single function. */ int pci_probe_reset_function(struct pci_dev *dev) { int rc; might_sleep(); rc = pci_dev_specific_reset(dev, 1); if (rc != -ENOTTY) return rc; if (pcie_has_flr(dev)) return 0; rc = pci_af_flr(dev, 1); if (rc != -ENOTTY) return rc; rc = pci_pm_reset(dev, 1); if (rc != -ENOTTY) return rc; rc = pci_dev_reset_slot_function(dev, 1); if (rc != -ENOTTY) return rc; return pci_parent_bus_reset(dev, 1); } /** * pci_reset_function - quiesce and reset a PCI device function * @dev: PCI device to reset * * Some devices allow an individual function to be reset without affecting * other functions in the same device. The PCI device must be responsive * to PCI config space in order to use this function. * * This function does not just reset the PCI portion of a device, but * clears all the state associated with the device. This function differs * from __pci_reset_function_locked() in that it saves and restores device state * over the reset and takes the PCI device lock. * * Returns 0 if the device function was successfully reset or negative if the * device doesn't support resetting a single function. */ int pci_reset_function(struct pci_dev *dev) { int rc; if (!dev->reset_fn) return -ENOTTY; pci_dev_lock(dev); pci_dev_save_and_disable(dev); rc = __pci_reset_function_locked(dev); pci_dev_restore(dev); pci_dev_unlock(dev); return rc; } EXPORT_SYMBOL_GPL(pci_reset_function); /** * pci_reset_function_locked - quiesce and reset a PCI device function * @dev: PCI device to reset * * Some devices allow an individual function to be reset without affecting * other functions in the same device. The PCI device must be responsive * to PCI config space in order to use this function. * * This function does not just reset the PCI portion of a device, but * clears all the state associated with the device. This function differs * from __pci_reset_function_locked() in that it saves and restores device state * over the reset. It also differs from pci_reset_function() in that it * requires the PCI device lock to be held. * * Returns 0 if the device function was successfully reset or negative if the * device doesn't support resetting a single function. */ int pci_reset_function_locked(struct pci_dev *dev) { int rc; if (!dev->reset_fn) return -ENOTTY; pci_dev_save_and_disable(dev); rc = __pci_reset_function_locked(dev); pci_dev_restore(dev); return rc; } EXPORT_SYMBOL_GPL(pci_reset_function_locked); /** * pci_try_reset_function - quiesce and reset a PCI device function * @dev: PCI device to reset * * Same as above, except return -EAGAIN if unable to lock device. */ int pci_try_reset_function(struct pci_dev *dev) { int rc; if (!dev->reset_fn) return -ENOTTY; if (!pci_dev_trylock(dev)) return -EAGAIN; pci_dev_save_and_disable(dev); rc = __pci_reset_function_locked(dev); pci_dev_restore(dev); pci_dev_unlock(dev); return rc; } EXPORT_SYMBOL_GPL(pci_try_reset_function); /* Do any devices on or below this bus prevent a bus reset? */ static bool pci_bus_resetable(struct pci_bus *bus) { struct pci_dev *dev; if (bus->self && (bus->self->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET)) return false; list_for_each_entry(dev, &bus->devices, bus_list) { if (dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET || (dev->subordinate && !pci_bus_resetable(dev->subordinate))) return false; } return true; } /* Lock devices from the top of the tree down */ static void pci_bus_lock(struct pci_bus *bus) { struct pci_dev *dev; list_for_each_entry(dev, &bus->devices, bus_list) { pci_dev_lock(dev); if (dev->subordinate) pci_bus_lock(dev->subordinate); } } /* Unlock devices from the bottom of the tree up */ static void pci_bus_unlock(struct pci_bus *bus) { struct pci_dev *dev; list_for_each_entry(dev, &bus->devices, bus_list) { if (dev->subordinate) pci_bus_unlock(dev->subordinate); pci_dev_unlock(dev); } } /* Return 1 on successful lock, 0 on contention */ static int pci_bus_trylock(struct pci_bus *bus) { struct pci_dev *dev; list_for_each_entry(dev, &bus->devices, bus_list) { if (!pci_dev_trylock(dev)) goto unlock; if (dev->subordinate) { if (!pci_bus_trylock(dev->subordinate)) { pci_dev_unlock(dev); goto unlock; } } } return 1; unlock: list_for_each_entry_continue_reverse(dev, &bus->devices, bus_list) { if (dev->subordinate) pci_bus_unlock(dev->subordinate); pci_dev_unlock(dev); } return 0; } /* Do any devices on or below this slot prevent a bus reset? */ static bool pci_slot_resetable(struct pci_slot *slot) { struct pci_dev *dev; if (slot->bus->self && (slot->bus->self->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET)) return false; list_for_each_entry(dev, &slot->bus->devices, bus_list) { if (!dev->slot || dev->slot != slot) continue; if (dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET || (dev->subordinate && !pci_bus_resetable(dev->subordinate))) return false; } return true; } /* Lock devices from the top of the tree down */ static void pci_slot_lock(struct pci_slot *slot) { struct pci_dev *dev; list_for_each_entry(dev, &slot->bus->devices, bus_list) { if (!dev->slot || dev->slot != slot) continue; pci_dev_lock(dev); if (dev->subordinate) pci_bus_lock(dev->subordinate); } } /* Unlock devices from the bottom of the tree up */ static void pci_slot_unlock(struct pci_slot *slot) { struct pci_dev *dev; list_for_each_entry(dev, &slot->bus->devices, bus_list) { if (!dev->slot || dev->slot != slot) continue; if (dev->subordinate) pci_bus_unlock(dev->subordinate); pci_dev_unlock(dev); } } /* Return 1 on successful lock, 0 on contention */ static int pci_slot_trylock(struct pci_slot *slot) { struct pci_dev *dev; list_for_each_entry(dev, &slot->bus->devices, bus_list) { if (!dev->slot || dev->slot != slot) continue; if (!pci_dev_trylock(dev)) goto unlock; if (dev->subordinate) { if (!pci_bus_trylock(dev->subordinate)) { pci_dev_unlock(dev); goto unlock; } } } return 1; unlock: list_for_each_entry_continue_reverse(dev, &slot->bus->devices, bus_list) { if (!dev->slot || dev->slot != slot) continue; if (dev->subordinate) pci_bus_unlock(dev->subordinate); pci_dev_unlock(dev); } return 0; } /* * Save and disable devices from the top of the tree down while holding * the @dev mutex lock for the entire tree. */ static void pci_bus_save_and_disable_locked(struct pci_bus *bus) { struct pci_dev *dev; list_for_each_entry(dev, &bus->devices, bus_list) { pci_dev_save_and_disable(dev); if (dev->subordinate) pci_bus_save_and_disable_locked(dev->subordinate); } } /* * Restore devices from top of the tree down while holding @dev mutex lock * for the entire tree. Parent bridges need to be restored before we can * get to subordinate devices. */ static void pci_bus_restore_locked(struct pci_bus *bus) { struct pci_dev *dev; list_for_each_entry(dev, &bus->devices, bus_list) { pci_dev_restore(dev); if (dev->subordinate) pci_bus_restore_locked(dev->subordinate); } } /* * Save and disable devices from the top of the tree down while holding * the @dev mutex lock for the entire tree. */ static void pci_slot_save_and_disable_locked(struct pci_slot *slot) { struct pci_dev *dev; list_for_each_entry(dev, &slot->bus->devices, bus_list) { if (!dev->slot || dev->slot != slot) continue; pci_dev_save_and_disable(dev); if (dev->subordinate) pci_bus_save_and_disable_locked(dev->subordinate); } } /* * Restore devices from top of the tree down while holding @dev mutex lock * for the entire tree. Parent bridges need to be restored before we can * get to subordinate devices. */ static void pci_slot_restore_locked(struct pci_slot *slot) { struct pci_dev *dev; list_for_each_entry(dev, &slot->bus->devices, bus_list) { if (!dev->slot || dev->slot != slot) continue; pci_dev_restore(dev); if (dev->subordinate) pci_bus_restore_locked(dev->subordinate); } } static int pci_slot_reset(struct pci_slot *slot, int probe) { int rc; if (!slot || !pci_slot_resetable(slot)) return -ENOTTY; if (!probe) pci_slot_lock(slot); might_sleep(); rc = pci_reset_hotplug_slot(slot->hotplug, probe); if (!probe) pci_slot_unlock(slot); return rc; } /** * pci_probe_reset_slot - probe whether a PCI slot can be reset * @slot: PCI slot to probe * * Return 0 if slot can be reset, negative if a slot reset is not supported. */ int pci_probe_reset_slot(struct pci_slot *slot) { return pci_slot_reset(slot, 1); } EXPORT_SYMBOL_GPL(pci_probe_reset_slot); /** * __pci_reset_slot - Try to reset a PCI slot * @slot: PCI slot to reset * * A PCI bus may host multiple slots, each slot may support a reset mechanism * independent of other slots. For instance, some slots may support slot power * control. In the case of a 1:1 bus to slot architecture, this function may * wrap the bus reset to avoid spurious slot related events such as hotplug. * Generally a slot reset should be attempted before a bus reset. All of the * function of the slot and any subordinate buses behind the slot are reset * through this function. PCI config space of all devices in the slot and * behind the slot is saved before and restored after reset. * * Same as above except return -EAGAIN if the slot cannot be locked */ static int __pci_reset_slot(struct pci_slot *slot) { int rc; rc = pci_slot_reset(slot, 1); if (rc) return rc; if (pci_slot_trylock(slot)) { pci_slot_save_and_disable_locked(slot); might_sleep(); rc = pci_reset_hotplug_slot(slot->hotplug, 0); pci_slot_restore_locked(slot); pci_slot_unlock(slot); } else rc = -EAGAIN; return rc; } static int pci_bus_reset(struct pci_bus *bus, int probe) { int ret; if (!bus->self || !pci_bus_resetable(bus)) return -ENOTTY; if (probe) return 0; pci_bus_lock(bus); might_sleep(); ret = pci_bridge_secondary_bus_reset(bus->self); pci_bus_unlock(bus); return ret; } /** * pci_bus_error_reset - reset the bridge's subordinate bus * @bridge: The parent device that connects to the bus to reset * * This function will first try to reset the slots on this bus if the method is * available. If slot reset fails or is not available, this will fall back to a * secondary bus reset. */ int pci_bus_error_reset(struct pci_dev *bridge) { struct pci_bus *bus = bridge->subordinate; struct pci_slot *slot; if (!bus) return -ENOTTY; mutex_lock(&pci_slot_mutex); if (list_empty(&bus->slots)) goto bus_reset; list_for_each_entry(slot, &bus->slots, list) if (pci_probe_reset_slot(slot)) goto bus_reset; list_for_each_entry(slot, &bus->slots, list) if (pci_slot_reset(slot, 0)) goto bus_reset; mutex_unlock(&pci_slot_mutex); return 0; bus_reset: mutex_unlock(&pci_slot_mutex); return pci_bus_reset(bridge->subordinate, 0); } /** * pci_probe_reset_bus - probe whether a PCI bus can be reset * @bus: PCI bus to probe * * Return 0 if bus can be reset, negative if a bus reset is not supported. */ int pci_probe_reset_bus(struct pci_bus *bus) { return pci_bus_reset(bus, 1); } EXPORT_SYMBOL_GPL(pci_probe_reset_bus); /** * __pci_reset_bus - Try to reset a PCI bus * @bus: top level PCI bus to reset * * Same as above except return -EAGAIN if the bus cannot be locked */ static int __pci_reset_bus(struct pci_bus *bus) { int rc; rc = pci_bus_reset(bus, 1); if (rc) return rc; if (pci_bus_trylock(bus)) { pci_bus_save_and_disable_locked(bus); might_sleep(); rc = pci_bridge_secondary_bus_reset(bus->self); pci_bus_restore_locked(bus); pci_bus_unlock(bus); } else rc = -EAGAIN; return rc; } /** * pci_reset_bus - Try to reset a PCI bus * @pdev: top level PCI device to reset via slot/bus * * Same as above except return -EAGAIN if the bus cannot be locked */ int pci_reset_bus(struct pci_dev *pdev) { return (!pci_probe_reset_slot(pdev->slot)) ? __pci_reset_slot(pdev->slot) : __pci_reset_bus(pdev->bus); } EXPORT_SYMBOL_GPL(pci_reset_bus); /** * pcix_get_max_mmrbc - get PCI-X maximum designed memory read byte count * @dev: PCI device to query * * Returns mmrbc: maximum designed memory read count in bytes or * appropriate error value. */ int pcix_get_max_mmrbc(struct pci_dev *dev) { int cap; u32 stat; cap = pci_find_capability(dev, PCI_CAP_ID_PCIX); if (!cap) return -EINVAL; if (pci_read_config_dword(dev, cap + PCI_X_STATUS, &stat)) return -EINVAL; return 512 << ((stat & PCI_X_STATUS_MAX_READ) >> 21); } EXPORT_SYMBOL(pcix_get_max_mmrbc); /** * pcix_get_mmrbc - get PCI-X maximum memory read byte count * @dev: PCI device to query * * Returns mmrbc: maximum memory read count in bytes or appropriate error * value. */ int pcix_get_mmrbc(struct pci_dev *dev) { int cap; u16 cmd; cap = pci_find_capability(dev, PCI_CAP_ID_PCIX); if (!cap) return -EINVAL; if (pci_read_config_word(dev, cap + PCI_X_CMD, &cmd)) return -EINVAL; return 512 << ((cmd & PCI_X_CMD_MAX_READ) >> 2); } EXPORT_SYMBOL(pcix_get_mmrbc); /** * pcix_set_mmrbc - set PCI-X maximum memory read byte count * @dev: PCI device to query * @mmrbc: maximum memory read count in bytes * valid values are 512, 1024, 2048, 4096 * * If possible sets maximum memory read byte count, some bridges have errata * that prevent this. */ int pcix_set_mmrbc(struct pci_dev *dev, int mmrbc) { int cap; u32 stat, v, o; u16 cmd; if (mmrbc < 512 || mmrbc > 4096 || !is_power_of_2(mmrbc)) return -EINVAL; v = ffs(mmrbc) - 10; cap = pci_find_capability(dev, PCI_CAP_ID_PCIX); if (!cap) return -EINVAL; if (pci_read_config_dword(dev, cap + PCI_X_STATUS, &stat)) return -EINVAL; if (v > (stat & PCI_X_STATUS_MAX_READ) >> 21) return -E2BIG; if (pci_read_config_word(dev, cap + PCI_X_CMD, &cmd)) return -EINVAL; o = (cmd & PCI_X_CMD_MAX_READ) >> 2; if (o != v) { if (v > o && (dev->bus->bus_flags & PCI_BUS_FLAGS_NO_MMRBC)) return -EIO; cmd &= ~PCI_X_CMD_MAX_READ; cmd |= v << 2; if (pci_write_config_word(dev, cap + PCI_X_CMD, cmd)) return -EIO; } return 0; } EXPORT_SYMBOL(pcix_set_mmrbc); /** * pcie_get_readrq - get PCI Express read request size * @dev: PCI device to query * * Returns maximum memory read request in bytes or appropriate error value. */ int pcie_get_readrq(struct pci_dev *dev) { u16 ctl; pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &ctl); return 128 << ((ctl & PCI_EXP_DEVCTL_READRQ) >> 12); } EXPORT_SYMBOL(pcie_get_readrq); /** * pcie_set_readrq - set PCI Express maximum memory read request * @dev: PCI device to query * @rq: maximum memory read count in bytes * valid values are 128, 256, 512, 1024, 2048, 4096 * * If possible sets maximum memory read request in bytes */ int pcie_set_readrq(struct pci_dev *dev, int rq) { u16 v; int ret; if (rq < 128 || rq > 4096 || !is_power_of_2(rq)) return -EINVAL; /* * If using the "performance" PCIe config, we clamp the read rq * size to the max packet size to keep the host bridge from * generating requests larger than we can cope with. */ if (pcie_bus_config == PCIE_BUS_PERFORMANCE) { int mps = pcie_get_mps(dev); if (mps < rq) rq = mps; } v = (ffs(rq) - 8) << 12; ret = pcie_capability_clear_and_set_word(dev, PCI_EXP_DEVCTL, PCI_EXP_DEVCTL_READRQ, v); return pcibios_err_to_errno(ret); } EXPORT_SYMBOL(pcie_set_readrq); /** * pcie_get_mps - get PCI Express maximum payload size * @dev: PCI device to query * * Returns maximum payload size in bytes */ int pcie_get_mps(struct pci_dev *dev) { u16 ctl; pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &ctl); return 128 << ((ctl & PCI_EXP_DEVCTL_PAYLOAD) >> 5); } EXPORT_SYMBOL(pcie_get_mps); /** * pcie_set_mps - set PCI Express maximum payload size * @dev: PCI device to query * @mps: maximum payload size in bytes * valid values are 128, 256, 512, 1024, 2048, 4096 * * If possible sets maximum payload size */ int pcie_set_mps(struct pci_dev *dev, int mps) { u16 v; int ret; if (mps < 128 || mps > 4096 || !is_power_of_2(mps)) return -EINVAL; v = ffs(mps) - 8; if (v > dev->pcie_mpss) return -EINVAL; v <<= 5; ret = pcie_capability_clear_and_set_word(dev, PCI_EXP_DEVCTL, PCI_EXP_DEVCTL_PAYLOAD, v); return pcibios_err_to_errno(ret); } EXPORT_SYMBOL(pcie_set_mps); /** * pcie_bandwidth_available - determine minimum link settings of a PCIe * device and its bandwidth limitation * @dev: PCI device to query * @limiting_dev: storage for device causing the bandwidth limitation * @speed: storage for speed of limiting device * @width: storage for width of limiting device * * Walk up the PCI device chain and find the point where the minimum * bandwidth is available. Return the bandwidth available there and (if * limiting_dev, speed, and width pointers are supplied) information about * that point. The bandwidth returned is in Mb/s, i.e., megabits/second of * raw bandwidth. */ u32 pcie_bandwidth_available(struct pci_dev *dev, struct pci_dev **limiting_dev, enum pci_bus_speed *speed, enum pcie_link_width *width) { u16 lnksta; enum pci_bus_speed next_speed; enum pcie_link_width next_width; u32 bw, next_bw; if (speed) *speed = PCI_SPEED_UNKNOWN; if (width) *width = PCIE_LNK_WIDTH_UNKNOWN; bw = 0; while (dev) { pcie_capability_read_word(dev, PCI_EXP_LNKSTA, &lnksta); next_speed = pcie_link_speed[lnksta & PCI_EXP_LNKSTA_CLS]; next_width = (lnksta & PCI_EXP_LNKSTA_NLW) >> PCI_EXP_LNKSTA_NLW_SHIFT; next_bw = next_width * PCIE_SPEED2MBS_ENC(next_speed); /* Check if current device limits the total bandwidth */ if (!bw || next_bw <= bw) { bw = next_bw; if (limiting_dev) *limiting_dev = dev; if (speed) *speed = next_speed; if (width) *width = next_width; } dev = pci_upstream_bridge(dev); } return bw; } EXPORT_SYMBOL(pcie_bandwidth_available); /** * pcie_get_speed_cap - query for the PCI device's link speed capability * @dev: PCI device to query * * Query the PCI device speed capability. Return the maximum link speed * supported by the device. */ enum pci_bus_speed pcie_get_speed_cap(struct pci_dev *dev) { u32 lnkcap2, lnkcap; /* * Link Capabilities 2 was added in PCIe r3.0, sec 7.8.18. The * implementation note there recommends using the Supported Link * Speeds Vector in Link Capabilities 2 when supported. * * Without Link Capabilities 2, i.e., prior to PCIe r3.0, software * should use the Supported Link Speeds field in Link Capabilities, * where only 2.5 GT/s and 5.0 GT/s speeds were defined. */ pcie_capability_read_dword(dev, PCI_EXP_LNKCAP2, &lnkcap2); /* PCIe r3.0-compliant */ if (lnkcap2) return PCIE_LNKCAP2_SLS2SPEED(lnkcap2); pcie_capability_read_dword(dev, PCI_EXP_LNKCAP, &lnkcap); if ((lnkcap & PCI_EXP_LNKCAP_SLS) == PCI_EXP_LNKCAP_SLS_5_0GB) return PCIE_SPEED_5_0GT; else if ((lnkcap & PCI_EXP_LNKCAP_SLS) == PCI_EXP_LNKCAP_SLS_2_5GB) return PCIE_SPEED_2_5GT; return PCI_SPEED_UNKNOWN; } EXPORT_SYMBOL(pcie_get_speed_cap); /** * pcie_get_width_cap - query for the PCI device's link width capability * @dev: PCI device to query * * Query the PCI device width capability. Return the maximum link width * supported by the device. */ enum pcie_link_width pcie_get_width_cap(struct pci_dev *dev) { u32 lnkcap; pcie_capability_read_dword(dev, PCI_EXP_LNKCAP, &lnkcap); if (lnkcap) return (lnkcap & PCI_EXP_LNKCAP_MLW) >> 4; return PCIE_LNK_WIDTH_UNKNOWN; } EXPORT_SYMBOL(pcie_get_width_cap); /** * pcie_bandwidth_capable - calculate a PCI device's link bandwidth capability * @dev: PCI device * @speed: storage for link speed * @width: storage for link width * * Calculate a PCI device's link bandwidth by querying for its link speed * and width, multiplying them, and applying encoding overhead. The result * is in Mb/s, i.e., megabits/second of raw bandwidth. */ u32 pcie_bandwidth_capable(struct pci_dev *dev, enum pci_bus_speed *speed, enum pcie_link_width *width) { *speed = pcie_get_speed_cap(dev); *width = pcie_get_width_cap(dev); if (*speed == PCI_SPEED_UNKNOWN || *width == PCIE_LNK_WIDTH_UNKNOWN) return 0; return *width * PCIE_SPEED2MBS_ENC(*speed); } /** * __pcie_print_link_status - Report the PCI device's link speed and width * @dev: PCI device to query * @verbose: Print info even when enough bandwidth is available * * If the available bandwidth at the device is less than the device is * capable of, report the device's maximum possible bandwidth and the * upstream link that limits its performance. If @verbose, always print * the available bandwidth, even if the device isn't constrained. */ void __pcie_print_link_status(struct pci_dev *dev, bool verbose) { enum pcie_link_width width, width_cap; enum pci_bus_speed speed, speed_cap; struct pci_dev *limiting_dev = NULL; u32 bw_avail, bw_cap; bw_cap = pcie_bandwidth_capable(dev, &speed_cap, &width_cap); bw_avail = pcie_bandwidth_available(dev, &limiting_dev, &speed, &width); if (bw_avail >= bw_cap && verbose) pci_info(dev, "%u.%03u Gb/s available PCIe bandwidth (%s x%d link)\n", bw_cap / 1000, bw_cap % 1000, pci_speed_string(speed_cap), width_cap); else if (bw_avail < bw_cap) pci_info(dev, "%u.%03u Gb/s available PCIe bandwidth, limited by %s x%d link at %s (capable of %u.%03u Gb/s with %s x%d link)\n", bw_avail / 1000, bw_avail % 1000, pci_speed_string(speed), width, limiting_dev ? pci_name(limiting_dev) : "<unknown>", bw_cap / 1000, bw_cap % 1000, pci_speed_string(speed_cap), width_cap); } /** * pcie_print_link_status - Report the PCI device's link speed and width * @dev: PCI device to query * * Report the available bandwidth at the device. */ void pcie_print_link_status(struct pci_dev *dev) { __pcie_print_link_status(dev, true); } EXPORT_SYMBOL(pcie_print_link_status); /** * pci_select_bars - Make BAR mask from the type of resource * @dev: the PCI device for which BAR mask is made * @flags: resource type mask to be selected * * This helper routine makes bar mask from the type of resource. */ int pci_select_bars(struct pci_dev *dev, unsigned long flags) { int i, bars = 0; for (i = 0; i < PCI_NUM_RESOURCES; i++) if (pci_resource_flags(dev, i) & flags) bars |= (1 << i); return bars; } EXPORT_SYMBOL(pci_select_bars); /* Some architectures require additional programming to enable VGA */ static arch_set_vga_state_t arch_set_vga_state; void __init pci_register_set_vga_state(arch_set_vga_state_t func) { arch_set_vga_state = func; /* NULL disables */ } static int pci_set_vga_state_arch(struct pci_dev *dev, bool decode, unsigned int command_bits, u32 flags) { if (arch_set_vga_state) return arch_set_vga_state(dev, decode, command_bits, flags); return 0; } /** * pci_set_vga_state - set VGA decode state on device and parents if requested * @dev: the PCI device * @decode: true = enable decoding, false = disable decoding * @command_bits: PCI_COMMAND_IO and/or PCI_COMMAND_MEMORY * @flags: traverse ancestors and change bridges * CHANGE_BRIDGE_ONLY / CHANGE_BRIDGE */ int pci_set_vga_state(struct pci_dev *dev, bool decode, unsigned int command_bits, u32 flags) { struct pci_bus *bus; struct pci_dev *bridge; u16 cmd; int rc; WARN_ON((flags & PCI_VGA_STATE_CHANGE_DECODES) && (command_bits & ~(PCI_COMMAND_IO|PCI_COMMAND_MEMORY))); /* ARCH specific VGA enables */ rc = pci_set_vga_state_arch(dev, decode, command_bits, flags); if (rc) return rc; if (flags & PCI_VGA_STATE_CHANGE_DECODES) { pci_read_config_word(dev, PCI_COMMAND, &cmd); if (decode == true) cmd |= command_bits; else cmd &= ~command_bits; pci_write_config_word(dev, PCI_COMMAND, cmd); } if (!(flags & PCI_VGA_STATE_CHANGE_BRIDGE)) return 0; bus = dev->bus; while (bus) { bridge = bus->self; if (bridge) { pci_read_config_word(bridge, PCI_BRIDGE_CONTROL, &cmd); if (decode == true) cmd |= PCI_BRIDGE_CTL_VGA; else cmd &= ~PCI_BRIDGE_CTL_VGA; pci_write_config_word(bridge, PCI_BRIDGE_CONTROL, cmd); } bus = bus->parent; } return 0; } #ifdef CONFIG_ACPI bool pci_pr3_present(struct pci_dev *pdev) { struct acpi_device *adev; if (acpi_disabled) return false; adev = ACPI_COMPANION(&pdev->dev); if (!adev) return false; return adev->power.flags.power_resources && acpi_has_method(adev->handle, "_PR3"); } EXPORT_SYMBOL_GPL(pci_pr3_present); #endif /** * pci_add_dma_alias - Add a DMA devfn alias for a device * @dev: the PCI device for which alias is added * @devfn_from: alias slot and function * @nr_devfns: number of subsequent devfns to alias * * This helper encodes an 8-bit devfn as a bit number in dma_alias_mask * which is used to program permissible bus-devfn source addresses for DMA * requests in an IOMMU. These aliases factor into IOMMU group creation * and are useful for devices generating DMA requests beyond or different * from their logical bus-devfn. Examples include device quirks where the * device simply uses the wrong devfn, as well as non-transparent bridges * where the alias may be a proxy for devices in another domain. * * IOMMU group creation is performed during device discovery or addition, * prior to any potential DMA mapping and therefore prior to driver probing * (especially for userspace assigned devices where IOMMU group definition * cannot be left as a userspace activity). DMA aliases should therefore * be configured via quirks, such as the PCI fixup header quirk. */ void pci_add_dma_alias(struct pci_dev *dev, u8 devfn_from, unsigned nr_devfns) { int devfn_to; nr_devfns = min(nr_devfns, (unsigned) MAX_NR_DEVFNS - devfn_from); devfn_to = devfn_from + nr_devfns - 1; if (!dev->dma_alias_mask) dev->dma_alias_mask = bitmap_zalloc(MAX_NR_DEVFNS, GFP_KERNEL); if (!dev->dma_alias_mask) { pci_warn(dev, "Unable to allocate DMA alias mask\n"); return; } bitmap_set(dev->dma_alias_mask, devfn_from, nr_devfns); if (nr_devfns == 1) pci_info(dev, "Enabling fixed DMA alias to %02x.%d\n", PCI_SLOT(devfn_from), PCI_FUNC(devfn_from)); else if (nr_devfns > 1) pci_info(dev, "Enabling fixed DMA alias for devfn range from %02x.%d to %02x.%d\n", PCI_SLOT(devfn_from), PCI_FUNC(devfn_from), PCI_SLOT(devfn_to), PCI_FUNC(devfn_to)); } bool pci_devs_are_dma_aliases(struct pci_dev *dev1, struct pci_dev *dev2) { return (dev1->dma_alias_mask && test_bit(dev2->devfn, dev1->dma_alias_mask)) || (dev2->dma_alias_mask && test_bit(dev1->devfn, dev2->dma_alias_mask)) || pci_real_dma_dev(dev1) == dev2 || pci_real_dma_dev(dev2) == dev1; } bool pci_device_is_present(struct pci_dev *pdev) { u32 v; if (pci_dev_is_disconnected(pdev)) return false; return pci_bus_read_dev_vendor_id(pdev->bus, pdev->devfn, &v, 0); } EXPORT_SYMBOL_GPL(pci_device_is_present); void pci_ignore_hotplug(struct pci_dev *dev) { struct pci_dev *bridge = dev->bus->self; dev->ignore_hotplug = 1; /* Propagate the "ignore hotplug" setting to the parent bridge. */ if (bridge) bridge->ignore_hotplug = 1; } EXPORT_SYMBOL_GPL(pci_ignore_hotplug); /** * pci_real_dma_dev - Get PCI DMA device for PCI device * @dev: the PCI device that may have a PCI DMA alias * * Permits the platform to provide architecture-specific functionality to * devices needing to alias DMA to another PCI device on another PCI bus. If * the PCI device is on the same bus, it is recommended to use * pci_add_dma_alias(). This is the default implementation. Architecture * implementations can override this. */ struct pci_dev __weak *pci_real_dma_dev(struct pci_dev *dev) { return dev; } resource_size_t __weak pcibios_default_alignment(void) { return 0; } /* * Arches that don't want to expose struct resource to userland as-is in * sysfs and /proc can implement their own pci_resource_to_user(). */ void __weak pci_resource_to_user(const struct pci_dev *dev, int bar, const struct resource *rsrc, resource_size_t *start, resource_size_t *end) { *start = rsrc->start; *end = rsrc->end; } static char *resource_alignment_param; static DEFINE_SPINLOCK(resource_alignment_lock); /** * pci_specified_resource_alignment - get resource alignment specified by user. * @dev: the PCI device to get * @resize: whether or not to change resources' size when reassigning alignment * * RETURNS: Resource alignment if it is specified. * Zero if it is not specified. */ static resource_size_t pci_specified_resource_alignment(struct pci_dev *dev, bool *resize) { int align_order, count; resource_size_t align = pcibios_default_alignment(); const char *p; int ret; spin_lock(&resource_alignment_lock); p = resource_alignment_param; if (!p || !*p) goto out; if (pci_has_flag(PCI_PROBE_ONLY)) { align = 0; pr_info_once("PCI: Ignoring requested alignments (PCI_PROBE_ONLY)\n"); goto out; } while (*p) { count = 0; if (sscanf(p, "%d%n", &align_order, &count) == 1 && p[count] == '@') { p += count + 1; } else { align_order = -1; } ret = pci_dev_str_match(dev, p, &p); if (ret == 1) { *resize = true; if (align_order == -1) align = PAGE_SIZE; else align = 1 << align_order; break; } else if (ret < 0) { pr_err("PCI: Can't parse resource_alignment parameter: %s\n", p); break; } if (*p != ';' && *p != ',') { /* End of param or invalid format */ break; } p++; } out: spin_unlock(&resource_alignment_lock); return align; } static void pci_request_resource_alignment(struct pci_dev *dev, int bar, resource_size_t align, bool resize) { struct resource *r = &dev->resource[bar]; resource_size_t size; if (!(r->flags & IORESOURCE_MEM)) return; if (r->flags & IORESOURCE_PCI_FIXED) { pci_info(dev, "BAR%d %pR: ignoring requested alignment %#llx\n", bar, r, (unsigned long long)align); return; } size = resource_size(r); if (size >= align) return; /* * Increase the alignment of the resource. There are two ways we * can do this: * * 1) Increase the size of the resource. BARs are aligned on their * size, so when we reallocate space for this resource, we'll * allocate it with the larger alignment. This also prevents * assignment of any other BARs inside the alignment region, so * if we're requesting page alignment, this means no other BARs * will share the page. * * The disadvantage is that this makes the resource larger than * the hardware BAR, which may break drivers that compute things * based on the resource size, e.g., to find registers at a * fixed offset before the end of the BAR. * * 2) Retain the resource size, but use IORESOURCE_STARTALIGN and * set r->start to the desired alignment. By itself this * doesn't prevent other BARs being put inside the alignment * region, but if we realign *every* resource of every device in * the system, none of them will share an alignment region. * * When the user has requested alignment for only some devices via * the "pci=resource_alignment" argument, "resize" is true and we * use the first method. Otherwise we assume we're aligning all * devices and we use the second. */ pci_info(dev, "BAR%d %pR: requesting alignment to %#llx\n", bar, r, (unsigned long long)align); if (resize) { r->start = 0; r->end = align - 1; } else { r->flags &= ~IORESOURCE_SIZEALIGN; r->flags |= IORESOURCE_STARTALIGN; r->start = align; r->end = r->start + size - 1; } r->flags |= IORESOURCE_UNSET; } /* * This function disables memory decoding and releases memory resources * of the device specified by kernel's boot parameter 'pci=resource_alignment='. * It also rounds up size to specified alignment. * Later on, the kernel will assign page-aligned memory resource back * to the device. */ void pci_reassigndev_resource_alignment(struct pci_dev *dev) { int i; struct resource *r; resource_size_t align; u16 command; bool resize = false; /* * VF BARs are read-only zero according to SR-IOV spec r1.1, sec * 3.4.1.11. Their resources are allocated from the space * described by the VF BARx register in the PF's SR-IOV capability. * We can't influence their alignment here. */ if (dev->is_virtfn) return; /* check if specified PCI is target device to reassign */ align = pci_specified_resource_alignment(dev, &resize); if (!align) return; if (dev->hdr_type == PCI_HEADER_TYPE_NORMAL && (dev->class >> 8) == PCI_CLASS_BRIDGE_HOST) { pci_warn(dev, "Can't reassign resources to host bridge\n"); return; } pci_read_config_word(dev, PCI_COMMAND, &command); command &= ~PCI_COMMAND_MEMORY; pci_write_config_word(dev, PCI_COMMAND, command); for (i = 0; i <= PCI_ROM_RESOURCE; i++) pci_request_resource_alignment(dev, i, align, resize); /* * Need to disable bridge's resource window, * to enable the kernel to reassign new resource * window later on. */ if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) { for (i = PCI_BRIDGE_RESOURCES; i < PCI_NUM_RESOURCES; i++) { r = &dev->resource[i]; if (!(r->flags & IORESOURCE_MEM)) continue; r->flags |= IORESOURCE_UNSET; r->end = resource_size(r) - 1; r->start = 0; } pci_disable_bridge_window(dev); } } static ssize_t resource_alignment_show(struct bus_type *bus, char *buf) { size_t count = 0; spin_lock(&resource_alignment_lock); if (resource_alignment_param) count = snprintf(buf, PAGE_SIZE, "%s", resource_alignment_param); spin_unlock(&resource_alignment_lock); /* * When set by the command line, resource_alignment_param will not * have a trailing line feed, which is ugly. So conditionally add * it here. */ if (count >= 2 && buf[count - 2] != '\n' && count < PAGE_SIZE - 1) { buf[count - 1] = '\n'; buf[count++] = 0; } return count; } static ssize_t resource_alignment_store(struct bus_type *bus, const char *buf, size_t count) { char *param = kstrndup(buf, count, GFP_KERNEL); if (!param) return -ENOMEM; spin_lock(&resource_alignment_lock); kfree(resource_alignment_param); resource_alignment_param = param; spin_unlock(&resource_alignment_lock); return count; } static BUS_ATTR_RW(resource_alignment); static int __init pci_resource_alignment_sysfs_init(void) { return bus_create_file(&pci_bus_type, &bus_attr_resource_alignment); } late_initcall(pci_resource_alignment_sysfs_init); static void pci_no_domains(void) { #ifdef CONFIG_PCI_DOMAINS pci_domains_supported = 0; #endif } #ifdef CONFIG_PCI_DOMAINS_GENERIC static atomic_t __domain_nr = ATOMIC_INIT(-1); static int pci_get_new_domain_nr(void) { return atomic_inc_return(&__domain_nr); } static int of_pci_bus_find_domain_nr(struct device *parent) { static int use_dt_domains = -1; int domain = -1; if (parent) domain = of_get_pci_domain_nr(parent->of_node); /* * Check DT domain and use_dt_domains values. * * If DT domain property is valid (domain >= 0) and * use_dt_domains != 0, the DT assignment is valid since this means * we have not previously allocated a domain number by using * pci_get_new_domain_nr(); we should also update use_dt_domains to * 1, to indicate that we have just assigned a domain number from * DT. * * If DT domain property value is not valid (ie domain < 0), and we * have not previously assigned a domain number from DT * (use_dt_domains != 1) we should assign a domain number by * using the: * * pci_get_new_domain_nr() * * API and update the use_dt_domains value to keep track of method we * are using to assign domain numbers (use_dt_domains = 0). * * All other combinations imply we have a platform that is trying * to mix domain numbers obtained from DT and pci_get_new_domain_nr(), * which is a recipe for domain mishandling and it is prevented by * invalidating the domain value (domain = -1) and printing a * corresponding error. */ if (domain >= 0 && use_dt_domains) { use_dt_domains = 1; } else if (domain < 0 && use_dt_domains != 1) { use_dt_domains = 0; domain = pci_get_new_domain_nr(); } else { if (parent) pr_err("Node %pOF has ", parent->of_node); pr_err("Inconsistent \"linux,pci-domain\" property in DT\n"); domain = -1; } return domain; } int pci_bus_find_domain_nr(struct pci_bus *bus, struct device *parent) { return acpi_disabled ? of_pci_bus_find_domain_nr(parent) : acpi_pci_bus_find_domain_nr(bus); } #endif /** * pci_ext_cfg_avail - can we access extended PCI config space? * * Returns 1 if we can access PCI extended config space (offsets * greater than 0xff). This is the default implementation. Architecture * implementations can override this. */ int __weak pci_ext_cfg_avail(void) { return 1; } void __weak pci_fixup_cardbus(struct pci_bus *bus) { } EXPORT_SYMBOL(pci_fixup_cardbus); static int __init pci_setup(char *str) { while (str) { char *k = strchr(str, ','); if (k) *k++ = 0; if (*str && (str = pcibios_setup(str)) && *str) { if (!strcmp(str, "nomsi")) { pci_no_msi(); } else if (!strncmp(str, "noats", 5)) { pr_info("PCIe: ATS is disabled\n"); pcie_ats_disabled = true; } else if (!strcmp(str, "noaer")) { pci_no_aer(); } else if (!strcmp(str, "earlydump")) { pci_early_dump = true; } else if (!strncmp(str, "realloc=", 8)) { pci_realloc_get_opt(str + 8); } else if (!strncmp(str, "realloc", 7)) { pci_realloc_get_opt("on"); } else if (!strcmp(str, "nodomains")) { pci_no_domains(); } else if (!strncmp(str, "noari", 5)) { pcie_ari_disabled = true; } else if (!strncmp(str, "cbiosize=", 9)) { pci_cardbus_io_size = memparse(str + 9, &str); } else if (!strncmp(str, "cbmemsize=", 10)) { pci_cardbus_mem_size = memparse(str + 10, &str); } else if (!strncmp(str, "resource_alignment=", 19)) { resource_alignment_param = str + 19; } else if (!strncmp(str, "ecrc=", 5)) { pcie_ecrc_get_policy(str + 5); } else if (!strncmp(str, "hpiosize=", 9)) { pci_hotplug_io_size = memparse(str + 9, &str); } else if (!strncmp(str, "hpmmiosize=", 11)) { pci_hotplug_mmio_size = memparse(str + 11, &str); } else if (!strncmp(str, "hpmmioprefsize=", 15)) { pci_hotplug_mmio_pref_size = memparse(str + 15, &str); } else if (!strncmp(str, "hpmemsize=", 10)) { pci_hotplug_mmio_size = memparse(str + 10, &str); pci_hotplug_mmio_pref_size = pci_hotplug_mmio_size; } else if (!strncmp(str, "hpbussize=", 10)) { pci_hotplug_bus_size = simple_strtoul(str + 10, &str, 0); if (pci_hotplug_bus_size > 0xff) pci_hotplug_bus_size = DEFAULT_HOTPLUG_BUS_SIZE; } else if (!strncmp(str, "pcie_bus_tune_off", 17)) { pcie_bus_config = PCIE_BUS_TUNE_OFF; } else if (!strncmp(str, "pcie_bus_safe", 13)) { pcie_bus_config = PCIE_BUS_SAFE; } else if (!strncmp(str, "pcie_bus_perf", 13)) { pcie_bus_config = PCIE_BUS_PERFORMANCE; } else if (!strncmp(str, "pcie_bus_peer2peer", 18)) { pcie_bus_config = PCIE_BUS_PEER2PEER; } else if (!strncmp(str, "pcie_scan_all", 13)) { pci_add_flags(PCI_SCAN_ALL_PCIE_DEVS); } else if (!strncmp(str, "disable_acs_redir=", 18)) { disable_acs_redir_param = str + 18; } else { pr_err("PCI: Unknown option `%s'\n", str); } } str = k; } return 0; } early_param("pci", pci_setup); /* * 'resource_alignment_param' and 'disable_acs_redir_param' are initialized * in pci_setup(), above, to point to data in the __initdata section which * will be freed after the init sequence is complete. We can't allocate memory * in pci_setup() because some architectures do not have any memory allocation * service available during an early_param() call. So we allocate memory and * copy the variable here before the init section is freed. * */ static int __init pci_realloc_setup_params(void) { resource_alignment_param = kstrdup(resource_alignment_param, GFP_KERNEL); disable_acs_redir_param = kstrdup(disable_acs_redir_param, GFP_KERNEL); return 0; } pure_initcall(pci_realloc_setup_params);
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