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Release 4.17 drivers/pci/access.c

Directory: drivers/pci
// SPDX-License-Identifier: GPL-2.0
#include <linux/pci.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/ioport.h>
#include <linux/wait.h>

#include "pci.h"

/*
 * This interrupt-safe spinlock protects all accesses to PCI
 * configuration space.
 */

DEFINE_RAW_SPINLOCK(pci_lock);

/*
 * Wrappers for all PCI configuration access functions.  They just check
 * alignment, do locking and call the low-level functions pointed to
 * by pci_dev->ops.
 */


#define PCI_byte_BAD 0

#define PCI_word_BAD (pos & 1)

#define PCI_dword_BAD (pos & 3)

#ifdef CONFIG_PCI_LOCKLESS_CONFIG

# define pci_lock_config(f)	do { (void)(f); } while (0)

# define pci_unlock_config(f)	do { (void)(f); } while (0)
#else

# define pci_lock_config(f)	raw_spin_lock_irqsave(&pci_lock, f)

# define pci_unlock_config(f)	raw_spin_unlock_irqrestore(&pci_lock, f)
#endif


#define PCI_OP_READ(size, type, len) \
int pci_bus_read_config_##size \
        (struct pci_bus *bus, unsigned int devfn, int pos, type *value) \
{                                                                       \
        int res;                                                        \
        unsigned long flags;                                            \
        u32 data = 0;                                                   \
        if (PCI_##size##_BAD) return PCIBIOS_BAD_REGISTER_NUMBER;       \
        pci_lock_config(flags);                                         \
        res = bus->ops->read(bus, devfn, pos, len, &data);              \
        *value = (type)data;                                            \
        pci_unlock_config(flags);                                       \
        return res;                                                     \
}


#define PCI_OP_WRITE(size, type, len) \
int pci_bus_write_config_##size \
        (struct pci_bus *bus, unsigned int devfn, int pos, type value)  \
{                                                                       \
        int res;                                                        \
        unsigned long flags;                                            \
        if (PCI_##size##_BAD) return PCIBIOS_BAD_REGISTER_NUMBER;       \
        pci_lock_config(flags);                                         \
        res = bus->ops->write(bus, devfn, pos, len, value);             \
        pci_unlock_config(flags);                                       \
        return res;                                                     \
}

PCI_OP_READ(byte, u8, 1)
PCI_OP_READ(word, u16, 2)
PCI_OP_READ(dword, u32, 4)
PCI_OP_WRITE(byte, u8, 1)
PCI_OP_WRITE(word, u16, 2)
PCI_OP_WRITE(dword, u32, 4)

EXPORT_SYMBOL(pci_bus_read_config_byte);
EXPORT_SYMBOL(pci_bus_read_config_word);
EXPORT_SYMBOL(pci_bus_read_config_dword);
EXPORT_SYMBOL(pci_bus_write_config_byte);
EXPORT_SYMBOL(pci_bus_write_config_word);
EXPORT_SYMBOL(pci_bus_write_config_dword);


int pci_generic_config_read(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 *val) { void __iomem *addr; addr = bus->ops->map_bus(bus, devfn, where); if (!addr) { *val = ~0; return PCIBIOS_DEVICE_NOT_FOUND; } if (size == 1) *val = readb(addr); else if (size == 2) *val = readw(addr); else *val = readl(addr); return PCIBIOS_SUCCESSFUL; }

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EXPORT_SYMBOL_GPL(pci_generic_config_read);
int pci_generic_config_write(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 val) { void __iomem *addr; addr = bus->ops->map_bus(bus, devfn, where); if (!addr) return PCIBIOS_DEVICE_NOT_FOUND; if (size == 1) writeb(val, addr); else if (size == 2) writew(val, addr); else writel(val, addr); return PCIBIOS_SUCCESSFUL; }

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EXPORT_SYMBOL_GPL(pci_generic_config_write);
int pci_generic_config_read32(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 *val) { void __iomem *addr; addr = bus->ops->map_bus(bus, devfn, where & ~0x3); if (!addr) { *val = ~0; return PCIBIOS_DEVICE_NOT_FOUND; } *val = readl(addr); if (size <= 2) *val = (*val >> (8 * (where & 3))) & ((1 << (size * 8)) - 1); return PCIBIOS_SUCCESSFUL; }

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EXPORT_SYMBOL_GPL(pci_generic_config_read32);
int pci_generic_config_write32(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 val) { void __iomem *addr; u32 mask, tmp; addr = bus->ops->map_bus(bus, devfn, where & ~0x3); if (!addr) return PCIBIOS_DEVICE_NOT_FOUND; if (size == 4) { writel(val, addr); return PCIBIOS_SUCCESSFUL; } /* * In general, hardware that supports only 32-bit writes on PCI is * not spec-compliant. For example, software may perform a 16-bit * write. If the hardware only supports 32-bit accesses, we must * do a 32-bit read, merge in the 16 bits we intend to write, * followed by a 32-bit write. If the 16 bits we *don't* intend to * write happen to have any RW1C (write-one-to-clear) bits set, we * just inadvertently cleared something we shouldn't have. */ dev_warn_ratelimited(&bus->dev, "%d-byte config write to %04x:%02x:%02x.%d offset %#x may corrupt adjacent RW1C bits\n", size, pci_domain_nr(bus), bus->number, PCI_SLOT(devfn), PCI_FUNC(devfn), where); mask = ~(((1 << (size * 8)) - 1) << ((where & 0x3) * 8)); tmp = readl(addr) & mask; tmp |= val << ((where & 0x3) * 8); writel(tmp, addr); return PCIBIOS_SUCCESSFUL; }

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Rob Herring13980.35%150.00%
Björn Helgaas3419.65%150.00%
Total173100.00%2100.00%

EXPORT_SYMBOL_GPL(pci_generic_config_write32); /** * pci_bus_set_ops - Set raw operations of pci bus * @bus: pci bus struct * @ops: new raw operations * * Return previous raw operations */
struct pci_ops *pci_bus_set_ops(struct pci_bus *bus, struct pci_ops *ops) { struct pci_ops *old_ops; unsigned long flags; raw_spin_lock_irqsave(&pci_lock, flags); old_ops = bus->ops; bus->ops = ops; raw_spin_unlock_irqrestore(&pci_lock, flags); return old_ops; }

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Huang Ying5596.49%150.00%
Thomas Gleixner23.51%150.00%
Total57100.00%2100.00%

EXPORT_SYMBOL(pci_bus_set_ops); /* * The following routines are to prevent the user from accessing PCI config * space when it's unsafe to do so. Some devices require this during BIST and * we're required to prevent it during D-state transitions. * * We have a bit per device to indicate it's blocked and a global wait queue * for callers to sleep on until devices are unblocked. */ static DECLARE_WAIT_QUEUE_HEAD(pci_cfg_wait);
static noinline void pci_wait_cfg(struct pci_dev *dev) { DECLARE_WAITQUEUE(wait, current); __add_wait_queue(&pci_cfg_wait, &wait); do { set_current_state(TASK_UNINTERRUPTIBLE); raw_spin_unlock_irq(&pci_lock); schedule(); raw_spin_lock_irq(&pci_lock); } while (dev->block_cfg_access); __remove_wait_queue(&pci_cfg_wait, &wait); }

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Matthew Wilcox4465.67%125.00%
Brian King1725.37%125.00%
Jan Kiszka45.97%125.00%
Thomas Gleixner22.99%125.00%
Total67100.00%4100.00%

/* Returns 0 on success, negative values indicate error. */ #define PCI_USER_READ_CONFIG(size, type) \ int pci_user_read_config_##size \ (struct pci_dev *dev, int pos, type *val) \ { \ int ret = PCIBIOS_SUCCESSFUL; \ u32 data = -1; \ if (PCI_##size##_BAD) \ return -EINVAL; \ raw_spin_lock_irq(&pci_lock); \ if (unlikely(dev->block_cfg_access)) \ pci_wait_cfg(dev); \ ret = dev->bus->ops->read(dev->bus, dev->devfn, \ pos, sizeof(type), &data); \ raw_spin_unlock_irq(&pci_lock); \ *val = (type)data; \ return pcibios_err_to_errno(ret); \ } \ EXPORT_SYMBOL_GPL(pci_user_read_config_##size); /* Returns 0 on success, negative values indicate error. */ #define PCI_USER_WRITE_CONFIG(size, type) \ int pci_user_write_config_##size \ (struct pci_dev *dev, int pos, type val) \ { \ int ret = PCIBIOS_SUCCESSFUL; \ if (PCI_##size##_BAD) \ return -EINVAL; \ raw_spin_lock_irq(&pci_lock); \ if (unlikely(dev->block_cfg_access)) \ pci_wait_cfg(dev); \ ret = dev->bus->ops->write(dev->bus, dev->devfn, \ pos, sizeof(type), val); \ raw_spin_unlock_irq(&pci_lock); \ return pcibios_err_to_errno(ret); \ } \ EXPORT_SYMBOL_GPL(pci_user_write_config_##size); PCI_USER_READ_CONFIG(byte, u8) PCI_USER_READ_CONFIG(word, u16) PCI_USER_READ_CONFIG(dword, u32) PCI_USER_WRITE_CONFIG(byte, u8) PCI_USER_WRITE_CONFIG(word, u16) PCI_USER_WRITE_CONFIG(dword, u32) /** * pci_cfg_access_lock - Lock PCI config reads/writes * @dev: pci device struct * * When access is locked, any userspace reads or writes to config * space and concurrent lock requests will sleep until access is * allowed via pci_cfg_access_unlock() again. */
void pci_cfg_access_lock(struct pci_dev *dev) { might_sleep(); raw_spin_lock_irq(&pci_lock); if (dev->block_cfg_access) pci_wait_cfg(dev); dev->block_cfg_access = 1; raw_spin_unlock_irq(&pci_lock); }

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Jan Kiszka4197.62%150.00%
Brian King12.38%150.00%
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EXPORT_SYMBOL_GPL(pci_cfg_access_lock); /** * pci_cfg_access_trylock - try to lock PCI config reads/writes * @dev: pci device struct * * Same as pci_cfg_access_lock, but will return 0 if access is * already locked, 1 otherwise. This function can be used from * atomic contexts. */
bool pci_cfg_access_trylock(struct pci_dev *dev) { unsigned long flags; bool locked = true; raw_spin_lock_irqsave(&pci_lock, flags); if (dev->block_cfg_access) locked = false; else dev->block_cfg_access = 1; raw_spin_unlock_irqrestore(&pci_lock, flags); return locked; }

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Brian King3156.36%125.00%
Jan Kiszka1832.73%125.00%
Matthew Wilcox47.27%125.00%
Thomas Gleixner23.64%125.00%
Total55100.00%4100.00%

EXPORT_SYMBOL_GPL(pci_cfg_access_trylock); /** * pci_cfg_access_unlock - Unlock PCI config reads/writes * @dev: pci device struct * * This function allows PCI config accesses to resume. */
void pci_cfg_access_unlock(struct pci_dev *dev) { unsigned long flags; raw_spin_lock_irqsave(&pci_lock, flags); /* * This indicates a problem in the caller, but we don't need * to kill them, unlike a double-block above. */ WARN_ON(!dev->block_cfg_access); dev->block_cfg_access = 0; raw_spin_unlock_irqrestore(&pci_lock, flags); wake_up_all(&pci_cfg_wait); }

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Brian King3262.75%116.67%
Björn Helgaas713.73%233.33%
Matthew Wilcox713.73%116.67%
Jan Kiszka35.88%116.67%
Thomas Gleixner23.92%116.67%
Total51100.00%6100.00%

EXPORT_SYMBOL_GPL(pci_cfg_access_unlock);
static inline int pcie_cap_version(const struct pci_dev *dev) { return pcie_caps_reg(dev) & PCI_EXP_FLAGS_VERS; }

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Jiang Liu1885.71%150.00%
Myron Stowe314.29%150.00%
Total21100.00%2100.00%


static bool pcie_downstream_port(const struct pci_dev *dev) { int type = pci_pcie_type(dev); return type == PCI_EXP_TYPE_ROOT_PORT || type == PCI_EXP_TYPE_DOWNSTREAM || type == PCI_EXP_TYPE_PCIE_BRIDGE; }

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Björn Helgaas33100.00%2100.00%
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bool pcie_cap_has_lnkctl(const struct pci_dev *dev) { int type = pci_pcie_type(dev); return type == PCI_EXP_TYPE_ENDPOINT || type == PCI_EXP_TYPE_LEG_END || type == PCI_EXP_TYPE_ROOT_PORT || type == PCI_EXP_TYPE_UPSTREAM || type == PCI_EXP_TYPE_DOWNSTREAM || type == PCI_EXP_TYPE_PCI_BRIDGE || type == PCI_EXP_TYPE_PCIE_BRIDGE; }

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Jiang Liu3062.50%150.00%
Björn Helgaas1837.50%150.00%
Total48100.00%2100.00%


static inline bool pcie_cap_has_sltctl(const struct pci_dev *dev) { return pcie_downstream_port(dev) && pcie_caps_reg(dev) & PCI_EXP_FLAGS_SLOT; }

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Myron Stowe311.54%133.33%
Björn Helgaas27.69%133.33%
Total26100.00%3100.00%


static inline bool pcie_cap_has_rtctl(const struct pci_dev *dev) { int type = pci_pcie_type(dev); return type == PCI_EXP_TYPE_ROOT_PORT || type == PCI_EXP_TYPE_RC_EC; }

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static bool pcie_capability_reg_implemented(struct pci_dev *dev, int pos) { if (!pci_is_pcie(dev)) return false; switch (pos) { case PCI_EXP_FLAGS: return true; case PCI_EXP_DEVCAP: case PCI_EXP_DEVCTL: case PCI_EXP_DEVSTA: return true; case PCI_EXP_LNKCAP: case PCI_EXP_LNKCTL: case PCI_EXP_LNKSTA: return pcie_cap_has_lnkctl(dev); case PCI_EXP_SLTCAP: case PCI_EXP_SLTCTL: case PCI_EXP_SLTSTA: return pcie_cap_has_sltctl(dev); case PCI_EXP_RTCTL: case PCI_EXP_RTCAP: case PCI_EXP_RTSTA: return pcie_cap_has_rtctl(dev); case PCI_EXP_DEVCAP2: case PCI_EXP_DEVCTL2: case PCI_EXP_LNKCAP2: case PCI_EXP_LNKCTL2: case PCI_EXP_LNKSTA2: return pcie_cap_version(dev) > 1; default: return false; } }

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Jiang Liu11998.35%133.33%
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Alex Williamson10.83%133.33%
Total121100.00%3100.00%

/* * Note that these accessor functions are only for the "PCI Express * Capability" (see PCIe spec r3.0, sec 7.8). They do not apply to the * other "PCI Express Extended Capabilities" (AER, VC, ACS, MFVC, etc.) */
int pcie_capability_read_word(struct pci_dev *dev, int pos, u16 *val) { int ret; *val = 0; if (pos & 1) return -EINVAL; if (pcie_capability_reg_implemented(dev, pos)) { ret = pci_read_config_word(dev, pci_pcie_cap(dev) + pos, val); /* * Reset *val to 0 if pci_read_config_word() fails, it may * have been written as 0xFFFF if hardware error happens * during pci_read_config_word(). */ if (ret) *val = 0; return ret; } /* * For Functions that do not implement the Slot Capabilities, * Slot Status, and Slot Control registers, these spaces must * be hardwired to 0b, with the exception of the Presence Detect * State bit in the Slot Status register of Downstream Ports, * which must be hardwired to 1b. (PCIe Base Spec 3.0, sec 7.8) */ if (pci_is_pcie(dev) && pcie_downstream_port(dev) && pos == PCI_EXP_SLTSTA) *val = PCI_EXP_SLTSTA_PDS; return 0; }

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Jiang Liu9696.00%150.00%
Björn Helgaas44.00%150.00%
Total100100.00%2100.00%

EXPORT_SYMBOL(pcie_capability_read_word);
int pcie_capability_read_dword(struct pci_dev *dev, int pos, u32 *val) { int ret; *val = 0; if (pos & 3) return -EINVAL; if (pcie_capability_reg_implemented(dev, pos)) { ret = pci_read_config_dword(dev, pci_pcie_cap(dev) + pos, val); /* * Reset *val to 0 if pci_read_config_dword() fails, it may * have been written as 0xFFFFFFFF if hardware error happens * during pci_read_config_dword(). */ if (ret) *val = 0; return ret; } if (pci_is_pcie(dev) && pcie_downstream_port(dev) && pos == PCI_EXP_SLTSTA) *val = PCI_EXP_SLTSTA_PDS; return 0; }

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Jiang Liu9595.96%150.00%
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EXPORT_SYMBOL(pcie_capability_read_dword);
int pcie_capability_write_word(struct pci_dev *dev, int pos, u16 val) { if (pos & 1) return -EINVAL; if (!pcie_capability_reg_implemented(dev, pos)) return 0; return pci_write_config_word(dev, pci_pcie_cap(dev) + pos, val); }

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EXPORT_SYMBOL(pcie_capability_write_word);
int pcie_capability_write_dword(struct pci_dev *dev, int pos, u32 val) { if (pos & 3) return -EINVAL; if (!pcie_capability_reg_implemented(dev, pos)) return 0; return pci_write_config_dword(dev, pci_pcie_cap(dev) + pos, val); }

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Jiang Liu54100.00%1100.00%
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EXPORT_SYMBOL(pcie_capability_write_dword);
int pcie_capability_clear_and_set_word(struct pci_dev *dev, int pos, u16 clear, u16 set) { int ret; u16 val; ret = pcie_capability_read_word(dev, pos, &val); if (!ret) { val &= ~clear; val |= set; ret = pcie_capability_write_word(dev, pos, val); } return ret; }

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Jiang Liu67100.00%1100.00%
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EXPORT_SYMBOL(pcie_capability_clear_and_set_word);
int pcie_capability_clear_and_set_dword(struct pci_dev *dev, int pos, u32 clear, u32 set) { int ret; u32 val; ret = pcie_capability_read_dword(dev, pos, &val); if (!ret) { val &= ~clear; val |= set; ret = pcie_capability_write_dword(dev, pos, val); } return ret; }

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Jiang Liu67100.00%1100.00%
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EXPORT_SYMBOL(pcie_capability_clear_and_set_dword);
int pci_read_config_byte(const struct pci_dev *dev, int where, u8 *val) { if (pci_dev_is_disconnected(dev)) { *val = ~0; return PCIBIOS_DEVICE_NOT_FOUND; } return pci_bus_read_config_byte(dev->bus, dev->devfn, where, val); }

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Keith Busch5198.08%266.67%
Brian Norris11.92%133.33%
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EXPORT_SYMBOL(pci_read_config_byte);
int pci_read_config_word(const struct pci_dev *dev, int where, u16 *val) { if (pci_dev_is_disconnected(dev)) { *val = ~0; return PCIBIOS_DEVICE_NOT_FOUND; } return pci_bus_read_config_word(dev->bus, dev->devfn, where, val); }

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Keith Busch5198.08%266.67%
Brian Norris11.92%133.33%
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EXPORT_SYMBOL(pci_read_config_word);
int pci_read_config_dword(const struct pci_dev *dev, int where, u32 *val) { if (pci_dev_is_disconnected(dev)) { *val = ~0; return PCIBIOS_DEVICE_NOT_FOUND; } return pci_bus_read_config_dword(dev->bus, dev->devfn, where, val); }

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Keith Busch5198.08%266.67%
Brian Norris11.92%133.33%
Total52100.00%3100.00%

EXPORT_SYMBOL(pci_read_config_dword);
int pci_write_config_byte(const struct pci_dev *dev, int where, u8 val) { if (pci_dev_is_disconnected(dev)) return PCIBIOS_DEVICE_NOT_FOUND; return pci_bus_write_config_byte(dev->bus, dev->devfn, where, val); }

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Keith Busch4297.67%266.67%
Brian Norris12.33%133.33%
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EXPORT_SYMBOL(pci_write_config_byte);
int pci_write_config_word(const struct pci_dev *dev, int where, u16 val) { if (pci_dev_is_disconnected(dev)) return PCIBIOS_DEVICE_NOT_FOUND; return pci_bus_write_config_word(dev->bus, dev->devfn, where, val); }

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Keith Busch4297.67%266.67%
Brian Norris12.33%133.33%
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EXPORT_SYMBOL(pci_write_config_word);
int pci_write_config_dword(const struct pci_dev *dev, int where, u32 val) { if (pci_dev_is_disconnected(dev)) return PCIBIOS_DEVICE_NOT_FOUND; return pci_bus_write_config_dword(dev->bus, dev->devfn, where, val); }

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Keith Busch4297.67%266.67%
Brian Norris12.33%133.33%
Total43100.00%3100.00%

EXPORT_SYMBOL(pci_write_config_dword);

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Jiang Liu68232.52%13.33%
Rob Herring46121.98%13.33%
Keith Busch30914.74%26.67%
Brian King1436.82%13.33%
Björn Helgaas1055.01%826.67%
Patrick Mochel833.96%13.33%
Jan Kiszka763.62%13.33%
Matthew Wilcox643.05%13.33%
Huang Ying612.91%13.33%
Thomas Gleixner492.34%310.00%
Matthew Dobson341.62%13.33%
Brian Norris70.33%26.67%
Greg Kroah-Hartman60.29%13.33%
Myron Stowe60.29%13.33%
Tejun Heo30.14%13.33%
Adrian Bunk30.14%13.33%
Gavin Shan20.10%13.33%
Greg Thelen20.10%13.33%
Alex Williamson10.05%13.33%
Total2097100.00%30100.00%
Directory: drivers/pci
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