cregit-Linux how code gets into the kernel

Release 4.10 arch/x86/kernel/pci-dma.c

Directory: arch/x86/kernel
#include <linux/dma-mapping.h>
#include <linux/dma-debug.h>
#include <linux/dmar.h>
#include <linux/export.h>
#include <linux/bootmem.h>
#include <linux/gfp.h>
#include <linux/pci.h>
#include <linux/kmemleak.h>

#include <asm/proto.h>
#include <asm/dma.h>
#include <asm/iommu.h>
#include <asm/gart.h>
#include <asm/calgary.h>
#include <asm/x86_init.h>
#include <asm/iommu_table.h>


static int forbid_dac __read_mostly;


struct dma_map_ops *dma_ops = &nommu_dma_ops;

EXPORT_SYMBOL(dma_ops);


static int iommu_sac_force __read_mostly;

#ifdef CONFIG_IOMMU_DEBUG

int panic_on_overflow __read_mostly = 1;

int force_iommu __read_mostly = 1;
#else

int panic_on_overflow __read_mostly = 0;

int force_iommu __read_mostly = 0;
#endif


int iommu_merge __read_mostly = 0;


int no_iommu __read_mostly;
/* Set this to 1 if there is a HW IOMMU in the system */

int iommu_detected __read_mostly = 0;

/*
 * This variable becomes 1 if iommu=pt is passed on the kernel command line.
 * If this variable is 1, IOMMU implementations do no DMA translation for
 * devices and allow every device to access to whole physical memory. This is
 * useful if a user wants to use an IOMMU only for KVM device assignment to
 * guests and not for driver dma translation.
 */

int iommu_pass_through __read_mostly;

extern struct iommu_table_entry __iommu_table[], __iommu_table_end[];

/* Dummy device used for NULL arguments (normally ISA). */

struct device x86_dma_fallback_dev = {
	.init_name = "fallback device",
	.coherent_dma_mask = ISA_DMA_BIT_MASK,
	.dma_mask = &x86_dma_fallback_dev.coherent_dma_mask,
};

EXPORT_SYMBOL(x86_dma_fallback_dev);

/* Number of entries preallocated for DMA-API debugging */

#define PREALLOC_DMA_DEBUG_ENTRIES       65536


void __init pci_iommu_alloc(void) { struct iommu_table_entry *p; sort_iommu_table(__iommu_table, __iommu_table_end); check_iommu_entries(__iommu_table, __iommu_table_end); for (p = __iommu_table; p < __iommu_table_end; p++) { if (p && p->detect && p->detect() > 0) { p->flags |= IOMMU_DETECTED; if (p->early_init) p->early_init(); if (p->flags & IOMMU_FINISH_IF_DETECTED) break; } } }

Contributors

PersonTokensPropCommitsCommitProp
konrad rzeszutek wilkkonrad rzeszutek wilk7183.53%240.00%
glauber de oliveira costaglauber de oliveira costa89.41%120.00%
fujita tomonorifujita tomonori67.06%240.00%
Total85100.00%5100.00%


void *dma_generic_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_addr, gfp_t flag, unsigned long attrs) { unsigned long dma_mask; struct page *page; unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT; dma_addr_t addr; dma_mask = dma_alloc_coherent_mask(dev, flag); flag &= ~__GFP_ZERO; again: page = NULL; /* CMA can be used only in the context which permits sleeping */ if (gfpflags_allow_blocking(flag)) { page = dma_alloc_from_contiguous(dev, count, get_order(size)); if (page && page_to_phys(page) + size > dma_mask) { dma_release_from_contiguous(dev, page, count); page = NULL; } } /* fallback */ if (!page) page = alloc_pages_node(dev_to_node(dev), flag, get_order(size)); if (!page) return NULL; addr = page_to_phys(page); if (addr + size > dma_mask) { __free_pages(page, get_order(size)); if (dma_mask < DMA_BIT_MASK(32) && !(flag & GFP_DMA)) { flag = (flag & ~GFP_DMA32) | GFP_DMA; goto again; } return NULL; } memset(page_address(page), 0, size); *dma_addr = addr; return page_address(page); }

Contributors

PersonTokensPropCommitsCommitProp
fujita tomonorifujita tomonori14159.75%218.18%
akinobu mitaakinobu mita4418.64%218.18%
marek szyprowskimarek szyprowski4016.95%327.27%
yang hongyangyang hongyang41.69%19.09%
mel gormanmel gorman31.27%19.09%
krzysztof kozlowskikrzysztof kozlowski20.85%19.09%
andrzej pietrasiewiczandrzej pietrasiewicz20.85%19.09%
Total236100.00%11100.00%


void dma_generic_free_coherent(struct device *dev, size_t size, void *vaddr, dma_addr_t dma_addr, unsigned long attrs) { unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT; struct page *page = virt_to_page(vaddr); if (!dma_release_from_contiguous(dev, page, count)) free_pages((unsigned long)vaddr, get_order(size)); }

Contributors

PersonTokensPropCommitsCommitProp
marek szyprowskimarek szyprowski6997.18%150.00%
krzysztof kozlowskikrzysztof kozlowski22.82%150.00%
Total71100.00%2100.00%


bool arch_dma_alloc_attrs(struct device **dev, gfp_t *gfp) { if (!*dev) *dev = &x86_dma_fallback_dev; *gfp &= ~(__GFP_DMA | __GFP_HIGHMEM | __GFP_DMA32); *gfp = dma_alloc_coherent_gfp_flags(*dev, *gfp); if (!is_device_dma_capable(*dev)) return false; return true; }

Contributors

PersonTokensPropCommitsCommitProp
denys vlasenkodenys vlasenko3350.00%125.00%
ville syrjalaville syrjala1218.18%125.00%
jun'ichi nomurajun'ichi nomura1218.18%125.00%
christoph hellwigchristoph hellwig913.64%125.00%
Total66100.00%4100.00%

EXPORT_SYMBOL(arch_dma_alloc_attrs); /* * See <Documentation/x86/x86_64/boot-options.txt> for the iommu kernel * parameter documentation. */
static __init int iommu_setup(char *p) { iommu_merge = 1; if (!p) return -EINVAL; while (*p) { if (!strncmp(p, "off", 3)) no_iommu = 1; /* gart_parse_options has more force support */ if (!strncmp(p, "force", 5)) force_iommu = 1; if (!strncmp(p, "noforce", 7)) { iommu_merge = 0; force_iommu = 0; } if (!strncmp(p, "biomerge", 8)) { iommu_merge = 1; force_iommu = 1; } if (!strncmp(p, "panic", 5)) panic_on_overflow = 1; if (!strncmp(p, "nopanic", 7)) panic_on_overflow = 0; if (!strncmp(p, "merge", 5)) { iommu_merge = 1; force_iommu = 1; } if (!strncmp(p, "nomerge", 7)) iommu_merge = 0; if (!strncmp(p, "forcesac", 8)) iommu_sac_force = 1; if (!strncmp(p, "allowdac", 8)) forbid_dac = 0; if (!strncmp(p, "nodac", 5)) forbid_dac = 1; if (!strncmp(p, "usedac", 6)) { forbid_dac = -1; return 1; } #ifdef CONFIG_SWIOTLB if (!strncmp(p, "soft", 4)) swiotlb = 1; #endif if (!strncmp(p, "pt", 2)) iommu_pass_through = 1; gart_parse_options(p); #ifdef CONFIG_CALGARY_IOMMU if (!strncmp(p, "calgary", 7)) use_calgary = 1; #endif /* CONFIG_CALGARY_IOMMU */ p += strcspn(p, ","); if (*p == ',') ++p; } return 0; }

Contributors

PersonTokensPropCommitsCommitProp
glauber de oliveira costaglauber de oliveira costa31694.61%250.00%
fenghua yufenghua yu164.79%125.00%
david woodhousedavid woodhouse20.60%125.00%
Total334100.00%4100.00%

early_param("iommu", iommu_setup);
int dma_supported(struct device *dev, u64 mask) { struct dma_map_ops *ops = get_dma_ops(dev); #ifdef CONFIG_PCI if (mask > 0xffffffff && forbid_dac > 0) { dev_info(dev, "PCI: Disallowing DAC for device\n"); return 0; } #endif if (ops->dma_supported) return ops->dma_supported(dev, mask); /* Copied from i386. Doesn't make much sense, because it will only work for pci_alloc_coherent. The caller just has to use GFP_DMA in this case. */ if (mask < DMA_BIT_MASK(24)) return 0; /* Tell the device to use SAC when IOMMU force is on. This allows the driver to use cheaper accesses in some cases. Problem with this is that if we overflow the IOMMU area and return DAC as fallback address the device may not handle it correctly. As a special case some controllers have a 39bit address mode that is as efficient as 32bit (aic79xx). Don't force SAC for these. Assume all masks <= 40 bits are of this type. Normally this doesn't make any difference, but gives more gentle handling of IOMMU overflow. */ if (iommu_sac_force && (mask >= DMA_BIT_MASK(40))) { dev_info(dev, "Force SAC with mask %Lx\n", mask); return 0; } return 1; }

Contributors

PersonTokensPropCommitsCommitProp
glauber de oliveira costaglauber de oliveira costa8476.36%116.67%
fujita tomonorifujita tomonori1210.91%233.33%
yang hongyangyang hongyang87.27%233.33%
greg kroah-hartmangreg kroah-hartman65.45%116.67%
Total110100.00%6100.00%

EXPORT_SYMBOL(dma_supported);
static int __init pci_iommu_init(void) { struct iommu_table_entry *p; dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES); #ifdef CONFIG_PCI dma_debug_add_bus(&pci_bus_type); #endif x86_init.iommu.iommu_init(); for (p = __iommu_table; p < __iommu_table_end; p++) { if (p && (p->flags & IOMMU_DETECTED) && p->late_init) p->late_init(); } return 0; }

Contributors

PersonTokensPropCommitsCommitProp
konrad rzeszutek wilkkonrad rzeszutek wilk3546.05%116.67%
joerg roedeljoerg roedel1621.05%233.33%
fujita tomonorifujita tomonori1317.11%233.33%
glauber de oliveira costaglauber de oliveira costa1215.79%116.67%
Total76100.00%6100.00%

/* Must execute after PCI subsystem */ rootfs_initcall(pci_iommu_init); #ifdef CONFIG_PCI /* Many VIA bridges seem to corrupt data for DAC. Disable it here */
static void via_no_dac(struct pci_dev *dev) { if (forbid_dac == 0) { dev_info(&dev->dev, "disabling DAC on VIA PCI bridge\n"); forbid_dac = 1; } }

Contributors

PersonTokensPropCommitsCommitProp
fenghua yufenghua yu2678.79%150.00%
bjorn helgaasbjorn helgaas721.21%150.00%
Total33100.00%2100.00%

DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_VIA, PCI_ANY_ID, PCI_CLASS_BRIDGE_PCI, 8, via_no_dac); #endif

Overall Contributors

PersonTokensPropCommitsCommitProp
glauber de oliveira costaglauber de oliveira costa54144.38%915.00%
fujita tomonorifujita tomonori17714.52%915.00%
konrad rzeszutek wilkkonrad rzeszutek wilk1189.68%23.33%
marek szyprowskimarek szyprowski1098.94%35.00%
fenghua yufenghua yu645.25%35.00%
akinobu mitaakinobu mita443.61%23.33%
denys vlasenkodenys vlasenko373.04%23.33%
joerg roedeljoerg roedel362.95%610.00%
ville syrjalaville syrjala120.98%11.67%
yang hongyangyang hongyang120.98%35.00%
jun'ichi nomurajun'ichi nomura120.98%11.67%
christoph hellwigchristoph hellwig100.82%11.67%
bjorn helgaasbjorn helgaas70.57%11.67%
greg kroah-hartmangreg kroah-hartman60.49%11.67%
yinghai luyinghai lu50.41%11.67%
krzysztof kozlowskikrzysztof kozlowski40.33%11.67%
mel gormanmel gorman30.25%11.67%
david woodhousedavid woodhouse30.25%23.33%
paul gortmakerpaul gortmaker30.25%11.67%
tejun heotejun heo30.25%11.67%
catalin marinascatalin marinas30.25%11.67%
andrzej pietrasiewiczandrzej pietrasiewicz20.16%11.67%
jan beulichjan beulich20.16%11.67%
justin mattockjustin mattock10.08%11.67%
paul bollepaul bolle10.08%11.67%
maarten lankhorstmaarten lankhorst10.08%11.67%
dmitri vorobievdmitri vorobiev10.08%11.67%
ingo molnaringo molnar10.08%11.67%
kay sieverskay sievers10.08%11.67%
Total1219100.00%60100.00%
Directory: arch/x86/kernel
Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.