forked from Minki/linux
b7f09ae583
Currently arch/x86/kernel/pci-dma.c always adds __GFP_NORETRY to the allocation flags, because it wants to be reasonably sure not to deadlock when calling alloc_pages(). But really that should only be done in two cases: - when allocating memory in the lower 16 MB DMA zone. If there's no free memory there, waiting or OOM killing is of no use - when optimistically trying an allocation in the DMA32 zone when dma_mask < DMA_32BIT_MASK hoping that the allocation happens to fall within the limits of the dma_mask Also blindly adding __GFP_NORETRY to the the gfp variable might not be a good idea since we then also use it when calling dma_ops->alloc_coherent(). Clearing it might also not be a good idea, dma_alloc_coherent()'s caller might have set it on purpose. The gfp variable should not be clobbered. [ mingo@elte.hu: converted to delta patch ontop of previous version. ] Signed-off-by: Miquel van Smoorenburg <miquels@cistron.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
533 lines
12 KiB
C
533 lines
12 KiB
C
#include <linux/dma-mapping.h>
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#include <linux/dmar.h>
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#include <linux/bootmem.h>
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#include <linux/pci.h>
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#include <asm/proto.h>
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#include <asm/dma.h>
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#include <asm/gart.h>
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#include <asm/calgary.h>
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int forbid_dac __read_mostly;
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EXPORT_SYMBOL(forbid_dac);
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const struct dma_mapping_ops *dma_ops;
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EXPORT_SYMBOL(dma_ops);
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static int iommu_sac_force __read_mostly;
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#ifdef CONFIG_IOMMU_DEBUG
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int panic_on_overflow __read_mostly = 1;
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int force_iommu __read_mostly = 1;
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#else
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int panic_on_overflow __read_mostly = 0;
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int force_iommu __read_mostly = 0;
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#endif
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int iommu_merge __read_mostly = 0;
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int no_iommu __read_mostly;
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/* Set this to 1 if there is a HW IOMMU in the system */
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int iommu_detected __read_mostly = 0;
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/* This tells the BIO block layer to assume merging. Default to off
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because we cannot guarantee merging later. */
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int iommu_bio_merge __read_mostly = 0;
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EXPORT_SYMBOL(iommu_bio_merge);
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dma_addr_t bad_dma_address __read_mostly = 0;
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EXPORT_SYMBOL(bad_dma_address);
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/* Dummy device used for NULL arguments (normally ISA). Better would
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be probably a smaller DMA mask, but this is bug-to-bug compatible
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to older i386. */
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struct device fallback_dev = {
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.bus_id = "fallback device",
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.coherent_dma_mask = DMA_32BIT_MASK,
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.dma_mask = &fallback_dev.coherent_dma_mask,
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};
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int dma_set_mask(struct device *dev, u64 mask)
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{
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if (!dev->dma_mask || !dma_supported(dev, mask))
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return -EIO;
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*dev->dma_mask = mask;
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return 0;
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}
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EXPORT_SYMBOL(dma_set_mask);
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#ifdef CONFIG_X86_64
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static __initdata void *dma32_bootmem_ptr;
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static unsigned long dma32_bootmem_size __initdata = (128ULL<<20);
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static int __init parse_dma32_size_opt(char *p)
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{
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if (!p)
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return -EINVAL;
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dma32_bootmem_size = memparse(p, &p);
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return 0;
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}
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early_param("dma32_size", parse_dma32_size_opt);
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void __init dma32_reserve_bootmem(void)
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{
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unsigned long size, align;
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if (end_pfn <= MAX_DMA32_PFN)
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return;
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align = 64ULL<<20;
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size = round_up(dma32_bootmem_size, align);
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dma32_bootmem_ptr = __alloc_bootmem_nopanic(size, align,
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__pa(MAX_DMA_ADDRESS));
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if (dma32_bootmem_ptr)
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dma32_bootmem_size = size;
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else
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dma32_bootmem_size = 0;
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}
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static void __init dma32_free_bootmem(void)
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{
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int node;
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if (end_pfn <= MAX_DMA32_PFN)
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return;
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if (!dma32_bootmem_ptr)
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return;
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for_each_online_node(node)
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free_bootmem_node(NODE_DATA(node), __pa(dma32_bootmem_ptr),
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dma32_bootmem_size);
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dma32_bootmem_ptr = NULL;
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dma32_bootmem_size = 0;
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}
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void __init pci_iommu_alloc(void)
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{
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/* free the range so iommu could get some range less than 4G */
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dma32_free_bootmem();
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/*
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* The order of these functions is important for
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* fall-back/fail-over reasons
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*/
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#ifdef CONFIG_GART_IOMMU
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gart_iommu_hole_init();
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#endif
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#ifdef CONFIG_CALGARY_IOMMU
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detect_calgary();
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#endif
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detect_intel_iommu();
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#ifdef CONFIG_SWIOTLB
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pci_swiotlb_init();
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#endif
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}
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#endif
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/*
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* See <Documentation/x86_64/boot-options.txt> for the iommu kernel parameter
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* documentation.
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*/
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static __init int iommu_setup(char *p)
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{
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iommu_merge = 1;
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if (!p)
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return -EINVAL;
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while (*p) {
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if (!strncmp(p, "off", 3))
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no_iommu = 1;
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/* gart_parse_options has more force support */
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if (!strncmp(p, "force", 5))
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force_iommu = 1;
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if (!strncmp(p, "noforce", 7)) {
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iommu_merge = 0;
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force_iommu = 0;
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}
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if (!strncmp(p, "biomerge", 8)) {
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iommu_bio_merge = 4096;
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iommu_merge = 1;
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force_iommu = 1;
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}
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if (!strncmp(p, "panic", 5))
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panic_on_overflow = 1;
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if (!strncmp(p, "nopanic", 7))
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panic_on_overflow = 0;
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if (!strncmp(p, "merge", 5)) {
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iommu_merge = 1;
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force_iommu = 1;
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}
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if (!strncmp(p, "nomerge", 7))
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iommu_merge = 0;
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if (!strncmp(p, "forcesac", 8))
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iommu_sac_force = 1;
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if (!strncmp(p, "allowdac", 8))
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forbid_dac = 0;
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if (!strncmp(p, "nodac", 5))
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forbid_dac = -1;
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if (!strncmp(p, "usedac", 6)) {
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forbid_dac = -1;
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return 1;
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}
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#ifdef CONFIG_SWIOTLB
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if (!strncmp(p, "soft", 4))
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swiotlb = 1;
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#endif
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#ifdef CONFIG_GART_IOMMU
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gart_parse_options(p);
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#endif
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#ifdef CONFIG_CALGARY_IOMMU
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if (!strncmp(p, "calgary", 7))
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use_calgary = 1;
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#endif /* CONFIG_CALGARY_IOMMU */
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p += strcspn(p, ",");
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if (*p == ',')
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++p;
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}
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return 0;
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}
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early_param("iommu", iommu_setup);
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#ifdef CONFIG_X86_32
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int dma_declare_coherent_memory(struct device *dev, dma_addr_t bus_addr,
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dma_addr_t device_addr, size_t size, int flags)
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{
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void __iomem *mem_base = NULL;
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int pages = size >> PAGE_SHIFT;
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int bitmap_size = BITS_TO_LONGS(pages) * sizeof(long);
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if ((flags & (DMA_MEMORY_MAP | DMA_MEMORY_IO)) == 0)
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goto out;
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if (!size)
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goto out;
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if (dev->dma_mem)
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goto out;
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/* FIXME: this routine just ignores DMA_MEMORY_INCLUDES_CHILDREN */
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mem_base = ioremap(bus_addr, size);
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if (!mem_base)
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goto out;
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dev->dma_mem = kzalloc(sizeof(struct dma_coherent_mem), GFP_KERNEL);
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if (!dev->dma_mem)
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goto out;
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dev->dma_mem->bitmap = kzalloc(bitmap_size, GFP_KERNEL);
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if (!dev->dma_mem->bitmap)
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goto free1_out;
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dev->dma_mem->virt_base = mem_base;
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dev->dma_mem->device_base = device_addr;
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dev->dma_mem->size = pages;
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dev->dma_mem->flags = flags;
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if (flags & DMA_MEMORY_MAP)
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return DMA_MEMORY_MAP;
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return DMA_MEMORY_IO;
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free1_out:
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kfree(dev->dma_mem);
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out:
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if (mem_base)
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iounmap(mem_base);
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return 0;
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}
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EXPORT_SYMBOL(dma_declare_coherent_memory);
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void dma_release_declared_memory(struct device *dev)
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{
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struct dma_coherent_mem *mem = dev->dma_mem;
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if (!mem)
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return;
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dev->dma_mem = NULL;
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iounmap(mem->virt_base);
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kfree(mem->bitmap);
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kfree(mem);
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}
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EXPORT_SYMBOL(dma_release_declared_memory);
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void *dma_mark_declared_memory_occupied(struct device *dev,
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dma_addr_t device_addr, size_t size)
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{
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struct dma_coherent_mem *mem = dev->dma_mem;
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int pos, err;
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int pages = (size + (device_addr & ~PAGE_MASK) + PAGE_SIZE - 1);
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pages >>= PAGE_SHIFT;
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if (!mem)
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return ERR_PTR(-EINVAL);
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pos = (device_addr - mem->device_base) >> PAGE_SHIFT;
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err = bitmap_allocate_region(mem->bitmap, pos, get_order(pages));
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if (err != 0)
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return ERR_PTR(err);
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return mem->virt_base + (pos << PAGE_SHIFT);
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}
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EXPORT_SYMBOL(dma_mark_declared_memory_occupied);
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static int dma_alloc_from_coherent_mem(struct device *dev, ssize_t size,
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dma_addr_t *dma_handle, void **ret)
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{
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struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL;
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int order = get_order(size);
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if (mem) {
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int page = bitmap_find_free_region(mem->bitmap, mem->size,
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order);
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if (page >= 0) {
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*dma_handle = mem->device_base + (page << PAGE_SHIFT);
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*ret = mem->virt_base + (page << PAGE_SHIFT);
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memset(*ret, 0, size);
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}
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if (mem->flags & DMA_MEMORY_EXCLUSIVE)
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*ret = NULL;
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}
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return (mem != NULL);
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}
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static int dma_release_coherent(struct device *dev, int order, void *vaddr)
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{
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struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL;
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if (mem && vaddr >= mem->virt_base && vaddr <
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(mem->virt_base + (mem->size << PAGE_SHIFT))) {
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int page = (vaddr - mem->virt_base) >> PAGE_SHIFT;
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bitmap_release_region(mem->bitmap, page, order);
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return 1;
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}
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return 0;
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}
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#else
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#define dma_alloc_from_coherent_mem(dev, size, handle, ret) (0)
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#define dma_release_coherent(dev, order, vaddr) (0)
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#endif /* CONFIG_X86_32 */
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int dma_supported(struct device *dev, u64 mask)
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{
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#ifdef CONFIG_PCI
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if (mask > 0xffffffff && forbid_dac > 0) {
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printk(KERN_INFO "PCI: Disallowing DAC for device %s\n",
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dev->bus_id);
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return 0;
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}
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#endif
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if (dma_ops->dma_supported)
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return dma_ops->dma_supported(dev, mask);
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/* Copied from i386. Doesn't make much sense, because it will
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only work for pci_alloc_coherent.
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The caller just has to use GFP_DMA in this case. */
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if (mask < DMA_24BIT_MASK)
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return 0;
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/* Tell the device to use SAC when IOMMU force is on. This
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allows the driver to use cheaper accesses in some cases.
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Problem with this is that if we overflow the IOMMU area and
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return DAC as fallback address the device may not handle it
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correctly.
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As a special case some controllers have a 39bit address
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mode that is as efficient as 32bit (aic79xx). Don't force
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SAC for these. Assume all masks <= 40 bits are of this
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type. Normally this doesn't make any difference, but gives
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more gentle handling of IOMMU overflow. */
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if (iommu_sac_force && (mask >= DMA_40BIT_MASK)) {
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printk(KERN_INFO "%s: Force SAC with mask %Lx\n",
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dev->bus_id, mask);
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return 0;
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}
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return 1;
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}
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EXPORT_SYMBOL(dma_supported);
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/* Allocate DMA memory on node near device */
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noinline struct page *
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dma_alloc_pages(struct device *dev, gfp_t gfp, unsigned order)
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{
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int node;
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node = dev_to_node(dev);
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return alloc_pages_node(node, gfp, order);
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}
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/*
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* Allocate memory for a coherent mapping.
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*/
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void *
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dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_handle,
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gfp_t gfp)
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{
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void *memory = NULL;
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struct page *page;
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unsigned long dma_mask = 0;
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dma_addr_t bus;
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int noretry = 0;
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/* ignore region specifiers */
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gfp &= ~(__GFP_DMA | __GFP_HIGHMEM | __GFP_DMA32);
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if (dma_alloc_from_coherent_mem(dev, size, dma_handle, &memory))
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return memory;
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if (!dev) {
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dev = &fallback_dev;
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gfp |= GFP_DMA;
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}
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dma_mask = dev->coherent_dma_mask;
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if (dma_mask == 0)
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dma_mask = (gfp & GFP_DMA) ? DMA_24BIT_MASK : DMA_32BIT_MASK;
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/* Device not DMA able */
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if (dev->dma_mask == NULL)
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return NULL;
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/* Don't invoke OOM killer or retry in lower 16MB DMA zone */
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if (gfp & __GFP_DMA)
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noretry = 1;
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#ifdef CONFIG_X86_64
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/* Why <=? Even when the mask is smaller than 4GB it is often
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larger than 16MB and in this case we have a chance of
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finding fitting memory in the next higher zone first. If
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not retry with true GFP_DMA. -AK */
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if (dma_mask <= DMA_32BIT_MASK && !(gfp & GFP_DMA)) {
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gfp |= GFP_DMA32;
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if (dma_mask < DMA_32BIT_MASK)
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noretry = 1;
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}
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#endif
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again:
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page = dma_alloc_pages(dev,
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noretry ? gfp | __GFP_NORETRY : gfp, get_order(size));
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if (page == NULL)
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return NULL;
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{
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int high, mmu;
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bus = page_to_phys(page);
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memory = page_address(page);
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high = (bus + size) >= dma_mask;
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mmu = high;
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if (force_iommu && !(gfp & GFP_DMA))
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mmu = 1;
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else if (high) {
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free_pages((unsigned long)memory,
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get_order(size));
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/* Don't use the 16MB ZONE_DMA unless absolutely
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needed. It's better to use remapping first. */
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if (dma_mask < DMA_32BIT_MASK && !(gfp & GFP_DMA)) {
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gfp = (gfp & ~GFP_DMA32) | GFP_DMA;
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goto again;
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}
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/* Let low level make its own zone decisions */
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gfp &= ~(GFP_DMA32|GFP_DMA);
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if (dma_ops->alloc_coherent)
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return dma_ops->alloc_coherent(dev, size,
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dma_handle, gfp);
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return NULL;
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}
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memset(memory, 0, size);
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if (!mmu) {
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*dma_handle = bus;
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return memory;
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}
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}
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if (dma_ops->alloc_coherent) {
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free_pages((unsigned long)memory, get_order(size));
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gfp &= ~(GFP_DMA|GFP_DMA32);
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return dma_ops->alloc_coherent(dev, size, dma_handle, gfp);
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}
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if (dma_ops->map_simple) {
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*dma_handle = dma_ops->map_simple(dev, virt_to_phys(memory),
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size,
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PCI_DMA_BIDIRECTIONAL);
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if (*dma_handle != bad_dma_address)
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return memory;
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}
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if (panic_on_overflow)
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panic("dma_alloc_coherent: IOMMU overflow by %lu bytes\n",
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(unsigned long)size);
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free_pages((unsigned long)memory, get_order(size));
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return NULL;
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}
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EXPORT_SYMBOL(dma_alloc_coherent);
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/*
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* Unmap coherent memory.
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* The caller must ensure that the device has finished accessing the mapping.
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*/
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void dma_free_coherent(struct device *dev, size_t size,
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void *vaddr, dma_addr_t bus)
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{
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int order = get_order(size);
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WARN_ON(irqs_disabled()); /* for portability */
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if (dma_release_coherent(dev, order, vaddr))
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return;
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if (dma_ops->unmap_single)
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dma_ops->unmap_single(dev, bus, size, 0);
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free_pages((unsigned long)vaddr, order);
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}
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EXPORT_SYMBOL(dma_free_coherent);
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static int __init pci_iommu_init(void)
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{
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#ifdef CONFIG_CALGARY_IOMMU
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calgary_iommu_init();
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#endif
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intel_iommu_init();
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#ifdef CONFIG_GART_IOMMU
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gart_iommu_init();
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#endif
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no_iommu_init();
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return 0;
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}
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void pci_iommu_shutdown(void)
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{
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|
gart_iommu_shutdown();
|
|
}
|
|
/* Must execute after PCI subsystem */
|
|
fs_initcall(pci_iommu_init);
|
|
|
|
#ifdef CONFIG_PCI
|
|
/* Many VIA bridges seem to corrupt data for DAC. Disable it here */
|
|
|
|
static __devinit void via_no_dac(struct pci_dev *dev)
|
|
{
|
|
if ((dev->class >> 8) == PCI_CLASS_BRIDGE_PCI && forbid_dac == 0) {
|
|
printk(KERN_INFO "PCI: VIA PCI bridge detected."
|
|
"Disabling DAC.\n");
|
|
forbid_dac = 1;
|
|
}
|
|
}
|
|
DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_VIA, PCI_ANY_ID, via_no_dac);
|
|
#endif
|