diff options
Diffstat (limited to 'drivers/iommu/intel-iommu.c')
| -rw-r--r-- | drivers/iommu/intel-iommu.c | 94 |
1 files changed, 76 insertions, 18 deletions
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index 14e4b3722428..115ff26e9ced 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -31,7 +31,6 @@ #include <linux/pci.h> #include <linux/dmar.h> #include <linux/dma-mapping.h> -#include <linux/dma-direct.h> #include <linux/mempool.h> #include <linux/memory.h> #include <linux/cpu.h> @@ -485,14 +484,37 @@ static int dmar_forcedac; static int intel_iommu_strict; static int intel_iommu_superpage = 1; static int intel_iommu_ecs = 1; +static int intel_iommu_pasid28; static int iommu_identity_mapping; #define IDENTMAP_ALL 1 #define IDENTMAP_GFX 2 #define IDENTMAP_AZALIA 4 -#define ecs_enabled(iommu) (intel_iommu_ecs && ecap_ecs(iommu->ecap)) -#define pasid_enabled(iommu) (ecs_enabled(iommu) && ecap_pasid(iommu->ecap)) +/* Broadwell and Skylake have broken ECS support — normal so-called "second + * level" translation of DMA requests-without-PASID doesn't actually happen + * unless you also set the NESTE bit in an extended context-entry. Which of + * course means that SVM doesn't work because it's trying to do nested + * translation of the physical addresses it finds in the process page tables, + * through the IOVA->phys mapping found in the "second level" page tables. + * + * The VT-d specification was retroactively changed to change the definition + * of the capability bits and pretend that Broadwell/Skylake never happened... + * but unfortunately the wrong bit was changed. It's ECS which is broken, but + * for some reason it was the PASID capability bit which was redefined (from + * bit 28 on BDW/SKL to bit 40 in future). + * + * So our test for ECS needs to eschew those implementations which set the old + * PASID capabiity bit 28, since those are the ones on which ECS is broken. + * Unless we are working around the 'pasid28' limitations, that is, by putting + * the device into passthrough mode for normal DMA and thus masking the bug. + */ +#define ecs_enabled(iommu) (intel_iommu_ecs && ecap_ecs(iommu->ecap) && \ + (intel_iommu_pasid28 || !ecap_broken_pasid(iommu->ecap))) +/* PASID support is thus enabled if ECS is enabled and *either* of the old + * or new capability bits are set. */ +#define pasid_enabled(iommu) (ecs_enabled(iommu) && \ + (ecap_pasid(iommu->ecap) || ecap_broken_pasid(iommu->ecap))) int intel_iommu_gfx_mapped; EXPORT_SYMBOL_GPL(intel_iommu_gfx_mapped); @@ -555,6 +577,11 @@ static int __init intel_iommu_setup(char *str) printk(KERN_INFO "Intel-IOMMU: disable extended context table support\n"); intel_iommu_ecs = 0; + } else if (!strncmp(str, "pasid28", 7)) { + printk(KERN_INFO + "Intel-IOMMU: enable pre-production PASID support\n"); + intel_iommu_pasid28 = 1; + iommu_identity_mapping |= IDENTMAP_GFX; } else if (!strncmp(str, "tboot_noforce", 13)) { printk(KERN_INFO "Intel-IOMMU: not forcing on after tboot. This could expose security risk for tboot\n"); @@ -3713,30 +3740,61 @@ static void *intel_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_handle, gfp_t flags, unsigned long attrs) { - void *vaddr; + struct page *page = NULL; + int order; - vaddr = dma_direct_alloc(dev, size, dma_handle, flags, attrs); - if (iommu_no_mapping(dev) || !vaddr) - return vaddr; + size = PAGE_ALIGN(size); + order = get_order(size); - *dma_handle = __intel_map_single(dev, virt_to_phys(vaddr), - PAGE_ALIGN(size), DMA_BIDIRECTIONAL, - dev->coherent_dma_mask); - if (!*dma_handle) - goto out_free_pages; - return vaddr; + if (!iommu_no_mapping(dev)) + flags &= ~(GFP_DMA | GFP_DMA32); + else if (dev->coherent_dma_mask < dma_get_required_mask(dev)) { + if (dev->coherent_dma_mask < DMA_BIT_MASK(32)) + flags |= GFP_DMA; + else + flags |= GFP_DMA32; + } + + if (gfpflags_allow_blocking(flags)) { + unsigned int count = size >> PAGE_SHIFT; + + page = dma_alloc_from_contiguous(dev, count, order, flags); + if (page && iommu_no_mapping(dev) && + page_to_phys(page) + size > dev->coherent_dma_mask) { + dma_release_from_contiguous(dev, page, count); + page = NULL; + } + } + + if (!page) + page = alloc_pages(flags, order); + if (!page) + return NULL; + memset(page_address(page), 0, size); + + *dma_handle = __intel_map_single(dev, page_to_phys(page), size, + DMA_BIDIRECTIONAL, + dev->coherent_dma_mask); + if (*dma_handle) + return page_address(page); + if (!dma_release_from_contiguous(dev, page, size >> PAGE_SHIFT)) + __free_pages(page, order); -out_free_pages: - dma_direct_free(dev, size, vaddr, *dma_handle, attrs); return NULL; } static void intel_free_coherent(struct device *dev, size_t size, void *vaddr, dma_addr_t dma_handle, unsigned long attrs) { - if (!iommu_no_mapping(dev)) - intel_unmap(dev, dma_handle, PAGE_ALIGN(size)); - dma_direct_free(dev, size, vaddr, dma_handle, attrs); + int order; + struct page *page = virt_to_page(vaddr); + + size = PAGE_ALIGN(size); + order = get_order(size); + + intel_unmap(dev, dma_handle, size); + if (!dma_release_from_contiguous(dev, page, size >> PAGE_SHIFT)) + __free_pages(page, order); } static void intel_unmap_sg(struct device *dev, struct scatterlist *sglist, |