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-rw-r--r--arch/x86/Kconfig12
-rw-r--r--drivers/pci/intel-iommu.c106
2 files changed, 95 insertions, 23 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index c07f7220590..738bdc6b0f8 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1913,6 +1913,18 @@ config DMAR_DEFAULT_ON
recommended you say N here while the DMAR code remains
experimental.
+config DMAR_BROKEN_GFX_WA
+ def_bool n
+ prompt "Workaround broken graphics drivers (going away soon)"
+ depends on DMAR
+ ---help---
+ Current Graphics drivers tend to use physical address
+ for DMA and avoid using DMA APIs. Setting this config
+ option permits the IOMMU driver to set a unity map for
+ all the OS-visible memory. Hence the driver can continue
+ to use physical addresses for DMA, at least until this
+ option is removed in the 2.6.32 kernel.
+
config DMAR_FLOPPY_WA
def_bool y
depends on DMAR
diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c
index 53075424a43..360fb67a30d 100644
--- a/drivers/pci/intel-iommu.c
+++ b/drivers/pci/intel-iommu.c
@@ -2117,6 +2117,47 @@ static int domain_add_dev_info(struct dmar_domain *domain,
return 0;
}
+static int iommu_should_identity_map(struct pci_dev *pdev, int startup)
+{
+ if (iommu_identity_mapping == 2)
+ return IS_GFX_DEVICE(pdev);
+
+ /*
+ * We want to start off with all devices in the 1:1 domain, and
+ * take them out later if we find they can't access all of memory.
+ *
+ * However, we can't do this for PCI devices behind bridges,
+ * because all PCI devices behind the same bridge will end up
+ * with the same source-id on their transactions.
+ *
+ * Practically speaking, we can't change things around for these
+ * devices at run-time, because we can't be sure there'll be no
+ * DMA transactions in flight for any of their siblings.
+ *
+ * So PCI devices (unless they're on the root bus) as well as
+ * their parent PCI-PCI or PCIe-PCI bridges must be left _out_ of
+ * the 1:1 domain, just in _case_ one of their siblings turns out
+ * not to be able to map all of memory.
+ */
+ if (!pdev->is_pcie) {
+ if (!pci_is_root_bus(pdev->bus))
+ return 0;
+ if (pdev->class >> 8 == PCI_CLASS_BRIDGE_PCI)
+ return 0;
+ } else if (pdev->pcie_type == PCI_EXP_TYPE_PCI_BRIDGE)
+ return 0;
+
+ /*
+ * At boot time, we don't yet know if devices will be 64-bit capable.
+ * Assume that they will -- if they turn out not to be, then we can
+ * take them out of the 1:1 domain later.
+ */
+ if (!startup)
+ return pdev->dma_mask > DMA_BIT_MASK(32);
+
+ return 1;
+}
+
static int iommu_prepare_static_identity_mapping(void)
{
struct pci_dev *pdev = NULL;
@@ -2127,16 +2168,18 @@ static int iommu_prepare_static_identity_mapping(void)
return -EFAULT;
for_each_pci_dev(pdev) {
- printk(KERN_INFO "IOMMU: identity mapping for device %s\n",
- pci_name(pdev));
+ if (iommu_should_identity_map(pdev, 1)) {
+ printk(KERN_INFO "IOMMU: identity mapping for device %s\n",
+ pci_name(pdev));
- ret = domain_context_mapping(si_domain, pdev,
- CONTEXT_TT_MULTI_LEVEL);
- if (ret)
- return ret;
- ret = domain_add_dev_info(si_domain, pdev);
- if (ret)
- return ret;
+ ret = domain_context_mapping(si_domain, pdev,
+ CONTEXT_TT_MULTI_LEVEL);
+ if (ret)
+ return ret;
+ ret = domain_add_dev_info(si_domain, pdev);
+ if (ret)
+ return ret;
+ }
}
return 0;
@@ -2291,6 +2334,10 @@ int __init init_dmars(void)
* identity mapping if iommu_identity_mapping is set.
*/
if (!iommu_pass_through) {
+#ifdef CONFIG_DMAR_BROKEN_GFX_WA
+ if (!iommu_identity_mapping)
+ iommu_identity_mapping = 2;
+#endif
if (iommu_identity_mapping)
iommu_prepare_static_identity_mapping();
/*
@@ -2368,15 +2415,15 @@ error:
return ret;
}
+/* Returns a number of VTD pages, but aligned to MM page size */
static inline unsigned long aligned_nrpages(unsigned long host_addr,
size_t size)
{
host_addr &= ~PAGE_MASK;
- host_addr += size + PAGE_SIZE - 1;
-
- return host_addr >> VTD_PAGE_SHIFT;
+ return PAGE_ALIGN(host_addr + size) >> VTD_PAGE_SHIFT;
}
+/* This takes a number of _MM_ pages, not VTD pages */
static struct iova *intel_alloc_iova(struct device *dev,
struct dmar_domain *domain,
unsigned long nrpages, uint64_t dma_mask)
@@ -2443,16 +2490,24 @@ static int iommu_dummy(struct pci_dev *pdev)
}
/* Check if the pdev needs to go through non-identity map and unmap process.*/
-static int iommu_no_mapping(struct pci_dev *pdev)
+static int iommu_no_mapping(struct device *dev)
{
+ struct pci_dev *pdev;
int found;
+ if (unlikely(dev->bus != &pci_bus_type))
+ return 1;
+
+ pdev = to_pci_dev(dev);
+ if (iommu_dummy(pdev))
+ return 1;
+
if (!iommu_identity_mapping)
- return iommu_dummy(pdev);
+ return 0;
found = identity_mapping(pdev);
if (found) {
- if (pdev->dma_mask > DMA_BIT_MASK(32))
+ if (iommu_should_identity_map(pdev, 0))
return 1;
else {
/*
@@ -2469,9 +2524,12 @@ static int iommu_no_mapping(struct pci_dev *pdev)
* In case of a detached 64 bit DMA device from vm, the device
* is put into si_domain for identity mapping.
*/
- if (pdev->dma_mask > DMA_BIT_MASK(32)) {
+ if (iommu_should_identity_map(pdev, 0)) {
int ret;
ret = domain_add_dev_info(si_domain, pdev);
+ if (ret)
+ return 0;
+ ret = domain_context_mapping(si_domain, pdev, CONTEXT_TT_MULTI_LEVEL);
if (!ret) {
printk(KERN_INFO "64bit %s uses identity mapping\n",
pci_name(pdev));
@@ -2480,7 +2538,7 @@ static int iommu_no_mapping(struct pci_dev *pdev)
}
}
- return iommu_dummy(pdev);
+ return 0;
}
static dma_addr_t __intel_map_single(struct device *hwdev, phys_addr_t paddr,
@@ -2496,7 +2554,7 @@ static dma_addr_t __intel_map_single(struct device *hwdev, phys_addr_t paddr,
BUG_ON(dir == DMA_NONE);
- if (iommu_no_mapping(pdev))
+ if (iommu_no_mapping(hwdev))
return paddr;
domain = get_valid_domain_for_dev(pdev);
@@ -2506,7 +2564,8 @@ static dma_addr_t __intel_map_single(struct device *hwdev, phys_addr_t paddr,
iommu = domain_get_iommu(domain);
size = aligned_nrpages(paddr, size);
- iova = intel_alloc_iova(hwdev, domain, size, pdev->dma_mask);
+ iova = intel_alloc_iova(hwdev, domain, dma_to_mm_pfn(size),
+ pdev->dma_mask);
if (!iova)
goto error;
@@ -2635,7 +2694,7 @@ static void intel_unmap_page(struct device *dev, dma_addr_t dev_addr,
struct iova *iova;
struct intel_iommu *iommu;
- if (iommu_no_mapping(pdev))
+ if (iommu_no_mapping(dev))
return;
domain = find_domain(pdev);
@@ -2726,7 +2785,7 @@ static void intel_unmap_sg(struct device *hwdev, struct scatterlist *sglist,
struct iova *iova;
struct intel_iommu *iommu;
- if (iommu_no_mapping(pdev))
+ if (iommu_no_mapping(hwdev))
return;
domain = find_domain(pdev);
@@ -2785,7 +2844,7 @@ static int intel_map_sg(struct device *hwdev, struct scatterlist *sglist, int ne
struct intel_iommu *iommu;
BUG_ON(dir == DMA_NONE);
- if (iommu_no_mapping(pdev))
+ if (iommu_no_mapping(hwdev))
return intel_nontranslate_map_sg(hwdev, sglist, nelems, dir);
domain = get_valid_domain_for_dev(pdev);
@@ -2797,7 +2856,8 @@ static int intel_map_sg(struct device *hwdev, struct scatterlist *sglist, int ne
for_each_sg(sglist, sg, nelems, i)
size += aligned_nrpages(sg->offset, sg->length);
- iova = intel_alloc_iova(hwdev, domain, size, pdev->dma_mask);
+ iova = intel_alloc_iova(hwdev, domain, dma_to_mm_pfn(size),
+ pdev->dma_mask);
if (!iova) {
sglist->dma_length = 0;
return 0;
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-14 16:12:31 +0000