Merge git://git.infradead.org/iommu-2.6

* git://git.infradead.org/iommu-2.6:
  intel-iommu: Don't use identity mapping for PCI devices behind bridges
  intel-iommu: Use iommu_should_identity_map() at startup time too.
  intel-iommu: No mapping for non-PCI devices
  intel-iommu: Restore DMAR_BROKEN_GFX_WA option for broken graphics drivers
  intel-iommu: Add iommu_should_identity_map() function
  intel-iommu: Fix reattaching of devices to identity mapping domain
  intel-iommu: Don't set identity mapping for bypassed graphics devices
  intel-iommu: Fix dma vs. mm page confusion with aligned_nrpages()

1 files changed, 83 insertions, 23 deletions

diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c
index 53075424a434..360fb67a30d7 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;