Intel IOMMU Pass Through Support
[safe/jmp/linux-2.6] / drivers / pci / intel-iommu.c
index 001b328..1312182 100644 (file)
@@ -53,6 +53,8 @@
 
 #define DEFAULT_DOMAIN_ADDRESS_WIDTH 48
 
+#define MAX_AGAW_WIDTH 64
+
 #define DOMAIN_MAX_ADDR(gaw) ((((u64)1) << gaw) - 1)
 
 #define IOVA_PFN(addr)         ((addr) >> PAGE_SHIFT)
@@ -127,8 +129,6 @@ static inline void context_set_fault_enable(struct context_entry *context)
        context->lo &= (((u64)-1) << 2) | 1;
 }
 
-#define CONTEXT_TT_MULTI_LEVEL 0
-
 static inline void context_set_translation_type(struct context_entry *context,
                                                unsigned long value)
 {
@@ -288,6 +288,7 @@ int dmar_disabled = 1;
 static int __initdata dmar_map_gfx = 1;
 static int dmar_forcedac;
 static int intel_iommu_strict;
+int iommu_pass_through;
 
 #define DUMMY_DEVICE_DOMAIN_INFO ((struct device_domain_info *)(-1))
 static DEFINE_SPINLOCK(device_domain_lock);
@@ -397,17 +398,13 @@ void free_iova_mem(struct iova *iova)
 
 static inline int width_to_agaw(int width);
 
-/* calculate agaw for each iommu.
- * "SAGAW" may be different across iommus, use a default agaw, and
- * get a supported less agaw for iommus that don't support the default agaw.
- */
-int iommu_calculate_agaw(struct intel_iommu *iommu)
+static int __iommu_calculate_agaw(struct intel_iommu *iommu, int max_gaw)
 {
        unsigned long sagaw;
        int agaw = -1;
 
        sagaw = cap_sagaw(iommu->cap);
-       for (agaw = width_to_agaw(DEFAULT_DOMAIN_ADDRESS_WIDTH);
+       for (agaw = width_to_agaw(max_gaw);
             agaw >= 0; agaw--) {
                if (test_bit(agaw, &sagaw))
                        break;
@@ -416,6 +413,24 @@ int iommu_calculate_agaw(struct intel_iommu *iommu)
        return agaw;
 }
 
+/*
+ * Calculate max SAGAW for each iommu.
+ */
+int iommu_calculate_max_sagaw(struct intel_iommu *iommu)
+{
+       return __iommu_calculate_agaw(iommu, MAX_AGAW_WIDTH);
+}
+
+/*
+ * calculate agaw for each iommu.
+ * "SAGAW" may be different across iommus, use a default agaw, and
+ * get a supported less agaw for iommus that don't support the default agaw.
+ */
+int iommu_calculate_agaw(struct intel_iommu *iommu)
+{
+       return __iommu_calculate_agaw(iommu, DEFAULT_DOMAIN_ADDRESS_WIDTH);
+}
+
 /* in native case, each domain is related to only one iommu */
 static struct intel_iommu *domain_get_iommu(struct dmar_domain *domain)
 {
@@ -1321,8 +1336,8 @@ static void domain_exit(struct dmar_domain *domain)
        free_domain_mem(domain);
 }
 
-static int domain_context_mapping_one(struct dmar_domain *domain,
-                                     int segment, u8 bus, u8 devfn)
+static int domain_context_mapping_one(struct dmar_domain *domain, int segment,
+                                u8 bus, u8 devfn, int translation)
 {
        struct context_entry *context;
        unsigned long flags;
@@ -1335,7 +1350,10 @@ static int domain_context_mapping_one(struct dmar_domain *domain,
 
        pr_debug("Set context mapping for %02x:%02x.%d\n",
                bus, PCI_SLOT(devfn), PCI_FUNC(devfn));
+
        BUG_ON(!domain->pgd);
+       BUG_ON(translation != CONTEXT_TT_PASS_THROUGH &&
+              translation != CONTEXT_TT_MULTI_LEVEL);
 
        iommu = device_to_iommu(segment, bus, devfn);
        if (!iommu)
@@ -1395,9 +1413,18 @@ static int domain_context_mapping_one(struct dmar_domain *domain,
        }
 
        context_set_domain_id(context, id);
-       context_set_address_width(context, iommu->agaw);
-       context_set_address_root(context, virt_to_phys(pgd));
-       context_set_translation_type(context, CONTEXT_TT_MULTI_LEVEL);
+
+       /*
+        * In pass through mode, AW must be programmed to indicate the largest
+        * AGAW value supported by hardware. And ASR is ignored by hardware.
+        */
+       if (likely(translation == CONTEXT_TT_MULTI_LEVEL)) {
+               context_set_address_width(context, iommu->agaw);
+               context_set_address_root(context, virt_to_phys(pgd));
+       } else
+               context_set_address_width(context, iommu->msagaw);
+
+       context_set_translation_type(context, translation);
        context_set_fault_enable(context);
        context_set_present(context);
        domain_flush_cache(domain, context, sizeof(*context));
@@ -1422,13 +1449,15 @@ static int domain_context_mapping_one(struct dmar_domain *domain,
 }
 
 static int
-domain_context_mapping(struct dmar_domain *domain, struct pci_dev *pdev)
+domain_context_mapping(struct dmar_domain *domain, struct pci_dev *pdev,
+                       int translation)
 {
        int ret;
        struct pci_dev *tmp, *parent;
 
        ret = domain_context_mapping_one(domain, pci_domain_nr(pdev->bus),
-                                        pdev->bus->number, pdev->devfn);
+                                        pdev->bus->number, pdev->devfn,
+                                        translation);
        if (ret)
                return ret;
 
@@ -1442,7 +1471,7 @@ domain_context_mapping(struct dmar_domain *domain, struct pci_dev *pdev)
                ret = domain_context_mapping_one(domain,
                                                 pci_domain_nr(parent->bus),
                                                 parent->bus->number,
-                                                parent->devfn);
+                                                parent->devfn, translation);
                if (ret)
                        return ret;
                parent = parent->bus->self;
@@ -1450,12 +1479,14 @@ domain_context_mapping(struct dmar_domain *domain, struct pci_dev *pdev)
        if (tmp->is_pcie) /* this is a PCIE-to-PCI bridge */
                return domain_context_mapping_one(domain,
                                        pci_domain_nr(tmp->subordinate),
-                                       tmp->subordinate->number, 0);
+                                       tmp->subordinate->number, 0,
+                                       translation);
        else /* this is a legacy PCI bridge */
                return domain_context_mapping_one(domain,
                                                  pci_domain_nr(tmp->bus),
                                                  tmp->bus->number,
-                                                 tmp->devfn);
+                                                 tmp->devfn,
+                                                 translation);
 }
 
 static int domain_context_mapped(struct pci_dev *pdev)
@@ -1752,7 +1783,7 @@ static int iommu_prepare_identity_map(struct pci_dev *pdev,
                goto error;
 
        /* context entry init */
-       ret = domain_context_mapping(domain, pdev);
+       ret = domain_context_mapping(domain, pdev, CONTEXT_TT_MULTI_LEVEL);
        if (!ret)
                return 0;
 error:
@@ -1853,6 +1884,23 @@ static inline void iommu_prepare_isa(void)
 }
 #endif /* !CONFIG_DMAR_FLPY_WA */
 
+/* Initialize each context entry as pass through.*/
+static int __init init_context_pass_through(void)
+{
+       struct pci_dev *pdev = NULL;
+       struct dmar_domain *domain;
+       int ret;
+
+       for_each_pci_dev(pdev) {
+               domain = get_domain_for_dev(pdev, DEFAULT_DOMAIN_ADDRESS_WIDTH);
+               ret = domain_context_mapping(domain, pdev,
+                                            CONTEXT_TT_PASS_THROUGH);
+               if (ret)
+                       return ret;
+       }
+       return 0;
+}
+
 static int __init init_dmars(void)
 {
        struct dmar_drhd_unit *drhd;
@@ -1860,6 +1908,7 @@ static int __init init_dmars(void)
        struct pci_dev *pdev;
        struct intel_iommu *iommu;
        int i, ret;
+       int pass_through = 1;
 
        /*
         * for each drhd
@@ -1913,7 +1962,15 @@ static int __init init_dmars(void)
                        printk(KERN_ERR "IOMMU: allocate root entry failed\n");
                        goto error;
                }
+               if (!ecap_pass_through(iommu->ecap))
+                       pass_through = 0;
        }
+       if (iommu_pass_through)
+               if (!pass_through) {
+                       printk(KERN_INFO
+                              "Pass Through is not supported by hardware.\n");
+                       iommu_pass_through = 0;
+               }
 
        /*
         * Start from the sane iommu hardware state.
@@ -1976,37 +2033,57 @@ static int __init init_dmars(void)
                               "IOMMU: enable interrupt remapping failed\n");
        }
 #endif
+       /*
+        * If pass through is set and enabled, context entries of all pci
+        * devices are intialized by pass through translation type.
+        */
+       if (iommu_pass_through) {
+               ret = init_context_pass_through();
+               if (ret) {
+                       printk(KERN_ERR "IOMMU: Pass through init failed.\n");
+                       iommu_pass_through = 0;
+               }
+       }
 
        /*
-        * For each rmrr
-        *   for each dev attached to rmrr
-        *   do
-        *     locate drhd for dev, alloc domain for dev
-        *     allocate free domain
-        *     allocate page table entries for rmrr
-        *     if context not allocated for bus
-        *           allocate and init context
-        *           set present in root table for this bus
-        *     init context with domain, translation etc
-        *    endfor
-        * endfor
+        * If pass through is not set or not enabled, setup context entries for
+        * identity mappings for rmrr, gfx, and isa.
         */
-       for_each_rmrr_units(rmrr) {
-               for (i = 0; i < rmrr->devices_cnt; i++) {
-                       pdev = rmrr->devices[i];
-                       /* some BIOS lists non-exist devices in DMAR table */
-                       if (!pdev)
-                               continue;
-                       ret = iommu_prepare_rmrr_dev(rmrr, pdev);
-                       if (ret)
-                               printk(KERN_ERR
+       if (!iommu_pass_through) {
+               /*
+                * For each rmrr
+                *   for each dev attached to rmrr
+                *   do
+                *     locate drhd for dev, alloc domain for dev
+                *     allocate free domain
+                *     allocate page table entries for rmrr
+                *     if context not allocated for bus
+                *           allocate and init context
+                *           set present in root table for this bus
+                *     init context with domain, translation etc
+                *    endfor
+                * endfor
+                */
+               for_each_rmrr_units(rmrr) {
+                       for (i = 0; i < rmrr->devices_cnt; i++) {
+                               pdev = rmrr->devices[i];
+                               /*
+                                * some BIOS lists non-exist devices in DMAR
+                                * table.
+                                */
+                               if (!pdev)
+                                       continue;
+                               ret = iommu_prepare_rmrr_dev(rmrr, pdev);
+                               if (ret)
+                                       printk(KERN_ERR
                                 "IOMMU: mapping reserved region failed\n");
+                       }
                }
-       }
 
-       iommu_prepare_gfx_mapping();
+               iommu_prepare_gfx_mapping();
 
-       iommu_prepare_isa();
+               iommu_prepare_isa();
+       }
 
        /*
         * for each drhd
@@ -2117,7 +2194,8 @@ get_valid_domain_for_dev(struct pci_dev *pdev)
 
        /* make sure context mapping is ok */
        if (unlikely(!domain_context_mapped(pdev))) {
-               ret = domain_context_mapping(domain, pdev);
+               ret = domain_context_mapping(domain, pdev,
+                                            CONTEXT_TT_MULTI_LEVEL);
                if (ret) {
                        printk(KERN_ERR
                                "Domain context map for %s failed",
@@ -2786,7 +2864,7 @@ int __init intel_iommu_init(void)
         * Check the need for DMA-remapping initialization now.
         * Above initialization will also be used by Interrupt-remapping.
         */
-       if (no_iommu || swiotlb || dmar_disabled)
+       if (no_iommu || (swiotlb && !iommu_pass_through) || dmar_disabled)
                return -ENODEV;
 
        iommu_init_mempool();
@@ -2806,7 +2884,15 @@ int __init intel_iommu_init(void)
 
        init_timer(&unmap_timer);
        force_iommu = 1;
-       dma_ops = &intel_dma_ops;
+
+       if (!iommu_pass_through) {
+               printk(KERN_INFO
+                      "Multi-level page-table translation for DMAR.\n");
+               dma_ops = &intel_dma_ops;
+       } else
+               printk(KERN_INFO
+                      "DMAR: Pass through translation for DMAR.\n");
+
        init_iommu_sysfs();
 
        register_iommu(&intel_iommu_ops);
@@ -3146,7 +3232,7 @@ static int intel_iommu_attach_device(struct iommu_domain *domain,
                return -EFAULT;
        }
 
-       ret = domain_context_mapping(dmar_domain, pdev);
+       ret = domain_context_mapping(dmar_domain, pdev, CONTEXT_TT_MULTI_LEVEL);
        if (ret)
                return ret;