intel-iommu: Clean up identity mapping code, remove CONFIG_DMAR_GFX_WA

There's no need for the GFX workaround now we have 'iommu=pt' for the
cases where people really care about performance. There's no need to
have a special case for just one type of device.

This also speeds up the iommu=pt path and reduces memory usage by
setting up the si_domain _once_ and then using it for all devices,
rather than giving each device its own private page tables.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

1 files changed, 32 insertions, 75 deletions

diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c
index 3a4f347e2f88..fc121967cb5b 100644
--- a/drivers/pci/intel-iommu.c
+++ b/drivers/pci/intel-iommu.c
@@ -1889,11 +1889,7 @@ static int iommu_prepare_identity_map(struct pci_dev *pdev,
                "IOMMU: Setting identity map for device %s [0x%Lx - 0x%Lx]\n",
                pci_name(pdev), start, end);
 
-        if (iommu_identity_mapping)
-                domain = si_domain;
-        else
-                /* page table init */
-                domain = get_domain_for_dev(pdev, DEFAULT_DOMAIN_ADDRESS_WIDTH);
+        domain = get_domain_for_dev(pdev, DEFAULT_DOMAIN_ADDRESS_WIDTH);
         if (!domain)
                 return -ENOMEM;
 
@@ -1922,64 +1918,6 @@ static inline int iommu_prepare_rmrr_dev(struct dmar_rmrr_unit *rmrr,
                 rmrr->end_address + 1);
 }
 
-struct iommu_prepare_data {
-        struct pci_dev *pdev;
-        int ret;
-};
-
-static int __init iommu_prepare_work_fn(unsigned long start_pfn,
-                                         unsigned long end_pfn, void *datax)
-{
-        struct iommu_prepare_data *data;
-
-        data = (struct iommu_prepare_data *)datax;
-
-        data->ret = iommu_prepare_identity_map(data->pdev,
-                                start_pfn<<PAGE_SHIFT, end_pfn<<PAGE_SHIFT);
-        return data->ret;
-
-}
-
-static int __init iommu_prepare_with_active_regions(struct pci_dev *pdev)
-{
-        int nid;
-        struct iommu_prepare_data data;
-
-        data.pdev = pdev;
-        data.ret = 0;
-
-        for_each_online_node(nid) {
-                work_with_active_regions(nid, iommu_prepare_work_fn, &data);
-                if (data.ret)
-                        return data.ret;
-        }
-        return data.ret;
-}
-
-#ifdef CONFIG_DMAR_GFX_WA
-static void __init iommu_prepare_gfx_mapping(void)
-{
-        struct pci_dev *pdev = NULL;
-        int ret;
-
-        for_each_pci_dev(pdev) {
-                if (pdev->dev.archdata.iommu == DUMMY_DEVICE_DOMAIN_INFO ||
-                                !IS_GFX_DEVICE(pdev))
-                        continue;
-                printk(KERN_INFO "IOMMU: gfx device %s 1-1 mapping\n",
-                        pci_name(pdev));
-                ret = iommu_prepare_with_active_regions(pdev);
-                if (ret)
-                        printk(KERN_ERR "IOMMU: mapping reserved region failed\n");
-        }
-}
-#else /* !CONFIG_DMAR_GFX_WA */
-static inline void iommu_prepare_gfx_mapping(void)
-{
-        return;
-}
-#endif
-
 #ifdef CONFIG_DMAR_FLOPPY_WA
 static inline void iommu_prepare_isa(void)
 {
@@ -1990,12 +1928,12 @@ static inline void iommu_prepare_isa(void)
         if (!pdev)
                 return;
 
-        printk(KERN_INFO "IOMMU: Prepare 0-16M unity mapping for LPC\n");
+        printk(KERN_INFO "IOMMU: Prepare 0-16MiB unity mapping for LPC\n");
         ret = iommu_prepare_identity_map(pdev, 0, 16*1024*1024);
 
         if (ret)
-                printk(KERN_ERR "IOMMU: Failed to create 0-64M identity map, "
-                        "floppy might not work\n");
+                printk(KERN_ERR "IOMMU: Failed to create 0-16MiB identity map; "
+                       "floppy might not work\n");
 
 }
 #else
@@ -2023,16 +1961,30 @@ static int __init init_context_pass_through(void)
 }
 
 static int md_domain_init(struct dmar_domain *domain, int guest_width);
+
+static int __init si_domain_work_fn(unsigned long start_pfn,
+                                    unsigned long end_pfn, void *datax)
+{
+        int *ret = datax;
+
+        *ret = iommu_domain_identity_map(si_domain,
+                                         (uint64_t)start_pfn << PAGE_SHIFT,
+                                         (uint64_t)end_pfn << PAGE_SHIFT);
+        return *ret;
+
+}
+
 static int si_domain_init(void)
 {
         struct dmar_drhd_unit *drhd;
         struct intel_iommu *iommu;
-        int ret = 0;
+        int nid, ret = 0;
 
         si_domain = alloc_domain();
         if (!si_domain)
                 return -EFAULT;
 
+        pr_debug("Identity mapping domain is domain %d\n", si_domain->id);
 
         for_each_active_iommu(iommu, drhd) {
                 ret = iommu_attach_domain(si_domain, iommu);
@@ -2049,6 +2001,12 @@ static int si_domain_init(void)
 
         si_domain->flags = DOMAIN_FLAG_STATIC_IDENTITY;
 
+        for_each_online_node(nid) {
+                work_with_active_regions(nid, si_domain_work_fn, &ret);
+                if (ret)
+                        return ret;
+        }
+
         return 0;
 }
 
@@ -2102,13 +2060,14 @@ static int iommu_prepare_static_identity_mapping(void)
         if (ret)
                 return -EFAULT;
 
-        printk(KERN_INFO "IOMMU: Setting identity map:\n");
         for_each_pci_dev(pdev) {
-                ret = iommu_prepare_with_active_regions(pdev);
-                if (ret) {
-                        printk(KERN_INFO "1:1 mapping to one domain failed.\n");
-                        return -EFAULT;
-                }
+                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;
@@ -2299,8 +2258,6 @@ int __init init_dmars(void)
                         }
                 }
 
-                iommu_prepare_gfx_mapping();
-
                 iommu_prepare_isa();
         }