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>

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index d1430ef..c07f722 100644 (file)
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1913,25 +1913,14 @@ config DMAR_DEFAULT_ON
          recommended you say N here while the DMAR code remains
          experimental.
 
-config DMAR_GFX_WA
-       def_bool y
-       prompt "Support for Graphics workaround"
-       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.
-
 config DMAR_FLOPPY_WA
        def_bool y
        depends on DMAR
        ---help---
-         Floppy disk drivers are know to bypass DMA API calls
+         Floppy disk drivers are known to bypass DMA API calls
          thereby failing to work when IOMMU is enabled. This
          workaround will setup a 1:1 mapping for the first
-         16M to make floppy (an ISA device) work.
+         16MiB to make floppy (an ISA device) work.
 
 config INTR_REMAP
        bool "Support for Interrupt Remapping (EXPERIMENTAL)"

diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c
index 3a4f347..fc12196 100644 (file)
--- 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();
        }