x86, AMD IOMMU: add functions to initialize unity mappings

This patch adds the functions which will initialize the unity mappings in the
device page tables.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Cc: iommu@lists.linux-foundation.org
Cc: bhavna.sarathy@amd.com
Cc: Sebastian.Biemueller@amd.com
Cc: robert.richter@amd.com
Cc: joro@8bytes.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c
index a24ee4a5203a38293df29bac3ec1ace71f6973e0..1d70f5e6f4385994dfe9343bc488bf0bcdbf175f 100644 (file)
--- a/arch/x86/kernel/amd_iommu.c
+++ b/arch/x86/kernel/amd_iommu.c
@@ -37,6 +37,9 @@ struct command {
        u32 data[4];
 };
 
+static int dma_ops_unity_map(struct dma_ops_domain *dma_dom,
+                            struct unity_map_entry *e);
+
 static int __iommu_queue_command(struct amd_iommu *iommu, struct command *cmd)
 {
        u32 tail, head;
@@ -144,3 +147,122 @@ static int iommu_flush_pages(struct amd_iommu *iommu, u16 domid,
        return 0;
 }
 
+static int iommu_map(struct protection_domain *dom,
+                    unsigned long bus_addr,
+                    unsigned long phys_addr,
+                    int prot)
+{
+       u64 __pte, *pte, *page;
+
+       bus_addr  = PAGE_ALIGN(bus_addr);
+       phys_addr = PAGE_ALIGN(bus_addr);
+
+       /* only support 512GB address spaces for now */
+       if (bus_addr > IOMMU_MAP_SIZE_L3 || !(prot & IOMMU_PROT_MASK))
+               return -EINVAL;
+
+       pte = &dom->pt_root[IOMMU_PTE_L2_INDEX(bus_addr)];
+
+       if (!IOMMU_PTE_PRESENT(*pte)) {
+               page = (u64 *)get_zeroed_page(GFP_KERNEL);
+               if (!page)
+                       return -ENOMEM;
+               *pte = IOMMU_L2_PDE(virt_to_phys(page));
+       }
+
+       pte = IOMMU_PTE_PAGE(*pte);
+       pte = &pte[IOMMU_PTE_L1_INDEX(bus_addr)];
+
+       if (!IOMMU_PTE_PRESENT(*pte)) {
+               page = (u64 *)get_zeroed_page(GFP_KERNEL);
+               if (!page)
+                       return -ENOMEM;
+               *pte = IOMMU_L1_PDE(virt_to_phys(page));
+       }
+
+       pte = IOMMU_PTE_PAGE(*pte);
+       pte = &pte[IOMMU_PTE_L0_INDEX(bus_addr)];
+
+       if (IOMMU_PTE_PRESENT(*pte))
+               return -EBUSY;
+
+       __pte = phys_addr | IOMMU_PTE_P;
+       if (prot & IOMMU_PROT_IR)
+               __pte |= IOMMU_PTE_IR;
+       if (prot & IOMMU_PROT_IW)
+               __pte |= IOMMU_PTE_IW;
+
+       *pte = __pte;
+
+       return 0;
+}
+
+static int iommu_for_unity_map(struct amd_iommu *iommu,
+                              struct unity_map_entry *entry)
+{
+       u16 bdf, i;
+
+       for (i = entry->devid_start; i <= entry->devid_end; ++i) {
+               bdf = amd_iommu_alias_table[i];
+               if (amd_iommu_rlookup_table[bdf] == iommu)
+                       return 1;
+       }
+
+       return 0;
+}
+
+static int iommu_init_unity_mappings(struct amd_iommu *iommu)
+{
+       struct unity_map_entry *entry;
+       int ret;
+
+       list_for_each_entry(entry, &amd_iommu_unity_map, list) {
+               if (!iommu_for_unity_map(iommu, entry))
+                       continue;
+               ret = dma_ops_unity_map(iommu->default_dom, entry);
+               if (ret)
+                       return ret;
+       }
+
+       return 0;
+}
+
+static int dma_ops_unity_map(struct dma_ops_domain *dma_dom,
+                            struct unity_map_entry *e)
+{
+       u64 addr;
+       int ret;
+
+       for (addr = e->address_start; addr < e->address_end;
+            addr += PAGE_SIZE) {
+               ret = iommu_map(&dma_dom->domain, addr, addr, e->prot);
+               if (ret)
+                       return ret;
+               /*
+                * if unity mapping is in aperture range mark the page
+                * as allocated in the aperture
+                */
+               if (addr < dma_dom->aperture_size)
+                       __set_bit(addr >> PAGE_SHIFT, dma_dom->bitmap);
+       }
+
+       return 0;
+}
+
+static int init_unity_mappings_for_device(struct dma_ops_domain *dma_dom,
+                                         u16 devid)
+{
+       struct unity_map_entry *e;
+       int ret;
+
+       list_for_each_entry(e, &amd_iommu_unity_map, list) {
+               if (!(devid >= e->devid_start && devid <= e->devid_end))
+                       continue;
+               ret = dma_ops_unity_map(dma_dom, e);
+               if (ret)
+                       return ret;
+       }
+
+       return 0;
+}
+