x86, AMD IOMMU: add generic dma_ops mapping functions

This patch adds the generic functions to map and unmap pages to a protection
domain for dma_ops usage.

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>

1 files changed, 105 insertions, 0 deletions

diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c
index 47e80b5814bf..e00a3e7ba356 100644
--- a/arch/x86/kernel/amd_iommu.c
+++ b/arch/x86/kernel/amd_iommu.c
@@ -536,3 +536,108 @@ static int get_device_resources(struct device *dev,
         return 1;
 }
 
+static dma_addr_t dma_ops_domain_map(struct amd_iommu *iommu,
+                                     struct dma_ops_domain *dom,
+                                     unsigned long address,
+                                     phys_addr_t paddr,
+                                     int direction)
+{
+        u64 *pte, __pte;
+
+        WARN_ON(address > dom->aperture_size);
+
+        paddr &= PAGE_MASK;
+
+        pte  = dom->pte_pages[IOMMU_PTE_L1_INDEX(address)];
+        pte += IOMMU_PTE_L0_INDEX(address);
+
+        __pte = paddr | IOMMU_PTE_P | IOMMU_PTE_FC;
+
+        if (direction == DMA_TO_DEVICE)
+                __pte |= IOMMU_PTE_IR;
+        else if (direction == DMA_FROM_DEVICE)
+                __pte |= IOMMU_PTE_IW;
+        else if (direction == DMA_BIDIRECTIONAL)
+                __pte |= IOMMU_PTE_IR | IOMMU_PTE_IW;
+
+        WARN_ON(*pte);
+
+        *pte = __pte;
+
+        return (dma_addr_t)address;
+}
+
+static void dma_ops_domain_unmap(struct amd_iommu *iommu,
+                                 struct dma_ops_domain *dom,
+                                 unsigned long address)
+{
+        u64 *pte;
+
+        if (address >= dom->aperture_size)
+                return;
+
+        WARN_ON(address & 0xfffULL || address > dom->aperture_size);
+
+        pte  = dom->pte_pages[IOMMU_PTE_L1_INDEX(address)];
+        pte += IOMMU_PTE_L0_INDEX(address);
+
+        WARN_ON(!*pte);
+
+        *pte = 0ULL;
+}
+
+static dma_addr_t __map_single(struct device *dev,
+                               struct amd_iommu *iommu,
+                               struct dma_ops_domain *dma_dom,
+                               phys_addr_t paddr,
+                               size_t size,
+                               int dir)
+{
+        dma_addr_t offset = paddr & ~PAGE_MASK;
+        dma_addr_t address, start;
+        unsigned int pages;
+        int i;
+
+        pages = to_pages(paddr, size);
+        paddr &= PAGE_MASK;
+
+        address = dma_ops_alloc_addresses(dev, dma_dom, pages);
+        if (unlikely(address == bad_dma_address))
+                goto out;
+
+        start = address;
+        for (i = 0; i < pages; ++i) {
+                dma_ops_domain_map(iommu, dma_dom, start, paddr, dir);
+                paddr += PAGE_SIZE;
+                start += PAGE_SIZE;
+        }
+        address += offset;
+
+out:
+        return address;
+}
+
+static void __unmap_single(struct amd_iommu *iommu,
+                           struct dma_ops_domain *dma_dom,
+                           dma_addr_t dma_addr,
+                           size_t size,
+                           int dir)
+{
+        dma_addr_t i, start;
+        unsigned int pages;
+
+        if ((dma_addr == 0) || (dma_addr + size > dma_dom->aperture_size))
+                return;
+
+        pages = to_pages(dma_addr, size);
+        dma_addr &= PAGE_MASK;
+        start = dma_addr;
+
+        for (i = 0; i < pages; ++i) {
+                dma_ops_domain_unmap(iommu, dma_dom, start);
+                start += PAGE_SIZE;
+        }
+
+        dma_ops_free_addresses(dma_dom, dma_addr, pages);
+}
+