x86, AMD IOMMU: add mapping functions for scatter gather lists

This patch adds the dma_ops functions for mapping and unmapping scatter gather
lists.

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 b4079f6..f4747fe 100644 (file)
--- a/arch/x86/kernel/amd_iommu.c
+++ b/arch/x86/kernel/amd_iommu.c
@@ -700,3 +700,101 @@ static void unmap_single(struct device *dev, dma_addr_t dma_addr,
        spin_unlock_irqrestore(&domain->lock, flags);
 }
 
+static int map_sg_no_iommu(struct device *dev, struct scatterlist *sglist,
+                          int nelems, int dir)
+{
+       struct scatterlist *s;
+       int i;
+
+       for_each_sg(sglist, s, nelems, i) {
+               s->dma_address = (dma_addr_t)sg_phys(s);
+               s->dma_length  = s->length;
+       }
+
+       return nelems;
+}
+
+static int map_sg(struct device *dev, struct scatterlist *sglist,
+                 int nelems, int dir)
+{
+       unsigned long flags;
+       struct amd_iommu *iommu;
+       struct protection_domain *domain;
+       u16 devid;
+       int i;
+       struct scatterlist *s;
+       phys_addr_t paddr;
+       int mapped_elems = 0;
+
+       get_device_resources(dev, &iommu, &domain, &devid);
+
+       if (!iommu || !domain)
+               return map_sg_no_iommu(dev, sglist, nelems, dir);
+
+       spin_lock_irqsave(&domain->lock, flags);
+
+       for_each_sg(sglist, s, nelems, i) {
+               paddr = sg_phys(s);
+
+               s->dma_address = __map_single(dev, iommu, domain->priv,
+                                             paddr, s->length, dir);
+
+               if (s->dma_address) {
+                       s->dma_length = s->length;
+                       mapped_elems++;
+               } else
+                       goto unmap;
+               if (iommu_has_npcache(iommu))
+                       iommu_flush_pages(iommu, domain->id, s->dma_address,
+                                         s->dma_length);
+       }
+
+       if (iommu->need_sync)
+               iommu_completion_wait(iommu);
+
+out:
+       spin_unlock_irqrestore(&domain->lock, flags);
+
+       return mapped_elems;
+unmap:
+       for_each_sg(sglist, s, mapped_elems, i) {
+               if (s->dma_address)
+                       __unmap_single(iommu, domain->priv, s->dma_address,
+                                      s->dma_length, dir);
+               s->dma_address = s->dma_length = 0;
+       }
+
+       mapped_elems = 0;
+
+       goto out;
+}
+
+static void unmap_sg(struct device *dev, struct scatterlist *sglist,
+                    int nelems, int dir)
+{
+       unsigned long flags;
+       struct amd_iommu *iommu;
+       struct protection_domain *domain;
+       struct scatterlist *s;
+       u16 devid;
+       int i;
+
+       if (!get_device_resources(dev, &iommu, &domain, &devid))
+               return;
+
+       spin_lock_irqsave(&domain->lock, flags);
+
+       for_each_sg(sglist, s, nelems, i) {
+               __unmap_single(iommu, domain->priv, s->dma_address,
+                              s->dma_length, dir);
+               iommu_flush_pages(iommu, domain->id, s->dma_address,
+                                 s->dma_length);
+               s->dma_address = s->dma_length = 0;
+       }
+
+       if (iommu->need_sync)
+               iommu_completion_wait(iommu);
+
+       spin_unlock_irqrestore(&domain->lock, flags);
+}
+