1 files changed, 74 insertions, 0 deletions

diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c
index f4747fe70aaa..aab9125ac0b2 100644
--- a/arch/x86/kernel/amd_iommu.c
+++ b/arch/x86/kernel/amd_iommu.c
@@ -798,3 +798,77 @@ static void unmap_sg(struct device *dev, struct scatterlist *sglist,
         spin_unlock_irqrestore(&domain->lock, flags);
 }
 
+static void *alloc_coherent(struct device *dev, size_t size,
+                            dma_addr_t *dma_addr, gfp_t flag)
+{
+        unsigned long flags;
+        void *virt_addr;
+        struct amd_iommu *iommu;
+        struct protection_domain *domain;
+        u16 devid;
+        phys_addr_t paddr;
+
+        virt_addr = (void *)__get_free_pages(flag, get_order(size));
+        if (!virt_addr)
+                return 0;
+
+        memset(virt_addr, 0, size);
+        paddr = virt_to_phys(virt_addr);
+
+        get_device_resources(dev, &iommu, &domain, &devid);
+
+        if (!iommu || !domain) {
+                *dma_addr = (dma_addr_t)paddr;
+                return virt_addr;
+        }
+
+        spin_lock_irqsave(&domain->lock, flags);
+
+        *dma_addr = __map_single(dev, iommu, domain->priv, paddr,
+                                 size, DMA_BIDIRECTIONAL);
+
+        if (*dma_addr == bad_dma_address) {
+                free_pages((unsigned long)virt_addr, get_order(size));
+                virt_addr = NULL;
+                goto out;
+        }
+
+        if (iommu_has_npcache(iommu))
+                iommu_flush_pages(iommu, domain->id, *dma_addr, size);
+
+        if (iommu->need_sync)
+                iommu_completion_wait(iommu);
+
+out:
+        spin_unlock_irqrestore(&domain->lock, flags);
+
+        return virt_addr;
+}
+
+static void free_coherent(struct device *dev, size_t size,
+                          void *virt_addr, dma_addr_t dma_addr)
+{
+        unsigned long flags;
+        struct amd_iommu *iommu;
+        struct protection_domain *domain;
+        u16 devid;
+
+        get_device_resources(dev, &iommu, &domain, &devid);
+
+        if (!iommu || !domain)
+                goto free_mem;
+
+        spin_lock_irqsave(&domain->lock, flags);
+
+        __unmap_single(iommu, domain->priv, dma_addr, size, DMA_BIDIRECTIONAL);
+        iommu_flush_pages(iommu, domain->id, dma_addr, size);
+
+        if (iommu->need_sync)
+                iommu_completion_wait(iommu);
+
+        spin_unlock_irqrestore(&domain->lock, flags);
+
+free_mem:
+        free_pages((unsigned long)virt_addr, get_order(size));
+}
+