x86, AMD IOMMU: add address allocation and deallocation functions

This patch adds the address allocator to the AMD IOMMU code.

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, 48 insertions, 0 deletions

diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c
index 1d70f5e6f438..69d8d024387e 100644
--- a/arch/x86/kernel/amd_iommu.c
+++ b/arch/x86/kernel/amd_iommu.c
@@ -266,3 +266,51 @@ static int init_unity_mappings_for_device(struct dma_ops_domain *dma_dom,
         return 0;
 }
 
+static unsigned long dma_mask_to_pages(unsigned long mask)
+{
+        return (mask >> PAGE_SHIFT) +
+                (PAGE_ALIGN(mask & ~PAGE_MASK) >> PAGE_SHIFT);
+}
+
+static unsigned long dma_ops_alloc_addresses(struct device *dev,
+                                             struct dma_ops_domain *dom,
+                                             unsigned int pages)
+{
+        unsigned long limit = dma_mask_to_pages(*dev->dma_mask);
+        unsigned long address;
+        unsigned long size = dom->aperture_size >> PAGE_SHIFT;
+        unsigned long boundary_size;
+
+        boundary_size = ALIGN(dma_get_seg_boundary(dev) + 1,
+                        PAGE_SIZE) >> PAGE_SHIFT;
+        limit = limit < size ? limit : size;
+
+        if (dom->next_bit >= limit)
+                dom->next_bit = 0;
+
+        address = iommu_area_alloc(dom->bitmap, limit, dom->next_bit, pages,
+                        0 , boundary_size, 0);
+        if (address == -1)
+                address = iommu_area_alloc(dom->bitmap, limit, 0, pages,
+                                0, boundary_size, 0);
+
+        if (likely(address != -1)) {
+                set_bit_string(dom->bitmap, address, pages);
+                dom->next_bit = address + pages;
+                address <<= PAGE_SHIFT;
+        } else
+                address = bad_dma_address;
+
+        WARN_ON((address + (PAGE_SIZE*pages)) > dom->aperture_size);
+
+        return address;
+}
+
+static void dma_ops_free_addresses(struct dma_ops_domain *dom,
+                                   unsigned long address,
+                                   unsigned int pages)
+{
+        address >>= PAGE_SHIFT;
+        iommu_area_free(dom->bitmap, address, pages);
+}
+