Merge tag 'dma-mapping-4.21-1' of git://git.infradead.org/users/hch/dma-mapping

Pull dma-mapping fixes from Christoph Hellwig:
 "Fix various regressions introduced in this cycles:

   - fix dma-debug tracking for the map_page / map_single
     consolidatation

   - properly stub out DMA mapping symbols for !HAS_DMA builds to avoid
     link failures

   - fix AMD Gart direct mappings

   - setup the dma address for no kernel mappings using the remap
     allocator"

* tag 'dma-mapping-4.21-1' of git://git.infradead.org/users/hch/dma-mapping:
  dma-direct: fix DMA_ATTR_NO_KERNEL_MAPPING for remapped allocations
  x86/amd_gart: fix unmapping of non-GART mappings
  dma-mapping: remove a few unused exports
  dma-mapping: properly stub out the DMA API for !CONFIG_HAS_DMA
  dma-mapping: remove dmam_{declare,release}_coherent_memory
  dma-mapping: implement dmam_alloc_coherent using dmam_alloc_attrs
  dma-mapping: implement dma_map_single_attrs using dma_map_page_attrs

1 files changed, 9 insertions, 1 deletions

diff --git a/arch/x86/kernel/amd_gart_64.c b/arch/x86/kernel/amd_gart_64.c
index e0ff3ac8c127..2c0aa34af69c 100644
--- a/arch/x86/kernel/amd_gart_64.c
+++ b/arch/x86/kernel/amd_gart_64.c
@@ -256,7 +256,15 @@ static void gart_unmap_page(struct device *dev, dma_addr_t dma_addr,
 	int npages;
 	int i;
 
-	if (dma_addr == DMA_MAPPING_ERROR ||
+	if (WARN_ON_ONCE(dma_addr == DMA_MAPPING_ERROR))
+		return;
+
+	/*
+	 * This driver will not always use a GART mapping, but might have
+	 * created a direct mapping instead.  If that is the case there is
+	 * nothing to unmap here.
+	 */
+	if (dma_addr < iommu_bus_base ||
 	    dma_addr >= iommu_bus_base + iommu_size)
 		return;