Merge tag 'dma-mapping-7.3-2026-10-09' of git://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux

c8d4256f · Linus Torvalds <[email protected]> · 2026-10-10 00:49:55 +02:00

Pull dma-mapping fixes from Marek Szyprowski:
 "Two more fixes for the corner cases in the DMA-mapping SWIOTLB code
  (Peng Fan and Marek Szyprowski)"

* tag 'dma-mapping-7.3-2026-10-09' of git://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux:
  swiotlb: fix default_swiotlb_limit() for non-growable default pool
  iommu/dma: skip swiotlb bounce for DMA_ATTR_MMIO in iommu_dma_map_phys

Commit: c8d4256f1081c191773de9f46e2ad8f5e8d05d30
Parents: fc1c2501 · 911655ab

Merge commit. Changes below are compared with the first parent: fc1c2501.

Changes

2 files changed · +5 −5

File	Status	Add	Del	Content
drivers/iommu/dma-iommu.c	modified	+2	−2	View file
kernel/dma/swiotlb.c	modified	+3	−3	View file

drivers/iommu/dma-iommu.c

View file

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 58c6245..68ee578 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -1228,9 +1228,9 @@ dma_addr_t iommu_dma_map_phys(struct device *dev, phys_addr_t phys, size_t size,
 	 * If both the physical buffer start address and size are page aligned,
 	 * we don't need to use a bounce page.
 	 */
-	if (dev_use_swiotlb(dev, size, dir) &&
+	if (!(attrs & DMA_ATTR_MMIO) && dev_use_swiotlb(dev, size, dir) &&
 	    iova_unaligned(iovad, phys, size)) {
-		if (attrs & (DMA_ATTR_MMIO | DMA_ATTR_REQUIRE_COHERENT))
+		if (attrs & DMA_ATTR_REQUIRE_COHERENT)
 			return DMA_MAPPING_ERROR;
 
 		phys = iommu_dma_map_swiotlb(dev, phys, size, dir, attrs);

kernel/dma/swiotlb.c

View file

diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index aa2f1c4..5edea93 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -1844,10 +1844,10 @@ phys_addr_t default_swiotlb_base(void)
 phys_addr_t default_swiotlb_limit(void)
 {
 #ifdef CONFIG_SWIOTLB_DYNAMIC
-	return io_tlb_default_mem.phys_limit;
-#else
-	return io_tlb_default_mem.defpool.end - 1;
+	if (io_tlb_default_mem.can_grow)
+		return io_tlb_default_mem.phys_limit;
 #endif
+	return io_tlb_default_mem.defpool.end - 1;
 }
 
 #ifdef CONFIG_DEBUG_FS