| Message ID | 20260512090408.794195-14-aneesh.kumar@kernel.org (mailing list archive) |
|---|---|
| State | Handled Elsewhere |
| Headers | show |
| Series | dma-mapping: Use DMA_ATTR_CC_SHARED through direct, pool and swiotlb paths | expand |
"Aneesh Kumar K.V (Arm)" <aneesh.kumar@kernel.org> writes: > gart_alloc_coherent() first allocates memory through dma_direct_alloc(), > which returns a direct-mapped DMA address in dma_addr. When force_iommu is > enabled, the buffer is then remapped. > > Do not overwrite dma_addr before dma_map_area() has succeeded. Keep the > dma_map_area result in a temporary variable so the direct DMA address > remains available for dma_direct_free() on the error path. > > Signed-off-by: Aneesh Kumar K.V (Arm) <aneesh.kumar@kernel.org> > --- > arch/x86/kernel/amd_gart_64.c | 10 ++++++---- > 1 file changed, 6 insertions(+), 4 deletions(-) > > diff --git a/arch/x86/kernel/amd_gart_64.c b/arch/x86/kernel/amd_gart_64.c > index b5f1f031d45b..a109649c5649 100644 > --- a/arch/x86/kernel/amd_gart_64.c > +++ b/arch/x86/kernel/amd_gart_64.c > @@ -467,18 +467,20 @@ gart_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_addr, > gfp_t flag, unsigned long attrs) > { > void *vaddr; > + dma_addr_t dma_map_addr; > > vaddr = dma_direct_alloc(dev, size, dma_addr, flag, attrs); > if (!vaddr || > !force_iommu || dev->coherent_dma_mask <= DMA_BIT_MASK(24)) > return vaddr; > > - *dma_addr = dma_map_area(dev, virt_to_phys(vaddr), size, > - DMA_BIDIRECTIONAL, > - (1UL << get_order(size)) - 1, attrs); > + dma_map_addr = dma_map_area(dev, virt_to_phys(vaddr), size, > + DMA_BIDIRECTIONAL, > + (1UL << get_order(size)) - 1, attrs); > flush_gart(); > - if (unlikely(*dma_addr == DMA_MAPPING_ERROR)) > + if (unlikely(dma_map_addr == DMA_MAPPING_ERROR)) > goto out_free; > + *dma_addr = dma_map_addr; > return vaddr; > out_free: > dma_direct_free(dev, size, vaddr, *dma_addr, attrs); > -- > 2.43.0 > This needs corresponding changes on the gart_free_coherent() side as well. https://sashiko.dev/#/patchset/20260512090408.794195-1-aneesh.kumar%40kernel.org?part=13 I will avoid making that change as part of this series, since I assume it would require specific testing. -aneesh
diff --git a/arch/x86/kernel/amd_gart_64.c b/arch/x86/kernel/amd_gart_64.c index b5f1f031d45b..a109649c5649 100644 --- a/arch/x86/kernel/amd_gart_64.c +++ b/arch/x86/kernel/amd_gart_64.c @@ -467,18 +467,20 @@ gart_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_addr, gfp_t flag, unsigned long attrs) { void *vaddr; + dma_addr_t dma_map_addr; vaddr = dma_direct_alloc(dev, size, dma_addr, flag, attrs); if (!vaddr || !force_iommu || dev->coherent_dma_mask <= DMA_BIT_MASK(24)) return vaddr; - *dma_addr = dma_map_area(dev, virt_to_phys(vaddr), size, - DMA_BIDIRECTIONAL, - (1UL << get_order(size)) - 1, attrs); + dma_map_addr = dma_map_area(dev, virt_to_phys(vaddr), size, + DMA_BIDIRECTIONAL, + (1UL << get_order(size)) - 1, attrs); flush_gart(); - if (unlikely(*dma_addr == DMA_MAPPING_ERROR)) + if (unlikely(dma_map_addr == DMA_MAPPING_ERROR)) goto out_free; + *dma_addr = dma_map_addr; return vaddr; out_free: dma_direct_free(dev, size, vaddr, *dma_addr, attrs);
gart_alloc_coherent() first allocates memory through dma_direct_alloc(), which returns a direct-mapped DMA address in dma_addr. When force_iommu is enabled, the buffer is then remapped. Do not overwrite dma_addr before dma_map_area() has succeeded. Keep the dma_map_area result in a temporary variable so the direct DMA address remains available for dma_direct_free() on the error path. Signed-off-by: Aneesh Kumar K.V (Arm) <aneesh.kumar@kernel.org> --- arch/x86/kernel/amd_gart_64.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-)