Propagate force_dma_unencrypted() into DMA_ATTR_CC_SHARED in the dma-direct allocation path and use the attribute to drive the related decisions.
This updates dma_direct_alloc(), dma_direct_free(), and dma_direct_alloc_pages() to fold the forced unencrypted case into attrs. Signed-off-by: Aneesh Kumar K.V (Arm) <[email protected]> --- kernel/dma/direct.c | 44 ++++++++++++++++++++++++++++++++++++-------- 1 file changed, 36 insertions(+), 8 deletions(-) diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c index b958f150718a..0c2e1f8436ce 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -201,16 +201,31 @@ void *dma_direct_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs) { bool remap = false, set_uncached = false; - bool mark_mem_decrypt = true; + bool mark_mem_decrypt = false; struct page *page; void *ret; + /* + * DMA_ATTR_CC_SHARED is not a caller-visible dma_alloc_*() + * attribute. The direct allocator uses it internally after it has + * decided that the backing pages must be shared/decrypted, so the + * rest of the allocation path can consistently select DMA addresses, + * choose compatible pools and restore encryption on free. + */ + if (attrs & DMA_ATTR_CC_SHARED) + return NULL; + + if (force_dma_unencrypted(dev)) { + attrs |= DMA_ATTR_CC_SHARED; + mark_mem_decrypt = true; + } + size = PAGE_ALIGN(size); if (attrs & DMA_ATTR_NO_WARN) gfp |= __GFP_NOWARN; - if ((attrs & DMA_ATTR_NO_KERNEL_MAPPING) && - !force_dma_unencrypted(dev) && !is_swiotlb_for_alloc(dev)) + if (((attrs & (DMA_ATTR_NO_KERNEL_MAPPING | DMA_ATTR_CC_SHARED)) == + DMA_ATTR_NO_KERNEL_MAPPING) && !is_swiotlb_for_alloc(dev)) return dma_direct_alloc_no_mapping(dev, size, dma_handle, gfp); if (!dev_is_dma_coherent(dev)) { @@ -244,7 +259,7 @@ void *dma_direct_alloc(struct device *dev, size_t size, * Remapping or decrypting memory may block, allocate the memory from * the atomic pools instead if we aren't allowed block. */ - if ((remap || force_dma_unencrypted(dev)) && + if ((remap || (attrs & DMA_ATTR_CC_SHARED)) && dma_direct_use_pool(dev, gfp)) return dma_direct_alloc_from_pool(dev, size, dma_handle, gfp); @@ -318,11 +333,20 @@ void *dma_direct_alloc(struct device *dev, size_t size, void dma_direct_free(struct device *dev, size_t size, void *cpu_addr, dma_addr_t dma_addr, unsigned long attrs) { - bool mark_mem_encrypted = true; + bool mark_mem_encrypted = false; unsigned int page_order = get_order(size); - if ((attrs & DMA_ATTR_NO_KERNEL_MAPPING) && - !force_dma_unencrypted(dev) && !is_swiotlb_for_alloc(dev)) { + /* + * if the device had requested for an unencrypted buffer, + * convert it to encrypted on free + */ + if (force_dma_unencrypted(dev)) { + attrs |= DMA_ATTR_CC_SHARED; + mark_mem_encrypted = true; + } + + if (((attrs & (DMA_ATTR_NO_KERNEL_MAPPING | DMA_ATTR_CC_SHARED)) == + DMA_ATTR_NO_KERNEL_MAPPING) && !is_swiotlb_for_alloc(dev)) { /* cpu_addr is a struct page cookie, not a kernel address */ dma_free_contiguous(dev, cpu_addr, size); return; @@ -365,10 +389,14 @@ void dma_direct_free(struct device *dev, size_t size, struct page *dma_direct_alloc_pages(struct device *dev, size_t size, dma_addr_t *dma_handle, enum dma_data_direction dir, gfp_t gfp) { + unsigned long attrs = 0; struct page *page; void *ret; - if (force_dma_unencrypted(dev) && dma_direct_use_pool(dev, gfp)) + if (force_dma_unencrypted(dev)) + attrs |= DMA_ATTR_CC_SHARED; + + if ((attrs & DMA_ATTR_CC_SHARED) && dma_direct_use_pool(dev, gfp)) return dma_direct_alloc_from_pool(dev, size, dma_handle, gfp); if (is_swiotlb_for_alloc(dev)) { -- 2.43.0
