From b45e3d35e2df444878d62ce241a4e53a83ebd36c Mon Sep 17 00:00:00 2001 From: "Aneesh Kumar K.V (Arm)" Date: Fri, 17 Jul 2026 23:34:32 +0530 Subject: [PATCH] dma-mapping: make dma_pgprot() honor __DMA_ATTR_ALLOC_CC_SHARED Fold encrypted/decrypted pgprot selection into dma_pgprot() so callers do not need to adjust the page protection separately. Update dma_pgprot() to apply pgprot_decrypted() when DMA_ATTR_CC_SHARED or __DMA_ATTR_ALLOC_CC_SHARED is set and pgprot_encrypted() otherwise Convert the dma-direct mmap paths to pass DMA_ATTR_CC_SHARED instead of open-coding force_dma_unencrypted() handling around dma_pgprot(). Reviewed-by: Jason Gunthorpe Tested-by: Jiri Pirko Tested-by: Michael Kelley Tested-by: Mostafa Saleh Signed-off-by: Aneesh Kumar K.V (Arm) Link: https://lore.kernel.org/r/20260717180442.110954-15-aneesh.kumar@kernel.org Signed-off-by: Marek Szyprowski --- kernel/dma/direct.c | 8 +++----- kernel/dma/mapping.c | 16 ++++++++++++---- 2 files changed, 15 insertions(+), 9 deletions(-) diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c index c6561ed05cb0..b58bd1610aff 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -286,9 +286,6 @@ void *dma_direct_alloc(struct device *dev, size_t size, if (remap) { pgprot_t prot = dma_pgprot(dev, PAGE_KERNEL, attrs); - if (force_dma_unencrypted(dev)) - prot = pgprot_decrypted(prot); - /* remove any dirty cache lines on the kernel alias */ arch_dma_prep_coherent(page, size); @@ -608,9 +605,10 @@ int dma_direct_mmap(struct device *dev, struct vm_area_struct *vma, unsigned long pfn = PHYS_PFN(dma_to_phys(dev, dma_addr)); int ret = -ENXIO; - vma->vm_page_prot = dma_pgprot(dev, vma->vm_page_prot, attrs); if (force_dma_unencrypted(dev)) - vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot); + attrs |= DMA_ATTR_CC_SHARED; + + vma->vm_page_prot = dma_pgprot(dev, vma->vm_page_prot, attrs); if (dma_mmap_from_dev_coherent(dev, vma, cpu_addr, size, &ret)) return ret; diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c index d2f70b6ccd0f..a628820fd10e 100644 --- a/kernel/dma/mapping.c +++ b/kernel/dma/mapping.c @@ -537,13 +537,21 @@ EXPORT_SYMBOL(dma_get_sgtable_attrs); */ pgprot_t dma_pgprot(struct device *dev, pgprot_t prot, unsigned long attrs) { + pgprot_t dma_prot; + if (dev_is_dma_coherent(dev)) - return prot; + dma_prot = prot; #ifdef CONFIG_ARCH_HAS_DMA_WRITE_COMBINE - if (attrs & DMA_ATTR_WRITE_COMBINE) - return pgprot_writecombine(prot); + else if (attrs & DMA_ATTR_WRITE_COMBINE) + dma_prot = pgprot_writecombine(prot); #endif - return pgprot_dmacoherent(prot); + else + dma_prot = pgprot_dmacoherent(prot); + + if (attrs & (DMA_ATTR_CC_SHARED | __DMA_ATTR_ALLOC_CC_SHARED)) + return pgprot_decrypted(dma_prot); + else + return pgprot_encrypted(dma_prot); } #endif /* CONFIG_MMU */