From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5086434A78E; Mon, 27 Apr 2026 05:55:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777269357; cv=none; b=TQ+F/h4gQwSImlKVSLBljroqlvPhNiB6/ku4bAEl2qzb1BnD52QwqAe3hI07I8/ClWfuEt4pkrFyst+CnX5+QL6sd3t0D3yKtwYHU9BpsrCjHn1HJLZFotqCpW71ZwFcdh2kpn0oGjR/b4SYqA+ON8T2SyRnN1D57fyjqp8qYmw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777269357; c=relaxed/simple; bh=AKZl3hyjk4W1rC0aLWScXZTr07h4gBnRtI18zLYuxp0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=IweMIfyNMGlkuZQsfDykaRo1TXSVgHqP2BcQL5H5otwfC7CZUy9xDRW1STovsPv/MxikEaAP+xwBZbaVciRMWSoR3RDSyb6Uy2V9VPl1WTheZ3rq0qRqh2U5+ZkL8YJzKAoUa1AaFvppJUPDYtlsTArQ5ccoNqnP6rC4mLo2kY4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ohS2YRWY; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ohS2YRWY" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E3998C19425; Mon, 27 Apr 2026 05:55:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1777269356; bh=AKZl3hyjk4W1rC0aLWScXZTr07h4gBnRtI18zLYuxp0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ohS2YRWYZOk+mbH14uaSWgTPUGXxh4Fjfd/qMnTWcNvHdBrHlyGaAClhxAXqBr3ho kBT5YATwCKY3M9l8zfY0u4d17QGd3uRYkdGH+bYcDT27RiPO1jMn/RFYoG489rIX8G DfVVm/K1zoUiJOsskdlWJhSd96YUVQRud+2PQNxAf4zcqEJ7RmzQIUzjq3/R3Q2sC6 k3GnTWuQdcjv+U69NslnSgtxi6lFBOQPZPQTDR85IhVYj8wKSDA5SyWI0BqlFrzzFm 4oGA30DIDFg5n1X+4bCNcom4K7MasXk8hIE8kbHWKVctuE7NYm2kblH7CznpwaOEGe l4z3EESxvloww== From: "Aneesh Kumar K.V (Arm)" To: iommu@lists.linux.dev, linux-kernel@vger.kernel.org Cc: "Aneesh Kumar K.V (Arm)" , Robin Murphy , Marek Szyprowski , Will Deacon , Marc Zyngier , Steven Price , Suzuki K Poulose , Catalin Marinas , Jiri Pirko , Jason Gunthorpe , Mostafa Saleh , Petr Tesarik , Alexey Kardashevskiy , Dan Williams , Xu Yilun Subject: [PATCH v3 6/9] dma-direct: pass attrs to dma_capable() for DMA_ATTR_CC_SHARED checks Date: Mon, 27 Apr 2026 11:25:06 +0530 Message-ID: <20260427055509.898190-7-aneesh.kumar@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260427055509.898190-1-aneesh.kumar@kernel.org> References: <20260427055509.898190-1-aneesh.kumar@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Teach dma_capable() about DMA_ATTR_CC_SHARED so the capability check can reject encrypted DMA addresses for devices that require unencrypted/shared DMA. Also propagate DMA_ATTR_CC_SHARED in swiotlb_map() when the selected SWIOTLB pool is decrypted so the capability check sees the correct DMA address attribute. Signed-off-by: Aneesh Kumar K.V (Arm) --- arch/x86/kernel/amd_gart_64.c | 30 ++++++++++++++++-------------- drivers/xen/swiotlb-xen.c | 9 ++++++--- include/linux/dma-direct.h | 9 ++++++++- kernel/dma/direct.h | 6 +++--- kernel/dma/swiotlb.c | 8 +++++--- 5 files changed, 38 insertions(+), 24 deletions(-) diff --git a/arch/x86/kernel/amd_gart_64.c b/arch/x86/kernel/amd_gart_64.c index e8000a56732e..b5f1f031d45b 100644 --- a/arch/x86/kernel/amd_gart_64.c +++ b/arch/x86/kernel/amd_gart_64.c @@ -180,22 +180,23 @@ static void iommu_full(struct device *dev, size_t size, int dir) } static inline int -need_iommu(struct device *dev, unsigned long addr, size_t size) +need_iommu(struct device *dev, unsigned long addr, size_t size, unsigned long attrs) { - return force_iommu || !dma_capable(dev, addr, size, true); + return force_iommu || !dma_capable(dev, addr, size, true, attrs); } static inline int -nonforced_iommu(struct device *dev, unsigned long addr, size_t size) +nonforced_iommu(struct device *dev, unsigned long addr, size_t size, + unsigned long attrs) { - return !dma_capable(dev, addr, size, true); + return !dma_capable(dev, addr, size, true, attrs); } /* Map a single continuous physical area into the IOMMU. * Caller needs to check if the iommu is needed and flush. */ static dma_addr_t dma_map_area(struct device *dev, dma_addr_t phys_mem, - size_t size, int dir, unsigned long align_mask) + size_t size, int dir, unsigned long align_mask, unsigned long attrs) { unsigned long npages = iommu_num_pages(phys_mem, size, PAGE_SIZE); unsigned long iommu_page; @@ -206,7 +207,7 @@ static dma_addr_t dma_map_area(struct device *dev, dma_addr_t phys_mem, iommu_page = alloc_iommu(dev, npages, align_mask); if (iommu_page == -1) { - if (!nonforced_iommu(dev, phys_mem, size)) + if (!nonforced_iommu(dev, phys_mem, size, attrs)) return phys_mem; if (panic_on_overflow) panic("dma_map_area overflow %lu bytes\n", size); @@ -231,10 +232,10 @@ static dma_addr_t gart_map_phys(struct device *dev, phys_addr_t paddr, if (unlikely(attrs & DMA_ATTR_MMIO)) return DMA_MAPPING_ERROR; - if (!need_iommu(dev, paddr, size)) + if (!need_iommu(dev, paddr, size, attrs)) return paddr; - bus = dma_map_area(dev, paddr, size, dir, 0); + bus = dma_map_area(dev, paddr, size, dir, 0, attrs); flush_gart(); return bus; @@ -289,7 +290,7 @@ static void gart_unmap_sg(struct device *dev, struct scatterlist *sg, int nents, /* Fallback for dma_map_sg in case of overflow */ static int dma_map_sg_nonforce(struct device *dev, struct scatterlist *sg, - int nents, int dir) + int nents, int dir, unsigned long attrs) { struct scatterlist *s; int i; @@ -301,8 +302,8 @@ static int dma_map_sg_nonforce(struct device *dev, struct scatterlist *sg, for_each_sg(sg, s, nents, i) { unsigned long addr = sg_phys(s); - if (nonforced_iommu(dev, addr, s->length)) { - addr = dma_map_area(dev, addr, s->length, dir, 0); + if (nonforced_iommu(dev, addr, s->length, attrs)) { + addr = dma_map_area(dev, addr, s->length, dir, 0, attrs); if (addr == DMA_MAPPING_ERROR) { if (i > 0) gart_unmap_sg(dev, sg, i, dir, 0); @@ -401,7 +402,7 @@ static int gart_map_sg(struct device *dev, struct scatterlist *sg, int nents, s->dma_address = addr; BUG_ON(s->length == 0); - nextneed = need_iommu(dev, addr, s->length); + nextneed = need_iommu(dev, addr, s->length, attrs); /* Handle the previous not yet processed entries */ if (i > start) { @@ -449,7 +450,7 @@ static int gart_map_sg(struct device *dev, struct scatterlist *sg, int nents, /* When it was forced or merged try again in a dumb way */ if (force_iommu || iommu_merge) { - out = dma_map_sg_nonforce(dev, sg, nents, dir); + out = dma_map_sg_nonforce(dev, sg, nents, dir, attrs); if (out > 0) return out; } @@ -473,7 +474,8 @@ gart_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_addr, return vaddr; *dma_addr = dma_map_area(dev, virt_to_phys(vaddr), size, - DMA_BIDIRECTIONAL, (1UL << get_order(size)) - 1); + DMA_BIDIRECTIONAL, + (1UL << get_order(size)) - 1, attrs); flush_gart(); if (unlikely(*dma_addr == DMA_MAPPING_ERROR)) goto out_free; diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c index 2cbf2b588f5b..7584c6f42141 100644 --- a/drivers/xen/swiotlb-xen.c +++ b/drivers/xen/swiotlb-xen.c @@ -212,7 +212,7 @@ static dma_addr_t xen_swiotlb_map_phys(struct device *dev, phys_addr_t phys, BUG_ON(dir == DMA_NONE); if (attrs & DMA_ATTR_MMIO) { - if (unlikely(!dma_capable(dev, phys, size, false))) { + if (unlikely(!dma_capable(dev, phys, size, false, attrs))) { dev_err_once( dev, "DMA addr %pa+%zu overflow (mask %llx, bus limit %llx).\n", @@ -231,7 +231,7 @@ static dma_addr_t xen_swiotlb_map_phys(struct device *dev, phys_addr_t phys, * we can safely return the device addr and not worry about bounce * buffering it. */ - if (dma_capable(dev, dev_addr, size, true) && + if (dma_capable(dev, dev_addr, size, true, attrs) && !dma_kmalloc_needs_bounce(dev, size, dir) && !range_straddles_page_boundary(phys, size) && !xen_arch_need_swiotlb(dev, phys, dev_addr) && @@ -250,10 +250,13 @@ static dma_addr_t xen_swiotlb_map_phys(struct device *dev, phys_addr_t phys, phys = map; dev_addr = xen_phys_to_dma(dev, map); + if (dev->dma_io_tlb_mem->decrypted) + attrs |= DMA_ATTR_CC_SHARED; + /* * Ensure that the address returned is DMA'ble */ - if (unlikely(!dma_capable(dev, dev_addr, size, true))) { + if (unlikely(!dma_capable(dev, dev_addr, size, true, attrs))) { __swiotlb_tbl_unmap_single(dev, map, size, dir, attrs | DMA_ATTR_SKIP_CPU_SYNC, swiotlb_find_pool(dev, map)); diff --git a/include/linux/dma-direct.h b/include/linux/dma-direct.h index 94fad4e7c11e..1281d91050a4 100644 --- a/include/linux/dma-direct.h +++ b/include/linux/dma-direct.h @@ -135,12 +135,19 @@ static inline bool force_dma_unencrypted(struct device *dev) #endif /* CONFIG_ARCH_HAS_FORCE_DMA_UNENCRYPTED */ static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size, - bool is_ram) + bool is_ram, unsigned long attrs) { dma_addr_t end = addr + size - 1; if (addr == DMA_MAPPING_ERROR) return false; + /* + * if phys addr attribute is encrypted but the + * device is forcing an encrypted dma addr + */ + if (!(attrs & DMA_ATTR_CC_SHARED) && force_dma_unencrypted(dev)) + return false; + if (is_ram && !IS_ENABLED(CONFIG_ARCH_DMA_ADDR_T_64BIT) && min(addr, end) < phys_to_dma(dev, PFN_PHYS(min_low_pfn))) return false; diff --git a/kernel/dma/direct.h b/kernel/dma/direct.h index 7140c208c123..e05dc7649366 100644 --- a/kernel/dma/direct.h +++ b/kernel/dma/direct.h @@ -101,15 +101,15 @@ static inline dma_addr_t dma_direct_map_phys(struct device *dev, if (attrs & DMA_ATTR_MMIO) { dma_addr = phys; - if (unlikely(!dma_capable(dev, dma_addr, size, false))) + if (unlikely(!dma_capable(dev, dma_addr, size, false, attrs))) goto err_overflow; } else if (attrs & DMA_ATTR_CC_SHARED) { dma_addr = phys_to_dma_unencrypted(dev, phys); - if (unlikely(!dma_capable(dev, dma_addr, size, false))) + if (unlikely(!dma_capable(dev, dma_addr, size, false, attrs))) goto err_overflow; } else { dma_addr = phys_to_dma(dev, phys); - if (unlikely(!dma_capable(dev, dma_addr, size, true)) || + if (unlikely(!dma_capable(dev, dma_addr, size, true, attrs)) || dma_kmalloc_needs_bounce(dev, size, dir)) { if (is_swiotlb_active(dev) && !(attrs & DMA_ATTR_REQUIRE_COHERENT)) diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index dad351988daf..0d3ae9a0130a 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -1640,12 +1640,14 @@ dma_addr_t swiotlb_map(struct device *dev, phys_addr_t paddr, size_t size, /* * Use the allocated io_tlb_mem encryption type to determine dma addr. */ - if (dev->dma_io_tlb_mem->decrypted) + if (dev->dma_io_tlb_mem->decrypted) { dma_addr = phys_to_dma_unencrypted(dev, swiotlb_addr); - else + attrs |= DMA_ATTR_CC_SHARED; + } else { dma_addr = phys_to_dma_encrypted(dev, swiotlb_addr); + } - if (unlikely(!dma_capable(dev, dma_addr, size, true))) { + if (unlikely(!dma_capable(dev, dma_addr, size, true, attrs))) { __swiotlb_tbl_unmap_single(dev, swiotlb_addr, size, dir, attrs | DMA_ATTR_SKIP_CPU_SYNC, swiotlb_find_pool(dev, swiotlb_addr)); -- 2.43.0