From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 279D53E1224; Thu, 4 Jun 2026 08:43:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780562589; cv=none; b=GkYm74GArQmJp01MI3GgWlSNUyyRqsEA3onQHV2TYlKiKL6hQt0aWDOKowTItNml6VZ3zKR4zjAcFMRoiTlBYFp77ere8cSb3eljOyRHn2v4yq7ZAa5B6FfW7klNC10UtuCQlTA2ld7/isj1ix5T119AMF7eGVCEyTWRGUydsFU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780562589; c=relaxed/simple; bh=TegZPjM3rQ+HL/D+iEWYjVCfP3sBZRjsMLXnOkhdCHY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=O777Bcy3Ontk1Xj8ti+nlfzLvfhvKFzKFZl8NAu71souscijAsvw3QWlhE5lJOdSJSRz4bPpdbkB+1rBkULSA3y0c2Qckbm5pTdkRHjv5CVZVYK6kQJ79HiOlShZx41/qvmDE8+yvAARbaNRIbiEExUozyYFqecuxClhebN7RB8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=nB9gQ4aF; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="nB9gQ4aF" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 44D721F00893; Thu, 4 Jun 2026 08:42:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1780562587; bh=28gAGxAT6yyFPOrZbknmeVeC1tPuyb3t0ezhz06WVCM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=nB9gQ4aFlKUpGUcihtsmI/cFkRNvSLQlBMVfFfId6za3U9oIZifeElqfvJ/gMMYLV kK9nLDYi/76JeTYI0eOMh6Ev87PICHvhy0d1ZKgpW4V7V0HhFFF5pltK8QUwBgbaaU AfTbyxMYiMbryQfwJ65A2G2jc3RkvI/TeFKscmT4OobGaUuPuVSaPsf+Y9qMoAzQ+w qQShsxWWYTx1w+YWqV2DLGX6UxvSmK9OjRoCDsr0peBDdamrU4PWYXtZy55sxBwaSo WpS//rd8RA5c1c8l+zl23/OHY/f2k3XfRfr004sW3x9c754aQDpKx39tz9vKXx6uZO kzFmq6SY4lRqw== From: "Aneesh Kumar K.V (Arm)" To: iommu@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-coco@lists.linux.dev 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 , linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, Madhavan Srinivasan , Michael Ellerman , Nicholas Piggin , "Christophe Leroy (CS GROUP)" , Alexander Gordeev , Gerald Schaefer , Heiko Carstens , Vasily Gorbik , Christian Borntraeger , Sven Schnelle , x86@kernel.org, Michael Kelley Subject: [PATCH v6 19/20] swiotlb: Preserve allocation virtual address for dynamic pools Date: Thu, 4 Jun 2026 14:09:58 +0530 Message-ID: <20260604083959.1265923-20-aneesh.kumar@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260604083959.1265923-1-aneesh.kumar@kernel.org> References: <20260604083959.1265923-1-aneesh.kumar@kernel.org> Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit swiotlb_alloc_tlb() can allocate from the DMA atomic pool when a decrypted pool is needed from atomic context. With CONFIG_DMA_DIRECT_REMAP, the atomic pool is backed by remapped virtual addresses, which are not the same as the direct-map addresses returned by phys_to_virt(). swiotlb_init_io_tlb_pool() currently reconstructs the pool virtual address from the physical start address. For atomic-pool backed allocations this stores the wrong address in pool->vaddr. Later, swiotlb_free_tlb() passes that address to dma_free_from_pool(), which will fail to recognize the chunk Pass the virtual address returned by the allocation path into swiotlb_init_io_tlb_pool(), and store that address in pool->vaddr. This keeps the pool free path using the same virtual address as the allocator. Tested-by: Michael Kelley Tested-by: Mostafa Saleh Signed-off-by: Aneesh Kumar K.V (Arm) --- kernel/dma/swiotlb.c | 32 +++++++++++++++++++------------- 1 file changed, 19 insertions(+), 13 deletions(-) diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index 14d834ca298b..e4bd8c9eaeda 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -302,9 +302,9 @@ void __init swiotlb_update_mem_attributes(void) } static void swiotlb_init_io_tlb_pool(struct io_tlb_pool *mem, phys_addr_t start, - unsigned long nslabs, bool late_alloc, unsigned int nareas) + void *vaddr, unsigned long nslabs, bool late_alloc, + unsigned int nareas) { - void *vaddr = phys_to_virt(start); unsigned long bytes = nslabs << IO_TLB_SHIFT, i; mem->nslabs = nslabs; @@ -445,7 +445,7 @@ void __init swiotlb_init_remap(bool addressing_limit, unsigned int flags, return; } - swiotlb_init_io_tlb_pool(mem, __pa(tlb), nslabs, false, nareas); + swiotlb_init_io_tlb_pool(mem, __pa(tlb), tlb, nslabs, false, nareas); add_mem_pool(&io_tlb_default_mem, mem); if (flags & SWIOTLB_VERBOSE) @@ -553,7 +553,7 @@ int swiotlb_init_late(size_t size, gfp_t gfp_mask, } } - swiotlb_init_io_tlb_pool(mem, virt_to_phys(vstart), nslabs, true, + swiotlb_init_io_tlb_pool(mem, virt_to_phys(vstart), vstart, nslabs, true, nareas); add_mem_pool(&io_tlb_default_mem, mem); @@ -664,25 +664,26 @@ static struct page *alloc_dma_pages(gfp_t gfp, size_t bytes, * @phys_limit: Maximum allowed physical address of the buffer. * @attrs: DMA attributes for the allocation. * @gfp: GFP flags for the allocation. + * @vaddr: Receives the virtual address for the allocated buffer. * * Return: Allocated pages, or %NULL on allocation failure. */ static struct page *swiotlb_alloc_tlb(struct device *dev, size_t bytes, - u64 phys_limit, unsigned long attrs, gfp_t gfp) + u64 phys_limit, unsigned long attrs, gfp_t gfp, void **vaddr) { struct page *page; + *vaddr = NULL; + /* * Allocate from the atomic pools if memory is encrypted and * the allocation is atomic, because decrypting may block. */ if (!gfpflags_allow_blocking(gfp) && (attrs & DMA_ATTR_CC_SHARED)) { - void *vaddr; - if (!IS_ENABLED(CONFIG_DMA_COHERENT_POOL)) return NULL; - return dma_alloc_from_pool(dev, bytes, &vaddr, gfp, + return dma_alloc_from_pool(dev, bytes, vaddr, gfp, attrs, dma_coherent_ok); } @@ -705,6 +706,8 @@ static struct page *swiotlb_alloc_tlb(struct device *dev, size_t bytes, return NULL; } + if (page) + *vaddr = phys_to_virt(page_to_phys(page)); return page; } @@ -750,6 +753,7 @@ static struct io_tlb_pool *swiotlb_alloc_pool(struct device *dev, { struct io_tlb_pool *pool; unsigned int slot_order; + void *tlb_vaddr; struct page *tlb; size_t pool_size; size_t tlb_size; @@ -767,7 +771,8 @@ static struct io_tlb_pool *swiotlb_alloc_pool(struct device *dev, pool->unencrypted = !!(attrs & DMA_ATTR_CC_SHARED); tlb_size = nslabs << IO_TLB_SHIFT; - while (!(tlb = swiotlb_alloc_tlb(dev, tlb_size, phys_limit, attrs, gfp))) { + while (!(tlb = swiotlb_alloc_tlb(dev, tlb_size, phys_limit, attrs, gfp, + &tlb_vaddr))) { if (nslabs <= minslabs) goto error_tlb; nslabs = ALIGN(nslabs >> 1, IO_TLB_SEGSIZE); @@ -781,12 +786,12 @@ static struct io_tlb_pool *swiotlb_alloc_pool(struct device *dev, if (!pool->slots) goto error_slots; - swiotlb_init_io_tlb_pool(pool, page_to_phys(tlb), nslabs, true, nareas); + swiotlb_init_io_tlb_pool(pool, page_to_phys(tlb), tlb_vaddr, nslabs, + true, nareas); return pool; error_slots: - swiotlb_free_tlb(page_address(tlb), tlb_size, - !!(attrs & DMA_ATTR_CC_SHARED)); + swiotlb_free_tlb(tlb_vaddr, tlb_size, !!(attrs & DMA_ATTR_CC_SHARED)); error_tlb: kfree(pool); error: @@ -1995,7 +2000,8 @@ static int rmem_swiotlb_device_init(struct reserved_mem *rmem, mem->unencrypted = false; } - swiotlb_init_io_tlb_pool(pool, rmem->base, nslabs, + swiotlb_init_io_tlb_pool(pool, rmem->base, phys_to_virt(rmem->base), + nslabs, false, nareas); mem->force_bounce = true; mem->for_alloc = true; -- 2.43.0