From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 9B553CD4F5B for ; Fri, 22 May 2026 04:32:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=PnWTr5M4G1txOK8iaNSiBBsCv6diWB65cB7qFD+glq0=; b=goCruFZBFGMagWJzflfNV3ZhMa /koIqGDpuzIPWzdTfYLB/wFCLHj/Y9XTuuedMqhDQ2FHHXsTGa9MnefpazwTU2LE0Cy+cOQ/3aHlC l2cM2S28WLbwqDInIWXTNCXvtiP8WTK1nO2K86ltiyXv7yDfsHLmSHF+ZYY9tl/29NisTVHWQU2gK 9FkdV79MQz+jlPOD9AEnncn4577HDaK/5srpkwskd/+DpoQIDPo65QjfON0lhQZugFhzuPNVj/fy1 txLEtdHXb5tL/LbHJ+LvavNO0hdAUhzW20VOXK1B99tYRTTeoTHvj3FUaxnXZz733LnjqDGFZVj1l pEjcVkPg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wQHYg-00000009lAB-1M2j; Fri, 22 May 2026 04:32:26 +0000 Received: from sea.source.kernel.org ([2600:3c0a:e001:78e:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wQHYd-00000009l8e-28lw for linux-arm-kernel@lists.infradead.org; Fri, 22 May 2026 04:32:25 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 30ADB43480; Fri, 22 May 2026 04:32:23 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A6AC31F00A3D; Fri, 22 May 2026 04:32:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1779424343; bh=PnWTr5M4G1txOK8iaNSiBBsCv6diWB65cB7qFD+glq0=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=N1Lo4X9/X/2KPv5cK2+3UKHdUXj1cGz7UQ49YpR4OgSBfR0+o5/zbRv9Z7cltDb50 FwgTU/8k/2hexHUy4YbuJemEE6lSzfhi66i39msOSQ4Bz6GNyATpcOm1rMYcXf9OWR clSxELElIXK8J5eNJg8255eiDlYEt34uyOkGHxaOA8zTgaijkHvaF4GQFHLw9OI/+1 a3X51B2vggGH+Uo3Y7IFjEncwGqJZZBJcVWIhpJCeRKnOYZ/QJLuxl5i5wYmtzgx/h 1Av8uIqZ12flfvo+MlDQ6FpOex14s+fq2H0CWER71C8OgvcFFRmUhvSte73qn524+a UwGNG8l5DiBgA== 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 Subject: [PATCH v5 20/20] swiotlb: Preserve allocation virtual address for dynamic pools Date: Fri, 22 May 2026 09:58:15 +0530 Message-ID: <20260522042815.370873-21-aneesh.kumar@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260522042815.370873-1-aneesh.kumar@kernel.org> References: <20260522042815.370873-1-aneesh.kumar@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260521_213224_097612_60D458AF X-CRM114-Status: GOOD ( 17.00 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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. 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