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 93FF0C44523 for ; Fri, 17 Jul 2026 18:06:07 +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=A2xG7pWlX3DyXnh9sUcAESvn/UCw3OvXFeAcACc1di8=; b=WhWT1uF6t04CPka1hFTs+2/H1B H6yo+zw00gLWSf5/xzL/znKFVMyDgumQgSGYiRaygQCivpR1M7rFqwSkZY2pqbbL5mD78J9tQYQOd 7i9AZUU3OGu2p80PIFgX6uDm4je4EZpH2+zLVmsJyH2vnwt939fhD1rk72psKoXwQ9YXNc8xNzm74 wWytq0KhemNBJpWOiZ4AfaA9inJEzcyggK1PUrXT2lCUiN+IKUwIe2Im8lVol0/vZWvVt5rG9xgIh 5YTGMTMICcvVmnO4myl6ieUNqEFN/5TXbacEPqdCdmVeu80EwgNeYG6X1gwkiyEDbJCz6lgFztBGk Rds2yvLQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wkmwj-00000002wuP-247Q; Fri, 17 Jul 2026 18:06:01 +0000 Received: from sea.source.kernel.org ([172.234.252.31]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wkmwi-00000002wsY-17Wt for linux-arm-kernel@lists.infradead.org; Fri, 17 Jul 2026 18:06:00 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 0913743987; Fri, 17 Jul 2026 18:06:00 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DA8261F00A3A; Fri, 17 Jul 2026 18:05:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784311559; bh=A2xG7pWlX3DyXnh9sUcAESvn/UCw3OvXFeAcACc1di8=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=SF5vvtJO3IbG6SWDEmipvnsY5zIIKPP50kIEmreUNc+etmS+ZMoAWrFL1m2vhzKBE GmWBbg/bud2Wyo7Dwf91o5Z6k9jjSkd+KsHSejHMJhS0Pcxujm96j6y5ZE5UGVP2KW vcfvSblOJ7LEhbymOLpl8R+gkDSNRXUbzP9z2bh1zvMwVrCnHpHh8a/qXonVUZaQbl 7QBzqSiG+5JS8w9tuw2nAwGIG5napwdWBIvOCgjdD8Hdosi3yMghH+A4I6QazTK/Xg J/pBNma9rPOPgdR0nX1wj9vU9ODaSSv3pXdBbXng+bf/Yv+oPoEaTms2QqmDGqaG8l Zfum5zzJ3Sd8w== 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, Jason Gunthorpe , Michael Kelley Subject: [PATCH v8 05/23] swiotlb: Preserve allocation virtual address for dynamic pools Date: Fri, 17 Jul 2026 23:34:23 +0530 Message-ID: <20260717180442.110954-6-aneesh.kumar@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260717180442.110954-1-aneesh.kumar@kernel.org> References: <20260717180442.110954-1-aneesh.kumar@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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. Fixes: 79636caad361 ("swiotlb: if swiotlb is full, fall back to a transient memory pool") Reviewed-by: Jason Gunthorpe Tested-by: Michael Kelley Tested-by: Mostafa Saleh Reviewed-by: Petr Tesarik Signed-off-by: Aneesh Kumar K.V (Arm) --- kernel/dma/swiotlb.c | 31 +++++++++++++++++++------------ 1 file changed, 19 insertions(+), 12 deletions(-) diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index 1abd3e6146f4..6e8db52866bf 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -266,9 +266,9 @@ 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; @@ -409,7 +409,7 @@ 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) @@ -507,7 +507,7 @@ int swiotlb_init_late(size_t size, gfp_t gfp_mask, set_memory_decrypted((unsigned long)vstart, (nslabs << IO_TLB_SHIFT) >> PAGE_SHIFT); - 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); @@ -605,25 +605,26 @@ static struct page *alloc_dma_pages(gfp_t gfp, size_t bytes, u64 phys_limit) * @bytes: Size of the buffer. * @phys_limit: Maximum allowed physical address of the buffer. * @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, gfp_t gfp) + u64 phys_limit, 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) && dev && force_dma_unencrypted(dev)) { - 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, dma_coherent_ok); } @@ -645,6 +646,8 @@ 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; } @@ -685,6 +688,7 @@ 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; @@ -701,7 +705,8 @@ static struct io_tlb_pool *swiotlb_alloc_pool(struct device *dev, pool->areas = (void *)pool + sizeof(*pool); tlb_size = nslabs << IO_TLB_SHIFT; - while (!(tlb = swiotlb_alloc_tlb(dev, tlb_size, phys_limit, gfp))) { + while (!(tlb = swiotlb_alloc_tlb(dev, tlb_size, phys_limit, gfp, + &tlb_vaddr))) { if (nslabs <= minslabs) goto error_tlb; nslabs = ALIGN(nslabs >> 1, IO_TLB_SEGSIZE); @@ -715,11 +720,12 @@ 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); + swiotlb_free_tlb(tlb_vaddr, tlb_size); error_tlb: kfree(pool); error: @@ -1851,7 +1857,8 @@ static int rmem_swiotlb_device_init(struct reserved_mem *rmem, set_memory_decrypted((unsigned long)phys_to_virt(rmem->base), rmem->size >> PAGE_SHIFT); - 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