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 E67C340876; Mon, 1 Apr 2024 16:50:40 +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=1711990241; cv=none; b=BcWOxHkwhrSMVG75owPSf0kIOCeaVc1cjZ04dEGTo99oiudH6J27BY9eITG6HmNjfploEZy/2wnm3Lb4NUbhuStRaqJ95gIPyeLHZi+zLMtIkvNiz95jiD9D137E29IuuDfrKFMFa6eZeYebN+5oqmQQ/kXwv7fkBEL1OyRQ/NQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711990241; c=relaxed/simple; bh=9+Wa5HP77h5phw56+vIBjCVHuCv6duYsTXPFHQuw47Q=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=WsJhPnkrlWe/C5QqlImykdfkufGQSbmklBhA38a0brBHTIQyoPNfV05ynuHVdq6bhbhoidht026RUjkvBPYs+Aw9YsPpEMgjAwdXWXu9TSY3NO/9z5fBhICP+GxprOkTCrEsDoM9f3R7ekO0LHj5ofZap78CsK+dChj5k+m2ZQ0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Rc9Iu0Km; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="Rc9Iu0Km" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 63D6FC433F1; Mon, 1 Apr 2024 16:50:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1711990240; bh=9+Wa5HP77h5phw56+vIBjCVHuCv6duYsTXPFHQuw47Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Rc9Iu0Kmk9b/YmhTD5gcgiyql2uBDoHQ+WW+NILWgQjDbDYJyb71E74YjXORW4NPr nw2zrY4CPh0IX4P130aQA7k4rg5B8DsUvMd/iOumovX2/XsTKiFjYPao56NElKTDGq 2H6s/TQOJqpjnWGv9NwluosPWHawX+DQoDSm4Fd4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Nicolin Chen , Will Deacon , Michael Kelley , Christoph Hellwig , Sasha Levin Subject: [PATCH 6.6 290/396] swiotlb: Fix alignment checks when both allocation and DMA masks are present Date: Mon, 1 Apr 2024 17:45:39 +0200 Message-ID: <20240401152556.550855173@linuxfoundation.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240401152547.867452742@linuxfoundation.org> References: <20240401152547.867452742@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Will Deacon [ Upstream commit 51b30ecb73b481d5fac6ccf2ecb4a309c9ee3310 ] Nicolin reports that swiotlb buffer allocations fail for an NVME device behind an IOMMU using 64KiB pages. This is because we end up with a minimum allocation alignment of 64KiB (for the IOMMU to map the buffer safely) but a minimum DMA alignment mask corresponding to a 4KiB NVME page (i.e. preserving the 4KiB page offset from the original allocation). If the original address is not 4KiB-aligned, the allocation will fail because swiotlb_search_pool_area() erroneously compares these unmasked bits with the 64KiB-aligned candidate allocation. Tweak swiotlb_search_pool_area() so that the DMA alignment mask is reduced based on the required alignment of the allocation. Fixes: 82612d66d51d ("iommu: Allow the dma-iommu api to use bounce buffers") Link: https://lore.kernel.org/r/cover.1707851466.git.nicolinc@nvidia.com Reported-by: Nicolin Chen Signed-off-by: Will Deacon Reviewed-by: Michael Kelley Tested-by: Nicolin Chen Tested-by: Michael Kelley Signed-off-by: Christoph Hellwig Signed-off-by: Sasha Levin --- kernel/dma/swiotlb.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index ded5a1f9e8f82..675ae318f74f8 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -981,8 +981,7 @@ static int swiotlb_area_find_slots(struct device *dev, struct io_tlb_pool *pool, dma_addr_t tbl_dma_addr = phys_to_dma_unencrypted(dev, pool->start) & boundary_mask; unsigned long max_slots = get_max_slots(boundary_mask); - unsigned int iotlb_align_mask = - dma_get_min_align_mask(dev) & ~(IO_TLB_SIZE - 1); + unsigned int iotlb_align_mask = dma_get_min_align_mask(dev); unsigned int nslots = nr_slots(alloc_size), stride; unsigned int offset = swiotlb_align_offset(dev, orig_addr); unsigned int index, slots_checked, count = 0, i; @@ -993,6 +992,14 @@ static int swiotlb_area_find_slots(struct device *dev, struct io_tlb_pool *pool, BUG_ON(!nslots); BUG_ON(area_index >= pool->nareas); + /* + * Ensure that the allocation is at least slot-aligned and update + * 'iotlb_align_mask' to ignore bits that will be preserved when + * offsetting into the allocation. + */ + alloc_align_mask |= (IO_TLB_SIZE - 1); + iotlb_align_mask &= ~alloc_align_mask; + /* * For mappings with an alignment requirement don't bother looping to * unaligned slots once we found an aligned one. -- 2.43.0