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 8617A40876; Mon, 1 Apr 2024 17:07:40 +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=1711991260; cv=none; b=XSqo3zqTT8e42t98nj1u1i//38x/4izU8fOossgCwHlE3Dp/ifJuPvEJoo3AiapLzs7pUnP/VD5ZahPHCMmB/bCE7PmxlFS4TjMtoNmIwJNTuYFblkRz2x4RI8mohIe4JDCiQfe5gYJIIriOStft3bbxsTRVRdDZVGw0sZfwOuo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711991260; c=relaxed/simple; bh=3aqVHnoDRkNYGC5eyLAqIoLQTEdl1oQ3THHRrVPCDjY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=qfdIQSRnxw4R41sSufkdXtAsxUDLZMqJgpD+nFX3goaN7hyK83A+GToV6GSNwRTHHeRzOdiqbTHz9f5n02RxgZxXItIYYwU/DUXs8OfH6gCCe8U/96CaTCSigtgcUqTeY8oMGhMTWaLylV9B7CwEj2mAj8um777V5OPph7oSrvU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=tpElKnT8; 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="tpElKnT8" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EE2E6C433F1; Mon, 1 Apr 2024 17:07:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1711991260; bh=3aqVHnoDRkNYGC5eyLAqIoLQTEdl1oQ3THHRrVPCDjY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=tpElKnT8Z3IFYFARrOg8j1/zAZRCGhNLPqtkBjwAyCBsOlCvYr698vUq1u9EpP65r N0wzxwcy9e2Y8hIzG9e0zGGYJxem4x84kOHTR3q6I9pFQbrDfISfhFSONhndh2HXQd 3AlCKWRemTQ/HxJCfVTgRz0hv6pnpFAgru02A0fY= 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 6.1 182/272] swiotlb: Fix alignment checks when both allocation and DMA masks are present Date: Mon, 1 Apr 2024 17:46:12 +0200 Message-ID: <20240401152536.498310354@linuxfoundation.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240401152530.237785232@linuxfoundation.org> References: <20240401152530.237785232@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 6.1-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 ad6333c3fe1ff..db89ac94e7db4 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -654,8 +654,7 @@ static int swiotlb_do_find_slots(struct device *dev, int area_index, dma_addr_t tbl_dma_addr = phys_to_dma_unencrypted(dev, mem->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 index, wrap, count = 0, i; unsigned int offset = swiotlb_align_offset(dev, orig_addr); @@ -666,6 +665,14 @@ static int swiotlb_do_find_slots(struct device *dev, int area_index, BUG_ON(!nslots); BUG_ON(area_index >= mem->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. For allocations of -- 2.43.0