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 3718A45BE4; Mon, 1 Apr 2024 16:04:32 +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=1711987472; cv=none; b=maeyWdArwjHt3IbngPq8cbXTJWjnjGAul6dKG5WZNNrFWZTgh+Nk2tTJ8j96wcgfcRTQ8JMSFRi6tzkG8vDFDEMRRvzkc/3VNZ0kQAaonZZfYKXDwCsMDLQk97TO7aVRSueUMsyzvwwFWMYJt4F1Aj6z7VcdkdRd8c5KbGiKrvc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711987472; c=relaxed/simple; bh=p/lFXcWYnz3OsQLlgkfljt/5jjKuR5DuJuDCN6cu7yM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=NTmTvei+2pFjcu7fKmIGNPNJ6t0mC3nxb7AcRxuvKoUNKTugFqYIwASZNW2UDrKDKf3aqQNHl3OnztDHcOLjos11lIvqVZu5wVzIGewV0ZcHOD8NNmGpgknaGLNKoRoxKUa0c46lhgxPl32JwSksjroCVNRRECrWnunW9HTWDKM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ORtMY22i; 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="ORtMY22i" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B290EC433F1; Mon, 1 Apr 2024 16:04:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1711987472; bh=p/lFXcWYnz3OsQLlgkfljt/5jjKuR5DuJuDCN6cu7yM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ORtMY22irz5g5mWm9DeMGTQ0GJlgVHRdAwwwabpkL3PR9pmAqD5wMyb1BuPg0oPLq LHOlVreetZ86c75ntlRTe5kWrQLhflThOP2X+M4jah/KUaT/BsI8Jpesb459JW6eEo jg6udDl7NDg36heeaMKokCiBq+t2Eeg0MgSyiA3Q= 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 6.8 259/399] swiotlb: Fix alignment checks when both allocation and DMA masks are present Date: Mon, 1 Apr 2024 17:43:45 +0200 Message-ID: <20240401152556.904612505@linuxfoundation.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240401152549.131030308@linuxfoundation.org> References: <20240401152549.131030308@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 6.8-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 a619e22fecbf7..877c4b8fad195 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -981,8 +981,7 @@ static int swiotlb_search_pool_area(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_search_pool_area(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