Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   Rishabh Bhatnagar <risbhat@amazon.com>
To:     <linux-kernel@vger.kernel.org>, <linux-nvme@lists.infradead.org>,
        <stable@vger.kernel.org>
CC:     <hch@lst.de>, <sagi@grimberg.me>, <axboe@fb.com>,
        <kbusch@kernel.org>, <mbacco@amazon.com>, <benh@amazon.com>,
        <sjpark@amazon.com>, "Rishabh Bhatnagar" <risbhat@amazon.com>
Subject: [PATCH v2] nvme-pci: Set min align mask before calculating max_hw_sectors
Date:   Thu, 29 Sep 2022 18:22:59 +0000
Message-ID: <20220929182259.22523-1-risbhat@amazon.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Content-Type: text/plain
Precedence: bulk

In cases where swiotlb is enabled dma_max_mapping_size takes into
account the min align mask for the device. Right now the mask is
set after the max hw sectors are calculated which might result in
a request size that overflows the swiotlb buffer.
Set the min align mask for nvme driver before calling
dma_max_mapping_size while calculating max hw sectors.

Fixes: 7637de311bd2 ("nvme-pci: limit max_hw_sectors based on the DMA max mapping size")
Cc: stable@vger.kernel.org
Signed-off-by: Rishabh Bhatnagar <risbhat@amazon.com>
---
 Changes in V2:
 - Add Cc: <stable@vger.kernel.org> tag
 - Improve the commit text
 - Add patch version

 Changes in V1:
 - Add fixes tag

 drivers/nvme/host/pci.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 98864b853eef..30e71e41a0a2 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -2834,6 +2834,8 @@ static void nvme_reset_work(struct work_struct *work)
 		nvme_start_admin_queue(&dev->ctrl);
 	}
 
+	dma_set_min_align_mask(dev->dev, NVME_CTRL_PAGE_SIZE - 1);
+
 	/*
 	 * Limit the max command size to prevent iod->sg allocations going
 	 * over a single page.
@@ -2846,7 +2848,6 @@ static void nvme_reset_work(struct work_struct *work)
 	 * Don't limit the IOMMU merged segment size.
 	 */
 	dma_set_max_seg_size(dev->dev, 0xffffffff);
-	dma_set_min_align_mask(dev->dev, NVME_CTRL_PAGE_SIZE - 1);
 
 	mutex_unlock(&dev->shutdown_lock);
 
-- 
2.37.1