Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Christoph Hellwig <hch@lst.de>,
        Atish Patra <Atish.Patra@wdc.com>,
        Sagi Grimberg <sagi@grimberg.me>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.2 133/215] nvme-pci: limit max_hw_sectors based on the DMA max mapping size
Date:   Mon, 29 Jul 2019 21:22:09 +0200
Message-Id: <20190729190802.565753706@linuxfoundation.org>
In-Reply-To: <20190729190739.971253303@linuxfoundation.org>
References: <20190729190739.971253303@linuxfoundation.org>
User-Agent: quilt/0.66
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

[ Upstream commit 7637de311bd2124b298a072852448b940d8a34b9 ]

When running a NVMe device that is attached to a addressing
challenged PCIe root port that requires bounce buffering, our
request sizes can easily overflow the swiotlb bounce buffer
size.  Limit the maximum I/O size to the limit exposed by
the DMA mapping subsystem.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reported-by: Atish Patra <Atish.Patra@wdc.com>
Tested-by: Atish Patra <Atish.Patra@wdc.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 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 245b6e2151c1..7fbcd72c438f 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -2521,7 +2521,8 @@ static void nvme_reset_work(struct work_struct *work)
 	 * Limit the max command size to prevent iod->sg allocations going
 	 * over a single page.
 	 */
-	dev->ctrl.max_hw_sectors = NVME_MAX_KB_SZ << 1;
+	dev->ctrl.max_hw_sectors = min_t(u32,
+		NVME_MAX_KB_SZ << 1, dma_max_mapping_size(dev->dev) >> 9);
 	dev->ctrl.max_segments = NVME_MAX_SEGS;
 
 	/*
-- 
2.20.1