nvme-pci: clear the prp2 field when not used

[ Upstream commit a56ea6147facce4ac1fc38675455f9733d96232b ]

If the prp2 field is not filled in nvme_setup_prp_simple(), the prp2
field is garbage data. According to nvme spec, the prp2 is reserved if
the data transfer does not cross a memory page boundary, so clear it to
zero if it is not used.

Signed-off-by: Lei Rao <lei.rao@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 772bdc6..d49df71 100644 (file)
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -814,6 +814,8 @@ static blk_status_t nvme_setup_prp_simple(struct nvme_dev *dev,
        cmnd->dptr.prp1 = cpu_to_le64(iod->first_dma);
        if (bv->bv_len > first_prp_len)
                cmnd->dptr.prp2 = cpu_to_le64(iod->first_dma + first_prp_len);
+       else
+               cmnd->dptr.prp2 = 0;
        return BLK_STS_OK;
 }