nvme-pci: clear the prp2 field when not used

stable inclusion
from stable-v5.10.160
commit 74b139c63f0775cf79266e9d9546c62b73fb3385
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I7P7OH

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=74b139c63f0775cf79266e9d9546c62b73fb3385

--------------------------------

[ Upstream commit a56ea614 ]

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: NLei Rao <lei.rao@intel.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: Nsanglipeng <sanglipeng1@jd.com>

drivers/nvme/host/pci.c

@@ -817,6 +817,8 @@ 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;
 }