[PATCH 5.15.y 1/2] nvme: fix interpretation of DMRSL

[Sasha Levin <sashal@kernel.org>]

From: Tom Yan <tom.ty89@gmail.com>

[ Upstream commit 1a86924e4f464757546d7f7bdc469be237918395 ]

DMRSLl is in the unit of logical blocks, while max_discard_sectors is
in the unit of "linux sector".

Signed-off-by: Tom Yan <tom.ty89@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Stable-dep-of: 40f0496b617b ("nvme: respect NVME_QUIRK_DISABLE_WRITE_ZEROES when wzsl is set")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/nvme/host/core.c | 6 ++++--
 drivers/nvme/host/nvme.h | 1 +
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index f3071bd11fdd3..1e0a7baa77f56 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -1736,6 +1736,9 @@ static void nvme_config_discard(struct gendisk *disk, struct nvme_ns *ns)
 	if (blk_queue_flag_test_and_set(QUEUE_FLAG_DISCARD, queue))
 		return;
 
+	if (ctrl->dmrsl && ctrl->dmrsl <= nvme_sect_to_lba(ns, UINT_MAX))
+		ctrl->max_discard_sectors = nvme_lba_to_sect(ns, ctrl->dmrsl);
+
 	blk_queue_max_discard_sectors(queue, ctrl->max_discard_sectors);
 	blk_queue_max_discard_segments(queue, ctrl->max_discard_segments);
 
@@ -2948,8 +2951,7 @@ static int nvme_init_non_mdts_limits(struct nvme_ctrl *ctrl)
 
 	if (id->dmrl)
 		ctrl->max_discard_segments = id->dmrl;
-	if (id->dmrsl)
-		ctrl->max_discard_sectors = le32_to_cpu(id->dmrsl);
+	ctrl->dmrsl = le32_to_cpu(id->dmrsl);
 	if (id->wzsl)
 		ctrl->max_zeroes_sectors = nvme_mps_to_sectors(ctrl, id->wzsl);
 
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index c6cd3d65065c8..1a394ab8098ad 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -299,6 +299,7 @@ struct nvme_ctrl {
 #endif
 	u16 crdt[3];
 	u16 oncs;
+	u32 dmrsl;
 	u16 oacs;
 	u16 nssa;
 	u16 nr_streams;
-- 
2.53.0