[PATCH v3 4/7] nvme: register stream info with block layer

[Kanchan Joshi]

nvme registes number of streams with block layer, which will use that
for write-hint to streamid conversion. Registration is done for each
namespace. Since NVMe spec allow all available streams (within subsystem)
to be used by all namespaces, no attempt has been made to add reservation
at namespace level.

Signed-off-by: Kanchan Joshi <joshi.k@xxxxxxxxxxx>
---
 drivers/nvme/host/core.c | 19 ++++++-------------
 1 file changed, 6 insertions(+), 13 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 150e497..e34386b 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -513,14 +513,7 @@ static int nvme_configure_directives(struct nvme_ctrl *ctrl)
 		return ret;
 
 	ctrl->nssa = le16_to_cpu(s.nssa);
-	if (ctrl->nssa < BLK_MAX_WRITE_HINTS - 1) {
-		dev_info(ctrl->device, "too few streams (%u) available\n",
-					ctrl->nssa);
-		nvme_disable_streams(ctrl);
-		return 0;
-	}
-
-	ctrl->nr_streams = min_t(unsigned, ctrl->nssa, BLK_MAX_WRITE_HINTS - 1);
+	ctrl->nr_streams = ctrl->nssa;
 	dev_info(ctrl->device, "Using %u streams\n", ctrl->nr_streams);
 	return 0;
 }
@@ -533,12 +526,9 @@ static void nvme_assign_write_stream(struct nvme_ctrl *ctrl,
 				     struct request *req, u16 *control,
 				     u32 *dsmgmt)
 {
-	enum rw_hint streamid = req->write_hint;
+	enum rw_hint streamid = req->streamid;
 
-	if (streamid == WRITE_LIFE_NOT_SET || streamid == WRITE_LIFE_NONE)
-		streamid = 0;
-	else {
-		streamid--;
+	if (streamid != 0) {
 		if (WARN_ON_ONCE(streamid > ctrl->nr_streams))
 			return;
 
@@ -3138,6 +3128,7 @@ static int nvme_setup_streams_ns(struct nvme_ctrl *ctrl, struct nvme_ns *ns)
 {
 	struct streams_directive_params s;
 	int ret;
+	u16 nr_streams;
 
 	if (!ctrl->nr_streams)
 		return 0;
@@ -3149,6 +3140,8 @@ static int nvme_setup_streams_ns(struct nvme_ctrl *ctrl, struct nvme_ns *ns)
 	ns->sws = le32_to_cpu(s.sws);
 	ns->sgs = le16_to_cpu(s.sgs);
 
+	nr_streams = min_t(unsigned, ctrl->nr_streams, BLK_MAX_WRITE_HINTS - 1);
+	blk_queue_stream_limits(ns->queue, nr_streams);
 	if (ns->sws) {
 		unsigned int bs = 1 << ns->lba_shift;
 
-- 
2.7.4