[PATCHv2 11/11] nvme: use fdp streams if write stream is provided

Keith Busch
2025-02-03T18:53:24Z

From: Keith Busch <kbusch@kernel.org>

Maps a user requested write stream to an FDP placement ID if possible.

Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Nitesh Shetty <nj.shetty@samsung.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
---
drivers/nvme/host/core.c | 31 ++++++++++++++++++++++++++++++-
drivers/nvme/host/nvme.h | 1 +
2 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index c8bc58b8ee3aa..d14c23916671d 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -674,6 +674,7 @@ static void nvme_free_ns_head(struct kref *ref)
ida_free(&head->subsys->ns_ida, head->instance);
cleanup_srcu_struct(&head->srcu);
nvme_put_subsystem(head->subsys);
+ kfree(head->plids);
kfree(head);
}

@@ -997,6 +998,18 @@ static inline blk_status_t nvme_setup_rw(struct nvme_ns *ns,
if (req->cmd_flags & REQ_RAHEAD)
dsmgmt |= NVME_RW_DSM_FREQ_PREFETCH;

+ if (op == nvme_cmd_write && ns->head->nr_plids) {
+ u16 write_stream = req->bio->bi_write_stream;
+
+ if (WARN_ON_ONCE(write_stream > ns->head->nr_plids))
+ return BLK_STS_INVAL;
+
+ if (write_stream) {
+ dsmgmt |= ns->head->plids[write_stream - 1] << 16;
+ control |= NVME_RW_DTYPE_DPLCMT;
+ }
+ }
+
if (req->cmd_flags & REQ_ATOMIC && !nvme_valid_atomic_write(req))
return BLK_STS_INVAL;

@@ -2241,7 +2254,7 @@ static int nvme_query_fdp_info(struct nvme_ns *ns, struct nvme_ns_info *info)
struct nvme_fdp_config fdp;
struct nvme_command c = {};
size_t size;
- int ret;
+ int i, ret;

/*
* The FDP configuration is static for the lifetime of the namespace,
@@ -2281,6 +2294,22 @@ static int nvme_query_fdp_info(struct nvme_ns *ns, struct nvme_ns_info *info)
}

head->nr_plids = le16_to_cpu(ruhs->nruhsd);
+ if (!head->nr_plids)
+ goto free;
+
+ head->plids = kcalloc(head->nr_plids, sizeof(head->plids),
+ GFP_KERNEL);
+ if (!head->plids) {
+ dev_warn(ctrl->device,
+ "failed to allocate %u FDP placement IDs\n",
+ head->nr_plids);
+ head->nr_plids = 0;
+ ret = -ENOMEM;
+ goto free;
+ }
+
+ for (i = 0; i < head->nr_plids; i++)
+ head->plids[i] = le16_to_cpu(ruhs->ruhsd[i].pid);
free:
kfree(ruhs);
return ret;
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index b63164cf6b274..59ba31c48cf66 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -498,6 +498,7 @@ struct nvme_ns_head {
struct gendisk *disk;

u16 nr_plids;
+ u16 *plids;
#ifdef CONFIG_NVME_MULTIPATH
struct bio_list requeue_list;
spinlock_t requeue_lock;
--
2.43.5