nvme: disable fabrics SQ flow control when asked by the user
As for now, we don't care about sq_head pointer updates anyway, so
at least allow the controller to micro-optimize by omiting this update.
Note that we will probably need to support it when a controller
that requires this comes along.
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/drivers/nvme/host/fabrics.c b/drivers/nvme/host/fabrics.c
index bd0969d..10074ac 100644
--- a/drivers/nvme/host/fabrics.c
+++ b/drivers/nvme/host/fabrics.c
@@ -392,6 +392,9 @@ int nvmf_connect_admin_queue(struct nvme_ctrl *ctrl)
cmd.connect.kato = ctrl->opts->discovery_nqn ? 0 :
cpu_to_le32((ctrl->kato + NVME_KATO_GRACE) * 1000);
+ if (ctrl->opts->disable_sqflow)
+ cmd.connect.cattr |= NVME_CONNECT_DISABLE_SQFLOW;
+
data = kzalloc(sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;
@@ -451,6 +454,9 @@ int nvmf_connect_io_queue(struct nvme_ctrl *ctrl, u16 qid)
cmd.connect.qid = cpu_to_le16(qid);
cmd.connect.sqsize = cpu_to_le16(ctrl->sqsize);
+ if (ctrl->opts->disable_sqflow)
+ cmd.connect.cattr |= NVME_CONNECT_DISABLE_SQFLOW;
+
data = kzalloc(sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;
@@ -607,6 +613,7 @@ static const match_table_t opt_tokens = {
{ NVMF_OPT_HOST_TRADDR, "host_traddr=%s" },
{ NVMF_OPT_HOST_ID, "hostid=%s" },
{ NVMF_OPT_DUP_CONNECT, "duplicate_connect" },
+ { NVMF_OPT_DISABLE_SQFLOW, "disable_sqflow" },
{ NVMF_OPT_ERR, NULL }
};
@@ -817,6 +824,9 @@ static int nvmf_parse_options(struct nvmf_ctrl_options *opts,
case NVMF_OPT_DUP_CONNECT:
opts->duplicate_connect = true;
break;
+ case NVMF_OPT_DISABLE_SQFLOW:
+ opts->disable_sqflow = true;
+ break;
default:
pr_warn("unknown parameter or missing value '%s' in ctrl creation request\n",
p);
@@ -933,7 +943,8 @@ EXPORT_SYMBOL_GPL(nvmf_free_options);
#define NVMF_REQUIRED_OPTS (NVMF_OPT_TRANSPORT | NVMF_OPT_NQN)
#define NVMF_ALLOWED_OPTS (NVMF_OPT_QUEUE_SIZE | NVMF_OPT_NR_IO_QUEUES | \
NVMF_OPT_KATO | NVMF_OPT_HOSTNQN | \
- NVMF_OPT_HOST_ID | NVMF_OPT_DUP_CONNECT)
+ NVMF_OPT_HOST_ID | NVMF_OPT_DUP_CONNECT |\
+ NVMF_OPT_DISABLE_SQFLOW)
static struct nvme_ctrl *
nvmf_create_ctrl(struct device *dev, const char *buf, size_t count)