[RFC PATCH V2 2/2] nvme: rdma: use ib_device's max_qp_wr to limit sqsize

[Guixin Liu <kanie@linux.alibaba.com>]

Currently, the host is limited to creating queues with a depth of
128. To enable larger queue sizes, constrain the sqsize based on
the ib_device's max_qp_wr capability.
In addition, the queue size is restricted between 16 and 1024 in
nvmf_parse_options(), so the final value of queue depth will not
biger than 1024.

And also remove unused NVME_RDMA_MAX_QUEUE_SIZE macro.

Signed-off-by: Guixin Liu <kanie@linux.alibaba.com>
---
 drivers/nvme/host/rdma.c  | 14 ++++++++------
 include/linux/nvme-rdma.h |  2 --
 2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/nvme/host/rdma.c b/drivers/nvme/host/rdma.c
index 81e2621..982f3e4 100644
--- a/drivers/nvme/host/rdma.c
+++ b/drivers/nvme/host/rdma.c
@@ -489,8 +489,7 @@ static int nvme_rdma_create_cq(struct ib_device *ibdev,
 static int nvme_rdma_create_queue_ib(struct nvme_rdma_queue *queue)
 {
 	struct ib_device *ibdev;
-	const int send_wr_factor = 3;			/* MR, SEND, INV */
-	const int cq_factor = send_wr_factor + 1;	/* + RECV */
+	const int cq_factor = NVME_RDMA_SEND_WR_FACTOR + 1;	/* + RECV */
 	int ret, pages_per_mr;
 
 	queue->device = nvme_rdma_find_get_device(queue->cm_id);
@@ -508,7 +507,7 @@ static int nvme_rdma_create_queue_ib(struct nvme_rdma_queue *queue)
 	if (ret)
 		goto out_put_dev;
 
-	ret = nvme_rdma_create_qp(queue, send_wr_factor);
+	ret = nvme_rdma_create_qp(queue, NVME_RDMA_SEND_WR_FACTOR);
 	if (ret)
 		goto out_destroy_ib_cq;
 
@@ -1006,6 +1005,7 @@ static int nvme_rdma_setup_ctrl(struct nvme_rdma_ctrl *ctrl, bool new)
 {
 	int ret;
 	bool changed;
+	int ib_max_qsize;
 
 	ret = nvme_rdma_configure_admin_queue(ctrl, new);
 	if (ret)
@@ -1030,11 +1030,13 @@ static int nvme_rdma_setup_ctrl(struct nvme_rdma_ctrl *ctrl, bool new)
 			ctrl->ctrl.opts->queue_size, ctrl->ctrl.sqsize + 1);
 	}
 
-	if (ctrl->ctrl.sqsize + 1 > NVME_RDMA_MAX_QUEUE_SIZE) {
+	ib_max_qsize = ctrl->device->dev->attrs.max_qp_wr /
+			(NVME_RDMA_SEND_WR_FACTOR + 1);
+	if (ctrl->ctrl.sqsize + 1 > ib_max_qsize) {
 		dev_warn(ctrl->ctrl.device,
 			"ctrl sqsize %u > max queue size %u, clamping down\n",
-			ctrl->ctrl.sqsize + 1, NVME_RDMA_MAX_QUEUE_SIZE);
-		ctrl->ctrl.sqsize = NVME_RDMA_MAX_QUEUE_SIZE - 1;
+			ctrl->ctrl.sqsize + 1, ib_max_qsize);
+		ctrl->ctrl.sqsize = ib_max_qsize - 1;
 	}
 
 	if (ctrl->ctrl.sqsize + 1 > ctrl->ctrl.maxcmd) {
diff --git a/include/linux/nvme-rdma.h b/include/linux/nvme-rdma.h
index c19858b..67ee770 100644
--- a/include/linux/nvme-rdma.h
+++ b/include/linux/nvme-rdma.h
@@ -6,8 +6,6 @@
 #ifndef _LINUX_NVME_RDMA_H
 #define _LINUX_NVME_RDMA_H
 
-#define NVME_RDMA_MAX_QUEUE_SIZE	128
-
 #define NVME_RDMA_SEND_WR_FACTOR 3  /* MR, SEND, INV */
 
 enum nvme_rdma_cm_fmt {
-- 
1.8.3.1