Subject: [for-next v2 13/17] net/mlx5: Use mlx5_cmd_do() in core create_{cq,dct}

From: Saeed Mahameed <[email-masked]>
Date: Wed, 23 Feb 2022 15:39:26 -0800

From: Saeed Mahameed <[email-masked]>

mlx5_core_create_{cq/dct} functions are non-trivial mlx5 commands
functions. They check command execution status themselves and hide
valuable FW failure information.

For mlx5_core/eth kernel user this is what we actually want, but for a
devx/rdma user the hidden information is essential and should be propagated
up to the caller, thus we convert these commands to use mlx5_cmd_do
to return the FW/driver and command outbox status as is, and let the caller
decide what to do with it.

For kernel callers of mlx5_core_create_{cq/dct} or those who only care about
the binary status (FAIL/SUCCESS) they must check status themselves via
mlx5_cmd_check() to restore the current behavior.

err = mlx5_create_cq(in, out)
err = mlx5_cmd_check(err, in, out)
if (err)
    // handle err

For DEVX users and those who care about full visibility, They will just
propagate the error to user space, and app can check if err == -EREMOTEIO,
then outbox.{status,syndrome} are valid.

API Note:
mlx5_cmd_check() must be used by kernel users since it allows the driver
to intercept the command execution status and return a driver simulated
status in case of driver induced error handling or reset/recovery flows.

Signed-off-by: Saeed Mahameed <[email-masked]>
Signed-off-by: Saeed Mahameed <[email-masked]>
---
 drivers/infiniband/hw/mlx5/devx.c            |  6 +++---
 drivers/infiniband/hw/mlx5/qp.c              |  1 +
 drivers/infiniband/hw/mlx5/qpc.c             |  2 +-
 drivers/net/ethernet/mellanox/mlx5/core/cq.c | 17 ++++++++++++++---
 include/linux/mlx5/cq.h                      |  2 ++
 5 files changed, 21 insertions(+), 7 deletions(-)

diff --git a/drivers/infiniband/hw/mlx5/devx.c b/drivers/infiniband/hw/mlx5/devx.c
index 08b7f6bc56c3..1f62c0ede048 100644
--- a/drivers/infiniband/hw/mlx5/devx.c
+++ b/drivers/infiniband/hw/mlx5/devx.c
@@ -1497,9 +1497,9 @@ static int UVERBS_HANDLER(MLX5_IB_METHOD_DEVX_OBJ_CREATE)(
 		   !is_apu_cq(dev, cmd_in)) {
 		obj->flags |= DEVX_OBJ_FLAGS_CQ;
 		obj->core_cq.comp = devx_cq_comp;
-		err = mlx5_core_create_cq(dev->mdev, &obj->core_cq,
-					  cmd_in, cmd_in_len, cmd_out,
-					  cmd_out_len);
+		err = mlx5_create_cq(dev->mdev, &obj->core_cq,
+				     cmd_in, cmd_in_len, cmd_out,
+				     cmd_out_len);
 	} else {
 		err = mlx5_cmd_exec(dev->mdev, cmd_in,
 				    cmd_in_len,
diff --git a/drivers/infiniband/hw/mlx5/qp.c b/drivers/infiniband/hw/mlx5/qp.c
index 29475cf8c7c3..b7fe47107d76 100644
--- a/drivers/infiniband/hw/mlx5/qp.c
+++ b/drivers/infiniband/hw/mlx5/qp.c
@@ -4465,6 +4465,7 @@ static int mlx5_ib_modify_dct(struct ib_qp *ibqp, struct ib_qp_attr *attr,
 		err = mlx5_core_create_dct(dev, &qp->dct.mdct, qp->dct.in,
 					   MLX5_ST_SZ_BYTES(create_dct_in), out,
 					   sizeof(out));
+		err = mlx5_cmd_check(dev->mdev, err, qp->dct.in, out);
 		if (err)
 			return err;
 		resp.dctn = qp->dct.mdct.mqp.qpn;
diff --git a/drivers/infiniband/hw/mlx5/qpc.c b/drivers/infiniband/hw/mlx5/qpc.c
index 8844eacf2380..542e4c63a8de 100644
--- a/drivers/infiniband/hw/mlx5/qpc.c
+++ b/drivers/infiniband/hw/mlx5/qpc.c
@@ -220,7 +220,7 @@ int mlx5_core_create_dct(struct mlx5_ib_dev *dev, struct mlx5_core_dct *dct,
 	init_completion(&dct->drained);
 	MLX5_SET(create_dct_in, in, opcode, MLX5_CMD_OP_CREATE_DCT);
 
-	err = mlx5_cmd_exec(dev->mdev, in, inlen, out, outlen);
+	err = mlx5_cmd_do(dev->mdev, in, inlen, out, outlen);
 	if (err)
 		return err;
 
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/cq.c b/drivers/net/ethernet/mellanox/mlx5/core/cq.c
index 5371ad0a12eb..15a74966be7d 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/cq.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/cq.c
@@ -86,8 +86,9 @@ static void mlx5_add_cq_to_tasklet(struct mlx5_core_cq *cq,
 	spin_unlock_irqrestore(&tasklet_ctx->lock, flags);
 }
 
-int mlx5_core_create_cq(struct mlx5_core_dev *dev, struct mlx5_core_cq *cq,
-			u32 *in, int inlen, u32 *out, int outlen)
+/* Callers must verify outbox status in case of err */
+int mlx5_create_cq(struct mlx5_core_dev *dev, struct mlx5_core_cq *cq,
+		   u32 *in, int inlen, u32 *out, int outlen)
 {
 	int eqn = MLX5_GET(cqc, MLX5_ADDR_OF(create_cq_in, in, cq_context),
 			   c_eqn_or_apu_element);
@@ -101,7 +102,7 @@ int mlx5_core_create_cq(struct mlx5_core_dev *dev, struct mlx5_core_cq *cq,
 
 	memset(out, 0, outlen);
 	MLX5_SET(create_cq_in, in, opcode, MLX5_CMD_OP_CREATE_CQ);
-	err = mlx5_cmd_exec(dev, in, inlen, out, outlen);
+	err = mlx5_cmd_do(dev, in, inlen, out, outlen);
 	if (err)
 		return err;
 
@@ -148,6 +149,16 @@ int mlx5_core_create_cq(struct mlx5_core_dev *dev, struct mlx5_core_cq *cq,
 	mlx5_cmd_exec_in(dev, destroy_cq, din);
 	return err;
 }
+EXPORT_SYMBOL(mlx5_create_cq);
+
+/* oubox is checked and err val is normalized */
+int mlx5_core_create_cq(struct mlx5_core_dev *dev, struct mlx5_core_cq *cq,
+			u32 *in, int inlen, u32 *out, int outlen)
+{
+	int err = mlx5_create_cq(dev, cq, in, inlen, out, outlen);
+
+	return mlx5_cmd_check(dev, err, in, out);
+}
 EXPORT_SYMBOL(mlx5_core_create_cq);
 
 int mlx5_core_destroy_cq(struct mlx5_core_dev *dev, struct mlx5_core_cq *cq)
diff --git a/include/linux/mlx5/cq.h b/include/linux/mlx5/cq.h
index 7bfb67363434..cb15308b5cb0 100644
--- a/include/linux/mlx5/cq.h
+++ b/include/linux/mlx5/cq.h
@@ -183,6 +183,8 @@ static inline void mlx5_cq_put(struct mlx5_core_cq *cq)
 		complete(&cq->free);
 }
 
+int mlx5_create_cq(struct mlx5_core_dev *dev, struct mlx5_core_cq *cq,
+		   u32 *in, int inlen, u32 *out, int outlen);
 int mlx5_core_create_cq(struct mlx5_core_dev *dev, struct mlx5_core_cq *cq,
 			u32 *in, int inlen, u32 *out, int outlen);
 int mlx5_core_destroy_cq(struct mlx5_core_dev *dev, struct mlx5_core_cq *cq);
-- 
2.35.1