[PATCH for-next] RDMA/efa: Entropy in admin commands id

[Gal Pressman <galpress@xxxxxxxxxx>]

From: Daniel Kranzdorf <dkkranzd@xxxxxxxxxx>

Make admin commands id easier to distinguish by using relevant bits from
the producer counter.
This allows us to differentiate admin commands with the same producer
index (happens after admin queue overlap), which is helpful when
debugging.

Signed-off-by: Daniel Kranzdorf <dkkranzd@xxxxxxxxxx>
Reviewed-by: Firas JahJah <firasj@xxxxxxxxxx>
Reviewed-by: Yossi Leybovich <sleybo@xxxxxxxxxx>
Signed-off-by: Gal Pressman <galpress@xxxxxxxxxx>
---
 drivers/infiniband/hw/efa/efa_com.c | 44 +++++++++++++++--------------
 1 file changed, 23 insertions(+), 21 deletions(-)

diff --git a/drivers/infiniband/hw/efa/efa_com.c b/drivers/infiniband/hw/efa/efa_com.c
index ec04ced9fd2b..2cb42484b0f8 100644
--- a/drivers/infiniband/hw/efa/efa_com.c
+++ b/drivers/infiniband/hw/efa/efa_com.c
@@ -278,36 +278,34 @@ static void efa_com_dealloc_ctx_id(struct efa_com_admin_queue *aq,
 static inline void efa_com_put_comp_ctx(struct efa_com_admin_queue *aq,
 					struct efa_comp_ctx *comp_ctx)
 {
-	u16 comp_id = comp_ctx->user_cqe->acq_common_descriptor.command &
-		      EFA_ADMIN_ACQ_COMMON_DESC_COMMAND_ID_MASK;
+	u16 cmd_id = comp_ctx->user_cqe->acq_common_descriptor.command &
+		     EFA_ADMIN_ACQ_COMMON_DESC_COMMAND_ID_MASK;
+	u16 ctx_id = cmd_id & (aq->depth - 1);
 
-	ibdev_dbg(aq->efa_dev, "Putting completion command_id %d\n", comp_id);
+	ibdev_dbg(aq->efa_dev, "Put completion command_id %#x\n", cmd_id);
 	comp_ctx->occupied = 0;
-	efa_com_dealloc_ctx_id(aq, comp_id);
+	efa_com_dealloc_ctx_id(aq, ctx_id);
 }
 
 static struct efa_comp_ctx *efa_com_get_comp_ctx(struct efa_com_admin_queue *aq,
-						 u16 command_id, bool capture)
+						 u16 cmd_id, bool capture)
 {
-	if (command_id >= aq->depth) {
-		ibdev_err(aq->efa_dev,
-			  "command id is larger than the queue size. cmd_id: %u queue size %d\n",
-			  command_id, aq->depth);
-		return NULL;
-	}
+	u16 ctx_id = cmd_id & (aq->depth - 1);
 
-	if (aq->comp_ctx[command_id].occupied && capture) {
-		ibdev_err(aq->efa_dev, "Completion context is occupied\n");
+	if (aq->comp_ctx[ctx_id].occupied && capture) {
+		ibdev_err(aq->efa_dev,
+			  "Completion context for command_id %#x is occupied\n",
+			  cmd_id);
 		return NULL;
 	}
 
 	if (capture) {
-		aq->comp_ctx[command_id].occupied = 1;
-		ibdev_dbg(aq->efa_dev, "Taking completion ctxt command_id %d\n",
-			  command_id);
+		aq->comp_ctx[ctx_id].occupied = 1;
+		ibdev_dbg(aq->efa_dev,
+			  "Take completion ctxt for command_id %#x\n", cmd_id);
 	}
 
-	return &aq->comp_ctx[command_id];
+	return &aq->comp_ctx[ctx_id];
 }
 
 static struct efa_comp_ctx *__efa_com_submit_admin_cmd(struct efa_com_admin_queue *aq,
@@ -318,6 +316,7 @@ static struct efa_comp_ctx *__efa_com_submit_admin_cmd(struct efa_com_admin_queu
 {
 	struct efa_comp_ctx *comp_ctx;
 	u16 queue_size_mask;
+	u16 cmd_id;
 	u16 ctx_id;
 	u16 pi;
 
@@ -326,13 +325,16 @@ static struct efa_comp_ctx *__efa_com_submit_admin_cmd(struct efa_com_admin_queu
 
 	ctx_id = efa_com_alloc_ctx_id(aq);
 
+	/* cmd_id LSBs are the ctx_id and MSBs are entropy bits from pc */
+	cmd_id = ctx_id & queue_size_mask;
+	cmd_id |= aq->sq.pc & ~queue_size_mask;
+	cmd_id &= EFA_ADMIN_AQ_COMMON_DESC_COMMAND_ID_MASK;
+
+	cmd->aq_common_descriptor.command_id = cmd_id;
 	cmd->aq_common_descriptor.flags |= aq->sq.phase &
 		EFA_ADMIN_AQ_COMMON_DESC_PHASE_MASK;
 
-	cmd->aq_common_descriptor.command_id |= ctx_id &
-		EFA_ADMIN_AQ_COMMON_DESC_COMMAND_ID_MASK;
-
-	comp_ctx = efa_com_get_comp_ctx(aq, ctx_id, true);
+	comp_ctx = efa_com_get_comp_ctx(aq, cmd_id, true);
 	if (!comp_ctx) {
 		efa_com_dealloc_ctx_id(aq, ctx_id);
 		return ERR_PTR(-EINVAL);
-- 
2.22.0