Subject: [PATCH net-next 07/16] net/mlx5e: Remove the outer loop when allocating legacy RQ WQEs

From: Saeed Mahameed <[email-masked]>
Date: Fri, 30 Sep 2022 09:28:54 -0700

From: Maxim Mikityanskiy <[email-masked]>

Legacy RQ WQEs are allocated in a loop in small batches (8 WQEs). As
partial batches are allowed, there is no point to have a loop in a loop,
so the outer loop is removed, and the batch size is increased up to the
total number of WQEs to allocate, still not smaller than 8.

Signed-off-by: Maxim Mikityanskiy <[email-masked]>
Reviewed-by: Tariq Toukan <[email-masked]>
Signed-off-by: Saeed Mahameed <[email-masked]>
---
 .../net/ethernet/mellanox/mlx5/core/en_rx.c   | 37 ++++++++-----------
 drivers/net/ethernet/mellanox/mlx5/core/wq.h  |  2 +-
 2 files changed, 17 insertions(+), 22 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
index 80f2b5960782..d620c1ed9b80 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
@@ -424,7 +424,7 @@ static void mlx5e_dealloc_rx_wqe(struct mlx5e_rq *rq, u16 ix)
 	mlx5e_free_rx_wqe(rq, wi, false);
 }
 
-static int mlx5e_alloc_rx_wqes(struct mlx5e_rq *rq, u16 ix, u8 wqe_bulk)
+static int mlx5e_alloc_rx_wqes(struct mlx5e_rq *rq, u16 ix, int wqe_bulk)
 {
 	struct mlx5_wq_cyc *wq = &rq->wqe.wq;
 	int i;
@@ -805,38 +805,33 @@ static void mlx5e_dealloc_rx_mpwqe(struct mlx5e_rq *rq, u16 ix)
 INDIRECT_CALLABLE_SCOPE bool mlx5e_post_rx_wqes(struct mlx5e_rq *rq)
 {
 	struct mlx5_wq_cyc *wq = &rq->wqe.wq;
+	int wqe_bulk, count;
 	bool busy = false;
-	u8 wqe_bulk;
+	u16 head;
 
 	if (unlikely(!test_bit(MLX5E_RQ_STATE_ENABLED, &rq->state)))
 		return false;
 
-	wqe_bulk = rq->wqe.info.wqe_bulk;
-
-	if (mlx5_wq_cyc_missing(wq) < wqe_bulk)
+	if (mlx5_wq_cyc_missing(wq) < rq->wqe.info.wqe_bulk)
 		return false;
 
 	if (rq->page_pool)
 		page_pool_nid_changed(rq->page_pool, numa_mem_id());
 
-	do {
-		u16 head = mlx5_wq_cyc_get_head(wq);
-		int count;
-		u8 bulk;
+	wqe_bulk = mlx5_wq_cyc_missing(wq);
+	head = mlx5_wq_cyc_get_head(wq);
 
-		/* Don't allow any newly allocated WQEs to share the same page
-		 * with old WQEs that aren't completed yet. Stop earlier.
-		 */
-		bulk = wqe_bulk - ((head + wqe_bulk) & rq->wqe.info.wqe_index_mask);
+	/* Don't allow any newly allocated WQEs to share the same page with old
+	 * WQEs that aren't completed yet. Stop earlier.
+	 */
+	wqe_bulk -= (head + wqe_bulk) & rq->wqe.info.wqe_index_mask;
 
-		count = mlx5e_alloc_rx_wqes(rq, head, bulk);
-		mlx5_wq_cyc_push_n(wq, count);
-		if (unlikely(count != bulk)) {
-			rq->stats->buff_alloc_err++;
-			busy = true;
-			break;
-		}
-	} while (mlx5_wq_cyc_missing(wq) >= wqe_bulk);
+	count = mlx5e_alloc_rx_wqes(rq, head, wqe_bulk);
+	mlx5_wq_cyc_push_n(wq, count);
+	if (unlikely(count != wqe_bulk)) {
+		rq->stats->buff_alloc_err++;
+		busy = true;
+	}
 
 	/* ensure wqes are visible to device before updating doorbell record */
 	dma_wmb();
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/wq.h b/drivers/net/ethernet/mellanox/mlx5/core/wq.h
index e5c4dcd1425e..4d629e5ddbc7 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/wq.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/wq.h
@@ -123,7 +123,7 @@ static inline void mlx5_wq_cyc_push(struct mlx5_wq_cyc *wq)
 	wq->cur_sz++;
 }
 
-static inline void mlx5_wq_cyc_push_n(struct mlx5_wq_cyc *wq, u8 n)
+static inline void mlx5_wq_cyc_push_n(struct mlx5_wq_cyc *wq, u16 n)
 {
 	wq->wqe_ctr += n;
 	wq->cur_sz += n;
-- 
2.37.3