net/mlx5e: RX, Remove internal page_cache

This patch removes the internal rx page_cache and uses the generic
page_pool api only. It used to be that the page_pool couldn't handle all
the mlx5 driver usecases, but with the introduction of skb recycling and
page fragmentaton in the page_pool full switch can now be made. Some
benfits of this transition:
* Better page recycling in the cases when the page_cache was suffering
  from head of queue blocking. The page_pool doesn't have this issue.
* DMA mapping/unmapping can be managed by the page_pool.
* mlx5e_rq size reduced by more than 50% due to the page_cache array
  being deleted.

This patch only removes the page_cache. Downstream patches will enable
the required page_pool features and will add further fine-tuning.

Signed-off-by: Dragos Tatulea <dtatulea@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

1 files changed, 0 insertions, 53 deletions

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
index 7057db954f6f..192f12a7d9a9 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
@@ -271,60 +271,10 @@ static inline u32 mlx5e_decompress_cqes_start(struct mlx5e_rq *rq,
 	return mlx5e_decompress_cqes_cont(rq, wq, 1, budget_rem);
 }
 
-static inline bool mlx5e_rx_cache_put(struct mlx5e_rq *rq, struct page *page)
-{
-	struct mlx5e_page_cache *cache = &rq->page_cache;
-	u32 tail_next = (cache->tail + 1) & (MLX5E_CACHE_SIZE - 1);
-	struct mlx5e_rq_stats *stats = rq->stats;
-
-	if (tail_next == cache->head) {
-		stats->cache_full++;
-		return false;
-	}
-
-	if (!dev_page_is_reusable(page)) {
-		stats->cache_waive++;
-		return false;
-	}
-
-	cache->page_cache[cache->tail] = page;
-	cache->tail = tail_next;
-	return true;
-}
-
-static inline bool mlx5e_rx_cache_get(struct mlx5e_rq *rq, struct page **pagep)
-{
-	struct mlx5e_page_cache *cache = &rq->page_cache;
-	struct mlx5e_rq_stats *stats = rq->stats;
-	dma_addr_t addr;
-
-	if (unlikely(cache->head == cache->tail)) {
-		stats->cache_empty++;
-		return false;
-	}
-
-	if (page_ref_count(cache->page_cache[cache->head]) != 1) {
-		stats->cache_busy++;
-		return false;
-	}
-
-	*pagep = cache->page_cache[cache->head];
-	cache->head = (cache->head + 1) & (MLX5E_CACHE_SIZE - 1);
-	stats->cache_reuse++;
-
-	addr = page_pool_get_dma_addr(*pagep);
-	/* Non-XSK always uses PAGE_SIZE. */
-	dma_sync_single_for_device(rq->pdev, addr, PAGE_SIZE, rq->buff.map_dir);
-	return true;
-}
-
 static inline int mlx5e_page_alloc_pool(struct mlx5e_rq *rq, struct page **pagep)
 {
 	dma_addr_t addr;
 
-	if (mlx5e_rx_cache_get(rq, pagep))
-		return 0;
-
 	*pagep = page_pool_dev_alloc_pages(rq->page_pool);
 	if (unlikely(!*pagep))
 		return -ENOMEM;
@@ -353,9 +303,6 @@ void mlx5e_page_dma_unmap(struct mlx5e_rq *rq, struct page *page)
 void mlx5e_page_release_dynamic(struct mlx5e_rq *rq, struct page *page, bool recycle)
 {
 	if (likely(recycle)) {
-		if (mlx5e_rx_cache_put(rq, page))
-			return;
-
 		mlx5e_page_dma_unmap(rq, page);
 		page_pool_recycle_direct(rq->page_pool, page);
 	} else {