mlx4: reduce rx ring page_cache size

We only need to store the page and dma address.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Acked-by: NTariq Toukan <tariqt@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlx4/en_rx.c

@@ -250,7 +250,10 @@ static int mlx4_en_prepare_rx_desc(struct mlx4_en_priv *priv,
 					(index << priv->log_rx_info);
 
 	if (ring->page_cache.index > 0) {
-		frags[0] = ring->page_cache.buf[--ring->page_cache.index];
+		ring->page_cache.index--;
+		frags[0].page = ring->page_cache.buf[ring->page_cache.index].page;
+		frags[0].dma  = ring->page_cache.buf[ring->page_cache.index].dma;
+		frags[0].page_offset = XDP_PACKET_HEADROOM;
 		rx_desc->data[0].addr = cpu_to_be64(frags[0].dma +
 						    frags[0].page_offset);
 		return 0;
@@ -537,7 +540,9 @@ bool mlx4_en_rx_recycle(struct mlx4_en_rx_ring *ring,
 	if (cache->index >= MLX4_EN_CACHE_SIZE)
 		return false;
 
-	cache->buf[cache->index++] = *frame;
+	cache->buf[cache->index].page = frame->page;
+	cache->buf[cache->index].dma = frame->dma;
+	cache->index++;
 	return true;
 }
 
@@ -567,11 +572,9 @@ void mlx4_en_deactivate_rx_ring(struct mlx4_en_priv *priv,
 	int i;
 
 	for (i = 0; i < ring->page_cache.index; i++) {
-		struct mlx4_en_rx_alloc *frame = &ring->page_cache.buf[i];
-
-		dma_unmap_page(priv->ddev, frame->dma, frame->page_size,
-			       priv->dma_dir);
-		put_page(frame->page);
+		dma_unmap_page(priv->ddev, ring->page_cache.buf[i].dma,
+			       PAGE_SIZE, priv->dma_dir);
+		put_page(ring->page_cache.buf[i].page);
 	}
 	ring->page_cache.index = 0;
 	mlx4_en_free_rx_buf(priv, ring);

drivers/net/ethernet/mellanox/mlx4/en_tx.c

@@ -354,8 +354,6 @@ u32 mlx4_en_recycle_tx_desc(struct mlx4_en_priv *priv,
 	struct mlx4_en_rx_alloc frame = {
 		.page = tx_info->page,
 		.dma = tx_info->map0_dma,
-		.page_offset = XDP_PACKET_HEADROOM,
-		.page_size = PAGE_SIZE,
 	};
 
 	if (!mlx4_en_rx_recycle(ring->recycle_ring, &frame)) {

drivers/net/ethernet/mellanox/mlx4/mlx4_en.h

@@ -268,9 +268,13 @@ struct mlx4_en_rx_alloc {
 };
 
 #define MLX4_EN_CACHE_SIZE (2 * NAPI_POLL_WEIGHT)
+
 struct mlx4_en_page_cache {
 	u32 index;
-	struct mlx4_en_rx_alloc buf[MLX4_EN_CACHE_SIZE];
+	struct {
+		struct page	*page;
+		dma_addr_t	dma;
+	} buf[MLX4_EN_CACHE_SIZE];
 };
 
 struct mlx4_en_priv;