From: Eric Dumazet <edumazet@google.com>
Date: Wed, 8 Mar 2017 16:17:11 +0000 (-0800)
Subject: mlx4: removal of frag_sizes[]
X-Git-Tag: v4.12-rc1~64^3~496^2~7
X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=60c7f5ae5416a8491216bcccf6b3b3d842d69fa4;p=uclinux-h8%2Flinux.git

mlx4: removal of frag_sizes[]

We will soon use order-0 pages, and frag truesize will more precisely
match real sizes.

In the new model, we prefer to use <= 2048 bytes fragments, so that
we can use page-recycle technique on PAGE_SIZE=4096 arches.

We will still pack as much frames as possible on arches with big
pages, like PowerPC.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/drivers/net/ethernet/mellanox/mlx4/en_rx.c b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
index 453313d404e3..0c61c1200f2a 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
@@ -1181,13 +1181,6 @@ int mlx4_en_poll_rx_cq(struct napi_struct *napi, int budget)
 	return done;
 }
 
-static const int frag_sizes[] = {
-	FRAG_SZ0,
-	FRAG_SZ1,
-	FRAG_SZ2,
-	FRAG_SZ3
-};
-
 void mlx4_en_calc_rx_buf(struct net_device *dev)
 {
 	struct mlx4_en_priv *priv = netdev_priv(dev);
@@ -1211,13 +1204,16 @@ void mlx4_en_calc_rx_buf(struct net_device *dev)
 		int buf_size = 0;
 
 		while (buf_size < eff_mtu) {
-			priv->frag_info[i].frag_size =
-				(eff_mtu > buf_size + frag_sizes[i]) ?
-					frag_sizes[i] : eff_mtu - buf_size;
-			priv->frag_info[i].frag_stride =
-				ALIGN(priv->frag_info[i].frag_size,
-				      SMP_CACHE_BYTES);
-			buf_size += priv->frag_info[i].frag_size;
+			int frag_size = eff_mtu - buf_size;
+
+			if (i < MLX4_EN_MAX_RX_FRAGS - 1)
+				frag_size = min(frag_size, 2048);
+
+			priv->frag_info[i].frag_size = frag_size;
+
+			priv->frag_info[i].frag_stride = ALIGN(frag_size,
+							       SMP_CACHE_BYTES);
+			buf_size += frag_size;
 			i++;
 		}
 		priv->rx_page_order = MLX4_EN_ALLOC_PREFER_ORDER;
diff --git a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
index c98940c6acd0..608396dc6d95 100644
--- a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
+++ b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
@@ -105,14 +105,6 @@
 #define MLX4_EN_ALLOC_PREFER_ORDER min_t(int, get_order(32768),		\
 					 PAGE_ALLOC_COSTLY_ORDER)
 
-/* Receive fragment sizes; we use at most 3 fragments (for 9600 byte MTU
- * and 4K allocations) */
-enum {
-	FRAG_SZ0 = 1536 - NET_IP_ALIGN,
-	FRAG_SZ1 = 4096,
-	FRAG_SZ2 = 4096,
-	FRAG_SZ3 = MLX4_EN_ALLOC_SIZE
-};
 #define MLX4_EN_MAX_RX_FRAGS	4
 
 /* Maximum ring sizes */