From: Alaa Hleihel <alaa@mellanox.com>
Date: Tue, 9 Oct 2018 12:06:52 +0300
Subject: net/mlx4_en: Use minimal rx and tx ring sizes on kdump kernel
Patch-mainline: v4.20-rc1
Git-commit: 27055454b43009b6775a7ce70907bb298f4fab1e
References: bsc#1103989 FATE#326004

When memory is limited (on kdump kernel), reduce size of rx and tx rings.
Also reduce the number of rx rings.

Signed-off-by: Alaa Hleihel <alaa@mellanox.com>
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/mellanox/mlx4/en_main.c |    9 +++++++--
 drivers/net/ethernet/mellanox/mlx4/mlx4_en.h |    2 +-
 2 files changed, 8 insertions(+), 3 deletions(-)

--- a/drivers/net/ethernet/mellanox/mlx4/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_main.c
@@ -167,8 +167,13 @@ static void mlx4_en_get_profile(struct m
 		params->prof[i].rx_ppp = pfcrx;
 		params->prof[i].tx_pause = !(pfcrx || pfctx);
 		params->prof[i].tx_ppp = pfctx;
-		params->prof[i].tx_ring_size = MLX4_EN_DEF_TX_RING_SIZE;
-		params->prof[i].rx_ring_size = MLX4_EN_DEF_RX_RING_SIZE;
+		if (mlx4_low_memory_profile()) {
+			params->prof[i].tx_ring_size = MLX4_EN_MIN_TX_SIZE;
+			params->prof[i].rx_ring_size = MLX4_EN_MIN_RX_SIZE;
+		} else {
+			params->prof[i].tx_ring_size = MLX4_EN_DEF_TX_RING_SIZE;
+			params->prof[i].rx_ring_size = MLX4_EN_DEF_RX_RING_SIZE;
+		}
 		params->prof[i].num_up = MLX4_EN_NUM_UP_LOW;
 		params->prof[i].num_tx_rings_p_up = params->max_num_tx_rings_p_up;
 		params->prof[i].tx_ring_num[TX] = params->max_num_tx_rings_p_up *
--- a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
+++ b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
@@ -72,7 +72,7 @@
 #define MLX4_EN_PAGE_SIZE	(1 << MLX4_EN_PAGE_SHIFT)
 #define DEF_RX_RINGS		16
 #define MAX_RX_RINGS		128
-#define MIN_RX_RINGS		4
+#define MIN_RX_RINGS		1
 #define LOG_TXBB_SIZE		6
 #define TXBB_SIZE		BIT(LOG_TXBB_SIZE)
 #define HEADROOM		(2048 / TXBB_SIZE + 1)