bnx2: Set rx buffer water marks based on MTU.

The default rx buffer water marks for XOFF/XON are for 1500 MTU.  At
larger MTUs, these water marks need to be adjusted for effective
flow control.

Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: Matt Carlson <mcarlson@broadcom.com>
Signed-off-by: Benjamin Li <benli@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/bnx2.c b/drivers/net/bnx2.c
index d28cbce..a52ffdc 100644 (file)
--- a/drivers/net/bnx2.c
+++ b/drivers/net/bnx2.c
@@ -4473,7 +4473,7 @@ bnx2_reset_chip(struct bnx2 *bp, u32 reset_code)
 static int
 bnx2_init_chip(struct bnx2 *bp)
 {
-       u32 val;
+       u32 val, mtu;
        int rc, i;
 
        /* Make sure the interrupt is not active. */
@@ -4565,11 +4565,19 @@ bnx2_init_chip(struct bnx2 *bp)
        REG_WR(bp, BNX2_EMAC_BACKOFF_SEED, val);
 
        /* Program the MTU.  Also include 4 bytes for CRC32. */
-       val = bp->dev->mtu + ETH_HLEN + 4;
+       mtu = bp->dev->mtu;
+       val = mtu + ETH_HLEN + ETH_FCS_LEN;
        if (val > (MAX_ETHERNET_PACKET_SIZE + 4))
                val |= BNX2_EMAC_RX_MTU_SIZE_JUMBO_ENA;
        REG_WR(bp, BNX2_EMAC_RX_MTU_SIZE, val);
 
+       if (mtu < 1500)
+               mtu = 1500;
+
+       bnx2_reg_wr_ind(bp, BNX2_RBUF_CONFIG, BNX2_RBUF_CONFIG_VAL(mtu));
+       bnx2_reg_wr_ind(bp, BNX2_RBUF_CONFIG2, BNX2_RBUF_CONFIG2_VAL(mtu));
+       bnx2_reg_wr_ind(bp, BNX2_RBUF_CONFIG3, BNX2_RBUF_CONFIG3_VAL(mtu));
+
        for (i = 0; i < BNX2_MAX_MSIX_VEC; i++)
                bp->bnx2_napi[i].last_status_idx = 0;
 

diff --git a/drivers/net/bnx2.h b/drivers/net/bnx2.h
index 617d953..2b9649a 100644 (file)
--- a/drivers/net/bnx2.h
+++ b/drivers/net/bnx2.h
@@ -4199,7 +4199,14 @@ struct l2_fhdr {
 
 #define BNX2_RBUF_CONFIG                               0x0020000c
 #define BNX2_RBUF_CONFIG_XOFF_TRIP                      (0x3ffL<<0)
+#define BNX2_RBUF_CONFIG_XOFF_TRIP_VAL(mtu)             \
+       ((((mtu) - 1500) * 31 / 1000) + 54)
 #define BNX2_RBUF_CONFIG_XON_TRIP                       (0x3ffL<<16)
+#define BNX2_RBUF_CONFIG_XON_TRIP_VAL(mtu)              \
+       ((((mtu) - 1500) * 39 / 1000) + 66)
+#define BNX2_RBUF_CONFIG_VAL(mtu)                       \
+       (BNX2_RBUF_CONFIG_XOFF_TRIP_VAL(mtu) |           \
+       (BNX2_RBUF_CONFIG_XON_TRIP_VAL(mtu) << 16))
 
 #define BNX2_RBUF_FW_BUF_ALLOC                         0x00200010
 #define BNX2_RBUF_FW_BUF_ALLOC_VALUE                    (0x1ffL<<7)
@@ -4221,11 +4228,25 @@ struct l2_fhdr {
 
 #define BNX2_RBUF_CONFIG2                              0x0020001c
 #define BNX2_RBUF_CONFIG2_MAC_DROP_TRIP                         (0x3ffL<<0)
+#define BNX2_RBUF_CONFIG2_MAC_DROP_TRIP_VAL(mtu)        \
+       ((((mtu) - 1500) * 4 / 1000) + 5)
 #define BNX2_RBUF_CONFIG2_MAC_KEEP_TRIP                         (0x3ffL<<16)
+#define BNX2_RBUF_CONFIG2_MAC_KEEP_TRIP_VAL(mtu)        \
+       ((((mtu) - 1500) * 2 / 100) + 30)
+#define BNX2_RBUF_CONFIG2_VAL(mtu)                      \
+       (BNX2_RBUF_CONFIG2_MAC_DROP_TRIP_VAL(mtu) |      \
+       (BNX2_RBUF_CONFIG2_MAC_KEEP_TRIP_VAL(mtu) << 16))
 
 #define BNX2_RBUF_CONFIG3                              0x00200020
 #define BNX2_RBUF_CONFIG3_CU_DROP_TRIP                  (0x3ffL<<0)
+#define BNX2_RBUF_CONFIG3_CU_DROP_TRIP_VAL(mtu)                 \
+       ((((mtu) - 1500) * 12 / 1000) + 18)
 #define BNX2_RBUF_CONFIG3_CU_KEEP_TRIP                  (0x3ffL<<16)
+#define BNX2_RBUF_CONFIG3_CU_KEEP_TRIP_VAL(mtu)                 \
+       ((((mtu) - 1500) * 2 / 100) + 30)
+#define BNX2_RBUF_CONFIG3_VAL(mtu)                      \
+       (BNX2_RBUF_CONFIG3_CU_DROP_TRIP_VAL(mtu) |       \
+       (BNX2_RBUF_CONFIG3_CU_KEEP_TRIP_VAL(mtu) << 16))
 
 #define BNX2_RBUF_PKT_DATA                             0x00208000
 #define BNX2_RBUF_CLIST_DATA                           0x00210000