bnx2x: organize BDs calculation for stop/resume

Put the numbers used for stop/resume queue in a single place and
fix the condition for sanity check.

Signed-off-by: Dmitry Kravkov <dmitry@broadcom.com>
Signed-off-by: Eilon Greenstein <eilong@broadcom.com>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x.h b/drivers/net/ethernet/broadcom/bnx2x/bnx2x.h
index 52f33b8..dbe9791 100644 (file)
--- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x.h
+++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x.h
@@ -614,6 +614,22 @@ struct bnx2x_fastpath {
 #define TX_BD(x)               ((x) & MAX_TX_BD)
 #define TX_BD_POFF(x)          ((x) & MAX_TX_DESC_CNT)
 
+/* number of NEXT_PAGE descriptors may be required during placement */
+#define NEXT_CNT_PER_TX_PKT(bds)       \
+                               (((bds) + MAX_TX_DESC_CNT - 1) / \
+                                MAX_TX_DESC_CNT * NEXT_PAGE_TX_DESC_CNT)
+/* max BDs per tx packet w/o next_pages:
+ * START_BD            - describes packed
+ * START_BD(splitted)  - includes unpaged data segment for GSO
+ * PARSING_BD          - for TSO and CSUM data
+ * Frag BDs            - decribes pages for frags
+ */
+#define BDS_PER_TX_PKT         3
+#define MAX_BDS_PER_TX_PKT     (MAX_SKB_FRAGS + BDS_PER_TX_PKT)
+/* max BDs per tx packet including next pages */
+#define MAX_DESC_PER_TX_PKT    (MAX_BDS_PER_TX_PKT + \
+                                NEXT_CNT_PER_TX_PKT(MAX_BDS_PER_TX_PKT))
+
 /* The RX BD ring is special, each bd is 8 bytes but the last one is 16 */
 #define NUM_RX_RINGS           8
 #define RX_DESC_CNT            (BCM_PAGE_SIZE / sizeof(struct eth_rx_bd))

diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c
index 5aeb034..e879e19 100644 (file)
--- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c
+++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c
@@ -221,7 +221,7 @@ int bnx2x_tx_int(struct bnx2x *bp, struct bnx2x_fp_txdata *txdata)
 
                if ((netif_tx_queue_stopped(txq)) &&
                    (bp->state == BNX2X_STATE_OPEN) &&
-                   (bnx2x_tx_avail(bp, txdata) >= MAX_SKB_FRAGS + 4))
+                   (bnx2x_tx_avail(bp, txdata) >= MAX_DESC_PER_TX_PKT))
                        netif_tx_wake_queue(txq);
 
                __netif_tx_unlock(txq);
@@ -2948,7 +2948,9 @@ netdev_tx_t bnx2x_start_xmit(struct sk_buff *skb, struct net_device *dev)
           txdata->cid, fp_index, txdata_index, txdata, fp); */
 
        if (unlikely(bnx2x_tx_avail(bp, txdata) <
-                    (skb_shinfo(skb)->nr_frags + 3))) {
+                       skb_shinfo(skb)->nr_frags +
+                       BDS_PER_TX_PKT +
+                       NEXT_CNT_PER_TX_PKT(MAX_BDS_PER_TX_PKT))) {
                bnx2x_fp_qstats(bp, txdata->parent_fp)->driver_xoff++;
                netif_tx_stop_queue(txq);
                BNX2X_ERR("BUG! Tx ring full when queue awake!\n");
@@ -3223,7 +3225,7 @@ netdev_tx_t bnx2x_start_xmit(struct sk_buff *skb, struct net_device *dev)
 
        txdata->tx_bd_prod += nbd;
 
-       if (unlikely(bnx2x_tx_avail(bp, txdata) < MAX_SKB_FRAGS + 4)) {
+       if (unlikely(bnx2x_tx_avail(bp, txdata) < MAX_DESC_PER_TX_PKT)) {
                netif_tx_stop_queue(txq);
 
                /* paired memory barrier is in bnx2x_tx_int(), we have to keep
@@ -3232,7 +3234,7 @@ netdev_tx_t bnx2x_start_xmit(struct sk_buff *skb, struct net_device *dev)
                smp_mb();
 
                bnx2x_fp_qstats(bp, txdata->parent_fp)->driver_xoff++;
-               if (bnx2x_tx_avail(bp, txdata) >= MAX_SKB_FRAGS + 4)
+               if (bnx2x_tx_avail(bp, txdata) >= MAX_DESC_PER_TX_PKT)
                        netif_tx_wake_queue(txq);
        }
        txdata->tx_pkt++;