src/patches/suse-2.6.27.39/patches.drivers/bnx2x-Barriers-for-the-compiler.patch

   1 From 237907c1ded8a1a447cea7c4f97ab853e8b46052 Mon Sep 17 00:00:00 2001
   2 From: Eilon Greenstein <eilong@broadcom.com>
   3 Date: Wed, 14 Jan 2009 06:42:44 +0000
   4 Subject: bnx2x: Barriers for the compiler
   5 Acked-by: Karsten Keil <kkeil@novell.com>
   6 Reference: bnc#472500
   7
   8 To make sure no swapping are made by the compiler, changed HAS_WORK to inline
   9 functions and added all the necessary barriers
  10
  11 Signed-off-by: Eilon Greenstein <eilong@broadcom.com>
  12 Signed-off-by: David S. Miller <davem@davemloft.net>
  13 ---
  14  drivers/net/bnx2x.h      |    9 +--------
  15  drivers/net/bnx2x_main.c |   37 ++++++++++++++++++++++++++-----------
  16  2 files changed, 27 insertions(+), 19 deletions(-)
  17
  18 Index: linux-2.6.27-bnx2x_2/drivers/net/bnx2x.h
  19 ===================================================================
  20 --- linux-2.6.27-bnx2x_2.orig/drivers/net/bnx2x.h
  21 +++ linux-2.6.27-bnx2x_2/drivers/net/bnx2x.h
  22 @@ -271,14 +271,7 @@ struct bnx2x_fastpath {
  23
  24  #define bnx2x_fp(bp, nr, var)          (bp->fp[nr].var)
  25
  26 -#define BNX2X_HAS_TX_WORK(fp) \
  27 -                       ((fp->tx_pkt_prod != le16_to_cpu(*fp->tx_cons_sb)) || \
  28 -                        (fp->tx_pkt_prod != fp->tx_pkt_cons))
  29 -
  30 -#define BNX2X_HAS_RX_WORK(fp) \
  31 -                       (fp->rx_comp_cons != rx_cons_sb)
  32 -
  33 -#define BNX2X_HAS_WORK(fp)     (BNX2X_HAS_RX_WORK(fp) || BNX2X_HAS_TX_WORK(fp))
  34 +#define BNX2X_HAS_WORK(fp)     (bnx2x_has_rx_work(fp) || bnx2x_has_tx_work(fp))
  35
  36
  37  /* MC hsi */
  38 Index: linux-2.6.27-bnx2x_2/drivers/net/bnx2x_main.c
  39 ===================================================================
  40 --- linux-2.6.27-bnx2x_2.orig/drivers/net/bnx2x_main.c
  41 +++ linux-2.6.27-bnx2x_2/drivers/net/bnx2x_main.c
  42 @@ -733,6 +733,17 @@ static u16 bnx2x_ack_int(struct bnx2x *b
  43   * fast path service functions
  44   */
  45
  46 +static inline int bnx2x_has_tx_work(struct bnx2x_fastpath *fp)
  47 +{
  48 +       u16 tx_cons_sb;
  49 +
  50 +       /* Tell compiler that status block fields can change */
  51 +       barrier();
  52 +       tx_cons_sb = le16_to_cpu(*fp->tx_cons_sb);
  53 +       return ((fp->tx_pkt_prod != tx_cons_sb) ||
  54 +               (fp->tx_pkt_prod != fp->tx_pkt_cons));
  55 +}
  56 +
  57  /* free skb in the packet ring at pos idx
  58   * return idx of last bd freed
  59   */
  60 @@ -6696,7 +6707,7 @@ static int bnx2x_nic_unload(struct bnx2x
  61
  62                 cnt = 1000;
  63                 smp_rmb();
  64 -               while (BNX2X_HAS_TX_WORK(fp)) {
  65 +               while (bnx2x_has_tx_work(fp)) {
  66
  67                         bnx2x_tx_int(fp, 1000);
  68                         if (!cnt) {
  69 @@ -9285,6 +9296,18 @@ static int bnx2x_set_power_state(struct
  70         return 0;
  71  }
  72
  73 +static inline int bnx2x_has_rx_work(struct bnx2x_fastpath *fp)
  74 +{
  75 +       u16 rx_cons_sb;
  76 +
  77 +       /* Tell compiler that status block fields can change */
  78 +       barrier();
  79 +       rx_cons_sb = le16_to_cpu(*fp->rx_cons_sb);
  80 +       if ((rx_cons_sb & MAX_RCQ_DESC_CNT) == MAX_RCQ_DESC_CNT)
  81 +               rx_cons_sb++;
  82 +       return (fp->rx_comp_cons != rx_cons_sb);
  83 +}
  84 +
  85  /*
  86   * net_device service functions
  87   */
  88 @@ -9295,7 +9318,6 @@ static int bnx2x_poll(struct napi_struct
  89                                                  napi);
  90         struct bnx2x *bp = fp->bp;
  91         int work_done = 0;
  92 -       u16 rx_cons_sb;
  93
  94  #ifdef BNX2X_STOP_ON_ERROR
  95         if (unlikely(bp->panic))
  96 @@ -9308,19 +9330,12 @@ static int bnx2x_poll(struct napi_struct
  97
  98         bnx2x_update_fpsb_idx(fp);
  99
 100 -       if (BNX2X_HAS_TX_WORK(fp))
 101 +       if (bnx2x_has_tx_work(fp))
 102                 bnx2x_tx_int(fp, budget);
 103
 104 -       rx_cons_sb = le16_to_cpu(*fp->rx_cons_sb);
 105 -       if ((rx_cons_sb & MAX_RCQ_DESC_CNT) == MAX_RCQ_DESC_CNT)
 106 -               rx_cons_sb++;
 107 -       if (BNX2X_HAS_RX_WORK(fp))
 108 +       if (bnx2x_has_rx_work(fp))
 109                 work_done = bnx2x_rx_int(fp, budget);
 110 -
 111         rmb(); /* BNX2X_HAS_WORK() reads the status block */
 112 -       rx_cons_sb = le16_to_cpu(*fp->rx_cons_sb);
 113 -       if ((rx_cons_sb & MAX_RCQ_DESC_CNT) == MAX_RCQ_DESC_CNT)
 114 -               rx_cons_sb++;
 115
 116         /* must not complete if we consumed full budget */
 117         if ((work_done < budget) && !BNX2X_HAS_WORK(fp)) {