tg3: Fix tg3_get_stats64 for 5700 / 5701 devs

tg3_get_stats64() takes tp->lock when dealing with non-serdes bcm5700
and bcm5701 devices.  However, functions that call tg3_halt() have
already acquired tp->lock.  When tg3_get_stats64() is called in
tg3_halt(), deadlock will occur.

This patch fixes the problem by separating the stat gathering code into
a new tg3_get_nstats() function.  tg3_get_stats64() is recoded to call
this function and take tp->lock.  The code that takes tp->lock in
tg3_calc_crc_errors() has been removed.  Function signatures have been
cleaned up too.

(cherry picked from commit 65ec698d1368fc64d0b93fb703783d25ec550577)
Signed-off-by: Matt Carlson <mcarlson@broadcom.com>
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Joe Jin <joe.jin@oracle.com>

diff --git a/drivers/net/tg3.c b/drivers/net/tg3.c
index d563cb44c168929457bde68063db258f9fe4a4a0..44d335c92130c9199543dd24fcd12dba1b86a315 100644 (file)
--- a/drivers/net/tg3.c
+++ b/drivers/net/tg3.c
@@ -8007,10 +8007,8 @@ static int tg3_chip_reset(struct tg3 *tp)
        return 0;
 }
 
-static struct rtnl_link_stats64 *tg3_get_stats64(struct net_device *,
-                                                struct rtnl_link_stats64 *);
-static struct tg3_ethtool_stats *tg3_get_estats(struct tg3 *,
-                                               struct tg3_ethtool_stats *);
+static void tg3_get_nstats(struct tg3 *, struct rtnl_link_stats64 *);
+static void tg3_get_estats(struct tg3 *, struct tg3_ethtool_stats *);
 
 /* tp->lock is held. */
 static int tg3_halt(struct tg3 *tp, int kind, int silent)
@@ -8031,7 +8029,7 @@ static int tg3_halt(struct tg3 *tp, int kind, int silent)
 
        if (tp->hw_stats) {
                /* Save the stats across chip resets... */
-               tg3_get_stats64(tp->dev, &tp->net_stats_prev),
+               tg3_get_nstats(tp, &tp->net_stats_prev),
                tg3_get_estats(tp, &tp->estats_prev);
 
                /* And make sure the next sample is new data */
@@ -10131,7 +10129,7 @@ static inline u64 get_stat64(tg3_stat64_t *val)
        return ((u64)val->high << 32) | ((u64)val->low);
 }
 
-static u64 calc_crc_errors(struct tg3 *tp)
+static u64 tg3_calc_crc_errors(struct tg3 *tp)
 {
        struct tg3_hw_stats *hw_stats = tp->hw_stats;
 
@@ -10140,14 +10138,12 @@ static u64 calc_crc_errors(struct tg3 *tp)
             GET_ASIC_REV(tp->pci_chip_rev_id) == ASIC_REV_5701)) {
                u32 val;
 
-               spin_lock_bh(&tp->lock);
                if (!tg3_readphy(tp, MII_TG3_TEST1, &val)) {
                        tg3_writephy(tp, MII_TG3_TEST1,
                                     val | MII_TG3_TEST1_CRC_EN);
                        tg3_readphy(tp, MII_TG3_RXR_COUNTERS, &val);
                } else
                        val = 0;
-               spin_unlock_bh(&tp->lock);
 
                tp->phy_crc_errors += val;
 
@@ -10161,12 +10157,14 @@ static u64 calc_crc_errors(struct tg3 *tp)
        estats->member =        old_estats->member + \
                                get_stat64(&hw_stats->member)
 
-static struct tg3_ethtool_stats *tg3_get_estats(struct tg3 *tp,
-                                              struct tg3_ethtool_stats *estats)
+static void tg3_get_estats(struct tg3 *tp, struct tg3_ethtool_stats *estats)
 {
        struct tg3_ethtool_stats *old_estats = &tp->estats_prev;
        struct tg3_hw_stats *hw_stats = tp->hw_stats;
 
+       if (!hw_stats)
+               return;
+
        ESTAT_ADD(rx_octets);
        ESTAT_ADD(rx_fragments);
        ESTAT_ADD(rx_ucast_packets);
@@ -10244,20 +10242,13 @@ static struct tg3_ethtool_stats *tg3_get_estats(struct tg3 *tp,
        ESTAT_ADD(nic_tx_threshold_hit);
 
        ESTAT_ADD(mbuf_lwm_thresh_hit);
-
-       return estats;
 }
 
-static struct rtnl_link_stats64 *tg3_get_stats64(struct net_device *dev,
-                                                struct rtnl_link_stats64 *stats)
+static void tg3_get_nstats(struct tg3 *tp, struct rtnl_link_stats64 *stats)
 {
-       struct tg3 *tp = netdev_priv(dev);
        struct rtnl_link_stats64 *old_stats = &tp->net_stats_prev;
        struct tg3_hw_stats *hw_stats = tp->hw_stats;
 
-       if (!hw_stats)
-               return old_stats;
-
        stats->rx_packets = old_stats->rx_packets +
                get_stat64(&hw_stats->rx_ucast_packets) +
                get_stat64(&hw_stats->rx_mcast_packets) +
@@ -10300,15 +10291,13 @@ static struct rtnl_link_stats64 *tg3_get_stats64(struct net_device *dev,
                get_stat64(&hw_stats->tx_carrier_sense_errors);
 
        stats->rx_crc_errors = old_stats->rx_crc_errors +
-               calc_crc_errors(tp);
+               tg3_calc_crc_errors(tp);
 
        stats->rx_missed_errors = old_stats->rx_missed_errors +
                get_stat64(&hw_stats->rx_discards);
 
        stats->rx_dropped = tp->rx_dropped;
        stats->tx_dropped = tp->tx_dropped;
-
-       return stats;
 }
 
 static int tg3_get_regs_len(struct net_device *dev)
@@ -12290,6 +12279,21 @@ static int tg3_change_mtu(struct net_device *dev, int new_mtu)
        return err;
 }
 
+static struct rtnl_link_stats64 *tg3_get_stats64(struct net_device *dev,
+                                               struct rtnl_link_stats64 *stats)
+{
+       struct tg3 *tp = netdev_priv(dev);
+
+       if (!tp->hw_stats)
+               return &tp->net_stats_prev;
+
+       spin_lock_bh(&tp->lock);
+       tg3_get_nstats(tp, stats);
+       spin_unlock_bh(&tp->lock);
+
+       return stats;
+}
+
 static const struct net_device_ops tg3_netdev_ops = {
        .ndo_open               = tg3_open,
        .ndo_stop               = tg3_close,