sky2: implement 64 bit stats

This implements 64 bit statistics support and fixes races when reading
counter values. The PHY counters can only be accessed 16 bits at a time,
so they are subject to carry races.

NB:
  * TX/RX counters are maintained in software because the the hardware packet count
    is only a 32 bit value.

  * Error counters are really only 32 bit.

  * Old 32 bit counter fields in dev->stats still used for some
    software counters

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 42 insertions, 0 deletions

diff --git a/drivers/net/sky2.h b/drivers/net/sky2.h
index 61891a6cacc..80bdc404f1e 100644
--- a/drivers/net/sky2.h
+++ b/drivers/net/sky2.h
@@ -2200,6 +2200,12 @@ enum flow_control {
 	FC_BOTH	= 3,
 };
 
+struct sky2_stats {
+	struct u64_stats_sync syncp;
+	u64		packets;
+	u64		bytes;
+};
+
 struct sky2_port {
 	struct sky2_hw	     *hw;
 	struct net_device    *netdev;
@@ -2209,6 +2215,8 @@ struct sky2_port {
 
 	struct tx_ring_info  *tx_ring;
 	struct sky2_tx_le    *tx_le;
+	struct sky2_stats    tx_stats;
+
 	u16		     tx_ring_size;
 	u16		     tx_cons;		/* next le to check */
 	u16		     tx_prod;		/* next le to use */
@@ -2221,6 +2229,7 @@ struct sky2_port {
 
 	struct rx_ring_info  *rx_ring ____cacheline_aligned_in_smp;
 	struct sky2_rx_le    *rx_le;
+	struct sky2_stats    rx_stats;
 
 	u16		     rx_next;		/* next re to check */
 	u16		     rx_put;		/* next le index to use */
@@ -2346,6 +2355,39 @@ static inline u32 gma_read32(struct sky2_hw *hw, unsigned port, unsigned reg)
 		| (u32) sky2_read16(hw, base+4) << 16;
 }
 
+static inline u64 gma_read64(struct sky2_hw *hw, unsigned port, unsigned reg)
+{
+	unsigned base = SK_GMAC_REG(port, reg);
+
+	return (u64) sky2_read16(hw, base)
+		| (u64) sky2_read16(hw, base+4) << 16
+		| (u64) sky2_read16(hw, base+8) << 32
+		| (u64) sky2_read16(hw, base+12) << 48;
+}
+
+/* There is no way to atomically read32 bit values from PHY, so retry */
+static inline u32 get_stats32(struct sky2_hw *hw, unsigned port, unsigned reg)
+{
+	u32 val;
+
+	do {
+		val = gma_read32(hw, port, reg);
+	} while (gma_read32(hw, port, reg) != val);
+
+	return val;
+}
+
+static inline u64 get_stats64(struct sky2_hw *hw, unsigned port, unsigned reg)
+{
+	u64 val;
+
+	do {
+		val = gma_read64(hw, port, reg);
+	} while (gma_read64(hw, port, reg) != val);
+
+	return val;
+}
+
 static inline void gma_write16(const struct sky2_hw *hw, unsigned port, int r, u16 v)
 {
 	sky2_write16(hw, SK_GMAC_REG(port,r), v);