Re: [PATCH v3 net-next] net: dsa: microchip: Add MIB counter reading support

[Andrew Lunn]

> + for (i = 0; i < dev->mib_port_cnt; i++) {
> + p = >ports[i];
> + if (!p->on)
> + continue;
> + mib = >mib;
> + mutex_lock(>cnt_mutex);
> +
> + /* read only dropped counters when link is not up */
> + if (p->link_down)
> + p->link_down = 0;
> + else if (!p->link_up)
> + mib->cnt_ptr = dev->reg_mib_cnt;

So this is the code you were referring to, when i asked if it can be
up and down at the same time.

I'm having a hard time understand this. Please try to implement this
some other way to make it clear what is going on.

 Andrew

[PATCH v3 net-next] net: dsa: microchip: Add MIB counter reading support

[Tristram.Ha]

From: Tristram Ha 

Add MIB counter reading support.

Signed-off-by: Tristram Ha 
Reviewed-by: Woojung Huh 
---
v3
- Use new timer_setup API

v2
- Only MIB counter related code in patch

v1
- Simplify MIB counter reading code

 drivers/net/dsa/microchip/ksz9477.c| 121 ++---
 drivers/net/dsa/microchip/ksz_common.c | 100 +++
 drivers/net/dsa/microchip/ksz_common.h |   2 +
 drivers/net/dsa/microchip/ksz_priv.h   |   7 +-
 4 files changed, 185 insertions(+), 45 deletions(-)

diff --git a/drivers/net/dsa/microchip/ksz9477.c 
b/drivers/net/dsa/microchip/ksz9477.c
index 801117a..8bae36b1 100644
--- a/drivers/net/dsa/microchip/ksz9477.c
+++ b/drivers/net/dsa/microchip/ksz9477.c
@@ -271,6 +271,76 @@ static int ksz9477_reset_switch(struct ksz_device *dev)
return 0;
 }
 
+static void ksz9477_r_mib_cnt(struct ksz_device *dev, int port, u16 addr,
+ u64 *cnt)
+{
+   u32 data;
+   int timeout;
+   struct ksz_port *p = >ports[port];
+
+   /* retain the flush/freeze bit */
+   data = p->freeze ? MIB_COUNTER_FLUSH_FREEZE : 0;
+   data |= MIB_COUNTER_READ;
+   data |= (addr << MIB_COUNTER_INDEX_S);
+   ksz_pwrite32(dev, port, REG_PORT_MIB_CTRL_STAT__4, data);
+
+   timeout = 1000;
+   do {
+   ksz_pread32(dev, port, REG_PORT_MIB_CTRL_STAT__4,
+   );
+   usleep_range(1, 10);
+   if (!(data & MIB_COUNTER_READ))
+   break;
+   } while (timeout-- > 0);
+
+   /* failed to read MIB. get out of loop */
+   if (!timeout) {
+   dev_dbg(dev->dev, "Failed to get MIB\n");
+   return;
+   }
+
+   /* count resets upon read */
+   ksz_pread32(dev, port, REG_PORT_MIB_DATA, );
+   *cnt += data;
+}
+
+static void ksz9477_r_mib_pkt(struct ksz_device *dev, int port, u16 addr,
+ u64 *dropped, u64 *cnt)
+{
+   addr = ksz9477_mib_names[addr].index;
+   ksz9477_r_mib_cnt(dev, port, addr, cnt);
+}
+
+static void ksz9477_freeze_mib(struct ksz_device *dev, int port, bool freeze)
+{
+   struct ksz_port *p = >ports[port];
+   u32 val = freeze ? MIB_COUNTER_FLUSH_FREEZE : 0;
+
+   /* enable/disable the port for flush/freeze function */
+   mutex_lock(>mib.cnt_mutex);
+   ksz_pwrite32(dev, port, REG_PORT_MIB_CTRL_STAT__4, val);
+
+   /* used by MIB counter reading code to know freeze is enabled */
+   p->freeze = freeze;
+   mutex_unlock(>mib.cnt_mutex);
+}
+
+static void ksz9477_port_init_cnt(struct ksz_device *dev, int port)
+{
+   struct ksz_port_mib *mib = >ports[port].mib;
+
+   /* flush all enabled port MIB counters */
+   mutex_lock(>cnt_mutex);
+   ksz_pwrite32(dev, port, REG_PORT_MIB_CTRL_STAT__4,
+MIB_COUNTER_FLUSH_FREEZE);
+   ksz_write8(dev, REG_SW_MAC_CTRL_6, SW_MIB_COUNTER_FLUSH);
+   ksz_pwrite32(dev, port, REG_PORT_MIB_CTRL_STAT__4, 0);
+   mutex_unlock(>cnt_mutex);
+
+   mib->cnt_ptr = 0;
+   memset(mib->counters, 0, dev->mib_cnt * sizeof(u64));
+}
+
 static enum dsa_tag_protocol ksz9477_get_tag_protocol(struct dsa_switch *ds,
  int port)
 {
@@ -350,47 +420,6 @@ static void ksz9477_get_strings(struct dsa_switch *ds, int 
port, uint8_t *buf)
}
 }
 
-static void ksz_get_ethtool_stats(struct dsa_switch *ds, int port,
- uint64_t *buf)
-{
-   struct ksz_device *dev = ds->priv;
-   int i;
-   u32 data;
-   int timeout;
-
-   mutex_lock(>stats_mutex);
-
-   for (i = 0; i < TOTAL_SWITCH_COUNTER_NUM; i++) {
-   data = MIB_COUNTER_READ;
-   data |= ((ksz9477_mib_names[i].index & 0xFF) <<
-   MIB_COUNTER_INDEX_S);
-   ksz_pwrite32(dev, port, REG_PORT_MIB_CTRL_STAT__4, data);
-
-   timeout = 1000;
-   do {
-   ksz_pread32(dev, port, REG_PORT_MIB_CTRL_STAT__4,
-   );
-   usleep_range(1, 10);
-   if (!(data & MIB_COUNTER_READ))
-   break;
-   } while (timeout-- > 0);
-
-   /* failed to read MIB. get out of loop */
-   if (!timeout) {
-   dev_dbg(dev->dev, "Failed to get MIB\n");
-   break;
-   }
-
-   /* count resets upon read */
-   ksz_pread32(dev, port, REG_PORT_MIB_DATA, );
-
-   dev->mib_value[i] += (uint64_t)data;
-   buf[i] = dev->mib_value[i];
-   }
-
-   mutex_unlock(>stats_mutex);
-}
-
 static void ksz9477_cfg_port_member(struct ksz_device *dev, int port,
u8 member)
 {
@@ -1159,9 +1188,14 @@