Merge branch 'net-dsa-microchip-add-MIB-counters-support'

Tristram Ha says:

====================
net: dsa: microchip: add MIB counters support

This series of patches is to modify the KSZ9477 DSA driver to read MIB
counters periodically to avoid overflow.

The MIB counters should be read only when there is link.  Otherwise it is
a waste of time as hardware never increases the counters.

Functions are added to check the port link status so that MIB counters
read call is used efficiently.

v4
- Use readx_poll_timeout
- Fix using mutex in a timer callback function problem
- use dp->slave directly instead of checking whether it is valid
- Add port_cleanup function in a separate patch
- Add a mutex so that changing device variables is safe

v3
- Use netif_carrier_ok instead of checking the phy device pointer

v2
- Create macro similar to readx_poll_timeout to use with switch
- Create ksz_port_cleanup function so that variables like on_ports and
  live_ports can be updated inside it

v1
- Use readx_poll_timeout
- Do not clear MIB counters when port is enabled
- Do not advertise 1000 half-duplex mode when port is enabled
- Do not use freeze function as MIB counters may miss counts
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

Author: davem330

drivers/net/dsa/microchip/ksz9477.c

@@ -2,24 +2,21 @@
 /*
  * Microchip KSZ9477 switch driver main logic
  *
- * Copyright (C) 2017-2018 Microchip Technology Inc.
+ * Copyright (C) 2017-2019 Microchip Technology Inc.
  */
 
-#include <linux/delay.h>
-#include <linux/export.h>
-#include <linux/gpio.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/iopoll.h>
 #include <linux/platform_data/microchip-ksz.h>
 #include <linux/phy.h>
-#include <linux/etherdevice.h>
 #include <linux/if_bridge.h>
 #include <net/dsa.h>
 #include <net/switchdev.h>
 
 #include "ksz_priv.h"
-#include "ksz_common.h"
 #include "ksz9477_reg.h"
+#include "ksz_common.h"
 
 static const struct {
 	int index;
@@ -259,6 +256,75 @@ 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)
+{
+	struct ksz_poll_ctx ctx = {
+		.dev = dev,
+		.port = port,
+		.offset = REG_PORT_MIB_CTRL_STAT__4,
+	};
+	struct ksz_port *p = &dev->ports[port];
+	u32 data;
+	int ret;
+
+	/* 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);
+
+	ret = readx_poll_timeout(ksz_pread32_poll, &ctx, data,
+				 !(data & MIB_COUNTER_READ), 10, 1000);
+
+	/* failed to read MIB. get out of loop */
+	if (ret < 0) {
+		dev_dbg(dev->dev, "Failed to get MIB\n");
+		return;
+	}
+
+	/* count resets upon read */
+	ksz_pread32(dev, port, REG_PORT_MIB_DATA, &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)
+{
+	u32 val = freeze ? MIB_COUNTER_FLUSH_FREEZE : 0;
+	struct ksz_port *p = &dev->ports[port];
+
+	/* enable/disable the port for flush/freeze function */
+	mutex_lock(&p->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(&p->mib.cnt_mutex);
+}
+
+static void ksz9477_port_init_cnt(struct ksz_device *dev, int port)
+{
+	struct ksz_port_mib *mib = &dev->ports[port].mib;
+
+	/* flush all enabled port MIB counters */
+	mutex_lock(&mib->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(&mib->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)
 {
@@ -342,47 +408,6 @@ static void ksz9477_get_strings(struct dsa_switch *ds, int port,
 	}
 }
 
-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(&dev->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,
-				    &data);
-			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, &data);
-
-		dev->mib_value[i] += (uint64_t)data;
-		buf[i] = dev->mib_value[i];
-	}
-
-	mutex_unlock(&dev->stats_mutex);
-}
-
 static void ksz9477_cfg_port_member(struct ksz_device *dev, int port,
 				    u8 member)
 {
@@ -425,12 +450,14 @@ static void ksz9477_port_stp_state_set(struct dsa_switch *ds, int port,
 			break;
 
 		member = dev->host_mask | p->vid_member;
+		mutex_lock(&dev->dev_mutex);
 
 		/* Port is a member of a bridge. */
 		if (dev->br_member & (1 << port)) {
 			dev->member |= (1 << port);
 			member = dev->member;
 		}
+		mutex_unlock(&dev->dev_mutex);
 		break;
 	case BR_STATE_BLOCKING:
 		data |= PORT_LEARN_DISABLE;
@@ -445,6 +472,7 @@ static void ksz9477_port_stp_state_set(struct dsa_switch *ds, int port,
 
 	ksz_pwrite8(dev, port, P_STP_CTRL, data);
 	p->stp_state = state;
+	mutex_lock(&dev->dev_mutex);
 	if (data & PORT_RX_ENABLE)
 		dev->rx_ports |= (1 << port);
 	else
@@ -469,6 +497,7 @@ static void ksz9477_port_stp_state_set(struct dsa_switch *ds, int port,
 	 */
 	if (forward != dev->member)
 		ksz_update_port_member(dev, port);
+	mutex_unlock(&dev->dev_mutex);
 }
 
 static void ksz9477_flush_dyn_mac_table(struct ksz_device *dev, int port)
@@ -966,6 +995,16 @@ static void ksz9477_port_mirror_del(struct dsa_switch *ds, int port,
 			     PORT_MIRROR_SNIFFER, false);
 }
 
+static void ksz9477_phy_setup(struct ksz_device *dev, int port,
+			      struct phy_device *phy)
+{
+	if (port < dev->phy_port_cnt) {
+		/* The MAC actually cannot run in 1000 half-duplex mode. */
+		phy_remove_link_mode(phy,
+				     ETHTOOL_LINK_MODE_1000baseT_Half_BIT);
+	}
+}
+
 static void ksz9477_port_setup(struct ksz_device *dev, int port, bool cpu_port)
 {
 	u8 data8;
@@ -1045,6 +1084,7 @@ static void ksz9477_port_setup(struct ksz_device *dev, int port, bool cpu_port)
 		ksz_pwrite8(dev, port, REG_PORT_XMII_CTRL_1, data8);
 		p->phydev.duplex = 1;
 	}
+	mutex_lock(&dev->dev_mutex);
 	if (cpu_port) {
 		member = dev->port_mask;
 		dev->on_ports = dev->host_mask;
@@ -1057,6 +1097,7 @@ static void ksz9477_port_setup(struct ksz_device *dev, int port, bool cpu_port)
 		if (p->phydev.link)
 			dev->live_ports |= (1 << port);
 	}
+	mutex_unlock(&dev->dev_mutex);
 	ksz9477_cfg_port_member(dev, port, member);
 
 	/* clear pending interrupts */
@@ -1141,9 +1182,14 @@ static int ksz9477_setup(struct dsa_switch *ds)
 	/* queue based egress rate limit */
 	ksz_cfg(dev, REG_SW_MAC_CTRL_5, SW_OUT_RATE_LIMIT_QUEUE_BASED, true);
 
+	/* enable global MIB counter freeze function */
+	ksz_cfg(dev, REG_SW_MAC_CTRL_6, SW_MIB_COUNTER_FREEZE, true);
+
 	/* start switch */
 	ksz_cfg(dev, REG_SW_OPERATION, SW_START, true);
 
+	ksz_init_mib_timer(dev);
+
 	return 0;
 }
 
@@ -1152,6 +1198,7 @@ static const struct dsa_switch_ops ksz9477_switch_ops = {
 	.setup			= ksz9477_setup,
 	.phy_read		= ksz9477_phy_read16,
 	.phy_write		= ksz9477_phy_write16,
+	.adjust_link		= ksz_adjust_link,
 	.port_enable		= ksz_enable_port,
 	.port_disable		= ksz_disable_port,
 	.get_strings		= ksz9477_get_strings,
@@ -1277,6 +1324,7 @@ static int ksz9477_switch_init(struct ksz_device *dev)
 	if (!dev->ports)
 		return -ENOMEM;
 	for (i = 0; i < dev->mib_port_cnt; i++) {
+		mutex_init(&dev->ports[i].mib.cnt_mutex);
 		dev->ports[i].mib.counters =
 			devm_kzalloc(dev->dev,
 				     sizeof(u64) *
@@ -1299,7 +1347,12 @@ static const struct ksz_dev_ops ksz9477_dev_ops = {
 	.get_port_addr = ksz9477_get_port_addr,
 	.cfg_port_member = ksz9477_cfg_port_member,
 	.flush_dyn_mac_table = ksz9477_flush_dyn_mac_table,
+	.phy_setup = ksz9477_phy_setup,
 	.port_setup = ksz9477_port_setup,
+	.r_mib_cnt = ksz9477_r_mib_cnt,
+	.r_mib_pkt = ksz9477_r_mib_pkt,
+	.freeze_mib = ksz9477_freeze_mib,
+	.port_init_cnt = ksz9477_port_init_cnt,
 	.shutdown = ksz9477_reset_switch,
 	.detect = ksz9477_switch_detect,
 	.init = ksz9477_switch_init,