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net: dsa: microchip: add MIB counter reading support
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Add background MIB counter reading support.

Port MIB counters should only be read when there is link.  Otherwise it is
a waste of time as hardware never increases those counters.  There are
exceptions as some switches keep track of dropped counts no matter what.

Signed-off-by: Tristram Ha <Tristram.Ha@microchip.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Tristram Ha authored and David S. Miller committed Feb 25, 2019
1 parent 42fc6a4 commit 7c6ff47
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Showing 4 changed files with 205 additions and 48 deletions.
123 changes: 81 additions & 42 deletions drivers/net/dsa/microchip/ksz9477.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -10,6 +10,7 @@
#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>
Expand All @@ -18,8 +19,8 @@
#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;
Expand Down Expand Up @@ -259,6 +260,75 @@ 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)
{
Expand Down Expand Up @@ -342,47 +412,6 @@ 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)
{
Expand Down Expand Up @@ -1151,9 +1180,14 @@ 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;
}

Expand Down Expand Up @@ -1287,6 +1321,7 @@ 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) *
Expand All @@ -1311,6 +1346,10 @@ static const struct ksz_dev_ops ksz9477_dev_ops = {
.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,
Expand Down
103 changes: 103 additions & 0 deletions drivers/net/dsa/microchip/ksz_common.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -40,6 +40,85 @@ void ksz_update_port_member(struct ksz_device *dev, int port)
}
EXPORT_SYMBOL_GPL(ksz_update_port_member);

static void port_r_cnt(struct ksz_device *dev, int port)
{
struct ksz_port_mib *mib = &dev->ports[port].mib;
u64 *dropped;

/* Some ports may not have MIB counters before SWITCH_COUNTER_NUM. */
while (mib->cnt_ptr < dev->reg_mib_cnt) {
dev->dev_ops->r_mib_cnt(dev, port, mib->cnt_ptr,
&mib->counters[mib->cnt_ptr]);
++mib->cnt_ptr;
}

/* last one in storage */
dropped = &mib->counters[dev->mib_cnt];

/* Some ports may not have MIB counters after SWITCH_COUNTER_NUM. */
while (mib->cnt_ptr < dev->mib_cnt) {
dev->dev_ops->r_mib_pkt(dev, port, mib->cnt_ptr,
dropped, &mib->counters[mib->cnt_ptr]);
++mib->cnt_ptr;
}
mib->cnt_ptr = 0;
}

static void ksz_mib_read_work(struct work_struct *work)
{
struct ksz_device *dev = container_of(work, struct ksz_device,
mib_read);
struct ksz_port_mib *mib;
struct ksz_port *p;
int i;

for (i = 0; i < dev->mib_port_cnt; i++) {
p = &dev->ports[i];
mib = &p->mib;
mutex_lock(&mib->cnt_mutex);

/* Only read MIB counters when the port is told to do.
* If not, read only dropped counters when link is not up.
*/
if (!p->read) {
const struct dsa_port *dp = dsa_to_port(dev->ds, i);

if (!netif_carrier_ok(dp->slave))
mib->cnt_ptr = dev->reg_mib_cnt;
}
port_r_cnt(dev, i);
p->read = false;
mutex_unlock(&mib->cnt_mutex);
}
}

static void mib_monitor(struct timer_list *t)
{
struct ksz_device *dev = from_timer(dev, t, mib_read_timer);

mod_timer(&dev->mib_read_timer, jiffies + dev->mib_read_interval);
schedule_work(&dev->mib_read);
}

void ksz_init_mib_timer(struct ksz_device *dev)
{
int i;

/* Read MIB counters every 30 seconds to avoid overflow. */
dev->mib_read_interval = msecs_to_jiffies(30000);

INIT_WORK(&dev->mib_read, ksz_mib_read_work);
timer_setup(&dev->mib_read_timer, mib_monitor, 0);

for (i = 0; i < dev->mib_port_cnt; i++)
dev->dev_ops->port_init_cnt(dev, i);

/* Start the timer 2 seconds later. */
dev->mib_read_timer.expires = jiffies + msecs_to_jiffies(2000);
add_timer(&dev->mib_read_timer);
}
EXPORT_SYMBOL_GPL(ksz_init_mib_timer);

int ksz_phy_read16(struct dsa_switch *ds, int addr, int reg)
{
struct ksz_device *dev = ds->priv;
Expand Down Expand Up @@ -72,6 +151,24 @@ int ksz_sset_count(struct dsa_switch *ds, int port, int sset)
}
EXPORT_SYMBOL_GPL(ksz_sset_count);

void ksz_get_ethtool_stats(struct dsa_switch *ds, int port, uint64_t *buf)
{
const struct dsa_port *dp = dsa_to_port(ds, port);
struct ksz_device *dev = ds->priv;
struct ksz_port_mib *mib;

mib = &dev->ports[port].mib;
mutex_lock(&mib->cnt_mutex);

/* Only read dropped counters if no link. */
if (!netif_carrier_ok(dp->slave))
mib->cnt_ptr = dev->reg_mib_cnt;
port_r_cnt(dev, port);
memcpy(buf, mib->counters, dev->mib_cnt * sizeof(u64));
mutex_unlock(&mib->cnt_mutex);
}
EXPORT_SYMBOL_GPL(ksz_get_ethtool_stats);

int ksz_port_bridge_join(struct dsa_switch *ds, int port,
struct net_device *br)
{
Expand Down Expand Up @@ -339,6 +436,12 @@ EXPORT_SYMBOL(ksz_switch_register);

void ksz_switch_remove(struct ksz_device *dev)
{
/* timer started */
if (dev->mib_read_timer.expires) {
del_timer_sync(&dev->mib_read_timer);
flush_work(&dev->mib_read);
}

dev->dev_ops->exit(dev);
dsa_unregister_switch(dev->ds);

Expand Down
18 changes: 17 additions & 1 deletion drivers/net/dsa/microchip/ksz_common.h
View file
Original file line number Diff line number Diff line change
@@ -1,19 +1,21 @@
/* SPDX-License-Identifier: GPL-2.0
* Microchip switch driver common header
*
* Copyright (C) 2017-2018 Microchip Technology Inc.
* Copyright (C) 2017-2019 Microchip Technology Inc.
*/

#ifndef __KSZ_COMMON_H
#define __KSZ_COMMON_H

void ksz_update_port_member(struct ksz_device *dev, int port);
void ksz_init_mib_timer(struct ksz_device *dev);

/* Common DSA access functions */

int ksz_phy_read16(struct dsa_switch *ds, int addr, int reg);
int ksz_phy_write16(struct dsa_switch *ds, int addr, int reg, u16 val);
int ksz_sset_count(struct dsa_switch *ds, int port, int sset);
void ksz_get_ethtool_stats(struct dsa_switch *ds, int port, uint64_t *buf);
int ksz_port_bridge_join(struct dsa_switch *ds, int port,
struct net_device *br);
void ksz_port_bridge_leave(struct dsa_switch *ds, int port,
Expand Down Expand Up @@ -211,4 +213,18 @@ static void ksz_port_cfg(struct ksz_device *dev, int port, int offset, u8 bits,
ksz_write8(dev, addr, data);
}

struct ksz_poll_ctx {
struct ksz_device *dev;
int port;
int offset;
};

static inline u32 ksz_pread32_poll(struct ksz_poll_ctx *ctx)
{
u32 data;

ksz_pread32(ctx->dev, ctx->port, ctx->offset, &data);
return data;
}

#endif
9 changes: 4 additions & 5 deletions drivers/net/dsa/microchip/ksz_priv.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -14,15 +14,14 @@
#include <linux/etherdevice.h>
#include <net/dsa.h>

#include "ksz9477_reg.h"

struct ksz_io_ops;

struct vlan_table {
u32 table[3];
};

struct ksz_port_mib {
struct mutex cnt_mutex; /* structure access */
u8 cnt_ptr;
u64 *counters;
};
Expand All @@ -38,7 +37,8 @@ struct ksz_port {
u32 fiber:1; /* port is fiber */
u32 sgmii:1; /* port is SGMII */
u32 force:1;
u32 link_just_down:1; /* link just goes down */
u32 read:1; /* read MIB counters in background */
u32 freeze:1; /* MIB counter freeze is enabled */

struct ksz_port_mib mib;
};
Expand Down Expand Up @@ -79,8 +79,6 @@ struct ksz_device {

struct vlan_table *vlan_cache;

u64 mib_value[TOTAL_SWITCH_COUNTER_NUM];

u8 *txbuf;

struct ksz_port *ports;
Expand Down Expand Up @@ -153,6 +151,7 @@ struct ksz_dev_ops {
u64 *cnt);
void (*r_mib_pkt)(struct ksz_device *dev, int port, u16 addr,
u64 *dropped, u64 *cnt);
void (*freeze_mib)(struct ksz_device *dev, int port, bool freeze);
void (*port_init_cnt)(struct ksz_device *dev, int port);
int (*shutdown)(struct ksz_device *dev);
int (*detect)(struct ksz_device *dev);
Expand Down

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