Revision 2bbd00aef0671bfe3c2ca5ba67097246257de125 authored by Johannes Weiner on 26 February 2021, 01:16:47 UTC, committed by Linus Torvalds on 26 February 2021, 17:41:00 UTC
On NOHZ, the periodic vmstat flushers on each CPU can go to sleep and won't wake up until stat changes are detected in the per-cpu deltas of the zone vmstat counters. In commit 75ef71840539 ("mm, vmstat: add infrastructure for per-node vmstats") per-node counters were introduced, and subsequently most stats were moved from the zone to the node level. However, the node counters weren't added to the NOHZ wakeup detection. In theory this can cause per-cpu errors to remain in the user-reported stats indefinitely. In practice this only affects a handful of sub counters (file_mapped, dirty and writeback e.g.) because other page state changes at the node level likely involve a change at the zone level as well (alloc and free, lru ops). Also, nobody has complained. Fix it up for completeness: wake up vmstat refreshing on node changes. Also remove the BUILD_BUG_ONs that assert counter size; we haven't relied on it since we added sizeof() to the range calculation in commit 13c9aaf7fa01 ("mm/vmstat.c: fix NUMA statistics updates"). Link: https://lkml.kernel.org/r/20210202184342.118513-1-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent a052d4d
gpio-bd70528.c
// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2018 ROHM Semiconductors
// gpio-bd70528.c ROHM BD70528MWV gpio driver
#include <linux/gpio/driver.h>
#include <linux/mfd/rohm-bd70528.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#define GPIO_IN_REG(offset) (BD70528_REG_GPIO1_IN + (offset) * 2)
#define GPIO_OUT_REG(offset) (BD70528_REG_GPIO1_OUT + (offset) * 2)
struct bd70528_gpio {
struct regmap *regmap;
struct device *dev;
struct gpio_chip gpio;
};
static int bd70528_set_debounce(struct bd70528_gpio *bdgpio,
unsigned int offset, unsigned int debounce)
{
u8 val;
switch (debounce) {
case 0:
val = BD70528_DEBOUNCE_DISABLE;
break;
case 1 ... 15000:
val = BD70528_DEBOUNCE_15MS;
break;
case 15001 ... 30000:
val = BD70528_DEBOUNCE_30MS;
break;
case 30001 ... 50000:
val = BD70528_DEBOUNCE_50MS;
break;
default:
dev_err(bdgpio->dev,
"Invalid debounce value %u\n", debounce);
return -EINVAL;
}
return regmap_update_bits(bdgpio->regmap, GPIO_IN_REG(offset),
BD70528_DEBOUNCE_MASK, val);
}
static int bd70528_get_direction(struct gpio_chip *chip, unsigned int offset)
{
struct bd70528_gpio *bdgpio = gpiochip_get_data(chip);
int val, ret;
/* Do we need to do something to IRQs here? */
ret = regmap_read(bdgpio->regmap, GPIO_OUT_REG(offset), &val);
if (ret) {
dev_err(bdgpio->dev, "Could not read gpio direction\n");
return ret;
}
if (val & BD70528_GPIO_OUT_EN_MASK)
return GPIO_LINE_DIRECTION_OUT;
return GPIO_LINE_DIRECTION_IN;
}
static int bd70528_gpio_set_config(struct gpio_chip *chip, unsigned int offset,
unsigned long config)
{
struct bd70528_gpio *bdgpio = gpiochip_get_data(chip);
switch (pinconf_to_config_param(config)) {
case PIN_CONFIG_DRIVE_OPEN_DRAIN:
return regmap_update_bits(bdgpio->regmap,
GPIO_OUT_REG(offset),
BD70528_GPIO_DRIVE_MASK,
BD70528_GPIO_OPEN_DRAIN);
break;
case PIN_CONFIG_DRIVE_PUSH_PULL:
return regmap_update_bits(bdgpio->regmap,
GPIO_OUT_REG(offset),
BD70528_GPIO_DRIVE_MASK,
BD70528_GPIO_PUSH_PULL);
break;
case PIN_CONFIG_INPUT_DEBOUNCE:
return bd70528_set_debounce(bdgpio, offset,
pinconf_to_config_argument(config));
break;
default:
break;
}
return -ENOTSUPP;
}
static int bd70528_direction_input(struct gpio_chip *chip, unsigned int offset)
{
struct bd70528_gpio *bdgpio = gpiochip_get_data(chip);
/* Do we need to do something to IRQs here? */
return regmap_update_bits(bdgpio->regmap, GPIO_OUT_REG(offset),
BD70528_GPIO_OUT_EN_MASK,
BD70528_GPIO_OUT_DISABLE);
}
static void bd70528_gpio_set(struct gpio_chip *chip, unsigned int offset,
int value)
{
int ret;
struct bd70528_gpio *bdgpio = gpiochip_get_data(chip);
u8 val = (value) ? BD70528_GPIO_OUT_HI : BD70528_GPIO_OUT_LO;
ret = regmap_update_bits(bdgpio->regmap, GPIO_OUT_REG(offset),
BD70528_GPIO_OUT_MASK, val);
if (ret)
dev_err(bdgpio->dev, "Could not set gpio to %d\n", value);
}
static int bd70528_direction_output(struct gpio_chip *chip, unsigned int offset,
int value)
{
struct bd70528_gpio *bdgpio = gpiochip_get_data(chip);
bd70528_gpio_set(chip, offset, value);
return regmap_update_bits(bdgpio->regmap, GPIO_OUT_REG(offset),
BD70528_GPIO_OUT_EN_MASK,
BD70528_GPIO_OUT_ENABLE);
}
#define GPIO_IN_STATE_MASK(offset) (BD70528_GPIO_IN_STATE_BASE << (offset))
static int bd70528_gpio_get_o(struct bd70528_gpio *bdgpio, unsigned int offset)
{
int ret;
unsigned int val;
ret = regmap_read(bdgpio->regmap, GPIO_OUT_REG(offset), &val);
if (!ret)
ret = !!(val & BD70528_GPIO_OUT_MASK);
else
dev_err(bdgpio->dev, "GPIO (out) state read failed\n");
return ret;
}
static int bd70528_gpio_get_i(struct bd70528_gpio *bdgpio, unsigned int offset)
{
unsigned int val;
int ret;
ret = regmap_read(bdgpio->regmap, BD70528_REG_GPIO_STATE, &val);
if (!ret)
ret = !(val & GPIO_IN_STATE_MASK(offset));
else
dev_err(bdgpio->dev, "GPIO (in) state read failed\n");
return ret;
}
static int bd70528_gpio_get(struct gpio_chip *chip, unsigned int offset)
{
int ret;
struct bd70528_gpio *bdgpio = gpiochip_get_data(chip);
/*
* There is a race condition where someone might be changing the
* GPIO direction after we get it but before we read the value. But
* application design where GPIO direction may be changed just when
* we read GPIO value would be pointless as reader could not know
* whether the returned high/low state is caused by input or output.
* Or then there must be other ways to mitigate the issue. Thus
* locking would make no sense.
*/
ret = bd70528_get_direction(chip, offset);
if (ret == GPIO_LINE_DIRECTION_OUT)
ret = bd70528_gpio_get_o(bdgpio, offset);
else if (ret == GPIO_LINE_DIRECTION_IN)
ret = bd70528_gpio_get_i(bdgpio, offset);
else
dev_err(bdgpio->dev, "failed to read GPIO direction\n");
return ret;
}
static int bd70528_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct bd70528_gpio *bdgpio;
int ret;
bdgpio = devm_kzalloc(dev, sizeof(*bdgpio), GFP_KERNEL);
if (!bdgpio)
return -ENOMEM;
bdgpio->dev = dev;
bdgpio->gpio.parent = dev->parent;
bdgpio->gpio.label = "bd70528-gpio";
bdgpio->gpio.owner = THIS_MODULE;
bdgpio->gpio.get_direction = bd70528_get_direction;
bdgpio->gpio.direction_input = bd70528_direction_input;
bdgpio->gpio.direction_output = bd70528_direction_output;
bdgpio->gpio.set_config = bd70528_gpio_set_config;
bdgpio->gpio.can_sleep = true;
bdgpio->gpio.get = bd70528_gpio_get;
bdgpio->gpio.set = bd70528_gpio_set;
bdgpio->gpio.ngpio = 4;
bdgpio->gpio.base = -1;
#ifdef CONFIG_OF_GPIO
bdgpio->gpio.of_node = dev->parent->of_node;
#endif
bdgpio->regmap = dev_get_regmap(dev->parent, NULL);
if (!bdgpio->regmap)
return -ENODEV;
ret = devm_gpiochip_add_data(dev, &bdgpio->gpio, bdgpio);
if (ret)
dev_err(dev, "gpio_init: Failed to add bd70528-gpio\n");
return ret;
}
static struct platform_driver bd70528_gpio = {
.driver = {
.name = "bd70528-gpio"
},
.probe = bd70528_probe,
};
module_platform_driver(bd70528_gpio);
MODULE_AUTHOR("Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>");
MODULE_DESCRIPTION("BD70528 voltage regulator driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:bd70528-gpio");
![swh spinner](/static/img/swh-spinner.gif)
Computing file changes ...