Immutable branch with restart handler patches for v3.18

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Merge tag 'tags/restart-handler-for-v3.18' into next

Immutable branch with restart handler patches for v3.18
This commit is contained in:
Sebastian Reichel 2014-09-26 19:45:11 +02:00
commit 1670d8569e
8 changed files with 165 additions and 42 deletions

View File

@ -114,18 +114,13 @@ void soft_restart(unsigned long addr)
BUG();
}
static void null_restart(enum reboot_mode reboot_mode, const char *cmd)
{
}
/*
* Function pointers to optional machine specific functions
*/
void (*pm_power_off)(void);
EXPORT_SYMBOL(pm_power_off);
void (*arm_pm_restart)(enum reboot_mode reboot_mode, const char *cmd) = null_restart;
EXPORT_SYMBOL_GPL(arm_pm_restart);
void (*arm_pm_restart)(enum reboot_mode reboot_mode, const char *cmd);
/*
* This is our default idle handler.
@ -230,7 +225,10 @@ void machine_restart(char *cmd)
local_irq_disable();
smp_send_stop();
arm_pm_restart(reboot_mode, cmd);
if (arm_pm_restart)
arm_pm_restart(reboot_mode, cmd);
else
do_kernel_restart(cmd);
/* Give a grace period for failure to restart of 1s */
mdelay(1000);

View File

@ -98,7 +98,6 @@ void (*pm_power_off)(void);
EXPORT_SYMBOL_GPL(pm_power_off);
void (*arm_pm_restart)(enum reboot_mode reboot_mode, const char *cmd);
EXPORT_SYMBOL_GPL(arm_pm_restart);
/*
* This is our default idle handler.
@ -180,6 +179,8 @@ void machine_restart(char *cmd)
/* Now call the architecture specific reboot code. */
if (arm_pm_restart)
arm_pm_restart(reboot_mode, cmd);
else
do_kernel_restart(cmd);
/*
* Whoops - the architecture was unable to reboot.

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@ -20,7 +20,8 @@
static void restart_poweroff_do_poweroff(void)
{
arm_pm_restart(REBOOT_HARD, NULL);
reboot_mode = REBOOT_HARD;
machine_restart(NULL);
}
static int restart_poweroff_probe(struct platform_device *pdev)

View File

@ -301,6 +301,28 @@ static struct miscdevice wdt_miscdev = {
.fops = &wdt_fops,
};
static int wdt_restart_handle(struct notifier_block *this, unsigned long mode,
void *cmd)
{
/*
* Cobalt devices have no way of rebooting themselves other
* than getting the watchdog to pull reset, so we restart the
* watchdog on reboot with no heartbeat.
*/
wdt_change(WDT_ENABLE);
/* loop until the watchdog fires */
while (true)
;
return NOTIFY_DONE;
}
static struct notifier_block wdt_restart_handler = {
.notifier_call = wdt_restart_handle,
.priority = 128,
};
/*
* Notifier for system down
*/
@ -311,15 +333,6 @@ static int wdt_notify_sys(struct notifier_block *this,
if (code == SYS_DOWN || code == SYS_HALT)
wdt_turnoff();
if (code == SYS_RESTART) {
/*
* Cobalt devices have no way of rebooting themselves other
* than getting the watchdog to pull reset, so we restart the
* watchdog on reboot with no heartbeat
*/
wdt_change(WDT_ENABLE);
pr_info("Watchdog timer is now enabled with no heartbeat - should reboot in ~1 second\n");
}
return NOTIFY_DONE;
}
@ -338,6 +351,7 @@ static void __exit alim7101_wdt_unload(void)
/* Deregister */
misc_deregister(&wdt_miscdev);
unregister_reboot_notifier(&wdt_notifier);
unregister_restart_handler(&wdt_restart_handler);
pci_dev_put(alim7101_pmu);
}
@ -390,11 +404,17 @@ static int __init alim7101_wdt_init(void)
goto err_out;
}
rc = register_restart_handler(&wdt_restart_handler);
if (rc) {
pr_err("cannot register restart handler (err=%d)\n", rc);
goto err_out_reboot;
}
rc = misc_register(&wdt_miscdev);
if (rc) {
pr_err("cannot register miscdev on minor=%d (err=%d)\n",
wdt_miscdev.minor, rc);
goto err_out_reboot;
goto err_out_restart;
}
if (nowayout)
@ -404,6 +424,8 @@ static int __init alim7101_wdt_init(void)
timeout, nowayout);
return 0;
err_out_restart:
unregister_restart_handler(&wdt_restart_handler);
err_out_reboot:
unregister_reboot_notifier(&wdt_notifier);
err_out:

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@ -15,12 +15,12 @@
#include <linux/module.h>
#include <linux/err.h>
#include <linux/kernel.h>
#include <linux/notifier.h>
#include <linux/platform_device.h>
#include <linux/reboot.h>
#include <linux/watchdog.h>
#include <linux/moduleparam.h>
#include <asm/system_misc.h>
#define REG_COUNT 0x4
#define REG_MODE 0x8
#define REG_ENABLE 0xC
@ -29,17 +29,22 @@ struct moxart_wdt_dev {
struct watchdog_device dev;
void __iomem *base;
unsigned int clock_frequency;
struct notifier_block restart_handler;
};
static struct moxart_wdt_dev *moxart_restart_ctx;
static int heartbeat;
static void moxart_wdt_restart(enum reboot_mode reboot_mode, const char *cmd)
static int moxart_restart_handle(struct notifier_block *this,
unsigned long mode, void *cmd)
{
writel(1, moxart_restart_ctx->base + REG_COUNT);
writel(0x5ab9, moxart_restart_ctx->base + REG_MODE);
writel(0x03, moxart_restart_ctx->base + REG_ENABLE);
struct moxart_wdt_dev *moxart_wdt = container_of(this,
struct moxart_wdt_dev,
restart_handler);
writel(1, moxart_wdt->base + REG_COUNT);
writel(0x5ab9, moxart_wdt->base + REG_MODE);
writel(0x03, moxart_wdt->base + REG_ENABLE);
return NOTIFY_DONE;
}
static int moxart_wdt_stop(struct watchdog_device *wdt_dev)
@ -136,8 +141,12 @@ static int moxart_wdt_probe(struct platform_device *pdev)
if (err)
return err;
moxart_restart_ctx = moxart_wdt;
arm_pm_restart = moxart_wdt_restart;
moxart_wdt->restart_handler.notifier_call = moxart_restart_handle;
moxart_wdt->restart_handler.priority = 128;
err = register_restart_handler(&moxart_wdt->restart_handler);
if (err)
dev_err(dev, "cannot register restart notifier (err=%d)\n",
err);
dev_dbg(dev, "Watchdog enabled (heartbeat=%d sec, nowayout=%d)\n",
moxart_wdt->dev.timeout, nowayout);
@ -149,9 +158,8 @@ static int moxart_wdt_remove(struct platform_device *pdev)
{
struct moxart_wdt_dev *moxart_wdt = platform_get_drvdata(pdev);
arm_pm_restart = NULL;
unregister_restart_handler(&moxart_wdt->restart_handler);
moxart_wdt_stop(&moxart_wdt->dev);
watchdog_unregister_device(&moxart_wdt->dev);
return 0;
}

View File

@ -21,14 +21,13 @@
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/notifier.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/reboot.h>
#include <linux/types.h>
#include <linux/watchdog.h>
#include <asm/system_misc.h>
#define WDT_MAX_TIMEOUT 16
#define WDT_MIN_TIMEOUT 1
#define WDT_MODE_TIMEOUT(n) ((n) << 3)
@ -50,6 +49,7 @@ static unsigned int timeout = WDT_MAX_TIMEOUT;
struct sunxi_wdt_dev {
struct watchdog_device wdt_dev;
void __iomem *wdt_base;
struct notifier_block restart_handler;
};
/*
@ -74,24 +74,29 @@ static const int wdt_timeout_map[] = {
[16] = 0xB, /* 16s */
};
static void __iomem *reboot_wdt_base;
static void sun4i_wdt_restart(enum reboot_mode mode, const char *cmd)
static int sunxi_restart_handle(struct notifier_block *this, unsigned long mode,
void *cmd)
{
struct sunxi_wdt_dev *sunxi_wdt = container_of(this,
struct sunxi_wdt_dev,
restart_handler);
void __iomem *wdt_base = sunxi_wdt->wdt_base;
/* Enable timer and set reset bit in the watchdog */
writel(WDT_MODE_EN | WDT_MODE_RST_EN, reboot_wdt_base + WDT_MODE);
writel(WDT_MODE_EN | WDT_MODE_RST_EN, wdt_base + WDT_MODE);
/*
* Restart the watchdog. The default (and lowest) interval
* value for the watchdog is 0.5s.
*/
writel(WDT_CTRL_RELOAD, reboot_wdt_base + WDT_CTRL);
writel(WDT_CTRL_RELOAD, wdt_base + WDT_CTRL);
while (1) {
mdelay(5);
writel(WDT_MODE_EN | WDT_MODE_RST_EN,
reboot_wdt_base + WDT_MODE);
writel(WDT_MODE_EN | WDT_MODE_RST_EN, wdt_base + WDT_MODE);
}
return NOTIFY_DONE;
}
static int sunxi_wdt_ping(struct watchdog_device *wdt_dev)
@ -205,8 +210,12 @@ static int sunxi_wdt_probe(struct platform_device *pdev)
if (unlikely(err))
return err;
reboot_wdt_base = sunxi_wdt->wdt_base;
arm_pm_restart = sun4i_wdt_restart;
sunxi_wdt->restart_handler.notifier_call = sunxi_restart_handle;
sunxi_wdt->restart_handler.priority = 128;
err = register_restart_handler(&sunxi_wdt->restart_handler);
if (err)
dev_err(&pdev->dev,
"cannot register restart handler (err=%d)\n", err);
dev_info(&pdev->dev, "Watchdog enabled (timeout=%d sec, nowayout=%d)",
sunxi_wdt->wdt_dev.timeout, nowayout);
@ -218,7 +227,7 @@ static int sunxi_wdt_remove(struct platform_device *pdev)
{
struct sunxi_wdt_dev *sunxi_wdt = platform_get_drvdata(pdev);
arm_pm_restart = NULL;
unregister_restart_handler(&sunxi_wdt->restart_handler);
watchdog_unregister_device(&sunxi_wdt->wdt_dev);
watchdog_set_drvdata(&sunxi_wdt->wdt_dev, NULL);

View File

@ -38,6 +38,9 @@ extern int reboot_force;
extern int register_reboot_notifier(struct notifier_block *);
extern int unregister_reboot_notifier(struct notifier_block *);
extern int register_restart_handler(struct notifier_block *);
extern int unregister_restart_handler(struct notifier_block *);
extern void do_kernel_restart(char *cmd);
/*
* Architecture-specific implementations of sys_reboot commands.

View File

@ -104,6 +104,87 @@ int unregister_reboot_notifier(struct notifier_block *nb)
}
EXPORT_SYMBOL(unregister_reboot_notifier);
/*
* Notifier list for kernel code which wants to be called
* to restart the system.
*/
static ATOMIC_NOTIFIER_HEAD(restart_handler_list);
/**
* register_restart_handler - Register function to be called to reset
* the system
* @nb: Info about handler function to be called
* @nb->priority: Handler priority. Handlers should follow the
* following guidelines for setting priorities.
* 0: Restart handler of last resort,
* with limited restart capabilities
* 128: Default restart handler; use if no other
* restart handler is expected to be available,
* and/or if restart functionality is
* sufficient to restart the entire system
* 255: Highest priority restart handler, will
* preempt all other restart handlers
*
* Registers a function with code to be called to restart the
* system.
*
* Registered functions will be called from machine_restart as last
* step of the restart sequence (if the architecture specific
* machine_restart function calls do_kernel_restart - see below
* for details).
* Registered functions are expected to restart the system immediately.
* If more than one function is registered, the restart handler priority
* selects which function will be called first.
*
* Restart handlers are expected to be registered from non-architecture
* code, typically from drivers. A typical use case would be a system
* where restart functionality is provided through a watchdog. Multiple
* restart handlers may exist; for example, one restart handler might
* restart the entire system, while another only restarts the CPU.
* In such cases, the restart handler which only restarts part of the
* hardware is expected to register with low priority to ensure that
* it only runs if no other means to restart the system is available.
*
* Currently always returns zero, as atomic_notifier_chain_register()
* always returns zero.
*/
int register_restart_handler(struct notifier_block *nb)
{
return atomic_notifier_chain_register(&restart_handler_list, nb);
}
EXPORT_SYMBOL(register_restart_handler);
/**
* unregister_restart_handler - Unregister previously registered
* restart handler
* @nb: Hook to be unregistered
*
* Unregisters a previously registered restart handler function.
*
* Returns zero on success, or %-ENOENT on failure.
*/
int unregister_restart_handler(struct notifier_block *nb)
{
return atomic_notifier_chain_unregister(&restart_handler_list, nb);
}
EXPORT_SYMBOL(unregister_restart_handler);
/**
* do_kernel_restart - Execute kernel restart handler call chain
*
* Calls functions registered with register_restart_handler.
*
* Expected to be called from machine_restart as last step of the restart
* sequence.
*
* Restarts the system immediately if a restart handler function has been
* registered. Otherwise does nothing.
*/
void do_kernel_restart(char *cmd)
{
atomic_notifier_call_chain(&restart_handler_list, reboot_mode, cmd);
}
void migrate_to_reboot_cpu(void)
{
/* The boot cpu is always logical cpu 0 */