diff options
| -rw-r--r-- | arch/arm/kernel/process.c | 12 | ||||
| -rw-r--r-- | arch/arm64/kernel/process.c | 3 | ||||
| -rw-r--r-- | drivers/power/reset/restart-poweroff.c | 3 | ||||
| -rw-r--r-- | drivers/watchdog/alim7101_wdt.c | 42 | ||||
| -rw-r--r-- | drivers/watchdog/moxart_wdt.c | 32 | ||||
| -rw-r--r-- | drivers/watchdog/sunxi_wdt.c | 31 | ||||
| -rw-r--r-- | include/linux/reboot.h | 3 | ||||
| -rw-r--r-- | kernel/reboot.c | 81 |
8 files changed, 165 insertions, 42 deletions
diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c index a0a691d1cbee..fe972a2f3df3 100644 --- a/arch/arm/kernel/process.c +++ b/arch/arm/kernel/process.c @@ -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); diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index 89f41f7d27dd..c3065dbc4fa2 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -72,7 +72,6 @@ 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. @@ -154,6 +153,8 @@ 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. diff --git a/drivers/power/reset/restart-poweroff.c b/drivers/power/reset/restart-poweroff.c index 3e51f8d29bfe..edd707ee7281 100644 --- a/drivers/power/reset/restart-poweroff.c +++ b/drivers/power/reset/restart-poweroff.c @@ -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) diff --git a/drivers/watchdog/alim7101_wdt.c b/drivers/watchdog/alim7101_wdt.c index 996b2f7d330e..665e0e7dfe1e 100644 --- a/drivers/watchdog/alim7101_wdt.c +++ b/drivers/watchdog/alim7101_wdt.c @@ -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: diff --git a/drivers/watchdog/moxart_wdt.c b/drivers/watchdog/moxart_wdt.c index 4aa3a8a876fe..a64405b82596 100644 --- a/drivers/watchdog/moxart_wdt.c +++ b/drivers/watchdog/moxart_wdt.c @@ -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; } diff --git a/drivers/watchdog/sunxi_wdt.c b/drivers/watchdog/sunxi_wdt.c index 60deb9d304c0..480bb557f353 100644 --- a/drivers/watchdog/sunxi_wdt.c +++ b/drivers/watchdog/sunxi_wdt.c @@ -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); diff --git a/include/linux/reboot.h b/include/linux/reboot.h index 48bf152761c7..67fc8fcdc4b0 100644 --- a/include/linux/reboot.h +++ b/include/linux/reboot.h @@ -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. diff --git a/kernel/reboot.c b/kernel/reboot.c index a3a9e240fcdb..5925f5ae8dff 100644 --- a/kernel/reboot.c +++ b/kernel/reboot.c @@ -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 */ |