diff options
Diffstat (limited to 'drivers/watchdog/mpcore_wdt.c')
| -rw-r--r-- | drivers/watchdog/mpcore_wdt.c | 98 |
1 files changed, 92 insertions, 6 deletions
diff --git a/drivers/watchdog/mpcore_wdt.c b/drivers/watchdog/mpcore_wdt.c index 7c741dc987b..96ae2465c25 100644 --- a/drivers/watchdog/mpcore_wdt.c +++ b/drivers/watchdog/mpcore_wdt.c @@ -35,11 +35,13 @@ #include <linux/uaccess.h> #include <linux/slab.h> #include <linux/io.h> +#include <linux/cpufreq.h> +#include <linux/kexec.h> #include <asm/smp_twd.h> struct mpcore_wdt { - unsigned long timer_alive; + cpumask_t timer_alive; struct device *dev; void __iomem *base; int irq; @@ -50,6 +52,8 @@ struct mpcore_wdt { static struct platform_device *mpcore_wdt_pdev; static DEFINE_SPINLOCK(wdt_lock); +static DEFINE_PER_CPU(unsigned long, mpcore_wdt_rate); + #define TIMER_MARGIN 60 static int mpcore_margin = TIMER_MARGIN; module_param(mpcore_margin, int, 0); @@ -70,6 +74,8 @@ MODULE_PARM_DESC(mpcore_noboot, "MPcore watchdog action, " "set to 1 to ignore reboots, 0 to reboot (default=" __MODULE_STRING(ONLY_TESTING) ")"); +#define MPCORE_WDT_PERIPHCLK_PRESCALER 2 + /* * This is the interrupt handler. Note that we only use this * in testing mode, so don't actually do a reboot here. @@ -102,9 +108,8 @@ static void mpcore_wdt_keepalive(struct mpcore_wdt *wdt) spin_lock(&wdt_lock); /* Assume prescale is set to 256 */ - count = __raw_readl(wdt->base + TWD_WDOG_COUNTER); - count = (0xFFFFFFFFU - count) * (HZ / 5); - count = (count / 256) * mpcore_margin; + count = per_cpu(mpcore_wdt_rate, smp_processor_id()) / 256; + count = count*mpcore_margin; /* Reload the counter */ writel(count + wdt->perturb, wdt->base + TWD_WDOG_LOAD); @@ -112,6 +117,56 @@ static void mpcore_wdt_keepalive(struct mpcore_wdt *wdt) spin_unlock(&wdt_lock); } +static void mpcore_wdt_set_rate(unsigned long new_rate) +{ + unsigned long count; + unsigned long long rate_tmp; + unsigned long old_rate; + + spin_lock(&wdt_lock); + old_rate = per_cpu(mpcore_wdt_rate, smp_processor_id()); + per_cpu(mpcore_wdt_rate, smp_processor_id()) = new_rate; + + if (mpcore_wdt_dev) { + struct mpcore_wdt *wdt = platform_get_drvdata(mpcore_wdt_dev); + count = readl(wdt->base + TWD_WDOG_COUNTER); + /* The goal: count = count * (new_rate/old_rate); */ + rate_tmp = (unsigned long long)count * new_rate; + do_div(rate_tmp, old_rate); + count = rate_tmp; + writel(count + wdt->perturb, wdt->base + TWD_WDOG_LOAD); + wdt->perturb = wdt->perturb ? 0 : 1; + } + spin_unlock(&wdt_lock); +} + +static void mpcore_wdt_update_cpu_frequency_on_cpu(void *data) +{ + struct cpufreq_freqs *freq = data; + mpcore_wdt_set_rate((freq->new * 1000) / + MPCORE_WDT_PERIPHCLK_PRESCALER); +} + +static int mpcore_wdt_cpufreq_notifier(struct notifier_block *nb, + unsigned long event, void *data) +{ + struct cpufreq_freqs *freq = data; + + if (event == CPUFREQ_RESUMECHANGE || + (event == CPUFREQ_PRECHANGE && freq->new > freq->old) || + (event == CPUFREQ_POSTCHANGE && freq->new < freq->old)) + smp_call_function_single(freq->cpu, + mpcore_wdt_update_cpu_frequency_on_cpu, + freq, 1); + + return 0; +} + +static struct notifier_block mpcore_wdt_cpufreq_notifier_block = { + .notifier_call = mpcore_wdt_cpufreq_notifier, +}; + + static void mpcore_wdt_stop(struct mpcore_wdt *wdt) { spin_lock(&wdt_lock); @@ -146,6 +201,20 @@ static int mpcore_wdt_set_heartbeat(int t) return 0; } +static int mpcore_wdt_stop_notifier(struct notifier_block *this, + unsigned long event, void *ptr) +{ + struct mpcore_wdt *wdt = platform_get_drvdata(mpcore_wdt_dev); + printk(KERN_INFO "Stopping watchdog on non-crashing core %u\n", + smp_processor_id()); + mpcore_wdt_stop(wdt); + return NOTIFY_STOP; +} + +static struct notifier_block mpcore_wdt_stop_block = { + .notifier_call = mpcore_wdt_stop_notifier, +}; + /* * /dev/watchdog handling */ @@ -153,7 +222,7 @@ static int mpcore_wdt_open(struct inode *inode, struct file *file) { struct mpcore_wdt *wdt = platform_get_drvdata(mpcore_wdt_pdev); - if (test_and_set_bit(0, &wdt->timer_alive)) + if (cpumask_test_and_set_cpu(smp_processor_id(), &wdt->timer_alive)) return -EBUSY; if (nowayout) @@ -161,6 +230,9 @@ static int mpcore_wdt_open(struct inode *inode, struct file *file) file->private_data = wdt; + atomic_notifier_chain_register(&crash_percpu_notifier_list, + &mpcore_wdt_stop_block); + /* * Activate timer */ @@ -184,7 +256,7 @@ static int mpcore_wdt_release(struct inode *inode, struct file *file) "unexpected close, not stopping watchdog!\n"); mpcore_wdt_keepalive(wdt); } - clear_bit(0, &wdt->timer_alive); + cpumask_clear_cpu(smp_processor_id(), &wdt->timer_alive); wdt->expect_close = 0; return 0; } @@ -427,6 +499,8 @@ static struct platform_driver mpcore_wdt_driver = { static int __init mpcore_wdt_init(void) { + int i; + /* * Check that the margin value is within it's range; * if not reset to the default @@ -437,6 +511,18 @@ static int __init mpcore_wdt_init(void) TIMER_MARGIN); } + cpufreq_register_notifier(&mpcore_wdt_cpufreq_notifier_block, + CPUFREQ_TRANSITION_NOTIFIER); + + for_each_online_cpu(i) + per_cpu(mpcore_wdt_rate, i) = + (cpufreq_get(i) * 1000) / MPCORE_WDT_PERIPHCLK_PRESCALER; + + for_each_online_cpu(i) + pr_info("mpcore_wdt: rate for core %d is %lu.%02luMHz.\n", i, + per_cpu(mpcore_wdt_rate, i) / 1000000, + (per_cpu(mpcore_wdt_rate, i) / 10000) % 100); + pr_info("MPcore Watchdog Timer: 0.1. mpcore_noboot=%d mpcore_margin=%d sec (nowayout= %d)\n", mpcore_noboot, mpcore_margin, nowayout); |