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watchdog: shwdt: Migrate to per-device locking.

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Presently we've been using global locking for everything. Push the
locking down to the per-device level in preparation for per-CPU
watchdogs.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This commit is contained in:
Paul Mundt 2012-05-10 15:15:08 +09:00
parent 1950f499df
commit f9fb360cb3
1 changed files with 19 additions and 15 deletions
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34
drivers/watchdog/shwdt.c
View file

@ -25,6 +25,7 @@
#include <linux/platform_device.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/spinlock.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/fs.h>
@ -65,8 +66,6 @@
static int clock_division_ratio = WTCSR_CKS_4096;
#define next_ping_period(cks) (jiffies + msecs_to_jiffies(cks - 4))
static DEFINE_SPINLOCK(shwdt_lock);
#define WATCHDOG_HEARTBEAT 30 /* 30 sec default heartbeat */
static int heartbeat = WATCHDOG_HEARTBEAT; /* in seconds */
static bool nowayout = WATCHDOG_NOWAYOUT;
@ -75,6 +74,7 @@ static unsigned long next_heartbeat;
struct sh_wdt {
void __iomem *base;
struct device *dev;
spinlock_t lock;
struct timer_list timer;
@ -88,7 +88,7 @@ static int sh_wdt_start(struct watchdog_device *wdt_dev)
unsigned long flags;
u8 csr;
spin_lock_irqsave(&shwdt_lock, flags);
spin_lock_irqsave(&wdt->lock, flags);
next_heartbeat = jiffies + (heartbeat * HZ);
mod_timer(&wdt->timer, next_ping_period(clock_division_ratio));
@ -117,7 +117,7 @@ static int sh_wdt_start(struct watchdog_device *wdt_dev)
csr &= ~RSTCSR_RSTS;
sh_wdt_write_rstcsr(csr);
#endif
spin_unlock_irqrestore(&shwdt_lock, flags);
spin_unlock_irqrestore(&wdt->lock, flags);
return 0;
}
@ -128,7 +128,7 @@ static int sh_wdt_stop(struct watchdog_device *wdt_dev)
unsigned long flags;
u8 csr;
spin_lock_irqsave(&shwdt_lock, flags);
spin_lock_irqsave(&wdt->lock, flags);
del_timer(&wdt->timer);
@ -136,33 +136,35 @@ static int sh_wdt_stop(struct watchdog_device *wdt_dev)
csr &= ~WTCSR_TME;
sh_wdt_write_csr(csr);
spin_unlock_irqrestore(&shwdt_lock, flags);
spin_unlock_irqrestore(&wdt->lock, flags);
return 0;
}
static int sh_wdt_keepalive(struct watchdog_device *wdt_dev)
{
struct sh_wdt *wdt = watchdog_get_drvdata(wdt_dev);
unsigned long flags;
spin_lock_irqsave(&shwdt_lock, flags);
spin_lock_irqsave(&wdt->lock, flags);
next_heartbeat = jiffies + (heartbeat * HZ);
spin_unlock_irqrestore(&shwdt_lock, flags);
spin_unlock_irqrestore(&wdt->lock, flags);
return 0;
}
static int sh_wdt_set_heartbeat(struct watchdog_device *wdt_dev, unsigned t)
{
struct sh_wdt *wdt = watchdog_get_drvdata(wdt_dev);
unsigned long flags;
if (unlikely(t < 1 || t > 3600)) /* arbitrary upper limit */
return -EINVAL;
spin_lock_irqsave(&shwdt_lock, flags);
spin_lock_irqsave(&wdt->lock, flags);
heartbeat = t;
wdt_dev->timeout = t;
spin_unlock_irqrestore(&shwdt_lock, flags);
spin_unlock_irqrestore(&wdt->lock, flags);
return 0;
}
@ -172,7 +174,7 @@ static void sh_wdt_ping(unsigned long data)
struct sh_wdt *wdt = (struct sh_wdt *)data;
unsigned long flags;
spin_lock_irqsave(&shwdt_lock, flags);
spin_lock_irqsave(&wdt->lock, flags);
if (time_before(jiffies, next_heartbeat)) {
u8 csr;
@ -186,7 +188,7 @@ static void sh_wdt_ping(unsigned long data)
} else
dev_warn(wdt->dev, "Heartbeat lost! Will not ping "
"the watchdog\n");
spin_unlock_irqrestore(&shwdt_lock, flags);
spin_unlock_irqrestore(&wdt->lock, flags);
}
static const struct watchdog_info sh_wdt_info = {
@ -238,12 +240,17 @@ static int __devinit sh_wdt_probe(struct platform_device *pdev)
wdt->dev = &pdev->dev;
watchdog_set_nowayout(&sh_wdt_dev, nowayout);
watchdog_set_drvdata(&sh_wdt_dev, wdt);
wdt->base = devm_ioremap(&pdev->dev, res->start, resource_size(res));
if (unlikely(!wdt->base)) {
rc = -ENXIO;
goto out_err;
}
spin_lock_init(&wdt->lock);
rc = sh_wdt_set_heartbeat(&sh_wdt_dev, heartbeat);
if (unlikely(rc)) {
/* Default timeout if invalid */
@ -257,9 +264,6 @@ static int __devinit sh_wdt_probe(struct platform_device *pdev)
dev_info(&pdev->dev, "configured with heartbeat=%d sec (nowayout=%d)\n",
sh_wdt_dev.timeout, nowayout);
watchdog_set_nowayout(&sh_wdt_dev, nowayout);
watchdog_set_drvdata(&sh_wdt_dev, wdt);
rc = watchdog_register_device(&sh_wdt_dev);
if (unlikely(rc)) {
dev_err(&pdev->dev, "Can't register watchdog (err=%d)\n", rc);