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Commit f9fb360c authored by Paul Mundt's avatar Paul Mundt
Browse files

watchdog: shwdt: Migrate to per-device locking. 



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: default avatarPaul Mundt <lethal@linux-sh.org>
parent 1950f499

drivers/watchdog/shwdt.c

+19 −15
Original line number Diff line number Diff line
@@ -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);