[PATCH 27/57] mpcore watchdog: unlocked_ioctl and BKl work

Alan Cox
2008-05-19T13:26:58Z

drivers/watchdog/mpcore_wdt.c | 53 +++++++++++++++++++++++++----------------
1 files changed, 32 insertions(+), 21 deletions(-)

diff --git a/drivers/watchdog/mpcore_wdt.c b/drivers/watchdog/mpcore_wdt.c
index 009573b..5e58f8b 100644
--- a/drivers/watchdog/mpcore_wdt.c
+++ b/drivers/watchdog/mpcore_wdt.c
@@ -29,9 +29,9 @@
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
+#include <linux/uaccess.h>

#include <asm/hardware/arm_twd.h>
-#include <asm/uaccess.h>

struct mpcore_wdt {
unsigned long timer_alive;
@@ -43,17 +43,20 @@ struct mpcore_wdt {
};

static struct platform_device *mpcore_wdt_dev;
-
extern unsigned int mpcore_timer_rate;

#define TIMER_MARGIN 60
static int mpcore_margin = TIMER_MARGIN;
module_param(mpcore_margin, int, 0);
-MODULE_PARM_DESC(mpcore_margin, "MPcore timer margin in seconds. (0<mpcore_margin<65536, default=" __MODULE_STRING(TIMER_MARGIN) ")");
+MODULE_PARM_DESC(mpcore_margin,
+ "MPcore timer margin in seconds. (0 < mpcore_margin < 65536, default="
+ __MODULE_STRING(TIMER_MARGIN) ")");

static int nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, int, 0);
-MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+MODULE_PARM_DESC(nowayout,
+ "Watchdog cannot be stopped once started (default="
+ __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");

#define ONLY_TESTING 0
static int mpcore_noboot = ONLY_TESTING;
@@ -70,14 +73,12 @@ static irqreturn_t mpcore_wdt_fire(int irq, void *arg)

/* Check it really was our interrupt */
if (readl(wdt->base + TWD_WDOG_INTSTAT)) {
- dev_printk(KERN_CRIT, wdt->dev, "Triggered - Reboot ignored.\n");
-
+ dev_printk(KERN_CRIT, wdt->dev,
+ "Triggered - Reboot ignored.\n");
/* Clear the interrupt on the watchdog */
writel(1, wdt->base + TWD_WDOG_INTSTAT);
-
return IRQ_HANDLED;
}
-
return IRQ_NONE;
}

@@ -96,22 +97,26 @@ static void mpcore_wdt_keepalive(struct mpcore_wdt *wdt)
count = (mpcore_timer_rate / 256) * mpcore_margin;

/* Reload the counter */
+ spin_lock(&wdt_lock);
writel(count + wdt->perturb, wdt->base + TWD_WDOG_LOAD);
-
wdt->perturb = wdt->perturb ? 0 : 1;
+ spin_unlock(&wdt_lock);
}

static void mpcore_wdt_stop(struct mpcore_wdt *wdt)
{
+ spin_lock(&wdt_lock);
writel(0x12345678, wdt->base + TWD_WDOG_DISABLE);
writel(0x87654321, wdt->base + TWD_WDOG_DISABLE);
writel(0x0, wdt->base + TWD_WDOG_CONTROL);
+ spin_unlock(&wdt_lock);
}

static void mpcore_wdt_start(struct mpcore_wdt *wdt)
{
dev_printk(KERN_INFO, wdt->dev, "enabling watchdog.\n");

+ spin_lock(&wdt_lock);
/* This loads the count register but does NOT start the count yet */
mpcore_wdt_keepalive(wdt);

@@ -122,6 +127,7 @@ static void mpcore_wdt_start(struct mpcore_wdt *wdt)
/* Enable watchdog - prescale=256, watchdog mode=1, enable=1 */
writel(0x0000FF09, wdt->base + TWD_WDOG_CONTROL);
}
+ spin_unlock(&wdt_lock);
}

static int mpcore_wdt_set_heartbeat(int t)
@@ -164,10 +170,11 @@ static int mpcore_wdt_release(struct inode *inode, struct file *file)
* Shut off the timer.
* Lock it in if it's a module and we set nowayout
*/
- if (wdt->expect_close == 42) {
+ if (wdt->expect_close == 42)
mpcore_wdt_stop(wdt);
- } else {
- dev_printk(KERN_CRIT, wdt->dev, "unexpected close, not stopping watchdog!\n");
+ else {
+ dev_printk(KERN_CRIT, wdt->dev,
+ "unexpected close, not stopping watchdog!\n");
mpcore_wdt_keepalive(wdt);
}
clear_bit(0, &wdt->timer_alive);
@@ -175,7 +182,8 @@ static int mpcore_wdt_release(struct inode *inode, struct file *file)
return 0;
}

-static ssize_t mpcore_wdt_write(struct file *file, const char *data, size_t len, loff_t *ppos)
+static ssize_t mpcore_wdt_write(struct file *file, const char *data,
+ size_t len, loff_t *ppos)
{
struct mpcore_wdt *wdt = file->private_data;

@@ -210,8 +218,8 @@ static struct watchdog_info ident = {
.identity = "MPcore Watchdog",
};

-static int mpcore_wdt_ioctl(struct inode *inode, struct file *file,
- unsigned int cmd, unsigned long arg)
+static long mpcore_wdt_ioctl(struct file *file, unsigned int cmd,
+ unsigned long arg)
{
struct mpcore_wdt *wdt = file->private_data;
int ret;
@@ -301,7 +309,7 @@ static const struct file_operations mpcore_wdt_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = mpcore_wdt_write,
- .ioctl = mpcore_wdt_ioctl,
+ .unlocked_ioctl = mpcore_wdt_ioctl,
.open = mpcore_wdt_open,
.release = mpcore_wdt_release,
};
@@ -349,14 +357,17 @@ static int __devinit mpcore_wdt_probe(struct platform_device *dev)
mpcore_wdt_miscdev.parent = &dev->dev;
ret = misc_register(&mpcore_wdt_miscdev);
if (ret) {
- dev_printk(KERN_ERR, _dev, "cannot register miscdev on minor=%d (err=%d)\n",
- WATCHDOG_MINOR, ret);
+ dev_printk(KERN_ERR, _dev,
+ "cannot register miscdev on minor=%d (err=%d)\n",
+ WATCHDOG_MINOR, ret);
goto err_misc;
}

- ret = request_irq(wdt->irq, mpcore_wdt_fire, IRQF_DISABLED, "mpcore_wdt", wdt);
+ ret = request_irq(wdt->irq, mpcore_wdt_fire, IRQF_DISABLED,
+ "mpcore_wdt", wdt);
if (ret) {
- dev_printk(KERN_ERR, _dev, "cannot register IRQ%d for watchdog\n", wdt->irq);
+ dev_printk(KERN_ERR, _dev,
+ "cannot register IRQ%d for watchdog\n", wdt->irq);
goto err_irq;
}

@@ -415,7 +426,7 @@ static int __init mpcore_wdt_init(void)
*/
if (mpcore_wdt_set_heartbeat(mpcore_margin)) {
mpcore_wdt_set_heartbeat(TIMER_MARGIN);
- printk(KERN_INFO "mpcore_margin value must be 0<mpcore_margin<65536, using %d\n",
+ printk(KERN_INFO "mpcore_margin value must be 0 < mpcore_margin < 65536, using %d\n",
TIMER_MARGIN);
}