[WATCHDOG 16/57] iop: watchdog switch to unlocked_ioctl
Alan Cox [Mon, 19 May 2008 13:06:14 +0000 (14:06 +0100)]
Review and switch to unlocked_ioctl

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

drivers/watchdog/iop_wdt.c

index bbbd91a..e54c888 100644 (file)
@@ -37,6 +37,7 @@
 static int nowayout = WATCHDOG_NOWAYOUT;
 static unsigned long wdt_status;
 static unsigned long boot_status;
+static spinlock_t wdt_lock;
 
 #define WDT_IN_USE             0
 #define WDT_OK_TO_CLOSE                1
@@ -68,8 +69,10 @@ static void wdt_enable(void)
        /* Arm and enable the Timer to starting counting down from 0xFFFF.FFFF
         * Takes approx. 10.7s to timeout
         */
+       spin_lock(&wdt_lock);
        write_wdtcr(IOP_WDTCR_EN_ARM);
        write_wdtcr(IOP_WDTCR_EN);
+       spin_unlock(&wdt_lock);
 }
 
 /* returns 0 if the timer was successfully disabled */
@@ -77,9 +80,11 @@ static int wdt_disable(void)
 {
        /* Stop Counting */
        if (wdt_supports_disable()) {
+               spin_lock(&wdt_lock);
                write_wdtcr(IOP_WDTCR_DIS_ARM);
                write_wdtcr(IOP_WDTCR_DIS);
                clear_bit(WDT_ENABLED, &wdt_status);
+               spin_unlock(&wdt_lock);
                printk(KERN_INFO "WATCHDOG: Disabled\n");
                return 0;
        } else
@@ -92,16 +97,12 @@ static int iop_wdt_open(struct inode *inode, struct file *file)
                return -EBUSY;
 
        clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
-
        wdt_enable();
-
        set_bit(WDT_ENABLED, &wdt_status);
-
        return nonseekable_open(inode, file);
 }
 
-static ssize_t
-iop_wdt_write(struct file *file, const char *data, size_t len,
+static ssize_t iop_wdt_write(struct file *file, const char *data, size_t len,
                  loff_t *ppos)
 {
        if (len) {
@@ -121,41 +122,39 @@ iop_wdt_write(struct file *file, const char *data, size_t len,
                }
                wdt_enable();
        }
-
        return len;
 }
 
-static struct watchdog_info ident = {
+static const struct watchdog_info ident = {
        .options = WDIOF_CARDRESET | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
        .identity = "iop watchdog",
 };
 
-static int
-iop_wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
-                 unsigned long arg)
+static long iop_wdt_ioctl(struct file *file,
+                               unsigned int cmd, unsigned long arg)
 {
        int options;
        int ret = -ENOTTY;
+       int __user *argp = (int __user *)arg;
 
        switch (cmd) {
        case WDIOC_GETSUPPORT:
-               if (copy_to_user
-                   ((struct watchdog_info *)arg, &ident, sizeof ident))
+               if (copy_to_user(argp, &ident, sizeof ident))
                        ret = -EFAULT;
                else
                        ret = 0;
                break;
 
        case WDIOC_GETSTATUS:
-               ret = put_user(0, (int *)arg);
+               ret = put_user(0, argp);
                break;
 
        case WDIOC_GETBOOTSTATUS:
-               ret = put_user(boot_status, (int *)arg);
+               ret = put_user(boot_status, argp);
                break;
 
        case WDIOC_GETTIMEOUT:
-               ret = put_user(iop_watchdog_timeout(), (int *)arg);
+               ret = put_user(iop_watchdog_timeout(), argp);
                break;
 
        case WDIOC_KEEPALIVE:
@@ -177,14 +176,12 @@ iop_wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
                        } else
                                ret = 0;
                }
-
                if (options & WDIOS_ENABLECARD) {
                        wdt_enable();
                        ret = 0;
                }
                break;
        }
-
        return ret;
 }
 
@@ -214,7 +211,7 @@ static const struct file_operations iop_wdt_fops = {
        .owner = THIS_MODULE,
        .llseek = no_llseek,
        .write = iop_wdt_write,
-       .ioctl = iop_wdt_ioctl,
+       .unlocked_ioctl = iop_wdt_ioctl,
        .open = iop_wdt_open,
        .release = iop_wdt_release,
 };
@@ -229,10 +226,8 @@ static int __init iop_wdt_init(void)
 {
        int ret;
 
-       ret = misc_register(&iop_wdt_miscdev);
-       if (ret == 0)
-               printk("iop watchdog timer: timeout %lu sec\n",
-                      iop_watchdog_timeout());
+       spin_lock_init(&wdt_lock);
+
 
        /* check if the reset was caused by the watchdog timer */
        boot_status = (read_rcsr() & IOP_RCSR_WDT) ? WDIOF_CARDRESET : 0;
@@ -242,6 +237,13 @@ static int __init iop_wdt_init(void)
         */
        write_wdtsr(IOP13XX_WDTCR_IB_RESET);
 
+       /* Register after we have the device set up so we cannot race
+          with an open */
+       ret = misc_register(&iop_wdt_miscdev);
+       if (ret == 0)
+               printk("iop watchdog timer: timeout %lu sec\n",
+                      iop_watchdog_timeout());
+
        return ret;
 }