[WATCHDOG 42/57] sc1200_wdt: clean up, fix locking and use unlocked_ioctl

Review and switch to unlocked_ioctl

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

1 files changed, 114 insertions, 89 deletions

diff --git a/drivers/watchdog/sc1200wdt.c b/drivers/watchdog/sc1200wdt.c
index 35cddff7020f..7e5c9cc97dee 100644
--- a/drivers/watchdog/sc1200wdt.c
+++ b/drivers/watchdog/sc1200wdt.c
@@ -15,14 +15,18 @@
  *
  *      Changelog:
  *      20020220 Zwane Mwaikambo        Code based on datasheet, no hardware.
- *      20020221 Zwane Mwaikambo        Cleanups as suggested by Jeff Garzik and Alan Cox.
+ *      20020221 Zwane Mwaikambo        Cleanups as suggested by Jeff Garzik
+ *                                      and Alan Cox.
  *      20020222 Zwane Mwaikambo        Added probing.
  *      20020225 Zwane Mwaikambo        Added ISAPNP support.
  *      20020412 Rob Radez              Broke out start/stop functions
- *               <rob@osinvestor.com>   Return proper status instead of temperature warning
- *                                      Add WDIOC_GETBOOTSTATUS and WDIOC_SETOPTIONS ioctls
+ *               <rob@osinvestor.com>   Return proper status instead of
+ *                                      temperature warning
+ *                                      Add WDIOC_GETBOOTSTATUS and
+ *                                      WDIOC_SETOPTIONS ioctls
  *                                      Fix CONFIG_WATCHDOG_NOWAYOUT
- *      20020530 Joel Becker            Add Matt Domsch's nowayout module option
+ *      20020530 Joel Becker            Add Matt Domsch's nowayout module
+ *                                      option
  *      20030116 Adam Belay             Updated to the latest pnp code
  *
  */
@@ -39,9 +43,8 @@
 #include <linux/pnp.h>
 #include <linux/fs.h>
 #include <linux/semaphore.h>
-
-#include <asm/io.h>
-#include <asm/uaccess.h>
+#include <linux/io.h>
+#include <linux/uaccess.h>
 
 #define SC1200_MODULE_VER       "build 20020303"
 #define SC1200_MODULE_NAME      "sc1200wdt"
@@ -72,7 +75,7 @@ static char banner[] __initdata = KERN_INFO PFX SC1200_MODULE_VER;
 static int timeout = 1;
 static int io = -1;
 static int io_len = 2;          /* for non plug and play */
-static struct semaphore open_sem;
+static unsigned long open_flag;
 static char expect_close;
 static DEFINE_SPINLOCK(sc1200wdt_lock); /* io port access serialisation */
 
@@ -81,7 +84,8 @@ static int isapnp = 1;
 static struct pnp_dev *wdt_dev;
 
 module_param(isapnp, int, 0);
-MODULE_PARM_DESC(isapnp, "When set to 0 driver ISA PnP support will be disabled");
+MODULE_PARM_DESC(isapnp,
+        "When set to 0 driver ISA PnP support will be disabled");
 #endif
 
 module_param(io, int, 0);
@@ -91,26 +95,40 @@ MODULE_PARM_DESC(timeout, "range is 0-255 minutes, default is 1");
 
 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) ")");
 
 
 
 /* Read from Data Register */
-static inline void sc1200wdt_read_data(unsigned char index, unsigned char *data)
+static inline void __sc1200wdt_read_data(unsigned char index,
+                                                unsigned char *data)
 {
-        spin_lock(&sc1200wdt_lock);
         outb_p(index, PMIR);
         *data = inb(PMDR);
-        spin_unlock(&sc1200wdt_lock);
 }
 
+static void sc1200wdt_read_data(unsigned char index, unsigned char *data)
+{
+        spin_lock(&sc1200wdt_lock);
+        __sc1200wdt_read_data(index, data);
+        spin_unlock(&sc1200wdt_lock);
+}
 
 /* Write to Data Register */
-static inline void sc1200wdt_write_data(unsigned char index, unsigned char data)
+static inline void __sc1200wdt_write_data(unsigned char index,
+                                                unsigned char data)
 {
-        spin_lock(&sc1200wdt_lock);
         outb_p(index, PMIR);
         outb(data, PMDR);
+}
+
+static inline void sc1200wdt_write_data(unsigned char index,
+                                                unsigned char data)
+{
+        spin_lock(&sc1200wdt_lock);
+        __sc1200wdt_write_data(index, data);
         spin_unlock(&sc1200wdt_lock);
 }
 
@@ -118,13 +136,16 @@ static inline void sc1200wdt_write_data(unsigned char index, unsigned char data)
 static void sc1200wdt_start(void)
 {
         unsigned char reg;
+        spin_lock(&sc1200wdt_lock);
 
-        sc1200wdt_read_data(WDCF, &reg);
+        __sc1200wdt_read_data(WDCF, &reg);
         /* assert WDO when any of the following interrupts are triggered too */
         reg |= (KBC_IRQ | MSE_IRQ | UART1_IRQ | UART2_IRQ);
-        sc1200wdt_write_data(WDCF, reg);
+        __sc1200wdt_write_data(WDCF, reg);
         /* set the timeout and get the ball rolling */
-        sc1200wdt_write_data(WDTO, timeout);
+        __sc1200wdt_write_data(WDTO, timeout);
+
+        spin_unlock(&sc1200wdt_lock);
 }
 
 
@@ -144,14 +165,15 @@ static inline int sc1200wdt_status(void)
          * KEEPALIVEPING which is a bit of a kludge because there's nothing
          * else for enabled/disabled status
          */
-        return (ret & 0x01) ? 0 : WDIOF_KEEPALIVEPING;  /* bits 1 - 7 are undefined */
+        return (ret & 0x01) ? 0 : WDIOF_KEEPALIVEPING;
+        /* bits 1 - 7 are undefined */
 }
 
 
 static int sc1200wdt_open(struct inode *inode, struct file *file)
 {
         /* allow one at a time */
-        if (down_trylock(&open_sem))
+        if (test_and_set_bit(0, &open_flag))
                 return -EBUSY;
 
         if (timeout > MAX_TIMEOUT)
@@ -164,71 +186,71 @@ static int sc1200wdt_open(struct inode *inode, struct file *file)
 }
 
 
-static int sc1200wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
+static long sc1200wdt_ioctl(struct file *file, unsigned int cmd,
+                                                unsigned long arg)
 {
         int new_timeout;
         void __user *argp = (void __user *)arg;
         int __user *p = argp;
-        static struct watchdog_info ident = {
-                .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
+        static const struct watchdog_info ident = {
+                .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT |
+                                                        WDIOF_MAGICCLOSE,
                 .firmware_version = 0,
                 .identity = "PC87307/PC97307",
         };
 
         switch (cmd) {
-                default:
-                        return -ENOTTY;
-
-                case WDIOC_GETSUPPORT:
-                        if (copy_to_user(argp, &ident, sizeof ident))
-                                return -EFAULT;
-                        return 0;
 
-                case WDIOC_GETSTATUS:
-                        return put_user(sc1200wdt_status(), p);
+        case WDIOC_GETSUPPORT:
+                if (copy_to_user(argp, &ident, sizeof ident))
+                        return -EFAULT;
+                return 0;
 
-                case WDIOC_GETBOOTSTATUS:
-                        return put_user(0, p);
+        case WDIOC_GETSTATUS:
+                return put_user(sc1200wdt_status(), p);
 
-                case WDIOC_KEEPALIVE:
-                        sc1200wdt_write_data(WDTO, timeout);
-                        return 0;
+        case WDIOC_GETBOOTSTATUS:
+                return put_user(0, p);
 
-                case WDIOC_SETTIMEOUT:
-                        if (get_user(new_timeout, p))
-                                return -EFAULT;
-
-                        /* the API states this is given in secs */
-                        new_timeout /= 60;
-                        if (new_timeout < 0 || new_timeout > MAX_TIMEOUT)
-                                return -EINVAL;
-
-                        timeout = new_timeout;
-                        sc1200wdt_write_data(WDTO, timeout);
-                        /* fall through and return the new timeout */
-
-                case WDIOC_GETTIMEOUT:
-                        return put_user(timeout * 60, p);
+        case WDIOC_KEEPALIVE:
+                sc1200wdt_write_data(WDTO, timeout);
+                return 0;
+
+        case WDIOC_SETTIMEOUT:
+                if (get_user(new_timeout, p))
+                        return -EFAULT;
+                /* the API states this is given in secs */
+                new_timeout /= 60;
+                if (new_timeout < 0 || new_timeout > MAX_TIMEOUT)
+                        return -EINVAL;
+                timeout = new_timeout;
+                sc1200wdt_write_data(WDTO, timeout);
+                /* fall through and return the new timeout */
 
-                case WDIOC_SETOPTIONS:
-                {
-                        int options, retval = -EINVAL;
+        case WDIOC_GETTIMEOUT:
+                return put_user(timeout * 60, p);
 
-                        if (get_user(options, p))
-                                return -EFAULT;
+        case WDIOC_SETOPTIONS:
+        {
+                int options, retval = -EINVAL;
 
-                        if (options & WDIOS_DISABLECARD) {
-                                sc1200wdt_stop();
-                                retval = 0;
-                        }
+                if (get_user(options, p))
+                        return -EFAULT;
 
-                        if (options & WDIOS_ENABLECARD) {
-                                sc1200wdt_start();
-                                retval = 0;
-                        }
+                if (options & WDIOS_DISABLECARD) {
+                        sc1200wdt_stop();
+                        retval = 0;
+                }
 
-                        return retval;
+                if (options & WDIOS_ENABLECARD) {
+                        sc1200wdt_start();
+                        retval = 0;
                 }
+
+                return retval;
+        }
+        default:
+                return -ENOTTY;
         }
 }
 
@@ -240,16 +262,18 @@ static int sc1200wdt_release(struct inode *inode, struct file *file)
                 printk(KERN_INFO PFX "Watchdog disabled\n");
         } else {
                 sc1200wdt_write_data(WDTO, timeout);
-                printk(KERN_CRIT PFX "Unexpected close!, timeout = %d min(s)\n", timeout);
+                printk(KERN_CRIT PFX
+                        "Unexpected close!, timeout = %d min(s)\n", timeout);
         }
-        up(&open_sem);
+        clear_bit(0, &open_flag);
         expect_close = 0;
 
         return 0;
 }
 
 
-static ssize_t sc1200wdt_write(struct file *file, const char __user *data, size_t len, loff_t *ppos)
+static ssize_t sc1200wdt_write(struct file *file, const char __user *data,
+                                                size_t len, loff_t *ppos)
 {
         if (len) {
                 if (!nowayout) {
@@ -275,7 +299,8 @@ static ssize_t sc1200wdt_write(struct file *file, const char __user *data, size_
 }
 
 
-static int sc1200wdt_notify_sys(struct notifier_block *this, unsigned long code, void *unused)
+static int sc1200wdt_notify_sys(struct notifier_block *this,
+                                        unsigned long code, void *unused)
 {
         if (code == SYS_DOWN || code == SYS_HALT)
                 sc1200wdt_stop();
@@ -284,23 +309,20 @@ static int sc1200wdt_notify_sys(struct notifier_block *this, unsigned long code,
 }
 
 
-static struct notifier_block sc1200wdt_notifier =
-{
+static struct notifier_block sc1200wdt_notifier = {
         .notifier_call =        sc1200wdt_notify_sys,
 };
 
-static const struct file_operations sc1200wdt_fops =
-{
+static const struct file_operations sc1200wdt_fops = {
         .owner          = THIS_MODULE,
         .llseek         = no_llseek,
         .write          = sc1200wdt_write,
-        .ioctl          = sc1200wdt_ioctl,
+        .unlocked_ioctl = sc1200wdt_ioctl,
         .open           = sc1200wdt_open,
         .release        = sc1200wdt_release,
 };
 
-static struct miscdevice sc1200wdt_miscdev =
-{
+static struct miscdevice sc1200wdt_miscdev = {
         .minor          = WATCHDOG_MINOR,
         .name           = "watchdog",
         .fops           = &sc1200wdt_fops,
@@ -312,14 +334,14 @@ static int __init sc1200wdt_probe(void)
         /* The probe works by reading the PMC3 register's default value of 0x0e
          * there is one caveat, if the device disables the parallel port or any
          * of the UARTs we won't be able to detect it.
-         * Nb. This could be done with accuracy by reading the SID registers, but
-         * we don't have access to those io regions.
+         * NB. This could be done with accuracy by reading the SID registers,
+         * but we don't have access to those io regions.
          */
 
         unsigned char reg;
 
         sc1200wdt_read_data(PMC3, &reg);
-        reg &= 0x0f;                            /* we don't want the UART busy bits */
+        reg &= 0x0f;            /* we don't want the UART busy bits */
         return (reg == 0x0e) ? 0 : -ENODEV;
 }
 
@@ -332,7 +354,8 @@ static struct pnp_device_id scl200wdt_pnp_devices[] = {
         {.id = ""},
 };
 
-static int scl200wdt_pnp_probe(struct pnp_dev * dev, const struct pnp_device_id *dev_id)
+static int scl200wdt_pnp_probe(struct pnp_dev *dev,
+                                        const struct pnp_device_id *dev_id)
 {
         /* this driver only supports one card at a time */
         if (wdt_dev || !isapnp)
@@ -347,13 +370,14 @@ static int scl200wdt_pnp_probe(struct pnp_dev * dev, const struct pnp_device_id
                 return -EBUSY;
         }
 
-        printk(KERN_INFO "scl200wdt: PnP device found at io port %#x/%d\n", io, io_len);
+        printk(KERN_INFO "scl200wdt: PnP device found at io port %#x/%d\n",
+                                                                io, io_len);
         return 0;
 }
 
-static void scl200wdt_pnp_remove(struct pnp_dev * dev)
+static void scl200wdt_pnp_remove(struct pnp_dev *dev)
 {
-        if (wdt_dev){
+        if (wdt_dev) {
                 release_region(io, io_len);
                 wdt_dev = NULL;
         }
@@ -375,8 +399,6 @@ static int __init sc1200wdt_init(void)
 
         printk("%s\n", banner);
 
-        sema_init(&open_sem, 1);
-
 #if defined CONFIG_PNP
         if (isapnp) {
                 ret = pnp_register_driver(&scl200wdt_pnp_driver);
@@ -410,13 +432,16 @@ static int __init sc1200wdt_init(void)
 
         ret = register_reboot_notifier(&sc1200wdt_notifier);
         if (ret) {
-                printk(KERN_ERR PFX "Unable to register reboot notifier err = %d\n", ret);
+                printk(KERN_ERR PFX
+                        "Unable to register reboot notifier err = %d\n", ret);
                 goto out_io;
         }
 
         ret = misc_register(&sc1200wdt_miscdev);
         if (ret) {
-                printk(KERN_ERR PFX "Unable to register miscdev on minor %d\n", WATCHDOG_MINOR);
+                printk(KERN_ERR PFX
+                        "Unable to register miscdev on minor %d\n",
+                                                        WATCHDOG_MINOR);
                 goto out_rbt;
         }
 
@@ -446,7 +471,7 @@ static void __exit sc1200wdt_exit(void)
         unregister_reboot_notifier(&sc1200wdt_notifier);
 
 #if defined CONFIG_PNP
-        if(isapnp)
+        if (isapnp)
                 pnp_unregister_driver(&scl200wdt_pnp_driver);
         else
 #endif