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

Alan Cox
2008-05-19T13:34:10Z

drivers/watchdog/sc1200wdt.c | 203 ++++++++++++++++++++++++------------------
1 files changed, 114 insertions(+), 89 deletions(-)

diff --git a/drivers/watchdog/sc1200wdt.c b/drivers/watchdog/sc1200wdt.c
index 35cddff..7e5c9cc 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