[PATCH 14/57] ibmasr: coding style, locking verify

Alan Cox
2008-05-19T13:22:50Z

There is a new #if 0 section here which is a suggested fix for the horrible
PCI hack in the existing code. Would be good if someone with a box that uses
this device could test it.
---

drivers/watchdog/ibmasr.c | 149 ++++++++++++++++++++++++++-------------------
1 files changed, 87 insertions(+), 62 deletions(-)

diff --git a/drivers/watchdog/ibmasr.c b/drivers/watchdog/ibmasr.c
index 94155f6..6824bf8 100644
--- a/drivers/watchdog/ibmasr.c
+++ b/drivers/watchdog/ibmasr.c
@@ -19,9 +19,8 @@
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/dmi.h>
-
-#include <asm/io.h>
-#include <asm/uaccess.h>
+#include <linux/io.h>
+#include <linux/uaccess.h>

enum {
@@ -70,10 +69,13 @@ static char asr_expect_close;
static unsigned int asr_type, asr_base, asr_length;
static unsigned int asr_read_addr, asr_write_addr;
static unsigned char asr_toggle_mask, asr_disable_mask;
+static spinlock_t asr_lock;

-static void asr_toggle(void)
+static void __asr_toggle(void)
{
- unsigned char reg = inb(asr_read_addr);
+ unsigned char reg;
+
+ reg = inb(asr_read_addr);

outb(reg & ~asr_toggle_mask, asr_write_addr);
reg = inb(asr_read_addr);
@@ -83,12 +85,21 @@ static void asr_toggle(void)

outb(reg & ~asr_toggle_mask, asr_write_addr);
reg = inb(asr_read_addr);
+ spin_unlock(&asr_lock);
+}
+
+static void asr_toggle(void)
+{
+ spin_lock(&asr_lock);
+ __asr_toggle();
+ spin_unlock(&asr_lock);
}

static void asr_enable(void)
{
unsigned char reg;

+ spin_lock(&asr_lock);
if (asr_type == ASMTYPE_TOPAZ) {
/* asr_write_addr == asr_read_addr */
reg = inb(asr_read_addr);
@@ -99,17 +110,21 @@ static void asr_enable(void)
* First make sure the hardware timer is reset by toggling
* ASR hardware timer line.
*/
- asr_toggle();
+ __asr_toggle();

reg = inb(asr_read_addr);
outb(reg & ~asr_disable_mask, asr_write_addr);
}
reg = inb(asr_read_addr);
+ spin_unlock(&asr_lock);
}

static void asr_disable(void)
{
- unsigned char reg = inb(asr_read_addr);
+ unsigned char reg;
+
+ spin_lock(&asr_lock);
+ reg = inb(asr_read_addr);

if (asr_type == ASMTYPE_TOPAZ)
/* asr_write_addr == asr_read_addr */
@@ -122,6 +137,7 @@ static void asr_disable(void)
outb(reg | asr_disable_mask, asr_write_addr);
}
reg = inb(asr_read_addr);
+ spin_unlock(&asr_lock);
}

static int __init asr_get_base_address(void)
@@ -133,7 +149,8 @@ static int __init asr_get_base_address(void)

switch (asr_type) {
case ASMTYPE_TOPAZ:
- /* SELECT SuperIO CHIP FOR QUERYING (WRITE 0x07 TO BOTH 0x2E and 0x2F) */
+ /* SELECT SuperIO CHIP FOR QUERYING
+ (WRITE 0x07 TO BOTH 0x2E and 0x2F) */
outb(0x07, 0x2e);
outb(0x07, 0x2f);

@@ -154,14 +171,26 @@ static int __init asr_get_base_address(void)

case ASMTYPE_JASPER:
type = "Jaspers ";
-
- /* FIXME: need to use pci_config_lock here, but it's not exported */
+#if 0
+ u32 r;
+ /* Suggested fix */
+ pdev = pci_get_bus_and_slot(0, DEVFN(0x1f, 0));
+ if (pdev == NULL)
+ return -ENODEV;
+ pci_read_config_dword(pdev, 0x58, &r);
+ asr_base = r & 0xFFFE;
+ pci_dev_put(pdev);
+#else
+ /* FIXME: need to use pci_config_lock here,
+ but it's not exported */

/* spin_lock_irqsave(&pci_config_lock, flags);*/

/* Select the SuperIO chip in the PCI I/O port register */
outl(0x8000f858, 0xcf8);

+ /* BUS 0, Slot 1F, fnc 0, offset 58 */
+
/*
* Read the base address for the SuperIO chip.
* Only the lower 16 bits are valid, but the address is word
@@ -170,7 +199,7 @@ static int __init asr_get_base_address(void)
asr_base = inl(0xcfc) & 0xfffe;

/* spin_unlock_irqrestore(&pci_config_lock, flags);*/
-
+#endif
asr_read_addr = asr_write_addr =
asr_base + JASPER_ASR_REG_OFFSET;
asr_toggle_mask = JASPER_ASR_TOGGLE_MASK;
@@ -241,11 +270,10 @@ static ssize_t asr_write(struct file *file, const char __user *buf,
return count;
}

-static int asr_ioctl(struct inode *inode, struct file *file,
- unsigned int cmd, unsigned long arg)
+static long asr_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
static const struct watchdog_info ident = {
- .options = WDIOF_KEEPALIVEPING |
+ .options = WDIOF_KEEPALIVEPING |
WDIOF_MAGICCLOSE,
.identity = "IBM ASR"
};
@@ -254,53 +282,45 @@ static int asr_ioctl(struct inode *inode, struct file *file,
int heartbeat;

switch (cmd) {
- case WDIOC_GETSUPPORT:
- return copy_to_user(argp, &ident, sizeof(ident)) ?
- -EFAULT : 0;
-
- case WDIOC_GETSTATUS:
- case WDIOC_GETBOOTSTATUS:
- return put_user(0, p);
-
- case WDIOC_KEEPALIVE:
+ case WDIOC_GETSUPPORT:
+ return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
+ case WDIOC_GETSTATUS:
+ case WDIOC_GETBOOTSTATUS:
+ return put_user(0, p);
+ case WDIOC_KEEPALIVE:
+ asr_toggle();
+ return 0;
+ /*
+ * The hardware has a fixed timeout value, so no WDIOC_SETTIMEOUT
+ * and WDIOC_GETTIMEOUT always returns 256.
+ */
+ case WDIOC_GETTIMEOUT:
+ heartbeat = 256;
+ return put_user(heartbeat, p);
+ case WDIOC_SETOPTIONS:
+ {
+ int new_options, retval = -EINVAL;
+ if (get_user(new_options, p))
+ return -EFAULT;
+ if (new_options & WDIOS_DISABLECARD) {
+ asr_disable();
+ retval = 0;
+ }
+ if (new_options & WDIOS_ENABLECARD) {
+ asr_enable();
asr_toggle();
- return 0;
-
- /*
- * The hardware has a fixed timeout value, so no WDIOC_SETTIMEOUT
- * and WDIOC_GETTIMEOUT always returns 256.
- */
- case WDIOC_GETTIMEOUT:
- heartbeat = 256;
- return put_user(heartbeat, p);
-
- case WDIOC_SETOPTIONS: {
- int new_options, retval = -EINVAL;
-
- if (get_user(new_options, p))
- return -EFAULT;
-
- if (new_options & WDIOS_DISABLECARD) {
- asr_disable();
- retval = 0;
- }
-
- if (new_options & WDIOS_ENABLECARD) {
- asr_enable();
- asr_toggle();
- retval = 0;
- }
-
- return retval;
+ retval = 0;
}
+ return retval;
+ }
+ default:
+ return -ENOTTY;
}
-
- return -ENOTTY;
}

static int asr_open(struct inode *inode, struct file *file)
{
- if(test_and_set_bit(0, &asr_is_open))
+ if (test_and_set_bit(0, &asr_is_open))
return -EBUSY;

asr_toggle();
@@ -314,7 +334,8 @@ static int asr_release(struct inode *inode, struct file *file)
if (asr_expect_close == 42)
asr_disable();
else {
- printk(KERN_CRIT PFX "unexpected close, not stopping watchdog!\n");
+ printk(KERN_CRIT PFX
+ "unexpected close, not stopping watchdog!\n");
asr_toggle();
}
clear_bit(0, &asr_is_open);
@@ -323,12 +344,12 @@ static int asr_release(struct inode *inode, struct file *file)
}

static const struct file_operations asr_fops = {
- .owner = THIS_MODULE,
- .llseek = no_llseek,
- .write = asr_write,
- .ioctl = asr_ioctl,
- .open = asr_open,
- .release = asr_release,
+ .owner = THIS_MODULE,
+ .llseek = no_llseek,
+ .write = asr_write,
+ .unlocked_ioctl = asr_ioctl,
+ .open = asr_open,
+ .release = asr_release,
};

static struct miscdevice asr_miscdev = {
@@ -367,6 +388,8 @@ static int __init ibmasr_init(void)
if (!asr_type)
return -ENODEV;

+ spin_lock_init(&asr_lock);
+
rc = asr_get_base_address();
if (rc)
return rc;
@@ -395,7 +418,9 @@ module_init(ibmasr_init);
module_exit(ibmasr_exit);

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) ")");

MODULE_DESCRIPTION("IBM Automatic Server Restart driver");
MODULE_AUTHOR("Andrey Panin");