x86: Switch apm to unlocked_kernel

This pushes the lock a fair way down and the final kill looks like it
should be an easy project for someone who wants to have a shot at it.

Signed-off-by: Alan Cox <alan@redhat.com>
Cc: mingo@redhat.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 15 insertions, 10 deletions

diff --git a/arch/x86/kernel/apm_32.c b/arch/x86/kernel/apm_32.c
index bf9290e29013..00e6d1370954 100644
--- a/arch/x86/kernel/apm_32.c
+++ b/arch/x86/kernel/apm_32.c
@@ -228,6 +228,7 @@
 #include <linux/suspend.h>
 #include <linux/kthread.h>
 #include <linux/jiffies.h>
+#include <linux/smp_lock.h>
 
 #include <asm/system.h>
 #include <asm/uaccess.h>
@@ -1149,7 +1150,7 @@ static void queue_event(apm_event_t event, struct apm_user *sender)
                                 as->event_tail = 0;
                 }
                 as->events[as->event_head] = event;
-                if ((!as->suser) || (!as->writer))
+                if (!as->suser || !as->writer)
                         continue;
                 switch (event) {
                 case APM_SYS_SUSPEND:
@@ -1396,7 +1397,7 @@ static void apm_mainloop(void)
 
 static int check_apm_user(struct apm_user *as, const char *func)
 {
-        if ((as == NULL) || (as->magic != APM_BIOS_MAGIC)) {
+        if (as == NULL || as->magic != APM_BIOS_MAGIC) {
                 printk(KERN_ERR "apm: %s passed bad filp\n", func);
                 return 1;
         }
@@ -1459,18 +1460,19 @@ static unsigned int do_poll(struct file *fp, poll_table *wait)
         return 0;
 }
 
-static int do_ioctl(struct inode *inode, struct file *filp,
-                    u_int cmd, u_long arg)
+static long do_ioctl(struct file *filp, u_int cmd, u_long arg)
 {
         struct apm_user *as;
+        int ret;
 
         as = filp->private_data;
         if (check_apm_user(as, "ioctl"))
                 return -EIO;
-        if ((!as->suser) || (!as->writer))
+        if (!as->suser || !as->writer)
                 return -EPERM;
         switch (cmd) {
         case APM_IOC_STANDBY:
+                lock_kernel();
                 if (as->standbys_read > 0) {
                         as->standbys_read--;
                         as->standbys_pending--;
@@ -1479,8 +1481,10 @@ static int do_ioctl(struct inode *inode, struct file *filp,
                         queue_event(APM_USER_STANDBY, as);
                 if (standbys_pending <= 0)
                         standby();
+                unlock_kernel();
                 break;
         case APM_IOC_SUSPEND:
+                lock_kernel();
                 if (as->suspends_read > 0) {
                         as->suspends_read--;
                         as->suspends_pending--;
@@ -1488,16 +1492,17 @@ static int do_ioctl(struct inode *inode, struct file *filp,
                 } else
                         queue_event(APM_USER_SUSPEND, as);
                 if (suspends_pending <= 0) {
-                        return suspend(1);
+                        ret = suspend(1);
                 } else {
                         as->suspend_wait = 1;
                         wait_event_interruptible(apm_suspend_waitqueue,
                                         as->suspend_wait == 0);
-                        return as->suspend_result;
+                        ret = as->suspend_result;
                 }
-                break;
+                unlock_kernel();
+                return ret;
         default:
-                return -EINVAL;
+                return -ENOTTY;
         }
         return 0;
 }
@@ -1860,7 +1865,7 @@ static const struct file_operations apm_bios_fops = {
         .owner          = THIS_MODULE,
         .read           = do_read,
         .poll           = do_poll,
-        .ioctl          = do_ioctl,
+        .unlocked_ioctl = do_ioctl,
         .open           = do_open,
         .release        = do_release,
 };