powerpc: sysdev: use lock guard for mutex

use guard(mutex) for scope based resource management of mutex
This would make the code simpler and easier to maintain.

More details on lock guards can be found at
https://lore.kernel.org/all/20230612093537.614161713@infradead.org/T/#u

Reviewed-by: Srikar Dronamraju <srikar@linux.ibm.com>
Signed-off-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20250505075333.184463-7-sshegde@linux.ibm.com

diff --git a/arch/powerpc/sysdev/fsl_mpic_timer_wakeup.c b/arch/powerpc/sysdev/fsl_mpic_timer_wakeup.c
index ce6c739c51e5109fbe315e1f82e741992d994481..06d9101a5d494d2fa0193c8263649290027ed18f 100644 (file)
--- a/arch/powerpc/sysdev/fsl_mpic_timer_wakeup.c
+++ b/arch/powerpc/sysdev/fsl_mpic_timer_wakeup.c
@@ -75,7 +75,7 @@ static ssize_t fsl_timer_wakeup_store(struct device *dev,
        if (kstrtoll(buf, 0, &interval))
                return -EINVAL;
 
-       mutex_lock(&sysfs_lock);
+       guard(mutex)(&sysfs_lock);
 
        if (fsl_wakeup->timer) {
                disable_irq_wake(fsl_wakeup->timer->irq);
@@ -83,31 +83,23 @@ static ssize_t fsl_timer_wakeup_store(struct device *dev,
                fsl_wakeup->timer = NULL;
        }
 
-       if (!interval) {
-               mutex_unlock(&sysfs_lock);
+       if (!interval)
                return count;
-       }
 
        fsl_wakeup->timer = mpic_request_timer(fsl_mpic_timer_irq,
                                                fsl_wakeup, interval);
-       if (!fsl_wakeup->timer) {
-               mutex_unlock(&sysfs_lock);
+       if (!fsl_wakeup->timer)
                return -EINVAL;
-       }
 
        ret = enable_irq_wake(fsl_wakeup->timer->irq);
        if (ret) {
                mpic_free_timer(fsl_wakeup->timer);
                fsl_wakeup->timer = NULL;
-               mutex_unlock(&sysfs_lock);
-
                return ret;
        }
 
        mpic_start_timer(fsl_wakeup->timer);
 
-       mutex_unlock(&sysfs_lock);
-
        return count;
 }