diff mbox series

xen/common: rwlock: Constify the parameter of _rw_is{,_write}_locked()

Message ID 20230130182858.86886-1-julien@xen.org (mailing list archive)
State New, archived
Headers show
Series xen/common: rwlock: Constify the parameter of _rw_is{,_write}_locked() | expand

Commit Message

Julien Grall Jan. 30, 2023, 6:28 p.m. UTC 
From: Julien Grall <jgrall@amazon.com>

The lock is not meant to be modified by _rw_is{,_write}_locked(). So
constify it.

This is helpful to be able to assert if the lock is taken when the
underlying structure is const.

Signed-off-by: Julien Grall <jgrall@amazon.com>
---
 xen/include/xen/rwlock.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Jan Beulich Jan. 31, 2023, 9:34 a.m. UTC | #1 
On 30.01.2023 19:28, Julien Grall wrote:
> From: Julien Grall <jgrall@amazon.com>
> 
> The lock is not meant to be modified by _rw_is{,_write}_locked(). So
> constify it.
> 
> This is helpful to be able to assert if the lock is taken when the
> underlying structure is const.
> 
> Signed-off-by: Julien Grall <jgrall@amazon.com>

Reviewed-by: Jan Beulich <jbeulich@suse.com>
(maybe also Requested-by)

Thanks for doing this on top of the spinlock change.

Jan
Julien Grall Jan. 31, 2023, 9:34 p.m. UTC | #2 
Hi Jan,

On 31/01/2023 09:34, Jan Beulich wrote:
> On 30.01.2023 19:28, Julien Grall wrote:
>> From: Julien Grall <jgrall@amazon.com>
>>
>> The lock is not meant to be modified by _rw_is{,_write}_locked(). So
>> constify it.
>>
>> This is helpful to be able to assert if the lock is taken when the
>> underlying structure is const.
>>
>> Signed-off-by: Julien Grall <jgrall@amazon.com>
> 
> Reviewed-by: Jan Beulich <jbeulich@suse.com>
> (maybe also Requested-by)

I will add a requested-by while committing (waiting for a push before 
doing it).

Cheers,
diff mbox series

Patch

diff --git a/xen/include/xen/rwlock.h b/xen/include/xen/rwlock.h
index b8d52a5aa939..e0d2b41c5c7e 100644
--- a/xen/include/xen/rwlock.h
+++ b/xen/include/xen/rwlock.h
@@ -149,7 +149,7 @@  static inline void _read_unlock_irqrestore(rwlock_t *lock, unsigned long flags)
     local_irq_restore(flags);
 }
 
-static inline int _rw_is_locked(rwlock_t *lock)
+static inline int _rw_is_locked(const rwlock_t *lock)
 {
     return atomic_read(&lock->cnts);
 }
@@ -254,7 +254,7 @@  static inline void _write_unlock_irqrestore(rwlock_t *lock, unsigned long flags)
     local_irq_restore(flags);
 }
 
-static inline int _rw_is_write_locked(rwlock_t *lock)
+static inline int _rw_is_write_locked(const rwlock_t *lock)
 {
     return (atomic_read(&lock->cnts) & _QW_WMASK) == _QW_LOCKED;
 }