8bc3bcc93a
For files only using THIS_MODULE and/or EXPORT_SYMBOL, map them onto including export.h -- or if the file isn't even using those, then just delete the include. Fix up any implicit include dependencies that were being masked by module.h along the way. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
34 lines
784 B
C
34 lines
784 B
C
#include <linux/export.h>
|
|
#include <linux/spinlock.h>
|
|
#include <linux/atomic.h>
|
|
|
|
/*
|
|
* This is an implementation of the notion of "decrement a
|
|
* reference count, and return locked if it decremented to zero".
|
|
*
|
|
* NOTE NOTE NOTE! This is _not_ equivalent to
|
|
*
|
|
* if (atomic_dec_and_test(&atomic)) {
|
|
* spin_lock(&lock);
|
|
* return 1;
|
|
* }
|
|
* return 0;
|
|
*
|
|
* because the spin-lock and the decrement must be
|
|
* "atomic".
|
|
*/
|
|
int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock)
|
|
{
|
|
/* Subtract 1 from counter unless that drops it to 0 (ie. it was 1) */
|
|
if (atomic_add_unless(atomic, -1, 1))
|
|
return 0;
|
|
|
|
/* Otherwise do it the slow way */
|
|
spin_lock(lock);
|
|
if (atomic_dec_and_test(atomic))
|
|
return 1;
|
|
spin_unlock(lock);
|
|
return 0;
|
|
}
|
|
|
|
EXPORT_SYMBOL(_atomic_dec_and_lock);
|