mirror of
https://github.com/torvalds/linux.git
synced 2024-12-28 22:02:28 +00:00
e54d2f6152
sync_bitops functions are equivalent to the SMP implementation of the original functions, independently from CONFIG_SMP being defined. We need them because _set_bit etc are not SMP safe if !CONFIG_SMP. But under Xen you might be communicating with a completely external entity who might be on another CPU (e.g. two uniprocessor guests communicating via event channels and grant tables). So we need a variant of the bit ops which are SMP safe even on a UP kernel. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
28 lines
1.0 KiB
C
28 lines
1.0 KiB
C
#ifndef __ASM_SYNC_BITOPS_H__
|
|
#define __ASM_SYNC_BITOPS_H__
|
|
|
|
#include <asm/bitops.h>
|
|
#include <asm/system.h>
|
|
|
|
/* sync_bitops functions are equivalent to the SMP implementation of the
|
|
* original functions, independently from CONFIG_SMP being defined.
|
|
*
|
|
* We need them because _set_bit etc are not SMP safe if !CONFIG_SMP. But
|
|
* under Xen you might be communicating with a completely external entity
|
|
* who might be on another CPU (e.g. two uniprocessor guests communicating
|
|
* via event channels and grant tables). So we need a variant of the bit
|
|
* ops which are SMP safe even on a UP kernel.
|
|
*/
|
|
|
|
#define sync_set_bit(nr, p) _set_bit(nr, p)
|
|
#define sync_clear_bit(nr, p) _clear_bit(nr, p)
|
|
#define sync_change_bit(nr, p) _change_bit(nr, p)
|
|
#define sync_test_and_set_bit(nr, p) _test_and_set_bit(nr, p)
|
|
#define sync_test_and_clear_bit(nr, p) _test_and_clear_bit(nr, p)
|
|
#define sync_test_and_change_bit(nr, p) _test_and_change_bit(nr, p)
|
|
#define sync_test_bit(nr, addr) test_bit(nr, addr)
|
|
#define sync_cmpxchg cmpxchg
|
|
|
|
|
|
#endif
|