mutex_32.h File Reference

#include <asm/alternative.h>

Go to the source code of this file.

Macros
#define	__mutex_fastpath_lock(count, fail_fn)
#define	__mutex_fastpath_unlock(count, fail_fn)
#define	__mutex_slowpath_needs_to_unlock()   1

Macro Definition Documentation

#define __mutex_fastpath_lock	(		count,
			fail_fn
	)

Value:

do {                                \
    unsigned int dummy;                 \
								\
	typecheck(atomic_t *, count);              \
    typecheck_fn(void (*)(atomic_t *), fail_fn);        \
                                \
    asm volatile(LOCK_PREFIX "   decl (%%eax)\n"        \
             "   jns 1f \n"             \
             "   call " #fail_fn "\n"           \
             "1:\n"                 \
             : "=a" (dummy)             \
             : "a" (count)              \
             : "memory", "ecx", "edx");         \
} while (0)

Definition at line 24 of file mutex_32.h.

#define __mutex_fastpath_unlock	(		count,
			fail_fn
	)

Value:

do {                                \
    unsigned int dummy;                 \
								\
	typecheck(atomic_t *, count);              \
    typecheck_fn(void (*)(atomic_t *), fail_fn);        \
                                \
    asm volatile(LOCK_PREFIX "   incl (%%eax)\n"        \
             "   jg 1f\n"               \
             "   call " #fail_fn "\n"           \
             "1:\n"                 \
             : "=a" (dummy)             \
             : "a" (count)              \
             : "memory", "ecx", "edx");         \
} while (0)

__mutex_fastpath_unlock - try to promote the mutex from 0 to 1 : pointer of type atomic_t : function to call if the original value was not 0

try to promote the mutex from 0 to 1. if it wasn't 0, call <fail_fn>. In the failure case, this function is allowed to either set the value to 1, or to set it to a value lower than 1.

If the implementation sets it to a value of lower than 1, the __mutex_slowpath_needs_to_unlock() macro needs to return 1, it needs to return 0 otherwise.

Definition at line 73 of file mutex_32.h.

#define __mutex_slowpath_needs_to_unlock

(

)

1

Definition at line 89 of file mutex_32.h.