Home | History | Annotate | Line # | Download | only in acpica
acpi_func.h revision 1.1 
      1 /*	$NetBSD: acpi_func.h,v 1.1 2008/05/24 22:16:20 jmcneill Exp $	*/
      2 
      3 #include <machine/cpufunc.h>
      4 
      5 #include <sys/atomic.h>
      6 
      7 #define GL_ACQUIRED	(-1)
      8 #define GL_BUSY		0
      9 #define GL_BIT_PENDING	1
     10 #define GL_BIT_OWNED	2
     11 #define GL_BIT_MASK	(GL_BIT_PENDING | GL_BIT_OWNED)
     12 
     13 #define ACPI_ACQUIRE_GLOBAL_LOCK(GLptr, Acq) 				\
     14 do { 									\
     15 	(Acq) = acpi_acquire_global_lock(&((GLptr)->GlobalLock));	\
     16 } while (0)
     17 
     18 #define ACPI_RELEASE_GLOBAL_LOCK(GLptr, Acq) 				\
     19 do {									\
     20 	(Acq) = acpi_release_global_lock(&((GLptr)->GlobalLock));	\
     21 } while (0)
     22 
     23 static inline int
     24 acpi_acquire_global_lock(uint32_t *lock)
     25 {
     26 	uint32_t new, old, val;
     27 
     28 	do {
     29 		old = *lock;
     30 		new = ((old & ~GL_BIT_MASK) | GL_BIT_OWNED) |
     31 		    ((old >> 1) & GL_BIT_PENDING);
     32 		val = atomic_cas_32(lock, old, new);
     33 	} while (__predict_false(val != old));
     34 
     35 	return ((new < GL_BIT_MASK) ? GL_ACQUIRED : GL_BUSY);
     36 }
     37 
     38 static inline int
     39 acpi_release_global_lock(uint32_t *lock)
     40 {
     41 	uint32_t new, old, val;
     42 
     43 	do {
     44 		old = *lock;
     45 		new = old & ~GL_BIT_MASK;
     46 		val = atomic_cas_32(lock, old, new);
     47 	} while (__predict_false(val != old));
     48 
     49 	return old & GL_BIT_PENDING;
     50 }
     51 
     52 #define	ACPI_FLUSH_CPU_CACHE()		wbinvd()
     53