sys/dev/acpi/acpica/acpi_func.h

   1 /*      $NetBSD: acpi_func.h,v 1.10 2008/05/24 22:02:31 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()