xnu-792.6.22.tar.gz

[apple/xnu.git] / iokit / IOKit / ppc / IOSharedLockImp.h

diff --git a/iokit/IOKit/ppc/IOSharedLockImp.h b/iokit/IOKit/ppc/IOSharedLockImp.h
index 3bff4b078b9707f98e84e84d607a858f3748ac32..3644a328c120a2b64527999cdbc46395db1233e7 100644 (file)
--- a/iokit/IOKit/ppc/IOSharedLockImp.h
+++ b/iokit/IOKit/ppc/IOSharedLockImp.h
@@ -49,16 +49,10 @@
 #define _IOKIT_IOSHAREDLOCKIMP_H
 
 #include <architecture/ppc/asm_help.h>
-
-// 'Till we're building in kernel
-.macro DISABLE_PREEMPTION
-#ifdef KERNEL
-#endif
-.endmacro
-.macro ENABLE_PREEMPTION
 #ifdef KERNEL
+#undef END
+#include <mach/ppc/asm.h>
 #endif
-.endmacro
 
 /*
  *     void
@@ -72,33 +66,47 @@
 
 #ifndef KERNEL
 LEAF(_ev_lock)
-       li      a6,1                    // lock value
-       lwarx   a7,0,a0                 // CEMV10
-9:
-       sync
-       lwarx   a7,0,a0                 // read the lock
-       cmpwi   cr0,a7,0                // is it busy?
-       bne-    9b                      // yes, spin
-       sync
-       stwcx.  a6,0,a0                 // try to get the lock
-       bne-    9b                      // failed, try again
-       isync
-       blr                             // got it, return
+
+               li              a6,1                    // lock value
+               
+8:             lwz             a7,0(a0)                // Get lock word
+               mr.             a7,a7                   // Is it held?
+               bne--   8b                              // Yup...
+
+9:             lwarx   a7,0,a0                 // read the lock
+               mr.             a7,a7                   // Is it held?
+               bne--   7f                              // yes, kill reservation
+               stwcx.  a6,0,a0                 // try to get the lock
+               bne--   9b                              // failed, try again
+               isync
+               blr                                             // got it, return
+               
+7:             li              a7,-4                   // Point to a spot in the red zone
+               stwcx.  a7,a7,r1                // Kill reservation
+               b               8b                              // Go wait some more...
+               
+               
 END(_ev_lock)
 
 LEAF(_IOSpinLock)
-       li      a6,1                    // lock value
-       lwarx   a7,0,a0                 // CEMV10
-9:
-       sync
-       lwarx   a7,0,a0                 // read the lock
-       cmpwi   cr0,a7,0                // is it busy?
-       bne-    9b                      // yes, spin
-       sync
-       stwcx.  a6,0,a0                 // try to get the lock
-       bne-    9b                      // failed, try again
-       isync
-       blr                             // got it, return
+
+               li              a6,1                    // lock value
+               
+8:             lwz             a7,0(a0)                // Get lock word
+               mr.             a7,a7                   // Is it held?
+               bne--   8b                              // Yup...
+
+9:             lwarx   a7,0,a0                 // read the lock
+               mr.             a7,a7                   // Is it held?
+               bne--   7f                              // yes, kill reservation
+               stwcx.  a6,0,a0                 // try to get the lock
+               bne--   9b                              // failed, try again
+               isync
+               blr                                             // got it, return
+               
+7:             li              a7,-4                   // Point to a spot in the red zone
+               stwcx.  a7,a7,r1                // Kill reservation
+               b               8b                              // Go wait some more...
 END(_IOSpinLock)
 #endif
 
@@ -114,7 +122,6 @@ LEAF(_ev_unlock)
        sync
        li      a7,0
        stw     a7,0(a0)
-       ENABLE_PREEMPTION()
        blr
 END(_ev_unlock)
 
@@ -122,7 +129,6 @@ LEAF(_IOSpinUnlock)
        sync
        li      a7,0
        stw     a7,0(a0)
-       ENABLE_PREEMPTION()
        blr
 END(_IOSpinUnlock)
 
@@ -135,45 +141,53 @@ END(_IOSpinUnlock)
  */
 
 LEAF(_ev_try_lock)
-       li      a6,1                    // lock value
-        DISABLE_PREEMPTION()
-       lwarx   a7,0,a0                 // CEMV10
-8:
-       sync
-       lwarx   a7,0,a0                 // read the lock
-       cmpwi   cr0,a7,0                // is it busy?
-       bne-    9f                      // yes, give up
-       sync
-       stwcx.  a6,0,a0                 // try to get the lock
-       bne-    8b                      // failed, try again
-       li      a0,1                    // return TRUE
-       isync
-       blr
-9:
-       ENABLE_PREEMPTION()
-       li      a0,0                    // return FALSE
-       blr
+               li              a6,1                    // lock value
+               
+               lwz             a7,0(a0)                // Get lock word
+               mr.             a7,a7                   // Is it held?
+               bne--   6f                              // Yup...
+
+9:             lwarx   a7,0,a0                 // read the lock
+               mr.             a7,a7                   // Is it held?
+               bne--   7f                              // yes, kill reservation
+               stwcx.  a6,0,a0                 // try to get the lock
+               bne--   9b                              // failed, try again
+               li              a0,1                    // return TRUE
+               isync
+               blr                                             // got it, return
+               
+7:             li              a7,-4                   // Point to a spot in the red zone
+               stwcx.  a7,a7,r1                // Kill reservation
+
+6:
+               li      a0,0                            // return FALSE
+               blr
+               
 END(_ev_try_lock)
 
 LEAF(_IOTrySpinLock)
-       li      a6,1                    // lock value
-        DISABLE_PREEMPTION()
-       lwarx   a7,0,a0                 // CEMV10
-8:
-       sync
-       lwarx   a7,0,a0                 // read the lock
-       cmpwi   cr0,a7,0                // is it busy?
-       bne-    9f                      // yes, give up
-       sync
-       stwcx.  a6,0,a0                 // try to get the lock
-       bne-    8b                      // failed, try again
-       li      a0,1                    // return TRUE
-       isync
-       blr
-9:
-       ENABLE_PREEMPTION()
-       li      a0,0                    // return FALSE
-       blr
+               li              a6,1                    // lock value
+               
+               lwz             a7,0(a0)                // Get lock word
+               mr.             a7,a7                   // Is it held?
+               bne--   6f                              // Yup...
+
+9:             lwarx   a7,0,a0                 // read the lock
+               mr.             a7,a7                   // Is it held?
+               bne--   7f                              // yes, kill reservation
+               stwcx.  a6,0,a0                 // try to get the lock
+               bne--   9b                              // failed, try again
+               li              a0,1                    // return TRUE
+               isync
+               blr                                             // got it, return
+               
+7:             li              a7,-4                   // Point to a spot in the red zone
+               stwcx.  a7,a7,r1                // Kill reservation
+
+6:
+               li      a0,0                            // return FALSE
+               blr
+               
 END(_IOTrySpinLock)
 
 #endif /* ! _IOKIT_IOSHAREDLOCKIMP_H */