Merge commit 'v2.6.26-rc9' into sched/devel

[pandora-kernel.git] / include / asm-powerpc / delay.h

diff --git a/include/asm-powerpc/delay.h b/include/asm-powerpc/delay.h
index 1492aa9..f9200a6 100644 (file)
--- a/include/asm-powerpc/delay.h
+++ b/include/asm-powerpc/delay.h
@@ -1,5 +1,6 @@
 #ifndef _ASM_POWERPC_DELAY_H
 #define _ASM_POWERPC_DELAY_H
+#ifdef __KERNEL__
 
 /*
  * Copyright 1996, Paul Mackerras.
@@ -13,43 +14,21 @@
  * Anton Blanchard.
  */
 
-extern unsigned long tb_ticks_per_usec;
+extern void __delay(unsigned long loops);
+extern void udelay(unsigned long usecs);
 
+/*
+ * On shared processor machines the generic implementation of mdelay can
+ * result in large errors. While each iteration of the loop inside mdelay
+ * is supposed to take 1ms, the hypervisor could sleep our partition for
+ * longer (eg 10ms). With the right timing these errors can add up.
+ *
+ * Since there is no 32bit overflow issue on 64bit kernels, just call
+ * udelay directly.
+ */
 #ifdef CONFIG_PPC64
-/* define these here to prevent circular dependencies */
-/* these instructions control the thread priority on multi-threaded cpus */
-#define __HMT_low()    asm volatile("or 1,1,1")
-#define __HMT_medium() asm volatile("or 2,2,2")
-#else
-#define __HMT_low()
-#define __HMT_medium()
+#define mdelay(n)      udelay((n) * 1000)
 #endif
 
-#define __barrier()    asm volatile("" ::: "memory")
-
-static inline unsigned long __get_tb(void)
-{
-       unsigned long rval;
-
-       asm volatile("mftb %0" : "=r" (rval));
-       return rval;
-}
-
-static inline void __delay(unsigned long loops)
-{
-       unsigned long start = __get_tb();
-
-       while((__get_tb() - start) < loops)
-               __HMT_low();
-       __HMT_medium();
-       __barrier();
-}
-
-static inline void udelay(unsigned long usecs)
-{
-       unsigned long loops = tb_ticks_per_usec * usecs;
-
-       __delay(loops);
-}
-
+#endif /* __KERNEL__ */
 #endif /* _ASM_POWERPC_DELAY_H */