#ifndef _ASM_POWERPC_DELAY_H
#define _ASM_POWERPC_DELAY_H
+#ifdef __KERNEL__
/*
* Copyright 1996, Paul Mackerras.
* 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 */