powerpc: Fix delay functions for 601 processors
My earlier merge of delay.h introduced a timebase-based udelay for
32-bit machines but also broke the 601, which doesn't have the
timebase register. This fixes it by using the 601's RTC register on
the 601, and also moves __delay() and udelay() to be out-of-line in
arch/powerpc/kernel/time.c. These functions aren't really performance
critical, after all.
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/kernel/misc_32.S b/arch/powerpc/kernel/misc_32.S
index f6d84a7..624a983 100644
--- a/arch/powerpc/kernel/misc_32.S
+++ b/arch/powerpc/kernel/misc_32.S
@@ -27,14 +27,6 @@
.text
- .align 5
-_GLOBAL(__delay)
- cmpwi 0,r3,0
- mtctr r3
- beqlr
-1: bdnz 1b
- blr
-
/*
* This returns the high 64 bits of the product of two 64-bit numbers.
*/
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index 070b4b4..de84797 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -130,6 +130,34 @@
*/
DEFINE_PER_CPU(unsigned long, last_jiffy);
+void __delay(unsigned long loops)
+{
+ unsigned long start;
+ int diff;
+
+ if (__USE_RTC()) {
+ start = get_rtcl();
+ do {
+ /* the RTCL register wraps at 1000000000 */
+ diff = get_rtcl() - start;
+ if (diff < 0)
+ diff += 1000000000;
+ } while (diff < loops);
+ } else {
+ start = get_tbl();
+ while (get_tbl() - start < loops)
+ HMT_low();
+ HMT_medium();
+ }
+}
+EXPORT_SYMBOL(__delay);
+
+void udelay(unsigned long usecs)
+{
+ __delay(tb_ticks_per_usec * usecs);
+}
+EXPORT_SYMBOL(udelay);
+
static __inline__ void timer_check_rtc(void)
{
/*
diff --git a/include/asm-powerpc/delay.h b/include/asm-powerpc/delay.h
index 1492aa9..54fe1f4 100644
--- a/include/asm-powerpc/delay.h
+++ b/include/asm-powerpc/delay.h
@@ -13,43 +13,7 @@
* Anton Blanchard.
*/
-extern unsigned long tb_ticks_per_usec;
-
-#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()
-#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);
-}
+extern void __delay(unsigned long loops);
+extern void udelay(unsigned long usecs);
#endif /* _ASM_POWERPC_DELAY_H */