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>

3 files changed, 30 insertions, 46 deletions

diff --git a/arch/powerpc/kernel/misc_32.S b/arch/powerpc/kernel/misc_32.S
index f6d84a75ed26..624a983a9676 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 070b4b458aaf..de8479769bb7 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -130,6 +130,34 @@ unsigned long tb_last_stamp;
  */
 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 1492aa9ab716..54fe1f4f8fd0 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 */