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>

1 files changed, 28 insertions, 0 deletions

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)
 {
         /*