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Diffstat (limited to 'arch/blackfin/include/asm/delay.h')
-rw-r--r--arch/blackfin/include/asm/delay.h35
1 files changed, 6 insertions, 29 deletions
diff --git a/arch/blackfin/include/asm/delay.h b/arch/blackfin/include/asm/delay.h
index 0889c3abb593..c31f91cc1d5d 100644
--- a/arch/blackfin/include/asm/delay.h
+++ b/arch/blackfin/include/asm/delay.h
@@ -13,29 +13,7 @@
static inline void __delay(unsigned long loops)
{
- if (ANOMALY_05000312) {
- /* Interrupted loads to loop registers -> bad */
- unsigned long tmp;
- __asm__ __volatile__(
- "[--SP] = LC0;"
- "[--SP] = LT0;"
- "[--SP] = LB0;"
- "LSETUP (1f,1f) LC0 = %1;"
- "1: NOP;"
- /* We take advantage of the fact that LC0 is 0 at
- * the end of the loop. Otherwise we'd need some
- * NOPs after the CLI here.
- */
- "CLI %0;"
- "LB0 = [SP++];"
- "LT0 = [SP++];"
- "LC0 = [SP++];"
- "STI %0;"
- : "=d" (tmp)
- : "a" (loops)
- );
- } else
- __asm__ __volatile__ (
+__asm__ __volatile__ (
"LSETUP(1f, 1f) LC0 = %0;"
"1: NOP;"
:
@@ -47,16 +25,15 @@ static inline void __delay(unsigned long loops)
#include <linux/param.h> /* needed for HZ */
/*
- * Use only for very small delays ( < 1 msec). Should probably use a
- * lookup table, really, as the multiplications take much too long with
- * short delays. This is a "reasonable" implementation, though (and the
- * first constant multiplications gets optimized away if the delay is
- * a constant)
+ * close approximation borrowed from m68knommu to avoid 64-bit math
*/
+
+#define HZSCALE (268435456 / (1000000/HZ))
+
static inline void udelay(unsigned long usecs)
{
extern unsigned long loops_per_jiffy;
- __delay(usecs * loops_per_jiffy / (1000000 / HZ));
+ __delay((((usecs * HZSCALE) >> 11) * (loops_per_jiffy >> 11)) >> 6);
}
#endif