diff options
Diffstat (limited to 'arch/powerpc/boot/util.S')
| -rw-r--r-- | arch/powerpc/boot/util.S | 24 |
1 files changed, 4 insertions, 20 deletions
diff --git a/arch/powerpc/boot/util.S b/arch/powerpc/boot/util.S index f11f0589a669..6a92376daf3f 100644 --- a/arch/powerpc/boot/util.S +++ b/arch/powerpc/boot/util.S @@ -18,7 +18,7 @@ .text -/* udelay (on non-601 processors) needs to know the period of the +/* udelay needs to know the period of the * timebase in nanoseconds. This used to be hardcoded to be 60ns * (period of 66MHz/4). Now a variable is used that is initialized to * 60 for backward compatibility, but it can be overridden as necessary @@ -37,32 +37,16 @@ timebase_period_ns: */ .globl udelay udelay: - mfspr r4,SPRN_PVR - srwi r4,r4,16 - cmpwi 0,r4,1 /* 601 ? */ - bne .Ludelay_not_601 -00: li r0,86 /* Instructions / microsecond? */ - mtctr r0 -10: addi r0,r0,0 /* NOP */ - bdnz 10b - subic. r3,r3,1 - bne 00b - blr - -.Ludelay_not_601: mulli r4,r3,1000 /* nanoseconds */ /* Change r4 to be the number of ticks using: * (nanoseconds + (timebase_period_ns - 1 )) / timebase_period_ns * timebase_period_ns defaults to 60 (16.6MHz) */ mflr r5 - bl 0f + bcl 20,31,0f 0: mflr r6 mtlr r5 - lis r5,0b@ha - addi r5,r5,0b@l - subf r5,r5,r6 /* In case we're relocated */ - addis r5,r5,timebase_period_ns@ha - lwz r5,timebase_period_ns@l(r5) + addis r5,r6,(timebase_period_ns-0b)@ha + lwz r5,(timebase_period_ns-0b)@l(r5) add r4,r4,r5 addi r4,r4,-1 divw r4,r4,r5 /* BUS ticks */ |