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[POWERPC] Fix timekeeping on PowerPC 601 

Recent changes to the timekeeping code broke support for the PowerPC 601
processor which doesn't have the usual timebase facility but a slightly
different thing called (yuck) the RTC.

This fixes it, boot tested on an old 601 based PowerMac 7200.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This commit is contained in:
Benjamin Herrenschmidt 2007-09-19 14:21:56 +10:00 committed by Paul Mackerras
parent 7b5acbaac3
commit c27da33969
2 changed files with 10 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
arch/powerpc/kernel/time.c
View File

@ -239,7 +239,7 @@ static void snapshot_tb_and_purr(void *data)
struct cpu_purr_data *p = &__get_cpu_var(cpu_purr_data);
local_irq_save(flags);
p->tb = mftb();
p->tb = get_tb_or_rtc();
p->purr = mfspr(SPRN_PURR);
wmb();
p->initialized = 1;
@ -317,7 +317,7 @@ static void snapshot_purr(void)
*/
void snapshot_timebase(void)
{
__get_cpu_var(last_jiffy) = get_tb();
__get_cpu_var(last_jiffy) = get_tb_or_rtc();
snapshot_purr();
}
@ -684,6 +684,8 @@ void timer_interrupt(struct pt_regs * regs)
write_seqlock(&xtime_lock);
tb_next_jiffy = tb_last_jiffy + tb_ticks_per_jiffy;
if (__USE_RTC() && tb_next_jiffy >= 1000000000)
tb_next_jiffy -= 1000000000;
if (per_cpu(last_jiffy, cpu) >= tb_next_jiffy) {
tb_last_jiffy = tb_next_jiffy;
do_timer(1);
@ -977,7 +979,7 @@ void __init time_init(void)
tb_to_ns_scale = scale;
tb_to_ns_shift = shift;
/* Save the current timebase to pretty up CONFIG_PRINTK_TIME */
boot_tb = get_tb();
boot_tb = get_tb_or_rtc();
tm = get_boot_time();

5
include/asm-powerpc/time.h
View File

@ -149,6 +149,11 @@ static inline u64 get_tb(void)
}
#endif /* !CONFIG_PPC64 */
static inline u64 get_tb_or_rtc(void)
{
return __USE_RTC() ? get_rtc() : get_tb();
}
static inline void set_tb(unsigned int upper, unsigned int lower)
{
mtspr(SPRN_TBWL, 0);