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authorBenjamin Herrenschmidt <benh@kernel.crashing.org>2007-09-19 14:21:56 +1000
committerPaul Mackerras <paulus@samba.org>2007-09-19 15:26:34 +1000
commitc27da339698145a9383e052c1070a950d30da478 (patch)
tree817025c780b6be5d80405c90f4c5fb88086b6cb8
parent7b5acbaac3f94ab810a977c0ec4e5fcabbf51bed (diff)
downloadlinux-linaro-c27da339698145a9383e052c1070a950d30da478.tar.gz
[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>
-rw-r--r--arch/powerpc/kernel/time.c8
-rw-r--r--include/asm-powerpc/time.h5
2 files changed, 10 insertions, 3 deletions
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index 727a6699f2f..c627cf86d1e 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -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();
diff --git a/include/asm-powerpc/time.h b/include/asm-powerpc/time.h
index d7f5ddfbaac..c104c15c662 100644
--- a/include/asm-powerpc/time.h
+++ b/include/asm-powerpc/time.h
@@ -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);