From: Benjamin Herrenschmidt Date: Wed, 19 Sep 2007 04:21:56 +0000 (+1000) Subject: [POWERPC] Fix timekeeping on PowerPC 601 X-Git-Tag: v2.6.23-rc7~8^2 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c27da339698145a9383e052c1070a950d30da478;p=linux-2.6 [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 Signed-off-by: Paul Mackerras --- diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c index 727a6699f2..c627cf86d1 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 d7f5ddfbaa..c104c15c66 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);