diff options
Diffstat (limited to 'arch/powerpc/kernel/time.c')
| -rw-r--r-- | arch/powerpc/kernel/time.c | 100 |
1 files changed, 4 insertions, 96 deletions
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c index cf3f8db7e0e3..67feb3524460 100644 --- a/arch/powerpc/kernel/time.c +++ b/arch/powerpc/kernel/time.c @@ -82,6 +82,7 @@ static struct clocksource clocksource_timebase = { .flags = CLOCK_SOURCE_IS_CONTINUOUS, .mask = CLOCKSOURCE_MASK(64), .read = timebase_read, + .vdso_clock_mode = VDSO_CLOCKMODE_ARCHTIMER, }; #define DECREMENTER_DEFAULT_MAX 0x7FFFFFFF @@ -576,14 +577,11 @@ void timer_interrupt(struct pt_regs *regs) struct pt_regs *old_regs; u64 now; - /* Some implementations of hotplug will get timer interrupts while - * offline, just ignore these and we also need to set - * decrementers_next_tb as MAX to make sure __check_irq_replay - * don't replay timer interrupt when return, otherwise we'll trap - * here infinitely :( + /* + * Some implementations of hotplug will get timer interrupts while + * offline, just ignore these. */ if (unlikely(!cpu_online(smp_processor_id()))) { - *next_tb = ~(u64)0; set_dec(decrementer_max); return; } @@ -855,95 +853,6 @@ static notrace u64 timebase_read(struct clocksource *cs) return (u64)get_tb(); } - -void update_vsyscall(struct timekeeper *tk) -{ - struct timespec64 xt; - struct clocksource *clock = tk->tkr_mono.clock; - u32 mult = tk->tkr_mono.mult; - u32 shift = tk->tkr_mono.shift; - u64 cycle_last = tk->tkr_mono.cycle_last; - u64 new_tb_to_xs, new_stamp_xsec; - u64 frac_sec; - - if (clock != &clocksource_timebase) - return; - - xt.tv_sec = tk->xtime_sec; - xt.tv_nsec = (long)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift); - - /* Make userspace gettimeofday spin until we're done. */ - ++vdso_data->tb_update_count; - smp_mb(); - - /* - * This computes ((2^20 / 1e9) * mult) >> shift as a - * 0.64 fixed-point fraction. - * The computation in the else clause below won't overflow - * (as long as the timebase frequency is >= 1.049 MHz) - * but loses precision because we lose the low bits of the constant - * in the shift. Note that 19342813113834067 ~= 2^(20+64) / 1e9. - * For a shift of 24 the error is about 0.5e-9, or about 0.5ns - * over a second. (Shift values are usually 22, 23 or 24.) - * For high frequency clocks such as the 512MHz timebase clock - * on POWER[6789], the mult value is small (e.g. 32768000) - * and so we can shift the constant by 16 initially - * (295147905179 ~= 2^(20+64-16) / 1e9) and then do the - * remaining shifts after the multiplication, which gives a - * more accurate result (e.g. with mult = 32768000, shift = 24, - * the error is only about 1.2e-12, or 0.7ns over 10 minutes). - */ - if (mult <= 62500000 && clock->shift >= 16) - new_tb_to_xs = ((u64) mult * 295147905179ULL) >> (clock->shift - 16); - else - new_tb_to_xs = (u64) mult * (19342813113834067ULL >> clock->shift); - - /* - * Compute the fractional second in units of 2^-32 seconds. - * The fractional second is tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift - * in nanoseconds, so multiplying that by 2^32 / 1e9 gives - * it in units of 2^-32 seconds. - * We assume shift <= 32 because clocks_calc_mult_shift() - * generates shift values in the range 0 - 32. - */ - frac_sec = tk->tkr_mono.xtime_nsec << (32 - shift); - do_div(frac_sec, NSEC_PER_SEC); - - /* - * Work out new stamp_xsec value for any legacy users of systemcfg. - * stamp_xsec is in units of 2^-20 seconds. - */ - new_stamp_xsec = frac_sec >> 12; - new_stamp_xsec += tk->xtime_sec * XSEC_PER_SEC; - - /* - * tb_update_count is used to allow the userspace gettimeofday code - * to assure itself that it sees a consistent view of the tb_to_xs and - * stamp_xsec variables. It reads the tb_update_count, then reads - * tb_to_xs and stamp_xsec and then reads tb_update_count again. If - * the two values of tb_update_count match and are even then the - * tb_to_xs and stamp_xsec values are consistent. If not, then it - * loops back and reads them again until this criteria is met. - */ - vdso_data->tb_orig_stamp = cycle_last; - vdso_data->stamp_xsec = new_stamp_xsec; - vdso_data->tb_to_xs = new_tb_to_xs; - vdso_data->wtom_clock_sec = tk->wall_to_monotonic.tv_sec; - vdso_data->wtom_clock_nsec = tk->wall_to_monotonic.tv_nsec; - vdso_data->stamp_xtime_sec = xt.tv_sec; - vdso_data->stamp_xtime_nsec = xt.tv_nsec; - vdso_data->stamp_sec_fraction = frac_sec; - vdso_data->hrtimer_res = hrtimer_resolution; - smp_wmb(); - ++(vdso_data->tb_update_count); -} - -void update_vsyscall_tz(void) -{ - vdso_data->tz_minuteswest = sys_tz.tz_minuteswest; - vdso_data->tz_dsttime = sys_tz.tz_dsttime; -} - static void __init clocksource_init(void) { struct clocksource *clock = &clocksource_timebase; @@ -1103,7 +1012,6 @@ void __init time_init(void) sys_tz.tz_dsttime = 0; } - vdso_data->tb_update_count = 0; vdso_data->tb_ticks_per_sec = tb_ticks_per_sec; /* initialise and enable the large decrementer (if we have one) */ |