diff options
Diffstat (limited to 'arch/s390/kernel/time.c')
| -rw-r--r-- | arch/s390/kernel/time.c | 86 |
1 files changed, 14 insertions, 72 deletions
diff --git a/arch/s390/kernel/time.c b/arch/s390/kernel/time.c index 4e9949800562..0bfcc492987e 100644 --- a/arch/s390/kernel/time.c +++ b/arch/s390/kernel/time.c @@ -50,10 +50,6 @@ #include <asm/cio.h> #include "entry.h" -/* change this if you have some constant time drift */ -#define USECS_PER_JIFFY ((unsigned long) 1000000/HZ) -#define CLK_TICKS_PER_JIFFY ((unsigned long) USECS_PER_JIFFY << 12) - u64 sched_clock_base_cc = -1; /* Force to data section. */ EXPORT_SYMBOL_GPL(sched_clock_base_cc); @@ -282,13 +278,8 @@ extern struct timezone sys_tz; void update_vsyscall_tz(void) { - /* Make userspace gettimeofday spin until we're done. */ - ++vdso_data->tb_update_count; - smp_wmb(); vdso_data->tz_minuteswest = sys_tz.tz_minuteswest; vdso_data->tz_dsttime = sys_tz.tz_dsttime; - smp_wmb(); - ++vdso_data->tb_update_count; } /* @@ -318,51 +309,12 @@ void __init time_init(void) vtime_init(); } -/* - * The time is "clock". old is what we think the time is. - * Adjust the value by a multiple of jiffies and add the delta to ntp. - * "delay" is an approximation how long the synchronization took. If - * the time correction is positive, then "delay" is subtracted from - * the time difference and only the remaining part is passed to ntp. - */ -static unsigned long long adjust_time(unsigned long long old, - unsigned long long clock, - unsigned long long delay) -{ - unsigned long long delta, ticks; - struct timex adjust; - - if (clock > old) { - /* It is later than we thought. */ - delta = ticks = clock - old; - delta = ticks = (delta < delay) ? 0 : delta - delay; - delta -= do_div(ticks, CLK_TICKS_PER_JIFFY); - adjust.offset = ticks * (1000000 / HZ); - } else { - /* It is earlier than we thought. */ - delta = ticks = old - clock; - delta -= do_div(ticks, CLK_TICKS_PER_JIFFY); - delta = -delta; - adjust.offset = -ticks * (1000000 / HZ); - } - sched_clock_base_cc += delta; - if (adjust.offset != 0) { - pr_notice("The ETR interface has adjusted the clock " - "by %li microseconds\n", adjust.offset); - adjust.modes = ADJ_OFFSET_SINGLESHOT; - do_adjtimex(&adjust); - } - return delta; -} - static DEFINE_PER_CPU(atomic_t, clock_sync_word); static DEFINE_MUTEX(clock_sync_mutex); static unsigned long clock_sync_flags; -#define CLOCK_SYNC_HAS_ETR 0 -#define CLOCK_SYNC_HAS_STP 1 -#define CLOCK_SYNC_ETR 2 -#define CLOCK_SYNC_STP 3 +#define CLOCK_SYNC_HAS_STP 0 +#define CLOCK_SYNC_STP 1 /* * The get_clock function for the physical clock. It will get the current @@ -384,34 +336,32 @@ int get_phys_clock(unsigned long long *clock) if (sw0 == sw1 && (sw0 & 0x80000000U)) /* Success: time is in sync. */ return 0; - if (!test_bit(CLOCK_SYNC_HAS_ETR, &clock_sync_flags) && - !test_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags)) + if (!test_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags)) return -EOPNOTSUPP; - if (!test_bit(CLOCK_SYNC_ETR, &clock_sync_flags) && - !test_bit(CLOCK_SYNC_STP, &clock_sync_flags)) + if (!test_bit(CLOCK_SYNC_STP, &clock_sync_flags)) return -EACCES; return -EAGAIN; } EXPORT_SYMBOL(get_phys_clock); /* - * Make get_sync_clock return -EAGAIN. + * Make get_phys_clock() return -EAGAIN. */ static void disable_sync_clock(void *dummy) { atomic_t *sw_ptr = this_cpu_ptr(&clock_sync_word); /* - * Clear the in-sync bit 2^31. All get_sync_clock calls will + * Clear the in-sync bit 2^31. All get_phys_clock calls will * fail until the sync bit is turned back on. In addition * increase the "sequence" counter to avoid the race of an - * etr event and the complete recovery against get_sync_clock. + * stp event and the complete recovery against get_phys_clock. */ atomic_andnot(0x80000000, sw_ptr); atomic_inc(sw_ptr); } /* - * Make get_sync_clock return 0 again. + * Make get_phys_clock() return 0 again. * Needs to be called from a context disabled for preemption. */ static void enable_sync_clock(void) @@ -434,7 +384,7 @@ static inline int check_sync_clock(void) return rc; } -/* Single threaded workqueue used for etr and stp sync events */ +/* Single threaded workqueue used for stp sync events */ static struct workqueue_struct *time_sync_wq; static void __init time_init_wq(void) @@ -448,20 +398,12 @@ struct clock_sync_data { atomic_t cpus; int in_sync; unsigned long long fixup_cc; - int etr_port; - struct etr_aib *etr_aib; }; static void clock_sync_cpu(struct clock_sync_data *sync) { atomic_dec(&sync->cpus); enable_sync_clock(); - /* - * This looks like a busy wait loop but it isn't. etr_sync_cpus - * is called on all other cpus while the TOD clocks is stopped. - * __udelay will stop the cpu on an enabled wait psw until the - * TOD is running again. - */ while (sync->in_sync == 0) { __udelay(1); /* @@ -582,7 +524,7 @@ void stp_queue_work(void) static int stp_sync_clock(void *data) { static int first; - unsigned long long old_clock, delta, new_clock, clock_delta; + unsigned long long clock_delta; struct clock_sync_data *stp_sync; struct ptff_qto qto; int rc; @@ -605,18 +547,18 @@ static int stp_sync_clock(void *data) if (stp_info.todoff[0] || stp_info.todoff[1] || stp_info.todoff[2] || stp_info.todoff[3] || stp_info.tmd != 2) { - old_clock = get_tod_clock(); rc = chsc_sstpc(stp_page, STP_OP_SYNC, 0, &clock_delta); if (rc == 0) { - new_clock = old_clock + clock_delta; - delta = adjust_time(old_clock, new_clock, 0); + /* fixup the monotonic sched clock */ + sched_clock_base_cc += clock_delta; if (ptff_query(PTFF_QTO) && ptff(&qto, sizeof(qto), PTFF_QTO) == 0) /* Update LPAR offset */ lpar_offset = qto.tod_epoch_difference; atomic_notifier_call_chain(&s390_epoch_delta_notifier, 0, &clock_delta); - fixup_clock_comparator(delta); + stp_sync->fixup_cc = clock_delta; + fixup_clock_comparator(clock_delta); rc = chsc_sstpi(stp_page, &stp_info, sizeof(struct stp_sstpi)); if (rc == 0 && stp_info.tmd != 2) |