summaryrefslogtreecommitdiffstats
path: root/arch/s390/kernel/time.c
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--arch/s390/kernel/time.c923
1 files changed, 923 insertions, 0 deletions
diff --git a/arch/s390/kernel/time.c b/arch/s390/kernel/time.c
new file mode 100644
index 000000000..11c32b228
--- /dev/null
+++ b/arch/s390/kernel/time.c
@@ -0,0 +1,923 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Time of day based timer functions.
+ *
+ * S390 version
+ * Copyright IBM Corp. 1999, 2008
+ * Author(s): Hartmut Penner (hp@de.ibm.com),
+ * Martin Schwidefsky (schwidefsky@de.ibm.com),
+ * Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com)
+ *
+ * Derived from "arch/i386/kernel/time.c"
+ * Copyright (C) 1991, 1992, 1995 Linus Torvalds
+ */
+
+#define KMSG_COMPONENT "time"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+
+#include <linux/kernel_stat.h>
+#include <linux/errno.h>
+#include <linux/export.h>
+#include <linux/sched.h>
+#include <linux/sched/clock.h>
+#include <linux/kernel.h>
+#include <linux/param.h>
+#include <linux/string.h>
+#include <linux/mm.h>
+#include <linux/interrupt.h>
+#include <linux/cpu.h>
+#include <linux/stop_machine.h>
+#include <linux/time.h>
+#include <linux/device.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/smp.h>
+#include <linux/types.h>
+#include <linux/profile.h>
+#include <linux/timex.h>
+#include <linux/notifier.h>
+#include <linux/timekeeper_internal.h>
+#include <linux/clockchips.h>
+#include <linux/gfp.h>
+#include <linux/kprobes.h>
+#include <linux/uaccess.h>
+#include <asm/facility.h>
+#include <asm/delay.h>
+#include <asm/div64.h>
+#include <asm/vdso.h>
+#include <asm/irq.h>
+#include <asm/irq_regs.h>
+#include <asm/vtimer.h>
+#include <asm/stp.h>
+#include <asm/cio.h>
+#include "entry.h"
+
+unsigned char tod_clock_base[16] __aligned(8) = {
+ /* Force to data section. */
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff
+};
+EXPORT_SYMBOL_GPL(tod_clock_base);
+
+u64 clock_comparator_max = -1ULL;
+EXPORT_SYMBOL_GPL(clock_comparator_max);
+
+static DEFINE_PER_CPU(struct clock_event_device, comparators);
+
+ATOMIC_NOTIFIER_HEAD(s390_epoch_delta_notifier);
+EXPORT_SYMBOL(s390_epoch_delta_notifier);
+
+unsigned char ptff_function_mask[16];
+
+static unsigned long long lpar_offset;
+static unsigned long long initial_leap_seconds;
+static unsigned long long tod_steering_end;
+static long long tod_steering_delta;
+
+/*
+ * Get time offsets with PTFF
+ */
+void __init time_early_init(void)
+{
+ struct ptff_qto qto;
+ struct ptff_qui qui;
+
+ /* Initialize TOD steering parameters */
+ tod_steering_end = *(unsigned long long *) &tod_clock_base[1];
+ vdso_data->ts_end = tod_steering_end;
+
+ if (!test_facility(28))
+ return;
+
+ ptff(&ptff_function_mask, sizeof(ptff_function_mask), PTFF_QAF);
+
+ /* get LPAR offset */
+ if (ptff_query(PTFF_QTO) && ptff(&qto, sizeof(qto), PTFF_QTO) == 0)
+ lpar_offset = qto.tod_epoch_difference;
+
+ /* get initial leap seconds */
+ if (ptff_query(PTFF_QUI) && ptff(&qui, sizeof(qui), PTFF_QUI) == 0)
+ initial_leap_seconds = (unsigned long long)
+ ((long) qui.old_leap * 4096000000L);
+}
+
+/*
+ * Scheduler clock - returns current time in nanosec units.
+ */
+unsigned long long notrace sched_clock(void)
+{
+ return tod_to_ns(get_tod_clock_monotonic());
+}
+NOKPROBE_SYMBOL(sched_clock);
+
+/*
+ * Monotonic_clock - returns # of nanoseconds passed since time_init()
+ */
+unsigned long long monotonic_clock(void)
+{
+ return sched_clock();
+}
+EXPORT_SYMBOL(monotonic_clock);
+
+static void ext_to_timespec64(unsigned char *clk, struct timespec64 *xt)
+{
+ unsigned long long high, low, rem, sec, nsec;
+
+ /* Split extendnd TOD clock to micro-seconds and sub-micro-seconds */
+ high = (*(unsigned long long *) clk) >> 4;
+ low = (*(unsigned long long *)&clk[7]) << 4;
+ /* Calculate seconds and nano-seconds */
+ sec = high;
+ rem = do_div(sec, 1000000);
+ nsec = (((low >> 32) + (rem << 32)) * 1000) >> 32;
+
+ xt->tv_sec = sec;
+ xt->tv_nsec = nsec;
+}
+
+void clock_comparator_work(void)
+{
+ struct clock_event_device *cd;
+
+ S390_lowcore.clock_comparator = clock_comparator_max;
+ cd = this_cpu_ptr(&comparators);
+ cd->event_handler(cd);
+}
+
+static int s390_next_event(unsigned long delta,
+ struct clock_event_device *evt)
+{
+ S390_lowcore.clock_comparator = get_tod_clock() + delta;
+ set_clock_comparator(S390_lowcore.clock_comparator);
+ return 0;
+}
+
+/*
+ * Set up lowcore and control register of the current cpu to
+ * enable TOD clock and clock comparator interrupts.
+ */
+void init_cpu_timer(void)
+{
+ struct clock_event_device *cd;
+ int cpu;
+
+ S390_lowcore.clock_comparator = clock_comparator_max;
+ set_clock_comparator(S390_lowcore.clock_comparator);
+
+ cpu = smp_processor_id();
+ cd = &per_cpu(comparators, cpu);
+ cd->name = "comparator";
+ cd->features = CLOCK_EVT_FEAT_ONESHOT;
+ cd->mult = 16777;
+ cd->shift = 12;
+ cd->min_delta_ns = 1;
+ cd->min_delta_ticks = 1;
+ cd->max_delta_ns = LONG_MAX;
+ cd->max_delta_ticks = ULONG_MAX;
+ cd->rating = 400;
+ cd->cpumask = cpumask_of(cpu);
+ cd->set_next_event = s390_next_event;
+
+ clockevents_register_device(cd);
+
+ /* Enable clock comparator timer interrupt. */
+ __ctl_set_bit(0,11);
+
+ /* Always allow the timing alert external interrupt. */
+ __ctl_set_bit(0, 4);
+}
+
+static void clock_comparator_interrupt(struct ext_code ext_code,
+ unsigned int param32,
+ unsigned long param64)
+{
+ inc_irq_stat(IRQEXT_CLK);
+ if (S390_lowcore.clock_comparator == clock_comparator_max)
+ set_clock_comparator(S390_lowcore.clock_comparator);
+}
+
+static void stp_timing_alert(struct stp_irq_parm *);
+
+static void timing_alert_interrupt(struct ext_code ext_code,
+ unsigned int param32, unsigned long param64)
+{
+ inc_irq_stat(IRQEXT_TLA);
+ if (param32 & 0x00038000)
+ stp_timing_alert((struct stp_irq_parm *) &param32);
+}
+
+static void stp_reset(void);
+
+void read_persistent_clock64(struct timespec64 *ts)
+{
+ unsigned char clk[STORE_CLOCK_EXT_SIZE];
+ __u64 delta;
+
+ delta = initial_leap_seconds + TOD_UNIX_EPOCH;
+ get_tod_clock_ext(clk);
+ *(__u64 *) &clk[1] -= delta;
+ if (*(__u64 *) &clk[1] > delta)
+ clk[0]--;
+ ext_to_timespec64(clk, ts);
+}
+
+void __init read_persistent_wall_and_boot_offset(struct timespec64 *wall_time,
+ struct timespec64 *boot_offset)
+{
+ unsigned char clk[STORE_CLOCK_EXT_SIZE];
+ struct timespec64 boot_time;
+ __u64 delta;
+
+ delta = initial_leap_seconds + TOD_UNIX_EPOCH;
+ memcpy(clk, tod_clock_base, STORE_CLOCK_EXT_SIZE);
+ *(__u64 *)&clk[1] -= delta;
+ if (*(__u64 *)&clk[1] > delta)
+ clk[0]--;
+ ext_to_timespec64(clk, &boot_time);
+
+ read_persistent_clock64(wall_time);
+ *boot_offset = timespec64_sub(*wall_time, boot_time);
+}
+
+static u64 read_tod_clock(struct clocksource *cs)
+{
+ unsigned long long now, adj;
+
+ preempt_disable(); /* protect from changes to steering parameters */
+ now = get_tod_clock();
+ adj = tod_steering_end - now;
+ if (unlikely((s64) adj >= 0))
+ /*
+ * manually steer by 1 cycle every 2^16 cycles. This
+ * corresponds to shifting the tod delta by 15. 1s is
+ * therefore steered in ~9h. The adjust will decrease
+ * over time, until it finally reaches 0.
+ */
+ now += (tod_steering_delta < 0) ? (adj >> 15) : -(adj >> 15);
+ preempt_enable();
+ return now;
+}
+
+static struct clocksource clocksource_tod = {
+ .name = "tod",
+ .rating = 400,
+ .read = read_tod_clock,
+ .mask = -1ULL,
+ .mult = 1000,
+ .shift = 12,
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+struct clocksource * __init clocksource_default_clock(void)
+{
+ return &clocksource_tod;
+}
+
+void update_vsyscall(struct timekeeper *tk)
+{
+ u64 nsecps;
+
+ if (tk->tkr_mono.clock != &clocksource_tod)
+ return;
+
+ /* Make userspace gettimeofday spin until we're done. */
+ ++vdso_data->tb_update_count;
+ smp_wmb();
+ vdso_data->xtime_tod_stamp = tk->tkr_mono.cycle_last;
+ vdso_data->xtime_clock_sec = tk->xtime_sec;
+ vdso_data->xtime_clock_nsec = tk->tkr_mono.xtime_nsec;
+ vdso_data->wtom_clock_sec =
+ tk->xtime_sec + tk->wall_to_monotonic.tv_sec;
+ vdso_data->wtom_clock_nsec = tk->tkr_mono.xtime_nsec +
+ + ((u64) tk->wall_to_monotonic.tv_nsec << tk->tkr_mono.shift);
+ nsecps = (u64) NSEC_PER_SEC << tk->tkr_mono.shift;
+ while (vdso_data->wtom_clock_nsec >= nsecps) {
+ vdso_data->wtom_clock_nsec -= nsecps;
+ vdso_data->wtom_clock_sec++;
+ }
+
+ vdso_data->xtime_coarse_sec = tk->xtime_sec;
+ vdso_data->xtime_coarse_nsec =
+ (long)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift);
+ vdso_data->wtom_coarse_sec =
+ vdso_data->xtime_coarse_sec + tk->wall_to_monotonic.tv_sec;
+ vdso_data->wtom_coarse_nsec =
+ vdso_data->xtime_coarse_nsec + tk->wall_to_monotonic.tv_nsec;
+ while (vdso_data->wtom_coarse_nsec >= NSEC_PER_SEC) {
+ vdso_data->wtom_coarse_nsec -= NSEC_PER_SEC;
+ vdso_data->wtom_coarse_sec++;
+ }
+
+ vdso_data->tk_mult = tk->tkr_mono.mult;
+ vdso_data->tk_shift = tk->tkr_mono.shift;
+ vdso_data->hrtimer_res = hrtimer_resolution;
+ smp_wmb();
+ ++vdso_data->tb_update_count;
+}
+
+extern struct timezone sys_tz;
+
+void update_vsyscall_tz(void)
+{
+ vdso_data->tz_minuteswest = sys_tz.tz_minuteswest;
+ vdso_data->tz_dsttime = sys_tz.tz_dsttime;
+}
+
+/*
+ * Initialize the TOD clock and the CPU timer of
+ * the boot cpu.
+ */
+void __init time_init(void)
+{
+ /* Reset time synchronization interfaces. */
+ stp_reset();
+
+ /* request the clock comparator external interrupt */
+ if (register_external_irq(EXT_IRQ_CLK_COMP, clock_comparator_interrupt))
+ panic("Couldn't request external interrupt 0x1004");
+
+ /* request the timing alert external interrupt */
+ if (register_external_irq(EXT_IRQ_TIMING_ALERT, timing_alert_interrupt))
+ panic("Couldn't request external interrupt 0x1406");
+
+ if (__clocksource_register(&clocksource_tod) != 0)
+ panic("Could not register TOD clock source");
+
+ /* Enable TOD clock interrupts on the boot cpu. */
+ init_cpu_timer();
+
+ /* Enable cpu timer interrupts on the boot cpu. */
+ vtime_init();
+}
+
+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_STP 0
+#define CLOCK_SYNC_STP 1
+#define CLOCK_SYNC_STPINFO_VALID 2
+
+/*
+ * The get_clock function for the physical clock. It will get the current
+ * TOD clock, subtract the LPAR offset and write the result to *clock.
+ * The function returns 0 if the clock is in sync with the external time
+ * source. If the clock mode is local it will return -EOPNOTSUPP and
+ * -EAGAIN if the clock is not in sync with the external reference.
+ */
+int get_phys_clock(unsigned long *clock)
+{
+ atomic_t *sw_ptr;
+ unsigned int sw0, sw1;
+
+ sw_ptr = &get_cpu_var(clock_sync_word);
+ sw0 = atomic_read(sw_ptr);
+ *clock = get_tod_clock() - lpar_offset;
+ sw1 = atomic_read(sw_ptr);
+ put_cpu_var(clock_sync_word);
+ if (sw0 == sw1 && (sw0 & 0x80000000U))
+ /* Success: time is in sync. */
+ return 0;
+ if (!test_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags))
+ return -EOPNOTSUPP;
+ if (!test_bit(CLOCK_SYNC_STP, &clock_sync_flags))
+ return -EACCES;
+ return -EAGAIN;
+}
+EXPORT_SYMBOL(get_phys_clock);
+
+/*
+ * 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_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
+ * stp event and the complete recovery against get_phys_clock.
+ */
+ atomic_andnot(0x80000000, sw_ptr);
+ atomic_inc(sw_ptr);
+}
+
+/*
+ * Make get_phys_clock() return 0 again.
+ * Needs to be called from a context disabled for preemption.
+ */
+static void enable_sync_clock(void)
+{
+ atomic_t *sw_ptr = this_cpu_ptr(&clock_sync_word);
+ atomic_or(0x80000000, sw_ptr);
+}
+
+/*
+ * Function to check if the clock is in sync.
+ */
+static inline int check_sync_clock(void)
+{
+ atomic_t *sw_ptr;
+ int rc;
+
+ sw_ptr = &get_cpu_var(clock_sync_word);
+ rc = (atomic_read(sw_ptr) & 0x80000000U) != 0;
+ put_cpu_var(clock_sync_word);
+ return rc;
+}
+
+/*
+ * Apply clock delta to the global data structures.
+ * This is called once on the CPU that performed the clock sync.
+ */
+static void clock_sync_global(unsigned long long delta)
+{
+ unsigned long now, adj;
+ struct ptff_qto qto;
+
+ /* Fixup the monotonic sched clock. */
+ *(unsigned long long *) &tod_clock_base[1] += delta;
+ if (*(unsigned long long *) &tod_clock_base[1] < delta)
+ /* Epoch overflow */
+ tod_clock_base[0]++;
+ /* Adjust TOD steering parameters. */
+ vdso_data->tb_update_count++;
+ now = get_tod_clock();
+ adj = tod_steering_end - now;
+ if (unlikely((s64) adj >= 0))
+ /* Calculate how much of the old adjustment is left. */
+ tod_steering_delta = (tod_steering_delta < 0) ?
+ -(adj >> 15) : (adj >> 15);
+ tod_steering_delta += delta;
+ if ((abs(tod_steering_delta) >> 48) != 0)
+ panic("TOD clock sync offset %lli is too large to drift\n",
+ tod_steering_delta);
+ tod_steering_end = now + (abs(tod_steering_delta) << 15);
+ vdso_data->ts_dir = (tod_steering_delta < 0) ? 0 : 1;
+ vdso_data->ts_end = tod_steering_end;
+ vdso_data->tb_update_count++;
+ /* Update LPAR offset. */
+ if (ptff_query(PTFF_QTO) && ptff(&qto, sizeof(qto), PTFF_QTO) == 0)
+ lpar_offset = qto.tod_epoch_difference;
+ /* Call the TOD clock change notifier. */
+ atomic_notifier_call_chain(&s390_epoch_delta_notifier, 0, &delta);
+}
+
+/*
+ * Apply clock delta to the per-CPU data structures of this CPU.
+ * This is called for each online CPU after the call to clock_sync_global.
+ */
+static void clock_sync_local(unsigned long long delta)
+{
+ /* Add the delta to the clock comparator. */
+ if (S390_lowcore.clock_comparator != clock_comparator_max) {
+ S390_lowcore.clock_comparator += delta;
+ set_clock_comparator(S390_lowcore.clock_comparator);
+ }
+ /* Adjust the last_update_clock time-stamp. */
+ S390_lowcore.last_update_clock += delta;
+}
+
+/* Single threaded workqueue used for stp sync events */
+static struct workqueue_struct *time_sync_wq;
+
+static void __init time_init_wq(void)
+{
+ if (time_sync_wq)
+ return;
+ time_sync_wq = create_singlethread_workqueue("timesync");
+}
+
+struct clock_sync_data {
+ atomic_t cpus;
+ int in_sync;
+ unsigned long long clock_delta;
+};
+
+/*
+ * Server Time Protocol (STP) code.
+ */
+static bool stp_online;
+static struct stp_sstpi stp_info;
+static void *stp_page;
+
+static void stp_work_fn(struct work_struct *work);
+static DEFINE_MUTEX(stp_work_mutex);
+static DECLARE_WORK(stp_work, stp_work_fn);
+static struct timer_list stp_timer;
+
+static int __init early_parse_stp(char *p)
+{
+ return kstrtobool(p, &stp_online);
+}
+early_param("stp", early_parse_stp);
+
+/*
+ * Reset STP attachment.
+ */
+static void __init stp_reset(void)
+{
+ int rc;
+
+ stp_page = (void *) get_zeroed_page(GFP_ATOMIC);
+ rc = chsc_sstpc(stp_page, STP_OP_CTRL, 0x0000, NULL);
+ if (rc == 0)
+ set_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags);
+ else if (stp_online) {
+ pr_warn("The real or virtual hardware system does not provide an STP interface\n");
+ free_page((unsigned long) stp_page);
+ stp_page = NULL;
+ stp_online = false;
+ }
+}
+
+static void stp_timeout(struct timer_list *unused)
+{
+ queue_work(time_sync_wq, &stp_work);
+}
+
+static int __init stp_init(void)
+{
+ if (!test_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags))
+ return 0;
+ timer_setup(&stp_timer, stp_timeout, 0);
+ time_init_wq();
+ if (!stp_online)
+ return 0;
+ queue_work(time_sync_wq, &stp_work);
+ return 0;
+}
+
+arch_initcall(stp_init);
+
+/*
+ * STP timing alert. There are three causes:
+ * 1) timing status change
+ * 2) link availability change
+ * 3) time control parameter change
+ * In all three cases we are only interested in the clock source state.
+ * If a STP clock source is now available use it.
+ */
+static void stp_timing_alert(struct stp_irq_parm *intparm)
+{
+ if (intparm->tsc || intparm->lac || intparm->tcpc)
+ queue_work(time_sync_wq, &stp_work);
+}
+
+/*
+ * STP sync check machine check. This is called when the timing state
+ * changes from the synchronized state to the unsynchronized state.
+ * After a STP sync check the clock is not in sync. The machine check
+ * is broadcasted to all cpus at the same time.
+ */
+int stp_sync_check(void)
+{
+ disable_sync_clock(NULL);
+ return 1;
+}
+
+/*
+ * STP island condition machine check. This is called when an attached
+ * server attempts to communicate over an STP link and the servers
+ * have matching CTN ids and have a valid stratum-1 configuration
+ * but the configurations do not match.
+ */
+int stp_island_check(void)
+{
+ disable_sync_clock(NULL);
+ return 1;
+}
+
+void stp_queue_work(void)
+{
+ queue_work(time_sync_wq, &stp_work);
+}
+
+static int __store_stpinfo(void)
+{
+ int rc = chsc_sstpi(stp_page, &stp_info, sizeof(struct stp_sstpi));
+
+ if (rc)
+ clear_bit(CLOCK_SYNC_STPINFO_VALID, &clock_sync_flags);
+ else
+ set_bit(CLOCK_SYNC_STPINFO_VALID, &clock_sync_flags);
+ return rc;
+}
+
+static int stpinfo_valid(void)
+{
+ return stp_online && test_bit(CLOCK_SYNC_STPINFO_VALID, &clock_sync_flags);
+}
+
+static int stp_sync_clock(void *data)
+{
+ struct clock_sync_data *sync = data;
+ unsigned long long clock_delta;
+ static int first;
+ int rc;
+
+ enable_sync_clock();
+ if (xchg(&first, 1) == 0) {
+ /* Wait until all other cpus entered the sync function. */
+ while (atomic_read(&sync->cpus) != 0)
+ cpu_relax();
+ rc = 0;
+ if (stp_info.todoff[0] || stp_info.todoff[1] ||
+ stp_info.todoff[2] || stp_info.todoff[3] ||
+ stp_info.tmd != 2) {
+ rc = chsc_sstpc(stp_page, STP_OP_SYNC, 0,
+ &clock_delta);
+ if (rc == 0) {
+ sync->clock_delta = clock_delta;
+ clock_sync_global(clock_delta);
+ rc = __store_stpinfo();
+ if (rc == 0 && stp_info.tmd != 2)
+ rc = -EAGAIN;
+ }
+ }
+ sync->in_sync = rc ? -EAGAIN : 1;
+ xchg(&first, 0);
+ } else {
+ /* Slave */
+ atomic_dec(&sync->cpus);
+ /* Wait for in_sync to be set. */
+ while (READ_ONCE(sync->in_sync) == 0)
+ __udelay(1);
+ }
+ if (sync->in_sync != 1)
+ /* Didn't work. Clear per-cpu in sync bit again. */
+ disable_sync_clock(NULL);
+ /* Apply clock delta to per-CPU fields of this CPU. */
+ clock_sync_local(sync->clock_delta);
+
+ return 0;
+}
+
+/*
+ * STP work. Check for the STP state and take over the clock
+ * synchronization if the STP clock source is usable.
+ */
+static void stp_work_fn(struct work_struct *work)
+{
+ struct clock_sync_data stp_sync;
+ int rc;
+
+ /* prevent multiple execution. */
+ mutex_lock(&stp_work_mutex);
+
+ if (!stp_online) {
+ chsc_sstpc(stp_page, STP_OP_CTRL, 0x0000, NULL);
+ del_timer_sync(&stp_timer);
+ goto out_unlock;
+ }
+
+ rc = chsc_sstpc(stp_page, STP_OP_CTRL, 0xb0e0, NULL);
+ if (rc)
+ goto out_unlock;
+
+ rc = __store_stpinfo();
+ if (rc || stp_info.c == 0)
+ goto out_unlock;
+
+ /* Skip synchronization if the clock is already in sync. */
+ if (check_sync_clock())
+ goto out_unlock;
+
+ memset(&stp_sync, 0, sizeof(stp_sync));
+ cpus_read_lock();
+ atomic_set(&stp_sync.cpus, num_online_cpus() - 1);
+ stop_machine_cpuslocked(stp_sync_clock, &stp_sync, cpu_online_mask);
+ cpus_read_unlock();
+
+ if (!check_sync_clock())
+ /*
+ * There is a usable clock but the synchonization failed.
+ * Retry after a second.
+ */
+ mod_timer(&stp_timer, jiffies + HZ);
+
+out_unlock:
+ mutex_unlock(&stp_work_mutex);
+}
+
+/*
+ * STP subsys sysfs interface functions
+ */
+static struct bus_type stp_subsys = {
+ .name = "stp",
+ .dev_name = "stp",
+};
+
+static ssize_t stp_ctn_id_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ ssize_t ret = -ENODATA;
+
+ mutex_lock(&stp_work_mutex);
+ if (stpinfo_valid())
+ ret = sprintf(buf, "%016llx\n",
+ *(unsigned long long *) stp_info.ctnid);
+ mutex_unlock(&stp_work_mutex);
+ return ret;
+}
+
+static DEVICE_ATTR(ctn_id, 0400, stp_ctn_id_show, NULL);
+
+static ssize_t stp_ctn_type_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ ssize_t ret = -ENODATA;
+
+ mutex_lock(&stp_work_mutex);
+ if (stpinfo_valid())
+ ret = sprintf(buf, "%i\n", stp_info.ctn);
+ mutex_unlock(&stp_work_mutex);
+ return ret;
+}
+
+static DEVICE_ATTR(ctn_type, 0400, stp_ctn_type_show, NULL);
+
+static ssize_t stp_dst_offset_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ ssize_t ret = -ENODATA;
+
+ mutex_lock(&stp_work_mutex);
+ if (stpinfo_valid() && (stp_info.vbits & 0x2000))
+ ret = sprintf(buf, "%i\n", (int)(s16) stp_info.dsto);
+ mutex_unlock(&stp_work_mutex);
+ return ret;
+}
+
+static DEVICE_ATTR(dst_offset, 0400, stp_dst_offset_show, NULL);
+
+static ssize_t stp_leap_seconds_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ ssize_t ret = -ENODATA;
+
+ mutex_lock(&stp_work_mutex);
+ if (stpinfo_valid() && (stp_info.vbits & 0x8000))
+ ret = sprintf(buf, "%i\n", (int)(s16) stp_info.leaps);
+ mutex_unlock(&stp_work_mutex);
+ return ret;
+}
+
+static DEVICE_ATTR(leap_seconds, 0400, stp_leap_seconds_show, NULL);
+
+static ssize_t stp_stratum_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ ssize_t ret = -ENODATA;
+
+ mutex_lock(&stp_work_mutex);
+ if (stpinfo_valid())
+ ret = sprintf(buf, "%i\n", (int)(s16) stp_info.stratum);
+ mutex_unlock(&stp_work_mutex);
+ return ret;
+}
+
+static DEVICE_ATTR(stratum, 0400, stp_stratum_show, NULL);
+
+static ssize_t stp_time_offset_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ ssize_t ret = -ENODATA;
+
+ mutex_lock(&stp_work_mutex);
+ if (stpinfo_valid() && (stp_info.vbits & 0x0800))
+ ret = sprintf(buf, "%i\n", (int) stp_info.tto);
+ mutex_unlock(&stp_work_mutex);
+ return ret;
+}
+
+static DEVICE_ATTR(time_offset, 0400, stp_time_offset_show, NULL);
+
+static ssize_t stp_time_zone_offset_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ ssize_t ret = -ENODATA;
+
+ mutex_lock(&stp_work_mutex);
+ if (stpinfo_valid() && (stp_info.vbits & 0x4000))
+ ret = sprintf(buf, "%i\n", (int)(s16) stp_info.tzo);
+ mutex_unlock(&stp_work_mutex);
+ return ret;
+}
+
+static DEVICE_ATTR(time_zone_offset, 0400,
+ stp_time_zone_offset_show, NULL);
+
+static ssize_t stp_timing_mode_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ ssize_t ret = -ENODATA;
+
+ mutex_lock(&stp_work_mutex);
+ if (stpinfo_valid())
+ ret = sprintf(buf, "%i\n", stp_info.tmd);
+ mutex_unlock(&stp_work_mutex);
+ return ret;
+}
+
+static DEVICE_ATTR(timing_mode, 0400, stp_timing_mode_show, NULL);
+
+static ssize_t stp_timing_state_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ ssize_t ret = -ENODATA;
+
+ mutex_lock(&stp_work_mutex);
+ if (stpinfo_valid())
+ ret = sprintf(buf, "%i\n", stp_info.tst);
+ mutex_unlock(&stp_work_mutex);
+ return ret;
+}
+
+static DEVICE_ATTR(timing_state, 0400, stp_timing_state_show, NULL);
+
+static ssize_t stp_online_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ return sprintf(buf, "%i\n", stp_online);
+}
+
+static ssize_t stp_online_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ unsigned int value;
+
+ value = simple_strtoul(buf, NULL, 0);
+ if (value != 0 && value != 1)
+ return -EINVAL;
+ if (!test_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags))
+ return -EOPNOTSUPP;
+ mutex_lock(&clock_sync_mutex);
+ stp_online = value;
+ if (stp_online)
+ set_bit(CLOCK_SYNC_STP, &clock_sync_flags);
+ else
+ clear_bit(CLOCK_SYNC_STP, &clock_sync_flags);
+ queue_work(time_sync_wq, &stp_work);
+ mutex_unlock(&clock_sync_mutex);
+ return count;
+}
+
+/*
+ * Can't use DEVICE_ATTR because the attribute should be named
+ * stp/online but dev_attr_online already exists in this file ..
+ */
+static struct device_attribute dev_attr_stp_online = {
+ .attr = { .name = "online", .mode = 0600 },
+ .show = stp_online_show,
+ .store = stp_online_store,
+};
+
+static struct device_attribute *stp_attributes[] = {
+ &dev_attr_ctn_id,
+ &dev_attr_ctn_type,
+ &dev_attr_dst_offset,
+ &dev_attr_leap_seconds,
+ &dev_attr_stp_online,
+ &dev_attr_stratum,
+ &dev_attr_time_offset,
+ &dev_attr_time_zone_offset,
+ &dev_attr_timing_mode,
+ &dev_attr_timing_state,
+ NULL
+};
+
+static int __init stp_init_sysfs(void)
+{
+ struct device_attribute **attr;
+ int rc;
+
+ rc = subsys_system_register(&stp_subsys, NULL);
+ if (rc)
+ goto out;
+ for (attr = stp_attributes; *attr; attr++) {
+ rc = device_create_file(stp_subsys.dev_root, *attr);
+ if (rc)
+ goto out_unreg;
+ }
+ return 0;
+out_unreg:
+ for (; attr >= stp_attributes; attr--)
+ device_remove_file(stp_subsys.dev_root, *attr);
+ bus_unregister(&stp_subsys);
+out:
+ return rc;
+}
+
+device_initcall(stp_init_sysfs);
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-01 05:53:14 +0000