// SPDX-License-Identifier: GPL-2.0
/*
* Time of day based timer functions.
*
* S390 version
* Copyright IBM Corp. 1999, 2008
* Author(s): Hartmut Penner ([email protected]),
* Martin Schwidefsky ([email protected]),
* Denis Joseph Barrow ([email protected],[email protected])
*
* 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 <vdso/vsyscall.h>
#include <vdso/clocksource.h>
#include <vdso/helpers.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"
union tod_clock tod_clock_base __section(".data");
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 lpar_offset;
static unsigned long initial_leap_seconds;
static unsigned long tod_steering_end;
static long tod_steering_delta;
/*
* Get time offsets with PTFF
*/
void __init time_early_init(void)
{
struct ptff_qto qto;
struct ptff_qui qui;
int cs;
/* Initialize TOD steering parameters */
tod_steering_end = tod_clock_base.tod;
for (cs = 0; cs < CS_BASES; cs++)
vdso_data[cs].arch_data.tod_steering_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) qui.old_leap * 4096000000L);
}
unsigned long long noinstr sched_clock_noinstr(void)
{
return tod_to_ns(__get_tod_clock_monotonic());
}
/*
* 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);
static void ext_to_timespec64(union tod_clock *clk, struct timespec64 *xt)
{
unsigned long rem, sec, nsec;
sec = clk->us;
rem = do_div(sec, 1000000);
nsec = ((clk->sus + (rem << 12)) * 125) >> 9;
xt->tv_sec = sec;
xt->tv_nsec = nsec;
}
void clock_comparator_work(void)
{
struct clock_event_device *cd;
get_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)
{
get_lowcore()->clock_comparator = get_tod_clock() + delta;
set_clock_comparator(get_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;
get_lowcore()->clock_comparator = clock_comparator_max;
set_clock_comparator(get_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. */
local_ctl_set_bit(0, CR0_CLOCK_COMPARATOR_SUBMASK_BIT);
/* Always allow the timing alert external interrupt. */
local_ctl_set_bit(0, CR0_ETR_SUBMASK_BIT);
}
static void clock_comparator_interrupt(struct ext_code ext_code,
unsigned int param32,
unsigned long param64)
{
inc_irq_stat(IRQEXT_CLK);
if (get_lowcore()->clock_comparator == clock_comparator_max)
set_clock_comparator(get_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 *) ¶m32);
}
static void stp_reset(void);
void read_persistent_clock64(struct timespec64 *ts)
{
union tod_clock clk;
u64 delta;
delta = initial_leap_seconds + TOD_UNIX_EPOCH;
store_tod_clock_ext(&clk);
clk.eitod -= delta;
ext_to_timespec64(&clk, ts);
}
void __init read_persistent_wall_and_boot_offset(struct timespec64 *wall_time,
struct timespec64 *boot_offset)
{
struct timespec64 boot_time;
union tod_clock clk;
u64 delta;
delta = initial_leap_seconds + TOD_UNIX_EPOCH;
clk = tod_clock_base;
clk.eitod -= delta;
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 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 = CLOCKSOURCE_MASK(64),
.mult = 4096000,
.shift = 24,
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
.vdso_clock_mode = VDSO_CLOCKMODE_TOD,
};
struct clocksource * __init clocksource_default_clock(void)
{
return &clocksource_tod;
}
/*
* 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(stp_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(long delta)
{
unsigned long now, adj;
struct ptff_qto qto;
int cs;
/* Fixup the monotonic sched clock. */
tod_clock_base.eitod += delta;
/* Adjust TOD steering parameters. */
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 %li is too large to drift\n",
tod_steering_delta);
tod_steering_end = now + (abs(tod_steering_delta) << 15);
for (cs = 0; cs < CS_BASES; cs++) {
vdso_data[cs].arch_data.tod_steering_end = tod_steering_end;
vdso_data[cs].arch_data.tod_steering_delta = tod_steering_delta;
}
/* 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(long delta)
{
/* Add the delta to the clock comparator. */
if (get_lowcore()->clock_comparator != clock_comparator_max) {
get_lowcore()->clock_comparator += delta;
set_clock_comparator(get_lowcore()->clock_comparator);
}
/* Adjust the last_update_clock time-stamp. */
get_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;
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 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;
long clock_delta, flags;
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 || stp_info.tmd != 2) {
flags = vdso_update_begin();
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;
}
vdso_update_end(flags);
}
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;
}
static int stp_clear_leap(void)
{
struct __kernel_timex txc;
int ret;
memset(&txc, 0, sizeof(txc));
ret = do_adjtimex(&txc);
if (ret < 0)
return ret;
txc.modes = ADJ_STATUS;
txc.status &= ~(STA_INS|STA_DEL);
return do_adjtimex(&txc);
}
static void stp_check_leap(void)
{
struct stp_stzi stzi;
struct stp_lsoib *lsoib = &stzi.lsoib;
struct __kernel_timex txc;
int64_t timediff;
int leapdiff, ret;
if (!stp_info.lu || !check_sync_clock()) {
/*
* Either a scheduled leap second was removed by the operator,
* or STP is out of sync. In both cases, clear the leap second
* kernel flags.
*/
if (stp_clear_leap() < 0)
pr_err("failed to clear leap second flags\n");
return;
}
if (chsc_stzi(stp_page, &stzi, sizeof(stzi))) {
pr_err("stzi failed\n");
return;
}
timediff = tod_to_ns(lsoib->nlsout - get_tod_clock()) / NSEC_PER_SEC;
leapdiff = lsoib->nlso - lsoib->also;
if (leapdiff != 1 && leapdiff != -1) {
pr_err("Cannot schedule %d leap seconds\n", leapdiff);
return;
}
if (timediff < 0) {
if (stp_clear_leap() < 0)
pr_err("failed to clear leap second flags\n");
} else if (timediff < 7200) {
memset(&txc, 0, sizeof(txc));
ret = do_adjtimex(&txc);
if (ret < 0)
return;
txc.modes = ADJ_STATUS;
if (leapdiff > 0)
txc.status |= STA_INS;
else
txc.status |= STA_DEL;
ret = do_adjtimex(&txc);
if (ret < 0)
pr_err("failed to set leap second flags\n");
/* arm Timer to clear leap second flags */
mod_timer(&stp_timer, jiffies + msecs_to_jiffies(14400 * MSEC_PER_SEC));
} else {
/* The day the leap second is scheduled for hasn't been reached. Retry
* in one hour.
*/
mod_timer(&stp_timer, jiffies + msecs_to_jiffies(3600 * MSEC_PER_SEC));
}
}
/*
* 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_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, 0xf0e0, 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()) {
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 synchronization failed.
* Retry after a second.
*/
mod_timer(&stp_timer, jiffies + msecs_to_jiffies(MSEC_PER_SEC));
else if (stp_info.lu)
stp_check_leap();
out_unlock:
mutex_unlock(&stp_mutex);
}
/*
* STP subsys sysfs interface functions
*/
static const struct bus_type stp_subsys = {
.name = "stp",
.dev_name = "stp",
};
static ssize_t ctn_id_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
ssize_t ret = -ENODATA;
mutex_lock(&stp_mutex);
if (stpinfo_valid())
ret = sprintf(buf, "%016lx\n",
*(unsigned long *) stp_info.ctnid);
mutex_unlock(&stp_mutex);
return ret;
}
static DEVICE_ATTR_RO(ctn_id);
static ssize_t ctn_type_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
ssize_t ret = -ENODATA;
mutex_lock(&stp_mutex);
if (stpinfo_valid())
ret = sprintf(buf, "%i\n", stp_info.ctn);
mutex_unlock(&stp_mutex);
return ret;
}
static DEVICE_ATTR_RO(ctn_type);
static ssize_t dst_offset_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
ssize_t ret = -ENODATA;
mutex_lock(&stp_mutex);
if (stpinfo_valid() && (stp_info.vbits & 0x2000))
ret = sprintf(buf, "%i\n", (int)(s16) stp_info.dsto);
mutex_unlock(&stp_mutex);
return ret;
}
static DEVICE_ATTR_RO(dst_offset);
static ssize_t leap_seconds_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
ssize_t ret = -ENODATA;
mutex_lock(&stp_mutex);
if (stpinfo_valid() && (stp_info.vbits & 0x8000))
ret = sprintf(buf, "%i\n", (int)(s16) stp_info.leaps);
mutex_unlock(&stp_mutex);
return ret;
}
static DEVICE_ATTR_RO(leap_seconds);
static ssize_t leap_seconds_scheduled_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct stp_stzi stzi;
ssize_t ret;
mutex_lock(&stp_mutex);
if (!stpinfo_valid() || !(stp_info.vbits & 0x8000) || !stp_info.lu) {
mutex_unlock(&stp_mutex);
return -ENODATA;
}
ret = chsc_stzi(stp_page, &stzi, sizeof(stzi));
mutex_unlock(&stp_mutex);
if (ret < 0)
return ret;
if (!stzi.lsoib.p)
return sprintf(buf, "0,0\n");
return sprintf(buf, "%lu,%d\n",
tod_to_ns(stzi.lsoib.nlsout - TOD_UNIX_EPOCH) / NSEC_PER_SEC,
stzi.lsoib.nlso - stzi.lsoib.also);
}
static DEVICE_ATTR_RO(leap_seconds_scheduled);
static ssize_t stratum_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
ssize_t ret = -ENODATA;
mutex_lock(&stp_mutex);
if (stpinfo_valid())
ret = sprintf(buf, "%i\n", (int)(s16) stp_info.stratum);
mutex_unlock(&stp_mutex);
return ret;
}
static DEVICE_ATTR_RO(stratum);
static ssize_t time_offset_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
ssize_t ret = -ENODATA;
mutex_lock(&stp_mutex);
if (stpinfo_valid() && (stp_info.vbits & 0x0800))
ret = sprintf(buf, "%i\n", (int) stp_info.tto);
mutex_unlock(&stp_mutex);
return ret;
}
static DEVICE_ATTR_RO(time_offset);
static ssize_t time_zone_offset_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
ssize_t ret = -ENODATA;
mutex_lock(&stp_mutex);
if (stpinfo_valid() && (stp_info.vbits & 0x4000))
ret = sprintf(buf, "%i\n", (int)(s16) stp_info.tzo);
mutex_unlock(&stp_mutex);
return ret;
}
static DEVICE_ATTR_RO(time_zone_offset);
static ssize_t timing_mode_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
ssize_t ret = -ENODATA;
mutex_lock(&stp_mutex);
if (stpinfo_valid())
ret = sprintf(buf, "%i\n", stp_info.tmd);
mutex_unlock(&stp_mutex);
return ret;
}
static DEVICE_ATTR_RO(timing_mode);
static ssize_t timing_state_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
ssize_t ret = -ENODATA;
mutex_lock(&stp_mutex);
if (stpinfo_valid())
ret = sprintf(buf, "%i\n", stp_info.tst);
mutex_unlock(&stp_mutex);
return ret;
}
static DEVICE_ATTR_RO(timing_state);
static ssize_t online_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
return sprintf(buf, "%i\n", stp_online);
}
static ssize_t 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(&stp_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(&stp_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 DEVICE_ATTR_RW(online);
static struct attribute *stp_dev_attrs[] = {
&dev_attr_ctn_id.attr,
&dev_attr_ctn_type.attr,
&dev_attr_dst_offset.attr,
&dev_attr_leap_seconds.attr,
&dev_attr_online.attr,
&dev_attr_leap_seconds_scheduled.attr,
&dev_attr_stratum.attr,
&dev_attr_time_offset.attr,
&dev_attr_time_zone_offset.attr,
&dev_attr_timing_mode.attr,
&dev_attr_timing_state.attr,
NULL
};
ATTRIBUTE_GROUPS(stp_dev);
static int __init stp_init_sysfs(void)
{
return subsys_system_register(&stp_subsys, stp_dev_groups);
}
device_initcall(stp_init_sysfs);
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