linux_dsm_epyc7002/arch/s390/kernel/time.c

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/*
* arch/s390/kernel/time.c
* 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/errno.h>
#include <linux/module.h>
#include <linux/sched.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/sysdev.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/clocksource.h>
#include <linux/clockchips.h>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 15:04:11 +07:00
#include <linux/gfp.h>
#include <linux/kprobes.h>
#include <asm/uaccess.h>
#include <asm/delay.h>
#include <asm/s390_ext.h>
#include <asm/div64.h>
#include <asm/vdso.h>
#include <asm/irq.h>
#include <asm/irq_regs.h>
#include <asm/timer.h>
#include <asm/etr.h>
#include <asm/cio.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);
static DEFINE_PER_CPU(struct clock_event_device, comparators);
/*
* Scheduler clock - returns current time in nanosec units.
*/
unsigned long long notrace __kprobes sched_clock(void)
{
return (get_clock_monotonic() * 125) >> 9;
}
/*
* Monotonic_clock - returns # of nanoseconds passed since time_init()
*/
unsigned long long monotonic_clock(void)
{
return sched_clock();
}
EXPORT_SYMBOL(monotonic_clock);
void tod_to_timeval(__u64 todval, struct timespec *xt)
{
unsigned long long sec;
sec = todval >> 12;
do_div(sec, 1000000);
xt->tv_sec = sec;
todval -= (sec * 1000000) << 12;
xt->tv_nsec = ((todval * 1000) >> 12);
}
EXPORT_SYMBOL(tod_to_timeval);
void clock_comparator_work(void)
{
struct clock_event_device *cd;
S390_lowcore.clock_comparator = -1ULL;
set_clock_comparator(S390_lowcore.clock_comparator);
cd = &__get_cpu_var(comparators);
cd->event_handler(cd);
}
/*
* Fixup the clock comparator.
*/
static void fixup_clock_comparator(unsigned long long delta)
{
/* If nobody is waiting there's nothing to fix. */
if (S390_lowcore.clock_comparator == -1ULL)
return;
S390_lowcore.clock_comparator += delta;
set_clock_comparator(S390_lowcore.clock_comparator);
}
static int s390_next_event(unsigned long delta,
struct clock_event_device *evt)
{
S390_lowcore.clock_comparator = get_clock() + delta;
set_clock_comparator(S390_lowcore.clock_comparator);
return 0;
}
static void s390_set_mode(enum clock_event_mode mode,
struct clock_event_device *evt)
{
}
/*
* 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 = -1ULL;
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->max_delta_ns = LONG_MAX;
cd->rating = 400;
cd->cpumask = cpumask_of(cpu);
cd->set_next_event = s390_next_event;
cd->set_mode = s390_set_mode;
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(unsigned int ext_int_code,
unsigned int param32,
unsigned long param64)
{
if (S390_lowcore.clock_comparator == -1ULL)
set_clock_comparator(S390_lowcore.clock_comparator);
}
static void etr_timing_alert(struct etr_irq_parm *);
static void stp_timing_alert(struct stp_irq_parm *);
static void timing_alert_interrupt(unsigned int ext_int_code,
unsigned int param32, unsigned long param64)
{
if (param32 & 0x00c40000)
etr_timing_alert((struct etr_irq_parm *) &param32);
if (param32 & 0x00038000)
stp_timing_alert((struct stp_irq_parm *) &param32);
}
static void etr_reset(void);
static void stp_reset(void);
void read_persistent_clock(struct timespec *ts)
{
tod_to_timeval(get_clock() - TOD_UNIX_EPOCH, ts);
}
void read_boot_clock(struct timespec *ts)
{
tod_to_timeval(sched_clock_base_cc - TOD_UNIX_EPOCH, ts);
}
static cycle_t read_tod_clock(struct clocksource *cs)
{
return get_clock();
}
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 timespec *wall_time, struct timespec *wtm,
struct clocksource *clock, u32 mult)
{
if (clock != &clocksource_tod)
return;
/* Make userspace gettimeofday spin until we're done. */
++vdso_data->tb_update_count;
smp_wmb();
vdso_data->xtime_tod_stamp = clock->cycle_last;
vdso_data->xtime_clock_sec = wall_time->tv_sec;
vdso_data->xtime_clock_nsec = wall_time->tv_nsec;
vdso_data->wtom_clock_sec = wtm->tv_sec;
vdso_data->wtom_clock_nsec = wtm->tv_nsec;
vdso_data->ntp_mult = mult;
smp_wmb();
++vdso_data->tb_update_count;
}
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;
}
/*
* Initialize the TOD clock and the CPU timer of
* the boot cpu.
*/
void __init time_init(void)
{
/* Reset time synchronization interfaces. */
etr_reset();
stp_reset();
/* request the clock comparator external interrupt */
if (register_external_interrupt(0x1004, clock_comparator_interrupt))
panic("Couldn't request external interrupt 0x1004");
/* request the timing alert external interrupt */
if (register_external_interrupt(0x1406, 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();
}
/*
* 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
/*
* The synchronous get_clock function. It will write the current clock
* value to the clock pointer and return 0 if the clock is in sync with
* the external time source. If the clock mode is local it will return
* -ENOSYS and -EAGAIN if the clock is not in sync with the external
* reference.
*/
int get_sync_clock(unsigned long 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_clock();
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_ETR, &clock_sync_flags) &&
!test_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags))
return -ENOSYS;
if (!test_bit(CLOCK_SYNC_ETR, &clock_sync_flags) &&
!test_bit(CLOCK_SYNC_STP, &clock_sync_flags))
return -EACCES;
return -EAGAIN;
}
EXPORT_SYMBOL(get_sync_clock);
/*
* Make get_sync_clock return -EAGAIN.
*/
static void disable_sync_clock(void *dummy)
{
atomic_t *sw_ptr = &__get_cpu_var(clock_sync_word);
/*
* Clear the in-sync bit 2^31. All get_sync_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.
*/
atomic_clear_mask(0x80000000, sw_ptr);
atomic_inc(sw_ptr);
}
/*
* Make get_sync_clock return 0 again.
* Needs to be called from a context disabled for preemption.
*/
static void enable_sync_clock(void)
{
atomic_t *sw_ptr = &__get_cpu_var(clock_sync_word);
atomic_set_mask(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;
}
/* Single threaded workqueue used for etr and 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");
}
/*
* External Time Reference (ETR) code.
*/
static int etr_port0_online;
static int etr_port1_online;
static int etr_steai_available;
static int __init early_parse_etr(char *p)
{
if (strncmp(p, "off", 3) == 0)
etr_port0_online = etr_port1_online = 0;
else if (strncmp(p, "port0", 5) == 0)
etr_port0_online = 1;
else if (strncmp(p, "port1", 5) == 0)
etr_port1_online = 1;
else if (strncmp(p, "on", 2) == 0)
etr_port0_online = etr_port1_online = 1;
return 0;
}
early_param("etr", early_parse_etr);
enum etr_event {
ETR_EVENT_PORT0_CHANGE,
ETR_EVENT_PORT1_CHANGE,
ETR_EVENT_PORT_ALERT,
ETR_EVENT_SYNC_CHECK,
ETR_EVENT_SWITCH_LOCAL,
ETR_EVENT_UPDATE,
};
/*
* Valid bit combinations of the eacr register are (x = don't care):
* e0 e1 dp p0 p1 ea es sl
* 0 0 x 0 0 0 0 0 initial, disabled state
* 0 0 x 0 1 1 0 0 port 1 online
* 0 0 x 1 0 1 0 0 port 0 online
* 0 0 x 1 1 1 0 0 both ports online
* 0 1 x 0 1 1 0 0 port 1 online and usable, ETR or PPS mode
* 0 1 x 0 1 1 0 1 port 1 online, usable and ETR mode
* 0 1 x 0 1 1 1 0 port 1 online, usable, PPS mode, in-sync
* 0 1 x 0 1 1 1 1 port 1 online, usable, ETR mode, in-sync
* 0 1 x 1 1 1 0 0 both ports online, port 1 usable
* 0 1 x 1 1 1 1 0 both ports online, port 1 usable, PPS mode, in-sync
* 0 1 x 1 1 1 1 1 both ports online, port 1 usable, ETR mode, in-sync
* 1 0 x 1 0 1 0 0 port 0 online and usable, ETR or PPS mode
* 1 0 x 1 0 1 0 1 port 0 online, usable and ETR mode
* 1 0 x 1 0 1 1 0 port 0 online, usable, PPS mode, in-sync
* 1 0 x 1 0 1 1 1 port 0 online, usable, ETR mode, in-sync
* 1 0 x 1 1 1 0 0 both ports online, port 0 usable
* 1 0 x 1 1 1 1 0 both ports online, port 0 usable, PPS mode, in-sync
* 1 0 x 1 1 1 1 1 both ports online, port 0 usable, ETR mode, in-sync
* 1 1 x 1 1 1 1 0 both ports online & usable, ETR, in-sync
* 1 1 x 1 1 1 1 1 both ports online & usable, ETR, in-sync
*/
static struct etr_eacr etr_eacr;
static u64 etr_tolec; /* time of last eacr update */
static struct etr_aib etr_port0;
static int etr_port0_uptodate;
static struct etr_aib etr_port1;
static int etr_port1_uptodate;
static unsigned long etr_events;
static struct timer_list etr_timer;
static void etr_timeout(unsigned long dummy);
static void etr_work_fn(struct work_struct *work);
static DEFINE_MUTEX(etr_work_mutex);
static DECLARE_WORK(etr_work, etr_work_fn);
/*
* Reset ETR attachment.
*/
static void etr_reset(void)
{
etr_eacr = (struct etr_eacr) {
.e0 = 0, .e1 = 0, ._pad0 = 4, .dp = 0,
.p0 = 0, .p1 = 0, ._pad1 = 0, .ea = 0,
.es = 0, .sl = 0 };
if (etr_setr(&etr_eacr) == 0) {
etr_tolec = get_clock();
set_bit(CLOCK_SYNC_HAS_ETR, &clock_sync_flags);
if (etr_port0_online && etr_port1_online)
set_bit(CLOCK_SYNC_ETR, &clock_sync_flags);
} else if (etr_port0_online || etr_port1_online) {
pr_warning("The real or virtual hardware system does "
"not provide an ETR interface\n");
etr_port0_online = etr_port1_online = 0;
}
}
static int __init etr_init(void)
{
struct etr_aib aib;
if (!test_bit(CLOCK_SYNC_HAS_ETR, &clock_sync_flags))
return 0;
time_init_wq();
/* Check if this machine has the steai instruction. */
if (etr_steai(&aib, ETR_STEAI_STEPPING_PORT) == 0)
etr_steai_available = 1;
setup_timer(&etr_timer, etr_timeout, 0UL);
if (etr_port0_online) {
set_bit(ETR_EVENT_PORT0_CHANGE, &etr_events);
queue_work(time_sync_wq, &etr_work);
}
if (etr_port1_online) {
set_bit(ETR_EVENT_PORT1_CHANGE, &etr_events);
queue_work(time_sync_wq, &etr_work);
}
return 0;
}
arch_initcall(etr_init);
/*
* Two sorts of ETR machine checks. The architecture reads:
* "When a machine-check niterruption occurs and if a switch-to-local or
* ETR-sync-check interrupt request is pending but disabled, this pending
* disabled interruption request is indicated and is cleared".
* Which means that we can get etr_switch_to_local events from the machine
* check handler although the interruption condition is disabled. Lovely..
*/
/*
* Switch to local machine check. This is called when the last usable
* ETR port goes inactive. After switch to local the clock is not in sync.
*/
void etr_switch_to_local(void)
{
if (!etr_eacr.sl)
return;
disable_sync_clock(NULL);
if (!test_and_set_bit(ETR_EVENT_SWITCH_LOCAL, &etr_events)) {
etr_eacr.es = etr_eacr.sl = 0;
etr_setr(&etr_eacr);
queue_work(time_sync_wq, &etr_work);
}
}
/*
* ETR sync check machine check. This is called when the ETR OTE and the
* local clock OTE are farther apart than the ETR sync check tolerance.
* After a ETR sync check the clock is not in sync. The machine check
* is broadcasted to all cpus at the same time.
*/
void etr_sync_check(void)
{
if (!etr_eacr.es)
return;
disable_sync_clock(NULL);
if (!test_and_set_bit(ETR_EVENT_SYNC_CHECK, &etr_events)) {
etr_eacr.es = 0;
etr_setr(&etr_eacr);
queue_work(time_sync_wq, &etr_work);
}
}
/*
* ETR timing alert. There are two causes:
* 1) port state change, check the usability of the port
* 2) port alert, one of the ETR-data-validity bits (v1-v2 bits of the
* sldr-status word) or ETR-data word 1 (edf1) or ETR-data word 3 (edf3)
* or ETR-data word 4 (edf4) has changed.
*/
static void etr_timing_alert(struct etr_irq_parm *intparm)
{
if (intparm->pc0)
/* ETR port 0 state change. */
set_bit(ETR_EVENT_PORT0_CHANGE, &etr_events);
if (intparm->pc1)
/* ETR port 1 state change. */
set_bit(ETR_EVENT_PORT1_CHANGE, &etr_events);
if (intparm->eai)
/*
* ETR port alert on either port 0, 1 or both.
* Both ports are not up-to-date now.
*/
set_bit(ETR_EVENT_PORT_ALERT, &etr_events);
queue_work(time_sync_wq, &etr_work);
}
static void etr_timeout(unsigned long dummy)
{
set_bit(ETR_EVENT_UPDATE, &etr_events);
queue_work(time_sync_wq, &etr_work);
}
/*
* Check if the etr mode is pss.
*/
static inline int etr_mode_is_pps(struct etr_eacr eacr)
{
return eacr.es && !eacr.sl;
}
/*
* Check if the etr mode is etr.
*/
static inline int etr_mode_is_etr(struct etr_eacr eacr)
{
return eacr.es && eacr.sl;
}
/*
* Check if the port can be used for TOD synchronization.
* For PPS mode the port has to receive OTEs. For ETR mode
* the port has to receive OTEs, the ETR stepping bit has to
* be zero and the validity bits for data frame 1, 2, and 3
* have to be 1.
*/
static int etr_port_valid(struct etr_aib *aib, int port)
{
unsigned int psc;
/* Check that this port is receiving OTEs. */
if (aib->tsp == 0)
return 0;
psc = port ? aib->esw.psc1 : aib->esw.psc0;
if (psc == etr_lpsc_pps_mode)
return 1;
if (psc == etr_lpsc_operational_step)
return !aib->esw.y && aib->slsw.v1 &&
aib->slsw.v2 && aib->slsw.v3;
return 0;
}
/*
* Check if two ports are on the same network.
*/
static int etr_compare_network(struct etr_aib *aib1, struct etr_aib *aib2)
{
// FIXME: any other fields we have to compare?
return aib1->edf1.net_id == aib2->edf1.net_id;
}
/*
* Wrapper for etr_stei that converts physical port states
* to logical port states to be consistent with the output
* of stetr (see etr_psc vs. etr_lpsc).
*/
static void etr_steai_cv(struct etr_aib *aib, unsigned int func)
{
BUG_ON(etr_steai(aib, func) != 0);
/* Convert port state to logical port state. */
if (aib->esw.psc0 == 1)
aib->esw.psc0 = 2;
else if (aib->esw.psc0 == 0 && aib->esw.p == 0)
aib->esw.psc0 = 1;
if (aib->esw.psc1 == 1)
aib->esw.psc1 = 2;
else if (aib->esw.psc1 == 0 && aib->esw.p == 1)
aib->esw.psc1 = 1;
}
/*
* Check if the aib a2 is still connected to the same attachment as
* aib a1, the etv values differ by one and a2 is valid.
*/
static int etr_aib_follows(struct etr_aib *a1, struct etr_aib *a2, int p)
{
int state_a1, state_a2;
/* Paranoia check: e0/e1 should better be the same. */
if (a1->esw.eacr.e0 != a2->esw.eacr.e0 ||
a1->esw.eacr.e1 != a2->esw.eacr.e1)
return 0;
/* Still connected to the same etr ? */
state_a1 = p ? a1->esw.psc1 : a1->esw.psc0;
state_a2 = p ? a2->esw.psc1 : a2->esw.psc0;
if (state_a1 == etr_lpsc_operational_step) {
if (state_a2 != etr_lpsc_operational_step ||
a1->edf1.net_id != a2->edf1.net_id ||
a1->edf1.etr_id != a2->edf1.etr_id ||
a1->edf1.etr_pn != a2->edf1.etr_pn)
return 0;
} else if (state_a2 != etr_lpsc_pps_mode)
return 0;
/* The ETV value of a2 needs to be ETV of a1 + 1. */
if (a1->edf2.etv + 1 != a2->edf2.etv)
return 0;
if (!etr_port_valid(a2, p))
return 0;
return 1;
}
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);
/*
* A different cpu changes *in_sync. Therefore use
* barrier() to force memory access.
*/
barrier();
}
if (sync->in_sync != 1)
/* Didn't work. Clear per-cpu in sync bit again. */
disable_sync_clock(NULL);
/*
* This round of TOD syncing is done. Set the clock comparator
* to the next tick and let the processor continue.
*/
fixup_clock_comparator(sync->fixup_cc);
}
/*
* Sync the TOD clock using the port refered to by aibp. This port
* has to be enabled and the other port has to be disabled. The
* last eacr update has to be more than 1.6 seconds in the past.
*/
static int etr_sync_clock(void *data)
{
static int first;
unsigned long long clock, old_clock, delay, delta;
struct clock_sync_data *etr_sync;
struct etr_aib *sync_port, *aib;
int port;
int rc;
etr_sync = data;
if (xchg(&first, 1) == 1) {
/* Slave */
clock_sync_cpu(etr_sync);
return 0;
}
/* Wait until all other cpus entered the sync function. */
while (atomic_read(&etr_sync->cpus) != 0)
cpu_relax();
port = etr_sync->etr_port;
aib = etr_sync->etr_aib;
sync_port = (port == 0) ? &etr_port0 : &etr_port1;
enable_sync_clock();
/* Set clock to next OTE. */
__ctl_set_bit(14, 21);
__ctl_set_bit(0, 29);
clock = ((unsigned long long) (aib->edf2.etv + 1)) << 32;
old_clock = get_clock();
if (set_clock(clock) == 0) {
__udelay(1); /* Wait for the clock to start. */
__ctl_clear_bit(0, 29);
__ctl_clear_bit(14, 21);
etr_stetr(aib);
/* Adjust Linux timing variables. */
delay = (unsigned long long)
(aib->edf2.etv - sync_port->edf2.etv) << 32;
delta = adjust_time(old_clock, clock, delay);
etr_sync->fixup_cc = delta;
fixup_clock_comparator(delta);
/* Verify that the clock is properly set. */
if (!etr_aib_follows(sync_port, aib, port)) {
/* Didn't work. */
disable_sync_clock(NULL);
etr_sync->in_sync = -EAGAIN;
rc = -EAGAIN;
} else {
etr_sync->in_sync = 1;
rc = 0;
}
} else {
/* Could not set the clock ?!? */
__ctl_clear_bit(0, 29);
__ctl_clear_bit(14, 21);
disable_sync_clock(NULL);
etr_sync->in_sync = -EAGAIN;
rc = -EAGAIN;
}
xchg(&first, 0);
return rc;
}
static int etr_sync_clock_stop(struct etr_aib *aib, int port)
{
struct clock_sync_data etr_sync;
struct etr_aib *sync_port;
int follows;
int rc;
/* Check if the current aib is adjacent to the sync port aib. */
sync_port = (port == 0) ? &etr_port0 : &etr_port1;
follows = etr_aib_follows(sync_port, aib, port);
memcpy(sync_port, aib, sizeof(*aib));
if (!follows)
return -EAGAIN;
memset(&etr_sync, 0, sizeof(etr_sync));
etr_sync.etr_aib = aib;
etr_sync.etr_port = port;
get_online_cpus();
atomic_set(&etr_sync.cpus, num_online_cpus() - 1);
rc = stop_machine(etr_sync_clock, &etr_sync, &cpu_online_map);
put_online_cpus();
return rc;
}
/*
* Handle the immediate effects of the different events.
* The port change event is used for online/offline changes.
*/
static struct etr_eacr etr_handle_events(struct etr_eacr eacr)
{
if (test_and_clear_bit(ETR_EVENT_SYNC_CHECK, &etr_events))
eacr.es = 0;
if (test_and_clear_bit(ETR_EVENT_SWITCH_LOCAL, &etr_events))
eacr.es = eacr.sl = 0;
if (test_and_clear_bit(ETR_EVENT_PORT_ALERT, &etr_events))
etr_port0_uptodate = etr_port1_uptodate = 0;
if (test_and_clear_bit(ETR_EVENT_PORT0_CHANGE, &etr_events)) {
if (eacr.e0)
/*
* Port change of an enabled port. We have to
* assume that this can have caused an stepping
* port switch.
*/
etr_tolec = get_clock();
eacr.p0 = etr_port0_online;
if (!eacr.p0)
eacr.e0 = 0;
etr_port0_uptodate = 0;
}
if (test_and_clear_bit(ETR_EVENT_PORT1_CHANGE, &etr_events)) {
if (eacr.e1)
/*
* Port change of an enabled port. We have to
* assume that this can have caused an stepping
* port switch.
*/
etr_tolec = get_clock();
eacr.p1 = etr_port1_online;
if (!eacr.p1)
eacr.e1 = 0;
etr_port1_uptodate = 0;
}
clear_bit(ETR_EVENT_UPDATE, &etr_events);
return eacr;
}
/*
* Set up a timer that expires after the etr_tolec + 1.6 seconds if
* one of the ports needs an update.
*/
static void etr_set_tolec_timeout(unsigned long long now)
{
unsigned long micros;
if ((!etr_eacr.p0 || etr_port0_uptodate) &&
(!etr_eacr.p1 || etr_port1_uptodate))
return;
micros = (now > etr_tolec) ? ((now - etr_tolec) >> 12) : 0;
micros = (micros > 1600000) ? 0 : 1600000 - micros;
mod_timer(&etr_timer, jiffies + (micros * HZ) / 1000000 + 1);
}
/*
* Set up a time that expires after 1/2 second.
*/
static void etr_set_sync_timeout(void)
{
mod_timer(&etr_timer, jiffies + HZ/2);
}
/*
* Update the aib information for one or both ports.
*/
static struct etr_eacr etr_handle_update(struct etr_aib *aib,
struct etr_eacr eacr)
{
/* With both ports disabled the aib information is useless. */
if (!eacr.e0 && !eacr.e1)
return eacr;
/* Update port0 or port1 with aib stored in etr_work_fn. */
if (aib->esw.q == 0) {
/* Information for port 0 stored. */
if (eacr.p0 && !etr_port0_uptodate) {
etr_port0 = *aib;
if (etr_port0_online)
etr_port0_uptodate = 1;
}
} else {
/* Information for port 1 stored. */
if (eacr.p1 && !etr_port1_uptodate) {
etr_port1 = *aib;
if (etr_port0_online)
etr_port1_uptodate = 1;
}
}
/*
* Do not try to get the alternate port aib if the clock
* is not in sync yet.
*/
if (!eacr.es || !check_sync_clock())
return eacr;
/*
* If steai is available we can get the information about
* the other port immediately. If only stetr is available the
* data-port bit toggle has to be used.
*/
if (etr_steai_available) {
if (eacr.p0 && !etr_port0_uptodate) {
etr_steai_cv(&etr_port0, ETR_STEAI_PORT_0);
etr_port0_uptodate = 1;
}
if (eacr.p1 && !etr_port1_uptodate) {
etr_steai_cv(&etr_port1, ETR_STEAI_PORT_1);
etr_port1_uptodate = 1;
}
} else {
/*
* One port was updated above, if the other
* port is not uptodate toggle dp bit.
*/
if ((eacr.p0 && !etr_port0_uptodate) ||
(eacr.p1 && !etr_port1_uptodate))
eacr.dp ^= 1;
else
eacr.dp = 0;
}
return eacr;
}
/*
* Write new etr control register if it differs from the current one.
* Return 1 if etr_tolec has been updated as well.
*/
static void etr_update_eacr(struct etr_eacr eacr)
{
int dp_changed;
if (memcmp(&etr_eacr, &eacr, sizeof(eacr)) == 0)
/* No change, return. */
return;
/*
* The disable of an active port of the change of the data port
* bit can/will cause a change in the data port.
*/
dp_changed = etr_eacr.e0 > eacr.e0 || etr_eacr.e1 > eacr.e1 ||
(etr_eacr.dp ^ eacr.dp) != 0;
etr_eacr = eacr;
etr_setr(&etr_eacr);
if (dp_changed)
etr_tolec = get_clock();
}
/*
* ETR work. In this function you'll find the main logic. In
* particular this is the only function that calls etr_update_eacr(),
* it "controls" the etr control register.
*/
static void etr_work_fn(struct work_struct *work)
{
unsigned long long now;
struct etr_eacr eacr;
struct etr_aib aib;
int sync_port;
/* prevent multiple execution. */
mutex_lock(&etr_work_mutex);
/* Create working copy of etr_eacr. */
eacr = etr_eacr;
/* Check for the different events and their immediate effects. */
eacr = etr_handle_events(eacr);
/* Check if ETR is supposed to be active. */
eacr.ea = eacr.p0 || eacr.p1;
if (!eacr.ea) {
/* Both ports offline. Reset everything. */
eacr.dp = eacr.es = eacr.sl = 0;
on_each_cpu(disable_sync_clock, NULL, 1);
del_timer_sync(&etr_timer);
etr_update_eacr(eacr);
goto out_unlock;
}
/* Store aib to get the current ETR status word. */
BUG_ON(etr_stetr(&aib) != 0);
etr_port0.esw = etr_port1.esw = aib.esw; /* Copy status word. */
now = get_clock();
/*
* Update the port information if the last stepping port change
* or data port change is older than 1.6 seconds.
*/
if (now >= etr_tolec + (1600000 << 12))
eacr = etr_handle_update(&aib, eacr);
/*
* Select ports to enable. The prefered synchronization mode is PPS.
* If a port can be enabled depends on a number of things:
* 1) The port needs to be online and uptodate. A port is not
* disabled just because it is not uptodate, but it is only
* enabled if it is uptodate.
* 2) The port needs to have the same mode (pps / etr).
* 3) The port needs to be usable -> etr_port_valid() == 1
* 4) To enable the second port the clock needs to be in sync.
* 5) If both ports are useable and are ETR ports, the network id
* has to be the same.
* The eacr.sl bit is used to indicate etr mode vs. pps mode.
*/
if (eacr.p0 && aib.esw.psc0 == etr_lpsc_pps_mode) {
eacr.sl = 0;
eacr.e0 = 1;
if (!etr_mode_is_pps(etr_eacr))
eacr.es = 0;
if (!eacr.es || !eacr.p1 || aib.esw.psc1 != etr_lpsc_pps_mode)
eacr.e1 = 0;
// FIXME: uptodate checks ?
else if (etr_port0_uptodate && etr_port1_uptodate)
eacr.e1 = 1;
sync_port = (etr_port0_uptodate &&
etr_port_valid(&etr_port0, 0)) ? 0 : -1;
} else if (eacr.p1 && aib.esw.psc1 == etr_lpsc_pps_mode) {
eacr.sl = 0;
eacr.e0 = 0;
eacr.e1 = 1;
if (!etr_mode_is_pps(etr_eacr))
eacr.es = 0;
sync_port = (etr_port1_uptodate &&
etr_port_valid(&etr_port1, 1)) ? 1 : -1;
} else if (eacr.p0 && aib.esw.psc0 == etr_lpsc_operational_step) {
eacr.sl = 1;
eacr.e0 = 1;
if (!etr_mode_is_etr(etr_eacr))
eacr.es = 0;
if (!eacr.es || !eacr.p1 ||
aib.esw.psc1 != etr_lpsc_operational_alt)
eacr.e1 = 0;
else if (etr_port0_uptodate && etr_port1_uptodate &&
etr_compare_network(&etr_port0, &etr_port1))
eacr.e1 = 1;
sync_port = (etr_port0_uptodate &&
etr_port_valid(&etr_port0, 0)) ? 0 : -1;
} else if (eacr.p1 && aib.esw.psc1 == etr_lpsc_operational_step) {
eacr.sl = 1;
eacr.e0 = 0;
eacr.e1 = 1;
if (!etr_mode_is_etr(etr_eacr))
eacr.es = 0;
sync_port = (etr_port1_uptodate &&
etr_port_valid(&etr_port1, 1)) ? 1 : -1;
} else {
/* Both ports not usable. */
eacr.es = eacr.sl = 0;
sync_port = -1;
}
/*
* If the clock is in sync just update the eacr and return.
* If there is no valid sync port wait for a port update.
*/
if ((eacr.es && check_sync_clock()) || sync_port < 0) {
etr_update_eacr(eacr);
etr_set_tolec_timeout(now);
goto out_unlock;
}
/*
* Prepare control register for clock syncing
* (reset data port bit, set sync check control.
*/
eacr.dp = 0;
eacr.es = 1;
/*
* Update eacr and try to synchronize the clock. If the update
* of eacr caused a stepping port switch (or if we have to
* assume that a stepping port switch has occured) or the
* clock syncing failed, reset the sync check control bit
* and set up a timer to try again after 0.5 seconds
*/
etr_update_eacr(eacr);
if (now < etr_tolec + (1600000 << 12) ||
etr_sync_clock_stop(&aib, sync_port) != 0) {
/* Sync failed. Try again in 1/2 second. */
eacr.es = 0;
etr_update_eacr(eacr);
etr_set_sync_timeout();
} else
etr_set_tolec_timeout(now);
out_unlock:
mutex_unlock(&etr_work_mutex);
}
/*
* Sysfs interface functions
*/
static struct sysdev_class etr_sysclass = {
.name = "etr",
};
static struct sys_device etr_port0_dev = {
.id = 0,
.cls = &etr_sysclass,
};
static struct sys_device etr_port1_dev = {
.id = 1,
.cls = &etr_sysclass,
};
/*
* ETR class attributes
*/
static ssize_t etr_stepping_port_show(struct sysdev_class *class,
struct sysdev_class_attribute *attr,
char *buf)
{
return sprintf(buf, "%i\n", etr_port0.esw.p);
}
static SYSDEV_CLASS_ATTR(stepping_port, 0400, etr_stepping_port_show, NULL);
static ssize_t etr_stepping_mode_show(struct sysdev_class *class,
struct sysdev_class_attribute *attr,
char *buf)
{
char *mode_str;
if (etr_mode_is_pps(etr_eacr))
mode_str = "pps";
else if (etr_mode_is_etr(etr_eacr))
mode_str = "etr";
else
mode_str = "local";
return sprintf(buf, "%s\n", mode_str);
}
static SYSDEV_CLASS_ATTR(stepping_mode, 0400, etr_stepping_mode_show, NULL);
/*
* ETR port attributes
*/
static inline struct etr_aib *etr_aib_from_dev(struct sys_device *dev)
{
if (dev == &etr_port0_dev)
return etr_port0_online ? &etr_port0 : NULL;
else
return etr_port1_online ? &etr_port1 : NULL;
}
static ssize_t etr_online_show(struct sys_device *dev,
struct sysdev_attribute *attr,
char *buf)
{
unsigned int online;
online = (dev == &etr_port0_dev) ? etr_port0_online : etr_port1_online;
return sprintf(buf, "%i\n", online);
}
static ssize_t etr_online_store(struct sys_device *dev,
struct sysdev_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_ETR, &clock_sync_flags))
return -EOPNOTSUPP;
mutex_lock(&clock_sync_mutex);
if (dev == &etr_port0_dev) {
if (etr_port0_online == value)
goto out; /* Nothing to do. */
etr_port0_online = value;
if (etr_port0_online && etr_port1_online)
set_bit(CLOCK_SYNC_ETR, &clock_sync_flags);
else
clear_bit(CLOCK_SYNC_ETR, &clock_sync_flags);
set_bit(ETR_EVENT_PORT0_CHANGE, &etr_events);
queue_work(time_sync_wq, &etr_work);
} else {
if (etr_port1_online == value)
goto out; /* Nothing to do. */
etr_port1_online = value;
if (etr_port0_online && etr_port1_online)
set_bit(CLOCK_SYNC_ETR, &clock_sync_flags);
else
clear_bit(CLOCK_SYNC_ETR, &clock_sync_flags);
set_bit(ETR_EVENT_PORT1_CHANGE, &etr_events);
queue_work(time_sync_wq, &etr_work);
}
out:
mutex_unlock(&clock_sync_mutex);
return count;
}
static SYSDEV_ATTR(online, 0600, etr_online_show, etr_online_store);
static ssize_t etr_stepping_control_show(struct sys_device *dev,
struct sysdev_attribute *attr,
char *buf)
{
return sprintf(buf, "%i\n", (dev == &etr_port0_dev) ?
etr_eacr.e0 : etr_eacr.e1);
}
static SYSDEV_ATTR(stepping_control, 0400, etr_stepping_control_show, NULL);
static ssize_t etr_mode_code_show(struct sys_device *dev,
struct sysdev_attribute *attr, char *buf)
{
if (!etr_port0_online && !etr_port1_online)
/* Status word is not uptodate if both ports are offline. */
return -ENODATA;
return sprintf(buf, "%i\n", (dev == &etr_port0_dev) ?
etr_port0.esw.psc0 : etr_port0.esw.psc1);
}
static SYSDEV_ATTR(state_code, 0400, etr_mode_code_show, NULL);
static ssize_t etr_untuned_show(struct sys_device *dev,
struct sysdev_attribute *attr, char *buf)
{
struct etr_aib *aib = etr_aib_from_dev(dev);
if (!aib || !aib->slsw.v1)
return -ENODATA;
return sprintf(buf, "%i\n", aib->edf1.u);
}
static SYSDEV_ATTR(untuned, 0400, etr_untuned_show, NULL);
static ssize_t etr_network_id_show(struct sys_device *dev,
struct sysdev_attribute *attr, char *buf)
{
struct etr_aib *aib = etr_aib_from_dev(dev);
if (!aib || !aib->slsw.v1)
return -ENODATA;
return sprintf(buf, "%i\n", aib->edf1.net_id);
}
static SYSDEV_ATTR(network, 0400, etr_network_id_show, NULL);
static ssize_t etr_id_show(struct sys_device *dev,
struct sysdev_attribute *attr, char *buf)
{
struct etr_aib *aib = etr_aib_from_dev(dev);
if (!aib || !aib->slsw.v1)
return -ENODATA;
return sprintf(buf, "%i\n", aib->edf1.etr_id);
}
static SYSDEV_ATTR(id, 0400, etr_id_show, NULL);
static ssize_t etr_port_number_show(struct sys_device *dev,
struct sysdev_attribute *attr, char *buf)
{
struct etr_aib *aib = etr_aib_from_dev(dev);
if (!aib || !aib->slsw.v1)
return -ENODATA;
return sprintf(buf, "%i\n", aib->edf1.etr_pn);
}
static SYSDEV_ATTR(port, 0400, etr_port_number_show, NULL);
static ssize_t etr_coupled_show(struct sys_device *dev,
struct sysdev_attribute *attr, char *buf)
{
struct etr_aib *aib = etr_aib_from_dev(dev);
if (!aib || !aib->slsw.v3)
return -ENODATA;
return sprintf(buf, "%i\n", aib->edf3.c);
}
static SYSDEV_ATTR(coupled, 0400, etr_coupled_show, NULL);
static ssize_t etr_local_time_show(struct sys_device *dev,
struct sysdev_attribute *attr, char *buf)
{
struct etr_aib *aib = etr_aib_from_dev(dev);
if (!aib || !aib->slsw.v3)
return -ENODATA;
return sprintf(buf, "%i\n", aib->edf3.blto);
}
static SYSDEV_ATTR(local_time, 0400, etr_local_time_show, NULL);
static ssize_t etr_utc_offset_show(struct sys_device *dev,
struct sysdev_attribute *attr, char *buf)
{
struct etr_aib *aib = etr_aib_from_dev(dev);
if (!aib || !aib->slsw.v3)
return -ENODATA;
return sprintf(buf, "%i\n", aib->edf3.buo);
}
static SYSDEV_ATTR(utc_offset, 0400, etr_utc_offset_show, NULL);
static struct sysdev_attribute *etr_port_attributes[] = {
&attr_online,
&attr_stepping_control,
&attr_state_code,
&attr_untuned,
&attr_network,
&attr_id,
&attr_port,
&attr_coupled,
&attr_local_time,
&attr_utc_offset,
NULL
};
static int __init etr_register_port(struct sys_device *dev)
{
struct sysdev_attribute **attr;
int rc;
rc = sysdev_register(dev);
if (rc)
goto out;
for (attr = etr_port_attributes; *attr; attr++) {
rc = sysdev_create_file(dev, *attr);
if (rc)
goto out_unreg;
}
return 0;
out_unreg:
for (; attr >= etr_port_attributes; attr--)
sysdev_remove_file(dev, *attr);
sysdev_unregister(dev);
out:
return rc;
}
static void __init etr_unregister_port(struct sys_device *dev)
{
struct sysdev_attribute **attr;
for (attr = etr_port_attributes; *attr; attr++)
sysdev_remove_file(dev, *attr);
sysdev_unregister(dev);
}
static int __init etr_init_sysfs(void)
{
int rc;
rc = sysdev_class_register(&etr_sysclass);
if (rc)
goto out;
rc = sysdev_class_create_file(&etr_sysclass, &attr_stepping_port);
if (rc)
goto out_unreg_class;
rc = sysdev_class_create_file(&etr_sysclass, &attr_stepping_mode);
if (rc)
goto out_remove_stepping_port;
rc = etr_register_port(&etr_port0_dev);
if (rc)
goto out_remove_stepping_mode;
rc = etr_register_port(&etr_port1_dev);
if (rc)
goto out_remove_port0;
return 0;
out_remove_port0:
etr_unregister_port(&etr_port0_dev);
out_remove_stepping_mode:
sysdev_class_remove_file(&etr_sysclass, &attr_stepping_mode);
out_remove_stepping_port:
sysdev_class_remove_file(&etr_sysclass, &attr_stepping_port);
out_unreg_class:
sysdev_class_unregister(&etr_sysclass);
out:
return rc;
}
device_initcall(etr_init_sysfs);
/*
* Server Time Protocol (STP) code.
*/
static int 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)
{
if (strncmp(p, "off", 3) == 0)
stp_online = 0;
else if (strncmp(p, "on", 2) == 0)
stp_online = 1;
return 0;
}
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);
if (rc == 0)
set_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags);
else if (stp_online) {
pr_warning("The real or virtual hardware system does "
"not provide an STP interface\n");
free_page((unsigned long) stp_page);
stp_page = NULL;
stp_online = 0;
}
}
static void stp_timeout(unsigned long dummy)
{
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;
setup_timer(&stp_timer, stp_timeout, 0UL);
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.
*/
void stp_sync_check(void)
{
disable_sync_clock(NULL);
queue_work(time_sync_wq, &stp_work);
}
/*
* 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.
*/
void stp_island_check(void)
{
disable_sync_clock(NULL);
queue_work(time_sync_wq, &stp_work);
}
static int stp_sync_clock(void *data)
{
static int first;
unsigned long long old_clock, delta;
struct clock_sync_data *stp_sync;
int rc;
stp_sync = data;
if (xchg(&first, 1) == 1) {
/* Slave */
clock_sync_cpu(stp_sync);
return 0;
}
/* Wait until all other cpus entered the sync function. */
while (atomic_read(&stp_sync->cpus) != 0)
cpu_relax();
enable_sync_clock();
rc = 0;
if (stp_info.todoff[0] || stp_info.todoff[1] ||
stp_info.todoff[2] || stp_info.todoff[3] ||
stp_info.tmd != 2) {
old_clock = get_clock();
rc = chsc_sstpc(stp_page, STP_OP_SYNC, 0);
if (rc == 0) {
delta = adjust_time(old_clock, get_clock(), 0);
fixup_clock_comparator(delta);
rc = chsc_sstpi(stp_page, &stp_info,
sizeof(struct stp_sstpi));
if (rc == 0 && stp_info.tmd != 2)
rc = -EAGAIN;
}
}
if (rc) {
disable_sync_clock(NULL);
stp_sync->in_sync = -EAGAIN;
} else
stp_sync->in_sync = 1;
xchg(&first, 0);
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);
del_timer_sync(&stp_timer);
goto out_unlock;
}
rc = chsc_sstpc(stp_page, STP_OP_CTRL, 0xb0e0);
if (rc)
goto out_unlock;
rc = chsc_sstpi(stp_page, &stp_info, sizeof(struct stp_sstpi));
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));
get_online_cpus();
atomic_set(&stp_sync.cpus, num_online_cpus() - 1);
stop_machine(stp_sync_clock, &stp_sync, &cpu_online_map);
put_online_cpus();
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 class sysfs interface functions
*/
static struct sysdev_class stp_sysclass = {
.name = "stp",
};
static ssize_t stp_ctn_id_show(struct sysdev_class *class,
struct sysdev_class_attribute *attr,
char *buf)
{
if (!stp_online)
return -ENODATA;
return sprintf(buf, "%016llx\n",
*(unsigned long long *) stp_info.ctnid);
}
static SYSDEV_CLASS_ATTR(ctn_id, 0400, stp_ctn_id_show, NULL);
static ssize_t stp_ctn_type_show(struct sysdev_class *class,
struct sysdev_class_attribute *attr,
char *buf)
{
if (!stp_online)
return -ENODATA;
return sprintf(buf, "%i\n", stp_info.ctn);
}
static SYSDEV_CLASS_ATTR(ctn_type, 0400, stp_ctn_type_show, NULL);
static ssize_t stp_dst_offset_show(struct sysdev_class *class,
struct sysdev_class_attribute *attr,
char *buf)
{
if (!stp_online || !(stp_info.vbits & 0x2000))
return -ENODATA;
return sprintf(buf, "%i\n", (int)(s16) stp_info.dsto);
}
static SYSDEV_CLASS_ATTR(dst_offset, 0400, stp_dst_offset_show, NULL);
static ssize_t stp_leap_seconds_show(struct sysdev_class *class,
struct sysdev_class_attribute *attr,
char *buf)
{
if (!stp_online || !(stp_info.vbits & 0x8000))
return -ENODATA;
return sprintf(buf, "%i\n", (int)(s16) stp_info.leaps);
}
static SYSDEV_CLASS_ATTR(leap_seconds, 0400, stp_leap_seconds_show, NULL);
static ssize_t stp_stratum_show(struct sysdev_class *class,
struct sysdev_class_attribute *attr,
char *buf)
{
if (!stp_online)
return -ENODATA;
return sprintf(buf, "%i\n", (int)(s16) stp_info.stratum);
}
static SYSDEV_CLASS_ATTR(stratum, 0400, stp_stratum_show, NULL);
static ssize_t stp_time_offset_show(struct sysdev_class *class,
struct sysdev_class_attribute *attr,
char *buf)
{
if (!stp_online || !(stp_info.vbits & 0x0800))
return -ENODATA;
return sprintf(buf, "%i\n", (int) stp_info.tto);
}
static SYSDEV_CLASS_ATTR(time_offset, 0400, stp_time_offset_show, NULL);
static ssize_t stp_time_zone_offset_show(struct sysdev_class *class,
struct sysdev_class_attribute *attr,
char *buf)
{
if (!stp_online || !(stp_info.vbits & 0x4000))
return -ENODATA;
return sprintf(buf, "%i\n", (int)(s16) stp_info.tzo);
}
static SYSDEV_CLASS_ATTR(time_zone_offset, 0400,
stp_time_zone_offset_show, NULL);
static ssize_t stp_timing_mode_show(struct sysdev_class *class,
struct sysdev_class_attribute *attr,
char *buf)
{
if (!stp_online)
return -ENODATA;
return sprintf(buf, "%i\n", stp_info.tmd);
}
static SYSDEV_CLASS_ATTR(timing_mode, 0400, stp_timing_mode_show, NULL);
static ssize_t stp_timing_state_show(struct sysdev_class *class,
struct sysdev_class_attribute *attr,
char *buf)
{
if (!stp_online)
return -ENODATA;
return sprintf(buf, "%i\n", stp_info.tst);
}
static SYSDEV_CLASS_ATTR(timing_state, 0400, stp_timing_state_show, NULL);
static ssize_t stp_online_show(struct sysdev_class *class,
struct sysdev_class_attribute *attr,
char *buf)
{
return sprintf(buf, "%i\n", stp_online);
}
static ssize_t stp_online_store(struct sysdev_class *class,
struct sysdev_class_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 SYSDEV_CLASS_ATTR because the attribute should be named
* stp/online but attr_online already exists in this file ..
*/
static struct sysdev_class_attribute attr_stp_online = {
.attr = { .name = "online", .mode = 0600 },
.show = stp_online_show,
.store = stp_online_store,
};
static struct sysdev_class_attribute *stp_attributes[] = {
&attr_ctn_id,
&attr_ctn_type,
&attr_dst_offset,
&attr_leap_seconds,
&attr_stp_online,
&attr_stratum,
&attr_time_offset,
&attr_time_zone_offset,
&attr_timing_mode,
&attr_timing_state,
NULL
};
static int __init stp_init_sysfs(void)
{
struct sysdev_class_attribute **attr;
int rc;
rc = sysdev_class_register(&stp_sysclass);
if (rc)
goto out;
for (attr = stp_attributes; *attr; attr++) {
rc = sysdev_class_create_file(&stp_sysclass, *attr);
if (rc)
goto out_unreg;
}
return 0;
out_unreg:
for (; attr >= stp_attributes; attr--)
sysdev_class_remove_file(&stp_sysclass, *attr);
sysdev_class_unregister(&stp_sysclass);
out:
return rc;
}
device_initcall(stp_init_sysfs);