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authorMartin Schwidefsky <schwidefsky@de.ibm.com>2008-07-14 09:58:56 +0200
committerHeiko Carstens <heiko.carstens@de.ibm.com>2008-07-14 10:02:09 +0200
commitd2fec595511b5718bdb65645b3d5d99800d97943 (patch)
treea94c3560fc2ad6aa89d61d646f73f4d7c1dfcc9b /arch/s390
parent761cdf6aacdb76f819050f4938cdab1f4cdcb945 (diff)
[S390] stp support.
Add support for clock synchronization with the server time protocol. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Diffstat (limited to 'arch/s390')
-rw-r--r--arch/s390/kernel/time.c634
1 files changed, 484 insertions, 150 deletions
diff --git a/arch/s390/kernel/time.c b/arch/s390/kernel/time.c
index 7aec676fefd..7418bebb547 100644
--- a/arch/s390/kernel/time.c
+++ b/arch/s390/kernel/time.c
@@ -3,7 +3,7 @@
* Time of day based timer functions.
*
* S390 version
- * Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
+ * 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)
@@ -31,6 +31,7 @@
#include <linux/notifier.h>
#include <linux/clocksource.h>
#include <linux/clockchips.h>
+#include <linux/bootmem.h>
#include <asm/uaccess.h>
#include <asm/delay.h>
#include <asm/s390_ext.h>
@@ -162,7 +163,7 @@ void init_cpu_timer(void)
/* Enable clock comparator timer interrupt. */
__ctl_set_bit(0,11);
- /* Always allow ETR external interrupts, even without an ETR. */
+ /* Always allow the timing alert external interrupt. */
__ctl_set_bit(0, 4);
}
@@ -170,8 +171,21 @@ static void clock_comparator_interrupt(__u16 code)
{
}
+static void etr_timing_alert(struct etr_irq_parm *);
+static void stp_timing_alert(struct stp_irq_parm *);
+
+static void timing_alert_interrupt(__u16 code)
+{
+ if (S390_lowcore.ext_params & 0x00c40000)
+ etr_timing_alert((struct etr_irq_parm *)
+ &S390_lowcore.ext_params);
+ if (S390_lowcore.ext_params & 0x00038000)
+ stp_timing_alert((struct stp_irq_parm *)
+ &S390_lowcore.ext_params);
+}
+
static void etr_reset(void);
-static void etr_ext_handler(__u16);
+static void stp_reset(void);
/*
* Get the TOD clock running.
@@ -181,6 +195,7 @@ static u64 __init reset_tod_clock(void)
u64 time;
etr_reset();
+ stp_reset();
if (store_clock(&time) == 0)
return time;
/* TOD clock not running. Set the clock to Unix Epoch. */
@@ -231,8 +246,9 @@ void __init time_init(void)
if (clocksource_register(&clocksource_tod) != 0)
panic("Could not register TOD clock source");
- /* request the etr external interrupt */
- if (register_early_external_interrupt(0x1406, etr_ext_handler,
+ /* request the timing alert external interrupt */
+ if (register_early_external_interrupt(0x1406,
+ timing_alert_interrupt,
&ext_int_etr_cc) != 0)
panic("Couldn't request external interrupt 0x1406");
@@ -245,10 +261,112 @@ void __init time_init(void)
}
/*
+ * 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);
+ }
+ jiffies_timer_cc += delta;
+ if (adjust.offset != 0) {
+ printk(KERN_NOTICE "etr: time adjusted by %li micro-seconds\n",
+ adjust.offset);
+ adjust.modes = ADJ_OFFSET_SINGLESHOT;
+ do_adjtimex(&adjust);
+ }
+ return delta;
+}
+
+static DEFINE_PER_CPU(atomic_t, clock_sync_word);
+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_sync);
+ 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);
+}
+
+/*
* 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)
{
@@ -273,12 +391,6 @@ enum etr_event {
ETR_EVENT_UPDATE,
};
-enum etr_flags {
- ETR_FLAG_ENOSYS,
- ETR_FLAG_EACCES,
- ETR_FLAG_STEAI,
-};
-
/*
* Valid bit combinations of the eacr register are (x = don't care):
* e0 e1 dp p0 p1 ea es sl
@@ -305,74 +417,18 @@ enum etr_flags {
*/
static struct etr_eacr etr_eacr;
static u64 etr_tolec; /* time of last eacr update */
-static unsigned long etr_flags;
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 DEFINE_PER_CPU(atomic_t, etr_sync_word);
static void etr_timeout(unsigned long dummy);
static void etr_work_fn(struct work_struct *work);
static DECLARE_WORK(etr_work, etr_work_fn);
/*
- * The etr 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. This function is what ETR is all about..
- */
-int get_sync_clock(unsigned long long *clock)
-{
- atomic_t *sw_ptr;
- unsigned int sw0, sw1;
-
- sw_ptr = &get_cpu_var(etr_sync_word);
- sw0 = atomic_read(sw_ptr);
- *clock = get_clock();
- sw1 = atomic_read(sw_ptr);
- put_cpu_var(etr_sync_sync);
- if (sw0 == sw1 && (sw0 & 0x80000000U))
- /* Success: time is in sync. */
- return 0;
- if (test_bit(ETR_FLAG_ENOSYS, &etr_flags))
- return -ENOSYS;
- if (test_bit(ETR_FLAG_EACCES, &etr_flags))
- return -EACCES;
- return -EAGAIN;
-}
-EXPORT_SYMBOL(get_sync_clock);
-
-/*
- * Make get_sync_clock return -EAGAIN.
- */
-static void etr_disable_sync_clock(void *dummy)
-{
- atomic_t *sw_ptr = &__get_cpu_var(etr_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 etr_enable_sync_clock(void)
-{
- atomic_t *sw_ptr = &__get_cpu_var(etr_sync_word);
- atomic_set_mask(0x80000000, sw_ptr);
-}
-
-/*
* Reset ETR attachment.
*/
static void etr_reset(void)
@@ -381,15 +437,13 @@ static void etr_reset(void)
.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)
+ if (etr_setr(&etr_eacr) == 0) {
etr_tolec = get_clock();
- else {
- set_bit(ETR_FLAG_ENOSYS, &etr_flags);
- if (etr_port0_online || etr_port1_online) {
- printk(KERN_WARNING "Running on non ETR capable "
- "machine, only local mode available.\n");
- etr_port0_online = etr_port1_online = 0;
- }
+ set_bit(CLOCK_SYNC_HAS_ETR, &clock_sync_flags);
+ } else if (etr_port0_online || etr_port1_online) {
+ printk(KERN_WARNING "Running on non ETR capable "
+ "machine, only local mode available.\n");
+ etr_port0_online = etr_port1_online = 0;
}
}
@@ -397,14 +451,12 @@ static int __init etr_init(void)
{
struct etr_aib aib;
- if (test_bit(ETR_FLAG_ENOSYS, &etr_flags))
+ if (!test_bit(CLOCK_SYNC_HAS_ETR, &clock_sync_flags))
return 0;
/* Check if this machine has the steai instruction. */
if (etr_steai(&aib, ETR_STEAI_STEPPING_PORT) == 0)
- set_bit(ETR_FLAG_STEAI, &etr_flags);
+ etr_steai_available = 1;
setup_timer(&etr_timer, etr_timeout, 0UL);
- if (!etr_port0_online && !etr_port1_online)
- set_bit(ETR_FLAG_EACCES, &etr_flags);
if (etr_port0_online) {
set_bit(ETR_EVENT_PORT0_CHANGE, &etr_events);
schedule_work(&etr_work);
@@ -435,7 +487,8 @@ void etr_switch_to_local(void)
{
if (!etr_eacr.sl)
return;
- etr_disable_sync_clock(NULL);
+ if (test_bit(CLOCK_SYNC_ETR, &clock_sync_flags))
+ disable_sync_clock(NULL);
set_bit(ETR_EVENT_SWITCH_LOCAL, &etr_events);
schedule_work(&etr_work);
}
@@ -450,23 +503,21 @@ void etr_sync_check(void)
{
if (!etr_eacr.es)
return;
- etr_disable_sync_clock(NULL);
+ if (test_bit(CLOCK_SYNC_ETR, &clock_sync_flags))
+ disable_sync_clock(NULL);
set_bit(ETR_EVENT_SYNC_CHECK, &etr_events);
schedule_work(&etr_work);
}
/*
- * ETR external interrupt. There are two causes:
+ * 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_ext_handler(__u16 code)
+static void etr_timing_alert(struct etr_irq_parm *intparm)
{
- struct etr_interruption_parameter *intparm =
- (struct etr_interruption_parameter *) &S390_lowcore.ext_params;
-
if (intparm->pc0)
/* ETR port 0 state change. */
set_bit(ETR_EVENT_PORT0_CHANGE, &etr_events);
@@ -591,58 +642,23 @@ static int etr_aib_follows(struct etr_aib *a1, struct etr_aib *a2, int p)
return 1;
}
-/*
- * 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 etr_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);
- }
- jiffies_timer_cc += delta;
- if (adjust.offset != 0) {
- printk(KERN_NOTICE "etr: time adjusted by %li micro-seconds\n",
- adjust.offset);
- adjust.modes = ADJ_OFFSET_SINGLESHOT;
- do_adjtimex(&adjust);
- }
- return delta;
-}
-
-static struct {
+struct clock_sync_data {
int in_sync;
unsigned long long fixup_cc;
-} etr_sync;
+};
-static void etr_sync_cpu_start(void *dummy)
+static void clock_sync_cpu_start(void *dummy)
{
- etr_enable_sync_clock();
+ struct clock_sync_data *sync = dummy;
+
+ 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 (etr_sync.in_sync == 0) {
+ while (sync->in_sync == 0) {
__udelay(1);
/*
* A different cpu changes *in_sync. Therefore use
@@ -650,17 +666,17 @@ static void etr_sync_cpu_start(void *dummy)
*/
barrier();
}
- if (etr_sync.in_sync != 1)
+ if (sync->in_sync != 1)
/* Didn't work. Clear per-cpu in sync bit again. */
- etr_disable_sync_clock(NULL);
+ 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(etr_sync.fixup_cc);
+ fixup_clock_comparator(sync->fixup_cc);
}
-static void etr_sync_cpu_end(void *dummy)
+static void clock_sync_cpu_end(void *dummy)
{
}
@@ -672,6 +688,7 @@ static void etr_sync_cpu_end(void *dummy)
static int etr_sync_clock(struct etr_aib *aib, int port)
{
struct etr_aib *sync_port;
+ struct clock_sync_data etr_sync;
unsigned long long clock, old_clock, delay, delta;
int follows;
int rc;
@@ -690,9 +707,9 @@ static int etr_sync_clock(struct etr_aib *aib, int port)
*/
memset(&etr_sync, 0, sizeof(etr_sync));
preempt_disable();
- smp_call_function(etr_sync_cpu_start, NULL, 0, 0);
+ smp_call_function(clock_sync_cpu_start, &etr_sync, 0, 0);
local_irq_disable();
- etr_enable_sync_clock();
+ enable_sync_clock();
/* Set clock to next OTE. */
__ctl_set_bit(14, 21);
@@ -707,13 +724,13 @@ static int etr_sync_clock(struct etr_aib *aib, int port)
/* Adjust Linux timing variables. */
delay = (unsigned long long)
(aib->edf2.etv - sync_port->edf2.etv) << 32;
- delta = etr_adjust_time(old_clock, clock, delay);
+ 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. */
- etr_disable_sync_clock(NULL);
+ disable_sync_clock(NULL);
etr_sync.in_sync = -EAGAIN;
rc = -EAGAIN;
} else {
@@ -724,12 +741,12 @@ static int etr_sync_clock(struct etr_aib *aib, int port)
/* Could not set the clock ?!? */
__ctl_clear_bit(0, 29);
__ctl_clear_bit(14, 21);
- etr_disable_sync_clock(NULL);
+ disable_sync_clock(NULL);
etr_sync.in_sync = -EAGAIN;
rc = -EAGAIN;
}
local_irq_enable();
- smp_call_function(etr_sync_cpu_end,NULL,0,0);
+ smp_call_function(clock_sync_cpu_end, NULL, 0, 0);
preempt_enable();
return rc;
}
@@ -832,7 +849,7 @@ static struct etr_eacr etr_handle_update(struct etr_aib *aib,
* Do not try to get the alternate port aib if the clock
* is not in sync yet.
*/
- if (!eacr.es)
+ if (!test_bit(CLOCK_SYNC_STP, &clock_sync_flags) && !eacr.es)
return eacr;
/*
@@ -840,7 +857,7 @@ static struct etr_eacr etr_handle_update(struct etr_aib *aib,
* the other port immediately. If only stetr is available the
* data-port bit toggle has to be used.
*/
- if (test_bit(ETR_FLAG_STEAI, &etr_flags)) {
+ if (etr_steai_available) {
if (eacr.p0 && !etr_port0_uptodate) {
etr_steai_cv(&etr_port0, ETR_STEAI_PORT_0);
etr_port0_uptodate = 1;
@@ -909,10 +926,10 @@ static void etr_work_fn(struct work_struct *work)
if (!eacr.ea) {
/* Both ports offline. Reset everything. */
eacr.dp = eacr.es = eacr.sl = 0;
- on_each_cpu(etr_disable_sync_clock, NULL, 0, 1);
+ on_each_cpu(disable_sync_clock, NULL, 0, 1);
del_timer_sync(&etr_timer);
etr_update_eacr(eacr);
- set_bit(ETR_FLAG_EACCES, &etr_flags);
+ clear_bit(CLOCK_SYNC_ETR, &clock_sync_flags);
return;
}
@@ -953,7 +970,6 @@ static void etr_work_fn(struct work_struct *work)
eacr.e1 = 1;
sync_port = (etr_port0_uptodate &&
etr_port_valid(&etr_port0, 0)) ? 0 : -1;
- clear_bit(ETR_FLAG_EACCES, &etr_flags);
} else if (eacr.p1 && aib.esw.psc1 == etr_lpsc_pps_mode) {
eacr.sl = 0;
eacr.e0 = 0;
@@ -962,7 +978,6 @@ static void etr_work_fn(struct work_struct *work)
eacr.es = 0;
sync_port = (etr_port1_uptodate &&
etr_port_valid(&etr_port1, 1)) ? 1 : -1;
- clear_bit(ETR_FLAG_EACCES, &etr_flags);
} else if (eacr.p0 && aib.esw.psc0 == etr_lpsc_operational_step) {
eacr.sl = 1;
eacr.e0 = 1;
@@ -976,7 +991,6 @@ static void etr_work_fn(struct work_struct *work)
eacr.e1 = 1;
sync_port = (etr_port0_uptodate &&
etr_port_valid(&etr_port0, 0)) ? 0 : -1;
- clear_bit(ETR_FLAG_EACCES, &etr_flags);
} else if (eacr.p1 && aib.esw.psc1 == etr_lpsc_operational_step) {
eacr.sl = 1;
eacr.e0 = 0;
@@ -985,19 +999,22 @@ static void etr_work_fn(struct work_struct *work)
eacr.es = 0;
sync_port = (etr_port1_uptodate &&
etr_port_valid(&etr_port1, 1)) ? 1 : -1;
- clear_bit(ETR_FLAG_EACCES, &etr_flags);
} else {
/* Both ports not usable. */
eacr.es = eacr.sl = 0;
sync_port = -1;
- set_bit(ETR_FLAG_EACCES, &etr_flags);
+ clear_bit(CLOCK_SYNC_ETR, &clock_sync_flags);
}
+ if (!test_bit(CLOCK_SYNC_ETR, &clock_sync_flags))
+ eacr.es = 0;
+
/*
* 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 || sync_port < 0) {
+ if (test_bit(CLOCK_SYNC_STP, &clock_sync_flags) ||
+ eacr.es || sync_port < 0) {
etr_update_eacr(eacr);
etr_set_tolec_timeout(now);
return;
@@ -1018,11 +1035,13 @@ static void etr_work_fn(struct work_struct *work)
* and set up a timer to try again after 0.5 seconds
*/
etr_update_eacr(eacr);
+ set_bit(CLOCK_SYNC_ETR, &clock_sync_flags);
if (now < etr_tolec + (1600000 << 12) ||
etr_sync_clock(&aib, sync_port) != 0) {
/* Sync failed. Try again in 1/2 second. */
eacr.es = 0;
etr_update_eacr(eacr);
+ clear_bit(CLOCK_SYNC_ETR, &clock_sync_flags);
etr_set_sync_timeout();
} else
etr_set_tolec_timeout(now);
@@ -1097,8 +1116,8 @@ static ssize_t etr_online_store(struct sys_device *dev,
value = simple_strtoul(buf, NULL, 0);
if (value != 0 && value != 1)
return -EINVAL;
- if (test_bit(ETR_FLAG_ENOSYS, &etr_flags))
- return -ENOSYS;
+ if (!test_bit(CLOCK_SYNC_HAS_ETR, &clock_sync_flags))
+ return -EOPNOTSUPP;
if (dev == &etr_port0_dev) {
if (etr_port0_online == value)
return count; /* Nothing to do. */
@@ -1292,3 +1311,318 @@ out:
}
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 DECLARE_WORK(stp_work, stp_work_fn);
+
+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 stp_reset(void)
+{
+ int rc;
+
+ stp_page = alloc_bootmem_pages(PAGE_SIZE);
+ rc = chsc_sstpc(stp_page, STP_OP_CTRL, 0x0000);
+ if (rc == 1)
+ set_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags);
+ else if (stp_online) {
+ printk(KERN_WARNING "Running on non STP capable machine.\n");
+ free_bootmem((unsigned long) stp_page, PAGE_SIZE);
+ stp_page = NULL;
+ stp_online = 0;
+ }
+}
+
+static int __init stp_init(void)
+{
+ if (test_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags) && stp_online)
+ schedule_work(&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)
+ schedule_work(&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)
+{
+ if (!test_bit(CLOCK_SYNC_STP, &clock_sync_flags))
+ return;
+ disable_sync_clock(NULL);
+ schedule_work(&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)
+{
+ if (!test_bit(CLOCK_SYNC_STP, &clock_sync_flags))
+ return;
+ disable_sync_clock(NULL);
+ schedule_work(&stp_work);
+}
+
+/*
+ * STP tasklet. 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;
+ unsigned long long old_clock, delta;
+ int rc;
+
+ if (!stp_online) {
+ chsc_sstpc(stp_page, STP_OP_CTRL, 0x0000);
+ return;
+ }
+
+ rc = chsc_sstpc(stp_page, STP_OP_CTRL, 0xb0e0);
+ if (rc)
+ return;
+
+ rc = chsc_sstpi(stp_page, &stp_info, sizeof(struct stp_sstpi));
+ if (rc || stp_info.c == 0)
+ return;
+
+ /*
+ * Catch all other cpus and make them wait until we have
+ * successfully synced the clock. smp_call_function will
+ * return after all other cpus are in clock_sync_cpu_start.
+ */
+ memset(&stp_sync, 0, sizeof(stp_sync));
+ preempt_disable();
+ smp_call_function(clock_sync_cpu_start, &stp_sync, 0, 0);
+ local_irq_disable();
+ enable_sync_clock();
+
+ set_bit(CLOCK_SYNC_STP, &clock_sync_flags);
+ if (test_and_clear_bit(CLOCK_SYNC_ETR, &clock_sync_flags))
+ schedule_work(&etr_work);
+
+ 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;
+ clear_bit(CLOCK_SYNC_STP, &clock_sync_flags);
+ if (etr_port0_online || etr_port1_online)
+ schedule_work(&etr_work);
+ } else
+ stp_sync.in_sync = 1;
+
+ local_irq_enable();
+ smp_call_function(clock_sync_cpu_end, NULL, 0, 0);
+ preempt_enable();
+}
+
+/*
+ * STP class sysfs interface functions
+ */
+static struct sysdev_class stp_sysclass = {
+ .name = "stp",
+};
+
+static ssize_t stp_ctn_id_show(struct sysdev_class *class, 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, 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, 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, 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, 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, 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, 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, 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, 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, char *buf)
+{
+ return sprintf(buf, "%i\n", stp_online);
+}
+
+static ssize_t stp_online_store(struct sysdev_class *class,
+ 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;
+ stp_online = value;
+ schedule_work(&stp_work);
+ 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);