#include <asm/irq.h>
#include <asm/irq_regs.h>
#include <asm/timer.h>
+#include <asm/etr.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)
+/* The value of the TOD clock for 1.1.1970. */
+#define TOD_UNIX_EPOCH 0x7d91048bca000000ULL
+
/*
* Create a small time difference between the timer interrupts
* on the different cpus to avoid lock contention.
#define TICK_SIZE tick
static ext_int_info_t ext_int_info_cc;
+static ext_int_info_t ext_int_etr_cc;
static u64 init_timer_cc;
static u64 jiffies_timer_cc;
static u64 xtime_cc;
#define s390_do_profile() do { ; } while(0)
#endif /* CONFIG_PROFILING */
-
/*
- * timer_interrupt() needs to keep up the real-time clock,
- * as well as call the "do_timer()" routine every clocktick
+ * Advance the per cpu tick counter up to the time given with the
+ * "time" argument. The per cpu update consists of accounting
+ * the virtual cpu time, calling update_process_times and calling
+ * the profiling hook. If xtime is before time it is advanced as well.
*/
-void account_ticks(void)
+void account_ticks(u64 time)
{
- __u64 tmp;
__u32 ticks;
+ __u64 tmp;
/* Calculate how many ticks have passed. */
- if (S390_lowcore.int_clock < S390_lowcore.jiffy_timer) {
- /*
- * We have to program the clock comparator even if
- * no tick has passed. That happens if e.g. an i/o
- * interrupt wakes up an idle processor that has
- * switched off its hz timer.
- */
- tmp = S390_lowcore.jiffy_timer + CPU_DEVIATION;
- asm volatile ("SCKC %0" : : "m" (tmp));
+ if (time < S390_lowcore.jiffy_timer)
return;
- }
- tmp = S390_lowcore.int_clock - S390_lowcore.jiffy_timer;
+ tmp = time - S390_lowcore.jiffy_timer;
if (tmp >= 2*CLK_TICKS_PER_JIFFY) { /* more than two ticks ? */
ticks = __div(tmp, CLK_TICKS_PER_JIFFY) + 1;
S390_lowcore.jiffy_timer +=
S390_lowcore.jiffy_timer += CLK_TICKS_PER_JIFFY;
}
- /* set clock comparator for next tick */
- tmp = S390_lowcore.jiffy_timer + CPU_DEVIATION;
- asm volatile ("SCKC %0" : : "m" (tmp));
-
#ifdef CONFIG_SMP
/*
* Do not rely on the boot cpu to do the calls to do_timer.
if (timer >= jiffies_timer_cc)
todval = timer;
}
- asm volatile ("SCKC %0" : : "m" (todval));
+ set_clock_comparator(todval);
}
/*
if (!cpu_isset(smp_processor_id(), nohz_cpu_mask))
return;
- account_ticks();
+ account_ticks(get_clock());
+ set_clock_comparator(S390_lowcore.jiffy_timer + CPU_DEVIATION);
cpu_clear(smp_processor_id(), nohz_cpu_mask);
}
#endif
/*
- * Start the clock comparator on the current CPU.
+ * Set up per cpu jiffy timer and set the clock comparator.
+ */
+static void setup_jiffy_timer(void)
+{
+ /* Set up clock comparator to next jiffy. */
+ S390_lowcore.jiffy_timer =
+ jiffies_timer_cc + (jiffies_64 + 1) * CLK_TICKS_PER_JIFFY;
+ set_clock_comparator(S390_lowcore.jiffy_timer + CPU_DEVIATION);
+}
+
+/*
+ * Set up lowcore and control register of the current cpu to
+ * enable TOD clock and clock comparator interrupts.
*/
void init_cpu_timer(void)
{
- unsigned long cr0;
- __u64 timer;
+ setup_jiffy_timer();
+
+ /* Enable clock comparator timer interrupt. */
+ __ctl_set_bit(0,11);
+
+ /* Always allow ETR external interrupts, even without an ETR. */
+ __ctl_set_bit(0, 4);
+}
+
+static void clock_comparator_interrupt(__u16 code)
+{
+ /* set clock comparator for next tick */
+ set_clock_comparator(S390_lowcore.jiffy_timer + CPU_DEVIATION);
+}
+
+static void etr_reset(void);
+static void etr_init(void);
+static void etr_ext_handler(__u16);
+
+/*
+ * Get the TOD clock running.
+ */
+static u64 __init reset_tod_clock(void)
+{
+ u64 time;
+
+ etr_reset();
+ if (store_clock(&time) == 0)
+ return time;
+ /* TOD clock not running. Set the clock to Unix Epoch. */
+ if (set_clock(TOD_UNIX_EPOCH) != 0 || store_clock(&time) != 0)
+ panic("TOD clock not operational.");
- timer = jiffies_timer_cc + jiffies_64 * CLK_TICKS_PER_JIFFY;
- S390_lowcore.jiffy_timer = timer + CLK_TICKS_PER_JIFFY;
- timer += CLK_TICKS_PER_JIFFY + CPU_DEVIATION;
- asm volatile ("SCKC %0" : : "m" (timer));
- /* allow clock comparator timer interrupt */
- __ctl_store(cr0, 0, 0);
- cr0 |= 0x800;
- __ctl_load(cr0, 0, 0);
+ return TOD_UNIX_EPOCH;
}
static cycle_t read_tod_clock(void)
*/
void __init time_init(void)
{
- __u64 set_time_cc;
- int cc;
-
- /* kick the TOD clock */
- asm volatile(
- " stck 0(%2)\n"
- " ipm %0\n"
- " srl %0,28"
- : "=d" (cc), "=m" (init_timer_cc)
- : "a" (&init_timer_cc) : "cc");
- switch (cc) {
- case 0: /* clock in set state: all is fine */
- break;
- case 1: /* clock in non-set state: FIXME */
- printk("time_init: TOD clock in non-set state\n");
- break;
- case 2: /* clock in error state: FIXME */
- printk("time_init: TOD clock in error state\n");
- break;
- case 3: /* clock in stopped or not-operational state: FIXME */
- printk("time_init: TOD clock stopped/non-operational\n");
- break;
- }
+ init_timer_cc = reset_tod_clock();
+ xtime_cc = init_timer_cc + CLK_TICKS_PER_JIFFY;
jiffies_timer_cc = init_timer_cc - jiffies_64 * CLK_TICKS_PER_JIFFY;
/* set xtime */
- xtime_cc = init_timer_cc + CLK_TICKS_PER_JIFFY;
- set_time_cc = init_timer_cc - 0x8126d60e46000000LL +
- (0x3c26700LL*1000000*4096);
- tod_to_timeval(set_time_cc, &xtime);
+ tod_to_timeval(init_timer_cc - TOD_UNIX_EPOCH, &xtime);
set_normalized_timespec(&wall_to_monotonic,
-xtime.tv_sec, -xtime.tv_nsec);
/* request the clock comparator external interrupt */
- if (register_early_external_interrupt(0x1004, NULL,
+ if (register_early_external_interrupt(0x1004,
+ clock_comparator_interrupt,
&ext_int_info_cc) != 0)
panic("Couldn't request external interrupt 0x1004");
if (clocksource_register(&clocksource_tod) != 0)
panic("Could not register TOD clock source");
- init_cpu_timer();
+ /* request the etr external interrupt */
+ if (register_early_external_interrupt(0x1406, etr_ext_handler,
+ &ext_int_etr_cc) != 0)
+ panic("Couldn't request external interrupt 0x1406");
+
+ /* Enable TOD clock interrupts on the boot cpu. */
+ init_cpu_timer();
#ifdef CONFIG_NO_IDLE_HZ
nohz_init();
#ifdef CONFIG_VIRT_TIMER
vtime_init();
#endif
+ etr_init();
+}
+
+/*
+ * External Time Reference (ETR) code.
+ */
+static int etr_port0_online;
+static int etr_port1_online;
+
+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,
+};
+
+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
+ * 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 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 struct tasklet_struct etr_tasklet;
+static DEFINE_PER_CPU(atomic_t, etr_sync_word);
+
+static void etr_timeout(unsigned long dummy);
+static void etr_tasklet_fn(unsigned long dummy);
+
+/*
+ * 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)
+{
+ 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();
+ 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;
+ }
+ }
+}
+
+static void etr_init(void)
+{
+ struct etr_aib aib;
+
+ if (test_bit(ETR_FLAG_ENOSYS, &etr_flags))
+ return;
+ /* Check if this machine has the steai instruction. */
+ if (etr_steai(&aib, ETR_STEAI_STEPPING_PORT) == 0)
+ set_bit(ETR_FLAG_STEAI, &etr_flags);
+ setup_timer(&etr_timer, etr_timeout, 0UL);
+ tasklet_init(&etr_tasklet, etr_tasklet_fn, 0);
+ 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);
+ tasklet_hi_schedule(&etr_tasklet);
+ }
+ if (etr_port1_online) {
+ set_bit(ETR_EVENT_PORT1_CHANGE, &etr_events);
+ tasklet_hi_schedule(&etr_tasklet);
+ }
+}
+
+/*
+ * 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;
+ etr_disable_sync_clock(NULL);
+ set_bit(ETR_EVENT_SWITCH_LOCAL, &etr_events);
+ tasklet_hi_schedule(&etr_tasklet);
+}
+
+/*
+ * 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;
+ etr_disable_sync_clock(NULL);
+ set_bit(ETR_EVENT_SYNC_CHECK, &etr_events);
+ tasklet_hi_schedule(&etr_tasklet);
+}
+
+/*
+ * ETR external interrupt. 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)
+{
+ 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);
+ 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);
+ tasklet_hi_schedule(&etr_tasklet);
+}
+
+static void etr_timeout(unsigned long dummy)
+{
+ set_bit(ETR_EVENT_UPDATE, &etr_events);
+ tasklet_hi_schedule(&etr_tasklet);
+}
+
+/*
+ * 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;
+}
+
+/*
+ * The time is "clock". xtime 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 void etr_adjust_time(unsigned long long clock, unsigned long long delay)
+{
+ unsigned long long delta, ticks;
+ struct timex adjust;
+
+ /*
+ * We don't have to take the xtime lock because the cpu
+ * executing etr_adjust_time is running disabled in
+ * tasklet context and all other cpus are looping in
+ * etr_sync_cpu_start.
+ */
+ if (clock > xtime_cc) {
+ /* It is later than we thought. */
+ delta = ticks = clock - xtime_cc;
+ delta = ticks = (delta < delay) ? 0 : delta - delay;
+ delta -= do_div(ticks, CLK_TICKS_PER_JIFFY);
+ init_timer_cc = init_timer_cc + delta;
+ jiffies_timer_cc = jiffies_timer_cc + delta;
+ xtime_cc = xtime_cc + delta;
+ adjust.offset = ticks * (1000000 / HZ);
+ } else {
+ /* It is earlier than we thought. */
+ delta = ticks = xtime_cc - clock;
+ delta -= do_div(ticks, CLK_TICKS_PER_JIFFY);
+ init_timer_cc = init_timer_cc - delta;
+ jiffies_timer_cc = jiffies_timer_cc - delta;
+ xtime_cc = xtime_cc - delta;
+ adjust.offset = -ticks * (1000000 / HZ);
+ }
+ 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);
+ }
+}
+
+static void etr_sync_cpu_start(void *dummy)
+{
+ int *in_sync = dummy;
+
+ etr_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 (*in_sync == 0)
+ __udelay(1);
+ if (*in_sync != 1)
+ /* Didn't work. Clear per-cpu in sync bit again. */
+ etr_disable_sync_clock(NULL);
+ /*
+ * This round of TOD syncing is done. Set the clock comparator
+ * to the next tick and let the processor continue.
+ */
+ setup_jiffy_timer();
+}
+
+static void etr_sync_cpu_end(void *dummy)
+{
+}
+
+/*
+ * 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(struct etr_aib *aib, int port)
+{
+ struct etr_aib *sync_port;
+ unsigned long long clock, delay;
+ int in_sync, 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;
+
+ /*
+ * 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 etr_sync_cpu_start.
+ */
+ in_sync = 0;
+ preempt_disable();
+ smp_call_function(etr_sync_cpu_start,&in_sync,0,0);
+ local_irq_disable();
+ etr_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;
+ 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;
+ etr_adjust_time(clock, delay);
+ setup_jiffy_timer();
+ /* Verify that the clock is properly set. */
+ if (!etr_aib_follows(sync_port, aib, port)) {
+ /* Didn't work. */
+ etr_disable_sync_clock(NULL);
+ in_sync = -EAGAIN;
+ rc = -EAGAIN;
+ } else {
+ in_sync = 1;
+ rc = 0;
+ }
+ } else {
+ /* Could not set the clock ?!? */
+ __ctl_clear_bit(0, 29);
+ __ctl_clear_bit(14, 21);
+ etr_disable_sync_clock(NULL);
+ in_sync = -EAGAIN;
+ rc = -EAGAIN;
+ }
+ local_irq_enable();
+ smp_call_function(etr_sync_cpu_end,NULL,0,0);
+ preempt_enable();
+ 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_tasklet_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)
+ 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 (test_bit(ETR_FLAG_STEAI, &etr_flags)) {
+ 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 tasklet. 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_tasklet_fn(unsigned long dummy)
+{
+ unsigned long long now;
+ struct etr_eacr eacr;
+ struct etr_aib aib;
+ int sync_port;
+
+ /* 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(etr_disable_sync_clock, NULL, 0, 1);
+ del_timer_sync(&etr_timer);
+ etr_update_eacr(eacr);
+ set_bit(ETR_FLAG_EACCES, &etr_flags);
+ return;
+ }
+
+ /* 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;
+ clear_bit(ETR_FLAG_EACCES, &etr_flags);
+ } 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;
+ clear_bit(ETR_FLAG_EACCES, &etr_flags);
+ } 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;
+ clear_bit(ETR_FLAG_EACCES, &etr_flags);
+ } 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;
+ 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);
+ }
+
+ /*
+ * 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) {
+ etr_update_eacr(eacr);
+ etr_set_tolec_timeout(now);
+ return;
+ }
+
+ /*
+ * 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(&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);
+}
+
+/*
+ * Sysfs interface functions
+ */
+static struct sysdev_class etr_sysclass = {
+ set_kset_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, 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, 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, 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,
+ 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(ETR_FLAG_ENOSYS, &etr_flags))
+ return -ENOSYS;
+ if (dev == &etr_port0_dev) {
+ if (etr_port0_online == value)
+ return count; /* Nothing to do. */
+ etr_port0_online = value;
+ set_bit(ETR_EVENT_PORT0_CHANGE, &etr_events);
+ tasklet_hi_schedule(&etr_tasklet);
+ } else {
+ if (etr_port1_online == value)
+ return count; /* Nothing to do. */
+ etr_port1_online = value;
+ set_bit(ETR_EVENT_PORT1_CHANGE, &etr_events);
+ tasklet_hi_schedule(&etr_tasklet);
+ }
+ return count;
+}
+
+static SYSDEV_ATTR(online, 0600, etr_online_show, etr_online_store);
+
+static ssize_t etr_stepping_control_show(struct sys_device *dev, 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, 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, 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, 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, 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, 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, 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, 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, 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);
projects / linux-2.6 / commitdiff