diff options
Diffstat (limited to 'arch/s390/kernel/time.c')
| -rw-r--r-- | arch/s390/kernel/time.c | 1179 |
1 files changed, 1117 insertions, 62 deletions
diff --git a/arch/s390/kernel/time.c b/arch/s390/kernel/time.c index 5d4a190fa30..39a72d3cb89 100644 --- a/arch/s390/kernel/time.c +++ b/arch/s390/kernel/time.c @@ -37,11 +37,15 @@ #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. @@ -51,6 +55,7 @@ #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; @@ -89,29 +94,21 @@ void tod_to_timeval(__u64 todval, struct timespec *xtime) #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 += @@ -124,10 +121,6 @@ void account_ticks(void) 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. @@ -210,7 +203,7 @@ static inline void stop_hz_timer(void) if (timer >= jiffies_timer_cc) todval = timer; } - asm volatile ("SCKC %0" : : "m" (todval)); + set_clock_comparator(todval); } /* @@ -223,7 +216,8 @@ static inline void start_hz_timer(void) 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); } @@ -254,21 +248,56 @@ static void __init nohz_init(void) #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) @@ -293,48 +322,31 @@ static struct clocksource clocksource_tod = { */ 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(); @@ -343,5 +355,1048 @@ void __init time_init(void) #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); |