xref: /linux/arch/s390/kernel/time.c (revision c537b994505099b7197e7d3125b942ecbcc51eb6)
1 /*
2  *  arch/s390/kernel/time.c
3  *    Time of day based timer functions.
4  *
5  *  S390 version
6  *    Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
7  *    Author(s): Hartmut Penner (hp@de.ibm.com),
8  *               Martin Schwidefsky (schwidefsky@de.ibm.com),
9  *               Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com)
10  *
11  *  Derived from "arch/i386/kernel/time.c"
12  *    Copyright (C) 1991, 1992, 1995  Linus Torvalds
13  */
14 
15 #include <linux/errno.h>
16 #include <linux/module.h>
17 #include <linux/sched.h>
18 #include <linux/kernel.h>
19 #include <linux/param.h>
20 #include <linux/string.h>
21 #include <linux/mm.h>
22 #include <linux/interrupt.h>
23 #include <linux/time.h>
24 #include <linux/delay.h>
25 #include <linux/init.h>
26 #include <linux/smp.h>
27 #include <linux/types.h>
28 #include <linux/profile.h>
29 #include <linux/timex.h>
30 #include <linux/notifier.h>
31 #include <linux/clocksource.h>
32 
33 #include <asm/uaccess.h>
34 #include <asm/delay.h>
35 #include <asm/s390_ext.h>
36 #include <asm/div64.h>
37 #include <asm/irq.h>
38 #include <asm/irq_regs.h>
39 #include <asm/timer.h>
40 #include <asm/etr.h>
41 
42 /* change this if you have some constant time drift */
43 #define USECS_PER_JIFFY     ((unsigned long) 1000000/HZ)
44 #define CLK_TICKS_PER_JIFFY ((unsigned long) USECS_PER_JIFFY << 12)
45 
46 /* The value of the TOD clock for 1.1.1970. */
47 #define TOD_UNIX_EPOCH 0x7d91048bca000000ULL
48 
49 /*
50  * Create a small time difference between the timer interrupts
51  * on the different cpus to avoid lock contention.
52  */
53 #define CPU_DEVIATION       (smp_processor_id() << 12)
54 
55 #define TICK_SIZE tick
56 
57 static ext_int_info_t ext_int_info_cc;
58 static ext_int_info_t ext_int_etr_cc;
59 static u64 init_timer_cc;
60 static u64 jiffies_timer_cc;
61 static u64 xtime_cc;
62 
63 /*
64  * Scheduler clock - returns current time in nanosec units.
65  */
66 unsigned long long sched_clock(void)
67 {
68 	return ((get_clock() - jiffies_timer_cc) * 125) >> 9;
69 }
70 
71 /*
72  * Monotonic_clock - returns # of nanoseconds passed since time_init()
73  */
74 unsigned long long monotonic_clock(void)
75 {
76 	return sched_clock();
77 }
78 EXPORT_SYMBOL(monotonic_clock);
79 
80 void tod_to_timeval(__u64 todval, struct timespec *xtime)
81 {
82 	unsigned long long sec;
83 
84 	sec = todval >> 12;
85 	do_div(sec, 1000000);
86 	xtime->tv_sec = sec;
87 	todval -= (sec * 1000000) << 12;
88 	xtime->tv_nsec = ((todval * 1000) >> 12);
89 }
90 
91 #ifdef CONFIG_PROFILING
92 #define s390_do_profile()	profile_tick(CPU_PROFILING)
93 #else
94 #define s390_do_profile()	do { ; } while(0)
95 #endif /* CONFIG_PROFILING */
96 
97 /*
98  * Advance the per cpu tick counter up to the time given with the
99  * "time" argument. The per cpu update consists of accounting
100  * the virtual cpu time, calling update_process_times and calling
101  * the profiling hook. If xtime is before time it is advanced as well.
102  */
103 void account_ticks(u64 time)
104 {
105 	__u32 ticks;
106 	__u64 tmp;
107 
108 	/* Calculate how many ticks have passed. */
109 	if (time < S390_lowcore.jiffy_timer)
110 		return;
111 	tmp = time - S390_lowcore.jiffy_timer;
112 	if (tmp >= 2*CLK_TICKS_PER_JIFFY) {  /* more than two ticks ? */
113 		ticks = __div(tmp, CLK_TICKS_PER_JIFFY) + 1;
114 		S390_lowcore.jiffy_timer +=
115 			CLK_TICKS_PER_JIFFY * (__u64) ticks;
116 	} else if (tmp >= CLK_TICKS_PER_JIFFY) {
117 		ticks = 2;
118 		S390_lowcore.jiffy_timer += 2*CLK_TICKS_PER_JIFFY;
119 	} else {
120 		ticks = 1;
121 		S390_lowcore.jiffy_timer += CLK_TICKS_PER_JIFFY;
122 	}
123 
124 #ifdef CONFIG_SMP
125 	/*
126 	 * Do not rely on the boot cpu to do the calls to do_timer.
127 	 * Spread it over all cpus instead.
128 	 */
129 	write_seqlock(&xtime_lock);
130 	if (S390_lowcore.jiffy_timer > xtime_cc) {
131 		__u32 xticks;
132 		tmp = S390_lowcore.jiffy_timer - xtime_cc;
133 		if (tmp >= 2*CLK_TICKS_PER_JIFFY) {
134 			xticks = __div(tmp, CLK_TICKS_PER_JIFFY);
135 			xtime_cc += (__u64) xticks * CLK_TICKS_PER_JIFFY;
136 		} else {
137 			xticks = 1;
138 			xtime_cc += CLK_TICKS_PER_JIFFY;
139 		}
140 		do_timer(xticks);
141 	}
142 	write_sequnlock(&xtime_lock);
143 #else
144 	do_timer(ticks);
145 #endif
146 
147 #ifdef CONFIG_VIRT_CPU_ACCOUNTING
148 	account_tick_vtime(current);
149 #else
150 	while (ticks--)
151 		update_process_times(user_mode(get_irq_regs()));
152 #endif
153 
154 	s390_do_profile();
155 }
156 
157 #ifdef CONFIG_NO_IDLE_HZ
158 
159 #ifdef CONFIG_NO_IDLE_HZ_INIT
160 int sysctl_hz_timer = 0;
161 #else
162 int sysctl_hz_timer = 1;
163 #endif
164 
165 /*
166  * Stop the HZ tick on the current CPU.
167  * Only cpu_idle may call this function.
168  */
169 static void stop_hz_timer(void)
170 {
171 	unsigned long flags;
172 	unsigned long seq, next;
173 	__u64 timer, todval;
174 	int cpu = smp_processor_id();
175 
176 	if (sysctl_hz_timer != 0)
177 		return;
178 
179 	cpu_set(cpu, nohz_cpu_mask);
180 
181 	/*
182 	 * Leave the clock comparator set up for the next timer
183 	 * tick if either rcu or a softirq is pending.
184 	 */
185 	if (rcu_needs_cpu(cpu) || local_softirq_pending()) {
186 		cpu_clear(cpu, nohz_cpu_mask);
187 		return;
188 	}
189 
190 	/*
191 	 * This cpu is going really idle. Set up the clock comparator
192 	 * for the next event.
193 	 */
194 	next = next_timer_interrupt();
195 	do {
196 		seq = read_seqbegin_irqsave(&xtime_lock, flags);
197 		timer = ((__u64) next) - ((__u64) jiffies) + jiffies_64;
198 	} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
199 	todval = -1ULL;
200 	/* Be careful about overflows. */
201 	if (timer < (-1ULL / CLK_TICKS_PER_JIFFY)) {
202 		timer = jiffies_timer_cc + timer * CLK_TICKS_PER_JIFFY;
203 		if (timer >= jiffies_timer_cc)
204 			todval = timer;
205 	}
206 	set_clock_comparator(todval);
207 }
208 
209 /*
210  * Start the HZ tick on the current CPU.
211  * Only cpu_idle may call this function.
212  */
213 static void start_hz_timer(void)
214 {
215 	BUG_ON(!in_interrupt());
216 
217 	if (!cpu_isset(smp_processor_id(), nohz_cpu_mask))
218 		return;
219 	account_ticks(get_clock());
220 	set_clock_comparator(S390_lowcore.jiffy_timer + CPU_DEVIATION);
221 	cpu_clear(smp_processor_id(), nohz_cpu_mask);
222 }
223 
224 static int nohz_idle_notify(struct notifier_block *self,
225 			    unsigned long action, void *hcpu)
226 {
227 	switch (action) {
228 	case CPU_IDLE:
229 		stop_hz_timer();
230 		break;
231 	case CPU_NOT_IDLE:
232 		start_hz_timer();
233 		break;
234 	}
235 	return NOTIFY_OK;
236 }
237 
238 static struct notifier_block nohz_idle_nb = {
239 	.notifier_call = nohz_idle_notify,
240 };
241 
242 static void __init nohz_init(void)
243 {
244 	if (register_idle_notifier(&nohz_idle_nb))
245 		panic("Couldn't register idle notifier");
246 }
247 
248 #endif
249 
250 /*
251  * Set up per cpu jiffy timer and set the clock comparator.
252  */
253 static void setup_jiffy_timer(void)
254 {
255 	/* Set up clock comparator to next jiffy. */
256 	S390_lowcore.jiffy_timer =
257 		jiffies_timer_cc + (jiffies_64 + 1) * CLK_TICKS_PER_JIFFY;
258 	set_clock_comparator(S390_lowcore.jiffy_timer + CPU_DEVIATION);
259 }
260 
261 /*
262  * Set up lowcore and control register of the current cpu to
263  * enable TOD clock and clock comparator interrupts.
264  */
265 void init_cpu_timer(void)
266 {
267 	setup_jiffy_timer();
268 
269 	/* Enable clock comparator timer interrupt. */
270 	__ctl_set_bit(0,11);
271 
272 	/* Always allow ETR external interrupts, even without an ETR. */
273 	__ctl_set_bit(0, 4);
274 }
275 
276 static void clock_comparator_interrupt(__u16 code)
277 {
278 	/* set clock comparator for next tick */
279 	set_clock_comparator(S390_lowcore.jiffy_timer + CPU_DEVIATION);
280 }
281 
282 static void etr_reset(void);
283 static void etr_init(void);
284 static void etr_ext_handler(__u16);
285 
286 /*
287  * Get the TOD clock running.
288  */
289 static u64 __init reset_tod_clock(void)
290 {
291 	u64 time;
292 
293 	etr_reset();
294 	if (store_clock(&time) == 0)
295 		return time;
296 	/* TOD clock not running. Set the clock to Unix Epoch. */
297 	if (set_clock(TOD_UNIX_EPOCH) != 0 || store_clock(&time) != 0)
298 		panic("TOD clock not operational.");
299 
300 	return TOD_UNIX_EPOCH;
301 }
302 
303 static cycle_t read_tod_clock(void)
304 {
305 	return get_clock();
306 }
307 
308 static struct clocksource clocksource_tod = {
309 	.name		= "tod",
310 	.rating		= 100,
311 	.read		= read_tod_clock,
312 	.mask		= -1ULL,
313 	.mult		= 1000,
314 	.shift		= 12,
315 	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
316 };
317 
318 
319 /*
320  * Initialize the TOD clock and the CPU timer of
321  * the boot cpu.
322  */
323 void __init time_init(void)
324 {
325 	init_timer_cc = reset_tod_clock();
326 	xtime_cc = init_timer_cc + CLK_TICKS_PER_JIFFY;
327 	jiffies_timer_cc = init_timer_cc - jiffies_64 * CLK_TICKS_PER_JIFFY;
328 
329 	/* set xtime */
330 	tod_to_timeval(init_timer_cc - TOD_UNIX_EPOCH, &xtime);
331         set_normalized_timespec(&wall_to_monotonic,
332                                 -xtime.tv_sec, -xtime.tv_nsec);
333 
334 	/* request the clock comparator external interrupt */
335 	if (register_early_external_interrupt(0x1004,
336 					      clock_comparator_interrupt,
337 					      &ext_int_info_cc) != 0)
338                 panic("Couldn't request external interrupt 0x1004");
339 
340 	if (clocksource_register(&clocksource_tod) != 0)
341 		panic("Could not register TOD clock source");
342 
343 	/* request the etr external interrupt */
344 	if (register_early_external_interrupt(0x1406, etr_ext_handler,
345 					      &ext_int_etr_cc) != 0)
346 		panic("Couldn't request external interrupt 0x1406");
347 
348 	/* Enable TOD clock interrupts on the boot cpu. */
349 	init_cpu_timer();
350 
351 #ifdef CONFIG_NO_IDLE_HZ
352 	nohz_init();
353 #endif
354 
355 #ifdef CONFIG_VIRT_TIMER
356 	vtime_init();
357 #endif
358 	etr_init();
359 }
360 
361 /*
362  * External Time Reference (ETR) code.
363  */
364 static int etr_port0_online;
365 static int etr_port1_online;
366 
367 static int __init early_parse_etr(char *p)
368 {
369 	if (strncmp(p, "off", 3) == 0)
370 		etr_port0_online = etr_port1_online = 0;
371 	else if (strncmp(p, "port0", 5) == 0)
372 		etr_port0_online = 1;
373 	else if (strncmp(p, "port1", 5) == 0)
374 		etr_port1_online = 1;
375 	else if (strncmp(p, "on", 2) == 0)
376 		etr_port0_online = etr_port1_online = 1;
377 	return 0;
378 }
379 early_param("etr", early_parse_etr);
380 
381 enum etr_event {
382 	ETR_EVENT_PORT0_CHANGE,
383 	ETR_EVENT_PORT1_CHANGE,
384 	ETR_EVENT_PORT_ALERT,
385 	ETR_EVENT_SYNC_CHECK,
386 	ETR_EVENT_SWITCH_LOCAL,
387 	ETR_EVENT_UPDATE,
388 };
389 
390 enum etr_flags {
391 	ETR_FLAG_ENOSYS,
392 	ETR_FLAG_EACCES,
393 	ETR_FLAG_STEAI,
394 };
395 
396 /*
397  * Valid bit combinations of the eacr register are (x = don't care):
398  * e0 e1 dp p0 p1 ea es sl
399  *  0  0  x  0	0  0  0  0  initial, disabled state
400  *  0  0  x  0	1  1  0  0  port 1 online
401  *  0  0  x  1	0  1  0  0  port 0 online
402  *  0  0  x  1	1  1  0  0  both ports online
403  *  0  1  x  0	1  1  0  0  port 1 online and usable, ETR or PPS mode
404  *  0  1  x  0	1  1  0  1  port 1 online, usable and ETR mode
405  *  0  1  x  0	1  1  1  0  port 1 online, usable, PPS mode, in-sync
406  *  0  1  x  0	1  1  1  1  port 1 online, usable, ETR mode, in-sync
407  *  0  1  x  1	1  1  0  0  both ports online, port 1 usable
408  *  0  1  x  1	1  1  1  0  both ports online, port 1 usable, PPS mode, in-sync
409  *  0  1  x  1	1  1  1  1  both ports online, port 1 usable, ETR mode, in-sync
410  *  1  0  x  1	0  1  0  0  port 0 online and usable, ETR or PPS mode
411  *  1  0  x  1	0  1  0  1  port 0 online, usable and ETR mode
412  *  1  0  x  1	0  1  1  0  port 0 online, usable, PPS mode, in-sync
413  *  1  0  x  1	0  1  1  1  port 0 online, usable, ETR mode, in-sync
414  *  1  0  x  1	1  1  0  0  both ports online, port 0 usable
415  *  1  0  x  1	1  1  1  0  both ports online, port 0 usable, PPS mode, in-sync
416  *  1  0  x  1	1  1  1  1  both ports online, port 0 usable, ETR mode, in-sync
417  *  1  1  x  1	1  1  1  0  both ports online & usable, ETR, in-sync
418  *  1  1  x  1	1  1  1  1  both ports online & usable, ETR, in-sync
419  */
420 static struct etr_eacr etr_eacr;
421 static u64 etr_tolec;			/* time of last eacr update */
422 static unsigned long etr_flags;
423 static struct etr_aib etr_port0;
424 static int etr_port0_uptodate;
425 static struct etr_aib etr_port1;
426 static int etr_port1_uptodate;
427 static unsigned long etr_events;
428 static struct timer_list etr_timer;
429 static struct tasklet_struct etr_tasklet;
430 static DEFINE_PER_CPU(atomic_t, etr_sync_word);
431 
432 static void etr_timeout(unsigned long dummy);
433 static void etr_tasklet_fn(unsigned long dummy);
434 
435 /*
436  * The etr get_clock function. It will write the current clock value
437  * to the clock pointer and return 0 if the clock is in sync with the
438  * external time source. If the clock mode is local it will return
439  * -ENOSYS and -EAGAIN if the clock is not in sync with the external
440  * reference. This function is what ETR is all about..
441  */
442 int get_sync_clock(unsigned long long *clock)
443 {
444 	atomic_t *sw_ptr;
445 	unsigned int sw0, sw1;
446 
447 	sw_ptr = &get_cpu_var(etr_sync_word);
448 	sw0 = atomic_read(sw_ptr);
449 	*clock = get_clock();
450 	sw1 = atomic_read(sw_ptr);
451 	put_cpu_var(etr_sync_sync);
452 	if (sw0 == sw1 && (sw0 & 0x80000000U))
453 		/* Success: time is in sync. */
454 		return 0;
455 	if (test_bit(ETR_FLAG_ENOSYS, &etr_flags))
456 		return -ENOSYS;
457 	if (test_bit(ETR_FLAG_EACCES, &etr_flags))
458 		return -EACCES;
459 	return -EAGAIN;
460 }
461 EXPORT_SYMBOL(get_sync_clock);
462 
463 /*
464  * Make get_sync_clock return -EAGAIN.
465  */
466 static void etr_disable_sync_clock(void *dummy)
467 {
468 	atomic_t *sw_ptr = &__get_cpu_var(etr_sync_word);
469 	/*
470 	 * Clear the in-sync bit 2^31. All get_sync_clock calls will
471 	 * fail until the sync bit is turned back on. In addition
472 	 * increase the "sequence" counter to avoid the race of an
473 	 * etr event and the complete recovery against get_sync_clock.
474 	 */
475 	atomic_clear_mask(0x80000000, sw_ptr);
476 	atomic_inc(sw_ptr);
477 }
478 
479 /*
480  * Make get_sync_clock return 0 again.
481  * Needs to be called from a context disabled for preemption.
482  */
483 static void etr_enable_sync_clock(void)
484 {
485 	atomic_t *sw_ptr = &__get_cpu_var(etr_sync_word);
486 	atomic_set_mask(0x80000000, sw_ptr);
487 }
488 
489 /*
490  * Reset ETR attachment.
491  */
492 static void etr_reset(void)
493 {
494 	etr_eacr =  (struct etr_eacr) {
495 		.e0 = 0, .e1 = 0, ._pad0 = 4, .dp = 0,
496 		.p0 = 0, .p1 = 0, ._pad1 = 0, .ea = 0,
497 		.es = 0, .sl = 0 };
498 	if (etr_setr(&etr_eacr) == 0)
499 		etr_tolec = get_clock();
500 	else {
501 		set_bit(ETR_FLAG_ENOSYS, &etr_flags);
502 		if (etr_port0_online || etr_port1_online) {
503 			printk(KERN_WARNING "Running on non ETR capable "
504 			       "machine, only local mode available.\n");
505 			etr_port0_online = etr_port1_online = 0;
506 		}
507 	}
508 }
509 
510 static void etr_init(void)
511 {
512 	struct etr_aib aib;
513 
514 	if (test_bit(ETR_FLAG_ENOSYS, &etr_flags))
515 		return;
516 	/* Check if this machine has the steai instruction. */
517 	if (etr_steai(&aib, ETR_STEAI_STEPPING_PORT) == 0)
518 		set_bit(ETR_FLAG_STEAI, &etr_flags);
519 	setup_timer(&etr_timer, etr_timeout, 0UL);
520 	tasklet_init(&etr_tasklet, etr_tasklet_fn, 0);
521 	if (!etr_port0_online && !etr_port1_online)
522 		set_bit(ETR_FLAG_EACCES, &etr_flags);
523 	if (etr_port0_online) {
524 		set_bit(ETR_EVENT_PORT0_CHANGE, &etr_events);
525 		tasklet_hi_schedule(&etr_tasklet);
526 	}
527 	if (etr_port1_online) {
528 		set_bit(ETR_EVENT_PORT1_CHANGE, &etr_events);
529 		tasklet_hi_schedule(&etr_tasklet);
530 	}
531 }
532 
533 /*
534  * Two sorts of ETR machine checks. The architecture reads:
535  * "When a machine-check niterruption occurs and if a switch-to-local or
536  *  ETR-sync-check interrupt request is pending but disabled, this pending
537  *  disabled interruption request is indicated and is cleared".
538  * Which means that we can get etr_switch_to_local events from the machine
539  * check handler although the interruption condition is disabled. Lovely..
540  */
541 
542 /*
543  * Switch to local machine check. This is called when the last usable
544  * ETR port goes inactive. After switch to local the clock is not in sync.
545  */
546 void etr_switch_to_local(void)
547 {
548 	if (!etr_eacr.sl)
549 		return;
550 	etr_disable_sync_clock(NULL);
551 	set_bit(ETR_EVENT_SWITCH_LOCAL, &etr_events);
552 	tasklet_hi_schedule(&etr_tasklet);
553 }
554 
555 /*
556  * ETR sync check machine check. This is called when the ETR OTE and the
557  * local clock OTE are farther apart than the ETR sync check tolerance.
558  * After a ETR sync check the clock is not in sync. The machine check
559  * is broadcasted to all cpus at the same time.
560  */
561 void etr_sync_check(void)
562 {
563 	if (!etr_eacr.es)
564 		return;
565 	etr_disable_sync_clock(NULL);
566 	set_bit(ETR_EVENT_SYNC_CHECK, &etr_events);
567 	tasklet_hi_schedule(&etr_tasklet);
568 }
569 
570 /*
571  * ETR external interrupt. There are two causes:
572  * 1) port state change, check the usability of the port
573  * 2) port alert, one of the ETR-data-validity bits (v1-v2 bits of the
574  *    sldr-status word) or ETR-data word 1 (edf1) or ETR-data word 3 (edf3)
575  *    or ETR-data word 4 (edf4) has changed.
576  */
577 static void etr_ext_handler(__u16 code)
578 {
579 	struct etr_interruption_parameter *intparm =
580 		(struct etr_interruption_parameter *) &S390_lowcore.ext_params;
581 
582 	if (intparm->pc0)
583 		/* ETR port 0 state change. */
584 		set_bit(ETR_EVENT_PORT0_CHANGE, &etr_events);
585 	if (intparm->pc1)
586 		/* ETR port 1 state change. */
587 		set_bit(ETR_EVENT_PORT1_CHANGE, &etr_events);
588 	if (intparm->eai)
589 		/*
590 		 * ETR port alert on either port 0, 1 or both.
591 		 * Both ports are not up-to-date now.
592 		 */
593 		set_bit(ETR_EVENT_PORT_ALERT, &etr_events);
594 	tasklet_hi_schedule(&etr_tasklet);
595 }
596 
597 static void etr_timeout(unsigned long dummy)
598 {
599 	set_bit(ETR_EVENT_UPDATE, &etr_events);
600 	tasklet_hi_schedule(&etr_tasklet);
601 }
602 
603 /*
604  * Check if the etr mode is pss.
605  */
606 static inline int etr_mode_is_pps(struct etr_eacr eacr)
607 {
608 	return eacr.es && !eacr.sl;
609 }
610 
611 /*
612  * Check if the etr mode is etr.
613  */
614 static inline int etr_mode_is_etr(struct etr_eacr eacr)
615 {
616 	return eacr.es && eacr.sl;
617 }
618 
619 /*
620  * Check if the port can be used for TOD synchronization.
621  * For PPS mode the port has to receive OTEs. For ETR mode
622  * the port has to receive OTEs, the ETR stepping bit has to
623  * be zero and the validity bits for data frame 1, 2, and 3
624  * have to be 1.
625  */
626 static int etr_port_valid(struct etr_aib *aib, int port)
627 {
628 	unsigned int psc;
629 
630 	/* Check that this port is receiving OTEs. */
631 	if (aib->tsp == 0)
632 		return 0;
633 
634 	psc = port ? aib->esw.psc1 : aib->esw.psc0;
635 	if (psc == etr_lpsc_pps_mode)
636 		return 1;
637 	if (psc == etr_lpsc_operational_step)
638 		return !aib->esw.y && aib->slsw.v1 &&
639 			aib->slsw.v2 && aib->slsw.v3;
640 	return 0;
641 }
642 
643 /*
644  * Check if two ports are on the same network.
645  */
646 static int etr_compare_network(struct etr_aib *aib1, struct etr_aib *aib2)
647 {
648 	// FIXME: any other fields we have to compare?
649 	return aib1->edf1.net_id == aib2->edf1.net_id;
650 }
651 
652 /*
653  * Wrapper for etr_stei that converts physical port states
654  * to logical port states to be consistent with the output
655  * of stetr (see etr_psc vs. etr_lpsc).
656  */
657 static void etr_steai_cv(struct etr_aib *aib, unsigned int func)
658 {
659 	BUG_ON(etr_steai(aib, func) != 0);
660 	/* Convert port state to logical port state. */
661 	if (aib->esw.psc0 == 1)
662 		aib->esw.psc0 = 2;
663 	else if (aib->esw.psc0 == 0 && aib->esw.p == 0)
664 		aib->esw.psc0 = 1;
665 	if (aib->esw.psc1 == 1)
666 		aib->esw.psc1 = 2;
667 	else if (aib->esw.psc1 == 0 && aib->esw.p == 1)
668 		aib->esw.psc1 = 1;
669 }
670 
671 /*
672  * Check if the aib a2 is still connected to the same attachment as
673  * aib a1, the etv values differ by one and a2 is valid.
674  */
675 static int etr_aib_follows(struct etr_aib *a1, struct etr_aib *a2, int p)
676 {
677 	int state_a1, state_a2;
678 
679 	/* Paranoia check: e0/e1 should better be the same. */
680 	if (a1->esw.eacr.e0 != a2->esw.eacr.e0 ||
681 	    a1->esw.eacr.e1 != a2->esw.eacr.e1)
682 		return 0;
683 
684 	/* Still connected to the same etr ? */
685 	state_a1 = p ? a1->esw.psc1 : a1->esw.psc0;
686 	state_a2 = p ? a2->esw.psc1 : a2->esw.psc0;
687 	if (state_a1 == etr_lpsc_operational_step) {
688 		if (state_a2 != etr_lpsc_operational_step ||
689 		    a1->edf1.net_id != a2->edf1.net_id ||
690 		    a1->edf1.etr_id != a2->edf1.etr_id ||
691 		    a1->edf1.etr_pn != a2->edf1.etr_pn)
692 			return 0;
693 	} else if (state_a2 != etr_lpsc_pps_mode)
694 		return 0;
695 
696 	/* The ETV value of a2 needs to be ETV of a1 + 1. */
697 	if (a1->edf2.etv + 1 != a2->edf2.etv)
698 		return 0;
699 
700 	if (!etr_port_valid(a2, p))
701 		return 0;
702 
703 	return 1;
704 }
705 
706 /*
707  * The time is "clock". xtime is what we think the time is.
708  * Adjust the value by a multiple of jiffies and add the delta to ntp.
709  * "delay" is an approximation how long the synchronization took. If
710  * the time correction is positive, then "delay" is subtracted from
711  * the time difference and only the remaining part is passed to ntp.
712  */
713 static void etr_adjust_time(unsigned long long clock, unsigned long long delay)
714 {
715 	unsigned long long delta, ticks;
716 	struct timex adjust;
717 
718 	/*
719 	 * We don't have to take the xtime lock because the cpu
720 	 * executing etr_adjust_time is running disabled in
721 	 * tasklet context and all other cpus are looping in
722 	 * etr_sync_cpu_start.
723 	 */
724 	if (clock > xtime_cc) {
725 		/* It is later than we thought. */
726 		delta = ticks = clock - xtime_cc;
727 		delta = ticks = (delta < delay) ? 0 : delta - delay;
728 		delta -= do_div(ticks, CLK_TICKS_PER_JIFFY);
729 		init_timer_cc = init_timer_cc + delta;
730 		jiffies_timer_cc = jiffies_timer_cc + delta;
731 		xtime_cc = xtime_cc + delta;
732 		adjust.offset = ticks * (1000000 / HZ);
733 	} else {
734 		/* It is earlier than we thought. */
735 		delta = ticks = xtime_cc - clock;
736 		delta -= do_div(ticks, CLK_TICKS_PER_JIFFY);
737 		init_timer_cc = init_timer_cc - delta;
738 		jiffies_timer_cc = jiffies_timer_cc - delta;
739 		xtime_cc = xtime_cc - delta;
740 		adjust.offset = -ticks * (1000000 / HZ);
741 	}
742 	if (adjust.offset != 0) {
743 		printk(KERN_NOTICE "etr: time adjusted by %li micro-seconds\n",
744 		       adjust.offset);
745 		adjust.modes = ADJ_OFFSET_SINGLESHOT;
746 		do_adjtimex(&adjust);
747 	}
748 }
749 
750 #ifdef CONFIG_SMP
751 static void etr_sync_cpu_start(void *dummy)
752 {
753 	int *in_sync = dummy;
754 
755 	etr_enable_sync_clock();
756 	/*
757 	 * This looks like a busy wait loop but it isn't. etr_sync_cpus
758 	 * is called on all other cpus while the TOD clocks is stopped.
759 	 * __udelay will stop the cpu on an enabled wait psw until the
760 	 * TOD is running again.
761 	 */
762 	while (*in_sync == 0) {
763 		__udelay(1);
764 		/*
765 		 * A different cpu changes *in_sync. Therefore use
766 		 * barrier() to force memory access.
767 		 */
768 		barrier();
769 	}
770 	if (*in_sync != 1)
771 		/* Didn't work. Clear per-cpu in sync bit again. */
772 		etr_disable_sync_clock(NULL);
773 	/*
774 	 * This round of TOD syncing is done. Set the clock comparator
775 	 * to the next tick and let the processor continue.
776 	 */
777 	setup_jiffy_timer();
778 }
779 
780 static void etr_sync_cpu_end(void *dummy)
781 {
782 }
783 #endif /* CONFIG_SMP */
784 
785 /*
786  * Sync the TOD clock using the port refered to by aibp. This port
787  * has to be enabled and the other port has to be disabled. The
788  * last eacr update has to be more than 1.6 seconds in the past.
789  */
790 static int etr_sync_clock(struct etr_aib *aib, int port)
791 {
792 	struct etr_aib *sync_port;
793 	unsigned long long clock, delay;
794 	int in_sync, follows;
795 	int rc;
796 
797 	/* Check if the current aib is adjacent to the sync port aib. */
798 	sync_port = (port == 0) ? &etr_port0 : &etr_port1;
799 	follows = etr_aib_follows(sync_port, aib, port);
800 	memcpy(sync_port, aib, sizeof(*aib));
801 	if (!follows)
802 		return -EAGAIN;
803 
804 	/*
805 	 * Catch all other cpus and make them wait until we have
806 	 * successfully synced the clock. smp_call_function will
807 	 * return after all other cpus are in etr_sync_cpu_start.
808 	 */
809 	in_sync = 0;
810 	preempt_disable();
811 	smp_call_function(etr_sync_cpu_start,&in_sync,0,0);
812 	local_irq_disable();
813 	etr_enable_sync_clock();
814 
815 	/* Set clock to next OTE. */
816 	__ctl_set_bit(14, 21);
817 	__ctl_set_bit(0, 29);
818 	clock = ((unsigned long long) (aib->edf2.etv + 1)) << 32;
819 	if (set_clock(clock) == 0) {
820 		__udelay(1);	/* Wait for the clock to start. */
821 		__ctl_clear_bit(0, 29);
822 		__ctl_clear_bit(14, 21);
823 		etr_stetr(aib);
824 		/* Adjust Linux timing variables. */
825 		delay = (unsigned long long)
826 			(aib->edf2.etv - sync_port->edf2.etv) << 32;
827 		etr_adjust_time(clock, delay);
828 		setup_jiffy_timer();
829 		/* Verify that the clock is properly set. */
830 		if (!etr_aib_follows(sync_port, aib, port)) {
831 			/* Didn't work. */
832 			etr_disable_sync_clock(NULL);
833 			in_sync = -EAGAIN;
834 			rc = -EAGAIN;
835 		} else {
836 			in_sync = 1;
837 			rc = 0;
838 		}
839 	} else {
840 		/* Could not set the clock ?!? */
841 		__ctl_clear_bit(0, 29);
842 		__ctl_clear_bit(14, 21);
843 		etr_disable_sync_clock(NULL);
844 		in_sync = -EAGAIN;
845 		rc = -EAGAIN;
846 	}
847 	local_irq_enable();
848 	smp_call_function(etr_sync_cpu_end,NULL,0,0);
849 	preempt_enable();
850 	return rc;
851 }
852 
853 /*
854  * Handle the immediate effects of the different events.
855  * The port change event is used for online/offline changes.
856  */
857 static struct etr_eacr etr_handle_events(struct etr_eacr eacr)
858 {
859 	if (test_and_clear_bit(ETR_EVENT_SYNC_CHECK, &etr_events))
860 		eacr.es = 0;
861 	if (test_and_clear_bit(ETR_EVENT_SWITCH_LOCAL, &etr_events))
862 		eacr.es = eacr.sl = 0;
863 	if (test_and_clear_bit(ETR_EVENT_PORT_ALERT, &etr_events))
864 		etr_port0_uptodate = etr_port1_uptodate = 0;
865 
866 	if (test_and_clear_bit(ETR_EVENT_PORT0_CHANGE, &etr_events)) {
867 		if (eacr.e0)
868 			/*
869 			 * Port change of an enabled port. We have to
870 			 * assume that this can have caused an stepping
871 			 * port switch.
872 			 */
873 			etr_tolec = get_clock();
874 		eacr.p0 = etr_port0_online;
875 		if (!eacr.p0)
876 			eacr.e0 = 0;
877 		etr_port0_uptodate = 0;
878 	}
879 	if (test_and_clear_bit(ETR_EVENT_PORT1_CHANGE, &etr_events)) {
880 		if (eacr.e1)
881 			/*
882 			 * Port change of an enabled port. We have to
883 			 * assume that this can have caused an stepping
884 			 * port switch.
885 			 */
886 			etr_tolec = get_clock();
887 		eacr.p1 = etr_port1_online;
888 		if (!eacr.p1)
889 			eacr.e1 = 0;
890 		etr_port1_uptodate = 0;
891 	}
892 	clear_bit(ETR_EVENT_UPDATE, &etr_events);
893 	return eacr;
894 }
895 
896 /*
897  * Set up a timer that expires after the etr_tolec + 1.6 seconds if
898  * one of the ports needs an update.
899  */
900 static void etr_set_tolec_timeout(unsigned long long now)
901 {
902 	unsigned long micros;
903 
904 	if ((!etr_eacr.p0 || etr_port0_uptodate) &&
905 	    (!etr_eacr.p1 || etr_port1_uptodate))
906 		return;
907 	micros = (now > etr_tolec) ? ((now - etr_tolec) >> 12) : 0;
908 	micros = (micros > 1600000) ? 0 : 1600000 - micros;
909 	mod_timer(&etr_timer, jiffies + (micros * HZ) / 1000000 + 1);
910 }
911 
912 /*
913  * Set up a time that expires after 1/2 second.
914  */
915 static void etr_set_sync_timeout(void)
916 {
917 	mod_timer(&etr_timer, jiffies + HZ/2);
918 }
919 
920 /*
921  * Update the aib information for one or both ports.
922  */
923 static struct etr_eacr etr_handle_update(struct etr_aib *aib,
924 					 struct etr_eacr eacr)
925 {
926 	/* With both ports disabled the aib information is useless. */
927 	if (!eacr.e0 && !eacr.e1)
928 		return eacr;
929 
930 	/* Update port0 or port1 with aib stored in etr_tasklet_fn. */
931 	if (aib->esw.q == 0) {
932 		/* Information for port 0 stored. */
933 		if (eacr.p0 && !etr_port0_uptodate) {
934 			etr_port0 = *aib;
935 			if (etr_port0_online)
936 				etr_port0_uptodate = 1;
937 		}
938 	} else {
939 		/* Information for port 1 stored. */
940 		if (eacr.p1 && !etr_port1_uptodate) {
941 			etr_port1 = *aib;
942 			if (etr_port0_online)
943 				etr_port1_uptodate = 1;
944 		}
945 	}
946 
947 	/*
948 	 * Do not try to get the alternate port aib if the clock
949 	 * is not in sync yet.
950 	 */
951 	if (!eacr.es)
952 		return eacr;
953 
954 	/*
955 	 * If steai is available we can get the information about
956 	 * the other port immediately. If only stetr is available the
957 	 * data-port bit toggle has to be used.
958 	 */
959 	if (test_bit(ETR_FLAG_STEAI, &etr_flags)) {
960 		if (eacr.p0 && !etr_port0_uptodate) {
961 			etr_steai_cv(&etr_port0, ETR_STEAI_PORT_0);
962 			etr_port0_uptodate = 1;
963 		}
964 		if (eacr.p1 && !etr_port1_uptodate) {
965 			etr_steai_cv(&etr_port1, ETR_STEAI_PORT_1);
966 			etr_port1_uptodate = 1;
967 		}
968 	} else {
969 		/*
970 		 * One port was updated above, if the other
971 		 * port is not uptodate toggle dp bit.
972 		 */
973 		if ((eacr.p0 && !etr_port0_uptodate) ||
974 		    (eacr.p1 && !etr_port1_uptodate))
975 			eacr.dp ^= 1;
976 		else
977 			eacr.dp = 0;
978 	}
979 	return eacr;
980 }
981 
982 /*
983  * Write new etr control register if it differs from the current one.
984  * Return 1 if etr_tolec has been updated as well.
985  */
986 static void etr_update_eacr(struct etr_eacr eacr)
987 {
988 	int dp_changed;
989 
990 	if (memcmp(&etr_eacr, &eacr, sizeof(eacr)) == 0)
991 		/* No change, return. */
992 		return;
993 	/*
994 	 * The disable of an active port of the change of the data port
995 	 * bit can/will cause a change in the data port.
996 	 */
997 	dp_changed = etr_eacr.e0 > eacr.e0 || etr_eacr.e1 > eacr.e1 ||
998 		(etr_eacr.dp ^ eacr.dp) != 0;
999 	etr_eacr = eacr;
1000 	etr_setr(&etr_eacr);
1001 	if (dp_changed)
1002 		etr_tolec = get_clock();
1003 }
1004 
1005 /*
1006  * ETR tasklet. In this function you'll find the main logic. In
1007  * particular this is the only function that calls etr_update_eacr(),
1008  * it "controls" the etr control register.
1009  */
1010 static void etr_tasklet_fn(unsigned long dummy)
1011 {
1012 	unsigned long long now;
1013 	struct etr_eacr eacr;
1014 	struct etr_aib aib;
1015 	int sync_port;
1016 
1017 	/* Create working copy of etr_eacr. */
1018 	eacr = etr_eacr;
1019 
1020 	/* Check for the different events and their immediate effects. */
1021 	eacr = etr_handle_events(eacr);
1022 
1023 	/* Check if ETR is supposed to be active. */
1024 	eacr.ea = eacr.p0 || eacr.p1;
1025 	if (!eacr.ea) {
1026 		/* Both ports offline. Reset everything. */
1027 		eacr.dp = eacr.es = eacr.sl = 0;
1028 		on_each_cpu(etr_disable_sync_clock, NULL, 0, 1);
1029 		del_timer_sync(&etr_timer);
1030 		etr_update_eacr(eacr);
1031 		set_bit(ETR_FLAG_EACCES, &etr_flags);
1032 		return;
1033 	}
1034 
1035 	/* Store aib to get the current ETR status word. */
1036 	BUG_ON(etr_stetr(&aib) != 0);
1037 	etr_port0.esw = etr_port1.esw = aib.esw;	/* Copy status word. */
1038 	now = get_clock();
1039 
1040 	/*
1041 	 * Update the port information if the last stepping port change
1042 	 * or data port change is older than 1.6 seconds.
1043 	 */
1044 	if (now >= etr_tolec + (1600000 << 12))
1045 		eacr = etr_handle_update(&aib, eacr);
1046 
1047 	/*
1048 	 * Select ports to enable. The prefered synchronization mode is PPS.
1049 	 * If a port can be enabled depends on a number of things:
1050 	 * 1) The port needs to be online and uptodate. A port is not
1051 	 *    disabled just because it is not uptodate, but it is only
1052 	 *    enabled if it is uptodate.
1053 	 * 2) The port needs to have the same mode (pps / etr).
1054 	 * 3) The port needs to be usable -> etr_port_valid() == 1
1055 	 * 4) To enable the second port the clock needs to be in sync.
1056 	 * 5) If both ports are useable and are ETR ports, the network id
1057 	 *    has to be the same.
1058 	 * The eacr.sl bit is used to indicate etr mode vs. pps mode.
1059 	 */
1060 	if (eacr.p0 && aib.esw.psc0 == etr_lpsc_pps_mode) {
1061 		eacr.sl = 0;
1062 		eacr.e0 = 1;
1063 		if (!etr_mode_is_pps(etr_eacr))
1064 			eacr.es = 0;
1065 		if (!eacr.es || !eacr.p1 || aib.esw.psc1 != etr_lpsc_pps_mode)
1066 			eacr.e1 = 0;
1067 		// FIXME: uptodate checks ?
1068 		else if (etr_port0_uptodate && etr_port1_uptodate)
1069 			eacr.e1 = 1;
1070 		sync_port = (etr_port0_uptodate &&
1071 			     etr_port_valid(&etr_port0, 0)) ? 0 : -1;
1072 		clear_bit(ETR_FLAG_EACCES, &etr_flags);
1073 	} else if (eacr.p1 && aib.esw.psc1 == etr_lpsc_pps_mode) {
1074 		eacr.sl = 0;
1075 		eacr.e0 = 0;
1076 		eacr.e1 = 1;
1077 		if (!etr_mode_is_pps(etr_eacr))
1078 			eacr.es = 0;
1079 		sync_port = (etr_port1_uptodate &&
1080 			     etr_port_valid(&etr_port1, 1)) ? 1 : -1;
1081 		clear_bit(ETR_FLAG_EACCES, &etr_flags);
1082 	} else if (eacr.p0 && aib.esw.psc0 == etr_lpsc_operational_step) {
1083 		eacr.sl = 1;
1084 		eacr.e0 = 1;
1085 		if (!etr_mode_is_etr(etr_eacr))
1086 			eacr.es = 0;
1087 		if (!eacr.es || !eacr.p1 ||
1088 		    aib.esw.psc1 != etr_lpsc_operational_alt)
1089 			eacr.e1 = 0;
1090 		else if (etr_port0_uptodate && etr_port1_uptodate &&
1091 			 etr_compare_network(&etr_port0, &etr_port1))
1092 			eacr.e1 = 1;
1093 		sync_port = (etr_port0_uptodate &&
1094 			     etr_port_valid(&etr_port0, 0)) ? 0 : -1;
1095 		clear_bit(ETR_FLAG_EACCES, &etr_flags);
1096 	} else if (eacr.p1 && aib.esw.psc1 == etr_lpsc_operational_step) {
1097 		eacr.sl = 1;
1098 		eacr.e0 = 0;
1099 		eacr.e1 = 1;
1100 		if (!etr_mode_is_etr(etr_eacr))
1101 			eacr.es = 0;
1102 		sync_port = (etr_port1_uptodate &&
1103 			     etr_port_valid(&etr_port1, 1)) ? 1 : -1;
1104 		clear_bit(ETR_FLAG_EACCES, &etr_flags);
1105 	} else {
1106 		/* Both ports not usable. */
1107 		eacr.es = eacr.sl = 0;
1108 		sync_port = -1;
1109 		set_bit(ETR_FLAG_EACCES, &etr_flags);
1110 	}
1111 
1112 	/*
1113 	 * If the clock is in sync just update the eacr and return.
1114 	 * If there is no valid sync port wait for a port update.
1115 	 */
1116 	if (eacr.es || sync_port < 0) {
1117 		etr_update_eacr(eacr);
1118 		etr_set_tolec_timeout(now);
1119 		return;
1120 	}
1121 
1122 	/*
1123 	 * Prepare control register for clock syncing
1124 	 * (reset data port bit, set sync check control.
1125 	 */
1126 	eacr.dp = 0;
1127 	eacr.es = 1;
1128 
1129 	/*
1130 	 * Update eacr and try to synchronize the clock. If the update
1131 	 * of eacr caused a stepping port switch (or if we have to
1132 	 * assume that a stepping port switch has occured) or the
1133 	 * clock syncing failed, reset the sync check control bit
1134 	 * and set up a timer to try again after 0.5 seconds
1135 	 */
1136 	etr_update_eacr(eacr);
1137 	if (now < etr_tolec + (1600000 << 12) ||
1138 	    etr_sync_clock(&aib, sync_port) != 0) {
1139 		/* Sync failed. Try again in 1/2 second. */
1140 		eacr.es = 0;
1141 		etr_update_eacr(eacr);
1142 		etr_set_sync_timeout();
1143 	} else
1144 		etr_set_tolec_timeout(now);
1145 }
1146 
1147 /*
1148  * Sysfs interface functions
1149  */
1150 static struct sysdev_class etr_sysclass = {
1151 	set_kset_name("etr")
1152 };
1153 
1154 static struct sys_device etr_port0_dev = {
1155 	.id	= 0,
1156 	.cls	= &etr_sysclass,
1157 };
1158 
1159 static struct sys_device etr_port1_dev = {
1160 	.id	= 1,
1161 	.cls	= &etr_sysclass,
1162 };
1163 
1164 /*
1165  * ETR class attributes
1166  */
1167 static ssize_t etr_stepping_port_show(struct sysdev_class *class, char *buf)
1168 {
1169 	return sprintf(buf, "%i\n", etr_port0.esw.p);
1170 }
1171 
1172 static SYSDEV_CLASS_ATTR(stepping_port, 0400, etr_stepping_port_show, NULL);
1173 
1174 static ssize_t etr_stepping_mode_show(struct sysdev_class *class, char *buf)
1175 {
1176 	char *mode_str;
1177 
1178 	if (etr_mode_is_pps(etr_eacr))
1179 		mode_str = "pps";
1180 	else if (etr_mode_is_etr(etr_eacr))
1181 		mode_str = "etr";
1182 	else
1183 		mode_str = "local";
1184 	return sprintf(buf, "%s\n", mode_str);
1185 }
1186 
1187 static SYSDEV_CLASS_ATTR(stepping_mode, 0400, etr_stepping_mode_show, NULL);
1188 
1189 /*
1190  * ETR port attributes
1191  */
1192 static inline struct etr_aib *etr_aib_from_dev(struct sys_device *dev)
1193 {
1194 	if (dev == &etr_port0_dev)
1195 		return etr_port0_online ? &etr_port0 : NULL;
1196 	else
1197 		return etr_port1_online ? &etr_port1 : NULL;
1198 }
1199 
1200 static ssize_t etr_online_show(struct sys_device *dev, char *buf)
1201 {
1202 	unsigned int online;
1203 
1204 	online = (dev == &etr_port0_dev) ? etr_port0_online : etr_port1_online;
1205 	return sprintf(buf, "%i\n", online);
1206 }
1207 
1208 static ssize_t etr_online_store(struct sys_device *dev,
1209 			      const char *buf, size_t count)
1210 {
1211 	unsigned int value;
1212 
1213 	value = simple_strtoul(buf, NULL, 0);
1214 	if (value != 0 && value != 1)
1215 		return -EINVAL;
1216 	if (test_bit(ETR_FLAG_ENOSYS, &etr_flags))
1217 		return -ENOSYS;
1218 	if (dev == &etr_port0_dev) {
1219 		if (etr_port0_online == value)
1220 			return count;	/* Nothing to do. */
1221 		etr_port0_online = value;
1222 		set_bit(ETR_EVENT_PORT0_CHANGE, &etr_events);
1223 		tasklet_hi_schedule(&etr_tasklet);
1224 	} else {
1225 		if (etr_port1_online == value)
1226 			return count;	/* Nothing to do. */
1227 		etr_port1_online = value;
1228 		set_bit(ETR_EVENT_PORT1_CHANGE, &etr_events);
1229 		tasklet_hi_schedule(&etr_tasklet);
1230 	}
1231 	return count;
1232 }
1233 
1234 static SYSDEV_ATTR(online, 0600, etr_online_show, etr_online_store);
1235 
1236 static ssize_t etr_stepping_control_show(struct sys_device *dev, char *buf)
1237 {
1238 	return sprintf(buf, "%i\n", (dev == &etr_port0_dev) ?
1239 		       etr_eacr.e0 : etr_eacr.e1);
1240 }
1241 
1242 static SYSDEV_ATTR(stepping_control, 0400, etr_stepping_control_show, NULL);
1243 
1244 static ssize_t etr_mode_code_show(struct sys_device *dev, char *buf)
1245 {
1246 	if (!etr_port0_online && !etr_port1_online)
1247 		/* Status word is not uptodate if both ports are offline. */
1248 		return -ENODATA;
1249 	return sprintf(buf, "%i\n", (dev == &etr_port0_dev) ?
1250 		       etr_port0.esw.psc0 : etr_port0.esw.psc1);
1251 }
1252 
1253 static SYSDEV_ATTR(state_code, 0400, etr_mode_code_show, NULL);
1254 
1255 static ssize_t etr_untuned_show(struct sys_device *dev, char *buf)
1256 {
1257 	struct etr_aib *aib = etr_aib_from_dev(dev);
1258 
1259 	if (!aib || !aib->slsw.v1)
1260 		return -ENODATA;
1261 	return sprintf(buf, "%i\n", aib->edf1.u);
1262 }
1263 
1264 static SYSDEV_ATTR(untuned, 0400, etr_untuned_show, NULL);
1265 
1266 static ssize_t etr_network_id_show(struct sys_device *dev, char *buf)
1267 {
1268 	struct etr_aib *aib = etr_aib_from_dev(dev);
1269 
1270 	if (!aib || !aib->slsw.v1)
1271 		return -ENODATA;
1272 	return sprintf(buf, "%i\n", aib->edf1.net_id);
1273 }
1274 
1275 static SYSDEV_ATTR(network, 0400, etr_network_id_show, NULL);
1276 
1277 static ssize_t etr_id_show(struct sys_device *dev, char *buf)
1278 {
1279 	struct etr_aib *aib = etr_aib_from_dev(dev);
1280 
1281 	if (!aib || !aib->slsw.v1)
1282 		return -ENODATA;
1283 	return sprintf(buf, "%i\n", aib->edf1.etr_id);
1284 }
1285 
1286 static SYSDEV_ATTR(id, 0400, etr_id_show, NULL);
1287 
1288 static ssize_t etr_port_number_show(struct sys_device *dev, char *buf)
1289 {
1290 	struct etr_aib *aib = etr_aib_from_dev(dev);
1291 
1292 	if (!aib || !aib->slsw.v1)
1293 		return -ENODATA;
1294 	return sprintf(buf, "%i\n", aib->edf1.etr_pn);
1295 }
1296 
1297 static SYSDEV_ATTR(port, 0400, etr_port_number_show, NULL);
1298 
1299 static ssize_t etr_coupled_show(struct sys_device *dev, char *buf)
1300 {
1301 	struct etr_aib *aib = etr_aib_from_dev(dev);
1302 
1303 	if (!aib || !aib->slsw.v3)
1304 		return -ENODATA;
1305 	return sprintf(buf, "%i\n", aib->edf3.c);
1306 }
1307 
1308 static SYSDEV_ATTR(coupled, 0400, etr_coupled_show, NULL);
1309 
1310 static ssize_t etr_local_time_show(struct sys_device *dev, char *buf)
1311 {
1312 	struct etr_aib *aib = etr_aib_from_dev(dev);
1313 
1314 	if (!aib || !aib->slsw.v3)
1315 		return -ENODATA;
1316 	return sprintf(buf, "%i\n", aib->edf3.blto);
1317 }
1318 
1319 static SYSDEV_ATTR(local_time, 0400, etr_local_time_show, NULL);
1320 
1321 static ssize_t etr_utc_offset_show(struct sys_device *dev, char *buf)
1322 {
1323 	struct etr_aib *aib = etr_aib_from_dev(dev);
1324 
1325 	if (!aib || !aib->slsw.v3)
1326 		return -ENODATA;
1327 	return sprintf(buf, "%i\n", aib->edf3.buo);
1328 }
1329 
1330 static SYSDEV_ATTR(utc_offset, 0400, etr_utc_offset_show, NULL);
1331 
1332 static struct sysdev_attribute *etr_port_attributes[] = {
1333 	&attr_online,
1334 	&attr_stepping_control,
1335 	&attr_state_code,
1336 	&attr_untuned,
1337 	&attr_network,
1338 	&attr_id,
1339 	&attr_port,
1340 	&attr_coupled,
1341 	&attr_local_time,
1342 	&attr_utc_offset,
1343 	NULL
1344 };
1345 
1346 static int __init etr_register_port(struct sys_device *dev)
1347 {
1348 	struct sysdev_attribute **attr;
1349 	int rc;
1350 
1351 	rc = sysdev_register(dev);
1352 	if (rc)
1353 		goto out;
1354 	for (attr = etr_port_attributes; *attr; attr++) {
1355 		rc = sysdev_create_file(dev, *attr);
1356 		if (rc)
1357 			goto out_unreg;
1358 	}
1359 	return 0;
1360 out_unreg:
1361 	for (; attr >= etr_port_attributes; attr--)
1362 		sysdev_remove_file(dev, *attr);
1363 	sysdev_unregister(dev);
1364 out:
1365 	return rc;
1366 }
1367 
1368 static void __init etr_unregister_port(struct sys_device *dev)
1369 {
1370 	struct sysdev_attribute **attr;
1371 
1372 	for (attr = etr_port_attributes; *attr; attr++)
1373 		sysdev_remove_file(dev, *attr);
1374 	sysdev_unregister(dev);
1375 }
1376 
1377 static int __init etr_init_sysfs(void)
1378 {
1379 	int rc;
1380 
1381 	rc = sysdev_class_register(&etr_sysclass);
1382 	if (rc)
1383 		goto out;
1384 	rc = sysdev_class_create_file(&etr_sysclass, &attr_stepping_port);
1385 	if (rc)
1386 		goto out_unreg_class;
1387 	rc = sysdev_class_create_file(&etr_sysclass, &attr_stepping_mode);
1388 	if (rc)
1389 		goto out_remove_stepping_port;
1390 	rc = etr_register_port(&etr_port0_dev);
1391 	if (rc)
1392 		goto out_remove_stepping_mode;
1393 	rc = etr_register_port(&etr_port1_dev);
1394 	if (rc)
1395 		goto out_remove_port0;
1396 	return 0;
1397 
1398 out_remove_port0:
1399 	etr_unregister_port(&etr_port0_dev);
1400 out_remove_stepping_mode:
1401 	sysdev_class_remove_file(&etr_sysclass, &attr_stepping_mode);
1402 out_remove_stepping_port:
1403 	sysdev_class_remove_file(&etr_sysclass, &attr_stepping_port);
1404 out_unreg_class:
1405 	sysdev_class_unregister(&etr_sysclass);
1406 out:
1407 	return rc;
1408 }
1409 
1410 device_initcall(etr_init_sysfs);
1411