xref: /linux/arch/s390/kernel/time.c (revision a1e58bbdc969c3fe60addca7f2729779d22a83c1)
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/sysdev.h>
25 #include <linux/delay.h>
26 #include <linux/init.h>
27 #include <linux/smp.h>
28 #include <linux/types.h>
29 #include <linux/profile.h>
30 #include <linux/timex.h>
31 #include <linux/notifier.h>
32 #include <linux/clocksource.h>
33 
34 #include <asm/uaccess.h>
35 #include <asm/delay.h>
36 #include <asm/s390_ext.h>
37 #include <asm/div64.h>
38 #include <asm/irq.h>
39 #include <asm/irq_regs.h>
40 #include <asm/timer.h>
41 #include <asm/etr.h>
42 
43 /* change this if you have some constant time drift */
44 #define USECS_PER_JIFFY     ((unsigned long) 1000000/HZ)
45 #define CLK_TICKS_PER_JIFFY ((unsigned long) USECS_PER_JIFFY << 12)
46 
47 /* The value of the TOD clock for 1.1.1970. */
48 #define TOD_UNIX_EPOCH 0x7d91048bca000000ULL
49 
50 /*
51  * Create a small time difference between the timer interrupts
52  * on the different cpus to avoid lock contention.
53  */
54 #define CPU_DEVIATION       (smp_processor_id() << 12)
55 
56 #define TICK_SIZE tick
57 
58 static ext_int_info_t ext_int_info_cc;
59 static ext_int_info_t ext_int_etr_cc;
60 static u64 init_timer_cc;
61 static u64 jiffies_timer_cc;
62 static u64 xtime_cc;
63 
64 /*
65  * Scheduler clock - returns current time in nanosec units.
66  */
67 unsigned long long sched_clock(void)
68 {
69 	return ((get_clock() - jiffies_timer_cc) * 125) >> 9;
70 }
71 
72 /*
73  * Monotonic_clock - returns # of nanoseconds passed since time_init()
74  */
75 unsigned long long monotonic_clock(void)
76 {
77 	return sched_clock();
78 }
79 EXPORT_SYMBOL(monotonic_clock);
80 
81 void tod_to_timeval(__u64 todval, struct timespec *xtime)
82 {
83 	unsigned long long sec;
84 
85 	sec = todval >> 12;
86 	do_div(sec, 1000000);
87 	xtime->tv_sec = sec;
88 	todval -= (sec * 1000000) << 12;
89 	xtime->tv_nsec = ((todval * 1000) >> 12);
90 }
91 
92 #ifdef CONFIG_PROFILING
93 #define s390_do_profile()	profile_tick(CPU_PROFILING)
94 #else
95 #define s390_do_profile()	do { ; } while(0)
96 #endif /* CONFIG_PROFILING */
97 
98 /*
99  * Advance the per cpu tick counter up to the time given with the
100  * "time" argument. The per cpu update consists of accounting
101  * the virtual cpu time, calling update_process_times and calling
102  * the profiling hook. If xtime is before time it is advanced as well.
103  */
104 void account_ticks(u64 time)
105 {
106 	__u32 ticks;
107 	__u64 tmp;
108 
109 	/* Calculate how many ticks have passed. */
110 	if (time < S390_lowcore.jiffy_timer)
111 		return;
112 	tmp = time - S390_lowcore.jiffy_timer;
113 	if (tmp >= 2*CLK_TICKS_PER_JIFFY) {  /* more than two ticks ? */
114 		ticks = __div(tmp, CLK_TICKS_PER_JIFFY) + 1;
115 		S390_lowcore.jiffy_timer +=
116 			CLK_TICKS_PER_JIFFY * (__u64) ticks;
117 	} else if (tmp >= CLK_TICKS_PER_JIFFY) {
118 		ticks = 2;
119 		S390_lowcore.jiffy_timer += 2*CLK_TICKS_PER_JIFFY;
120 	} else {
121 		ticks = 1;
122 		S390_lowcore.jiffy_timer += CLK_TICKS_PER_JIFFY;
123 	}
124 
125 #ifdef CONFIG_SMP
126 	/*
127 	 * Do not rely on the boot cpu to do the calls to do_timer.
128 	 * Spread it over all cpus instead.
129 	 */
130 	write_seqlock(&xtime_lock);
131 	if (S390_lowcore.jiffy_timer > xtime_cc) {
132 		__u32 xticks;
133 		tmp = S390_lowcore.jiffy_timer - xtime_cc;
134 		if (tmp >= 2*CLK_TICKS_PER_JIFFY) {
135 			xticks = __div(tmp, CLK_TICKS_PER_JIFFY);
136 			xtime_cc += (__u64) xticks * CLK_TICKS_PER_JIFFY;
137 		} else {
138 			xticks = 1;
139 			xtime_cc += CLK_TICKS_PER_JIFFY;
140 		}
141 		do_timer(xticks);
142 	}
143 	write_sequnlock(&xtime_lock);
144 #else
145 	do_timer(ticks);
146 #endif
147 
148 	while (ticks--)
149 		update_process_times(user_mode(get_irq_regs()));
150 
151 	s390_do_profile();
152 }
153 
154 #ifdef CONFIG_NO_IDLE_HZ
155 
156 #ifdef CONFIG_NO_IDLE_HZ_INIT
157 int sysctl_hz_timer = 0;
158 #else
159 int sysctl_hz_timer = 1;
160 #endif
161 
162 /*
163  * Stop the HZ tick on the current CPU.
164  * Only cpu_idle may call this function.
165  */
166 static void stop_hz_timer(void)
167 {
168 	unsigned long flags;
169 	unsigned long seq, next;
170 	__u64 timer, todval;
171 	int cpu = smp_processor_id();
172 
173 	if (sysctl_hz_timer != 0)
174 		return;
175 
176 	cpu_set(cpu, nohz_cpu_mask);
177 
178 	/*
179 	 * Leave the clock comparator set up for the next timer
180 	 * tick if either rcu or a softirq is pending.
181 	 */
182 	if (rcu_needs_cpu(cpu) || local_softirq_pending()) {
183 		cpu_clear(cpu, nohz_cpu_mask);
184 		return;
185 	}
186 
187 	/*
188 	 * This cpu is going really idle. Set up the clock comparator
189 	 * for the next event.
190 	 */
191 	next = next_timer_interrupt();
192 	do {
193 		seq = read_seqbegin_irqsave(&xtime_lock, flags);
194 		timer = ((__u64) next) - ((__u64) jiffies) + jiffies_64;
195 	} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
196 	todval = -1ULL;
197 	/* Be careful about overflows. */
198 	if (timer < (-1ULL / CLK_TICKS_PER_JIFFY)) {
199 		timer = jiffies_timer_cc + timer * CLK_TICKS_PER_JIFFY;
200 		if (timer >= jiffies_timer_cc)
201 			todval = timer;
202 	}
203 	set_clock_comparator(todval);
204 }
205 
206 /*
207  * Start the HZ tick on the current CPU.
208  * Only cpu_idle may call this function.
209  */
210 static void start_hz_timer(void)
211 {
212 	if (!cpu_isset(smp_processor_id(), nohz_cpu_mask))
213 		return;
214 	account_ticks(get_clock());
215 	set_clock_comparator(S390_lowcore.jiffy_timer + CPU_DEVIATION);
216 	cpu_clear(smp_processor_id(), nohz_cpu_mask);
217 }
218 
219 static int nohz_idle_notify(struct notifier_block *self,
220 			    unsigned long action, void *hcpu)
221 {
222 	switch (action) {
223 	case S390_CPU_IDLE:
224 		stop_hz_timer();
225 		break;
226 	case S390_CPU_NOT_IDLE:
227 		start_hz_timer();
228 		break;
229 	}
230 	return NOTIFY_OK;
231 }
232 
233 static struct notifier_block nohz_idle_nb = {
234 	.notifier_call = nohz_idle_notify,
235 };
236 
237 static void __init nohz_init(void)
238 {
239 	if (register_idle_notifier(&nohz_idle_nb))
240 		panic("Couldn't register idle notifier");
241 }
242 
243 #endif
244 
245 /*
246  * Set up per cpu jiffy timer and set the clock comparator.
247  */
248 static void setup_jiffy_timer(void)
249 {
250 	/* Set up clock comparator to next jiffy. */
251 	S390_lowcore.jiffy_timer =
252 		jiffies_timer_cc + (jiffies_64 + 1) * CLK_TICKS_PER_JIFFY;
253 	set_clock_comparator(S390_lowcore.jiffy_timer + CPU_DEVIATION);
254 }
255 
256 /*
257  * Set up lowcore and control register of the current cpu to
258  * enable TOD clock and clock comparator interrupts.
259  */
260 void init_cpu_timer(void)
261 {
262 	setup_jiffy_timer();
263 
264 	/* Enable clock comparator timer interrupt. */
265 	__ctl_set_bit(0,11);
266 
267 	/* Always allow ETR external interrupts, even without an ETR. */
268 	__ctl_set_bit(0, 4);
269 }
270 
271 static void clock_comparator_interrupt(__u16 code)
272 {
273 	/* set clock comparator for next tick */
274 	set_clock_comparator(S390_lowcore.jiffy_timer + CPU_DEVIATION);
275 }
276 
277 static void etr_reset(void);
278 static void etr_ext_handler(__u16);
279 
280 /*
281  * Get the TOD clock running.
282  */
283 static u64 __init reset_tod_clock(void)
284 {
285 	u64 time;
286 
287 	etr_reset();
288 	if (store_clock(&time) == 0)
289 		return time;
290 	/* TOD clock not running. Set the clock to Unix Epoch. */
291 	if (set_clock(TOD_UNIX_EPOCH) != 0 || store_clock(&time) != 0)
292 		panic("TOD clock not operational.");
293 
294 	return TOD_UNIX_EPOCH;
295 }
296 
297 static cycle_t read_tod_clock(void)
298 {
299 	return get_clock();
300 }
301 
302 static struct clocksource clocksource_tod = {
303 	.name		= "tod",
304 	.rating		= 400,
305 	.read		= read_tod_clock,
306 	.mask		= -1ULL,
307 	.mult		= 1000,
308 	.shift		= 12,
309 	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
310 };
311 
312 
313 /*
314  * Initialize the TOD clock and the CPU timer of
315  * the boot cpu.
316  */
317 void __init time_init(void)
318 {
319 	init_timer_cc = reset_tod_clock();
320 	xtime_cc = init_timer_cc + CLK_TICKS_PER_JIFFY;
321 	jiffies_timer_cc = init_timer_cc - jiffies_64 * CLK_TICKS_PER_JIFFY;
322 
323 	/* set xtime */
324 	tod_to_timeval(init_timer_cc - TOD_UNIX_EPOCH, &xtime);
325         set_normalized_timespec(&wall_to_monotonic,
326                                 -xtime.tv_sec, -xtime.tv_nsec);
327 
328 	/* request the clock comparator external interrupt */
329 	if (register_early_external_interrupt(0x1004,
330 					      clock_comparator_interrupt,
331 					      &ext_int_info_cc) != 0)
332                 panic("Couldn't request external interrupt 0x1004");
333 
334 	if (clocksource_register(&clocksource_tod) != 0)
335 		panic("Could not register TOD clock source");
336 
337 	/* request the etr external interrupt */
338 	if (register_early_external_interrupt(0x1406, etr_ext_handler,
339 					      &ext_int_etr_cc) != 0)
340 		panic("Couldn't request external interrupt 0x1406");
341 
342 	/* Enable TOD clock interrupts on the boot cpu. */
343 	init_cpu_timer();
344 
345 #ifdef CONFIG_NO_IDLE_HZ
346 	nohz_init();
347 #endif
348 
349 #ifdef CONFIG_VIRT_TIMER
350 	vtime_init();
351 #endif
352 }
353 
354 /*
355  * External Time Reference (ETR) code.
356  */
357 static int etr_port0_online;
358 static int etr_port1_online;
359 
360 static int __init early_parse_etr(char *p)
361 {
362 	if (strncmp(p, "off", 3) == 0)
363 		etr_port0_online = etr_port1_online = 0;
364 	else if (strncmp(p, "port0", 5) == 0)
365 		etr_port0_online = 1;
366 	else if (strncmp(p, "port1", 5) == 0)
367 		etr_port1_online = 1;
368 	else if (strncmp(p, "on", 2) == 0)
369 		etr_port0_online = etr_port1_online = 1;
370 	return 0;
371 }
372 early_param("etr", early_parse_etr);
373 
374 enum etr_event {
375 	ETR_EVENT_PORT0_CHANGE,
376 	ETR_EVENT_PORT1_CHANGE,
377 	ETR_EVENT_PORT_ALERT,
378 	ETR_EVENT_SYNC_CHECK,
379 	ETR_EVENT_SWITCH_LOCAL,
380 	ETR_EVENT_UPDATE,
381 };
382 
383 enum etr_flags {
384 	ETR_FLAG_ENOSYS,
385 	ETR_FLAG_EACCES,
386 	ETR_FLAG_STEAI,
387 };
388 
389 /*
390  * Valid bit combinations of the eacr register are (x = don't care):
391  * e0 e1 dp p0 p1 ea es sl
392  *  0  0  x  0	0  0  0  0  initial, disabled state
393  *  0  0  x  0	1  1  0  0  port 1 online
394  *  0  0  x  1	0  1  0  0  port 0 online
395  *  0  0  x  1	1  1  0  0  both ports online
396  *  0  1  x  0	1  1  0  0  port 1 online and usable, ETR or PPS mode
397  *  0  1  x  0	1  1  0  1  port 1 online, usable and ETR mode
398  *  0  1  x  0	1  1  1  0  port 1 online, usable, PPS mode, in-sync
399  *  0  1  x  0	1  1  1  1  port 1 online, usable, ETR mode, in-sync
400  *  0  1  x  1	1  1  0  0  both ports online, port 1 usable
401  *  0  1  x  1	1  1  1  0  both ports online, port 1 usable, PPS mode, in-sync
402  *  0  1  x  1	1  1  1  1  both ports online, port 1 usable, ETR mode, in-sync
403  *  1  0  x  1	0  1  0  0  port 0 online and usable, ETR or PPS mode
404  *  1  0  x  1	0  1  0  1  port 0 online, usable and ETR mode
405  *  1  0  x  1	0  1  1  0  port 0 online, usable, PPS mode, in-sync
406  *  1  0  x  1	0  1  1  1  port 0 online, usable, ETR mode, in-sync
407  *  1  0  x  1	1  1  0  0  both ports online, port 0 usable
408  *  1  0  x  1	1  1  1  0  both ports online, port 0 usable, PPS mode, in-sync
409  *  1  0  x  1	1  1  1  1  both ports online, port 0 usable, ETR mode, in-sync
410  *  1  1  x  1	1  1  1  0  both ports online & usable, ETR, in-sync
411  *  1  1  x  1	1  1  1  1  both ports online & usable, ETR, in-sync
412  */
413 static struct etr_eacr etr_eacr;
414 static u64 etr_tolec;			/* time of last eacr update */
415 static unsigned long etr_flags;
416 static struct etr_aib etr_port0;
417 static int etr_port0_uptodate;
418 static struct etr_aib etr_port1;
419 static int etr_port1_uptodate;
420 static unsigned long etr_events;
421 static struct timer_list etr_timer;
422 static DEFINE_PER_CPU(atomic_t, etr_sync_word);
423 
424 static void etr_timeout(unsigned long dummy);
425 static void etr_work_fn(struct work_struct *work);
426 static DECLARE_WORK(etr_work, etr_work_fn);
427 
428 /*
429  * The etr get_clock function. It will write the current clock value
430  * to the clock pointer and return 0 if the clock is in sync with the
431  * external time source. If the clock mode is local it will return
432  * -ENOSYS and -EAGAIN if the clock is not in sync with the external
433  * reference. This function is what ETR is all about..
434  */
435 int get_sync_clock(unsigned long long *clock)
436 {
437 	atomic_t *sw_ptr;
438 	unsigned int sw0, sw1;
439 
440 	sw_ptr = &get_cpu_var(etr_sync_word);
441 	sw0 = atomic_read(sw_ptr);
442 	*clock = get_clock();
443 	sw1 = atomic_read(sw_ptr);
444 	put_cpu_var(etr_sync_sync);
445 	if (sw0 == sw1 && (sw0 & 0x80000000U))
446 		/* Success: time is in sync. */
447 		return 0;
448 	if (test_bit(ETR_FLAG_ENOSYS, &etr_flags))
449 		return -ENOSYS;
450 	if (test_bit(ETR_FLAG_EACCES, &etr_flags))
451 		return -EACCES;
452 	return -EAGAIN;
453 }
454 EXPORT_SYMBOL(get_sync_clock);
455 
456 /*
457  * Make get_sync_clock return -EAGAIN.
458  */
459 static void etr_disable_sync_clock(void *dummy)
460 {
461 	atomic_t *sw_ptr = &__get_cpu_var(etr_sync_word);
462 	/*
463 	 * Clear the in-sync bit 2^31. All get_sync_clock calls will
464 	 * fail until the sync bit is turned back on. In addition
465 	 * increase the "sequence" counter to avoid the race of an
466 	 * etr event and the complete recovery against get_sync_clock.
467 	 */
468 	atomic_clear_mask(0x80000000, sw_ptr);
469 	atomic_inc(sw_ptr);
470 }
471 
472 /*
473  * Make get_sync_clock return 0 again.
474  * Needs to be called from a context disabled for preemption.
475  */
476 static void etr_enable_sync_clock(void)
477 {
478 	atomic_t *sw_ptr = &__get_cpu_var(etr_sync_word);
479 	atomic_set_mask(0x80000000, sw_ptr);
480 }
481 
482 /*
483  * Reset ETR attachment.
484  */
485 static void etr_reset(void)
486 {
487 	etr_eacr =  (struct etr_eacr) {
488 		.e0 = 0, .e1 = 0, ._pad0 = 4, .dp = 0,
489 		.p0 = 0, .p1 = 0, ._pad1 = 0, .ea = 0,
490 		.es = 0, .sl = 0 };
491 	if (etr_setr(&etr_eacr) == 0)
492 		etr_tolec = get_clock();
493 	else {
494 		set_bit(ETR_FLAG_ENOSYS, &etr_flags);
495 		if (etr_port0_online || etr_port1_online) {
496 			printk(KERN_WARNING "Running on non ETR capable "
497 			       "machine, only local mode available.\n");
498 			etr_port0_online = etr_port1_online = 0;
499 		}
500 	}
501 }
502 
503 static int __init etr_init(void)
504 {
505 	struct etr_aib aib;
506 
507 	if (test_bit(ETR_FLAG_ENOSYS, &etr_flags))
508 		return 0;
509 	/* Check if this machine has the steai instruction. */
510 	if (etr_steai(&aib, ETR_STEAI_STEPPING_PORT) == 0)
511 		set_bit(ETR_FLAG_STEAI, &etr_flags);
512 	setup_timer(&etr_timer, etr_timeout, 0UL);
513 	if (!etr_port0_online && !etr_port1_online)
514 		set_bit(ETR_FLAG_EACCES, &etr_flags);
515 	if (etr_port0_online) {
516 		set_bit(ETR_EVENT_PORT0_CHANGE, &etr_events);
517 		schedule_work(&etr_work);
518 	}
519 	if (etr_port1_online) {
520 		set_bit(ETR_EVENT_PORT1_CHANGE, &etr_events);
521 		schedule_work(&etr_work);
522 	}
523 	return 0;
524 }
525 
526 arch_initcall(etr_init);
527 
528 /*
529  * Two sorts of ETR machine checks. The architecture reads:
530  * "When a machine-check niterruption occurs and if a switch-to-local or
531  *  ETR-sync-check interrupt request is pending but disabled, this pending
532  *  disabled interruption request is indicated and is cleared".
533  * Which means that we can get etr_switch_to_local events from the machine
534  * check handler although the interruption condition is disabled. Lovely..
535  */
536 
537 /*
538  * Switch to local machine check. This is called when the last usable
539  * ETR port goes inactive. After switch to local the clock is not in sync.
540  */
541 void etr_switch_to_local(void)
542 {
543 	if (!etr_eacr.sl)
544 		return;
545 	etr_disable_sync_clock(NULL);
546 	set_bit(ETR_EVENT_SWITCH_LOCAL, &etr_events);
547 	schedule_work(&etr_work);
548 }
549 
550 /*
551  * ETR sync check machine check. This is called when the ETR OTE and the
552  * local clock OTE are farther apart than the ETR sync check tolerance.
553  * After a ETR sync check the clock is not in sync. The machine check
554  * is broadcasted to all cpus at the same time.
555  */
556 void etr_sync_check(void)
557 {
558 	if (!etr_eacr.es)
559 		return;
560 	etr_disable_sync_clock(NULL);
561 	set_bit(ETR_EVENT_SYNC_CHECK, &etr_events);
562 	schedule_work(&etr_work);
563 }
564 
565 /*
566  * ETR external interrupt. There are two causes:
567  * 1) port state change, check the usability of the port
568  * 2) port alert, one of the ETR-data-validity bits (v1-v2 bits of the
569  *    sldr-status word) or ETR-data word 1 (edf1) or ETR-data word 3 (edf3)
570  *    or ETR-data word 4 (edf4) has changed.
571  */
572 static void etr_ext_handler(__u16 code)
573 {
574 	struct etr_interruption_parameter *intparm =
575 		(struct etr_interruption_parameter *) &S390_lowcore.ext_params;
576 
577 	if (intparm->pc0)
578 		/* ETR port 0 state change. */
579 		set_bit(ETR_EVENT_PORT0_CHANGE, &etr_events);
580 	if (intparm->pc1)
581 		/* ETR port 1 state change. */
582 		set_bit(ETR_EVENT_PORT1_CHANGE, &etr_events);
583 	if (intparm->eai)
584 		/*
585 		 * ETR port alert on either port 0, 1 or both.
586 		 * Both ports are not up-to-date now.
587 		 */
588 		set_bit(ETR_EVENT_PORT_ALERT, &etr_events);
589 	schedule_work(&etr_work);
590 }
591 
592 static void etr_timeout(unsigned long dummy)
593 {
594 	set_bit(ETR_EVENT_UPDATE, &etr_events);
595 	schedule_work(&etr_work);
596 }
597 
598 /*
599  * Check if the etr mode is pss.
600  */
601 static inline int etr_mode_is_pps(struct etr_eacr eacr)
602 {
603 	return eacr.es && !eacr.sl;
604 }
605 
606 /*
607  * Check if the etr mode is etr.
608  */
609 static inline int etr_mode_is_etr(struct etr_eacr eacr)
610 {
611 	return eacr.es && eacr.sl;
612 }
613 
614 /*
615  * Check if the port can be used for TOD synchronization.
616  * For PPS mode the port has to receive OTEs. For ETR mode
617  * the port has to receive OTEs, the ETR stepping bit has to
618  * be zero and the validity bits for data frame 1, 2, and 3
619  * have to be 1.
620  */
621 static int etr_port_valid(struct etr_aib *aib, int port)
622 {
623 	unsigned int psc;
624 
625 	/* Check that this port is receiving OTEs. */
626 	if (aib->tsp == 0)
627 		return 0;
628 
629 	psc = port ? aib->esw.psc1 : aib->esw.psc0;
630 	if (psc == etr_lpsc_pps_mode)
631 		return 1;
632 	if (psc == etr_lpsc_operational_step)
633 		return !aib->esw.y && aib->slsw.v1 &&
634 			aib->slsw.v2 && aib->slsw.v3;
635 	return 0;
636 }
637 
638 /*
639  * Check if two ports are on the same network.
640  */
641 static int etr_compare_network(struct etr_aib *aib1, struct etr_aib *aib2)
642 {
643 	// FIXME: any other fields we have to compare?
644 	return aib1->edf1.net_id == aib2->edf1.net_id;
645 }
646 
647 /*
648  * Wrapper for etr_stei that converts physical port states
649  * to logical port states to be consistent with the output
650  * of stetr (see etr_psc vs. etr_lpsc).
651  */
652 static void etr_steai_cv(struct etr_aib *aib, unsigned int func)
653 {
654 	BUG_ON(etr_steai(aib, func) != 0);
655 	/* Convert port state to logical port state. */
656 	if (aib->esw.psc0 == 1)
657 		aib->esw.psc0 = 2;
658 	else if (aib->esw.psc0 == 0 && aib->esw.p == 0)
659 		aib->esw.psc0 = 1;
660 	if (aib->esw.psc1 == 1)
661 		aib->esw.psc1 = 2;
662 	else if (aib->esw.psc1 == 0 && aib->esw.p == 1)
663 		aib->esw.psc1 = 1;
664 }
665 
666 /*
667  * Check if the aib a2 is still connected to the same attachment as
668  * aib a1, the etv values differ by one and a2 is valid.
669  */
670 static int etr_aib_follows(struct etr_aib *a1, struct etr_aib *a2, int p)
671 {
672 	int state_a1, state_a2;
673 
674 	/* Paranoia check: e0/e1 should better be the same. */
675 	if (a1->esw.eacr.e0 != a2->esw.eacr.e0 ||
676 	    a1->esw.eacr.e1 != a2->esw.eacr.e1)
677 		return 0;
678 
679 	/* Still connected to the same etr ? */
680 	state_a1 = p ? a1->esw.psc1 : a1->esw.psc0;
681 	state_a2 = p ? a2->esw.psc1 : a2->esw.psc0;
682 	if (state_a1 == etr_lpsc_operational_step) {
683 		if (state_a2 != etr_lpsc_operational_step ||
684 		    a1->edf1.net_id != a2->edf1.net_id ||
685 		    a1->edf1.etr_id != a2->edf1.etr_id ||
686 		    a1->edf1.etr_pn != a2->edf1.etr_pn)
687 			return 0;
688 	} else if (state_a2 != etr_lpsc_pps_mode)
689 		return 0;
690 
691 	/* The ETV value of a2 needs to be ETV of a1 + 1. */
692 	if (a1->edf2.etv + 1 != a2->edf2.etv)
693 		return 0;
694 
695 	if (!etr_port_valid(a2, p))
696 		return 0;
697 
698 	return 1;
699 }
700 
701 /*
702  * The time is "clock". xtime is what we think the time is.
703  * Adjust the value by a multiple of jiffies and add the delta to ntp.
704  * "delay" is an approximation how long the synchronization took. If
705  * the time correction is positive, then "delay" is subtracted from
706  * the time difference and only the remaining part is passed to ntp.
707  */
708 static void etr_adjust_time(unsigned long long clock, unsigned long long delay)
709 {
710 	unsigned long long delta, ticks;
711 	struct timex adjust;
712 
713 	/*
714 	 * We don't have to take the xtime lock because the cpu
715 	 * executing etr_adjust_time is running disabled in
716 	 * tasklet context and all other cpus are looping in
717 	 * etr_sync_cpu_start.
718 	 */
719 	if (clock > xtime_cc) {
720 		/* It is later than we thought. */
721 		delta = ticks = clock - xtime_cc;
722 		delta = ticks = (delta < delay) ? 0 : delta - delay;
723 		delta -= do_div(ticks, CLK_TICKS_PER_JIFFY);
724 		init_timer_cc = init_timer_cc + delta;
725 		jiffies_timer_cc = jiffies_timer_cc + delta;
726 		xtime_cc = xtime_cc + delta;
727 		adjust.offset = ticks * (1000000 / HZ);
728 	} else {
729 		/* It is earlier than we thought. */
730 		delta = ticks = xtime_cc - clock;
731 		delta -= do_div(ticks, CLK_TICKS_PER_JIFFY);
732 		init_timer_cc = init_timer_cc - delta;
733 		jiffies_timer_cc = jiffies_timer_cc - delta;
734 		xtime_cc = xtime_cc - delta;
735 		adjust.offset = -ticks * (1000000 / HZ);
736 	}
737 	if (adjust.offset != 0) {
738 		printk(KERN_NOTICE "etr: time adjusted by %li micro-seconds\n",
739 		       adjust.offset);
740 		adjust.modes = ADJ_OFFSET_SINGLESHOT;
741 		do_adjtimex(&adjust);
742 	}
743 }
744 
745 static void etr_sync_cpu_start(void *dummy)
746 {
747 	int *in_sync = dummy;
748 
749 	etr_enable_sync_clock();
750 	/*
751 	 * This looks like a busy wait loop but it isn't. etr_sync_cpus
752 	 * is called on all other cpus while the TOD clocks is stopped.
753 	 * __udelay will stop the cpu on an enabled wait psw until the
754 	 * TOD is running again.
755 	 */
756 	while (*in_sync == 0) {
757 		__udelay(1);
758 		/*
759 		 * A different cpu changes *in_sync. Therefore use
760 		 * barrier() to force memory access.
761 		 */
762 		barrier();
763 	}
764 	if (*in_sync != 1)
765 		/* Didn't work. Clear per-cpu in sync bit again. */
766 		etr_disable_sync_clock(NULL);
767 	/*
768 	 * This round of TOD syncing is done. Set the clock comparator
769 	 * to the next tick and let the processor continue.
770 	 */
771 	setup_jiffy_timer();
772 }
773 
774 static void etr_sync_cpu_end(void *dummy)
775 {
776 }
777 
778 /*
779  * Sync the TOD clock using the port refered to by aibp. This port
780  * has to be enabled and the other port has to be disabled. The
781  * last eacr update has to be more than 1.6 seconds in the past.
782  */
783 static int etr_sync_clock(struct etr_aib *aib, int port)
784 {
785 	struct etr_aib *sync_port;
786 	unsigned long long clock, delay;
787 	int in_sync, follows;
788 	int rc;
789 
790 	/* Check if the current aib is adjacent to the sync port aib. */
791 	sync_port = (port == 0) ? &etr_port0 : &etr_port1;
792 	follows = etr_aib_follows(sync_port, aib, port);
793 	memcpy(sync_port, aib, sizeof(*aib));
794 	if (!follows)
795 		return -EAGAIN;
796 
797 	/*
798 	 * Catch all other cpus and make them wait until we have
799 	 * successfully synced the clock. smp_call_function will
800 	 * return after all other cpus are in etr_sync_cpu_start.
801 	 */
802 	in_sync = 0;
803 	preempt_disable();
804 	smp_call_function(etr_sync_cpu_start,&in_sync,0,0);
805 	local_irq_disable();
806 	etr_enable_sync_clock();
807 
808 	/* Set clock to next OTE. */
809 	__ctl_set_bit(14, 21);
810 	__ctl_set_bit(0, 29);
811 	clock = ((unsigned long long) (aib->edf2.etv + 1)) << 32;
812 	if (set_clock(clock) == 0) {
813 		__udelay(1);	/* Wait for the clock to start. */
814 		__ctl_clear_bit(0, 29);
815 		__ctl_clear_bit(14, 21);
816 		etr_stetr(aib);
817 		/* Adjust Linux timing variables. */
818 		delay = (unsigned long long)
819 			(aib->edf2.etv - sync_port->edf2.etv) << 32;
820 		etr_adjust_time(clock, delay);
821 		setup_jiffy_timer();
822 		/* Verify that the clock is properly set. */
823 		if (!etr_aib_follows(sync_port, aib, port)) {
824 			/* Didn't work. */
825 			etr_disable_sync_clock(NULL);
826 			in_sync = -EAGAIN;
827 			rc = -EAGAIN;
828 		} else {
829 			in_sync = 1;
830 			rc = 0;
831 		}
832 	} else {
833 		/* Could not set the clock ?!? */
834 		__ctl_clear_bit(0, 29);
835 		__ctl_clear_bit(14, 21);
836 		etr_disable_sync_clock(NULL);
837 		in_sync = -EAGAIN;
838 		rc = -EAGAIN;
839 	}
840 	local_irq_enable();
841 	smp_call_function(etr_sync_cpu_end,NULL,0,0);
842 	preempt_enable();
843 	return rc;
844 }
845 
846 /*
847  * Handle the immediate effects of the different events.
848  * The port change event is used for online/offline changes.
849  */
850 static struct etr_eacr etr_handle_events(struct etr_eacr eacr)
851 {
852 	if (test_and_clear_bit(ETR_EVENT_SYNC_CHECK, &etr_events))
853 		eacr.es = 0;
854 	if (test_and_clear_bit(ETR_EVENT_SWITCH_LOCAL, &etr_events))
855 		eacr.es = eacr.sl = 0;
856 	if (test_and_clear_bit(ETR_EVENT_PORT_ALERT, &etr_events))
857 		etr_port0_uptodate = etr_port1_uptodate = 0;
858 
859 	if (test_and_clear_bit(ETR_EVENT_PORT0_CHANGE, &etr_events)) {
860 		if (eacr.e0)
861 			/*
862 			 * Port change of an enabled port. We have to
863 			 * assume that this can have caused an stepping
864 			 * port switch.
865 			 */
866 			etr_tolec = get_clock();
867 		eacr.p0 = etr_port0_online;
868 		if (!eacr.p0)
869 			eacr.e0 = 0;
870 		etr_port0_uptodate = 0;
871 	}
872 	if (test_and_clear_bit(ETR_EVENT_PORT1_CHANGE, &etr_events)) {
873 		if (eacr.e1)
874 			/*
875 			 * Port change of an enabled port. We have to
876 			 * assume that this can have caused an stepping
877 			 * port switch.
878 			 */
879 			etr_tolec = get_clock();
880 		eacr.p1 = etr_port1_online;
881 		if (!eacr.p1)
882 			eacr.e1 = 0;
883 		etr_port1_uptodate = 0;
884 	}
885 	clear_bit(ETR_EVENT_UPDATE, &etr_events);
886 	return eacr;
887 }
888 
889 /*
890  * Set up a timer that expires after the etr_tolec + 1.6 seconds if
891  * one of the ports needs an update.
892  */
893 static void etr_set_tolec_timeout(unsigned long long now)
894 {
895 	unsigned long micros;
896 
897 	if ((!etr_eacr.p0 || etr_port0_uptodate) &&
898 	    (!etr_eacr.p1 || etr_port1_uptodate))
899 		return;
900 	micros = (now > etr_tolec) ? ((now - etr_tolec) >> 12) : 0;
901 	micros = (micros > 1600000) ? 0 : 1600000 - micros;
902 	mod_timer(&etr_timer, jiffies + (micros * HZ) / 1000000 + 1);
903 }
904 
905 /*
906  * Set up a time that expires after 1/2 second.
907  */
908 static void etr_set_sync_timeout(void)
909 {
910 	mod_timer(&etr_timer, jiffies + HZ/2);
911 }
912 
913 /*
914  * Update the aib information for one or both ports.
915  */
916 static struct etr_eacr etr_handle_update(struct etr_aib *aib,
917 					 struct etr_eacr eacr)
918 {
919 	/* With both ports disabled the aib information is useless. */
920 	if (!eacr.e0 && !eacr.e1)
921 		return eacr;
922 
923 	/* Update port0 or port1 with aib stored in etr_work_fn. */
924 	if (aib->esw.q == 0) {
925 		/* Information for port 0 stored. */
926 		if (eacr.p0 && !etr_port0_uptodate) {
927 			etr_port0 = *aib;
928 			if (etr_port0_online)
929 				etr_port0_uptodate = 1;
930 		}
931 	} else {
932 		/* Information for port 1 stored. */
933 		if (eacr.p1 && !etr_port1_uptodate) {
934 			etr_port1 = *aib;
935 			if (etr_port0_online)
936 				etr_port1_uptodate = 1;
937 		}
938 	}
939 
940 	/*
941 	 * Do not try to get the alternate port aib if the clock
942 	 * is not in sync yet.
943 	 */
944 	if (!eacr.es)
945 		return eacr;
946 
947 	/*
948 	 * If steai is available we can get the information about
949 	 * the other port immediately. If only stetr is available the
950 	 * data-port bit toggle has to be used.
951 	 */
952 	if (test_bit(ETR_FLAG_STEAI, &etr_flags)) {
953 		if (eacr.p0 && !etr_port0_uptodate) {
954 			etr_steai_cv(&etr_port0, ETR_STEAI_PORT_0);
955 			etr_port0_uptodate = 1;
956 		}
957 		if (eacr.p1 && !etr_port1_uptodate) {
958 			etr_steai_cv(&etr_port1, ETR_STEAI_PORT_1);
959 			etr_port1_uptodate = 1;
960 		}
961 	} else {
962 		/*
963 		 * One port was updated above, if the other
964 		 * port is not uptodate toggle dp bit.
965 		 */
966 		if ((eacr.p0 && !etr_port0_uptodate) ||
967 		    (eacr.p1 && !etr_port1_uptodate))
968 			eacr.dp ^= 1;
969 		else
970 			eacr.dp = 0;
971 	}
972 	return eacr;
973 }
974 
975 /*
976  * Write new etr control register if it differs from the current one.
977  * Return 1 if etr_tolec has been updated as well.
978  */
979 static void etr_update_eacr(struct etr_eacr eacr)
980 {
981 	int dp_changed;
982 
983 	if (memcmp(&etr_eacr, &eacr, sizeof(eacr)) == 0)
984 		/* No change, return. */
985 		return;
986 	/*
987 	 * The disable of an active port of the change of the data port
988 	 * bit can/will cause a change in the data port.
989 	 */
990 	dp_changed = etr_eacr.e0 > eacr.e0 || etr_eacr.e1 > eacr.e1 ||
991 		(etr_eacr.dp ^ eacr.dp) != 0;
992 	etr_eacr = eacr;
993 	etr_setr(&etr_eacr);
994 	if (dp_changed)
995 		etr_tolec = get_clock();
996 }
997 
998 /*
999  * ETR tasklet. In this function you'll find the main logic. In
1000  * particular this is the only function that calls etr_update_eacr(),
1001  * it "controls" the etr control register.
1002  */
1003 static void etr_work_fn(struct work_struct *work)
1004 {
1005 	unsigned long long now;
1006 	struct etr_eacr eacr;
1007 	struct etr_aib aib;
1008 	int sync_port;
1009 
1010 	/* Create working copy of etr_eacr. */
1011 	eacr = etr_eacr;
1012 
1013 	/* Check for the different events and their immediate effects. */
1014 	eacr = etr_handle_events(eacr);
1015 
1016 	/* Check if ETR is supposed to be active. */
1017 	eacr.ea = eacr.p0 || eacr.p1;
1018 	if (!eacr.ea) {
1019 		/* Both ports offline. Reset everything. */
1020 		eacr.dp = eacr.es = eacr.sl = 0;
1021 		on_each_cpu(etr_disable_sync_clock, NULL, 0, 1);
1022 		del_timer_sync(&etr_timer);
1023 		etr_update_eacr(eacr);
1024 		set_bit(ETR_FLAG_EACCES, &etr_flags);
1025 		return;
1026 	}
1027 
1028 	/* Store aib to get the current ETR status word. */
1029 	BUG_ON(etr_stetr(&aib) != 0);
1030 	etr_port0.esw = etr_port1.esw = aib.esw;	/* Copy status word. */
1031 	now = get_clock();
1032 
1033 	/*
1034 	 * Update the port information if the last stepping port change
1035 	 * or data port change is older than 1.6 seconds.
1036 	 */
1037 	if (now >= etr_tolec + (1600000 << 12))
1038 		eacr = etr_handle_update(&aib, eacr);
1039 
1040 	/*
1041 	 * Select ports to enable. The prefered synchronization mode is PPS.
1042 	 * If a port can be enabled depends on a number of things:
1043 	 * 1) The port needs to be online and uptodate. A port is not
1044 	 *    disabled just because it is not uptodate, but it is only
1045 	 *    enabled if it is uptodate.
1046 	 * 2) The port needs to have the same mode (pps / etr).
1047 	 * 3) The port needs to be usable -> etr_port_valid() == 1
1048 	 * 4) To enable the second port the clock needs to be in sync.
1049 	 * 5) If both ports are useable and are ETR ports, the network id
1050 	 *    has to be the same.
1051 	 * The eacr.sl bit is used to indicate etr mode vs. pps mode.
1052 	 */
1053 	if (eacr.p0 && aib.esw.psc0 == etr_lpsc_pps_mode) {
1054 		eacr.sl = 0;
1055 		eacr.e0 = 1;
1056 		if (!etr_mode_is_pps(etr_eacr))
1057 			eacr.es = 0;
1058 		if (!eacr.es || !eacr.p1 || aib.esw.psc1 != etr_lpsc_pps_mode)
1059 			eacr.e1 = 0;
1060 		// FIXME: uptodate checks ?
1061 		else if (etr_port0_uptodate && etr_port1_uptodate)
1062 			eacr.e1 = 1;
1063 		sync_port = (etr_port0_uptodate &&
1064 			     etr_port_valid(&etr_port0, 0)) ? 0 : -1;
1065 		clear_bit(ETR_FLAG_EACCES, &etr_flags);
1066 	} else if (eacr.p1 && aib.esw.psc1 == etr_lpsc_pps_mode) {
1067 		eacr.sl = 0;
1068 		eacr.e0 = 0;
1069 		eacr.e1 = 1;
1070 		if (!etr_mode_is_pps(etr_eacr))
1071 			eacr.es = 0;
1072 		sync_port = (etr_port1_uptodate &&
1073 			     etr_port_valid(&etr_port1, 1)) ? 1 : -1;
1074 		clear_bit(ETR_FLAG_EACCES, &etr_flags);
1075 	} else if (eacr.p0 && aib.esw.psc0 == etr_lpsc_operational_step) {
1076 		eacr.sl = 1;
1077 		eacr.e0 = 1;
1078 		if (!etr_mode_is_etr(etr_eacr))
1079 			eacr.es = 0;
1080 		if (!eacr.es || !eacr.p1 ||
1081 		    aib.esw.psc1 != etr_lpsc_operational_alt)
1082 			eacr.e1 = 0;
1083 		else if (etr_port0_uptodate && etr_port1_uptodate &&
1084 			 etr_compare_network(&etr_port0, &etr_port1))
1085 			eacr.e1 = 1;
1086 		sync_port = (etr_port0_uptodate &&
1087 			     etr_port_valid(&etr_port0, 0)) ? 0 : -1;
1088 		clear_bit(ETR_FLAG_EACCES, &etr_flags);
1089 	} else if (eacr.p1 && aib.esw.psc1 == etr_lpsc_operational_step) {
1090 		eacr.sl = 1;
1091 		eacr.e0 = 0;
1092 		eacr.e1 = 1;
1093 		if (!etr_mode_is_etr(etr_eacr))
1094 			eacr.es = 0;
1095 		sync_port = (etr_port1_uptodate &&
1096 			     etr_port_valid(&etr_port1, 1)) ? 1 : -1;
1097 		clear_bit(ETR_FLAG_EACCES, &etr_flags);
1098 	} else {
1099 		/* Both ports not usable. */
1100 		eacr.es = eacr.sl = 0;
1101 		sync_port = -1;
1102 		set_bit(ETR_FLAG_EACCES, &etr_flags);
1103 	}
1104 
1105 	/*
1106 	 * If the clock is in sync just update the eacr and return.
1107 	 * If there is no valid sync port wait for a port update.
1108 	 */
1109 	if (eacr.es || sync_port < 0) {
1110 		etr_update_eacr(eacr);
1111 		etr_set_tolec_timeout(now);
1112 		return;
1113 	}
1114 
1115 	/*
1116 	 * Prepare control register for clock syncing
1117 	 * (reset data port bit, set sync check control.
1118 	 */
1119 	eacr.dp = 0;
1120 	eacr.es = 1;
1121 
1122 	/*
1123 	 * Update eacr and try to synchronize the clock. If the update
1124 	 * of eacr caused a stepping port switch (or if we have to
1125 	 * assume that a stepping port switch has occured) or the
1126 	 * clock syncing failed, reset the sync check control bit
1127 	 * and set up a timer to try again after 0.5 seconds
1128 	 */
1129 	etr_update_eacr(eacr);
1130 	if (now < etr_tolec + (1600000 << 12) ||
1131 	    etr_sync_clock(&aib, sync_port) != 0) {
1132 		/* Sync failed. Try again in 1/2 second. */
1133 		eacr.es = 0;
1134 		etr_update_eacr(eacr);
1135 		etr_set_sync_timeout();
1136 	} else
1137 		etr_set_tolec_timeout(now);
1138 }
1139 
1140 /*
1141  * Sysfs interface functions
1142  */
1143 static struct sysdev_class etr_sysclass = {
1144 	.name	= "etr",
1145 };
1146 
1147 static struct sys_device etr_port0_dev = {
1148 	.id	= 0,
1149 	.cls	= &etr_sysclass,
1150 };
1151 
1152 static struct sys_device etr_port1_dev = {
1153 	.id	= 1,
1154 	.cls	= &etr_sysclass,
1155 };
1156 
1157 /*
1158  * ETR class attributes
1159  */
1160 static ssize_t etr_stepping_port_show(struct sysdev_class *class, char *buf)
1161 {
1162 	return sprintf(buf, "%i\n", etr_port0.esw.p);
1163 }
1164 
1165 static SYSDEV_CLASS_ATTR(stepping_port, 0400, etr_stepping_port_show, NULL);
1166 
1167 static ssize_t etr_stepping_mode_show(struct sysdev_class *class, char *buf)
1168 {
1169 	char *mode_str;
1170 
1171 	if (etr_mode_is_pps(etr_eacr))
1172 		mode_str = "pps";
1173 	else if (etr_mode_is_etr(etr_eacr))
1174 		mode_str = "etr";
1175 	else
1176 		mode_str = "local";
1177 	return sprintf(buf, "%s\n", mode_str);
1178 }
1179 
1180 static SYSDEV_CLASS_ATTR(stepping_mode, 0400, etr_stepping_mode_show, NULL);
1181 
1182 /*
1183  * ETR port attributes
1184  */
1185 static inline struct etr_aib *etr_aib_from_dev(struct sys_device *dev)
1186 {
1187 	if (dev == &etr_port0_dev)
1188 		return etr_port0_online ? &etr_port0 : NULL;
1189 	else
1190 		return etr_port1_online ? &etr_port1 : NULL;
1191 }
1192 
1193 static ssize_t etr_online_show(struct sys_device *dev, char *buf)
1194 {
1195 	unsigned int online;
1196 
1197 	online = (dev == &etr_port0_dev) ? etr_port0_online : etr_port1_online;
1198 	return sprintf(buf, "%i\n", online);
1199 }
1200 
1201 static ssize_t etr_online_store(struct sys_device *dev,
1202 			      const char *buf, size_t count)
1203 {
1204 	unsigned int value;
1205 
1206 	value = simple_strtoul(buf, NULL, 0);
1207 	if (value != 0 && value != 1)
1208 		return -EINVAL;
1209 	if (test_bit(ETR_FLAG_ENOSYS, &etr_flags))
1210 		return -ENOSYS;
1211 	if (dev == &etr_port0_dev) {
1212 		if (etr_port0_online == value)
1213 			return count;	/* Nothing to do. */
1214 		etr_port0_online = value;
1215 		set_bit(ETR_EVENT_PORT0_CHANGE, &etr_events);
1216 		schedule_work(&etr_work);
1217 	} else {
1218 		if (etr_port1_online == value)
1219 			return count;	/* Nothing to do. */
1220 		etr_port1_online = value;
1221 		set_bit(ETR_EVENT_PORT1_CHANGE, &etr_events);
1222 		schedule_work(&etr_work);
1223 	}
1224 	return count;
1225 }
1226 
1227 static SYSDEV_ATTR(online, 0600, etr_online_show, etr_online_store);
1228 
1229 static ssize_t etr_stepping_control_show(struct sys_device *dev, char *buf)
1230 {
1231 	return sprintf(buf, "%i\n", (dev == &etr_port0_dev) ?
1232 		       etr_eacr.e0 : etr_eacr.e1);
1233 }
1234 
1235 static SYSDEV_ATTR(stepping_control, 0400, etr_stepping_control_show, NULL);
1236 
1237 static ssize_t etr_mode_code_show(struct sys_device *dev, char *buf)
1238 {
1239 	if (!etr_port0_online && !etr_port1_online)
1240 		/* Status word is not uptodate if both ports are offline. */
1241 		return -ENODATA;
1242 	return sprintf(buf, "%i\n", (dev == &etr_port0_dev) ?
1243 		       etr_port0.esw.psc0 : etr_port0.esw.psc1);
1244 }
1245 
1246 static SYSDEV_ATTR(state_code, 0400, etr_mode_code_show, NULL);
1247 
1248 static ssize_t etr_untuned_show(struct sys_device *dev, char *buf)
1249 {
1250 	struct etr_aib *aib = etr_aib_from_dev(dev);
1251 
1252 	if (!aib || !aib->slsw.v1)
1253 		return -ENODATA;
1254 	return sprintf(buf, "%i\n", aib->edf1.u);
1255 }
1256 
1257 static SYSDEV_ATTR(untuned, 0400, etr_untuned_show, NULL);
1258 
1259 static ssize_t etr_network_id_show(struct sys_device *dev, char *buf)
1260 {
1261 	struct etr_aib *aib = etr_aib_from_dev(dev);
1262 
1263 	if (!aib || !aib->slsw.v1)
1264 		return -ENODATA;
1265 	return sprintf(buf, "%i\n", aib->edf1.net_id);
1266 }
1267 
1268 static SYSDEV_ATTR(network, 0400, etr_network_id_show, NULL);
1269 
1270 static ssize_t etr_id_show(struct sys_device *dev, char *buf)
1271 {
1272 	struct etr_aib *aib = etr_aib_from_dev(dev);
1273 
1274 	if (!aib || !aib->slsw.v1)
1275 		return -ENODATA;
1276 	return sprintf(buf, "%i\n", aib->edf1.etr_id);
1277 }
1278 
1279 static SYSDEV_ATTR(id, 0400, etr_id_show, NULL);
1280 
1281 static ssize_t etr_port_number_show(struct sys_device *dev, char *buf)
1282 {
1283 	struct etr_aib *aib = etr_aib_from_dev(dev);
1284 
1285 	if (!aib || !aib->slsw.v1)
1286 		return -ENODATA;
1287 	return sprintf(buf, "%i\n", aib->edf1.etr_pn);
1288 }
1289 
1290 static SYSDEV_ATTR(port, 0400, etr_port_number_show, NULL);
1291 
1292 static ssize_t etr_coupled_show(struct sys_device *dev, char *buf)
1293 {
1294 	struct etr_aib *aib = etr_aib_from_dev(dev);
1295 
1296 	if (!aib || !aib->slsw.v3)
1297 		return -ENODATA;
1298 	return sprintf(buf, "%i\n", aib->edf3.c);
1299 }
1300 
1301 static SYSDEV_ATTR(coupled, 0400, etr_coupled_show, NULL);
1302 
1303 static ssize_t etr_local_time_show(struct sys_device *dev, char *buf)
1304 {
1305 	struct etr_aib *aib = etr_aib_from_dev(dev);
1306 
1307 	if (!aib || !aib->slsw.v3)
1308 		return -ENODATA;
1309 	return sprintf(buf, "%i\n", aib->edf3.blto);
1310 }
1311 
1312 static SYSDEV_ATTR(local_time, 0400, etr_local_time_show, NULL);
1313 
1314 static ssize_t etr_utc_offset_show(struct sys_device *dev, char *buf)
1315 {
1316 	struct etr_aib *aib = etr_aib_from_dev(dev);
1317 
1318 	if (!aib || !aib->slsw.v3)
1319 		return -ENODATA;
1320 	return sprintf(buf, "%i\n", aib->edf3.buo);
1321 }
1322 
1323 static SYSDEV_ATTR(utc_offset, 0400, etr_utc_offset_show, NULL);
1324 
1325 static struct sysdev_attribute *etr_port_attributes[] = {
1326 	&attr_online,
1327 	&attr_stepping_control,
1328 	&attr_state_code,
1329 	&attr_untuned,
1330 	&attr_network,
1331 	&attr_id,
1332 	&attr_port,
1333 	&attr_coupled,
1334 	&attr_local_time,
1335 	&attr_utc_offset,
1336 	NULL
1337 };
1338 
1339 static int __init etr_register_port(struct sys_device *dev)
1340 {
1341 	struct sysdev_attribute **attr;
1342 	int rc;
1343 
1344 	rc = sysdev_register(dev);
1345 	if (rc)
1346 		goto out;
1347 	for (attr = etr_port_attributes; *attr; attr++) {
1348 		rc = sysdev_create_file(dev, *attr);
1349 		if (rc)
1350 			goto out_unreg;
1351 	}
1352 	return 0;
1353 out_unreg:
1354 	for (; attr >= etr_port_attributes; attr--)
1355 		sysdev_remove_file(dev, *attr);
1356 	sysdev_unregister(dev);
1357 out:
1358 	return rc;
1359 }
1360 
1361 static void __init etr_unregister_port(struct sys_device *dev)
1362 {
1363 	struct sysdev_attribute **attr;
1364 
1365 	for (attr = etr_port_attributes; *attr; attr++)
1366 		sysdev_remove_file(dev, *attr);
1367 	sysdev_unregister(dev);
1368 }
1369 
1370 static int __init etr_init_sysfs(void)
1371 {
1372 	int rc;
1373 
1374 	rc = sysdev_class_register(&etr_sysclass);
1375 	if (rc)
1376 		goto out;
1377 	rc = sysdev_class_create_file(&etr_sysclass, &attr_stepping_port);
1378 	if (rc)
1379 		goto out_unreg_class;
1380 	rc = sysdev_class_create_file(&etr_sysclass, &attr_stepping_mode);
1381 	if (rc)
1382 		goto out_remove_stepping_port;
1383 	rc = etr_register_port(&etr_port0_dev);
1384 	if (rc)
1385 		goto out_remove_stepping_mode;
1386 	rc = etr_register_port(&etr_port1_dev);
1387 	if (rc)
1388 		goto out_remove_port0;
1389 	return 0;
1390 
1391 out_remove_port0:
1392 	etr_unregister_port(&etr_port0_dev);
1393 out_remove_stepping_mode:
1394 	sysdev_class_remove_file(&etr_sysclass, &attr_stepping_mode);
1395 out_remove_stepping_port:
1396 	sysdev_class_remove_file(&etr_sysclass, &attr_stepping_port);
1397 out_unreg_class:
1398 	sysdev_class_unregister(&etr_sysclass);
1399 out:
1400 	return rc;
1401 }
1402 
1403 device_initcall(etr_init_sysfs);
1404