xref: /linux/arch/x86/kernel/hpet.c (revision a5766f11cfd3a0c03450d99c8fe548c2940be884)
1 #include <linux/clocksource.h>
2 #include <linux/clockchips.h>
3 #include <linux/delay.h>
4 #include <linux/errno.h>
5 #include <linux/hpet.h>
6 #include <linux/init.h>
7 #include <linux/sysdev.h>
8 #include <linux/pm.h>
9 
10 #include <asm/fixmap.h>
11 #include <asm/hpet.h>
12 #include <asm/i8253.h>
13 #include <asm/io.h>
14 
15 #define HPET_MASK	CLOCKSOURCE_MASK(32)
16 #define HPET_SHIFT	22
17 
18 /* FSEC = 10^-15
19    NSEC = 10^-9 */
20 #define FSEC_PER_NSEC	1000000L
21 
22 /*
23  * HPET address is set in acpi/boot.c, when an ACPI entry exists
24  */
25 unsigned long hpet_address;
26 static void __iomem *hpet_virt_address;
27 
28 unsigned long hpet_readl(unsigned long a)
29 {
30 	return readl(hpet_virt_address + a);
31 }
32 
33 static inline void hpet_writel(unsigned long d, unsigned long a)
34 {
35 	writel(d, hpet_virt_address + a);
36 }
37 
38 #ifdef CONFIG_X86_64
39 #include <asm/pgtable.h>
40 #endif
41 
42 static inline void hpet_set_mapping(void)
43 {
44 	hpet_virt_address = ioremap_nocache(hpet_address, HPET_MMAP_SIZE);
45 #ifdef CONFIG_X86_64
46 	__set_fixmap(VSYSCALL_HPET, hpet_address, PAGE_KERNEL_VSYSCALL_NOCACHE);
47 #endif
48 }
49 
50 static inline void hpet_clear_mapping(void)
51 {
52 	iounmap(hpet_virt_address);
53 	hpet_virt_address = NULL;
54 }
55 
56 /*
57  * HPET command line enable / disable
58  */
59 static int boot_hpet_disable;
60 int hpet_force_user;
61 
62 static int __init hpet_setup(char* str)
63 {
64 	if (str) {
65 		if (!strncmp("disable", str, 7))
66 			boot_hpet_disable = 1;
67 		if (!strncmp("force", str, 5))
68 			hpet_force_user = 1;
69 	}
70 	return 1;
71 }
72 __setup("hpet=", hpet_setup);
73 
74 static int __init disable_hpet(char *str)
75 {
76 	boot_hpet_disable = 1;
77 	return 1;
78 }
79 __setup("nohpet", disable_hpet);
80 
81 static inline int is_hpet_capable(void)
82 {
83 	return (!boot_hpet_disable && hpet_address);
84 }
85 
86 /*
87  * HPET timer interrupt enable / disable
88  */
89 static int hpet_legacy_int_enabled;
90 
91 /**
92  * is_hpet_enabled - check whether the hpet timer interrupt is enabled
93  */
94 int is_hpet_enabled(void)
95 {
96 	return is_hpet_capable() && hpet_legacy_int_enabled;
97 }
98 EXPORT_SYMBOL_GPL(is_hpet_enabled);
99 
100 /*
101  * When the hpet driver (/dev/hpet) is enabled, we need to reserve
102  * timer 0 and timer 1 in case of RTC emulation.
103  */
104 #ifdef CONFIG_HPET
105 static void hpet_reserve_platform_timers(unsigned long id)
106 {
107 	struct hpet __iomem *hpet = hpet_virt_address;
108 	struct hpet_timer __iomem *timer = &hpet->hpet_timers[2];
109 	unsigned int nrtimers, i;
110 	struct hpet_data hd;
111 
112 	nrtimers = ((id & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT) + 1;
113 
114 	memset(&hd, 0, sizeof (hd));
115 	hd.hd_phys_address = hpet_address;
116 	hd.hd_address = hpet;
117 	hd.hd_nirqs = nrtimers;
118 	hpet_reserve_timer(&hd, 0);
119 
120 #ifdef CONFIG_HPET_EMULATE_RTC
121 	hpet_reserve_timer(&hd, 1);
122 #endif
123 
124 	/*
125 	 * NOTE that hd_irq[] reflects IOAPIC input pins (LEGACY_8254
126 	 * is wrong for i8259!) not the output IRQ.  Many BIOS writers
127 	 * don't bother configuring *any* comparator interrupts.
128 	 */
129 	hd.hd_irq[0] = HPET_LEGACY_8254;
130 	hd.hd_irq[1] = HPET_LEGACY_RTC;
131 
132 	for (i = 2; i < nrtimers; timer++, i++) {
133 		hd.hd_irq[i] = (readl(&timer->hpet_config) & Tn_INT_ROUTE_CNF_MASK) >>
134 			Tn_INT_ROUTE_CNF_SHIFT;
135 	}
136 
137 	hpet_alloc(&hd);
138 
139 }
140 #else
141 static void hpet_reserve_platform_timers(unsigned long id) { }
142 #endif
143 
144 /*
145  * Common hpet info
146  */
147 static unsigned long hpet_period;
148 
149 static void hpet_legacy_set_mode(enum clock_event_mode mode,
150 			  struct clock_event_device *evt);
151 static int hpet_legacy_next_event(unsigned long delta,
152 			   struct clock_event_device *evt);
153 
154 /*
155  * The hpet clock event device
156  */
157 static struct clock_event_device hpet_clockevent = {
158 	.name		= "hpet",
159 	.features	= CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
160 	.set_mode	= hpet_legacy_set_mode,
161 	.set_next_event = hpet_legacy_next_event,
162 	.shift		= 32,
163 	.irq		= 0,
164 	.rating		= 50,
165 };
166 
167 static void hpet_start_counter(void)
168 {
169 	unsigned long cfg = hpet_readl(HPET_CFG);
170 
171 	cfg &= ~HPET_CFG_ENABLE;
172 	hpet_writel(cfg, HPET_CFG);
173 	hpet_writel(0, HPET_COUNTER);
174 	hpet_writel(0, HPET_COUNTER + 4);
175 	cfg |= HPET_CFG_ENABLE;
176 	hpet_writel(cfg, HPET_CFG);
177 }
178 
179 static void hpet_resume_device(void)
180 {
181 	force_hpet_resume();
182 }
183 
184 static void hpet_restart_counter(void)
185 {
186 	hpet_resume_device();
187 	hpet_start_counter();
188 }
189 
190 static void hpet_enable_legacy_int(void)
191 {
192 	unsigned long cfg = hpet_readl(HPET_CFG);
193 
194 	cfg |= HPET_CFG_LEGACY;
195 	hpet_writel(cfg, HPET_CFG);
196 	hpet_legacy_int_enabled = 1;
197 }
198 
199 static void hpet_legacy_clockevent_register(void)
200 {
201 	/* Start HPET legacy interrupts */
202 	hpet_enable_legacy_int();
203 
204 	/*
205 	 * The mult factor is defined as (include/linux/clockchips.h)
206 	 *  mult/2^shift = cyc/ns (in contrast to ns/cyc in clocksource.h)
207 	 * hpet_period is in units of femtoseconds (per cycle), so
208 	 *  mult/2^shift = cyc/ns = 10^6/hpet_period
209 	 *  mult = (10^6 * 2^shift)/hpet_period
210 	 *  mult = (FSEC_PER_NSEC << hpet_clockevent.shift)/hpet_period
211 	 */
212 	hpet_clockevent.mult = div_sc((unsigned long) FSEC_PER_NSEC,
213 				      hpet_period, hpet_clockevent.shift);
214 	/* Calculate the min / max delta */
215 	hpet_clockevent.max_delta_ns = clockevent_delta2ns(0x7FFFFFFF,
216 							   &hpet_clockevent);
217 	/* 5 usec minimum reprogramming delta. */
218 	hpet_clockevent.min_delta_ns = 5000;
219 
220 	/*
221 	 * Start hpet with the boot cpu mask and make it
222 	 * global after the IO_APIC has been initialized.
223 	 */
224 	hpet_clockevent.cpumask = cpumask_of_cpu(smp_processor_id());
225 	clockevents_register_device(&hpet_clockevent);
226 	global_clock_event = &hpet_clockevent;
227 	printk(KERN_DEBUG "hpet clockevent registered\n");
228 }
229 
230 static void hpet_legacy_set_mode(enum clock_event_mode mode,
231 			  struct clock_event_device *evt)
232 {
233 	unsigned long cfg, cmp, now;
234 	uint64_t delta;
235 
236 	switch(mode) {
237 	case CLOCK_EVT_MODE_PERIODIC:
238 		delta = ((uint64_t)(NSEC_PER_SEC/HZ)) * hpet_clockevent.mult;
239 		delta >>= hpet_clockevent.shift;
240 		now = hpet_readl(HPET_COUNTER);
241 		cmp = now + (unsigned long) delta;
242 		cfg = hpet_readl(HPET_T0_CFG);
243 		cfg |= HPET_TN_ENABLE | HPET_TN_PERIODIC |
244 		       HPET_TN_SETVAL | HPET_TN_32BIT;
245 		hpet_writel(cfg, HPET_T0_CFG);
246 		/*
247 		 * The first write after writing TN_SETVAL to the
248 		 * config register sets the counter value, the second
249 		 * write sets the period.
250 		 */
251 		hpet_writel(cmp, HPET_T0_CMP);
252 		udelay(1);
253 		hpet_writel((unsigned long) delta, HPET_T0_CMP);
254 		break;
255 
256 	case CLOCK_EVT_MODE_ONESHOT:
257 		cfg = hpet_readl(HPET_T0_CFG);
258 		cfg &= ~HPET_TN_PERIODIC;
259 		cfg |= HPET_TN_ENABLE | HPET_TN_32BIT;
260 		hpet_writel(cfg, HPET_T0_CFG);
261 		break;
262 
263 	case CLOCK_EVT_MODE_UNUSED:
264 	case CLOCK_EVT_MODE_SHUTDOWN:
265 		cfg = hpet_readl(HPET_T0_CFG);
266 		cfg &= ~HPET_TN_ENABLE;
267 		hpet_writel(cfg, HPET_T0_CFG);
268 		break;
269 
270 	case CLOCK_EVT_MODE_RESUME:
271 		hpet_enable_legacy_int();
272 		break;
273 	}
274 }
275 
276 static int hpet_legacy_next_event(unsigned long delta,
277 				  struct clock_event_device *evt)
278 {
279 	u32 cnt;
280 
281 	cnt = hpet_readl(HPET_COUNTER);
282 	cnt += (u32) delta;
283 	hpet_writel(cnt, HPET_T0_CMP);
284 
285 	/*
286 	 * We need to read back the CMP register to make sure that
287 	 * what we wrote hit the chip before we compare it to the
288 	 * counter.
289 	 */
290 	WARN_ON((u32)hpet_readl(HPET_T0_CMP) != cnt);
291 
292 	return (s32)((u32)hpet_readl(HPET_COUNTER) - cnt) >= 0 ? -ETIME : 0;
293 }
294 
295 /*
296  * Clock source related code
297  */
298 static cycle_t read_hpet(void)
299 {
300 	return (cycle_t)hpet_readl(HPET_COUNTER);
301 }
302 
303 #ifdef CONFIG_X86_64
304 static cycle_t __vsyscall_fn vread_hpet(void)
305 {
306 	return readl((const void __iomem *)fix_to_virt(VSYSCALL_HPET) + 0xf0);
307 }
308 #endif
309 
310 static struct clocksource clocksource_hpet = {
311 	.name		= "hpet",
312 	.rating		= 250,
313 	.read		= read_hpet,
314 	.mask		= HPET_MASK,
315 	.shift		= HPET_SHIFT,
316 	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
317 	.resume		= hpet_restart_counter,
318 #ifdef CONFIG_X86_64
319 	.vread		= vread_hpet,
320 #endif
321 };
322 
323 static int hpet_clocksource_register(void)
324 {
325 	u64 start, now;
326 	cycle_t t1;
327 
328 	/* Start the counter */
329 	hpet_start_counter();
330 
331 	/* Verify whether hpet counter works */
332 	t1 = read_hpet();
333 	rdtscll(start);
334 
335 	/*
336 	 * We don't know the TSC frequency yet, but waiting for
337 	 * 200000 TSC cycles is safe:
338 	 * 4 GHz == 50us
339 	 * 1 GHz == 200us
340 	 */
341 	do {
342 		rep_nop();
343 		rdtscll(now);
344 	} while ((now - start) < 200000UL);
345 
346 	if (t1 == read_hpet()) {
347 		printk(KERN_WARNING
348 		       "HPET counter not counting. HPET disabled\n");
349 		return -ENODEV;
350 	}
351 
352 	/*
353 	 * The definition of mult is (include/linux/clocksource.h)
354 	 * mult/2^shift = ns/cyc and hpet_period is in units of fsec/cyc
355 	 * so we first need to convert hpet_period to ns/cyc units:
356 	 *  mult/2^shift = ns/cyc = hpet_period/10^6
357 	 *  mult = (hpet_period * 2^shift)/10^6
358 	 *  mult = (hpet_period << shift)/FSEC_PER_NSEC
359 	 */
360 	clocksource_hpet.mult = div_sc(hpet_period, FSEC_PER_NSEC, HPET_SHIFT);
361 
362 	clocksource_register(&clocksource_hpet);
363 
364 	return 0;
365 }
366 
367 /**
368  * hpet_enable - Try to setup the HPET timer. Returns 1 on success.
369  */
370 int __init hpet_enable(void)
371 {
372 	unsigned long id;
373 	int i;
374 
375 	if (!is_hpet_capable())
376 		return 0;
377 
378 	hpet_set_mapping();
379 
380 	/*
381 	 * Read the period and check for a sane value:
382 	 */
383 	hpet_period = hpet_readl(HPET_PERIOD);
384 
385 	/*
386 	 * AMD SB700 based systems with spread spectrum enabled use a
387 	 * SMM based HPET emulation to provide proper frequency
388 	 * setting. The SMM code is initialized with the first HPET
389 	 * register access and takes some time to complete. During
390 	 * this time the config register reads 0xffffffff. We check
391 	 * for max. 1000 loops whether the config register reads a non
392 	 * 0xffffffff value to make sure that HPET is up and running
393 	 * before we go further. A counting loop is safe, as the HPET
394 	 * access takes thousands of CPU cycles. On non SB700 based
395 	 * machines this check is only done once and has no side
396 	 * effects.
397 	 */
398 	for (i = 0; hpet_readl(HPET_CFG) == 0xFFFFFFFF; i++) {
399 		if (i == 1000) {
400 			printk(KERN_WARNING
401 			       "HPET config register value = 0xFFFFFFFF. "
402 			       "Disabling HPET\n");
403 			goto out_nohpet;
404 		}
405 	}
406 
407 	if (hpet_period < HPET_MIN_PERIOD || hpet_period > HPET_MAX_PERIOD)
408 		goto out_nohpet;
409 
410 	/*
411 	 * Read the HPET ID register to retrieve the IRQ routing
412 	 * information and the number of channels
413 	 */
414 	id = hpet_readl(HPET_ID);
415 
416 #ifdef CONFIG_HPET_EMULATE_RTC
417 	/*
418 	 * The legacy routing mode needs at least two channels, tick timer
419 	 * and the rtc emulation channel.
420 	 */
421 	if (!(id & HPET_ID_NUMBER))
422 		goto out_nohpet;
423 #endif
424 
425 	if (hpet_clocksource_register())
426 		goto out_nohpet;
427 
428 	if (id & HPET_ID_LEGSUP) {
429 		hpet_legacy_clockevent_register();
430 		return 1;
431 	}
432 	return 0;
433 
434 out_nohpet:
435 	hpet_clear_mapping();
436 	boot_hpet_disable = 1;
437 	return 0;
438 }
439 
440 /*
441  * Needs to be late, as the reserve_timer code calls kalloc !
442  *
443  * Not a problem on i386 as hpet_enable is called from late_time_init,
444  * but on x86_64 it is necessary !
445  */
446 static __init int hpet_late_init(void)
447 {
448 	if (boot_hpet_disable)
449 		return -ENODEV;
450 
451 	if (!hpet_address) {
452 		if (!force_hpet_address)
453 			return -ENODEV;
454 
455 		hpet_address = force_hpet_address;
456 		hpet_enable();
457 		if (!hpet_virt_address)
458 			return -ENODEV;
459 	}
460 
461 	hpet_reserve_platform_timers(hpet_readl(HPET_ID));
462 
463 	return 0;
464 }
465 fs_initcall(hpet_late_init);
466 
467 void hpet_disable(void)
468 {
469 	if (is_hpet_capable()) {
470 		unsigned long cfg = hpet_readl(HPET_CFG);
471 
472 		if (hpet_legacy_int_enabled) {
473 			cfg &= ~HPET_CFG_LEGACY;
474 			hpet_legacy_int_enabled = 0;
475 		}
476 		cfg &= ~HPET_CFG_ENABLE;
477 		hpet_writel(cfg, HPET_CFG);
478 	}
479 }
480 
481 #ifdef CONFIG_HPET_EMULATE_RTC
482 
483 /* HPET in LegacyReplacement Mode eats up RTC interrupt line. When, HPET
484  * is enabled, we support RTC interrupt functionality in software.
485  * RTC has 3 kinds of interrupts:
486  * 1) Update Interrupt - generate an interrupt, every sec, when RTC clock
487  *    is updated
488  * 2) Alarm Interrupt - generate an interrupt at a specific time of day
489  * 3) Periodic Interrupt - generate periodic interrupt, with frequencies
490  *    2Hz-8192Hz (2Hz-64Hz for non-root user) (all freqs in powers of 2)
491  * (1) and (2) above are implemented using polling at a frequency of
492  * 64 Hz. The exact frequency is a tradeoff between accuracy and interrupt
493  * overhead. (DEFAULT_RTC_INT_FREQ)
494  * For (3), we use interrupts at 64Hz or user specified periodic
495  * frequency, whichever is higher.
496  */
497 #include <linux/mc146818rtc.h>
498 #include <linux/rtc.h>
499 #include <asm/rtc.h>
500 
501 #define DEFAULT_RTC_INT_FREQ	64
502 #define DEFAULT_RTC_SHIFT	6
503 #define RTC_NUM_INTS		1
504 
505 static unsigned long hpet_rtc_flags;
506 static int hpet_prev_update_sec;
507 static struct rtc_time hpet_alarm_time;
508 static unsigned long hpet_pie_count;
509 static unsigned long hpet_t1_cmp;
510 static unsigned long hpet_default_delta;
511 static unsigned long hpet_pie_delta;
512 static unsigned long hpet_pie_limit;
513 
514 static rtc_irq_handler irq_handler;
515 
516 /*
517  * Registers a IRQ handler.
518  */
519 int hpet_register_irq_handler(rtc_irq_handler handler)
520 {
521 	if (!is_hpet_enabled())
522 		return -ENODEV;
523 	if (irq_handler)
524 		return -EBUSY;
525 
526 	irq_handler = handler;
527 
528 	return 0;
529 }
530 EXPORT_SYMBOL_GPL(hpet_register_irq_handler);
531 
532 /*
533  * Deregisters the IRQ handler registered with hpet_register_irq_handler()
534  * and does cleanup.
535  */
536 void hpet_unregister_irq_handler(rtc_irq_handler handler)
537 {
538 	if (!is_hpet_enabled())
539 		return;
540 
541 	irq_handler = NULL;
542 	hpet_rtc_flags = 0;
543 }
544 EXPORT_SYMBOL_GPL(hpet_unregister_irq_handler);
545 
546 /*
547  * Timer 1 for RTC emulation. We use one shot mode, as periodic mode
548  * is not supported by all HPET implementations for timer 1.
549  *
550  * hpet_rtc_timer_init() is called when the rtc is initialized.
551  */
552 int hpet_rtc_timer_init(void)
553 {
554 	unsigned long cfg, cnt, delta, flags;
555 
556 	if (!is_hpet_enabled())
557 		return 0;
558 
559 	if (!hpet_default_delta) {
560 		uint64_t clc;
561 
562 		clc = (uint64_t) hpet_clockevent.mult * NSEC_PER_SEC;
563 		clc >>= hpet_clockevent.shift + DEFAULT_RTC_SHIFT;
564 		hpet_default_delta = (unsigned long) clc;
565 	}
566 
567 	if (!(hpet_rtc_flags & RTC_PIE) || hpet_pie_limit)
568 		delta = hpet_default_delta;
569 	else
570 		delta = hpet_pie_delta;
571 
572 	local_irq_save(flags);
573 
574 	cnt = delta + hpet_readl(HPET_COUNTER);
575 	hpet_writel(cnt, HPET_T1_CMP);
576 	hpet_t1_cmp = cnt;
577 
578 	cfg = hpet_readl(HPET_T1_CFG);
579 	cfg &= ~HPET_TN_PERIODIC;
580 	cfg |= HPET_TN_ENABLE | HPET_TN_32BIT;
581 	hpet_writel(cfg, HPET_T1_CFG);
582 
583 	local_irq_restore(flags);
584 
585 	return 1;
586 }
587 EXPORT_SYMBOL_GPL(hpet_rtc_timer_init);
588 
589 /*
590  * The functions below are called from rtc driver.
591  * Return 0 if HPET is not being used.
592  * Otherwise do the necessary changes and return 1.
593  */
594 int hpet_mask_rtc_irq_bit(unsigned long bit_mask)
595 {
596 	if (!is_hpet_enabled())
597 		return 0;
598 
599 	hpet_rtc_flags &= ~bit_mask;
600 	return 1;
601 }
602 EXPORT_SYMBOL_GPL(hpet_mask_rtc_irq_bit);
603 
604 int hpet_set_rtc_irq_bit(unsigned long bit_mask)
605 {
606 	unsigned long oldbits = hpet_rtc_flags;
607 
608 	if (!is_hpet_enabled())
609 		return 0;
610 
611 	hpet_rtc_flags |= bit_mask;
612 
613 	if ((bit_mask & RTC_UIE) && !(oldbits & RTC_UIE))
614 		hpet_prev_update_sec = -1;
615 
616 	if (!oldbits)
617 		hpet_rtc_timer_init();
618 
619 	return 1;
620 }
621 EXPORT_SYMBOL_GPL(hpet_set_rtc_irq_bit);
622 
623 int hpet_set_alarm_time(unsigned char hrs, unsigned char min,
624 			unsigned char sec)
625 {
626 	if (!is_hpet_enabled())
627 		return 0;
628 
629 	hpet_alarm_time.tm_hour = hrs;
630 	hpet_alarm_time.tm_min = min;
631 	hpet_alarm_time.tm_sec = sec;
632 
633 	return 1;
634 }
635 EXPORT_SYMBOL_GPL(hpet_set_alarm_time);
636 
637 int hpet_set_periodic_freq(unsigned long freq)
638 {
639 	uint64_t clc;
640 
641 	if (!is_hpet_enabled())
642 		return 0;
643 
644 	if (freq <= DEFAULT_RTC_INT_FREQ)
645 		hpet_pie_limit = DEFAULT_RTC_INT_FREQ / freq;
646 	else {
647 		clc = (uint64_t) hpet_clockevent.mult * NSEC_PER_SEC;
648 		do_div(clc, freq);
649 		clc >>= hpet_clockevent.shift;
650 		hpet_pie_delta = (unsigned long) clc;
651 	}
652 	return 1;
653 }
654 EXPORT_SYMBOL_GPL(hpet_set_periodic_freq);
655 
656 int hpet_rtc_dropped_irq(void)
657 {
658 	return is_hpet_enabled();
659 }
660 EXPORT_SYMBOL_GPL(hpet_rtc_dropped_irq);
661 
662 static void hpet_rtc_timer_reinit(void)
663 {
664 	unsigned long cfg, delta;
665 	int lost_ints = -1;
666 
667 	if (unlikely(!hpet_rtc_flags)) {
668 		cfg = hpet_readl(HPET_T1_CFG);
669 		cfg &= ~HPET_TN_ENABLE;
670 		hpet_writel(cfg, HPET_T1_CFG);
671 		return;
672 	}
673 
674 	if (!(hpet_rtc_flags & RTC_PIE) || hpet_pie_limit)
675 		delta = hpet_default_delta;
676 	else
677 		delta = hpet_pie_delta;
678 
679 	/*
680 	 * Increment the comparator value until we are ahead of the
681 	 * current count.
682 	 */
683 	do {
684 		hpet_t1_cmp += delta;
685 		hpet_writel(hpet_t1_cmp, HPET_T1_CMP);
686 		lost_ints++;
687 	} while ((long)(hpet_readl(HPET_COUNTER) - hpet_t1_cmp) > 0);
688 
689 	if (lost_ints) {
690 		if (hpet_rtc_flags & RTC_PIE)
691 			hpet_pie_count += lost_ints;
692 		if (printk_ratelimit())
693 			printk(KERN_WARNING "hpet1: lost %d rtc interrupts\n",
694 				lost_ints);
695 	}
696 }
697 
698 irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id)
699 {
700 	struct rtc_time curr_time;
701 	unsigned long rtc_int_flag = 0;
702 
703 	hpet_rtc_timer_reinit();
704 	memset(&curr_time, 0, sizeof(struct rtc_time));
705 
706 	if (hpet_rtc_flags & (RTC_UIE | RTC_AIE))
707 		get_rtc_time(&curr_time);
708 
709 	if (hpet_rtc_flags & RTC_UIE &&
710 	    curr_time.tm_sec != hpet_prev_update_sec) {
711 		if (hpet_prev_update_sec >= 0)
712 			rtc_int_flag = RTC_UF;
713 		hpet_prev_update_sec = curr_time.tm_sec;
714 	}
715 
716 	if (hpet_rtc_flags & RTC_PIE &&
717 	    ++hpet_pie_count >= hpet_pie_limit) {
718 		rtc_int_flag |= RTC_PF;
719 		hpet_pie_count = 0;
720 	}
721 
722 	if (hpet_rtc_flags & RTC_AIE &&
723 	    (curr_time.tm_sec == hpet_alarm_time.tm_sec) &&
724 	    (curr_time.tm_min == hpet_alarm_time.tm_min) &&
725 	    (curr_time.tm_hour == hpet_alarm_time.tm_hour))
726 			rtc_int_flag |= RTC_AF;
727 
728 	if (rtc_int_flag) {
729 		rtc_int_flag |= (RTC_IRQF | (RTC_NUM_INTS << 8));
730 		if (irq_handler)
731 			irq_handler(rtc_int_flag, dev_id);
732 	}
733 	return IRQ_HANDLED;
734 }
735 EXPORT_SYMBOL_GPL(hpet_rtc_interrupt);
736 #endif
737