1#include <linux/clocksource.h>
2#include <linux/clockchips.h>
3#include <linux/interrupt.h>
4#include <linux/export.h>
5#include <linux/delay.h>
6#include <linux/errno.h>
7#include <linux/i8253.h>
8#include <linux/slab.h>
9#include <linux/hpet.h>
10#include <linux/init.h>
11#include <linux/cpu.h>
12#include <linux/pm.h>
13#include <linux/io.h>
14
15#include <asm/cpufeature.h>
16#include <asm/irqdomain.h>
17#include <asm/fixmap.h>
18#include <asm/hpet.h>
19#include <asm/time.h>
20
21#define HPET_MASK CLOCKSOURCE_MASK(32)
22
23
24
25#define FSEC_PER_NSEC 1000000L
26
27#define HPET_DEV_USED_BIT 2
28#define HPET_DEV_USED (1 << HPET_DEV_USED_BIT)
29#define HPET_DEV_VALID 0x8
30#define HPET_DEV_FSB_CAP 0x1000
31#define HPET_DEV_PERI_CAP 0x2000
32
33#define HPET_MIN_CYCLES 128
34#define HPET_MIN_PROG_DELTA (HPET_MIN_CYCLES + (HPET_MIN_CYCLES >> 1))
35
36
37
38
39unsigned long hpet_address;
40u8 hpet_blockid;
41bool hpet_msi_disable;
42
43#ifdef CONFIG_PCI_MSI
44static unsigned int hpet_num_timers;
45#endif
46static void __iomem *hpet_virt_address;
47
48struct hpet_dev {
49 struct clock_event_device evt;
50 unsigned int num;
51 int cpu;
52 unsigned int irq;
53 unsigned int flags;
54 char name[10];
55};
56
57static inline struct hpet_dev *EVT_TO_HPET_DEV(struct clock_event_device *evtdev)
58{
59 return container_of(evtdev, struct hpet_dev, evt);
60}
61
62inline unsigned int hpet_readl(unsigned int a)
63{
64 return readl(hpet_virt_address + a);
65}
66
67static inline void hpet_writel(unsigned int d, unsigned int a)
68{
69 writel(d, hpet_virt_address + a);
70}
71
72#ifdef CONFIG_X86_64
73#include <asm/pgtable.h>
74#endif
75
76static inline void hpet_set_mapping(void)
77{
78 hpet_virt_address = ioremap_nocache(hpet_address, HPET_MMAP_SIZE);
79}
80
81static inline void hpet_clear_mapping(void)
82{
83 iounmap(hpet_virt_address);
84 hpet_virt_address = NULL;
85}
86
87
88
89
90bool boot_hpet_disable;
91bool hpet_force_user;
92static bool hpet_verbose;
93
94static int __init hpet_setup(char *str)
95{
96 while (str) {
97 char *next = strchr(str, ',');
98
99 if (next)
100 *next++ = 0;
101 if (!strncmp("disable", str, 7))
102 boot_hpet_disable = true;
103 if (!strncmp("force", str, 5))
104 hpet_force_user = true;
105 if (!strncmp("verbose", str, 7))
106 hpet_verbose = true;
107 str = next;
108 }
109 return 1;
110}
111__setup("hpet=", hpet_setup);
112
113static int __init disable_hpet(char *str)
114{
115 boot_hpet_disable = true;
116 return 1;
117}
118__setup("nohpet", disable_hpet);
119
120static inline int is_hpet_capable(void)
121{
122 return !boot_hpet_disable && hpet_address;
123}
124
125
126
127
128static bool hpet_legacy_int_enabled;
129
130
131
132
133int is_hpet_enabled(void)
134{
135 return is_hpet_capable() && hpet_legacy_int_enabled;
136}
137EXPORT_SYMBOL_GPL(is_hpet_enabled);
138
139static void _hpet_print_config(const char *function, int line)
140{
141 u32 i, timers, l, h;
142 printk(KERN_INFO "hpet: %s(%d):\n", function, line);
143 l = hpet_readl(HPET_ID);
144 h = hpet_readl(HPET_PERIOD);
145 timers = ((l & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT) + 1;
146 printk(KERN_INFO "hpet: ID: 0x%x, PERIOD: 0x%x\n", l, h);
147 l = hpet_readl(HPET_CFG);
148 h = hpet_readl(HPET_STATUS);
149 printk(KERN_INFO "hpet: CFG: 0x%x, STATUS: 0x%x\n", l, h);
150 l = hpet_readl(HPET_COUNTER);
151 h = hpet_readl(HPET_COUNTER+4);
152 printk(KERN_INFO "hpet: COUNTER_l: 0x%x, COUNTER_h: 0x%x\n", l, h);
153
154 for (i = 0; i < timers; i++) {
155 l = hpet_readl(HPET_Tn_CFG(i));
156 h = hpet_readl(HPET_Tn_CFG(i)+4);
157 printk(KERN_INFO "hpet: T%d: CFG_l: 0x%x, CFG_h: 0x%x\n",
158 i, l, h);
159 l = hpet_readl(HPET_Tn_CMP(i));
160 h = hpet_readl(HPET_Tn_CMP(i)+4);
161 printk(KERN_INFO "hpet: T%d: CMP_l: 0x%x, CMP_h: 0x%x\n",
162 i, l, h);
163 l = hpet_readl(HPET_Tn_ROUTE(i));
164 h = hpet_readl(HPET_Tn_ROUTE(i)+4);
165 printk(KERN_INFO "hpet: T%d ROUTE_l: 0x%x, ROUTE_h: 0x%x\n",
166 i, l, h);
167 }
168}
169
170#define hpet_print_config() \
171do { \
172 if (hpet_verbose) \
173 _hpet_print_config(__func__, __LINE__); \
174} while (0)
175
176
177
178
179
180#ifdef CONFIG_HPET
181
182static void hpet_reserve_msi_timers(struct hpet_data *hd);
183
184static void hpet_reserve_platform_timers(unsigned int id)
185{
186 struct hpet __iomem *hpet = hpet_virt_address;
187 struct hpet_timer __iomem *timer = &hpet->hpet_timers[2];
188 unsigned int nrtimers, i;
189 struct hpet_data hd;
190
191 nrtimers = ((id & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT) + 1;
192
193 memset(&hd, 0, sizeof(hd));
194 hd.hd_phys_address = hpet_address;
195 hd.hd_address = hpet;
196 hd.hd_nirqs = nrtimers;
197 hpet_reserve_timer(&hd, 0);
198
199#ifdef CONFIG_HPET_EMULATE_RTC
200 hpet_reserve_timer(&hd, 1);
201#endif
202
203
204
205
206
207
208 hd.hd_irq[0] = HPET_LEGACY_8254;
209 hd.hd_irq[1] = HPET_LEGACY_RTC;
210
211 for (i = 2; i < nrtimers; timer++, i++) {
212 hd.hd_irq[i] = (readl(&timer->hpet_config) &
213 Tn_INT_ROUTE_CNF_MASK) >> Tn_INT_ROUTE_CNF_SHIFT;
214 }
215
216 hpet_reserve_msi_timers(&hd);
217
218 hpet_alloc(&hd);
219
220}
221#else
222static void hpet_reserve_platform_timers(unsigned int id) { }
223#endif
224
225
226
227
228static unsigned long hpet_freq;
229
230static struct clock_event_device hpet_clockevent;
231
232static void hpet_stop_counter(void)
233{
234 u32 cfg = hpet_readl(HPET_CFG);
235 cfg &= ~HPET_CFG_ENABLE;
236 hpet_writel(cfg, HPET_CFG);
237}
238
239static void hpet_reset_counter(void)
240{
241 hpet_writel(0, HPET_COUNTER);
242 hpet_writel(0, HPET_COUNTER + 4);
243}
244
245static void hpet_start_counter(void)
246{
247 unsigned int cfg = hpet_readl(HPET_CFG);
248 cfg |= HPET_CFG_ENABLE;
249 hpet_writel(cfg, HPET_CFG);
250}
251
252static void hpet_restart_counter(void)
253{
254 hpet_stop_counter();
255 hpet_reset_counter();
256 hpet_start_counter();
257}
258
259static void hpet_resume_device(void)
260{
261 force_hpet_resume();
262}
263
264static void hpet_resume_counter(struct clocksource *cs)
265{
266 hpet_resume_device();
267 hpet_restart_counter();
268}
269
270static void hpet_enable_legacy_int(void)
271{
272 unsigned int cfg = hpet_readl(HPET_CFG);
273
274 cfg |= HPET_CFG_LEGACY;
275 hpet_writel(cfg, HPET_CFG);
276 hpet_legacy_int_enabled = true;
277}
278
279static void hpet_legacy_clockevent_register(void)
280{
281
282 hpet_enable_legacy_int();
283
284
285
286
287
288 hpet_clockevent.cpumask = cpumask_of(boot_cpu_data.cpu_index);
289 clockevents_config_and_register(&hpet_clockevent, hpet_freq,
290 HPET_MIN_PROG_DELTA, 0x7FFFFFFF);
291 global_clock_event = &hpet_clockevent;
292 printk(KERN_DEBUG "hpet clockevent registered\n");
293}
294
295static int hpet_set_periodic(struct clock_event_device *evt, int timer)
296{
297 unsigned int cfg, cmp, now;
298 uint64_t delta;
299
300 hpet_stop_counter();
301 delta = ((uint64_t)(NSEC_PER_SEC / HZ)) * evt->mult;
302 delta >>= evt->shift;
303 now = hpet_readl(HPET_COUNTER);
304 cmp = now + (unsigned int)delta;
305 cfg = hpet_readl(HPET_Tn_CFG(timer));
306 cfg |= HPET_TN_ENABLE | HPET_TN_PERIODIC | HPET_TN_SETVAL |
307 HPET_TN_32BIT;
308 hpet_writel(cfg, HPET_Tn_CFG(timer));
309 hpet_writel(cmp, HPET_Tn_CMP(timer));
310 udelay(1);
311
312
313
314
315
316
317
318 hpet_writel((unsigned int)delta, HPET_Tn_CMP(timer));
319 hpet_start_counter();
320 hpet_print_config();
321
322 return 0;
323}
324
325static int hpet_set_oneshot(struct clock_event_device *evt, int timer)
326{
327 unsigned int cfg;
328
329 cfg = hpet_readl(HPET_Tn_CFG(timer));
330 cfg &= ~HPET_TN_PERIODIC;
331 cfg |= HPET_TN_ENABLE | HPET_TN_32BIT;
332 hpet_writel(cfg, HPET_Tn_CFG(timer));
333
334 return 0;
335}
336
337static int hpet_shutdown(struct clock_event_device *evt, int timer)
338{
339 unsigned int cfg;
340
341 cfg = hpet_readl(HPET_Tn_CFG(timer));
342 cfg &= ~HPET_TN_ENABLE;
343 hpet_writel(cfg, HPET_Tn_CFG(timer));
344
345 return 0;
346}
347
348static int hpet_resume(struct clock_event_device *evt)
349{
350 hpet_enable_legacy_int();
351 hpet_print_config();
352 return 0;
353}
354
355static int hpet_next_event(unsigned long delta,
356 struct clock_event_device *evt, int timer)
357{
358 u32 cnt;
359 s32 res;
360
361 cnt = hpet_readl(HPET_COUNTER);
362 cnt += (u32) delta;
363 hpet_writel(cnt, HPET_Tn_CMP(timer));
364
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387 res = (s32)(cnt - hpet_readl(HPET_COUNTER));
388
389 return res < HPET_MIN_CYCLES ? -ETIME : 0;
390}
391
392static int hpet_legacy_shutdown(struct clock_event_device *evt)
393{
394 return hpet_shutdown(evt, 0);
395}
396
397static int hpet_legacy_set_oneshot(struct clock_event_device *evt)
398{
399 return hpet_set_oneshot(evt, 0);
400}
401
402static int hpet_legacy_set_periodic(struct clock_event_device *evt)
403{
404 return hpet_set_periodic(evt, 0);
405}
406
407static int hpet_legacy_resume(struct clock_event_device *evt)
408{
409 return hpet_resume(evt);
410}
411
412static int hpet_legacy_next_event(unsigned long delta,
413 struct clock_event_device *evt)
414{
415 return hpet_next_event(delta, evt, 0);
416}
417
418
419
420
421static struct clock_event_device hpet_clockevent = {
422 .name = "hpet",
423 .features = CLOCK_EVT_FEAT_PERIODIC |
424 CLOCK_EVT_FEAT_ONESHOT,
425 .set_state_periodic = hpet_legacy_set_periodic,
426 .set_state_oneshot = hpet_legacy_set_oneshot,
427 .set_state_shutdown = hpet_legacy_shutdown,
428 .tick_resume = hpet_legacy_resume,
429 .set_next_event = hpet_legacy_next_event,
430 .irq = 0,
431 .rating = 50,
432};
433
434
435
436
437#ifdef CONFIG_PCI_MSI
438
439static DEFINE_PER_CPU(struct hpet_dev *, cpu_hpet_dev);
440static struct hpet_dev *hpet_devs;
441static struct irq_domain *hpet_domain;
442
443void hpet_msi_unmask(struct irq_data *data)
444{
445 struct hpet_dev *hdev = irq_data_get_irq_handler_data(data);
446 unsigned int cfg;
447
448
449 cfg = hpet_readl(HPET_Tn_CFG(hdev->num));
450 cfg |= HPET_TN_ENABLE | HPET_TN_FSB;
451 hpet_writel(cfg, HPET_Tn_CFG(hdev->num));
452}
453
454void hpet_msi_mask(struct irq_data *data)
455{
456 struct hpet_dev *hdev = irq_data_get_irq_handler_data(data);
457 unsigned int cfg;
458
459
460 cfg = hpet_readl(HPET_Tn_CFG(hdev->num));
461 cfg &= ~(HPET_TN_ENABLE | HPET_TN_FSB);
462 hpet_writel(cfg, HPET_Tn_CFG(hdev->num));
463}
464
465void hpet_msi_write(struct hpet_dev *hdev, struct msi_msg *msg)
466{
467 hpet_writel(msg->data, HPET_Tn_ROUTE(hdev->num));
468 hpet_writel(msg->address_lo, HPET_Tn_ROUTE(hdev->num) + 4);
469}
470
471void hpet_msi_read(struct hpet_dev *hdev, struct msi_msg *msg)
472{
473 msg->data = hpet_readl(HPET_Tn_ROUTE(hdev->num));
474 msg->address_lo = hpet_readl(HPET_Tn_ROUTE(hdev->num) + 4);
475 msg->address_hi = 0;
476}
477
478static int hpet_msi_shutdown(struct clock_event_device *evt)
479{
480 struct hpet_dev *hdev = EVT_TO_HPET_DEV(evt);
481
482 return hpet_shutdown(evt, hdev->num);
483}
484
485static int hpet_msi_set_oneshot(struct clock_event_device *evt)
486{
487 struct hpet_dev *hdev = EVT_TO_HPET_DEV(evt);
488
489 return hpet_set_oneshot(evt, hdev->num);
490}
491
492static int hpet_msi_set_periodic(struct clock_event_device *evt)
493{
494 struct hpet_dev *hdev = EVT_TO_HPET_DEV(evt);
495
496 return hpet_set_periodic(evt, hdev->num);
497}
498
499static int hpet_msi_resume(struct clock_event_device *evt)
500{
501 struct hpet_dev *hdev = EVT_TO_HPET_DEV(evt);
502 struct irq_data *data = irq_get_irq_data(hdev->irq);
503 struct msi_msg msg;
504
505
506 irq_chip_compose_msi_msg(data, &msg);
507 hpet_msi_write(hdev, &msg);
508 hpet_msi_unmask(data);
509 return 0;
510}
511
512static int hpet_msi_next_event(unsigned long delta,
513 struct clock_event_device *evt)
514{
515 struct hpet_dev *hdev = EVT_TO_HPET_DEV(evt);
516 return hpet_next_event(delta, evt, hdev->num);
517}
518
519static irqreturn_t hpet_interrupt_handler(int irq, void *data)
520{
521 struct hpet_dev *dev = (struct hpet_dev *)data;
522 struct clock_event_device *hevt = &dev->evt;
523
524 if (!hevt->event_handler) {
525 printk(KERN_INFO "Spurious HPET timer interrupt on HPET timer %d\n",
526 dev->num);
527 return IRQ_HANDLED;
528 }
529
530 hevt->event_handler(hevt);
531 return IRQ_HANDLED;
532}
533
534static int hpet_setup_irq(struct hpet_dev *dev)
535{
536
537 if (request_irq(dev->irq, hpet_interrupt_handler,
538 IRQF_TIMER | IRQF_NOBALANCING,
539 dev->name, dev))
540 return -1;
541
542 disable_irq(dev->irq);
543 irq_set_affinity(dev->irq, cpumask_of(dev->cpu));
544 enable_irq(dev->irq);
545
546 printk(KERN_DEBUG "hpet: %s irq %d for MSI\n",
547 dev->name, dev->irq);
548
549 return 0;
550}
551
552
553static void init_one_hpet_msi_clockevent(struct hpet_dev *hdev, int cpu)
554{
555 struct clock_event_device *evt = &hdev->evt;
556
557 WARN_ON(cpu != smp_processor_id());
558 if (!(hdev->flags & HPET_DEV_VALID))
559 return;
560
561 hdev->cpu = cpu;
562 per_cpu(cpu_hpet_dev, cpu) = hdev;
563 evt->name = hdev->name;
564 hpet_setup_irq(hdev);
565 evt->irq = hdev->irq;
566
567 evt->rating = 110;
568 evt->features = CLOCK_EVT_FEAT_ONESHOT;
569 if (hdev->flags & HPET_DEV_PERI_CAP) {
570 evt->features |= CLOCK_EVT_FEAT_PERIODIC;
571 evt->set_state_periodic = hpet_msi_set_periodic;
572 }
573
574 evt->set_state_shutdown = hpet_msi_shutdown;
575 evt->set_state_oneshot = hpet_msi_set_oneshot;
576 evt->tick_resume = hpet_msi_resume;
577 evt->set_next_event = hpet_msi_next_event;
578 evt->cpumask = cpumask_of(hdev->cpu);
579
580 clockevents_config_and_register(evt, hpet_freq, HPET_MIN_PROG_DELTA,
581 0x7FFFFFFF);
582}
583
584#ifdef CONFIG_HPET
585
586#define RESERVE_TIMERS 1
587#else
588#define RESERVE_TIMERS 0
589#endif
590
591static void hpet_msi_capability_lookup(unsigned int start_timer)
592{
593 unsigned int id;
594 unsigned int num_timers;
595 unsigned int num_timers_used = 0;
596 int i, irq;
597
598 if (hpet_msi_disable)
599 return;
600
601 if (boot_cpu_has(X86_FEATURE_ARAT))
602 return;
603 id = hpet_readl(HPET_ID);
604
605 num_timers = ((id & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT);
606 num_timers++;
607 hpet_print_config();
608
609 hpet_domain = hpet_create_irq_domain(hpet_blockid);
610 if (!hpet_domain)
611 return;
612
613 hpet_devs = kzalloc(sizeof(struct hpet_dev) * num_timers, GFP_KERNEL);
614 if (!hpet_devs)
615 return;
616
617 hpet_num_timers = num_timers;
618
619 for (i = start_timer; i < num_timers - RESERVE_TIMERS; i++) {
620 struct hpet_dev *hdev = &hpet_devs[num_timers_used];
621 unsigned int cfg = hpet_readl(HPET_Tn_CFG(i));
622
623
624 if (!(cfg & HPET_TN_FSB_CAP))
625 continue;
626
627 hdev->flags = 0;
628 if (cfg & HPET_TN_PERIODIC_CAP)
629 hdev->flags |= HPET_DEV_PERI_CAP;
630 sprintf(hdev->name, "hpet%d", i);
631 hdev->num = i;
632
633 irq = hpet_assign_irq(hpet_domain, hdev, hdev->num);
634 if (irq <= 0)
635 continue;
636
637 hdev->irq = irq;
638 hdev->flags |= HPET_DEV_FSB_CAP;
639 hdev->flags |= HPET_DEV_VALID;
640 num_timers_used++;
641 if (num_timers_used == num_possible_cpus())
642 break;
643 }
644
645 printk(KERN_INFO "HPET: %d timers in total, %d timers will be used for per-cpu timer\n",
646 num_timers, num_timers_used);
647}
648
649#ifdef CONFIG_HPET
650static void hpet_reserve_msi_timers(struct hpet_data *hd)
651{
652 int i;
653
654 if (!hpet_devs)
655 return;
656
657 for (i = 0; i < hpet_num_timers; i++) {
658 struct hpet_dev *hdev = &hpet_devs[i];
659
660 if (!(hdev->flags & HPET_DEV_VALID))
661 continue;
662
663 hd->hd_irq[hdev->num] = hdev->irq;
664 hpet_reserve_timer(hd, hdev->num);
665 }
666}
667#endif
668
669static struct hpet_dev *hpet_get_unused_timer(void)
670{
671 int i;
672
673 if (!hpet_devs)
674 return NULL;
675
676 for (i = 0; i < hpet_num_timers; i++) {
677 struct hpet_dev *hdev = &hpet_devs[i];
678
679 if (!(hdev->flags & HPET_DEV_VALID))
680 continue;
681 if (test_and_set_bit(HPET_DEV_USED_BIT,
682 (unsigned long *)&hdev->flags))
683 continue;
684 return hdev;
685 }
686 return NULL;
687}
688
689struct hpet_work_struct {
690 struct delayed_work work;
691 struct completion complete;
692};
693
694static void hpet_work(struct work_struct *w)
695{
696 struct hpet_dev *hdev;
697 int cpu = smp_processor_id();
698 struct hpet_work_struct *hpet_work;
699
700 hpet_work = container_of(w, struct hpet_work_struct, work.work);
701
702 hdev = hpet_get_unused_timer();
703 if (hdev)
704 init_one_hpet_msi_clockevent(hdev, cpu);
705
706 complete(&hpet_work->complete);
707}
708
709static int hpet_cpuhp_online(unsigned int cpu)
710{
711 struct hpet_work_struct work;
712
713 INIT_DELAYED_WORK_ONSTACK(&work.work, hpet_work);
714 init_completion(&work.complete);
715
716 schedule_delayed_work_on(cpu, &work.work, 0);
717 wait_for_completion(&work.complete);
718 destroy_delayed_work_on_stack(&work.work);
719 return 0;
720}
721
722static int hpet_cpuhp_dead(unsigned int cpu)
723{
724 struct hpet_dev *hdev = per_cpu(cpu_hpet_dev, cpu);
725
726 if (!hdev)
727 return 0;
728 free_irq(hdev->irq, hdev);
729 hdev->flags &= ~HPET_DEV_USED;
730 per_cpu(cpu_hpet_dev, cpu) = NULL;
731 return 0;
732}
733#else
734
735static void hpet_msi_capability_lookup(unsigned int start_timer)
736{
737 return;
738}
739
740#ifdef CONFIG_HPET
741static void hpet_reserve_msi_timers(struct hpet_data *hd)
742{
743 return;
744}
745#endif
746
747#define hpet_cpuhp_online NULL
748#define hpet_cpuhp_dead NULL
749
750#endif
751
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754
755#if defined(CONFIG_SMP) && defined(CONFIG_64BIT)
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778union hpet_lock {
779 struct {
780 arch_spinlock_t lock;
781 u32 value;
782 };
783 u64 lockval;
784};
785
786static union hpet_lock hpet __cacheline_aligned = {
787 { .lock = __ARCH_SPIN_LOCK_UNLOCKED, },
788};
789
790static u64 read_hpet(struct clocksource *cs)
791{
792 unsigned long flags;
793 union hpet_lock old, new;
794
795 BUILD_BUG_ON(sizeof(union hpet_lock) != 8);
796
797
798
799
800 if (in_nmi())
801 return (u64)hpet_readl(HPET_COUNTER);
802
803
804
805
806 old.lockval = READ_ONCE(hpet.lockval);
807
808 if (arch_spin_is_locked(&old.lock))
809 goto contended;
810
811 local_irq_save(flags);
812 if (arch_spin_trylock(&hpet.lock)) {
813 new.value = hpet_readl(HPET_COUNTER);
814
815
816
817 WRITE_ONCE(hpet.value, new.value);
818 arch_spin_unlock(&hpet.lock);
819 local_irq_restore(flags);
820 return (u64)new.value;
821 }
822 local_irq_restore(flags);
823
824contended:
825
826
827
828
829
830
831
832
833
834
835
836
837 do {
838 cpu_relax();
839 new.lockval = READ_ONCE(hpet.lockval);
840 } while ((new.value == old.value) && arch_spin_is_locked(&new.lock));
841
842 return (u64)new.value;
843}
844#else
845
846
847
848static u64 read_hpet(struct clocksource *cs)
849{
850 return (u64)hpet_readl(HPET_COUNTER);
851}
852#endif
853
854static struct clocksource clocksource_hpet = {
855 .name = "hpet",
856 .rating = 250,
857 .read = read_hpet,
858 .mask = HPET_MASK,
859 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
860 .resume = hpet_resume_counter,
861};
862
863static int hpet_clocksource_register(void)
864{
865 u64 start, now;
866 u64 t1;
867
868
869 hpet_restart_counter();
870
871
872 t1 = hpet_readl(HPET_COUNTER);
873 start = rdtsc();
874
875
876
877
878
879
880
881 do {
882 rep_nop();
883 now = rdtsc();
884 } while ((now - start) < 200000UL);
885
886 if (t1 == hpet_readl(HPET_COUNTER)) {
887 printk(KERN_WARNING
888 "HPET counter not counting. HPET disabled\n");
889 return -ENODEV;
890 }
891
892 clocksource_register_hz(&clocksource_hpet, (u32)hpet_freq);
893 return 0;
894}
895
896static u32 *hpet_boot_cfg;
897
898
899
900
901int __init hpet_enable(void)
902{
903 u32 hpet_period, cfg, id;
904 u64 freq;
905 unsigned int i, last;
906
907 if (!is_hpet_capable())
908 return 0;
909
910 hpet_set_mapping();
911
912
913
914
915 hpet_period = hpet_readl(HPET_PERIOD);
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930 for (i = 0; hpet_readl(HPET_CFG) == 0xFFFFFFFF; i++) {
931 if (i == 1000) {
932 printk(KERN_WARNING
933 "HPET config register value = 0xFFFFFFFF. "
934 "Disabling HPET\n");
935 goto out_nohpet;
936 }
937 }
938
939 if (hpet_period < HPET_MIN_PERIOD || hpet_period > HPET_MAX_PERIOD)
940 goto out_nohpet;
941
942
943
944
945
946 freq = FSEC_PER_SEC;
947 do_div(freq, hpet_period);
948 hpet_freq = freq;
949
950
951
952
953
954 id = hpet_readl(HPET_ID);
955 hpet_print_config();
956
957 last = (id & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT;
958
959#ifdef CONFIG_HPET_EMULATE_RTC
960
961
962
963
964 if (!last)
965 goto out_nohpet;
966#endif
967
968 cfg = hpet_readl(HPET_CFG);
969 hpet_boot_cfg = kmalloc((last + 2) * sizeof(*hpet_boot_cfg),
970 GFP_KERNEL);
971 if (hpet_boot_cfg)
972 *hpet_boot_cfg = cfg;
973 else
974 pr_warn("HPET initial state will not be saved\n");
975 cfg &= ~(HPET_CFG_ENABLE | HPET_CFG_LEGACY);
976 hpet_writel(cfg, HPET_CFG);
977 if (cfg)
978 pr_warn("HPET: Unrecognized bits %#x set in global cfg\n",
979 cfg);
980
981 for (i = 0; i <= last; ++i) {
982 cfg = hpet_readl(HPET_Tn_CFG(i));
983 if (hpet_boot_cfg)
984 hpet_boot_cfg[i + 1] = cfg;
985 cfg &= ~(HPET_TN_ENABLE | HPET_TN_LEVEL | HPET_TN_FSB);
986 hpet_writel(cfg, HPET_Tn_CFG(i));
987 cfg &= ~(HPET_TN_PERIODIC | HPET_TN_PERIODIC_CAP
988 | HPET_TN_64BIT_CAP | HPET_TN_32BIT | HPET_TN_ROUTE
989 | HPET_TN_FSB | HPET_TN_FSB_CAP);
990 if (cfg)
991 pr_warn("HPET: Unrecognized bits %#x set in cfg#%u\n",
992 cfg, i);
993 }
994 hpet_print_config();
995
996 if (hpet_clocksource_register())
997 goto out_nohpet;
998
999 if (id & HPET_ID_LEGSUP) {
1000 hpet_legacy_clockevent_register();
1001 return 1;
1002 }
1003 return 0;
1004
1005out_nohpet:
1006 hpet_clear_mapping();
1007 hpet_address = 0;
1008 return 0;
1009}
1010
1011
1012
1013
1014
1015
1016
1017static __init int hpet_late_init(void)
1018{
1019 int ret;
1020
1021 if (boot_hpet_disable)
1022 return -ENODEV;
1023
1024 if (!hpet_address) {
1025 if (!force_hpet_address)
1026 return -ENODEV;
1027
1028 hpet_address = force_hpet_address;
1029 hpet_enable();
1030 }
1031
1032 if (!hpet_virt_address)
1033 return -ENODEV;
1034
1035 if (hpet_readl(HPET_ID) & HPET_ID_LEGSUP)
1036 hpet_msi_capability_lookup(2);
1037 else
1038 hpet_msi_capability_lookup(0);
1039
1040 hpet_reserve_platform_timers(hpet_readl(HPET_ID));
1041 hpet_print_config();
1042
1043 if (hpet_msi_disable)
1044 return 0;
1045
1046 if (boot_cpu_has(X86_FEATURE_ARAT))
1047 return 0;
1048
1049
1050 ret = cpuhp_setup_state(CPUHP_AP_X86_HPET_ONLINE, "x86/hpet:online",
1051 hpet_cpuhp_online, NULL);
1052 if (ret)
1053 return ret;
1054 ret = cpuhp_setup_state(CPUHP_X86_HPET_DEAD, "x86/hpet:dead", NULL,
1055 hpet_cpuhp_dead);
1056 if (ret)
1057 goto err_cpuhp;
1058 return 0;
1059
1060err_cpuhp:
1061 cpuhp_remove_state(CPUHP_AP_X86_HPET_ONLINE);
1062 return ret;
1063}
1064fs_initcall(hpet_late_init);
1065
1066void hpet_disable(void)
1067{
1068 if (is_hpet_capable() && hpet_virt_address) {
1069 unsigned int cfg = hpet_readl(HPET_CFG), id, last;
1070
1071 if (hpet_boot_cfg)
1072 cfg = *hpet_boot_cfg;
1073 else if (hpet_legacy_int_enabled) {
1074 cfg &= ~HPET_CFG_LEGACY;
1075 hpet_legacy_int_enabled = false;
1076 }
1077 cfg &= ~HPET_CFG_ENABLE;
1078 hpet_writel(cfg, HPET_CFG);
1079
1080 if (!hpet_boot_cfg)
1081 return;
1082
1083 id = hpet_readl(HPET_ID);
1084 last = ((id & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT);
1085
1086 for (id = 0; id <= last; ++id)
1087 hpet_writel(hpet_boot_cfg[id + 1], HPET_Tn_CFG(id));
1088
1089 if (*hpet_boot_cfg & HPET_CFG_ENABLE)
1090 hpet_writel(*hpet_boot_cfg, HPET_CFG);
1091 }
1092}
1093
1094#ifdef CONFIG_HPET_EMULATE_RTC
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110#include <linux/mc146818rtc.h>
1111#include <linux/rtc.h>
1112
1113#define DEFAULT_RTC_INT_FREQ 64
1114#define DEFAULT_RTC_SHIFT 6
1115#define RTC_NUM_INTS 1
1116
1117static unsigned long hpet_rtc_flags;
1118static int hpet_prev_update_sec;
1119static struct rtc_time hpet_alarm_time;
1120static unsigned long hpet_pie_count;
1121static u32 hpet_t1_cmp;
1122static u32 hpet_default_delta;
1123static u32 hpet_pie_delta;
1124static unsigned long hpet_pie_limit;
1125
1126static rtc_irq_handler irq_handler;
1127
1128
1129
1130
1131static inline int hpet_cnt_ahead(u32 c1, u32 c2)
1132{
1133 return (s32)(c2 - c1) < 0;
1134}
1135
1136
1137
1138
1139int hpet_register_irq_handler(rtc_irq_handler handler)
1140{
1141 if (!is_hpet_enabled())
1142 return -ENODEV;
1143 if (irq_handler)
1144 return -EBUSY;
1145
1146 irq_handler = handler;
1147
1148 return 0;
1149}
1150EXPORT_SYMBOL_GPL(hpet_register_irq_handler);
1151
1152
1153
1154
1155
1156void hpet_unregister_irq_handler(rtc_irq_handler handler)
1157{
1158 if (!is_hpet_enabled())
1159 return;
1160
1161 irq_handler = NULL;
1162 hpet_rtc_flags = 0;
1163}
1164EXPORT_SYMBOL_GPL(hpet_unregister_irq_handler);
1165
1166
1167
1168
1169
1170
1171
1172int hpet_rtc_timer_init(void)
1173{
1174 unsigned int cfg, cnt, delta;
1175 unsigned long flags;
1176
1177 if (!is_hpet_enabled())
1178 return 0;
1179
1180 if (!hpet_default_delta) {
1181 uint64_t clc;
1182
1183 clc = (uint64_t) hpet_clockevent.mult * NSEC_PER_SEC;
1184 clc >>= hpet_clockevent.shift + DEFAULT_RTC_SHIFT;
1185 hpet_default_delta = clc;
1186 }
1187
1188 if (!(hpet_rtc_flags & RTC_PIE) || hpet_pie_limit)
1189 delta = hpet_default_delta;
1190 else
1191 delta = hpet_pie_delta;
1192
1193 local_irq_save(flags);
1194
1195 cnt = delta + hpet_readl(HPET_COUNTER);
1196 hpet_writel(cnt, HPET_T1_CMP);
1197 hpet_t1_cmp = cnt;
1198
1199 cfg = hpet_readl(HPET_T1_CFG);
1200 cfg &= ~HPET_TN_PERIODIC;
1201 cfg |= HPET_TN_ENABLE | HPET_TN_32BIT;
1202 hpet_writel(cfg, HPET_T1_CFG);
1203
1204 local_irq_restore(flags);
1205
1206 return 1;
1207}
1208EXPORT_SYMBOL_GPL(hpet_rtc_timer_init);
1209
1210static void hpet_disable_rtc_channel(void)
1211{
1212 u32 cfg = hpet_readl(HPET_T1_CFG);
1213 cfg &= ~HPET_TN_ENABLE;
1214 hpet_writel(cfg, HPET_T1_CFG);
1215}
1216
1217
1218
1219
1220
1221
1222int hpet_mask_rtc_irq_bit(unsigned long bit_mask)
1223{
1224 if (!is_hpet_enabled())
1225 return 0;
1226
1227 hpet_rtc_flags &= ~bit_mask;
1228 if (unlikely(!hpet_rtc_flags))
1229 hpet_disable_rtc_channel();
1230
1231 return 1;
1232}
1233EXPORT_SYMBOL_GPL(hpet_mask_rtc_irq_bit);
1234
1235int hpet_set_rtc_irq_bit(unsigned long bit_mask)
1236{
1237 unsigned long oldbits = hpet_rtc_flags;
1238
1239 if (!is_hpet_enabled())
1240 return 0;
1241
1242 hpet_rtc_flags |= bit_mask;
1243
1244 if ((bit_mask & RTC_UIE) && !(oldbits & RTC_UIE))
1245 hpet_prev_update_sec = -1;
1246
1247 if (!oldbits)
1248 hpet_rtc_timer_init();
1249
1250 return 1;
1251}
1252EXPORT_SYMBOL_GPL(hpet_set_rtc_irq_bit);
1253
1254int hpet_set_alarm_time(unsigned char hrs, unsigned char min,
1255 unsigned char sec)
1256{
1257 if (!is_hpet_enabled())
1258 return 0;
1259
1260 hpet_alarm_time.tm_hour = hrs;
1261 hpet_alarm_time.tm_min = min;
1262 hpet_alarm_time.tm_sec = sec;
1263
1264 return 1;
1265}
1266EXPORT_SYMBOL_GPL(hpet_set_alarm_time);
1267
1268int hpet_set_periodic_freq(unsigned long freq)
1269{
1270 uint64_t clc;
1271
1272 if (!is_hpet_enabled())
1273 return 0;
1274
1275 if (freq <= DEFAULT_RTC_INT_FREQ)
1276 hpet_pie_limit = DEFAULT_RTC_INT_FREQ / freq;
1277 else {
1278 clc = (uint64_t) hpet_clockevent.mult * NSEC_PER_SEC;
1279 do_div(clc, freq);
1280 clc >>= hpet_clockevent.shift;
1281 hpet_pie_delta = clc;
1282 hpet_pie_limit = 0;
1283 }
1284 return 1;
1285}
1286EXPORT_SYMBOL_GPL(hpet_set_periodic_freq);
1287
1288int hpet_rtc_dropped_irq(void)
1289{
1290 return is_hpet_enabled();
1291}
1292EXPORT_SYMBOL_GPL(hpet_rtc_dropped_irq);
1293
1294static void hpet_rtc_timer_reinit(void)
1295{
1296 unsigned int delta;
1297 int lost_ints = -1;
1298
1299 if (unlikely(!hpet_rtc_flags))
1300 hpet_disable_rtc_channel();
1301
1302 if (!(hpet_rtc_flags & RTC_PIE) || hpet_pie_limit)
1303 delta = hpet_default_delta;
1304 else
1305 delta = hpet_pie_delta;
1306
1307
1308
1309
1310
1311 do {
1312 hpet_t1_cmp += delta;
1313 hpet_writel(hpet_t1_cmp, HPET_T1_CMP);
1314 lost_ints++;
1315 } while (!hpet_cnt_ahead(hpet_t1_cmp, hpet_readl(HPET_COUNTER)));
1316
1317 if (lost_ints) {
1318 if (hpet_rtc_flags & RTC_PIE)
1319 hpet_pie_count += lost_ints;
1320 if (printk_ratelimit())
1321 printk(KERN_WARNING "hpet1: lost %d rtc interrupts\n",
1322 lost_ints);
1323 }
1324}
1325
1326irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id)
1327{
1328 struct rtc_time curr_time;
1329 unsigned long rtc_int_flag = 0;
1330
1331 hpet_rtc_timer_reinit();
1332 memset(&curr_time, 0, sizeof(struct rtc_time));
1333
1334 if (hpet_rtc_flags & (RTC_UIE | RTC_AIE))
1335 mc146818_get_time(&curr_time);
1336
1337 if (hpet_rtc_flags & RTC_UIE &&
1338 curr_time.tm_sec != hpet_prev_update_sec) {
1339 if (hpet_prev_update_sec >= 0)
1340 rtc_int_flag = RTC_UF;
1341 hpet_prev_update_sec = curr_time.tm_sec;
1342 }
1343
1344 if (hpet_rtc_flags & RTC_PIE &&
1345 ++hpet_pie_count >= hpet_pie_limit) {
1346 rtc_int_flag |= RTC_PF;
1347 hpet_pie_count = 0;
1348 }
1349
1350 if (hpet_rtc_flags & RTC_AIE &&
1351 (curr_time.tm_sec == hpet_alarm_time.tm_sec) &&
1352 (curr_time.tm_min == hpet_alarm_time.tm_min) &&
1353 (curr_time.tm_hour == hpet_alarm_time.tm_hour))
1354 rtc_int_flag |= RTC_AF;
1355
1356 if (rtc_int_flag) {
1357 rtc_int_flag |= (RTC_IRQF | (RTC_NUM_INTS << 8));
1358 if (irq_handler)
1359 irq_handler(rtc_int_flag, dev_id);
1360 }
1361 return IRQ_HANDLED;
1362}
1363EXPORT_SYMBOL_GPL(hpet_rtc_interrupt);
1364#endif
1365