Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
[sfrench/cifs-2.6.git] / arch / x86 / kernel / hpet.c
1 #include <linux/clocksource.h>
2 #include <linux/clockchips.h>
3 #include <linux/interrupt.h>
4 #include <linux/sysdev.h>
5 #include <linux/delay.h>
6 #include <linux/errno.h>
7 #include <linux/hpet.h>
8 #include <linux/init.h>
9 #include <linux/cpu.h>
10 #include <linux/pm.h>
11 #include <linux/io.h>
12
13 #include <asm/fixmap.h>
14 #include <asm/i8253.h>
15 #include <asm/hpet.h>
16
17 #define HPET_MASK                       CLOCKSOURCE_MASK(32)
18 #define HPET_SHIFT                      22
19
20 /* FSEC = 10^-15
21    NSEC = 10^-9 */
22 #define FSEC_PER_NSEC                   1000000L
23
24 #define HPET_DEV_USED_BIT               2
25 #define HPET_DEV_USED                   (1 << HPET_DEV_USED_BIT)
26 #define HPET_DEV_VALID                  0x8
27 #define HPET_DEV_FSB_CAP                0x1000
28 #define HPET_DEV_PERI_CAP               0x2000
29
30 #define EVT_TO_HPET_DEV(evt) container_of(evt, struct hpet_dev, evt)
31
32 /*
33  * HPET address is set in acpi/boot.c, when an ACPI entry exists
34  */
35 unsigned long                           hpet_address;
36 #ifdef CONFIG_PCI_MSI
37 static unsigned long                    hpet_num_timers;
38 #endif
39 static void __iomem                     *hpet_virt_address;
40
41 struct hpet_dev {
42         struct clock_event_device       evt;
43         unsigned int                    num;
44         int                             cpu;
45         unsigned int                    irq;
46         unsigned int                    flags;
47         char                            name[10];
48 };
49
50 unsigned long hpet_readl(unsigned long a)
51 {
52         return readl(hpet_virt_address + a);
53 }
54
55 static inline void hpet_writel(unsigned long d, unsigned long a)
56 {
57         writel(d, hpet_virt_address + a);
58 }
59
60 #ifdef CONFIG_X86_64
61 #include <asm/pgtable.h>
62 #endif
63
64 static inline void hpet_set_mapping(void)
65 {
66         hpet_virt_address = ioremap_nocache(hpet_address, HPET_MMAP_SIZE);
67 #ifdef CONFIG_X86_64
68         __set_fixmap(VSYSCALL_HPET, hpet_address, PAGE_KERNEL_VSYSCALL_NOCACHE);
69 #endif
70 }
71
72 static inline void hpet_clear_mapping(void)
73 {
74         iounmap(hpet_virt_address);
75         hpet_virt_address = NULL;
76 }
77
78 /*
79  * HPET command line enable / disable
80  */
81 static int boot_hpet_disable;
82 int hpet_force_user;
83 static int hpet_verbose;
84
85 static int __init hpet_setup(char *str)
86 {
87         if (str) {
88                 if (!strncmp("disable", str, 7))
89                         boot_hpet_disable = 1;
90                 if (!strncmp("force", str, 5))
91                         hpet_force_user = 1;
92                 if (!strncmp("verbose", str, 7))
93                         hpet_verbose = 1;
94         }
95         return 1;
96 }
97 __setup("hpet=", hpet_setup);
98
99 static int __init disable_hpet(char *str)
100 {
101         boot_hpet_disable = 1;
102         return 1;
103 }
104 __setup("nohpet", disable_hpet);
105
106 static inline int is_hpet_capable(void)
107 {
108         return !boot_hpet_disable && hpet_address;
109 }
110
111 /*
112  * HPET timer interrupt enable / disable
113  */
114 static int hpet_legacy_int_enabled;
115
116 /**
117  * is_hpet_enabled - check whether the hpet timer interrupt is enabled
118  */
119 int is_hpet_enabled(void)
120 {
121         return is_hpet_capable() && hpet_legacy_int_enabled;
122 }
123 EXPORT_SYMBOL_GPL(is_hpet_enabled);
124
125 static void _hpet_print_config(const char *function, int line)
126 {
127         u32 i, timers, l, h;
128         printk(KERN_INFO "hpet: %s(%d):\n", function, line);
129         l = hpet_readl(HPET_ID);
130         h = hpet_readl(HPET_PERIOD);
131         timers = ((l & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT) + 1;
132         printk(KERN_INFO "hpet: ID: 0x%x, PERIOD: 0x%x\n", l, h);
133         l = hpet_readl(HPET_CFG);
134         h = hpet_readl(HPET_STATUS);
135         printk(KERN_INFO "hpet: CFG: 0x%x, STATUS: 0x%x\n", l, h);
136         l = hpet_readl(HPET_COUNTER);
137         h = hpet_readl(HPET_COUNTER+4);
138         printk(KERN_INFO "hpet: COUNTER_l: 0x%x, COUNTER_h: 0x%x\n", l, h);
139
140         for (i = 0; i < timers; i++) {
141                 l = hpet_readl(HPET_Tn_CFG(i));
142                 h = hpet_readl(HPET_Tn_CFG(i)+4);
143                 printk(KERN_INFO "hpet: T%d: CFG_l: 0x%x, CFG_h: 0x%x\n",
144                        i, l, h);
145                 l = hpet_readl(HPET_Tn_CMP(i));
146                 h = hpet_readl(HPET_Tn_CMP(i)+4);
147                 printk(KERN_INFO "hpet: T%d: CMP_l: 0x%x, CMP_h: 0x%x\n",
148                        i, l, h);
149                 l = hpet_readl(HPET_Tn_ROUTE(i));
150                 h = hpet_readl(HPET_Tn_ROUTE(i)+4);
151                 printk(KERN_INFO "hpet: T%d ROUTE_l: 0x%x, ROUTE_h: 0x%x\n",
152                        i, l, h);
153         }
154 }
155
156 #define hpet_print_config()                                     \
157 do {                                                            \
158         if (hpet_verbose)                                       \
159                 _hpet_print_config(__FUNCTION__, __LINE__);     \
160 } while (0)
161
162 /*
163  * When the hpet driver (/dev/hpet) is enabled, we need to reserve
164  * timer 0 and timer 1 in case of RTC emulation.
165  */
166 #ifdef CONFIG_HPET
167
168 static void hpet_reserve_msi_timers(struct hpet_data *hd);
169
170 static void hpet_reserve_platform_timers(unsigned long id)
171 {
172         struct hpet __iomem *hpet = hpet_virt_address;
173         struct hpet_timer __iomem *timer = &hpet->hpet_timers[2];
174         unsigned int nrtimers, i;
175         struct hpet_data hd;
176
177         nrtimers = ((id & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT) + 1;
178
179         memset(&hd, 0, sizeof(hd));
180         hd.hd_phys_address      = hpet_address;
181         hd.hd_address           = hpet;
182         hd.hd_nirqs             = nrtimers;
183         hpet_reserve_timer(&hd, 0);
184
185 #ifdef CONFIG_HPET_EMULATE_RTC
186         hpet_reserve_timer(&hd, 1);
187 #endif
188
189         /*
190          * NOTE that hd_irq[] reflects IOAPIC input pins (LEGACY_8254
191          * is wrong for i8259!) not the output IRQ.  Many BIOS writers
192          * don't bother configuring *any* comparator interrupts.
193          */
194         hd.hd_irq[0] = HPET_LEGACY_8254;
195         hd.hd_irq[1] = HPET_LEGACY_RTC;
196
197         for (i = 2; i < nrtimers; timer++, i++) {
198                 hd.hd_irq[i] = (readl(&timer->hpet_config) &
199                         Tn_INT_ROUTE_CNF_MASK) >> Tn_INT_ROUTE_CNF_SHIFT;
200         }
201
202         hpet_reserve_msi_timers(&hd);
203
204         hpet_alloc(&hd);
205
206 }
207 #else
208 static void hpet_reserve_platform_timers(unsigned long id) { }
209 #endif
210
211 /*
212  * Common hpet info
213  */
214 static unsigned long hpet_period;
215
216 static void hpet_legacy_set_mode(enum clock_event_mode mode,
217                           struct clock_event_device *evt);
218 static int hpet_legacy_next_event(unsigned long delta,
219                            struct clock_event_device *evt);
220
221 /*
222  * The hpet clock event device
223  */
224 static struct clock_event_device hpet_clockevent = {
225         .name           = "hpet",
226         .features       = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
227         .set_mode       = hpet_legacy_set_mode,
228         .set_next_event = hpet_legacy_next_event,
229         .shift          = 32,
230         .irq            = 0,
231         .rating         = 50,
232 };
233
234 static void hpet_stop_counter(void)
235 {
236         unsigned long cfg = hpet_readl(HPET_CFG);
237         cfg &= ~HPET_CFG_ENABLE;
238         hpet_writel(cfg, HPET_CFG);
239 }
240
241 static void hpet_reset_counter(void)
242 {
243         hpet_writel(0, HPET_COUNTER);
244         hpet_writel(0, HPET_COUNTER + 4);
245 }
246
247 static void hpet_start_counter(void)
248 {
249         unsigned long cfg = hpet_readl(HPET_CFG);
250         cfg |= HPET_CFG_ENABLE;
251         hpet_writel(cfg, HPET_CFG);
252 }
253
254 static void hpet_restart_counter(void)
255 {
256         hpet_stop_counter();
257         hpet_reset_counter();
258         hpet_start_counter();
259 }
260
261 static void hpet_resume_device(void)
262 {
263         force_hpet_resume();
264 }
265
266 static void hpet_resume_counter(void)
267 {
268         hpet_resume_device();
269         hpet_restart_counter();
270 }
271
272 static void hpet_enable_legacy_int(void)
273 {
274         unsigned long cfg = hpet_readl(HPET_CFG);
275
276         cfg |= HPET_CFG_LEGACY;
277         hpet_writel(cfg, HPET_CFG);
278         hpet_legacy_int_enabled = 1;
279 }
280
281 static void hpet_legacy_clockevent_register(void)
282 {
283         /* Start HPET legacy interrupts */
284         hpet_enable_legacy_int();
285
286         /*
287          * The mult factor is defined as (include/linux/clockchips.h)
288          *  mult/2^shift = cyc/ns (in contrast to ns/cyc in clocksource.h)
289          * hpet_period is in units of femtoseconds (per cycle), so
290          *  mult/2^shift = cyc/ns = 10^6/hpet_period
291          *  mult = (10^6 * 2^shift)/hpet_period
292          *  mult = (FSEC_PER_NSEC << hpet_clockevent.shift)/hpet_period
293          */
294         hpet_clockevent.mult = div_sc((unsigned long) FSEC_PER_NSEC,
295                                       hpet_period, hpet_clockevent.shift);
296         /* Calculate the min / max delta */
297         hpet_clockevent.max_delta_ns = clockevent_delta2ns(0x7FFFFFFF,
298                                                            &hpet_clockevent);
299         /* 5 usec minimum reprogramming delta. */
300         hpet_clockevent.min_delta_ns = 5000;
301
302         /*
303          * Start hpet with the boot cpu mask and make it
304          * global after the IO_APIC has been initialized.
305          */
306         hpet_clockevent.cpumask = cpumask_of(smp_processor_id());
307         clockevents_register_device(&hpet_clockevent);
308         global_clock_event = &hpet_clockevent;
309         printk(KERN_DEBUG "hpet clockevent registered\n");
310 }
311
312 static int hpet_setup_msi_irq(unsigned int irq);
313
314 static void hpet_set_mode(enum clock_event_mode mode,
315                           struct clock_event_device *evt, int timer)
316 {
317         unsigned long cfg, cmp, now;
318         uint64_t delta;
319
320         switch (mode) {
321         case CLOCK_EVT_MODE_PERIODIC:
322                 hpet_stop_counter();
323                 delta = ((uint64_t)(NSEC_PER_SEC/HZ)) * evt->mult;
324                 delta >>= evt->shift;
325                 now = hpet_readl(HPET_COUNTER);
326                 cmp = now + (unsigned long) delta;
327                 cfg = hpet_readl(HPET_Tn_CFG(timer));
328                 /* Make sure we use edge triggered interrupts */
329                 cfg &= ~HPET_TN_LEVEL;
330                 cfg |= HPET_TN_ENABLE | HPET_TN_PERIODIC |
331                        HPET_TN_SETVAL | HPET_TN_32BIT;
332                 hpet_writel(cfg, HPET_Tn_CFG(timer));
333                 hpet_writel(cmp, HPET_Tn_CMP(timer));
334                 udelay(1);
335                 /*
336                  * HPET on AMD 81xx needs a second write (with HPET_TN_SETVAL
337                  * cleared) to T0_CMP to set the period. The HPET_TN_SETVAL
338                  * bit is automatically cleared after the first write.
339                  * (See AMD-8111 HyperTransport I/O Hub Data Sheet,
340                  * Publication # 24674)
341                  */
342                 hpet_writel((unsigned long) delta, HPET_Tn_CMP(timer));
343                 hpet_start_counter();
344                 hpet_print_config();
345                 break;
346
347         case CLOCK_EVT_MODE_ONESHOT:
348                 cfg = hpet_readl(HPET_Tn_CFG(timer));
349                 cfg &= ~HPET_TN_PERIODIC;
350                 cfg |= HPET_TN_ENABLE | HPET_TN_32BIT;
351                 hpet_writel(cfg, HPET_Tn_CFG(timer));
352                 break;
353
354         case CLOCK_EVT_MODE_UNUSED:
355         case CLOCK_EVT_MODE_SHUTDOWN:
356                 cfg = hpet_readl(HPET_Tn_CFG(timer));
357                 cfg &= ~HPET_TN_ENABLE;
358                 hpet_writel(cfg, HPET_Tn_CFG(timer));
359                 break;
360
361         case CLOCK_EVT_MODE_RESUME:
362                 if (timer == 0) {
363                         hpet_enable_legacy_int();
364                 } else {
365                         struct hpet_dev *hdev = EVT_TO_HPET_DEV(evt);
366                         hpet_setup_msi_irq(hdev->irq);
367                         disable_irq(hdev->irq);
368                         irq_set_affinity(hdev->irq, cpumask_of(hdev->cpu));
369                         enable_irq(hdev->irq);
370                 }
371                 hpet_print_config();
372                 break;
373         }
374 }
375
376 static int hpet_next_event(unsigned long delta,
377                            struct clock_event_device *evt, int timer)
378 {
379         u32 cnt;
380
381         cnt = hpet_readl(HPET_COUNTER);
382         cnt += (u32) delta;
383         hpet_writel(cnt, HPET_Tn_CMP(timer));
384
385         /*
386          * We need to read back the CMP register to make sure that
387          * what we wrote hit the chip before we compare it to the
388          * counter.
389          */
390         WARN_ON_ONCE((u32)hpet_readl(HPET_Tn_CMP(timer)) != cnt);
391
392         return (s32)((u32)hpet_readl(HPET_COUNTER) - cnt) >= 0 ? -ETIME : 0;
393 }
394
395 static void hpet_legacy_set_mode(enum clock_event_mode mode,
396                         struct clock_event_device *evt)
397 {
398         hpet_set_mode(mode, evt, 0);
399 }
400
401 static int hpet_legacy_next_event(unsigned long delta,
402                         struct clock_event_device *evt)
403 {
404         return hpet_next_event(delta, evt, 0);
405 }
406
407 /*
408  * HPET MSI Support
409  */
410 #ifdef CONFIG_PCI_MSI
411
412 static DEFINE_PER_CPU(struct hpet_dev *, cpu_hpet_dev);
413 static struct hpet_dev  *hpet_devs;
414
415 void hpet_msi_unmask(unsigned int irq)
416 {
417         struct hpet_dev *hdev = get_irq_data(irq);
418         unsigned long cfg;
419
420         /* unmask it */
421         cfg = hpet_readl(HPET_Tn_CFG(hdev->num));
422         cfg |= HPET_TN_FSB;
423         hpet_writel(cfg, HPET_Tn_CFG(hdev->num));
424 }
425
426 void hpet_msi_mask(unsigned int irq)
427 {
428         unsigned long cfg;
429         struct hpet_dev *hdev = get_irq_data(irq);
430
431         /* mask it */
432         cfg = hpet_readl(HPET_Tn_CFG(hdev->num));
433         cfg &= ~HPET_TN_FSB;
434         hpet_writel(cfg, HPET_Tn_CFG(hdev->num));
435 }
436
437 void hpet_msi_write(unsigned int irq, struct msi_msg *msg)
438 {
439         struct hpet_dev *hdev = get_irq_data(irq);
440
441         hpet_writel(msg->data, HPET_Tn_ROUTE(hdev->num));
442         hpet_writel(msg->address_lo, HPET_Tn_ROUTE(hdev->num) + 4);
443 }
444
445 void hpet_msi_read(unsigned int irq, struct msi_msg *msg)
446 {
447         struct hpet_dev *hdev = get_irq_data(irq);
448
449         msg->data = hpet_readl(HPET_Tn_ROUTE(hdev->num));
450         msg->address_lo = hpet_readl(HPET_Tn_ROUTE(hdev->num) + 4);
451         msg->address_hi = 0;
452 }
453
454 static void hpet_msi_set_mode(enum clock_event_mode mode,
455                                 struct clock_event_device *evt)
456 {
457         struct hpet_dev *hdev = EVT_TO_HPET_DEV(evt);
458         hpet_set_mode(mode, evt, hdev->num);
459 }
460
461 static int hpet_msi_next_event(unsigned long delta,
462                                 struct clock_event_device *evt)
463 {
464         struct hpet_dev *hdev = EVT_TO_HPET_DEV(evt);
465         return hpet_next_event(delta, evt, hdev->num);
466 }
467
468 static int hpet_setup_msi_irq(unsigned int irq)
469 {
470         if (arch_setup_hpet_msi(irq)) {
471                 destroy_irq(irq);
472                 return -EINVAL;
473         }
474         return 0;
475 }
476
477 static int hpet_assign_irq(struct hpet_dev *dev)
478 {
479         unsigned int irq;
480
481         irq = create_irq();
482         if (!irq)
483                 return -EINVAL;
484
485         set_irq_data(irq, dev);
486
487         if (hpet_setup_msi_irq(irq))
488                 return -EINVAL;
489
490         dev->irq = irq;
491         return 0;
492 }
493
494 static irqreturn_t hpet_interrupt_handler(int irq, void *data)
495 {
496         struct hpet_dev *dev = (struct hpet_dev *)data;
497         struct clock_event_device *hevt = &dev->evt;
498
499         if (!hevt->event_handler) {
500                 printk(KERN_INFO "Spurious HPET timer interrupt on HPET timer %d\n",
501                                 dev->num);
502                 return IRQ_HANDLED;
503         }
504
505         hevt->event_handler(hevt);
506         return IRQ_HANDLED;
507 }
508
509 static int hpet_setup_irq(struct hpet_dev *dev)
510 {
511
512         if (request_irq(dev->irq, hpet_interrupt_handler,
513                         IRQF_TIMER | IRQF_DISABLED | IRQF_NOBALANCING,
514                         dev->name, dev))
515                 return -1;
516
517         disable_irq(dev->irq);
518         irq_set_affinity(dev->irq, cpumask_of(dev->cpu));
519         enable_irq(dev->irq);
520
521         printk(KERN_DEBUG "hpet: %s irq %d for MSI\n",
522                          dev->name, dev->irq);
523
524         return 0;
525 }
526
527 /* This should be called in specific @cpu */
528 static void init_one_hpet_msi_clockevent(struct hpet_dev *hdev, int cpu)
529 {
530         struct clock_event_device *evt = &hdev->evt;
531         uint64_t hpet_freq;
532
533         WARN_ON(cpu != smp_processor_id());
534         if (!(hdev->flags & HPET_DEV_VALID))
535                 return;
536
537         if (hpet_setup_msi_irq(hdev->irq))
538                 return;
539
540         hdev->cpu = cpu;
541         per_cpu(cpu_hpet_dev, cpu) = hdev;
542         evt->name = hdev->name;
543         hpet_setup_irq(hdev);
544         evt->irq = hdev->irq;
545
546         evt->rating = 110;
547         evt->features = CLOCK_EVT_FEAT_ONESHOT;
548         if (hdev->flags & HPET_DEV_PERI_CAP)
549                 evt->features |= CLOCK_EVT_FEAT_PERIODIC;
550
551         evt->set_mode = hpet_msi_set_mode;
552         evt->set_next_event = hpet_msi_next_event;
553         evt->shift = 32;
554
555         /*
556          * The period is a femto seconds value. We need to calculate the
557          * scaled math multiplication factor for nanosecond to hpet tick
558          * conversion.
559          */
560         hpet_freq = 1000000000000000ULL;
561         do_div(hpet_freq, hpet_period);
562         evt->mult = div_sc((unsigned long) hpet_freq,
563                                       NSEC_PER_SEC, evt->shift);
564         /* Calculate the max delta */
565         evt->max_delta_ns = clockevent_delta2ns(0x7FFFFFFF, evt);
566         /* 5 usec minimum reprogramming delta. */
567         evt->min_delta_ns = 5000;
568
569         evt->cpumask = cpumask_of(hdev->cpu);
570         clockevents_register_device(evt);
571 }
572
573 #ifdef CONFIG_HPET
574 /* Reserve at least one timer for userspace (/dev/hpet) */
575 #define RESERVE_TIMERS 1
576 #else
577 #define RESERVE_TIMERS 0
578 #endif
579
580 static void hpet_msi_capability_lookup(unsigned int start_timer)
581 {
582         unsigned int id;
583         unsigned int num_timers;
584         unsigned int num_timers_used = 0;
585         int i;
586
587         id = hpet_readl(HPET_ID);
588
589         num_timers = ((id & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT);
590         num_timers++; /* Value read out starts from 0 */
591         hpet_print_config();
592
593         hpet_devs = kzalloc(sizeof(struct hpet_dev) * num_timers, GFP_KERNEL);
594         if (!hpet_devs)
595                 return;
596
597         hpet_num_timers = num_timers;
598
599         for (i = start_timer; i < num_timers - RESERVE_TIMERS; i++) {
600                 struct hpet_dev *hdev = &hpet_devs[num_timers_used];
601                 unsigned long cfg = hpet_readl(HPET_Tn_CFG(i));
602
603                 /* Only consider HPET timer with MSI support */
604                 if (!(cfg & HPET_TN_FSB_CAP))
605                         continue;
606
607                 hdev->flags = 0;
608                 if (cfg & HPET_TN_PERIODIC_CAP)
609                         hdev->flags |= HPET_DEV_PERI_CAP;
610                 hdev->num = i;
611
612                 sprintf(hdev->name, "hpet%d", i);
613                 if (hpet_assign_irq(hdev))
614                         continue;
615
616                 hdev->flags |= HPET_DEV_FSB_CAP;
617                 hdev->flags |= HPET_DEV_VALID;
618                 num_timers_used++;
619                 if (num_timers_used == num_possible_cpus())
620                         break;
621         }
622
623         printk(KERN_INFO "HPET: %d timers in total, %d timers will be used for per-cpu timer\n",
624                 num_timers, num_timers_used);
625 }
626
627 #ifdef CONFIG_HPET
628 static void hpet_reserve_msi_timers(struct hpet_data *hd)
629 {
630         int i;
631
632         if (!hpet_devs)
633                 return;
634
635         for (i = 0; i < hpet_num_timers; i++) {
636                 struct hpet_dev *hdev = &hpet_devs[i];
637
638                 if (!(hdev->flags & HPET_DEV_VALID))
639                         continue;
640
641                 hd->hd_irq[hdev->num] = hdev->irq;
642                 hpet_reserve_timer(hd, hdev->num);
643         }
644 }
645 #endif
646
647 static struct hpet_dev *hpet_get_unused_timer(void)
648 {
649         int i;
650
651         if (!hpet_devs)
652                 return NULL;
653
654         for (i = 0; i < hpet_num_timers; i++) {
655                 struct hpet_dev *hdev = &hpet_devs[i];
656
657                 if (!(hdev->flags & HPET_DEV_VALID))
658                         continue;
659                 if (test_and_set_bit(HPET_DEV_USED_BIT,
660                         (unsigned long *)&hdev->flags))
661                         continue;
662                 return hdev;
663         }
664         return NULL;
665 }
666
667 struct hpet_work_struct {
668         struct delayed_work work;
669         struct completion complete;
670 };
671
672 static void hpet_work(struct work_struct *w)
673 {
674         struct hpet_dev *hdev;
675         int cpu = smp_processor_id();
676         struct hpet_work_struct *hpet_work;
677
678         hpet_work = container_of(w, struct hpet_work_struct, work.work);
679
680         hdev = hpet_get_unused_timer();
681         if (hdev)
682                 init_one_hpet_msi_clockevent(hdev, cpu);
683
684         complete(&hpet_work->complete);
685 }
686
687 static int hpet_cpuhp_notify(struct notifier_block *n,
688                 unsigned long action, void *hcpu)
689 {
690         unsigned long cpu = (unsigned long)hcpu;
691         struct hpet_work_struct work;
692         struct hpet_dev *hdev = per_cpu(cpu_hpet_dev, cpu);
693
694         switch (action & 0xf) {
695         case CPU_ONLINE:
696                 INIT_DELAYED_WORK_ON_STACK(&work.work, hpet_work);
697                 init_completion(&work.complete);
698                 /* FIXME: add schedule_work_on() */
699                 schedule_delayed_work_on(cpu, &work.work, 0);
700                 wait_for_completion(&work.complete);
701                 destroy_timer_on_stack(&work.work.timer);
702                 break;
703         case CPU_DEAD:
704                 if (hdev) {
705                         free_irq(hdev->irq, hdev);
706                         hdev->flags &= ~HPET_DEV_USED;
707                         per_cpu(cpu_hpet_dev, cpu) = NULL;
708                 }
709                 break;
710         }
711         return NOTIFY_OK;
712 }
713 #else
714
715 static int hpet_setup_msi_irq(unsigned int irq)
716 {
717         return 0;
718 }
719 static void hpet_msi_capability_lookup(unsigned int start_timer)
720 {
721         return;
722 }
723
724 #ifdef CONFIG_HPET
725 static void hpet_reserve_msi_timers(struct hpet_data *hd)
726 {
727         return;
728 }
729 #endif
730
731 static int hpet_cpuhp_notify(struct notifier_block *n,
732                 unsigned long action, void *hcpu)
733 {
734         return NOTIFY_OK;
735 }
736
737 #endif
738
739 /*
740  * Clock source related code
741  */
742 static cycle_t read_hpet(struct clocksource *cs)
743 {
744         return (cycle_t)hpet_readl(HPET_COUNTER);
745 }
746
747 #ifdef CONFIG_X86_64
748 static cycle_t __vsyscall_fn vread_hpet(void)
749 {
750         return readl((const void __iomem *)fix_to_virt(VSYSCALL_HPET) + 0xf0);
751 }
752 #endif
753
754 static struct clocksource clocksource_hpet = {
755         .name           = "hpet",
756         .rating         = 250,
757         .read           = read_hpet,
758         .mask           = HPET_MASK,
759         .shift          = HPET_SHIFT,
760         .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
761         .resume         = hpet_resume_counter,
762 #ifdef CONFIG_X86_64
763         .vread          = vread_hpet,
764 #endif
765 };
766
767 static int hpet_clocksource_register(void)
768 {
769         u64 start, now;
770         cycle_t t1;
771
772         /* Start the counter */
773         hpet_restart_counter();
774
775         /* Verify whether hpet counter works */
776         t1 = hpet_readl(HPET_COUNTER);
777         rdtscll(start);
778
779         /*
780          * We don't know the TSC frequency yet, but waiting for
781          * 200000 TSC cycles is safe:
782          * 4 GHz == 50us
783          * 1 GHz == 200us
784          */
785         do {
786                 rep_nop();
787                 rdtscll(now);
788         } while ((now - start) < 200000UL);
789
790         if (t1 == hpet_readl(HPET_COUNTER)) {
791                 printk(KERN_WARNING
792                        "HPET counter not counting. HPET disabled\n");
793                 return -ENODEV;
794         }
795
796         /*
797          * The definition of mult is (include/linux/clocksource.h)
798          * mult/2^shift = ns/cyc and hpet_period is in units of fsec/cyc
799          * so we first need to convert hpet_period to ns/cyc units:
800          *  mult/2^shift = ns/cyc = hpet_period/10^6
801          *  mult = (hpet_period * 2^shift)/10^6
802          *  mult = (hpet_period << shift)/FSEC_PER_NSEC
803          */
804         clocksource_hpet.mult = div_sc(hpet_period, FSEC_PER_NSEC, HPET_SHIFT);
805
806         clocksource_register(&clocksource_hpet);
807
808         return 0;
809 }
810
811 /**
812  * hpet_enable - Try to setup the HPET timer. Returns 1 on success.
813  */
814 int __init hpet_enable(void)
815 {
816         unsigned long id;
817         int i;
818
819         if (!is_hpet_capable())
820                 return 0;
821
822         hpet_set_mapping();
823
824         /*
825          * Read the period and check for a sane value:
826          */
827         hpet_period = hpet_readl(HPET_PERIOD);
828
829         /*
830          * AMD SB700 based systems with spread spectrum enabled use a
831          * SMM based HPET emulation to provide proper frequency
832          * setting. The SMM code is initialized with the first HPET
833          * register access and takes some time to complete. During
834          * this time the config register reads 0xffffffff. We check
835          * for max. 1000 loops whether the config register reads a non
836          * 0xffffffff value to make sure that HPET is up and running
837          * before we go further. A counting loop is safe, as the HPET
838          * access takes thousands of CPU cycles. On non SB700 based
839          * machines this check is only done once and has no side
840          * effects.
841          */
842         for (i = 0; hpet_readl(HPET_CFG) == 0xFFFFFFFF; i++) {
843                 if (i == 1000) {
844                         printk(KERN_WARNING
845                                "HPET config register value = 0xFFFFFFFF. "
846                                "Disabling HPET\n");
847                         goto out_nohpet;
848                 }
849         }
850
851         if (hpet_period < HPET_MIN_PERIOD || hpet_period > HPET_MAX_PERIOD)
852                 goto out_nohpet;
853
854         /*
855          * Read the HPET ID register to retrieve the IRQ routing
856          * information and the number of channels
857          */
858         id = hpet_readl(HPET_ID);
859         hpet_print_config();
860
861 #ifdef CONFIG_HPET_EMULATE_RTC
862         /*
863          * The legacy routing mode needs at least two channels, tick timer
864          * and the rtc emulation channel.
865          */
866         if (!(id & HPET_ID_NUMBER))
867                 goto out_nohpet;
868 #endif
869
870         if (hpet_clocksource_register())
871                 goto out_nohpet;
872
873         if (id & HPET_ID_LEGSUP) {
874                 hpet_legacy_clockevent_register();
875                 hpet_msi_capability_lookup(2);
876                 return 1;
877         }
878         hpet_msi_capability_lookup(0);
879         return 0;
880
881 out_nohpet:
882         hpet_clear_mapping();
883         hpet_address = 0;
884         return 0;
885 }
886
887 /*
888  * Needs to be late, as the reserve_timer code calls kalloc !
889  *
890  * Not a problem on i386 as hpet_enable is called from late_time_init,
891  * but on x86_64 it is necessary !
892  */
893 static __init int hpet_late_init(void)
894 {
895         int cpu;
896
897         if (boot_hpet_disable)
898                 return -ENODEV;
899
900         if (!hpet_address) {
901                 if (!force_hpet_address)
902                         return -ENODEV;
903
904                 hpet_address = force_hpet_address;
905                 hpet_enable();
906         }
907
908         if (!hpet_virt_address)
909                 return -ENODEV;
910
911         hpet_reserve_platform_timers(hpet_readl(HPET_ID));
912         hpet_print_config();
913
914         for_each_online_cpu(cpu) {
915                 hpet_cpuhp_notify(NULL, CPU_ONLINE, (void *)(long)cpu);
916         }
917
918         /* This notifier should be called after workqueue is ready */
919         hotcpu_notifier(hpet_cpuhp_notify, -20);
920
921         return 0;
922 }
923 fs_initcall(hpet_late_init);
924
925 void hpet_disable(void)
926 {
927         if (is_hpet_capable()) {
928                 unsigned long cfg = hpet_readl(HPET_CFG);
929
930                 if (hpet_legacy_int_enabled) {
931                         cfg &= ~HPET_CFG_LEGACY;
932                         hpet_legacy_int_enabled = 0;
933                 }
934                 cfg &= ~HPET_CFG_ENABLE;
935                 hpet_writel(cfg, HPET_CFG);
936         }
937 }
938
939 #ifdef CONFIG_HPET_EMULATE_RTC
940
941 /* HPET in LegacyReplacement Mode eats up RTC interrupt line. When, HPET
942  * is enabled, we support RTC interrupt functionality in software.
943  * RTC has 3 kinds of interrupts:
944  * 1) Update Interrupt - generate an interrupt, every sec, when RTC clock
945  *    is updated
946  * 2) Alarm Interrupt - generate an interrupt at a specific time of day
947  * 3) Periodic Interrupt - generate periodic interrupt, with frequencies
948  *    2Hz-8192Hz (2Hz-64Hz for non-root user) (all freqs in powers of 2)
949  * (1) and (2) above are implemented using polling at a frequency of
950  * 64 Hz. The exact frequency is a tradeoff between accuracy and interrupt
951  * overhead. (DEFAULT_RTC_INT_FREQ)
952  * For (3), we use interrupts at 64Hz or user specified periodic
953  * frequency, whichever is higher.
954  */
955 #include <linux/mc146818rtc.h>
956 #include <linux/rtc.h>
957 #include <asm/rtc.h>
958
959 #define DEFAULT_RTC_INT_FREQ    64
960 #define DEFAULT_RTC_SHIFT       6
961 #define RTC_NUM_INTS            1
962
963 static unsigned long hpet_rtc_flags;
964 static int hpet_prev_update_sec;
965 static struct rtc_time hpet_alarm_time;
966 static unsigned long hpet_pie_count;
967 static u32 hpet_t1_cmp;
968 static unsigned long hpet_default_delta;
969 static unsigned long hpet_pie_delta;
970 static unsigned long hpet_pie_limit;
971
972 static rtc_irq_handler irq_handler;
973
974 /*
975  * Check that the hpet counter c1 is ahead of the c2
976  */
977 static inline int hpet_cnt_ahead(u32 c1, u32 c2)
978 {
979         return (s32)(c2 - c1) < 0;
980 }
981
982 /*
983  * Registers a IRQ handler.
984  */
985 int hpet_register_irq_handler(rtc_irq_handler handler)
986 {
987         if (!is_hpet_enabled())
988                 return -ENODEV;
989         if (irq_handler)
990                 return -EBUSY;
991
992         irq_handler = handler;
993
994         return 0;
995 }
996 EXPORT_SYMBOL_GPL(hpet_register_irq_handler);
997
998 /*
999  * Deregisters the IRQ handler registered with hpet_register_irq_handler()
1000  * and does cleanup.
1001  */
1002 void hpet_unregister_irq_handler(rtc_irq_handler handler)
1003 {
1004         if (!is_hpet_enabled())
1005                 return;
1006
1007         irq_handler = NULL;
1008         hpet_rtc_flags = 0;
1009 }
1010 EXPORT_SYMBOL_GPL(hpet_unregister_irq_handler);
1011
1012 /*
1013  * Timer 1 for RTC emulation. We use one shot mode, as periodic mode
1014  * is not supported by all HPET implementations for timer 1.
1015  *
1016  * hpet_rtc_timer_init() is called when the rtc is initialized.
1017  */
1018 int hpet_rtc_timer_init(void)
1019 {
1020         unsigned long cfg, cnt, delta, flags;
1021
1022         if (!is_hpet_enabled())
1023                 return 0;
1024
1025         if (!hpet_default_delta) {
1026                 uint64_t clc;
1027
1028                 clc = (uint64_t) hpet_clockevent.mult * NSEC_PER_SEC;
1029                 clc >>= hpet_clockevent.shift + DEFAULT_RTC_SHIFT;
1030                 hpet_default_delta = (unsigned long) clc;
1031         }
1032
1033         if (!(hpet_rtc_flags & RTC_PIE) || hpet_pie_limit)
1034                 delta = hpet_default_delta;
1035         else
1036                 delta = hpet_pie_delta;
1037
1038         local_irq_save(flags);
1039
1040         cnt = delta + hpet_readl(HPET_COUNTER);
1041         hpet_writel(cnt, HPET_T1_CMP);
1042         hpet_t1_cmp = cnt;
1043
1044         cfg = hpet_readl(HPET_T1_CFG);
1045         cfg &= ~HPET_TN_PERIODIC;
1046         cfg |= HPET_TN_ENABLE | HPET_TN_32BIT;
1047         hpet_writel(cfg, HPET_T1_CFG);
1048
1049         local_irq_restore(flags);
1050
1051         return 1;
1052 }
1053 EXPORT_SYMBOL_GPL(hpet_rtc_timer_init);
1054
1055 /*
1056  * The functions below are called from rtc driver.
1057  * Return 0 if HPET is not being used.
1058  * Otherwise do the necessary changes and return 1.
1059  */
1060 int hpet_mask_rtc_irq_bit(unsigned long bit_mask)
1061 {
1062         if (!is_hpet_enabled())
1063                 return 0;
1064
1065         hpet_rtc_flags &= ~bit_mask;
1066         return 1;
1067 }
1068 EXPORT_SYMBOL_GPL(hpet_mask_rtc_irq_bit);
1069
1070 int hpet_set_rtc_irq_bit(unsigned long bit_mask)
1071 {
1072         unsigned long oldbits = hpet_rtc_flags;
1073
1074         if (!is_hpet_enabled())
1075                 return 0;
1076
1077         hpet_rtc_flags |= bit_mask;
1078
1079         if ((bit_mask & RTC_UIE) && !(oldbits & RTC_UIE))
1080                 hpet_prev_update_sec = -1;
1081
1082         if (!oldbits)
1083                 hpet_rtc_timer_init();
1084
1085         return 1;
1086 }
1087 EXPORT_SYMBOL_GPL(hpet_set_rtc_irq_bit);
1088
1089 int hpet_set_alarm_time(unsigned char hrs, unsigned char min,
1090                         unsigned char sec)
1091 {
1092         if (!is_hpet_enabled())
1093                 return 0;
1094
1095         hpet_alarm_time.tm_hour = hrs;
1096         hpet_alarm_time.tm_min = min;
1097         hpet_alarm_time.tm_sec = sec;
1098
1099         return 1;
1100 }
1101 EXPORT_SYMBOL_GPL(hpet_set_alarm_time);
1102
1103 int hpet_set_periodic_freq(unsigned long freq)
1104 {
1105         uint64_t clc;
1106
1107         if (!is_hpet_enabled())
1108                 return 0;
1109
1110         if (freq <= DEFAULT_RTC_INT_FREQ)
1111                 hpet_pie_limit = DEFAULT_RTC_INT_FREQ / freq;
1112         else {
1113                 clc = (uint64_t) hpet_clockevent.mult * NSEC_PER_SEC;
1114                 do_div(clc, freq);
1115                 clc >>= hpet_clockevent.shift;
1116                 hpet_pie_delta = (unsigned long) clc;
1117         }
1118         return 1;
1119 }
1120 EXPORT_SYMBOL_GPL(hpet_set_periodic_freq);
1121
1122 int hpet_rtc_dropped_irq(void)
1123 {
1124         return is_hpet_enabled();
1125 }
1126 EXPORT_SYMBOL_GPL(hpet_rtc_dropped_irq);
1127
1128 static void hpet_rtc_timer_reinit(void)
1129 {
1130         unsigned long cfg, delta;
1131         int lost_ints = -1;
1132
1133         if (unlikely(!hpet_rtc_flags)) {
1134                 cfg = hpet_readl(HPET_T1_CFG);
1135                 cfg &= ~HPET_TN_ENABLE;
1136                 hpet_writel(cfg, HPET_T1_CFG);
1137                 return;
1138         }
1139
1140         if (!(hpet_rtc_flags & RTC_PIE) || hpet_pie_limit)
1141                 delta = hpet_default_delta;
1142         else
1143                 delta = hpet_pie_delta;
1144
1145         /*
1146          * Increment the comparator value until we are ahead of the
1147          * current count.
1148          */
1149         do {
1150                 hpet_t1_cmp += delta;
1151                 hpet_writel(hpet_t1_cmp, HPET_T1_CMP);
1152                 lost_ints++;
1153         } while (!hpet_cnt_ahead(hpet_t1_cmp, hpet_readl(HPET_COUNTER)));
1154
1155         if (lost_ints) {
1156                 if (hpet_rtc_flags & RTC_PIE)
1157                         hpet_pie_count += lost_ints;
1158                 if (printk_ratelimit())
1159                         printk(KERN_WARNING "hpet1: lost %d rtc interrupts\n",
1160                                 lost_ints);
1161         }
1162 }
1163
1164 irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id)
1165 {
1166         struct rtc_time curr_time;
1167         unsigned long rtc_int_flag = 0;
1168
1169         hpet_rtc_timer_reinit();
1170         memset(&curr_time, 0, sizeof(struct rtc_time));
1171
1172         if (hpet_rtc_flags & (RTC_UIE | RTC_AIE))
1173                 get_rtc_time(&curr_time);
1174
1175         if (hpet_rtc_flags & RTC_UIE &&
1176             curr_time.tm_sec != hpet_prev_update_sec) {
1177                 if (hpet_prev_update_sec >= 0)
1178                         rtc_int_flag = RTC_UF;
1179                 hpet_prev_update_sec = curr_time.tm_sec;
1180         }
1181
1182         if (hpet_rtc_flags & RTC_PIE &&
1183             ++hpet_pie_count >= hpet_pie_limit) {
1184                 rtc_int_flag |= RTC_PF;
1185                 hpet_pie_count = 0;
1186         }
1187
1188         if (hpet_rtc_flags & RTC_AIE &&
1189             (curr_time.tm_sec == hpet_alarm_time.tm_sec) &&
1190             (curr_time.tm_min == hpet_alarm_time.tm_min) &&
1191             (curr_time.tm_hour == hpet_alarm_time.tm_hour))
1192                         rtc_int_flag |= RTC_AF;
1193
1194         if (rtc_int_flag) {
1195                 rtc_int_flag |= (RTC_IRQF | (RTC_NUM_INTS << 8));
1196                 if (irq_handler)
1197                         irq_handler(rtc_int_flag, dev_id);
1198         }
1199         return IRQ_HANDLED;
1200 }
1201 EXPORT_SYMBOL_GPL(hpet_rtc_interrupt);
1202 #endif