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/irqdomain.h> 16 #include <asm/fixmap.h> 17 #include <asm/hpet.h> 18 #include <asm/time.h> 19 20 #define HPET_MASK CLOCKSOURCE_MASK(32) 21 22 /* FSEC = 10^-15 23 NSEC = 10^-9 */ 24 #define FSEC_PER_NSEC 1000000L 25 26 #define HPET_DEV_USED_BIT 2 27 #define HPET_DEV_USED (1 << HPET_DEV_USED_BIT) 28 #define HPET_DEV_VALID 0x8 29 #define HPET_DEV_FSB_CAP 0x1000 30 #define HPET_DEV_PERI_CAP 0x2000 31 32 #define HPET_MIN_CYCLES 128 33 #define HPET_MIN_PROG_DELTA (HPET_MIN_CYCLES + (HPET_MIN_CYCLES >> 1)) 34 35 /* 36 * HPET address is set in acpi/boot.c, when an ACPI entry exists 37 */ 38 unsigned long hpet_address; 39 u8 hpet_blockid; /* OS timer block num */ 40 u8 hpet_msi_disable; 41 42 #ifdef CONFIG_PCI_MSI 43 static unsigned long hpet_num_timers; 44 #endif 45 static void __iomem *hpet_virt_address; 46 47 struct hpet_dev { 48 struct clock_event_device evt; 49 unsigned int num; 50 int cpu; 51 unsigned int irq; 52 unsigned int flags; 53 char name[10]; 54 }; 55 56 inline struct hpet_dev *EVT_TO_HPET_DEV(struct clock_event_device *evtdev) 57 { 58 return container_of(evtdev, struct hpet_dev, evt); 59 } 60 61 inline unsigned int hpet_readl(unsigned int a) 62 { 63 return readl(hpet_virt_address + a); 64 } 65 66 static inline void hpet_writel(unsigned int d, unsigned int a) 67 { 68 writel(d, hpet_virt_address + a); 69 } 70 71 #ifdef CONFIG_X86_64 72 #include <asm/pgtable.h> 73 #endif 74 75 static inline void hpet_set_mapping(void) 76 { 77 hpet_virt_address = ioremap_nocache(hpet_address, HPET_MMAP_SIZE); 78 } 79 80 static inline void hpet_clear_mapping(void) 81 { 82 iounmap(hpet_virt_address); 83 hpet_virt_address = NULL; 84 } 85 86 /* 87 * HPET command line enable / disable 88 */ 89 int boot_hpet_disable; 90 int hpet_force_user; 91 static int hpet_verbose; 92 93 static int __init hpet_setup(char *str) 94 { 95 while (str) { 96 char *next = strchr(str, ','); 97 98 if (next) 99 *next++ = 0; 100 if (!strncmp("disable", str, 7)) 101 boot_hpet_disable = 1; 102 if (!strncmp("force", str, 5)) 103 hpet_force_user = 1; 104 if (!strncmp("verbose", str, 7)) 105 hpet_verbose = 1; 106 str = next; 107 } 108 return 1; 109 } 110 __setup("hpet=", hpet_setup); 111 112 static int __init disable_hpet(char *str) 113 { 114 boot_hpet_disable = 1; 115 return 1; 116 } 117 __setup("nohpet", disable_hpet); 118 119 static inline int is_hpet_capable(void) 120 { 121 return !boot_hpet_disable && hpet_address; 122 } 123 124 /* 125 * HPET timer interrupt enable / disable 126 */ 127 static int hpet_legacy_int_enabled; 128 129 /** 130 * is_hpet_enabled - check whether the hpet timer interrupt is enabled 131 */ 132 int is_hpet_enabled(void) 133 { 134 return is_hpet_capable() && hpet_legacy_int_enabled; 135 } 136 EXPORT_SYMBOL_GPL(is_hpet_enabled); 137 138 static void _hpet_print_config(const char *function, int line) 139 { 140 u32 i, timers, l, h; 141 printk(KERN_INFO "hpet: %s(%d):\n", function, line); 142 l = hpet_readl(HPET_ID); 143 h = hpet_readl(HPET_PERIOD); 144 timers = ((l & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT) + 1; 145 printk(KERN_INFO "hpet: ID: 0x%x, PERIOD: 0x%x\n", l, h); 146 l = hpet_readl(HPET_CFG); 147 h = hpet_readl(HPET_STATUS); 148 printk(KERN_INFO "hpet: CFG: 0x%x, STATUS: 0x%x\n", l, h); 149 l = hpet_readl(HPET_COUNTER); 150 h = hpet_readl(HPET_COUNTER+4); 151 printk(KERN_INFO "hpet: COUNTER_l: 0x%x, COUNTER_h: 0x%x\n", l, h); 152 153 for (i = 0; i < timers; i++) { 154 l = hpet_readl(HPET_Tn_CFG(i)); 155 h = hpet_readl(HPET_Tn_CFG(i)+4); 156 printk(KERN_INFO "hpet: T%d: CFG_l: 0x%x, CFG_h: 0x%x\n", 157 i, l, h); 158 l = hpet_readl(HPET_Tn_CMP(i)); 159 h = hpet_readl(HPET_Tn_CMP(i)+4); 160 printk(KERN_INFO "hpet: T%d: CMP_l: 0x%x, CMP_h: 0x%x\n", 161 i, l, h); 162 l = hpet_readl(HPET_Tn_ROUTE(i)); 163 h = hpet_readl(HPET_Tn_ROUTE(i)+4); 164 printk(KERN_INFO "hpet: T%d ROUTE_l: 0x%x, ROUTE_h: 0x%x\n", 165 i, l, h); 166 } 167 } 168 169 #define hpet_print_config() \ 170 do { \ 171 if (hpet_verbose) \ 172 _hpet_print_config(__func__, __LINE__); \ 173 } while (0) 174 175 /* 176 * When the hpet driver (/dev/hpet) is enabled, we need to reserve 177 * timer 0 and timer 1 in case of RTC emulation. 178 */ 179 #ifdef CONFIG_HPET 180 181 static void hpet_reserve_msi_timers(struct hpet_data *hd); 182 183 static void hpet_reserve_platform_timers(unsigned int id) 184 { 185 struct hpet __iomem *hpet = hpet_virt_address; 186 struct hpet_timer __iomem *timer = &hpet->hpet_timers[2]; 187 unsigned int nrtimers, i; 188 struct hpet_data hd; 189 190 nrtimers = ((id & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT) + 1; 191 192 memset(&hd, 0, sizeof(hd)); 193 hd.hd_phys_address = hpet_address; 194 hd.hd_address = hpet; 195 hd.hd_nirqs = nrtimers; 196 hpet_reserve_timer(&hd, 0); 197 198 #ifdef CONFIG_HPET_EMULATE_RTC 199 hpet_reserve_timer(&hd, 1); 200 #endif 201 202 /* 203 * NOTE that hd_irq[] reflects IOAPIC input pins (LEGACY_8254 204 * is wrong for i8259!) not the output IRQ. Many BIOS writers 205 * don't bother configuring *any* comparator interrupts. 206 */ 207 hd.hd_irq[0] = HPET_LEGACY_8254; 208 hd.hd_irq[1] = HPET_LEGACY_RTC; 209 210 for (i = 2; i < nrtimers; timer++, i++) { 211 hd.hd_irq[i] = (readl(&timer->hpet_config) & 212 Tn_INT_ROUTE_CNF_MASK) >> Tn_INT_ROUTE_CNF_SHIFT; 213 } 214 215 hpet_reserve_msi_timers(&hd); 216 217 hpet_alloc(&hd); 218 219 } 220 #else 221 static void hpet_reserve_platform_timers(unsigned int id) { } 222 #endif 223 224 /* 225 * Common hpet info 226 */ 227 static unsigned long hpet_freq; 228 229 static struct clock_event_device hpet_clockevent; 230 231 static void hpet_stop_counter(void) 232 { 233 unsigned long cfg = hpet_readl(HPET_CFG); 234 cfg &= ~HPET_CFG_ENABLE; 235 hpet_writel(cfg, HPET_CFG); 236 } 237 238 static void hpet_reset_counter(void) 239 { 240 hpet_writel(0, HPET_COUNTER); 241 hpet_writel(0, HPET_COUNTER + 4); 242 } 243 244 static void hpet_start_counter(void) 245 { 246 unsigned int cfg = hpet_readl(HPET_CFG); 247 cfg |= HPET_CFG_ENABLE; 248 hpet_writel(cfg, HPET_CFG); 249 } 250 251 static void hpet_restart_counter(void) 252 { 253 hpet_stop_counter(); 254 hpet_reset_counter(); 255 hpet_start_counter(); 256 } 257 258 static void hpet_resume_device(void) 259 { 260 force_hpet_resume(); 261 } 262 263 static void hpet_resume_counter(struct clocksource *cs) 264 { 265 hpet_resume_device(); 266 hpet_restart_counter(); 267 } 268 269 static void hpet_enable_legacy_int(void) 270 { 271 unsigned int cfg = hpet_readl(HPET_CFG); 272 273 cfg |= HPET_CFG_LEGACY; 274 hpet_writel(cfg, HPET_CFG); 275 hpet_legacy_int_enabled = 1; 276 } 277 278 static void hpet_legacy_clockevent_register(void) 279 { 280 /* Start HPET legacy interrupts */ 281 hpet_enable_legacy_int(); 282 283 /* 284 * Start hpet with the boot cpu mask and make it 285 * global after the IO_APIC has been initialized. 286 */ 287 hpet_clockevent.cpumask = cpumask_of(smp_processor_id()); 288 clockevents_config_and_register(&hpet_clockevent, hpet_freq, 289 HPET_MIN_PROG_DELTA, 0x7FFFFFFF); 290 global_clock_event = &hpet_clockevent; 291 printk(KERN_DEBUG "hpet clockevent registered\n"); 292 } 293 294 static int hpet_set_periodic(struct clock_event_device *evt, int timer) 295 { 296 unsigned int cfg, cmp, now; 297 uint64_t delta; 298 299 hpet_stop_counter(); 300 delta = ((uint64_t)(NSEC_PER_SEC / HZ)) * evt->mult; 301 delta >>= evt->shift; 302 now = hpet_readl(HPET_COUNTER); 303 cmp = now + (unsigned int)delta; 304 cfg = hpet_readl(HPET_Tn_CFG(timer)); 305 cfg |= HPET_TN_ENABLE | HPET_TN_PERIODIC | HPET_TN_SETVAL | 306 HPET_TN_32BIT; 307 hpet_writel(cfg, HPET_Tn_CFG(timer)); 308 hpet_writel(cmp, HPET_Tn_CMP(timer)); 309 udelay(1); 310 /* 311 * HPET on AMD 81xx needs a second write (with HPET_TN_SETVAL 312 * cleared) to T0_CMP to set the period. The HPET_TN_SETVAL 313 * bit is automatically cleared after the first write. 314 * (See AMD-8111 HyperTransport I/O Hub Data Sheet, 315 * Publication # 24674) 316 */ 317 hpet_writel((unsigned int)delta, HPET_Tn_CMP(timer)); 318 hpet_start_counter(); 319 hpet_print_config(); 320 321 return 0; 322 } 323 324 static int hpet_set_oneshot(struct clock_event_device *evt, int timer) 325 { 326 unsigned int cfg; 327 328 cfg = hpet_readl(HPET_Tn_CFG(timer)); 329 cfg &= ~HPET_TN_PERIODIC; 330 cfg |= HPET_TN_ENABLE | HPET_TN_32BIT; 331 hpet_writel(cfg, HPET_Tn_CFG(timer)); 332 333 return 0; 334 } 335 336 static int hpet_shutdown(struct clock_event_device *evt, int timer) 337 { 338 unsigned int cfg; 339 340 cfg = hpet_readl(HPET_Tn_CFG(timer)); 341 cfg &= ~HPET_TN_ENABLE; 342 hpet_writel(cfg, HPET_Tn_CFG(timer)); 343 344 return 0; 345 } 346 347 static int hpet_resume(struct clock_event_device *evt, int timer) 348 { 349 if (!timer) { 350 hpet_enable_legacy_int(); 351 } else { 352 struct hpet_dev *hdev = EVT_TO_HPET_DEV(evt); 353 354 irq_domain_activate_irq(irq_get_irq_data(hdev->irq)); 355 disable_irq(hdev->irq); 356 irq_set_affinity(hdev->irq, cpumask_of(hdev->cpu)); 357 enable_irq(hdev->irq); 358 } 359 hpet_print_config(); 360 361 return 0; 362 } 363 364 static int hpet_next_event(unsigned long delta, 365 struct clock_event_device *evt, int timer) 366 { 367 u32 cnt; 368 s32 res; 369 370 cnt = hpet_readl(HPET_COUNTER); 371 cnt += (u32) delta; 372 hpet_writel(cnt, HPET_Tn_CMP(timer)); 373 374 /* 375 * HPETs are a complete disaster. The compare register is 376 * based on a equal comparison and neither provides a less 377 * than or equal functionality (which would require to take 378 * the wraparound into account) nor a simple count down event 379 * mode. Further the write to the comparator register is 380 * delayed internally up to two HPET clock cycles in certain 381 * chipsets (ATI, ICH9,10). Some newer AMD chipsets have even 382 * longer delays. We worked around that by reading back the 383 * compare register, but that required another workaround for 384 * ICH9,10 chips where the first readout after write can 385 * return the old stale value. We already had a minimum 386 * programming delta of 5us enforced, but a NMI or SMI hitting 387 * between the counter readout and the comparator write can 388 * move us behind that point easily. Now instead of reading 389 * the compare register back several times, we make the ETIME 390 * decision based on the following: Return ETIME if the 391 * counter value after the write is less than HPET_MIN_CYCLES 392 * away from the event or if the counter is already ahead of 393 * the event. The minimum programming delta for the generic 394 * clockevents code is set to 1.5 * HPET_MIN_CYCLES. 395 */ 396 res = (s32)(cnt - hpet_readl(HPET_COUNTER)); 397 398 return res < HPET_MIN_CYCLES ? -ETIME : 0; 399 } 400 401 static int hpet_legacy_shutdown(struct clock_event_device *evt) 402 { 403 return hpet_shutdown(evt, 0); 404 } 405 406 static int hpet_legacy_set_oneshot(struct clock_event_device *evt) 407 { 408 return hpet_set_oneshot(evt, 0); 409 } 410 411 static int hpet_legacy_set_periodic(struct clock_event_device *evt) 412 { 413 return hpet_set_periodic(evt, 0); 414 } 415 416 static int hpet_legacy_resume(struct clock_event_device *evt) 417 { 418 return hpet_resume(evt, 0); 419 } 420 421 static int hpet_legacy_next_event(unsigned long delta, 422 struct clock_event_device *evt) 423 { 424 return hpet_next_event(delta, evt, 0); 425 } 426 427 /* 428 * The hpet clock event device 429 */ 430 static struct clock_event_device hpet_clockevent = { 431 .name = "hpet", 432 .features = CLOCK_EVT_FEAT_PERIODIC | 433 CLOCK_EVT_FEAT_ONESHOT, 434 .set_state_periodic = hpet_legacy_set_periodic, 435 .set_state_oneshot = hpet_legacy_set_oneshot, 436 .set_state_shutdown = hpet_legacy_shutdown, 437 .tick_resume = hpet_legacy_resume, 438 .set_next_event = hpet_legacy_next_event, 439 .irq = 0, 440 .rating = 50, 441 }; 442 443 /* 444 * HPET MSI Support 445 */ 446 #ifdef CONFIG_PCI_MSI 447 448 static DEFINE_PER_CPU(struct hpet_dev *, cpu_hpet_dev); 449 static struct hpet_dev *hpet_devs; 450 static struct irq_domain *hpet_domain; 451 452 void hpet_msi_unmask(struct irq_data *data) 453 { 454 struct hpet_dev *hdev = irq_data_get_irq_handler_data(data); 455 unsigned int cfg; 456 457 /* unmask it */ 458 cfg = hpet_readl(HPET_Tn_CFG(hdev->num)); 459 cfg |= HPET_TN_ENABLE | HPET_TN_FSB; 460 hpet_writel(cfg, HPET_Tn_CFG(hdev->num)); 461 } 462 463 void hpet_msi_mask(struct irq_data *data) 464 { 465 struct hpet_dev *hdev = irq_data_get_irq_handler_data(data); 466 unsigned int cfg; 467 468 /* mask it */ 469 cfg = hpet_readl(HPET_Tn_CFG(hdev->num)); 470 cfg &= ~(HPET_TN_ENABLE | HPET_TN_FSB); 471 hpet_writel(cfg, HPET_Tn_CFG(hdev->num)); 472 } 473 474 void hpet_msi_write(struct hpet_dev *hdev, struct msi_msg *msg) 475 { 476 hpet_writel(msg->data, HPET_Tn_ROUTE(hdev->num)); 477 hpet_writel(msg->address_lo, HPET_Tn_ROUTE(hdev->num) + 4); 478 } 479 480 void hpet_msi_read(struct hpet_dev *hdev, struct msi_msg *msg) 481 { 482 msg->data = hpet_readl(HPET_Tn_ROUTE(hdev->num)); 483 msg->address_lo = hpet_readl(HPET_Tn_ROUTE(hdev->num) + 4); 484 msg->address_hi = 0; 485 } 486 487 static int hpet_msi_shutdown(struct clock_event_device *evt) 488 { 489 struct hpet_dev *hdev = EVT_TO_HPET_DEV(evt); 490 491 return hpet_shutdown(evt, hdev->num); 492 } 493 494 static int hpet_msi_set_oneshot(struct clock_event_device *evt) 495 { 496 struct hpet_dev *hdev = EVT_TO_HPET_DEV(evt); 497 498 return hpet_set_oneshot(evt, hdev->num); 499 } 500 501 static int hpet_msi_set_periodic(struct clock_event_device *evt) 502 { 503 struct hpet_dev *hdev = EVT_TO_HPET_DEV(evt); 504 505 return hpet_set_periodic(evt, hdev->num); 506 } 507 508 static int hpet_msi_resume(struct clock_event_device *evt) 509 { 510 struct hpet_dev *hdev = EVT_TO_HPET_DEV(evt); 511 512 return hpet_resume(evt, hdev->num); 513 } 514 515 static int hpet_msi_next_event(unsigned long delta, 516 struct clock_event_device *evt) 517 { 518 struct hpet_dev *hdev = EVT_TO_HPET_DEV(evt); 519 return hpet_next_event(delta, evt, hdev->num); 520 } 521 522 static irqreturn_t hpet_interrupt_handler(int irq, void *data) 523 { 524 struct hpet_dev *dev = (struct hpet_dev *)data; 525 struct clock_event_device *hevt = &dev->evt; 526 527 if (!hevt->event_handler) { 528 printk(KERN_INFO "Spurious HPET timer interrupt on HPET timer %d\n", 529 dev->num); 530 return IRQ_HANDLED; 531 } 532 533 hevt->event_handler(hevt); 534 return IRQ_HANDLED; 535 } 536 537 static int hpet_setup_irq(struct hpet_dev *dev) 538 { 539 540 if (request_irq(dev->irq, hpet_interrupt_handler, 541 IRQF_TIMER | IRQF_NOBALANCING, 542 dev->name, dev)) 543 return -1; 544 545 disable_irq(dev->irq); 546 irq_set_affinity(dev->irq, cpumask_of(dev->cpu)); 547 enable_irq(dev->irq); 548 549 printk(KERN_DEBUG "hpet: %s irq %d for MSI\n", 550 dev->name, dev->irq); 551 552 return 0; 553 } 554 555 /* This should be called in specific @cpu */ 556 static void init_one_hpet_msi_clockevent(struct hpet_dev *hdev, int cpu) 557 { 558 struct clock_event_device *evt = &hdev->evt; 559 560 WARN_ON(cpu != smp_processor_id()); 561 if (!(hdev->flags & HPET_DEV_VALID)) 562 return; 563 564 hdev->cpu = cpu; 565 per_cpu(cpu_hpet_dev, cpu) = hdev; 566 evt->name = hdev->name; 567 hpet_setup_irq(hdev); 568 evt->irq = hdev->irq; 569 570 evt->rating = 110; 571 evt->features = CLOCK_EVT_FEAT_ONESHOT; 572 if (hdev->flags & HPET_DEV_PERI_CAP) { 573 evt->features |= CLOCK_EVT_FEAT_PERIODIC; 574 evt->set_state_periodic = hpet_msi_set_periodic; 575 } 576 577 evt->set_state_shutdown = hpet_msi_shutdown; 578 evt->set_state_oneshot = hpet_msi_set_oneshot; 579 evt->tick_resume = hpet_msi_resume; 580 evt->set_next_event = hpet_msi_next_event; 581 evt->cpumask = cpumask_of(hdev->cpu); 582 583 clockevents_config_and_register(evt, hpet_freq, HPET_MIN_PROG_DELTA, 584 0x7FFFFFFF); 585 } 586 587 #ifdef CONFIG_HPET 588 /* Reserve at least one timer for userspace (/dev/hpet) */ 589 #define RESERVE_TIMERS 1 590 #else 591 #define RESERVE_TIMERS 0 592 #endif 593 594 static void hpet_msi_capability_lookup(unsigned int start_timer) 595 { 596 unsigned int id; 597 unsigned int num_timers; 598 unsigned int num_timers_used = 0; 599 int i, irq; 600 601 if (hpet_msi_disable) 602 return; 603 604 if (boot_cpu_has(X86_FEATURE_ARAT)) 605 return; 606 id = hpet_readl(HPET_ID); 607 608 num_timers = ((id & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT); 609 num_timers++; /* Value read out starts from 0 */ 610 hpet_print_config(); 611 612 hpet_domain = hpet_create_irq_domain(hpet_blockid); 613 if (!hpet_domain) 614 return; 615 616 hpet_devs = kzalloc(sizeof(struct hpet_dev) * num_timers, GFP_KERNEL); 617 if (!hpet_devs) 618 return; 619 620 hpet_num_timers = num_timers; 621 622 for (i = start_timer; i < num_timers - RESERVE_TIMERS; i++) { 623 struct hpet_dev *hdev = &hpet_devs[num_timers_used]; 624 unsigned int cfg = hpet_readl(HPET_Tn_CFG(i)); 625 626 /* Only consider HPET timer with MSI support */ 627 if (!(cfg & HPET_TN_FSB_CAP)) 628 continue; 629 630 hdev->flags = 0; 631 if (cfg & HPET_TN_PERIODIC_CAP) 632 hdev->flags |= HPET_DEV_PERI_CAP; 633 sprintf(hdev->name, "hpet%d", i); 634 hdev->num = i; 635 636 irq = hpet_assign_irq(hpet_domain, hdev, hdev->num); 637 if (irq <= 0) 638 continue; 639 640 hdev->irq = irq; 641 hdev->flags |= HPET_DEV_FSB_CAP; 642 hdev->flags |= HPET_DEV_VALID; 643 num_timers_used++; 644 if (num_timers_used == num_possible_cpus()) 645 break; 646 } 647 648 printk(KERN_INFO "HPET: %d timers in total, %d timers will be used for per-cpu timer\n", 649 num_timers, num_timers_used); 650 } 651 652 #ifdef CONFIG_HPET 653 static void hpet_reserve_msi_timers(struct hpet_data *hd) 654 { 655 int i; 656 657 if (!hpet_devs) 658 return; 659 660 for (i = 0; i < hpet_num_timers; i++) { 661 struct hpet_dev *hdev = &hpet_devs[i]; 662 663 if (!(hdev->flags & HPET_DEV_VALID)) 664 continue; 665 666 hd->hd_irq[hdev->num] = hdev->irq; 667 hpet_reserve_timer(hd, hdev->num); 668 } 669 } 670 #endif 671 672 static struct hpet_dev *hpet_get_unused_timer(void) 673 { 674 int i; 675 676 if (!hpet_devs) 677 return NULL; 678 679 for (i = 0; i < hpet_num_timers; i++) { 680 struct hpet_dev *hdev = &hpet_devs[i]; 681 682 if (!(hdev->flags & HPET_DEV_VALID)) 683 continue; 684 if (test_and_set_bit(HPET_DEV_USED_BIT, 685 (unsigned long *)&hdev->flags)) 686 continue; 687 return hdev; 688 } 689 return NULL; 690 } 691 692 struct hpet_work_struct { 693 struct delayed_work work; 694 struct completion complete; 695 }; 696 697 static void hpet_work(struct work_struct *w) 698 { 699 struct hpet_dev *hdev; 700 int cpu = smp_processor_id(); 701 struct hpet_work_struct *hpet_work; 702 703 hpet_work = container_of(w, struct hpet_work_struct, work.work); 704 705 hdev = hpet_get_unused_timer(); 706 if (hdev) 707 init_one_hpet_msi_clockevent(hdev, cpu); 708 709 complete(&hpet_work->complete); 710 } 711 712 static int hpet_cpuhp_notify(struct notifier_block *n, 713 unsigned long action, void *hcpu) 714 { 715 unsigned long cpu = (unsigned long)hcpu; 716 struct hpet_work_struct work; 717 struct hpet_dev *hdev = per_cpu(cpu_hpet_dev, cpu); 718 719 switch (action & 0xf) { 720 case CPU_ONLINE: 721 INIT_DELAYED_WORK_ONSTACK(&work.work, hpet_work); 722 init_completion(&work.complete); 723 /* FIXME: add schedule_work_on() */ 724 schedule_delayed_work_on(cpu, &work.work, 0); 725 wait_for_completion(&work.complete); 726 destroy_delayed_work_on_stack(&work.work); 727 break; 728 case CPU_DEAD: 729 if (hdev) { 730 free_irq(hdev->irq, hdev); 731 hdev->flags &= ~HPET_DEV_USED; 732 per_cpu(cpu_hpet_dev, cpu) = NULL; 733 } 734 break; 735 } 736 return NOTIFY_OK; 737 } 738 #else 739 740 static void hpet_msi_capability_lookup(unsigned int start_timer) 741 { 742 return; 743 } 744 745 #ifdef CONFIG_HPET 746 static void hpet_reserve_msi_timers(struct hpet_data *hd) 747 { 748 return; 749 } 750 #endif 751 752 static int hpet_cpuhp_notify(struct notifier_block *n, 753 unsigned long action, void *hcpu) 754 { 755 return NOTIFY_OK; 756 } 757 758 #endif 759 760 /* 761 * Clock source related code 762 */ 763 static cycle_t read_hpet(struct clocksource *cs) 764 { 765 return (cycle_t)hpet_readl(HPET_COUNTER); 766 } 767 768 static struct clocksource clocksource_hpet = { 769 .name = "hpet", 770 .rating = 250, 771 .read = read_hpet, 772 .mask = HPET_MASK, 773 .flags = CLOCK_SOURCE_IS_CONTINUOUS, 774 .resume = hpet_resume_counter, 775 .archdata = { .vclock_mode = VCLOCK_HPET }, 776 }; 777 778 static int hpet_clocksource_register(void) 779 { 780 u64 start, now; 781 cycle_t t1; 782 783 /* Start the counter */ 784 hpet_restart_counter(); 785 786 /* Verify whether hpet counter works */ 787 t1 = hpet_readl(HPET_COUNTER); 788 start = rdtsc(); 789 790 /* 791 * We don't know the TSC frequency yet, but waiting for 792 * 200000 TSC cycles is safe: 793 * 4 GHz == 50us 794 * 1 GHz == 200us 795 */ 796 do { 797 rep_nop(); 798 now = rdtsc(); 799 } while ((now - start) < 200000UL); 800 801 if (t1 == hpet_readl(HPET_COUNTER)) { 802 printk(KERN_WARNING 803 "HPET counter not counting. HPET disabled\n"); 804 return -ENODEV; 805 } 806 807 clocksource_register_hz(&clocksource_hpet, (u32)hpet_freq); 808 return 0; 809 } 810 811 static u32 *hpet_boot_cfg; 812 813 /** 814 * hpet_enable - Try to setup the HPET timer. Returns 1 on success. 815 */ 816 int __init hpet_enable(void) 817 { 818 u32 hpet_period, cfg, id; 819 u64 freq; 820 unsigned int i, last; 821 822 if (!is_hpet_capable()) 823 return 0; 824 825 hpet_set_mapping(); 826 827 /* 828 * Read the period and check for a sane value: 829 */ 830 hpet_period = hpet_readl(HPET_PERIOD); 831 832 /* 833 * AMD SB700 based systems with spread spectrum enabled use a 834 * SMM based HPET emulation to provide proper frequency 835 * setting. The SMM code is initialized with the first HPET 836 * register access and takes some time to complete. During 837 * this time the config register reads 0xffffffff. We check 838 * for max. 1000 loops whether the config register reads a non 839 * 0xffffffff value to make sure that HPET is up and running 840 * before we go further. A counting loop is safe, as the HPET 841 * access takes thousands of CPU cycles. On non SB700 based 842 * machines this check is only done once and has no side 843 * effects. 844 */ 845 for (i = 0; hpet_readl(HPET_CFG) == 0xFFFFFFFF; i++) { 846 if (i == 1000) { 847 printk(KERN_WARNING 848 "HPET config register value = 0xFFFFFFFF. " 849 "Disabling HPET\n"); 850 goto out_nohpet; 851 } 852 } 853 854 if (hpet_period < HPET_MIN_PERIOD || hpet_period > HPET_MAX_PERIOD) 855 goto out_nohpet; 856 857 /* 858 * The period is a femto seconds value. Convert it to a 859 * frequency. 860 */ 861 freq = FSEC_PER_SEC; 862 do_div(freq, hpet_period); 863 hpet_freq = freq; 864 865 /* 866 * Read the HPET ID register to retrieve the IRQ routing 867 * information and the number of channels 868 */ 869 id = hpet_readl(HPET_ID); 870 hpet_print_config(); 871 872 last = (id & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT; 873 874 #ifdef CONFIG_HPET_EMULATE_RTC 875 /* 876 * The legacy routing mode needs at least two channels, tick timer 877 * and the rtc emulation channel. 878 */ 879 if (!last) 880 goto out_nohpet; 881 #endif 882 883 cfg = hpet_readl(HPET_CFG); 884 hpet_boot_cfg = kmalloc((last + 2) * sizeof(*hpet_boot_cfg), 885 GFP_KERNEL); 886 if (hpet_boot_cfg) 887 *hpet_boot_cfg = cfg; 888 else 889 pr_warn("HPET initial state will not be saved\n"); 890 cfg &= ~(HPET_CFG_ENABLE | HPET_CFG_LEGACY); 891 hpet_writel(cfg, HPET_CFG); 892 if (cfg) 893 pr_warn("HPET: Unrecognized bits %#x set in global cfg\n", 894 cfg); 895 896 for (i = 0; i <= last; ++i) { 897 cfg = hpet_readl(HPET_Tn_CFG(i)); 898 if (hpet_boot_cfg) 899 hpet_boot_cfg[i + 1] = cfg; 900 cfg &= ~(HPET_TN_ENABLE | HPET_TN_LEVEL | HPET_TN_FSB); 901 hpet_writel(cfg, HPET_Tn_CFG(i)); 902 cfg &= ~(HPET_TN_PERIODIC | HPET_TN_PERIODIC_CAP 903 | HPET_TN_64BIT_CAP | HPET_TN_32BIT | HPET_TN_ROUTE 904 | HPET_TN_FSB | HPET_TN_FSB_CAP); 905 if (cfg) 906 pr_warn("HPET: Unrecognized bits %#x set in cfg#%u\n", 907 cfg, i); 908 } 909 hpet_print_config(); 910 911 if (hpet_clocksource_register()) 912 goto out_nohpet; 913 914 if (id & HPET_ID_LEGSUP) { 915 hpet_legacy_clockevent_register(); 916 return 1; 917 } 918 return 0; 919 920 out_nohpet: 921 hpet_clear_mapping(); 922 hpet_address = 0; 923 return 0; 924 } 925 926 /* 927 * Needs to be late, as the reserve_timer code calls kalloc ! 928 * 929 * Not a problem on i386 as hpet_enable is called from late_time_init, 930 * but on x86_64 it is necessary ! 931 */ 932 static __init int hpet_late_init(void) 933 { 934 int cpu; 935 936 if (boot_hpet_disable) 937 return -ENODEV; 938 939 if (!hpet_address) { 940 if (!force_hpet_address) 941 return -ENODEV; 942 943 hpet_address = force_hpet_address; 944 hpet_enable(); 945 } 946 947 if (!hpet_virt_address) 948 return -ENODEV; 949 950 if (hpet_readl(HPET_ID) & HPET_ID_LEGSUP) 951 hpet_msi_capability_lookup(2); 952 else 953 hpet_msi_capability_lookup(0); 954 955 hpet_reserve_platform_timers(hpet_readl(HPET_ID)); 956 hpet_print_config(); 957 958 if (hpet_msi_disable) 959 return 0; 960 961 if (boot_cpu_has(X86_FEATURE_ARAT)) 962 return 0; 963 964 cpu_notifier_register_begin(); 965 for_each_online_cpu(cpu) { 966 hpet_cpuhp_notify(NULL, CPU_ONLINE, (void *)(long)cpu); 967 } 968 969 /* This notifier should be called after workqueue is ready */ 970 __hotcpu_notifier(hpet_cpuhp_notify, -20); 971 cpu_notifier_register_done(); 972 973 return 0; 974 } 975 fs_initcall(hpet_late_init); 976 977 void hpet_disable(void) 978 { 979 if (is_hpet_capable() && hpet_virt_address) { 980 unsigned int cfg = hpet_readl(HPET_CFG), id, last; 981 982 if (hpet_boot_cfg) 983 cfg = *hpet_boot_cfg; 984 else if (hpet_legacy_int_enabled) { 985 cfg &= ~HPET_CFG_LEGACY; 986 hpet_legacy_int_enabled = 0; 987 } 988 cfg &= ~HPET_CFG_ENABLE; 989 hpet_writel(cfg, HPET_CFG); 990 991 if (!hpet_boot_cfg) 992 return; 993 994 id = hpet_readl(HPET_ID); 995 last = ((id & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT); 996 997 for (id = 0; id <= last; ++id) 998 hpet_writel(hpet_boot_cfg[id + 1], HPET_Tn_CFG(id)); 999 1000 if (*hpet_boot_cfg & HPET_CFG_ENABLE) 1001 hpet_writel(*hpet_boot_cfg, HPET_CFG); 1002 } 1003 } 1004 1005 #ifdef CONFIG_HPET_EMULATE_RTC 1006 1007 /* HPET in LegacyReplacement Mode eats up RTC interrupt line. When, HPET 1008 * is enabled, we support RTC interrupt functionality in software. 1009 * RTC has 3 kinds of interrupts: 1010 * 1) Update Interrupt - generate an interrupt, every sec, when RTC clock 1011 * is updated 1012 * 2) Alarm Interrupt - generate an interrupt at a specific time of day 1013 * 3) Periodic Interrupt - generate periodic interrupt, with frequencies 1014 * 2Hz-8192Hz (2Hz-64Hz for non-root user) (all freqs in powers of 2) 1015 * (1) and (2) above are implemented using polling at a frequency of 1016 * 64 Hz. The exact frequency is a tradeoff between accuracy and interrupt 1017 * overhead. (DEFAULT_RTC_INT_FREQ) 1018 * For (3), we use interrupts at 64Hz or user specified periodic 1019 * frequency, whichever is higher. 1020 */ 1021 #include <linux/mc146818rtc.h> 1022 #include <linux/rtc.h> 1023 #include <asm/rtc.h> 1024 1025 #define DEFAULT_RTC_INT_FREQ 64 1026 #define DEFAULT_RTC_SHIFT 6 1027 #define RTC_NUM_INTS 1 1028 1029 static unsigned long hpet_rtc_flags; 1030 static int hpet_prev_update_sec; 1031 static struct rtc_time hpet_alarm_time; 1032 static unsigned long hpet_pie_count; 1033 static u32 hpet_t1_cmp; 1034 static u32 hpet_default_delta; 1035 static u32 hpet_pie_delta; 1036 static unsigned long hpet_pie_limit; 1037 1038 static rtc_irq_handler irq_handler; 1039 1040 /* 1041 * Check that the hpet counter c1 is ahead of the c2 1042 */ 1043 static inline int hpet_cnt_ahead(u32 c1, u32 c2) 1044 { 1045 return (s32)(c2 - c1) < 0; 1046 } 1047 1048 /* 1049 * Registers a IRQ handler. 1050 */ 1051 int hpet_register_irq_handler(rtc_irq_handler handler) 1052 { 1053 if (!is_hpet_enabled()) 1054 return -ENODEV; 1055 if (irq_handler) 1056 return -EBUSY; 1057 1058 irq_handler = handler; 1059 1060 return 0; 1061 } 1062 EXPORT_SYMBOL_GPL(hpet_register_irq_handler); 1063 1064 /* 1065 * Deregisters the IRQ handler registered with hpet_register_irq_handler() 1066 * and does cleanup. 1067 */ 1068 void hpet_unregister_irq_handler(rtc_irq_handler handler) 1069 { 1070 if (!is_hpet_enabled()) 1071 return; 1072 1073 irq_handler = NULL; 1074 hpet_rtc_flags = 0; 1075 } 1076 EXPORT_SYMBOL_GPL(hpet_unregister_irq_handler); 1077 1078 /* 1079 * Timer 1 for RTC emulation. We use one shot mode, as periodic mode 1080 * is not supported by all HPET implementations for timer 1. 1081 * 1082 * hpet_rtc_timer_init() is called when the rtc is initialized. 1083 */ 1084 int hpet_rtc_timer_init(void) 1085 { 1086 unsigned int cfg, cnt, delta; 1087 unsigned long flags; 1088 1089 if (!is_hpet_enabled()) 1090 return 0; 1091 1092 if (!hpet_default_delta) { 1093 uint64_t clc; 1094 1095 clc = (uint64_t) hpet_clockevent.mult * NSEC_PER_SEC; 1096 clc >>= hpet_clockevent.shift + DEFAULT_RTC_SHIFT; 1097 hpet_default_delta = clc; 1098 } 1099 1100 if (!(hpet_rtc_flags & RTC_PIE) || hpet_pie_limit) 1101 delta = hpet_default_delta; 1102 else 1103 delta = hpet_pie_delta; 1104 1105 local_irq_save(flags); 1106 1107 cnt = delta + hpet_readl(HPET_COUNTER); 1108 hpet_writel(cnt, HPET_T1_CMP); 1109 hpet_t1_cmp = cnt; 1110 1111 cfg = hpet_readl(HPET_T1_CFG); 1112 cfg &= ~HPET_TN_PERIODIC; 1113 cfg |= HPET_TN_ENABLE | HPET_TN_32BIT; 1114 hpet_writel(cfg, HPET_T1_CFG); 1115 1116 local_irq_restore(flags); 1117 1118 return 1; 1119 } 1120 EXPORT_SYMBOL_GPL(hpet_rtc_timer_init); 1121 1122 static void hpet_disable_rtc_channel(void) 1123 { 1124 unsigned long cfg; 1125 cfg = hpet_readl(HPET_T1_CFG); 1126 cfg &= ~HPET_TN_ENABLE; 1127 hpet_writel(cfg, HPET_T1_CFG); 1128 } 1129 1130 /* 1131 * The functions below are called from rtc driver. 1132 * Return 0 if HPET is not being used. 1133 * Otherwise do the necessary changes and return 1. 1134 */ 1135 int hpet_mask_rtc_irq_bit(unsigned long bit_mask) 1136 { 1137 if (!is_hpet_enabled()) 1138 return 0; 1139 1140 hpet_rtc_flags &= ~bit_mask; 1141 if (unlikely(!hpet_rtc_flags)) 1142 hpet_disable_rtc_channel(); 1143 1144 return 1; 1145 } 1146 EXPORT_SYMBOL_GPL(hpet_mask_rtc_irq_bit); 1147 1148 int hpet_set_rtc_irq_bit(unsigned long bit_mask) 1149 { 1150 unsigned long oldbits = hpet_rtc_flags; 1151 1152 if (!is_hpet_enabled()) 1153 return 0; 1154 1155 hpet_rtc_flags |= bit_mask; 1156 1157 if ((bit_mask & RTC_UIE) && !(oldbits & RTC_UIE)) 1158 hpet_prev_update_sec = -1; 1159 1160 if (!oldbits) 1161 hpet_rtc_timer_init(); 1162 1163 return 1; 1164 } 1165 EXPORT_SYMBOL_GPL(hpet_set_rtc_irq_bit); 1166 1167 int hpet_set_alarm_time(unsigned char hrs, unsigned char min, 1168 unsigned char sec) 1169 { 1170 if (!is_hpet_enabled()) 1171 return 0; 1172 1173 hpet_alarm_time.tm_hour = hrs; 1174 hpet_alarm_time.tm_min = min; 1175 hpet_alarm_time.tm_sec = sec; 1176 1177 return 1; 1178 } 1179 EXPORT_SYMBOL_GPL(hpet_set_alarm_time); 1180 1181 int hpet_set_periodic_freq(unsigned long freq) 1182 { 1183 uint64_t clc; 1184 1185 if (!is_hpet_enabled()) 1186 return 0; 1187 1188 if (freq <= DEFAULT_RTC_INT_FREQ) 1189 hpet_pie_limit = DEFAULT_RTC_INT_FREQ / freq; 1190 else { 1191 clc = (uint64_t) hpet_clockevent.mult * NSEC_PER_SEC; 1192 do_div(clc, freq); 1193 clc >>= hpet_clockevent.shift; 1194 hpet_pie_delta = clc; 1195 hpet_pie_limit = 0; 1196 } 1197 return 1; 1198 } 1199 EXPORT_SYMBOL_GPL(hpet_set_periodic_freq); 1200 1201 int hpet_rtc_dropped_irq(void) 1202 { 1203 return is_hpet_enabled(); 1204 } 1205 EXPORT_SYMBOL_GPL(hpet_rtc_dropped_irq); 1206 1207 static void hpet_rtc_timer_reinit(void) 1208 { 1209 unsigned int delta; 1210 int lost_ints = -1; 1211 1212 if (unlikely(!hpet_rtc_flags)) 1213 hpet_disable_rtc_channel(); 1214 1215 if (!(hpet_rtc_flags & RTC_PIE) || hpet_pie_limit) 1216 delta = hpet_default_delta; 1217 else 1218 delta = hpet_pie_delta; 1219 1220 /* 1221 * Increment the comparator value until we are ahead of the 1222 * current count. 1223 */ 1224 do { 1225 hpet_t1_cmp += delta; 1226 hpet_writel(hpet_t1_cmp, HPET_T1_CMP); 1227 lost_ints++; 1228 } while (!hpet_cnt_ahead(hpet_t1_cmp, hpet_readl(HPET_COUNTER))); 1229 1230 if (lost_ints) { 1231 if (hpet_rtc_flags & RTC_PIE) 1232 hpet_pie_count += lost_ints; 1233 if (printk_ratelimit()) 1234 printk(KERN_WARNING "hpet1: lost %d rtc interrupts\n", 1235 lost_ints); 1236 } 1237 } 1238 1239 irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id) 1240 { 1241 struct rtc_time curr_time; 1242 unsigned long rtc_int_flag = 0; 1243 1244 hpet_rtc_timer_reinit(); 1245 memset(&curr_time, 0, sizeof(struct rtc_time)); 1246 1247 if (hpet_rtc_flags & (RTC_UIE | RTC_AIE)) 1248 get_rtc_time(&curr_time); 1249 1250 if (hpet_rtc_flags & RTC_UIE && 1251 curr_time.tm_sec != hpet_prev_update_sec) { 1252 if (hpet_prev_update_sec >= 0) 1253 rtc_int_flag = RTC_UF; 1254 hpet_prev_update_sec = curr_time.tm_sec; 1255 } 1256 1257 if (hpet_rtc_flags & RTC_PIE && 1258 ++hpet_pie_count >= hpet_pie_limit) { 1259 rtc_int_flag |= RTC_PF; 1260 hpet_pie_count = 0; 1261 } 1262 1263 if (hpet_rtc_flags & RTC_AIE && 1264 (curr_time.tm_sec == hpet_alarm_time.tm_sec) && 1265 (curr_time.tm_min == hpet_alarm_time.tm_min) && 1266 (curr_time.tm_hour == hpet_alarm_time.tm_hour)) 1267 rtc_int_flag |= RTC_AF; 1268 1269 if (rtc_int_flag) { 1270 rtc_int_flag |= (RTC_IRQF | (RTC_NUM_INTS << 8)); 1271 if (irq_handler) 1272 irq_handler(rtc_int_flag, dev_id); 1273 } 1274 return IRQ_HANDLED; 1275 } 1276 EXPORT_SYMBOL_GPL(hpet_rtc_interrupt); 1277 #endif 1278