1 /* 2 * Local APIC related interfaces to support IOAPIC, MSI, HT_IRQ etc. 3 * 4 * Copyright (C) 1997, 1998, 1999, 2000, 2009 Ingo Molnar, Hajnalka Szabo 5 * Moved from arch/x86/kernel/apic/io_apic.c. 6 * Jiang Liu <jiang.liu@linux.intel.com> 7 * Enable support of hierarchical irqdomains 8 * 9 * This program is free software; you can redistribute it and/or modify 10 * it under the terms of the GNU General Public License version 2 as 11 * published by the Free Software Foundation. 12 */ 13 #include <linux/interrupt.h> 14 #include <linux/init.h> 15 #include <linux/compiler.h> 16 #include <linux/slab.h> 17 #include <asm/irqdomain.h> 18 #include <asm/hw_irq.h> 19 #include <asm/apic.h> 20 #include <asm/i8259.h> 21 #include <asm/desc.h> 22 #include <asm/irq_remapping.h> 23 24 struct apic_chip_data { 25 struct irq_cfg cfg; 26 cpumask_var_t domain; 27 cpumask_var_t old_domain; 28 u8 move_in_progress : 1; 29 }; 30 31 struct irq_domain *x86_vector_domain; 32 EXPORT_SYMBOL_GPL(x86_vector_domain); 33 static DEFINE_RAW_SPINLOCK(vector_lock); 34 static cpumask_var_t vector_cpumask, vector_searchmask, searched_cpumask; 35 static struct irq_chip lapic_controller; 36 #ifdef CONFIG_X86_IO_APIC 37 static struct apic_chip_data *legacy_irq_data[NR_IRQS_LEGACY]; 38 #endif 39 40 void lock_vector_lock(void) 41 { 42 /* Used to the online set of cpus does not change 43 * during assign_irq_vector. 44 */ 45 raw_spin_lock(&vector_lock); 46 } 47 48 void unlock_vector_lock(void) 49 { 50 raw_spin_unlock(&vector_lock); 51 } 52 53 static struct apic_chip_data *apic_chip_data(struct irq_data *irq_data) 54 { 55 if (!irq_data) 56 return NULL; 57 58 while (irq_data->parent_data) 59 irq_data = irq_data->parent_data; 60 61 return irq_data->chip_data; 62 } 63 64 struct irq_cfg *irqd_cfg(struct irq_data *irq_data) 65 { 66 struct apic_chip_data *data = apic_chip_data(irq_data); 67 68 return data ? &data->cfg : NULL; 69 } 70 EXPORT_SYMBOL_GPL(irqd_cfg); 71 72 struct irq_cfg *irq_cfg(unsigned int irq) 73 { 74 return irqd_cfg(irq_get_irq_data(irq)); 75 } 76 77 static struct apic_chip_data *alloc_apic_chip_data(int node) 78 { 79 struct apic_chip_data *data; 80 81 data = kzalloc_node(sizeof(*data), GFP_KERNEL, node); 82 if (!data) 83 return NULL; 84 if (!zalloc_cpumask_var_node(&data->domain, GFP_KERNEL, node)) 85 goto out_data; 86 if (!zalloc_cpumask_var_node(&data->old_domain, GFP_KERNEL, node)) 87 goto out_domain; 88 return data; 89 out_domain: 90 free_cpumask_var(data->domain); 91 out_data: 92 kfree(data); 93 return NULL; 94 } 95 96 static void free_apic_chip_data(struct apic_chip_data *data) 97 { 98 if (data) { 99 free_cpumask_var(data->domain); 100 free_cpumask_var(data->old_domain); 101 kfree(data); 102 } 103 } 104 105 static int __assign_irq_vector(int irq, struct apic_chip_data *d, 106 const struct cpumask *mask) 107 { 108 /* 109 * NOTE! The local APIC isn't very good at handling 110 * multiple interrupts at the same interrupt level. 111 * As the interrupt level is determined by taking the 112 * vector number and shifting that right by 4, we 113 * want to spread these out a bit so that they don't 114 * all fall in the same interrupt level. 115 * 116 * Also, we've got to be careful not to trash gate 117 * 0x80, because int 0x80 is hm, kind of importantish. ;) 118 */ 119 static int current_vector = FIRST_EXTERNAL_VECTOR + VECTOR_OFFSET_START; 120 static int current_offset = VECTOR_OFFSET_START % 16; 121 int cpu, vector; 122 123 /* 124 * If there is still a move in progress or the previous move has not 125 * been cleaned up completely, tell the caller to come back later. 126 */ 127 if (d->move_in_progress || 128 cpumask_intersects(d->old_domain, cpu_online_mask)) 129 return -EBUSY; 130 131 /* Only try and allocate irqs on cpus that are present */ 132 cpumask_clear(d->old_domain); 133 cpumask_clear(searched_cpumask); 134 cpu = cpumask_first_and(mask, cpu_online_mask); 135 while (cpu < nr_cpu_ids) { 136 int new_cpu, offset; 137 138 /* Get the possible target cpus for @mask/@cpu from the apic */ 139 apic->vector_allocation_domain(cpu, vector_cpumask, mask); 140 141 /* 142 * Clear the offline cpus from @vector_cpumask for searching 143 * and verify whether the result overlaps with @mask. If true, 144 * then the call to apic->cpu_mask_to_apicid_and() will 145 * succeed as well. If not, no point in trying to find a 146 * vector in this mask. 147 */ 148 cpumask_and(vector_searchmask, vector_cpumask, cpu_online_mask); 149 if (!cpumask_intersects(vector_searchmask, mask)) 150 goto next_cpu; 151 152 if (cpumask_subset(vector_cpumask, d->domain)) { 153 if (cpumask_equal(vector_cpumask, d->domain)) 154 goto success; 155 /* 156 * Mark the cpus which are not longer in the mask for 157 * cleanup. 158 */ 159 cpumask_andnot(d->old_domain, d->domain, vector_cpumask); 160 vector = d->cfg.vector; 161 goto update; 162 } 163 164 vector = current_vector; 165 offset = current_offset; 166 next: 167 vector += 16; 168 if (vector >= first_system_vector) { 169 offset = (offset + 1) % 16; 170 vector = FIRST_EXTERNAL_VECTOR + offset; 171 } 172 173 /* If the search wrapped around, try the next cpu */ 174 if (unlikely(current_vector == vector)) 175 goto next_cpu; 176 177 if (test_bit(vector, used_vectors)) 178 goto next; 179 180 for_each_cpu(new_cpu, vector_searchmask) { 181 if (!IS_ERR_OR_NULL(per_cpu(vector_irq, new_cpu)[vector])) 182 goto next; 183 } 184 /* Found one! */ 185 current_vector = vector; 186 current_offset = offset; 187 /* Schedule the old vector for cleanup on all cpus */ 188 if (d->cfg.vector) 189 cpumask_copy(d->old_domain, d->domain); 190 for_each_cpu(new_cpu, vector_searchmask) 191 per_cpu(vector_irq, new_cpu)[vector] = irq_to_desc(irq); 192 goto update; 193 194 next_cpu: 195 /* 196 * We exclude the current @vector_cpumask from the requested 197 * @mask and try again with the next online cpu in the 198 * result. We cannot modify @mask, so we use @vector_cpumask 199 * as a temporary buffer here as it will be reassigned when 200 * calling apic->vector_allocation_domain() above. 201 */ 202 cpumask_or(searched_cpumask, searched_cpumask, vector_cpumask); 203 cpumask_andnot(vector_cpumask, mask, searched_cpumask); 204 cpu = cpumask_first_and(vector_cpumask, cpu_online_mask); 205 continue; 206 } 207 return -ENOSPC; 208 209 update: 210 /* 211 * Exclude offline cpus from the cleanup mask and set the 212 * move_in_progress flag when the result is not empty. 213 */ 214 cpumask_and(d->old_domain, d->old_domain, cpu_online_mask); 215 d->move_in_progress = !cpumask_empty(d->old_domain); 216 d->cfg.old_vector = d->move_in_progress ? d->cfg.vector : 0; 217 d->cfg.vector = vector; 218 cpumask_copy(d->domain, vector_cpumask); 219 success: 220 /* 221 * Cache destination APIC IDs into cfg->dest_apicid. This cannot fail 222 * as we already established, that mask & d->domain & cpu_online_mask 223 * is not empty. 224 */ 225 BUG_ON(apic->cpu_mask_to_apicid_and(mask, d->domain, 226 &d->cfg.dest_apicid)); 227 return 0; 228 } 229 230 static int assign_irq_vector(int irq, struct apic_chip_data *data, 231 const struct cpumask *mask) 232 { 233 int err; 234 unsigned long flags; 235 236 raw_spin_lock_irqsave(&vector_lock, flags); 237 err = __assign_irq_vector(irq, data, mask); 238 raw_spin_unlock_irqrestore(&vector_lock, flags); 239 return err; 240 } 241 242 static int assign_irq_vector_policy(int irq, int node, 243 struct apic_chip_data *data, 244 struct irq_alloc_info *info) 245 { 246 if (info && info->mask) 247 return assign_irq_vector(irq, data, info->mask); 248 if (node != NUMA_NO_NODE && 249 assign_irq_vector(irq, data, cpumask_of_node(node)) == 0) 250 return 0; 251 return assign_irq_vector(irq, data, apic->target_cpus()); 252 } 253 254 static void clear_irq_vector(int irq, struct apic_chip_data *data) 255 { 256 struct irq_desc *desc; 257 int cpu, vector; 258 259 BUG_ON(!data->cfg.vector); 260 261 vector = data->cfg.vector; 262 for_each_cpu_and(cpu, data->domain, cpu_online_mask) 263 per_cpu(vector_irq, cpu)[vector] = VECTOR_UNUSED; 264 265 data->cfg.vector = 0; 266 cpumask_clear(data->domain); 267 268 /* 269 * If move is in progress or the old_domain mask is not empty, 270 * i.e. the cleanup IPI has not been processed yet, we need to remove 271 * the old references to desc from all cpus vector tables. 272 */ 273 if (!data->move_in_progress && cpumask_empty(data->old_domain)) 274 return; 275 276 desc = irq_to_desc(irq); 277 for_each_cpu_and(cpu, data->old_domain, cpu_online_mask) { 278 for (vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS; 279 vector++) { 280 if (per_cpu(vector_irq, cpu)[vector] != desc) 281 continue; 282 per_cpu(vector_irq, cpu)[vector] = VECTOR_UNUSED; 283 break; 284 } 285 } 286 data->move_in_progress = 0; 287 } 288 289 void init_irq_alloc_info(struct irq_alloc_info *info, 290 const struct cpumask *mask) 291 { 292 memset(info, 0, sizeof(*info)); 293 info->mask = mask; 294 } 295 296 void copy_irq_alloc_info(struct irq_alloc_info *dst, struct irq_alloc_info *src) 297 { 298 if (src) 299 *dst = *src; 300 else 301 memset(dst, 0, sizeof(*dst)); 302 } 303 304 static void x86_vector_free_irqs(struct irq_domain *domain, 305 unsigned int virq, unsigned int nr_irqs) 306 { 307 struct apic_chip_data *apic_data; 308 struct irq_data *irq_data; 309 unsigned long flags; 310 int i; 311 312 for (i = 0; i < nr_irqs; i++) { 313 irq_data = irq_domain_get_irq_data(x86_vector_domain, virq + i); 314 if (irq_data && irq_data->chip_data) { 315 raw_spin_lock_irqsave(&vector_lock, flags); 316 clear_irq_vector(virq + i, irq_data->chip_data); 317 apic_data = irq_data->chip_data; 318 irq_domain_reset_irq_data(irq_data); 319 raw_spin_unlock_irqrestore(&vector_lock, flags); 320 free_apic_chip_data(apic_data); 321 #ifdef CONFIG_X86_IO_APIC 322 if (virq + i < nr_legacy_irqs()) 323 legacy_irq_data[virq + i] = NULL; 324 #endif 325 } 326 } 327 } 328 329 static int x86_vector_alloc_irqs(struct irq_domain *domain, unsigned int virq, 330 unsigned int nr_irqs, void *arg) 331 { 332 struct irq_alloc_info *info = arg; 333 struct apic_chip_data *data; 334 struct irq_data *irq_data; 335 int i, err, node; 336 337 if (disable_apic) 338 return -ENXIO; 339 340 /* Currently vector allocator can't guarantee contiguous allocations */ 341 if ((info->flags & X86_IRQ_ALLOC_CONTIGUOUS_VECTORS) && nr_irqs > 1) 342 return -ENOSYS; 343 344 for (i = 0; i < nr_irqs; i++) { 345 irq_data = irq_domain_get_irq_data(domain, virq + i); 346 BUG_ON(!irq_data); 347 node = irq_data_get_node(irq_data); 348 #ifdef CONFIG_X86_IO_APIC 349 if (virq + i < nr_legacy_irqs() && legacy_irq_data[virq + i]) 350 data = legacy_irq_data[virq + i]; 351 else 352 #endif 353 data = alloc_apic_chip_data(node); 354 if (!data) { 355 err = -ENOMEM; 356 goto error; 357 } 358 359 irq_data->chip = &lapic_controller; 360 irq_data->chip_data = data; 361 irq_data->hwirq = virq + i; 362 err = assign_irq_vector_policy(virq + i, node, data, info); 363 if (err) 364 goto error; 365 } 366 367 return 0; 368 369 error: 370 x86_vector_free_irqs(domain, virq, i + 1); 371 return err; 372 } 373 374 static const struct irq_domain_ops x86_vector_domain_ops = { 375 .alloc = x86_vector_alloc_irqs, 376 .free = x86_vector_free_irqs, 377 }; 378 379 int __init arch_probe_nr_irqs(void) 380 { 381 int nr; 382 383 if (nr_irqs > (NR_VECTORS * nr_cpu_ids)) 384 nr_irqs = NR_VECTORS * nr_cpu_ids; 385 386 nr = (gsi_top + nr_legacy_irqs()) + 8 * nr_cpu_ids; 387 #if defined(CONFIG_PCI_MSI) || defined(CONFIG_HT_IRQ) 388 /* 389 * for MSI and HT dyn irq 390 */ 391 if (gsi_top <= NR_IRQS_LEGACY) 392 nr += 8 * nr_cpu_ids; 393 else 394 nr += gsi_top * 16; 395 #endif 396 if (nr < nr_irqs) 397 nr_irqs = nr; 398 399 /* 400 * We don't know if PIC is present at this point so we need to do 401 * probe() to get the right number of legacy IRQs. 402 */ 403 return legacy_pic->probe(); 404 } 405 406 #ifdef CONFIG_X86_IO_APIC 407 static void init_legacy_irqs(void) 408 { 409 int i, node = cpu_to_node(0); 410 struct apic_chip_data *data; 411 412 /* 413 * For legacy IRQ's, start with assigning irq0 to irq15 to 414 * ISA_IRQ_VECTOR(i) for all cpu's. 415 */ 416 for (i = 0; i < nr_legacy_irqs(); i++) { 417 data = legacy_irq_data[i] = alloc_apic_chip_data(node); 418 BUG_ON(!data); 419 420 data->cfg.vector = ISA_IRQ_VECTOR(i); 421 cpumask_setall(data->domain); 422 irq_set_chip_data(i, data); 423 } 424 } 425 #else 426 static void init_legacy_irqs(void) { } 427 #endif 428 429 int __init arch_early_irq_init(void) 430 { 431 init_legacy_irqs(); 432 433 x86_vector_domain = irq_domain_add_tree(NULL, &x86_vector_domain_ops, 434 NULL); 435 BUG_ON(x86_vector_domain == NULL); 436 irq_set_default_host(x86_vector_domain); 437 438 arch_init_msi_domain(x86_vector_domain); 439 arch_init_htirq_domain(x86_vector_domain); 440 441 BUG_ON(!alloc_cpumask_var(&vector_cpumask, GFP_KERNEL)); 442 BUG_ON(!alloc_cpumask_var(&vector_searchmask, GFP_KERNEL)); 443 BUG_ON(!alloc_cpumask_var(&searched_cpumask, GFP_KERNEL)); 444 445 return arch_early_ioapic_init(); 446 } 447 448 /* Initialize vector_irq on a new cpu */ 449 static void __setup_vector_irq(int cpu) 450 { 451 struct apic_chip_data *data; 452 struct irq_desc *desc; 453 int irq, vector; 454 455 /* Mark the inuse vectors */ 456 for_each_irq_desc(irq, desc) { 457 struct irq_data *idata = irq_desc_get_irq_data(desc); 458 459 data = apic_chip_data(idata); 460 if (!data || !cpumask_test_cpu(cpu, data->domain)) 461 continue; 462 vector = data->cfg.vector; 463 per_cpu(vector_irq, cpu)[vector] = desc; 464 } 465 /* Mark the free vectors */ 466 for (vector = 0; vector < NR_VECTORS; ++vector) { 467 desc = per_cpu(vector_irq, cpu)[vector]; 468 if (IS_ERR_OR_NULL(desc)) 469 continue; 470 471 data = apic_chip_data(irq_desc_get_irq_data(desc)); 472 if (!cpumask_test_cpu(cpu, data->domain)) 473 per_cpu(vector_irq, cpu)[vector] = VECTOR_UNUSED; 474 } 475 } 476 477 /* 478 * Setup the vector to irq mappings. Must be called with vector_lock held. 479 */ 480 void setup_vector_irq(int cpu) 481 { 482 int irq; 483 484 lockdep_assert_held(&vector_lock); 485 /* 486 * On most of the platforms, legacy PIC delivers the interrupts on the 487 * boot cpu. But there are certain platforms where PIC interrupts are 488 * delivered to multiple cpu's. If the legacy IRQ is handled by the 489 * legacy PIC, for the new cpu that is coming online, setup the static 490 * legacy vector to irq mapping: 491 */ 492 for (irq = 0; irq < nr_legacy_irqs(); irq++) 493 per_cpu(vector_irq, cpu)[ISA_IRQ_VECTOR(irq)] = irq_to_desc(irq); 494 495 __setup_vector_irq(cpu); 496 } 497 498 static int apic_retrigger_irq(struct irq_data *irq_data) 499 { 500 struct apic_chip_data *data = apic_chip_data(irq_data); 501 unsigned long flags; 502 int cpu; 503 504 raw_spin_lock_irqsave(&vector_lock, flags); 505 cpu = cpumask_first_and(data->domain, cpu_online_mask); 506 apic->send_IPI_mask(cpumask_of(cpu), data->cfg.vector); 507 raw_spin_unlock_irqrestore(&vector_lock, flags); 508 509 return 1; 510 } 511 512 void apic_ack_edge(struct irq_data *data) 513 { 514 irq_complete_move(irqd_cfg(data)); 515 irq_move_irq(data); 516 ack_APIC_irq(); 517 } 518 519 static int apic_set_affinity(struct irq_data *irq_data, 520 const struct cpumask *dest, bool force) 521 { 522 struct apic_chip_data *data = irq_data->chip_data; 523 int err, irq = irq_data->irq; 524 525 if (!config_enabled(CONFIG_SMP)) 526 return -EPERM; 527 528 if (!cpumask_intersects(dest, cpu_online_mask)) 529 return -EINVAL; 530 531 err = assign_irq_vector(irq, data, dest); 532 return err ? err : IRQ_SET_MASK_OK; 533 } 534 535 static struct irq_chip lapic_controller = { 536 .irq_ack = apic_ack_edge, 537 .irq_set_affinity = apic_set_affinity, 538 .irq_retrigger = apic_retrigger_irq, 539 }; 540 541 #ifdef CONFIG_SMP 542 static void __send_cleanup_vector(struct apic_chip_data *data) 543 { 544 raw_spin_lock(&vector_lock); 545 cpumask_and(data->old_domain, data->old_domain, cpu_online_mask); 546 data->move_in_progress = 0; 547 if (!cpumask_empty(data->old_domain)) 548 apic->send_IPI_mask(data->old_domain, IRQ_MOVE_CLEANUP_VECTOR); 549 raw_spin_unlock(&vector_lock); 550 } 551 552 void send_cleanup_vector(struct irq_cfg *cfg) 553 { 554 struct apic_chip_data *data; 555 556 data = container_of(cfg, struct apic_chip_data, cfg); 557 if (data->move_in_progress) 558 __send_cleanup_vector(data); 559 } 560 561 asmlinkage __visible void smp_irq_move_cleanup_interrupt(void) 562 { 563 unsigned vector, me; 564 565 entering_ack_irq(); 566 567 /* Prevent vectors vanishing under us */ 568 raw_spin_lock(&vector_lock); 569 570 me = smp_processor_id(); 571 for (vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS; vector++) { 572 struct apic_chip_data *data; 573 struct irq_desc *desc; 574 unsigned int irr; 575 576 retry: 577 desc = __this_cpu_read(vector_irq[vector]); 578 if (IS_ERR_OR_NULL(desc)) 579 continue; 580 581 if (!raw_spin_trylock(&desc->lock)) { 582 raw_spin_unlock(&vector_lock); 583 cpu_relax(); 584 raw_spin_lock(&vector_lock); 585 goto retry; 586 } 587 588 data = apic_chip_data(irq_desc_get_irq_data(desc)); 589 if (!data) 590 goto unlock; 591 592 /* 593 * Nothing to cleanup if irq migration is in progress 594 * or this cpu is not set in the cleanup mask. 595 */ 596 if (data->move_in_progress || 597 !cpumask_test_cpu(me, data->old_domain)) 598 goto unlock; 599 600 /* 601 * We have two cases to handle here: 602 * 1) vector is unchanged but the target mask got reduced 603 * 2) vector and the target mask has changed 604 * 605 * #1 is obvious, but in #2 we have two vectors with the same 606 * irq descriptor: the old and the new vector. So we need to 607 * make sure that we only cleanup the old vector. The new 608 * vector has the current @vector number in the config and 609 * this cpu is part of the target mask. We better leave that 610 * one alone. 611 */ 612 if (vector == data->cfg.vector && 613 cpumask_test_cpu(me, data->domain)) 614 goto unlock; 615 616 irr = apic_read(APIC_IRR + (vector / 32 * 0x10)); 617 /* 618 * Check if the vector that needs to be cleanedup is 619 * registered at the cpu's IRR. If so, then this is not 620 * the best time to clean it up. Lets clean it up in the 621 * next attempt by sending another IRQ_MOVE_CLEANUP_VECTOR 622 * to myself. 623 */ 624 if (irr & (1 << (vector % 32))) { 625 apic->send_IPI_self(IRQ_MOVE_CLEANUP_VECTOR); 626 goto unlock; 627 } 628 __this_cpu_write(vector_irq[vector], VECTOR_UNUSED); 629 cpumask_clear_cpu(me, data->old_domain); 630 unlock: 631 raw_spin_unlock(&desc->lock); 632 } 633 634 raw_spin_unlock(&vector_lock); 635 636 exiting_irq(); 637 } 638 639 static void __irq_complete_move(struct irq_cfg *cfg, unsigned vector) 640 { 641 unsigned me; 642 struct apic_chip_data *data; 643 644 data = container_of(cfg, struct apic_chip_data, cfg); 645 if (likely(!data->move_in_progress)) 646 return; 647 648 me = smp_processor_id(); 649 if (vector == data->cfg.vector && cpumask_test_cpu(me, data->domain)) 650 __send_cleanup_vector(data); 651 } 652 653 void irq_complete_move(struct irq_cfg *cfg) 654 { 655 __irq_complete_move(cfg, ~get_irq_regs()->orig_ax); 656 } 657 658 /* 659 * Called from fixup_irqs() with @desc->lock held and interrupts disabled. 660 */ 661 void irq_force_complete_move(struct irq_desc *desc) 662 { 663 struct irq_data *irqdata = irq_desc_get_irq_data(desc); 664 struct apic_chip_data *data = apic_chip_data(irqdata); 665 struct irq_cfg *cfg = data ? &data->cfg : NULL; 666 unsigned int cpu; 667 668 if (!cfg) 669 return; 670 671 /* 672 * This is tricky. If the cleanup of @data->old_domain has not been 673 * done yet, then the following setaffinity call will fail with 674 * -EBUSY. This can leave the interrupt in a stale state. 675 * 676 * All CPUs are stuck in stop machine with interrupts disabled so 677 * calling __irq_complete_move() would be completely pointless. 678 */ 679 raw_spin_lock(&vector_lock); 680 /* 681 * Clean out all offline cpus (including the outgoing one) from the 682 * old_domain mask. 683 */ 684 cpumask_and(data->old_domain, data->old_domain, cpu_online_mask); 685 686 /* 687 * If move_in_progress is cleared and the old_domain mask is empty, 688 * then there is nothing to cleanup. fixup_irqs() will take care of 689 * the stale vectors on the outgoing cpu. 690 */ 691 if (!data->move_in_progress && cpumask_empty(data->old_domain)) { 692 raw_spin_unlock(&vector_lock); 693 return; 694 } 695 696 /* 697 * 1) The interrupt is in move_in_progress state. That means that we 698 * have not seen an interrupt since the io_apic was reprogrammed to 699 * the new vector. 700 * 701 * 2) The interrupt has fired on the new vector, but the cleanup IPIs 702 * have not been processed yet. 703 */ 704 if (data->move_in_progress) { 705 /* 706 * In theory there is a race: 707 * 708 * set_ioapic(new_vector) <-- Interrupt is raised before update 709 * is effective, i.e. it's raised on 710 * the old vector. 711 * 712 * So if the target cpu cannot handle that interrupt before 713 * the old vector is cleaned up, we get a spurious interrupt 714 * and in the worst case the ioapic irq line becomes stale. 715 * 716 * But in case of cpu hotplug this should be a non issue 717 * because if the affinity update happens right before all 718 * cpus rendevouz in stop machine, there is no way that the 719 * interrupt can be blocked on the target cpu because all cpus 720 * loops first with interrupts enabled in stop machine, so the 721 * old vector is not yet cleaned up when the interrupt fires. 722 * 723 * So the only way to run into this issue is if the delivery 724 * of the interrupt on the apic/system bus would be delayed 725 * beyond the point where the target cpu disables interrupts 726 * in stop machine. I doubt that it can happen, but at least 727 * there is a theroretical chance. Virtualization might be 728 * able to expose this, but AFAICT the IOAPIC emulation is not 729 * as stupid as the real hardware. 730 * 731 * Anyway, there is nothing we can do about that at this point 732 * w/o refactoring the whole fixup_irq() business completely. 733 * We print at least the irq number and the old vector number, 734 * so we have the necessary information when a problem in that 735 * area arises. 736 */ 737 pr_warn("IRQ fixup: irq %d move in progress, old vector %d\n", 738 irqdata->irq, cfg->old_vector); 739 } 740 /* 741 * If old_domain is not empty, then other cpus still have the irq 742 * descriptor set in their vector array. Clean it up. 743 */ 744 for_each_cpu(cpu, data->old_domain) 745 per_cpu(vector_irq, cpu)[cfg->old_vector] = VECTOR_UNUSED; 746 747 /* Cleanup the left overs of the (half finished) move */ 748 cpumask_clear(data->old_domain); 749 data->move_in_progress = 0; 750 raw_spin_unlock(&vector_lock); 751 } 752 #endif 753 754 static void __init print_APIC_field(int base) 755 { 756 int i; 757 758 printk(KERN_DEBUG); 759 760 for (i = 0; i < 8; i++) 761 pr_cont("%08x", apic_read(base + i*0x10)); 762 763 pr_cont("\n"); 764 } 765 766 static void __init print_local_APIC(void *dummy) 767 { 768 unsigned int i, v, ver, maxlvt; 769 u64 icr; 770 771 pr_debug("printing local APIC contents on CPU#%d/%d:\n", 772 smp_processor_id(), hard_smp_processor_id()); 773 v = apic_read(APIC_ID); 774 pr_info("... APIC ID: %08x (%01x)\n", v, read_apic_id()); 775 v = apic_read(APIC_LVR); 776 pr_info("... APIC VERSION: %08x\n", v); 777 ver = GET_APIC_VERSION(v); 778 maxlvt = lapic_get_maxlvt(); 779 780 v = apic_read(APIC_TASKPRI); 781 pr_debug("... APIC TASKPRI: %08x (%02x)\n", v, v & APIC_TPRI_MASK); 782 783 /* !82489DX */ 784 if (APIC_INTEGRATED(ver)) { 785 if (!APIC_XAPIC(ver)) { 786 v = apic_read(APIC_ARBPRI); 787 pr_debug("... APIC ARBPRI: %08x (%02x)\n", 788 v, v & APIC_ARBPRI_MASK); 789 } 790 v = apic_read(APIC_PROCPRI); 791 pr_debug("... APIC PROCPRI: %08x\n", v); 792 } 793 794 /* 795 * Remote read supported only in the 82489DX and local APIC for 796 * Pentium processors. 797 */ 798 if (!APIC_INTEGRATED(ver) || maxlvt == 3) { 799 v = apic_read(APIC_RRR); 800 pr_debug("... APIC RRR: %08x\n", v); 801 } 802 803 v = apic_read(APIC_LDR); 804 pr_debug("... APIC LDR: %08x\n", v); 805 if (!x2apic_enabled()) { 806 v = apic_read(APIC_DFR); 807 pr_debug("... APIC DFR: %08x\n", v); 808 } 809 v = apic_read(APIC_SPIV); 810 pr_debug("... APIC SPIV: %08x\n", v); 811 812 pr_debug("... APIC ISR field:\n"); 813 print_APIC_field(APIC_ISR); 814 pr_debug("... APIC TMR field:\n"); 815 print_APIC_field(APIC_TMR); 816 pr_debug("... APIC IRR field:\n"); 817 print_APIC_field(APIC_IRR); 818 819 /* !82489DX */ 820 if (APIC_INTEGRATED(ver)) { 821 /* Due to the Pentium erratum 3AP. */ 822 if (maxlvt > 3) 823 apic_write(APIC_ESR, 0); 824 825 v = apic_read(APIC_ESR); 826 pr_debug("... APIC ESR: %08x\n", v); 827 } 828 829 icr = apic_icr_read(); 830 pr_debug("... APIC ICR: %08x\n", (u32)icr); 831 pr_debug("... APIC ICR2: %08x\n", (u32)(icr >> 32)); 832 833 v = apic_read(APIC_LVTT); 834 pr_debug("... APIC LVTT: %08x\n", v); 835 836 if (maxlvt > 3) { 837 /* PC is LVT#4. */ 838 v = apic_read(APIC_LVTPC); 839 pr_debug("... APIC LVTPC: %08x\n", v); 840 } 841 v = apic_read(APIC_LVT0); 842 pr_debug("... APIC LVT0: %08x\n", v); 843 v = apic_read(APIC_LVT1); 844 pr_debug("... APIC LVT1: %08x\n", v); 845 846 if (maxlvt > 2) { 847 /* ERR is LVT#3. */ 848 v = apic_read(APIC_LVTERR); 849 pr_debug("... APIC LVTERR: %08x\n", v); 850 } 851 852 v = apic_read(APIC_TMICT); 853 pr_debug("... APIC TMICT: %08x\n", v); 854 v = apic_read(APIC_TMCCT); 855 pr_debug("... APIC TMCCT: %08x\n", v); 856 v = apic_read(APIC_TDCR); 857 pr_debug("... APIC TDCR: %08x\n", v); 858 859 if (boot_cpu_has(X86_FEATURE_EXTAPIC)) { 860 v = apic_read(APIC_EFEAT); 861 maxlvt = (v >> 16) & 0xff; 862 pr_debug("... APIC EFEAT: %08x\n", v); 863 v = apic_read(APIC_ECTRL); 864 pr_debug("... APIC ECTRL: %08x\n", v); 865 for (i = 0; i < maxlvt; i++) { 866 v = apic_read(APIC_EILVTn(i)); 867 pr_debug("... APIC EILVT%d: %08x\n", i, v); 868 } 869 } 870 pr_cont("\n"); 871 } 872 873 static void __init print_local_APICs(int maxcpu) 874 { 875 int cpu; 876 877 if (!maxcpu) 878 return; 879 880 preempt_disable(); 881 for_each_online_cpu(cpu) { 882 if (cpu >= maxcpu) 883 break; 884 smp_call_function_single(cpu, print_local_APIC, NULL, 1); 885 } 886 preempt_enable(); 887 } 888 889 static void __init print_PIC(void) 890 { 891 unsigned int v; 892 unsigned long flags; 893 894 if (!nr_legacy_irqs()) 895 return; 896 897 pr_debug("\nprinting PIC contents\n"); 898 899 raw_spin_lock_irqsave(&i8259A_lock, flags); 900 901 v = inb(0xa1) << 8 | inb(0x21); 902 pr_debug("... PIC IMR: %04x\n", v); 903 904 v = inb(0xa0) << 8 | inb(0x20); 905 pr_debug("... PIC IRR: %04x\n", v); 906 907 outb(0x0b, 0xa0); 908 outb(0x0b, 0x20); 909 v = inb(0xa0) << 8 | inb(0x20); 910 outb(0x0a, 0xa0); 911 outb(0x0a, 0x20); 912 913 raw_spin_unlock_irqrestore(&i8259A_lock, flags); 914 915 pr_debug("... PIC ISR: %04x\n", v); 916 917 v = inb(0x4d1) << 8 | inb(0x4d0); 918 pr_debug("... PIC ELCR: %04x\n", v); 919 } 920 921 static int show_lapic __initdata = 1; 922 static __init int setup_show_lapic(char *arg) 923 { 924 int num = -1; 925 926 if (strcmp(arg, "all") == 0) { 927 show_lapic = CONFIG_NR_CPUS; 928 } else { 929 get_option(&arg, &num); 930 if (num >= 0) 931 show_lapic = num; 932 } 933 934 return 1; 935 } 936 __setup("show_lapic=", setup_show_lapic); 937 938 static int __init print_ICs(void) 939 { 940 if (apic_verbosity == APIC_QUIET) 941 return 0; 942 943 print_PIC(); 944 945 /* don't print out if apic is not there */ 946 if (!cpu_has_apic && !apic_from_smp_config()) 947 return 0; 948 949 print_local_APICs(show_lapic); 950 print_IO_APICs(); 951 952 return 0; 953 } 954 955 late_initcall(print_ICs); 956