msi.c revision fc4afc7b2bdd81e2dbded5a8222676d3161758d3
1/* 2 * File: msi.c 3 * Purpose: PCI Message Signaled Interrupt (MSI) 4 * 5 * Copyright (C) 2003-2004 Intel 6 * Copyright (C) Tom Long Nguyen (tom.l.nguyen@intel.com) 7 */ 8 9#include <linux/err.h> 10#include <linux/mm.h> 11#include <linux/irq.h> 12#include <linux/interrupt.h> 13#include <linux/init.h> 14#include <linux/ioport.h> 15#include <linux/smp_lock.h> 16#include <linux/pci.h> 17#include <linux/proc_fs.h> 18#include <linux/msi.h> 19 20#include <asm/errno.h> 21#include <asm/io.h> 22#include <asm/smp.h> 23 24#include "pci.h" 25#include "msi.h" 26 27static struct kmem_cache* msi_cachep; 28 29static int pci_msi_enable = 1; 30 31static int msi_cache_init(void) 32{ 33 msi_cachep = kmem_cache_create("msi_cache", sizeof(struct msi_desc), 34 0, SLAB_HWCACHE_ALIGN, NULL, NULL); 35 if (!msi_cachep) 36 return -ENOMEM; 37 38 return 0; 39} 40 41static void msi_set_enable(struct pci_dev *dev, int enable) 42{ 43 int pos; 44 u16 control; 45 46 pos = pci_find_capability(dev, PCI_CAP_ID_MSI); 47 if (pos) { 48 pci_read_config_word(dev, pos + PCI_MSI_FLAGS, &control); 49 control &= ~PCI_MSI_FLAGS_ENABLE; 50 if (enable) 51 control |= PCI_MSI_FLAGS_ENABLE; 52 pci_write_config_word(dev, pos + PCI_MSI_FLAGS, control); 53 } 54} 55 56static void msix_set_enable(struct pci_dev *dev, int enable) 57{ 58 int pos; 59 u16 control; 60 61 pos = pci_find_capability(dev, PCI_CAP_ID_MSIX); 62 if (pos) { 63 pci_read_config_word(dev, pos + PCI_MSIX_FLAGS, &control); 64 control &= ~PCI_MSIX_FLAGS_ENABLE; 65 if (enable) 66 control |= PCI_MSIX_FLAGS_ENABLE; 67 pci_write_config_word(dev, pos + PCI_MSIX_FLAGS, control); 68 } 69} 70 71static void msix_flush_writes(unsigned int irq) 72{ 73 struct msi_desc *entry; 74 75 entry = get_irq_msi(irq); 76 BUG_ON(!entry || !entry->dev); 77 switch (entry->msi_attrib.type) { 78 case PCI_CAP_ID_MSI: 79 /* nothing to do */ 80 break; 81 case PCI_CAP_ID_MSIX: 82 { 83 int offset = entry->msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE + 84 PCI_MSIX_ENTRY_VECTOR_CTRL_OFFSET; 85 readl(entry->mask_base + offset); 86 break; 87 } 88 default: 89 BUG(); 90 break; 91 } 92} 93 94static void msi_set_mask_bit(unsigned int irq, int flag) 95{ 96 struct msi_desc *entry; 97 98 entry = get_irq_msi(irq); 99 BUG_ON(!entry || !entry->dev); 100 switch (entry->msi_attrib.type) { 101 case PCI_CAP_ID_MSI: 102 if (entry->msi_attrib.maskbit) { 103 int pos; 104 u32 mask_bits; 105 106 pos = (long)entry->mask_base; 107 pci_read_config_dword(entry->dev, pos, &mask_bits); 108 mask_bits &= ~(1); 109 mask_bits |= flag; 110 pci_write_config_dword(entry->dev, pos, mask_bits); 111 } else { 112 msi_set_enable(entry->dev, !flag); 113 } 114 break; 115 case PCI_CAP_ID_MSIX: 116 { 117 int offset = entry->msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE + 118 PCI_MSIX_ENTRY_VECTOR_CTRL_OFFSET; 119 writel(flag, entry->mask_base + offset); 120 readl(entry->mask_base + offset); 121 break; 122 } 123 default: 124 BUG(); 125 break; 126 } 127 entry->msi_attrib.masked = !!flag; 128} 129 130void read_msi_msg(unsigned int irq, struct msi_msg *msg) 131{ 132 struct msi_desc *entry = get_irq_msi(irq); 133 switch(entry->msi_attrib.type) { 134 case PCI_CAP_ID_MSI: 135 { 136 struct pci_dev *dev = entry->dev; 137 int pos = entry->msi_attrib.pos; 138 u16 data; 139 140 pci_read_config_dword(dev, msi_lower_address_reg(pos), 141 &msg->address_lo); 142 if (entry->msi_attrib.is_64) { 143 pci_read_config_dword(dev, msi_upper_address_reg(pos), 144 &msg->address_hi); 145 pci_read_config_word(dev, msi_data_reg(pos, 1), &data); 146 } else { 147 msg->address_hi = 0; 148 pci_read_config_word(dev, msi_data_reg(pos, 1), &data); 149 } 150 msg->data = data; 151 break; 152 } 153 case PCI_CAP_ID_MSIX: 154 { 155 void __iomem *base; 156 base = entry->mask_base + 157 entry->msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE; 158 159 msg->address_lo = readl(base + PCI_MSIX_ENTRY_LOWER_ADDR_OFFSET); 160 msg->address_hi = readl(base + PCI_MSIX_ENTRY_UPPER_ADDR_OFFSET); 161 msg->data = readl(base + PCI_MSIX_ENTRY_DATA_OFFSET); 162 break; 163 } 164 default: 165 BUG(); 166 } 167} 168 169void write_msi_msg(unsigned int irq, struct msi_msg *msg) 170{ 171 struct msi_desc *entry = get_irq_msi(irq); 172 switch (entry->msi_attrib.type) { 173 case PCI_CAP_ID_MSI: 174 { 175 struct pci_dev *dev = entry->dev; 176 int pos = entry->msi_attrib.pos; 177 178 pci_write_config_dword(dev, msi_lower_address_reg(pos), 179 msg->address_lo); 180 if (entry->msi_attrib.is_64) { 181 pci_write_config_dword(dev, msi_upper_address_reg(pos), 182 msg->address_hi); 183 pci_write_config_word(dev, msi_data_reg(pos, 1), 184 msg->data); 185 } else { 186 pci_write_config_word(dev, msi_data_reg(pos, 0), 187 msg->data); 188 } 189 break; 190 } 191 case PCI_CAP_ID_MSIX: 192 { 193 void __iomem *base; 194 base = entry->mask_base + 195 entry->msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE; 196 197 writel(msg->address_lo, 198 base + PCI_MSIX_ENTRY_LOWER_ADDR_OFFSET); 199 writel(msg->address_hi, 200 base + PCI_MSIX_ENTRY_UPPER_ADDR_OFFSET); 201 writel(msg->data, base + PCI_MSIX_ENTRY_DATA_OFFSET); 202 break; 203 } 204 default: 205 BUG(); 206 } 207 entry->msg = *msg; 208} 209 210void mask_msi_irq(unsigned int irq) 211{ 212 msi_set_mask_bit(irq, 1); 213 msix_flush_writes(irq); 214} 215 216void unmask_msi_irq(unsigned int irq) 217{ 218 msi_set_mask_bit(irq, 0); 219 msix_flush_writes(irq); 220} 221 222static int msi_free_irq(struct pci_dev* dev, int irq); 223 224static int msi_init(void) 225{ 226 static int status = -ENOMEM; 227 228 if (!status) 229 return status; 230 231 status = msi_cache_init(); 232 if (status < 0) { 233 pci_msi_enable = 0; 234 printk(KERN_WARNING "PCI: MSI cache init failed\n"); 235 return status; 236 } 237 238 return status; 239} 240 241static struct msi_desc* alloc_msi_entry(void) 242{ 243 struct msi_desc *entry; 244 245 entry = kmem_cache_zalloc(msi_cachep, GFP_KERNEL); 246 if (!entry) 247 return NULL; 248 249 entry->link.tail = entry->link.head = 0; /* single message */ 250 entry->dev = NULL; 251 252 return entry; 253} 254 255#ifdef CONFIG_PM 256static void __pci_restore_msi_state(struct pci_dev *dev) 257{ 258 int pos; 259 u16 control; 260 struct msi_desc *entry; 261 262 if (!dev->msi_enabled) 263 return; 264 265 entry = get_irq_msi(dev->irq); 266 pos = entry->msi_attrib.pos; 267 268 pci_intx(dev, 0); /* disable intx */ 269 msi_set_enable(dev, 0); 270 write_msi_msg(dev->irq, &entry->msg); 271 if (entry->msi_attrib.maskbit) 272 msi_set_mask_bit(dev->irq, entry->msi_attrib.masked); 273 274 pci_read_config_word(dev, pos + PCI_MSI_FLAGS, &control); 275 control &= ~(PCI_MSI_FLAGS_QSIZE | PCI_MSI_FLAGS_ENABLE); 276 if (entry->msi_attrib.maskbit || !entry->msi_attrib.masked) 277 control |= PCI_MSI_FLAGS_ENABLE; 278 pci_write_config_word(dev, pos + PCI_MSI_FLAGS, control); 279} 280 281static void __pci_restore_msix_state(struct pci_dev *dev) 282{ 283 int pos; 284 int irq, head, tail = 0; 285 struct msi_desc *entry; 286 u16 control; 287 288 if (!dev->msix_enabled) 289 return; 290 291 /* route the table */ 292 pci_intx(dev, 0); /* disable intx */ 293 msix_set_enable(dev, 0); 294 irq = head = dev->first_msi_irq; 295 entry = get_irq_msi(irq); 296 pos = entry->msi_attrib.pos; 297 while (head != tail) { 298 entry = get_irq_msi(irq); 299 write_msi_msg(irq, &entry->msg); 300 msi_set_mask_bit(irq, entry->msi_attrib.masked); 301 302 tail = entry->link.tail; 303 irq = tail; 304 } 305 306 pci_read_config_word(dev, pos + PCI_MSIX_FLAGS, &control); 307 control &= ~PCI_MSIX_FLAGS_MASKALL; 308 control |= PCI_MSIX_FLAGS_ENABLE; 309 pci_write_config_word(dev, pos + PCI_MSIX_FLAGS, control); 310} 311 312void pci_restore_msi_state(struct pci_dev *dev) 313{ 314 __pci_restore_msi_state(dev); 315 __pci_restore_msix_state(dev); 316} 317#endif /* CONFIG_PM */ 318 319/** 320 * msi_capability_init - configure device's MSI capability structure 321 * @dev: pointer to the pci_dev data structure of MSI device function 322 * 323 * Setup the MSI capability structure of device function with a single 324 * MSI irq, regardless of device function is capable of handling 325 * multiple messages. A return of zero indicates the successful setup 326 * of an entry zero with the new MSI irq or non-zero for otherwise. 327 **/ 328static int msi_capability_init(struct pci_dev *dev) 329{ 330 struct msi_desc *entry; 331 int pos, irq; 332 u16 control; 333 334 msi_set_enable(dev, 0); /* Ensure msi is disabled as I set it up */ 335 336 pos = pci_find_capability(dev, PCI_CAP_ID_MSI); 337 pci_read_config_word(dev, msi_control_reg(pos), &control); 338 /* MSI Entry Initialization */ 339 entry = alloc_msi_entry(); 340 if (!entry) 341 return -ENOMEM; 342 343 entry->msi_attrib.type = PCI_CAP_ID_MSI; 344 entry->msi_attrib.is_64 = is_64bit_address(control); 345 entry->msi_attrib.entry_nr = 0; 346 entry->msi_attrib.maskbit = is_mask_bit_support(control); 347 entry->msi_attrib.masked = 1; 348 entry->msi_attrib.default_irq = dev->irq; /* Save IOAPIC IRQ */ 349 entry->msi_attrib.pos = pos; 350 if (is_mask_bit_support(control)) { 351 entry->mask_base = (void __iomem *)(long)msi_mask_bits_reg(pos, 352 is_64bit_address(control)); 353 } 354 entry->dev = dev; 355 if (entry->msi_attrib.maskbit) { 356 unsigned int maskbits, temp; 357 /* All MSIs are unmasked by default, Mask them all */ 358 pci_read_config_dword(dev, 359 msi_mask_bits_reg(pos, is_64bit_address(control)), 360 &maskbits); 361 temp = (1 << multi_msi_capable(control)); 362 temp = ((temp - 1) & ~temp); 363 maskbits |= temp; 364 pci_write_config_dword(dev, 365 msi_mask_bits_reg(pos, is_64bit_address(control)), 366 maskbits); 367 } 368 /* Configure MSI capability structure */ 369 irq = arch_setup_msi_irq(dev, entry); 370 if (irq < 0) { 371 kmem_cache_free(msi_cachep, entry); 372 return irq; 373 } 374 entry->link.head = irq; 375 entry->link.tail = irq; 376 dev->first_msi_irq = irq; 377 set_irq_msi(irq, entry); 378 379 /* Set MSI enabled bits */ 380 pci_intx(dev, 0); /* disable intx */ 381 msi_set_enable(dev, 1); 382 dev->msi_enabled = 1; 383 384 dev->irq = irq; 385 return 0; 386} 387 388/** 389 * msix_capability_init - configure device's MSI-X capability 390 * @dev: pointer to the pci_dev data structure of MSI-X device function 391 * @entries: pointer to an array of struct msix_entry entries 392 * @nvec: number of @entries 393 * 394 * Setup the MSI-X capability structure of device function with a 395 * single MSI-X irq. A return of zero indicates the successful setup of 396 * requested MSI-X entries with allocated irqs or non-zero for otherwise. 397 **/ 398static int msix_capability_init(struct pci_dev *dev, 399 struct msix_entry *entries, int nvec) 400{ 401 struct msi_desc *head = NULL, *tail = NULL, *entry = NULL; 402 int irq, pos, i, j, nr_entries, temp = 0; 403 unsigned long phys_addr; 404 u32 table_offset; 405 u16 control; 406 u8 bir; 407 void __iomem *base; 408 409 msix_set_enable(dev, 0);/* Ensure msix is disabled as I set it up */ 410 411 pos = pci_find_capability(dev, PCI_CAP_ID_MSIX); 412 /* Request & Map MSI-X table region */ 413 pci_read_config_word(dev, msi_control_reg(pos), &control); 414 nr_entries = multi_msix_capable(control); 415 416 pci_read_config_dword(dev, msix_table_offset_reg(pos), &table_offset); 417 bir = (u8)(table_offset & PCI_MSIX_FLAGS_BIRMASK); 418 table_offset &= ~PCI_MSIX_FLAGS_BIRMASK; 419 phys_addr = pci_resource_start (dev, bir) + table_offset; 420 base = ioremap_nocache(phys_addr, nr_entries * PCI_MSIX_ENTRY_SIZE); 421 if (base == NULL) 422 return -ENOMEM; 423 424 /* MSI-X Table Initialization */ 425 for (i = 0; i < nvec; i++) { 426 entry = alloc_msi_entry(); 427 if (!entry) 428 break; 429 430 j = entries[i].entry; 431 entry->msi_attrib.type = PCI_CAP_ID_MSIX; 432 entry->msi_attrib.is_64 = 1; 433 entry->msi_attrib.entry_nr = j; 434 entry->msi_attrib.maskbit = 1; 435 entry->msi_attrib.masked = 1; 436 entry->msi_attrib.default_irq = dev->irq; 437 entry->msi_attrib.pos = pos; 438 entry->dev = dev; 439 entry->mask_base = base; 440 441 /* Configure MSI-X capability structure */ 442 irq = arch_setup_msi_irq(dev, entry); 443 if (irq < 0) { 444 kmem_cache_free(msi_cachep, entry); 445 break; 446 } 447 entries[i].vector = irq; 448 if (!head) { 449 entry->link.head = irq; 450 entry->link.tail = irq; 451 head = entry; 452 } else { 453 entry->link.head = temp; 454 entry->link.tail = tail->link.tail; 455 tail->link.tail = irq; 456 head->link.head = irq; 457 } 458 temp = irq; 459 tail = entry; 460 461 set_irq_msi(irq, entry); 462 } 463 if (i != nvec) { 464 int avail = i - 1; 465 i--; 466 for (; i >= 0; i--) { 467 irq = (entries + i)->vector; 468 msi_free_irq(dev, irq); 469 (entries + i)->vector = 0; 470 } 471 /* If we had some success report the number of irqs 472 * we succeeded in setting up. 473 */ 474 if (avail <= 0) 475 avail = -EBUSY; 476 return avail; 477 } 478 dev->first_msi_irq = entries[0].vector; 479 /* Set MSI-X enabled bits */ 480 pci_intx(dev, 0); /* disable intx */ 481 msix_set_enable(dev, 1); 482 dev->msix_enabled = 1; 483 484 return 0; 485} 486 487/** 488 * pci_msi_supported - check whether MSI may be enabled on device 489 * @dev: pointer to the pci_dev data structure of MSI device function 490 * 491 * Look at global flags, the device itself, and its parent busses 492 * to return 0 if MSI are supported for the device. 493 **/ 494static 495int pci_msi_supported(struct pci_dev * dev) 496{ 497 struct pci_bus *bus; 498 499 /* MSI must be globally enabled and supported by the device */ 500 if (!pci_msi_enable || !dev || dev->no_msi) 501 return -EINVAL; 502 503 /* Any bridge which does NOT route MSI transactions from it's 504 * secondary bus to it's primary bus must set NO_MSI flag on 505 * the secondary pci_bus. 506 * We expect only arch-specific PCI host bus controller driver 507 * or quirks for specific PCI bridges to be setting NO_MSI. 508 */ 509 for (bus = dev->bus; bus; bus = bus->parent) 510 if (bus->bus_flags & PCI_BUS_FLAGS_NO_MSI) 511 return -EINVAL; 512 513 return 0; 514} 515 516/** 517 * pci_enable_msi - configure device's MSI capability structure 518 * @dev: pointer to the pci_dev data structure of MSI device function 519 * 520 * Setup the MSI capability structure of device function with 521 * a single MSI irq upon its software driver call to request for 522 * MSI mode enabled on its hardware device function. A return of zero 523 * indicates the successful setup of an entry zero with the new MSI 524 * irq or non-zero for otherwise. 525 **/ 526int pci_enable_msi(struct pci_dev* dev) 527{ 528 int pos, status; 529 530 if (pci_msi_supported(dev) < 0) 531 return -EINVAL; 532 533 status = msi_init(); 534 if (status < 0) 535 return status; 536 537 pos = pci_find_capability(dev, PCI_CAP_ID_MSI); 538 if (!pos) 539 return -EINVAL; 540 541 WARN_ON(!!dev->msi_enabled); 542 543 /* Check whether driver already requested for MSI-X irqs */ 544 if (dev->msix_enabled) { 545 printk(KERN_INFO "PCI: %s: Can't enable MSI. " 546 "Device already has MSI-X enabled\n", 547 pci_name(dev)); 548 return -EINVAL; 549 } 550 status = msi_capability_init(dev); 551 return status; 552} 553 554void pci_disable_msi(struct pci_dev* dev) 555{ 556 struct msi_desc *entry; 557 int default_irq; 558 559 if (!pci_msi_enable) 560 return; 561 if (!dev) 562 return; 563 564 if (!dev->msi_enabled) 565 return; 566 567 msi_set_enable(dev, 0); 568 pci_intx(dev, 1); /* enable intx */ 569 dev->msi_enabled = 0; 570 571 entry = get_irq_msi(dev->first_msi_irq); 572 if (!entry || !entry->dev || entry->msi_attrib.type != PCI_CAP_ID_MSI) { 573 return; 574 } 575 576 BUG_ON(irq_has_action(dev->first_msi_irq)); 577 578 default_irq = entry->msi_attrib.default_irq; 579 msi_free_irq(dev, dev->first_msi_irq); 580 581 /* Restore dev->irq to its default pin-assertion irq */ 582 dev->irq = default_irq; 583 584 dev->first_msi_irq = 0; 585} 586 587static int msi_free_irq(struct pci_dev* dev, int irq) 588{ 589 struct msi_desc *entry; 590 int head, entry_nr, type; 591 void __iomem *base; 592 593 entry = get_irq_msi(irq); 594 if (!entry || entry->dev != dev) { 595 return -EINVAL; 596 } 597 type = entry->msi_attrib.type; 598 entry_nr = entry->msi_attrib.entry_nr; 599 head = entry->link.head; 600 base = entry->mask_base; 601 get_irq_msi(entry->link.head)->link.tail = entry->link.tail; 602 get_irq_msi(entry->link.tail)->link.head = entry->link.head; 603 604 arch_teardown_msi_irq(irq); 605 kmem_cache_free(msi_cachep, entry); 606 607 if (type == PCI_CAP_ID_MSIX) { 608 writel(1, base + entry_nr * PCI_MSIX_ENTRY_SIZE + 609 PCI_MSIX_ENTRY_VECTOR_CTRL_OFFSET); 610 611 if (head == irq) 612 iounmap(base); 613 } 614 615 return 0; 616} 617 618/** 619 * pci_enable_msix - configure device's MSI-X capability structure 620 * @dev: pointer to the pci_dev data structure of MSI-X device function 621 * @entries: pointer to an array of MSI-X entries 622 * @nvec: number of MSI-X irqs requested for allocation by device driver 623 * 624 * Setup the MSI-X capability structure of device function with the number 625 * of requested irqs upon its software driver call to request for 626 * MSI-X mode enabled on its hardware device function. A return of zero 627 * indicates the successful configuration of MSI-X capability structure 628 * with new allocated MSI-X irqs. A return of < 0 indicates a failure. 629 * Or a return of > 0 indicates that driver request is exceeding the number 630 * of irqs available. Driver should use the returned value to re-send 631 * its request. 632 **/ 633int pci_enable_msix(struct pci_dev* dev, struct msix_entry *entries, int nvec) 634{ 635 int status, pos, nr_entries; 636 int i, j; 637 u16 control; 638 639 if (!entries || pci_msi_supported(dev) < 0) 640 return -EINVAL; 641 642 status = msi_init(); 643 if (status < 0) 644 return status; 645 646 pos = pci_find_capability(dev, PCI_CAP_ID_MSIX); 647 if (!pos) 648 return -EINVAL; 649 650 pci_read_config_word(dev, msi_control_reg(pos), &control); 651 nr_entries = multi_msix_capable(control); 652 if (nvec > nr_entries) 653 return -EINVAL; 654 655 /* Check for any invalid entries */ 656 for (i = 0; i < nvec; i++) { 657 if (entries[i].entry >= nr_entries) 658 return -EINVAL; /* invalid entry */ 659 for (j = i + 1; j < nvec; j++) { 660 if (entries[i].entry == entries[j].entry) 661 return -EINVAL; /* duplicate entry */ 662 } 663 } 664 WARN_ON(!!dev->msix_enabled); 665 666 /* Check whether driver already requested for MSI irq */ 667 if (dev->msi_enabled) { 668 printk(KERN_INFO "PCI: %s: Can't enable MSI-X. " 669 "Device already has an MSI irq assigned\n", 670 pci_name(dev)); 671 return -EINVAL; 672 } 673 status = msix_capability_init(dev, entries, nvec); 674 return status; 675} 676 677static void msix_free_all_irqs(struct pci_dev *dev) 678{ 679 int irq, head, tail = 0; 680 681 irq = head = dev->first_msi_irq; 682 while (head != tail) { 683 tail = get_irq_msi(irq)->link.tail; 684 685 BUG_ON(irq_has_action(irq)); 686 687 if (irq != head) 688 msi_free_irq(dev, irq); 689 irq = tail; 690 } 691 msi_free_irq(dev, irq); 692 dev->first_msi_irq = 0; 693} 694 695void pci_disable_msix(struct pci_dev* dev) 696{ 697 if (!pci_msi_enable) 698 return; 699 if (!dev) 700 return; 701 702 if (!dev->msix_enabled) 703 return; 704 705 msix_set_enable(dev, 0); 706 pci_intx(dev, 1); /* enable intx */ 707 dev->msix_enabled = 0; 708 709 msix_free_all_irqs(dev); 710} 711 712/** 713 * msi_remove_pci_irq_vectors - reclaim MSI(X) irqs to unused state 714 * @dev: pointer to the pci_dev data structure of MSI(X) device function 715 * 716 * Being called during hotplug remove, from which the device function 717 * is hot-removed. All previous assigned MSI/MSI-X irqs, if 718 * allocated for this device function, are reclaimed to unused state, 719 * which may be used later on. 720 **/ 721void msi_remove_pci_irq_vectors(struct pci_dev* dev) 722{ 723 if (!pci_msi_enable || !dev) 724 return; 725 726 if (dev->msi_enabled) { 727 BUG_ON(irq_has_action(dev->first_msi_irq)); 728 msi_free_irq(dev, dev->first_msi_irq); 729 } 730 731 if (dev->msix_enabled) 732 msix_free_all_irqs(dev); 733} 734 735void pci_no_msi(void) 736{ 737 pci_msi_enable = 0; 738} 739 740EXPORT_SYMBOL(pci_enable_msi); 741EXPORT_SYMBOL(pci_disable_msi); 742EXPORT_SYMBOL(pci_enable_msix); 743EXPORT_SYMBOL(pci_disable_msix); 744