pci_link.c 23 KB

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  1. // SPDX-License-Identifier: GPL-2.0-or-later
  2. /*
  3. * pci_link.c - ACPI PCI Interrupt Link Device Driver ($Revision: 34 $)
  4. *
  5. * Copyright (C) 2001, 2002 Andy Grover <[email protected]>
  6. * Copyright (C) 2001, 2002 Paul Diefenbaugh <[email protected]>
  7. * Copyright (C) 2002 Dominik Brodowski <[email protected]>
  8. *
  9. * TBD:
  10. * 1. Support more than one IRQ resource entry per link device (index).
  11. * 2. Implement start/stop mechanism and use ACPI Bus Driver facilities
  12. * for IRQ management (e.g. start()->_SRS).
  13. */
  14. #define pr_fmt(fmt) "ACPI: PCI: " fmt
  15. #include <linux/syscore_ops.h>
  16. #include <linux/kernel.h>
  17. #include <linux/module.h>
  18. #include <linux/init.h>
  19. #include <linux/types.h>
  20. #include <linux/spinlock.h>
  21. #include <linux/pm.h>
  22. #include <linux/pci.h>
  23. #include <linux/mutex.h>
  24. #include <linux/slab.h>
  25. #include <linux/acpi.h>
  26. #include <linux/irq.h>
  27. #include "internal.h"
  28. #define ACPI_PCI_LINK_CLASS "pci_irq_routing"
  29. #define ACPI_PCI_LINK_DEVICE_NAME "PCI Interrupt Link"
  30. #define ACPI_PCI_LINK_MAX_POSSIBLE 16
  31. static int acpi_pci_link_add(struct acpi_device *device,
  32. const struct acpi_device_id *not_used);
  33. static void acpi_pci_link_remove(struct acpi_device *device);
  34. static const struct acpi_device_id link_device_ids[] = {
  35. {"PNP0C0F", 0},
  36. {"", 0},
  37. };
  38. static struct acpi_scan_handler pci_link_handler = {
  39. .ids = link_device_ids,
  40. .attach = acpi_pci_link_add,
  41. .detach = acpi_pci_link_remove,
  42. };
  43. /*
  44. * If a link is initialized, we never change its active and initialized
  45. * later even the link is disable. Instead, we just repick the active irq
  46. */
  47. struct acpi_pci_link_irq {
  48. u32 active; /* Current IRQ */
  49. u8 triggering; /* All IRQs */
  50. u8 polarity; /* All IRQs */
  51. u8 resource_type;
  52. u8 possible_count;
  53. u32 possible[ACPI_PCI_LINK_MAX_POSSIBLE];
  54. u8 initialized:1;
  55. u8 reserved:7;
  56. };
  57. struct acpi_pci_link {
  58. struct list_head list;
  59. struct acpi_device *device;
  60. struct acpi_pci_link_irq irq;
  61. int refcnt;
  62. };
  63. static LIST_HEAD(acpi_link_list);
  64. static DEFINE_MUTEX(acpi_link_lock);
  65. static int sci_irq = -1, sci_penalty;
  66. /* --------------------------------------------------------------------------
  67. PCI Link Device Management
  68. -------------------------------------------------------------------------- */
  69. /*
  70. * set context (link) possible list from resource list
  71. */
  72. static acpi_status acpi_pci_link_check_possible(struct acpi_resource *resource,
  73. void *context)
  74. {
  75. struct acpi_pci_link *link = context;
  76. acpi_handle handle = link->device->handle;
  77. u32 i;
  78. switch (resource->type) {
  79. case ACPI_RESOURCE_TYPE_START_DEPENDENT:
  80. case ACPI_RESOURCE_TYPE_END_TAG:
  81. return AE_OK;
  82. case ACPI_RESOURCE_TYPE_IRQ:
  83. {
  84. struct acpi_resource_irq *p = &resource->data.irq;
  85. if (!p->interrupt_count) {
  86. acpi_handle_debug(handle,
  87. "Blank _PRS IRQ resource\n");
  88. return AE_OK;
  89. }
  90. for (i = 0;
  91. (i < p->interrupt_count
  92. && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
  93. if (!p->interrupts[i]) {
  94. acpi_handle_debug(handle,
  95. "Invalid _PRS IRQ %d\n",
  96. p->interrupts[i]);
  97. continue;
  98. }
  99. link->irq.possible[i] = p->interrupts[i];
  100. link->irq.possible_count++;
  101. }
  102. link->irq.triggering = p->triggering;
  103. link->irq.polarity = p->polarity;
  104. link->irq.resource_type = ACPI_RESOURCE_TYPE_IRQ;
  105. break;
  106. }
  107. case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
  108. {
  109. struct acpi_resource_extended_irq *p =
  110. &resource->data.extended_irq;
  111. if (!p->interrupt_count) {
  112. acpi_handle_debug(handle,
  113. "Blank _PRS EXT IRQ resource\n");
  114. return AE_OK;
  115. }
  116. for (i = 0;
  117. (i < p->interrupt_count
  118. && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
  119. if (!p->interrupts[i]) {
  120. acpi_handle_debug(handle,
  121. "Invalid _PRS IRQ %d\n",
  122. p->interrupts[i]);
  123. continue;
  124. }
  125. link->irq.possible[i] = p->interrupts[i];
  126. link->irq.possible_count++;
  127. }
  128. link->irq.triggering = p->triggering;
  129. link->irq.polarity = p->polarity;
  130. link->irq.resource_type = ACPI_RESOURCE_TYPE_EXTENDED_IRQ;
  131. break;
  132. }
  133. default:
  134. acpi_handle_debug(handle, "_PRS resource type 0x%x is not IRQ\n",
  135. resource->type);
  136. return AE_OK;
  137. }
  138. return AE_CTRL_TERMINATE;
  139. }
  140. static int acpi_pci_link_get_possible(struct acpi_pci_link *link)
  141. {
  142. acpi_handle handle = link->device->handle;
  143. acpi_status status;
  144. status = acpi_walk_resources(handle, METHOD_NAME__PRS,
  145. acpi_pci_link_check_possible, link);
  146. if (ACPI_FAILURE(status)) {
  147. acpi_handle_debug(handle, "_PRS not present or invalid");
  148. return 0;
  149. }
  150. acpi_handle_debug(handle, "Found %d possible IRQs\n",
  151. link->irq.possible_count);
  152. return 0;
  153. }
  154. static acpi_status acpi_pci_link_check_current(struct acpi_resource *resource,
  155. void *context)
  156. {
  157. int *irq = context;
  158. switch (resource->type) {
  159. case ACPI_RESOURCE_TYPE_START_DEPENDENT:
  160. case ACPI_RESOURCE_TYPE_END_TAG:
  161. return AE_OK;
  162. case ACPI_RESOURCE_TYPE_IRQ:
  163. {
  164. struct acpi_resource_irq *p = &resource->data.irq;
  165. if (!p->interrupt_count) {
  166. /*
  167. * IRQ descriptors may have no IRQ# bits set,
  168. * particularly those w/ _STA disabled
  169. */
  170. pr_debug("Blank _CRS IRQ resource\n");
  171. return AE_OK;
  172. }
  173. *irq = p->interrupts[0];
  174. break;
  175. }
  176. case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
  177. {
  178. struct acpi_resource_extended_irq *p =
  179. &resource->data.extended_irq;
  180. if (!p->interrupt_count) {
  181. /*
  182. * extended IRQ descriptors must
  183. * return at least 1 IRQ
  184. */
  185. pr_debug("Blank _CRS EXT IRQ resource\n");
  186. return AE_OK;
  187. }
  188. *irq = p->interrupts[0];
  189. break;
  190. }
  191. break;
  192. default:
  193. pr_debug("_CRS resource type 0x%x is not IRQ\n",
  194. resource->type);
  195. return AE_OK;
  196. }
  197. return AE_CTRL_TERMINATE;
  198. }
  199. /*
  200. * Run _CRS and set link->irq.active
  201. *
  202. * return value:
  203. * 0 - success
  204. * !0 - failure
  205. */
  206. static int acpi_pci_link_get_current(struct acpi_pci_link *link)
  207. {
  208. acpi_handle handle = link->device->handle;
  209. acpi_status status;
  210. int result = 0;
  211. int irq = 0;
  212. link->irq.active = 0;
  213. /* in practice, status disabled is meaningless, ignore it */
  214. if (acpi_strict) {
  215. /* Query _STA, set link->device->status */
  216. result = acpi_bus_get_status(link->device);
  217. if (result) {
  218. acpi_handle_err(handle, "Unable to read status\n");
  219. goto end;
  220. }
  221. if (!link->device->status.enabled) {
  222. acpi_handle_debug(handle, "Link disabled\n");
  223. return 0;
  224. }
  225. }
  226. /*
  227. * Query and parse _CRS to get the current IRQ assignment.
  228. */
  229. status = acpi_walk_resources(handle, METHOD_NAME__CRS,
  230. acpi_pci_link_check_current, &irq);
  231. if (ACPI_FAILURE(status)) {
  232. acpi_evaluation_failure_warn(handle, "_CRS", status);
  233. result = -ENODEV;
  234. goto end;
  235. }
  236. if (acpi_strict && !irq) {
  237. acpi_handle_err(handle, "_CRS returned 0\n");
  238. result = -ENODEV;
  239. }
  240. link->irq.active = irq;
  241. acpi_handle_debug(handle, "Link at IRQ %d \n", link->irq.active);
  242. end:
  243. return result;
  244. }
  245. static int acpi_pci_link_set(struct acpi_pci_link *link, int irq)
  246. {
  247. struct {
  248. struct acpi_resource res;
  249. struct acpi_resource end;
  250. } *resource;
  251. struct acpi_buffer buffer = { 0, NULL };
  252. acpi_handle handle = link->device->handle;
  253. acpi_status status;
  254. int result;
  255. if (!irq)
  256. return -EINVAL;
  257. resource = kzalloc(sizeof(*resource) + 1, irqs_disabled() ? GFP_ATOMIC: GFP_KERNEL);
  258. if (!resource)
  259. return -ENOMEM;
  260. buffer.length = sizeof(*resource) + 1;
  261. buffer.pointer = resource;
  262. switch (link->irq.resource_type) {
  263. case ACPI_RESOURCE_TYPE_IRQ:
  264. resource->res.type = ACPI_RESOURCE_TYPE_IRQ;
  265. resource->res.length = sizeof(struct acpi_resource);
  266. resource->res.data.irq.triggering = link->irq.triggering;
  267. resource->res.data.irq.polarity =
  268. link->irq.polarity;
  269. if (link->irq.triggering == ACPI_EDGE_SENSITIVE)
  270. resource->res.data.irq.shareable =
  271. ACPI_EXCLUSIVE;
  272. else
  273. resource->res.data.irq.shareable = ACPI_SHARED;
  274. resource->res.data.irq.interrupt_count = 1;
  275. resource->res.data.irq.interrupts[0] = irq;
  276. break;
  277. case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
  278. resource->res.type = ACPI_RESOURCE_TYPE_EXTENDED_IRQ;
  279. resource->res.length = sizeof(struct acpi_resource);
  280. resource->res.data.extended_irq.producer_consumer =
  281. ACPI_CONSUMER;
  282. resource->res.data.extended_irq.triggering =
  283. link->irq.triggering;
  284. resource->res.data.extended_irq.polarity =
  285. link->irq.polarity;
  286. if (link->irq.triggering == ACPI_EDGE_SENSITIVE)
  287. resource->res.data.extended_irq.shareable =
  288. ACPI_EXCLUSIVE;
  289. else
  290. resource->res.data.extended_irq.shareable = ACPI_SHARED;
  291. resource->res.data.extended_irq.interrupt_count = 1;
  292. resource->res.data.extended_irq.interrupts[0] = irq;
  293. /* ignore resource_source, it's optional */
  294. break;
  295. default:
  296. acpi_handle_err(handle, "Invalid resource type %d\n",
  297. link->irq.resource_type);
  298. result = -EINVAL;
  299. goto end;
  300. }
  301. resource->end.type = ACPI_RESOURCE_TYPE_END_TAG;
  302. resource->end.length = sizeof(struct acpi_resource);
  303. /* Attempt to set the resource */
  304. status = acpi_set_current_resources(link->device->handle, &buffer);
  305. /* check for total failure */
  306. if (ACPI_FAILURE(status)) {
  307. acpi_evaluation_failure_warn(handle, "_SRS", status);
  308. result = -ENODEV;
  309. goto end;
  310. }
  311. /* Query _STA, set device->status */
  312. result = acpi_bus_get_status(link->device);
  313. if (result) {
  314. acpi_handle_err(handle, "Unable to read status\n");
  315. goto end;
  316. }
  317. if (!link->device->status.enabled)
  318. acpi_handle_warn(handle, "Disabled and referenced, BIOS bug\n");
  319. /* Query _CRS, set link->irq.active */
  320. result = acpi_pci_link_get_current(link);
  321. if (result) {
  322. goto end;
  323. }
  324. /*
  325. * Is current setting not what we set?
  326. * set link->irq.active
  327. */
  328. if (link->irq.active != irq) {
  329. /*
  330. * policy: when _CRS doesn't return what we just _SRS
  331. * assume _SRS worked and override _CRS value.
  332. */
  333. acpi_handle_warn(handle, "BIOS reported IRQ %d, using IRQ %d\n",
  334. link->irq.active, irq);
  335. link->irq.active = irq;
  336. }
  337. acpi_handle_debug(handle, "Set IRQ %d\n", link->irq.active);
  338. end:
  339. kfree(resource);
  340. return result;
  341. }
  342. /* --------------------------------------------------------------------------
  343. PCI Link IRQ Management
  344. -------------------------------------------------------------------------- */
  345. /*
  346. * "acpi_irq_balance" (default in APIC mode) enables ACPI to use PIC Interrupt
  347. * Link Devices to move the PIRQs around to minimize sharing.
  348. *
  349. * "acpi_irq_nobalance" (default in PIC mode) tells ACPI not to move any PIC IRQs
  350. * that the BIOS has already set to active. This is necessary because
  351. * ACPI has no automatic means of knowing what ISA IRQs are used. Note that
  352. * if the BIOS doesn't set a Link Device active, ACPI needs to program it
  353. * even if acpi_irq_nobalance is set.
  354. *
  355. * A tables of penalties avoids directing PCI interrupts to well known
  356. * ISA IRQs. Boot params are available to over-ride the default table:
  357. *
  358. * List interrupts that are free for PCI use.
  359. * acpi_irq_pci=n[,m]
  360. *
  361. * List interrupts that should not be used for PCI:
  362. * acpi_irq_isa=n[,m]
  363. *
  364. * Note that PCI IRQ routers have a list of possible IRQs,
  365. * which may not include the IRQs this table says are available.
  366. *
  367. * Since this heuristic can't tell the difference between a link
  368. * that no device will attach to, vs. a link which may be shared
  369. * by multiple active devices -- it is not optimal.
  370. *
  371. * If interrupt performance is that important, get an IO-APIC system
  372. * with a pin dedicated to each device. Or for that matter, an MSI
  373. * enabled system.
  374. */
  375. #define ACPI_MAX_ISA_IRQS 16
  376. #define PIRQ_PENALTY_PCI_POSSIBLE (16*16)
  377. #define PIRQ_PENALTY_PCI_USING (16*16*16)
  378. #define PIRQ_PENALTY_ISA_TYPICAL (16*16*16*16)
  379. #define PIRQ_PENALTY_ISA_USED (16*16*16*16*16)
  380. #define PIRQ_PENALTY_ISA_ALWAYS (16*16*16*16*16*16)
  381. static int acpi_isa_irq_penalty[ACPI_MAX_ISA_IRQS] = {
  382. PIRQ_PENALTY_ISA_ALWAYS, /* IRQ0 timer */
  383. PIRQ_PENALTY_ISA_ALWAYS, /* IRQ1 keyboard */
  384. PIRQ_PENALTY_ISA_ALWAYS, /* IRQ2 cascade */
  385. PIRQ_PENALTY_ISA_TYPICAL, /* IRQ3 serial */
  386. PIRQ_PENALTY_ISA_TYPICAL, /* IRQ4 serial */
  387. PIRQ_PENALTY_ISA_TYPICAL, /* IRQ5 sometimes SoundBlaster */
  388. PIRQ_PENALTY_ISA_TYPICAL, /* IRQ6 */
  389. PIRQ_PENALTY_ISA_TYPICAL, /* IRQ7 parallel, spurious */
  390. PIRQ_PENALTY_ISA_TYPICAL, /* IRQ8 rtc, sometimes */
  391. 0, /* IRQ9 PCI, often acpi */
  392. 0, /* IRQ10 PCI */
  393. 0, /* IRQ11 PCI */
  394. PIRQ_PENALTY_ISA_USED, /* IRQ12 mouse */
  395. PIRQ_PENALTY_ISA_USED, /* IRQ13 fpe, sometimes */
  396. PIRQ_PENALTY_ISA_USED, /* IRQ14 ide0 */
  397. PIRQ_PENALTY_ISA_USED, /* IRQ15 ide1 */
  398. /* >IRQ15 */
  399. };
  400. static int acpi_irq_pci_sharing_penalty(int irq)
  401. {
  402. struct acpi_pci_link *link;
  403. int penalty = 0;
  404. int i;
  405. list_for_each_entry(link, &acpi_link_list, list) {
  406. /*
  407. * If a link is active, penalize its IRQ heavily
  408. * so we try to choose a different IRQ.
  409. */
  410. if (link->irq.active && link->irq.active == irq)
  411. penalty += PIRQ_PENALTY_PCI_USING;
  412. /*
  413. * penalize the IRQs PCI might use, but not as severely.
  414. */
  415. for (i = 0; i < link->irq.possible_count; i++)
  416. if (link->irq.possible[i] == irq)
  417. penalty += PIRQ_PENALTY_PCI_POSSIBLE /
  418. link->irq.possible_count;
  419. }
  420. return penalty;
  421. }
  422. static int acpi_irq_get_penalty(int irq)
  423. {
  424. int penalty = 0;
  425. if (irq == sci_irq)
  426. penalty += sci_penalty;
  427. if (irq < ACPI_MAX_ISA_IRQS)
  428. return penalty + acpi_isa_irq_penalty[irq];
  429. return penalty + acpi_irq_pci_sharing_penalty(irq);
  430. }
  431. int __init acpi_irq_penalty_init(void)
  432. {
  433. struct acpi_pci_link *link;
  434. int i;
  435. /*
  436. * Update penalties to facilitate IRQ balancing.
  437. */
  438. list_for_each_entry(link, &acpi_link_list, list) {
  439. /*
  440. * reflect the possible and active irqs in the penalty table --
  441. * useful for breaking ties.
  442. */
  443. if (link->irq.possible_count) {
  444. int penalty =
  445. PIRQ_PENALTY_PCI_POSSIBLE /
  446. link->irq.possible_count;
  447. for (i = 0; i < link->irq.possible_count; i++) {
  448. if (link->irq.possible[i] < ACPI_MAX_ISA_IRQS)
  449. acpi_isa_irq_penalty[link->irq.
  450. possible[i]] +=
  451. penalty;
  452. }
  453. } else if (link->irq.active &&
  454. (link->irq.active < ACPI_MAX_ISA_IRQS)) {
  455. acpi_isa_irq_penalty[link->irq.active] +=
  456. PIRQ_PENALTY_PCI_POSSIBLE;
  457. }
  458. }
  459. return 0;
  460. }
  461. static int acpi_irq_balance = -1; /* 0: static, 1: balance */
  462. static int acpi_pci_link_allocate(struct acpi_pci_link *link)
  463. {
  464. acpi_handle handle = link->device->handle;
  465. int irq;
  466. int i;
  467. if (link->irq.initialized) {
  468. if (link->refcnt == 0)
  469. /* This means the link is disabled but initialized */
  470. acpi_pci_link_set(link, link->irq.active);
  471. return 0;
  472. }
  473. /*
  474. * search for active IRQ in list of possible IRQs.
  475. */
  476. for (i = 0; i < link->irq.possible_count; ++i) {
  477. if (link->irq.active == link->irq.possible[i])
  478. break;
  479. }
  480. /*
  481. * forget active IRQ that is not in possible list
  482. */
  483. if (i == link->irq.possible_count) {
  484. if (acpi_strict)
  485. acpi_handle_warn(handle, "_CRS %d not found in _PRS\n",
  486. link->irq.active);
  487. link->irq.active = 0;
  488. }
  489. /*
  490. * if active found, use it; else pick entry from end of possible list.
  491. */
  492. if (link->irq.active)
  493. irq = link->irq.active;
  494. else
  495. irq = link->irq.possible[link->irq.possible_count - 1];
  496. if (acpi_irq_balance || !link->irq.active) {
  497. /*
  498. * Select the best IRQ. This is done in reverse to promote
  499. * the use of IRQs 9, 10, 11, and >15.
  500. */
  501. for (i = (link->irq.possible_count - 1); i >= 0; i--) {
  502. if (acpi_irq_get_penalty(irq) >
  503. acpi_irq_get_penalty(link->irq.possible[i]))
  504. irq = link->irq.possible[i];
  505. }
  506. }
  507. if (acpi_irq_get_penalty(irq) >= PIRQ_PENALTY_ISA_ALWAYS) {
  508. acpi_handle_err(handle,
  509. "No IRQ available. Try pci=noacpi or acpi=off\n");
  510. return -ENODEV;
  511. }
  512. /* Attempt to enable the link device at this IRQ. */
  513. if (acpi_pci_link_set(link, irq)) {
  514. acpi_handle_err(handle,
  515. "Unable to set IRQ. Try pci=noacpi or acpi=off\n");
  516. return -ENODEV;
  517. } else {
  518. if (link->irq.active < ACPI_MAX_ISA_IRQS)
  519. acpi_isa_irq_penalty[link->irq.active] +=
  520. PIRQ_PENALTY_PCI_USING;
  521. acpi_handle_info(handle, "Enabled at IRQ %d\n",
  522. link->irq.active);
  523. }
  524. link->irq.initialized = 1;
  525. return 0;
  526. }
  527. /*
  528. * acpi_pci_link_allocate_irq
  529. * success: return IRQ >= 0
  530. * failure: return -1
  531. */
  532. int acpi_pci_link_allocate_irq(acpi_handle handle, int index, int *triggering,
  533. int *polarity, char **name)
  534. {
  535. struct acpi_device *device = acpi_fetch_acpi_dev(handle);
  536. struct acpi_pci_link *link;
  537. if (!device) {
  538. acpi_handle_err(handle, "Invalid link device\n");
  539. return -1;
  540. }
  541. link = acpi_driver_data(device);
  542. if (!link) {
  543. acpi_handle_err(handle, "Invalid link context\n");
  544. return -1;
  545. }
  546. /* TBD: Support multiple index (IRQ) entries per Link Device */
  547. if (index) {
  548. acpi_handle_err(handle, "Invalid index %d\n", index);
  549. return -1;
  550. }
  551. mutex_lock(&acpi_link_lock);
  552. if (acpi_pci_link_allocate(link)) {
  553. mutex_unlock(&acpi_link_lock);
  554. return -1;
  555. }
  556. if (!link->irq.active) {
  557. mutex_unlock(&acpi_link_lock);
  558. acpi_handle_err(handle, "Link active IRQ is 0!\n");
  559. return -1;
  560. }
  561. link->refcnt++;
  562. mutex_unlock(&acpi_link_lock);
  563. if (triggering)
  564. *triggering = link->irq.triggering;
  565. if (polarity)
  566. *polarity = link->irq.polarity;
  567. if (name)
  568. *name = acpi_device_bid(link->device);
  569. acpi_handle_debug(handle, "Link is referenced\n");
  570. return link->irq.active;
  571. }
  572. /*
  573. * We don't change link's irq information here. After it is reenabled, we
  574. * continue use the info
  575. */
  576. int acpi_pci_link_free_irq(acpi_handle handle)
  577. {
  578. struct acpi_device *device = acpi_fetch_acpi_dev(handle);
  579. struct acpi_pci_link *link;
  580. if (!device) {
  581. acpi_handle_err(handle, "Invalid link device\n");
  582. return -1;
  583. }
  584. link = acpi_driver_data(device);
  585. if (!link) {
  586. acpi_handle_err(handle, "Invalid link context\n");
  587. return -1;
  588. }
  589. mutex_lock(&acpi_link_lock);
  590. if (!link->irq.initialized) {
  591. mutex_unlock(&acpi_link_lock);
  592. acpi_handle_err(handle, "Link isn't initialized\n");
  593. return -1;
  594. }
  595. #ifdef FUTURE_USE
  596. /*
  597. * The Link reference count allows us to _DISable an unused link
  598. * and suspend time, and set it again on resume.
  599. * However, 2.6.12 still has irq_router.resume
  600. * which blindly restores the link state.
  601. * So we disable the reference count method
  602. * to prevent duplicate acpi_pci_link_set()
  603. * which would harm some systems
  604. */
  605. link->refcnt--;
  606. #endif
  607. acpi_handle_debug(handle, "Link is dereferenced\n");
  608. if (link->refcnt == 0)
  609. acpi_evaluate_object(link->device->handle, "_DIS", NULL, NULL);
  610. mutex_unlock(&acpi_link_lock);
  611. return link->irq.active;
  612. }
  613. /* --------------------------------------------------------------------------
  614. Driver Interface
  615. -------------------------------------------------------------------------- */
  616. static int acpi_pci_link_add(struct acpi_device *device,
  617. const struct acpi_device_id *not_used)
  618. {
  619. acpi_handle handle = device->handle;
  620. struct acpi_pci_link *link;
  621. int result;
  622. int i;
  623. link = kzalloc(sizeof(struct acpi_pci_link), GFP_KERNEL);
  624. if (!link)
  625. return -ENOMEM;
  626. link->device = device;
  627. strcpy(acpi_device_name(device), ACPI_PCI_LINK_DEVICE_NAME);
  628. strcpy(acpi_device_class(device), ACPI_PCI_LINK_CLASS);
  629. device->driver_data = link;
  630. mutex_lock(&acpi_link_lock);
  631. result = acpi_pci_link_get_possible(link);
  632. if (result)
  633. goto end;
  634. /* query and set link->irq.active */
  635. acpi_pci_link_get_current(link);
  636. pr_info("Interrupt link %s configured for IRQ %d\n",
  637. acpi_device_bid(device), link->irq.active);
  638. for (i = 0; i < link->irq.possible_count; i++) {
  639. if (link->irq.active != link->irq.possible[i])
  640. acpi_handle_debug(handle, "Possible IRQ %d\n",
  641. link->irq.possible[i]);
  642. }
  643. if (!link->device->status.enabled)
  644. pr_info("Interrupt link %s disabled\n", acpi_device_bid(device));
  645. list_add_tail(&link->list, &acpi_link_list);
  646. end:
  647. /* disable all links -- to be activated on use */
  648. acpi_evaluate_object(handle, "_DIS", NULL, NULL);
  649. mutex_unlock(&acpi_link_lock);
  650. if (result)
  651. kfree(link);
  652. return result < 0 ? result : 1;
  653. }
  654. static int acpi_pci_link_resume(struct acpi_pci_link *link)
  655. {
  656. if (link->refcnt && link->irq.active && link->irq.initialized)
  657. return (acpi_pci_link_set(link, link->irq.active));
  658. return 0;
  659. }
  660. static void irqrouter_resume(void)
  661. {
  662. struct acpi_pci_link *link;
  663. list_for_each_entry(link, &acpi_link_list, list) {
  664. acpi_pci_link_resume(link);
  665. }
  666. }
  667. static void acpi_pci_link_remove(struct acpi_device *device)
  668. {
  669. struct acpi_pci_link *link;
  670. link = acpi_driver_data(device);
  671. mutex_lock(&acpi_link_lock);
  672. list_del(&link->list);
  673. mutex_unlock(&acpi_link_lock);
  674. kfree(link);
  675. }
  676. /*
  677. * modify acpi_isa_irq_penalty[] from cmdline
  678. */
  679. static int __init acpi_irq_penalty_update(char *str, int used)
  680. {
  681. int i;
  682. for (i = 0; i < 16; i++) {
  683. int retval;
  684. int irq;
  685. int new_penalty;
  686. retval = get_option(&str, &irq);
  687. if (!retval)
  688. break; /* no number found */
  689. /* see if this is a ISA IRQ */
  690. if ((irq < 0) || (irq >= ACPI_MAX_ISA_IRQS))
  691. continue;
  692. if (used)
  693. new_penalty = acpi_isa_irq_penalty[irq] +
  694. PIRQ_PENALTY_ISA_USED;
  695. else
  696. new_penalty = 0;
  697. acpi_isa_irq_penalty[irq] = new_penalty;
  698. if (retval != 2) /* no next number */
  699. break;
  700. }
  701. return 1;
  702. }
  703. /*
  704. * We'd like PNP to call this routine for the
  705. * single ISA_USED value for each legacy device.
  706. * But instead it calls us with each POSSIBLE setting.
  707. * There is no ISA_POSSIBLE weight, so we simply use
  708. * the (small) PCI_USING penalty.
  709. */
  710. void acpi_penalize_isa_irq(int irq, int active)
  711. {
  712. if ((irq >= 0) && (irq < ARRAY_SIZE(acpi_isa_irq_penalty)))
  713. acpi_isa_irq_penalty[irq] +=
  714. (active ? PIRQ_PENALTY_ISA_USED : PIRQ_PENALTY_PCI_USING);
  715. }
  716. bool acpi_isa_irq_available(int irq)
  717. {
  718. return irq >= 0 && (irq >= ARRAY_SIZE(acpi_isa_irq_penalty) ||
  719. acpi_irq_get_penalty(irq) < PIRQ_PENALTY_ISA_ALWAYS);
  720. }
  721. void acpi_penalize_sci_irq(int irq, int trigger, int polarity)
  722. {
  723. sci_irq = irq;
  724. if (trigger == ACPI_MADT_TRIGGER_LEVEL &&
  725. polarity == ACPI_MADT_POLARITY_ACTIVE_LOW)
  726. sci_penalty = PIRQ_PENALTY_PCI_USING;
  727. else
  728. sci_penalty = PIRQ_PENALTY_ISA_ALWAYS;
  729. }
  730. /*
  731. * Over-ride default table to reserve additional IRQs for use by ISA
  732. * e.g. acpi_irq_isa=5
  733. * Useful for telling ACPI how not to interfere with your ISA sound card.
  734. */
  735. static int __init acpi_irq_isa(char *str)
  736. {
  737. return acpi_irq_penalty_update(str, 1);
  738. }
  739. __setup("acpi_irq_isa=", acpi_irq_isa);
  740. /*
  741. * Over-ride default table to free additional IRQs for use by PCI
  742. * e.g. acpi_irq_pci=7,15
  743. * Used for acpi_irq_balance to free up IRQs to reduce PCI IRQ sharing.
  744. */
  745. static int __init acpi_irq_pci(char *str)
  746. {
  747. return acpi_irq_penalty_update(str, 0);
  748. }
  749. __setup("acpi_irq_pci=", acpi_irq_pci);
  750. static int __init acpi_irq_nobalance_set(char *str)
  751. {
  752. acpi_irq_balance = 0;
  753. return 1;
  754. }
  755. __setup("acpi_irq_nobalance", acpi_irq_nobalance_set);
  756. static int __init acpi_irq_balance_set(char *str)
  757. {
  758. acpi_irq_balance = 1;
  759. return 1;
  760. }
  761. __setup("acpi_irq_balance", acpi_irq_balance_set);
  762. static struct syscore_ops irqrouter_syscore_ops = {
  763. .resume = irqrouter_resume,
  764. };
  765. void __init acpi_pci_link_init(void)
  766. {
  767. if (acpi_noirq)
  768. return;
  769. if (acpi_irq_balance == -1) {
  770. /* no command line switch: enable balancing in IOAPIC mode */
  771. if (acpi_irq_model == ACPI_IRQ_MODEL_IOAPIC)
  772. acpi_irq_balance = 1;
  773. else
  774. acpi_irq_balance = 0;
  775. }
  776. register_syscore_ops(&irqrouter_syscore_ops);
  777. acpi_scan_add_handler(&pci_link_handler);
  778. }