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1 /*
2 * pci_root.c - ACPI PCI Root Bridge Driver ($Revision: 40 $)
3 *
4 * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
5 * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
6 *
7 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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 as published by
11 * the Free Software Foundation; either version 2 of the License, or (at
12 * your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful, but
15 * WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License along
20 * with this program; if not, write to the Free Software Foundation, Inc.,
21 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
22 *
23 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
24 */
25
26 #include <linux/kernel.h>
27 #include <linux/module.h>
28 #include <linux/init.h>
29 #include <linux/types.h>
30 #include <linux/mutex.h>
31 #include <linux/pm.h>
32 #include <linux/pm_runtime.h>
33 #include <linux/pci.h>
34 #include <linux/pci-acpi.h>
35 #include <linux/pci-aspm.h>
36 #include <linux/dmar.h>
37 #include <linux/acpi.h>
38 #include <linux/slab.h>
39 #include <linux/dmi.h>
40 #include <acpi/apei.h> /* for acpi_hest_init() */
41
42 #include "internal.h"
43
44 #define _COMPONENT ACPI_PCI_COMPONENT
45 ACPI_MODULE_NAME("pci_root");
46 #define ACPI_PCI_ROOT_CLASS "pci_bridge"
47 #define ACPI_PCI_ROOT_DEVICE_NAME "PCI Root Bridge"
48 static int acpi_pci_root_add(struct acpi_device *device,
49 const struct acpi_device_id *not_used);
50 static void acpi_pci_root_remove(struct acpi_device *device);
51
52 static int acpi_pci_root_scan_dependent(struct acpi_device *adev)
53 {
54 acpiphp_check_host_bridge(adev);
55 return 0;
56 }
57
58 #define ACPI_PCIE_REQ_SUPPORT (OSC_PCI_EXT_CONFIG_SUPPORT \
59 | OSC_PCI_ASPM_SUPPORT \
60 | OSC_PCI_CLOCK_PM_SUPPORT \
61 | OSC_PCI_MSI_SUPPORT)
62
63 static const struct acpi_device_id root_device_ids[] = {
64 {"PNP0A03", 0},
65 {"", 0},
66 };
67
68 static struct acpi_scan_handler pci_root_handler = {
69 .ids = root_device_ids,
70 .attach = acpi_pci_root_add,
71 .detach = acpi_pci_root_remove,
72 .hotplug = {
73 .enabled = true,
74 .scan_dependent = acpi_pci_root_scan_dependent,
75 },
76 };
77
78 static DEFINE_MUTEX(osc_lock);
79
80 /**
81 * acpi_is_root_bridge - determine whether an ACPI CA node is a PCI root bridge
82 * @handle - the ACPI CA node in question.
83 *
84 * Note: we could make this API take a struct acpi_device * instead, but
85 * for now, it's more convenient to operate on an acpi_handle.
86 */
87 int acpi_is_root_bridge(acpi_handle handle)
88 {
89 int ret;
90 struct acpi_device *device;
91
92 ret = acpi_bus_get_device(handle, &device);
93 if (ret)
94 return 0;
95
96 ret = acpi_match_device_ids(device, root_device_ids);
97 if (ret)
98 return 0;
99 else
100 return 1;
101 }
102 EXPORT_SYMBOL_GPL(acpi_is_root_bridge);
103
104 static acpi_status
105 get_root_bridge_busnr_callback(struct acpi_resource *resource, void *data)
106 {
107 struct resource *res = data;
108 struct acpi_resource_address64 address;
109 acpi_status status;
110
111 status = acpi_resource_to_address64(resource, &address);
112 if (ACPI_FAILURE(status))
113 return AE_OK;
114
115 if ((address.address.address_length > 0) &&
116 (address.resource_type == ACPI_BUS_NUMBER_RANGE)) {
117 res->start = address.address.minimum;
118 res->end = address.address.minimum + address.address.address_length - 1;
119 }
120
121 return AE_OK;
122 }
123
124 static acpi_status try_get_root_bridge_busnr(acpi_handle handle,
125 struct resource *res)
126 {
127 acpi_status status;
128
129 res->start = -1;
130 status =
131 acpi_walk_resources(handle, METHOD_NAME__CRS,
132 get_root_bridge_busnr_callback, res);
133 if (ACPI_FAILURE(status))
134 return status;
135 if (res->start == -1)
136 return AE_ERROR;
137 return AE_OK;
138 }
139
140 struct pci_osc_bit_struct {
141 u32 bit;
142 char *desc;
143 };
144
145 static struct pci_osc_bit_struct pci_osc_support_bit[] = {
146 { OSC_PCI_EXT_CONFIG_SUPPORT, "ExtendedConfig" },
147 { OSC_PCI_ASPM_SUPPORT, "ASPM" },
148 { OSC_PCI_CLOCK_PM_SUPPORT, "ClockPM" },
149 { OSC_PCI_SEGMENT_GROUPS_SUPPORT, "Segments" },
150 { OSC_PCI_MSI_SUPPORT, "MSI" },
151 };
152
153 static struct pci_osc_bit_struct pci_osc_control_bit[] = {
154 { OSC_PCI_EXPRESS_NATIVE_HP_CONTROL, "PCIeHotplug" },
155 { OSC_PCI_SHPC_NATIVE_HP_CONTROL, "SHPCHotplug" },
156 { OSC_PCI_EXPRESS_PME_CONTROL, "PME" },
157 { OSC_PCI_EXPRESS_AER_CONTROL, "AER" },
158 { OSC_PCI_EXPRESS_CAPABILITY_CONTROL, "PCIeCapability" },
159 };
160
161 static void decode_osc_bits(struct acpi_pci_root *root, char *msg, u32 word,
162 struct pci_osc_bit_struct *table, int size)
163 {
164 char buf[80];
165 int i, len = 0;
166 struct pci_osc_bit_struct *entry;
167
168 buf[0] = '\0';
169 for (i = 0, entry = table; i < size; i++, entry++)
170 if (word & entry->bit)
171 len += snprintf(buf + len, sizeof(buf) - len, "%s%s",
172 len ? " " : "", entry->desc);
173
174 dev_info(&root->device->dev, "_OSC: %s [%s]\n", msg, buf);
175 }
176
177 static void decode_osc_support(struct acpi_pci_root *root, char *msg, u32 word)
178 {
179 decode_osc_bits(root, msg, word, pci_osc_support_bit,
180 ARRAY_SIZE(pci_osc_support_bit));
181 }
182
183 static void decode_osc_control(struct acpi_pci_root *root, char *msg, u32 word)
184 {
185 decode_osc_bits(root, msg, word, pci_osc_control_bit,
186 ARRAY_SIZE(pci_osc_control_bit));
187 }
188
189 static u8 pci_osc_uuid_str[] = "33DB4D5B-1FF7-401C-9657-7441C03DD766";
190
191 static acpi_status acpi_pci_run_osc(acpi_handle handle,
192 const u32 *capbuf, u32 *retval)
193 {
194 struct acpi_osc_context context = {
195 .uuid_str = pci_osc_uuid_str,
196 .rev = 1,
197 .cap.length = 12,
198 .cap.pointer = (void *)capbuf,
199 };
200 acpi_status status;
201
202 status = acpi_run_osc(handle, &context);
203 if (ACPI_SUCCESS(status)) {
204 *retval = *((u32 *)(context.ret.pointer + 8));
205 kfree(context.ret.pointer);
206 }
207 return status;
208 }
209
210 static acpi_status acpi_pci_query_osc(struct acpi_pci_root *root,
211 u32 support,
212 u32 *control)
213 {
214 acpi_status status;
215 u32 result, capbuf[3];
216
217 support &= OSC_PCI_SUPPORT_MASKS;
218 support |= root->osc_support_set;
219
220 capbuf[OSC_QUERY_DWORD] = OSC_QUERY_ENABLE;
221 capbuf[OSC_SUPPORT_DWORD] = support;
222 if (control) {
223 *control &= OSC_PCI_CONTROL_MASKS;
224 capbuf[OSC_CONTROL_DWORD] = *control | root->osc_control_set;
225 } else {
226 /* Run _OSC query only with existing controls. */
227 capbuf[OSC_CONTROL_DWORD] = root->osc_control_set;
228 }
229
230 status = acpi_pci_run_osc(root->device->handle, capbuf, &result);
231 if (ACPI_SUCCESS(status)) {
232 root->osc_support_set = support;
233 if (control)
234 *control = result;
235 }
236 return status;
237 }
238
239 static acpi_status acpi_pci_osc_support(struct acpi_pci_root *root, u32 flags)
240 {
241 acpi_status status;
242
243 mutex_lock(&osc_lock);
244 status = acpi_pci_query_osc(root, flags, NULL);
245 mutex_unlock(&osc_lock);
246 return status;
247 }
248
249 struct acpi_pci_root *acpi_pci_find_root(acpi_handle handle)
250 {
251 struct acpi_pci_root *root;
252 struct acpi_device *device;
253
254 if (acpi_bus_get_device(handle, &device) ||
255 acpi_match_device_ids(device, root_device_ids))
256 return NULL;
257
258 root = acpi_driver_data(device);
259
260 return root;
261 }
262 EXPORT_SYMBOL_GPL(acpi_pci_find_root);
263
264 struct acpi_handle_node {
265 struct list_head node;
266 acpi_handle handle;
267 };
268
269 /**
270 * acpi_get_pci_dev - convert ACPI CA handle to struct pci_dev
271 * @handle: the handle in question
272 *
273 * Given an ACPI CA handle, the desired PCI device is located in the
274 * list of PCI devices.
275 *
276 * If the device is found, its reference count is increased and this
277 * function returns a pointer to its data structure. The caller must
278 * decrement the reference count by calling pci_dev_put().
279 * If no device is found, %NULL is returned.
280 */
281 struct pci_dev *acpi_get_pci_dev(acpi_handle handle)
282 {
283 int dev, fn;
284 unsigned long long adr;
285 acpi_status status;
286 acpi_handle phandle;
287 struct pci_bus *pbus;
288 struct pci_dev *pdev = NULL;
289 struct acpi_handle_node *node, *tmp;
290 struct acpi_pci_root *root;
291 LIST_HEAD(device_list);
292
293 /*
294 * Walk up the ACPI CA namespace until we reach a PCI root bridge.
295 */
296 phandle = handle;
297 while (!acpi_is_root_bridge(phandle)) {
298 node = kzalloc(sizeof(struct acpi_handle_node), GFP_KERNEL);
299 if (!node)
300 goto out;
301
302 INIT_LIST_HEAD(&node->node);
303 node->handle = phandle;
304 list_add(&node->node, &device_list);
305
306 status = acpi_get_parent(phandle, &phandle);
307 if (ACPI_FAILURE(status))
308 goto out;
309 }
310
311 root = acpi_pci_find_root(phandle);
312 if (!root)
313 goto out;
314
315 pbus = root->bus;
316
317 /*
318 * Now, walk back down the PCI device tree until we return to our
319 * original handle. Assumes that everything between the PCI root
320 * bridge and the device we're looking for must be a P2P bridge.
321 */
322 list_for_each_entry(node, &device_list, node) {
323 acpi_handle hnd = node->handle;
324 status = acpi_evaluate_integer(hnd, "_ADR", NULL, &adr);
325 if (ACPI_FAILURE(status))
326 goto out;
327 dev = (adr >> 16) & 0xffff;
328 fn = adr & 0xffff;
329
330 pdev = pci_get_slot(pbus, PCI_DEVFN(dev, fn));
331 if (!pdev || hnd == handle)
332 break;
333
334 pbus = pdev->subordinate;
335 pci_dev_put(pdev);
336
337 /*
338 * This function may be called for a non-PCI device that has a
339 * PCI parent (eg. a disk under a PCI SATA controller). In that
340 * case pdev->subordinate will be NULL for the parent.
341 */
342 if (!pbus) {
343 dev_dbg(&pdev->dev, "Not a PCI-to-PCI bridge\n");
344 pdev = NULL;
345 break;
346 }
347 }
348 out:
349 list_for_each_entry_safe(node, tmp, &device_list, node)
350 kfree(node);
351
352 return pdev;
353 }
354 EXPORT_SYMBOL_GPL(acpi_get_pci_dev);
355
356 /**
357 * acpi_pci_osc_control_set - Request control of PCI root _OSC features.
358 * @handle: ACPI handle of a PCI root bridge (or PCIe Root Complex).
359 * @mask: Mask of _OSC bits to request control of, place to store control mask.
360 * @req: Mask of _OSC bits the control of is essential to the caller.
361 *
362 * Run _OSC query for @mask and if that is successful, compare the returned
363 * mask of control bits with @req. If all of the @req bits are set in the
364 * returned mask, run _OSC request for it.
365 *
366 * The variable at the @mask address may be modified regardless of whether or
367 * not the function returns success. On success it will contain the mask of
368 * _OSC bits the BIOS has granted control of, but its contents are meaningless
369 * on failure.
370 **/
371 acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 *mask, u32 req)
372 {
373 struct acpi_pci_root *root;
374 acpi_status status = AE_OK;
375 u32 ctrl, capbuf[3];
376
377 if (!mask)
378 return AE_BAD_PARAMETER;
379
380 ctrl = *mask & OSC_PCI_CONTROL_MASKS;
381 if ((ctrl & req) != req)
382 return AE_TYPE;
383
384 root = acpi_pci_find_root(handle);
385 if (!root)
386 return AE_NOT_EXIST;
387
388 mutex_lock(&osc_lock);
389
390 *mask = ctrl | root->osc_control_set;
391 /* No need to evaluate _OSC if the control was already granted. */
392 if ((root->osc_control_set & ctrl) == ctrl)
393 goto out;
394
395 /* Need to check the available controls bits before requesting them. */
396 while (*mask) {
397 status = acpi_pci_query_osc(root, root->osc_support_set, mask);
398 if (ACPI_FAILURE(status))
399 goto out;
400 if (ctrl == *mask)
401 break;
402 decode_osc_control(root, "platform does not support",
403 ctrl & ~(*mask));
404 ctrl = *mask;
405 }
406
407 if ((ctrl & req) != req) {
408 decode_osc_control(root, "not requesting control; platform does not support",
409 req & ~(ctrl));
410 status = AE_SUPPORT;
411 goto out;
412 }
413
414 capbuf[OSC_QUERY_DWORD] = 0;
415 capbuf[OSC_SUPPORT_DWORD] = root->osc_support_set;
416 capbuf[OSC_CONTROL_DWORD] = ctrl;
417 status = acpi_pci_run_osc(handle, capbuf, mask);
418 if (ACPI_SUCCESS(status))
419 root->osc_control_set = *mask;
420 out:
421 mutex_unlock(&osc_lock);
422 return status;
423 }
424 EXPORT_SYMBOL(acpi_pci_osc_control_set);
425
426 static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm)
427 {
428 u32 support, control, requested;
429 acpi_status status;
430 struct acpi_device *device = root->device;
431 acpi_handle handle = device->handle;
432
433 /*
434 * Apple always return failure on _OSC calls when _OSI("Darwin") has
435 * been called successfully. We know the feature set supported by the
436 * platform, so avoid calling _OSC at all
437 */
438
439 if (dmi_match(DMI_SYS_VENDOR, "Apple Inc.")) {
440 root->osc_control_set = ~OSC_PCI_EXPRESS_PME_CONTROL;
441 decode_osc_control(root, "OS assumes control of",
442 root->osc_control_set);
443 return;
444 }
445
446 /*
447 * All supported architectures that use ACPI have support for
448 * PCI domains, so we indicate this in _OSC support capabilities.
449 */
450 support = OSC_PCI_SEGMENT_GROUPS_SUPPORT;
451 if (pci_ext_cfg_avail())
452 support |= OSC_PCI_EXT_CONFIG_SUPPORT;
453 if (pcie_aspm_support_enabled())
454 support |= OSC_PCI_ASPM_SUPPORT | OSC_PCI_CLOCK_PM_SUPPORT;
455 if (pci_msi_enabled())
456 support |= OSC_PCI_MSI_SUPPORT;
457
458 decode_osc_support(root, "OS supports", support);
459 status = acpi_pci_osc_support(root, support);
460 if (ACPI_FAILURE(status)) {
461 dev_info(&device->dev, "_OSC failed (%s); disabling ASPM\n",
462 acpi_format_exception(status));
463 *no_aspm = 1;
464 return;
465 }
466
467 if (pcie_ports_disabled) {
468 dev_info(&device->dev, "PCIe port services disabled; not requesting _OSC control\n");
469 return;
470 }
471
472 if ((support & ACPI_PCIE_REQ_SUPPORT) != ACPI_PCIE_REQ_SUPPORT) {
473 decode_osc_support(root, "not requesting OS control; OS requires",
474 ACPI_PCIE_REQ_SUPPORT);
475 return;
476 }
477
478 control = OSC_PCI_EXPRESS_CAPABILITY_CONTROL
479 | OSC_PCI_EXPRESS_NATIVE_HP_CONTROL
480 | OSC_PCI_EXPRESS_PME_CONTROL;
481
482 if (pci_aer_available()) {
483 if (aer_acpi_firmware_first())
484 dev_info(&device->dev,
485 "PCIe AER handled by firmware\n");
486 else
487 control |= OSC_PCI_EXPRESS_AER_CONTROL;
488 }
489
490 requested = control;
491 status = acpi_pci_osc_control_set(handle, &control,
492 OSC_PCI_EXPRESS_CAPABILITY_CONTROL);
493 if (ACPI_SUCCESS(status)) {
494 decode_osc_control(root, "OS now controls", control);
495 if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) {
496 /*
497 * We have ASPM control, but the FADT indicates that
498 * it's unsupported. Leave existing configuration
499 * intact and prevent the OS from touching it.
500 */
501 dev_info(&device->dev, "FADT indicates ASPM is unsupported, using BIOS configuration\n");
502 *no_aspm = 1;
503 }
504 } else {
505 decode_osc_control(root, "OS requested", requested);
506 decode_osc_control(root, "platform willing to grant", control);
507 dev_info(&device->dev, "_OSC failed (%s); disabling ASPM\n",
508 acpi_format_exception(status));
509
510 /*
511 * We want to disable ASPM here, but aspm_disabled
512 * needs to remain in its state from boot so that we
513 * properly handle PCIe 1.1 devices. So we set this
514 * flag here, to defer the action until after the ACPI
515 * root scan.
516 */
517 *no_aspm = 1;
518 }
519 }
520
521 static int acpi_pci_root_add(struct acpi_device *device,
522 const struct acpi_device_id *not_used)
523 {
524 unsigned long long segment, bus;
525 acpi_status status;
526 int result;
527 struct acpi_pci_root *root;
528 acpi_handle handle = device->handle;
529 int no_aspm = 0;
530 bool hotadd = system_state != SYSTEM_BOOTING;
531
532 root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL);
533 if (!root)
534 return -ENOMEM;
535
536 segment = 0;
537 status = acpi_evaluate_integer(handle, METHOD_NAME__SEG, NULL,
538 &segment);
539 if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
540 dev_err(&device->dev, "can't evaluate _SEG\n");
541 result = -ENODEV;
542 goto end;
543 }
544
545 /* Check _CRS first, then _BBN. If no _BBN, default to zero. */
546 root->secondary.flags = IORESOURCE_BUS;
547 status = try_get_root_bridge_busnr(handle, &root->secondary);
548 if (ACPI_FAILURE(status)) {
549 /*
550 * We need both the start and end of the downstream bus range
551 * to interpret _CBA (MMCONFIG base address), so it really is
552 * supposed to be in _CRS. If we don't find it there, all we
553 * can do is assume [_BBN-0xFF] or [0-0xFF].
554 */
555 root->secondary.end = 0xFF;
556 dev_warn(&device->dev,
557 FW_BUG "no secondary bus range in _CRS\n");
558 status = acpi_evaluate_integer(handle, METHOD_NAME__BBN,
559 NULL, &bus);
560 if (ACPI_SUCCESS(status))
561 root->secondary.start = bus;
562 else if (status == AE_NOT_FOUND)
563 root->secondary.start = 0;
564 else {
565 dev_err(&device->dev, "can't evaluate _BBN\n");
566 result = -ENODEV;
567 goto end;
568 }
569 }
570
571 root->device = device;
572 root->segment = segment & 0xFFFF;
573 strcpy(acpi_device_name(device), ACPI_PCI_ROOT_DEVICE_NAME);
574 strcpy(acpi_device_class(device), ACPI_PCI_ROOT_CLASS);
575 device->driver_data = root;
576
577 if (hotadd && dmar_device_add(handle)) {
578 result = -ENXIO;
579 goto end;
580 }
581
582 pr_info(PREFIX "%s [%s] (domain %04x %pR)\n",
583 acpi_device_name(device), acpi_device_bid(device),
584 root->segment, &root->secondary);
585
586 root->mcfg_addr = acpi_pci_root_get_mcfg_addr(handle);
587
588 negotiate_os_control(root, &no_aspm);
589
590 /*
591 * TBD: Need PCI interface for enumeration/configuration of roots.
592 */
593
594 /*
595 * Scan the Root Bridge
596 * --------------------
597 * Must do this prior to any attempt to bind the root device, as the
598 * PCI namespace does not get created until this call is made (and
599 * thus the root bridge's pci_dev does not exist).
600 */
601 root->bus = pci_acpi_scan_root(root);
602 if (!root->bus) {
603 dev_err(&device->dev,
604 "Bus %04x:%02x not present in PCI namespace\n",
605 root->segment, (unsigned int)root->secondary.start);
606 device->driver_data = NULL;
607 result = -ENODEV;
608 goto remove_dmar;
609 }
610
611 if (no_aspm)
612 pcie_no_aspm();
613
614 pci_acpi_add_bus_pm_notifier(device);
615 if (device->wakeup.flags.run_wake)
616 device_set_run_wake(root->bus->bridge, true);
617
618 if (hotadd) {
619 pcibios_resource_survey_bus(root->bus);
620 pci_assign_unassigned_root_bus_resources(root->bus);
621 acpi_ioapic_add(root);
622 }
623
624 pci_lock_rescan_remove();
625 pci_bus_add_devices(root->bus);
626 pci_unlock_rescan_remove();
627 return 1;
628
629 remove_dmar:
630 if (hotadd)
631 dmar_device_remove(handle);
632 end:
633 kfree(root);
634 return result;
635 }
636
637 static void acpi_pci_root_remove(struct acpi_device *device)
638 {
639 struct acpi_pci_root *root = acpi_driver_data(device);
640
641 pci_lock_rescan_remove();
642
643 pci_stop_root_bus(root->bus);
644
645 WARN_ON(acpi_ioapic_remove(root));
646
647 device_set_run_wake(root->bus->bridge, false);
648 pci_acpi_remove_bus_pm_notifier(device);
649
650 pci_remove_root_bus(root->bus);
651
652 dmar_device_remove(device->handle);
653
654 pci_unlock_rescan_remove();
655
656 kfree(root);
657 }
658
659 void __init acpi_pci_root_init(void)
660 {
661 acpi_hest_init();
662 if (acpi_pci_disabled)
663 return;
664
665 pci_acpi_crs_quirks();
666 acpi_scan_add_handler_with_hotplug(&pci_root_handler, "pci_root");
667 }