xref: /linux/drivers/pci/pci-acpi.c (revision 9052e9c95d908d6c3d7570aadc8898e1d871c8bb)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * PCI support in ACPI
4  *
5  * Copyright (C) 2005 David Shaohua Li <shaohua.li@intel.com>
6  * Copyright (C) 2004 Tom Long Nguyen <tom.l.nguyen@intel.com>
7  * Copyright (C) 2004 Intel Corp.
8  */
9 
10 #include <linux/delay.h>
11 #include <linux/init.h>
12 #include <linux/irqdomain.h>
13 #include <linux/pci.h>
14 #include <linux/msi.h>
15 #include <linux/pci_hotplug.h>
16 #include <linux/module.h>
17 #include <linux/pci-acpi.h>
18 #include <linux/pm_runtime.h>
19 #include <linux/pm_qos.h>
20 #include <linux/rwsem.h>
21 #include "pci.h"
22 
23 /*
24  * The GUID is defined in the PCI Firmware Specification available here:
25  * https://www.pcisig.com/members/downloads/pcifw_r3_1_13Dec10.pdf
26  */
27 const guid_t pci_acpi_dsm_guid =
28 	GUID_INIT(0xe5c937d0, 0x3553, 0x4d7a,
29 		  0x91, 0x17, 0xea, 0x4d, 0x19, 0xc3, 0x43, 0x4d);
30 
31 #if defined(CONFIG_PCI_QUIRKS) && defined(CONFIG_ARM64)
32 static int acpi_get_rc_addr(struct acpi_device *adev, struct resource *res)
33 {
34 	struct device *dev = &adev->dev;
35 	struct resource_entry *entry;
36 	struct list_head list;
37 	unsigned long flags;
38 	int ret;
39 
40 	INIT_LIST_HEAD(&list);
41 	flags = IORESOURCE_MEM;
42 	ret = acpi_dev_get_resources(adev, &list,
43 				     acpi_dev_filter_resource_type_cb,
44 				     (void *) flags);
45 	if (ret < 0) {
46 		dev_err(dev, "failed to parse _CRS method, error code %d\n",
47 			ret);
48 		return ret;
49 	}
50 
51 	if (ret == 0) {
52 		dev_err(dev, "no IO and memory resources present in _CRS\n");
53 		return -EINVAL;
54 	}
55 
56 	entry = list_first_entry(&list, struct resource_entry, node);
57 	*res = *entry->res;
58 	acpi_dev_free_resource_list(&list);
59 	return 0;
60 }
61 
62 static acpi_status acpi_match_rc(acpi_handle handle, u32 lvl, void *context,
63 				 void **retval)
64 {
65 	u16 *segment = context;
66 	unsigned long long uid;
67 	acpi_status status;
68 
69 	status = acpi_evaluate_integer(handle, "_UID", NULL, &uid);
70 	if (ACPI_FAILURE(status) || uid != *segment)
71 		return AE_CTRL_DEPTH;
72 
73 	*(acpi_handle *)retval = handle;
74 	return AE_CTRL_TERMINATE;
75 }
76 
77 int acpi_get_rc_resources(struct device *dev, const char *hid, u16 segment,
78 			  struct resource *res)
79 {
80 	struct acpi_device *adev;
81 	acpi_status status;
82 	acpi_handle handle;
83 	int ret;
84 
85 	status = acpi_get_devices(hid, acpi_match_rc, &segment, &handle);
86 	if (ACPI_FAILURE(status)) {
87 		dev_err(dev, "can't find _HID %s device to locate resources\n",
88 			hid);
89 		return -ENODEV;
90 	}
91 
92 	ret = acpi_bus_get_device(handle, &adev);
93 	if (ret)
94 		return ret;
95 
96 	ret = acpi_get_rc_addr(adev, res);
97 	if (ret) {
98 		dev_err(dev, "can't get resource from %s\n",
99 			dev_name(&adev->dev));
100 		return ret;
101 	}
102 
103 	return 0;
104 }
105 #endif
106 
107 phys_addr_t acpi_pci_root_get_mcfg_addr(acpi_handle handle)
108 {
109 	acpi_status status = AE_NOT_EXIST;
110 	unsigned long long mcfg_addr;
111 
112 	if (handle)
113 		status = acpi_evaluate_integer(handle, METHOD_NAME__CBA,
114 					       NULL, &mcfg_addr);
115 	if (ACPI_FAILURE(status))
116 		return 0;
117 
118 	return (phys_addr_t)mcfg_addr;
119 }
120 
121 /* _HPX PCI Setting Record (Type 0); same as _HPP */
122 struct hpx_type0 {
123 	u32 revision;		/* Not present in _HPP */
124 	u8  cache_line_size;	/* Not applicable to PCIe */
125 	u8  latency_timer;	/* Not applicable to PCIe */
126 	u8  enable_serr;
127 	u8  enable_perr;
128 };
129 
130 static struct hpx_type0 pci_default_type0 = {
131 	.revision = 1,
132 	.cache_line_size = 8,
133 	.latency_timer = 0x40,
134 	.enable_serr = 0,
135 	.enable_perr = 0,
136 };
137 
138 static void program_hpx_type0(struct pci_dev *dev, struct hpx_type0 *hpx)
139 {
140 	u16 pci_cmd, pci_bctl;
141 
142 	if (!hpx)
143 		hpx = &pci_default_type0;
144 
145 	if (hpx->revision > 1) {
146 		pci_warn(dev, "PCI settings rev %d not supported; using defaults\n",
147 			 hpx->revision);
148 		hpx = &pci_default_type0;
149 	}
150 
151 	pci_write_config_byte(dev, PCI_CACHE_LINE_SIZE, hpx->cache_line_size);
152 	pci_write_config_byte(dev, PCI_LATENCY_TIMER, hpx->latency_timer);
153 	pci_read_config_word(dev, PCI_COMMAND, &pci_cmd);
154 	if (hpx->enable_serr)
155 		pci_cmd |= PCI_COMMAND_SERR;
156 	if (hpx->enable_perr)
157 		pci_cmd |= PCI_COMMAND_PARITY;
158 	pci_write_config_word(dev, PCI_COMMAND, pci_cmd);
159 
160 	/* Program bridge control value */
161 	if ((dev->class >> 8) == PCI_CLASS_BRIDGE_PCI) {
162 		pci_write_config_byte(dev, PCI_SEC_LATENCY_TIMER,
163 				      hpx->latency_timer);
164 		pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &pci_bctl);
165 		if (hpx->enable_perr)
166 			pci_bctl |= PCI_BRIDGE_CTL_PARITY;
167 		pci_write_config_word(dev, PCI_BRIDGE_CONTROL, pci_bctl);
168 	}
169 }
170 
171 static acpi_status decode_type0_hpx_record(union acpi_object *record,
172 					   struct hpx_type0 *hpx0)
173 {
174 	int i;
175 	union acpi_object *fields = record->package.elements;
176 	u32 revision = fields[1].integer.value;
177 
178 	switch (revision) {
179 	case 1:
180 		if (record->package.count != 6)
181 			return AE_ERROR;
182 		for (i = 2; i < 6; i++)
183 			if (fields[i].type != ACPI_TYPE_INTEGER)
184 				return AE_ERROR;
185 		hpx0->revision        = revision;
186 		hpx0->cache_line_size = fields[2].integer.value;
187 		hpx0->latency_timer   = fields[3].integer.value;
188 		hpx0->enable_serr     = fields[4].integer.value;
189 		hpx0->enable_perr     = fields[5].integer.value;
190 		break;
191 	default:
192 		pr_warn("%s: Type 0 Revision %d record not supported\n",
193 		       __func__, revision);
194 		return AE_ERROR;
195 	}
196 	return AE_OK;
197 }
198 
199 /* _HPX PCI-X Setting Record (Type 1) */
200 struct hpx_type1 {
201 	u32 revision;
202 	u8  max_mem_read;
203 	u8  avg_max_split;
204 	u16 tot_max_split;
205 };
206 
207 static void program_hpx_type1(struct pci_dev *dev, struct hpx_type1 *hpx)
208 {
209 	int pos;
210 
211 	if (!hpx)
212 		return;
213 
214 	pos = pci_find_capability(dev, PCI_CAP_ID_PCIX);
215 	if (!pos)
216 		return;
217 
218 	pci_warn(dev, "PCI-X settings not supported\n");
219 }
220 
221 static acpi_status decode_type1_hpx_record(union acpi_object *record,
222 					   struct hpx_type1 *hpx1)
223 {
224 	int i;
225 	union acpi_object *fields = record->package.elements;
226 	u32 revision = fields[1].integer.value;
227 
228 	switch (revision) {
229 	case 1:
230 		if (record->package.count != 5)
231 			return AE_ERROR;
232 		for (i = 2; i < 5; i++)
233 			if (fields[i].type != ACPI_TYPE_INTEGER)
234 				return AE_ERROR;
235 		hpx1->revision      = revision;
236 		hpx1->max_mem_read  = fields[2].integer.value;
237 		hpx1->avg_max_split = fields[3].integer.value;
238 		hpx1->tot_max_split = fields[4].integer.value;
239 		break;
240 	default:
241 		pr_warn("%s: Type 1 Revision %d record not supported\n",
242 		       __func__, revision);
243 		return AE_ERROR;
244 	}
245 	return AE_OK;
246 }
247 
248 static bool pcie_root_rcb_set(struct pci_dev *dev)
249 {
250 	struct pci_dev *rp = pcie_find_root_port(dev);
251 	u16 lnkctl;
252 
253 	if (!rp)
254 		return false;
255 
256 	pcie_capability_read_word(rp, PCI_EXP_LNKCTL, &lnkctl);
257 	if (lnkctl & PCI_EXP_LNKCTL_RCB)
258 		return true;
259 
260 	return false;
261 }
262 
263 /* _HPX PCI Express Setting Record (Type 2) */
264 struct hpx_type2 {
265 	u32 revision;
266 	u32 unc_err_mask_and;
267 	u32 unc_err_mask_or;
268 	u32 unc_err_sever_and;
269 	u32 unc_err_sever_or;
270 	u32 cor_err_mask_and;
271 	u32 cor_err_mask_or;
272 	u32 adv_err_cap_and;
273 	u32 adv_err_cap_or;
274 	u16 pci_exp_devctl_and;
275 	u16 pci_exp_devctl_or;
276 	u16 pci_exp_lnkctl_and;
277 	u16 pci_exp_lnkctl_or;
278 	u32 sec_unc_err_sever_and;
279 	u32 sec_unc_err_sever_or;
280 	u32 sec_unc_err_mask_and;
281 	u32 sec_unc_err_mask_or;
282 };
283 
284 static void program_hpx_type2(struct pci_dev *dev, struct hpx_type2 *hpx)
285 {
286 	int pos;
287 	u32 reg32;
288 
289 	if (!hpx)
290 		return;
291 
292 	if (!pci_is_pcie(dev))
293 		return;
294 
295 	if (hpx->revision > 1) {
296 		pci_warn(dev, "PCIe settings rev %d not supported\n",
297 			 hpx->revision);
298 		return;
299 	}
300 
301 	/*
302 	 * Don't allow _HPX to change MPS or MRRS settings.  We manage
303 	 * those to make sure they're consistent with the rest of the
304 	 * platform.
305 	 */
306 	hpx->pci_exp_devctl_and |= PCI_EXP_DEVCTL_PAYLOAD |
307 				    PCI_EXP_DEVCTL_READRQ;
308 	hpx->pci_exp_devctl_or &= ~(PCI_EXP_DEVCTL_PAYLOAD |
309 				    PCI_EXP_DEVCTL_READRQ);
310 
311 	/* Initialize Device Control Register */
312 	pcie_capability_clear_and_set_word(dev, PCI_EXP_DEVCTL,
313 			~hpx->pci_exp_devctl_and, hpx->pci_exp_devctl_or);
314 
315 	/* Initialize Link Control Register */
316 	if (pcie_cap_has_lnkctl(dev)) {
317 
318 		/*
319 		 * If the Root Port supports Read Completion Boundary of
320 		 * 128, set RCB to 128.  Otherwise, clear it.
321 		 */
322 		hpx->pci_exp_lnkctl_and |= PCI_EXP_LNKCTL_RCB;
323 		hpx->pci_exp_lnkctl_or &= ~PCI_EXP_LNKCTL_RCB;
324 		if (pcie_root_rcb_set(dev))
325 			hpx->pci_exp_lnkctl_or |= PCI_EXP_LNKCTL_RCB;
326 
327 		pcie_capability_clear_and_set_word(dev, PCI_EXP_LNKCTL,
328 			~hpx->pci_exp_lnkctl_and, hpx->pci_exp_lnkctl_or);
329 	}
330 
331 	/* Find Advanced Error Reporting Enhanced Capability */
332 	pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
333 	if (!pos)
334 		return;
335 
336 	/* Initialize Uncorrectable Error Mask Register */
337 	pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_MASK, &reg32);
338 	reg32 = (reg32 & hpx->unc_err_mask_and) | hpx->unc_err_mask_or;
339 	pci_write_config_dword(dev, pos + PCI_ERR_UNCOR_MASK, reg32);
340 
341 	/* Initialize Uncorrectable Error Severity Register */
342 	pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_SEVER, &reg32);
343 	reg32 = (reg32 & hpx->unc_err_sever_and) | hpx->unc_err_sever_or;
344 	pci_write_config_dword(dev, pos + PCI_ERR_UNCOR_SEVER, reg32);
345 
346 	/* Initialize Correctable Error Mask Register */
347 	pci_read_config_dword(dev, pos + PCI_ERR_COR_MASK, &reg32);
348 	reg32 = (reg32 & hpx->cor_err_mask_and) | hpx->cor_err_mask_or;
349 	pci_write_config_dword(dev, pos + PCI_ERR_COR_MASK, reg32);
350 
351 	/* Initialize Advanced Error Capabilities and Control Register */
352 	pci_read_config_dword(dev, pos + PCI_ERR_CAP, &reg32);
353 	reg32 = (reg32 & hpx->adv_err_cap_and) | hpx->adv_err_cap_or;
354 
355 	/* Don't enable ECRC generation or checking if unsupported */
356 	if (!(reg32 & PCI_ERR_CAP_ECRC_GENC))
357 		reg32 &= ~PCI_ERR_CAP_ECRC_GENE;
358 	if (!(reg32 & PCI_ERR_CAP_ECRC_CHKC))
359 		reg32 &= ~PCI_ERR_CAP_ECRC_CHKE;
360 	pci_write_config_dword(dev, pos + PCI_ERR_CAP, reg32);
361 
362 	/*
363 	 * FIXME: The following two registers are not supported yet.
364 	 *
365 	 *   o Secondary Uncorrectable Error Severity Register
366 	 *   o Secondary Uncorrectable Error Mask Register
367 	 */
368 }
369 
370 static acpi_status decode_type2_hpx_record(union acpi_object *record,
371 					   struct hpx_type2 *hpx2)
372 {
373 	int i;
374 	union acpi_object *fields = record->package.elements;
375 	u32 revision = fields[1].integer.value;
376 
377 	switch (revision) {
378 	case 1:
379 		if (record->package.count != 18)
380 			return AE_ERROR;
381 		for (i = 2; i < 18; i++)
382 			if (fields[i].type != ACPI_TYPE_INTEGER)
383 				return AE_ERROR;
384 		hpx2->revision      = revision;
385 		hpx2->unc_err_mask_and      = fields[2].integer.value;
386 		hpx2->unc_err_mask_or       = fields[3].integer.value;
387 		hpx2->unc_err_sever_and     = fields[4].integer.value;
388 		hpx2->unc_err_sever_or      = fields[5].integer.value;
389 		hpx2->cor_err_mask_and      = fields[6].integer.value;
390 		hpx2->cor_err_mask_or       = fields[7].integer.value;
391 		hpx2->adv_err_cap_and       = fields[8].integer.value;
392 		hpx2->adv_err_cap_or        = fields[9].integer.value;
393 		hpx2->pci_exp_devctl_and    = fields[10].integer.value;
394 		hpx2->pci_exp_devctl_or     = fields[11].integer.value;
395 		hpx2->pci_exp_lnkctl_and    = fields[12].integer.value;
396 		hpx2->pci_exp_lnkctl_or     = fields[13].integer.value;
397 		hpx2->sec_unc_err_sever_and = fields[14].integer.value;
398 		hpx2->sec_unc_err_sever_or  = fields[15].integer.value;
399 		hpx2->sec_unc_err_mask_and  = fields[16].integer.value;
400 		hpx2->sec_unc_err_mask_or   = fields[17].integer.value;
401 		break;
402 	default:
403 		pr_warn("%s: Type 2 Revision %d record not supported\n",
404 		       __func__, revision);
405 		return AE_ERROR;
406 	}
407 	return AE_OK;
408 }
409 
410 /* _HPX PCI Express Setting Record (Type 3) */
411 struct hpx_type3 {
412 	u16 device_type;
413 	u16 function_type;
414 	u16 config_space_location;
415 	u16 pci_exp_cap_id;
416 	u16 pci_exp_cap_ver;
417 	u16 pci_exp_vendor_id;
418 	u16 dvsec_id;
419 	u16 dvsec_rev;
420 	u16 match_offset;
421 	u32 match_mask_and;
422 	u32 match_value;
423 	u16 reg_offset;
424 	u32 reg_mask_and;
425 	u32 reg_mask_or;
426 };
427 
428 enum hpx_type3_dev_type {
429 	HPX_TYPE_ENDPOINT	= BIT(0),
430 	HPX_TYPE_LEG_END	= BIT(1),
431 	HPX_TYPE_RC_END		= BIT(2),
432 	HPX_TYPE_RC_EC		= BIT(3),
433 	HPX_TYPE_ROOT_PORT	= BIT(4),
434 	HPX_TYPE_UPSTREAM	= BIT(5),
435 	HPX_TYPE_DOWNSTREAM	= BIT(6),
436 	HPX_TYPE_PCI_BRIDGE	= BIT(7),
437 	HPX_TYPE_PCIE_BRIDGE	= BIT(8),
438 };
439 
440 static u16 hpx3_device_type(struct pci_dev *dev)
441 {
442 	u16 pcie_type = pci_pcie_type(dev);
443 	static const int pcie_to_hpx3_type[] = {
444 		[PCI_EXP_TYPE_ENDPOINT]    = HPX_TYPE_ENDPOINT,
445 		[PCI_EXP_TYPE_LEG_END]     = HPX_TYPE_LEG_END,
446 		[PCI_EXP_TYPE_RC_END]      = HPX_TYPE_RC_END,
447 		[PCI_EXP_TYPE_RC_EC]       = HPX_TYPE_RC_EC,
448 		[PCI_EXP_TYPE_ROOT_PORT]   = HPX_TYPE_ROOT_PORT,
449 		[PCI_EXP_TYPE_UPSTREAM]    = HPX_TYPE_UPSTREAM,
450 		[PCI_EXP_TYPE_DOWNSTREAM]  = HPX_TYPE_DOWNSTREAM,
451 		[PCI_EXP_TYPE_PCI_BRIDGE]  = HPX_TYPE_PCI_BRIDGE,
452 		[PCI_EXP_TYPE_PCIE_BRIDGE] = HPX_TYPE_PCIE_BRIDGE,
453 	};
454 
455 	if (pcie_type >= ARRAY_SIZE(pcie_to_hpx3_type))
456 		return 0;
457 
458 	return pcie_to_hpx3_type[pcie_type];
459 }
460 
461 enum hpx_type3_fn_type {
462 	HPX_FN_NORMAL		= BIT(0),
463 	HPX_FN_SRIOV_PHYS	= BIT(1),
464 	HPX_FN_SRIOV_VIRT	= BIT(2),
465 };
466 
467 static u8 hpx3_function_type(struct pci_dev *dev)
468 {
469 	if (dev->is_virtfn)
470 		return HPX_FN_SRIOV_VIRT;
471 	else if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_SRIOV) > 0)
472 		return HPX_FN_SRIOV_PHYS;
473 	else
474 		return HPX_FN_NORMAL;
475 }
476 
477 static bool hpx3_cap_ver_matches(u8 pcie_cap_id, u8 hpx3_cap_id)
478 {
479 	u8 cap_ver = hpx3_cap_id & 0xf;
480 
481 	if ((hpx3_cap_id & BIT(4)) && cap_ver >= pcie_cap_id)
482 		return true;
483 	else if (cap_ver == pcie_cap_id)
484 		return true;
485 
486 	return false;
487 }
488 
489 enum hpx_type3_cfg_loc {
490 	HPX_CFG_PCICFG		= 0,
491 	HPX_CFG_PCIE_CAP	= 1,
492 	HPX_CFG_PCIE_CAP_EXT	= 2,
493 	HPX_CFG_VEND_CAP	= 3,
494 	HPX_CFG_DVSEC		= 4,
495 	HPX_CFG_MAX,
496 };
497 
498 static void program_hpx_type3_register(struct pci_dev *dev,
499 				       const struct hpx_type3 *reg)
500 {
501 	u32 match_reg, write_reg, header, orig_value;
502 	u16 pos;
503 
504 	if (!(hpx3_device_type(dev) & reg->device_type))
505 		return;
506 
507 	if (!(hpx3_function_type(dev) & reg->function_type))
508 		return;
509 
510 	switch (reg->config_space_location) {
511 	case HPX_CFG_PCICFG:
512 		pos = 0;
513 		break;
514 	case HPX_CFG_PCIE_CAP:
515 		pos = pci_find_capability(dev, reg->pci_exp_cap_id);
516 		if (pos == 0)
517 			return;
518 
519 		break;
520 	case HPX_CFG_PCIE_CAP_EXT:
521 		pos = pci_find_ext_capability(dev, reg->pci_exp_cap_id);
522 		if (pos == 0)
523 			return;
524 
525 		pci_read_config_dword(dev, pos, &header);
526 		if (!hpx3_cap_ver_matches(PCI_EXT_CAP_VER(header),
527 					  reg->pci_exp_cap_ver))
528 			return;
529 
530 		break;
531 	case HPX_CFG_VEND_CAP:
532 	case HPX_CFG_DVSEC:
533 	default:
534 		pci_warn(dev, "Encountered _HPX type 3 with unsupported config space location");
535 		return;
536 	}
537 
538 	pci_read_config_dword(dev, pos + reg->match_offset, &match_reg);
539 
540 	if ((match_reg & reg->match_mask_and) != reg->match_value)
541 		return;
542 
543 	pci_read_config_dword(dev, pos + reg->reg_offset, &write_reg);
544 	orig_value = write_reg;
545 	write_reg &= reg->reg_mask_and;
546 	write_reg |= reg->reg_mask_or;
547 
548 	if (orig_value == write_reg)
549 		return;
550 
551 	pci_write_config_dword(dev, pos + reg->reg_offset, write_reg);
552 
553 	pci_dbg(dev, "Applied _HPX3 at [0x%x]: 0x%08x -> 0x%08x",
554 		pos, orig_value, write_reg);
555 }
556 
557 static void program_hpx_type3(struct pci_dev *dev, struct hpx_type3 *hpx)
558 {
559 	if (!hpx)
560 		return;
561 
562 	if (!pci_is_pcie(dev))
563 		return;
564 
565 	program_hpx_type3_register(dev, hpx);
566 }
567 
568 static void parse_hpx3_register(struct hpx_type3 *hpx3_reg,
569 				union acpi_object *reg_fields)
570 {
571 	hpx3_reg->device_type            = reg_fields[0].integer.value;
572 	hpx3_reg->function_type          = reg_fields[1].integer.value;
573 	hpx3_reg->config_space_location  = reg_fields[2].integer.value;
574 	hpx3_reg->pci_exp_cap_id         = reg_fields[3].integer.value;
575 	hpx3_reg->pci_exp_cap_ver        = reg_fields[4].integer.value;
576 	hpx3_reg->pci_exp_vendor_id      = reg_fields[5].integer.value;
577 	hpx3_reg->dvsec_id               = reg_fields[6].integer.value;
578 	hpx3_reg->dvsec_rev              = reg_fields[7].integer.value;
579 	hpx3_reg->match_offset           = reg_fields[8].integer.value;
580 	hpx3_reg->match_mask_and         = reg_fields[9].integer.value;
581 	hpx3_reg->match_value            = reg_fields[10].integer.value;
582 	hpx3_reg->reg_offset             = reg_fields[11].integer.value;
583 	hpx3_reg->reg_mask_and           = reg_fields[12].integer.value;
584 	hpx3_reg->reg_mask_or            = reg_fields[13].integer.value;
585 }
586 
587 static acpi_status program_type3_hpx_record(struct pci_dev *dev,
588 					   union acpi_object *record)
589 {
590 	union acpi_object *fields = record->package.elements;
591 	u32 desc_count, expected_length, revision;
592 	union acpi_object *reg_fields;
593 	struct hpx_type3 hpx3;
594 	int i;
595 
596 	revision = fields[1].integer.value;
597 	switch (revision) {
598 	case 1:
599 		desc_count = fields[2].integer.value;
600 		expected_length = 3 + desc_count * 14;
601 
602 		if (record->package.count != expected_length)
603 			return AE_ERROR;
604 
605 		for (i = 2; i < expected_length; i++)
606 			if (fields[i].type != ACPI_TYPE_INTEGER)
607 				return AE_ERROR;
608 
609 		for (i = 0; i < desc_count; i++) {
610 			reg_fields = fields + 3 + i * 14;
611 			parse_hpx3_register(&hpx3, reg_fields);
612 			program_hpx_type3(dev, &hpx3);
613 		}
614 
615 		break;
616 	default:
617 		printk(KERN_WARNING
618 			"%s: Type 3 Revision %d record not supported\n",
619 			__func__, revision);
620 		return AE_ERROR;
621 	}
622 	return AE_OK;
623 }
624 
625 static acpi_status acpi_run_hpx(struct pci_dev *dev, acpi_handle handle)
626 {
627 	acpi_status status;
628 	struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
629 	union acpi_object *package, *record, *fields;
630 	struct hpx_type0 hpx0;
631 	struct hpx_type1 hpx1;
632 	struct hpx_type2 hpx2;
633 	u32 type;
634 	int i;
635 
636 	status = acpi_evaluate_object(handle, "_HPX", NULL, &buffer);
637 	if (ACPI_FAILURE(status))
638 		return status;
639 
640 	package = (union acpi_object *)buffer.pointer;
641 	if (package->type != ACPI_TYPE_PACKAGE) {
642 		status = AE_ERROR;
643 		goto exit;
644 	}
645 
646 	for (i = 0; i < package->package.count; i++) {
647 		record = &package->package.elements[i];
648 		if (record->type != ACPI_TYPE_PACKAGE) {
649 			status = AE_ERROR;
650 			goto exit;
651 		}
652 
653 		fields = record->package.elements;
654 		if (fields[0].type != ACPI_TYPE_INTEGER ||
655 		    fields[1].type != ACPI_TYPE_INTEGER) {
656 			status = AE_ERROR;
657 			goto exit;
658 		}
659 
660 		type = fields[0].integer.value;
661 		switch (type) {
662 		case 0:
663 			memset(&hpx0, 0, sizeof(hpx0));
664 			status = decode_type0_hpx_record(record, &hpx0);
665 			if (ACPI_FAILURE(status))
666 				goto exit;
667 			program_hpx_type0(dev, &hpx0);
668 			break;
669 		case 1:
670 			memset(&hpx1, 0, sizeof(hpx1));
671 			status = decode_type1_hpx_record(record, &hpx1);
672 			if (ACPI_FAILURE(status))
673 				goto exit;
674 			program_hpx_type1(dev, &hpx1);
675 			break;
676 		case 2:
677 			memset(&hpx2, 0, sizeof(hpx2));
678 			status = decode_type2_hpx_record(record, &hpx2);
679 			if (ACPI_FAILURE(status))
680 				goto exit;
681 			program_hpx_type2(dev, &hpx2);
682 			break;
683 		case 3:
684 			status = program_type3_hpx_record(dev, record);
685 			if (ACPI_FAILURE(status))
686 				goto exit;
687 			break;
688 		default:
689 			pr_err("%s: Type %d record not supported\n",
690 			       __func__, type);
691 			status = AE_ERROR;
692 			goto exit;
693 		}
694 	}
695  exit:
696 	kfree(buffer.pointer);
697 	return status;
698 }
699 
700 static acpi_status acpi_run_hpp(struct pci_dev *dev, acpi_handle handle)
701 {
702 	acpi_status status;
703 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
704 	union acpi_object *package, *fields;
705 	struct hpx_type0 hpx0;
706 	int i;
707 
708 	memset(&hpx0, 0, sizeof(hpx0));
709 
710 	status = acpi_evaluate_object(handle, "_HPP", NULL, &buffer);
711 	if (ACPI_FAILURE(status))
712 		return status;
713 
714 	package = (union acpi_object *) buffer.pointer;
715 	if (package->type != ACPI_TYPE_PACKAGE ||
716 	    package->package.count != 4) {
717 		status = AE_ERROR;
718 		goto exit;
719 	}
720 
721 	fields = package->package.elements;
722 	for (i = 0; i < 4; i++) {
723 		if (fields[i].type != ACPI_TYPE_INTEGER) {
724 			status = AE_ERROR;
725 			goto exit;
726 		}
727 	}
728 
729 	hpx0.revision        = 1;
730 	hpx0.cache_line_size = fields[0].integer.value;
731 	hpx0.latency_timer   = fields[1].integer.value;
732 	hpx0.enable_serr     = fields[2].integer.value;
733 	hpx0.enable_perr     = fields[3].integer.value;
734 
735 	program_hpx_type0(dev, &hpx0);
736 
737 exit:
738 	kfree(buffer.pointer);
739 	return status;
740 }
741 
742 /* pci_acpi_program_hp_params
743  *
744  * @dev - the pci_dev for which we want parameters
745  */
746 int pci_acpi_program_hp_params(struct pci_dev *dev)
747 {
748 	acpi_status status;
749 	acpi_handle handle, phandle;
750 	struct pci_bus *pbus;
751 
752 	if (acpi_pci_disabled)
753 		return -ENODEV;
754 
755 	handle = NULL;
756 	for (pbus = dev->bus; pbus; pbus = pbus->parent) {
757 		handle = acpi_pci_get_bridge_handle(pbus);
758 		if (handle)
759 			break;
760 	}
761 
762 	/*
763 	 * _HPP settings apply to all child buses, until another _HPP is
764 	 * encountered. If we don't find an _HPP for the input pci dev,
765 	 * look for it in the parent device scope since that would apply to
766 	 * this pci dev.
767 	 */
768 	while (handle) {
769 		status = acpi_run_hpx(dev, handle);
770 		if (ACPI_SUCCESS(status))
771 			return 0;
772 		status = acpi_run_hpp(dev, handle);
773 		if (ACPI_SUCCESS(status))
774 			return 0;
775 		if (acpi_is_root_bridge(handle))
776 			break;
777 		status = acpi_get_parent(handle, &phandle);
778 		if (ACPI_FAILURE(status))
779 			break;
780 		handle = phandle;
781 	}
782 	return -ENODEV;
783 }
784 
785 /**
786  * pciehp_is_native - Check whether a hotplug port is handled by the OS
787  * @bridge: Hotplug port to check
788  *
789  * Returns true if the given @bridge is handled by the native PCIe hotplug
790  * driver.
791  */
792 bool pciehp_is_native(struct pci_dev *bridge)
793 {
794 	const struct pci_host_bridge *host;
795 	u32 slot_cap;
796 
797 	if (!IS_ENABLED(CONFIG_HOTPLUG_PCI_PCIE))
798 		return false;
799 
800 	pcie_capability_read_dword(bridge, PCI_EXP_SLTCAP, &slot_cap);
801 	if (!(slot_cap & PCI_EXP_SLTCAP_HPC))
802 		return false;
803 
804 	if (pcie_ports_native)
805 		return true;
806 
807 	host = pci_find_host_bridge(bridge->bus);
808 	return host->native_pcie_hotplug;
809 }
810 
811 /**
812  * shpchp_is_native - Check whether a hotplug port is handled by the OS
813  * @bridge: Hotplug port to check
814  *
815  * Returns true if the given @bridge is handled by the native SHPC hotplug
816  * driver.
817  */
818 bool shpchp_is_native(struct pci_dev *bridge)
819 {
820 	return bridge->shpc_managed;
821 }
822 
823 /**
824  * pci_acpi_wake_bus - Root bus wakeup notification fork function.
825  * @context: Device wakeup context.
826  */
827 static void pci_acpi_wake_bus(struct acpi_device_wakeup_context *context)
828 {
829 	struct acpi_device *adev;
830 	struct acpi_pci_root *root;
831 
832 	adev = container_of(context, struct acpi_device, wakeup.context);
833 	root = acpi_driver_data(adev);
834 	pci_pme_wakeup_bus(root->bus);
835 }
836 
837 /**
838  * pci_acpi_wake_dev - PCI device wakeup notification work function.
839  * @context: Device wakeup context.
840  */
841 static void pci_acpi_wake_dev(struct acpi_device_wakeup_context *context)
842 {
843 	struct pci_dev *pci_dev;
844 
845 	pci_dev = to_pci_dev(context->dev);
846 
847 	if (pci_dev->pme_poll)
848 		pci_dev->pme_poll = false;
849 
850 	if (pci_dev->current_state == PCI_D3cold) {
851 		pci_wakeup_event(pci_dev);
852 		pm_request_resume(&pci_dev->dev);
853 		return;
854 	}
855 
856 	/* Clear PME Status if set. */
857 	if (pci_dev->pme_support)
858 		pci_check_pme_status(pci_dev);
859 
860 	pci_wakeup_event(pci_dev);
861 	pm_request_resume(&pci_dev->dev);
862 
863 	pci_pme_wakeup_bus(pci_dev->subordinate);
864 }
865 
866 /**
867  * pci_acpi_add_bus_pm_notifier - Register PM notifier for root PCI bus.
868  * @dev: PCI root bridge ACPI device.
869  */
870 acpi_status pci_acpi_add_bus_pm_notifier(struct acpi_device *dev)
871 {
872 	return acpi_add_pm_notifier(dev, NULL, pci_acpi_wake_bus);
873 }
874 
875 /**
876  * pci_acpi_add_pm_notifier - Register PM notifier for given PCI device.
877  * @dev: ACPI device to add the notifier for.
878  * @pci_dev: PCI device to check for the PME status if an event is signaled.
879  */
880 acpi_status pci_acpi_add_pm_notifier(struct acpi_device *dev,
881 				     struct pci_dev *pci_dev)
882 {
883 	return acpi_add_pm_notifier(dev, &pci_dev->dev, pci_acpi_wake_dev);
884 }
885 
886 /*
887  * _SxD returns the D-state with the highest power
888  * (lowest D-state number) supported in the S-state "x".
889  *
890  * If the devices does not have a _PRW
891  * (Power Resources for Wake) supporting system wakeup from "x"
892  * then the OS is free to choose a lower power (higher number
893  * D-state) than the return value from _SxD.
894  *
895  * But if _PRW is enabled at S-state "x", the OS
896  * must not choose a power lower than _SxD --
897  * unless the device has an _SxW method specifying
898  * the lowest power (highest D-state number) the device
899  * may enter while still able to wake the system.
900  *
901  * ie. depending on global OS policy:
902  *
903  * if (_PRW at S-state x)
904  *	choose from highest power _SxD to lowest power _SxW
905  * else // no _PRW at S-state x
906  *	choose highest power _SxD or any lower power
907  */
908 
909 static pci_power_t acpi_pci_choose_state(struct pci_dev *pdev)
910 {
911 	int acpi_state, d_max;
912 
913 	if (pdev->no_d3cold)
914 		d_max = ACPI_STATE_D3_HOT;
915 	else
916 		d_max = ACPI_STATE_D3_COLD;
917 	acpi_state = acpi_pm_device_sleep_state(&pdev->dev, NULL, d_max);
918 	if (acpi_state < 0)
919 		return PCI_POWER_ERROR;
920 
921 	switch (acpi_state) {
922 	case ACPI_STATE_D0:
923 		return PCI_D0;
924 	case ACPI_STATE_D1:
925 		return PCI_D1;
926 	case ACPI_STATE_D2:
927 		return PCI_D2;
928 	case ACPI_STATE_D3_HOT:
929 		return PCI_D3hot;
930 	case ACPI_STATE_D3_COLD:
931 		return PCI_D3cold;
932 	}
933 	return PCI_POWER_ERROR;
934 }
935 
936 static struct acpi_device *acpi_pci_find_companion(struct device *dev);
937 
938 void pci_set_acpi_fwnode(struct pci_dev *dev)
939 {
940 	if (!dev_fwnode(&dev->dev) && !pci_dev_is_added(dev))
941 		ACPI_COMPANION_SET(&dev->dev,
942 				   acpi_pci_find_companion(&dev->dev));
943 }
944 
945 /**
946  * pci_dev_acpi_reset - do a function level reset using _RST method
947  * @dev: device to reset
948  * @probe: if true, return 0 if device supports _RST
949  */
950 int pci_dev_acpi_reset(struct pci_dev *dev, bool probe)
951 {
952 	acpi_handle handle = ACPI_HANDLE(&dev->dev);
953 
954 	if (!handle || !acpi_has_method(handle, "_RST"))
955 		return -ENOTTY;
956 
957 	if (probe)
958 		return 0;
959 
960 	if (ACPI_FAILURE(acpi_evaluate_object(handle, "_RST", NULL, NULL))) {
961 		pci_warn(dev, "ACPI _RST failed\n");
962 		return -ENOTTY;
963 	}
964 
965 	return 0;
966 }
967 
968 static bool acpi_pci_power_manageable(struct pci_dev *dev)
969 {
970 	struct acpi_device *adev = ACPI_COMPANION(&dev->dev);
971 
972 	if (!adev)
973 		return false;
974 	return acpi_device_power_manageable(adev);
975 }
976 
977 static bool acpi_pci_bridge_d3(struct pci_dev *dev)
978 {
979 	const union acpi_object *obj;
980 	struct acpi_device *adev;
981 	struct pci_dev *rpdev;
982 
983 	if (!dev->is_hotplug_bridge)
984 		return false;
985 
986 	/* Assume D3 support if the bridge is power-manageable by ACPI. */
987 	if (acpi_pci_power_manageable(dev))
988 		return true;
989 
990 	/*
991 	 * The ACPI firmware will provide the device-specific properties through
992 	 * _DSD configuration object. Look for the 'HotPlugSupportInD3' property
993 	 * for the root port and if it is set we know the hierarchy behind it
994 	 * supports D3 just fine.
995 	 */
996 	rpdev = pcie_find_root_port(dev);
997 	if (!rpdev)
998 		return false;
999 
1000 	adev = ACPI_COMPANION(&rpdev->dev);
1001 	if (!adev)
1002 		return false;
1003 
1004 	if (acpi_dev_get_property(adev, "HotPlugSupportInD3",
1005 				   ACPI_TYPE_INTEGER, &obj) < 0)
1006 		return false;
1007 
1008 	return obj->integer.value == 1;
1009 }
1010 
1011 static int acpi_pci_set_power_state(struct pci_dev *dev, pci_power_t state)
1012 {
1013 	struct acpi_device *adev = ACPI_COMPANION(&dev->dev);
1014 	static const u8 state_conv[] = {
1015 		[PCI_D0] = ACPI_STATE_D0,
1016 		[PCI_D1] = ACPI_STATE_D1,
1017 		[PCI_D2] = ACPI_STATE_D2,
1018 		[PCI_D3hot] = ACPI_STATE_D3_HOT,
1019 		[PCI_D3cold] = ACPI_STATE_D3_COLD,
1020 	};
1021 	int error = -EINVAL;
1022 
1023 	/* If the ACPI device has _EJ0, ignore the device */
1024 	if (!adev || acpi_has_method(adev->handle, "_EJ0"))
1025 		return -ENODEV;
1026 
1027 	switch (state) {
1028 	case PCI_D3cold:
1029 		if (dev_pm_qos_flags(&dev->dev, PM_QOS_FLAG_NO_POWER_OFF) ==
1030 				PM_QOS_FLAGS_ALL) {
1031 			error = -EBUSY;
1032 			break;
1033 		}
1034 		fallthrough;
1035 	case PCI_D0:
1036 	case PCI_D1:
1037 	case PCI_D2:
1038 	case PCI_D3hot:
1039 		error = acpi_device_set_power(adev, state_conv[state]);
1040 	}
1041 
1042 	if (!error)
1043 		pci_dbg(dev, "power state changed by ACPI to %s\n",
1044 		        acpi_power_state_string(adev->power.state));
1045 
1046 	return error;
1047 }
1048 
1049 static pci_power_t acpi_pci_get_power_state(struct pci_dev *dev)
1050 {
1051 	struct acpi_device *adev = ACPI_COMPANION(&dev->dev);
1052 	static const pci_power_t state_conv[] = {
1053 		[ACPI_STATE_D0]      = PCI_D0,
1054 		[ACPI_STATE_D1]      = PCI_D1,
1055 		[ACPI_STATE_D2]      = PCI_D2,
1056 		[ACPI_STATE_D3_HOT]  = PCI_D3hot,
1057 		[ACPI_STATE_D3_COLD] = PCI_D3cold,
1058 	};
1059 	int state;
1060 
1061 	if (!adev || !acpi_device_power_manageable(adev))
1062 		return PCI_UNKNOWN;
1063 
1064 	state = adev->power.state;
1065 	if (state == ACPI_STATE_UNKNOWN)
1066 		return PCI_UNKNOWN;
1067 
1068 	return state_conv[state];
1069 }
1070 
1071 static void acpi_pci_refresh_power_state(struct pci_dev *dev)
1072 {
1073 	struct acpi_device *adev = ACPI_COMPANION(&dev->dev);
1074 
1075 	if (adev && acpi_device_power_manageable(adev))
1076 		acpi_device_update_power(adev, NULL);
1077 }
1078 
1079 static int acpi_pci_propagate_wakeup(struct pci_bus *bus, bool enable)
1080 {
1081 	while (bus->parent) {
1082 		if (acpi_pm_device_can_wakeup(&bus->self->dev))
1083 			return acpi_pm_set_device_wakeup(&bus->self->dev, enable);
1084 
1085 		bus = bus->parent;
1086 	}
1087 
1088 	/* We have reached the root bus. */
1089 	if (bus->bridge) {
1090 		if (acpi_pm_device_can_wakeup(bus->bridge))
1091 			return acpi_pm_set_device_wakeup(bus->bridge, enable);
1092 	}
1093 	return 0;
1094 }
1095 
1096 static int acpi_pci_wakeup(struct pci_dev *dev, bool enable)
1097 {
1098 	if (acpi_pm_device_can_wakeup(&dev->dev))
1099 		return acpi_pm_set_device_wakeup(&dev->dev, enable);
1100 
1101 	return acpi_pci_propagate_wakeup(dev->bus, enable);
1102 }
1103 
1104 static bool acpi_pci_need_resume(struct pci_dev *dev)
1105 {
1106 	struct acpi_device *adev = ACPI_COMPANION(&dev->dev);
1107 
1108 	/*
1109 	 * In some cases (eg. Samsung 305V4A) leaving a bridge in suspend over
1110 	 * system-wide suspend/resume confuses the platform firmware, so avoid
1111 	 * doing that.  According to Section 16.1.6 of ACPI 6.2, endpoint
1112 	 * devices are expected to be in D3 before invoking the S3 entry path
1113 	 * from the firmware, so they should not be affected by this issue.
1114 	 */
1115 	if (pci_is_bridge(dev) && acpi_target_system_state() != ACPI_STATE_S0)
1116 		return true;
1117 
1118 	if (!adev || !acpi_device_power_manageable(adev))
1119 		return false;
1120 
1121 	if (adev->wakeup.flags.valid &&
1122 	    device_may_wakeup(&dev->dev) != !!adev->wakeup.prepare_count)
1123 		return true;
1124 
1125 	if (acpi_target_system_state() == ACPI_STATE_S0)
1126 		return false;
1127 
1128 	return !!adev->power.flags.dsw_present;
1129 }
1130 
1131 static const struct pci_platform_pm_ops acpi_pci_platform_pm = {
1132 	.bridge_d3 = acpi_pci_bridge_d3,
1133 	.is_manageable = acpi_pci_power_manageable,
1134 	.set_state = acpi_pci_set_power_state,
1135 	.get_state = acpi_pci_get_power_state,
1136 	.refresh_state = acpi_pci_refresh_power_state,
1137 	.choose_state = acpi_pci_choose_state,
1138 	.set_wakeup = acpi_pci_wakeup,
1139 	.need_resume = acpi_pci_need_resume,
1140 };
1141 
1142 void acpi_pci_add_bus(struct pci_bus *bus)
1143 {
1144 	union acpi_object *obj;
1145 	struct pci_host_bridge *bridge;
1146 
1147 	if (acpi_pci_disabled || !bus->bridge || !ACPI_HANDLE(bus->bridge))
1148 		return;
1149 
1150 	acpi_pci_slot_enumerate(bus);
1151 	acpiphp_enumerate_slots(bus);
1152 
1153 	/*
1154 	 * For a host bridge, check its _DSM for function 8 and if
1155 	 * that is available, mark it in pci_host_bridge.
1156 	 */
1157 	if (!pci_is_root_bus(bus))
1158 		return;
1159 
1160 	obj = acpi_evaluate_dsm(ACPI_HANDLE(bus->bridge), &pci_acpi_dsm_guid, 3,
1161 				DSM_PCI_POWER_ON_RESET_DELAY, NULL);
1162 	if (!obj)
1163 		return;
1164 
1165 	if (obj->type == ACPI_TYPE_INTEGER && obj->integer.value == 1) {
1166 		bridge = pci_find_host_bridge(bus);
1167 		bridge->ignore_reset_delay = 1;
1168 	}
1169 	ACPI_FREE(obj);
1170 }
1171 
1172 void acpi_pci_remove_bus(struct pci_bus *bus)
1173 {
1174 	if (acpi_pci_disabled || !bus->bridge)
1175 		return;
1176 
1177 	acpiphp_remove_slots(bus);
1178 	acpi_pci_slot_remove(bus);
1179 }
1180 
1181 /* ACPI bus type */
1182 
1183 
1184 static DECLARE_RWSEM(pci_acpi_companion_lookup_sem);
1185 static struct acpi_device *(*pci_acpi_find_companion_hook)(struct pci_dev *);
1186 
1187 /**
1188  * pci_acpi_set_companion_lookup_hook - Set ACPI companion lookup callback.
1189  * @func: ACPI companion lookup callback pointer or NULL.
1190  *
1191  * Set a special ACPI companion lookup callback for PCI devices whose companion
1192  * objects in the ACPI namespace have _ADR with non-standard bus-device-function
1193  * encodings.
1194  *
1195  * Return 0 on success or a negative error code on failure (in which case no
1196  * changes are made).
1197  *
1198  * The caller is responsible for the appropriate ordering of the invocations of
1199  * this function with respect to the enumeration of the PCI devices needing the
1200  * callback installed by it.
1201  */
1202 int pci_acpi_set_companion_lookup_hook(struct acpi_device *(*func)(struct pci_dev *))
1203 {
1204 	int ret;
1205 
1206 	if (!func)
1207 		return -EINVAL;
1208 
1209 	down_write(&pci_acpi_companion_lookup_sem);
1210 
1211 	if (pci_acpi_find_companion_hook) {
1212 		ret = -EBUSY;
1213 	} else {
1214 		pci_acpi_find_companion_hook = func;
1215 		ret = 0;
1216 	}
1217 
1218 	up_write(&pci_acpi_companion_lookup_sem);
1219 
1220 	return ret;
1221 }
1222 EXPORT_SYMBOL_GPL(pci_acpi_set_companion_lookup_hook);
1223 
1224 /**
1225  * pci_acpi_clear_companion_lookup_hook - Clear ACPI companion lookup callback.
1226  *
1227  * Clear the special ACPI companion lookup callback previously set by
1228  * pci_acpi_set_companion_lookup_hook().  Block until the last running instance
1229  * of the callback returns before clearing it.
1230  *
1231  * The caller is responsible for the appropriate ordering of the invocations of
1232  * this function with respect to the enumeration of the PCI devices needing the
1233  * callback cleared by it.
1234  */
1235 void pci_acpi_clear_companion_lookup_hook(void)
1236 {
1237 	down_write(&pci_acpi_companion_lookup_sem);
1238 
1239 	pci_acpi_find_companion_hook = NULL;
1240 
1241 	up_write(&pci_acpi_companion_lookup_sem);
1242 }
1243 EXPORT_SYMBOL_GPL(pci_acpi_clear_companion_lookup_hook);
1244 
1245 static struct acpi_device *acpi_pci_find_companion(struct device *dev)
1246 {
1247 	struct pci_dev *pci_dev = to_pci_dev(dev);
1248 	struct acpi_device *adev;
1249 	bool check_children;
1250 	u64 addr;
1251 
1252 	down_read(&pci_acpi_companion_lookup_sem);
1253 
1254 	adev = pci_acpi_find_companion_hook ?
1255 		pci_acpi_find_companion_hook(pci_dev) : NULL;
1256 
1257 	up_read(&pci_acpi_companion_lookup_sem);
1258 
1259 	if (adev)
1260 		return adev;
1261 
1262 	check_children = pci_is_bridge(pci_dev);
1263 	/* Please ref to ACPI spec for the syntax of _ADR */
1264 	addr = (PCI_SLOT(pci_dev->devfn) << 16) | PCI_FUNC(pci_dev->devfn);
1265 	adev = acpi_find_child_device(ACPI_COMPANION(dev->parent), addr,
1266 				      check_children);
1267 
1268 	/*
1269 	 * There may be ACPI device objects in the ACPI namespace that are
1270 	 * children of the device object representing the host bridge, but don't
1271 	 * represent PCI devices.  Both _HID and _ADR may be present for them,
1272 	 * even though that is against the specification (for example, see
1273 	 * Section 6.1 of ACPI 6.3), but in many cases the _ADR returns 0 which
1274 	 * appears to indicate that they should not be taken into consideration
1275 	 * as potential companions of PCI devices on the root bus.
1276 	 *
1277 	 * To catch this special case, disregard the returned device object if
1278 	 * it has a valid _HID, addr is 0 and the PCI device at hand is on the
1279 	 * root bus.
1280 	 */
1281 	if (adev && adev->pnp.type.platform_id && !addr &&
1282 	    pci_is_root_bus(pci_dev->bus))
1283 		return NULL;
1284 
1285 	return adev;
1286 }
1287 
1288 /**
1289  * pci_acpi_optimize_delay - optimize PCI D3 and D3cold delay from ACPI
1290  * @pdev: the PCI device whose delay is to be updated
1291  * @handle: ACPI handle of this device
1292  *
1293  * Update the d3hot_delay and d3cold_delay of a PCI device from the ACPI _DSM
1294  * control method of either the device itself or the PCI host bridge.
1295  *
1296  * Function 8, "Reset Delay," applies to the entire hierarchy below a PCI
1297  * host bridge.  If it returns one, the OS may assume that all devices in
1298  * the hierarchy have already completed power-on reset delays.
1299  *
1300  * Function 9, "Device Readiness Durations," applies only to the object
1301  * where it is located.  It returns delay durations required after various
1302  * events if the device requires less time than the spec requires.  Delays
1303  * from this function take precedence over the Reset Delay function.
1304  *
1305  * These _DSM functions are defined by the draft ECN of January 28, 2014,
1306  * titled "ACPI additions for FW latency optimizations."
1307  */
1308 static void pci_acpi_optimize_delay(struct pci_dev *pdev,
1309 				    acpi_handle handle)
1310 {
1311 	struct pci_host_bridge *bridge = pci_find_host_bridge(pdev->bus);
1312 	int value;
1313 	union acpi_object *obj, *elements;
1314 
1315 	if (bridge->ignore_reset_delay)
1316 		pdev->d3cold_delay = 0;
1317 
1318 	obj = acpi_evaluate_dsm(handle, &pci_acpi_dsm_guid, 3,
1319 				DSM_PCI_DEVICE_READINESS_DURATIONS, NULL);
1320 	if (!obj)
1321 		return;
1322 
1323 	if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 5) {
1324 		elements = obj->package.elements;
1325 		if (elements[0].type == ACPI_TYPE_INTEGER) {
1326 			value = (int)elements[0].integer.value / 1000;
1327 			if (value < PCI_PM_D3COLD_WAIT)
1328 				pdev->d3cold_delay = value;
1329 		}
1330 		if (elements[3].type == ACPI_TYPE_INTEGER) {
1331 			value = (int)elements[3].integer.value / 1000;
1332 			if (value < PCI_PM_D3HOT_WAIT)
1333 				pdev->d3hot_delay = value;
1334 		}
1335 	}
1336 	ACPI_FREE(obj);
1337 }
1338 
1339 static void pci_acpi_set_external_facing(struct pci_dev *dev)
1340 {
1341 	u8 val;
1342 
1343 	if (pci_pcie_type(dev) != PCI_EXP_TYPE_ROOT_PORT)
1344 		return;
1345 	if (device_property_read_u8(&dev->dev, "ExternalFacingPort", &val))
1346 		return;
1347 
1348 	/*
1349 	 * These root ports expose PCIe (including DMA) outside of the
1350 	 * system.  Everything downstream from them is external.
1351 	 */
1352 	if (val)
1353 		dev->external_facing = 1;
1354 }
1355 
1356 static void pci_acpi_setup(struct device *dev)
1357 {
1358 	struct pci_dev *pci_dev = to_pci_dev(dev);
1359 	struct acpi_device *adev = ACPI_COMPANION(dev);
1360 
1361 	if (!adev)
1362 		return;
1363 
1364 	pci_acpi_optimize_delay(pci_dev, adev->handle);
1365 	pci_acpi_set_external_facing(pci_dev);
1366 	pci_acpi_add_edr_notifier(pci_dev);
1367 
1368 	pci_acpi_add_pm_notifier(adev, pci_dev);
1369 	if (!adev->wakeup.flags.valid)
1370 		return;
1371 
1372 	device_set_wakeup_capable(dev, true);
1373 	/*
1374 	 * For bridges that can do D3 we enable wake automatically (as
1375 	 * we do for the power management itself in that case). The
1376 	 * reason is that the bridge may have additional methods such as
1377 	 * _DSW that need to be called.
1378 	 */
1379 	if (pci_dev->bridge_d3)
1380 		device_wakeup_enable(dev);
1381 
1382 	acpi_pci_wakeup(pci_dev, false);
1383 	acpi_device_power_add_dependent(adev, dev);
1384 }
1385 
1386 static void pci_acpi_cleanup(struct device *dev)
1387 {
1388 	struct acpi_device *adev = ACPI_COMPANION(dev);
1389 	struct pci_dev *pci_dev = to_pci_dev(dev);
1390 
1391 	if (!adev)
1392 		return;
1393 
1394 	pci_acpi_remove_edr_notifier(pci_dev);
1395 	pci_acpi_remove_pm_notifier(adev);
1396 	if (adev->wakeup.flags.valid) {
1397 		acpi_device_power_remove_dependent(adev, dev);
1398 		if (pci_dev->bridge_d3)
1399 			device_wakeup_disable(dev);
1400 
1401 		device_set_wakeup_capable(dev, false);
1402 	}
1403 }
1404 
1405 static bool pci_acpi_bus_match(struct device *dev)
1406 {
1407 	return dev_is_pci(dev);
1408 }
1409 
1410 static struct acpi_bus_type acpi_pci_bus = {
1411 	.name = "PCI",
1412 	.match = pci_acpi_bus_match,
1413 	.find_companion = acpi_pci_find_companion,
1414 	.setup = pci_acpi_setup,
1415 	.cleanup = pci_acpi_cleanup,
1416 };
1417 
1418 
1419 static struct fwnode_handle *(*pci_msi_get_fwnode_cb)(struct device *dev);
1420 
1421 /**
1422  * pci_msi_register_fwnode_provider - Register callback to retrieve fwnode
1423  * @fn:       Callback matching a device to a fwnode that identifies a PCI
1424  *            MSI domain.
1425  *
1426  * This should be called by irqchip driver, which is the parent of
1427  * the MSI domain to provide callback interface to query fwnode.
1428  */
1429 void
1430 pci_msi_register_fwnode_provider(struct fwnode_handle *(*fn)(struct device *))
1431 {
1432 	pci_msi_get_fwnode_cb = fn;
1433 }
1434 
1435 /**
1436  * pci_host_bridge_acpi_msi_domain - Retrieve MSI domain of a PCI host bridge
1437  * @bus:      The PCI host bridge bus.
1438  *
1439  * This function uses the callback function registered by
1440  * pci_msi_register_fwnode_provider() to retrieve the irq_domain with
1441  * type DOMAIN_BUS_PCI_MSI of the specified host bridge bus.
1442  * This returns NULL on error or when the domain is not found.
1443  */
1444 struct irq_domain *pci_host_bridge_acpi_msi_domain(struct pci_bus *bus)
1445 {
1446 	struct fwnode_handle *fwnode;
1447 
1448 	if (!pci_msi_get_fwnode_cb)
1449 		return NULL;
1450 
1451 	fwnode = pci_msi_get_fwnode_cb(&bus->dev);
1452 	if (!fwnode)
1453 		return NULL;
1454 
1455 	return irq_find_matching_fwnode(fwnode, DOMAIN_BUS_PCI_MSI);
1456 }
1457 
1458 static int __init acpi_pci_init(void)
1459 {
1460 	int ret;
1461 
1462 	if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_MSI) {
1463 		pr_info("ACPI FADT declares the system doesn't support MSI, so disable it\n");
1464 		pci_no_msi();
1465 	}
1466 
1467 	if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) {
1468 		pr_info("ACPI FADT declares the system doesn't support PCIe ASPM, so disable it\n");
1469 		pcie_no_aspm();
1470 	}
1471 
1472 	ret = register_acpi_bus_type(&acpi_pci_bus);
1473 	if (ret)
1474 		return 0;
1475 
1476 	pci_set_platform_pm(&acpi_pci_platform_pm);
1477 	acpi_pci_slot_init();
1478 	acpiphp_init();
1479 
1480 	return 0;
1481 }
1482 arch_initcall(acpi_pci_init);
1483