xref: /openbmc/linux/drivers/pci/pci-acpi.c (revision 6abeae2a)
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 "pci.h"
21 
22 /*
23  * The GUID is defined in the PCI Firmware Specification available here:
24  * https://www.pcisig.com/members/downloads/pcifw_r3_1_13Dec10.pdf
25  */
26 const guid_t pci_acpi_dsm_guid =
27 	GUID_INIT(0xe5c937d0, 0x3553, 0x4d7a,
28 		  0x91, 0x17, 0xea, 0x4d, 0x19, 0xc3, 0x43, 0x4d);
29 
30 #if defined(CONFIG_PCI_QUIRKS) && defined(CONFIG_ARM64)
31 static int acpi_get_rc_addr(struct acpi_device *adev, struct resource *res)
32 {
33 	struct device *dev = &adev->dev;
34 	struct resource_entry *entry;
35 	struct list_head list;
36 	unsigned long flags;
37 	int ret;
38 
39 	INIT_LIST_HEAD(&list);
40 	flags = IORESOURCE_MEM;
41 	ret = acpi_dev_get_resources(adev, &list,
42 				     acpi_dev_filter_resource_type_cb,
43 				     (void *) flags);
44 	if (ret < 0) {
45 		dev_err(dev, "failed to parse _CRS method, error code %d\n",
46 			ret);
47 		return ret;
48 	}
49 
50 	if (ret == 0) {
51 		dev_err(dev, "no IO and memory resources present in _CRS\n");
52 		return -EINVAL;
53 	}
54 
55 	entry = list_first_entry(&list, struct resource_entry, node);
56 	*res = *entry->res;
57 	acpi_dev_free_resource_list(&list);
58 	return 0;
59 }
60 
61 static acpi_status acpi_match_rc(acpi_handle handle, u32 lvl, void *context,
62 				 void **retval)
63 {
64 	u16 *segment = context;
65 	unsigned long long uid;
66 	acpi_status status;
67 
68 	status = acpi_evaluate_integer(handle, "_UID", NULL, &uid);
69 	if (ACPI_FAILURE(status) || uid != *segment)
70 		return AE_CTRL_DEPTH;
71 
72 	*(acpi_handle *)retval = handle;
73 	return AE_CTRL_TERMINATE;
74 }
75 
76 int acpi_get_rc_resources(struct device *dev, const char *hid, u16 segment,
77 			  struct resource *res)
78 {
79 	struct acpi_device *adev;
80 	acpi_status status;
81 	acpi_handle handle;
82 	int ret;
83 
84 	status = acpi_get_devices(hid, acpi_match_rc, &segment, &handle);
85 	if (ACPI_FAILURE(status)) {
86 		dev_err(dev, "can't find _HID %s device to locate resources\n",
87 			hid);
88 		return -ENODEV;
89 	}
90 
91 	ret = acpi_bus_get_device(handle, &adev);
92 	if (ret)
93 		return ret;
94 
95 	ret = acpi_get_rc_addr(adev, res);
96 	if (ret) {
97 		dev_err(dev, "can't get resource from %s\n",
98 			dev_name(&adev->dev));
99 		return ret;
100 	}
101 
102 	return 0;
103 }
104 #endif
105 
106 phys_addr_t acpi_pci_root_get_mcfg_addr(acpi_handle handle)
107 {
108 	acpi_status status = AE_NOT_EXIST;
109 	unsigned long long mcfg_addr;
110 
111 	if (handle)
112 		status = acpi_evaluate_integer(handle, METHOD_NAME__CBA,
113 					       NULL, &mcfg_addr);
114 	if (ACPI_FAILURE(status))
115 		return 0;
116 
117 	return (phys_addr_t)mcfg_addr;
118 }
119 
120 /* _HPX PCI Setting Record (Type 0); same as _HPP */
121 struct hpx_type0 {
122 	u32 revision;		/* Not present in _HPP */
123 	u8  cache_line_size;	/* Not applicable to PCIe */
124 	u8  latency_timer;	/* Not applicable to PCIe */
125 	u8  enable_serr;
126 	u8  enable_perr;
127 };
128 
129 static struct hpx_type0 pci_default_type0 = {
130 	.revision = 1,
131 	.cache_line_size = 8,
132 	.latency_timer = 0x40,
133 	.enable_serr = 0,
134 	.enable_perr = 0,
135 };
136 
137 static void program_hpx_type0(struct pci_dev *dev, struct hpx_type0 *hpx)
138 {
139 	u16 pci_cmd, pci_bctl;
140 
141 	if (!hpx)
142 		hpx = &pci_default_type0;
143 
144 	if (hpx->revision > 1) {
145 		pci_warn(dev, "PCI settings rev %d not supported; using defaults\n",
146 			 hpx->revision);
147 		hpx = &pci_default_type0;
148 	}
149 
150 	pci_write_config_byte(dev, PCI_CACHE_LINE_SIZE, hpx->cache_line_size);
151 	pci_write_config_byte(dev, PCI_LATENCY_TIMER, hpx->latency_timer);
152 	pci_read_config_word(dev, PCI_COMMAND, &pci_cmd);
153 	if (hpx->enable_serr)
154 		pci_cmd |= PCI_COMMAND_SERR;
155 	if (hpx->enable_perr)
156 		pci_cmd |= PCI_COMMAND_PARITY;
157 	pci_write_config_word(dev, PCI_COMMAND, pci_cmd);
158 
159 	/* Program bridge control value */
160 	if ((dev->class >> 8) == PCI_CLASS_BRIDGE_PCI) {
161 		pci_write_config_byte(dev, PCI_SEC_LATENCY_TIMER,
162 				      hpx->latency_timer);
163 		pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &pci_bctl);
164 		if (hpx->enable_perr)
165 			pci_bctl |= PCI_BRIDGE_CTL_PARITY;
166 		pci_write_config_word(dev, PCI_BRIDGE_CONTROL, pci_bctl);
167 	}
168 }
169 
170 static acpi_status decode_type0_hpx_record(union acpi_object *record,
171 					   struct hpx_type0 *hpx0)
172 {
173 	int i;
174 	union acpi_object *fields = record->package.elements;
175 	u32 revision = fields[1].integer.value;
176 
177 	switch (revision) {
178 	case 1:
179 		if (record->package.count != 6)
180 			return AE_ERROR;
181 		for (i = 2; i < 6; i++)
182 			if (fields[i].type != ACPI_TYPE_INTEGER)
183 				return AE_ERROR;
184 		hpx0->revision        = revision;
185 		hpx0->cache_line_size = fields[2].integer.value;
186 		hpx0->latency_timer   = fields[3].integer.value;
187 		hpx0->enable_serr     = fields[4].integer.value;
188 		hpx0->enable_perr     = fields[5].integer.value;
189 		break;
190 	default:
191 		pr_warn("%s: Type 0 Revision %d record not supported\n",
192 		       __func__, revision);
193 		return AE_ERROR;
194 	}
195 	return AE_OK;
196 }
197 
198 /* _HPX PCI-X Setting Record (Type 1) */
199 struct hpx_type1 {
200 	u32 revision;
201 	u8  max_mem_read;
202 	u8  avg_max_split;
203 	u16 tot_max_split;
204 };
205 
206 static void program_hpx_type1(struct pci_dev *dev, struct hpx_type1 *hpx)
207 {
208 	int pos;
209 
210 	if (!hpx)
211 		return;
212 
213 	pos = pci_find_capability(dev, PCI_CAP_ID_PCIX);
214 	if (!pos)
215 		return;
216 
217 	pci_warn(dev, "PCI-X settings not supported\n");
218 }
219 
220 static acpi_status decode_type1_hpx_record(union acpi_object *record,
221 					   struct hpx_type1 *hpx1)
222 {
223 	int i;
224 	union acpi_object *fields = record->package.elements;
225 	u32 revision = fields[1].integer.value;
226 
227 	switch (revision) {
228 	case 1:
229 		if (record->package.count != 5)
230 			return AE_ERROR;
231 		for (i = 2; i < 5; i++)
232 			if (fields[i].type != ACPI_TYPE_INTEGER)
233 				return AE_ERROR;
234 		hpx1->revision      = revision;
235 		hpx1->max_mem_read  = fields[2].integer.value;
236 		hpx1->avg_max_split = fields[3].integer.value;
237 		hpx1->tot_max_split = fields[4].integer.value;
238 		break;
239 	default:
240 		pr_warn("%s: Type 1 Revision %d record not supported\n",
241 		       __func__, revision);
242 		return AE_ERROR;
243 	}
244 	return AE_OK;
245 }
246 
247 static bool pcie_root_rcb_set(struct pci_dev *dev)
248 {
249 	struct pci_dev *rp = pcie_find_root_port(dev);
250 	u16 lnkctl;
251 
252 	if (!rp)
253 		return false;
254 
255 	pcie_capability_read_word(rp, PCI_EXP_LNKCTL, &lnkctl);
256 	if (lnkctl & PCI_EXP_LNKCTL_RCB)
257 		return true;
258 
259 	return false;
260 }
261 
262 /* _HPX PCI Express Setting Record (Type 2) */
263 struct hpx_type2 {
264 	u32 revision;
265 	u32 unc_err_mask_and;
266 	u32 unc_err_mask_or;
267 	u32 unc_err_sever_and;
268 	u32 unc_err_sever_or;
269 	u32 cor_err_mask_and;
270 	u32 cor_err_mask_or;
271 	u32 adv_err_cap_and;
272 	u32 adv_err_cap_or;
273 	u16 pci_exp_devctl_and;
274 	u16 pci_exp_devctl_or;
275 	u16 pci_exp_lnkctl_and;
276 	u16 pci_exp_lnkctl_or;
277 	u32 sec_unc_err_sever_and;
278 	u32 sec_unc_err_sever_or;
279 	u32 sec_unc_err_mask_and;
280 	u32 sec_unc_err_mask_or;
281 };
282 
283 static void program_hpx_type2(struct pci_dev *dev, struct hpx_type2 *hpx)
284 {
285 	int pos;
286 	u32 reg32;
287 
288 	if (!hpx)
289 		return;
290 
291 	if (!pci_is_pcie(dev))
292 		return;
293 
294 	if (hpx->revision > 1) {
295 		pci_warn(dev, "PCIe settings rev %d not supported\n",
296 			 hpx->revision);
297 		return;
298 	}
299 
300 	/*
301 	 * Don't allow _HPX to change MPS or MRRS settings.  We manage
302 	 * those to make sure they're consistent with the rest of the
303 	 * platform.
304 	 */
305 	hpx->pci_exp_devctl_and |= PCI_EXP_DEVCTL_PAYLOAD |
306 				    PCI_EXP_DEVCTL_READRQ;
307 	hpx->pci_exp_devctl_or &= ~(PCI_EXP_DEVCTL_PAYLOAD |
308 				    PCI_EXP_DEVCTL_READRQ);
309 
310 	/* Initialize Device Control Register */
311 	pcie_capability_clear_and_set_word(dev, PCI_EXP_DEVCTL,
312 			~hpx->pci_exp_devctl_and, hpx->pci_exp_devctl_or);
313 
314 	/* Initialize Link Control Register */
315 	if (pcie_cap_has_lnkctl(dev)) {
316 
317 		/*
318 		 * If the Root Port supports Read Completion Boundary of
319 		 * 128, set RCB to 128.  Otherwise, clear it.
320 		 */
321 		hpx->pci_exp_lnkctl_and |= PCI_EXP_LNKCTL_RCB;
322 		hpx->pci_exp_lnkctl_or &= ~PCI_EXP_LNKCTL_RCB;
323 		if (pcie_root_rcb_set(dev))
324 			hpx->pci_exp_lnkctl_or |= PCI_EXP_LNKCTL_RCB;
325 
326 		pcie_capability_clear_and_set_word(dev, PCI_EXP_LNKCTL,
327 			~hpx->pci_exp_lnkctl_and, hpx->pci_exp_lnkctl_or);
328 	}
329 
330 	/* Find Advanced Error Reporting Enhanced Capability */
331 	pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
332 	if (!pos)
333 		return;
334 
335 	/* Initialize Uncorrectable Error Mask Register */
336 	pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_MASK, &reg32);
337 	reg32 = (reg32 & hpx->unc_err_mask_and) | hpx->unc_err_mask_or;
338 	pci_write_config_dword(dev, pos + PCI_ERR_UNCOR_MASK, reg32);
339 
340 	/* Initialize Uncorrectable Error Severity Register */
341 	pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_SEVER, &reg32);
342 	reg32 = (reg32 & hpx->unc_err_sever_and) | hpx->unc_err_sever_or;
343 	pci_write_config_dword(dev, pos + PCI_ERR_UNCOR_SEVER, reg32);
344 
345 	/* Initialize Correctable Error Mask Register */
346 	pci_read_config_dword(dev, pos + PCI_ERR_COR_MASK, &reg32);
347 	reg32 = (reg32 & hpx->cor_err_mask_and) | hpx->cor_err_mask_or;
348 	pci_write_config_dword(dev, pos + PCI_ERR_COR_MASK, reg32);
349 
350 	/* Initialize Advanced Error Capabilities and Control Register */
351 	pci_read_config_dword(dev, pos + PCI_ERR_CAP, &reg32);
352 	reg32 = (reg32 & hpx->adv_err_cap_and) | hpx->adv_err_cap_or;
353 
354 	/* Don't enable ECRC generation or checking if unsupported */
355 	if (!(reg32 & PCI_ERR_CAP_ECRC_GENC))
356 		reg32 &= ~PCI_ERR_CAP_ECRC_GENE;
357 	if (!(reg32 & PCI_ERR_CAP_ECRC_CHKC))
358 		reg32 &= ~PCI_ERR_CAP_ECRC_CHKE;
359 	pci_write_config_dword(dev, pos + PCI_ERR_CAP, reg32);
360 
361 	/*
362 	 * FIXME: The following two registers are not supported yet.
363 	 *
364 	 *   o Secondary Uncorrectable Error Severity Register
365 	 *   o Secondary Uncorrectable Error Mask Register
366 	 */
367 }
368 
369 static acpi_status decode_type2_hpx_record(union acpi_object *record,
370 					   struct hpx_type2 *hpx2)
371 {
372 	int i;
373 	union acpi_object *fields = record->package.elements;
374 	u32 revision = fields[1].integer.value;
375 
376 	switch (revision) {
377 	case 1:
378 		if (record->package.count != 18)
379 			return AE_ERROR;
380 		for (i = 2; i < 18; i++)
381 			if (fields[i].type != ACPI_TYPE_INTEGER)
382 				return AE_ERROR;
383 		hpx2->revision      = revision;
384 		hpx2->unc_err_mask_and      = fields[2].integer.value;
385 		hpx2->unc_err_mask_or       = fields[3].integer.value;
386 		hpx2->unc_err_sever_and     = fields[4].integer.value;
387 		hpx2->unc_err_sever_or      = fields[5].integer.value;
388 		hpx2->cor_err_mask_and      = fields[6].integer.value;
389 		hpx2->cor_err_mask_or       = fields[7].integer.value;
390 		hpx2->adv_err_cap_and       = fields[8].integer.value;
391 		hpx2->adv_err_cap_or        = fields[9].integer.value;
392 		hpx2->pci_exp_devctl_and    = fields[10].integer.value;
393 		hpx2->pci_exp_devctl_or     = fields[11].integer.value;
394 		hpx2->pci_exp_lnkctl_and    = fields[12].integer.value;
395 		hpx2->pci_exp_lnkctl_or     = fields[13].integer.value;
396 		hpx2->sec_unc_err_sever_and = fields[14].integer.value;
397 		hpx2->sec_unc_err_sever_or  = fields[15].integer.value;
398 		hpx2->sec_unc_err_mask_and  = fields[16].integer.value;
399 		hpx2->sec_unc_err_mask_or   = fields[17].integer.value;
400 		break;
401 	default:
402 		pr_warn("%s: Type 2 Revision %d record not supported\n",
403 		       __func__, revision);
404 		return AE_ERROR;
405 	}
406 	return AE_OK;
407 }
408 
409 /* _HPX PCI Express Setting Record (Type 3) */
410 struct hpx_type3 {
411 	u16 device_type;
412 	u16 function_type;
413 	u16 config_space_location;
414 	u16 pci_exp_cap_id;
415 	u16 pci_exp_cap_ver;
416 	u16 pci_exp_vendor_id;
417 	u16 dvsec_id;
418 	u16 dvsec_rev;
419 	u16 match_offset;
420 	u32 match_mask_and;
421 	u32 match_value;
422 	u16 reg_offset;
423 	u32 reg_mask_and;
424 	u32 reg_mask_or;
425 };
426 
427 enum hpx_type3_dev_type {
428 	HPX_TYPE_ENDPOINT	= BIT(0),
429 	HPX_TYPE_LEG_END	= BIT(1),
430 	HPX_TYPE_RC_END		= BIT(2),
431 	HPX_TYPE_RC_EC		= BIT(3),
432 	HPX_TYPE_ROOT_PORT	= BIT(4),
433 	HPX_TYPE_UPSTREAM	= BIT(5),
434 	HPX_TYPE_DOWNSTREAM	= BIT(6),
435 	HPX_TYPE_PCI_BRIDGE	= BIT(7),
436 	HPX_TYPE_PCIE_BRIDGE	= BIT(8),
437 };
438 
439 static u16 hpx3_device_type(struct pci_dev *dev)
440 {
441 	u16 pcie_type = pci_pcie_type(dev);
442 	static const int pcie_to_hpx3_type[] = {
443 		[PCI_EXP_TYPE_ENDPOINT]    = HPX_TYPE_ENDPOINT,
444 		[PCI_EXP_TYPE_LEG_END]     = HPX_TYPE_LEG_END,
445 		[PCI_EXP_TYPE_RC_END]      = HPX_TYPE_RC_END,
446 		[PCI_EXP_TYPE_RC_EC]       = HPX_TYPE_RC_EC,
447 		[PCI_EXP_TYPE_ROOT_PORT]   = HPX_TYPE_ROOT_PORT,
448 		[PCI_EXP_TYPE_UPSTREAM]    = HPX_TYPE_UPSTREAM,
449 		[PCI_EXP_TYPE_DOWNSTREAM]  = HPX_TYPE_DOWNSTREAM,
450 		[PCI_EXP_TYPE_PCI_BRIDGE]  = HPX_TYPE_PCI_BRIDGE,
451 		[PCI_EXP_TYPE_PCIE_BRIDGE] = HPX_TYPE_PCIE_BRIDGE,
452 	};
453 
454 	if (pcie_type >= ARRAY_SIZE(pcie_to_hpx3_type))
455 		return 0;
456 
457 	return pcie_to_hpx3_type[pcie_type];
458 }
459 
460 enum hpx_type3_fn_type {
461 	HPX_FN_NORMAL		= BIT(0),
462 	HPX_FN_SRIOV_PHYS	= BIT(1),
463 	HPX_FN_SRIOV_VIRT	= BIT(2),
464 };
465 
466 static u8 hpx3_function_type(struct pci_dev *dev)
467 {
468 	if (dev->is_virtfn)
469 		return HPX_FN_SRIOV_VIRT;
470 	else if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_SRIOV) > 0)
471 		return HPX_FN_SRIOV_PHYS;
472 	else
473 		return HPX_FN_NORMAL;
474 }
475 
476 static bool hpx3_cap_ver_matches(u8 pcie_cap_id, u8 hpx3_cap_id)
477 {
478 	u8 cap_ver = hpx3_cap_id & 0xf;
479 
480 	if ((hpx3_cap_id & BIT(4)) && cap_ver >= pcie_cap_id)
481 		return true;
482 	else if (cap_ver == pcie_cap_id)
483 		return true;
484 
485 	return false;
486 }
487 
488 enum hpx_type3_cfg_loc {
489 	HPX_CFG_PCICFG		= 0,
490 	HPX_CFG_PCIE_CAP	= 1,
491 	HPX_CFG_PCIE_CAP_EXT	= 2,
492 	HPX_CFG_VEND_CAP	= 3,
493 	HPX_CFG_DVSEC		= 4,
494 	HPX_CFG_MAX,
495 };
496 
497 static void program_hpx_type3_register(struct pci_dev *dev,
498 				       const struct hpx_type3 *reg)
499 {
500 	u32 match_reg, write_reg, header, orig_value;
501 	u16 pos;
502 
503 	if (!(hpx3_device_type(dev) & reg->device_type))
504 		return;
505 
506 	if (!(hpx3_function_type(dev) & reg->function_type))
507 		return;
508 
509 	switch (reg->config_space_location) {
510 	case HPX_CFG_PCICFG:
511 		pos = 0;
512 		break;
513 	case HPX_CFG_PCIE_CAP:
514 		pos = pci_find_capability(dev, reg->pci_exp_cap_id);
515 		if (pos == 0)
516 			return;
517 
518 		break;
519 	case HPX_CFG_PCIE_CAP_EXT:
520 		pos = pci_find_ext_capability(dev, reg->pci_exp_cap_id);
521 		if (pos == 0)
522 			return;
523 
524 		pci_read_config_dword(dev, pos, &header);
525 		if (!hpx3_cap_ver_matches(PCI_EXT_CAP_VER(header),
526 					  reg->pci_exp_cap_ver))
527 			return;
528 
529 		break;
530 	case HPX_CFG_VEND_CAP:
531 	case HPX_CFG_DVSEC:
532 	default:
533 		pci_warn(dev, "Encountered _HPX type 3 with unsupported config space location");
534 		return;
535 	}
536 
537 	pci_read_config_dword(dev, pos + reg->match_offset, &match_reg);
538 
539 	if ((match_reg & reg->match_mask_and) != reg->match_value)
540 		return;
541 
542 	pci_read_config_dword(dev, pos + reg->reg_offset, &write_reg);
543 	orig_value = write_reg;
544 	write_reg &= reg->reg_mask_and;
545 	write_reg |= reg->reg_mask_or;
546 
547 	if (orig_value == write_reg)
548 		return;
549 
550 	pci_write_config_dword(dev, pos + reg->reg_offset, write_reg);
551 
552 	pci_dbg(dev, "Applied _HPX3 at [0x%x]: 0x%08x -> 0x%08x",
553 		pos, orig_value, write_reg);
554 }
555 
556 static void program_hpx_type3(struct pci_dev *dev, struct hpx_type3 *hpx)
557 {
558 	if (!hpx)
559 		return;
560 
561 	if (!pci_is_pcie(dev))
562 		return;
563 
564 	program_hpx_type3_register(dev, hpx);
565 }
566 
567 static void parse_hpx3_register(struct hpx_type3 *hpx3_reg,
568 				union acpi_object *reg_fields)
569 {
570 	hpx3_reg->device_type            = reg_fields[0].integer.value;
571 	hpx3_reg->function_type          = reg_fields[1].integer.value;
572 	hpx3_reg->config_space_location  = reg_fields[2].integer.value;
573 	hpx3_reg->pci_exp_cap_id         = reg_fields[3].integer.value;
574 	hpx3_reg->pci_exp_cap_ver        = reg_fields[4].integer.value;
575 	hpx3_reg->pci_exp_vendor_id      = reg_fields[5].integer.value;
576 	hpx3_reg->dvsec_id               = reg_fields[6].integer.value;
577 	hpx3_reg->dvsec_rev              = reg_fields[7].integer.value;
578 	hpx3_reg->match_offset           = reg_fields[8].integer.value;
579 	hpx3_reg->match_mask_and         = reg_fields[9].integer.value;
580 	hpx3_reg->match_value            = reg_fields[10].integer.value;
581 	hpx3_reg->reg_offset             = reg_fields[11].integer.value;
582 	hpx3_reg->reg_mask_and           = reg_fields[12].integer.value;
583 	hpx3_reg->reg_mask_or            = reg_fields[13].integer.value;
584 }
585 
586 static acpi_status program_type3_hpx_record(struct pci_dev *dev,
587 					   union acpi_object *record)
588 {
589 	union acpi_object *fields = record->package.elements;
590 	u32 desc_count, expected_length, revision;
591 	union acpi_object *reg_fields;
592 	struct hpx_type3 hpx3;
593 	int i;
594 
595 	revision = fields[1].integer.value;
596 	switch (revision) {
597 	case 1:
598 		desc_count = fields[2].integer.value;
599 		expected_length = 3 + desc_count * 14;
600 
601 		if (record->package.count != expected_length)
602 			return AE_ERROR;
603 
604 		for (i = 2; i < expected_length; i++)
605 			if (fields[i].type != ACPI_TYPE_INTEGER)
606 				return AE_ERROR;
607 
608 		for (i = 0; i < desc_count; i++) {
609 			reg_fields = fields + 3 + i * 14;
610 			parse_hpx3_register(&hpx3, reg_fields);
611 			program_hpx_type3(dev, &hpx3);
612 		}
613 
614 		break;
615 	default:
616 		printk(KERN_WARNING
617 			"%s: Type 3 Revision %d record not supported\n",
618 			__func__, revision);
619 		return AE_ERROR;
620 	}
621 	return AE_OK;
622 }
623 
624 static acpi_status acpi_run_hpx(struct pci_dev *dev, acpi_handle handle)
625 {
626 	acpi_status status;
627 	struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
628 	union acpi_object *package, *record, *fields;
629 	struct hpx_type0 hpx0;
630 	struct hpx_type1 hpx1;
631 	struct hpx_type2 hpx2;
632 	u32 type;
633 	int i;
634 
635 	status = acpi_evaluate_object(handle, "_HPX", NULL, &buffer);
636 	if (ACPI_FAILURE(status))
637 		return status;
638 
639 	package = (union acpi_object *)buffer.pointer;
640 	if (package->type != ACPI_TYPE_PACKAGE) {
641 		status = AE_ERROR;
642 		goto exit;
643 	}
644 
645 	for (i = 0; i < package->package.count; i++) {
646 		record = &package->package.elements[i];
647 		if (record->type != ACPI_TYPE_PACKAGE) {
648 			status = AE_ERROR;
649 			goto exit;
650 		}
651 
652 		fields = record->package.elements;
653 		if (fields[0].type != ACPI_TYPE_INTEGER ||
654 		    fields[1].type != ACPI_TYPE_INTEGER) {
655 			status = AE_ERROR;
656 			goto exit;
657 		}
658 
659 		type = fields[0].integer.value;
660 		switch (type) {
661 		case 0:
662 			memset(&hpx0, 0, sizeof(hpx0));
663 			status = decode_type0_hpx_record(record, &hpx0);
664 			if (ACPI_FAILURE(status))
665 				goto exit;
666 			program_hpx_type0(dev, &hpx0);
667 			break;
668 		case 1:
669 			memset(&hpx1, 0, sizeof(hpx1));
670 			status = decode_type1_hpx_record(record, &hpx1);
671 			if (ACPI_FAILURE(status))
672 				goto exit;
673 			program_hpx_type1(dev, &hpx1);
674 			break;
675 		case 2:
676 			memset(&hpx2, 0, sizeof(hpx2));
677 			status = decode_type2_hpx_record(record, &hpx2);
678 			if (ACPI_FAILURE(status))
679 				goto exit;
680 			program_hpx_type2(dev, &hpx2);
681 			break;
682 		case 3:
683 			status = program_type3_hpx_record(dev, record);
684 			if (ACPI_FAILURE(status))
685 				goto exit;
686 			break;
687 		default:
688 			pr_err("%s: Type %d record not supported\n",
689 			       __func__, type);
690 			status = AE_ERROR;
691 			goto exit;
692 		}
693 	}
694  exit:
695 	kfree(buffer.pointer);
696 	return status;
697 }
698 
699 static acpi_status acpi_run_hpp(struct pci_dev *dev, acpi_handle handle)
700 {
701 	acpi_status status;
702 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
703 	union acpi_object *package, *fields;
704 	struct hpx_type0 hpx0;
705 	int i;
706 
707 	memset(&hpx0, 0, sizeof(hpx0));
708 
709 	status = acpi_evaluate_object(handle, "_HPP", NULL, &buffer);
710 	if (ACPI_FAILURE(status))
711 		return status;
712 
713 	package = (union acpi_object *) buffer.pointer;
714 	if (package->type != ACPI_TYPE_PACKAGE ||
715 	    package->package.count != 4) {
716 		status = AE_ERROR;
717 		goto exit;
718 	}
719 
720 	fields = package->package.elements;
721 	for (i = 0; i < 4; i++) {
722 		if (fields[i].type != ACPI_TYPE_INTEGER) {
723 			status = AE_ERROR;
724 			goto exit;
725 		}
726 	}
727 
728 	hpx0.revision        = 1;
729 	hpx0.cache_line_size = fields[0].integer.value;
730 	hpx0.latency_timer   = fields[1].integer.value;
731 	hpx0.enable_serr     = fields[2].integer.value;
732 	hpx0.enable_perr     = fields[3].integer.value;
733 
734 	program_hpx_type0(dev, &hpx0);
735 
736 exit:
737 	kfree(buffer.pointer);
738 	return status;
739 }
740 
741 /* pci_acpi_program_hp_params
742  *
743  * @dev - the pci_dev for which we want parameters
744  */
745 int pci_acpi_program_hp_params(struct pci_dev *dev)
746 {
747 	acpi_status status;
748 	acpi_handle handle, phandle;
749 	struct pci_bus *pbus;
750 
751 	if (acpi_pci_disabled)
752 		return -ENODEV;
753 
754 	handle = NULL;
755 	for (pbus = dev->bus; pbus; pbus = pbus->parent) {
756 		handle = acpi_pci_get_bridge_handle(pbus);
757 		if (handle)
758 			break;
759 	}
760 
761 	/*
762 	 * _HPP settings apply to all child buses, until another _HPP is
763 	 * encountered. If we don't find an _HPP for the input pci dev,
764 	 * look for it in the parent device scope since that would apply to
765 	 * this pci dev.
766 	 */
767 	while (handle) {
768 		status = acpi_run_hpx(dev, handle);
769 		if (ACPI_SUCCESS(status))
770 			return 0;
771 		status = acpi_run_hpp(dev, handle);
772 		if (ACPI_SUCCESS(status))
773 			return 0;
774 		if (acpi_is_root_bridge(handle))
775 			break;
776 		status = acpi_get_parent(handle, &phandle);
777 		if (ACPI_FAILURE(status))
778 			break;
779 		handle = phandle;
780 	}
781 	return -ENODEV;
782 }
783 
784 /**
785  * pciehp_is_native - Check whether a hotplug port is handled by the OS
786  * @bridge: Hotplug port to check
787  *
788  * Returns true if the given @bridge is handled by the native PCIe hotplug
789  * driver.
790  */
791 bool pciehp_is_native(struct pci_dev *bridge)
792 {
793 	const struct pci_host_bridge *host;
794 	u32 slot_cap;
795 
796 	if (!IS_ENABLED(CONFIG_HOTPLUG_PCI_PCIE))
797 		return false;
798 
799 	pcie_capability_read_dword(bridge, PCI_EXP_SLTCAP, &slot_cap);
800 	if (!(slot_cap & PCI_EXP_SLTCAP_HPC))
801 		return false;
802 
803 	if (pcie_ports_native)
804 		return true;
805 
806 	host = pci_find_host_bridge(bridge->bus);
807 	return host->native_pcie_hotplug;
808 }
809 
810 /**
811  * shpchp_is_native - Check whether a hotplug port is handled by the OS
812  * @bridge: Hotplug port to check
813  *
814  * Returns true if the given @bridge is handled by the native SHPC hotplug
815  * driver.
816  */
817 bool shpchp_is_native(struct pci_dev *bridge)
818 {
819 	return bridge->shpc_managed;
820 }
821 
822 /**
823  * pci_acpi_wake_bus - Root bus wakeup notification fork function.
824  * @context: Device wakeup context.
825  */
826 static void pci_acpi_wake_bus(struct acpi_device_wakeup_context *context)
827 {
828 	struct acpi_device *adev;
829 	struct acpi_pci_root *root;
830 
831 	adev = container_of(context, struct acpi_device, wakeup.context);
832 	root = acpi_driver_data(adev);
833 	pci_pme_wakeup_bus(root->bus);
834 }
835 
836 /**
837  * pci_acpi_wake_dev - PCI device wakeup notification work function.
838  * @context: Device wakeup context.
839  */
840 static void pci_acpi_wake_dev(struct acpi_device_wakeup_context *context)
841 {
842 	struct pci_dev *pci_dev;
843 
844 	pci_dev = to_pci_dev(context->dev);
845 
846 	if (pci_dev->pme_poll)
847 		pci_dev->pme_poll = false;
848 
849 	if (pci_dev->current_state == PCI_D3cold) {
850 		pci_wakeup_event(pci_dev);
851 		pm_request_resume(&pci_dev->dev);
852 		return;
853 	}
854 
855 	/* Clear PME Status if set. */
856 	if (pci_dev->pme_support)
857 		pci_check_pme_status(pci_dev);
858 
859 	pci_wakeup_event(pci_dev);
860 	pm_request_resume(&pci_dev->dev);
861 
862 	pci_pme_wakeup_bus(pci_dev->subordinate);
863 }
864 
865 /**
866  * pci_acpi_add_bus_pm_notifier - Register PM notifier for root PCI bus.
867  * @dev: PCI root bridge ACPI device.
868  */
869 acpi_status pci_acpi_add_bus_pm_notifier(struct acpi_device *dev)
870 {
871 	return acpi_add_pm_notifier(dev, NULL, pci_acpi_wake_bus);
872 }
873 
874 /**
875  * pci_acpi_add_pm_notifier - Register PM notifier for given PCI device.
876  * @dev: ACPI device to add the notifier for.
877  * @pci_dev: PCI device to check for the PME status if an event is signaled.
878  */
879 acpi_status pci_acpi_add_pm_notifier(struct acpi_device *dev,
880 				     struct pci_dev *pci_dev)
881 {
882 	return acpi_add_pm_notifier(dev, &pci_dev->dev, pci_acpi_wake_dev);
883 }
884 
885 /*
886  * _SxD returns the D-state with the highest power
887  * (lowest D-state number) supported in the S-state "x".
888  *
889  * If the devices does not have a _PRW
890  * (Power Resources for Wake) supporting system wakeup from "x"
891  * then the OS is free to choose a lower power (higher number
892  * D-state) than the return value from _SxD.
893  *
894  * But if _PRW is enabled at S-state "x", the OS
895  * must not choose a power lower than _SxD --
896  * unless the device has an _SxW method specifying
897  * the lowest power (highest D-state number) the device
898  * may enter while still able to wake the system.
899  *
900  * ie. depending on global OS policy:
901  *
902  * if (_PRW at S-state x)
903  *	choose from highest power _SxD to lowest power _SxW
904  * else // no _PRW at S-state x
905  *	choose highest power _SxD or any lower power
906  */
907 
908 static pci_power_t acpi_pci_choose_state(struct pci_dev *pdev)
909 {
910 	int acpi_state, d_max;
911 
912 	if (pdev->no_d3cold)
913 		d_max = ACPI_STATE_D3_HOT;
914 	else
915 		d_max = ACPI_STATE_D3_COLD;
916 	acpi_state = acpi_pm_device_sleep_state(&pdev->dev, NULL, d_max);
917 	if (acpi_state < 0)
918 		return PCI_POWER_ERROR;
919 
920 	switch (acpi_state) {
921 	case ACPI_STATE_D0:
922 		return PCI_D0;
923 	case ACPI_STATE_D1:
924 		return PCI_D1;
925 	case ACPI_STATE_D2:
926 		return PCI_D2;
927 	case ACPI_STATE_D3_HOT:
928 		return PCI_D3hot;
929 	case ACPI_STATE_D3_COLD:
930 		return PCI_D3cold;
931 	}
932 	return PCI_POWER_ERROR;
933 }
934 
935 static struct acpi_device *acpi_pci_find_companion(struct device *dev);
936 
937 static bool acpi_pci_bridge_d3(struct pci_dev *dev)
938 {
939 	const struct fwnode_handle *fwnode;
940 	struct acpi_device *adev;
941 	struct pci_dev *root;
942 	u8 val;
943 
944 	if (!dev->is_hotplug_bridge)
945 		return false;
946 
947 	/* Assume D3 support if the bridge is power-manageable by ACPI. */
948 	adev = ACPI_COMPANION(&dev->dev);
949 	if (!adev && !pci_dev_is_added(dev)) {
950 		adev = acpi_pci_find_companion(&dev->dev);
951 		ACPI_COMPANION_SET(&dev->dev, adev);
952 	}
953 
954 	if (adev && acpi_device_power_manageable(adev))
955 		return true;
956 
957 	/*
958 	 * Look for a special _DSD property for the root port and if it
959 	 * is set we know the hierarchy behind it supports D3 just fine.
960 	 */
961 	root = pcie_find_root_port(dev);
962 	if (!root)
963 		return false;
964 
965 	adev = ACPI_COMPANION(&root->dev);
966 	if (root == dev) {
967 		/*
968 		 * It is possible that the ACPI companion is not yet bound
969 		 * for the root port so look it up manually here.
970 		 */
971 		if (!adev && !pci_dev_is_added(root))
972 			adev = acpi_pci_find_companion(&root->dev);
973 	}
974 
975 	if (!adev)
976 		return false;
977 
978 	fwnode = acpi_fwnode_handle(adev);
979 	if (fwnode_property_read_u8(fwnode, "HotPlugSupportInD3", &val))
980 		return false;
981 
982 	return val == 1;
983 }
984 
985 static bool acpi_pci_power_manageable(struct pci_dev *dev)
986 {
987 	struct acpi_device *adev = ACPI_COMPANION(&dev->dev);
988 	return adev ? acpi_device_power_manageable(adev) : false;
989 }
990 
991 static int acpi_pci_set_power_state(struct pci_dev *dev, pci_power_t state)
992 {
993 	struct acpi_device *adev = ACPI_COMPANION(&dev->dev);
994 	static const u8 state_conv[] = {
995 		[PCI_D0] = ACPI_STATE_D0,
996 		[PCI_D1] = ACPI_STATE_D1,
997 		[PCI_D2] = ACPI_STATE_D2,
998 		[PCI_D3hot] = ACPI_STATE_D3_HOT,
999 		[PCI_D3cold] = ACPI_STATE_D3_COLD,
1000 	};
1001 	int error = -EINVAL;
1002 
1003 	/* If the ACPI device has _EJ0, ignore the device */
1004 	if (!adev || acpi_has_method(adev->handle, "_EJ0"))
1005 		return -ENODEV;
1006 
1007 	switch (state) {
1008 	case PCI_D3cold:
1009 		if (dev_pm_qos_flags(&dev->dev, PM_QOS_FLAG_NO_POWER_OFF) ==
1010 				PM_QOS_FLAGS_ALL) {
1011 			error = -EBUSY;
1012 			break;
1013 		}
1014 		fallthrough;
1015 	case PCI_D0:
1016 	case PCI_D1:
1017 	case PCI_D2:
1018 	case PCI_D3hot:
1019 		error = acpi_device_set_power(adev, state_conv[state]);
1020 	}
1021 
1022 	if (!error)
1023 		pci_dbg(dev, "power state changed by ACPI to %s\n",
1024 			 acpi_power_state_string(state_conv[state]));
1025 
1026 	return error;
1027 }
1028 
1029 static pci_power_t acpi_pci_get_power_state(struct pci_dev *dev)
1030 {
1031 	struct acpi_device *adev = ACPI_COMPANION(&dev->dev);
1032 	static const pci_power_t state_conv[] = {
1033 		[ACPI_STATE_D0]      = PCI_D0,
1034 		[ACPI_STATE_D1]      = PCI_D1,
1035 		[ACPI_STATE_D2]      = PCI_D2,
1036 		[ACPI_STATE_D3_HOT]  = PCI_D3hot,
1037 		[ACPI_STATE_D3_COLD] = PCI_D3cold,
1038 	};
1039 	int state;
1040 
1041 	if (!adev || !acpi_device_power_manageable(adev))
1042 		return PCI_UNKNOWN;
1043 
1044 	state = adev->power.state;
1045 	if (state == ACPI_STATE_UNKNOWN)
1046 		return PCI_UNKNOWN;
1047 
1048 	return state_conv[state];
1049 }
1050 
1051 static void acpi_pci_refresh_power_state(struct pci_dev *dev)
1052 {
1053 	struct acpi_device *adev = ACPI_COMPANION(&dev->dev);
1054 
1055 	if (adev && acpi_device_power_manageable(adev))
1056 		acpi_device_update_power(adev, NULL);
1057 }
1058 
1059 static int acpi_pci_propagate_wakeup(struct pci_bus *bus, bool enable)
1060 {
1061 	while (bus->parent) {
1062 		if (acpi_pm_device_can_wakeup(&bus->self->dev))
1063 			return acpi_pm_set_device_wakeup(&bus->self->dev, enable);
1064 
1065 		bus = bus->parent;
1066 	}
1067 
1068 	/* We have reached the root bus. */
1069 	if (bus->bridge) {
1070 		if (acpi_pm_device_can_wakeup(bus->bridge))
1071 			return acpi_pm_set_device_wakeup(bus->bridge, enable);
1072 	}
1073 	return 0;
1074 }
1075 
1076 static int acpi_pci_wakeup(struct pci_dev *dev, bool enable)
1077 {
1078 	if (acpi_pm_device_can_wakeup(&dev->dev))
1079 		return acpi_pm_set_device_wakeup(&dev->dev, enable);
1080 
1081 	return acpi_pci_propagate_wakeup(dev->bus, enable);
1082 }
1083 
1084 static bool acpi_pci_need_resume(struct pci_dev *dev)
1085 {
1086 	struct acpi_device *adev = ACPI_COMPANION(&dev->dev);
1087 
1088 	/*
1089 	 * In some cases (eg. Samsung 305V4A) leaving a bridge in suspend over
1090 	 * system-wide suspend/resume confuses the platform firmware, so avoid
1091 	 * doing that.  According to Section 16.1.6 of ACPI 6.2, endpoint
1092 	 * devices are expected to be in D3 before invoking the S3 entry path
1093 	 * from the firmware, so they should not be affected by this issue.
1094 	 */
1095 	if (pci_is_bridge(dev) && acpi_target_system_state() != ACPI_STATE_S0)
1096 		return true;
1097 
1098 	if (!adev || !acpi_device_power_manageable(adev))
1099 		return false;
1100 
1101 	if (adev->wakeup.flags.valid &&
1102 	    device_may_wakeup(&dev->dev) != !!adev->wakeup.prepare_count)
1103 		return true;
1104 
1105 	if (acpi_target_system_state() == ACPI_STATE_S0)
1106 		return false;
1107 
1108 	return !!adev->power.flags.dsw_present;
1109 }
1110 
1111 static const struct pci_platform_pm_ops acpi_pci_platform_pm = {
1112 	.bridge_d3 = acpi_pci_bridge_d3,
1113 	.is_manageable = acpi_pci_power_manageable,
1114 	.set_state = acpi_pci_set_power_state,
1115 	.get_state = acpi_pci_get_power_state,
1116 	.refresh_state = acpi_pci_refresh_power_state,
1117 	.choose_state = acpi_pci_choose_state,
1118 	.set_wakeup = acpi_pci_wakeup,
1119 	.need_resume = acpi_pci_need_resume,
1120 };
1121 
1122 void acpi_pci_add_bus(struct pci_bus *bus)
1123 {
1124 	union acpi_object *obj;
1125 	struct pci_host_bridge *bridge;
1126 
1127 	if (acpi_pci_disabled || !bus->bridge || !ACPI_HANDLE(bus->bridge))
1128 		return;
1129 
1130 	acpi_pci_slot_enumerate(bus);
1131 	acpiphp_enumerate_slots(bus);
1132 
1133 	/*
1134 	 * For a host bridge, check its _DSM for function 8 and if
1135 	 * that is available, mark it in pci_host_bridge.
1136 	 */
1137 	if (!pci_is_root_bus(bus))
1138 		return;
1139 
1140 	obj = acpi_evaluate_dsm(ACPI_HANDLE(bus->bridge), &pci_acpi_dsm_guid, 3,
1141 				DSM_PCI_POWER_ON_RESET_DELAY, NULL);
1142 	if (!obj)
1143 		return;
1144 
1145 	if (obj->type == ACPI_TYPE_INTEGER && obj->integer.value == 1) {
1146 		bridge = pci_find_host_bridge(bus);
1147 		bridge->ignore_reset_delay = 1;
1148 	}
1149 	ACPI_FREE(obj);
1150 }
1151 
1152 void acpi_pci_remove_bus(struct pci_bus *bus)
1153 {
1154 	if (acpi_pci_disabled || !bus->bridge)
1155 		return;
1156 
1157 	acpiphp_remove_slots(bus);
1158 	acpi_pci_slot_remove(bus);
1159 }
1160 
1161 /* ACPI bus type */
1162 static struct acpi_device *acpi_pci_find_companion(struct device *dev)
1163 {
1164 	struct pci_dev *pci_dev = to_pci_dev(dev);
1165 	struct acpi_device *adev;
1166 	bool check_children;
1167 	u64 addr;
1168 
1169 	check_children = pci_is_bridge(pci_dev);
1170 	/* Please ref to ACPI spec for the syntax of _ADR */
1171 	addr = (PCI_SLOT(pci_dev->devfn) << 16) | PCI_FUNC(pci_dev->devfn);
1172 	adev = acpi_find_child_device(ACPI_COMPANION(dev->parent), addr,
1173 				      check_children);
1174 
1175 	/*
1176 	 * There may be ACPI device objects in the ACPI namespace that are
1177 	 * children of the device object representing the host bridge, but don't
1178 	 * represent PCI devices.  Both _HID and _ADR may be present for them,
1179 	 * even though that is against the specification (for example, see
1180 	 * Section 6.1 of ACPI 6.3), but in many cases the _ADR returns 0 which
1181 	 * appears to indicate that they should not be taken into consideration
1182 	 * as potential companions of PCI devices on the root bus.
1183 	 *
1184 	 * To catch this special case, disregard the returned device object if
1185 	 * it has a valid _HID, addr is 0 and the PCI device at hand is on the
1186 	 * root bus.
1187 	 */
1188 	if (adev && adev->pnp.type.platform_id && !addr &&
1189 	    pci_is_root_bus(pci_dev->bus))
1190 		return NULL;
1191 
1192 	return adev;
1193 }
1194 
1195 /**
1196  * pci_acpi_optimize_delay - optimize PCI D3 and D3cold delay from ACPI
1197  * @pdev: the PCI device whose delay is to be updated
1198  * @handle: ACPI handle of this device
1199  *
1200  * Update the d3hot_delay and d3cold_delay of a PCI device from the ACPI _DSM
1201  * control method of either the device itself or the PCI host bridge.
1202  *
1203  * Function 8, "Reset Delay," applies to the entire hierarchy below a PCI
1204  * host bridge.  If it returns one, the OS may assume that all devices in
1205  * the hierarchy have already completed power-on reset delays.
1206  *
1207  * Function 9, "Device Readiness Durations," applies only to the object
1208  * where it is located.  It returns delay durations required after various
1209  * events if the device requires less time than the spec requires.  Delays
1210  * from this function take precedence over the Reset Delay function.
1211  *
1212  * These _DSM functions are defined by the draft ECN of January 28, 2014,
1213  * titled "ACPI additions for FW latency optimizations."
1214  */
1215 static void pci_acpi_optimize_delay(struct pci_dev *pdev,
1216 				    acpi_handle handle)
1217 {
1218 	struct pci_host_bridge *bridge = pci_find_host_bridge(pdev->bus);
1219 	int value;
1220 	union acpi_object *obj, *elements;
1221 
1222 	if (bridge->ignore_reset_delay)
1223 		pdev->d3cold_delay = 0;
1224 
1225 	obj = acpi_evaluate_dsm(handle, &pci_acpi_dsm_guid, 3,
1226 				DSM_PCI_DEVICE_READINESS_DURATIONS, NULL);
1227 	if (!obj)
1228 		return;
1229 
1230 	if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 5) {
1231 		elements = obj->package.elements;
1232 		if (elements[0].type == ACPI_TYPE_INTEGER) {
1233 			value = (int)elements[0].integer.value / 1000;
1234 			if (value < PCI_PM_D3COLD_WAIT)
1235 				pdev->d3cold_delay = value;
1236 		}
1237 		if (elements[3].type == ACPI_TYPE_INTEGER) {
1238 			value = (int)elements[3].integer.value / 1000;
1239 			if (value < PCI_PM_D3HOT_WAIT)
1240 				pdev->d3hot_delay = value;
1241 		}
1242 	}
1243 	ACPI_FREE(obj);
1244 }
1245 
1246 static void pci_acpi_set_external_facing(struct pci_dev *dev)
1247 {
1248 	u8 val;
1249 
1250 	if (pci_pcie_type(dev) != PCI_EXP_TYPE_ROOT_PORT)
1251 		return;
1252 	if (device_property_read_u8(&dev->dev, "ExternalFacingPort", &val))
1253 		return;
1254 
1255 	/*
1256 	 * These root ports expose PCIe (including DMA) outside of the
1257 	 * system.  Everything downstream from them is external.
1258 	 */
1259 	if (val)
1260 		dev->external_facing = 1;
1261 }
1262 
1263 static void pci_acpi_setup(struct device *dev)
1264 {
1265 	struct pci_dev *pci_dev = to_pci_dev(dev);
1266 	struct acpi_device *adev = ACPI_COMPANION(dev);
1267 
1268 	if (!adev)
1269 		return;
1270 
1271 	pci_acpi_optimize_delay(pci_dev, adev->handle);
1272 	pci_acpi_set_external_facing(pci_dev);
1273 	pci_acpi_add_edr_notifier(pci_dev);
1274 
1275 	pci_acpi_add_pm_notifier(adev, pci_dev);
1276 	if (!adev->wakeup.flags.valid)
1277 		return;
1278 
1279 	device_set_wakeup_capable(dev, true);
1280 	/*
1281 	 * For bridges that can do D3 we enable wake automatically (as
1282 	 * we do for the power management itself in that case). The
1283 	 * reason is that the bridge may have additional methods such as
1284 	 * _DSW that need to be called.
1285 	 */
1286 	if (pci_dev->bridge_d3)
1287 		device_wakeup_enable(dev);
1288 
1289 	acpi_pci_wakeup(pci_dev, false);
1290 	acpi_device_power_add_dependent(adev, dev);
1291 }
1292 
1293 static void pci_acpi_cleanup(struct device *dev)
1294 {
1295 	struct acpi_device *adev = ACPI_COMPANION(dev);
1296 	struct pci_dev *pci_dev = to_pci_dev(dev);
1297 
1298 	if (!adev)
1299 		return;
1300 
1301 	pci_acpi_remove_edr_notifier(pci_dev);
1302 	pci_acpi_remove_pm_notifier(adev);
1303 	if (adev->wakeup.flags.valid) {
1304 		acpi_device_power_remove_dependent(adev, dev);
1305 		if (pci_dev->bridge_d3)
1306 			device_wakeup_disable(dev);
1307 
1308 		device_set_wakeup_capable(dev, false);
1309 	}
1310 }
1311 
1312 static bool pci_acpi_bus_match(struct device *dev)
1313 {
1314 	return dev_is_pci(dev);
1315 }
1316 
1317 static struct acpi_bus_type acpi_pci_bus = {
1318 	.name = "PCI",
1319 	.match = pci_acpi_bus_match,
1320 	.find_companion = acpi_pci_find_companion,
1321 	.setup = pci_acpi_setup,
1322 	.cleanup = pci_acpi_cleanup,
1323 };
1324 
1325 
1326 static struct fwnode_handle *(*pci_msi_get_fwnode_cb)(struct device *dev);
1327 
1328 /**
1329  * pci_msi_register_fwnode_provider - Register callback to retrieve fwnode
1330  * @fn:       Callback matching a device to a fwnode that identifies a PCI
1331  *            MSI domain.
1332  *
1333  * This should be called by irqchip driver, which is the parent of
1334  * the MSI domain to provide callback interface to query fwnode.
1335  */
1336 void
1337 pci_msi_register_fwnode_provider(struct fwnode_handle *(*fn)(struct device *))
1338 {
1339 	pci_msi_get_fwnode_cb = fn;
1340 }
1341 
1342 /**
1343  * pci_host_bridge_acpi_msi_domain - Retrieve MSI domain of a PCI host bridge
1344  * @bus:      The PCI host bridge bus.
1345  *
1346  * This function uses the callback function registered by
1347  * pci_msi_register_fwnode_provider() to retrieve the irq_domain with
1348  * type DOMAIN_BUS_PCI_MSI of the specified host bridge bus.
1349  * This returns NULL on error or when the domain is not found.
1350  */
1351 struct irq_domain *pci_host_bridge_acpi_msi_domain(struct pci_bus *bus)
1352 {
1353 	struct fwnode_handle *fwnode;
1354 
1355 	if (!pci_msi_get_fwnode_cb)
1356 		return NULL;
1357 
1358 	fwnode = pci_msi_get_fwnode_cb(&bus->dev);
1359 	if (!fwnode)
1360 		return NULL;
1361 
1362 	return irq_find_matching_fwnode(fwnode, DOMAIN_BUS_PCI_MSI);
1363 }
1364 
1365 static int __init acpi_pci_init(void)
1366 {
1367 	int ret;
1368 
1369 	if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_MSI) {
1370 		pr_info("ACPI FADT declares the system doesn't support MSI, so disable it\n");
1371 		pci_no_msi();
1372 	}
1373 
1374 	if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) {
1375 		pr_info("ACPI FADT declares the system doesn't support PCIe ASPM, so disable it\n");
1376 		pcie_no_aspm();
1377 	}
1378 
1379 	ret = register_acpi_bus_type(&acpi_pci_bus);
1380 	if (ret)
1381 		return 0;
1382 
1383 	pci_set_platform_pm(&acpi_pci_platform_pm);
1384 	acpi_pci_slot_init();
1385 	acpiphp_init();
1386 
1387 	return 0;
1388 }
1389 arch_initcall(acpi_pci_init);
1390