xref: /openbmc/linux/drivers/pci/pci-acpi.c (revision db66795f)
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
25  * here to PCI-SIG members:
26  * https://members.pcisig.com/wg/PCI-SIG/document/15350
27  */
28 const guid_t pci_acpi_dsm_guid =
29 	GUID_INIT(0xe5c937d0, 0x3553, 0x4d7a,
30 		  0x91, 0x17, 0xea, 0x4d, 0x19, 0xc3, 0x43, 0x4d);
31 
32 #if defined(CONFIG_PCI_QUIRKS) && defined(CONFIG_ARM64)
33 static int acpi_get_rc_addr(struct acpi_device *adev, struct resource *res)
34 {
35 	struct device *dev = &adev->dev;
36 	struct resource_entry *entry;
37 	struct list_head list;
38 	unsigned long flags;
39 	int ret;
40 
41 	INIT_LIST_HEAD(&list);
42 	flags = IORESOURCE_MEM;
43 	ret = acpi_dev_get_resources(adev, &list,
44 				     acpi_dev_filter_resource_type_cb,
45 				     (void *) flags);
46 	if (ret < 0) {
47 		dev_err(dev, "failed to parse _CRS method, error code %d\n",
48 			ret);
49 		return ret;
50 	}
51 
52 	if (ret == 0) {
53 		dev_err(dev, "no IO and memory resources present in _CRS\n");
54 		return -EINVAL;
55 	}
56 
57 	entry = list_first_entry(&list, struct resource_entry, node);
58 	*res = *entry->res;
59 	acpi_dev_free_resource_list(&list);
60 	return 0;
61 }
62 
63 static acpi_status acpi_match_rc(acpi_handle handle, u32 lvl, void *context,
64 				 void **retval)
65 {
66 	u16 *segment = context;
67 	unsigned long long uid;
68 	acpi_status status;
69 
70 	status = acpi_evaluate_integer(handle, METHOD_NAME__UID, NULL, &uid);
71 	if (ACPI_FAILURE(status) || uid != *segment)
72 		return AE_CTRL_DEPTH;
73 
74 	*(acpi_handle *)retval = handle;
75 	return AE_CTRL_TERMINATE;
76 }
77 
78 int acpi_get_rc_resources(struct device *dev, const char *hid, u16 segment,
79 			  struct resource *res)
80 {
81 	struct acpi_device *adev;
82 	acpi_status status;
83 	acpi_handle handle;
84 	int ret;
85 
86 	status = acpi_get_devices(hid, acpi_match_rc, &segment, &handle);
87 	if (ACPI_FAILURE(status)) {
88 		dev_err(dev, "can't find _HID %s device to locate resources\n",
89 			hid);
90 		return -ENODEV;
91 	}
92 
93 	adev = acpi_fetch_acpi_dev(handle);
94 	if (!adev)
95 		return -ENODEV;
96 
97 	ret = acpi_get_rc_addr(adev, res);
98 	if (ret) {
99 		dev_err(dev, "can't get resource from %s\n",
100 			dev_name(&adev->dev));
101 		return ret;
102 	}
103 
104 	return 0;
105 }
106 #endif
107 
108 phys_addr_t acpi_pci_root_get_mcfg_addr(acpi_handle handle)
109 {
110 	acpi_status status = AE_NOT_EXIST;
111 	unsigned long long mcfg_addr;
112 
113 	if (handle)
114 		status = acpi_evaluate_integer(handle, METHOD_NAME__CBA,
115 					       NULL, &mcfg_addr);
116 	if (ACPI_FAILURE(status))
117 		return 0;
118 
119 	return (phys_addr_t)mcfg_addr;
120 }
121 
122 /* _HPX PCI Setting Record (Type 0); same as _HPP */
123 struct hpx_type0 {
124 	u32 revision;		/* Not present in _HPP */
125 	u8  cache_line_size;	/* Not applicable to PCIe */
126 	u8  latency_timer;	/* Not applicable to PCIe */
127 	u8  enable_serr;
128 	u8  enable_perr;
129 };
130 
131 static struct hpx_type0 pci_default_type0 = {
132 	.revision = 1,
133 	.cache_line_size = 8,
134 	.latency_timer = 0x40,
135 	.enable_serr = 0,
136 	.enable_perr = 0,
137 };
138 
139 static void program_hpx_type0(struct pci_dev *dev, struct hpx_type0 *hpx)
140 {
141 	u16 pci_cmd, pci_bctl;
142 
143 	if (!hpx)
144 		hpx = &pci_default_type0;
145 
146 	if (hpx->revision > 1) {
147 		pci_warn(dev, "PCI settings rev %d not supported; using defaults\n",
148 			 hpx->revision);
149 		hpx = &pci_default_type0;
150 	}
151 
152 	pci_write_config_byte(dev, PCI_CACHE_LINE_SIZE, hpx->cache_line_size);
153 	pci_write_config_byte(dev, PCI_LATENCY_TIMER, hpx->latency_timer);
154 	pci_read_config_word(dev, PCI_COMMAND, &pci_cmd);
155 	if (hpx->enable_serr)
156 		pci_cmd |= PCI_COMMAND_SERR;
157 	if (hpx->enable_perr)
158 		pci_cmd |= PCI_COMMAND_PARITY;
159 	pci_write_config_word(dev, PCI_COMMAND, pci_cmd);
160 
161 	/* Program bridge control value */
162 	if ((dev->class >> 8) == PCI_CLASS_BRIDGE_PCI) {
163 		pci_write_config_byte(dev, PCI_SEC_LATENCY_TIMER,
164 				      hpx->latency_timer);
165 		pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &pci_bctl);
166 		if (hpx->enable_perr)
167 			pci_bctl |= PCI_BRIDGE_CTL_PARITY;
168 		pci_write_config_word(dev, PCI_BRIDGE_CONTROL, pci_bctl);
169 	}
170 }
171 
172 static acpi_status decode_type0_hpx_record(union acpi_object *record,
173 					   struct hpx_type0 *hpx0)
174 {
175 	int i;
176 	union acpi_object *fields = record->package.elements;
177 	u32 revision = fields[1].integer.value;
178 
179 	switch (revision) {
180 	case 1:
181 		if (record->package.count != 6)
182 			return AE_ERROR;
183 		for (i = 2; i < 6; i++)
184 			if (fields[i].type != ACPI_TYPE_INTEGER)
185 				return AE_ERROR;
186 		hpx0->revision        = revision;
187 		hpx0->cache_line_size = fields[2].integer.value;
188 		hpx0->latency_timer   = fields[3].integer.value;
189 		hpx0->enable_serr     = fields[4].integer.value;
190 		hpx0->enable_perr     = fields[5].integer.value;
191 		break;
192 	default:
193 		pr_warn("%s: Type 0 Revision %d record not supported\n",
194 		       __func__, revision);
195 		return AE_ERROR;
196 	}
197 	return AE_OK;
198 }
199 
200 /* _HPX PCI-X Setting Record (Type 1) */
201 struct hpx_type1 {
202 	u32 revision;
203 	u8  max_mem_read;
204 	u8  avg_max_split;
205 	u16 tot_max_split;
206 };
207 
208 static void program_hpx_type1(struct pci_dev *dev, struct hpx_type1 *hpx)
209 {
210 	int pos;
211 
212 	if (!hpx)
213 		return;
214 
215 	pos = pci_find_capability(dev, PCI_CAP_ID_PCIX);
216 	if (!pos)
217 		return;
218 
219 	pci_warn(dev, "PCI-X settings not supported\n");
220 }
221 
222 static acpi_status decode_type1_hpx_record(union acpi_object *record,
223 					   struct hpx_type1 *hpx1)
224 {
225 	int i;
226 	union acpi_object *fields = record->package.elements;
227 	u32 revision = fields[1].integer.value;
228 
229 	switch (revision) {
230 	case 1:
231 		if (record->package.count != 5)
232 			return AE_ERROR;
233 		for (i = 2; i < 5; i++)
234 			if (fields[i].type != ACPI_TYPE_INTEGER)
235 				return AE_ERROR;
236 		hpx1->revision      = revision;
237 		hpx1->max_mem_read  = fields[2].integer.value;
238 		hpx1->avg_max_split = fields[3].integer.value;
239 		hpx1->tot_max_split = fields[4].integer.value;
240 		break;
241 	default:
242 		pr_warn("%s: Type 1 Revision %d record not supported\n",
243 		       __func__, revision);
244 		return AE_ERROR;
245 	}
246 	return AE_OK;
247 }
248 
249 static bool pcie_root_rcb_set(struct pci_dev *dev)
250 {
251 	struct pci_dev *rp = pcie_find_root_port(dev);
252 	u16 lnkctl;
253 
254 	if (!rp)
255 		return false;
256 
257 	pcie_capability_read_word(rp, PCI_EXP_LNKCTL, &lnkctl);
258 	if (lnkctl & PCI_EXP_LNKCTL_RCB)
259 		return true;
260 
261 	return false;
262 }
263 
264 /* _HPX PCI Express Setting Record (Type 2) */
265 struct hpx_type2 {
266 	u32 revision;
267 	u32 unc_err_mask_and;
268 	u32 unc_err_mask_or;
269 	u32 unc_err_sever_and;
270 	u32 unc_err_sever_or;
271 	u32 cor_err_mask_and;
272 	u32 cor_err_mask_or;
273 	u32 adv_err_cap_and;
274 	u32 adv_err_cap_or;
275 	u16 pci_exp_devctl_and;
276 	u16 pci_exp_devctl_or;
277 	u16 pci_exp_lnkctl_and;
278 	u16 pci_exp_lnkctl_or;
279 	u32 sec_unc_err_sever_and;
280 	u32 sec_unc_err_sever_or;
281 	u32 sec_unc_err_mask_and;
282 	u32 sec_unc_err_mask_or;
283 };
284 
285 static void program_hpx_type2(struct pci_dev *dev, struct hpx_type2 *hpx)
286 {
287 	int pos;
288 	u32 reg32;
289 
290 	if (!hpx)
291 		return;
292 
293 	if (!pci_is_pcie(dev))
294 		return;
295 
296 	if (hpx->revision > 1) {
297 		pci_warn(dev, "PCIe settings rev %d not supported\n",
298 			 hpx->revision);
299 		return;
300 	}
301 
302 	/*
303 	 * Don't allow _HPX to change MPS or MRRS settings.  We manage
304 	 * those to make sure they're consistent with the rest of the
305 	 * platform.
306 	 */
307 	hpx->pci_exp_devctl_and |= PCI_EXP_DEVCTL_PAYLOAD |
308 				    PCI_EXP_DEVCTL_READRQ;
309 	hpx->pci_exp_devctl_or &= ~(PCI_EXP_DEVCTL_PAYLOAD |
310 				    PCI_EXP_DEVCTL_READRQ);
311 
312 	/* Initialize Device Control Register */
313 	pcie_capability_clear_and_set_word(dev, PCI_EXP_DEVCTL,
314 			~hpx->pci_exp_devctl_and, hpx->pci_exp_devctl_or);
315 
316 	/* Initialize Link Control Register */
317 	if (pcie_cap_has_lnkctl(dev)) {
318 
319 		/*
320 		 * If the Root Port supports Read Completion Boundary of
321 		 * 128, set RCB to 128.  Otherwise, clear it.
322 		 */
323 		hpx->pci_exp_lnkctl_and |= PCI_EXP_LNKCTL_RCB;
324 		hpx->pci_exp_lnkctl_or &= ~PCI_EXP_LNKCTL_RCB;
325 		if (pcie_root_rcb_set(dev))
326 			hpx->pci_exp_lnkctl_or |= PCI_EXP_LNKCTL_RCB;
327 
328 		pcie_capability_clear_and_set_word(dev, PCI_EXP_LNKCTL,
329 			~hpx->pci_exp_lnkctl_and, hpx->pci_exp_lnkctl_or);
330 	}
331 
332 	/* Find Advanced Error Reporting Enhanced Capability */
333 	pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
334 	if (!pos)
335 		return;
336 
337 	/* Initialize Uncorrectable Error Mask Register */
338 	pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_MASK, &reg32);
339 	reg32 = (reg32 & hpx->unc_err_mask_and) | hpx->unc_err_mask_or;
340 	pci_write_config_dword(dev, pos + PCI_ERR_UNCOR_MASK, reg32);
341 
342 	/* Initialize Uncorrectable Error Severity Register */
343 	pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_SEVER, &reg32);
344 	reg32 = (reg32 & hpx->unc_err_sever_and) | hpx->unc_err_sever_or;
345 	pci_write_config_dword(dev, pos + PCI_ERR_UNCOR_SEVER, reg32);
346 
347 	/* Initialize Correctable Error Mask Register */
348 	pci_read_config_dword(dev, pos + PCI_ERR_COR_MASK, &reg32);
349 	reg32 = (reg32 & hpx->cor_err_mask_and) | hpx->cor_err_mask_or;
350 	pci_write_config_dword(dev, pos + PCI_ERR_COR_MASK, reg32);
351 
352 	/* Initialize Advanced Error Capabilities and Control Register */
353 	pci_read_config_dword(dev, pos + PCI_ERR_CAP, &reg32);
354 	reg32 = (reg32 & hpx->adv_err_cap_and) | hpx->adv_err_cap_or;
355 
356 	/* Don't enable ECRC generation or checking if unsupported */
357 	if (!(reg32 & PCI_ERR_CAP_ECRC_GENC))
358 		reg32 &= ~PCI_ERR_CAP_ECRC_GENE;
359 	if (!(reg32 & PCI_ERR_CAP_ECRC_CHKC))
360 		reg32 &= ~PCI_ERR_CAP_ECRC_CHKE;
361 	pci_write_config_dword(dev, pos + PCI_ERR_CAP, reg32);
362 
363 	/*
364 	 * FIXME: The following two registers are not supported yet.
365 	 *
366 	 *   o Secondary Uncorrectable Error Severity Register
367 	 *   o Secondary Uncorrectable Error Mask Register
368 	 */
369 }
370 
371 static acpi_status decode_type2_hpx_record(union acpi_object *record,
372 					   struct hpx_type2 *hpx2)
373 {
374 	int i;
375 	union acpi_object *fields = record->package.elements;
376 	u32 revision = fields[1].integer.value;
377 
378 	switch (revision) {
379 	case 1:
380 		if (record->package.count != 18)
381 			return AE_ERROR;
382 		for (i = 2; i < 18; i++)
383 			if (fields[i].type != ACPI_TYPE_INTEGER)
384 				return AE_ERROR;
385 		hpx2->revision      = revision;
386 		hpx2->unc_err_mask_and      = fields[2].integer.value;
387 		hpx2->unc_err_mask_or       = fields[3].integer.value;
388 		hpx2->unc_err_sever_and     = fields[4].integer.value;
389 		hpx2->unc_err_sever_or      = fields[5].integer.value;
390 		hpx2->cor_err_mask_and      = fields[6].integer.value;
391 		hpx2->cor_err_mask_or       = fields[7].integer.value;
392 		hpx2->adv_err_cap_and       = fields[8].integer.value;
393 		hpx2->adv_err_cap_or        = fields[9].integer.value;
394 		hpx2->pci_exp_devctl_and    = fields[10].integer.value;
395 		hpx2->pci_exp_devctl_or     = fields[11].integer.value;
396 		hpx2->pci_exp_lnkctl_and    = fields[12].integer.value;
397 		hpx2->pci_exp_lnkctl_or     = fields[13].integer.value;
398 		hpx2->sec_unc_err_sever_and = fields[14].integer.value;
399 		hpx2->sec_unc_err_sever_or  = fields[15].integer.value;
400 		hpx2->sec_unc_err_mask_and  = fields[16].integer.value;
401 		hpx2->sec_unc_err_mask_or   = fields[17].integer.value;
402 		break;
403 	default:
404 		pr_warn("%s: Type 2 Revision %d record not supported\n",
405 		       __func__, revision);
406 		return AE_ERROR;
407 	}
408 	return AE_OK;
409 }
410 
411 /* _HPX PCI Express Setting Record (Type 3) */
412 struct hpx_type3 {
413 	u16 device_type;
414 	u16 function_type;
415 	u16 config_space_location;
416 	u16 pci_exp_cap_id;
417 	u16 pci_exp_cap_ver;
418 	u16 pci_exp_vendor_id;
419 	u16 dvsec_id;
420 	u16 dvsec_rev;
421 	u16 match_offset;
422 	u32 match_mask_and;
423 	u32 match_value;
424 	u16 reg_offset;
425 	u32 reg_mask_and;
426 	u32 reg_mask_or;
427 };
428 
429 enum hpx_type3_dev_type {
430 	HPX_TYPE_ENDPOINT	= BIT(0),
431 	HPX_TYPE_LEG_END	= BIT(1),
432 	HPX_TYPE_RC_END		= BIT(2),
433 	HPX_TYPE_RC_EC		= BIT(3),
434 	HPX_TYPE_ROOT_PORT	= BIT(4),
435 	HPX_TYPE_UPSTREAM	= BIT(5),
436 	HPX_TYPE_DOWNSTREAM	= BIT(6),
437 	HPX_TYPE_PCI_BRIDGE	= BIT(7),
438 	HPX_TYPE_PCIE_BRIDGE	= BIT(8),
439 };
440 
441 static u16 hpx3_device_type(struct pci_dev *dev)
442 {
443 	u16 pcie_type = pci_pcie_type(dev);
444 	static const int pcie_to_hpx3_type[] = {
445 		[PCI_EXP_TYPE_ENDPOINT]    = HPX_TYPE_ENDPOINT,
446 		[PCI_EXP_TYPE_LEG_END]     = HPX_TYPE_LEG_END,
447 		[PCI_EXP_TYPE_RC_END]      = HPX_TYPE_RC_END,
448 		[PCI_EXP_TYPE_RC_EC]       = HPX_TYPE_RC_EC,
449 		[PCI_EXP_TYPE_ROOT_PORT]   = HPX_TYPE_ROOT_PORT,
450 		[PCI_EXP_TYPE_UPSTREAM]    = HPX_TYPE_UPSTREAM,
451 		[PCI_EXP_TYPE_DOWNSTREAM]  = HPX_TYPE_DOWNSTREAM,
452 		[PCI_EXP_TYPE_PCI_BRIDGE]  = HPX_TYPE_PCI_BRIDGE,
453 		[PCI_EXP_TYPE_PCIE_BRIDGE] = HPX_TYPE_PCIE_BRIDGE,
454 	};
455 
456 	if (pcie_type >= ARRAY_SIZE(pcie_to_hpx3_type))
457 		return 0;
458 
459 	return pcie_to_hpx3_type[pcie_type];
460 }
461 
462 enum hpx_type3_fn_type {
463 	HPX_FN_NORMAL		= BIT(0),
464 	HPX_FN_SRIOV_PHYS	= BIT(1),
465 	HPX_FN_SRIOV_VIRT	= BIT(2),
466 };
467 
468 static u8 hpx3_function_type(struct pci_dev *dev)
469 {
470 	if (dev->is_virtfn)
471 		return HPX_FN_SRIOV_VIRT;
472 	else if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_SRIOV) > 0)
473 		return HPX_FN_SRIOV_PHYS;
474 	else
475 		return HPX_FN_NORMAL;
476 }
477 
478 static bool hpx3_cap_ver_matches(u8 pcie_cap_id, u8 hpx3_cap_id)
479 {
480 	u8 cap_ver = hpx3_cap_id & 0xf;
481 
482 	if ((hpx3_cap_id & BIT(4)) && cap_ver >= pcie_cap_id)
483 		return true;
484 	else if (cap_ver == pcie_cap_id)
485 		return true;
486 
487 	return false;
488 }
489 
490 enum hpx_type3_cfg_loc {
491 	HPX_CFG_PCICFG		= 0,
492 	HPX_CFG_PCIE_CAP	= 1,
493 	HPX_CFG_PCIE_CAP_EXT	= 2,
494 	HPX_CFG_VEND_CAP	= 3,
495 	HPX_CFG_DVSEC		= 4,
496 	HPX_CFG_MAX,
497 };
498 
499 static void program_hpx_type3_register(struct pci_dev *dev,
500 				       const struct hpx_type3 *reg)
501 {
502 	u32 match_reg, write_reg, header, orig_value;
503 	u16 pos;
504 
505 	if (!(hpx3_device_type(dev) & reg->device_type))
506 		return;
507 
508 	if (!(hpx3_function_type(dev) & reg->function_type))
509 		return;
510 
511 	switch (reg->config_space_location) {
512 	case HPX_CFG_PCICFG:
513 		pos = 0;
514 		break;
515 	case HPX_CFG_PCIE_CAP:
516 		pos = pci_find_capability(dev, reg->pci_exp_cap_id);
517 		if (pos == 0)
518 			return;
519 
520 		break;
521 	case HPX_CFG_PCIE_CAP_EXT:
522 		pos = pci_find_ext_capability(dev, reg->pci_exp_cap_id);
523 		if (pos == 0)
524 			return;
525 
526 		pci_read_config_dword(dev, pos, &header);
527 		if (!hpx3_cap_ver_matches(PCI_EXT_CAP_VER(header),
528 					  reg->pci_exp_cap_ver))
529 			return;
530 
531 		break;
532 	case HPX_CFG_VEND_CAP:
533 	case HPX_CFG_DVSEC:
534 	default:
535 		pci_warn(dev, "Encountered _HPX type 3 with unsupported config space location");
536 		return;
537 	}
538 
539 	pci_read_config_dword(dev, pos + reg->match_offset, &match_reg);
540 
541 	if ((match_reg & reg->match_mask_and) != reg->match_value)
542 		return;
543 
544 	pci_read_config_dword(dev, pos + reg->reg_offset, &write_reg);
545 	orig_value = write_reg;
546 	write_reg &= reg->reg_mask_and;
547 	write_reg |= reg->reg_mask_or;
548 
549 	if (orig_value == write_reg)
550 		return;
551 
552 	pci_write_config_dword(dev, pos + reg->reg_offset, write_reg);
553 
554 	pci_dbg(dev, "Applied _HPX3 at [0x%x]: 0x%08x -> 0x%08x",
555 		pos, orig_value, write_reg);
556 }
557 
558 static void program_hpx_type3(struct pci_dev *dev, struct hpx_type3 *hpx)
559 {
560 	if (!hpx)
561 		return;
562 
563 	if (!pci_is_pcie(dev))
564 		return;
565 
566 	program_hpx_type3_register(dev, hpx);
567 }
568 
569 static void parse_hpx3_register(struct hpx_type3 *hpx3_reg,
570 				union acpi_object *reg_fields)
571 {
572 	hpx3_reg->device_type            = reg_fields[0].integer.value;
573 	hpx3_reg->function_type          = reg_fields[1].integer.value;
574 	hpx3_reg->config_space_location  = reg_fields[2].integer.value;
575 	hpx3_reg->pci_exp_cap_id         = reg_fields[3].integer.value;
576 	hpx3_reg->pci_exp_cap_ver        = reg_fields[4].integer.value;
577 	hpx3_reg->pci_exp_vendor_id      = reg_fields[5].integer.value;
578 	hpx3_reg->dvsec_id               = reg_fields[6].integer.value;
579 	hpx3_reg->dvsec_rev              = reg_fields[7].integer.value;
580 	hpx3_reg->match_offset           = reg_fields[8].integer.value;
581 	hpx3_reg->match_mask_and         = reg_fields[9].integer.value;
582 	hpx3_reg->match_value            = reg_fields[10].integer.value;
583 	hpx3_reg->reg_offset             = reg_fields[11].integer.value;
584 	hpx3_reg->reg_mask_and           = reg_fields[12].integer.value;
585 	hpx3_reg->reg_mask_or            = reg_fields[13].integer.value;
586 }
587 
588 static acpi_status program_type3_hpx_record(struct pci_dev *dev,
589 					   union acpi_object *record)
590 {
591 	union acpi_object *fields = record->package.elements;
592 	u32 desc_count, expected_length, revision;
593 	union acpi_object *reg_fields;
594 	struct hpx_type3 hpx3;
595 	int i;
596 
597 	revision = fields[1].integer.value;
598 	switch (revision) {
599 	case 1:
600 		desc_count = fields[2].integer.value;
601 		expected_length = 3 + desc_count * 14;
602 
603 		if (record->package.count != expected_length)
604 			return AE_ERROR;
605 
606 		for (i = 2; i < expected_length; i++)
607 			if (fields[i].type != ACPI_TYPE_INTEGER)
608 				return AE_ERROR;
609 
610 		for (i = 0; i < desc_count; i++) {
611 			reg_fields = fields + 3 + i * 14;
612 			parse_hpx3_register(&hpx3, reg_fields);
613 			program_hpx_type3(dev, &hpx3);
614 		}
615 
616 		break;
617 	default:
618 		printk(KERN_WARNING
619 			"%s: Type 3 Revision %d record not supported\n",
620 			__func__, revision);
621 		return AE_ERROR;
622 	}
623 	return AE_OK;
624 }
625 
626 static acpi_status acpi_run_hpx(struct pci_dev *dev, acpi_handle handle)
627 {
628 	acpi_status status;
629 	struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
630 	union acpi_object *package, *record, *fields;
631 	struct hpx_type0 hpx0;
632 	struct hpx_type1 hpx1;
633 	struct hpx_type2 hpx2;
634 	u32 type;
635 	int i;
636 
637 	status = acpi_evaluate_object(handle, "_HPX", NULL, &buffer);
638 	if (ACPI_FAILURE(status))
639 		return status;
640 
641 	package = (union acpi_object *)buffer.pointer;
642 	if (package->type != ACPI_TYPE_PACKAGE) {
643 		status = AE_ERROR;
644 		goto exit;
645 	}
646 
647 	for (i = 0; i < package->package.count; i++) {
648 		record = &package->package.elements[i];
649 		if (record->type != ACPI_TYPE_PACKAGE) {
650 			status = AE_ERROR;
651 			goto exit;
652 		}
653 
654 		fields = record->package.elements;
655 		if (fields[0].type != ACPI_TYPE_INTEGER ||
656 		    fields[1].type != ACPI_TYPE_INTEGER) {
657 			status = AE_ERROR;
658 			goto exit;
659 		}
660 
661 		type = fields[0].integer.value;
662 		switch (type) {
663 		case 0:
664 			memset(&hpx0, 0, sizeof(hpx0));
665 			status = decode_type0_hpx_record(record, &hpx0);
666 			if (ACPI_FAILURE(status))
667 				goto exit;
668 			program_hpx_type0(dev, &hpx0);
669 			break;
670 		case 1:
671 			memset(&hpx1, 0, sizeof(hpx1));
672 			status = decode_type1_hpx_record(record, &hpx1);
673 			if (ACPI_FAILURE(status))
674 				goto exit;
675 			program_hpx_type1(dev, &hpx1);
676 			break;
677 		case 2:
678 			memset(&hpx2, 0, sizeof(hpx2));
679 			status = decode_type2_hpx_record(record, &hpx2);
680 			if (ACPI_FAILURE(status))
681 				goto exit;
682 			program_hpx_type2(dev, &hpx2);
683 			break;
684 		case 3:
685 			status = program_type3_hpx_record(dev, record);
686 			if (ACPI_FAILURE(status))
687 				goto exit;
688 			break;
689 		default:
690 			pr_err("%s: Type %d record not supported\n",
691 			       __func__, type);
692 			status = AE_ERROR;
693 			goto exit;
694 		}
695 	}
696  exit:
697 	kfree(buffer.pointer);
698 	return status;
699 }
700 
701 static acpi_status acpi_run_hpp(struct pci_dev *dev, acpi_handle handle)
702 {
703 	acpi_status status;
704 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
705 	union acpi_object *package, *fields;
706 	struct hpx_type0 hpx0;
707 	int i;
708 
709 	memset(&hpx0, 0, sizeof(hpx0));
710 
711 	status = acpi_evaluate_object(handle, "_HPP", NULL, &buffer);
712 	if (ACPI_FAILURE(status))
713 		return status;
714 
715 	package = (union acpi_object *) buffer.pointer;
716 	if (package->type != ACPI_TYPE_PACKAGE ||
717 	    package->package.count != 4) {
718 		status = AE_ERROR;
719 		goto exit;
720 	}
721 
722 	fields = package->package.elements;
723 	for (i = 0; i < 4; i++) {
724 		if (fields[i].type != ACPI_TYPE_INTEGER) {
725 			status = AE_ERROR;
726 			goto exit;
727 		}
728 	}
729 
730 	hpx0.revision        = 1;
731 	hpx0.cache_line_size = fields[0].integer.value;
732 	hpx0.latency_timer   = fields[1].integer.value;
733 	hpx0.enable_serr     = fields[2].integer.value;
734 	hpx0.enable_perr     = fields[3].integer.value;
735 
736 	program_hpx_type0(dev, &hpx0);
737 
738 exit:
739 	kfree(buffer.pointer);
740 	return status;
741 }
742 
743 /* pci_acpi_program_hp_params
744  *
745  * @dev - the pci_dev for which we want parameters
746  */
747 int pci_acpi_program_hp_params(struct pci_dev *dev)
748 {
749 	acpi_status status;
750 	acpi_handle handle, phandle;
751 	struct pci_bus *pbus;
752 
753 	if (acpi_pci_disabled)
754 		return -ENODEV;
755 
756 	handle = NULL;
757 	for (pbus = dev->bus; pbus; pbus = pbus->parent) {
758 		handle = acpi_pci_get_bridge_handle(pbus);
759 		if (handle)
760 			break;
761 	}
762 
763 	/*
764 	 * _HPP settings apply to all child buses, until another _HPP is
765 	 * encountered. If we don't find an _HPP for the input pci dev,
766 	 * look for it in the parent device scope since that would apply to
767 	 * this pci dev.
768 	 */
769 	while (handle) {
770 		status = acpi_run_hpx(dev, handle);
771 		if (ACPI_SUCCESS(status))
772 			return 0;
773 		status = acpi_run_hpp(dev, handle);
774 		if (ACPI_SUCCESS(status))
775 			return 0;
776 		if (acpi_is_root_bridge(handle))
777 			break;
778 		status = acpi_get_parent(handle, &phandle);
779 		if (ACPI_FAILURE(status))
780 			break;
781 		handle = phandle;
782 	}
783 	return -ENODEV;
784 }
785 
786 /**
787  * pciehp_is_native - Check whether a hotplug port is handled by the OS
788  * @bridge: Hotplug port to check
789  *
790  * Returns true if the given @bridge is handled by the native PCIe hotplug
791  * driver.
792  */
793 bool pciehp_is_native(struct pci_dev *bridge)
794 {
795 	const struct pci_host_bridge *host;
796 	u32 slot_cap;
797 
798 	if (!IS_ENABLED(CONFIG_HOTPLUG_PCI_PCIE))
799 		return false;
800 
801 	pcie_capability_read_dword(bridge, PCI_EXP_SLTCAP, &slot_cap);
802 	if (!(slot_cap & PCI_EXP_SLTCAP_HPC))
803 		return false;
804 
805 	if (pcie_ports_native)
806 		return true;
807 
808 	host = pci_find_host_bridge(bridge->bus);
809 	return host->native_pcie_hotplug;
810 }
811 
812 /**
813  * shpchp_is_native - Check whether a hotplug port is handled by the OS
814  * @bridge: Hotplug port to check
815  *
816  * Returns true if the given @bridge is handled by the native SHPC hotplug
817  * driver.
818  */
819 bool shpchp_is_native(struct pci_dev *bridge)
820 {
821 	return bridge->shpc_managed;
822 }
823 
824 /**
825  * pci_acpi_wake_bus - Root bus wakeup notification fork function.
826  * @context: Device wakeup context.
827  */
828 static void pci_acpi_wake_bus(struct acpi_device_wakeup_context *context)
829 {
830 	struct acpi_device *adev;
831 	struct acpi_pci_root *root;
832 
833 	adev = container_of(context, struct acpi_device, wakeup.context);
834 	root = acpi_driver_data(adev);
835 	pci_pme_wakeup_bus(root->bus);
836 }
837 
838 /**
839  * pci_acpi_wake_dev - PCI device wakeup notification work function.
840  * @context: Device wakeup context.
841  */
842 static void pci_acpi_wake_dev(struct acpi_device_wakeup_context *context)
843 {
844 	struct pci_dev *pci_dev;
845 
846 	pci_dev = to_pci_dev(context->dev);
847 
848 	if (pci_dev->pme_poll)
849 		pci_dev->pme_poll = false;
850 
851 	if (pci_dev->current_state == PCI_D3cold) {
852 		pci_wakeup_event(pci_dev);
853 		pm_request_resume(&pci_dev->dev);
854 		return;
855 	}
856 
857 	/* Clear PME Status if set. */
858 	if (pci_dev->pme_support)
859 		pci_check_pme_status(pci_dev);
860 
861 	pci_wakeup_event(pci_dev);
862 	pm_request_resume(&pci_dev->dev);
863 
864 	pci_pme_wakeup_bus(pci_dev->subordinate);
865 }
866 
867 /**
868  * pci_acpi_add_bus_pm_notifier - Register PM notifier for root PCI bus.
869  * @dev: PCI root bridge ACPI device.
870  */
871 acpi_status pci_acpi_add_bus_pm_notifier(struct acpi_device *dev)
872 {
873 	return acpi_add_pm_notifier(dev, NULL, pci_acpi_wake_bus);
874 }
875 
876 /**
877  * pci_acpi_add_pm_notifier - Register PM notifier for given PCI device.
878  * @dev: ACPI device to add the notifier for.
879  * @pci_dev: PCI device to check for the PME status if an event is signaled.
880  */
881 acpi_status pci_acpi_add_pm_notifier(struct acpi_device *dev,
882 				     struct pci_dev *pci_dev)
883 {
884 	return acpi_add_pm_notifier(dev, &pci_dev->dev, pci_acpi_wake_dev);
885 }
886 
887 /*
888  * _SxD returns the D-state with the highest power
889  * (lowest D-state number) supported in the S-state "x".
890  *
891  * If the devices does not have a _PRW
892  * (Power Resources for Wake) supporting system wakeup from "x"
893  * then the OS is free to choose a lower power (higher number
894  * D-state) than the return value from _SxD.
895  *
896  * But if _PRW is enabled at S-state "x", the OS
897  * must not choose a power lower than _SxD --
898  * unless the device has an _SxW method specifying
899  * the lowest power (highest D-state number) the device
900  * may enter while still able to wake the system.
901  *
902  * ie. depending on global OS policy:
903  *
904  * if (_PRW at S-state x)
905  *	choose from highest power _SxD to lowest power _SxW
906  * else // no _PRW at S-state x
907  *	choose highest power _SxD or any lower power
908  */
909 
910 pci_power_t acpi_pci_choose_state(struct pci_dev *pdev)
911 {
912 	int acpi_state, d_max;
913 
914 	if (pdev->no_d3cold)
915 		d_max = ACPI_STATE_D3_HOT;
916 	else
917 		d_max = ACPI_STATE_D3_COLD;
918 	acpi_state = acpi_pm_device_sleep_state(&pdev->dev, NULL, d_max);
919 	if (acpi_state < 0)
920 		return PCI_POWER_ERROR;
921 
922 	switch (acpi_state) {
923 	case ACPI_STATE_D0:
924 		return PCI_D0;
925 	case ACPI_STATE_D1:
926 		return PCI_D1;
927 	case ACPI_STATE_D2:
928 		return PCI_D2;
929 	case ACPI_STATE_D3_HOT:
930 		return PCI_D3hot;
931 	case ACPI_STATE_D3_COLD:
932 		return PCI_D3cold;
933 	}
934 	return PCI_POWER_ERROR;
935 }
936 
937 static struct acpi_device *acpi_pci_find_companion(struct device *dev);
938 
939 void pci_set_acpi_fwnode(struct pci_dev *dev)
940 {
941 	if (!dev_fwnode(&dev->dev) && !pci_dev_is_added(dev))
942 		ACPI_COMPANION_SET(&dev->dev,
943 				   acpi_pci_find_companion(&dev->dev));
944 }
945 
946 /**
947  * pci_dev_acpi_reset - do a function level reset using _RST method
948  * @dev: device to reset
949  * @probe: if true, return 0 if device supports _RST
950  */
951 int pci_dev_acpi_reset(struct pci_dev *dev, bool probe)
952 {
953 	acpi_handle handle = ACPI_HANDLE(&dev->dev);
954 
955 	if (!handle || !acpi_has_method(handle, "_RST"))
956 		return -ENOTTY;
957 
958 	if (probe)
959 		return 0;
960 
961 	if (ACPI_FAILURE(acpi_evaluate_object(handle, "_RST", NULL, NULL))) {
962 		pci_warn(dev, "ACPI _RST failed\n");
963 		return -ENOTTY;
964 	}
965 
966 	return 0;
967 }
968 
969 bool acpi_pci_power_manageable(struct pci_dev *dev)
970 {
971 	struct acpi_device *adev = ACPI_COMPANION(&dev->dev);
972 
973 	return adev && acpi_device_power_manageable(adev);
974 }
975 
976 bool acpi_pci_bridge_d3(struct pci_dev *dev)
977 {
978 	struct pci_dev *rpdev;
979 	struct acpi_device *adev, *rpadev;
980 	const union acpi_object *obj;
981 
982 	if (acpi_pci_disabled || !dev->is_hotplug_bridge)
983 		return false;
984 
985 	adev = ACPI_COMPANION(&dev->dev);
986 	if (adev) {
987 		/*
988 		 * If the bridge has _S0W, whether or not it can go into D3
989 		 * depends on what is returned by that object.  In particular,
990 		 * if the power state returned by _S0W is D2 or shallower,
991 		 * entering D3 should not be allowed.
992 		 */
993 		if (acpi_dev_power_state_for_wake(adev) <= ACPI_STATE_D2)
994 			return false;
995 
996 		/*
997 		 * Otherwise, assume that the bridge can enter D3 so long as it
998 		 * is power-manageable via ACPI.
999 		 */
1000 		if (acpi_device_power_manageable(adev))
1001 			return true;
1002 	}
1003 
1004 	rpdev = pcie_find_root_port(dev);
1005 	if (!rpdev)
1006 		return false;
1007 
1008 	if (rpdev == dev)
1009 		rpadev = adev;
1010 	else
1011 		rpadev = ACPI_COMPANION(&rpdev->dev);
1012 
1013 	if (!rpadev)
1014 		return false;
1015 
1016 	/*
1017 	 * If the Root Port cannot signal wakeup signals at all, i.e., it
1018 	 * doesn't supply a wakeup GPE via _PRW, it cannot signal hotplug
1019 	 * events from low-power states including D3hot and D3cold.
1020 	 */
1021 	if (!rpadev->wakeup.flags.valid)
1022 		return false;
1023 
1024 	/*
1025 	 * In the bridge-below-a-Root-Port case, evaluate _S0W for the Root Port
1026 	 * to verify whether or not it can signal wakeup from D3.
1027 	 */
1028 	if (rpadev != adev &&
1029 	    acpi_dev_power_state_for_wake(rpadev) <= ACPI_STATE_D2)
1030 		return false;
1031 
1032 	/*
1033 	 * The "HotPlugSupportInD3" property in a Root Port _DSD indicates
1034 	 * the Port can signal hotplug events while in D3.  We assume any
1035 	 * bridges *below* that Root Port can also signal hotplug events
1036 	 * while in D3.
1037 	 */
1038 	if (!acpi_dev_get_property(rpadev, "HotPlugSupportInD3",
1039 				   ACPI_TYPE_INTEGER, &obj) &&
1040 	    obj->integer.value == 1)
1041 		return true;
1042 
1043 	return false;
1044 }
1045 
1046 static void acpi_pci_config_space_access(struct pci_dev *dev, bool enable)
1047 {
1048 	int val = enable ? ACPI_REG_CONNECT : ACPI_REG_DISCONNECT;
1049 	int ret = acpi_evaluate_reg(ACPI_HANDLE(&dev->dev),
1050 				    ACPI_ADR_SPACE_PCI_CONFIG, val);
1051 	if (ret)
1052 		pci_dbg(dev, "ACPI _REG %s evaluation failed (%d)\n",
1053 			enable ? "connect" : "disconnect", ret);
1054 }
1055 
1056 int acpi_pci_set_power_state(struct pci_dev *dev, pci_power_t state)
1057 {
1058 	struct acpi_device *adev = ACPI_COMPANION(&dev->dev);
1059 	static const u8 state_conv[] = {
1060 		[PCI_D0] = ACPI_STATE_D0,
1061 		[PCI_D1] = ACPI_STATE_D1,
1062 		[PCI_D2] = ACPI_STATE_D2,
1063 		[PCI_D3hot] = ACPI_STATE_D3_HOT,
1064 		[PCI_D3cold] = ACPI_STATE_D3_COLD,
1065 	};
1066 	int error;
1067 
1068 	/* If the ACPI device has _EJ0, ignore the device */
1069 	if (!adev || acpi_has_method(adev->handle, "_EJ0"))
1070 		return -ENODEV;
1071 
1072 	switch (state) {
1073 	case PCI_D0:
1074 	case PCI_D1:
1075 	case PCI_D2:
1076 	case PCI_D3hot:
1077 	case PCI_D3cold:
1078 		break;
1079 	default:
1080 		return -EINVAL;
1081 	}
1082 
1083 	if (state == PCI_D3cold) {
1084 		if (dev_pm_qos_flags(&dev->dev, PM_QOS_FLAG_NO_POWER_OFF) ==
1085 				PM_QOS_FLAGS_ALL)
1086 			return -EBUSY;
1087 
1088 		/* Notify AML lack of PCI config space availability */
1089 		acpi_pci_config_space_access(dev, false);
1090 	}
1091 
1092 	error = acpi_device_set_power(adev, state_conv[state]);
1093 	if (error)
1094 		return error;
1095 
1096 	pci_dbg(dev, "power state changed by ACPI to %s\n",
1097 	        acpi_power_state_string(adev->power.state));
1098 
1099 	/*
1100 	 * Notify AML of PCI config space availability.  Config space is
1101 	 * accessible in all states except D3cold; the only transitions
1102 	 * that change availability are transitions to D3cold and from
1103 	 * D3cold to D0.
1104 	 */
1105 	if (state == PCI_D0)
1106 		acpi_pci_config_space_access(dev, true);
1107 
1108 	return 0;
1109 }
1110 
1111 pci_power_t acpi_pci_get_power_state(struct pci_dev *dev)
1112 {
1113 	struct acpi_device *adev = ACPI_COMPANION(&dev->dev);
1114 	static const pci_power_t state_conv[] = {
1115 		[ACPI_STATE_D0]      = PCI_D0,
1116 		[ACPI_STATE_D1]      = PCI_D1,
1117 		[ACPI_STATE_D2]      = PCI_D2,
1118 		[ACPI_STATE_D3_HOT]  = PCI_D3hot,
1119 		[ACPI_STATE_D3_COLD] = PCI_D3cold,
1120 	};
1121 	int state;
1122 
1123 	if (!adev || !acpi_device_power_manageable(adev))
1124 		return PCI_UNKNOWN;
1125 
1126 	state = adev->power.state;
1127 	if (state == ACPI_STATE_UNKNOWN)
1128 		return PCI_UNKNOWN;
1129 
1130 	return state_conv[state];
1131 }
1132 
1133 void acpi_pci_refresh_power_state(struct pci_dev *dev)
1134 {
1135 	struct acpi_device *adev = ACPI_COMPANION(&dev->dev);
1136 
1137 	if (adev && acpi_device_power_manageable(adev))
1138 		acpi_device_update_power(adev, NULL);
1139 }
1140 
1141 static int acpi_pci_propagate_wakeup(struct pci_bus *bus, bool enable)
1142 {
1143 	while (bus->parent) {
1144 		if (acpi_pm_device_can_wakeup(&bus->self->dev))
1145 			return acpi_pm_set_device_wakeup(&bus->self->dev, enable);
1146 
1147 		bus = bus->parent;
1148 	}
1149 
1150 	/* We have reached the root bus. */
1151 	if (bus->bridge) {
1152 		if (acpi_pm_device_can_wakeup(bus->bridge))
1153 			return acpi_pm_set_device_wakeup(bus->bridge, enable);
1154 	}
1155 	return 0;
1156 }
1157 
1158 int acpi_pci_wakeup(struct pci_dev *dev, bool enable)
1159 {
1160 	if (acpi_pci_disabled)
1161 		return 0;
1162 
1163 	if (acpi_pm_device_can_wakeup(&dev->dev))
1164 		return acpi_pm_set_device_wakeup(&dev->dev, enable);
1165 
1166 	return acpi_pci_propagate_wakeup(dev->bus, enable);
1167 }
1168 
1169 bool acpi_pci_need_resume(struct pci_dev *dev)
1170 {
1171 	struct acpi_device *adev;
1172 
1173 	if (acpi_pci_disabled)
1174 		return false;
1175 
1176 	/*
1177 	 * In some cases (eg. Samsung 305V4A) leaving a bridge in suspend over
1178 	 * system-wide suspend/resume confuses the platform firmware, so avoid
1179 	 * doing that.  According to Section 16.1.6 of ACPI 6.2, endpoint
1180 	 * devices are expected to be in D3 before invoking the S3 entry path
1181 	 * from the firmware, so they should not be affected by this issue.
1182 	 */
1183 	if (pci_is_bridge(dev) && acpi_target_system_state() != ACPI_STATE_S0)
1184 		return true;
1185 
1186 	adev = ACPI_COMPANION(&dev->dev);
1187 	if (!adev || !acpi_device_power_manageable(adev))
1188 		return false;
1189 
1190 	if (adev->wakeup.flags.valid &&
1191 	    device_may_wakeup(&dev->dev) != !!adev->wakeup.prepare_count)
1192 		return true;
1193 
1194 	if (acpi_target_system_state() == ACPI_STATE_S0)
1195 		return false;
1196 
1197 	return !!adev->power.flags.dsw_present;
1198 }
1199 
1200 void acpi_pci_add_bus(struct pci_bus *bus)
1201 {
1202 	union acpi_object *obj;
1203 	struct pci_host_bridge *bridge;
1204 
1205 	if (acpi_pci_disabled || !bus->bridge || !ACPI_HANDLE(bus->bridge))
1206 		return;
1207 
1208 	acpi_pci_slot_enumerate(bus);
1209 	acpiphp_enumerate_slots(bus);
1210 
1211 	/*
1212 	 * For a host bridge, check its _DSM for function 8 and if
1213 	 * that is available, mark it in pci_host_bridge.
1214 	 */
1215 	if (!pci_is_root_bus(bus))
1216 		return;
1217 
1218 	obj = acpi_evaluate_dsm(ACPI_HANDLE(bus->bridge), &pci_acpi_dsm_guid, 3,
1219 				DSM_PCI_POWER_ON_RESET_DELAY, NULL);
1220 	if (!obj)
1221 		return;
1222 
1223 	if (obj->type == ACPI_TYPE_INTEGER && obj->integer.value == 1) {
1224 		bridge = pci_find_host_bridge(bus);
1225 		bridge->ignore_reset_delay = 1;
1226 	}
1227 	ACPI_FREE(obj);
1228 }
1229 
1230 void acpi_pci_remove_bus(struct pci_bus *bus)
1231 {
1232 	if (acpi_pci_disabled || !bus->bridge)
1233 		return;
1234 
1235 	acpiphp_remove_slots(bus);
1236 	acpi_pci_slot_remove(bus);
1237 }
1238 
1239 /* ACPI bus type */
1240 
1241 
1242 static DECLARE_RWSEM(pci_acpi_companion_lookup_sem);
1243 static struct acpi_device *(*pci_acpi_find_companion_hook)(struct pci_dev *);
1244 
1245 /**
1246  * pci_acpi_set_companion_lookup_hook - Set ACPI companion lookup callback.
1247  * @func: ACPI companion lookup callback pointer or NULL.
1248  *
1249  * Set a special ACPI companion lookup callback for PCI devices whose companion
1250  * objects in the ACPI namespace have _ADR with non-standard bus-device-function
1251  * encodings.
1252  *
1253  * Return 0 on success or a negative error code on failure (in which case no
1254  * changes are made).
1255  *
1256  * The caller is responsible for the appropriate ordering of the invocations of
1257  * this function with respect to the enumeration of the PCI devices needing the
1258  * callback installed by it.
1259  */
1260 int pci_acpi_set_companion_lookup_hook(struct acpi_device *(*func)(struct pci_dev *))
1261 {
1262 	int ret;
1263 
1264 	if (!func)
1265 		return -EINVAL;
1266 
1267 	down_write(&pci_acpi_companion_lookup_sem);
1268 
1269 	if (pci_acpi_find_companion_hook) {
1270 		ret = -EBUSY;
1271 	} else {
1272 		pci_acpi_find_companion_hook = func;
1273 		ret = 0;
1274 	}
1275 
1276 	up_write(&pci_acpi_companion_lookup_sem);
1277 
1278 	return ret;
1279 }
1280 EXPORT_SYMBOL_GPL(pci_acpi_set_companion_lookup_hook);
1281 
1282 /**
1283  * pci_acpi_clear_companion_lookup_hook - Clear ACPI companion lookup callback.
1284  *
1285  * Clear the special ACPI companion lookup callback previously set by
1286  * pci_acpi_set_companion_lookup_hook().  Block until the last running instance
1287  * of the callback returns before clearing it.
1288  *
1289  * The caller is responsible for the appropriate ordering of the invocations of
1290  * this function with respect to the enumeration of the PCI devices needing the
1291  * callback cleared by it.
1292  */
1293 void pci_acpi_clear_companion_lookup_hook(void)
1294 {
1295 	down_write(&pci_acpi_companion_lookup_sem);
1296 
1297 	pci_acpi_find_companion_hook = NULL;
1298 
1299 	up_write(&pci_acpi_companion_lookup_sem);
1300 }
1301 EXPORT_SYMBOL_GPL(pci_acpi_clear_companion_lookup_hook);
1302 
1303 static struct acpi_device *acpi_pci_find_companion(struct device *dev)
1304 {
1305 	struct pci_dev *pci_dev = to_pci_dev(dev);
1306 	struct acpi_device *adev;
1307 	bool check_children;
1308 	u64 addr;
1309 
1310 	if (!dev->parent)
1311 		return NULL;
1312 
1313 	down_read(&pci_acpi_companion_lookup_sem);
1314 
1315 	adev = pci_acpi_find_companion_hook ?
1316 		pci_acpi_find_companion_hook(pci_dev) : NULL;
1317 
1318 	up_read(&pci_acpi_companion_lookup_sem);
1319 
1320 	if (adev)
1321 		return adev;
1322 
1323 	check_children = pci_is_bridge(pci_dev);
1324 	/* Please ref to ACPI spec for the syntax of _ADR */
1325 	addr = (PCI_SLOT(pci_dev->devfn) << 16) | PCI_FUNC(pci_dev->devfn);
1326 	adev = acpi_find_child_device(ACPI_COMPANION(dev->parent), addr,
1327 				      check_children);
1328 
1329 	/*
1330 	 * There may be ACPI device objects in the ACPI namespace that are
1331 	 * children of the device object representing the host bridge, but don't
1332 	 * represent PCI devices.  Both _HID and _ADR may be present for them,
1333 	 * even though that is against the specification (for example, see
1334 	 * Section 6.1 of ACPI 6.3), but in many cases the _ADR returns 0 which
1335 	 * appears to indicate that they should not be taken into consideration
1336 	 * as potential companions of PCI devices on the root bus.
1337 	 *
1338 	 * To catch this special case, disregard the returned device object if
1339 	 * it has a valid _HID, addr is 0 and the PCI device at hand is on the
1340 	 * root bus.
1341 	 */
1342 	if (adev && adev->pnp.type.platform_id && !addr &&
1343 	    pci_is_root_bus(pci_dev->bus))
1344 		return NULL;
1345 
1346 	return adev;
1347 }
1348 
1349 /**
1350  * pci_acpi_optimize_delay - optimize PCI D3 and D3cold delay from ACPI
1351  * @pdev: the PCI device whose delay is to be updated
1352  * @handle: ACPI handle of this device
1353  *
1354  * Update the d3hot_delay and d3cold_delay of a PCI device from the ACPI _DSM
1355  * control method of either the device itself or the PCI host bridge.
1356  *
1357  * Function 8, "Reset Delay," applies to the entire hierarchy below a PCI
1358  * host bridge.  If it returns one, the OS may assume that all devices in
1359  * the hierarchy have already completed power-on reset delays.
1360  *
1361  * Function 9, "Device Readiness Durations," applies only to the object
1362  * where it is located.  It returns delay durations required after various
1363  * events if the device requires less time than the spec requires.  Delays
1364  * from this function take precedence over the Reset Delay function.
1365  *
1366  * These _DSM functions are defined by the draft ECN of January 28, 2014,
1367  * titled "ACPI additions for FW latency optimizations."
1368  */
1369 static void pci_acpi_optimize_delay(struct pci_dev *pdev,
1370 				    acpi_handle handle)
1371 {
1372 	struct pci_host_bridge *bridge = pci_find_host_bridge(pdev->bus);
1373 	int value;
1374 	union acpi_object *obj, *elements;
1375 
1376 	if (bridge->ignore_reset_delay)
1377 		pdev->d3cold_delay = 0;
1378 
1379 	obj = acpi_evaluate_dsm(handle, &pci_acpi_dsm_guid, 3,
1380 				DSM_PCI_DEVICE_READINESS_DURATIONS, NULL);
1381 	if (!obj)
1382 		return;
1383 
1384 	if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 5) {
1385 		elements = obj->package.elements;
1386 		if (elements[0].type == ACPI_TYPE_INTEGER) {
1387 			value = (int)elements[0].integer.value / 1000;
1388 			if (value < PCI_PM_D3COLD_WAIT)
1389 				pdev->d3cold_delay = value;
1390 		}
1391 		if (elements[3].type == ACPI_TYPE_INTEGER) {
1392 			value = (int)elements[3].integer.value / 1000;
1393 			if (value < PCI_PM_D3HOT_WAIT)
1394 				pdev->d3hot_delay = value;
1395 		}
1396 	}
1397 	ACPI_FREE(obj);
1398 }
1399 
1400 static void pci_acpi_set_external_facing(struct pci_dev *dev)
1401 {
1402 	u8 val;
1403 
1404 	if (pci_pcie_type(dev) != PCI_EXP_TYPE_ROOT_PORT)
1405 		return;
1406 	if (device_property_read_u8(&dev->dev, "ExternalFacingPort", &val))
1407 		return;
1408 
1409 	/*
1410 	 * These root ports expose PCIe (including DMA) outside of the
1411 	 * system.  Everything downstream from them is external.
1412 	 */
1413 	if (val)
1414 		dev->external_facing = 1;
1415 }
1416 
1417 void pci_acpi_setup(struct device *dev, struct acpi_device *adev)
1418 {
1419 	struct pci_dev *pci_dev = to_pci_dev(dev);
1420 
1421 	pci_acpi_optimize_delay(pci_dev, adev->handle);
1422 	pci_acpi_set_external_facing(pci_dev);
1423 	pci_acpi_add_edr_notifier(pci_dev);
1424 
1425 	pci_acpi_add_pm_notifier(adev, pci_dev);
1426 	if (!adev->wakeup.flags.valid)
1427 		return;
1428 
1429 	device_set_wakeup_capable(dev, true);
1430 	/*
1431 	 * For bridges that can do D3 we enable wake automatically (as
1432 	 * we do for the power management itself in that case). The
1433 	 * reason is that the bridge may have additional methods such as
1434 	 * _DSW that need to be called.
1435 	 */
1436 	if (pci_dev->bridge_d3)
1437 		device_wakeup_enable(dev);
1438 
1439 	acpi_pci_wakeup(pci_dev, false);
1440 	acpi_device_power_add_dependent(adev, dev);
1441 
1442 	if (pci_is_bridge(pci_dev))
1443 		acpi_dev_power_up_children_with_adr(adev);
1444 }
1445 
1446 void pci_acpi_cleanup(struct device *dev, struct acpi_device *adev)
1447 {
1448 	struct pci_dev *pci_dev = to_pci_dev(dev);
1449 
1450 	pci_acpi_remove_edr_notifier(pci_dev);
1451 	pci_acpi_remove_pm_notifier(adev);
1452 	if (adev->wakeup.flags.valid) {
1453 		acpi_device_power_remove_dependent(adev, dev);
1454 		if (pci_dev->bridge_d3)
1455 			device_wakeup_disable(dev);
1456 
1457 		device_set_wakeup_capable(dev, false);
1458 	}
1459 }
1460 
1461 static struct fwnode_handle *(*pci_msi_get_fwnode_cb)(struct device *dev);
1462 
1463 /**
1464  * pci_msi_register_fwnode_provider - Register callback to retrieve fwnode
1465  * @fn:       Callback matching a device to a fwnode that identifies a PCI
1466  *            MSI domain.
1467  *
1468  * This should be called by irqchip driver, which is the parent of
1469  * the MSI domain to provide callback interface to query fwnode.
1470  */
1471 void
1472 pci_msi_register_fwnode_provider(struct fwnode_handle *(*fn)(struct device *))
1473 {
1474 	pci_msi_get_fwnode_cb = fn;
1475 }
1476 
1477 /**
1478  * pci_host_bridge_acpi_msi_domain - Retrieve MSI domain of a PCI host bridge
1479  * @bus:      The PCI host bridge bus.
1480  *
1481  * This function uses the callback function registered by
1482  * pci_msi_register_fwnode_provider() to retrieve the irq_domain with
1483  * type DOMAIN_BUS_PCI_MSI of the specified host bridge bus.
1484  * This returns NULL on error or when the domain is not found.
1485  */
1486 struct irq_domain *pci_host_bridge_acpi_msi_domain(struct pci_bus *bus)
1487 {
1488 	struct fwnode_handle *fwnode;
1489 
1490 	if (!pci_msi_get_fwnode_cb)
1491 		return NULL;
1492 
1493 	fwnode = pci_msi_get_fwnode_cb(&bus->dev);
1494 	if (!fwnode)
1495 		return NULL;
1496 
1497 	return irq_find_matching_fwnode(fwnode, DOMAIN_BUS_PCI_MSI);
1498 }
1499 
1500 static int __init acpi_pci_init(void)
1501 {
1502 	if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_MSI) {
1503 		pr_info("ACPI FADT declares the system doesn't support MSI, so disable it\n");
1504 		pci_no_msi();
1505 	}
1506 
1507 	if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) {
1508 		pr_info("ACPI FADT declares the system doesn't support PCIe ASPM, so disable it\n");
1509 		pcie_no_aspm();
1510 	}
1511 
1512 	if (acpi_pci_disabled)
1513 		return 0;
1514 
1515 	acpi_pci_slot_init();
1516 	acpiphp_init();
1517 
1518 	return 0;
1519 }
1520 arch_initcall(acpi_pci_init);
1521