xref: /openbmc/linux/drivers/pci/pcie/aer.c (revision 8957261c)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Implement the AER root port service driver. The driver registers an IRQ
4  * handler. When a root port triggers an AER interrupt, the IRQ handler
5  * collects root port status and schedules work.
6  *
7  * Copyright (C) 2006 Intel Corp.
8  *	Tom Long Nguyen (tom.l.nguyen@intel.com)
9  *	Zhang Yanmin (yanmin.zhang@intel.com)
10  *
11  * (C) Copyright 2009 Hewlett-Packard Development Company, L.P.
12  *    Andrew Patterson <andrew.patterson@hp.com>
13  */
14 
15 #define pr_fmt(fmt) "AER: " fmt
16 #define dev_fmt pr_fmt
17 
18 #include <linux/bitops.h>
19 #include <linux/cper.h>
20 #include <linux/pci.h>
21 #include <linux/pci-acpi.h>
22 #include <linux/sched.h>
23 #include <linux/kernel.h>
24 #include <linux/errno.h>
25 #include <linux/pm.h>
26 #include <linux/init.h>
27 #include <linux/interrupt.h>
28 #include <linux/delay.h>
29 #include <linux/kfifo.h>
30 #include <linux/slab.h>
31 #include <acpi/apei.h>
32 #include <ras/ras_event.h>
33 
34 #include "../pci.h"
35 #include "portdrv.h"
36 
37 #define AER_ERROR_SOURCES_MAX		128
38 
39 #define AER_MAX_TYPEOF_COR_ERRS		16	/* as per PCI_ERR_COR_STATUS */
40 #define AER_MAX_TYPEOF_UNCOR_ERRS	27	/* as per PCI_ERR_UNCOR_STATUS*/
41 
42 struct aer_err_source {
43 	unsigned int status;
44 	unsigned int id;
45 };
46 
47 struct aer_rpc {
48 	struct pci_dev *rpd;		/* Root Port device */
49 	DECLARE_KFIFO(aer_fifo, struct aer_err_source, AER_ERROR_SOURCES_MAX);
50 };
51 
52 /* AER stats for the device */
53 struct aer_stats {
54 
55 	/*
56 	 * Fields for all AER capable devices. They indicate the errors
57 	 * "as seen by this device". Note that this may mean that if an
58 	 * end point is causing problems, the AER counters may increment
59 	 * at its link partner (e.g. root port) because the errors will be
60 	 * "seen" by the link partner and not the problematic end point
61 	 * itself (which may report all counters as 0 as it never saw any
62 	 * problems).
63 	 */
64 	/* Counters for different type of correctable errors */
65 	u64 dev_cor_errs[AER_MAX_TYPEOF_COR_ERRS];
66 	/* Counters for different type of fatal uncorrectable errors */
67 	u64 dev_fatal_errs[AER_MAX_TYPEOF_UNCOR_ERRS];
68 	/* Counters for different type of nonfatal uncorrectable errors */
69 	u64 dev_nonfatal_errs[AER_MAX_TYPEOF_UNCOR_ERRS];
70 	/* Total number of ERR_COR sent by this device */
71 	u64 dev_total_cor_errs;
72 	/* Total number of ERR_FATAL sent by this device */
73 	u64 dev_total_fatal_errs;
74 	/* Total number of ERR_NONFATAL sent by this device */
75 	u64 dev_total_nonfatal_errs;
76 
77 	/*
78 	 * Fields for Root ports & root complex event collectors only, these
79 	 * indicate the total number of ERR_COR, ERR_FATAL, and ERR_NONFATAL
80 	 * messages received by the root port / event collector, INCLUDING the
81 	 * ones that are generated internally (by the rootport itself)
82 	 */
83 	u64 rootport_total_cor_errs;
84 	u64 rootport_total_fatal_errs;
85 	u64 rootport_total_nonfatal_errs;
86 };
87 
88 #define AER_LOG_TLP_MASKS		(PCI_ERR_UNC_POISON_TLP|	\
89 					PCI_ERR_UNC_ECRC|		\
90 					PCI_ERR_UNC_UNSUP|		\
91 					PCI_ERR_UNC_COMP_ABORT|		\
92 					PCI_ERR_UNC_UNX_COMP|		\
93 					PCI_ERR_UNC_MALF_TLP)
94 
95 #define SYSTEM_ERROR_INTR_ON_MESG_MASK	(PCI_EXP_RTCTL_SECEE|	\
96 					PCI_EXP_RTCTL_SENFEE|	\
97 					PCI_EXP_RTCTL_SEFEE)
98 #define ROOT_PORT_INTR_ON_MESG_MASK	(PCI_ERR_ROOT_CMD_COR_EN|	\
99 					PCI_ERR_ROOT_CMD_NONFATAL_EN|	\
100 					PCI_ERR_ROOT_CMD_FATAL_EN)
101 #define ERR_COR_ID(d)			(d & 0xffff)
102 #define ERR_UNCOR_ID(d)			(d >> 16)
103 
104 #define AER_ERR_STATUS_MASK		(PCI_ERR_ROOT_UNCOR_RCV |	\
105 					PCI_ERR_ROOT_COR_RCV |		\
106 					PCI_ERR_ROOT_MULTI_COR_RCV |	\
107 					PCI_ERR_ROOT_MULTI_UNCOR_RCV)
108 
109 static int pcie_aer_disable;
110 static pci_ers_result_t aer_root_reset(struct pci_dev *dev);
111 
112 void pci_no_aer(void)
113 {
114 	pcie_aer_disable = 1;
115 }
116 
117 bool pci_aer_available(void)
118 {
119 	return !pcie_aer_disable && pci_msi_enabled();
120 }
121 
122 #ifdef CONFIG_PCIE_ECRC
123 
124 #define ECRC_POLICY_DEFAULT 0		/* ECRC set by BIOS */
125 #define ECRC_POLICY_OFF     1		/* ECRC off for performance */
126 #define ECRC_POLICY_ON      2		/* ECRC on for data integrity */
127 
128 static int ecrc_policy = ECRC_POLICY_DEFAULT;
129 
130 static const char * const ecrc_policy_str[] = {
131 	[ECRC_POLICY_DEFAULT] = "bios",
132 	[ECRC_POLICY_OFF] = "off",
133 	[ECRC_POLICY_ON] = "on"
134 };
135 
136 /**
137  * enable_ecrc_checking - enable PCIe ECRC checking for a device
138  * @dev: the PCI device
139  *
140  * Returns 0 on success, or negative on failure.
141  */
142 static int enable_ecrc_checking(struct pci_dev *dev)
143 {
144 	int aer = dev->aer_cap;
145 	u32 reg32;
146 
147 	if (!aer)
148 		return -ENODEV;
149 
150 	pci_read_config_dword(dev, aer + PCI_ERR_CAP, &reg32);
151 	if (reg32 & PCI_ERR_CAP_ECRC_GENC)
152 		reg32 |= PCI_ERR_CAP_ECRC_GENE;
153 	if (reg32 & PCI_ERR_CAP_ECRC_CHKC)
154 		reg32 |= PCI_ERR_CAP_ECRC_CHKE;
155 	pci_write_config_dword(dev, aer + PCI_ERR_CAP, reg32);
156 
157 	return 0;
158 }
159 
160 /**
161  * disable_ecrc_checking - disables PCIe ECRC checking for a device
162  * @dev: the PCI device
163  *
164  * Returns 0 on success, or negative on failure.
165  */
166 static int disable_ecrc_checking(struct pci_dev *dev)
167 {
168 	int aer = dev->aer_cap;
169 	u32 reg32;
170 
171 	if (!aer)
172 		return -ENODEV;
173 
174 	pci_read_config_dword(dev, aer + PCI_ERR_CAP, &reg32);
175 	reg32 &= ~(PCI_ERR_CAP_ECRC_GENE | PCI_ERR_CAP_ECRC_CHKE);
176 	pci_write_config_dword(dev, aer + PCI_ERR_CAP, reg32);
177 
178 	return 0;
179 }
180 
181 /**
182  * pcie_set_ecrc_checking - set/unset PCIe ECRC checking for a device based on global policy
183  * @dev: the PCI device
184  */
185 void pcie_set_ecrc_checking(struct pci_dev *dev)
186 {
187 	if (!pcie_aer_is_native(dev))
188 		return;
189 
190 	switch (ecrc_policy) {
191 	case ECRC_POLICY_DEFAULT:
192 		return;
193 	case ECRC_POLICY_OFF:
194 		disable_ecrc_checking(dev);
195 		break;
196 	case ECRC_POLICY_ON:
197 		enable_ecrc_checking(dev);
198 		break;
199 	default:
200 		return;
201 	}
202 }
203 
204 /**
205  * pcie_ecrc_get_policy - parse kernel command-line ecrc option
206  * @str: ECRC policy from kernel command line to use
207  */
208 void pcie_ecrc_get_policy(char *str)
209 {
210 	int i;
211 
212 	i = match_string(ecrc_policy_str, ARRAY_SIZE(ecrc_policy_str), str);
213 	if (i < 0)
214 		return;
215 
216 	ecrc_policy = i;
217 }
218 #endif	/* CONFIG_PCIE_ECRC */
219 
220 #define	PCI_EXP_AER_FLAGS	(PCI_EXP_DEVCTL_CERE | PCI_EXP_DEVCTL_NFERE | \
221 				 PCI_EXP_DEVCTL_FERE | PCI_EXP_DEVCTL_URRE)
222 
223 int pcie_aer_is_native(struct pci_dev *dev)
224 {
225 	struct pci_host_bridge *host = pci_find_host_bridge(dev->bus);
226 
227 	if (!dev->aer_cap)
228 		return 0;
229 
230 	return pcie_ports_native || host->native_aer;
231 }
232 
233 static int pci_enable_pcie_error_reporting(struct pci_dev *dev)
234 {
235 	int rc;
236 
237 	if (!pcie_aer_is_native(dev))
238 		return -EIO;
239 
240 	rc = pcie_capability_set_word(dev, PCI_EXP_DEVCTL, PCI_EXP_AER_FLAGS);
241 	return pcibios_err_to_errno(rc);
242 }
243 
244 int pci_aer_clear_nonfatal_status(struct pci_dev *dev)
245 {
246 	int aer = dev->aer_cap;
247 	u32 status, sev;
248 
249 	if (!pcie_aer_is_native(dev))
250 		return -EIO;
251 
252 	/* Clear status bits for ERR_NONFATAL errors only */
253 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, &status);
254 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_SEVER, &sev);
255 	status &= ~sev;
256 	if (status)
257 		pci_write_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, status);
258 
259 	return 0;
260 }
261 EXPORT_SYMBOL_GPL(pci_aer_clear_nonfatal_status);
262 
263 void pci_aer_clear_fatal_status(struct pci_dev *dev)
264 {
265 	int aer = dev->aer_cap;
266 	u32 status, sev;
267 
268 	if (!pcie_aer_is_native(dev))
269 		return;
270 
271 	/* Clear status bits for ERR_FATAL errors only */
272 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, &status);
273 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_SEVER, &sev);
274 	status &= sev;
275 	if (status)
276 		pci_write_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, status);
277 }
278 
279 /**
280  * pci_aer_raw_clear_status - Clear AER error registers.
281  * @dev: the PCI device
282  *
283  * Clearing AER error status registers unconditionally, regardless of
284  * whether they're owned by firmware or the OS.
285  *
286  * Returns 0 on success, or negative on failure.
287  */
288 int pci_aer_raw_clear_status(struct pci_dev *dev)
289 {
290 	int aer = dev->aer_cap;
291 	u32 status;
292 	int port_type;
293 
294 	if (!aer)
295 		return -EIO;
296 
297 	port_type = pci_pcie_type(dev);
298 	if (port_type == PCI_EXP_TYPE_ROOT_PORT ||
299 	    port_type == PCI_EXP_TYPE_RC_EC) {
300 		pci_read_config_dword(dev, aer + PCI_ERR_ROOT_STATUS, &status);
301 		pci_write_config_dword(dev, aer + PCI_ERR_ROOT_STATUS, status);
302 	}
303 
304 	pci_read_config_dword(dev, aer + PCI_ERR_COR_STATUS, &status);
305 	pci_write_config_dword(dev, aer + PCI_ERR_COR_STATUS, status);
306 
307 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, &status);
308 	pci_write_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, status);
309 
310 	return 0;
311 }
312 
313 int pci_aer_clear_status(struct pci_dev *dev)
314 {
315 	if (!pcie_aer_is_native(dev))
316 		return -EIO;
317 
318 	return pci_aer_raw_clear_status(dev);
319 }
320 
321 void pci_save_aer_state(struct pci_dev *dev)
322 {
323 	int aer = dev->aer_cap;
324 	struct pci_cap_saved_state *save_state;
325 	u32 *cap;
326 
327 	if (!aer)
328 		return;
329 
330 	save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_ERR);
331 	if (!save_state)
332 		return;
333 
334 	cap = &save_state->cap.data[0];
335 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_MASK, cap++);
336 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_SEVER, cap++);
337 	pci_read_config_dword(dev, aer + PCI_ERR_COR_MASK, cap++);
338 	pci_read_config_dword(dev, aer + PCI_ERR_CAP, cap++);
339 	if (pcie_cap_has_rtctl(dev))
340 		pci_read_config_dword(dev, aer + PCI_ERR_ROOT_COMMAND, cap++);
341 }
342 
343 void pci_restore_aer_state(struct pci_dev *dev)
344 {
345 	int aer = dev->aer_cap;
346 	struct pci_cap_saved_state *save_state;
347 	u32 *cap;
348 
349 	if (!aer)
350 		return;
351 
352 	save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_ERR);
353 	if (!save_state)
354 		return;
355 
356 	cap = &save_state->cap.data[0];
357 	pci_write_config_dword(dev, aer + PCI_ERR_UNCOR_MASK, *cap++);
358 	pci_write_config_dword(dev, aer + PCI_ERR_UNCOR_SEVER, *cap++);
359 	pci_write_config_dword(dev, aer + PCI_ERR_COR_MASK, *cap++);
360 	pci_write_config_dword(dev, aer + PCI_ERR_CAP, *cap++);
361 	if (pcie_cap_has_rtctl(dev))
362 		pci_write_config_dword(dev, aer + PCI_ERR_ROOT_COMMAND, *cap++);
363 }
364 
365 void pci_aer_init(struct pci_dev *dev)
366 {
367 	int n;
368 
369 	dev->aer_cap = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
370 	if (!dev->aer_cap)
371 		return;
372 
373 	dev->aer_stats = kzalloc(sizeof(struct aer_stats), GFP_KERNEL);
374 
375 	/*
376 	 * We save/restore PCI_ERR_UNCOR_MASK, PCI_ERR_UNCOR_SEVER,
377 	 * PCI_ERR_COR_MASK, and PCI_ERR_CAP.  Root and Root Complex Event
378 	 * Collectors also implement PCI_ERR_ROOT_COMMAND (PCIe r5.0, sec
379 	 * 7.8.4).
380 	 */
381 	n = pcie_cap_has_rtctl(dev) ? 5 : 4;
382 	pci_add_ext_cap_save_buffer(dev, PCI_EXT_CAP_ID_ERR, sizeof(u32) * n);
383 
384 	pci_aer_clear_status(dev);
385 
386 	if (pci_aer_available())
387 		pci_enable_pcie_error_reporting(dev);
388 
389 	pcie_set_ecrc_checking(dev);
390 }
391 
392 void pci_aer_exit(struct pci_dev *dev)
393 {
394 	kfree(dev->aer_stats);
395 	dev->aer_stats = NULL;
396 }
397 
398 #define AER_AGENT_RECEIVER		0
399 #define AER_AGENT_REQUESTER		1
400 #define AER_AGENT_COMPLETER		2
401 #define AER_AGENT_TRANSMITTER		3
402 
403 #define AER_AGENT_REQUESTER_MASK(t)	((t == AER_CORRECTABLE) ?	\
404 	0 : (PCI_ERR_UNC_COMP_TIME|PCI_ERR_UNC_UNSUP))
405 #define AER_AGENT_COMPLETER_MASK(t)	((t == AER_CORRECTABLE) ?	\
406 	0 : PCI_ERR_UNC_COMP_ABORT)
407 #define AER_AGENT_TRANSMITTER_MASK(t)	((t == AER_CORRECTABLE) ?	\
408 	(PCI_ERR_COR_REP_ROLL|PCI_ERR_COR_REP_TIMER) : 0)
409 
410 #define AER_GET_AGENT(t, e)						\
411 	((e & AER_AGENT_COMPLETER_MASK(t)) ? AER_AGENT_COMPLETER :	\
412 	(e & AER_AGENT_REQUESTER_MASK(t)) ? AER_AGENT_REQUESTER :	\
413 	(e & AER_AGENT_TRANSMITTER_MASK(t)) ? AER_AGENT_TRANSMITTER :	\
414 	AER_AGENT_RECEIVER)
415 
416 #define AER_PHYSICAL_LAYER_ERROR	0
417 #define AER_DATA_LINK_LAYER_ERROR	1
418 #define AER_TRANSACTION_LAYER_ERROR	2
419 
420 #define AER_PHYSICAL_LAYER_ERROR_MASK(t) ((t == AER_CORRECTABLE) ?	\
421 	PCI_ERR_COR_RCVR : 0)
422 #define AER_DATA_LINK_LAYER_ERROR_MASK(t) ((t == AER_CORRECTABLE) ?	\
423 	(PCI_ERR_COR_BAD_TLP|						\
424 	PCI_ERR_COR_BAD_DLLP|						\
425 	PCI_ERR_COR_REP_ROLL|						\
426 	PCI_ERR_COR_REP_TIMER) : PCI_ERR_UNC_DLP)
427 
428 #define AER_GET_LAYER_ERROR(t, e)					\
429 	((e & AER_PHYSICAL_LAYER_ERROR_MASK(t)) ? AER_PHYSICAL_LAYER_ERROR : \
430 	(e & AER_DATA_LINK_LAYER_ERROR_MASK(t)) ? AER_DATA_LINK_LAYER_ERROR : \
431 	AER_TRANSACTION_LAYER_ERROR)
432 
433 /*
434  * AER error strings
435  */
436 static const char *aer_error_severity_string[] = {
437 	"Uncorrected (Non-Fatal)",
438 	"Uncorrected (Fatal)",
439 	"Corrected"
440 };
441 
442 static const char *aer_error_layer[] = {
443 	"Physical Layer",
444 	"Data Link Layer",
445 	"Transaction Layer"
446 };
447 
448 static const char *aer_correctable_error_string[] = {
449 	"RxErr",			/* Bit Position 0	*/
450 	NULL,
451 	NULL,
452 	NULL,
453 	NULL,
454 	NULL,
455 	"BadTLP",			/* Bit Position 6	*/
456 	"BadDLLP",			/* Bit Position 7	*/
457 	"Rollover",			/* Bit Position 8	*/
458 	NULL,
459 	NULL,
460 	NULL,
461 	"Timeout",			/* Bit Position 12	*/
462 	"NonFatalErr",			/* Bit Position 13	*/
463 	"CorrIntErr",			/* Bit Position 14	*/
464 	"HeaderOF",			/* Bit Position 15	*/
465 	NULL,				/* Bit Position 16	*/
466 	NULL,				/* Bit Position 17	*/
467 	NULL,				/* Bit Position 18	*/
468 	NULL,				/* Bit Position 19	*/
469 	NULL,				/* Bit Position 20	*/
470 	NULL,				/* Bit Position 21	*/
471 	NULL,				/* Bit Position 22	*/
472 	NULL,				/* Bit Position 23	*/
473 	NULL,				/* Bit Position 24	*/
474 	NULL,				/* Bit Position 25	*/
475 	NULL,				/* Bit Position 26	*/
476 	NULL,				/* Bit Position 27	*/
477 	NULL,				/* Bit Position 28	*/
478 	NULL,				/* Bit Position 29	*/
479 	NULL,				/* Bit Position 30	*/
480 	NULL,				/* Bit Position 31	*/
481 };
482 
483 static const char *aer_uncorrectable_error_string[] = {
484 	"Undefined",			/* Bit Position 0	*/
485 	NULL,
486 	NULL,
487 	NULL,
488 	"DLP",				/* Bit Position 4	*/
489 	"SDES",				/* Bit Position 5	*/
490 	NULL,
491 	NULL,
492 	NULL,
493 	NULL,
494 	NULL,
495 	NULL,
496 	"TLP",				/* Bit Position 12	*/
497 	"FCP",				/* Bit Position 13	*/
498 	"CmpltTO",			/* Bit Position 14	*/
499 	"CmpltAbrt",			/* Bit Position 15	*/
500 	"UnxCmplt",			/* Bit Position 16	*/
501 	"RxOF",				/* Bit Position 17	*/
502 	"MalfTLP",			/* Bit Position 18	*/
503 	"ECRC",				/* Bit Position 19	*/
504 	"UnsupReq",			/* Bit Position 20	*/
505 	"ACSViol",			/* Bit Position 21	*/
506 	"UncorrIntErr",			/* Bit Position 22	*/
507 	"BlockedTLP",			/* Bit Position 23	*/
508 	"AtomicOpBlocked",		/* Bit Position 24	*/
509 	"TLPBlockedErr",		/* Bit Position 25	*/
510 	"PoisonTLPBlocked",		/* Bit Position 26	*/
511 	NULL,				/* Bit Position 27	*/
512 	NULL,				/* Bit Position 28	*/
513 	NULL,				/* Bit Position 29	*/
514 	NULL,				/* Bit Position 30	*/
515 	NULL,				/* Bit Position 31	*/
516 };
517 
518 static const char *aer_agent_string[] = {
519 	"Receiver ID",
520 	"Requester ID",
521 	"Completer ID",
522 	"Transmitter ID"
523 };
524 
525 #define aer_stats_dev_attr(name, stats_array, strings_array,		\
526 			   total_string, total_field)			\
527 	static ssize_t							\
528 	name##_show(struct device *dev, struct device_attribute *attr,	\
529 		     char *buf)						\
530 {									\
531 	unsigned int i;							\
532 	struct pci_dev *pdev = to_pci_dev(dev);				\
533 	u64 *stats = pdev->aer_stats->stats_array;			\
534 	size_t len = 0;							\
535 									\
536 	for (i = 0; i < ARRAY_SIZE(pdev->aer_stats->stats_array); i++) {\
537 		if (strings_array[i])					\
538 			len += sysfs_emit_at(buf, len, "%s %llu\n",	\
539 					     strings_array[i],		\
540 					     stats[i]);			\
541 		else if (stats[i])					\
542 			len += sysfs_emit_at(buf, len,			\
543 					     #stats_array "_bit[%d] %llu\n",\
544 					     i, stats[i]);		\
545 	}								\
546 	len += sysfs_emit_at(buf, len, "TOTAL_%s %llu\n", total_string,	\
547 			     pdev->aer_stats->total_field);		\
548 	return len;							\
549 }									\
550 static DEVICE_ATTR_RO(name)
551 
552 aer_stats_dev_attr(aer_dev_correctable, dev_cor_errs,
553 		   aer_correctable_error_string, "ERR_COR",
554 		   dev_total_cor_errs);
555 aer_stats_dev_attr(aer_dev_fatal, dev_fatal_errs,
556 		   aer_uncorrectable_error_string, "ERR_FATAL",
557 		   dev_total_fatal_errs);
558 aer_stats_dev_attr(aer_dev_nonfatal, dev_nonfatal_errs,
559 		   aer_uncorrectable_error_string, "ERR_NONFATAL",
560 		   dev_total_nonfatal_errs);
561 
562 #define aer_stats_rootport_attr(name, field)				\
563 	static ssize_t							\
564 	name##_show(struct device *dev, struct device_attribute *attr,	\
565 		     char *buf)						\
566 {									\
567 	struct pci_dev *pdev = to_pci_dev(dev);				\
568 	return sysfs_emit(buf, "%llu\n", pdev->aer_stats->field);	\
569 }									\
570 static DEVICE_ATTR_RO(name)
571 
572 aer_stats_rootport_attr(aer_rootport_total_err_cor,
573 			 rootport_total_cor_errs);
574 aer_stats_rootport_attr(aer_rootport_total_err_fatal,
575 			 rootport_total_fatal_errs);
576 aer_stats_rootport_attr(aer_rootport_total_err_nonfatal,
577 			 rootport_total_nonfatal_errs);
578 
579 static struct attribute *aer_stats_attrs[] __ro_after_init = {
580 	&dev_attr_aer_dev_correctable.attr,
581 	&dev_attr_aer_dev_fatal.attr,
582 	&dev_attr_aer_dev_nonfatal.attr,
583 	&dev_attr_aer_rootport_total_err_cor.attr,
584 	&dev_attr_aer_rootport_total_err_fatal.attr,
585 	&dev_attr_aer_rootport_total_err_nonfatal.attr,
586 	NULL
587 };
588 
589 static umode_t aer_stats_attrs_are_visible(struct kobject *kobj,
590 					   struct attribute *a, int n)
591 {
592 	struct device *dev = kobj_to_dev(kobj);
593 	struct pci_dev *pdev = to_pci_dev(dev);
594 
595 	if (!pdev->aer_stats)
596 		return 0;
597 
598 	if ((a == &dev_attr_aer_rootport_total_err_cor.attr ||
599 	     a == &dev_attr_aer_rootport_total_err_fatal.attr ||
600 	     a == &dev_attr_aer_rootport_total_err_nonfatal.attr) &&
601 	    ((pci_pcie_type(pdev) != PCI_EXP_TYPE_ROOT_PORT) &&
602 	     (pci_pcie_type(pdev) != PCI_EXP_TYPE_RC_EC)))
603 		return 0;
604 
605 	return a->mode;
606 }
607 
608 const struct attribute_group aer_stats_attr_group = {
609 	.attrs  = aer_stats_attrs,
610 	.is_visible = aer_stats_attrs_are_visible,
611 };
612 
613 static void pci_dev_aer_stats_incr(struct pci_dev *pdev,
614 				   struct aer_err_info *info)
615 {
616 	unsigned long status = info->status & ~info->mask;
617 	int i, max = -1;
618 	u64 *counter = NULL;
619 	struct aer_stats *aer_stats = pdev->aer_stats;
620 
621 	if (!aer_stats)
622 		return;
623 
624 	switch (info->severity) {
625 	case AER_CORRECTABLE:
626 		aer_stats->dev_total_cor_errs++;
627 		counter = &aer_stats->dev_cor_errs[0];
628 		max = AER_MAX_TYPEOF_COR_ERRS;
629 		break;
630 	case AER_NONFATAL:
631 		aer_stats->dev_total_nonfatal_errs++;
632 		counter = &aer_stats->dev_nonfatal_errs[0];
633 		max = AER_MAX_TYPEOF_UNCOR_ERRS;
634 		break;
635 	case AER_FATAL:
636 		aer_stats->dev_total_fatal_errs++;
637 		counter = &aer_stats->dev_fatal_errs[0];
638 		max = AER_MAX_TYPEOF_UNCOR_ERRS;
639 		break;
640 	}
641 
642 	for_each_set_bit(i, &status, max)
643 		counter[i]++;
644 }
645 
646 static void pci_rootport_aer_stats_incr(struct pci_dev *pdev,
647 				 struct aer_err_source *e_src)
648 {
649 	struct aer_stats *aer_stats = pdev->aer_stats;
650 
651 	if (!aer_stats)
652 		return;
653 
654 	if (e_src->status & PCI_ERR_ROOT_COR_RCV)
655 		aer_stats->rootport_total_cor_errs++;
656 
657 	if (e_src->status & PCI_ERR_ROOT_UNCOR_RCV) {
658 		if (e_src->status & PCI_ERR_ROOT_FATAL_RCV)
659 			aer_stats->rootport_total_fatal_errs++;
660 		else
661 			aer_stats->rootport_total_nonfatal_errs++;
662 	}
663 }
664 
665 static void __print_tlp_header(struct pci_dev *dev,
666 			       struct aer_header_log_regs *t)
667 {
668 	pci_err(dev, "  TLP Header: %08x %08x %08x %08x\n",
669 		t->dw0, t->dw1, t->dw2, t->dw3);
670 }
671 
672 static void __aer_print_error(struct pci_dev *dev,
673 			      struct aer_err_info *info)
674 {
675 	const char **strings;
676 	unsigned long status = info->status & ~info->mask;
677 	const char *level, *errmsg;
678 	int i;
679 
680 	if (info->severity == AER_CORRECTABLE) {
681 		strings = aer_correctable_error_string;
682 		level = KERN_WARNING;
683 	} else {
684 		strings = aer_uncorrectable_error_string;
685 		level = KERN_ERR;
686 	}
687 
688 	for_each_set_bit(i, &status, 32) {
689 		errmsg = strings[i];
690 		if (!errmsg)
691 			errmsg = "Unknown Error Bit";
692 
693 		pci_printk(level, dev, "   [%2d] %-22s%s\n", i, errmsg,
694 				info->first_error == i ? " (First)" : "");
695 	}
696 	pci_dev_aer_stats_incr(dev, info);
697 }
698 
699 void aer_print_error(struct pci_dev *dev, struct aer_err_info *info)
700 {
701 	int layer, agent;
702 	int id = pci_dev_id(dev);
703 	const char *level;
704 
705 	if (!info->status) {
706 		pci_err(dev, "PCIe Bus Error: severity=%s, type=Inaccessible, (Unregistered Agent ID)\n",
707 			aer_error_severity_string[info->severity]);
708 		goto out;
709 	}
710 
711 	layer = AER_GET_LAYER_ERROR(info->severity, info->status);
712 	agent = AER_GET_AGENT(info->severity, info->status);
713 
714 	level = (info->severity == AER_CORRECTABLE) ? KERN_WARNING : KERN_ERR;
715 
716 	pci_printk(level, dev, "PCIe Bus Error: severity=%s, type=%s, (%s)\n",
717 		   aer_error_severity_string[info->severity],
718 		   aer_error_layer[layer], aer_agent_string[agent]);
719 
720 	pci_printk(level, dev, "  device [%04x:%04x] error status/mask=%08x/%08x\n",
721 		   dev->vendor, dev->device, info->status, info->mask);
722 
723 	__aer_print_error(dev, info);
724 
725 	if (info->tlp_header_valid)
726 		__print_tlp_header(dev, &info->tlp);
727 
728 out:
729 	if (info->id && info->error_dev_num > 1 && info->id == id)
730 		pci_err(dev, "  Error of this Agent is reported first\n");
731 
732 	trace_aer_event(dev_name(&dev->dev), (info->status & ~info->mask),
733 			info->severity, info->tlp_header_valid, &info->tlp);
734 }
735 
736 static void aer_print_port_info(struct pci_dev *dev, struct aer_err_info *info)
737 {
738 	u8 bus = info->id >> 8;
739 	u8 devfn = info->id & 0xff;
740 
741 	pci_info(dev, "%s%s error received: %04x:%02x:%02x.%d\n",
742 		 info->multi_error_valid ? "Multiple " : "",
743 		 aer_error_severity_string[info->severity],
744 		 pci_domain_nr(dev->bus), bus, PCI_SLOT(devfn),
745 		 PCI_FUNC(devfn));
746 }
747 
748 #ifdef CONFIG_ACPI_APEI_PCIEAER
749 int cper_severity_to_aer(int cper_severity)
750 {
751 	switch (cper_severity) {
752 	case CPER_SEV_RECOVERABLE:
753 		return AER_NONFATAL;
754 	case CPER_SEV_FATAL:
755 		return AER_FATAL;
756 	default:
757 		return AER_CORRECTABLE;
758 	}
759 }
760 EXPORT_SYMBOL_GPL(cper_severity_to_aer);
761 
762 void cper_print_aer(struct pci_dev *dev, int aer_severity,
763 		    struct aer_capability_regs *aer)
764 {
765 	int layer, agent, tlp_header_valid = 0;
766 	u32 status, mask;
767 	struct aer_err_info info;
768 
769 	if (aer_severity == AER_CORRECTABLE) {
770 		status = aer->cor_status;
771 		mask = aer->cor_mask;
772 	} else {
773 		status = aer->uncor_status;
774 		mask = aer->uncor_mask;
775 		tlp_header_valid = status & AER_LOG_TLP_MASKS;
776 	}
777 
778 	layer = AER_GET_LAYER_ERROR(aer_severity, status);
779 	agent = AER_GET_AGENT(aer_severity, status);
780 
781 	memset(&info, 0, sizeof(info));
782 	info.severity = aer_severity;
783 	info.status = status;
784 	info.mask = mask;
785 	info.first_error = PCI_ERR_CAP_FEP(aer->cap_control);
786 
787 	pci_err(dev, "aer_status: 0x%08x, aer_mask: 0x%08x\n", status, mask);
788 	__aer_print_error(dev, &info);
789 	pci_err(dev, "aer_layer=%s, aer_agent=%s\n",
790 		aer_error_layer[layer], aer_agent_string[agent]);
791 
792 	if (aer_severity != AER_CORRECTABLE)
793 		pci_err(dev, "aer_uncor_severity: 0x%08x\n",
794 			aer->uncor_severity);
795 
796 	if (tlp_header_valid)
797 		__print_tlp_header(dev, &aer->header_log);
798 
799 	trace_aer_event(dev_name(&dev->dev), (status & ~mask),
800 			aer_severity, tlp_header_valid, &aer->header_log);
801 }
802 #endif
803 
804 /**
805  * add_error_device - list device to be handled
806  * @e_info: pointer to error info
807  * @dev: pointer to pci_dev to be added
808  */
809 static int add_error_device(struct aer_err_info *e_info, struct pci_dev *dev)
810 {
811 	if (e_info->error_dev_num < AER_MAX_MULTI_ERR_DEVICES) {
812 		e_info->dev[e_info->error_dev_num] = pci_dev_get(dev);
813 		e_info->error_dev_num++;
814 		return 0;
815 	}
816 	return -ENOSPC;
817 }
818 
819 /**
820  * is_error_source - check whether the device is source of reported error
821  * @dev: pointer to pci_dev to be checked
822  * @e_info: pointer to reported error info
823  */
824 static bool is_error_source(struct pci_dev *dev, struct aer_err_info *e_info)
825 {
826 	int aer = dev->aer_cap;
827 	u32 status, mask;
828 	u16 reg16;
829 
830 	/*
831 	 * When bus id is equal to 0, it might be a bad id
832 	 * reported by root port.
833 	 */
834 	if ((PCI_BUS_NUM(e_info->id) != 0) &&
835 	    !(dev->bus->bus_flags & PCI_BUS_FLAGS_NO_AERSID)) {
836 		/* Device ID match? */
837 		if (e_info->id == pci_dev_id(dev))
838 			return true;
839 
840 		/* Continue id comparing if there is no multiple error */
841 		if (!e_info->multi_error_valid)
842 			return false;
843 	}
844 
845 	/*
846 	 * When either
847 	 *      1) bus id is equal to 0. Some ports might lose the bus
848 	 *              id of error source id;
849 	 *      2) bus flag PCI_BUS_FLAGS_NO_AERSID is set
850 	 *      3) There are multiple errors and prior ID comparing fails;
851 	 * We check AER status registers to find possible reporter.
852 	 */
853 	if (atomic_read(&dev->enable_cnt) == 0)
854 		return false;
855 
856 	/* Check if AER is enabled */
857 	pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &reg16);
858 	if (!(reg16 & PCI_EXP_AER_FLAGS))
859 		return false;
860 
861 	if (!aer)
862 		return false;
863 
864 	/* Check if error is recorded */
865 	if (e_info->severity == AER_CORRECTABLE) {
866 		pci_read_config_dword(dev, aer + PCI_ERR_COR_STATUS, &status);
867 		pci_read_config_dword(dev, aer + PCI_ERR_COR_MASK, &mask);
868 	} else {
869 		pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, &status);
870 		pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_MASK, &mask);
871 	}
872 	if (status & ~mask)
873 		return true;
874 
875 	return false;
876 }
877 
878 static int find_device_iter(struct pci_dev *dev, void *data)
879 {
880 	struct aer_err_info *e_info = (struct aer_err_info *)data;
881 
882 	if (is_error_source(dev, e_info)) {
883 		/* List this device */
884 		if (add_error_device(e_info, dev)) {
885 			/* We cannot handle more... Stop iteration */
886 			/* TODO: Should print error message here? */
887 			return 1;
888 		}
889 
890 		/* If there is only a single error, stop iteration */
891 		if (!e_info->multi_error_valid)
892 			return 1;
893 	}
894 	return 0;
895 }
896 
897 /**
898  * find_source_device - search through device hierarchy for source device
899  * @parent: pointer to Root Port pci_dev data structure
900  * @e_info: including detailed error information such like id
901  *
902  * Return true if found.
903  *
904  * Invoked by DPC when error is detected at the Root Port.
905  * Caller of this function must set id, severity, and multi_error_valid of
906  * struct aer_err_info pointed by @e_info properly.  This function must fill
907  * e_info->error_dev_num and e_info->dev[], based on the given information.
908  */
909 static bool find_source_device(struct pci_dev *parent,
910 		struct aer_err_info *e_info)
911 {
912 	struct pci_dev *dev = parent;
913 	int result;
914 
915 	/* Must reset in this function */
916 	e_info->error_dev_num = 0;
917 
918 	/* Is Root Port an agent that sends error message? */
919 	result = find_device_iter(dev, e_info);
920 	if (result)
921 		return true;
922 
923 	if (pci_pcie_type(parent) == PCI_EXP_TYPE_RC_EC)
924 		pcie_walk_rcec(parent, find_device_iter, e_info);
925 	else
926 		pci_walk_bus(parent->subordinate, find_device_iter, e_info);
927 
928 	if (!e_info->error_dev_num) {
929 		pci_info(parent, "can't find device of ID%04x\n", e_info->id);
930 		return false;
931 	}
932 	return true;
933 }
934 
935 /**
936  * handle_error_source - handle logging error into an event log
937  * @dev: pointer to pci_dev data structure of error source device
938  * @info: comprehensive error information
939  *
940  * Invoked when an error being detected by Root Port.
941  */
942 static void handle_error_source(struct pci_dev *dev, struct aer_err_info *info)
943 {
944 	int aer = dev->aer_cap;
945 
946 	if (info->severity == AER_CORRECTABLE) {
947 		/*
948 		 * Correctable error does not need software intervention.
949 		 * No need to go through error recovery process.
950 		 */
951 		if (aer)
952 			pci_write_config_dword(dev, aer + PCI_ERR_COR_STATUS,
953 					info->status);
954 		if (pcie_aer_is_native(dev)) {
955 			struct pci_driver *pdrv = dev->driver;
956 
957 			if (pdrv && pdrv->err_handler &&
958 			    pdrv->err_handler->cor_error_detected)
959 				pdrv->err_handler->cor_error_detected(dev);
960 			pcie_clear_device_status(dev);
961 		}
962 	} else if (info->severity == AER_NONFATAL)
963 		pcie_do_recovery(dev, pci_channel_io_normal, aer_root_reset);
964 	else if (info->severity == AER_FATAL)
965 		pcie_do_recovery(dev, pci_channel_io_frozen, aer_root_reset);
966 	pci_dev_put(dev);
967 }
968 
969 #ifdef CONFIG_ACPI_APEI_PCIEAER
970 
971 #define AER_RECOVER_RING_SIZE		16
972 
973 struct aer_recover_entry {
974 	u8	bus;
975 	u8	devfn;
976 	u16	domain;
977 	int	severity;
978 	struct aer_capability_regs *regs;
979 };
980 
981 static DEFINE_KFIFO(aer_recover_ring, struct aer_recover_entry,
982 		    AER_RECOVER_RING_SIZE);
983 
984 static void aer_recover_work_func(struct work_struct *work)
985 {
986 	struct aer_recover_entry entry;
987 	struct pci_dev *pdev;
988 
989 	while (kfifo_get(&aer_recover_ring, &entry)) {
990 		pdev = pci_get_domain_bus_and_slot(entry.domain, entry.bus,
991 						   entry.devfn);
992 		if (!pdev) {
993 			pr_err("no pci_dev for %04x:%02x:%02x.%x\n",
994 			       entry.domain, entry.bus,
995 			       PCI_SLOT(entry.devfn), PCI_FUNC(entry.devfn));
996 			continue;
997 		}
998 		cper_print_aer(pdev, entry.severity, entry.regs);
999 		if (entry.severity == AER_NONFATAL)
1000 			pcie_do_recovery(pdev, pci_channel_io_normal,
1001 					 aer_root_reset);
1002 		else if (entry.severity == AER_FATAL)
1003 			pcie_do_recovery(pdev, pci_channel_io_frozen,
1004 					 aer_root_reset);
1005 		pci_dev_put(pdev);
1006 	}
1007 }
1008 
1009 /*
1010  * Mutual exclusion for writers of aer_recover_ring, reader side don't
1011  * need lock, because there is only one reader and lock is not needed
1012  * between reader and writer.
1013  */
1014 static DEFINE_SPINLOCK(aer_recover_ring_lock);
1015 static DECLARE_WORK(aer_recover_work, aer_recover_work_func);
1016 
1017 void aer_recover_queue(int domain, unsigned int bus, unsigned int devfn,
1018 		       int severity, struct aer_capability_regs *aer_regs)
1019 {
1020 	struct aer_recover_entry entry = {
1021 		.bus		= bus,
1022 		.devfn		= devfn,
1023 		.domain		= domain,
1024 		.severity	= severity,
1025 		.regs		= aer_regs,
1026 	};
1027 
1028 	if (kfifo_in_spinlocked(&aer_recover_ring, &entry, 1,
1029 				 &aer_recover_ring_lock))
1030 		schedule_work(&aer_recover_work);
1031 	else
1032 		pr_err("buffer overflow in recovery for %04x:%02x:%02x.%x\n",
1033 		       domain, bus, PCI_SLOT(devfn), PCI_FUNC(devfn));
1034 }
1035 EXPORT_SYMBOL_GPL(aer_recover_queue);
1036 #endif
1037 
1038 /**
1039  * aer_get_device_error_info - read error status from dev and store it to info
1040  * @dev: pointer to the device expected to have a error record
1041  * @info: pointer to structure to store the error record
1042  *
1043  * Return 1 on success, 0 on error.
1044  *
1045  * Note that @info is reused among all error devices. Clear fields properly.
1046  */
1047 int aer_get_device_error_info(struct pci_dev *dev, struct aer_err_info *info)
1048 {
1049 	int type = pci_pcie_type(dev);
1050 	int aer = dev->aer_cap;
1051 	int temp;
1052 
1053 	/* Must reset in this function */
1054 	info->status = 0;
1055 	info->tlp_header_valid = 0;
1056 
1057 	/* The device might not support AER */
1058 	if (!aer)
1059 		return 0;
1060 
1061 	if (info->severity == AER_CORRECTABLE) {
1062 		pci_read_config_dword(dev, aer + PCI_ERR_COR_STATUS,
1063 			&info->status);
1064 		pci_read_config_dword(dev, aer + PCI_ERR_COR_MASK,
1065 			&info->mask);
1066 		if (!(info->status & ~info->mask))
1067 			return 0;
1068 	} else if (type == PCI_EXP_TYPE_ROOT_PORT ||
1069 		   type == PCI_EXP_TYPE_RC_EC ||
1070 		   type == PCI_EXP_TYPE_DOWNSTREAM ||
1071 		   info->severity == AER_NONFATAL) {
1072 
1073 		/* Link is still healthy for IO reads */
1074 		pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS,
1075 			&info->status);
1076 		pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_MASK,
1077 			&info->mask);
1078 		if (!(info->status & ~info->mask))
1079 			return 0;
1080 
1081 		/* Get First Error Pointer */
1082 		pci_read_config_dword(dev, aer + PCI_ERR_CAP, &temp);
1083 		info->first_error = PCI_ERR_CAP_FEP(temp);
1084 
1085 		if (info->status & AER_LOG_TLP_MASKS) {
1086 			info->tlp_header_valid = 1;
1087 			pci_read_config_dword(dev,
1088 				aer + PCI_ERR_HEADER_LOG, &info->tlp.dw0);
1089 			pci_read_config_dword(dev,
1090 				aer + PCI_ERR_HEADER_LOG + 4, &info->tlp.dw1);
1091 			pci_read_config_dword(dev,
1092 				aer + PCI_ERR_HEADER_LOG + 8, &info->tlp.dw2);
1093 			pci_read_config_dword(dev,
1094 				aer + PCI_ERR_HEADER_LOG + 12, &info->tlp.dw3);
1095 		}
1096 	}
1097 
1098 	return 1;
1099 }
1100 
1101 static inline void aer_process_err_devices(struct aer_err_info *e_info)
1102 {
1103 	int i;
1104 
1105 	/* Report all before handle them, not to lost records by reset etc. */
1106 	for (i = 0; i < e_info->error_dev_num && e_info->dev[i]; i++) {
1107 		if (aer_get_device_error_info(e_info->dev[i], e_info))
1108 			aer_print_error(e_info->dev[i], e_info);
1109 	}
1110 	for (i = 0; i < e_info->error_dev_num && e_info->dev[i]; i++) {
1111 		if (aer_get_device_error_info(e_info->dev[i], e_info))
1112 			handle_error_source(e_info->dev[i], e_info);
1113 	}
1114 }
1115 
1116 /**
1117  * aer_isr_one_error - consume an error detected by root port
1118  * @rpc: pointer to the root port which holds an error
1119  * @e_src: pointer to an error source
1120  */
1121 static void aer_isr_one_error(struct aer_rpc *rpc,
1122 		struct aer_err_source *e_src)
1123 {
1124 	struct pci_dev *pdev = rpc->rpd;
1125 	struct aer_err_info e_info;
1126 
1127 	pci_rootport_aer_stats_incr(pdev, e_src);
1128 
1129 	/*
1130 	 * There is a possibility that both correctable error and
1131 	 * uncorrectable error being logged. Report correctable error first.
1132 	 */
1133 	if (e_src->status & PCI_ERR_ROOT_COR_RCV) {
1134 		e_info.id = ERR_COR_ID(e_src->id);
1135 		e_info.severity = AER_CORRECTABLE;
1136 
1137 		if (e_src->status & PCI_ERR_ROOT_MULTI_COR_RCV)
1138 			e_info.multi_error_valid = 1;
1139 		else
1140 			e_info.multi_error_valid = 0;
1141 		aer_print_port_info(pdev, &e_info);
1142 
1143 		if (find_source_device(pdev, &e_info))
1144 			aer_process_err_devices(&e_info);
1145 	}
1146 
1147 	if (e_src->status & PCI_ERR_ROOT_UNCOR_RCV) {
1148 		e_info.id = ERR_UNCOR_ID(e_src->id);
1149 
1150 		if (e_src->status & PCI_ERR_ROOT_FATAL_RCV)
1151 			e_info.severity = AER_FATAL;
1152 		else
1153 			e_info.severity = AER_NONFATAL;
1154 
1155 		if (e_src->status & PCI_ERR_ROOT_MULTI_UNCOR_RCV)
1156 			e_info.multi_error_valid = 1;
1157 		else
1158 			e_info.multi_error_valid = 0;
1159 
1160 		aer_print_port_info(pdev, &e_info);
1161 
1162 		if (find_source_device(pdev, &e_info))
1163 			aer_process_err_devices(&e_info);
1164 	}
1165 }
1166 
1167 /**
1168  * aer_isr - consume errors detected by root port
1169  * @irq: IRQ assigned to Root Port
1170  * @context: pointer to Root Port data structure
1171  *
1172  * Invoked, as DPC, when root port records new detected error
1173  */
1174 static irqreturn_t aer_isr(int irq, void *context)
1175 {
1176 	struct pcie_device *dev = (struct pcie_device *)context;
1177 	struct aer_rpc *rpc = get_service_data(dev);
1178 	struct aer_err_source e_src;
1179 
1180 	if (kfifo_is_empty(&rpc->aer_fifo))
1181 		return IRQ_NONE;
1182 
1183 	while (kfifo_get(&rpc->aer_fifo, &e_src))
1184 		aer_isr_one_error(rpc, &e_src);
1185 	return IRQ_HANDLED;
1186 }
1187 
1188 /**
1189  * aer_irq - Root Port's ISR
1190  * @irq: IRQ assigned to Root Port
1191  * @context: pointer to Root Port data structure
1192  *
1193  * Invoked when Root Port detects AER messages.
1194  */
1195 static irqreturn_t aer_irq(int irq, void *context)
1196 {
1197 	struct pcie_device *pdev = (struct pcie_device *)context;
1198 	struct aer_rpc *rpc = get_service_data(pdev);
1199 	struct pci_dev *rp = rpc->rpd;
1200 	int aer = rp->aer_cap;
1201 	struct aer_err_source e_src = {};
1202 
1203 	pci_read_config_dword(rp, aer + PCI_ERR_ROOT_STATUS, &e_src.status);
1204 	if (!(e_src.status & AER_ERR_STATUS_MASK))
1205 		return IRQ_NONE;
1206 
1207 	pci_read_config_dword(rp, aer + PCI_ERR_ROOT_ERR_SRC, &e_src.id);
1208 	pci_write_config_dword(rp, aer + PCI_ERR_ROOT_STATUS, e_src.status);
1209 
1210 	if (!kfifo_put(&rpc->aer_fifo, e_src))
1211 		return IRQ_HANDLED;
1212 
1213 	return IRQ_WAKE_THREAD;
1214 }
1215 
1216 /**
1217  * aer_enable_rootport - enable Root Port's interrupts when receiving messages
1218  * @rpc: pointer to a Root Port data structure
1219  *
1220  * Invoked when PCIe bus loads AER service driver.
1221  */
1222 static void aer_enable_rootport(struct aer_rpc *rpc)
1223 {
1224 	struct pci_dev *pdev = rpc->rpd;
1225 	int aer = pdev->aer_cap;
1226 	u16 reg16;
1227 	u32 reg32;
1228 
1229 	/* Clear PCIe Capability's Device Status */
1230 	pcie_capability_read_word(pdev, PCI_EXP_DEVSTA, &reg16);
1231 	pcie_capability_write_word(pdev, PCI_EXP_DEVSTA, reg16);
1232 
1233 	/* Disable system error generation in response to error messages */
1234 	pcie_capability_clear_word(pdev, PCI_EXP_RTCTL,
1235 				   SYSTEM_ERROR_INTR_ON_MESG_MASK);
1236 
1237 	/* Clear error status */
1238 	pci_read_config_dword(pdev, aer + PCI_ERR_ROOT_STATUS, &reg32);
1239 	pci_write_config_dword(pdev, aer + PCI_ERR_ROOT_STATUS, reg32);
1240 	pci_read_config_dword(pdev, aer + PCI_ERR_COR_STATUS, &reg32);
1241 	pci_write_config_dword(pdev, aer + PCI_ERR_COR_STATUS, reg32);
1242 	pci_read_config_dword(pdev, aer + PCI_ERR_UNCOR_STATUS, &reg32);
1243 	pci_write_config_dword(pdev, aer + PCI_ERR_UNCOR_STATUS, reg32);
1244 
1245 	/* Enable Root Port's interrupt in response to error messages */
1246 	pci_read_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, &reg32);
1247 	reg32 |= ROOT_PORT_INTR_ON_MESG_MASK;
1248 	pci_write_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, reg32);
1249 }
1250 
1251 /**
1252  * aer_disable_rootport - disable Root Port's interrupts when receiving messages
1253  * @rpc: pointer to a Root Port data structure
1254  *
1255  * Invoked when PCIe bus unloads AER service driver.
1256  */
1257 static void aer_disable_rootport(struct aer_rpc *rpc)
1258 {
1259 	struct pci_dev *pdev = rpc->rpd;
1260 	int aer = pdev->aer_cap;
1261 	u32 reg32;
1262 
1263 	/* Disable Root's interrupt in response to error messages */
1264 	pci_read_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, &reg32);
1265 	reg32 &= ~ROOT_PORT_INTR_ON_MESG_MASK;
1266 	pci_write_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, reg32);
1267 
1268 	/* Clear Root's error status reg */
1269 	pci_read_config_dword(pdev, aer + PCI_ERR_ROOT_STATUS, &reg32);
1270 	pci_write_config_dword(pdev, aer + PCI_ERR_ROOT_STATUS, reg32);
1271 }
1272 
1273 /**
1274  * aer_remove - clean up resources
1275  * @dev: pointer to the pcie_dev data structure
1276  *
1277  * Invoked when PCI Express bus unloads or AER probe fails.
1278  */
1279 static void aer_remove(struct pcie_device *dev)
1280 {
1281 	struct aer_rpc *rpc = get_service_data(dev);
1282 
1283 	aer_disable_rootport(rpc);
1284 }
1285 
1286 /**
1287  * aer_probe - initialize resources
1288  * @dev: pointer to the pcie_dev data structure
1289  *
1290  * Invoked when PCI Express bus loads AER service driver.
1291  */
1292 static int aer_probe(struct pcie_device *dev)
1293 {
1294 	int status;
1295 	struct aer_rpc *rpc;
1296 	struct device *device = &dev->device;
1297 	struct pci_dev *port = dev->port;
1298 
1299 	BUILD_BUG_ON(ARRAY_SIZE(aer_correctable_error_string) <
1300 		     AER_MAX_TYPEOF_COR_ERRS);
1301 	BUILD_BUG_ON(ARRAY_SIZE(aer_uncorrectable_error_string) <
1302 		     AER_MAX_TYPEOF_UNCOR_ERRS);
1303 
1304 	/* Limit to Root Ports or Root Complex Event Collectors */
1305 	if ((pci_pcie_type(port) != PCI_EXP_TYPE_RC_EC) &&
1306 	    (pci_pcie_type(port) != PCI_EXP_TYPE_ROOT_PORT))
1307 		return -ENODEV;
1308 
1309 	rpc = devm_kzalloc(device, sizeof(struct aer_rpc), GFP_KERNEL);
1310 	if (!rpc)
1311 		return -ENOMEM;
1312 
1313 	rpc->rpd = port;
1314 	INIT_KFIFO(rpc->aer_fifo);
1315 	set_service_data(dev, rpc);
1316 
1317 	status = devm_request_threaded_irq(device, dev->irq, aer_irq, aer_isr,
1318 					   IRQF_SHARED, "aerdrv", dev);
1319 	if (status) {
1320 		pci_err(port, "request AER IRQ %d failed\n", dev->irq);
1321 		return status;
1322 	}
1323 
1324 	aer_enable_rootport(rpc);
1325 	pci_info(port, "enabled with IRQ %d\n", dev->irq);
1326 	return 0;
1327 }
1328 
1329 /**
1330  * aer_root_reset - reset Root Port hierarchy, RCEC, or RCiEP
1331  * @dev: pointer to Root Port, RCEC, or RCiEP
1332  *
1333  * Invoked by Port Bus driver when performing reset.
1334  */
1335 static pci_ers_result_t aer_root_reset(struct pci_dev *dev)
1336 {
1337 	int type = pci_pcie_type(dev);
1338 	struct pci_dev *root;
1339 	int aer;
1340 	struct pci_host_bridge *host = pci_find_host_bridge(dev->bus);
1341 	u32 reg32;
1342 	int rc;
1343 
1344 	/*
1345 	 * Only Root Ports and RCECs have AER Root Command and Root Status
1346 	 * registers.  If "dev" is an RCiEP, the relevant registers are in
1347 	 * the RCEC.
1348 	 */
1349 	if (type == PCI_EXP_TYPE_RC_END)
1350 		root = dev->rcec;
1351 	else
1352 		root = pcie_find_root_port(dev);
1353 
1354 	/*
1355 	 * If the platform retained control of AER, an RCiEP may not have
1356 	 * an RCEC visible to us, so dev->rcec ("root") may be NULL.  In
1357 	 * that case, firmware is responsible for these registers.
1358 	 */
1359 	aer = root ? root->aer_cap : 0;
1360 
1361 	if ((host->native_aer || pcie_ports_native) && aer) {
1362 		/* Disable Root's interrupt in response to error messages */
1363 		pci_read_config_dword(root, aer + PCI_ERR_ROOT_COMMAND, &reg32);
1364 		reg32 &= ~ROOT_PORT_INTR_ON_MESG_MASK;
1365 		pci_write_config_dword(root, aer + PCI_ERR_ROOT_COMMAND, reg32);
1366 	}
1367 
1368 	if (type == PCI_EXP_TYPE_RC_EC || type == PCI_EXP_TYPE_RC_END) {
1369 		rc = pcie_reset_flr(dev, PCI_RESET_DO_RESET);
1370 		if (!rc)
1371 			pci_info(dev, "has been reset\n");
1372 		else
1373 			pci_info(dev, "not reset (no FLR support: %d)\n", rc);
1374 	} else {
1375 		rc = pci_bus_error_reset(dev);
1376 		pci_info(dev, "%s Port link has been reset (%d)\n",
1377 			pci_is_root_bus(dev->bus) ? "Root" : "Downstream", rc);
1378 	}
1379 
1380 	if ((host->native_aer || pcie_ports_native) && aer) {
1381 		/* Clear Root Error Status */
1382 		pci_read_config_dword(root, aer + PCI_ERR_ROOT_STATUS, &reg32);
1383 		pci_write_config_dword(root, aer + PCI_ERR_ROOT_STATUS, reg32);
1384 
1385 		/* Enable Root Port's interrupt in response to error messages */
1386 		pci_read_config_dword(root, aer + PCI_ERR_ROOT_COMMAND, &reg32);
1387 		reg32 |= ROOT_PORT_INTR_ON_MESG_MASK;
1388 		pci_write_config_dword(root, aer + PCI_ERR_ROOT_COMMAND, reg32);
1389 	}
1390 
1391 	return rc ? PCI_ERS_RESULT_DISCONNECT : PCI_ERS_RESULT_RECOVERED;
1392 }
1393 
1394 static struct pcie_port_service_driver aerdriver = {
1395 	.name		= "aer",
1396 	.port_type	= PCIE_ANY_PORT,
1397 	.service	= PCIE_PORT_SERVICE_AER,
1398 
1399 	.probe		= aer_probe,
1400 	.remove		= aer_remove,
1401 };
1402 
1403 /**
1404  * pcie_aer_init - register AER root service driver
1405  *
1406  * Invoked when AER root service driver is loaded.
1407  */
1408 int __init pcie_aer_init(void)
1409 {
1410 	if (!pci_aer_available())
1411 		return -ENXIO;
1412 	return pcie_port_service_register(&aerdriver);
1413 }
1414