xref: /openbmc/linux/drivers/pci/pcie/aer.c (revision 6548d543)
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 <acpi/ghes.h>
33 #include <ras/ras_event.h>
34 
35 #include "../pci.h"
36 #include "portdrv.h"
37 
38 #define AER_ERROR_SOURCES_MAX		128
39 
40 #define AER_MAX_TYPEOF_COR_ERRS		16	/* as per PCI_ERR_COR_STATUS */
41 #define AER_MAX_TYPEOF_UNCOR_ERRS	27	/* as per PCI_ERR_UNCOR_STATUS*/
42 
43 struct aer_err_source {
44 	unsigned int status;
45 	unsigned int id;
46 };
47 
48 struct aer_rpc {
49 	struct pci_dev *rpd;		/* Root Port device */
50 	DECLARE_KFIFO(aer_fifo, struct aer_err_source, AER_ERROR_SOURCES_MAX);
51 };
52 
53 /* AER stats for the device */
54 struct aer_stats {
55 
56 	/*
57 	 * Fields for all AER capable devices. They indicate the errors
58 	 * "as seen by this device". Note that this may mean that if an
59 	 * end point is causing problems, the AER counters may increment
60 	 * at its link partner (e.g. root port) because the errors will be
61 	 * "seen" by the link partner and not the problematic end point
62 	 * itself (which may report all counters as 0 as it never saw any
63 	 * problems).
64 	 */
65 	/* Counters for different type of correctable errors */
66 	u64 dev_cor_errs[AER_MAX_TYPEOF_COR_ERRS];
67 	/* Counters for different type of fatal uncorrectable errors */
68 	u64 dev_fatal_errs[AER_MAX_TYPEOF_UNCOR_ERRS];
69 	/* Counters for different type of nonfatal uncorrectable errors */
70 	u64 dev_nonfatal_errs[AER_MAX_TYPEOF_UNCOR_ERRS];
71 	/* Total number of ERR_COR sent by this device */
72 	u64 dev_total_cor_errs;
73 	/* Total number of ERR_FATAL sent by this device */
74 	u64 dev_total_fatal_errs;
75 	/* Total number of ERR_NONFATAL sent by this device */
76 	u64 dev_total_nonfatal_errs;
77 
78 	/*
79 	 * Fields for Root ports & root complex event collectors only, these
80 	 * indicate the total number of ERR_COR, ERR_FATAL, and ERR_NONFATAL
81 	 * messages received by the root port / event collector, INCLUDING the
82 	 * ones that are generated internally (by the rootport itself)
83 	 */
84 	u64 rootport_total_cor_errs;
85 	u64 rootport_total_fatal_errs;
86 	u64 rootport_total_nonfatal_errs;
87 };
88 
89 #define AER_LOG_TLP_MASKS		(PCI_ERR_UNC_POISON_TLP|	\
90 					PCI_ERR_UNC_ECRC|		\
91 					PCI_ERR_UNC_UNSUP|		\
92 					PCI_ERR_UNC_COMP_ABORT|		\
93 					PCI_ERR_UNC_UNX_COMP|		\
94 					PCI_ERR_UNC_MALF_TLP)
95 
96 #define SYSTEM_ERROR_INTR_ON_MESG_MASK	(PCI_EXP_RTCTL_SECEE|	\
97 					PCI_EXP_RTCTL_SENFEE|	\
98 					PCI_EXP_RTCTL_SEFEE)
99 #define ROOT_PORT_INTR_ON_MESG_MASK	(PCI_ERR_ROOT_CMD_COR_EN|	\
100 					PCI_ERR_ROOT_CMD_NONFATAL_EN|	\
101 					PCI_ERR_ROOT_CMD_FATAL_EN)
102 #define ERR_COR_ID(d)			(d & 0xffff)
103 #define ERR_UNCOR_ID(d)			(d >> 16)
104 
105 #define AER_ERR_STATUS_MASK		(PCI_ERR_ROOT_UNCOR_RCV |	\
106 					PCI_ERR_ROOT_COR_RCV |		\
107 					PCI_ERR_ROOT_MULTI_COR_RCV |	\
108 					PCI_ERR_ROOT_MULTI_UNCOR_RCV)
109 
110 static int pcie_aer_disable;
111 static pci_ers_result_t aer_root_reset(struct pci_dev *dev);
112 
113 void pci_no_aer(void)
114 {
115 	pcie_aer_disable = 1;
116 }
117 
118 bool pci_aer_available(void)
119 {
120 	return !pcie_aer_disable && pci_msi_enabled();
121 }
122 
123 #ifdef CONFIG_PCIE_ECRC
124 
125 #define ECRC_POLICY_DEFAULT 0		/* ECRC set by BIOS */
126 #define ECRC_POLICY_OFF     1		/* ECRC off for performance */
127 #define ECRC_POLICY_ON      2		/* ECRC on for data integrity */
128 
129 static int ecrc_policy = ECRC_POLICY_DEFAULT;
130 
131 static const char * const ecrc_policy_str[] = {
132 	[ECRC_POLICY_DEFAULT] = "bios",
133 	[ECRC_POLICY_OFF] = "off",
134 	[ECRC_POLICY_ON] = "on"
135 };
136 
137 /**
138  * enable_ecrc_checking - enable PCIe ECRC checking for a device
139  * @dev: the PCI device
140  *
141  * Returns 0 on success, or negative on failure.
142  */
143 static int enable_ecrc_checking(struct pci_dev *dev)
144 {
145 	int aer = dev->aer_cap;
146 	u32 reg32;
147 
148 	if (!aer)
149 		return -ENODEV;
150 
151 	pci_read_config_dword(dev, aer + PCI_ERR_CAP, &reg32);
152 	if (reg32 & PCI_ERR_CAP_ECRC_GENC)
153 		reg32 |= PCI_ERR_CAP_ECRC_GENE;
154 	if (reg32 & PCI_ERR_CAP_ECRC_CHKC)
155 		reg32 |= PCI_ERR_CAP_ECRC_CHKE;
156 	pci_write_config_dword(dev, aer + PCI_ERR_CAP, reg32);
157 
158 	return 0;
159 }
160 
161 /**
162  * disable_ecrc_checking - disables PCIe ECRC checking for a device
163  * @dev: the PCI device
164  *
165  * Returns 0 on success, or negative on failure.
166  */
167 static int disable_ecrc_checking(struct pci_dev *dev)
168 {
169 	int aer = dev->aer_cap;
170 	u32 reg32;
171 
172 	if (!aer)
173 		return -ENODEV;
174 
175 	pci_read_config_dword(dev, aer + PCI_ERR_CAP, &reg32);
176 	reg32 &= ~(PCI_ERR_CAP_ECRC_GENE | PCI_ERR_CAP_ECRC_CHKE);
177 	pci_write_config_dword(dev, aer + PCI_ERR_CAP, reg32);
178 
179 	return 0;
180 }
181 
182 /**
183  * pcie_set_ecrc_checking - set/unset PCIe ECRC checking for a device based on global policy
184  * @dev: the PCI device
185  */
186 void pcie_set_ecrc_checking(struct pci_dev *dev)
187 {
188 	if (!pcie_aer_is_native(dev))
189 		return;
190 
191 	switch (ecrc_policy) {
192 	case ECRC_POLICY_DEFAULT:
193 		return;
194 	case ECRC_POLICY_OFF:
195 		disable_ecrc_checking(dev);
196 		break;
197 	case ECRC_POLICY_ON:
198 		enable_ecrc_checking(dev);
199 		break;
200 	default:
201 		return;
202 	}
203 }
204 
205 /**
206  * pcie_ecrc_get_policy - parse kernel command-line ecrc option
207  * @str: ECRC policy from kernel command line to use
208  */
209 void pcie_ecrc_get_policy(char *str)
210 {
211 	int i;
212 
213 	i = match_string(ecrc_policy_str, ARRAY_SIZE(ecrc_policy_str), str);
214 	if (i < 0)
215 		return;
216 
217 	ecrc_policy = i;
218 }
219 #endif	/* CONFIG_PCIE_ECRC */
220 
221 #define	PCI_EXP_AER_FLAGS	(PCI_EXP_DEVCTL_CERE | PCI_EXP_DEVCTL_NFERE | \
222 				 PCI_EXP_DEVCTL_FERE | PCI_EXP_DEVCTL_URRE)
223 
224 int pcie_aer_is_native(struct pci_dev *dev)
225 {
226 	struct pci_host_bridge *host = pci_find_host_bridge(dev->bus);
227 
228 	if (!dev->aer_cap)
229 		return 0;
230 
231 	return pcie_ports_native || host->native_aer;
232 }
233 EXPORT_SYMBOL_NS_GPL(pcie_aer_is_native, CXL);
234 
235 static int pci_enable_pcie_error_reporting(struct pci_dev *dev)
236 {
237 	int rc;
238 
239 	if (!pcie_aer_is_native(dev))
240 		return -EIO;
241 
242 	rc = pcie_capability_set_word(dev, PCI_EXP_DEVCTL, PCI_EXP_AER_FLAGS);
243 	return pcibios_err_to_errno(rc);
244 }
245 
246 int pci_aer_clear_nonfatal_status(struct pci_dev *dev)
247 {
248 	int aer = dev->aer_cap;
249 	u32 status, sev;
250 
251 	if (!pcie_aer_is_native(dev))
252 		return -EIO;
253 
254 	/* Clear status bits for ERR_NONFATAL errors only */
255 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, &status);
256 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_SEVER, &sev);
257 	status &= ~sev;
258 	if (status)
259 		pci_write_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, status);
260 
261 	return 0;
262 }
263 EXPORT_SYMBOL_GPL(pci_aer_clear_nonfatal_status);
264 
265 void pci_aer_clear_fatal_status(struct pci_dev *dev)
266 {
267 	int aer = dev->aer_cap;
268 	u32 status, sev;
269 
270 	if (!pcie_aer_is_native(dev))
271 		return;
272 
273 	/* Clear status bits for ERR_FATAL errors only */
274 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, &status);
275 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_SEVER, &sev);
276 	status &= sev;
277 	if (status)
278 		pci_write_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, status);
279 }
280 
281 /**
282  * pci_aer_raw_clear_status - Clear AER error registers.
283  * @dev: the PCI device
284  *
285  * Clearing AER error status registers unconditionally, regardless of
286  * whether they're owned by firmware or the OS.
287  *
288  * Returns 0 on success, or negative on failure.
289  */
290 int pci_aer_raw_clear_status(struct pci_dev *dev)
291 {
292 	int aer = dev->aer_cap;
293 	u32 status;
294 	int port_type;
295 
296 	if (!aer)
297 		return -EIO;
298 
299 	port_type = pci_pcie_type(dev);
300 	if (port_type == PCI_EXP_TYPE_ROOT_PORT ||
301 	    port_type == PCI_EXP_TYPE_RC_EC) {
302 		pci_read_config_dword(dev, aer + PCI_ERR_ROOT_STATUS, &status);
303 		pci_write_config_dword(dev, aer + PCI_ERR_ROOT_STATUS, status);
304 	}
305 
306 	pci_read_config_dword(dev, aer + PCI_ERR_COR_STATUS, &status);
307 	pci_write_config_dword(dev, aer + PCI_ERR_COR_STATUS, status);
308 
309 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, &status);
310 	pci_write_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, status);
311 
312 	return 0;
313 }
314 
315 int pci_aer_clear_status(struct pci_dev *dev)
316 {
317 	if (!pcie_aer_is_native(dev))
318 		return -EIO;
319 
320 	return pci_aer_raw_clear_status(dev);
321 }
322 
323 void pci_save_aer_state(struct pci_dev *dev)
324 {
325 	int aer = dev->aer_cap;
326 	struct pci_cap_saved_state *save_state;
327 	u32 *cap;
328 
329 	if (!aer)
330 		return;
331 
332 	save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_ERR);
333 	if (!save_state)
334 		return;
335 
336 	cap = &save_state->cap.data[0];
337 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_MASK, cap++);
338 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_SEVER, cap++);
339 	pci_read_config_dword(dev, aer + PCI_ERR_COR_MASK, cap++);
340 	pci_read_config_dword(dev, aer + PCI_ERR_CAP, cap++);
341 	if (pcie_cap_has_rtctl(dev))
342 		pci_read_config_dword(dev, aer + PCI_ERR_ROOT_COMMAND, cap++);
343 }
344 
345 void pci_restore_aer_state(struct pci_dev *dev)
346 {
347 	int aer = dev->aer_cap;
348 	struct pci_cap_saved_state *save_state;
349 	u32 *cap;
350 
351 	if (!aer)
352 		return;
353 
354 	save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_ERR);
355 	if (!save_state)
356 		return;
357 
358 	cap = &save_state->cap.data[0];
359 	pci_write_config_dword(dev, aer + PCI_ERR_UNCOR_MASK, *cap++);
360 	pci_write_config_dword(dev, aer + PCI_ERR_UNCOR_SEVER, *cap++);
361 	pci_write_config_dword(dev, aer + PCI_ERR_COR_MASK, *cap++);
362 	pci_write_config_dword(dev, aer + PCI_ERR_CAP, *cap++);
363 	if (pcie_cap_has_rtctl(dev))
364 		pci_write_config_dword(dev, aer + PCI_ERR_ROOT_COMMAND, *cap++);
365 }
366 
367 void pci_aer_init(struct pci_dev *dev)
368 {
369 	int n;
370 
371 	dev->aer_cap = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
372 	if (!dev->aer_cap)
373 		return;
374 
375 	dev->aer_stats = kzalloc(sizeof(struct aer_stats), GFP_KERNEL);
376 
377 	/*
378 	 * We save/restore PCI_ERR_UNCOR_MASK, PCI_ERR_UNCOR_SEVER,
379 	 * PCI_ERR_COR_MASK, and PCI_ERR_CAP.  Root and Root Complex Event
380 	 * Collectors also implement PCI_ERR_ROOT_COMMAND (PCIe r5.0, sec
381 	 * 7.8.4).
382 	 */
383 	n = pcie_cap_has_rtctl(dev) ? 5 : 4;
384 	pci_add_ext_cap_save_buffer(dev, PCI_EXT_CAP_ID_ERR, sizeof(u32) * n);
385 
386 	pci_aer_clear_status(dev);
387 
388 	if (pci_aer_available())
389 		pci_enable_pcie_error_reporting(dev);
390 
391 	pcie_set_ecrc_checking(dev);
392 }
393 
394 void pci_aer_exit(struct pci_dev *dev)
395 {
396 	kfree(dev->aer_stats);
397 	dev->aer_stats = NULL;
398 }
399 
400 #define AER_AGENT_RECEIVER		0
401 #define AER_AGENT_REQUESTER		1
402 #define AER_AGENT_COMPLETER		2
403 #define AER_AGENT_TRANSMITTER		3
404 
405 #define AER_AGENT_REQUESTER_MASK(t)	((t == AER_CORRECTABLE) ?	\
406 	0 : (PCI_ERR_UNC_COMP_TIME|PCI_ERR_UNC_UNSUP))
407 #define AER_AGENT_COMPLETER_MASK(t)	((t == AER_CORRECTABLE) ?	\
408 	0 : PCI_ERR_UNC_COMP_ABORT)
409 #define AER_AGENT_TRANSMITTER_MASK(t)	((t == AER_CORRECTABLE) ?	\
410 	(PCI_ERR_COR_REP_ROLL|PCI_ERR_COR_REP_TIMER) : 0)
411 
412 #define AER_GET_AGENT(t, e)						\
413 	((e & AER_AGENT_COMPLETER_MASK(t)) ? AER_AGENT_COMPLETER :	\
414 	(e & AER_AGENT_REQUESTER_MASK(t)) ? AER_AGENT_REQUESTER :	\
415 	(e & AER_AGENT_TRANSMITTER_MASK(t)) ? AER_AGENT_TRANSMITTER :	\
416 	AER_AGENT_RECEIVER)
417 
418 #define AER_PHYSICAL_LAYER_ERROR	0
419 #define AER_DATA_LINK_LAYER_ERROR	1
420 #define AER_TRANSACTION_LAYER_ERROR	2
421 
422 #define AER_PHYSICAL_LAYER_ERROR_MASK(t) ((t == AER_CORRECTABLE) ?	\
423 	PCI_ERR_COR_RCVR : 0)
424 #define AER_DATA_LINK_LAYER_ERROR_MASK(t) ((t == AER_CORRECTABLE) ?	\
425 	(PCI_ERR_COR_BAD_TLP|						\
426 	PCI_ERR_COR_BAD_DLLP|						\
427 	PCI_ERR_COR_REP_ROLL|						\
428 	PCI_ERR_COR_REP_TIMER) : PCI_ERR_UNC_DLP)
429 
430 #define AER_GET_LAYER_ERROR(t, e)					\
431 	((e & AER_PHYSICAL_LAYER_ERROR_MASK(t)) ? AER_PHYSICAL_LAYER_ERROR : \
432 	(e & AER_DATA_LINK_LAYER_ERROR_MASK(t)) ? AER_DATA_LINK_LAYER_ERROR : \
433 	AER_TRANSACTION_LAYER_ERROR)
434 
435 /*
436  * AER error strings
437  */
438 static const char *aer_error_severity_string[] = {
439 	"Uncorrected (Non-Fatal)",
440 	"Uncorrected (Fatal)",
441 	"Corrected"
442 };
443 
444 static const char *aer_error_layer[] = {
445 	"Physical Layer",
446 	"Data Link Layer",
447 	"Transaction Layer"
448 };
449 
450 static const char *aer_correctable_error_string[] = {
451 	"RxErr",			/* Bit Position 0	*/
452 	NULL,
453 	NULL,
454 	NULL,
455 	NULL,
456 	NULL,
457 	"BadTLP",			/* Bit Position 6	*/
458 	"BadDLLP",			/* Bit Position 7	*/
459 	"Rollover",			/* Bit Position 8	*/
460 	NULL,
461 	NULL,
462 	NULL,
463 	"Timeout",			/* Bit Position 12	*/
464 	"NonFatalErr",			/* Bit Position 13	*/
465 	"CorrIntErr",			/* Bit Position 14	*/
466 	"HeaderOF",			/* Bit Position 15	*/
467 	NULL,				/* Bit Position 16	*/
468 	NULL,				/* Bit Position 17	*/
469 	NULL,				/* Bit Position 18	*/
470 	NULL,				/* Bit Position 19	*/
471 	NULL,				/* Bit Position 20	*/
472 	NULL,				/* Bit Position 21	*/
473 	NULL,				/* Bit Position 22	*/
474 	NULL,				/* Bit Position 23	*/
475 	NULL,				/* Bit Position 24	*/
476 	NULL,				/* Bit Position 25	*/
477 	NULL,				/* Bit Position 26	*/
478 	NULL,				/* Bit Position 27	*/
479 	NULL,				/* Bit Position 28	*/
480 	NULL,				/* Bit Position 29	*/
481 	NULL,				/* Bit Position 30	*/
482 	NULL,				/* Bit Position 31	*/
483 };
484 
485 static const char *aer_uncorrectable_error_string[] = {
486 	"Undefined",			/* Bit Position 0	*/
487 	NULL,
488 	NULL,
489 	NULL,
490 	"DLP",				/* Bit Position 4	*/
491 	"SDES",				/* Bit Position 5	*/
492 	NULL,
493 	NULL,
494 	NULL,
495 	NULL,
496 	NULL,
497 	NULL,
498 	"TLP",				/* Bit Position 12	*/
499 	"FCP",				/* Bit Position 13	*/
500 	"CmpltTO",			/* Bit Position 14	*/
501 	"CmpltAbrt",			/* Bit Position 15	*/
502 	"UnxCmplt",			/* Bit Position 16	*/
503 	"RxOF",				/* Bit Position 17	*/
504 	"MalfTLP",			/* Bit Position 18	*/
505 	"ECRC",				/* Bit Position 19	*/
506 	"UnsupReq",			/* Bit Position 20	*/
507 	"ACSViol",			/* Bit Position 21	*/
508 	"UncorrIntErr",			/* Bit Position 22	*/
509 	"BlockedTLP",			/* Bit Position 23	*/
510 	"AtomicOpBlocked",		/* Bit Position 24	*/
511 	"TLPBlockedErr",		/* Bit Position 25	*/
512 	"PoisonTLPBlocked",		/* Bit Position 26	*/
513 	NULL,				/* Bit Position 27	*/
514 	NULL,				/* Bit Position 28	*/
515 	NULL,				/* Bit Position 29	*/
516 	NULL,				/* Bit Position 30	*/
517 	NULL,				/* Bit Position 31	*/
518 };
519 
520 static const char *aer_agent_string[] = {
521 	"Receiver ID",
522 	"Requester ID",
523 	"Completer ID",
524 	"Transmitter ID"
525 };
526 
527 #define aer_stats_dev_attr(name, stats_array, strings_array,		\
528 			   total_string, total_field)			\
529 	static ssize_t							\
530 	name##_show(struct device *dev, struct device_attribute *attr,	\
531 		     char *buf)						\
532 {									\
533 	unsigned int i;							\
534 	struct pci_dev *pdev = to_pci_dev(dev);				\
535 	u64 *stats = pdev->aer_stats->stats_array;			\
536 	size_t len = 0;							\
537 									\
538 	for (i = 0; i < ARRAY_SIZE(pdev->aer_stats->stats_array); i++) {\
539 		if (strings_array[i])					\
540 			len += sysfs_emit_at(buf, len, "%s %llu\n",	\
541 					     strings_array[i],		\
542 					     stats[i]);			\
543 		else if (stats[i])					\
544 			len += sysfs_emit_at(buf, len,			\
545 					     #stats_array "_bit[%d] %llu\n",\
546 					     i, stats[i]);		\
547 	}								\
548 	len += sysfs_emit_at(buf, len, "TOTAL_%s %llu\n", total_string,	\
549 			     pdev->aer_stats->total_field);		\
550 	return len;							\
551 }									\
552 static DEVICE_ATTR_RO(name)
553 
554 aer_stats_dev_attr(aer_dev_correctable, dev_cor_errs,
555 		   aer_correctable_error_string, "ERR_COR",
556 		   dev_total_cor_errs);
557 aer_stats_dev_attr(aer_dev_fatal, dev_fatal_errs,
558 		   aer_uncorrectable_error_string, "ERR_FATAL",
559 		   dev_total_fatal_errs);
560 aer_stats_dev_attr(aer_dev_nonfatal, dev_nonfatal_errs,
561 		   aer_uncorrectable_error_string, "ERR_NONFATAL",
562 		   dev_total_nonfatal_errs);
563 
564 #define aer_stats_rootport_attr(name, field)				\
565 	static ssize_t							\
566 	name##_show(struct device *dev, struct device_attribute *attr,	\
567 		     char *buf)						\
568 {									\
569 	struct pci_dev *pdev = to_pci_dev(dev);				\
570 	return sysfs_emit(buf, "%llu\n", pdev->aer_stats->field);	\
571 }									\
572 static DEVICE_ATTR_RO(name)
573 
574 aer_stats_rootport_attr(aer_rootport_total_err_cor,
575 			 rootport_total_cor_errs);
576 aer_stats_rootport_attr(aer_rootport_total_err_fatal,
577 			 rootport_total_fatal_errs);
578 aer_stats_rootport_attr(aer_rootport_total_err_nonfatal,
579 			 rootport_total_nonfatal_errs);
580 
581 static struct attribute *aer_stats_attrs[] __ro_after_init = {
582 	&dev_attr_aer_dev_correctable.attr,
583 	&dev_attr_aer_dev_fatal.attr,
584 	&dev_attr_aer_dev_nonfatal.attr,
585 	&dev_attr_aer_rootport_total_err_cor.attr,
586 	&dev_attr_aer_rootport_total_err_fatal.attr,
587 	&dev_attr_aer_rootport_total_err_nonfatal.attr,
588 	NULL
589 };
590 
591 static umode_t aer_stats_attrs_are_visible(struct kobject *kobj,
592 					   struct attribute *a, int n)
593 {
594 	struct device *dev = kobj_to_dev(kobj);
595 	struct pci_dev *pdev = to_pci_dev(dev);
596 
597 	if (!pdev->aer_stats)
598 		return 0;
599 
600 	if ((a == &dev_attr_aer_rootport_total_err_cor.attr ||
601 	     a == &dev_attr_aer_rootport_total_err_fatal.attr ||
602 	     a == &dev_attr_aer_rootport_total_err_nonfatal.attr) &&
603 	    ((pci_pcie_type(pdev) != PCI_EXP_TYPE_ROOT_PORT) &&
604 	     (pci_pcie_type(pdev) != PCI_EXP_TYPE_RC_EC)))
605 		return 0;
606 
607 	return a->mode;
608 }
609 
610 const struct attribute_group aer_stats_attr_group = {
611 	.attrs  = aer_stats_attrs,
612 	.is_visible = aer_stats_attrs_are_visible,
613 };
614 
615 static void pci_dev_aer_stats_incr(struct pci_dev *pdev,
616 				   struct aer_err_info *info)
617 {
618 	unsigned long status = info->status & ~info->mask;
619 	int i, max = -1;
620 	u64 *counter = NULL;
621 	struct aer_stats *aer_stats = pdev->aer_stats;
622 
623 	if (!aer_stats)
624 		return;
625 
626 	switch (info->severity) {
627 	case AER_CORRECTABLE:
628 		aer_stats->dev_total_cor_errs++;
629 		counter = &aer_stats->dev_cor_errs[0];
630 		max = AER_MAX_TYPEOF_COR_ERRS;
631 		break;
632 	case AER_NONFATAL:
633 		aer_stats->dev_total_nonfatal_errs++;
634 		counter = &aer_stats->dev_nonfatal_errs[0];
635 		max = AER_MAX_TYPEOF_UNCOR_ERRS;
636 		break;
637 	case AER_FATAL:
638 		aer_stats->dev_total_fatal_errs++;
639 		counter = &aer_stats->dev_fatal_errs[0];
640 		max = AER_MAX_TYPEOF_UNCOR_ERRS;
641 		break;
642 	}
643 
644 	for_each_set_bit(i, &status, max)
645 		counter[i]++;
646 }
647 
648 static void pci_rootport_aer_stats_incr(struct pci_dev *pdev,
649 				 struct aer_err_source *e_src)
650 {
651 	struct aer_stats *aer_stats = pdev->aer_stats;
652 
653 	if (!aer_stats)
654 		return;
655 
656 	if (e_src->status & PCI_ERR_ROOT_COR_RCV)
657 		aer_stats->rootport_total_cor_errs++;
658 
659 	if (e_src->status & PCI_ERR_ROOT_UNCOR_RCV) {
660 		if (e_src->status & PCI_ERR_ROOT_FATAL_RCV)
661 			aer_stats->rootport_total_fatal_errs++;
662 		else
663 			aer_stats->rootport_total_nonfatal_errs++;
664 	}
665 }
666 
667 static void __print_tlp_header(struct pci_dev *dev,
668 			       struct aer_header_log_regs *t)
669 {
670 	pci_err(dev, "  TLP Header: %08x %08x %08x %08x\n",
671 		t->dw0, t->dw1, t->dw2, t->dw3);
672 }
673 
674 static void __aer_print_error(struct pci_dev *dev,
675 			      struct aer_err_info *info)
676 {
677 	const char **strings;
678 	unsigned long status = info->status & ~info->mask;
679 	const char *level, *errmsg;
680 	int i;
681 
682 	if (info->severity == AER_CORRECTABLE) {
683 		strings = aer_correctable_error_string;
684 		level = KERN_WARNING;
685 	} else {
686 		strings = aer_uncorrectable_error_string;
687 		level = KERN_ERR;
688 	}
689 
690 	for_each_set_bit(i, &status, 32) {
691 		errmsg = strings[i];
692 		if (!errmsg)
693 			errmsg = "Unknown Error Bit";
694 
695 		pci_printk(level, dev, "   [%2d] %-22s%s\n", i, errmsg,
696 				info->first_error == i ? " (First)" : "");
697 	}
698 	pci_dev_aer_stats_incr(dev, info);
699 }
700 
701 void aer_print_error(struct pci_dev *dev, struct aer_err_info *info)
702 {
703 	int layer, agent;
704 	int id = pci_dev_id(dev);
705 	const char *level;
706 
707 	if (!info->status) {
708 		pci_err(dev, "PCIe Bus Error: severity=%s, type=Inaccessible, (Unregistered Agent ID)\n",
709 			aer_error_severity_string[info->severity]);
710 		goto out;
711 	}
712 
713 	layer = AER_GET_LAYER_ERROR(info->severity, info->status);
714 	agent = AER_GET_AGENT(info->severity, info->status);
715 
716 	level = (info->severity == AER_CORRECTABLE) ? KERN_WARNING : KERN_ERR;
717 
718 	pci_printk(level, dev, "PCIe Bus Error: severity=%s, type=%s, (%s)\n",
719 		   aer_error_severity_string[info->severity],
720 		   aer_error_layer[layer], aer_agent_string[agent]);
721 
722 	pci_printk(level, dev, "  device [%04x:%04x] error status/mask=%08x/%08x\n",
723 		   dev->vendor, dev->device, info->status, info->mask);
724 
725 	__aer_print_error(dev, info);
726 
727 	if (info->tlp_header_valid)
728 		__print_tlp_header(dev, &info->tlp);
729 
730 out:
731 	if (info->id && info->error_dev_num > 1 && info->id == id)
732 		pci_err(dev, "  Error of this Agent is reported first\n");
733 
734 	trace_aer_event(dev_name(&dev->dev), (info->status & ~info->mask),
735 			info->severity, info->tlp_header_valid, &info->tlp);
736 }
737 
738 static void aer_print_port_info(struct pci_dev *dev, struct aer_err_info *info)
739 {
740 	u8 bus = info->id >> 8;
741 	u8 devfn = info->id & 0xff;
742 
743 	pci_info(dev, "%s%s error message received from %04x:%02x:%02x.%d\n",
744 		 info->multi_error_valid ? "Multiple " : "",
745 		 aer_error_severity_string[info->severity],
746 		 pci_domain_nr(dev->bus), bus, PCI_SLOT(devfn),
747 		 PCI_FUNC(devfn));
748 }
749 
750 #ifdef CONFIG_ACPI_APEI_PCIEAER
751 int cper_severity_to_aer(int cper_severity)
752 {
753 	switch (cper_severity) {
754 	case CPER_SEV_RECOVERABLE:
755 		return AER_NONFATAL;
756 	case CPER_SEV_FATAL:
757 		return AER_FATAL;
758 	default:
759 		return AER_CORRECTABLE;
760 	}
761 }
762 EXPORT_SYMBOL_GPL(cper_severity_to_aer);
763 
764 void cper_print_aer(struct pci_dev *dev, int aer_severity,
765 		    struct aer_capability_regs *aer)
766 {
767 	int layer, agent, tlp_header_valid = 0;
768 	u32 status, mask;
769 	struct aer_err_info info;
770 
771 	if (aer_severity == AER_CORRECTABLE) {
772 		status = aer->cor_status;
773 		mask = aer->cor_mask;
774 	} else {
775 		status = aer->uncor_status;
776 		mask = aer->uncor_mask;
777 		tlp_header_valid = status & AER_LOG_TLP_MASKS;
778 	}
779 
780 	layer = AER_GET_LAYER_ERROR(aer_severity, status);
781 	agent = AER_GET_AGENT(aer_severity, status);
782 
783 	memset(&info, 0, sizeof(info));
784 	info.severity = aer_severity;
785 	info.status = status;
786 	info.mask = mask;
787 	info.first_error = PCI_ERR_CAP_FEP(aer->cap_control);
788 
789 	pci_err(dev, "aer_status: 0x%08x, aer_mask: 0x%08x\n", status, mask);
790 	__aer_print_error(dev, &info);
791 	pci_err(dev, "aer_layer=%s, aer_agent=%s\n",
792 		aer_error_layer[layer], aer_agent_string[agent]);
793 
794 	if (aer_severity != AER_CORRECTABLE)
795 		pci_err(dev, "aer_uncor_severity: 0x%08x\n",
796 			aer->uncor_severity);
797 
798 	if (tlp_header_valid)
799 		__print_tlp_header(dev, &aer->header_log);
800 
801 	trace_aer_event(dev_name(&dev->dev), (status & ~mask),
802 			aer_severity, tlp_header_valid, &aer->header_log);
803 }
804 #endif
805 
806 /**
807  * add_error_device - list device to be handled
808  * @e_info: pointer to error info
809  * @dev: pointer to pci_dev to be added
810  */
811 static int add_error_device(struct aer_err_info *e_info, struct pci_dev *dev)
812 {
813 	if (e_info->error_dev_num < AER_MAX_MULTI_ERR_DEVICES) {
814 		e_info->dev[e_info->error_dev_num] = pci_dev_get(dev);
815 		e_info->error_dev_num++;
816 		return 0;
817 	}
818 	return -ENOSPC;
819 }
820 
821 /**
822  * is_error_source - check whether the device is source of reported error
823  * @dev: pointer to pci_dev to be checked
824  * @e_info: pointer to reported error info
825  */
826 static bool is_error_source(struct pci_dev *dev, struct aer_err_info *e_info)
827 {
828 	int aer = dev->aer_cap;
829 	u32 status, mask;
830 	u16 reg16;
831 
832 	/*
833 	 * When bus id is equal to 0, it might be a bad id
834 	 * reported by root port.
835 	 */
836 	if ((PCI_BUS_NUM(e_info->id) != 0) &&
837 	    !(dev->bus->bus_flags & PCI_BUS_FLAGS_NO_AERSID)) {
838 		/* Device ID match? */
839 		if (e_info->id == pci_dev_id(dev))
840 			return true;
841 
842 		/* Continue id comparing if there is no multiple error */
843 		if (!e_info->multi_error_valid)
844 			return false;
845 	}
846 
847 	/*
848 	 * When either
849 	 *      1) bus id is equal to 0. Some ports might lose the bus
850 	 *              id of error source id;
851 	 *      2) bus flag PCI_BUS_FLAGS_NO_AERSID is set
852 	 *      3) There are multiple errors and prior ID comparing fails;
853 	 * We check AER status registers to find possible reporter.
854 	 */
855 	if (atomic_read(&dev->enable_cnt) == 0)
856 		return false;
857 
858 	/* Check if AER is enabled */
859 	pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &reg16);
860 	if (!(reg16 & PCI_EXP_AER_FLAGS))
861 		return false;
862 
863 	if (!aer)
864 		return false;
865 
866 	/* Check if error is recorded */
867 	if (e_info->severity == AER_CORRECTABLE) {
868 		pci_read_config_dword(dev, aer + PCI_ERR_COR_STATUS, &status);
869 		pci_read_config_dword(dev, aer + PCI_ERR_COR_MASK, &mask);
870 	} else {
871 		pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, &status);
872 		pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_MASK, &mask);
873 	}
874 	if (status & ~mask)
875 		return true;
876 
877 	return false;
878 }
879 
880 static int find_device_iter(struct pci_dev *dev, void *data)
881 {
882 	struct aer_err_info *e_info = (struct aer_err_info *)data;
883 
884 	if (is_error_source(dev, e_info)) {
885 		/* List this device */
886 		if (add_error_device(e_info, dev)) {
887 			/* We cannot handle more... Stop iteration */
888 			/* TODO: Should print error message here? */
889 			return 1;
890 		}
891 
892 		/* If there is only a single error, stop iteration */
893 		if (!e_info->multi_error_valid)
894 			return 1;
895 	}
896 	return 0;
897 }
898 
899 /**
900  * find_source_device - search through device hierarchy for source device
901  * @parent: pointer to Root Port pci_dev data structure
902  * @e_info: including detailed error information such like id
903  *
904  * Return true if found.
905  *
906  * Invoked by DPC when error is detected at the Root Port.
907  * Caller of this function must set id, severity, and multi_error_valid of
908  * struct aer_err_info pointed by @e_info properly.  This function must fill
909  * e_info->error_dev_num and e_info->dev[], based on the given information.
910  */
911 static bool find_source_device(struct pci_dev *parent,
912 		struct aer_err_info *e_info)
913 {
914 	struct pci_dev *dev = parent;
915 	int result;
916 
917 	/* Must reset in this function */
918 	e_info->error_dev_num = 0;
919 
920 	/* Is Root Port an agent that sends error message? */
921 	result = find_device_iter(dev, e_info);
922 	if (result)
923 		return true;
924 
925 	if (pci_pcie_type(parent) == PCI_EXP_TYPE_RC_EC)
926 		pcie_walk_rcec(parent, find_device_iter, e_info);
927 	else
928 		pci_walk_bus(parent->subordinate, find_device_iter, e_info);
929 
930 	if (!e_info->error_dev_num) {
931 		u8 bus = e_info->id >> 8;
932 		u8 devfn = e_info->id & 0xff;
933 
934 		pci_info(parent, "found no error details for %04x:%02x:%02x.%d\n",
935 			 pci_domain_nr(parent->bus), bus, PCI_SLOT(devfn),
936 			 PCI_FUNC(devfn));
937 		return false;
938 	}
939 	return true;
940 }
941 
942 /**
943  * handle_error_source - handle logging error into an event log
944  * @dev: pointer to pci_dev data structure of error source device
945  * @info: comprehensive error information
946  *
947  * Invoked when an error being detected by Root Port.
948  */
949 static void handle_error_source(struct pci_dev *dev, struct aer_err_info *info)
950 {
951 	int aer = dev->aer_cap;
952 
953 	if (info->severity == AER_CORRECTABLE) {
954 		/*
955 		 * Correctable error does not need software intervention.
956 		 * No need to go through error recovery process.
957 		 */
958 		if (aer)
959 			pci_write_config_dword(dev, aer + PCI_ERR_COR_STATUS,
960 					info->status);
961 		if (pcie_aer_is_native(dev)) {
962 			struct pci_driver *pdrv = dev->driver;
963 
964 			if (pdrv && pdrv->err_handler &&
965 			    pdrv->err_handler->cor_error_detected)
966 				pdrv->err_handler->cor_error_detected(dev);
967 			pcie_clear_device_status(dev);
968 		}
969 	} else if (info->severity == AER_NONFATAL)
970 		pcie_do_recovery(dev, pci_channel_io_normal, aer_root_reset);
971 	else if (info->severity == AER_FATAL)
972 		pcie_do_recovery(dev, pci_channel_io_frozen, aer_root_reset);
973 	pci_dev_put(dev);
974 }
975 
976 #ifdef CONFIG_ACPI_APEI_PCIEAER
977 
978 #define AER_RECOVER_RING_SIZE		16
979 
980 struct aer_recover_entry {
981 	u8	bus;
982 	u8	devfn;
983 	u16	domain;
984 	int	severity;
985 	struct aer_capability_regs *regs;
986 };
987 
988 static DEFINE_KFIFO(aer_recover_ring, struct aer_recover_entry,
989 		    AER_RECOVER_RING_SIZE);
990 
991 static void aer_recover_work_func(struct work_struct *work)
992 {
993 	struct aer_recover_entry entry;
994 	struct pci_dev *pdev;
995 
996 	while (kfifo_get(&aer_recover_ring, &entry)) {
997 		pdev = pci_get_domain_bus_and_slot(entry.domain, entry.bus,
998 						   entry.devfn);
999 		if (!pdev) {
1000 			pr_err("no pci_dev for %04x:%02x:%02x.%x\n",
1001 			       entry.domain, entry.bus,
1002 			       PCI_SLOT(entry.devfn), PCI_FUNC(entry.devfn));
1003 			continue;
1004 		}
1005 		cper_print_aer(pdev, entry.severity, entry.regs);
1006 		/*
1007 		 * Memory for aer_capability_regs(entry.regs) is being allocated from the
1008 		 * ghes_estatus_pool to protect it from overwriting when multiple sections
1009 		 * are present in the error status. Thus free the same after processing
1010 		 * the data.
1011 		 */
1012 		ghes_estatus_pool_region_free((unsigned long)entry.regs,
1013 					      sizeof(struct aer_capability_regs));
1014 
1015 		if (entry.severity == AER_NONFATAL)
1016 			pcie_do_recovery(pdev, pci_channel_io_normal,
1017 					 aer_root_reset);
1018 		else if (entry.severity == AER_FATAL)
1019 			pcie_do_recovery(pdev, pci_channel_io_frozen,
1020 					 aer_root_reset);
1021 		pci_dev_put(pdev);
1022 	}
1023 }
1024 
1025 /*
1026  * Mutual exclusion for writers of aer_recover_ring, reader side don't
1027  * need lock, because there is only one reader and lock is not needed
1028  * between reader and writer.
1029  */
1030 static DEFINE_SPINLOCK(aer_recover_ring_lock);
1031 static DECLARE_WORK(aer_recover_work, aer_recover_work_func);
1032 
1033 void aer_recover_queue(int domain, unsigned int bus, unsigned int devfn,
1034 		       int severity, struct aer_capability_regs *aer_regs)
1035 {
1036 	struct aer_recover_entry entry = {
1037 		.bus		= bus,
1038 		.devfn		= devfn,
1039 		.domain		= domain,
1040 		.severity	= severity,
1041 		.regs		= aer_regs,
1042 	};
1043 
1044 	if (kfifo_in_spinlocked(&aer_recover_ring, &entry, 1,
1045 				 &aer_recover_ring_lock))
1046 		schedule_work(&aer_recover_work);
1047 	else
1048 		pr_err("buffer overflow in recovery for %04x:%02x:%02x.%x\n",
1049 		       domain, bus, PCI_SLOT(devfn), PCI_FUNC(devfn));
1050 }
1051 EXPORT_SYMBOL_GPL(aer_recover_queue);
1052 #endif
1053 
1054 /**
1055  * aer_get_device_error_info - read error status from dev and store it to info
1056  * @dev: pointer to the device expected to have a error record
1057  * @info: pointer to structure to store the error record
1058  *
1059  * Return 1 on success, 0 on error.
1060  *
1061  * Note that @info is reused among all error devices. Clear fields properly.
1062  */
1063 int aer_get_device_error_info(struct pci_dev *dev, struct aer_err_info *info)
1064 {
1065 	int type = pci_pcie_type(dev);
1066 	int aer = dev->aer_cap;
1067 	int temp;
1068 
1069 	/* Must reset in this function */
1070 	info->status = 0;
1071 	info->tlp_header_valid = 0;
1072 
1073 	/* The device might not support AER */
1074 	if (!aer)
1075 		return 0;
1076 
1077 	if (info->severity == AER_CORRECTABLE) {
1078 		pci_read_config_dword(dev, aer + PCI_ERR_COR_STATUS,
1079 			&info->status);
1080 		pci_read_config_dword(dev, aer + PCI_ERR_COR_MASK,
1081 			&info->mask);
1082 		if (!(info->status & ~info->mask))
1083 			return 0;
1084 	} else if (type == PCI_EXP_TYPE_ROOT_PORT ||
1085 		   type == PCI_EXP_TYPE_RC_EC ||
1086 		   type == PCI_EXP_TYPE_DOWNSTREAM ||
1087 		   info->severity == AER_NONFATAL) {
1088 
1089 		/* Link is still healthy for IO reads */
1090 		pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS,
1091 			&info->status);
1092 		pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_MASK,
1093 			&info->mask);
1094 		if (!(info->status & ~info->mask))
1095 			return 0;
1096 
1097 		/* Get First Error Pointer */
1098 		pci_read_config_dword(dev, aer + PCI_ERR_CAP, &temp);
1099 		info->first_error = PCI_ERR_CAP_FEP(temp);
1100 
1101 		if (info->status & AER_LOG_TLP_MASKS) {
1102 			info->tlp_header_valid = 1;
1103 			pci_read_config_dword(dev,
1104 				aer + PCI_ERR_HEADER_LOG, &info->tlp.dw0);
1105 			pci_read_config_dword(dev,
1106 				aer + PCI_ERR_HEADER_LOG + 4, &info->tlp.dw1);
1107 			pci_read_config_dword(dev,
1108 				aer + PCI_ERR_HEADER_LOG + 8, &info->tlp.dw2);
1109 			pci_read_config_dword(dev,
1110 				aer + PCI_ERR_HEADER_LOG + 12, &info->tlp.dw3);
1111 		}
1112 	}
1113 
1114 	return 1;
1115 }
1116 
1117 static inline void aer_process_err_devices(struct aer_err_info *e_info)
1118 {
1119 	int i;
1120 
1121 	/* Report all before handle them, not to lost records by reset etc. */
1122 	for (i = 0; i < e_info->error_dev_num && e_info->dev[i]; i++) {
1123 		if (aer_get_device_error_info(e_info->dev[i], e_info))
1124 			aer_print_error(e_info->dev[i], e_info);
1125 	}
1126 	for (i = 0; i < e_info->error_dev_num && e_info->dev[i]; i++) {
1127 		if (aer_get_device_error_info(e_info->dev[i], e_info))
1128 			handle_error_source(e_info->dev[i], e_info);
1129 	}
1130 }
1131 
1132 /**
1133  * aer_isr_one_error - consume an error detected by root port
1134  * @rpc: pointer to the root port which holds an error
1135  * @e_src: pointer to an error source
1136  */
1137 static void aer_isr_one_error(struct aer_rpc *rpc,
1138 		struct aer_err_source *e_src)
1139 {
1140 	struct pci_dev *pdev = rpc->rpd;
1141 	struct aer_err_info e_info;
1142 
1143 	pci_rootport_aer_stats_incr(pdev, e_src);
1144 
1145 	/*
1146 	 * There is a possibility that both correctable error and
1147 	 * uncorrectable error being logged. Report correctable error first.
1148 	 */
1149 	if (e_src->status & PCI_ERR_ROOT_COR_RCV) {
1150 		e_info.id = ERR_COR_ID(e_src->id);
1151 		e_info.severity = AER_CORRECTABLE;
1152 
1153 		if (e_src->status & PCI_ERR_ROOT_MULTI_COR_RCV)
1154 			e_info.multi_error_valid = 1;
1155 		else
1156 			e_info.multi_error_valid = 0;
1157 		aer_print_port_info(pdev, &e_info);
1158 
1159 		if (find_source_device(pdev, &e_info))
1160 			aer_process_err_devices(&e_info);
1161 	}
1162 
1163 	if (e_src->status & PCI_ERR_ROOT_UNCOR_RCV) {
1164 		e_info.id = ERR_UNCOR_ID(e_src->id);
1165 
1166 		if (e_src->status & PCI_ERR_ROOT_FATAL_RCV)
1167 			e_info.severity = AER_FATAL;
1168 		else
1169 			e_info.severity = AER_NONFATAL;
1170 
1171 		if (e_src->status & PCI_ERR_ROOT_MULTI_UNCOR_RCV)
1172 			e_info.multi_error_valid = 1;
1173 		else
1174 			e_info.multi_error_valid = 0;
1175 
1176 		aer_print_port_info(pdev, &e_info);
1177 
1178 		if (find_source_device(pdev, &e_info))
1179 			aer_process_err_devices(&e_info);
1180 	}
1181 }
1182 
1183 /**
1184  * aer_isr - consume errors detected by root port
1185  * @irq: IRQ assigned to Root Port
1186  * @context: pointer to Root Port data structure
1187  *
1188  * Invoked, as DPC, when root port records new detected error
1189  */
1190 static irqreturn_t aer_isr(int irq, void *context)
1191 {
1192 	struct pcie_device *dev = (struct pcie_device *)context;
1193 	struct aer_rpc *rpc = get_service_data(dev);
1194 	struct aer_err_source e_src;
1195 
1196 	if (kfifo_is_empty(&rpc->aer_fifo))
1197 		return IRQ_NONE;
1198 
1199 	while (kfifo_get(&rpc->aer_fifo, &e_src))
1200 		aer_isr_one_error(rpc, &e_src);
1201 	return IRQ_HANDLED;
1202 }
1203 
1204 /**
1205  * aer_irq - Root Port's ISR
1206  * @irq: IRQ assigned to Root Port
1207  * @context: pointer to Root Port data structure
1208  *
1209  * Invoked when Root Port detects AER messages.
1210  */
1211 static irqreturn_t aer_irq(int irq, void *context)
1212 {
1213 	struct pcie_device *pdev = (struct pcie_device *)context;
1214 	struct aer_rpc *rpc = get_service_data(pdev);
1215 	struct pci_dev *rp = rpc->rpd;
1216 	int aer = rp->aer_cap;
1217 	struct aer_err_source e_src = {};
1218 
1219 	pci_read_config_dword(rp, aer + PCI_ERR_ROOT_STATUS, &e_src.status);
1220 	if (!(e_src.status & AER_ERR_STATUS_MASK))
1221 		return IRQ_NONE;
1222 
1223 	pci_read_config_dword(rp, aer + PCI_ERR_ROOT_ERR_SRC, &e_src.id);
1224 	pci_write_config_dword(rp, aer + PCI_ERR_ROOT_STATUS, e_src.status);
1225 
1226 	if (!kfifo_put(&rpc->aer_fifo, e_src))
1227 		return IRQ_HANDLED;
1228 
1229 	return IRQ_WAKE_THREAD;
1230 }
1231 
1232 /**
1233  * aer_enable_rootport - enable Root Port's interrupts when receiving messages
1234  * @rpc: pointer to a Root Port data structure
1235  *
1236  * Invoked when PCIe bus loads AER service driver.
1237  */
1238 static void aer_enable_rootport(struct aer_rpc *rpc)
1239 {
1240 	struct pci_dev *pdev = rpc->rpd;
1241 	int aer = pdev->aer_cap;
1242 	u16 reg16;
1243 	u32 reg32;
1244 
1245 	/* Clear PCIe Capability's Device Status */
1246 	pcie_capability_read_word(pdev, PCI_EXP_DEVSTA, &reg16);
1247 	pcie_capability_write_word(pdev, PCI_EXP_DEVSTA, reg16);
1248 
1249 	/* Disable system error generation in response to error messages */
1250 	pcie_capability_clear_word(pdev, PCI_EXP_RTCTL,
1251 				   SYSTEM_ERROR_INTR_ON_MESG_MASK);
1252 
1253 	/* Clear error status */
1254 	pci_read_config_dword(pdev, aer + PCI_ERR_ROOT_STATUS, &reg32);
1255 	pci_write_config_dword(pdev, aer + PCI_ERR_ROOT_STATUS, reg32);
1256 	pci_read_config_dword(pdev, aer + PCI_ERR_COR_STATUS, &reg32);
1257 	pci_write_config_dword(pdev, aer + PCI_ERR_COR_STATUS, reg32);
1258 	pci_read_config_dword(pdev, aer + PCI_ERR_UNCOR_STATUS, &reg32);
1259 	pci_write_config_dword(pdev, aer + PCI_ERR_UNCOR_STATUS, reg32);
1260 
1261 	/* Enable Root Port's interrupt in response to error messages */
1262 	pci_read_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, &reg32);
1263 	reg32 |= ROOT_PORT_INTR_ON_MESG_MASK;
1264 	pci_write_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, reg32);
1265 }
1266 
1267 /**
1268  * aer_disable_rootport - disable Root Port's interrupts when receiving messages
1269  * @rpc: pointer to a Root Port data structure
1270  *
1271  * Invoked when PCIe bus unloads AER service driver.
1272  */
1273 static void aer_disable_rootport(struct aer_rpc *rpc)
1274 {
1275 	struct pci_dev *pdev = rpc->rpd;
1276 	int aer = pdev->aer_cap;
1277 	u32 reg32;
1278 
1279 	/* Disable Root's interrupt in response to error messages */
1280 	pci_read_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, &reg32);
1281 	reg32 &= ~ROOT_PORT_INTR_ON_MESG_MASK;
1282 	pci_write_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, reg32);
1283 
1284 	/* Clear Root's error status reg */
1285 	pci_read_config_dword(pdev, aer + PCI_ERR_ROOT_STATUS, &reg32);
1286 	pci_write_config_dword(pdev, aer + PCI_ERR_ROOT_STATUS, reg32);
1287 }
1288 
1289 /**
1290  * aer_remove - clean up resources
1291  * @dev: pointer to the pcie_dev data structure
1292  *
1293  * Invoked when PCI Express bus unloads or AER probe fails.
1294  */
1295 static void aer_remove(struct pcie_device *dev)
1296 {
1297 	struct aer_rpc *rpc = get_service_data(dev);
1298 
1299 	aer_disable_rootport(rpc);
1300 }
1301 
1302 /**
1303  * aer_probe - initialize resources
1304  * @dev: pointer to the pcie_dev data structure
1305  *
1306  * Invoked when PCI Express bus loads AER service driver.
1307  */
1308 static int aer_probe(struct pcie_device *dev)
1309 {
1310 	int status;
1311 	struct aer_rpc *rpc;
1312 	struct device *device = &dev->device;
1313 	struct pci_dev *port = dev->port;
1314 
1315 	BUILD_BUG_ON(ARRAY_SIZE(aer_correctable_error_string) <
1316 		     AER_MAX_TYPEOF_COR_ERRS);
1317 	BUILD_BUG_ON(ARRAY_SIZE(aer_uncorrectable_error_string) <
1318 		     AER_MAX_TYPEOF_UNCOR_ERRS);
1319 
1320 	/* Limit to Root Ports or Root Complex Event Collectors */
1321 	if ((pci_pcie_type(port) != PCI_EXP_TYPE_RC_EC) &&
1322 	    (pci_pcie_type(port) != PCI_EXP_TYPE_ROOT_PORT))
1323 		return -ENODEV;
1324 
1325 	rpc = devm_kzalloc(device, sizeof(struct aer_rpc), GFP_KERNEL);
1326 	if (!rpc)
1327 		return -ENOMEM;
1328 
1329 	rpc->rpd = port;
1330 	INIT_KFIFO(rpc->aer_fifo);
1331 	set_service_data(dev, rpc);
1332 
1333 	status = devm_request_threaded_irq(device, dev->irq, aer_irq, aer_isr,
1334 					   IRQF_SHARED, "aerdrv", dev);
1335 	if (status) {
1336 		pci_err(port, "request AER IRQ %d failed\n", dev->irq);
1337 		return status;
1338 	}
1339 
1340 	aer_enable_rootport(rpc);
1341 	pci_info(port, "enabled with IRQ %d\n", dev->irq);
1342 	return 0;
1343 }
1344 
1345 /**
1346  * aer_root_reset - reset Root Port hierarchy, RCEC, or RCiEP
1347  * @dev: pointer to Root Port, RCEC, or RCiEP
1348  *
1349  * Invoked by Port Bus driver when performing reset.
1350  */
1351 static pci_ers_result_t aer_root_reset(struct pci_dev *dev)
1352 {
1353 	int type = pci_pcie_type(dev);
1354 	struct pci_dev *root;
1355 	int aer;
1356 	struct pci_host_bridge *host = pci_find_host_bridge(dev->bus);
1357 	u32 reg32;
1358 	int rc;
1359 
1360 	/*
1361 	 * Only Root Ports and RCECs have AER Root Command and Root Status
1362 	 * registers.  If "dev" is an RCiEP, the relevant registers are in
1363 	 * the RCEC.
1364 	 */
1365 	if (type == PCI_EXP_TYPE_RC_END)
1366 		root = dev->rcec;
1367 	else
1368 		root = pcie_find_root_port(dev);
1369 
1370 	/*
1371 	 * If the platform retained control of AER, an RCiEP may not have
1372 	 * an RCEC visible to us, so dev->rcec ("root") may be NULL.  In
1373 	 * that case, firmware is responsible for these registers.
1374 	 */
1375 	aer = root ? root->aer_cap : 0;
1376 
1377 	if ((host->native_aer || pcie_ports_native) && aer) {
1378 		/* Disable Root's interrupt in response to error messages */
1379 		pci_read_config_dword(root, aer + PCI_ERR_ROOT_COMMAND, &reg32);
1380 		reg32 &= ~ROOT_PORT_INTR_ON_MESG_MASK;
1381 		pci_write_config_dword(root, aer + PCI_ERR_ROOT_COMMAND, reg32);
1382 	}
1383 
1384 	if (type == PCI_EXP_TYPE_RC_EC || type == PCI_EXP_TYPE_RC_END) {
1385 		rc = pcie_reset_flr(dev, PCI_RESET_DO_RESET);
1386 		if (!rc)
1387 			pci_info(dev, "has been reset\n");
1388 		else
1389 			pci_info(dev, "not reset (no FLR support: %d)\n", rc);
1390 	} else {
1391 		rc = pci_bus_error_reset(dev);
1392 		pci_info(dev, "%s Port link has been reset (%d)\n",
1393 			pci_is_root_bus(dev->bus) ? "Root" : "Downstream", rc);
1394 	}
1395 
1396 	if ((host->native_aer || pcie_ports_native) && aer) {
1397 		/* Clear Root Error Status */
1398 		pci_read_config_dword(root, aer + PCI_ERR_ROOT_STATUS, &reg32);
1399 		pci_write_config_dword(root, aer + PCI_ERR_ROOT_STATUS, reg32);
1400 
1401 		/* Enable Root Port's interrupt in response to error messages */
1402 		pci_read_config_dword(root, aer + PCI_ERR_ROOT_COMMAND, &reg32);
1403 		reg32 |= ROOT_PORT_INTR_ON_MESG_MASK;
1404 		pci_write_config_dword(root, aer + PCI_ERR_ROOT_COMMAND, reg32);
1405 	}
1406 
1407 	return rc ? PCI_ERS_RESULT_DISCONNECT : PCI_ERS_RESULT_RECOVERED;
1408 }
1409 
1410 static struct pcie_port_service_driver aerdriver = {
1411 	.name		= "aer",
1412 	.port_type	= PCIE_ANY_PORT,
1413 	.service	= PCIE_PORT_SERVICE_AER,
1414 
1415 	.probe		= aer_probe,
1416 	.remove		= aer_remove,
1417 };
1418 
1419 /**
1420  * pcie_aer_init - register AER root service driver
1421  *
1422  * Invoked when AER root service driver is loaded.
1423  */
1424 int __init pcie_aer_init(void)
1425 {
1426 	if (!pci_aer_available())
1427 		return -ENXIO;
1428 	return pcie_port_service_register(&aerdriver);
1429 }
1430