xref: /openbmc/linux/drivers/pci/pcie/aer.c (revision c699ce1a)
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 	switch (ecrc_policy) {
188 	case ECRC_POLICY_DEFAULT:
189 		return;
190 	case ECRC_POLICY_OFF:
191 		disable_ecrc_checking(dev);
192 		break;
193 	case ECRC_POLICY_ON:
194 		enable_ecrc_checking(dev);
195 		break;
196 	default:
197 		return;
198 	}
199 }
200 
201 /**
202  * pcie_ecrc_get_policy - parse kernel command-line ecrc option
203  * @str: ECRC policy from kernel command line to use
204  */
205 void pcie_ecrc_get_policy(char *str)
206 {
207 	int i;
208 
209 	i = match_string(ecrc_policy_str, ARRAY_SIZE(ecrc_policy_str), str);
210 	if (i < 0)
211 		return;
212 
213 	ecrc_policy = i;
214 }
215 #endif	/* CONFIG_PCIE_ECRC */
216 
217 #define	PCI_EXP_AER_FLAGS	(PCI_EXP_DEVCTL_CERE | PCI_EXP_DEVCTL_NFERE | \
218 				 PCI_EXP_DEVCTL_FERE | PCI_EXP_DEVCTL_URRE)
219 
220 int pcie_aer_is_native(struct pci_dev *dev)
221 {
222 	struct pci_host_bridge *host = pci_find_host_bridge(dev->bus);
223 
224 	if (!dev->aer_cap)
225 		return 0;
226 
227 	return pcie_ports_native || host->native_aer;
228 }
229 
230 int pci_enable_pcie_error_reporting(struct pci_dev *dev)
231 {
232 	int rc;
233 
234 	if (!pcie_aer_is_native(dev))
235 		return -EIO;
236 
237 	rc = pcie_capability_set_word(dev, PCI_EXP_DEVCTL, PCI_EXP_AER_FLAGS);
238 	return pcibios_err_to_errno(rc);
239 }
240 EXPORT_SYMBOL_GPL(pci_enable_pcie_error_reporting);
241 
242 int pci_disable_pcie_error_reporting(struct pci_dev *dev)
243 {
244 	int rc;
245 
246 	if (!pcie_aer_is_native(dev))
247 		return -EIO;
248 
249 	rc = pcie_capability_clear_word(dev, PCI_EXP_DEVCTL, PCI_EXP_AER_FLAGS);
250 	return pcibios_err_to_errno(rc);
251 }
252 EXPORT_SYMBOL_GPL(pci_disable_pcie_error_reporting);
253 
254 int pci_aer_clear_nonfatal_status(struct pci_dev *dev)
255 {
256 	int aer = dev->aer_cap;
257 	u32 status, sev;
258 
259 	if (!pcie_aer_is_native(dev))
260 		return -EIO;
261 
262 	/* Clear status bits for ERR_NONFATAL errors only */
263 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, &status);
264 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_SEVER, &sev);
265 	status &= ~sev;
266 	if (status)
267 		pci_write_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, status);
268 
269 	return 0;
270 }
271 EXPORT_SYMBOL_GPL(pci_aer_clear_nonfatal_status);
272 
273 void pci_aer_clear_fatal_status(struct pci_dev *dev)
274 {
275 	int aer = dev->aer_cap;
276 	u32 status, sev;
277 
278 	if (!pcie_aer_is_native(dev))
279 		return;
280 
281 	/* Clear status bits for ERR_FATAL errors only */
282 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, &status);
283 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_SEVER, &sev);
284 	status &= sev;
285 	if (status)
286 		pci_write_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, status);
287 }
288 
289 /**
290  * pci_aer_raw_clear_status - Clear AER error registers.
291  * @dev: the PCI device
292  *
293  * Clearing AER error status registers unconditionally, regardless of
294  * whether they're owned by firmware or the OS.
295  *
296  * Returns 0 on success, or negative on failure.
297  */
298 int pci_aer_raw_clear_status(struct pci_dev *dev)
299 {
300 	int aer = dev->aer_cap;
301 	u32 status;
302 	int port_type;
303 
304 	if (!aer)
305 		return -EIO;
306 
307 	port_type = pci_pcie_type(dev);
308 	if (port_type == PCI_EXP_TYPE_ROOT_PORT ||
309 	    port_type == PCI_EXP_TYPE_RC_EC) {
310 		pci_read_config_dword(dev, aer + PCI_ERR_ROOT_STATUS, &status);
311 		pci_write_config_dword(dev, aer + PCI_ERR_ROOT_STATUS, status);
312 	}
313 
314 	pci_read_config_dword(dev, aer + PCI_ERR_COR_STATUS, &status);
315 	pci_write_config_dword(dev, aer + PCI_ERR_COR_STATUS, status);
316 
317 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, &status);
318 	pci_write_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, status);
319 
320 	return 0;
321 }
322 
323 int pci_aer_clear_status(struct pci_dev *dev)
324 {
325 	if (!pcie_aer_is_native(dev))
326 		return -EIO;
327 
328 	return pci_aer_raw_clear_status(dev);
329 }
330 
331 void pci_save_aer_state(struct pci_dev *dev)
332 {
333 	int aer = dev->aer_cap;
334 	struct pci_cap_saved_state *save_state;
335 	u32 *cap;
336 
337 	if (!aer)
338 		return;
339 
340 	save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_ERR);
341 	if (!save_state)
342 		return;
343 
344 	cap = &save_state->cap.data[0];
345 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_MASK, cap++);
346 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_SEVER, cap++);
347 	pci_read_config_dword(dev, aer + PCI_ERR_COR_MASK, cap++);
348 	pci_read_config_dword(dev, aer + PCI_ERR_CAP, cap++);
349 	if (pcie_cap_has_rtctl(dev))
350 		pci_read_config_dword(dev, aer + PCI_ERR_ROOT_COMMAND, cap++);
351 }
352 
353 void pci_restore_aer_state(struct pci_dev *dev)
354 {
355 	int aer = dev->aer_cap;
356 	struct pci_cap_saved_state *save_state;
357 	u32 *cap;
358 
359 	if (!aer)
360 		return;
361 
362 	save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_ERR);
363 	if (!save_state)
364 		return;
365 
366 	cap = &save_state->cap.data[0];
367 	pci_write_config_dword(dev, aer + PCI_ERR_UNCOR_MASK, *cap++);
368 	pci_write_config_dword(dev, aer + PCI_ERR_UNCOR_SEVER, *cap++);
369 	pci_write_config_dword(dev, aer + PCI_ERR_COR_MASK, *cap++);
370 	pci_write_config_dword(dev, aer + PCI_ERR_CAP, *cap++);
371 	if (pcie_cap_has_rtctl(dev))
372 		pci_write_config_dword(dev, aer + PCI_ERR_ROOT_COMMAND, *cap++);
373 }
374 
375 void pci_aer_init(struct pci_dev *dev)
376 {
377 	int n;
378 
379 	dev->aer_cap = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
380 	if (!dev->aer_cap)
381 		return;
382 
383 	dev->aer_stats = kzalloc(sizeof(struct aer_stats), GFP_KERNEL);
384 
385 	/*
386 	 * We save/restore PCI_ERR_UNCOR_MASK, PCI_ERR_UNCOR_SEVER,
387 	 * PCI_ERR_COR_MASK, and PCI_ERR_CAP.  Root and Root Complex Event
388 	 * Collectors also implement PCI_ERR_ROOT_COMMAND (PCIe r5.0, sec
389 	 * 7.8.4).
390 	 */
391 	n = pcie_cap_has_rtctl(dev) ? 5 : 4;
392 	pci_add_ext_cap_save_buffer(dev, PCI_EXT_CAP_ID_ERR, sizeof(u32) * n);
393 
394 	pci_aer_clear_status(dev);
395 
396 	if (pci_aer_available())
397 		pci_enable_pcie_error_reporting(dev);
398 
399 	pcie_set_ecrc_checking(dev);
400 }
401 
402 void pci_aer_exit(struct pci_dev *dev)
403 {
404 	kfree(dev->aer_stats);
405 	dev->aer_stats = NULL;
406 }
407 
408 #define AER_AGENT_RECEIVER		0
409 #define AER_AGENT_REQUESTER		1
410 #define AER_AGENT_COMPLETER		2
411 #define AER_AGENT_TRANSMITTER		3
412 
413 #define AER_AGENT_REQUESTER_MASK(t)	((t == AER_CORRECTABLE) ?	\
414 	0 : (PCI_ERR_UNC_COMP_TIME|PCI_ERR_UNC_UNSUP))
415 #define AER_AGENT_COMPLETER_MASK(t)	((t == AER_CORRECTABLE) ?	\
416 	0 : PCI_ERR_UNC_COMP_ABORT)
417 #define AER_AGENT_TRANSMITTER_MASK(t)	((t == AER_CORRECTABLE) ?	\
418 	(PCI_ERR_COR_REP_ROLL|PCI_ERR_COR_REP_TIMER) : 0)
419 
420 #define AER_GET_AGENT(t, e)						\
421 	((e & AER_AGENT_COMPLETER_MASK(t)) ? AER_AGENT_COMPLETER :	\
422 	(e & AER_AGENT_REQUESTER_MASK(t)) ? AER_AGENT_REQUESTER :	\
423 	(e & AER_AGENT_TRANSMITTER_MASK(t)) ? AER_AGENT_TRANSMITTER :	\
424 	AER_AGENT_RECEIVER)
425 
426 #define AER_PHYSICAL_LAYER_ERROR	0
427 #define AER_DATA_LINK_LAYER_ERROR	1
428 #define AER_TRANSACTION_LAYER_ERROR	2
429 
430 #define AER_PHYSICAL_LAYER_ERROR_MASK(t) ((t == AER_CORRECTABLE) ?	\
431 	PCI_ERR_COR_RCVR : 0)
432 #define AER_DATA_LINK_LAYER_ERROR_MASK(t) ((t == AER_CORRECTABLE) ?	\
433 	(PCI_ERR_COR_BAD_TLP|						\
434 	PCI_ERR_COR_BAD_DLLP|						\
435 	PCI_ERR_COR_REP_ROLL|						\
436 	PCI_ERR_COR_REP_TIMER) : PCI_ERR_UNC_DLP)
437 
438 #define AER_GET_LAYER_ERROR(t, e)					\
439 	((e & AER_PHYSICAL_LAYER_ERROR_MASK(t)) ? AER_PHYSICAL_LAYER_ERROR : \
440 	(e & AER_DATA_LINK_LAYER_ERROR_MASK(t)) ? AER_DATA_LINK_LAYER_ERROR : \
441 	AER_TRANSACTION_LAYER_ERROR)
442 
443 /*
444  * AER error strings
445  */
446 static const char *aer_error_severity_string[] = {
447 	"Uncorrected (Non-Fatal)",
448 	"Uncorrected (Fatal)",
449 	"Corrected"
450 };
451 
452 static const char *aer_error_layer[] = {
453 	"Physical Layer",
454 	"Data Link Layer",
455 	"Transaction Layer"
456 };
457 
458 static const char *aer_correctable_error_string[] = {
459 	"RxErr",			/* Bit Position 0	*/
460 	NULL,
461 	NULL,
462 	NULL,
463 	NULL,
464 	NULL,
465 	"BadTLP",			/* Bit Position 6	*/
466 	"BadDLLP",			/* Bit Position 7	*/
467 	"Rollover",			/* Bit Position 8	*/
468 	NULL,
469 	NULL,
470 	NULL,
471 	"Timeout",			/* Bit Position 12	*/
472 	"NonFatalErr",			/* Bit Position 13	*/
473 	"CorrIntErr",			/* Bit Position 14	*/
474 	"HeaderOF",			/* Bit Position 15	*/
475 	NULL,				/* Bit Position 16	*/
476 	NULL,				/* Bit Position 17	*/
477 	NULL,				/* Bit Position 18	*/
478 	NULL,				/* Bit Position 19	*/
479 	NULL,				/* Bit Position 20	*/
480 	NULL,				/* Bit Position 21	*/
481 	NULL,				/* Bit Position 22	*/
482 	NULL,				/* Bit Position 23	*/
483 	NULL,				/* Bit Position 24	*/
484 	NULL,				/* Bit Position 25	*/
485 	NULL,				/* Bit Position 26	*/
486 	NULL,				/* Bit Position 27	*/
487 	NULL,				/* Bit Position 28	*/
488 	NULL,				/* Bit Position 29	*/
489 	NULL,				/* Bit Position 30	*/
490 	NULL,				/* Bit Position 31	*/
491 };
492 
493 static const char *aer_uncorrectable_error_string[] = {
494 	"Undefined",			/* Bit Position 0	*/
495 	NULL,
496 	NULL,
497 	NULL,
498 	"DLP",				/* Bit Position 4	*/
499 	"SDES",				/* Bit Position 5	*/
500 	NULL,
501 	NULL,
502 	NULL,
503 	NULL,
504 	NULL,
505 	NULL,
506 	"TLP",				/* Bit Position 12	*/
507 	"FCP",				/* Bit Position 13	*/
508 	"CmpltTO",			/* Bit Position 14	*/
509 	"CmpltAbrt",			/* Bit Position 15	*/
510 	"UnxCmplt",			/* Bit Position 16	*/
511 	"RxOF",				/* Bit Position 17	*/
512 	"MalfTLP",			/* Bit Position 18	*/
513 	"ECRC",				/* Bit Position 19	*/
514 	"UnsupReq",			/* Bit Position 20	*/
515 	"ACSViol",			/* Bit Position 21	*/
516 	"UncorrIntErr",			/* Bit Position 22	*/
517 	"BlockedTLP",			/* Bit Position 23	*/
518 	"AtomicOpBlocked",		/* Bit Position 24	*/
519 	"TLPBlockedErr",		/* Bit Position 25	*/
520 	"PoisonTLPBlocked",		/* Bit Position 26	*/
521 	NULL,				/* Bit Position 27	*/
522 	NULL,				/* Bit Position 28	*/
523 	NULL,				/* Bit Position 29	*/
524 	NULL,				/* Bit Position 30	*/
525 	NULL,				/* Bit Position 31	*/
526 };
527 
528 static const char *aer_agent_string[] = {
529 	"Receiver ID",
530 	"Requester ID",
531 	"Completer ID",
532 	"Transmitter ID"
533 };
534 
535 #define aer_stats_dev_attr(name, stats_array, strings_array,		\
536 			   total_string, total_field)			\
537 	static ssize_t							\
538 	name##_show(struct device *dev, struct device_attribute *attr,	\
539 		     char *buf)						\
540 {									\
541 	unsigned int i;							\
542 	struct pci_dev *pdev = to_pci_dev(dev);				\
543 	u64 *stats = pdev->aer_stats->stats_array;			\
544 	size_t len = 0;							\
545 									\
546 	for (i = 0; i < ARRAY_SIZE(pdev->aer_stats->stats_array); i++) {\
547 		if (strings_array[i])					\
548 			len += sysfs_emit_at(buf, len, "%s %llu\n",	\
549 					     strings_array[i],		\
550 					     stats[i]);			\
551 		else if (stats[i])					\
552 			len += sysfs_emit_at(buf, len,			\
553 					     #stats_array "_bit[%d] %llu\n",\
554 					     i, stats[i]);		\
555 	}								\
556 	len += sysfs_emit_at(buf, len, "TOTAL_%s %llu\n", total_string,	\
557 			     pdev->aer_stats->total_field);		\
558 	return len;							\
559 }									\
560 static DEVICE_ATTR_RO(name)
561 
562 aer_stats_dev_attr(aer_dev_correctable, dev_cor_errs,
563 		   aer_correctable_error_string, "ERR_COR",
564 		   dev_total_cor_errs);
565 aer_stats_dev_attr(aer_dev_fatal, dev_fatal_errs,
566 		   aer_uncorrectable_error_string, "ERR_FATAL",
567 		   dev_total_fatal_errs);
568 aer_stats_dev_attr(aer_dev_nonfatal, dev_nonfatal_errs,
569 		   aer_uncorrectable_error_string, "ERR_NONFATAL",
570 		   dev_total_nonfatal_errs);
571 
572 #define aer_stats_rootport_attr(name, field)				\
573 	static ssize_t							\
574 	name##_show(struct device *dev, struct device_attribute *attr,	\
575 		     char *buf)						\
576 {									\
577 	struct pci_dev *pdev = to_pci_dev(dev);				\
578 	return sysfs_emit(buf, "%llu\n", pdev->aer_stats->field);	\
579 }									\
580 static DEVICE_ATTR_RO(name)
581 
582 aer_stats_rootport_attr(aer_rootport_total_err_cor,
583 			 rootport_total_cor_errs);
584 aer_stats_rootport_attr(aer_rootport_total_err_fatal,
585 			 rootport_total_fatal_errs);
586 aer_stats_rootport_attr(aer_rootport_total_err_nonfatal,
587 			 rootport_total_nonfatal_errs);
588 
589 static struct attribute *aer_stats_attrs[] __ro_after_init = {
590 	&dev_attr_aer_dev_correctable.attr,
591 	&dev_attr_aer_dev_fatal.attr,
592 	&dev_attr_aer_dev_nonfatal.attr,
593 	&dev_attr_aer_rootport_total_err_cor.attr,
594 	&dev_attr_aer_rootport_total_err_fatal.attr,
595 	&dev_attr_aer_rootport_total_err_nonfatal.attr,
596 	NULL
597 };
598 
599 static umode_t aer_stats_attrs_are_visible(struct kobject *kobj,
600 					   struct attribute *a, int n)
601 {
602 	struct device *dev = kobj_to_dev(kobj);
603 	struct pci_dev *pdev = to_pci_dev(dev);
604 
605 	if (!pdev->aer_stats)
606 		return 0;
607 
608 	if ((a == &dev_attr_aer_rootport_total_err_cor.attr ||
609 	     a == &dev_attr_aer_rootport_total_err_fatal.attr ||
610 	     a == &dev_attr_aer_rootport_total_err_nonfatal.attr) &&
611 	    ((pci_pcie_type(pdev) != PCI_EXP_TYPE_ROOT_PORT) &&
612 	     (pci_pcie_type(pdev) != PCI_EXP_TYPE_RC_EC)))
613 		return 0;
614 
615 	return a->mode;
616 }
617 
618 const struct attribute_group aer_stats_attr_group = {
619 	.attrs  = aer_stats_attrs,
620 	.is_visible = aer_stats_attrs_are_visible,
621 };
622 
623 static void pci_dev_aer_stats_incr(struct pci_dev *pdev,
624 				   struct aer_err_info *info)
625 {
626 	unsigned long status = info->status & ~info->mask;
627 	int i, max = -1;
628 	u64 *counter = NULL;
629 	struct aer_stats *aer_stats = pdev->aer_stats;
630 
631 	if (!aer_stats)
632 		return;
633 
634 	switch (info->severity) {
635 	case AER_CORRECTABLE:
636 		aer_stats->dev_total_cor_errs++;
637 		counter = &aer_stats->dev_cor_errs[0];
638 		max = AER_MAX_TYPEOF_COR_ERRS;
639 		break;
640 	case AER_NONFATAL:
641 		aer_stats->dev_total_nonfatal_errs++;
642 		counter = &aer_stats->dev_nonfatal_errs[0];
643 		max = AER_MAX_TYPEOF_UNCOR_ERRS;
644 		break;
645 	case AER_FATAL:
646 		aer_stats->dev_total_fatal_errs++;
647 		counter = &aer_stats->dev_fatal_errs[0];
648 		max = AER_MAX_TYPEOF_UNCOR_ERRS;
649 		break;
650 	}
651 
652 	for_each_set_bit(i, &status, max)
653 		counter[i]++;
654 }
655 
656 static void pci_rootport_aer_stats_incr(struct pci_dev *pdev,
657 				 struct aer_err_source *e_src)
658 {
659 	struct aer_stats *aer_stats = pdev->aer_stats;
660 
661 	if (!aer_stats)
662 		return;
663 
664 	if (e_src->status & PCI_ERR_ROOT_COR_RCV)
665 		aer_stats->rootport_total_cor_errs++;
666 
667 	if (e_src->status & PCI_ERR_ROOT_UNCOR_RCV) {
668 		if (e_src->status & PCI_ERR_ROOT_FATAL_RCV)
669 			aer_stats->rootport_total_fatal_errs++;
670 		else
671 			aer_stats->rootport_total_nonfatal_errs++;
672 	}
673 }
674 
675 static void __print_tlp_header(struct pci_dev *dev,
676 			       struct aer_header_log_regs *t)
677 {
678 	pci_err(dev, "  TLP Header: %08x %08x %08x %08x\n",
679 		t->dw0, t->dw1, t->dw2, t->dw3);
680 }
681 
682 static void __aer_print_error(struct pci_dev *dev,
683 			      struct aer_err_info *info)
684 {
685 	const char **strings;
686 	unsigned long status = info->status & ~info->mask;
687 	const char *level, *errmsg;
688 	int i;
689 
690 	if (info->severity == AER_CORRECTABLE) {
691 		strings = aer_correctable_error_string;
692 		level = KERN_WARNING;
693 	} else {
694 		strings = aer_uncorrectable_error_string;
695 		level = KERN_ERR;
696 	}
697 
698 	for_each_set_bit(i, &status, 32) {
699 		errmsg = strings[i];
700 		if (!errmsg)
701 			errmsg = "Unknown Error Bit";
702 
703 		pci_printk(level, dev, "   [%2d] %-22s%s\n", i, errmsg,
704 				info->first_error == i ? " (First)" : "");
705 	}
706 	pci_dev_aer_stats_incr(dev, info);
707 }
708 
709 void aer_print_error(struct pci_dev *dev, struct aer_err_info *info)
710 {
711 	int layer, agent;
712 	int id = ((dev->bus->number << 8) | dev->devfn);
713 	const char *level;
714 
715 	if (!info->status) {
716 		pci_err(dev, "PCIe Bus Error: severity=%s, type=Inaccessible, (Unregistered Agent ID)\n",
717 			aer_error_severity_string[info->severity]);
718 		goto out;
719 	}
720 
721 	layer = AER_GET_LAYER_ERROR(info->severity, info->status);
722 	agent = AER_GET_AGENT(info->severity, info->status);
723 
724 	level = (info->severity == AER_CORRECTABLE) ? KERN_WARNING : KERN_ERR;
725 
726 	pci_printk(level, dev, "PCIe Bus Error: severity=%s, type=%s, (%s)\n",
727 		   aer_error_severity_string[info->severity],
728 		   aer_error_layer[layer], aer_agent_string[agent]);
729 
730 	pci_printk(level, dev, "  device [%04x:%04x] error status/mask=%08x/%08x\n",
731 		   dev->vendor, dev->device, info->status, info->mask);
732 
733 	__aer_print_error(dev, info);
734 
735 	if (info->tlp_header_valid)
736 		__print_tlp_header(dev, &info->tlp);
737 
738 out:
739 	if (info->id && info->error_dev_num > 1 && info->id == id)
740 		pci_err(dev, "  Error of this Agent is reported first\n");
741 
742 	trace_aer_event(dev_name(&dev->dev), (info->status & ~info->mask),
743 			info->severity, info->tlp_header_valid, &info->tlp);
744 }
745 
746 static void aer_print_port_info(struct pci_dev *dev, struct aer_err_info *info)
747 {
748 	u8 bus = info->id >> 8;
749 	u8 devfn = info->id & 0xff;
750 
751 	pci_info(dev, "%s%s error received: %04x:%02x:%02x.%d\n",
752 		 info->multi_error_valid ? "Multiple " : "",
753 		 aer_error_severity_string[info->severity],
754 		 pci_domain_nr(dev->bus), bus, PCI_SLOT(devfn),
755 		 PCI_FUNC(devfn));
756 }
757 
758 #ifdef CONFIG_ACPI_APEI_PCIEAER
759 int cper_severity_to_aer(int cper_severity)
760 {
761 	switch (cper_severity) {
762 	case CPER_SEV_RECOVERABLE:
763 		return AER_NONFATAL;
764 	case CPER_SEV_FATAL:
765 		return AER_FATAL;
766 	default:
767 		return AER_CORRECTABLE;
768 	}
769 }
770 EXPORT_SYMBOL_GPL(cper_severity_to_aer);
771 
772 void cper_print_aer(struct pci_dev *dev, int aer_severity,
773 		    struct aer_capability_regs *aer)
774 {
775 	int layer, agent, tlp_header_valid = 0;
776 	u32 status, mask;
777 	struct aer_err_info info;
778 
779 	if (aer_severity == AER_CORRECTABLE) {
780 		status = aer->cor_status;
781 		mask = aer->cor_mask;
782 	} else {
783 		status = aer->uncor_status;
784 		mask = aer->uncor_mask;
785 		tlp_header_valid = status & AER_LOG_TLP_MASKS;
786 	}
787 
788 	layer = AER_GET_LAYER_ERROR(aer_severity, status);
789 	agent = AER_GET_AGENT(aer_severity, status);
790 
791 	memset(&info, 0, sizeof(info));
792 	info.severity = aer_severity;
793 	info.status = status;
794 	info.mask = mask;
795 	info.first_error = PCI_ERR_CAP_FEP(aer->cap_control);
796 
797 	pci_err(dev, "aer_status: 0x%08x, aer_mask: 0x%08x\n", status, mask);
798 	__aer_print_error(dev, &info);
799 	pci_err(dev, "aer_layer=%s, aer_agent=%s\n",
800 		aer_error_layer[layer], aer_agent_string[agent]);
801 
802 	if (aer_severity != AER_CORRECTABLE)
803 		pci_err(dev, "aer_uncor_severity: 0x%08x\n",
804 			aer->uncor_severity);
805 
806 	if (tlp_header_valid)
807 		__print_tlp_header(dev, &aer->header_log);
808 
809 	trace_aer_event(dev_name(&dev->dev), (status & ~mask),
810 			aer_severity, tlp_header_valid, &aer->header_log);
811 }
812 #endif
813 
814 /**
815  * add_error_device - list device to be handled
816  * @e_info: pointer to error info
817  * @dev: pointer to pci_dev to be added
818  */
819 static int add_error_device(struct aer_err_info *e_info, struct pci_dev *dev)
820 {
821 	if (e_info->error_dev_num < AER_MAX_MULTI_ERR_DEVICES) {
822 		e_info->dev[e_info->error_dev_num] = pci_dev_get(dev);
823 		e_info->error_dev_num++;
824 		return 0;
825 	}
826 	return -ENOSPC;
827 }
828 
829 /**
830  * is_error_source - check whether the device is source of reported error
831  * @dev: pointer to pci_dev to be checked
832  * @e_info: pointer to reported error info
833  */
834 static bool is_error_source(struct pci_dev *dev, struct aer_err_info *e_info)
835 {
836 	int aer = dev->aer_cap;
837 	u32 status, mask;
838 	u16 reg16;
839 
840 	/*
841 	 * When bus id is equal to 0, it might be a bad id
842 	 * reported by root port.
843 	 */
844 	if ((PCI_BUS_NUM(e_info->id) != 0) &&
845 	    !(dev->bus->bus_flags & PCI_BUS_FLAGS_NO_AERSID)) {
846 		/* Device ID match? */
847 		if (e_info->id == ((dev->bus->number << 8) | dev->devfn))
848 			return true;
849 
850 		/* Continue id comparing if there is no multiple error */
851 		if (!e_info->multi_error_valid)
852 			return false;
853 	}
854 
855 	/*
856 	 * When either
857 	 *      1) bus id is equal to 0. Some ports might lose the bus
858 	 *              id of error source id;
859 	 *      2) bus flag PCI_BUS_FLAGS_NO_AERSID is set
860 	 *      3) There are multiple errors and prior ID comparing fails;
861 	 * We check AER status registers to find possible reporter.
862 	 */
863 	if (atomic_read(&dev->enable_cnt) == 0)
864 		return false;
865 
866 	/* Check if AER is enabled */
867 	pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &reg16);
868 	if (!(reg16 & PCI_EXP_AER_FLAGS))
869 		return false;
870 
871 	if (!aer)
872 		return false;
873 
874 	/* Check if error is recorded */
875 	if (e_info->severity == AER_CORRECTABLE) {
876 		pci_read_config_dword(dev, aer + PCI_ERR_COR_STATUS, &status);
877 		pci_read_config_dword(dev, aer + PCI_ERR_COR_MASK, &mask);
878 	} else {
879 		pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, &status);
880 		pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_MASK, &mask);
881 	}
882 	if (status & ~mask)
883 		return true;
884 
885 	return false;
886 }
887 
888 static int find_device_iter(struct pci_dev *dev, void *data)
889 {
890 	struct aer_err_info *e_info = (struct aer_err_info *)data;
891 
892 	if (is_error_source(dev, e_info)) {
893 		/* List this device */
894 		if (add_error_device(e_info, dev)) {
895 			/* We cannot handle more... Stop iteration */
896 			/* TODO: Should print error message here? */
897 			return 1;
898 		}
899 
900 		/* If there is only a single error, stop iteration */
901 		if (!e_info->multi_error_valid)
902 			return 1;
903 	}
904 	return 0;
905 }
906 
907 /**
908  * find_source_device - search through device hierarchy for source device
909  * @parent: pointer to Root Port pci_dev data structure
910  * @e_info: including detailed error information such like id
911  *
912  * Return true if found.
913  *
914  * Invoked by DPC when error is detected at the Root Port.
915  * Caller of this function must set id, severity, and multi_error_valid of
916  * struct aer_err_info pointed by @e_info properly.  This function must fill
917  * e_info->error_dev_num and e_info->dev[], based on the given information.
918  */
919 static bool find_source_device(struct pci_dev *parent,
920 		struct aer_err_info *e_info)
921 {
922 	struct pci_dev *dev = parent;
923 	int result;
924 
925 	/* Must reset in this function */
926 	e_info->error_dev_num = 0;
927 
928 	/* Is Root Port an agent that sends error message? */
929 	result = find_device_iter(dev, e_info);
930 	if (result)
931 		return true;
932 
933 	if (pci_pcie_type(parent) == PCI_EXP_TYPE_RC_EC)
934 		pcie_walk_rcec(parent, find_device_iter, e_info);
935 	else
936 		pci_walk_bus(parent->subordinate, find_device_iter, e_info);
937 
938 	if (!e_info->error_dev_num) {
939 		pci_info(parent, "can't find device of ID%04x\n", e_info->id);
940 		return false;
941 	}
942 	return true;
943 }
944 
945 /**
946  * handle_error_source - handle logging error into an event log
947  * @dev: pointer to pci_dev data structure of error source device
948  * @info: comprehensive error information
949  *
950  * Invoked when an error being detected by Root Port.
951  */
952 static void handle_error_source(struct pci_dev *dev, struct aer_err_info *info)
953 {
954 	int aer = dev->aer_cap;
955 
956 	if (info->severity == AER_CORRECTABLE) {
957 		/*
958 		 * Correctable error does not need software intervention.
959 		 * No need to go through error recovery process.
960 		 */
961 		if (aer)
962 			pci_write_config_dword(dev, aer + PCI_ERR_COR_STATUS,
963 					info->status);
964 		if (pcie_aer_is_native(dev)) {
965 			struct pci_driver *pdrv = dev->driver;
966 
967 			if (pdrv && pdrv->err_handler &&
968 			    pdrv->err_handler->cor_error_detected)
969 				pdrv->err_handler->cor_error_detected(dev);
970 			pcie_clear_device_status(dev);
971 		}
972 	} else if (info->severity == AER_NONFATAL)
973 		pcie_do_recovery(dev, pci_channel_io_normal, aer_root_reset);
974 	else if (info->severity == AER_FATAL)
975 		pcie_do_recovery(dev, pci_channel_io_frozen, aer_root_reset);
976 	pci_dev_put(dev);
977 }
978 
979 #ifdef CONFIG_ACPI_APEI_PCIEAER
980 
981 #define AER_RECOVER_RING_ORDER		4
982 #define AER_RECOVER_RING_SIZE		(1 << AER_RECOVER_RING_ORDER)
983 
984 struct aer_recover_entry {
985 	u8	bus;
986 	u8	devfn;
987 	u16	domain;
988 	int	severity;
989 	struct aer_capability_regs *regs;
990 };
991 
992 static DEFINE_KFIFO(aer_recover_ring, struct aer_recover_entry,
993 		    AER_RECOVER_RING_SIZE);
994 
995 static void aer_recover_work_func(struct work_struct *work)
996 {
997 	struct aer_recover_entry entry;
998 	struct pci_dev *pdev;
999 
1000 	while (kfifo_get(&aer_recover_ring, &entry)) {
1001 		pdev = pci_get_domain_bus_and_slot(entry.domain, entry.bus,
1002 						   entry.devfn);
1003 		if (!pdev) {
1004 			pr_err("no pci_dev for %04x:%02x:%02x.%x\n",
1005 			       entry.domain, entry.bus,
1006 			       PCI_SLOT(entry.devfn), PCI_FUNC(entry.devfn));
1007 			continue;
1008 		}
1009 		cper_print_aer(pdev, entry.severity, entry.regs);
1010 		if (entry.severity == AER_NONFATAL)
1011 			pcie_do_recovery(pdev, pci_channel_io_normal,
1012 					 aer_root_reset);
1013 		else if (entry.severity == AER_FATAL)
1014 			pcie_do_recovery(pdev, pci_channel_io_frozen,
1015 					 aer_root_reset);
1016 		pci_dev_put(pdev);
1017 	}
1018 }
1019 
1020 /*
1021  * Mutual exclusion for writers of aer_recover_ring, reader side don't
1022  * need lock, because there is only one reader and lock is not needed
1023  * between reader and writer.
1024  */
1025 static DEFINE_SPINLOCK(aer_recover_ring_lock);
1026 static DECLARE_WORK(aer_recover_work, aer_recover_work_func);
1027 
1028 void aer_recover_queue(int domain, unsigned int bus, unsigned int devfn,
1029 		       int severity, struct aer_capability_regs *aer_regs)
1030 {
1031 	struct aer_recover_entry entry = {
1032 		.bus		= bus,
1033 		.devfn		= devfn,
1034 		.domain		= domain,
1035 		.severity	= severity,
1036 		.regs		= aer_regs,
1037 	};
1038 
1039 	if (kfifo_in_spinlocked(&aer_recover_ring, &entry, 1,
1040 				 &aer_recover_ring_lock))
1041 		schedule_work(&aer_recover_work);
1042 	else
1043 		pr_err("buffer overflow in recovery for %04x:%02x:%02x.%x\n",
1044 		       domain, bus, PCI_SLOT(devfn), PCI_FUNC(devfn));
1045 }
1046 EXPORT_SYMBOL_GPL(aer_recover_queue);
1047 #endif
1048 
1049 /**
1050  * aer_get_device_error_info - read error status from dev and store it to info
1051  * @dev: pointer to the device expected to have a error record
1052  * @info: pointer to structure to store the error record
1053  *
1054  * Return 1 on success, 0 on error.
1055  *
1056  * Note that @info is reused among all error devices. Clear fields properly.
1057  */
1058 int aer_get_device_error_info(struct pci_dev *dev, struct aer_err_info *info)
1059 {
1060 	int type = pci_pcie_type(dev);
1061 	int aer = dev->aer_cap;
1062 	int temp;
1063 
1064 	/* Must reset in this function */
1065 	info->status = 0;
1066 	info->tlp_header_valid = 0;
1067 
1068 	/* The device might not support AER */
1069 	if (!aer)
1070 		return 0;
1071 
1072 	if (info->severity == AER_CORRECTABLE) {
1073 		pci_read_config_dword(dev, aer + PCI_ERR_COR_STATUS,
1074 			&info->status);
1075 		pci_read_config_dword(dev, aer + PCI_ERR_COR_MASK,
1076 			&info->mask);
1077 		if (!(info->status & ~info->mask))
1078 			return 0;
1079 	} else if (type == PCI_EXP_TYPE_ROOT_PORT ||
1080 		   type == PCI_EXP_TYPE_RC_EC ||
1081 		   type == PCI_EXP_TYPE_DOWNSTREAM ||
1082 		   info->severity == AER_NONFATAL) {
1083 
1084 		/* Link is still healthy for IO reads */
1085 		pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS,
1086 			&info->status);
1087 		pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_MASK,
1088 			&info->mask);
1089 		if (!(info->status & ~info->mask))
1090 			return 0;
1091 
1092 		/* Get First Error Pointer */
1093 		pci_read_config_dword(dev, aer + PCI_ERR_CAP, &temp);
1094 		info->first_error = PCI_ERR_CAP_FEP(temp);
1095 
1096 		if (info->status & AER_LOG_TLP_MASKS) {
1097 			info->tlp_header_valid = 1;
1098 			pci_read_config_dword(dev,
1099 				aer + PCI_ERR_HEADER_LOG, &info->tlp.dw0);
1100 			pci_read_config_dword(dev,
1101 				aer + PCI_ERR_HEADER_LOG + 4, &info->tlp.dw1);
1102 			pci_read_config_dword(dev,
1103 				aer + PCI_ERR_HEADER_LOG + 8, &info->tlp.dw2);
1104 			pci_read_config_dword(dev,
1105 				aer + PCI_ERR_HEADER_LOG + 12, &info->tlp.dw3);
1106 		}
1107 	}
1108 
1109 	return 1;
1110 }
1111 
1112 static inline void aer_process_err_devices(struct aer_err_info *e_info)
1113 {
1114 	int i;
1115 
1116 	/* Report all before handle them, not to lost records by reset etc. */
1117 	for (i = 0; i < e_info->error_dev_num && e_info->dev[i]; i++) {
1118 		if (aer_get_device_error_info(e_info->dev[i], e_info))
1119 			aer_print_error(e_info->dev[i], e_info);
1120 	}
1121 	for (i = 0; i < e_info->error_dev_num && e_info->dev[i]; i++) {
1122 		if (aer_get_device_error_info(e_info->dev[i], e_info))
1123 			handle_error_source(e_info->dev[i], e_info);
1124 	}
1125 }
1126 
1127 /**
1128  * aer_isr_one_error - consume an error detected by root port
1129  * @rpc: pointer to the root port which holds an error
1130  * @e_src: pointer to an error source
1131  */
1132 static void aer_isr_one_error(struct aer_rpc *rpc,
1133 		struct aer_err_source *e_src)
1134 {
1135 	struct pci_dev *pdev = rpc->rpd;
1136 	struct aer_err_info e_info;
1137 
1138 	pci_rootport_aer_stats_incr(pdev, e_src);
1139 
1140 	/*
1141 	 * There is a possibility that both correctable error and
1142 	 * uncorrectable error being logged. Report correctable error first.
1143 	 */
1144 	if (e_src->status & PCI_ERR_ROOT_COR_RCV) {
1145 		e_info.id = ERR_COR_ID(e_src->id);
1146 		e_info.severity = AER_CORRECTABLE;
1147 
1148 		if (e_src->status & PCI_ERR_ROOT_MULTI_COR_RCV)
1149 			e_info.multi_error_valid = 1;
1150 		else
1151 			e_info.multi_error_valid = 0;
1152 		aer_print_port_info(pdev, &e_info);
1153 
1154 		if (find_source_device(pdev, &e_info))
1155 			aer_process_err_devices(&e_info);
1156 	}
1157 
1158 	if (e_src->status & PCI_ERR_ROOT_UNCOR_RCV) {
1159 		e_info.id = ERR_UNCOR_ID(e_src->id);
1160 
1161 		if (e_src->status & PCI_ERR_ROOT_FATAL_RCV)
1162 			e_info.severity = AER_FATAL;
1163 		else
1164 			e_info.severity = AER_NONFATAL;
1165 
1166 		if (e_src->status & PCI_ERR_ROOT_MULTI_UNCOR_RCV)
1167 			e_info.multi_error_valid = 1;
1168 		else
1169 			e_info.multi_error_valid = 0;
1170 
1171 		aer_print_port_info(pdev, &e_info);
1172 
1173 		if (find_source_device(pdev, &e_info))
1174 			aer_process_err_devices(&e_info);
1175 	}
1176 }
1177 
1178 /**
1179  * aer_isr - consume errors detected by root port
1180  * @irq: IRQ assigned to Root Port
1181  * @context: pointer to Root Port data structure
1182  *
1183  * Invoked, as DPC, when root port records new detected error
1184  */
1185 static irqreturn_t aer_isr(int irq, void *context)
1186 {
1187 	struct pcie_device *dev = (struct pcie_device *)context;
1188 	struct aer_rpc *rpc = get_service_data(dev);
1189 	struct aer_err_source e_src;
1190 
1191 	if (kfifo_is_empty(&rpc->aer_fifo))
1192 		return IRQ_NONE;
1193 
1194 	while (kfifo_get(&rpc->aer_fifo, &e_src))
1195 		aer_isr_one_error(rpc, &e_src);
1196 	return IRQ_HANDLED;
1197 }
1198 
1199 /**
1200  * aer_irq - Root Port's ISR
1201  * @irq: IRQ assigned to Root Port
1202  * @context: pointer to Root Port data structure
1203  *
1204  * Invoked when Root Port detects AER messages.
1205  */
1206 static irqreturn_t aer_irq(int irq, void *context)
1207 {
1208 	struct pcie_device *pdev = (struct pcie_device *)context;
1209 	struct aer_rpc *rpc = get_service_data(pdev);
1210 	struct pci_dev *rp = rpc->rpd;
1211 	int aer = rp->aer_cap;
1212 	struct aer_err_source e_src = {};
1213 
1214 	pci_read_config_dword(rp, aer + PCI_ERR_ROOT_STATUS, &e_src.status);
1215 	if (!(e_src.status & AER_ERR_STATUS_MASK))
1216 		return IRQ_NONE;
1217 
1218 	pci_read_config_dword(rp, aer + PCI_ERR_ROOT_ERR_SRC, &e_src.id);
1219 	pci_write_config_dword(rp, aer + PCI_ERR_ROOT_STATUS, e_src.status);
1220 
1221 	if (!kfifo_put(&rpc->aer_fifo, e_src))
1222 		return IRQ_HANDLED;
1223 
1224 	return IRQ_WAKE_THREAD;
1225 }
1226 
1227 static int set_device_error_reporting(struct pci_dev *dev, void *data)
1228 {
1229 	bool enable = *((bool *)data);
1230 	int type = pci_pcie_type(dev);
1231 
1232 	if ((type == PCI_EXP_TYPE_ROOT_PORT) ||
1233 	    (type == PCI_EXP_TYPE_RC_EC) ||
1234 	    (type == PCI_EXP_TYPE_UPSTREAM) ||
1235 	    (type == PCI_EXP_TYPE_DOWNSTREAM)) {
1236 		if (enable)
1237 			pci_enable_pcie_error_reporting(dev);
1238 		else
1239 			pci_disable_pcie_error_reporting(dev);
1240 	}
1241 
1242 	return 0;
1243 }
1244 
1245 /**
1246  * set_downstream_devices_error_reporting - enable/disable the error reporting  bits on the root port and its downstream ports.
1247  * @dev: pointer to root port's pci_dev data structure
1248  * @enable: true = enable error reporting, false = disable error reporting.
1249  */
1250 static void set_downstream_devices_error_reporting(struct pci_dev *dev,
1251 						   bool enable)
1252 {
1253 	set_device_error_reporting(dev, &enable);
1254 
1255 	if (pci_pcie_type(dev) == PCI_EXP_TYPE_RC_EC)
1256 		pcie_walk_rcec(dev, set_device_error_reporting, &enable);
1257 	else if (dev->subordinate)
1258 		pci_walk_bus(dev->subordinate, set_device_error_reporting,
1259 			     &enable);
1260 
1261 }
1262 
1263 /**
1264  * aer_enable_rootport - enable Root Port's interrupts when receiving messages
1265  * @rpc: pointer to a Root Port data structure
1266  *
1267  * Invoked when PCIe bus loads AER service driver.
1268  */
1269 static void aer_enable_rootport(struct aer_rpc *rpc)
1270 {
1271 	struct pci_dev *pdev = rpc->rpd;
1272 	int aer = pdev->aer_cap;
1273 	u16 reg16;
1274 	u32 reg32;
1275 
1276 	/* Clear PCIe Capability's Device Status */
1277 	pcie_capability_read_word(pdev, PCI_EXP_DEVSTA, &reg16);
1278 	pcie_capability_write_word(pdev, PCI_EXP_DEVSTA, reg16);
1279 
1280 	/* Disable system error generation in response to error messages */
1281 	pcie_capability_clear_word(pdev, PCI_EXP_RTCTL,
1282 				   SYSTEM_ERROR_INTR_ON_MESG_MASK);
1283 
1284 	/* Clear error status */
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 	pci_read_config_dword(pdev, aer + PCI_ERR_COR_STATUS, &reg32);
1288 	pci_write_config_dword(pdev, aer + PCI_ERR_COR_STATUS, reg32);
1289 	pci_read_config_dword(pdev, aer + PCI_ERR_UNCOR_STATUS, &reg32);
1290 	pci_write_config_dword(pdev, aer + PCI_ERR_UNCOR_STATUS, reg32);
1291 
1292 	/*
1293 	 * Enable error reporting for the root port device and downstream port
1294 	 * devices.
1295 	 */
1296 	set_downstream_devices_error_reporting(pdev, true);
1297 
1298 	/* Enable Root Port's interrupt in response to error messages */
1299 	pci_read_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, &reg32);
1300 	reg32 |= ROOT_PORT_INTR_ON_MESG_MASK;
1301 	pci_write_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, reg32);
1302 }
1303 
1304 /**
1305  * aer_disable_rootport - disable Root Port's interrupts when receiving messages
1306  * @rpc: pointer to a Root Port data structure
1307  *
1308  * Invoked when PCIe bus unloads AER service driver.
1309  */
1310 static void aer_disable_rootport(struct aer_rpc *rpc)
1311 {
1312 	struct pci_dev *pdev = rpc->rpd;
1313 	int aer = pdev->aer_cap;
1314 	u32 reg32;
1315 
1316 	/*
1317 	 * Disable error reporting for the root port device and downstream port
1318 	 * devices.
1319 	 */
1320 	set_downstream_devices_error_reporting(pdev, false);
1321 
1322 	/* Disable Root's interrupt in response to error messages */
1323 	pci_read_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, &reg32);
1324 	reg32 &= ~ROOT_PORT_INTR_ON_MESG_MASK;
1325 	pci_write_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, reg32);
1326 
1327 	/* Clear Root's error status reg */
1328 	pci_read_config_dword(pdev, aer + PCI_ERR_ROOT_STATUS, &reg32);
1329 	pci_write_config_dword(pdev, aer + PCI_ERR_ROOT_STATUS, reg32);
1330 }
1331 
1332 /**
1333  * aer_remove - clean up resources
1334  * @dev: pointer to the pcie_dev data structure
1335  *
1336  * Invoked when PCI Express bus unloads or AER probe fails.
1337  */
1338 static void aer_remove(struct pcie_device *dev)
1339 {
1340 	struct aer_rpc *rpc = get_service_data(dev);
1341 
1342 	aer_disable_rootport(rpc);
1343 }
1344 
1345 /**
1346  * aer_probe - initialize resources
1347  * @dev: pointer to the pcie_dev data structure
1348  *
1349  * Invoked when PCI Express bus loads AER service driver.
1350  */
1351 static int aer_probe(struct pcie_device *dev)
1352 {
1353 	int status;
1354 	struct aer_rpc *rpc;
1355 	struct device *device = &dev->device;
1356 	struct pci_dev *port = dev->port;
1357 
1358 	BUILD_BUG_ON(ARRAY_SIZE(aer_correctable_error_string) <
1359 		     AER_MAX_TYPEOF_COR_ERRS);
1360 	BUILD_BUG_ON(ARRAY_SIZE(aer_uncorrectable_error_string) <
1361 		     AER_MAX_TYPEOF_UNCOR_ERRS);
1362 
1363 	/* Limit to Root Ports or Root Complex Event Collectors */
1364 	if ((pci_pcie_type(port) != PCI_EXP_TYPE_RC_EC) &&
1365 	    (pci_pcie_type(port) != PCI_EXP_TYPE_ROOT_PORT))
1366 		return -ENODEV;
1367 
1368 	rpc = devm_kzalloc(device, sizeof(struct aer_rpc), GFP_KERNEL);
1369 	if (!rpc)
1370 		return -ENOMEM;
1371 
1372 	rpc->rpd = port;
1373 	INIT_KFIFO(rpc->aer_fifo);
1374 	set_service_data(dev, rpc);
1375 
1376 	status = devm_request_threaded_irq(device, dev->irq, aer_irq, aer_isr,
1377 					   IRQF_SHARED, "aerdrv", dev);
1378 	if (status) {
1379 		pci_err(port, "request AER IRQ %d failed\n", dev->irq);
1380 		return status;
1381 	}
1382 
1383 	aer_enable_rootport(rpc);
1384 	pci_info(port, "enabled with IRQ %d\n", dev->irq);
1385 	return 0;
1386 }
1387 
1388 /**
1389  * aer_root_reset - reset Root Port hierarchy, RCEC, or RCiEP
1390  * @dev: pointer to Root Port, RCEC, or RCiEP
1391  *
1392  * Invoked by Port Bus driver when performing reset.
1393  */
1394 static pci_ers_result_t aer_root_reset(struct pci_dev *dev)
1395 {
1396 	int type = pci_pcie_type(dev);
1397 	struct pci_dev *root;
1398 	int aer;
1399 	struct pci_host_bridge *host = pci_find_host_bridge(dev->bus);
1400 	u32 reg32;
1401 	int rc;
1402 
1403 	/*
1404 	 * Only Root Ports and RCECs have AER Root Command and Root Status
1405 	 * registers.  If "dev" is an RCiEP, the relevant registers are in
1406 	 * the RCEC.
1407 	 */
1408 	if (type == PCI_EXP_TYPE_RC_END)
1409 		root = dev->rcec;
1410 	else
1411 		root = pcie_find_root_port(dev);
1412 
1413 	/*
1414 	 * If the platform retained control of AER, an RCiEP may not have
1415 	 * an RCEC visible to us, so dev->rcec ("root") may be NULL.  In
1416 	 * that case, firmware is responsible for these registers.
1417 	 */
1418 	aer = root ? root->aer_cap : 0;
1419 
1420 	if ((host->native_aer || pcie_ports_native) && aer) {
1421 		/* Disable Root's interrupt in response to error messages */
1422 		pci_read_config_dword(root, aer + PCI_ERR_ROOT_COMMAND, &reg32);
1423 		reg32 &= ~ROOT_PORT_INTR_ON_MESG_MASK;
1424 		pci_write_config_dword(root, aer + PCI_ERR_ROOT_COMMAND, reg32);
1425 	}
1426 
1427 	if (type == PCI_EXP_TYPE_RC_EC || type == PCI_EXP_TYPE_RC_END) {
1428 		rc = pcie_reset_flr(dev, PCI_RESET_DO_RESET);
1429 		if (!rc)
1430 			pci_info(dev, "has been reset\n");
1431 		else
1432 			pci_info(dev, "not reset (no FLR support: %d)\n", rc);
1433 	} else {
1434 		rc = pci_bus_error_reset(dev);
1435 		pci_info(dev, "%s Port link has been reset (%d)\n",
1436 			pci_is_root_bus(dev->bus) ? "Root" : "Downstream", rc);
1437 	}
1438 
1439 	if ((host->native_aer || pcie_ports_native) && aer) {
1440 		/* Clear Root Error Status */
1441 		pci_read_config_dword(root, aer + PCI_ERR_ROOT_STATUS, &reg32);
1442 		pci_write_config_dword(root, aer + PCI_ERR_ROOT_STATUS, reg32);
1443 
1444 		/* Enable Root Port's interrupt in response to error messages */
1445 		pci_read_config_dword(root, aer + PCI_ERR_ROOT_COMMAND, &reg32);
1446 		reg32 |= ROOT_PORT_INTR_ON_MESG_MASK;
1447 		pci_write_config_dword(root, aer + PCI_ERR_ROOT_COMMAND, reg32);
1448 	}
1449 
1450 	return rc ? PCI_ERS_RESULT_DISCONNECT : PCI_ERS_RESULT_RECOVERED;
1451 }
1452 
1453 static struct pcie_port_service_driver aerdriver = {
1454 	.name		= "aer",
1455 	.port_type	= PCIE_ANY_PORT,
1456 	.service	= PCIE_PORT_SERVICE_AER,
1457 
1458 	.probe		= aer_probe,
1459 	.remove		= aer_remove,
1460 };
1461 
1462 /**
1463  * pcie_aer_init - register AER root service driver
1464  *
1465  * Invoked when AER root service driver is loaded.
1466  */
1467 int __init pcie_aer_init(void)
1468 {
1469 	if (!pci_aer_available())
1470 		return -ENXIO;
1471 	return pcie_port_service_register(&aerdriver);
1472 }
1473