xref: /openbmc/linux/drivers/pci/pcie/aer.c (revision 305c8388)
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 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 static int pcie_aer_disable;
105 static pci_ers_result_t aer_root_reset(struct pci_dev *dev);
106 
107 void pci_no_aer(void)
108 {
109 	pcie_aer_disable = 1;
110 }
111 
112 bool pci_aer_available(void)
113 {
114 	return !pcie_aer_disable && pci_msi_enabled();
115 }
116 
117 #ifdef CONFIG_PCIE_ECRC
118 
119 #define ECRC_POLICY_DEFAULT 0		/* ECRC set by BIOS */
120 #define ECRC_POLICY_OFF     1		/* ECRC off for performance */
121 #define ECRC_POLICY_ON      2		/* ECRC on for data integrity */
122 
123 static int ecrc_policy = ECRC_POLICY_DEFAULT;
124 
125 static const char * const ecrc_policy_str[] = {
126 	[ECRC_POLICY_DEFAULT] = "bios",
127 	[ECRC_POLICY_OFF] = "off",
128 	[ECRC_POLICY_ON] = "on"
129 };
130 
131 /**
132  * enable_ercr_checking - enable PCIe ECRC checking for a device
133  * @dev: the PCI device
134  *
135  * Returns 0 on success, or negative on failure.
136  */
137 static int enable_ecrc_checking(struct pci_dev *dev)
138 {
139 	int aer = dev->aer_cap;
140 	u32 reg32;
141 
142 	if (!aer)
143 		return -ENODEV;
144 
145 	pci_read_config_dword(dev, aer + PCI_ERR_CAP, &reg32);
146 	if (reg32 & PCI_ERR_CAP_ECRC_GENC)
147 		reg32 |= PCI_ERR_CAP_ECRC_GENE;
148 	if (reg32 & PCI_ERR_CAP_ECRC_CHKC)
149 		reg32 |= PCI_ERR_CAP_ECRC_CHKE;
150 	pci_write_config_dword(dev, aer + PCI_ERR_CAP, reg32);
151 
152 	return 0;
153 }
154 
155 /**
156  * disable_ercr_checking - disables PCIe ECRC checking for a device
157  * @dev: the PCI device
158  *
159  * Returns 0 on success, or negative on failure.
160  */
161 static int disable_ecrc_checking(struct pci_dev *dev)
162 {
163 	int aer = dev->aer_cap;
164 	u32 reg32;
165 
166 	if (!aer)
167 		return -ENODEV;
168 
169 	pci_read_config_dword(dev, aer + PCI_ERR_CAP, &reg32);
170 	reg32 &= ~(PCI_ERR_CAP_ECRC_GENE | PCI_ERR_CAP_ECRC_CHKE);
171 	pci_write_config_dword(dev, aer + PCI_ERR_CAP, reg32);
172 
173 	return 0;
174 }
175 
176 /**
177  * pcie_set_ecrc_checking - set/unset PCIe ECRC checking for a device based on global policy
178  * @dev: the PCI device
179  */
180 void pcie_set_ecrc_checking(struct pci_dev *dev)
181 {
182 	switch (ecrc_policy) {
183 	case ECRC_POLICY_DEFAULT:
184 		return;
185 	case ECRC_POLICY_OFF:
186 		disable_ecrc_checking(dev);
187 		break;
188 	case ECRC_POLICY_ON:
189 		enable_ecrc_checking(dev);
190 		break;
191 	default:
192 		return;
193 	}
194 }
195 
196 /**
197  * pcie_ecrc_get_policy - parse kernel command-line ecrc option
198  * @str: ECRC policy from kernel command line to use
199  */
200 void pcie_ecrc_get_policy(char *str)
201 {
202 	int i;
203 
204 	i = match_string(ecrc_policy_str, ARRAY_SIZE(ecrc_policy_str), str);
205 	if (i < 0)
206 		return;
207 
208 	ecrc_policy = i;
209 }
210 #endif	/* CONFIG_PCIE_ECRC */
211 
212 #define	PCI_EXP_AER_FLAGS	(PCI_EXP_DEVCTL_CERE | PCI_EXP_DEVCTL_NFERE | \
213 				 PCI_EXP_DEVCTL_FERE | PCI_EXP_DEVCTL_URRE)
214 
215 int pcie_aer_is_native(struct pci_dev *dev)
216 {
217 	struct pci_host_bridge *host = pci_find_host_bridge(dev->bus);
218 
219 	if (!dev->aer_cap)
220 		return 0;
221 
222 	return pcie_ports_native || host->native_aer;
223 }
224 
225 int pci_enable_pcie_error_reporting(struct pci_dev *dev)
226 {
227 	if (!pcie_aer_is_native(dev))
228 		return -EIO;
229 
230 	return pcie_capability_set_word(dev, PCI_EXP_DEVCTL, PCI_EXP_AER_FLAGS);
231 }
232 EXPORT_SYMBOL_GPL(pci_enable_pcie_error_reporting);
233 
234 int pci_disable_pcie_error_reporting(struct pci_dev *dev)
235 {
236 	if (!pcie_aer_is_native(dev))
237 		return -EIO;
238 
239 	return pcie_capability_clear_word(dev, PCI_EXP_DEVCTL,
240 					  PCI_EXP_AER_FLAGS);
241 }
242 EXPORT_SYMBOL_GPL(pci_disable_pcie_error_reporting);
243 
244 void pci_aer_clear_device_status(struct pci_dev *dev)
245 {
246 	u16 sta;
247 
248 	pcie_capability_read_word(dev, PCI_EXP_DEVSTA, &sta);
249 	pcie_capability_write_word(dev, PCI_EXP_DEVSTA, sta);
250 }
251 
252 int pci_aer_clear_nonfatal_status(struct pci_dev *dev)
253 {
254 	int aer = dev->aer_cap;
255 	u32 status, sev;
256 
257 	if (!pcie_aer_is_native(dev))
258 		return -EIO;
259 
260 	/* Clear status bits for ERR_NONFATAL errors only */
261 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, &status);
262 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_SEVER, &sev);
263 	status &= ~sev;
264 	if (status)
265 		pci_write_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, status);
266 
267 	return 0;
268 }
269 EXPORT_SYMBOL_GPL(pci_aer_clear_nonfatal_status);
270 
271 void pci_aer_clear_fatal_status(struct pci_dev *dev)
272 {
273 	int aer = dev->aer_cap;
274 	u32 status, sev;
275 
276 	if (!pcie_aer_is_native(dev))
277 		return;
278 
279 	/* Clear status bits for ERR_FATAL errors only */
280 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, &status);
281 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_SEVER, &sev);
282 	status &= sev;
283 	if (status)
284 		pci_write_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, status);
285 }
286 
287 /**
288  * pci_aer_raw_clear_status - Clear AER error registers.
289  * @dev: the PCI device
290  *
291  * Clearing AER error status registers unconditionally, regardless of
292  * whether they're owned by firmware or the OS.
293  *
294  * Returns 0 on success, or negative on failure.
295  */
296 int pci_aer_raw_clear_status(struct pci_dev *dev)
297 {
298 	int aer = dev->aer_cap;
299 	u32 status;
300 	int port_type;
301 
302 	if (!aer)
303 		return -EIO;
304 
305 	port_type = pci_pcie_type(dev);
306 	if (port_type == PCI_EXP_TYPE_ROOT_PORT) {
307 		pci_read_config_dword(dev, aer + PCI_ERR_ROOT_STATUS, &status);
308 		pci_write_config_dword(dev, aer + PCI_ERR_ROOT_STATUS, status);
309 	}
310 
311 	pci_read_config_dword(dev, aer + PCI_ERR_COR_STATUS, &status);
312 	pci_write_config_dword(dev, aer + PCI_ERR_COR_STATUS, status);
313 
314 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, &status);
315 	pci_write_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, status);
316 
317 	return 0;
318 }
319 
320 int pci_aer_clear_status(struct pci_dev *dev)
321 {
322 	if (!pcie_aer_is_native(dev))
323 		return -EIO;
324 
325 	return pci_aer_raw_clear_status(dev);
326 }
327 
328 void pci_save_aer_state(struct pci_dev *dev)
329 {
330 	int aer = dev->aer_cap;
331 	struct pci_cap_saved_state *save_state;
332 	u32 *cap;
333 
334 	if (!aer)
335 		return;
336 
337 	save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_ERR);
338 	if (!save_state)
339 		return;
340 
341 	cap = &save_state->cap.data[0];
342 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_MASK, cap++);
343 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_SEVER, cap++);
344 	pci_read_config_dword(dev, aer + PCI_ERR_COR_MASK, cap++);
345 	pci_read_config_dword(dev, aer + PCI_ERR_CAP, cap++);
346 	if (pcie_cap_has_rtctl(dev))
347 		pci_read_config_dword(dev, aer + PCI_ERR_ROOT_COMMAND, cap++);
348 }
349 
350 void pci_restore_aer_state(struct pci_dev *dev)
351 {
352 	int aer = dev->aer_cap;
353 	struct pci_cap_saved_state *save_state;
354 	u32 *cap;
355 
356 	if (!aer)
357 		return;
358 
359 	save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_ERR);
360 	if (!save_state)
361 		return;
362 
363 	cap = &save_state->cap.data[0];
364 	pci_write_config_dword(dev, aer + PCI_ERR_UNCOR_MASK, *cap++);
365 	pci_write_config_dword(dev, aer + PCI_ERR_UNCOR_SEVER, *cap++);
366 	pci_write_config_dword(dev, aer + PCI_ERR_COR_MASK, *cap++);
367 	pci_write_config_dword(dev, aer + PCI_ERR_CAP, *cap++);
368 	if (pcie_cap_has_rtctl(dev))
369 		pci_write_config_dword(dev, aer + PCI_ERR_ROOT_COMMAND, *cap++);
370 }
371 
372 void pci_aer_init(struct pci_dev *dev)
373 {
374 	int n;
375 
376 	dev->aer_cap = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
377 	if (!dev->aer_cap)
378 		return;
379 
380 	dev->aer_stats = kzalloc(sizeof(struct aer_stats), GFP_KERNEL);
381 
382 	/*
383 	 * We save/restore PCI_ERR_UNCOR_MASK, PCI_ERR_UNCOR_SEVER,
384 	 * PCI_ERR_COR_MASK, and PCI_ERR_CAP.  Root and Root Complex Event
385 	 * Collectors also implement PCI_ERR_ROOT_COMMAND (PCIe r5.0, sec
386 	 * 7.8.4).
387 	 */
388 	n = pcie_cap_has_rtctl(dev) ? 5 : 4;
389 	pci_add_ext_cap_save_buffer(dev, PCI_EXT_CAP_ID_ERR, sizeof(u32) * n);
390 
391 	pci_aer_clear_status(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[AER_MAX_TYPEOF_COR_ERRS] = {
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 };
468 
469 static const char *aer_uncorrectable_error_string[AER_MAX_TYPEOF_UNCOR_ERRS] = {
470 	"Undefined",			/* Bit Position 0	*/
471 	NULL,
472 	NULL,
473 	NULL,
474 	"DLP",				/* Bit Position 4	*/
475 	"SDES",				/* Bit Position 5	*/
476 	NULL,
477 	NULL,
478 	NULL,
479 	NULL,
480 	NULL,
481 	NULL,
482 	"TLP",				/* Bit Position 12	*/
483 	"FCP",				/* Bit Position 13	*/
484 	"CmpltTO",			/* Bit Position 14	*/
485 	"CmpltAbrt",			/* Bit Position 15	*/
486 	"UnxCmplt",			/* Bit Position 16	*/
487 	"RxOF",				/* Bit Position 17	*/
488 	"MalfTLP",			/* Bit Position 18	*/
489 	"ECRC",				/* Bit Position 19	*/
490 	"UnsupReq",			/* Bit Position 20	*/
491 	"ACSViol",			/* Bit Position 21	*/
492 	"UncorrIntErr",			/* Bit Position 22	*/
493 	"BlockedTLP",			/* Bit Position 23	*/
494 	"AtomicOpBlocked",		/* Bit Position 24	*/
495 	"TLPBlockedErr",		/* Bit Position 25	*/
496 	"PoisonTLPBlocked",		/* Bit Position 26	*/
497 };
498 
499 static const char *aer_agent_string[] = {
500 	"Receiver ID",
501 	"Requester ID",
502 	"Completer ID",
503 	"Transmitter ID"
504 };
505 
506 #define aer_stats_dev_attr(name, stats_array, strings_array,		\
507 			   total_string, total_field)			\
508 	static ssize_t							\
509 	name##_show(struct device *dev, struct device_attribute *attr,	\
510 		     char *buf)						\
511 {									\
512 	unsigned int i;							\
513 	char *str = buf;						\
514 	struct pci_dev *pdev = to_pci_dev(dev);				\
515 	u64 *stats = pdev->aer_stats->stats_array;			\
516 									\
517 	for (i = 0; i < ARRAY_SIZE(strings_array); i++) {		\
518 		if (strings_array[i])					\
519 			str += sprintf(str, "%s %llu\n",		\
520 				       strings_array[i], stats[i]);	\
521 		else if (stats[i])					\
522 			str += sprintf(str, #stats_array "_bit[%d] %llu\n",\
523 				       i, stats[i]);			\
524 	}								\
525 	str += sprintf(str, "TOTAL_%s %llu\n", total_string,		\
526 		       pdev->aer_stats->total_field);			\
527 	return str-buf;							\
528 }									\
529 static DEVICE_ATTR_RO(name)
530 
531 aer_stats_dev_attr(aer_dev_correctable, dev_cor_errs,
532 		   aer_correctable_error_string, "ERR_COR",
533 		   dev_total_cor_errs);
534 aer_stats_dev_attr(aer_dev_fatal, dev_fatal_errs,
535 		   aer_uncorrectable_error_string, "ERR_FATAL",
536 		   dev_total_fatal_errs);
537 aer_stats_dev_attr(aer_dev_nonfatal, dev_nonfatal_errs,
538 		   aer_uncorrectable_error_string, "ERR_NONFATAL",
539 		   dev_total_nonfatal_errs);
540 
541 #define aer_stats_rootport_attr(name, field)				\
542 	static ssize_t							\
543 	name##_show(struct device *dev, struct device_attribute *attr,	\
544 		     char *buf)						\
545 {									\
546 	struct pci_dev *pdev = to_pci_dev(dev);				\
547 	return sprintf(buf, "%llu\n", pdev->aer_stats->field);		\
548 }									\
549 static DEVICE_ATTR_RO(name)
550 
551 aer_stats_rootport_attr(aer_rootport_total_err_cor,
552 			 rootport_total_cor_errs);
553 aer_stats_rootport_attr(aer_rootport_total_err_fatal,
554 			 rootport_total_fatal_errs);
555 aer_stats_rootport_attr(aer_rootport_total_err_nonfatal,
556 			 rootport_total_nonfatal_errs);
557 
558 static struct attribute *aer_stats_attrs[] __ro_after_init = {
559 	&dev_attr_aer_dev_correctable.attr,
560 	&dev_attr_aer_dev_fatal.attr,
561 	&dev_attr_aer_dev_nonfatal.attr,
562 	&dev_attr_aer_rootport_total_err_cor.attr,
563 	&dev_attr_aer_rootport_total_err_fatal.attr,
564 	&dev_attr_aer_rootport_total_err_nonfatal.attr,
565 	NULL
566 };
567 
568 static umode_t aer_stats_attrs_are_visible(struct kobject *kobj,
569 					   struct attribute *a, int n)
570 {
571 	struct device *dev = kobj_to_dev(kobj);
572 	struct pci_dev *pdev = to_pci_dev(dev);
573 
574 	if (!pdev->aer_stats)
575 		return 0;
576 
577 	if ((a == &dev_attr_aer_rootport_total_err_cor.attr ||
578 	     a == &dev_attr_aer_rootport_total_err_fatal.attr ||
579 	     a == &dev_attr_aer_rootport_total_err_nonfatal.attr) &&
580 	    pci_pcie_type(pdev) != PCI_EXP_TYPE_ROOT_PORT)
581 		return 0;
582 
583 	return a->mode;
584 }
585 
586 const struct attribute_group aer_stats_attr_group = {
587 	.attrs  = aer_stats_attrs,
588 	.is_visible = aer_stats_attrs_are_visible,
589 };
590 
591 static void pci_dev_aer_stats_incr(struct pci_dev *pdev,
592 				   struct aer_err_info *info)
593 {
594 	unsigned long status = info->status & ~info->mask;
595 	int i, max = -1;
596 	u64 *counter = NULL;
597 	struct aer_stats *aer_stats = pdev->aer_stats;
598 
599 	if (!aer_stats)
600 		return;
601 
602 	switch (info->severity) {
603 	case AER_CORRECTABLE:
604 		aer_stats->dev_total_cor_errs++;
605 		counter = &aer_stats->dev_cor_errs[0];
606 		max = AER_MAX_TYPEOF_COR_ERRS;
607 		break;
608 	case AER_NONFATAL:
609 		aer_stats->dev_total_nonfatal_errs++;
610 		counter = &aer_stats->dev_nonfatal_errs[0];
611 		max = AER_MAX_TYPEOF_UNCOR_ERRS;
612 		break;
613 	case AER_FATAL:
614 		aer_stats->dev_total_fatal_errs++;
615 		counter = &aer_stats->dev_fatal_errs[0];
616 		max = AER_MAX_TYPEOF_UNCOR_ERRS;
617 		break;
618 	}
619 
620 	for_each_set_bit(i, &status, max)
621 		counter[i]++;
622 }
623 
624 static void pci_rootport_aer_stats_incr(struct pci_dev *pdev,
625 				 struct aer_err_source *e_src)
626 {
627 	struct aer_stats *aer_stats = pdev->aer_stats;
628 
629 	if (!aer_stats)
630 		return;
631 
632 	if (e_src->status & PCI_ERR_ROOT_COR_RCV)
633 		aer_stats->rootport_total_cor_errs++;
634 
635 	if (e_src->status & PCI_ERR_ROOT_UNCOR_RCV) {
636 		if (e_src->status & PCI_ERR_ROOT_FATAL_RCV)
637 			aer_stats->rootport_total_fatal_errs++;
638 		else
639 			aer_stats->rootport_total_nonfatal_errs++;
640 	}
641 }
642 
643 static void __print_tlp_header(struct pci_dev *dev,
644 			       struct aer_header_log_regs *t)
645 {
646 	pci_err(dev, "  TLP Header: %08x %08x %08x %08x\n",
647 		t->dw0, t->dw1, t->dw2, t->dw3);
648 }
649 
650 static void __aer_print_error(struct pci_dev *dev,
651 			      struct aer_err_info *info)
652 {
653 	unsigned long status = info->status & ~info->mask;
654 	const char *errmsg = NULL;
655 	int i;
656 
657 	for_each_set_bit(i, &status, 32) {
658 		if (info->severity == AER_CORRECTABLE)
659 			errmsg = i < ARRAY_SIZE(aer_correctable_error_string) ?
660 				aer_correctable_error_string[i] : NULL;
661 		else
662 			errmsg = i < ARRAY_SIZE(aer_uncorrectable_error_string) ?
663 				aer_uncorrectable_error_string[i] : NULL;
664 
665 		if (errmsg)
666 			pci_err(dev, "   [%2d] %-22s%s\n", i, errmsg,
667 				info->first_error == i ? " (First)" : "");
668 		else
669 			pci_err(dev, "   [%2d] Unknown Error Bit%s\n",
670 				i, info->first_error == i ? " (First)" : "");
671 	}
672 	pci_dev_aer_stats_incr(dev, info);
673 }
674 
675 void aer_print_error(struct pci_dev *dev, struct aer_err_info *info)
676 {
677 	int layer, agent;
678 	int id = ((dev->bus->number << 8) | dev->devfn);
679 
680 	if (!info->status) {
681 		pci_err(dev, "PCIe Bus Error: severity=%s, type=Inaccessible, (Unregistered Agent ID)\n",
682 			aer_error_severity_string[info->severity]);
683 		goto out;
684 	}
685 
686 	layer = AER_GET_LAYER_ERROR(info->severity, info->status);
687 	agent = AER_GET_AGENT(info->severity, info->status);
688 
689 	pci_err(dev, "PCIe Bus Error: severity=%s, type=%s, (%s)\n",
690 		aer_error_severity_string[info->severity],
691 		aer_error_layer[layer], aer_agent_string[agent]);
692 
693 	pci_err(dev, "  device [%04x:%04x] error status/mask=%08x/%08x\n",
694 		dev->vendor, dev->device,
695 		info->status, info->mask);
696 
697 	__aer_print_error(dev, info);
698 
699 	if (info->tlp_header_valid)
700 		__print_tlp_header(dev, &info->tlp);
701 
702 out:
703 	if (info->id && info->error_dev_num > 1 && info->id == id)
704 		pci_err(dev, "  Error of this Agent is reported first\n");
705 
706 	trace_aer_event(dev_name(&dev->dev), (info->status & ~info->mask),
707 			info->severity, info->tlp_header_valid, &info->tlp);
708 }
709 
710 static void aer_print_port_info(struct pci_dev *dev, struct aer_err_info *info)
711 {
712 	u8 bus = info->id >> 8;
713 	u8 devfn = info->id & 0xff;
714 
715 	pci_info(dev, "%s%s error received: %04x:%02x:%02x.%d\n",
716 		 info->multi_error_valid ? "Multiple " : "",
717 		 aer_error_severity_string[info->severity],
718 		 pci_domain_nr(dev->bus), bus, PCI_SLOT(devfn),
719 		 PCI_FUNC(devfn));
720 }
721 
722 #ifdef CONFIG_ACPI_APEI_PCIEAER
723 int cper_severity_to_aer(int cper_severity)
724 {
725 	switch (cper_severity) {
726 	case CPER_SEV_RECOVERABLE:
727 		return AER_NONFATAL;
728 	case CPER_SEV_FATAL:
729 		return AER_FATAL;
730 	default:
731 		return AER_CORRECTABLE;
732 	}
733 }
734 EXPORT_SYMBOL_GPL(cper_severity_to_aer);
735 
736 void cper_print_aer(struct pci_dev *dev, int aer_severity,
737 		    struct aer_capability_regs *aer)
738 {
739 	int layer, agent, tlp_header_valid = 0;
740 	u32 status, mask;
741 	struct aer_err_info info;
742 
743 	if (aer_severity == AER_CORRECTABLE) {
744 		status = aer->cor_status;
745 		mask = aer->cor_mask;
746 	} else {
747 		status = aer->uncor_status;
748 		mask = aer->uncor_mask;
749 		tlp_header_valid = status & AER_LOG_TLP_MASKS;
750 	}
751 
752 	layer = AER_GET_LAYER_ERROR(aer_severity, status);
753 	agent = AER_GET_AGENT(aer_severity, status);
754 
755 	memset(&info, 0, sizeof(info));
756 	info.severity = aer_severity;
757 	info.status = status;
758 	info.mask = mask;
759 	info.first_error = PCI_ERR_CAP_FEP(aer->cap_control);
760 
761 	pci_err(dev, "aer_status: 0x%08x, aer_mask: 0x%08x\n", status, mask);
762 	__aer_print_error(dev, &info);
763 	pci_err(dev, "aer_layer=%s, aer_agent=%s\n",
764 		aer_error_layer[layer], aer_agent_string[agent]);
765 
766 	if (aer_severity != AER_CORRECTABLE)
767 		pci_err(dev, "aer_uncor_severity: 0x%08x\n",
768 			aer->uncor_severity);
769 
770 	if (tlp_header_valid)
771 		__print_tlp_header(dev, &aer->header_log);
772 
773 	trace_aer_event(dev_name(&dev->dev), (status & ~mask),
774 			aer_severity, tlp_header_valid, &aer->header_log);
775 }
776 #endif
777 
778 /**
779  * add_error_device - list device to be handled
780  * @e_info: pointer to error info
781  * @dev: pointer to pci_dev to be added
782  */
783 static int add_error_device(struct aer_err_info *e_info, struct pci_dev *dev)
784 {
785 	if (e_info->error_dev_num < AER_MAX_MULTI_ERR_DEVICES) {
786 		e_info->dev[e_info->error_dev_num] = pci_dev_get(dev);
787 		e_info->error_dev_num++;
788 		return 0;
789 	}
790 	return -ENOSPC;
791 }
792 
793 /**
794  * is_error_source - check whether the device is source of reported error
795  * @dev: pointer to pci_dev to be checked
796  * @e_info: pointer to reported error info
797  */
798 static bool is_error_source(struct pci_dev *dev, struct aer_err_info *e_info)
799 {
800 	int aer = dev->aer_cap;
801 	u32 status, mask;
802 	u16 reg16;
803 
804 	/*
805 	 * When bus id is equal to 0, it might be a bad id
806 	 * reported by root port.
807 	 */
808 	if ((PCI_BUS_NUM(e_info->id) != 0) &&
809 	    !(dev->bus->bus_flags & PCI_BUS_FLAGS_NO_AERSID)) {
810 		/* Device ID match? */
811 		if (e_info->id == ((dev->bus->number << 8) | dev->devfn))
812 			return true;
813 
814 		/* Continue id comparing if there is no multiple error */
815 		if (!e_info->multi_error_valid)
816 			return false;
817 	}
818 
819 	/*
820 	 * When either
821 	 *      1) bus id is equal to 0. Some ports might lose the bus
822 	 *              id of error source id;
823 	 *      2) bus flag PCI_BUS_FLAGS_NO_AERSID is set
824 	 *      3) There are multiple errors and prior ID comparing fails;
825 	 * We check AER status registers to find possible reporter.
826 	 */
827 	if (atomic_read(&dev->enable_cnt) == 0)
828 		return false;
829 
830 	/* Check if AER is enabled */
831 	pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &reg16);
832 	if (!(reg16 & PCI_EXP_AER_FLAGS))
833 		return false;
834 
835 	if (!aer)
836 		return false;
837 
838 	/* Check if error is recorded */
839 	if (e_info->severity == AER_CORRECTABLE) {
840 		pci_read_config_dword(dev, aer + PCI_ERR_COR_STATUS, &status);
841 		pci_read_config_dword(dev, aer + PCI_ERR_COR_MASK, &mask);
842 	} else {
843 		pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, &status);
844 		pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_MASK, &mask);
845 	}
846 	if (status & ~mask)
847 		return true;
848 
849 	return false;
850 }
851 
852 static int find_device_iter(struct pci_dev *dev, void *data)
853 {
854 	struct aer_err_info *e_info = (struct aer_err_info *)data;
855 
856 	if (is_error_source(dev, e_info)) {
857 		/* List this device */
858 		if (add_error_device(e_info, dev)) {
859 			/* We cannot handle more... Stop iteration */
860 			/* TODO: Should print error message here? */
861 			return 1;
862 		}
863 
864 		/* If there is only a single error, stop iteration */
865 		if (!e_info->multi_error_valid)
866 			return 1;
867 	}
868 	return 0;
869 }
870 
871 /**
872  * find_source_device - search through device hierarchy for source device
873  * @parent: pointer to Root Port pci_dev data structure
874  * @e_info: including detailed error information such like id
875  *
876  * Return true if found.
877  *
878  * Invoked by DPC when error is detected at the Root Port.
879  * Caller of this function must set id, severity, and multi_error_valid of
880  * struct aer_err_info pointed by @e_info properly.  This function must fill
881  * e_info->error_dev_num and e_info->dev[], based on the given information.
882  */
883 static bool find_source_device(struct pci_dev *parent,
884 		struct aer_err_info *e_info)
885 {
886 	struct pci_dev *dev = parent;
887 	int result;
888 
889 	/* Must reset in this function */
890 	e_info->error_dev_num = 0;
891 
892 	/* Is Root Port an agent that sends error message? */
893 	result = find_device_iter(dev, e_info);
894 	if (result)
895 		return true;
896 
897 	pci_walk_bus(parent->subordinate, find_device_iter, e_info);
898 
899 	if (!e_info->error_dev_num) {
900 		pci_info(parent, "can't find device of ID%04x\n", e_info->id);
901 		return false;
902 	}
903 	return true;
904 }
905 
906 /**
907  * handle_error_source - handle logging error into an event log
908  * @dev: pointer to pci_dev data structure of error source device
909  * @info: comprehensive error information
910  *
911  * Invoked when an error being detected by Root Port.
912  */
913 static void handle_error_source(struct pci_dev *dev, struct aer_err_info *info)
914 {
915 	int aer = dev->aer_cap;
916 
917 	if (info->severity == AER_CORRECTABLE) {
918 		/*
919 		 * Correctable error does not need software intervention.
920 		 * No need to go through error recovery process.
921 		 */
922 		if (aer)
923 			pci_write_config_dword(dev, aer + PCI_ERR_COR_STATUS,
924 					info->status);
925 		pci_aer_clear_device_status(dev);
926 	} else if (info->severity == AER_NONFATAL)
927 		pcie_do_recovery(dev, pci_channel_io_normal, aer_root_reset);
928 	else if (info->severity == AER_FATAL)
929 		pcie_do_recovery(dev, pci_channel_io_frozen, aer_root_reset);
930 	pci_dev_put(dev);
931 }
932 
933 #ifdef CONFIG_ACPI_APEI_PCIEAER
934 
935 #define AER_RECOVER_RING_ORDER		4
936 #define AER_RECOVER_RING_SIZE		(1 << AER_RECOVER_RING_ORDER)
937 
938 struct aer_recover_entry {
939 	u8	bus;
940 	u8	devfn;
941 	u16	domain;
942 	int	severity;
943 	struct aer_capability_regs *regs;
944 };
945 
946 static DEFINE_KFIFO(aer_recover_ring, struct aer_recover_entry,
947 		    AER_RECOVER_RING_SIZE);
948 
949 static void aer_recover_work_func(struct work_struct *work)
950 {
951 	struct aer_recover_entry entry;
952 	struct pci_dev *pdev;
953 
954 	while (kfifo_get(&aer_recover_ring, &entry)) {
955 		pdev = pci_get_domain_bus_and_slot(entry.domain, entry.bus,
956 						   entry.devfn);
957 		if (!pdev) {
958 			pr_err("AER recover: Can not find pci_dev for %04x:%02x:%02x:%x\n",
959 			       entry.domain, entry.bus,
960 			       PCI_SLOT(entry.devfn), PCI_FUNC(entry.devfn));
961 			continue;
962 		}
963 		cper_print_aer(pdev, entry.severity, entry.regs);
964 		if (entry.severity == AER_NONFATAL)
965 			pcie_do_recovery(pdev, pci_channel_io_normal,
966 					 aer_root_reset);
967 		else if (entry.severity == AER_FATAL)
968 			pcie_do_recovery(pdev, pci_channel_io_frozen,
969 					 aer_root_reset);
970 		pci_dev_put(pdev);
971 	}
972 }
973 
974 /*
975  * Mutual exclusion for writers of aer_recover_ring, reader side don't
976  * need lock, because there is only one reader and lock is not needed
977  * between reader and writer.
978  */
979 static DEFINE_SPINLOCK(aer_recover_ring_lock);
980 static DECLARE_WORK(aer_recover_work, aer_recover_work_func);
981 
982 void aer_recover_queue(int domain, unsigned int bus, unsigned int devfn,
983 		       int severity, struct aer_capability_regs *aer_regs)
984 {
985 	struct aer_recover_entry entry = {
986 		.bus		= bus,
987 		.devfn		= devfn,
988 		.domain		= domain,
989 		.severity	= severity,
990 		.regs		= aer_regs,
991 	};
992 
993 	if (kfifo_in_spinlocked(&aer_recover_ring, &entry, 1,
994 				 &aer_recover_ring_lock))
995 		schedule_work(&aer_recover_work);
996 	else
997 		pr_err("AER recover: Buffer overflow when recovering AER for %04x:%02x:%02x:%x\n",
998 		       domain, bus, PCI_SLOT(devfn), PCI_FUNC(devfn));
999 }
1000 EXPORT_SYMBOL_GPL(aer_recover_queue);
1001 #endif
1002 
1003 /**
1004  * aer_get_device_error_info - read error status from dev and store it to info
1005  * @dev: pointer to the device expected to have a error record
1006  * @info: pointer to structure to store the error record
1007  *
1008  * Return 1 on success, 0 on error.
1009  *
1010  * Note that @info is reused among all error devices. Clear fields properly.
1011  */
1012 int aer_get_device_error_info(struct pci_dev *dev, struct aer_err_info *info)
1013 {
1014 	int aer = dev->aer_cap;
1015 	int temp;
1016 
1017 	/* Must reset in this function */
1018 	info->status = 0;
1019 	info->tlp_header_valid = 0;
1020 
1021 	/* The device might not support AER */
1022 	if (!aer)
1023 		return 0;
1024 
1025 	if (info->severity == AER_CORRECTABLE) {
1026 		pci_read_config_dword(dev, aer + PCI_ERR_COR_STATUS,
1027 			&info->status);
1028 		pci_read_config_dword(dev, aer + PCI_ERR_COR_MASK,
1029 			&info->mask);
1030 		if (!(info->status & ~info->mask))
1031 			return 0;
1032 	} else if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT ||
1033 	           pci_pcie_type(dev) == PCI_EXP_TYPE_DOWNSTREAM ||
1034 		   info->severity == AER_NONFATAL) {
1035 
1036 		/* Link is still healthy for IO reads */
1037 		pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS,
1038 			&info->status);
1039 		pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_MASK,
1040 			&info->mask);
1041 		if (!(info->status & ~info->mask))
1042 			return 0;
1043 
1044 		/* Get First Error Pointer */
1045 		pci_read_config_dword(dev, aer + PCI_ERR_CAP, &temp);
1046 		info->first_error = PCI_ERR_CAP_FEP(temp);
1047 
1048 		if (info->status & AER_LOG_TLP_MASKS) {
1049 			info->tlp_header_valid = 1;
1050 			pci_read_config_dword(dev,
1051 				aer + PCI_ERR_HEADER_LOG, &info->tlp.dw0);
1052 			pci_read_config_dword(dev,
1053 				aer + PCI_ERR_HEADER_LOG + 4, &info->tlp.dw1);
1054 			pci_read_config_dword(dev,
1055 				aer + PCI_ERR_HEADER_LOG + 8, &info->tlp.dw2);
1056 			pci_read_config_dword(dev,
1057 				aer + PCI_ERR_HEADER_LOG + 12, &info->tlp.dw3);
1058 		}
1059 	}
1060 
1061 	return 1;
1062 }
1063 
1064 static inline void aer_process_err_devices(struct aer_err_info *e_info)
1065 {
1066 	int i;
1067 
1068 	/* Report all before handle them, not to lost records by reset etc. */
1069 	for (i = 0; i < e_info->error_dev_num && e_info->dev[i]; i++) {
1070 		if (aer_get_device_error_info(e_info->dev[i], e_info))
1071 			aer_print_error(e_info->dev[i], e_info);
1072 	}
1073 	for (i = 0; i < e_info->error_dev_num && e_info->dev[i]; i++) {
1074 		if (aer_get_device_error_info(e_info->dev[i], e_info))
1075 			handle_error_source(e_info->dev[i], e_info);
1076 	}
1077 }
1078 
1079 /**
1080  * aer_isr_one_error - consume an error detected by root port
1081  * @rpc: pointer to the root port which holds an error
1082  * @e_src: pointer to an error source
1083  */
1084 static void aer_isr_one_error(struct aer_rpc *rpc,
1085 		struct aer_err_source *e_src)
1086 {
1087 	struct pci_dev *pdev = rpc->rpd;
1088 	struct aer_err_info e_info;
1089 
1090 	pci_rootport_aer_stats_incr(pdev, e_src);
1091 
1092 	/*
1093 	 * There is a possibility that both correctable error and
1094 	 * uncorrectable error being logged. Report correctable error first.
1095 	 */
1096 	if (e_src->status & PCI_ERR_ROOT_COR_RCV) {
1097 		e_info.id = ERR_COR_ID(e_src->id);
1098 		e_info.severity = AER_CORRECTABLE;
1099 
1100 		if (e_src->status & PCI_ERR_ROOT_MULTI_COR_RCV)
1101 			e_info.multi_error_valid = 1;
1102 		else
1103 			e_info.multi_error_valid = 0;
1104 		aer_print_port_info(pdev, &e_info);
1105 
1106 		if (find_source_device(pdev, &e_info))
1107 			aer_process_err_devices(&e_info);
1108 	}
1109 
1110 	if (e_src->status & PCI_ERR_ROOT_UNCOR_RCV) {
1111 		e_info.id = ERR_UNCOR_ID(e_src->id);
1112 
1113 		if (e_src->status & PCI_ERR_ROOT_FATAL_RCV)
1114 			e_info.severity = AER_FATAL;
1115 		else
1116 			e_info.severity = AER_NONFATAL;
1117 
1118 		if (e_src->status & PCI_ERR_ROOT_MULTI_UNCOR_RCV)
1119 			e_info.multi_error_valid = 1;
1120 		else
1121 			e_info.multi_error_valid = 0;
1122 
1123 		aer_print_port_info(pdev, &e_info);
1124 
1125 		if (find_source_device(pdev, &e_info))
1126 			aer_process_err_devices(&e_info);
1127 	}
1128 }
1129 
1130 /**
1131  * aer_isr - consume errors detected by root port
1132  * @irq: IRQ assigned to Root Port
1133  * @context: pointer to Root Port data structure
1134  *
1135  * Invoked, as DPC, when root port records new detected error
1136  */
1137 static irqreturn_t aer_isr(int irq, void *context)
1138 {
1139 	struct pcie_device *dev = (struct pcie_device *)context;
1140 	struct aer_rpc *rpc = get_service_data(dev);
1141 	struct aer_err_source uninitialized_var(e_src);
1142 
1143 	if (kfifo_is_empty(&rpc->aer_fifo))
1144 		return IRQ_NONE;
1145 
1146 	while (kfifo_get(&rpc->aer_fifo, &e_src))
1147 		aer_isr_one_error(rpc, &e_src);
1148 	return IRQ_HANDLED;
1149 }
1150 
1151 /**
1152  * aer_irq - Root Port's ISR
1153  * @irq: IRQ assigned to Root Port
1154  * @context: pointer to Root Port data structure
1155  *
1156  * Invoked when Root Port detects AER messages.
1157  */
1158 static irqreturn_t aer_irq(int irq, void *context)
1159 {
1160 	struct pcie_device *pdev = (struct pcie_device *)context;
1161 	struct aer_rpc *rpc = get_service_data(pdev);
1162 	struct pci_dev *rp = rpc->rpd;
1163 	int aer = rp->aer_cap;
1164 	struct aer_err_source e_src = {};
1165 
1166 	pci_read_config_dword(rp, aer + PCI_ERR_ROOT_STATUS, &e_src.status);
1167 	if (!(e_src.status & (PCI_ERR_ROOT_UNCOR_RCV|PCI_ERR_ROOT_COR_RCV)))
1168 		return IRQ_NONE;
1169 
1170 	pci_read_config_dword(rp, aer + PCI_ERR_ROOT_ERR_SRC, &e_src.id);
1171 	pci_write_config_dword(rp, aer + PCI_ERR_ROOT_STATUS, e_src.status);
1172 
1173 	if (!kfifo_put(&rpc->aer_fifo, e_src))
1174 		return IRQ_HANDLED;
1175 
1176 	return IRQ_WAKE_THREAD;
1177 }
1178 
1179 static int set_device_error_reporting(struct pci_dev *dev, void *data)
1180 {
1181 	bool enable = *((bool *)data);
1182 	int type = pci_pcie_type(dev);
1183 
1184 	if ((type == PCI_EXP_TYPE_ROOT_PORT) ||
1185 	    (type == PCI_EXP_TYPE_UPSTREAM) ||
1186 	    (type == PCI_EXP_TYPE_DOWNSTREAM)) {
1187 		if (enable)
1188 			pci_enable_pcie_error_reporting(dev);
1189 		else
1190 			pci_disable_pcie_error_reporting(dev);
1191 	}
1192 
1193 	if (enable)
1194 		pcie_set_ecrc_checking(dev);
1195 
1196 	return 0;
1197 }
1198 
1199 /**
1200  * set_downstream_devices_error_reporting - enable/disable the error reporting  bits on the root port and its downstream ports.
1201  * @dev: pointer to root port's pci_dev data structure
1202  * @enable: true = enable error reporting, false = disable error reporting.
1203  */
1204 static void set_downstream_devices_error_reporting(struct pci_dev *dev,
1205 						   bool enable)
1206 {
1207 	set_device_error_reporting(dev, &enable);
1208 
1209 	if (!dev->subordinate)
1210 		return;
1211 	pci_walk_bus(dev->subordinate, set_device_error_reporting, &enable);
1212 }
1213 
1214 /**
1215  * aer_enable_rootport - enable Root Port's interrupts when receiving messages
1216  * @rpc: pointer to a Root Port data structure
1217  *
1218  * Invoked when PCIe bus loads AER service driver.
1219  */
1220 static void aer_enable_rootport(struct aer_rpc *rpc)
1221 {
1222 	struct pci_dev *pdev = rpc->rpd;
1223 	int aer = pdev->aer_cap;
1224 	u16 reg16;
1225 	u32 reg32;
1226 
1227 	/* Clear PCIe Capability's Device Status */
1228 	pcie_capability_read_word(pdev, PCI_EXP_DEVSTA, &reg16);
1229 	pcie_capability_write_word(pdev, PCI_EXP_DEVSTA, reg16);
1230 
1231 	/* Disable system error generation in response to error messages */
1232 	pcie_capability_clear_word(pdev, PCI_EXP_RTCTL,
1233 				   SYSTEM_ERROR_INTR_ON_MESG_MASK);
1234 
1235 	/* Clear error status */
1236 	pci_read_config_dword(pdev, aer + PCI_ERR_ROOT_STATUS, &reg32);
1237 	pci_write_config_dword(pdev, aer + PCI_ERR_ROOT_STATUS, reg32);
1238 	pci_read_config_dword(pdev, aer + PCI_ERR_COR_STATUS, &reg32);
1239 	pci_write_config_dword(pdev, aer + PCI_ERR_COR_STATUS, reg32);
1240 	pci_read_config_dword(pdev, aer + PCI_ERR_UNCOR_STATUS, &reg32);
1241 	pci_write_config_dword(pdev, aer + PCI_ERR_UNCOR_STATUS, reg32);
1242 
1243 	/*
1244 	 * Enable error reporting for the root port device and downstream port
1245 	 * devices.
1246 	 */
1247 	set_downstream_devices_error_reporting(pdev, true);
1248 
1249 	/* Enable Root Port's interrupt in response to error messages */
1250 	pci_read_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, &reg32);
1251 	reg32 |= ROOT_PORT_INTR_ON_MESG_MASK;
1252 	pci_write_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, reg32);
1253 }
1254 
1255 /**
1256  * aer_disable_rootport - disable Root Port's interrupts when receiving messages
1257  * @rpc: pointer to a Root Port data structure
1258  *
1259  * Invoked when PCIe bus unloads AER service driver.
1260  */
1261 static void aer_disable_rootport(struct aer_rpc *rpc)
1262 {
1263 	struct pci_dev *pdev = rpc->rpd;
1264 	int aer = pdev->aer_cap;
1265 	u32 reg32;
1266 
1267 	/*
1268 	 * Disable error reporting for the root port device and downstream port
1269 	 * devices.
1270 	 */
1271 	set_downstream_devices_error_reporting(pdev, false);
1272 
1273 	/* Disable Root's interrupt in response to error messages */
1274 	pci_read_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, &reg32);
1275 	reg32 &= ~ROOT_PORT_INTR_ON_MESG_MASK;
1276 	pci_write_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, reg32);
1277 
1278 	/* Clear Root's error status reg */
1279 	pci_read_config_dword(pdev, aer + PCI_ERR_ROOT_STATUS, &reg32);
1280 	pci_write_config_dword(pdev, aer + PCI_ERR_ROOT_STATUS, reg32);
1281 }
1282 
1283 /**
1284  * aer_remove - clean up resources
1285  * @dev: pointer to the pcie_dev data structure
1286  *
1287  * Invoked when PCI Express bus unloads or AER probe fails.
1288  */
1289 static void aer_remove(struct pcie_device *dev)
1290 {
1291 	struct aer_rpc *rpc = get_service_data(dev);
1292 
1293 	aer_disable_rootport(rpc);
1294 }
1295 
1296 /**
1297  * aer_probe - initialize resources
1298  * @dev: pointer to the pcie_dev data structure
1299  *
1300  * Invoked when PCI Express bus loads AER service driver.
1301  */
1302 static int aer_probe(struct pcie_device *dev)
1303 {
1304 	int status;
1305 	struct aer_rpc *rpc;
1306 	struct device *device = &dev->device;
1307 	struct pci_dev *port = dev->port;
1308 
1309 	rpc = devm_kzalloc(device, sizeof(struct aer_rpc), GFP_KERNEL);
1310 	if (!rpc)
1311 		return -ENOMEM;
1312 
1313 	rpc->rpd = port;
1314 	INIT_KFIFO(rpc->aer_fifo);
1315 	set_service_data(dev, rpc);
1316 
1317 	status = devm_request_threaded_irq(device, dev->irq, aer_irq, aer_isr,
1318 					   IRQF_SHARED, "aerdrv", dev);
1319 	if (status) {
1320 		pci_err(port, "request AER IRQ %d failed\n", dev->irq);
1321 		return status;
1322 	}
1323 
1324 	aer_enable_rootport(rpc);
1325 	pci_info(port, "enabled with IRQ %d\n", dev->irq);
1326 	return 0;
1327 }
1328 
1329 /**
1330  * aer_root_reset - reset link on Root Port
1331  * @dev: pointer to Root Port's pci_dev data structure
1332  *
1333  * Invoked by Port Bus driver when performing link reset at Root Port.
1334  */
1335 static pci_ers_result_t aer_root_reset(struct pci_dev *dev)
1336 {
1337 	int aer = dev->aer_cap;
1338 	u32 reg32;
1339 	int rc;
1340 
1341 
1342 	/* Disable Root's interrupt in response to error messages */
1343 	pci_read_config_dword(dev, aer + PCI_ERR_ROOT_COMMAND, &reg32);
1344 	reg32 &= ~ROOT_PORT_INTR_ON_MESG_MASK;
1345 	pci_write_config_dword(dev, aer + PCI_ERR_ROOT_COMMAND, reg32);
1346 
1347 	rc = pci_bus_error_reset(dev);
1348 	pci_info(dev, "Root Port link has been reset\n");
1349 
1350 	/* Clear Root Error Status */
1351 	pci_read_config_dword(dev, aer + PCI_ERR_ROOT_STATUS, &reg32);
1352 	pci_write_config_dword(dev, aer + PCI_ERR_ROOT_STATUS, reg32);
1353 
1354 	/* Enable Root Port's interrupt in response to error messages */
1355 	pci_read_config_dword(dev, aer + PCI_ERR_ROOT_COMMAND, &reg32);
1356 	reg32 |= ROOT_PORT_INTR_ON_MESG_MASK;
1357 	pci_write_config_dword(dev, aer + PCI_ERR_ROOT_COMMAND, reg32);
1358 
1359 	return rc ? PCI_ERS_RESULT_DISCONNECT : PCI_ERS_RESULT_RECOVERED;
1360 }
1361 
1362 static struct pcie_port_service_driver aerdriver = {
1363 	.name		= "aer",
1364 	.port_type	= PCI_EXP_TYPE_ROOT_PORT,
1365 	.service	= PCIE_PORT_SERVICE_AER,
1366 
1367 	.probe		= aer_probe,
1368 	.remove		= aer_remove,
1369 };
1370 
1371 /**
1372  * aer_service_init - register AER root service driver
1373  *
1374  * Invoked when AER root service driver is loaded.
1375  */
1376 int __init pcie_aer_init(void)
1377 {
1378 	if (!pci_aer_available())
1379 		return -ENXIO;
1380 	return pcie_port_service_register(&aerdriver);
1381 }
1382