xref: /openbmc/linux/drivers/pci/pcie/aer.c (revision 17bfcd6a)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Implement the AER root port service driver. The driver registers an IRQ
4  * handler. When a root port triggers an AER interrupt, the IRQ handler
5  * collects root port status and schedules work.
6  *
7  * Copyright (C) 2006 Intel Corp.
8  *	Tom Long Nguyen (tom.l.nguyen@intel.com)
9  *	Zhang Yanmin (yanmin.zhang@intel.com)
10  *
11  * (C) Copyright 2009 Hewlett-Packard Development Company, L.P.
12  *    Andrew Patterson <andrew.patterson@hp.com>
13  */
14 
15 #define pr_fmt(fmt) "AER: " fmt
16 #define dev_fmt pr_fmt
17 
18 #include <linux/bitops.h>
19 #include <linux/cper.h>
20 #include <linux/pci.h>
21 #include <linux/pci-acpi.h>
22 #include <linux/sched.h>
23 #include <linux/kernel.h>
24 #include <linux/errno.h>
25 #include <linux/pm.h>
26 #include <linux/init.h>
27 #include <linux/interrupt.h>
28 #include <linux/delay.h>
29 #include <linux/kfifo.h>
30 #include <linux/slab.h>
31 #include <acpi/apei.h>
32 #include <ras/ras_event.h>
33 
34 #include "../pci.h"
35 #include "portdrv.h"
36 
37 #define AER_ERROR_SOURCES_MAX		128
38 
39 #define AER_MAX_TYPEOF_COR_ERRS		16	/* as per PCI_ERR_COR_STATUS */
40 #define AER_MAX_TYPEOF_UNCOR_ERRS	27	/* as per PCI_ERR_UNCOR_STATUS*/
41 
42 struct aer_err_source {
43 	unsigned int status;
44 	unsigned int id;
45 };
46 
47 struct aer_rpc {
48 	struct pci_dev *rpd;		/* Root Port device */
49 	DECLARE_KFIFO(aer_fifo, struct aer_err_source, AER_ERROR_SOURCES_MAX);
50 };
51 
52 /* AER stats for the device */
53 struct aer_stats {
54 
55 	/*
56 	 * Fields for all AER capable devices. They indicate the errors
57 	 * "as seen by this device". Note that this may mean that if an
58 	 * end point is causing problems, the AER counters may increment
59 	 * at its link partner (e.g. root port) because the errors will be
60 	 * "seen" by the link partner and not the problematic end point
61 	 * itself (which may report all counters as 0 as it never saw any
62 	 * problems).
63 	 */
64 	/* Counters for different type of correctable errors */
65 	u64 dev_cor_errs[AER_MAX_TYPEOF_COR_ERRS];
66 	/* Counters for different type of fatal uncorrectable errors */
67 	u64 dev_fatal_errs[AER_MAX_TYPEOF_UNCOR_ERRS];
68 	/* Counters for different type of nonfatal uncorrectable errors */
69 	u64 dev_nonfatal_errs[AER_MAX_TYPEOF_UNCOR_ERRS];
70 	/* Total number of ERR_COR sent by this device */
71 	u64 dev_total_cor_errs;
72 	/* Total number of ERR_FATAL sent by this device */
73 	u64 dev_total_fatal_errs;
74 	/* Total number of ERR_NONFATAL sent by this device */
75 	u64 dev_total_nonfatal_errs;
76 
77 	/*
78 	 * Fields for Root ports & root complex event collectors only, these
79 	 * indicate the total number of ERR_COR, ERR_FATAL, and ERR_NONFATAL
80 	 * messages received by the root port / event collector, INCLUDING the
81 	 * ones that are generated internally (by the rootport itself)
82 	 */
83 	u64 rootport_total_cor_errs;
84 	u64 rootport_total_fatal_errs;
85 	u64 rootport_total_nonfatal_errs;
86 };
87 
88 #define AER_LOG_TLP_MASKS		(PCI_ERR_UNC_POISON_TLP|	\
89 					PCI_ERR_UNC_ECRC|		\
90 					PCI_ERR_UNC_UNSUP|		\
91 					PCI_ERR_UNC_COMP_ABORT|		\
92 					PCI_ERR_UNC_UNX_COMP|		\
93 					PCI_ERR_UNC_MALF_TLP)
94 
95 #define SYSTEM_ERROR_INTR_ON_MESG_MASK	(PCI_EXP_RTCTL_SECEE|	\
96 					PCI_EXP_RTCTL_SENFEE|	\
97 					PCI_EXP_RTCTL_SEFEE)
98 #define ROOT_PORT_INTR_ON_MESG_MASK	(PCI_ERR_ROOT_CMD_COR_EN|	\
99 					PCI_ERR_ROOT_CMD_NONFATAL_EN|	\
100 					PCI_ERR_ROOT_CMD_FATAL_EN)
101 #define ERR_COR_ID(d)			(d & 0xffff)
102 #define ERR_UNCOR_ID(d)			(d >> 16)
103 
104 #define AER_ERR_STATUS_MASK		(PCI_ERR_ROOT_UNCOR_RCV |	\
105 					PCI_ERR_ROOT_COR_RCV |		\
106 					PCI_ERR_ROOT_MULTI_COR_RCV |	\
107 					PCI_ERR_ROOT_MULTI_UNCOR_RCV)
108 
109 static int pcie_aer_disable;
110 static pci_ers_result_t aer_root_reset(struct pci_dev *dev);
111 
112 void pci_no_aer(void)
113 {
114 	pcie_aer_disable = 1;
115 }
116 
117 bool pci_aer_available(void)
118 {
119 	return !pcie_aer_disable && pci_msi_enabled();
120 }
121 
122 #ifdef CONFIG_PCIE_ECRC
123 
124 #define ECRC_POLICY_DEFAULT 0		/* ECRC set by BIOS */
125 #define ECRC_POLICY_OFF     1		/* ECRC off for performance */
126 #define ECRC_POLICY_ON      2		/* ECRC on for data integrity */
127 
128 static int ecrc_policy = ECRC_POLICY_DEFAULT;
129 
130 static const char * const ecrc_policy_str[] = {
131 	[ECRC_POLICY_DEFAULT] = "bios",
132 	[ECRC_POLICY_OFF] = "off",
133 	[ECRC_POLICY_ON] = "on"
134 };
135 
136 /**
137  * enable_ecrc_checking - enable PCIe ECRC checking for a device
138  * @dev: the PCI device
139  *
140  * Returns 0 on success, or negative on failure.
141  */
142 static int enable_ecrc_checking(struct pci_dev *dev)
143 {
144 	int aer = dev->aer_cap;
145 	u32 reg32;
146 
147 	if (!aer)
148 		return -ENODEV;
149 
150 	pci_read_config_dword(dev, aer + PCI_ERR_CAP, &reg32);
151 	if (reg32 & PCI_ERR_CAP_ECRC_GENC)
152 		reg32 |= PCI_ERR_CAP_ECRC_GENE;
153 	if (reg32 & PCI_ERR_CAP_ECRC_CHKC)
154 		reg32 |= PCI_ERR_CAP_ECRC_CHKE;
155 	pci_write_config_dword(dev, aer + PCI_ERR_CAP, reg32);
156 
157 	return 0;
158 }
159 
160 /**
161  * disable_ecrc_checking - disables PCIe ECRC checking for a device
162  * @dev: the PCI device
163  *
164  * Returns 0 on success, or negative on failure.
165  */
166 static int disable_ecrc_checking(struct pci_dev *dev)
167 {
168 	int aer = dev->aer_cap;
169 	u32 reg32;
170 
171 	if (!aer)
172 		return -ENODEV;
173 
174 	pci_read_config_dword(dev, aer + PCI_ERR_CAP, &reg32);
175 	reg32 &= ~(PCI_ERR_CAP_ECRC_GENE | PCI_ERR_CAP_ECRC_CHKE);
176 	pci_write_config_dword(dev, aer + PCI_ERR_CAP, reg32);
177 
178 	return 0;
179 }
180 
181 /**
182  * pcie_set_ecrc_checking - set/unset PCIe ECRC checking for a device based on global policy
183  * @dev: the PCI device
184  */
185 void pcie_set_ecrc_checking(struct pci_dev *dev)
186 {
187 	if (!pcie_aer_is_native(dev))
188 		return;
189 
190 	switch (ecrc_policy) {
191 	case ECRC_POLICY_DEFAULT:
192 		return;
193 	case ECRC_POLICY_OFF:
194 		disable_ecrc_checking(dev);
195 		break;
196 	case ECRC_POLICY_ON:
197 		enable_ecrc_checking(dev);
198 		break;
199 	default:
200 		return;
201 	}
202 }
203 
204 /**
205  * pcie_ecrc_get_policy - parse kernel command-line ecrc option
206  * @str: ECRC policy from kernel command line to use
207  */
208 void pcie_ecrc_get_policy(char *str)
209 {
210 	int i;
211 
212 	i = match_string(ecrc_policy_str, ARRAY_SIZE(ecrc_policy_str), str);
213 	if (i < 0)
214 		return;
215 
216 	ecrc_policy = i;
217 }
218 #endif	/* CONFIG_PCIE_ECRC */
219 
220 #define	PCI_EXP_AER_FLAGS	(PCI_EXP_DEVCTL_CERE | PCI_EXP_DEVCTL_NFERE | \
221 				 PCI_EXP_DEVCTL_FERE | PCI_EXP_DEVCTL_URRE)
222 
223 int pcie_aer_is_native(struct pci_dev *dev)
224 {
225 	struct pci_host_bridge *host = pci_find_host_bridge(dev->bus);
226 
227 	if (!dev->aer_cap)
228 		return 0;
229 
230 	return pcie_ports_native || host->native_aer;
231 }
232 EXPORT_SYMBOL_NS_GPL(pcie_aer_is_native, CXL);
233 
234 static int pci_enable_pcie_error_reporting(struct pci_dev *dev)
235 {
236 	int rc;
237 
238 	if (!pcie_aer_is_native(dev))
239 		return -EIO;
240 
241 	rc = pcie_capability_set_word(dev, PCI_EXP_DEVCTL, PCI_EXP_AER_FLAGS);
242 	return pcibios_err_to_errno(rc);
243 }
244 
245 int pci_aer_clear_nonfatal_status(struct pci_dev *dev)
246 {
247 	int aer = dev->aer_cap;
248 	u32 status, sev;
249 
250 	if (!pcie_aer_is_native(dev))
251 		return -EIO;
252 
253 	/* Clear status bits for ERR_NONFATAL errors only */
254 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, &status);
255 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_SEVER, &sev);
256 	status &= ~sev;
257 	if (status)
258 		pci_write_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, status);
259 
260 	return 0;
261 }
262 EXPORT_SYMBOL_GPL(pci_aer_clear_nonfatal_status);
263 
264 void pci_aer_clear_fatal_status(struct pci_dev *dev)
265 {
266 	int aer = dev->aer_cap;
267 	u32 status, sev;
268 
269 	if (!pcie_aer_is_native(dev))
270 		return;
271 
272 	/* Clear status bits for ERR_FATAL errors only */
273 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, &status);
274 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_SEVER, &sev);
275 	status &= sev;
276 	if (status)
277 		pci_write_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, status);
278 }
279 
280 /**
281  * pci_aer_raw_clear_status - Clear AER error registers.
282  * @dev: the PCI device
283  *
284  * Clearing AER error status registers unconditionally, regardless of
285  * whether they're owned by firmware or the OS.
286  *
287  * Returns 0 on success, or negative on failure.
288  */
289 int pci_aer_raw_clear_status(struct pci_dev *dev)
290 {
291 	int aer = dev->aer_cap;
292 	u32 status;
293 	int port_type;
294 
295 	if (!aer)
296 		return -EIO;
297 
298 	port_type = pci_pcie_type(dev);
299 	if (port_type == PCI_EXP_TYPE_ROOT_PORT ||
300 	    port_type == PCI_EXP_TYPE_RC_EC) {
301 		pci_read_config_dword(dev, aer + PCI_ERR_ROOT_STATUS, &status);
302 		pci_write_config_dword(dev, aer + PCI_ERR_ROOT_STATUS, status);
303 	}
304 
305 	pci_read_config_dword(dev, aer + PCI_ERR_COR_STATUS, &status);
306 	pci_write_config_dword(dev, aer + PCI_ERR_COR_STATUS, status);
307 
308 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, &status);
309 	pci_write_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, status);
310 
311 	return 0;
312 }
313 
314 int pci_aer_clear_status(struct pci_dev *dev)
315 {
316 	if (!pcie_aer_is_native(dev))
317 		return -EIO;
318 
319 	return pci_aer_raw_clear_status(dev);
320 }
321 
322 void pci_save_aer_state(struct pci_dev *dev)
323 {
324 	int aer = dev->aer_cap;
325 	struct pci_cap_saved_state *save_state;
326 	u32 *cap;
327 
328 	if (!aer)
329 		return;
330 
331 	save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_ERR);
332 	if (!save_state)
333 		return;
334 
335 	cap = &save_state->cap.data[0];
336 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_MASK, cap++);
337 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_SEVER, cap++);
338 	pci_read_config_dword(dev, aer + PCI_ERR_COR_MASK, cap++);
339 	pci_read_config_dword(dev, aer + PCI_ERR_CAP, cap++);
340 	if (pcie_cap_has_rtctl(dev))
341 		pci_read_config_dword(dev, aer + PCI_ERR_ROOT_COMMAND, cap++);
342 }
343 
344 void pci_restore_aer_state(struct pci_dev *dev)
345 {
346 	int aer = dev->aer_cap;
347 	struct pci_cap_saved_state *save_state;
348 	u32 *cap;
349 
350 	if (!aer)
351 		return;
352 
353 	save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_ERR);
354 	if (!save_state)
355 		return;
356 
357 	cap = &save_state->cap.data[0];
358 	pci_write_config_dword(dev, aer + PCI_ERR_UNCOR_MASK, *cap++);
359 	pci_write_config_dword(dev, aer + PCI_ERR_UNCOR_SEVER, *cap++);
360 	pci_write_config_dword(dev, aer + PCI_ERR_COR_MASK, *cap++);
361 	pci_write_config_dword(dev, aer + PCI_ERR_CAP, *cap++);
362 	if (pcie_cap_has_rtctl(dev))
363 		pci_write_config_dword(dev, aer + PCI_ERR_ROOT_COMMAND, *cap++);
364 }
365 
366 void pci_aer_init(struct pci_dev *dev)
367 {
368 	int n;
369 
370 	dev->aer_cap = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
371 	if (!dev->aer_cap)
372 		return;
373 
374 	dev->aer_stats = kzalloc(sizeof(struct aer_stats), GFP_KERNEL);
375 
376 	/*
377 	 * We save/restore PCI_ERR_UNCOR_MASK, PCI_ERR_UNCOR_SEVER,
378 	 * PCI_ERR_COR_MASK, and PCI_ERR_CAP.  Root and Root Complex Event
379 	 * Collectors also implement PCI_ERR_ROOT_COMMAND (PCIe r5.0, sec
380 	 * 7.8.4).
381 	 */
382 	n = pcie_cap_has_rtctl(dev) ? 5 : 4;
383 	pci_add_ext_cap_save_buffer(dev, PCI_EXT_CAP_ID_ERR, sizeof(u32) * n);
384 
385 	pci_aer_clear_status(dev);
386 
387 	if (pci_aer_available())
388 		pci_enable_pcie_error_reporting(dev);
389 
390 	pcie_set_ecrc_checking(dev);
391 }
392 
393 void pci_aer_exit(struct pci_dev *dev)
394 {
395 	kfree(dev->aer_stats);
396 	dev->aer_stats = NULL;
397 }
398 
399 #define AER_AGENT_RECEIVER		0
400 #define AER_AGENT_REQUESTER		1
401 #define AER_AGENT_COMPLETER		2
402 #define AER_AGENT_TRANSMITTER		3
403 
404 #define AER_AGENT_REQUESTER_MASK(t)	((t == AER_CORRECTABLE) ?	\
405 	0 : (PCI_ERR_UNC_COMP_TIME|PCI_ERR_UNC_UNSUP))
406 #define AER_AGENT_COMPLETER_MASK(t)	((t == AER_CORRECTABLE) ?	\
407 	0 : PCI_ERR_UNC_COMP_ABORT)
408 #define AER_AGENT_TRANSMITTER_MASK(t)	((t == AER_CORRECTABLE) ?	\
409 	(PCI_ERR_COR_REP_ROLL|PCI_ERR_COR_REP_TIMER) : 0)
410 
411 #define AER_GET_AGENT(t, e)						\
412 	((e & AER_AGENT_COMPLETER_MASK(t)) ? AER_AGENT_COMPLETER :	\
413 	(e & AER_AGENT_REQUESTER_MASK(t)) ? AER_AGENT_REQUESTER :	\
414 	(e & AER_AGENT_TRANSMITTER_MASK(t)) ? AER_AGENT_TRANSMITTER :	\
415 	AER_AGENT_RECEIVER)
416 
417 #define AER_PHYSICAL_LAYER_ERROR	0
418 #define AER_DATA_LINK_LAYER_ERROR	1
419 #define AER_TRANSACTION_LAYER_ERROR	2
420 
421 #define AER_PHYSICAL_LAYER_ERROR_MASK(t) ((t == AER_CORRECTABLE) ?	\
422 	PCI_ERR_COR_RCVR : 0)
423 #define AER_DATA_LINK_LAYER_ERROR_MASK(t) ((t == AER_CORRECTABLE) ?	\
424 	(PCI_ERR_COR_BAD_TLP|						\
425 	PCI_ERR_COR_BAD_DLLP|						\
426 	PCI_ERR_COR_REP_ROLL|						\
427 	PCI_ERR_COR_REP_TIMER) : PCI_ERR_UNC_DLP)
428 
429 #define AER_GET_LAYER_ERROR(t, e)					\
430 	((e & AER_PHYSICAL_LAYER_ERROR_MASK(t)) ? AER_PHYSICAL_LAYER_ERROR : \
431 	(e & AER_DATA_LINK_LAYER_ERROR_MASK(t)) ? AER_DATA_LINK_LAYER_ERROR : \
432 	AER_TRANSACTION_LAYER_ERROR)
433 
434 /*
435  * AER error strings
436  */
437 static const char *aer_error_severity_string[] = {
438 	"Uncorrected (Non-Fatal)",
439 	"Uncorrected (Fatal)",
440 	"Corrected"
441 };
442 
443 static const char *aer_error_layer[] = {
444 	"Physical Layer",
445 	"Data Link Layer",
446 	"Transaction Layer"
447 };
448 
449 static const char *aer_correctable_error_string[] = {
450 	"RxErr",			/* Bit Position 0	*/
451 	NULL,
452 	NULL,
453 	NULL,
454 	NULL,
455 	NULL,
456 	"BadTLP",			/* Bit Position 6	*/
457 	"BadDLLP",			/* Bit Position 7	*/
458 	"Rollover",			/* Bit Position 8	*/
459 	NULL,
460 	NULL,
461 	NULL,
462 	"Timeout",			/* Bit Position 12	*/
463 	"NonFatalErr",			/* Bit Position 13	*/
464 	"CorrIntErr",			/* Bit Position 14	*/
465 	"HeaderOF",			/* Bit Position 15	*/
466 	NULL,				/* Bit Position 16	*/
467 	NULL,				/* Bit Position 17	*/
468 	NULL,				/* Bit Position 18	*/
469 	NULL,				/* Bit Position 19	*/
470 	NULL,				/* Bit Position 20	*/
471 	NULL,				/* Bit Position 21	*/
472 	NULL,				/* Bit Position 22	*/
473 	NULL,				/* Bit Position 23	*/
474 	NULL,				/* Bit Position 24	*/
475 	NULL,				/* Bit Position 25	*/
476 	NULL,				/* Bit Position 26	*/
477 	NULL,				/* Bit Position 27	*/
478 	NULL,				/* Bit Position 28	*/
479 	NULL,				/* Bit Position 29	*/
480 	NULL,				/* Bit Position 30	*/
481 	NULL,				/* Bit Position 31	*/
482 };
483 
484 static const char *aer_uncorrectable_error_string[] = {
485 	"Undefined",			/* Bit Position 0	*/
486 	NULL,
487 	NULL,
488 	NULL,
489 	"DLP",				/* Bit Position 4	*/
490 	"SDES",				/* Bit Position 5	*/
491 	NULL,
492 	NULL,
493 	NULL,
494 	NULL,
495 	NULL,
496 	NULL,
497 	"TLP",				/* Bit Position 12	*/
498 	"FCP",				/* Bit Position 13	*/
499 	"CmpltTO",			/* Bit Position 14	*/
500 	"CmpltAbrt",			/* Bit Position 15	*/
501 	"UnxCmplt",			/* Bit Position 16	*/
502 	"RxOF",				/* Bit Position 17	*/
503 	"MalfTLP",			/* Bit Position 18	*/
504 	"ECRC",				/* Bit Position 19	*/
505 	"UnsupReq",			/* Bit Position 20	*/
506 	"ACSViol",			/* Bit Position 21	*/
507 	"UncorrIntErr",			/* Bit Position 22	*/
508 	"BlockedTLP",			/* Bit Position 23	*/
509 	"AtomicOpBlocked",		/* Bit Position 24	*/
510 	"TLPBlockedErr",		/* Bit Position 25	*/
511 	"PoisonTLPBlocked",		/* Bit Position 26	*/
512 	NULL,				/* Bit Position 27	*/
513 	NULL,				/* Bit Position 28	*/
514 	NULL,				/* Bit Position 29	*/
515 	NULL,				/* Bit Position 30	*/
516 	NULL,				/* Bit Position 31	*/
517 };
518 
519 static const char *aer_agent_string[] = {
520 	"Receiver ID",
521 	"Requester ID",
522 	"Completer ID",
523 	"Transmitter ID"
524 };
525 
526 #define aer_stats_dev_attr(name, stats_array, strings_array,		\
527 			   total_string, total_field)			\
528 	static ssize_t							\
529 	name##_show(struct device *dev, struct device_attribute *attr,	\
530 		     char *buf)						\
531 {									\
532 	unsigned int i;							\
533 	struct pci_dev *pdev = to_pci_dev(dev);				\
534 	u64 *stats = pdev->aer_stats->stats_array;			\
535 	size_t len = 0;							\
536 									\
537 	for (i = 0; i < ARRAY_SIZE(pdev->aer_stats->stats_array); i++) {\
538 		if (strings_array[i])					\
539 			len += sysfs_emit_at(buf, len, "%s %llu\n",	\
540 					     strings_array[i],		\
541 					     stats[i]);			\
542 		else if (stats[i])					\
543 			len += sysfs_emit_at(buf, len,			\
544 					     #stats_array "_bit[%d] %llu\n",\
545 					     i, stats[i]);		\
546 	}								\
547 	len += sysfs_emit_at(buf, len, "TOTAL_%s %llu\n", total_string,	\
548 			     pdev->aer_stats->total_field);		\
549 	return len;							\
550 }									\
551 static DEVICE_ATTR_RO(name)
552 
553 aer_stats_dev_attr(aer_dev_correctable, dev_cor_errs,
554 		   aer_correctable_error_string, "ERR_COR",
555 		   dev_total_cor_errs);
556 aer_stats_dev_attr(aer_dev_fatal, dev_fatal_errs,
557 		   aer_uncorrectable_error_string, "ERR_FATAL",
558 		   dev_total_fatal_errs);
559 aer_stats_dev_attr(aer_dev_nonfatal, dev_nonfatal_errs,
560 		   aer_uncorrectable_error_string, "ERR_NONFATAL",
561 		   dev_total_nonfatal_errs);
562 
563 #define aer_stats_rootport_attr(name, field)				\
564 	static ssize_t							\
565 	name##_show(struct device *dev, struct device_attribute *attr,	\
566 		     char *buf)						\
567 {									\
568 	struct pci_dev *pdev = to_pci_dev(dev);				\
569 	return sysfs_emit(buf, "%llu\n", pdev->aer_stats->field);	\
570 }									\
571 static DEVICE_ATTR_RO(name)
572 
573 aer_stats_rootport_attr(aer_rootport_total_err_cor,
574 			 rootport_total_cor_errs);
575 aer_stats_rootport_attr(aer_rootport_total_err_fatal,
576 			 rootport_total_fatal_errs);
577 aer_stats_rootport_attr(aer_rootport_total_err_nonfatal,
578 			 rootport_total_nonfatal_errs);
579 
580 static struct attribute *aer_stats_attrs[] __ro_after_init = {
581 	&dev_attr_aer_dev_correctable.attr,
582 	&dev_attr_aer_dev_fatal.attr,
583 	&dev_attr_aer_dev_nonfatal.attr,
584 	&dev_attr_aer_rootport_total_err_cor.attr,
585 	&dev_attr_aer_rootport_total_err_fatal.attr,
586 	&dev_attr_aer_rootport_total_err_nonfatal.attr,
587 	NULL
588 };
589 
590 static umode_t aer_stats_attrs_are_visible(struct kobject *kobj,
591 					   struct attribute *a, int n)
592 {
593 	struct device *dev = kobj_to_dev(kobj);
594 	struct pci_dev *pdev = to_pci_dev(dev);
595 
596 	if (!pdev->aer_stats)
597 		return 0;
598 
599 	if ((a == &dev_attr_aer_rootport_total_err_cor.attr ||
600 	     a == &dev_attr_aer_rootport_total_err_fatal.attr ||
601 	     a == &dev_attr_aer_rootport_total_err_nonfatal.attr) &&
602 	    ((pci_pcie_type(pdev) != PCI_EXP_TYPE_ROOT_PORT) &&
603 	     (pci_pcie_type(pdev) != PCI_EXP_TYPE_RC_EC)))
604 		return 0;
605 
606 	return a->mode;
607 }
608 
609 const struct attribute_group aer_stats_attr_group = {
610 	.attrs  = aer_stats_attrs,
611 	.is_visible = aer_stats_attrs_are_visible,
612 };
613 
614 static void pci_dev_aer_stats_incr(struct pci_dev *pdev,
615 				   struct aer_err_info *info)
616 {
617 	unsigned long status = info->status & ~info->mask;
618 	int i, max = -1;
619 	u64 *counter = NULL;
620 	struct aer_stats *aer_stats = pdev->aer_stats;
621 
622 	if (!aer_stats)
623 		return;
624 
625 	switch (info->severity) {
626 	case AER_CORRECTABLE:
627 		aer_stats->dev_total_cor_errs++;
628 		counter = &aer_stats->dev_cor_errs[0];
629 		max = AER_MAX_TYPEOF_COR_ERRS;
630 		break;
631 	case AER_NONFATAL:
632 		aer_stats->dev_total_nonfatal_errs++;
633 		counter = &aer_stats->dev_nonfatal_errs[0];
634 		max = AER_MAX_TYPEOF_UNCOR_ERRS;
635 		break;
636 	case AER_FATAL:
637 		aer_stats->dev_total_fatal_errs++;
638 		counter = &aer_stats->dev_fatal_errs[0];
639 		max = AER_MAX_TYPEOF_UNCOR_ERRS;
640 		break;
641 	}
642 
643 	for_each_set_bit(i, &status, max)
644 		counter[i]++;
645 }
646 
647 static void pci_rootport_aer_stats_incr(struct pci_dev *pdev,
648 				 struct aer_err_source *e_src)
649 {
650 	struct aer_stats *aer_stats = pdev->aer_stats;
651 
652 	if (!aer_stats)
653 		return;
654 
655 	if (e_src->status & PCI_ERR_ROOT_COR_RCV)
656 		aer_stats->rootport_total_cor_errs++;
657 
658 	if (e_src->status & PCI_ERR_ROOT_UNCOR_RCV) {
659 		if (e_src->status & PCI_ERR_ROOT_FATAL_RCV)
660 			aer_stats->rootport_total_fatal_errs++;
661 		else
662 			aer_stats->rootport_total_nonfatal_errs++;
663 	}
664 }
665 
666 static void __print_tlp_header(struct pci_dev *dev,
667 			       struct aer_header_log_regs *t)
668 {
669 	pci_err(dev, "  TLP Header: %08x %08x %08x %08x\n",
670 		t->dw0, t->dw1, t->dw2, t->dw3);
671 }
672 
673 static void __aer_print_error(struct pci_dev *dev,
674 			      struct aer_err_info *info)
675 {
676 	const char **strings;
677 	unsigned long status = info->status & ~info->mask;
678 	const char *level, *errmsg;
679 	int i;
680 
681 	if (info->severity == AER_CORRECTABLE) {
682 		strings = aer_correctable_error_string;
683 		level = KERN_WARNING;
684 	} else {
685 		strings = aer_uncorrectable_error_string;
686 		level = KERN_ERR;
687 	}
688 
689 	for_each_set_bit(i, &status, 32) {
690 		errmsg = strings[i];
691 		if (!errmsg)
692 			errmsg = "Unknown Error Bit";
693 
694 		pci_printk(level, dev, "   [%2d] %-22s%s\n", i, errmsg,
695 				info->first_error == i ? " (First)" : "");
696 	}
697 	pci_dev_aer_stats_incr(dev, info);
698 }
699 
700 void aer_print_error(struct pci_dev *dev, struct aer_err_info *info)
701 {
702 	int layer, agent;
703 	int id = pci_dev_id(dev);
704 	const char *level;
705 
706 	if (!info->status) {
707 		pci_err(dev, "PCIe Bus Error: severity=%s, type=Inaccessible, (Unregistered Agent ID)\n",
708 			aer_error_severity_string[info->severity]);
709 		goto out;
710 	}
711 
712 	layer = AER_GET_LAYER_ERROR(info->severity, info->status);
713 	agent = AER_GET_AGENT(info->severity, info->status);
714 
715 	level = (info->severity == AER_CORRECTABLE) ? KERN_WARNING : KERN_ERR;
716 
717 	pci_printk(level, dev, "PCIe Bus Error: severity=%s, type=%s, (%s)\n",
718 		   aer_error_severity_string[info->severity],
719 		   aer_error_layer[layer], aer_agent_string[agent]);
720 
721 	pci_printk(level, dev, "  device [%04x:%04x] error status/mask=%08x/%08x\n",
722 		   dev->vendor, dev->device, info->status, info->mask);
723 
724 	__aer_print_error(dev, info);
725 
726 	if (info->tlp_header_valid)
727 		__print_tlp_header(dev, &info->tlp);
728 
729 out:
730 	if (info->id && info->error_dev_num > 1 && info->id == id)
731 		pci_err(dev, "  Error of this Agent is reported first\n");
732 
733 	trace_aer_event(dev_name(&dev->dev), (info->status & ~info->mask),
734 			info->severity, info->tlp_header_valid, &info->tlp);
735 }
736 
737 static void aer_print_port_info(struct pci_dev *dev, struct aer_err_info *info)
738 {
739 	u8 bus = info->id >> 8;
740 	u8 devfn = info->id & 0xff;
741 
742 	pci_info(dev, "%s%s error received: %04x:%02x:%02x.%d\n",
743 		 info->multi_error_valid ? "Multiple " : "",
744 		 aer_error_severity_string[info->severity],
745 		 pci_domain_nr(dev->bus), bus, PCI_SLOT(devfn),
746 		 PCI_FUNC(devfn));
747 }
748 
749 #ifdef CONFIG_ACPI_APEI_PCIEAER
750 int cper_severity_to_aer(int cper_severity)
751 {
752 	switch (cper_severity) {
753 	case CPER_SEV_RECOVERABLE:
754 		return AER_NONFATAL;
755 	case CPER_SEV_FATAL:
756 		return AER_FATAL;
757 	default:
758 		return AER_CORRECTABLE;
759 	}
760 }
761 EXPORT_SYMBOL_GPL(cper_severity_to_aer);
762 
763 void cper_print_aer(struct pci_dev *dev, int aer_severity,
764 		    struct aer_capability_regs *aer)
765 {
766 	int layer, agent, tlp_header_valid = 0;
767 	u32 status, mask;
768 	struct aer_err_info info;
769 
770 	if (aer_severity == AER_CORRECTABLE) {
771 		status = aer->cor_status;
772 		mask = aer->cor_mask;
773 	} else {
774 		status = aer->uncor_status;
775 		mask = aer->uncor_mask;
776 		tlp_header_valid = status & AER_LOG_TLP_MASKS;
777 	}
778 
779 	layer = AER_GET_LAYER_ERROR(aer_severity, status);
780 	agent = AER_GET_AGENT(aer_severity, status);
781 
782 	memset(&info, 0, sizeof(info));
783 	info.severity = aer_severity;
784 	info.status = status;
785 	info.mask = mask;
786 	info.first_error = PCI_ERR_CAP_FEP(aer->cap_control);
787 
788 	pci_err(dev, "aer_status: 0x%08x, aer_mask: 0x%08x\n", status, mask);
789 	__aer_print_error(dev, &info);
790 	pci_err(dev, "aer_layer=%s, aer_agent=%s\n",
791 		aer_error_layer[layer], aer_agent_string[agent]);
792 
793 	if (aer_severity != AER_CORRECTABLE)
794 		pci_err(dev, "aer_uncor_severity: 0x%08x\n",
795 			aer->uncor_severity);
796 
797 	if (tlp_header_valid)
798 		__print_tlp_header(dev, &aer->header_log);
799 
800 	trace_aer_event(dev_name(&dev->dev), (status & ~mask),
801 			aer_severity, tlp_header_valid, &aer->header_log);
802 }
803 #endif
804 
805 /**
806  * add_error_device - list device to be handled
807  * @e_info: pointer to error info
808  * @dev: pointer to pci_dev to be added
809  */
810 static int add_error_device(struct aer_err_info *e_info, struct pci_dev *dev)
811 {
812 	if (e_info->error_dev_num < AER_MAX_MULTI_ERR_DEVICES) {
813 		e_info->dev[e_info->error_dev_num] = pci_dev_get(dev);
814 		e_info->error_dev_num++;
815 		return 0;
816 	}
817 	return -ENOSPC;
818 }
819 
820 /**
821  * is_error_source - check whether the device is source of reported error
822  * @dev: pointer to pci_dev to be checked
823  * @e_info: pointer to reported error info
824  */
825 static bool is_error_source(struct pci_dev *dev, struct aer_err_info *e_info)
826 {
827 	int aer = dev->aer_cap;
828 	u32 status, mask;
829 	u16 reg16;
830 
831 	/*
832 	 * When bus id is equal to 0, it might be a bad id
833 	 * reported by root port.
834 	 */
835 	if ((PCI_BUS_NUM(e_info->id) != 0) &&
836 	    !(dev->bus->bus_flags & PCI_BUS_FLAGS_NO_AERSID)) {
837 		/* Device ID match? */
838 		if (e_info->id == pci_dev_id(dev))
839 			return true;
840 
841 		/* Continue id comparing if there is no multiple error */
842 		if (!e_info->multi_error_valid)
843 			return false;
844 	}
845 
846 	/*
847 	 * When either
848 	 *      1) bus id is equal to 0. Some ports might lose the bus
849 	 *              id of error source id;
850 	 *      2) bus flag PCI_BUS_FLAGS_NO_AERSID is set
851 	 *      3) There are multiple errors and prior ID comparing fails;
852 	 * We check AER status registers to find possible reporter.
853 	 */
854 	if (atomic_read(&dev->enable_cnt) == 0)
855 		return false;
856 
857 	/* Check if AER is enabled */
858 	pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &reg16);
859 	if (!(reg16 & PCI_EXP_AER_FLAGS))
860 		return false;
861 
862 	if (!aer)
863 		return false;
864 
865 	/* Check if error is recorded */
866 	if (e_info->severity == AER_CORRECTABLE) {
867 		pci_read_config_dword(dev, aer + PCI_ERR_COR_STATUS, &status);
868 		pci_read_config_dword(dev, aer + PCI_ERR_COR_MASK, &mask);
869 	} else {
870 		pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, &status);
871 		pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_MASK, &mask);
872 	}
873 	if (status & ~mask)
874 		return true;
875 
876 	return false;
877 }
878 
879 static int find_device_iter(struct pci_dev *dev, void *data)
880 {
881 	struct aer_err_info *e_info = (struct aer_err_info *)data;
882 
883 	if (is_error_source(dev, e_info)) {
884 		/* List this device */
885 		if (add_error_device(e_info, dev)) {
886 			/* We cannot handle more... Stop iteration */
887 			/* TODO: Should print error message here? */
888 			return 1;
889 		}
890 
891 		/* If there is only a single error, stop iteration */
892 		if (!e_info->multi_error_valid)
893 			return 1;
894 	}
895 	return 0;
896 }
897 
898 /**
899  * find_source_device - search through device hierarchy for source device
900  * @parent: pointer to Root Port pci_dev data structure
901  * @e_info: including detailed error information such like id
902  *
903  * Return true if found.
904  *
905  * Invoked by DPC when error is detected at the Root Port.
906  * Caller of this function must set id, severity, and multi_error_valid of
907  * struct aer_err_info pointed by @e_info properly.  This function must fill
908  * e_info->error_dev_num and e_info->dev[], based on the given information.
909  */
910 static bool find_source_device(struct pci_dev *parent,
911 		struct aer_err_info *e_info)
912 {
913 	struct pci_dev *dev = parent;
914 	int result;
915 
916 	/* Must reset in this function */
917 	e_info->error_dev_num = 0;
918 
919 	/* Is Root Port an agent that sends error message? */
920 	result = find_device_iter(dev, e_info);
921 	if (result)
922 		return true;
923 
924 	if (pci_pcie_type(parent) == PCI_EXP_TYPE_RC_EC)
925 		pcie_walk_rcec(parent, find_device_iter, e_info);
926 	else
927 		pci_walk_bus(parent->subordinate, find_device_iter, e_info);
928 
929 	if (!e_info->error_dev_num) {
930 		pci_info(parent, "can't find device of ID%04x\n", e_info->id);
931 		return false;
932 	}
933 	return true;
934 }
935 
936 /**
937  * handle_error_source - handle logging error into an event log
938  * @dev: pointer to pci_dev data structure of error source device
939  * @info: comprehensive error information
940  *
941  * Invoked when an error being detected by Root Port.
942  */
943 static void handle_error_source(struct pci_dev *dev, struct aer_err_info *info)
944 {
945 	int aer = dev->aer_cap;
946 
947 	if (info->severity == AER_CORRECTABLE) {
948 		/*
949 		 * Correctable error does not need software intervention.
950 		 * No need to go through error recovery process.
951 		 */
952 		if (aer)
953 			pci_write_config_dword(dev, aer + PCI_ERR_COR_STATUS,
954 					info->status);
955 		if (pcie_aer_is_native(dev)) {
956 			struct pci_driver *pdrv = dev->driver;
957 
958 			if (pdrv && pdrv->err_handler &&
959 			    pdrv->err_handler->cor_error_detected)
960 				pdrv->err_handler->cor_error_detected(dev);
961 			pcie_clear_device_status(dev);
962 		}
963 	} else if (info->severity == AER_NONFATAL)
964 		pcie_do_recovery(dev, pci_channel_io_normal, aer_root_reset);
965 	else if (info->severity == AER_FATAL)
966 		pcie_do_recovery(dev, pci_channel_io_frozen, aer_root_reset);
967 	pci_dev_put(dev);
968 }
969 
970 #ifdef CONFIG_ACPI_APEI_PCIEAER
971 
972 #define AER_RECOVER_RING_SIZE		16
973 
974 struct aer_recover_entry {
975 	u8	bus;
976 	u8	devfn;
977 	u16	domain;
978 	int	severity;
979 	struct aer_capability_regs *regs;
980 };
981 
982 static DEFINE_KFIFO(aer_recover_ring, struct aer_recover_entry,
983 		    AER_RECOVER_RING_SIZE);
984 
985 static void aer_recover_work_func(struct work_struct *work)
986 {
987 	struct aer_recover_entry entry;
988 	struct pci_dev *pdev;
989 
990 	while (kfifo_get(&aer_recover_ring, &entry)) {
991 		pdev = pci_get_domain_bus_and_slot(entry.domain, entry.bus,
992 						   entry.devfn);
993 		if (!pdev) {
994 			pr_err("no pci_dev for %04x:%02x:%02x.%x\n",
995 			       entry.domain, entry.bus,
996 			       PCI_SLOT(entry.devfn), PCI_FUNC(entry.devfn));
997 			continue;
998 		}
999 		cper_print_aer(pdev, entry.severity, entry.regs);
1000 		if (entry.severity == AER_NONFATAL)
1001 			pcie_do_recovery(pdev, pci_channel_io_normal,
1002 					 aer_root_reset);
1003 		else if (entry.severity == AER_FATAL)
1004 			pcie_do_recovery(pdev, pci_channel_io_frozen,
1005 					 aer_root_reset);
1006 		pci_dev_put(pdev);
1007 	}
1008 }
1009 
1010 /*
1011  * Mutual exclusion for writers of aer_recover_ring, reader side don't
1012  * need lock, because there is only one reader and lock is not needed
1013  * between reader and writer.
1014  */
1015 static DEFINE_SPINLOCK(aer_recover_ring_lock);
1016 static DECLARE_WORK(aer_recover_work, aer_recover_work_func);
1017 
1018 void aer_recover_queue(int domain, unsigned int bus, unsigned int devfn,
1019 		       int severity, struct aer_capability_regs *aer_regs)
1020 {
1021 	struct aer_recover_entry entry = {
1022 		.bus		= bus,
1023 		.devfn		= devfn,
1024 		.domain		= domain,
1025 		.severity	= severity,
1026 		.regs		= aer_regs,
1027 	};
1028 
1029 	if (kfifo_in_spinlocked(&aer_recover_ring, &entry, 1,
1030 				 &aer_recover_ring_lock))
1031 		schedule_work(&aer_recover_work);
1032 	else
1033 		pr_err("buffer overflow in recovery for %04x:%02x:%02x.%x\n",
1034 		       domain, bus, PCI_SLOT(devfn), PCI_FUNC(devfn));
1035 }
1036 EXPORT_SYMBOL_GPL(aer_recover_queue);
1037 #endif
1038 
1039 /**
1040  * aer_get_device_error_info - read error status from dev and store it to info
1041  * @dev: pointer to the device expected to have a error record
1042  * @info: pointer to structure to store the error record
1043  *
1044  * Return 1 on success, 0 on error.
1045  *
1046  * Note that @info is reused among all error devices. Clear fields properly.
1047  */
1048 int aer_get_device_error_info(struct pci_dev *dev, struct aer_err_info *info)
1049 {
1050 	int type = pci_pcie_type(dev);
1051 	int aer = dev->aer_cap;
1052 	int temp;
1053 
1054 	/* Must reset in this function */
1055 	info->status = 0;
1056 	info->tlp_header_valid = 0;
1057 
1058 	/* The device might not support AER */
1059 	if (!aer)
1060 		return 0;
1061 
1062 	if (info->severity == AER_CORRECTABLE) {
1063 		pci_read_config_dword(dev, aer + PCI_ERR_COR_STATUS,
1064 			&info->status);
1065 		pci_read_config_dword(dev, aer + PCI_ERR_COR_MASK,
1066 			&info->mask);
1067 		if (!(info->status & ~info->mask))
1068 			return 0;
1069 	} else if (type == PCI_EXP_TYPE_ROOT_PORT ||
1070 		   type == PCI_EXP_TYPE_RC_EC ||
1071 		   type == PCI_EXP_TYPE_DOWNSTREAM ||
1072 		   info->severity == AER_NONFATAL) {
1073 
1074 		/* Link is still healthy for IO reads */
1075 		pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS,
1076 			&info->status);
1077 		pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_MASK,
1078 			&info->mask);
1079 		if (!(info->status & ~info->mask))
1080 			return 0;
1081 
1082 		/* Get First Error Pointer */
1083 		pci_read_config_dword(dev, aer + PCI_ERR_CAP, &temp);
1084 		info->first_error = PCI_ERR_CAP_FEP(temp);
1085 
1086 		if (info->status & AER_LOG_TLP_MASKS) {
1087 			info->tlp_header_valid = 1;
1088 			pci_read_config_dword(dev,
1089 				aer + PCI_ERR_HEADER_LOG, &info->tlp.dw0);
1090 			pci_read_config_dword(dev,
1091 				aer + PCI_ERR_HEADER_LOG + 4, &info->tlp.dw1);
1092 			pci_read_config_dword(dev,
1093 				aer + PCI_ERR_HEADER_LOG + 8, &info->tlp.dw2);
1094 			pci_read_config_dword(dev,
1095 				aer + PCI_ERR_HEADER_LOG + 12, &info->tlp.dw3);
1096 		}
1097 	}
1098 
1099 	return 1;
1100 }
1101 
1102 static inline void aer_process_err_devices(struct aer_err_info *e_info)
1103 {
1104 	int i;
1105 
1106 	/* Report all before handle them, not to lost records by reset etc. */
1107 	for (i = 0; i < e_info->error_dev_num && e_info->dev[i]; i++) {
1108 		if (aer_get_device_error_info(e_info->dev[i], e_info))
1109 			aer_print_error(e_info->dev[i], e_info);
1110 	}
1111 	for (i = 0; i < e_info->error_dev_num && e_info->dev[i]; i++) {
1112 		if (aer_get_device_error_info(e_info->dev[i], e_info))
1113 			handle_error_source(e_info->dev[i], e_info);
1114 	}
1115 }
1116 
1117 /**
1118  * aer_isr_one_error - consume an error detected by root port
1119  * @rpc: pointer to the root port which holds an error
1120  * @e_src: pointer to an error source
1121  */
1122 static void aer_isr_one_error(struct aer_rpc *rpc,
1123 		struct aer_err_source *e_src)
1124 {
1125 	struct pci_dev *pdev = rpc->rpd;
1126 	struct aer_err_info e_info;
1127 
1128 	pci_rootport_aer_stats_incr(pdev, e_src);
1129 
1130 	/*
1131 	 * There is a possibility that both correctable error and
1132 	 * uncorrectable error being logged. Report correctable error first.
1133 	 */
1134 	if (e_src->status & PCI_ERR_ROOT_COR_RCV) {
1135 		e_info.id = ERR_COR_ID(e_src->id);
1136 		e_info.severity = AER_CORRECTABLE;
1137 
1138 		if (e_src->status & PCI_ERR_ROOT_MULTI_COR_RCV)
1139 			e_info.multi_error_valid = 1;
1140 		else
1141 			e_info.multi_error_valid = 0;
1142 		aer_print_port_info(pdev, &e_info);
1143 
1144 		if (find_source_device(pdev, &e_info))
1145 			aer_process_err_devices(&e_info);
1146 	}
1147 
1148 	if (e_src->status & PCI_ERR_ROOT_UNCOR_RCV) {
1149 		e_info.id = ERR_UNCOR_ID(e_src->id);
1150 
1151 		if (e_src->status & PCI_ERR_ROOT_FATAL_RCV)
1152 			e_info.severity = AER_FATAL;
1153 		else
1154 			e_info.severity = AER_NONFATAL;
1155 
1156 		if (e_src->status & PCI_ERR_ROOT_MULTI_UNCOR_RCV)
1157 			e_info.multi_error_valid = 1;
1158 		else
1159 			e_info.multi_error_valid = 0;
1160 
1161 		aer_print_port_info(pdev, &e_info);
1162 
1163 		if (find_source_device(pdev, &e_info))
1164 			aer_process_err_devices(&e_info);
1165 	}
1166 }
1167 
1168 /**
1169  * aer_isr - consume errors detected by root port
1170  * @irq: IRQ assigned to Root Port
1171  * @context: pointer to Root Port data structure
1172  *
1173  * Invoked, as DPC, when root port records new detected error
1174  */
1175 static irqreturn_t aer_isr(int irq, void *context)
1176 {
1177 	struct pcie_device *dev = (struct pcie_device *)context;
1178 	struct aer_rpc *rpc = get_service_data(dev);
1179 	struct aer_err_source e_src;
1180 
1181 	if (kfifo_is_empty(&rpc->aer_fifo))
1182 		return IRQ_NONE;
1183 
1184 	while (kfifo_get(&rpc->aer_fifo, &e_src))
1185 		aer_isr_one_error(rpc, &e_src);
1186 	return IRQ_HANDLED;
1187 }
1188 
1189 /**
1190  * aer_irq - Root Port's ISR
1191  * @irq: IRQ assigned to Root Port
1192  * @context: pointer to Root Port data structure
1193  *
1194  * Invoked when Root Port detects AER messages.
1195  */
1196 static irqreturn_t aer_irq(int irq, void *context)
1197 {
1198 	struct pcie_device *pdev = (struct pcie_device *)context;
1199 	struct aer_rpc *rpc = get_service_data(pdev);
1200 	struct pci_dev *rp = rpc->rpd;
1201 	int aer = rp->aer_cap;
1202 	struct aer_err_source e_src = {};
1203 
1204 	pci_read_config_dword(rp, aer + PCI_ERR_ROOT_STATUS, &e_src.status);
1205 	if (!(e_src.status & AER_ERR_STATUS_MASK))
1206 		return IRQ_NONE;
1207 
1208 	pci_read_config_dword(rp, aer + PCI_ERR_ROOT_ERR_SRC, &e_src.id);
1209 	pci_write_config_dword(rp, aer + PCI_ERR_ROOT_STATUS, e_src.status);
1210 
1211 	if (!kfifo_put(&rpc->aer_fifo, e_src))
1212 		return IRQ_HANDLED;
1213 
1214 	return IRQ_WAKE_THREAD;
1215 }
1216 
1217 /**
1218  * aer_enable_rootport - enable Root Port's interrupts when receiving messages
1219  * @rpc: pointer to a Root Port data structure
1220  *
1221  * Invoked when PCIe bus loads AER service driver.
1222  */
1223 static void aer_enable_rootport(struct aer_rpc *rpc)
1224 {
1225 	struct pci_dev *pdev = rpc->rpd;
1226 	int aer = pdev->aer_cap;
1227 	u16 reg16;
1228 	u32 reg32;
1229 
1230 	/* Clear PCIe Capability's Device Status */
1231 	pcie_capability_read_word(pdev, PCI_EXP_DEVSTA, &reg16);
1232 	pcie_capability_write_word(pdev, PCI_EXP_DEVSTA, reg16);
1233 
1234 	/* Disable system error generation in response to error messages */
1235 	pcie_capability_clear_word(pdev, PCI_EXP_RTCTL,
1236 				   SYSTEM_ERROR_INTR_ON_MESG_MASK);
1237 
1238 	/* Clear error status */
1239 	pci_read_config_dword(pdev, aer + PCI_ERR_ROOT_STATUS, &reg32);
1240 	pci_write_config_dword(pdev, aer + PCI_ERR_ROOT_STATUS, reg32);
1241 	pci_read_config_dword(pdev, aer + PCI_ERR_COR_STATUS, &reg32);
1242 	pci_write_config_dword(pdev, aer + PCI_ERR_COR_STATUS, reg32);
1243 	pci_read_config_dword(pdev, aer + PCI_ERR_UNCOR_STATUS, &reg32);
1244 	pci_write_config_dword(pdev, aer + PCI_ERR_UNCOR_STATUS, reg32);
1245 
1246 	/* Enable Root Port's interrupt in response to error messages */
1247 	pci_read_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, &reg32);
1248 	reg32 |= ROOT_PORT_INTR_ON_MESG_MASK;
1249 	pci_write_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, reg32);
1250 }
1251 
1252 /**
1253  * aer_disable_rootport - disable Root Port's interrupts when receiving messages
1254  * @rpc: pointer to a Root Port data structure
1255  *
1256  * Invoked when PCIe bus unloads AER service driver.
1257  */
1258 static void aer_disable_rootport(struct aer_rpc *rpc)
1259 {
1260 	struct pci_dev *pdev = rpc->rpd;
1261 	int aer = pdev->aer_cap;
1262 	u32 reg32;
1263 
1264 	/* Disable Root's interrupt in response to error messages */
1265 	pci_read_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, &reg32);
1266 	reg32 &= ~ROOT_PORT_INTR_ON_MESG_MASK;
1267 	pci_write_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, reg32);
1268 
1269 	/* Clear Root's error status reg */
1270 	pci_read_config_dword(pdev, aer + PCI_ERR_ROOT_STATUS, &reg32);
1271 	pci_write_config_dword(pdev, aer + PCI_ERR_ROOT_STATUS, reg32);
1272 }
1273 
1274 /**
1275  * aer_remove - clean up resources
1276  * @dev: pointer to the pcie_dev data structure
1277  *
1278  * Invoked when PCI Express bus unloads or AER probe fails.
1279  */
1280 static void aer_remove(struct pcie_device *dev)
1281 {
1282 	struct aer_rpc *rpc = get_service_data(dev);
1283 
1284 	aer_disable_rootport(rpc);
1285 }
1286 
1287 /**
1288  * aer_probe - initialize resources
1289  * @dev: pointer to the pcie_dev data structure
1290  *
1291  * Invoked when PCI Express bus loads AER service driver.
1292  */
1293 static int aer_probe(struct pcie_device *dev)
1294 {
1295 	int status;
1296 	struct aer_rpc *rpc;
1297 	struct device *device = &dev->device;
1298 	struct pci_dev *port = dev->port;
1299 
1300 	BUILD_BUG_ON(ARRAY_SIZE(aer_correctable_error_string) <
1301 		     AER_MAX_TYPEOF_COR_ERRS);
1302 	BUILD_BUG_ON(ARRAY_SIZE(aer_uncorrectable_error_string) <
1303 		     AER_MAX_TYPEOF_UNCOR_ERRS);
1304 
1305 	/* Limit to Root Ports or Root Complex Event Collectors */
1306 	if ((pci_pcie_type(port) != PCI_EXP_TYPE_RC_EC) &&
1307 	    (pci_pcie_type(port) != PCI_EXP_TYPE_ROOT_PORT))
1308 		return -ENODEV;
1309 
1310 	rpc = devm_kzalloc(device, sizeof(struct aer_rpc), GFP_KERNEL);
1311 	if (!rpc)
1312 		return -ENOMEM;
1313 
1314 	rpc->rpd = port;
1315 	INIT_KFIFO(rpc->aer_fifo);
1316 	set_service_data(dev, rpc);
1317 
1318 	status = devm_request_threaded_irq(device, dev->irq, aer_irq, aer_isr,
1319 					   IRQF_SHARED, "aerdrv", dev);
1320 	if (status) {
1321 		pci_err(port, "request AER IRQ %d failed\n", dev->irq);
1322 		return status;
1323 	}
1324 
1325 	aer_enable_rootport(rpc);
1326 	pci_info(port, "enabled with IRQ %d\n", dev->irq);
1327 	return 0;
1328 }
1329 
1330 /**
1331  * aer_root_reset - reset Root Port hierarchy, RCEC, or RCiEP
1332  * @dev: pointer to Root Port, RCEC, or RCiEP
1333  *
1334  * Invoked by Port Bus driver when performing reset.
1335  */
1336 static pci_ers_result_t aer_root_reset(struct pci_dev *dev)
1337 {
1338 	int type = pci_pcie_type(dev);
1339 	struct pci_dev *root;
1340 	int aer;
1341 	struct pci_host_bridge *host = pci_find_host_bridge(dev->bus);
1342 	u32 reg32;
1343 	int rc;
1344 
1345 	/*
1346 	 * Only Root Ports and RCECs have AER Root Command and Root Status
1347 	 * registers.  If "dev" is an RCiEP, the relevant registers are in
1348 	 * the RCEC.
1349 	 */
1350 	if (type == PCI_EXP_TYPE_RC_END)
1351 		root = dev->rcec;
1352 	else
1353 		root = pcie_find_root_port(dev);
1354 
1355 	/*
1356 	 * If the platform retained control of AER, an RCiEP may not have
1357 	 * an RCEC visible to us, so dev->rcec ("root") may be NULL.  In
1358 	 * that case, firmware is responsible for these registers.
1359 	 */
1360 	aer = root ? root->aer_cap : 0;
1361 
1362 	if ((host->native_aer || pcie_ports_native) && aer) {
1363 		/* Disable Root's interrupt in response to error messages */
1364 		pci_read_config_dword(root, aer + PCI_ERR_ROOT_COMMAND, &reg32);
1365 		reg32 &= ~ROOT_PORT_INTR_ON_MESG_MASK;
1366 		pci_write_config_dword(root, aer + PCI_ERR_ROOT_COMMAND, reg32);
1367 	}
1368 
1369 	if (type == PCI_EXP_TYPE_RC_EC || type == PCI_EXP_TYPE_RC_END) {
1370 		rc = pcie_reset_flr(dev, PCI_RESET_DO_RESET);
1371 		if (!rc)
1372 			pci_info(dev, "has been reset\n");
1373 		else
1374 			pci_info(dev, "not reset (no FLR support: %d)\n", rc);
1375 	} else {
1376 		rc = pci_bus_error_reset(dev);
1377 		pci_info(dev, "%s Port link has been reset (%d)\n",
1378 			pci_is_root_bus(dev->bus) ? "Root" : "Downstream", rc);
1379 	}
1380 
1381 	if ((host->native_aer || pcie_ports_native) && aer) {
1382 		/* Clear Root Error Status */
1383 		pci_read_config_dword(root, aer + PCI_ERR_ROOT_STATUS, &reg32);
1384 		pci_write_config_dword(root, aer + PCI_ERR_ROOT_STATUS, reg32);
1385 
1386 		/* Enable Root Port's interrupt in response to error messages */
1387 		pci_read_config_dword(root, aer + PCI_ERR_ROOT_COMMAND, &reg32);
1388 		reg32 |= ROOT_PORT_INTR_ON_MESG_MASK;
1389 		pci_write_config_dword(root, aer + PCI_ERR_ROOT_COMMAND, reg32);
1390 	}
1391 
1392 	return rc ? PCI_ERS_RESULT_DISCONNECT : PCI_ERS_RESULT_RECOVERED;
1393 }
1394 
1395 static struct pcie_port_service_driver aerdriver = {
1396 	.name		= "aer",
1397 	.port_type	= PCIE_ANY_PORT,
1398 	.service	= PCIE_PORT_SERVICE_AER,
1399 
1400 	.probe		= aer_probe,
1401 	.remove		= aer_remove,
1402 };
1403 
1404 /**
1405  * pcie_aer_init - register AER root service driver
1406  *
1407  * Invoked when AER root service driver is loaded.
1408  */
1409 int __init pcie_aer_init(void)
1410 {
1411 	if (!pci_aer_available())
1412 		return -ENXIO;
1413 	return pcie_port_service_register(&aerdriver);
1414 }
1415