xref: /linux/drivers/pci/pcie/aer.c (revision dea140198b846f7432d78566b7b0b83979c72c2b)
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/dev_printk.h>
21 #include <linux/pci.h>
22 #include <linux/pci-acpi.h>
23 #include <linux/sched.h>
24 #include <linux/kernel.h>
25 #include <linux/errno.h>
26 #include <linux/pm.h>
27 #include <linux/init.h>
28 #include <linux/interrupt.h>
29 #include <linux/delay.h>
30 #include <linux/kfifo.h>
31 #include <linux/slab.h>
32 #include <acpi/apei.h>
33 #include <acpi/ghes.h>
34 #include <ras/ras_event.h>
35 
36 #include "../pci.h"
37 #include "portdrv.h"
38 
39 #define aer_printk(level, pdev, fmt, arg...) \
40 	dev_printk(level, &(pdev)->dev, fmt, ##arg)
41 
42 #define AER_ERROR_SOURCES_MAX		128
43 
44 #define AER_MAX_TYPEOF_COR_ERRS		16	/* as per PCI_ERR_COR_STATUS */
45 #define AER_MAX_TYPEOF_UNCOR_ERRS	27	/* as per PCI_ERR_UNCOR_STATUS*/
46 
47 struct aer_err_source {
48 	u32 status;			/* PCI_ERR_ROOT_STATUS */
49 	u32 id;				/* PCI_ERR_ROOT_ERR_SRC */
50 };
51 
52 struct aer_rpc {
53 	struct pci_dev *rpd;		/* Root Port device */
54 	DECLARE_KFIFO(aer_fifo, struct aer_err_source, AER_ERROR_SOURCES_MAX);
55 };
56 
57 /* AER stats for the device */
58 struct aer_stats {
59 
60 	/*
61 	 * Fields for all AER capable devices. They indicate the errors
62 	 * "as seen by this device". Note that this may mean that if an
63 	 * Endpoint is causing problems, the AER counters may increment
64 	 * at its link partner (e.g. Root Port) because the errors will be
65 	 * "seen" by the link partner and not the problematic Endpoint
66 	 * itself (which may report all counters as 0 as it never saw any
67 	 * problems).
68 	 */
69 	/* Counters for different type of correctable errors */
70 	u64 dev_cor_errs[AER_MAX_TYPEOF_COR_ERRS];
71 	/* Counters for different type of fatal uncorrectable errors */
72 	u64 dev_fatal_errs[AER_MAX_TYPEOF_UNCOR_ERRS];
73 	/* Counters for different type of nonfatal uncorrectable errors */
74 	u64 dev_nonfatal_errs[AER_MAX_TYPEOF_UNCOR_ERRS];
75 	/* Total number of ERR_COR sent by this device */
76 	u64 dev_total_cor_errs;
77 	/* Total number of ERR_FATAL sent by this device */
78 	u64 dev_total_fatal_errs;
79 	/* Total number of ERR_NONFATAL sent by this device */
80 	u64 dev_total_nonfatal_errs;
81 
82 	/*
83 	 * Fields for Root Ports & Root Complex Event Collectors only; these
84 	 * indicate the total number of ERR_COR, ERR_FATAL, and ERR_NONFATAL
85 	 * messages received by the Root Port / Event Collector, INCLUDING the
86 	 * ones that are generated internally (by the Root Port itself)
87 	 */
88 	u64 rootport_total_cor_errs;
89 	u64 rootport_total_fatal_errs;
90 	u64 rootport_total_nonfatal_errs;
91 };
92 
93 #define AER_LOG_TLP_MASKS		(PCI_ERR_UNC_POISON_TLP|	\
94 					PCI_ERR_UNC_ECRC|		\
95 					PCI_ERR_UNC_UNSUP|		\
96 					PCI_ERR_UNC_COMP_ABORT|		\
97 					PCI_ERR_UNC_UNX_COMP|		\
98 					PCI_ERR_UNC_MALF_TLP)
99 
100 #define SYSTEM_ERROR_INTR_ON_MESG_MASK	(PCI_EXP_RTCTL_SECEE|	\
101 					PCI_EXP_RTCTL_SENFEE|	\
102 					PCI_EXP_RTCTL_SEFEE)
103 #define ROOT_PORT_INTR_ON_MESG_MASK	(PCI_ERR_ROOT_CMD_COR_EN|	\
104 					PCI_ERR_ROOT_CMD_NONFATAL_EN|	\
105 					PCI_ERR_ROOT_CMD_FATAL_EN)
106 #define ERR_COR_ID(d)			(d & 0xffff)
107 #define ERR_UNCOR_ID(d)			(d >> 16)
108 
109 #define AER_ERR_STATUS_MASK		(PCI_ERR_ROOT_UNCOR_RCV |	\
110 					PCI_ERR_ROOT_COR_RCV |		\
111 					PCI_ERR_ROOT_MULTI_COR_RCV |	\
112 					PCI_ERR_ROOT_MULTI_UNCOR_RCV)
113 
114 static int pcie_aer_disable;
115 static pci_ers_result_t aer_root_reset(struct pci_dev *dev);
116 
117 void pci_no_aer(void)
118 {
119 	pcie_aer_disable = 1;
120 }
121 
122 bool pci_aer_available(void)
123 {
124 	return !pcie_aer_disable && pci_msi_enabled();
125 }
126 
127 #ifdef CONFIG_PCIE_ECRC
128 
129 #define ECRC_POLICY_DEFAULT 0		/* ECRC set by BIOS */
130 #define ECRC_POLICY_OFF     1		/* ECRC off for performance */
131 #define ECRC_POLICY_ON      2		/* ECRC on for data integrity */
132 
133 static int ecrc_policy = ECRC_POLICY_DEFAULT;
134 
135 static const char * const ecrc_policy_str[] = {
136 	[ECRC_POLICY_DEFAULT] = "bios",
137 	[ECRC_POLICY_OFF] = "off",
138 	[ECRC_POLICY_ON] = "on"
139 };
140 
141 /**
142  * enable_ecrc_checking - enable PCIe ECRC checking for a device
143  * @dev: the PCI device
144  *
145  * Return: 0 on success, or negative on failure.
146  */
147 static int enable_ecrc_checking(struct pci_dev *dev)
148 {
149 	int aer = dev->aer_cap;
150 	u32 reg32;
151 
152 	if (!aer)
153 		return -ENODEV;
154 
155 	pci_read_config_dword(dev, aer + PCI_ERR_CAP, &reg32);
156 	if (reg32 & PCI_ERR_CAP_ECRC_GENC)
157 		reg32 |= PCI_ERR_CAP_ECRC_GENE;
158 	if (reg32 & PCI_ERR_CAP_ECRC_CHKC)
159 		reg32 |= PCI_ERR_CAP_ECRC_CHKE;
160 	pci_write_config_dword(dev, aer + PCI_ERR_CAP, reg32);
161 
162 	return 0;
163 }
164 
165 /**
166  * disable_ecrc_checking - disable PCIe ECRC checking for a device
167  * @dev: the PCI device
168  *
169  * Return: 0 on success, or negative on failure.
170  */
171 static int disable_ecrc_checking(struct pci_dev *dev)
172 {
173 	int aer = dev->aer_cap;
174 	u32 reg32;
175 
176 	if (!aer)
177 		return -ENODEV;
178 
179 	pci_read_config_dword(dev, aer + PCI_ERR_CAP, &reg32);
180 	reg32 &= ~(PCI_ERR_CAP_ECRC_GENE | PCI_ERR_CAP_ECRC_CHKE);
181 	pci_write_config_dword(dev, aer + PCI_ERR_CAP, reg32);
182 
183 	return 0;
184 }
185 
186 /**
187  * pcie_set_ecrc_checking - set/unset PCIe ECRC checking for a device based
188  * on global policy
189  * @dev: the PCI device
190  */
191 void pcie_set_ecrc_checking(struct pci_dev *dev)
192 {
193 	if (!pcie_aer_is_native(dev))
194 		return;
195 
196 	switch (ecrc_policy) {
197 	case ECRC_POLICY_DEFAULT:
198 		return;
199 	case ECRC_POLICY_OFF:
200 		disable_ecrc_checking(dev);
201 		break;
202 	case ECRC_POLICY_ON:
203 		enable_ecrc_checking(dev);
204 		break;
205 	default:
206 		return;
207 	}
208 }
209 
210 /**
211  * pcie_ecrc_get_policy - parse kernel command-line ecrc option
212  * @str: ECRC policy from kernel command line to use
213  */
214 void pcie_ecrc_get_policy(char *str)
215 {
216 	int i;
217 
218 	i = match_string(ecrc_policy_str, ARRAY_SIZE(ecrc_policy_str), str);
219 	if (i < 0)
220 		return;
221 
222 	ecrc_policy = i;
223 }
224 #endif	/* CONFIG_PCIE_ECRC */
225 
226 #define	PCI_EXP_AER_FLAGS	(PCI_EXP_DEVCTL_CERE | PCI_EXP_DEVCTL_NFERE | \
227 				 PCI_EXP_DEVCTL_FERE | PCI_EXP_DEVCTL_URRE)
228 
229 int pcie_aer_is_native(struct pci_dev *dev)
230 {
231 	struct pci_host_bridge *host = pci_find_host_bridge(dev->bus);
232 
233 	if (!dev->aer_cap)
234 		return 0;
235 
236 	return pcie_ports_native || host->native_aer;
237 }
238 EXPORT_SYMBOL_NS_GPL(pcie_aer_is_native, "CXL");
239 
240 static int pci_enable_pcie_error_reporting(struct pci_dev *dev)
241 {
242 	int rc;
243 
244 	if (!pcie_aer_is_native(dev))
245 		return -EIO;
246 
247 	rc = pcie_capability_set_word(dev, PCI_EXP_DEVCTL, PCI_EXP_AER_FLAGS);
248 	return pcibios_err_to_errno(rc);
249 }
250 
251 int pci_aer_clear_nonfatal_status(struct pci_dev *dev)
252 {
253 	int aer = dev->aer_cap;
254 	u32 status, sev;
255 
256 	if (!pcie_aer_is_native(dev))
257 		return -EIO;
258 
259 	/* Clear status bits for ERR_NONFATAL errors only */
260 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, &status);
261 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_SEVER, &sev);
262 	status &= ~sev;
263 	if (status)
264 		pci_write_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, status);
265 
266 	return 0;
267 }
268 EXPORT_SYMBOL_GPL(pci_aer_clear_nonfatal_status);
269 
270 void pci_aer_clear_fatal_status(struct pci_dev *dev)
271 {
272 	int aer = dev->aer_cap;
273 	u32 status, sev;
274 
275 	if (!pcie_aer_is_native(dev))
276 		return;
277 
278 	/* Clear status bits for ERR_FATAL errors only */
279 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, &status);
280 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_SEVER, &sev);
281 	status &= sev;
282 	if (status)
283 		pci_write_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, status);
284 }
285 
286 /**
287  * pci_aer_raw_clear_status - Clear AER error registers.
288  * @dev: the PCI device
289  *
290  * Clear AER error status registers unconditionally, regardless of
291  * whether they're owned by firmware or the OS.
292  *
293  * Return: 0 on success, or negative on failure.
294  */
295 int pci_aer_raw_clear_status(struct pci_dev *dev)
296 {
297 	int aer = dev->aer_cap;
298 	u32 status;
299 	int port_type;
300 
301 	if (!aer)
302 		return -EIO;
303 
304 	port_type = pci_pcie_type(dev);
305 	if (port_type == PCI_EXP_TYPE_ROOT_PORT ||
306 	    port_type == PCI_EXP_TYPE_RC_EC) {
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 r6.0, sec
386 	 * 7.8.4.9).
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 	if (pci_aer_available())
394 		pci_enable_pcie_error_reporting(dev);
395 
396 	pcie_set_ecrc_checking(dev);
397 }
398 
399 void pci_aer_exit(struct pci_dev *dev)
400 {
401 	kfree(dev->aer_stats);
402 	dev->aer_stats = NULL;
403 }
404 
405 #define AER_AGENT_RECEIVER		0
406 #define AER_AGENT_REQUESTER		1
407 #define AER_AGENT_COMPLETER		2
408 #define AER_AGENT_TRANSMITTER		3
409 
410 #define AER_AGENT_REQUESTER_MASK(t)	((t == AER_CORRECTABLE) ?	\
411 	0 : (PCI_ERR_UNC_COMP_TIME|PCI_ERR_UNC_UNSUP))
412 #define AER_AGENT_COMPLETER_MASK(t)	((t == AER_CORRECTABLE) ?	\
413 	0 : PCI_ERR_UNC_COMP_ABORT)
414 #define AER_AGENT_TRANSMITTER_MASK(t)	((t == AER_CORRECTABLE) ?	\
415 	(PCI_ERR_COR_REP_ROLL|PCI_ERR_COR_REP_TIMER) : 0)
416 
417 #define AER_GET_AGENT(t, e)						\
418 	((e & AER_AGENT_COMPLETER_MASK(t)) ? AER_AGENT_COMPLETER :	\
419 	(e & AER_AGENT_REQUESTER_MASK(t)) ? AER_AGENT_REQUESTER :	\
420 	(e & AER_AGENT_TRANSMITTER_MASK(t)) ? AER_AGENT_TRANSMITTER :	\
421 	AER_AGENT_RECEIVER)
422 
423 #define AER_PHYSICAL_LAYER_ERROR	0
424 #define AER_DATA_LINK_LAYER_ERROR	1
425 #define AER_TRANSACTION_LAYER_ERROR	2
426 
427 #define AER_PHYSICAL_LAYER_ERROR_MASK(t) ((t == AER_CORRECTABLE) ?	\
428 	PCI_ERR_COR_RCVR : 0)
429 #define AER_DATA_LINK_LAYER_ERROR_MASK(t) ((t == AER_CORRECTABLE) ?	\
430 	(PCI_ERR_COR_BAD_TLP|						\
431 	PCI_ERR_COR_BAD_DLLP|						\
432 	PCI_ERR_COR_REP_ROLL|						\
433 	PCI_ERR_COR_REP_TIMER) : PCI_ERR_UNC_DLP)
434 
435 #define AER_GET_LAYER_ERROR(t, e)					\
436 	((e & AER_PHYSICAL_LAYER_ERROR_MASK(t)) ? AER_PHYSICAL_LAYER_ERROR : \
437 	(e & AER_DATA_LINK_LAYER_ERROR_MASK(t)) ? AER_DATA_LINK_LAYER_ERROR : \
438 	AER_TRANSACTION_LAYER_ERROR)
439 
440 /*
441  * AER error strings
442  */
443 static const char * const aer_error_severity_string[] = {
444 	"Uncorrectable (Non-Fatal)",
445 	"Uncorrectable (Fatal)",
446 	"Correctable"
447 };
448 
449 static const char *aer_error_layer[] = {
450 	"Physical Layer",
451 	"Data Link Layer",
452 	"Transaction Layer"
453 };
454 
455 static const char *aer_correctable_error_string[] = {
456 	"RxErr",			/* Bit Position 0	*/
457 	NULL,
458 	NULL,
459 	NULL,
460 	NULL,
461 	NULL,
462 	"BadTLP",			/* Bit Position 6	*/
463 	"BadDLLP",			/* Bit Position 7	*/
464 	"Rollover",			/* Bit Position 8	*/
465 	NULL,
466 	NULL,
467 	NULL,
468 	"Timeout",			/* Bit Position 12	*/
469 	"NonFatalErr",			/* Bit Position 13	*/
470 	"CorrIntErr",			/* Bit Position 14	*/
471 	"HeaderOF",			/* Bit Position 15	*/
472 	NULL,				/* Bit Position 16	*/
473 	NULL,				/* Bit Position 17	*/
474 	NULL,				/* Bit Position 18	*/
475 	NULL,				/* Bit Position 19	*/
476 	NULL,				/* Bit Position 20	*/
477 	NULL,				/* Bit Position 21	*/
478 	NULL,				/* Bit Position 22	*/
479 	NULL,				/* Bit Position 23	*/
480 	NULL,				/* Bit Position 24	*/
481 	NULL,				/* Bit Position 25	*/
482 	NULL,				/* Bit Position 26	*/
483 	NULL,				/* Bit Position 27	*/
484 	NULL,				/* Bit Position 28	*/
485 	NULL,				/* Bit Position 29	*/
486 	NULL,				/* Bit Position 30	*/
487 	NULL,				/* Bit Position 31	*/
488 };
489 
490 static const char *aer_uncorrectable_error_string[] = {
491 	"Undefined",			/* Bit Position 0	*/
492 	NULL,
493 	NULL,
494 	NULL,
495 	"DLP",				/* Bit Position 4	*/
496 	"SDES",				/* Bit Position 5	*/
497 	NULL,
498 	NULL,
499 	NULL,
500 	NULL,
501 	NULL,
502 	NULL,
503 	"TLP",				/* Bit Position 12	*/
504 	"FCP",				/* Bit Position 13	*/
505 	"CmpltTO",			/* Bit Position 14	*/
506 	"CmpltAbrt",			/* Bit Position 15	*/
507 	"UnxCmplt",			/* Bit Position 16	*/
508 	"RxOF",				/* Bit Position 17	*/
509 	"MalfTLP",			/* Bit Position 18	*/
510 	"ECRC",				/* Bit Position 19	*/
511 	"UnsupReq",			/* Bit Position 20	*/
512 	"ACSViol",			/* Bit Position 21	*/
513 	"UncorrIntErr",			/* Bit Position 22	*/
514 	"BlockedTLP",			/* Bit Position 23	*/
515 	"AtomicOpBlocked",		/* Bit Position 24	*/
516 	"TLPBlockedErr",		/* Bit Position 25	*/
517 	"PoisonTLPBlocked",		/* Bit Position 26	*/
518 	NULL,				/* Bit Position 27	*/
519 	NULL,				/* Bit Position 28	*/
520 	NULL,				/* Bit Position 29	*/
521 	NULL,				/* Bit Position 30	*/
522 	NULL,				/* Bit Position 31	*/
523 };
524 
525 static const char *aer_agent_string[] = {
526 	"Receiver ID",
527 	"Requester ID",
528 	"Completer ID",
529 	"Transmitter ID"
530 };
531 
532 #define aer_stats_dev_attr(name, stats_array, strings_array,		\
533 			   total_string, total_field)			\
534 	static ssize_t							\
535 	name##_show(struct device *dev, struct device_attribute *attr,	\
536 		     char *buf)						\
537 {									\
538 	unsigned int i;							\
539 	struct pci_dev *pdev = to_pci_dev(dev);				\
540 	u64 *stats = pdev->aer_stats->stats_array;			\
541 	size_t len = 0;							\
542 									\
543 	for (i = 0; i < ARRAY_SIZE(pdev->aer_stats->stats_array); i++) {\
544 		if (strings_array[i])					\
545 			len += sysfs_emit_at(buf, len, "%s %llu\n",	\
546 					     strings_array[i],		\
547 					     stats[i]);			\
548 		else if (stats[i])					\
549 			len += sysfs_emit_at(buf, len,			\
550 					     #stats_array "_bit[%d] %llu\n",\
551 					     i, stats[i]);		\
552 	}								\
553 	len += sysfs_emit_at(buf, len, "TOTAL_%s %llu\n", total_string,	\
554 			     pdev->aer_stats->total_field);		\
555 	return len;							\
556 }									\
557 static DEVICE_ATTR_RO(name)
558 
559 aer_stats_dev_attr(aer_dev_correctable, dev_cor_errs,
560 		   aer_correctable_error_string, "ERR_COR",
561 		   dev_total_cor_errs);
562 aer_stats_dev_attr(aer_dev_fatal, dev_fatal_errs,
563 		   aer_uncorrectable_error_string, "ERR_FATAL",
564 		   dev_total_fatal_errs);
565 aer_stats_dev_attr(aer_dev_nonfatal, dev_nonfatal_errs,
566 		   aer_uncorrectable_error_string, "ERR_NONFATAL",
567 		   dev_total_nonfatal_errs);
568 
569 #define aer_stats_rootport_attr(name, field)				\
570 	static ssize_t							\
571 	name##_show(struct device *dev, struct device_attribute *attr,	\
572 		     char *buf)						\
573 {									\
574 	struct pci_dev *pdev = to_pci_dev(dev);				\
575 	return sysfs_emit(buf, "%llu\n", pdev->aer_stats->field);	\
576 }									\
577 static DEVICE_ATTR_RO(name)
578 
579 aer_stats_rootport_attr(aer_rootport_total_err_cor,
580 			 rootport_total_cor_errs);
581 aer_stats_rootport_attr(aer_rootport_total_err_fatal,
582 			 rootport_total_fatal_errs);
583 aer_stats_rootport_attr(aer_rootport_total_err_nonfatal,
584 			 rootport_total_nonfatal_errs);
585 
586 static struct attribute *aer_stats_attrs[] __ro_after_init = {
587 	&dev_attr_aer_dev_correctable.attr,
588 	&dev_attr_aer_dev_fatal.attr,
589 	&dev_attr_aer_dev_nonfatal.attr,
590 	&dev_attr_aer_rootport_total_err_cor.attr,
591 	&dev_attr_aer_rootport_total_err_fatal.attr,
592 	&dev_attr_aer_rootport_total_err_nonfatal.attr,
593 	NULL
594 };
595 
596 static umode_t aer_stats_attrs_are_visible(struct kobject *kobj,
597 					   struct attribute *a, int n)
598 {
599 	struct device *dev = kobj_to_dev(kobj);
600 	struct pci_dev *pdev = to_pci_dev(dev);
601 
602 	if (!pdev->aer_stats)
603 		return 0;
604 
605 	if ((a == &dev_attr_aer_rootport_total_err_cor.attr ||
606 	     a == &dev_attr_aer_rootport_total_err_fatal.attr ||
607 	     a == &dev_attr_aer_rootport_total_err_nonfatal.attr) &&
608 	    ((pci_pcie_type(pdev) != PCI_EXP_TYPE_ROOT_PORT) &&
609 	     (pci_pcie_type(pdev) != PCI_EXP_TYPE_RC_EC)))
610 		return 0;
611 
612 	return a->mode;
613 }
614 
615 const struct attribute_group aer_stats_attr_group = {
616 	.attrs  = aer_stats_attrs,
617 	.is_visible = aer_stats_attrs_are_visible,
618 };
619 
620 static void pci_dev_aer_stats_incr(struct pci_dev *pdev,
621 				   struct aer_err_info *info)
622 {
623 	unsigned long status = info->status & ~info->mask;
624 	int i, max = -1;
625 	u64 *counter = NULL;
626 	struct aer_stats *aer_stats = pdev->aer_stats;
627 
628 	if (!aer_stats)
629 		return;
630 
631 	switch (info->severity) {
632 	case AER_CORRECTABLE:
633 		aer_stats->dev_total_cor_errs++;
634 		counter = &aer_stats->dev_cor_errs[0];
635 		max = AER_MAX_TYPEOF_COR_ERRS;
636 		break;
637 	case AER_NONFATAL:
638 		aer_stats->dev_total_nonfatal_errs++;
639 		counter = &aer_stats->dev_nonfatal_errs[0];
640 		max = AER_MAX_TYPEOF_UNCOR_ERRS;
641 		break;
642 	case AER_FATAL:
643 		aer_stats->dev_total_fatal_errs++;
644 		counter = &aer_stats->dev_fatal_errs[0];
645 		max = AER_MAX_TYPEOF_UNCOR_ERRS;
646 		break;
647 	}
648 
649 	for_each_set_bit(i, &status, max)
650 		counter[i]++;
651 }
652 
653 static void pci_rootport_aer_stats_incr(struct pci_dev *pdev,
654 				 struct aer_err_source *e_src)
655 {
656 	struct aer_stats *aer_stats = pdev->aer_stats;
657 
658 	if (!aer_stats)
659 		return;
660 
661 	if (e_src->status & PCI_ERR_ROOT_COR_RCV)
662 		aer_stats->rootport_total_cor_errs++;
663 
664 	if (e_src->status & PCI_ERR_ROOT_UNCOR_RCV) {
665 		if (e_src->status & PCI_ERR_ROOT_FATAL_RCV)
666 			aer_stats->rootport_total_fatal_errs++;
667 		else
668 			aer_stats->rootport_total_nonfatal_errs++;
669 	}
670 }
671 
672 static void __aer_print_error(struct pci_dev *dev,
673 			      struct aer_err_info *info)
674 {
675 	const char **strings;
676 	unsigned long status = info->status & ~info->mask;
677 	const char *level, *errmsg;
678 	int i;
679 
680 	if (info->severity == AER_CORRECTABLE) {
681 		strings = aer_correctable_error_string;
682 		level = KERN_WARNING;
683 	} else {
684 		strings = aer_uncorrectable_error_string;
685 		level = KERN_ERR;
686 	}
687 
688 	for_each_set_bit(i, &status, 32) {
689 		errmsg = strings[i];
690 		if (!errmsg)
691 			errmsg = "Unknown Error Bit";
692 
693 		aer_printk(level, dev, "   [%2d] %-22s%s\n", i, errmsg,
694 				info->first_error == i ? " (First)" : "");
695 	}
696 	pci_dev_aer_stats_incr(dev, info);
697 }
698 
699 void aer_print_error(struct pci_dev *dev, struct aer_err_info *info)
700 {
701 	int layer, agent;
702 	int id = pci_dev_id(dev);
703 	const char *level;
704 
705 	if (!info->status) {
706 		pci_err(dev, "PCIe Bus Error: severity=%s, type=Inaccessible, (Unregistered Agent ID)\n",
707 			aer_error_severity_string[info->severity]);
708 		goto out;
709 	}
710 
711 	layer = AER_GET_LAYER_ERROR(info->severity, info->status);
712 	agent = AER_GET_AGENT(info->severity, info->status);
713 
714 	level = (info->severity == AER_CORRECTABLE) ? KERN_WARNING : KERN_ERR;
715 
716 	aer_printk(level, dev, "PCIe Bus Error: severity=%s, type=%s, (%s)\n",
717 		   aer_error_severity_string[info->severity],
718 		   aer_error_layer[layer], aer_agent_string[agent]);
719 
720 	aer_printk(level, dev, "  device [%04x:%04x] error status/mask=%08x/%08x\n",
721 		   dev->vendor, dev->device, info->status, info->mask);
722 
723 	__aer_print_error(dev, info);
724 
725 	if (info->tlp_header_valid)
726 		pcie_print_tlp_log(dev, &info->tlp, dev_fmt("  "));
727 
728 out:
729 	if (info->id && info->error_dev_num > 1 && info->id == id)
730 		pci_err(dev, "  Error of this Agent is reported first\n");
731 
732 	trace_aer_event(dev_name(&dev->dev), (info->status & ~info->mask),
733 			info->severity, info->tlp_header_valid, &info->tlp);
734 }
735 
736 static void aer_print_port_info(struct pci_dev *dev, struct aer_err_info *info)
737 {
738 	u8 bus = info->id >> 8;
739 	u8 devfn = info->id & 0xff;
740 
741 	pci_info(dev, "%s%s error message received from %04x:%02x:%02x.%d\n",
742 		 info->multi_error_valid ? "Multiple " : "",
743 		 aer_error_severity_string[info->severity],
744 		 pci_domain_nr(dev->bus), bus, PCI_SLOT(devfn),
745 		 PCI_FUNC(devfn));
746 }
747 
748 #ifdef CONFIG_ACPI_APEI_PCIEAER
749 int cper_severity_to_aer(int cper_severity)
750 {
751 	switch (cper_severity) {
752 	case CPER_SEV_RECOVERABLE:
753 		return AER_NONFATAL;
754 	case CPER_SEV_FATAL:
755 		return AER_FATAL;
756 	default:
757 		return AER_CORRECTABLE;
758 	}
759 }
760 EXPORT_SYMBOL_GPL(cper_severity_to_aer);
761 #endif
762 
763 void pci_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 		pcie_print_tlp_log(dev, &aer->header_log, dev_fmt("  "));
799 
800 	trace_aer_event(dev_name(&dev->dev), (status & ~mask),
801 			aer_severity, tlp_header_valid, &aer->header_log);
802 }
803 EXPORT_SYMBOL_NS_GPL(pci_print_aer, "CXL");
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 as 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 		u8 bus = e_info->id >> 8;
931 		u8 devfn = e_info->id & 0xff;
932 
933 		pci_info(parent, "found no error details for %04x:%02x:%02x.%d\n",
934 			 pci_domain_nr(parent->bus), bus, PCI_SLOT(devfn),
935 			 PCI_FUNC(devfn));
936 		return false;
937 	}
938 	return true;
939 }
940 
941 #ifdef CONFIG_PCIEAER_CXL
942 
943 /**
944  * pci_aer_unmask_internal_errors - unmask internal errors
945  * @dev: pointer to the pci_dev data structure
946  *
947  * Unmask internal errors in the Uncorrectable and Correctable Error
948  * Mask registers.
949  *
950  * Note: AER must be enabled and supported by the device which must be
951  * checked in advance, e.g. with pcie_aer_is_native().
952  */
953 static void pci_aer_unmask_internal_errors(struct pci_dev *dev)
954 {
955 	int aer = dev->aer_cap;
956 	u32 mask;
957 
958 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_MASK, &mask);
959 	mask &= ~PCI_ERR_UNC_INTN;
960 	pci_write_config_dword(dev, aer + PCI_ERR_UNCOR_MASK, mask);
961 
962 	pci_read_config_dword(dev, aer + PCI_ERR_COR_MASK, &mask);
963 	mask &= ~PCI_ERR_COR_INTERNAL;
964 	pci_write_config_dword(dev, aer + PCI_ERR_COR_MASK, mask);
965 }
966 
967 static bool is_cxl_mem_dev(struct pci_dev *dev)
968 {
969 	/*
970 	 * The capability, status, and control fields in Device 0,
971 	 * Function 0 DVSEC control the CXL functionality of the
972 	 * entire device (CXL 3.0, 8.1.3).
973 	 */
974 	if (dev->devfn != PCI_DEVFN(0, 0))
975 		return false;
976 
977 	/*
978 	 * CXL Memory Devices must have the 502h class code set (CXL
979 	 * 3.0, 8.1.12.1).
980 	 */
981 	if ((dev->class >> 8) != PCI_CLASS_MEMORY_CXL)
982 		return false;
983 
984 	return true;
985 }
986 
987 static bool cxl_error_is_native(struct pci_dev *dev)
988 {
989 	struct pci_host_bridge *host = pci_find_host_bridge(dev->bus);
990 
991 	return (pcie_ports_native || host->native_aer);
992 }
993 
994 static bool is_internal_error(struct aer_err_info *info)
995 {
996 	if (info->severity == AER_CORRECTABLE)
997 		return info->status & PCI_ERR_COR_INTERNAL;
998 
999 	return info->status & PCI_ERR_UNC_INTN;
1000 }
1001 
1002 static int cxl_rch_handle_error_iter(struct pci_dev *dev, void *data)
1003 {
1004 	struct aer_err_info *info = (struct aer_err_info *)data;
1005 	const struct pci_error_handlers *err_handler;
1006 
1007 	if (!is_cxl_mem_dev(dev) || !cxl_error_is_native(dev))
1008 		return 0;
1009 
1010 	/* Protect dev->driver */
1011 	device_lock(&dev->dev);
1012 
1013 	err_handler = dev->driver ? dev->driver->err_handler : NULL;
1014 	if (!err_handler)
1015 		goto out;
1016 
1017 	if (info->severity == AER_CORRECTABLE) {
1018 		if (err_handler->cor_error_detected)
1019 			err_handler->cor_error_detected(dev);
1020 	} else if (err_handler->error_detected) {
1021 		if (info->severity == AER_NONFATAL)
1022 			err_handler->error_detected(dev, pci_channel_io_normal);
1023 		else if (info->severity == AER_FATAL)
1024 			err_handler->error_detected(dev, pci_channel_io_frozen);
1025 	}
1026 out:
1027 	device_unlock(&dev->dev);
1028 	return 0;
1029 }
1030 
1031 static void cxl_rch_handle_error(struct pci_dev *dev, struct aer_err_info *info)
1032 {
1033 	/*
1034 	 * Internal errors of an RCEC indicate an AER error in an
1035 	 * RCH's downstream port. Check and handle them in the CXL.mem
1036 	 * device driver.
1037 	 */
1038 	if (pci_pcie_type(dev) == PCI_EXP_TYPE_RC_EC &&
1039 	    is_internal_error(info))
1040 		pcie_walk_rcec(dev, cxl_rch_handle_error_iter, info);
1041 }
1042 
1043 static int handles_cxl_error_iter(struct pci_dev *dev, void *data)
1044 {
1045 	bool *handles_cxl = data;
1046 
1047 	if (!*handles_cxl)
1048 		*handles_cxl = is_cxl_mem_dev(dev) && cxl_error_is_native(dev);
1049 
1050 	/* Non-zero terminates iteration */
1051 	return *handles_cxl;
1052 }
1053 
1054 static bool handles_cxl_errors(struct pci_dev *rcec)
1055 {
1056 	bool handles_cxl = false;
1057 
1058 	if (pci_pcie_type(rcec) == PCI_EXP_TYPE_RC_EC &&
1059 	    pcie_aer_is_native(rcec))
1060 		pcie_walk_rcec(rcec, handles_cxl_error_iter, &handles_cxl);
1061 
1062 	return handles_cxl;
1063 }
1064 
1065 static void cxl_rch_enable_rcec(struct pci_dev *rcec)
1066 {
1067 	if (!handles_cxl_errors(rcec))
1068 		return;
1069 
1070 	pci_aer_unmask_internal_errors(rcec);
1071 	pci_info(rcec, "CXL: Internal errors unmasked");
1072 }
1073 
1074 #else
1075 static inline void cxl_rch_enable_rcec(struct pci_dev *dev) { }
1076 static inline void cxl_rch_handle_error(struct pci_dev *dev,
1077 					struct aer_err_info *info) { }
1078 #endif
1079 
1080 /**
1081  * pci_aer_handle_error - handle logging error into an event log
1082  * @dev: pointer to pci_dev data structure of error source device
1083  * @info: comprehensive error information
1084  *
1085  * Invoked when an error being detected by Root Port.
1086  */
1087 static void pci_aer_handle_error(struct pci_dev *dev, struct aer_err_info *info)
1088 {
1089 	int aer = dev->aer_cap;
1090 
1091 	if (info->severity == AER_CORRECTABLE) {
1092 		/*
1093 		 * Correctable error does not need software intervention.
1094 		 * No need to go through error recovery process.
1095 		 */
1096 		if (aer)
1097 			pci_write_config_dword(dev, aer + PCI_ERR_COR_STATUS,
1098 					info->status);
1099 		if (pcie_aer_is_native(dev)) {
1100 			struct pci_driver *pdrv = dev->driver;
1101 
1102 			if (pdrv && pdrv->err_handler &&
1103 			    pdrv->err_handler->cor_error_detected)
1104 				pdrv->err_handler->cor_error_detected(dev);
1105 			pcie_clear_device_status(dev);
1106 		}
1107 	} else if (info->severity == AER_NONFATAL)
1108 		pcie_do_recovery(dev, pci_channel_io_normal, aer_root_reset);
1109 	else if (info->severity == AER_FATAL)
1110 		pcie_do_recovery(dev, pci_channel_io_frozen, aer_root_reset);
1111 }
1112 
1113 static void handle_error_source(struct pci_dev *dev, struct aer_err_info *info)
1114 {
1115 	cxl_rch_handle_error(dev, info);
1116 	pci_aer_handle_error(dev, info);
1117 	pci_dev_put(dev);
1118 }
1119 
1120 #ifdef CONFIG_ACPI_APEI_PCIEAER
1121 
1122 #define AER_RECOVER_RING_SIZE		16
1123 
1124 struct aer_recover_entry {
1125 	u8	bus;
1126 	u8	devfn;
1127 	u16	domain;
1128 	int	severity;
1129 	struct aer_capability_regs *regs;
1130 };
1131 
1132 static DEFINE_KFIFO(aer_recover_ring, struct aer_recover_entry,
1133 		    AER_RECOVER_RING_SIZE);
1134 
1135 static void aer_recover_work_func(struct work_struct *work)
1136 {
1137 	struct aer_recover_entry entry;
1138 	struct pci_dev *pdev;
1139 
1140 	while (kfifo_get(&aer_recover_ring, &entry)) {
1141 		pdev = pci_get_domain_bus_and_slot(entry.domain, entry.bus,
1142 						   entry.devfn);
1143 		if (!pdev) {
1144 			pr_err("no pci_dev for %04x:%02x:%02x.%x\n",
1145 			       entry.domain, entry.bus,
1146 			       PCI_SLOT(entry.devfn), PCI_FUNC(entry.devfn));
1147 			continue;
1148 		}
1149 		pci_print_aer(pdev, entry.severity, entry.regs);
1150 
1151 		/*
1152 		 * Memory for aer_capability_regs(entry.regs) is being
1153 		 * allocated from the ghes_estatus_pool to protect it from
1154 		 * overwriting when multiple sections are present in the
1155 		 * error status. Thus free the same after processing the
1156 		 * data.
1157 		 */
1158 		ghes_estatus_pool_region_free((unsigned long)entry.regs,
1159 					    sizeof(struct aer_capability_regs));
1160 
1161 		if (entry.severity == AER_NONFATAL)
1162 			pcie_do_recovery(pdev, pci_channel_io_normal,
1163 					 aer_root_reset);
1164 		else if (entry.severity == AER_FATAL)
1165 			pcie_do_recovery(pdev, pci_channel_io_frozen,
1166 					 aer_root_reset);
1167 		pci_dev_put(pdev);
1168 	}
1169 }
1170 
1171 /*
1172  * Mutual exclusion for writers of aer_recover_ring, reader side don't
1173  * need lock, because there is only one reader and lock is not needed
1174  * between reader and writer.
1175  */
1176 static DEFINE_SPINLOCK(aer_recover_ring_lock);
1177 static DECLARE_WORK(aer_recover_work, aer_recover_work_func);
1178 
1179 void aer_recover_queue(int domain, unsigned int bus, unsigned int devfn,
1180 		       int severity, struct aer_capability_regs *aer_regs)
1181 {
1182 	struct aer_recover_entry entry = {
1183 		.bus		= bus,
1184 		.devfn		= devfn,
1185 		.domain		= domain,
1186 		.severity	= severity,
1187 		.regs		= aer_regs,
1188 	};
1189 
1190 	if (kfifo_in_spinlocked(&aer_recover_ring, &entry, 1,
1191 				 &aer_recover_ring_lock))
1192 		schedule_work(&aer_recover_work);
1193 	else
1194 		pr_err("buffer overflow in recovery for %04x:%02x:%02x.%x\n",
1195 		       domain, bus, PCI_SLOT(devfn), PCI_FUNC(devfn));
1196 }
1197 EXPORT_SYMBOL_GPL(aer_recover_queue);
1198 #endif
1199 
1200 /**
1201  * aer_get_device_error_info - read error status from dev and store it to info
1202  * @dev: pointer to the device expected to have an error record
1203  * @info: pointer to structure to store the error record
1204  *
1205  * Return: 1 on success, 0 on error.
1206  *
1207  * Note that @info is reused among all error devices. Clear fields properly.
1208  */
1209 int aer_get_device_error_info(struct pci_dev *dev, struct aer_err_info *info)
1210 {
1211 	int type = pci_pcie_type(dev);
1212 	int aer = dev->aer_cap;
1213 	u32 aercc;
1214 
1215 	/* Must reset in this function */
1216 	info->status = 0;
1217 	info->tlp_header_valid = 0;
1218 
1219 	/* The device might not support AER */
1220 	if (!aer)
1221 		return 0;
1222 
1223 	if (info->severity == AER_CORRECTABLE) {
1224 		pci_read_config_dword(dev, aer + PCI_ERR_COR_STATUS,
1225 			&info->status);
1226 		pci_read_config_dword(dev, aer + PCI_ERR_COR_MASK,
1227 			&info->mask);
1228 		if (!(info->status & ~info->mask))
1229 			return 0;
1230 	} else if (type == PCI_EXP_TYPE_ROOT_PORT ||
1231 		   type == PCI_EXP_TYPE_RC_EC ||
1232 		   type == PCI_EXP_TYPE_DOWNSTREAM ||
1233 		   info->severity == AER_NONFATAL) {
1234 
1235 		/* Link is still healthy for IO reads */
1236 		pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS,
1237 			&info->status);
1238 		pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_MASK,
1239 			&info->mask);
1240 		if (!(info->status & ~info->mask))
1241 			return 0;
1242 
1243 		/* Get First Error Pointer */
1244 		pci_read_config_dword(dev, aer + PCI_ERR_CAP, &aercc);
1245 		info->first_error = PCI_ERR_CAP_FEP(aercc);
1246 
1247 		if (info->status & AER_LOG_TLP_MASKS) {
1248 			info->tlp_header_valid = 1;
1249 			pcie_read_tlp_log(dev, aer + PCI_ERR_HEADER_LOG,
1250 					  aer + PCI_ERR_PREFIX_LOG,
1251 					  aer_tlp_log_len(dev, aercc),
1252 					  aercc & PCI_ERR_CAP_TLP_LOG_FLIT,
1253 					  &info->tlp);
1254 		}
1255 	}
1256 
1257 	return 1;
1258 }
1259 
1260 static inline void aer_process_err_devices(struct aer_err_info *e_info)
1261 {
1262 	int i;
1263 
1264 	/* Report all before handling them, to not lose records by reset etc. */
1265 	for (i = 0; i < e_info->error_dev_num && e_info->dev[i]; i++) {
1266 		if (aer_get_device_error_info(e_info->dev[i], e_info))
1267 			aer_print_error(e_info->dev[i], e_info);
1268 	}
1269 	for (i = 0; i < e_info->error_dev_num && e_info->dev[i]; i++) {
1270 		if (aer_get_device_error_info(e_info->dev[i], e_info))
1271 			handle_error_source(e_info->dev[i], e_info);
1272 	}
1273 }
1274 
1275 /**
1276  * aer_isr_one_error - consume an error detected by Root Port
1277  * @rpc: pointer to the Root Port which holds an error
1278  * @e_src: pointer to an error source
1279  */
1280 static void aer_isr_one_error(struct aer_rpc *rpc,
1281 		struct aer_err_source *e_src)
1282 {
1283 	struct pci_dev *pdev = rpc->rpd;
1284 	struct aer_err_info e_info;
1285 
1286 	pci_rootport_aer_stats_incr(pdev, e_src);
1287 
1288 	/*
1289 	 * There is a possibility that both correctable error and
1290 	 * uncorrectable error being logged. Report correctable error first.
1291 	 */
1292 	if (e_src->status & PCI_ERR_ROOT_COR_RCV) {
1293 		e_info.id = ERR_COR_ID(e_src->id);
1294 		e_info.severity = AER_CORRECTABLE;
1295 
1296 		if (e_src->status & PCI_ERR_ROOT_MULTI_COR_RCV)
1297 			e_info.multi_error_valid = 1;
1298 		else
1299 			e_info.multi_error_valid = 0;
1300 		aer_print_port_info(pdev, &e_info);
1301 
1302 		if (find_source_device(pdev, &e_info))
1303 			aer_process_err_devices(&e_info);
1304 	}
1305 
1306 	if (e_src->status & PCI_ERR_ROOT_UNCOR_RCV) {
1307 		e_info.id = ERR_UNCOR_ID(e_src->id);
1308 
1309 		if (e_src->status & PCI_ERR_ROOT_FATAL_RCV)
1310 			e_info.severity = AER_FATAL;
1311 		else
1312 			e_info.severity = AER_NONFATAL;
1313 
1314 		if (e_src->status & PCI_ERR_ROOT_MULTI_UNCOR_RCV)
1315 			e_info.multi_error_valid = 1;
1316 		else
1317 			e_info.multi_error_valid = 0;
1318 
1319 		aer_print_port_info(pdev, &e_info);
1320 
1321 		if (find_source_device(pdev, &e_info))
1322 			aer_process_err_devices(&e_info);
1323 	}
1324 }
1325 
1326 /**
1327  * aer_isr - consume errors detected by Root Port
1328  * @irq: IRQ assigned to Root Port
1329  * @context: pointer to Root Port data structure
1330  *
1331  * Invoked, as DPC, when Root Port records new detected error
1332  */
1333 static irqreturn_t aer_isr(int irq, void *context)
1334 {
1335 	struct pcie_device *dev = (struct pcie_device *)context;
1336 	struct aer_rpc *rpc = get_service_data(dev);
1337 	struct aer_err_source e_src;
1338 
1339 	if (kfifo_is_empty(&rpc->aer_fifo))
1340 		return IRQ_NONE;
1341 
1342 	while (kfifo_get(&rpc->aer_fifo, &e_src))
1343 		aer_isr_one_error(rpc, &e_src);
1344 	return IRQ_HANDLED;
1345 }
1346 
1347 /**
1348  * aer_irq - Root Port's ISR
1349  * @irq: IRQ assigned to Root Port
1350  * @context: pointer to Root Port data structure
1351  *
1352  * Invoked when Root Port detects AER messages.
1353  */
1354 static irqreturn_t aer_irq(int irq, void *context)
1355 {
1356 	struct pcie_device *pdev = (struct pcie_device *)context;
1357 	struct aer_rpc *rpc = get_service_data(pdev);
1358 	struct pci_dev *rp = rpc->rpd;
1359 	int aer = rp->aer_cap;
1360 	struct aer_err_source e_src = {};
1361 
1362 	pci_read_config_dword(rp, aer + PCI_ERR_ROOT_STATUS, &e_src.status);
1363 	if (!(e_src.status & AER_ERR_STATUS_MASK))
1364 		return IRQ_NONE;
1365 
1366 	pci_read_config_dword(rp, aer + PCI_ERR_ROOT_ERR_SRC, &e_src.id);
1367 	pci_write_config_dword(rp, aer + PCI_ERR_ROOT_STATUS, e_src.status);
1368 
1369 	if (!kfifo_put(&rpc->aer_fifo, e_src))
1370 		return IRQ_HANDLED;
1371 
1372 	return IRQ_WAKE_THREAD;
1373 }
1374 
1375 static void aer_enable_irq(struct pci_dev *pdev)
1376 {
1377 	int aer = pdev->aer_cap;
1378 	u32 reg32;
1379 
1380 	/* Enable Root Port's interrupt in response to error messages */
1381 	pci_read_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, &reg32);
1382 	reg32 |= ROOT_PORT_INTR_ON_MESG_MASK;
1383 	pci_write_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, reg32);
1384 }
1385 
1386 static void aer_disable_irq(struct pci_dev *pdev)
1387 {
1388 	int aer = pdev->aer_cap;
1389 	u32 reg32;
1390 
1391 	/* Disable Root Port's interrupt in response to error messages */
1392 	pci_read_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, &reg32);
1393 	reg32 &= ~ROOT_PORT_INTR_ON_MESG_MASK;
1394 	pci_write_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, reg32);
1395 }
1396 
1397 /**
1398  * aer_enable_rootport - enable Root Port's interrupts when receiving messages
1399  * @rpc: pointer to a Root Port data structure
1400  *
1401  * Invoked when PCIe bus loads AER service driver.
1402  */
1403 static void aer_enable_rootport(struct aer_rpc *rpc)
1404 {
1405 	struct pci_dev *pdev = rpc->rpd;
1406 	int aer = pdev->aer_cap;
1407 	u16 reg16;
1408 	u32 reg32;
1409 
1410 	/* Clear PCIe Capability's Device Status */
1411 	pcie_capability_read_word(pdev, PCI_EXP_DEVSTA, &reg16);
1412 	pcie_capability_write_word(pdev, PCI_EXP_DEVSTA, reg16);
1413 
1414 	/* Disable system error generation in response to error messages */
1415 	pcie_capability_clear_word(pdev, PCI_EXP_RTCTL,
1416 				   SYSTEM_ERROR_INTR_ON_MESG_MASK);
1417 
1418 	/* Clear error status */
1419 	pci_read_config_dword(pdev, aer + PCI_ERR_ROOT_STATUS, &reg32);
1420 	pci_write_config_dword(pdev, aer + PCI_ERR_ROOT_STATUS, reg32);
1421 	pci_read_config_dword(pdev, aer + PCI_ERR_COR_STATUS, &reg32);
1422 	pci_write_config_dword(pdev, aer + PCI_ERR_COR_STATUS, reg32);
1423 	pci_read_config_dword(pdev, aer + PCI_ERR_UNCOR_STATUS, &reg32);
1424 	pci_write_config_dword(pdev, aer + PCI_ERR_UNCOR_STATUS, reg32);
1425 
1426 	aer_enable_irq(pdev);
1427 }
1428 
1429 /**
1430  * aer_disable_rootport - disable Root Port's interrupts when receiving messages
1431  * @rpc: pointer to a Root Port data structure
1432  *
1433  * Invoked when PCIe bus unloads AER service driver.
1434  */
1435 static void aer_disable_rootport(struct aer_rpc *rpc)
1436 {
1437 	struct pci_dev *pdev = rpc->rpd;
1438 	int aer = pdev->aer_cap;
1439 	u32 reg32;
1440 
1441 	aer_disable_irq(pdev);
1442 
1443 	/* Clear Root's error status reg */
1444 	pci_read_config_dword(pdev, aer + PCI_ERR_ROOT_STATUS, &reg32);
1445 	pci_write_config_dword(pdev, aer + PCI_ERR_ROOT_STATUS, reg32);
1446 }
1447 
1448 /**
1449  * aer_remove - clean up resources
1450  * @dev: pointer to the pcie_dev data structure
1451  *
1452  * Invoked when PCI Express bus unloads or AER probe fails.
1453  */
1454 static void aer_remove(struct pcie_device *dev)
1455 {
1456 	struct aer_rpc *rpc = get_service_data(dev);
1457 
1458 	aer_disable_rootport(rpc);
1459 }
1460 
1461 /**
1462  * aer_probe - initialize resources
1463  * @dev: pointer to the pcie_dev data structure
1464  *
1465  * Invoked when PCI Express bus loads AER service driver.
1466  */
1467 static int aer_probe(struct pcie_device *dev)
1468 {
1469 	int status;
1470 	struct aer_rpc *rpc;
1471 	struct device *device = &dev->device;
1472 	struct pci_dev *port = dev->port;
1473 
1474 	BUILD_BUG_ON(ARRAY_SIZE(aer_correctable_error_string) <
1475 		     AER_MAX_TYPEOF_COR_ERRS);
1476 	BUILD_BUG_ON(ARRAY_SIZE(aer_uncorrectable_error_string) <
1477 		     AER_MAX_TYPEOF_UNCOR_ERRS);
1478 
1479 	/* Limit to Root Ports or Root Complex Event Collectors */
1480 	if ((pci_pcie_type(port) != PCI_EXP_TYPE_RC_EC) &&
1481 	    (pci_pcie_type(port) != PCI_EXP_TYPE_ROOT_PORT))
1482 		return -ENODEV;
1483 
1484 	rpc = devm_kzalloc(device, sizeof(struct aer_rpc), GFP_KERNEL);
1485 	if (!rpc)
1486 		return -ENOMEM;
1487 
1488 	rpc->rpd = port;
1489 	INIT_KFIFO(rpc->aer_fifo);
1490 	set_service_data(dev, rpc);
1491 
1492 	status = devm_request_threaded_irq(device, dev->irq, aer_irq, aer_isr,
1493 					   IRQF_SHARED, "aerdrv", dev);
1494 	if (status) {
1495 		pci_err(port, "request AER IRQ %d failed\n", dev->irq);
1496 		return status;
1497 	}
1498 
1499 	cxl_rch_enable_rcec(port);
1500 	aer_enable_rootport(rpc);
1501 	pci_info(port, "enabled with IRQ %d\n", dev->irq);
1502 	return 0;
1503 }
1504 
1505 static int aer_suspend(struct pcie_device *dev)
1506 {
1507 	struct aer_rpc *rpc = get_service_data(dev);
1508 
1509 	aer_disable_rootport(rpc);
1510 	return 0;
1511 }
1512 
1513 static int aer_resume(struct pcie_device *dev)
1514 {
1515 	struct aer_rpc *rpc = get_service_data(dev);
1516 
1517 	aer_enable_rootport(rpc);
1518 	return 0;
1519 }
1520 
1521 /**
1522  * aer_root_reset - reset Root Port hierarchy, RCEC, or RCiEP
1523  * @dev: pointer to Root Port, RCEC, or RCiEP
1524  *
1525  * Invoked by Port Bus driver when performing reset.
1526  */
1527 static pci_ers_result_t aer_root_reset(struct pci_dev *dev)
1528 {
1529 	int type = pci_pcie_type(dev);
1530 	struct pci_dev *root;
1531 	int aer;
1532 	struct pci_host_bridge *host = pci_find_host_bridge(dev->bus);
1533 	u32 reg32;
1534 	int rc;
1535 
1536 	/*
1537 	 * Only Root Ports and RCECs have AER Root Command and Root Status
1538 	 * registers.  If "dev" is an RCiEP, the relevant registers are in
1539 	 * the RCEC.
1540 	 */
1541 	if (type == PCI_EXP_TYPE_RC_END)
1542 		root = dev->rcec;
1543 	else
1544 		root = pcie_find_root_port(dev);
1545 
1546 	/*
1547 	 * If the platform retained control of AER, an RCiEP may not have
1548 	 * an RCEC visible to us, so dev->rcec ("root") may be NULL.  In
1549 	 * that case, firmware is responsible for these registers.
1550 	 */
1551 	aer = root ? root->aer_cap : 0;
1552 
1553 	if ((host->native_aer || pcie_ports_native) && aer)
1554 		aer_disable_irq(root);
1555 
1556 	if (type == PCI_EXP_TYPE_RC_EC || type == PCI_EXP_TYPE_RC_END) {
1557 		rc = pcie_reset_flr(dev, PCI_RESET_DO_RESET);
1558 		if (!rc)
1559 			pci_info(dev, "has been reset\n");
1560 		else
1561 			pci_info(dev, "not reset (no FLR support: %d)\n", rc);
1562 	} else {
1563 		rc = pci_bus_error_reset(dev);
1564 		pci_info(dev, "%s Port link has been reset (%d)\n",
1565 			pci_is_root_bus(dev->bus) ? "Root" : "Downstream", rc);
1566 	}
1567 
1568 	if ((host->native_aer || pcie_ports_native) && aer) {
1569 		/* Clear Root Error Status */
1570 		pci_read_config_dword(root, aer + PCI_ERR_ROOT_STATUS, &reg32);
1571 		pci_write_config_dword(root, aer + PCI_ERR_ROOT_STATUS, reg32);
1572 
1573 		aer_enable_irq(root);
1574 	}
1575 
1576 	return rc ? PCI_ERS_RESULT_DISCONNECT : PCI_ERS_RESULT_RECOVERED;
1577 }
1578 
1579 static struct pcie_port_service_driver aerdriver = {
1580 	.name		= "aer",
1581 	.port_type	= PCIE_ANY_PORT,
1582 	.service	= PCIE_PORT_SERVICE_AER,
1583 
1584 	.probe		= aer_probe,
1585 	.suspend	= aer_suspend,
1586 	.resume		= aer_resume,
1587 	.remove		= aer_remove,
1588 };
1589 
1590 /**
1591  * pcie_aer_init - register AER service driver
1592  *
1593  * Invoked when AER service driver is loaded.
1594  */
1595 int __init pcie_aer_init(void)
1596 {
1597 	if (!pci_aer_available())
1598 		return -ENXIO;
1599 	return pcie_port_service_register(&aerdriver);
1600 }
1601