xref: /linux/drivers/pci/pcie/aer.c (revision db1ecca22edf27c5a3dd66af406c88b5b5ac7cc1)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Implement the AER root port service driver. The driver registers an IRQ
4  * handler. When a root port triggers an AER interrupt, the IRQ handler
5  * collects root port status and schedules work.
6  *
7  * Copyright (C) 2006 Intel Corp.
8  *	Tom Long Nguyen (tom.l.nguyen@intel.com)
9  *	Zhang Yanmin (yanmin.zhang@intel.com)
10  *
11  * (C) Copyright 2009 Hewlett-Packard Development Company, L.P.
12  *    Andrew Patterson <andrew.patterson@hp.com>
13  */
14 
15 #define pr_fmt(fmt) "AER: " fmt
16 #define dev_fmt pr_fmt
17 
18 #include <linux/bitops.h>
19 #include <linux/cper.h>
20 #include <linux/pci.h>
21 #include <linux/pci-acpi.h>
22 #include <linux/sched.h>
23 #include <linux/kernel.h>
24 #include <linux/errno.h>
25 #include <linux/pm.h>
26 #include <linux/init.h>
27 #include <linux/interrupt.h>
28 #include <linux/delay.h>
29 #include <linux/kfifo.h>
30 #include <linux/slab.h>
31 #include <acpi/apei.h>
32 #include <acpi/ghes.h>
33 #include <ras/ras_event.h>
34 
35 #include "../pci.h"
36 #include "portdrv.h"
37 
38 #define AER_ERROR_SOURCES_MAX		128
39 
40 #define AER_MAX_TYPEOF_COR_ERRS		16	/* as per PCI_ERR_COR_STATUS */
41 #define AER_MAX_TYPEOF_UNCOR_ERRS	27	/* as per PCI_ERR_UNCOR_STATUS*/
42 
43 struct aer_err_source {
44 	unsigned int status;
45 	unsigned int id;
46 };
47 
48 struct aer_rpc {
49 	struct pci_dev *rpd;		/* Root Port device */
50 	DECLARE_KFIFO(aer_fifo, struct aer_err_source, AER_ERROR_SOURCES_MAX);
51 };
52 
53 /* AER stats for the device */
54 struct aer_stats {
55 
56 	/*
57 	 * Fields for all AER capable devices. They indicate the errors
58 	 * "as seen by this device". Note that this may mean that if an
59 	 * end point is causing problems, the AER counters may increment
60 	 * at its link partner (e.g. root port) because the errors will be
61 	 * "seen" by the link partner and not the problematic end point
62 	 * itself (which may report all counters as 0 as it never saw any
63 	 * problems).
64 	 */
65 	/* Counters for different type of correctable errors */
66 	u64 dev_cor_errs[AER_MAX_TYPEOF_COR_ERRS];
67 	/* Counters for different type of fatal uncorrectable errors */
68 	u64 dev_fatal_errs[AER_MAX_TYPEOF_UNCOR_ERRS];
69 	/* Counters for different type of nonfatal uncorrectable errors */
70 	u64 dev_nonfatal_errs[AER_MAX_TYPEOF_UNCOR_ERRS];
71 	/* Total number of ERR_COR sent by this device */
72 	u64 dev_total_cor_errs;
73 	/* Total number of ERR_FATAL sent by this device */
74 	u64 dev_total_fatal_errs;
75 	/* Total number of ERR_NONFATAL sent by this device */
76 	u64 dev_total_nonfatal_errs;
77 
78 	/*
79 	 * Fields for Root ports & root complex event collectors only, these
80 	 * indicate the total number of ERR_COR, ERR_FATAL, and ERR_NONFATAL
81 	 * messages received by the root port / event collector, INCLUDING the
82 	 * ones that are generated internally (by the rootport itself)
83 	 */
84 	u64 rootport_total_cor_errs;
85 	u64 rootport_total_fatal_errs;
86 	u64 rootport_total_nonfatal_errs;
87 };
88 
89 #define AER_LOG_TLP_MASKS		(PCI_ERR_UNC_POISON_TLP|	\
90 					PCI_ERR_UNC_ECRC|		\
91 					PCI_ERR_UNC_UNSUP|		\
92 					PCI_ERR_UNC_COMP_ABORT|		\
93 					PCI_ERR_UNC_UNX_COMP|		\
94 					PCI_ERR_UNC_MALF_TLP)
95 
96 #define SYSTEM_ERROR_INTR_ON_MESG_MASK	(PCI_EXP_RTCTL_SECEE|	\
97 					PCI_EXP_RTCTL_SENFEE|	\
98 					PCI_EXP_RTCTL_SEFEE)
99 #define ROOT_PORT_INTR_ON_MESG_MASK	(PCI_ERR_ROOT_CMD_COR_EN|	\
100 					PCI_ERR_ROOT_CMD_NONFATAL_EN|	\
101 					PCI_ERR_ROOT_CMD_FATAL_EN)
102 #define ERR_COR_ID(d)			(d & 0xffff)
103 #define ERR_UNCOR_ID(d)			(d >> 16)
104 
105 #define AER_ERR_STATUS_MASK		(PCI_ERR_ROOT_UNCOR_RCV |	\
106 					PCI_ERR_ROOT_COR_RCV |		\
107 					PCI_ERR_ROOT_MULTI_COR_RCV |	\
108 					PCI_ERR_ROOT_MULTI_UNCOR_RCV)
109 
110 static int pcie_aer_disable;
111 static pci_ers_result_t aer_root_reset(struct pci_dev *dev);
112 
113 void pci_no_aer(void)
114 {
115 	pcie_aer_disable = 1;
116 }
117 
118 bool pci_aer_available(void)
119 {
120 	return !pcie_aer_disable && pci_msi_enabled();
121 }
122 
123 #ifdef CONFIG_PCIE_ECRC
124 
125 #define ECRC_POLICY_DEFAULT 0		/* ECRC set by BIOS */
126 #define ECRC_POLICY_OFF     1		/* ECRC off for performance */
127 #define ECRC_POLICY_ON      2		/* ECRC on for data integrity */
128 
129 static int ecrc_policy = ECRC_POLICY_DEFAULT;
130 
131 static const char * const ecrc_policy_str[] = {
132 	[ECRC_POLICY_DEFAULT] = "bios",
133 	[ECRC_POLICY_OFF] = "off",
134 	[ECRC_POLICY_ON] = "on"
135 };
136 
137 /**
138  * enable_ecrc_checking - enable PCIe ECRC checking for a device
139  * @dev: the PCI device
140  *
141  * Returns 0 on success, or negative on failure.
142  */
143 static int enable_ecrc_checking(struct pci_dev *dev)
144 {
145 	int aer = dev->aer_cap;
146 	u32 reg32;
147 
148 	if (!aer)
149 		return -ENODEV;
150 
151 	pci_read_config_dword(dev, aer + PCI_ERR_CAP, &reg32);
152 	if (reg32 & PCI_ERR_CAP_ECRC_GENC)
153 		reg32 |= PCI_ERR_CAP_ECRC_GENE;
154 	if (reg32 & PCI_ERR_CAP_ECRC_CHKC)
155 		reg32 |= PCI_ERR_CAP_ECRC_CHKE;
156 	pci_write_config_dword(dev, aer + PCI_ERR_CAP, reg32);
157 
158 	return 0;
159 }
160 
161 /**
162  * disable_ecrc_checking - disables PCIe ECRC checking for a device
163  * @dev: the PCI device
164  *
165  * Returns 0 on success, or negative on failure.
166  */
167 static int disable_ecrc_checking(struct pci_dev *dev)
168 {
169 	int aer = dev->aer_cap;
170 	u32 reg32;
171 
172 	if (!aer)
173 		return -ENODEV;
174 
175 	pci_read_config_dword(dev, aer + PCI_ERR_CAP, &reg32);
176 	reg32 &= ~(PCI_ERR_CAP_ECRC_GENE | PCI_ERR_CAP_ECRC_CHKE);
177 	pci_write_config_dword(dev, aer + PCI_ERR_CAP, reg32);
178 
179 	return 0;
180 }
181 
182 /**
183  * pcie_set_ecrc_checking - set/unset PCIe ECRC checking for a device based on global policy
184  * @dev: the PCI device
185  */
186 void pcie_set_ecrc_checking(struct pci_dev *dev)
187 {
188 	if (!pcie_aer_is_native(dev))
189 		return;
190 
191 	switch (ecrc_policy) {
192 	case ECRC_POLICY_DEFAULT:
193 		return;
194 	case ECRC_POLICY_OFF:
195 		disable_ecrc_checking(dev);
196 		break;
197 	case ECRC_POLICY_ON:
198 		enable_ecrc_checking(dev);
199 		break;
200 	default:
201 		return;
202 	}
203 }
204 
205 /**
206  * pcie_ecrc_get_policy - parse kernel command-line ecrc option
207  * @str: ECRC policy from kernel command line to use
208  */
209 void pcie_ecrc_get_policy(char *str)
210 {
211 	int i;
212 
213 	i = match_string(ecrc_policy_str, ARRAY_SIZE(ecrc_policy_str), str);
214 	if (i < 0)
215 		return;
216 
217 	ecrc_policy = i;
218 }
219 #endif	/* CONFIG_PCIE_ECRC */
220 
221 #define	PCI_EXP_AER_FLAGS	(PCI_EXP_DEVCTL_CERE | PCI_EXP_DEVCTL_NFERE | \
222 				 PCI_EXP_DEVCTL_FERE | PCI_EXP_DEVCTL_URRE)
223 
224 int pcie_aer_is_native(struct pci_dev *dev)
225 {
226 	struct pci_host_bridge *host = pci_find_host_bridge(dev->bus);
227 
228 	if (!dev->aer_cap)
229 		return 0;
230 
231 	return pcie_ports_native || host->native_aer;
232 }
233 EXPORT_SYMBOL_NS_GPL(pcie_aer_is_native, CXL);
234 
235 static int pci_enable_pcie_error_reporting(struct pci_dev *dev)
236 {
237 	int rc;
238 
239 	if (!pcie_aer_is_native(dev))
240 		return -EIO;
241 
242 	rc = pcie_capability_set_word(dev, PCI_EXP_DEVCTL, PCI_EXP_AER_FLAGS);
243 	return pcibios_err_to_errno(rc);
244 }
245 
246 int pci_aer_clear_nonfatal_status(struct pci_dev *dev)
247 {
248 	int aer = dev->aer_cap;
249 	u32 status, sev;
250 
251 	if (!pcie_aer_is_native(dev))
252 		return -EIO;
253 
254 	/* Clear status bits for ERR_NONFATAL errors only */
255 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, &status);
256 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_SEVER, &sev);
257 	status &= ~sev;
258 	if (status)
259 		pci_write_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, status);
260 
261 	return 0;
262 }
263 EXPORT_SYMBOL_GPL(pci_aer_clear_nonfatal_status);
264 
265 void pci_aer_clear_fatal_status(struct pci_dev *dev)
266 {
267 	int aer = dev->aer_cap;
268 	u32 status, sev;
269 
270 	if (!pcie_aer_is_native(dev))
271 		return;
272 
273 	/* Clear status bits for ERR_FATAL errors only */
274 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, &status);
275 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_SEVER, &sev);
276 	status &= sev;
277 	if (status)
278 		pci_write_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, status);
279 }
280 
281 /**
282  * pci_aer_raw_clear_status - Clear AER error registers.
283  * @dev: the PCI device
284  *
285  * Clearing AER error status registers unconditionally, regardless of
286  * whether they're owned by firmware or the OS.
287  *
288  * Returns 0 on success, or negative on failure.
289  */
290 int pci_aer_raw_clear_status(struct pci_dev *dev)
291 {
292 	int aer = dev->aer_cap;
293 	u32 status;
294 	int port_type;
295 
296 	if (!aer)
297 		return -EIO;
298 
299 	port_type = pci_pcie_type(dev);
300 	if (port_type == PCI_EXP_TYPE_ROOT_PORT ||
301 	    port_type == PCI_EXP_TYPE_RC_EC) {
302 		pci_read_config_dword(dev, aer + PCI_ERR_ROOT_STATUS, &status);
303 		pci_write_config_dword(dev, aer + PCI_ERR_ROOT_STATUS, status);
304 	}
305 
306 	pci_read_config_dword(dev, aer + PCI_ERR_COR_STATUS, &status);
307 	pci_write_config_dword(dev, aer + PCI_ERR_COR_STATUS, status);
308 
309 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, &status);
310 	pci_write_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, status);
311 
312 	return 0;
313 }
314 
315 int pci_aer_clear_status(struct pci_dev *dev)
316 {
317 	if (!pcie_aer_is_native(dev))
318 		return -EIO;
319 
320 	return pci_aer_raw_clear_status(dev);
321 }
322 
323 void pci_save_aer_state(struct pci_dev *dev)
324 {
325 	int aer = dev->aer_cap;
326 	struct pci_cap_saved_state *save_state;
327 	u32 *cap;
328 
329 	if (!aer)
330 		return;
331 
332 	save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_ERR);
333 	if (!save_state)
334 		return;
335 
336 	cap = &save_state->cap.data[0];
337 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_MASK, cap++);
338 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_SEVER, cap++);
339 	pci_read_config_dword(dev, aer + PCI_ERR_COR_MASK, cap++);
340 	pci_read_config_dword(dev, aer + PCI_ERR_CAP, cap++);
341 	if (pcie_cap_has_rtctl(dev))
342 		pci_read_config_dword(dev, aer + PCI_ERR_ROOT_COMMAND, cap++);
343 }
344 
345 void pci_restore_aer_state(struct pci_dev *dev)
346 {
347 	int aer = dev->aer_cap;
348 	struct pci_cap_saved_state *save_state;
349 	u32 *cap;
350 
351 	if (!aer)
352 		return;
353 
354 	save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_ERR);
355 	if (!save_state)
356 		return;
357 
358 	cap = &save_state->cap.data[0];
359 	pci_write_config_dword(dev, aer + PCI_ERR_UNCOR_MASK, *cap++);
360 	pci_write_config_dword(dev, aer + PCI_ERR_UNCOR_SEVER, *cap++);
361 	pci_write_config_dword(dev, aer + PCI_ERR_COR_MASK, *cap++);
362 	pci_write_config_dword(dev, aer + PCI_ERR_CAP, *cap++);
363 	if (pcie_cap_has_rtctl(dev))
364 		pci_write_config_dword(dev, aer + PCI_ERR_ROOT_COMMAND, *cap++);
365 }
366 
367 void pci_aer_init(struct pci_dev *dev)
368 {
369 	int n;
370 
371 	dev->aer_cap = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
372 	if (!dev->aer_cap)
373 		return;
374 
375 	dev->aer_stats = kzalloc(sizeof(struct aer_stats), GFP_KERNEL);
376 
377 	/*
378 	 * We save/restore PCI_ERR_UNCOR_MASK, PCI_ERR_UNCOR_SEVER,
379 	 * PCI_ERR_COR_MASK, and PCI_ERR_CAP.  Root and Root Complex Event
380 	 * Collectors also implement PCI_ERR_ROOT_COMMAND (PCIe r5.0, sec
381 	 * 7.8.4).
382 	 */
383 	n = pcie_cap_has_rtctl(dev) ? 5 : 4;
384 	pci_add_ext_cap_save_buffer(dev, PCI_EXT_CAP_ID_ERR, sizeof(u32) * n);
385 
386 	pci_aer_clear_status(dev);
387 
388 	if (pci_aer_available())
389 		pci_enable_pcie_error_reporting(dev);
390 
391 	pcie_set_ecrc_checking(dev);
392 }
393 
394 void pci_aer_exit(struct pci_dev *dev)
395 {
396 	kfree(dev->aer_stats);
397 	dev->aer_stats = NULL;
398 }
399 
400 #define AER_AGENT_RECEIVER		0
401 #define AER_AGENT_REQUESTER		1
402 #define AER_AGENT_COMPLETER		2
403 #define AER_AGENT_TRANSMITTER		3
404 
405 #define AER_AGENT_REQUESTER_MASK(t)	((t == AER_CORRECTABLE) ?	\
406 	0 : (PCI_ERR_UNC_COMP_TIME|PCI_ERR_UNC_UNSUP))
407 #define AER_AGENT_COMPLETER_MASK(t)	((t == AER_CORRECTABLE) ?	\
408 	0 : PCI_ERR_UNC_COMP_ABORT)
409 #define AER_AGENT_TRANSMITTER_MASK(t)	((t == AER_CORRECTABLE) ?	\
410 	(PCI_ERR_COR_REP_ROLL|PCI_ERR_COR_REP_TIMER) : 0)
411 
412 #define AER_GET_AGENT(t, e)						\
413 	((e & AER_AGENT_COMPLETER_MASK(t)) ? AER_AGENT_COMPLETER :	\
414 	(e & AER_AGENT_REQUESTER_MASK(t)) ? AER_AGENT_REQUESTER :	\
415 	(e & AER_AGENT_TRANSMITTER_MASK(t)) ? AER_AGENT_TRANSMITTER :	\
416 	AER_AGENT_RECEIVER)
417 
418 #define AER_PHYSICAL_LAYER_ERROR	0
419 #define AER_DATA_LINK_LAYER_ERROR	1
420 #define AER_TRANSACTION_LAYER_ERROR	2
421 
422 #define AER_PHYSICAL_LAYER_ERROR_MASK(t) ((t == AER_CORRECTABLE) ?	\
423 	PCI_ERR_COR_RCVR : 0)
424 #define AER_DATA_LINK_LAYER_ERROR_MASK(t) ((t == AER_CORRECTABLE) ?	\
425 	(PCI_ERR_COR_BAD_TLP|						\
426 	PCI_ERR_COR_BAD_DLLP|						\
427 	PCI_ERR_COR_REP_ROLL|						\
428 	PCI_ERR_COR_REP_TIMER) : PCI_ERR_UNC_DLP)
429 
430 #define AER_GET_LAYER_ERROR(t, e)					\
431 	((e & AER_PHYSICAL_LAYER_ERROR_MASK(t)) ? AER_PHYSICAL_LAYER_ERROR : \
432 	(e & AER_DATA_LINK_LAYER_ERROR_MASK(t)) ? AER_DATA_LINK_LAYER_ERROR : \
433 	AER_TRANSACTION_LAYER_ERROR)
434 
435 /*
436  * AER error strings
437  */
438 static const char *aer_error_severity_string[] = {
439 	"Uncorrected (Non-Fatal)",
440 	"Uncorrected (Fatal)",
441 	"Corrected"
442 };
443 
444 static const char *aer_error_layer[] = {
445 	"Physical Layer",
446 	"Data Link Layer",
447 	"Transaction Layer"
448 };
449 
450 static const char *aer_correctable_error_string[] = {
451 	"RxErr",			/* Bit Position 0	*/
452 	NULL,
453 	NULL,
454 	NULL,
455 	NULL,
456 	NULL,
457 	"BadTLP",			/* Bit Position 6	*/
458 	"BadDLLP",			/* Bit Position 7	*/
459 	"Rollover",			/* Bit Position 8	*/
460 	NULL,
461 	NULL,
462 	NULL,
463 	"Timeout",			/* Bit Position 12	*/
464 	"NonFatalErr",			/* Bit Position 13	*/
465 	"CorrIntErr",			/* Bit Position 14	*/
466 	"HeaderOF",			/* Bit Position 15	*/
467 	NULL,				/* Bit Position 16	*/
468 	NULL,				/* Bit Position 17	*/
469 	NULL,				/* Bit Position 18	*/
470 	NULL,				/* Bit Position 19	*/
471 	NULL,				/* Bit Position 20	*/
472 	NULL,				/* Bit Position 21	*/
473 	NULL,				/* Bit Position 22	*/
474 	NULL,				/* Bit Position 23	*/
475 	NULL,				/* Bit Position 24	*/
476 	NULL,				/* Bit Position 25	*/
477 	NULL,				/* Bit Position 26	*/
478 	NULL,				/* Bit Position 27	*/
479 	NULL,				/* Bit Position 28	*/
480 	NULL,				/* Bit Position 29	*/
481 	NULL,				/* Bit Position 30	*/
482 	NULL,				/* Bit Position 31	*/
483 };
484 
485 static const char *aer_uncorrectable_error_string[] = {
486 	"Undefined",			/* Bit Position 0	*/
487 	NULL,
488 	NULL,
489 	NULL,
490 	"DLP",				/* Bit Position 4	*/
491 	"SDES",				/* Bit Position 5	*/
492 	NULL,
493 	NULL,
494 	NULL,
495 	NULL,
496 	NULL,
497 	NULL,
498 	"TLP",				/* Bit Position 12	*/
499 	"FCP",				/* Bit Position 13	*/
500 	"CmpltTO",			/* Bit Position 14	*/
501 	"CmpltAbrt",			/* Bit Position 15	*/
502 	"UnxCmplt",			/* Bit Position 16	*/
503 	"RxOF",				/* Bit Position 17	*/
504 	"MalfTLP",			/* Bit Position 18	*/
505 	"ECRC",				/* Bit Position 19	*/
506 	"UnsupReq",			/* Bit Position 20	*/
507 	"ACSViol",			/* Bit Position 21	*/
508 	"UncorrIntErr",			/* Bit Position 22	*/
509 	"BlockedTLP",			/* Bit Position 23	*/
510 	"AtomicOpBlocked",		/* Bit Position 24	*/
511 	"TLPBlockedErr",		/* Bit Position 25	*/
512 	"PoisonTLPBlocked",		/* Bit Position 26	*/
513 	NULL,				/* Bit Position 27	*/
514 	NULL,				/* Bit Position 28	*/
515 	NULL,				/* Bit Position 29	*/
516 	NULL,				/* Bit Position 30	*/
517 	NULL,				/* Bit Position 31	*/
518 };
519 
520 static const char *aer_agent_string[] = {
521 	"Receiver ID",
522 	"Requester ID",
523 	"Completer ID",
524 	"Transmitter ID"
525 };
526 
527 #define aer_stats_dev_attr(name, stats_array, strings_array,		\
528 			   total_string, total_field)			\
529 	static ssize_t							\
530 	name##_show(struct device *dev, struct device_attribute *attr,	\
531 		     char *buf)						\
532 {									\
533 	unsigned int i;							\
534 	struct pci_dev *pdev = to_pci_dev(dev);				\
535 	u64 *stats = pdev->aer_stats->stats_array;			\
536 	size_t len = 0;							\
537 									\
538 	for (i = 0; i < ARRAY_SIZE(pdev->aer_stats->stats_array); i++) {\
539 		if (strings_array[i])					\
540 			len += sysfs_emit_at(buf, len, "%s %llu\n",	\
541 					     strings_array[i],		\
542 					     stats[i]);			\
543 		else if (stats[i])					\
544 			len += sysfs_emit_at(buf, len,			\
545 					     #stats_array "_bit[%d] %llu\n",\
546 					     i, stats[i]);		\
547 	}								\
548 	len += sysfs_emit_at(buf, len, "TOTAL_%s %llu\n", total_string,	\
549 			     pdev->aer_stats->total_field);		\
550 	return len;							\
551 }									\
552 static DEVICE_ATTR_RO(name)
553 
554 aer_stats_dev_attr(aer_dev_correctable, dev_cor_errs,
555 		   aer_correctable_error_string, "ERR_COR",
556 		   dev_total_cor_errs);
557 aer_stats_dev_attr(aer_dev_fatal, dev_fatal_errs,
558 		   aer_uncorrectable_error_string, "ERR_FATAL",
559 		   dev_total_fatal_errs);
560 aer_stats_dev_attr(aer_dev_nonfatal, dev_nonfatal_errs,
561 		   aer_uncorrectable_error_string, "ERR_NONFATAL",
562 		   dev_total_nonfatal_errs);
563 
564 #define aer_stats_rootport_attr(name, field)				\
565 	static ssize_t							\
566 	name##_show(struct device *dev, struct device_attribute *attr,	\
567 		     char *buf)						\
568 {									\
569 	struct pci_dev *pdev = to_pci_dev(dev);				\
570 	return sysfs_emit(buf, "%llu\n", pdev->aer_stats->field);	\
571 }									\
572 static DEVICE_ATTR_RO(name)
573 
574 aer_stats_rootport_attr(aer_rootport_total_err_cor,
575 			 rootport_total_cor_errs);
576 aer_stats_rootport_attr(aer_rootport_total_err_fatal,
577 			 rootport_total_fatal_errs);
578 aer_stats_rootport_attr(aer_rootport_total_err_nonfatal,
579 			 rootport_total_nonfatal_errs);
580 
581 static struct attribute *aer_stats_attrs[] __ro_after_init = {
582 	&dev_attr_aer_dev_correctable.attr,
583 	&dev_attr_aer_dev_fatal.attr,
584 	&dev_attr_aer_dev_nonfatal.attr,
585 	&dev_attr_aer_rootport_total_err_cor.attr,
586 	&dev_attr_aer_rootport_total_err_fatal.attr,
587 	&dev_attr_aer_rootport_total_err_nonfatal.attr,
588 	NULL
589 };
590 
591 static umode_t aer_stats_attrs_are_visible(struct kobject *kobj,
592 					   struct attribute *a, int n)
593 {
594 	struct device *dev = kobj_to_dev(kobj);
595 	struct pci_dev *pdev = to_pci_dev(dev);
596 
597 	if (!pdev->aer_stats)
598 		return 0;
599 
600 	if ((a == &dev_attr_aer_rootport_total_err_cor.attr ||
601 	     a == &dev_attr_aer_rootport_total_err_fatal.attr ||
602 	     a == &dev_attr_aer_rootport_total_err_nonfatal.attr) &&
603 	    ((pci_pcie_type(pdev) != PCI_EXP_TYPE_ROOT_PORT) &&
604 	     (pci_pcie_type(pdev) != PCI_EXP_TYPE_RC_EC)))
605 		return 0;
606 
607 	return a->mode;
608 }
609 
610 const struct attribute_group aer_stats_attr_group = {
611 	.attrs  = aer_stats_attrs,
612 	.is_visible = aer_stats_attrs_are_visible,
613 };
614 
615 static void pci_dev_aer_stats_incr(struct pci_dev *pdev,
616 				   struct aer_err_info *info)
617 {
618 	unsigned long status = info->status & ~info->mask;
619 	int i, max = -1;
620 	u64 *counter = NULL;
621 	struct aer_stats *aer_stats = pdev->aer_stats;
622 
623 	if (!aer_stats)
624 		return;
625 
626 	switch (info->severity) {
627 	case AER_CORRECTABLE:
628 		aer_stats->dev_total_cor_errs++;
629 		counter = &aer_stats->dev_cor_errs[0];
630 		max = AER_MAX_TYPEOF_COR_ERRS;
631 		break;
632 	case AER_NONFATAL:
633 		aer_stats->dev_total_nonfatal_errs++;
634 		counter = &aer_stats->dev_nonfatal_errs[0];
635 		max = AER_MAX_TYPEOF_UNCOR_ERRS;
636 		break;
637 	case AER_FATAL:
638 		aer_stats->dev_total_fatal_errs++;
639 		counter = &aer_stats->dev_fatal_errs[0];
640 		max = AER_MAX_TYPEOF_UNCOR_ERRS;
641 		break;
642 	}
643 
644 	for_each_set_bit(i, &status, max)
645 		counter[i]++;
646 }
647 
648 static void pci_rootport_aer_stats_incr(struct pci_dev *pdev,
649 				 struct aer_err_source *e_src)
650 {
651 	struct aer_stats *aer_stats = pdev->aer_stats;
652 
653 	if (!aer_stats)
654 		return;
655 
656 	if (e_src->status & PCI_ERR_ROOT_COR_RCV)
657 		aer_stats->rootport_total_cor_errs++;
658 
659 	if (e_src->status & PCI_ERR_ROOT_UNCOR_RCV) {
660 		if (e_src->status & PCI_ERR_ROOT_FATAL_RCV)
661 			aer_stats->rootport_total_fatal_errs++;
662 		else
663 			aer_stats->rootport_total_nonfatal_errs++;
664 	}
665 }
666 
667 static void __print_tlp_header(struct pci_dev *dev,
668 			       struct aer_header_log_regs *t)
669 {
670 	pci_err(dev, "  TLP Header: %08x %08x %08x %08x\n",
671 		t->dw0, t->dw1, t->dw2, t->dw3);
672 }
673 
674 static void __aer_print_error(struct pci_dev *dev,
675 			      struct aer_err_info *info)
676 {
677 	const char **strings;
678 	unsigned long status = info->status & ~info->mask;
679 	const char *level, *errmsg;
680 	int i;
681 
682 	if (info->severity == AER_CORRECTABLE) {
683 		strings = aer_correctable_error_string;
684 		level = KERN_WARNING;
685 	} else {
686 		strings = aer_uncorrectable_error_string;
687 		level = KERN_ERR;
688 	}
689 
690 	for_each_set_bit(i, &status, 32) {
691 		errmsg = strings[i];
692 		if (!errmsg)
693 			errmsg = "Unknown Error Bit";
694 
695 		pci_printk(level, dev, "   [%2d] %-22s%s\n", i, errmsg,
696 				info->first_error == i ? " (First)" : "");
697 	}
698 	pci_dev_aer_stats_incr(dev, info);
699 }
700 
701 void aer_print_error(struct pci_dev *dev, struct aer_err_info *info)
702 {
703 	int layer, agent;
704 	int id = pci_dev_id(dev);
705 	const char *level;
706 
707 	if (!info->status) {
708 		pci_err(dev, "PCIe Bus Error: severity=%s, type=Inaccessible, (Unregistered Agent ID)\n",
709 			aer_error_severity_string[info->severity]);
710 		goto out;
711 	}
712 
713 	layer = AER_GET_LAYER_ERROR(info->severity, info->status);
714 	agent = AER_GET_AGENT(info->severity, info->status);
715 
716 	level = (info->severity == AER_CORRECTABLE) ? KERN_WARNING : KERN_ERR;
717 
718 	pci_printk(level, dev, "PCIe Bus Error: severity=%s, type=%s, (%s)\n",
719 		   aer_error_severity_string[info->severity],
720 		   aer_error_layer[layer], aer_agent_string[agent]);
721 
722 	pci_printk(level, dev, "  device [%04x:%04x] error status/mask=%08x/%08x\n",
723 		   dev->vendor, dev->device, info->status, info->mask);
724 
725 	__aer_print_error(dev, info);
726 
727 	if (info->tlp_header_valid)
728 		__print_tlp_header(dev, &info->tlp);
729 
730 out:
731 	if (info->id && info->error_dev_num > 1 && info->id == id)
732 		pci_err(dev, "  Error of this Agent is reported first\n");
733 
734 	trace_aer_event(dev_name(&dev->dev), (info->status & ~info->mask),
735 			info->severity, info->tlp_header_valid, &info->tlp);
736 }
737 
738 static void aer_print_port_info(struct pci_dev *dev, struct aer_err_info *info)
739 {
740 	u8 bus = info->id >> 8;
741 	u8 devfn = info->id & 0xff;
742 
743 	pci_info(dev, "%s%s error received: %04x:%02x:%02x.%d\n",
744 		 info->multi_error_valid ? "Multiple " : "",
745 		 aer_error_severity_string[info->severity],
746 		 pci_domain_nr(dev->bus), bus, PCI_SLOT(devfn),
747 		 PCI_FUNC(devfn));
748 }
749 
750 #ifdef CONFIG_ACPI_APEI_PCIEAER
751 int cper_severity_to_aer(int cper_severity)
752 {
753 	switch (cper_severity) {
754 	case CPER_SEV_RECOVERABLE:
755 		return AER_NONFATAL;
756 	case CPER_SEV_FATAL:
757 		return AER_FATAL;
758 	default:
759 		return AER_CORRECTABLE;
760 	}
761 }
762 EXPORT_SYMBOL_GPL(cper_severity_to_aer);
763 #endif
764 
765 void pci_print_aer(struct pci_dev *dev, int aer_severity,
766 		   struct aer_capability_regs *aer)
767 {
768 	int layer, agent, tlp_header_valid = 0;
769 	u32 status, mask;
770 	struct aer_err_info info;
771 
772 	if (aer_severity == AER_CORRECTABLE) {
773 		status = aer->cor_status;
774 		mask = aer->cor_mask;
775 	} else {
776 		status = aer->uncor_status;
777 		mask = aer->uncor_mask;
778 		tlp_header_valid = status & AER_LOG_TLP_MASKS;
779 	}
780 
781 	layer = AER_GET_LAYER_ERROR(aer_severity, status);
782 	agent = AER_GET_AGENT(aer_severity, status);
783 
784 	memset(&info, 0, sizeof(info));
785 	info.severity = aer_severity;
786 	info.status = status;
787 	info.mask = mask;
788 	info.first_error = PCI_ERR_CAP_FEP(aer->cap_control);
789 
790 	pci_err(dev, "aer_status: 0x%08x, aer_mask: 0x%08x\n", status, mask);
791 	__aer_print_error(dev, &info);
792 	pci_err(dev, "aer_layer=%s, aer_agent=%s\n",
793 		aer_error_layer[layer], aer_agent_string[agent]);
794 
795 	if (aer_severity != AER_CORRECTABLE)
796 		pci_err(dev, "aer_uncor_severity: 0x%08x\n",
797 			aer->uncor_severity);
798 
799 	if (tlp_header_valid)
800 		__print_tlp_header(dev, &aer->header_log);
801 
802 	trace_aer_event(dev_name(&dev->dev), (status & ~mask),
803 			aer_severity, tlp_header_valid, &aer->header_log);
804 }
805 EXPORT_SYMBOL_NS_GPL(pci_print_aer, CXL);
806 
807 /**
808  * add_error_device - list device to be handled
809  * @e_info: pointer to error info
810  * @dev: pointer to pci_dev to be added
811  */
812 static int add_error_device(struct aer_err_info *e_info, struct pci_dev *dev)
813 {
814 	if (e_info->error_dev_num < AER_MAX_MULTI_ERR_DEVICES) {
815 		e_info->dev[e_info->error_dev_num] = pci_dev_get(dev);
816 		e_info->error_dev_num++;
817 		return 0;
818 	}
819 	return -ENOSPC;
820 }
821 
822 /**
823  * is_error_source - check whether the device is source of reported error
824  * @dev: pointer to pci_dev to be checked
825  * @e_info: pointer to reported error info
826  */
827 static bool is_error_source(struct pci_dev *dev, struct aer_err_info *e_info)
828 {
829 	int aer = dev->aer_cap;
830 	u32 status, mask;
831 	u16 reg16;
832 
833 	/*
834 	 * When bus id is equal to 0, it might be a bad id
835 	 * reported by root port.
836 	 */
837 	if ((PCI_BUS_NUM(e_info->id) != 0) &&
838 	    !(dev->bus->bus_flags & PCI_BUS_FLAGS_NO_AERSID)) {
839 		/* Device ID match? */
840 		if (e_info->id == pci_dev_id(dev))
841 			return true;
842 
843 		/* Continue id comparing if there is no multiple error */
844 		if (!e_info->multi_error_valid)
845 			return false;
846 	}
847 
848 	/*
849 	 * When either
850 	 *      1) bus id is equal to 0. Some ports might lose the bus
851 	 *              id of error source id;
852 	 *      2) bus flag PCI_BUS_FLAGS_NO_AERSID is set
853 	 *      3) There are multiple errors and prior ID comparing fails;
854 	 * We check AER status registers to find possible reporter.
855 	 */
856 	if (atomic_read(&dev->enable_cnt) == 0)
857 		return false;
858 
859 	/* Check if AER is enabled */
860 	pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &reg16);
861 	if (!(reg16 & PCI_EXP_AER_FLAGS))
862 		return false;
863 
864 	if (!aer)
865 		return false;
866 
867 	/* Check if error is recorded */
868 	if (e_info->severity == AER_CORRECTABLE) {
869 		pci_read_config_dword(dev, aer + PCI_ERR_COR_STATUS, &status);
870 		pci_read_config_dword(dev, aer + PCI_ERR_COR_MASK, &mask);
871 	} else {
872 		pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, &status);
873 		pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_MASK, &mask);
874 	}
875 	if (status & ~mask)
876 		return true;
877 
878 	return false;
879 }
880 
881 static int find_device_iter(struct pci_dev *dev, void *data)
882 {
883 	struct aer_err_info *e_info = (struct aer_err_info *)data;
884 
885 	if (is_error_source(dev, e_info)) {
886 		/* List this device */
887 		if (add_error_device(e_info, dev)) {
888 			/* We cannot handle more... Stop iteration */
889 			/* TODO: Should print error message here? */
890 			return 1;
891 		}
892 
893 		/* If there is only a single error, stop iteration */
894 		if (!e_info->multi_error_valid)
895 			return 1;
896 	}
897 	return 0;
898 }
899 
900 /**
901  * find_source_device - search through device hierarchy for source device
902  * @parent: pointer to Root Port pci_dev data structure
903  * @e_info: including detailed error information such like id
904  *
905  * Return true if found.
906  *
907  * Invoked by DPC when error is detected at the Root Port.
908  * Caller of this function must set id, severity, and multi_error_valid of
909  * struct aer_err_info pointed by @e_info properly.  This function must fill
910  * e_info->error_dev_num and e_info->dev[], based on the given information.
911  */
912 static bool find_source_device(struct pci_dev *parent,
913 		struct aer_err_info *e_info)
914 {
915 	struct pci_dev *dev = parent;
916 	int result;
917 
918 	/* Must reset in this function */
919 	e_info->error_dev_num = 0;
920 
921 	/* Is Root Port an agent that sends error message? */
922 	result = find_device_iter(dev, e_info);
923 	if (result)
924 		return true;
925 
926 	if (pci_pcie_type(parent) == PCI_EXP_TYPE_RC_EC)
927 		pcie_walk_rcec(parent, find_device_iter, e_info);
928 	else
929 		pci_walk_bus(parent->subordinate, find_device_iter, e_info);
930 
931 	if (!e_info->error_dev_num) {
932 		pci_info(parent, "can't find device of ID%04x\n", e_info->id);
933 		return false;
934 	}
935 	return true;
936 }
937 
938 #ifdef CONFIG_PCIEAER_CXL
939 
940 /**
941  * pci_aer_unmask_internal_errors - unmask internal errors
942  * @dev: pointer to the pcie_dev data structure
943  *
944  * Unmasks internal errors in the Uncorrectable and Correctable Error
945  * Mask registers.
946  *
947  * Note: AER must be enabled and supported by the device which must be
948  * checked in advance, e.g. with pcie_aer_is_native().
949  */
950 static void pci_aer_unmask_internal_errors(struct pci_dev *dev)
951 {
952 	int aer = dev->aer_cap;
953 	u32 mask;
954 
955 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_MASK, &mask);
956 	mask &= ~PCI_ERR_UNC_INTN;
957 	pci_write_config_dword(dev, aer + PCI_ERR_UNCOR_MASK, mask);
958 
959 	pci_read_config_dword(dev, aer + PCI_ERR_COR_MASK, &mask);
960 	mask &= ~PCI_ERR_COR_INTERNAL;
961 	pci_write_config_dword(dev, aer + PCI_ERR_COR_MASK, mask);
962 }
963 
964 static bool is_cxl_mem_dev(struct pci_dev *dev)
965 {
966 	/*
967 	 * The capability, status, and control fields in Device 0,
968 	 * Function 0 DVSEC control the CXL functionality of the
969 	 * entire device (CXL 3.0, 8.1.3).
970 	 */
971 	if (dev->devfn != PCI_DEVFN(0, 0))
972 		return false;
973 
974 	/*
975 	 * CXL Memory Devices must have the 502h class code set (CXL
976 	 * 3.0, 8.1.12.1).
977 	 */
978 	if ((dev->class >> 8) != PCI_CLASS_MEMORY_CXL)
979 		return false;
980 
981 	return true;
982 }
983 
984 static bool cxl_error_is_native(struct pci_dev *dev)
985 {
986 	struct pci_host_bridge *host = pci_find_host_bridge(dev->bus);
987 
988 	return (pcie_ports_native || host->native_aer);
989 }
990 
991 static bool is_internal_error(struct aer_err_info *info)
992 {
993 	if (info->severity == AER_CORRECTABLE)
994 		return info->status & PCI_ERR_COR_INTERNAL;
995 
996 	return info->status & PCI_ERR_UNC_INTN;
997 }
998 
999 static int cxl_rch_handle_error_iter(struct pci_dev *dev, void *data)
1000 {
1001 	struct aer_err_info *info = (struct aer_err_info *)data;
1002 	const struct pci_error_handlers *err_handler;
1003 
1004 	if (!is_cxl_mem_dev(dev) || !cxl_error_is_native(dev))
1005 		return 0;
1006 
1007 	/* protect dev->driver */
1008 	device_lock(&dev->dev);
1009 
1010 	err_handler = dev->driver ? dev->driver->err_handler : NULL;
1011 	if (!err_handler)
1012 		goto out;
1013 
1014 	if (info->severity == AER_CORRECTABLE) {
1015 		if (err_handler->cor_error_detected)
1016 			err_handler->cor_error_detected(dev);
1017 	} else if (err_handler->error_detected) {
1018 		if (info->severity == AER_NONFATAL)
1019 			err_handler->error_detected(dev, pci_channel_io_normal);
1020 		else if (info->severity == AER_FATAL)
1021 			err_handler->error_detected(dev, pci_channel_io_frozen);
1022 	}
1023 out:
1024 	device_unlock(&dev->dev);
1025 	return 0;
1026 }
1027 
1028 static void cxl_rch_handle_error(struct pci_dev *dev, struct aer_err_info *info)
1029 {
1030 	/*
1031 	 * Internal errors of an RCEC indicate an AER error in an
1032 	 * RCH's downstream port. Check and handle them in the CXL.mem
1033 	 * device driver.
1034 	 */
1035 	if (pci_pcie_type(dev) == PCI_EXP_TYPE_RC_EC &&
1036 	    is_internal_error(info))
1037 		pcie_walk_rcec(dev, cxl_rch_handle_error_iter, info);
1038 }
1039 
1040 static int handles_cxl_error_iter(struct pci_dev *dev, void *data)
1041 {
1042 	bool *handles_cxl = data;
1043 
1044 	if (!*handles_cxl)
1045 		*handles_cxl = is_cxl_mem_dev(dev) && cxl_error_is_native(dev);
1046 
1047 	/* Non-zero terminates iteration */
1048 	return *handles_cxl;
1049 }
1050 
1051 static bool handles_cxl_errors(struct pci_dev *rcec)
1052 {
1053 	bool handles_cxl = false;
1054 
1055 	if (pci_pcie_type(rcec) == PCI_EXP_TYPE_RC_EC &&
1056 	    pcie_aer_is_native(rcec))
1057 		pcie_walk_rcec(rcec, handles_cxl_error_iter, &handles_cxl);
1058 
1059 	return handles_cxl;
1060 }
1061 
1062 static void cxl_rch_enable_rcec(struct pci_dev *rcec)
1063 {
1064 	if (!handles_cxl_errors(rcec))
1065 		return;
1066 
1067 	pci_aer_unmask_internal_errors(rcec);
1068 	pci_info(rcec, "CXL: Internal errors unmasked");
1069 }
1070 
1071 #else
1072 static inline void cxl_rch_enable_rcec(struct pci_dev *dev) { }
1073 static inline void cxl_rch_handle_error(struct pci_dev *dev,
1074 					struct aer_err_info *info) { }
1075 #endif
1076 
1077 /**
1078  * pci_aer_handle_error - handle logging error into an event log
1079  * @dev: pointer to pci_dev data structure of error source device
1080  * @info: comprehensive error information
1081  *
1082  * Invoked when an error being detected by Root Port.
1083  */
1084 static void pci_aer_handle_error(struct pci_dev *dev, struct aer_err_info *info)
1085 {
1086 	int aer = dev->aer_cap;
1087 
1088 	if (info->severity == AER_CORRECTABLE) {
1089 		/*
1090 		 * Correctable error does not need software intervention.
1091 		 * No need to go through error recovery process.
1092 		 */
1093 		if (aer)
1094 			pci_write_config_dword(dev, aer + PCI_ERR_COR_STATUS,
1095 					info->status);
1096 		if (pcie_aer_is_native(dev)) {
1097 			struct pci_driver *pdrv = dev->driver;
1098 
1099 			if (pdrv && pdrv->err_handler &&
1100 			    pdrv->err_handler->cor_error_detected)
1101 				pdrv->err_handler->cor_error_detected(dev);
1102 			pcie_clear_device_status(dev);
1103 		}
1104 	} else if (info->severity == AER_NONFATAL)
1105 		pcie_do_recovery(dev, pci_channel_io_normal, aer_root_reset);
1106 	else if (info->severity == AER_FATAL)
1107 		pcie_do_recovery(dev, pci_channel_io_frozen, aer_root_reset);
1108 }
1109 
1110 static void handle_error_source(struct pci_dev *dev, struct aer_err_info *info)
1111 {
1112 	cxl_rch_handle_error(dev, info);
1113 	pci_aer_handle_error(dev, info);
1114 	pci_dev_put(dev);
1115 }
1116 
1117 #ifdef CONFIG_ACPI_APEI_PCIEAER
1118 
1119 #define AER_RECOVER_RING_SIZE		16
1120 
1121 struct aer_recover_entry {
1122 	u8	bus;
1123 	u8	devfn;
1124 	u16	domain;
1125 	int	severity;
1126 	struct aer_capability_regs *regs;
1127 };
1128 
1129 static DEFINE_KFIFO(aer_recover_ring, struct aer_recover_entry,
1130 		    AER_RECOVER_RING_SIZE);
1131 
1132 static void aer_recover_work_func(struct work_struct *work)
1133 {
1134 	struct aer_recover_entry entry;
1135 	struct pci_dev *pdev;
1136 
1137 	while (kfifo_get(&aer_recover_ring, &entry)) {
1138 		pdev = pci_get_domain_bus_and_slot(entry.domain, entry.bus,
1139 						   entry.devfn);
1140 		if (!pdev) {
1141 			pr_err("no pci_dev for %04x:%02x:%02x.%x\n",
1142 			       entry.domain, entry.bus,
1143 			       PCI_SLOT(entry.devfn), PCI_FUNC(entry.devfn));
1144 			continue;
1145 		}
1146 		pci_print_aer(pdev, entry.severity, entry.regs);
1147 		/*
1148 		 * Memory for aer_capability_regs(entry.regs) is being allocated from the
1149 		 * ghes_estatus_pool to protect it from overwriting when multiple sections
1150 		 * are present in the error status. Thus free the same after processing
1151 		 * the data.
1152 		 */
1153 		ghes_estatus_pool_region_free((unsigned long)entry.regs,
1154 					      sizeof(struct aer_capability_regs));
1155 
1156 		if (entry.severity == AER_NONFATAL)
1157 			pcie_do_recovery(pdev, pci_channel_io_normal,
1158 					 aer_root_reset);
1159 		else if (entry.severity == AER_FATAL)
1160 			pcie_do_recovery(pdev, pci_channel_io_frozen,
1161 					 aer_root_reset);
1162 		pci_dev_put(pdev);
1163 	}
1164 }
1165 
1166 /*
1167  * Mutual exclusion for writers of aer_recover_ring, reader side don't
1168  * need lock, because there is only one reader and lock is not needed
1169  * between reader and writer.
1170  */
1171 static DEFINE_SPINLOCK(aer_recover_ring_lock);
1172 static DECLARE_WORK(aer_recover_work, aer_recover_work_func);
1173 
1174 void aer_recover_queue(int domain, unsigned int bus, unsigned int devfn,
1175 		       int severity, struct aer_capability_regs *aer_regs)
1176 {
1177 	struct aer_recover_entry entry = {
1178 		.bus		= bus,
1179 		.devfn		= devfn,
1180 		.domain		= domain,
1181 		.severity	= severity,
1182 		.regs		= aer_regs,
1183 	};
1184 
1185 	if (kfifo_in_spinlocked(&aer_recover_ring, &entry, 1,
1186 				 &aer_recover_ring_lock))
1187 		schedule_work(&aer_recover_work);
1188 	else
1189 		pr_err("buffer overflow in recovery for %04x:%02x:%02x.%x\n",
1190 		       domain, bus, PCI_SLOT(devfn), PCI_FUNC(devfn));
1191 }
1192 EXPORT_SYMBOL_GPL(aer_recover_queue);
1193 #endif
1194 
1195 /**
1196  * aer_get_device_error_info - read error status from dev and store it to info
1197  * @dev: pointer to the device expected to have a error record
1198  * @info: pointer to structure to store the error record
1199  *
1200  * Return 1 on success, 0 on error.
1201  *
1202  * Note that @info is reused among all error devices. Clear fields properly.
1203  */
1204 int aer_get_device_error_info(struct pci_dev *dev, struct aer_err_info *info)
1205 {
1206 	int type = pci_pcie_type(dev);
1207 	int aer = dev->aer_cap;
1208 	int temp;
1209 
1210 	/* Must reset in this function */
1211 	info->status = 0;
1212 	info->tlp_header_valid = 0;
1213 
1214 	/* The device might not support AER */
1215 	if (!aer)
1216 		return 0;
1217 
1218 	if (info->severity == AER_CORRECTABLE) {
1219 		pci_read_config_dword(dev, aer + PCI_ERR_COR_STATUS,
1220 			&info->status);
1221 		pci_read_config_dword(dev, aer + PCI_ERR_COR_MASK,
1222 			&info->mask);
1223 		if (!(info->status & ~info->mask))
1224 			return 0;
1225 	} else if (type == PCI_EXP_TYPE_ROOT_PORT ||
1226 		   type == PCI_EXP_TYPE_RC_EC ||
1227 		   type == PCI_EXP_TYPE_DOWNSTREAM ||
1228 		   info->severity == AER_NONFATAL) {
1229 
1230 		/* Link is still healthy for IO reads */
1231 		pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS,
1232 			&info->status);
1233 		pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_MASK,
1234 			&info->mask);
1235 		if (!(info->status & ~info->mask))
1236 			return 0;
1237 
1238 		/* Get First Error Pointer */
1239 		pci_read_config_dword(dev, aer + PCI_ERR_CAP, &temp);
1240 		info->first_error = PCI_ERR_CAP_FEP(temp);
1241 
1242 		if (info->status & AER_LOG_TLP_MASKS) {
1243 			info->tlp_header_valid = 1;
1244 			pci_read_config_dword(dev,
1245 				aer + PCI_ERR_HEADER_LOG, &info->tlp.dw0);
1246 			pci_read_config_dword(dev,
1247 				aer + PCI_ERR_HEADER_LOG + 4, &info->tlp.dw1);
1248 			pci_read_config_dword(dev,
1249 				aer + PCI_ERR_HEADER_LOG + 8, &info->tlp.dw2);
1250 			pci_read_config_dword(dev,
1251 				aer + PCI_ERR_HEADER_LOG + 12, &info->tlp.dw3);
1252 		}
1253 	}
1254 
1255 	return 1;
1256 }
1257 
1258 static inline void aer_process_err_devices(struct aer_err_info *e_info)
1259 {
1260 	int i;
1261 
1262 	/* Report all before handle them, not to lost records by reset etc. */
1263 	for (i = 0; i < e_info->error_dev_num && e_info->dev[i]; i++) {
1264 		if (aer_get_device_error_info(e_info->dev[i], e_info))
1265 			aer_print_error(e_info->dev[i], e_info);
1266 	}
1267 	for (i = 0; i < e_info->error_dev_num && e_info->dev[i]; i++) {
1268 		if (aer_get_device_error_info(e_info->dev[i], e_info))
1269 			handle_error_source(e_info->dev[i], e_info);
1270 	}
1271 }
1272 
1273 /**
1274  * aer_isr_one_error - consume an error detected by root port
1275  * @rpc: pointer to the root port which holds an error
1276  * @e_src: pointer to an error source
1277  */
1278 static void aer_isr_one_error(struct aer_rpc *rpc,
1279 		struct aer_err_source *e_src)
1280 {
1281 	struct pci_dev *pdev = rpc->rpd;
1282 	struct aer_err_info e_info;
1283 
1284 	pci_rootport_aer_stats_incr(pdev, e_src);
1285 
1286 	/*
1287 	 * There is a possibility that both correctable error and
1288 	 * uncorrectable error being logged. Report correctable error first.
1289 	 */
1290 	if (e_src->status & PCI_ERR_ROOT_COR_RCV) {
1291 		e_info.id = ERR_COR_ID(e_src->id);
1292 		e_info.severity = AER_CORRECTABLE;
1293 
1294 		if (e_src->status & PCI_ERR_ROOT_MULTI_COR_RCV)
1295 			e_info.multi_error_valid = 1;
1296 		else
1297 			e_info.multi_error_valid = 0;
1298 		aer_print_port_info(pdev, &e_info);
1299 
1300 		if (find_source_device(pdev, &e_info))
1301 			aer_process_err_devices(&e_info);
1302 	}
1303 
1304 	if (e_src->status & PCI_ERR_ROOT_UNCOR_RCV) {
1305 		e_info.id = ERR_UNCOR_ID(e_src->id);
1306 
1307 		if (e_src->status & PCI_ERR_ROOT_FATAL_RCV)
1308 			e_info.severity = AER_FATAL;
1309 		else
1310 			e_info.severity = AER_NONFATAL;
1311 
1312 		if (e_src->status & PCI_ERR_ROOT_MULTI_UNCOR_RCV)
1313 			e_info.multi_error_valid = 1;
1314 		else
1315 			e_info.multi_error_valid = 0;
1316 
1317 		aer_print_port_info(pdev, &e_info);
1318 
1319 		if (find_source_device(pdev, &e_info))
1320 			aer_process_err_devices(&e_info);
1321 	}
1322 }
1323 
1324 /**
1325  * aer_isr - consume errors detected by root port
1326  * @irq: IRQ assigned to Root Port
1327  * @context: pointer to Root Port data structure
1328  *
1329  * Invoked, as DPC, when root port records new detected error
1330  */
1331 static irqreturn_t aer_isr(int irq, void *context)
1332 {
1333 	struct pcie_device *dev = (struct pcie_device *)context;
1334 	struct aer_rpc *rpc = get_service_data(dev);
1335 	struct aer_err_source e_src;
1336 
1337 	if (kfifo_is_empty(&rpc->aer_fifo))
1338 		return IRQ_NONE;
1339 
1340 	while (kfifo_get(&rpc->aer_fifo, &e_src))
1341 		aer_isr_one_error(rpc, &e_src);
1342 	return IRQ_HANDLED;
1343 }
1344 
1345 /**
1346  * aer_irq - Root Port's ISR
1347  * @irq: IRQ assigned to Root Port
1348  * @context: pointer to Root Port data structure
1349  *
1350  * Invoked when Root Port detects AER messages.
1351  */
1352 static irqreturn_t aer_irq(int irq, void *context)
1353 {
1354 	struct pcie_device *pdev = (struct pcie_device *)context;
1355 	struct aer_rpc *rpc = get_service_data(pdev);
1356 	struct pci_dev *rp = rpc->rpd;
1357 	int aer = rp->aer_cap;
1358 	struct aer_err_source e_src = {};
1359 
1360 	pci_read_config_dword(rp, aer + PCI_ERR_ROOT_STATUS, &e_src.status);
1361 	if (!(e_src.status & AER_ERR_STATUS_MASK))
1362 		return IRQ_NONE;
1363 
1364 	pci_read_config_dword(rp, aer + PCI_ERR_ROOT_ERR_SRC, &e_src.id);
1365 	pci_write_config_dword(rp, aer + PCI_ERR_ROOT_STATUS, e_src.status);
1366 
1367 	if (!kfifo_put(&rpc->aer_fifo, e_src))
1368 		return IRQ_HANDLED;
1369 
1370 	return IRQ_WAKE_THREAD;
1371 }
1372 
1373 static void aer_enable_irq(struct pci_dev *pdev)
1374 {
1375 	int aer = pdev->aer_cap;
1376 	u32 reg32;
1377 
1378 	/* Enable Root Port's interrupt in response to error messages */
1379 	pci_read_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, &reg32);
1380 	reg32 |= ROOT_PORT_INTR_ON_MESG_MASK;
1381 	pci_write_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, reg32);
1382 }
1383 
1384 static void aer_disable_irq(struct pci_dev *pdev)
1385 {
1386 	int aer = pdev->aer_cap;
1387 	u32 reg32;
1388 
1389 	/* Disable Root's interrupt in response to error messages */
1390 	pci_read_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, &reg32);
1391 	reg32 &= ~ROOT_PORT_INTR_ON_MESG_MASK;
1392 	pci_write_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, reg32);
1393 }
1394 
1395 /**
1396  * aer_enable_rootport - enable Root Port's interrupts when receiving messages
1397  * @rpc: pointer to a Root Port data structure
1398  *
1399  * Invoked when PCIe bus loads AER service driver.
1400  */
1401 static void aer_enable_rootport(struct aer_rpc *rpc)
1402 {
1403 	struct pci_dev *pdev = rpc->rpd;
1404 	int aer = pdev->aer_cap;
1405 	u16 reg16;
1406 	u32 reg32;
1407 
1408 	/* Clear PCIe Capability's Device Status */
1409 	pcie_capability_read_word(pdev, PCI_EXP_DEVSTA, &reg16);
1410 	pcie_capability_write_word(pdev, PCI_EXP_DEVSTA, reg16);
1411 
1412 	/* Disable system error generation in response to error messages */
1413 	pcie_capability_clear_word(pdev, PCI_EXP_RTCTL,
1414 				   SYSTEM_ERROR_INTR_ON_MESG_MASK);
1415 
1416 	/* Clear error status */
1417 	pci_read_config_dword(pdev, aer + PCI_ERR_ROOT_STATUS, &reg32);
1418 	pci_write_config_dword(pdev, aer + PCI_ERR_ROOT_STATUS, reg32);
1419 	pci_read_config_dword(pdev, aer + PCI_ERR_COR_STATUS, &reg32);
1420 	pci_write_config_dword(pdev, aer + PCI_ERR_COR_STATUS, reg32);
1421 	pci_read_config_dword(pdev, aer + PCI_ERR_UNCOR_STATUS, &reg32);
1422 	pci_write_config_dword(pdev, aer + PCI_ERR_UNCOR_STATUS, reg32);
1423 
1424 	aer_enable_irq(pdev);
1425 }
1426 
1427 /**
1428  * aer_disable_rootport - disable Root Port's interrupts when receiving messages
1429  * @rpc: pointer to a Root Port data structure
1430  *
1431  * Invoked when PCIe bus unloads AER service driver.
1432  */
1433 static void aer_disable_rootport(struct aer_rpc *rpc)
1434 {
1435 	struct pci_dev *pdev = rpc->rpd;
1436 	int aer = pdev->aer_cap;
1437 	u32 reg32;
1438 
1439 	aer_disable_irq(pdev);
1440 
1441 	/* Clear Root's error status reg */
1442 	pci_read_config_dword(pdev, aer + PCI_ERR_ROOT_STATUS, &reg32);
1443 	pci_write_config_dword(pdev, aer + PCI_ERR_ROOT_STATUS, reg32);
1444 }
1445 
1446 /**
1447  * aer_remove - clean up resources
1448  * @dev: pointer to the pcie_dev data structure
1449  *
1450  * Invoked when PCI Express bus unloads or AER probe fails.
1451  */
1452 static void aer_remove(struct pcie_device *dev)
1453 {
1454 	struct aer_rpc *rpc = get_service_data(dev);
1455 
1456 	aer_disable_rootport(rpc);
1457 }
1458 
1459 /**
1460  * aer_probe - initialize resources
1461  * @dev: pointer to the pcie_dev data structure
1462  *
1463  * Invoked when PCI Express bus loads AER service driver.
1464  */
1465 static int aer_probe(struct pcie_device *dev)
1466 {
1467 	int status;
1468 	struct aer_rpc *rpc;
1469 	struct device *device = &dev->device;
1470 	struct pci_dev *port = dev->port;
1471 
1472 	BUILD_BUG_ON(ARRAY_SIZE(aer_correctable_error_string) <
1473 		     AER_MAX_TYPEOF_COR_ERRS);
1474 	BUILD_BUG_ON(ARRAY_SIZE(aer_uncorrectable_error_string) <
1475 		     AER_MAX_TYPEOF_UNCOR_ERRS);
1476 
1477 	/* Limit to Root Ports or Root Complex Event Collectors */
1478 	if ((pci_pcie_type(port) != PCI_EXP_TYPE_RC_EC) &&
1479 	    (pci_pcie_type(port) != PCI_EXP_TYPE_ROOT_PORT))
1480 		return -ENODEV;
1481 
1482 	rpc = devm_kzalloc(device, sizeof(struct aer_rpc), GFP_KERNEL);
1483 	if (!rpc)
1484 		return -ENOMEM;
1485 
1486 	rpc->rpd = port;
1487 	INIT_KFIFO(rpc->aer_fifo);
1488 	set_service_data(dev, rpc);
1489 
1490 	status = devm_request_threaded_irq(device, dev->irq, aer_irq, aer_isr,
1491 					   IRQF_SHARED, "aerdrv", dev);
1492 	if (status) {
1493 		pci_err(port, "request AER IRQ %d failed\n", dev->irq);
1494 		return status;
1495 	}
1496 
1497 	cxl_rch_enable_rcec(port);
1498 	aer_enable_rootport(rpc);
1499 	pci_info(port, "enabled with IRQ %d\n", dev->irq);
1500 	return 0;
1501 }
1502 
1503 /**
1504  * aer_root_reset - reset Root Port hierarchy, RCEC, or RCiEP
1505  * @dev: pointer to Root Port, RCEC, or RCiEP
1506  *
1507  * Invoked by Port Bus driver when performing reset.
1508  */
1509 static pci_ers_result_t aer_root_reset(struct pci_dev *dev)
1510 {
1511 	int type = pci_pcie_type(dev);
1512 	struct pci_dev *root;
1513 	int aer;
1514 	struct pci_host_bridge *host = pci_find_host_bridge(dev->bus);
1515 	u32 reg32;
1516 	int rc;
1517 
1518 	/*
1519 	 * Only Root Ports and RCECs have AER Root Command and Root Status
1520 	 * registers.  If "dev" is an RCiEP, the relevant registers are in
1521 	 * the RCEC.
1522 	 */
1523 	if (type == PCI_EXP_TYPE_RC_END)
1524 		root = dev->rcec;
1525 	else
1526 		root = pcie_find_root_port(dev);
1527 
1528 	/*
1529 	 * If the platform retained control of AER, an RCiEP may not have
1530 	 * an RCEC visible to us, so dev->rcec ("root") may be NULL.  In
1531 	 * that case, firmware is responsible for these registers.
1532 	 */
1533 	aer = root ? root->aer_cap : 0;
1534 
1535 	if ((host->native_aer || pcie_ports_native) && aer)
1536 		aer_disable_irq(root);
1537 
1538 	if (type == PCI_EXP_TYPE_RC_EC || type == PCI_EXP_TYPE_RC_END) {
1539 		rc = pcie_reset_flr(dev, PCI_RESET_DO_RESET);
1540 		if (!rc)
1541 			pci_info(dev, "has been reset\n");
1542 		else
1543 			pci_info(dev, "not reset (no FLR support: %d)\n", rc);
1544 	} else {
1545 		rc = pci_bus_error_reset(dev);
1546 		pci_info(dev, "%s Port link has been reset (%d)\n",
1547 			pci_is_root_bus(dev->bus) ? "Root" : "Downstream", rc);
1548 	}
1549 
1550 	if ((host->native_aer || pcie_ports_native) && aer) {
1551 		/* Clear Root Error Status */
1552 		pci_read_config_dword(root, aer + PCI_ERR_ROOT_STATUS, &reg32);
1553 		pci_write_config_dword(root, aer + PCI_ERR_ROOT_STATUS, reg32);
1554 
1555 		aer_enable_irq(root);
1556 	}
1557 
1558 	return rc ? PCI_ERS_RESULT_DISCONNECT : PCI_ERS_RESULT_RECOVERED;
1559 }
1560 
1561 static struct pcie_port_service_driver aerdriver = {
1562 	.name		= "aer",
1563 	.port_type	= PCIE_ANY_PORT,
1564 	.service	= PCIE_PORT_SERVICE_AER,
1565 
1566 	.probe		= aer_probe,
1567 	.remove		= aer_remove,
1568 };
1569 
1570 /**
1571  * pcie_aer_init - register AER root service driver
1572  *
1573  * Invoked when AER root service driver is loaded.
1574  */
1575 int __init pcie_aer_init(void)
1576 {
1577 	if (!pci_aer_available())
1578 		return -ENXIO;
1579 	return pcie_port_service_register(&aerdriver);
1580 }
1581