xref: /linux/drivers/pci/pcie/aer.c (revision 2c1ed907520c50326b8f604907a8478b27881a2e)
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 	u32 status;			/* PCI_ERR_ROOT_STATUS */
45 	u32 id;				/* PCI_ERR_ROOT_ERR_SRC */
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 
pci_no_aer(void)113 void pci_no_aer(void)
114 {
115 	pcie_aer_disable = 1;
116 }
117 
pci_aer_available(void)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  */
enable_ecrc_checking(struct pci_dev * dev)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  */
disable_ecrc_checking(struct pci_dev * dev)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
184  * on global policy
185  * @dev: the PCI device
186  */
pcie_set_ecrc_checking(struct pci_dev * dev)187 void pcie_set_ecrc_checking(struct pci_dev *dev)
188 {
189 	if (!pcie_aer_is_native(dev))
190 		return;
191 
192 	switch (ecrc_policy) {
193 	case ECRC_POLICY_DEFAULT:
194 		return;
195 	case ECRC_POLICY_OFF:
196 		disable_ecrc_checking(dev);
197 		break;
198 	case ECRC_POLICY_ON:
199 		enable_ecrc_checking(dev);
200 		break;
201 	default:
202 		return;
203 	}
204 }
205 
206 /**
207  * pcie_ecrc_get_policy - parse kernel command-line ecrc option
208  * @str: ECRC policy from kernel command line to use
209  */
pcie_ecrc_get_policy(char * str)210 void pcie_ecrc_get_policy(char *str)
211 {
212 	int i;
213 
214 	i = match_string(ecrc_policy_str, ARRAY_SIZE(ecrc_policy_str), str);
215 	if (i < 0)
216 		return;
217 
218 	ecrc_policy = i;
219 }
220 #endif	/* CONFIG_PCIE_ECRC */
221 
222 #define	PCI_EXP_AER_FLAGS	(PCI_EXP_DEVCTL_CERE | PCI_EXP_DEVCTL_NFERE | \
223 				 PCI_EXP_DEVCTL_FERE | PCI_EXP_DEVCTL_URRE)
224 
pcie_aer_is_native(struct pci_dev * dev)225 int pcie_aer_is_native(struct pci_dev *dev)
226 {
227 	struct pci_host_bridge *host = pci_find_host_bridge(dev->bus);
228 
229 	if (!dev->aer_cap)
230 		return 0;
231 
232 	return pcie_ports_native || host->native_aer;
233 }
234 EXPORT_SYMBOL_NS_GPL(pcie_aer_is_native, "CXL");
235 
pci_enable_pcie_error_reporting(struct pci_dev * dev)236 static int pci_enable_pcie_error_reporting(struct pci_dev *dev)
237 {
238 	int rc;
239 
240 	if (!pcie_aer_is_native(dev))
241 		return -EIO;
242 
243 	rc = pcie_capability_set_word(dev, PCI_EXP_DEVCTL, PCI_EXP_AER_FLAGS);
244 	return pcibios_err_to_errno(rc);
245 }
246 
pci_aer_clear_nonfatal_status(struct pci_dev * dev)247 int pci_aer_clear_nonfatal_status(struct pci_dev *dev)
248 {
249 	int aer = dev->aer_cap;
250 	u32 status, sev;
251 
252 	if (!pcie_aer_is_native(dev))
253 		return -EIO;
254 
255 	/* Clear status bits for ERR_NONFATAL errors only */
256 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, &status);
257 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_SEVER, &sev);
258 	status &= ~sev;
259 	if (status)
260 		pci_write_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, status);
261 
262 	return 0;
263 }
264 EXPORT_SYMBOL_GPL(pci_aer_clear_nonfatal_status);
265 
pci_aer_clear_fatal_status(struct pci_dev * dev)266 void pci_aer_clear_fatal_status(struct pci_dev *dev)
267 {
268 	int aer = dev->aer_cap;
269 	u32 status, sev;
270 
271 	if (!pcie_aer_is_native(dev))
272 		return;
273 
274 	/* Clear status bits for ERR_FATAL errors only */
275 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, &status);
276 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_SEVER, &sev);
277 	status &= sev;
278 	if (status)
279 		pci_write_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, status);
280 }
281 
282 /**
283  * pci_aer_raw_clear_status - Clear AER error registers.
284  * @dev: the PCI device
285  *
286  * Clearing AER error status registers unconditionally, regardless of
287  * whether they're owned by firmware or the OS.
288  *
289  * Returns 0 on success, or negative on failure.
290  */
pci_aer_raw_clear_status(struct pci_dev * dev)291 int pci_aer_raw_clear_status(struct pci_dev *dev)
292 {
293 	int aer = dev->aer_cap;
294 	u32 status;
295 	int port_type;
296 
297 	if (!aer)
298 		return -EIO;
299 
300 	port_type = pci_pcie_type(dev);
301 	if (port_type == PCI_EXP_TYPE_ROOT_PORT ||
302 	    port_type == PCI_EXP_TYPE_RC_EC) {
303 		pci_read_config_dword(dev, aer + PCI_ERR_ROOT_STATUS, &status);
304 		pci_write_config_dword(dev, aer + PCI_ERR_ROOT_STATUS, status);
305 	}
306 
307 	pci_read_config_dword(dev, aer + PCI_ERR_COR_STATUS, &status);
308 	pci_write_config_dword(dev, aer + PCI_ERR_COR_STATUS, status);
309 
310 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, &status);
311 	pci_write_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, status);
312 
313 	return 0;
314 }
315 
pci_aer_clear_status(struct pci_dev * dev)316 int pci_aer_clear_status(struct pci_dev *dev)
317 {
318 	if (!pcie_aer_is_native(dev))
319 		return -EIO;
320 
321 	return pci_aer_raw_clear_status(dev);
322 }
323 
pci_save_aer_state(struct pci_dev * dev)324 void pci_save_aer_state(struct pci_dev *dev)
325 {
326 	int aer = dev->aer_cap;
327 	struct pci_cap_saved_state *save_state;
328 	u32 *cap;
329 
330 	if (!aer)
331 		return;
332 
333 	save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_ERR);
334 	if (!save_state)
335 		return;
336 
337 	cap = &save_state->cap.data[0];
338 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_MASK, cap++);
339 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_SEVER, cap++);
340 	pci_read_config_dword(dev, aer + PCI_ERR_COR_MASK, cap++);
341 	pci_read_config_dword(dev, aer + PCI_ERR_CAP, cap++);
342 	if (pcie_cap_has_rtctl(dev))
343 		pci_read_config_dword(dev, aer + PCI_ERR_ROOT_COMMAND, cap++);
344 }
345 
pci_restore_aer_state(struct pci_dev * dev)346 void pci_restore_aer_state(struct pci_dev *dev)
347 {
348 	int aer = dev->aer_cap;
349 	struct pci_cap_saved_state *save_state;
350 	u32 *cap;
351 
352 	if (!aer)
353 		return;
354 
355 	save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_ERR);
356 	if (!save_state)
357 		return;
358 
359 	cap = &save_state->cap.data[0];
360 	pci_write_config_dword(dev, aer + PCI_ERR_UNCOR_MASK, *cap++);
361 	pci_write_config_dword(dev, aer + PCI_ERR_UNCOR_SEVER, *cap++);
362 	pci_write_config_dword(dev, aer + PCI_ERR_COR_MASK, *cap++);
363 	pci_write_config_dword(dev, aer + PCI_ERR_CAP, *cap++);
364 	if (pcie_cap_has_rtctl(dev))
365 		pci_write_config_dword(dev, aer + PCI_ERR_ROOT_COMMAND, *cap++);
366 }
367 
pci_aer_init(struct pci_dev * dev)368 void pci_aer_init(struct pci_dev *dev)
369 {
370 	int n;
371 
372 	dev->aer_cap = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
373 	if (!dev->aer_cap)
374 		return;
375 
376 	dev->aer_stats = kzalloc(sizeof(struct aer_stats), GFP_KERNEL);
377 
378 	/*
379 	 * We save/restore PCI_ERR_UNCOR_MASK, PCI_ERR_UNCOR_SEVER,
380 	 * PCI_ERR_COR_MASK, and PCI_ERR_CAP.  Root and Root Complex Event
381 	 * Collectors also implement PCI_ERR_ROOT_COMMAND (PCIe r5.0, sec
382 	 * 7.8.4).
383 	 */
384 	n = pcie_cap_has_rtctl(dev) ? 5 : 4;
385 	pci_add_ext_cap_save_buffer(dev, PCI_EXT_CAP_ID_ERR, sizeof(u32) * n);
386 
387 	pci_aer_clear_status(dev);
388 
389 	if (pci_aer_available())
390 		pci_enable_pcie_error_reporting(dev);
391 
392 	pcie_set_ecrc_checking(dev);
393 }
394 
pci_aer_exit(struct pci_dev * dev)395 void pci_aer_exit(struct pci_dev *dev)
396 {
397 	kfree(dev->aer_stats);
398 	dev->aer_stats = NULL;
399 }
400 
401 #define AER_AGENT_RECEIVER		0
402 #define AER_AGENT_REQUESTER		1
403 #define AER_AGENT_COMPLETER		2
404 #define AER_AGENT_TRANSMITTER		3
405 
406 #define AER_AGENT_REQUESTER_MASK(t)	((t == AER_CORRECTABLE) ?	\
407 	0 : (PCI_ERR_UNC_COMP_TIME|PCI_ERR_UNC_UNSUP))
408 #define AER_AGENT_COMPLETER_MASK(t)	((t == AER_CORRECTABLE) ?	\
409 	0 : PCI_ERR_UNC_COMP_ABORT)
410 #define AER_AGENT_TRANSMITTER_MASK(t)	((t == AER_CORRECTABLE) ?	\
411 	(PCI_ERR_COR_REP_ROLL|PCI_ERR_COR_REP_TIMER) : 0)
412 
413 #define AER_GET_AGENT(t, e)						\
414 	((e & AER_AGENT_COMPLETER_MASK(t)) ? AER_AGENT_COMPLETER :	\
415 	(e & AER_AGENT_REQUESTER_MASK(t)) ? AER_AGENT_REQUESTER :	\
416 	(e & AER_AGENT_TRANSMITTER_MASK(t)) ? AER_AGENT_TRANSMITTER :	\
417 	AER_AGENT_RECEIVER)
418 
419 #define AER_PHYSICAL_LAYER_ERROR	0
420 #define AER_DATA_LINK_LAYER_ERROR	1
421 #define AER_TRANSACTION_LAYER_ERROR	2
422 
423 #define AER_PHYSICAL_LAYER_ERROR_MASK(t) ((t == AER_CORRECTABLE) ?	\
424 	PCI_ERR_COR_RCVR : 0)
425 #define AER_DATA_LINK_LAYER_ERROR_MASK(t) ((t == AER_CORRECTABLE) ?	\
426 	(PCI_ERR_COR_BAD_TLP|						\
427 	PCI_ERR_COR_BAD_DLLP|						\
428 	PCI_ERR_COR_REP_ROLL|						\
429 	PCI_ERR_COR_REP_TIMER) : PCI_ERR_UNC_DLP)
430 
431 #define AER_GET_LAYER_ERROR(t, e)					\
432 	((e & AER_PHYSICAL_LAYER_ERROR_MASK(t)) ? AER_PHYSICAL_LAYER_ERROR : \
433 	(e & AER_DATA_LINK_LAYER_ERROR_MASK(t)) ? AER_DATA_LINK_LAYER_ERROR : \
434 	AER_TRANSACTION_LAYER_ERROR)
435 
436 /*
437  * AER error strings
438  */
439 static const char * const aer_error_severity_string[] = {
440 	"Uncorrectable (Non-Fatal)",
441 	"Uncorrectable (Fatal)",
442 	"Correctable"
443 };
444 
445 static const char *aer_error_layer[] = {
446 	"Physical Layer",
447 	"Data Link Layer",
448 	"Transaction Layer"
449 };
450 
451 static const char *aer_correctable_error_string[] = {
452 	"RxErr",			/* Bit Position 0	*/
453 	NULL,
454 	NULL,
455 	NULL,
456 	NULL,
457 	NULL,
458 	"BadTLP",			/* Bit Position 6	*/
459 	"BadDLLP",			/* Bit Position 7	*/
460 	"Rollover",			/* Bit Position 8	*/
461 	NULL,
462 	NULL,
463 	NULL,
464 	"Timeout",			/* Bit Position 12	*/
465 	"NonFatalErr",			/* Bit Position 13	*/
466 	"CorrIntErr",			/* Bit Position 14	*/
467 	"HeaderOF",			/* Bit Position 15	*/
468 	NULL,				/* Bit Position 16	*/
469 	NULL,				/* Bit Position 17	*/
470 	NULL,				/* Bit Position 18	*/
471 	NULL,				/* Bit Position 19	*/
472 	NULL,				/* Bit Position 20	*/
473 	NULL,				/* Bit Position 21	*/
474 	NULL,				/* Bit Position 22	*/
475 	NULL,				/* Bit Position 23	*/
476 	NULL,				/* Bit Position 24	*/
477 	NULL,				/* Bit Position 25	*/
478 	NULL,				/* Bit Position 26	*/
479 	NULL,				/* Bit Position 27	*/
480 	NULL,				/* Bit Position 28	*/
481 	NULL,				/* Bit Position 29	*/
482 	NULL,				/* Bit Position 30	*/
483 	NULL,				/* Bit Position 31	*/
484 };
485 
486 static const char *aer_uncorrectable_error_string[] = {
487 	"Undefined",			/* Bit Position 0	*/
488 	NULL,
489 	NULL,
490 	NULL,
491 	"DLP",				/* Bit Position 4	*/
492 	"SDES",				/* Bit Position 5	*/
493 	NULL,
494 	NULL,
495 	NULL,
496 	NULL,
497 	NULL,
498 	NULL,
499 	"TLP",				/* Bit Position 12	*/
500 	"FCP",				/* Bit Position 13	*/
501 	"CmpltTO",			/* Bit Position 14	*/
502 	"CmpltAbrt",			/* Bit Position 15	*/
503 	"UnxCmplt",			/* Bit Position 16	*/
504 	"RxOF",				/* Bit Position 17	*/
505 	"MalfTLP",			/* Bit Position 18	*/
506 	"ECRC",				/* Bit Position 19	*/
507 	"UnsupReq",			/* Bit Position 20	*/
508 	"ACSViol",			/* Bit Position 21	*/
509 	"UncorrIntErr",			/* Bit Position 22	*/
510 	"BlockedTLP",			/* Bit Position 23	*/
511 	"AtomicOpBlocked",		/* Bit Position 24	*/
512 	"TLPBlockedErr",		/* Bit Position 25	*/
513 	"PoisonTLPBlocked",		/* Bit Position 26	*/
514 	NULL,				/* Bit Position 27	*/
515 	NULL,				/* Bit Position 28	*/
516 	NULL,				/* Bit Position 29	*/
517 	NULL,				/* Bit Position 30	*/
518 	NULL,				/* Bit Position 31	*/
519 };
520 
521 static const char *aer_agent_string[] = {
522 	"Receiver ID",
523 	"Requester ID",
524 	"Completer ID",
525 	"Transmitter ID"
526 };
527 
528 #define aer_stats_dev_attr(name, stats_array, strings_array,		\
529 			   total_string, total_field)			\
530 	static ssize_t							\
531 	name##_show(struct device *dev, struct device_attribute *attr,	\
532 		     char *buf)						\
533 {									\
534 	unsigned int i;							\
535 	struct pci_dev *pdev = to_pci_dev(dev);				\
536 	u64 *stats = pdev->aer_stats->stats_array;			\
537 	size_t len = 0;							\
538 									\
539 	for (i = 0; i < ARRAY_SIZE(pdev->aer_stats->stats_array); i++) {\
540 		if (strings_array[i])					\
541 			len += sysfs_emit_at(buf, len, "%s %llu\n",	\
542 					     strings_array[i],		\
543 					     stats[i]);			\
544 		else if (stats[i])					\
545 			len += sysfs_emit_at(buf, len,			\
546 					     #stats_array "_bit[%d] %llu\n",\
547 					     i, stats[i]);		\
548 	}								\
549 	len += sysfs_emit_at(buf, len, "TOTAL_%s %llu\n", total_string,	\
550 			     pdev->aer_stats->total_field);		\
551 	return len;							\
552 }									\
553 static DEVICE_ATTR_RO(name)
554 
555 aer_stats_dev_attr(aer_dev_correctable, dev_cor_errs,
556 		   aer_correctable_error_string, "ERR_COR",
557 		   dev_total_cor_errs);
558 aer_stats_dev_attr(aer_dev_fatal, dev_fatal_errs,
559 		   aer_uncorrectable_error_string, "ERR_FATAL",
560 		   dev_total_fatal_errs);
561 aer_stats_dev_attr(aer_dev_nonfatal, dev_nonfatal_errs,
562 		   aer_uncorrectable_error_string, "ERR_NONFATAL",
563 		   dev_total_nonfatal_errs);
564 
565 #define aer_stats_rootport_attr(name, field)				\
566 	static ssize_t							\
567 	name##_show(struct device *dev, struct device_attribute *attr,	\
568 		     char *buf)						\
569 {									\
570 	struct pci_dev *pdev = to_pci_dev(dev);				\
571 	return sysfs_emit(buf, "%llu\n", pdev->aer_stats->field);	\
572 }									\
573 static DEVICE_ATTR_RO(name)
574 
575 aer_stats_rootport_attr(aer_rootport_total_err_cor,
576 			 rootport_total_cor_errs);
577 aer_stats_rootport_attr(aer_rootport_total_err_fatal,
578 			 rootport_total_fatal_errs);
579 aer_stats_rootport_attr(aer_rootport_total_err_nonfatal,
580 			 rootport_total_nonfatal_errs);
581 
582 static struct attribute *aer_stats_attrs[] __ro_after_init = {
583 	&dev_attr_aer_dev_correctable.attr,
584 	&dev_attr_aer_dev_fatal.attr,
585 	&dev_attr_aer_dev_nonfatal.attr,
586 	&dev_attr_aer_rootport_total_err_cor.attr,
587 	&dev_attr_aer_rootport_total_err_fatal.attr,
588 	&dev_attr_aer_rootport_total_err_nonfatal.attr,
589 	NULL
590 };
591 
aer_stats_attrs_are_visible(struct kobject * kobj,struct attribute * a,int n)592 static umode_t aer_stats_attrs_are_visible(struct kobject *kobj,
593 					   struct attribute *a, int n)
594 {
595 	struct device *dev = kobj_to_dev(kobj);
596 	struct pci_dev *pdev = to_pci_dev(dev);
597 
598 	if (!pdev->aer_stats)
599 		return 0;
600 
601 	if ((a == &dev_attr_aer_rootport_total_err_cor.attr ||
602 	     a == &dev_attr_aer_rootport_total_err_fatal.attr ||
603 	     a == &dev_attr_aer_rootport_total_err_nonfatal.attr) &&
604 	    ((pci_pcie_type(pdev) != PCI_EXP_TYPE_ROOT_PORT) &&
605 	     (pci_pcie_type(pdev) != PCI_EXP_TYPE_RC_EC)))
606 		return 0;
607 
608 	return a->mode;
609 }
610 
611 const struct attribute_group aer_stats_attr_group = {
612 	.attrs  = aer_stats_attrs,
613 	.is_visible = aer_stats_attrs_are_visible,
614 };
615 
pci_dev_aer_stats_incr(struct pci_dev * pdev,struct aer_err_info * info)616 static void pci_dev_aer_stats_incr(struct pci_dev *pdev,
617 				   struct aer_err_info *info)
618 {
619 	unsigned long status = info->status & ~info->mask;
620 	int i, max = -1;
621 	u64 *counter = NULL;
622 	struct aer_stats *aer_stats = pdev->aer_stats;
623 
624 	if (!aer_stats)
625 		return;
626 
627 	switch (info->severity) {
628 	case AER_CORRECTABLE:
629 		aer_stats->dev_total_cor_errs++;
630 		counter = &aer_stats->dev_cor_errs[0];
631 		max = AER_MAX_TYPEOF_COR_ERRS;
632 		break;
633 	case AER_NONFATAL:
634 		aer_stats->dev_total_nonfatal_errs++;
635 		counter = &aer_stats->dev_nonfatal_errs[0];
636 		max = AER_MAX_TYPEOF_UNCOR_ERRS;
637 		break;
638 	case AER_FATAL:
639 		aer_stats->dev_total_fatal_errs++;
640 		counter = &aer_stats->dev_fatal_errs[0];
641 		max = AER_MAX_TYPEOF_UNCOR_ERRS;
642 		break;
643 	}
644 
645 	for_each_set_bit(i, &status, max)
646 		counter[i]++;
647 }
648 
pci_rootport_aer_stats_incr(struct pci_dev * pdev,struct aer_err_source * e_src)649 static void pci_rootport_aer_stats_incr(struct pci_dev *pdev,
650 				 struct aer_err_source *e_src)
651 {
652 	struct aer_stats *aer_stats = pdev->aer_stats;
653 
654 	if (!aer_stats)
655 		return;
656 
657 	if (e_src->status & PCI_ERR_ROOT_COR_RCV)
658 		aer_stats->rootport_total_cor_errs++;
659 
660 	if (e_src->status & PCI_ERR_ROOT_UNCOR_RCV) {
661 		if (e_src->status & PCI_ERR_ROOT_FATAL_RCV)
662 			aer_stats->rootport_total_fatal_errs++;
663 		else
664 			aer_stats->rootport_total_nonfatal_errs++;
665 	}
666 }
667 
__aer_print_error(struct pci_dev * dev,struct aer_err_info * info)668 static void __aer_print_error(struct pci_dev *dev,
669 			      struct aer_err_info *info)
670 {
671 	const char **strings;
672 	unsigned long status = info->status & ~info->mask;
673 	const char *level, *errmsg;
674 	int i;
675 
676 	if (info->severity == AER_CORRECTABLE) {
677 		strings = aer_correctable_error_string;
678 		level = KERN_WARNING;
679 	} else {
680 		strings = aer_uncorrectable_error_string;
681 		level = KERN_ERR;
682 	}
683 
684 	for_each_set_bit(i, &status, 32) {
685 		errmsg = strings[i];
686 		if (!errmsg)
687 			errmsg = "Unknown Error Bit";
688 
689 		pci_printk(level, dev, "   [%2d] %-22s%s\n", i, errmsg,
690 				info->first_error == i ? " (First)" : "");
691 	}
692 	pci_dev_aer_stats_incr(dev, info);
693 }
694 
aer_print_error(struct pci_dev * dev,struct aer_err_info * info)695 void aer_print_error(struct pci_dev *dev, struct aer_err_info *info)
696 {
697 	int layer, agent;
698 	int id = pci_dev_id(dev);
699 	const char *level;
700 
701 	if (!info->status) {
702 		pci_err(dev, "PCIe Bus Error: severity=%s, type=Inaccessible, (Unregistered Agent ID)\n",
703 			aer_error_severity_string[info->severity]);
704 		goto out;
705 	}
706 
707 	layer = AER_GET_LAYER_ERROR(info->severity, info->status);
708 	agent = AER_GET_AGENT(info->severity, info->status);
709 
710 	level = (info->severity == AER_CORRECTABLE) ? KERN_WARNING : KERN_ERR;
711 
712 	pci_printk(level, dev, "PCIe Bus Error: severity=%s, type=%s, (%s)\n",
713 		   aer_error_severity_string[info->severity],
714 		   aer_error_layer[layer], aer_agent_string[agent]);
715 
716 	pci_printk(level, dev, "  device [%04x:%04x] error status/mask=%08x/%08x\n",
717 		   dev->vendor, dev->device, info->status, info->mask);
718 
719 	__aer_print_error(dev, info);
720 
721 	if (info->tlp_header_valid)
722 		pcie_print_tlp_log(dev, &info->tlp, dev_fmt("  "));
723 
724 out:
725 	if (info->id && info->error_dev_num > 1 && info->id == id)
726 		pci_err(dev, "  Error of this Agent is reported first\n");
727 
728 	trace_aer_event(dev_name(&dev->dev), (info->status & ~info->mask),
729 			info->severity, info->tlp_header_valid, &info->tlp);
730 }
731 
aer_print_port_info(struct pci_dev * dev,struct aer_err_info * info)732 static void aer_print_port_info(struct pci_dev *dev, struct aer_err_info *info)
733 {
734 	u8 bus = info->id >> 8;
735 	u8 devfn = info->id & 0xff;
736 
737 	pci_info(dev, "%s%s error message received from %04x:%02x:%02x.%d\n",
738 		 info->multi_error_valid ? "Multiple " : "",
739 		 aer_error_severity_string[info->severity],
740 		 pci_domain_nr(dev->bus), bus, PCI_SLOT(devfn),
741 		 PCI_FUNC(devfn));
742 }
743 
744 #ifdef CONFIG_ACPI_APEI_PCIEAER
cper_severity_to_aer(int cper_severity)745 int cper_severity_to_aer(int cper_severity)
746 {
747 	switch (cper_severity) {
748 	case CPER_SEV_RECOVERABLE:
749 		return AER_NONFATAL;
750 	case CPER_SEV_FATAL:
751 		return AER_FATAL;
752 	default:
753 		return AER_CORRECTABLE;
754 	}
755 }
756 EXPORT_SYMBOL_GPL(cper_severity_to_aer);
757 #endif
758 
pci_print_aer(struct pci_dev * dev,int aer_severity,struct aer_capability_regs * aer)759 void pci_print_aer(struct pci_dev *dev, int aer_severity,
760 		   struct aer_capability_regs *aer)
761 {
762 	int layer, agent, tlp_header_valid = 0;
763 	u32 status, mask;
764 	struct aer_err_info info;
765 
766 	if (aer_severity == AER_CORRECTABLE) {
767 		status = aer->cor_status;
768 		mask = aer->cor_mask;
769 	} else {
770 		status = aer->uncor_status;
771 		mask = aer->uncor_mask;
772 		tlp_header_valid = status & AER_LOG_TLP_MASKS;
773 	}
774 
775 	layer = AER_GET_LAYER_ERROR(aer_severity, status);
776 	agent = AER_GET_AGENT(aer_severity, status);
777 
778 	memset(&info, 0, sizeof(info));
779 	info.severity = aer_severity;
780 	info.status = status;
781 	info.mask = mask;
782 	info.first_error = PCI_ERR_CAP_FEP(aer->cap_control);
783 
784 	pci_err(dev, "aer_status: 0x%08x, aer_mask: 0x%08x\n", status, mask);
785 	__aer_print_error(dev, &info);
786 	pci_err(dev, "aer_layer=%s, aer_agent=%s\n",
787 		aer_error_layer[layer], aer_agent_string[agent]);
788 
789 	if (aer_severity != AER_CORRECTABLE)
790 		pci_err(dev, "aer_uncor_severity: 0x%08x\n",
791 			aer->uncor_severity);
792 
793 	if (tlp_header_valid)
794 		pcie_print_tlp_log(dev, &aer->header_log, dev_fmt("  "));
795 
796 	trace_aer_event(dev_name(&dev->dev), (status & ~mask),
797 			aer_severity, tlp_header_valid, &aer->header_log);
798 }
799 EXPORT_SYMBOL_NS_GPL(pci_print_aer, "CXL");
800 
801 /**
802  * add_error_device - list device to be handled
803  * @e_info: pointer to error info
804  * @dev: pointer to pci_dev to be added
805  */
add_error_device(struct aer_err_info * e_info,struct pci_dev * dev)806 static int add_error_device(struct aer_err_info *e_info, struct pci_dev *dev)
807 {
808 	if (e_info->error_dev_num < AER_MAX_MULTI_ERR_DEVICES) {
809 		e_info->dev[e_info->error_dev_num] = pci_dev_get(dev);
810 		e_info->error_dev_num++;
811 		return 0;
812 	}
813 	return -ENOSPC;
814 }
815 
816 /**
817  * is_error_source - check whether the device is source of reported error
818  * @dev: pointer to pci_dev to be checked
819  * @e_info: pointer to reported error info
820  */
is_error_source(struct pci_dev * dev,struct aer_err_info * e_info)821 static bool is_error_source(struct pci_dev *dev, struct aer_err_info *e_info)
822 {
823 	int aer = dev->aer_cap;
824 	u32 status, mask;
825 	u16 reg16;
826 
827 	/*
828 	 * When bus id is equal to 0, it might be a bad id
829 	 * reported by root port.
830 	 */
831 	if ((PCI_BUS_NUM(e_info->id) != 0) &&
832 	    !(dev->bus->bus_flags & PCI_BUS_FLAGS_NO_AERSID)) {
833 		/* Device ID match? */
834 		if (e_info->id == pci_dev_id(dev))
835 			return true;
836 
837 		/* Continue id comparing if there is no multiple error */
838 		if (!e_info->multi_error_valid)
839 			return false;
840 	}
841 
842 	/*
843 	 * When either
844 	 *      1) bus id is equal to 0. Some ports might lose the bus
845 	 *              id of error source id;
846 	 *      2) bus flag PCI_BUS_FLAGS_NO_AERSID is set
847 	 *      3) There are multiple errors and prior ID comparing fails;
848 	 * We check AER status registers to find possible reporter.
849 	 */
850 	if (atomic_read(&dev->enable_cnt) == 0)
851 		return false;
852 
853 	/* Check if AER is enabled */
854 	pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &reg16);
855 	if (!(reg16 & PCI_EXP_AER_FLAGS))
856 		return false;
857 
858 	if (!aer)
859 		return false;
860 
861 	/* Check if error is recorded */
862 	if (e_info->severity == AER_CORRECTABLE) {
863 		pci_read_config_dword(dev, aer + PCI_ERR_COR_STATUS, &status);
864 		pci_read_config_dword(dev, aer + PCI_ERR_COR_MASK, &mask);
865 	} else {
866 		pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, &status);
867 		pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_MASK, &mask);
868 	}
869 	if (status & ~mask)
870 		return true;
871 
872 	return false;
873 }
874 
find_device_iter(struct pci_dev * dev,void * data)875 static int find_device_iter(struct pci_dev *dev, void *data)
876 {
877 	struct aer_err_info *e_info = (struct aer_err_info *)data;
878 
879 	if (is_error_source(dev, e_info)) {
880 		/* List this device */
881 		if (add_error_device(e_info, dev)) {
882 			/* We cannot handle more... Stop iteration */
883 			/* TODO: Should print error message here? */
884 			return 1;
885 		}
886 
887 		/* If there is only a single error, stop iteration */
888 		if (!e_info->multi_error_valid)
889 			return 1;
890 	}
891 	return 0;
892 }
893 
894 /**
895  * find_source_device - search through device hierarchy for source device
896  * @parent: pointer to Root Port pci_dev data structure
897  * @e_info: including detailed error information such like id
898  *
899  * Return true if found.
900  *
901  * Invoked by DPC when error is detected at the Root Port.
902  * Caller of this function must set id, severity, and multi_error_valid of
903  * struct aer_err_info pointed by @e_info properly.  This function must fill
904  * e_info->error_dev_num and e_info->dev[], based on the given information.
905  */
find_source_device(struct pci_dev * parent,struct aer_err_info * e_info)906 static bool find_source_device(struct pci_dev *parent,
907 		struct aer_err_info *e_info)
908 {
909 	struct pci_dev *dev = parent;
910 	int result;
911 
912 	/* Must reset in this function */
913 	e_info->error_dev_num = 0;
914 
915 	/* Is Root Port an agent that sends error message? */
916 	result = find_device_iter(dev, e_info);
917 	if (result)
918 		return true;
919 
920 	if (pci_pcie_type(parent) == PCI_EXP_TYPE_RC_EC)
921 		pcie_walk_rcec(parent, find_device_iter, e_info);
922 	else
923 		pci_walk_bus(parent->subordinate, find_device_iter, e_info);
924 
925 	if (!e_info->error_dev_num) {
926 		u8 bus = e_info->id >> 8;
927 		u8 devfn = e_info->id & 0xff;
928 
929 		pci_info(parent, "found no error details for %04x:%02x:%02x.%d\n",
930 			 pci_domain_nr(parent->bus), bus, PCI_SLOT(devfn),
931 			 PCI_FUNC(devfn));
932 		return false;
933 	}
934 	return true;
935 }
936 
937 #ifdef CONFIG_PCIEAER_CXL
938 
939 /**
940  * pci_aer_unmask_internal_errors - unmask internal errors
941  * @dev: pointer to the pcie_dev data structure
942  *
943  * Unmasks internal errors in the Uncorrectable and Correctable Error
944  * Mask registers.
945  *
946  * Note: AER must be enabled and supported by the device which must be
947  * checked in advance, e.g. with pcie_aer_is_native().
948  */
pci_aer_unmask_internal_errors(struct pci_dev * dev)949 static void pci_aer_unmask_internal_errors(struct pci_dev *dev)
950 {
951 	int aer = dev->aer_cap;
952 	u32 mask;
953 
954 	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_MASK, &mask);
955 	mask &= ~PCI_ERR_UNC_INTN;
956 	pci_write_config_dword(dev, aer + PCI_ERR_UNCOR_MASK, mask);
957 
958 	pci_read_config_dword(dev, aer + PCI_ERR_COR_MASK, &mask);
959 	mask &= ~PCI_ERR_COR_INTERNAL;
960 	pci_write_config_dword(dev, aer + PCI_ERR_COR_MASK, mask);
961 }
962 
is_cxl_mem_dev(struct pci_dev * dev)963 static bool is_cxl_mem_dev(struct pci_dev *dev)
964 {
965 	/*
966 	 * The capability, status, and control fields in Device 0,
967 	 * Function 0 DVSEC control the CXL functionality of the
968 	 * entire device (CXL 3.0, 8.1.3).
969 	 */
970 	if (dev->devfn != PCI_DEVFN(0, 0))
971 		return false;
972 
973 	/*
974 	 * CXL Memory Devices must have the 502h class code set (CXL
975 	 * 3.0, 8.1.12.1).
976 	 */
977 	if ((dev->class >> 8) != PCI_CLASS_MEMORY_CXL)
978 		return false;
979 
980 	return true;
981 }
982 
cxl_error_is_native(struct pci_dev * dev)983 static bool cxl_error_is_native(struct pci_dev *dev)
984 {
985 	struct pci_host_bridge *host = pci_find_host_bridge(dev->bus);
986 
987 	return (pcie_ports_native || host->native_aer);
988 }
989 
is_internal_error(struct aer_err_info * info)990 static bool is_internal_error(struct aer_err_info *info)
991 {
992 	if (info->severity == AER_CORRECTABLE)
993 		return info->status & PCI_ERR_COR_INTERNAL;
994 
995 	return info->status & PCI_ERR_UNC_INTN;
996 }
997 
cxl_rch_handle_error_iter(struct pci_dev * dev,void * data)998 static int cxl_rch_handle_error_iter(struct pci_dev *dev, void *data)
999 {
1000 	struct aer_err_info *info = (struct aer_err_info *)data;
1001 	const struct pci_error_handlers *err_handler;
1002 
1003 	if (!is_cxl_mem_dev(dev) || !cxl_error_is_native(dev))
1004 		return 0;
1005 
1006 	/* protect dev->driver */
1007 	device_lock(&dev->dev);
1008 
1009 	err_handler = dev->driver ? dev->driver->err_handler : NULL;
1010 	if (!err_handler)
1011 		goto out;
1012 
1013 	if (info->severity == AER_CORRECTABLE) {
1014 		if (err_handler->cor_error_detected)
1015 			err_handler->cor_error_detected(dev);
1016 	} else if (err_handler->error_detected) {
1017 		if (info->severity == AER_NONFATAL)
1018 			err_handler->error_detected(dev, pci_channel_io_normal);
1019 		else if (info->severity == AER_FATAL)
1020 			err_handler->error_detected(dev, pci_channel_io_frozen);
1021 	}
1022 out:
1023 	device_unlock(&dev->dev);
1024 	return 0;
1025 }
1026 
cxl_rch_handle_error(struct pci_dev * dev,struct aer_err_info * info)1027 static void cxl_rch_handle_error(struct pci_dev *dev, struct aer_err_info *info)
1028 {
1029 	/*
1030 	 * Internal errors of an RCEC indicate an AER error in an
1031 	 * RCH's downstream port. Check and handle them in the CXL.mem
1032 	 * device driver.
1033 	 */
1034 	if (pci_pcie_type(dev) == PCI_EXP_TYPE_RC_EC &&
1035 	    is_internal_error(info))
1036 		pcie_walk_rcec(dev, cxl_rch_handle_error_iter, info);
1037 }
1038 
handles_cxl_error_iter(struct pci_dev * dev,void * data)1039 static int handles_cxl_error_iter(struct pci_dev *dev, void *data)
1040 {
1041 	bool *handles_cxl = data;
1042 
1043 	if (!*handles_cxl)
1044 		*handles_cxl = is_cxl_mem_dev(dev) && cxl_error_is_native(dev);
1045 
1046 	/* Non-zero terminates iteration */
1047 	return *handles_cxl;
1048 }
1049 
handles_cxl_errors(struct pci_dev * rcec)1050 static bool handles_cxl_errors(struct pci_dev *rcec)
1051 {
1052 	bool handles_cxl = false;
1053 
1054 	if (pci_pcie_type(rcec) == PCI_EXP_TYPE_RC_EC &&
1055 	    pcie_aer_is_native(rcec))
1056 		pcie_walk_rcec(rcec, handles_cxl_error_iter, &handles_cxl);
1057 
1058 	return handles_cxl;
1059 }
1060 
cxl_rch_enable_rcec(struct pci_dev * rcec)1061 static void cxl_rch_enable_rcec(struct pci_dev *rcec)
1062 {
1063 	if (!handles_cxl_errors(rcec))
1064 		return;
1065 
1066 	pci_aer_unmask_internal_errors(rcec);
1067 	pci_info(rcec, "CXL: Internal errors unmasked");
1068 }
1069 
1070 #else
cxl_rch_enable_rcec(struct pci_dev * dev)1071 static inline void cxl_rch_enable_rcec(struct pci_dev *dev) { }
cxl_rch_handle_error(struct pci_dev * dev,struct aer_err_info * info)1072 static inline void cxl_rch_handle_error(struct pci_dev *dev,
1073 					struct aer_err_info *info) { }
1074 #endif
1075 
1076 /**
1077  * pci_aer_handle_error - handle logging error into an event log
1078  * @dev: pointer to pci_dev data structure of error source device
1079  * @info: comprehensive error information
1080  *
1081  * Invoked when an error being detected by Root Port.
1082  */
pci_aer_handle_error(struct pci_dev * dev,struct aer_err_info * info)1083 static void pci_aer_handle_error(struct pci_dev *dev, struct aer_err_info *info)
1084 {
1085 	int aer = dev->aer_cap;
1086 
1087 	if (info->severity == AER_CORRECTABLE) {
1088 		/*
1089 		 * Correctable error does not need software intervention.
1090 		 * No need to go through error recovery process.
1091 		 */
1092 		if (aer)
1093 			pci_write_config_dword(dev, aer + PCI_ERR_COR_STATUS,
1094 					info->status);
1095 		if (pcie_aer_is_native(dev)) {
1096 			struct pci_driver *pdrv = dev->driver;
1097 
1098 			if (pdrv && pdrv->err_handler &&
1099 			    pdrv->err_handler->cor_error_detected)
1100 				pdrv->err_handler->cor_error_detected(dev);
1101 			pcie_clear_device_status(dev);
1102 		}
1103 	} else if (info->severity == AER_NONFATAL)
1104 		pcie_do_recovery(dev, pci_channel_io_normal, aer_root_reset);
1105 	else if (info->severity == AER_FATAL)
1106 		pcie_do_recovery(dev, pci_channel_io_frozen, aer_root_reset);
1107 }
1108 
handle_error_source(struct pci_dev * dev,struct aer_err_info * info)1109 static void handle_error_source(struct pci_dev *dev, struct aer_err_info *info)
1110 {
1111 	cxl_rch_handle_error(dev, info);
1112 	pci_aer_handle_error(dev, info);
1113 	pci_dev_put(dev);
1114 }
1115 
1116 #ifdef CONFIG_ACPI_APEI_PCIEAER
1117 
1118 #define AER_RECOVER_RING_SIZE		16
1119 
1120 struct aer_recover_entry {
1121 	u8	bus;
1122 	u8	devfn;
1123 	u16	domain;
1124 	int	severity;
1125 	struct aer_capability_regs *regs;
1126 };
1127 
1128 static DEFINE_KFIFO(aer_recover_ring, struct aer_recover_entry,
1129 		    AER_RECOVER_RING_SIZE);
1130 
aer_recover_work_func(struct work_struct * work)1131 static void aer_recover_work_func(struct work_struct *work)
1132 {
1133 	struct aer_recover_entry entry;
1134 	struct pci_dev *pdev;
1135 
1136 	while (kfifo_get(&aer_recover_ring, &entry)) {
1137 		pdev = pci_get_domain_bus_and_slot(entry.domain, entry.bus,
1138 						   entry.devfn);
1139 		if (!pdev) {
1140 			pr_err("no pci_dev for %04x:%02x:%02x.%x\n",
1141 			       entry.domain, entry.bus,
1142 			       PCI_SLOT(entry.devfn), PCI_FUNC(entry.devfn));
1143 			continue;
1144 		}
1145 		pci_print_aer(pdev, entry.severity, entry.regs);
1146 
1147 		/*
1148 		 * Memory for aer_capability_regs(entry.regs) is being
1149 		 * allocated from the ghes_estatus_pool to protect it from
1150 		 * overwriting when multiple sections are present in the
1151 		 * error status. Thus free the same after processing the
1152 		 * data.
1153 		 */
1154 		ghes_estatus_pool_region_free((unsigned long)entry.regs,
1155 					    sizeof(struct aer_capability_regs));
1156 
1157 		if (entry.severity == AER_NONFATAL)
1158 			pcie_do_recovery(pdev, pci_channel_io_normal,
1159 					 aer_root_reset);
1160 		else if (entry.severity == AER_FATAL)
1161 			pcie_do_recovery(pdev, pci_channel_io_frozen,
1162 					 aer_root_reset);
1163 		pci_dev_put(pdev);
1164 	}
1165 }
1166 
1167 /*
1168  * Mutual exclusion for writers of aer_recover_ring, reader side don't
1169  * need lock, because there is only one reader and lock is not needed
1170  * between reader and writer.
1171  */
1172 static DEFINE_SPINLOCK(aer_recover_ring_lock);
1173 static DECLARE_WORK(aer_recover_work, aer_recover_work_func);
1174 
aer_recover_queue(int domain,unsigned int bus,unsigned int devfn,int severity,struct aer_capability_regs * aer_regs)1175 void aer_recover_queue(int domain, unsigned int bus, unsigned int devfn,
1176 		       int severity, struct aer_capability_regs *aer_regs)
1177 {
1178 	struct aer_recover_entry entry = {
1179 		.bus		= bus,
1180 		.devfn		= devfn,
1181 		.domain		= domain,
1182 		.severity	= severity,
1183 		.regs		= aer_regs,
1184 	};
1185 
1186 	if (kfifo_in_spinlocked(&aer_recover_ring, &entry, 1,
1187 				 &aer_recover_ring_lock))
1188 		schedule_work(&aer_recover_work);
1189 	else
1190 		pr_err("buffer overflow in recovery for %04x:%02x:%02x.%x\n",
1191 		       domain, bus, PCI_SLOT(devfn), PCI_FUNC(devfn));
1192 }
1193 EXPORT_SYMBOL_GPL(aer_recover_queue);
1194 #endif
1195 
1196 /**
1197  * aer_get_device_error_info - read error status from dev and store it to info
1198  * @dev: pointer to the device expected to have a error record
1199  * @info: pointer to structure to store the error record
1200  *
1201  * Return 1 on success, 0 on error.
1202  *
1203  * Note that @info is reused among all error devices. Clear fields properly.
1204  */
aer_get_device_error_info(struct pci_dev * dev,struct aer_err_info * info)1205 int aer_get_device_error_info(struct pci_dev *dev, struct aer_err_info *info)
1206 {
1207 	int type = pci_pcie_type(dev);
1208 	int aer = dev->aer_cap;
1209 	u32 aercc;
1210 
1211 	/* Must reset in this function */
1212 	info->status = 0;
1213 	info->tlp_header_valid = 0;
1214 
1215 	/* The device might not support AER */
1216 	if (!aer)
1217 		return 0;
1218 
1219 	if (info->severity == AER_CORRECTABLE) {
1220 		pci_read_config_dword(dev, aer + PCI_ERR_COR_STATUS,
1221 			&info->status);
1222 		pci_read_config_dword(dev, aer + PCI_ERR_COR_MASK,
1223 			&info->mask);
1224 		if (!(info->status & ~info->mask))
1225 			return 0;
1226 	} else if (type == PCI_EXP_TYPE_ROOT_PORT ||
1227 		   type == PCI_EXP_TYPE_RC_EC ||
1228 		   type == PCI_EXP_TYPE_DOWNSTREAM ||
1229 		   info->severity == AER_NONFATAL) {
1230 
1231 		/* Link is still healthy for IO reads */
1232 		pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS,
1233 			&info->status);
1234 		pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_MASK,
1235 			&info->mask);
1236 		if (!(info->status & ~info->mask))
1237 			return 0;
1238 
1239 		/* Get First Error Pointer */
1240 		pci_read_config_dword(dev, aer + PCI_ERR_CAP, &aercc);
1241 		info->first_error = PCI_ERR_CAP_FEP(aercc);
1242 
1243 		if (info->status & AER_LOG_TLP_MASKS) {
1244 			info->tlp_header_valid = 1;
1245 			pcie_read_tlp_log(dev, aer + PCI_ERR_HEADER_LOG,
1246 					  aer + PCI_ERR_PREFIX_LOG,
1247 					  aer_tlp_log_len(dev, aercc),
1248 					  &info->tlp);
1249 		}
1250 	}
1251 
1252 	return 1;
1253 }
1254 
aer_process_err_devices(struct aer_err_info * e_info)1255 static inline void aer_process_err_devices(struct aer_err_info *e_info)
1256 {
1257 	int i;
1258 
1259 	/* Report all before handle them, not to lost records by reset etc. */
1260 	for (i = 0; i < e_info->error_dev_num && e_info->dev[i]; i++) {
1261 		if (aer_get_device_error_info(e_info->dev[i], e_info))
1262 			aer_print_error(e_info->dev[i], e_info);
1263 	}
1264 	for (i = 0; i < e_info->error_dev_num && e_info->dev[i]; i++) {
1265 		if (aer_get_device_error_info(e_info->dev[i], e_info))
1266 			handle_error_source(e_info->dev[i], e_info);
1267 	}
1268 }
1269 
1270 /**
1271  * aer_isr_one_error - consume an error detected by root port
1272  * @rpc: pointer to the root port which holds an error
1273  * @e_src: pointer to an error source
1274  */
aer_isr_one_error(struct aer_rpc * rpc,struct aer_err_source * e_src)1275 static void aer_isr_one_error(struct aer_rpc *rpc,
1276 		struct aer_err_source *e_src)
1277 {
1278 	struct pci_dev *pdev = rpc->rpd;
1279 	struct aer_err_info e_info;
1280 
1281 	pci_rootport_aer_stats_incr(pdev, e_src);
1282 
1283 	/*
1284 	 * There is a possibility that both correctable error and
1285 	 * uncorrectable error being logged. Report correctable error first.
1286 	 */
1287 	if (e_src->status & PCI_ERR_ROOT_COR_RCV) {
1288 		e_info.id = ERR_COR_ID(e_src->id);
1289 		e_info.severity = AER_CORRECTABLE;
1290 
1291 		if (e_src->status & PCI_ERR_ROOT_MULTI_COR_RCV)
1292 			e_info.multi_error_valid = 1;
1293 		else
1294 			e_info.multi_error_valid = 0;
1295 		aer_print_port_info(pdev, &e_info);
1296 
1297 		if (find_source_device(pdev, &e_info))
1298 			aer_process_err_devices(&e_info);
1299 	}
1300 
1301 	if (e_src->status & PCI_ERR_ROOT_UNCOR_RCV) {
1302 		e_info.id = ERR_UNCOR_ID(e_src->id);
1303 
1304 		if (e_src->status & PCI_ERR_ROOT_FATAL_RCV)
1305 			e_info.severity = AER_FATAL;
1306 		else
1307 			e_info.severity = AER_NONFATAL;
1308 
1309 		if (e_src->status & PCI_ERR_ROOT_MULTI_UNCOR_RCV)
1310 			e_info.multi_error_valid = 1;
1311 		else
1312 			e_info.multi_error_valid = 0;
1313 
1314 		aer_print_port_info(pdev, &e_info);
1315 
1316 		if (find_source_device(pdev, &e_info))
1317 			aer_process_err_devices(&e_info);
1318 	}
1319 }
1320 
1321 /**
1322  * aer_isr - consume errors detected by root port
1323  * @irq: IRQ assigned to Root Port
1324  * @context: pointer to Root Port data structure
1325  *
1326  * Invoked, as DPC, when root port records new detected error
1327  */
aer_isr(int irq,void * context)1328 static irqreturn_t aer_isr(int irq, void *context)
1329 {
1330 	struct pcie_device *dev = (struct pcie_device *)context;
1331 	struct aer_rpc *rpc = get_service_data(dev);
1332 	struct aer_err_source e_src;
1333 
1334 	if (kfifo_is_empty(&rpc->aer_fifo))
1335 		return IRQ_NONE;
1336 
1337 	while (kfifo_get(&rpc->aer_fifo, &e_src))
1338 		aer_isr_one_error(rpc, &e_src);
1339 	return IRQ_HANDLED;
1340 }
1341 
1342 /**
1343  * aer_irq - Root Port's ISR
1344  * @irq: IRQ assigned to Root Port
1345  * @context: pointer to Root Port data structure
1346  *
1347  * Invoked when Root Port detects AER messages.
1348  */
aer_irq(int irq,void * context)1349 static irqreturn_t aer_irq(int irq, void *context)
1350 {
1351 	struct pcie_device *pdev = (struct pcie_device *)context;
1352 	struct aer_rpc *rpc = get_service_data(pdev);
1353 	struct pci_dev *rp = rpc->rpd;
1354 	int aer = rp->aer_cap;
1355 	struct aer_err_source e_src = {};
1356 
1357 	pci_read_config_dword(rp, aer + PCI_ERR_ROOT_STATUS, &e_src.status);
1358 	if (!(e_src.status & AER_ERR_STATUS_MASK))
1359 		return IRQ_NONE;
1360 
1361 	pci_read_config_dword(rp, aer + PCI_ERR_ROOT_ERR_SRC, &e_src.id);
1362 	pci_write_config_dword(rp, aer + PCI_ERR_ROOT_STATUS, e_src.status);
1363 
1364 	if (!kfifo_put(&rpc->aer_fifo, e_src))
1365 		return IRQ_HANDLED;
1366 
1367 	return IRQ_WAKE_THREAD;
1368 }
1369 
aer_enable_irq(struct pci_dev * pdev)1370 static void aer_enable_irq(struct pci_dev *pdev)
1371 {
1372 	int aer = pdev->aer_cap;
1373 	u32 reg32;
1374 
1375 	/* Enable Root Port's interrupt in response to error messages */
1376 	pci_read_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, &reg32);
1377 	reg32 |= ROOT_PORT_INTR_ON_MESG_MASK;
1378 	pci_write_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, reg32);
1379 }
1380 
aer_disable_irq(struct pci_dev * pdev)1381 static void aer_disable_irq(struct pci_dev *pdev)
1382 {
1383 	int aer = pdev->aer_cap;
1384 	u32 reg32;
1385 
1386 	/* Disable Root's interrupt in response to error messages */
1387 	pci_read_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, &reg32);
1388 	reg32 &= ~ROOT_PORT_INTR_ON_MESG_MASK;
1389 	pci_write_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, reg32);
1390 }
1391 
1392 /**
1393  * aer_enable_rootport - enable Root Port's interrupts when receiving messages
1394  * @rpc: pointer to a Root Port data structure
1395  *
1396  * Invoked when PCIe bus loads AER service driver.
1397  */
aer_enable_rootport(struct aer_rpc * rpc)1398 static void aer_enable_rootport(struct aer_rpc *rpc)
1399 {
1400 	struct pci_dev *pdev = rpc->rpd;
1401 	int aer = pdev->aer_cap;
1402 	u16 reg16;
1403 	u32 reg32;
1404 
1405 	/* Clear PCIe Capability's Device Status */
1406 	pcie_capability_read_word(pdev, PCI_EXP_DEVSTA, &reg16);
1407 	pcie_capability_write_word(pdev, PCI_EXP_DEVSTA, reg16);
1408 
1409 	/* Disable system error generation in response to error messages */
1410 	pcie_capability_clear_word(pdev, PCI_EXP_RTCTL,
1411 				   SYSTEM_ERROR_INTR_ON_MESG_MASK);
1412 
1413 	/* Clear error status */
1414 	pci_read_config_dword(pdev, aer + PCI_ERR_ROOT_STATUS, &reg32);
1415 	pci_write_config_dword(pdev, aer + PCI_ERR_ROOT_STATUS, reg32);
1416 	pci_read_config_dword(pdev, aer + PCI_ERR_COR_STATUS, &reg32);
1417 	pci_write_config_dword(pdev, aer + PCI_ERR_COR_STATUS, reg32);
1418 	pci_read_config_dword(pdev, aer + PCI_ERR_UNCOR_STATUS, &reg32);
1419 	pci_write_config_dword(pdev, aer + PCI_ERR_UNCOR_STATUS, reg32);
1420 
1421 	aer_enable_irq(pdev);
1422 }
1423 
1424 /**
1425  * aer_disable_rootport - disable Root Port's interrupts when receiving messages
1426  * @rpc: pointer to a Root Port data structure
1427  *
1428  * Invoked when PCIe bus unloads AER service driver.
1429  */
aer_disable_rootport(struct aer_rpc * rpc)1430 static void aer_disable_rootport(struct aer_rpc *rpc)
1431 {
1432 	struct pci_dev *pdev = rpc->rpd;
1433 	int aer = pdev->aer_cap;
1434 	u32 reg32;
1435 
1436 	aer_disable_irq(pdev);
1437 
1438 	/* Clear Root's error status reg */
1439 	pci_read_config_dword(pdev, aer + PCI_ERR_ROOT_STATUS, &reg32);
1440 	pci_write_config_dword(pdev, aer + PCI_ERR_ROOT_STATUS, reg32);
1441 }
1442 
1443 /**
1444  * aer_remove - clean up resources
1445  * @dev: pointer to the pcie_dev data structure
1446  *
1447  * Invoked when PCI Express bus unloads or AER probe fails.
1448  */
aer_remove(struct pcie_device * dev)1449 static void aer_remove(struct pcie_device *dev)
1450 {
1451 	struct aer_rpc *rpc = get_service_data(dev);
1452 
1453 	aer_disable_rootport(rpc);
1454 }
1455 
1456 /**
1457  * aer_probe - initialize resources
1458  * @dev: pointer to the pcie_dev data structure
1459  *
1460  * Invoked when PCI Express bus loads AER service driver.
1461  */
aer_probe(struct pcie_device * dev)1462 static int aer_probe(struct pcie_device *dev)
1463 {
1464 	int status;
1465 	struct aer_rpc *rpc;
1466 	struct device *device = &dev->device;
1467 	struct pci_dev *port = dev->port;
1468 
1469 	BUILD_BUG_ON(ARRAY_SIZE(aer_correctable_error_string) <
1470 		     AER_MAX_TYPEOF_COR_ERRS);
1471 	BUILD_BUG_ON(ARRAY_SIZE(aer_uncorrectable_error_string) <
1472 		     AER_MAX_TYPEOF_UNCOR_ERRS);
1473 
1474 	/* Limit to Root Ports or Root Complex Event Collectors */
1475 	if ((pci_pcie_type(port) != PCI_EXP_TYPE_RC_EC) &&
1476 	    (pci_pcie_type(port) != PCI_EXP_TYPE_ROOT_PORT))
1477 		return -ENODEV;
1478 
1479 	rpc = devm_kzalloc(device, sizeof(struct aer_rpc), GFP_KERNEL);
1480 	if (!rpc)
1481 		return -ENOMEM;
1482 
1483 	rpc->rpd = port;
1484 	INIT_KFIFO(rpc->aer_fifo);
1485 	set_service_data(dev, rpc);
1486 
1487 	status = devm_request_threaded_irq(device, dev->irq, aer_irq, aer_isr,
1488 					   IRQF_SHARED, "aerdrv", dev);
1489 	if (status) {
1490 		pci_err(port, "request AER IRQ %d failed\n", dev->irq);
1491 		return status;
1492 	}
1493 
1494 	cxl_rch_enable_rcec(port);
1495 	aer_enable_rootport(rpc);
1496 	pci_info(port, "enabled with IRQ %d\n", dev->irq);
1497 	return 0;
1498 }
1499 
aer_suspend(struct pcie_device * dev)1500 static int aer_suspend(struct pcie_device *dev)
1501 {
1502 	struct aer_rpc *rpc = get_service_data(dev);
1503 
1504 	aer_disable_rootport(rpc);
1505 	return 0;
1506 }
1507 
aer_resume(struct pcie_device * dev)1508 static int aer_resume(struct pcie_device *dev)
1509 {
1510 	struct aer_rpc *rpc = get_service_data(dev);
1511 
1512 	aer_enable_rootport(rpc);
1513 	return 0;
1514 }
1515 
1516 /**
1517  * aer_root_reset - reset Root Port hierarchy, RCEC, or RCiEP
1518  * @dev: pointer to Root Port, RCEC, or RCiEP
1519  *
1520  * Invoked by Port Bus driver when performing reset.
1521  */
aer_root_reset(struct pci_dev * dev)1522 static pci_ers_result_t aer_root_reset(struct pci_dev *dev)
1523 {
1524 	int type = pci_pcie_type(dev);
1525 	struct pci_dev *root;
1526 	int aer;
1527 	struct pci_host_bridge *host = pci_find_host_bridge(dev->bus);
1528 	u32 reg32;
1529 	int rc;
1530 
1531 	/*
1532 	 * Only Root Ports and RCECs have AER Root Command and Root Status
1533 	 * registers.  If "dev" is an RCiEP, the relevant registers are in
1534 	 * the RCEC.
1535 	 */
1536 	if (type == PCI_EXP_TYPE_RC_END)
1537 		root = dev->rcec;
1538 	else
1539 		root = pcie_find_root_port(dev);
1540 
1541 	/*
1542 	 * If the platform retained control of AER, an RCiEP may not have
1543 	 * an RCEC visible to us, so dev->rcec ("root") may be NULL.  In
1544 	 * that case, firmware is responsible for these registers.
1545 	 */
1546 	aer = root ? root->aer_cap : 0;
1547 
1548 	if ((host->native_aer || pcie_ports_native) && aer)
1549 		aer_disable_irq(root);
1550 
1551 	if (type == PCI_EXP_TYPE_RC_EC || type == PCI_EXP_TYPE_RC_END) {
1552 		rc = pcie_reset_flr(dev, PCI_RESET_DO_RESET);
1553 		if (!rc)
1554 			pci_info(dev, "has been reset\n");
1555 		else
1556 			pci_info(dev, "not reset (no FLR support: %d)\n", rc);
1557 	} else {
1558 		rc = pci_bus_error_reset(dev);
1559 		pci_info(dev, "%s Port link has been reset (%d)\n",
1560 			pci_is_root_bus(dev->bus) ? "Root" : "Downstream", rc);
1561 	}
1562 
1563 	if ((host->native_aer || pcie_ports_native) && aer) {
1564 		/* Clear Root Error Status */
1565 		pci_read_config_dword(root, aer + PCI_ERR_ROOT_STATUS, &reg32);
1566 		pci_write_config_dword(root, aer + PCI_ERR_ROOT_STATUS, reg32);
1567 
1568 		aer_enable_irq(root);
1569 	}
1570 
1571 	return rc ? PCI_ERS_RESULT_DISCONNECT : PCI_ERS_RESULT_RECOVERED;
1572 }
1573 
1574 static struct pcie_port_service_driver aerdriver = {
1575 	.name		= "aer",
1576 	.port_type	= PCIE_ANY_PORT,
1577 	.service	= PCIE_PORT_SERVICE_AER,
1578 
1579 	.probe		= aer_probe,
1580 	.suspend	= aer_suspend,
1581 	.resume		= aer_resume,
1582 	.remove		= aer_remove,
1583 };
1584 
1585 /**
1586  * pcie_aer_init - register AER root service driver
1587  *
1588  * Invoked when AER root service driver is loaded.
1589  */
pcie_aer_init(void)1590 int __init pcie_aer_init(void)
1591 {
1592 	if (!pci_aer_available())
1593 		return -ENXIO;
1594 	return pcie_port_service_register(&aerdriver);
1595 }
1596