1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * PCIe AER software error injection support.
4 *
5 * Debugging PCIe AER code is quite difficult because it is hard to
6 * trigger various real hardware errors. Software based error
7 * injection can fake almost all kinds of errors with the help of a
8 * user space helper tool aer-inject, which can be gotten from:
9 * https://www.kernel.org/pub/linux/utils/pci/aer-inject/
10 *
11 * Copyright 2009 Intel Corporation.
12 * Huang Ying <ying.huang@intel.com>
13 */
14
15 #define dev_fmt(fmt) "aer_inject: " fmt
16
17 #include <linux/module.h>
18 #include <linux/init.h>
19 #include <linux/interrupt.h>
20 #include <linux/miscdevice.h>
21 #include <linux/pci.h>
22 #include <linux/slab.h>
23 #include <linux/fs.h>
24 #include <linux/uaccess.h>
25 #include <linux/stddef.h>
26 #include <linux/device.h>
27
28 #include "portdrv.h"
29
30 /* Override the existing corrected and uncorrected error masks */
31 static bool aer_mask_override;
32 module_param(aer_mask_override, bool, 0);
33
34 struct aer_error_inj {
35 u8 bus;
36 u8 dev;
37 u8 fn;
38 u32 uncor_status;
39 u32 cor_status;
40 u32 header_log0;
41 u32 header_log1;
42 u32 header_log2;
43 u32 header_log3;
44 u32 domain;
45 };
46
47 struct aer_error {
48 struct list_head list;
49 u32 domain;
50 unsigned int bus;
51 unsigned int devfn;
52 int pos_cap_err;
53
54 u32 uncor_status;
55 u32 cor_status;
56 u32 header_log0;
57 u32 header_log1;
58 u32 header_log2;
59 u32 header_log3;
60 u32 root_status;
61 u32 source_id;
62 };
63
64 struct pci_bus_ops {
65 struct list_head list;
66 struct pci_bus *bus;
67 struct pci_ops *ops;
68 };
69
70 static LIST_HEAD(einjected);
71
72 static LIST_HEAD(pci_bus_ops_list);
73
74 /* Protect einjected and pci_bus_ops_list */
75 static DEFINE_SPINLOCK(inject_lock);
76
aer_error_init(struct aer_error * err,u32 domain,unsigned int bus,unsigned int devfn,int pos_cap_err)77 static void aer_error_init(struct aer_error *err, u32 domain,
78 unsigned int bus, unsigned int devfn,
79 int pos_cap_err)
80 {
81 INIT_LIST_HEAD(&err->list);
82 err->domain = domain;
83 err->bus = bus;
84 err->devfn = devfn;
85 err->pos_cap_err = pos_cap_err;
86 }
87
88 /* inject_lock must be held before calling */
__find_aer_error(u32 domain,unsigned int bus,unsigned int devfn)89 static struct aer_error *__find_aer_error(u32 domain, unsigned int bus,
90 unsigned int devfn)
91 {
92 struct aer_error *err;
93
94 list_for_each_entry(err, &einjected, list) {
95 if (domain == err->domain &&
96 bus == err->bus &&
97 devfn == err->devfn)
98 return err;
99 }
100 return NULL;
101 }
102
103 /* inject_lock must be held before calling */
__find_aer_error_by_dev(struct pci_dev * dev)104 static struct aer_error *__find_aer_error_by_dev(struct pci_dev *dev)
105 {
106 int domain = pci_domain_nr(dev->bus);
107 if (domain < 0)
108 return NULL;
109 return __find_aer_error(domain, dev->bus->number, dev->devfn);
110 }
111
112 /* inject_lock must be held before calling */
__find_pci_bus_ops(struct pci_bus * bus)113 static struct pci_ops *__find_pci_bus_ops(struct pci_bus *bus)
114 {
115 struct pci_bus_ops *bus_ops;
116
117 list_for_each_entry(bus_ops, &pci_bus_ops_list, list) {
118 if (bus_ops->bus == bus)
119 return bus_ops->ops;
120 }
121 return NULL;
122 }
123
pci_bus_ops_pop(void)124 static struct pci_bus_ops *pci_bus_ops_pop(void)
125 {
126 unsigned long flags;
127 struct pci_bus_ops *bus_ops;
128
129 spin_lock_irqsave(&inject_lock, flags);
130 bus_ops = list_first_entry_or_null(&pci_bus_ops_list,
131 struct pci_bus_ops, list);
132 if (bus_ops)
133 list_del(&bus_ops->list);
134 spin_unlock_irqrestore(&inject_lock, flags);
135 return bus_ops;
136 }
137
find_pci_config_dword(struct aer_error * err,int where,int * prw1cs)138 static u32 *find_pci_config_dword(struct aer_error *err, int where,
139 int *prw1cs)
140 {
141 int rw1cs = 0;
142 u32 *target = NULL;
143
144 if (err->pos_cap_err == -1)
145 return NULL;
146
147 switch (where - err->pos_cap_err) {
148 case PCI_ERR_UNCOR_STATUS:
149 target = &err->uncor_status;
150 rw1cs = 1;
151 break;
152 case PCI_ERR_COR_STATUS:
153 target = &err->cor_status;
154 rw1cs = 1;
155 break;
156 case PCI_ERR_HEADER_LOG:
157 target = &err->header_log0;
158 break;
159 case PCI_ERR_HEADER_LOG+4:
160 target = &err->header_log1;
161 break;
162 case PCI_ERR_HEADER_LOG+8:
163 target = &err->header_log2;
164 break;
165 case PCI_ERR_HEADER_LOG+12:
166 target = &err->header_log3;
167 break;
168 case PCI_ERR_ROOT_STATUS:
169 target = &err->root_status;
170 rw1cs = 1;
171 break;
172 case PCI_ERR_ROOT_ERR_SRC:
173 target = &err->source_id;
174 break;
175 }
176 if (prw1cs)
177 *prw1cs = rw1cs;
178 return target;
179 }
180
aer_inj_read(struct pci_bus * bus,unsigned int devfn,int where,int size,u32 * val)181 static int aer_inj_read(struct pci_bus *bus, unsigned int devfn, int where,
182 int size, u32 *val)
183 {
184 struct pci_ops *ops, *my_ops;
185 int rv;
186
187 ops = __find_pci_bus_ops(bus);
188 if (!ops)
189 return -1;
190
191 my_ops = bus->ops;
192 bus->ops = ops;
193 rv = ops->read(bus, devfn, where, size, val);
194 bus->ops = my_ops;
195
196 return rv;
197 }
198
aer_inj_write(struct pci_bus * bus,unsigned int devfn,int where,int size,u32 val)199 static int aer_inj_write(struct pci_bus *bus, unsigned int devfn, int where,
200 int size, u32 val)
201 {
202 struct pci_ops *ops, *my_ops;
203 int rv;
204
205 ops = __find_pci_bus_ops(bus);
206 if (!ops)
207 return -1;
208
209 my_ops = bus->ops;
210 bus->ops = ops;
211 rv = ops->write(bus, devfn, where, size, val);
212 bus->ops = my_ops;
213
214 return rv;
215 }
216
aer_inj_read_config(struct pci_bus * bus,unsigned int devfn,int where,int size,u32 * val)217 static int aer_inj_read_config(struct pci_bus *bus, unsigned int devfn,
218 int where, int size, u32 *val)
219 {
220 u32 *sim;
221 struct aer_error *err;
222 unsigned long flags;
223 int domain;
224 int rv;
225
226 spin_lock_irqsave(&inject_lock, flags);
227 if (size != sizeof(u32))
228 goto out;
229 domain = pci_domain_nr(bus);
230 if (domain < 0)
231 goto out;
232 err = __find_aer_error(domain, bus->number, devfn);
233 if (!err)
234 goto out;
235
236 sim = find_pci_config_dword(err, where, NULL);
237 if (sim) {
238 *val = *sim;
239 spin_unlock_irqrestore(&inject_lock, flags);
240 return 0;
241 }
242 out:
243 rv = aer_inj_read(bus, devfn, where, size, val);
244 spin_unlock_irqrestore(&inject_lock, flags);
245 return rv;
246 }
247
aer_inj_write_config(struct pci_bus * bus,unsigned int devfn,int where,int size,u32 val)248 static int aer_inj_write_config(struct pci_bus *bus, unsigned int devfn,
249 int where, int size, u32 val)
250 {
251 u32 *sim;
252 struct aer_error *err;
253 unsigned long flags;
254 int rw1cs;
255 int domain;
256 int rv;
257
258 spin_lock_irqsave(&inject_lock, flags);
259 if (size != sizeof(u32))
260 goto out;
261 domain = pci_domain_nr(bus);
262 if (domain < 0)
263 goto out;
264 err = __find_aer_error(domain, bus->number, devfn);
265 if (!err)
266 goto out;
267
268 sim = find_pci_config_dword(err, where, &rw1cs);
269 if (sim) {
270 if (rw1cs)
271 *sim ^= val;
272 else
273 *sim = val;
274 spin_unlock_irqrestore(&inject_lock, flags);
275 return 0;
276 }
277 out:
278 rv = aer_inj_write(bus, devfn, where, size, val);
279 spin_unlock_irqrestore(&inject_lock, flags);
280 return rv;
281 }
282
283 static struct pci_ops aer_inj_pci_ops = {
284 .read = aer_inj_read_config,
285 .write = aer_inj_write_config,
286 };
287
pci_bus_ops_init(struct pci_bus_ops * bus_ops,struct pci_bus * bus,struct pci_ops * ops)288 static void pci_bus_ops_init(struct pci_bus_ops *bus_ops,
289 struct pci_bus *bus,
290 struct pci_ops *ops)
291 {
292 INIT_LIST_HEAD(&bus_ops->list);
293 bus_ops->bus = bus;
294 bus_ops->ops = ops;
295 }
296
pci_bus_set_aer_ops(struct pci_bus * bus)297 static int pci_bus_set_aer_ops(struct pci_bus *bus)
298 {
299 struct pci_ops *ops;
300 struct pci_bus_ops *bus_ops;
301 unsigned long flags;
302
303 bus_ops = kmalloc(sizeof(*bus_ops), GFP_KERNEL);
304 if (!bus_ops)
305 return -ENOMEM;
306 ops = pci_bus_set_ops(bus, &aer_inj_pci_ops);
307 spin_lock_irqsave(&inject_lock, flags);
308 if (ops == &aer_inj_pci_ops)
309 goto out;
310 pci_bus_ops_init(bus_ops, bus, ops);
311 list_add(&bus_ops->list, &pci_bus_ops_list);
312 bus_ops = NULL;
313 out:
314 spin_unlock_irqrestore(&inject_lock, flags);
315 kfree(bus_ops);
316 return 0;
317 }
318
aer_inject(struct aer_error_inj * einj)319 static int aer_inject(struct aer_error_inj *einj)
320 {
321 struct aer_error *err, *rperr;
322 struct aer_error *err_alloc = NULL, *rperr_alloc = NULL;
323 struct pci_dev *dev, *rpdev;
324 struct pcie_device *edev;
325 struct device *device;
326 unsigned long flags;
327 unsigned int devfn = PCI_DEVFN(einj->dev, einj->fn);
328 int pos_cap_err, rp_pos_cap_err;
329 u32 sever, cor_mask, uncor_mask, cor_mask_orig = 0, uncor_mask_orig = 0;
330 int ret = 0;
331
332 dev = pci_get_domain_bus_and_slot(einj->domain, einj->bus, devfn);
333 if (!dev)
334 return -ENODEV;
335 rpdev = pcie_find_root_port(dev);
336 /* If Root Port not found, try to find an RCEC */
337 if (!rpdev)
338 rpdev = dev->rcec;
339 if (!rpdev) {
340 pci_err(dev, "Neither Root Port nor RCEC found\n");
341 ret = -ENODEV;
342 goto out_put;
343 }
344
345 pos_cap_err = dev->aer_cap;
346 if (!pos_cap_err) {
347 pci_err(dev, "Device doesn't support AER\n");
348 ret = -EPROTONOSUPPORT;
349 goto out_put;
350 }
351 pci_read_config_dword(dev, pos_cap_err + PCI_ERR_UNCOR_SEVER, &sever);
352 pci_read_config_dword(dev, pos_cap_err + PCI_ERR_COR_MASK, &cor_mask);
353 pci_read_config_dword(dev, pos_cap_err + PCI_ERR_UNCOR_MASK,
354 &uncor_mask);
355
356 rp_pos_cap_err = rpdev->aer_cap;
357 if (!rp_pos_cap_err) {
358 pci_err(rpdev, "Root port doesn't support AER\n");
359 ret = -EPROTONOSUPPORT;
360 goto out_put;
361 }
362
363 err_alloc = kzalloc(sizeof(struct aer_error), GFP_KERNEL);
364 if (!err_alloc) {
365 ret = -ENOMEM;
366 goto out_put;
367 }
368 rperr_alloc = kzalloc(sizeof(struct aer_error), GFP_KERNEL);
369 if (!rperr_alloc) {
370 ret = -ENOMEM;
371 goto out_put;
372 }
373
374 if (aer_mask_override) {
375 cor_mask_orig = cor_mask;
376 cor_mask &= !(einj->cor_status);
377 pci_write_config_dword(dev, pos_cap_err + PCI_ERR_COR_MASK,
378 cor_mask);
379
380 uncor_mask_orig = uncor_mask;
381 uncor_mask &= !(einj->uncor_status);
382 pci_write_config_dword(dev, pos_cap_err + PCI_ERR_UNCOR_MASK,
383 uncor_mask);
384 }
385
386 spin_lock_irqsave(&inject_lock, flags);
387
388 err = __find_aer_error_by_dev(dev);
389 if (!err) {
390 err = err_alloc;
391 err_alloc = NULL;
392 aer_error_init(err, einj->domain, einj->bus, devfn,
393 pos_cap_err);
394 list_add(&err->list, &einjected);
395 }
396 err->uncor_status |= einj->uncor_status;
397 err->cor_status |= einj->cor_status;
398 err->header_log0 = einj->header_log0;
399 err->header_log1 = einj->header_log1;
400 err->header_log2 = einj->header_log2;
401 err->header_log3 = einj->header_log3;
402
403 if (!aer_mask_override && einj->cor_status &&
404 !(einj->cor_status & ~cor_mask)) {
405 ret = -EINVAL;
406 pci_warn(dev, "The correctable error(s) is masked by device\n");
407 spin_unlock_irqrestore(&inject_lock, flags);
408 goto out_put;
409 }
410 if (!aer_mask_override && einj->uncor_status &&
411 !(einj->uncor_status & ~uncor_mask)) {
412 ret = -EINVAL;
413 pci_warn(dev, "The uncorrectable error(s) is masked by device\n");
414 spin_unlock_irqrestore(&inject_lock, flags);
415 goto out_put;
416 }
417
418 rperr = __find_aer_error_by_dev(rpdev);
419 if (!rperr) {
420 rperr = rperr_alloc;
421 rperr_alloc = NULL;
422 aer_error_init(rperr, pci_domain_nr(rpdev->bus),
423 rpdev->bus->number, rpdev->devfn,
424 rp_pos_cap_err);
425 list_add(&rperr->list, &einjected);
426 }
427 if (einj->cor_status) {
428 if (rperr->root_status & PCI_ERR_ROOT_COR_RCV)
429 rperr->root_status |= PCI_ERR_ROOT_MULTI_COR_RCV;
430 else
431 rperr->root_status |= PCI_ERR_ROOT_COR_RCV;
432 rperr->source_id &= 0xffff0000;
433 rperr->source_id |= (einj->bus << 8) | devfn;
434 }
435 if (einj->uncor_status) {
436 if (rperr->root_status & PCI_ERR_ROOT_UNCOR_RCV)
437 rperr->root_status |= PCI_ERR_ROOT_MULTI_UNCOR_RCV;
438 if (sever & einj->uncor_status) {
439 rperr->root_status |= PCI_ERR_ROOT_FATAL_RCV;
440 if (!(rperr->root_status & PCI_ERR_ROOT_UNCOR_RCV))
441 rperr->root_status |= PCI_ERR_ROOT_FIRST_FATAL;
442 } else
443 rperr->root_status |= PCI_ERR_ROOT_NONFATAL_RCV;
444 rperr->root_status |= PCI_ERR_ROOT_UNCOR_RCV;
445 rperr->source_id &= 0x0000ffff;
446 rperr->source_id |= ((einj->bus << 8) | devfn) << 16;
447 }
448 spin_unlock_irqrestore(&inject_lock, flags);
449
450 if (aer_mask_override) {
451 pci_write_config_dword(dev, pos_cap_err + PCI_ERR_COR_MASK,
452 cor_mask_orig);
453 pci_write_config_dword(dev, pos_cap_err + PCI_ERR_UNCOR_MASK,
454 uncor_mask_orig);
455 }
456
457 ret = pci_bus_set_aer_ops(dev->bus);
458 if (ret)
459 goto out_put;
460 ret = pci_bus_set_aer_ops(rpdev->bus);
461 if (ret)
462 goto out_put;
463
464 device = pcie_port_find_device(rpdev, PCIE_PORT_SERVICE_AER);
465 if (device) {
466 edev = to_pcie_device(device);
467 if (!get_service_data(edev)) {
468 pci_warn(edev->port, "AER service is not initialized\n");
469 ret = -EPROTONOSUPPORT;
470 goto out_put;
471 }
472 pci_info(edev->port, "Injecting errors %08x/%08x into device %s\n",
473 einj->cor_status, einj->uncor_status, pci_name(dev));
474 ret = irq_inject_interrupt(edev->irq);
475 } else {
476 pci_err(rpdev, "AER device not found\n");
477 ret = -ENODEV;
478 }
479 out_put:
480 kfree(err_alloc);
481 kfree(rperr_alloc);
482 pci_dev_put(dev);
483 return ret;
484 }
485
aer_inject_write(struct file * filp,const char __user * ubuf,size_t usize,loff_t * off)486 static ssize_t aer_inject_write(struct file *filp, const char __user *ubuf,
487 size_t usize, loff_t *off)
488 {
489 struct aer_error_inj einj;
490 int ret;
491
492 if (!capable(CAP_SYS_ADMIN))
493 return -EPERM;
494 if (usize < offsetof(struct aer_error_inj, domain) ||
495 usize > sizeof(einj))
496 return -EINVAL;
497
498 memset(&einj, 0, sizeof(einj));
499 if (copy_from_user(&einj, ubuf, usize))
500 return -EFAULT;
501
502 ret = aer_inject(&einj);
503 return ret ? ret : usize;
504 }
505
506 static const struct file_operations aer_inject_fops = {
507 .write = aer_inject_write,
508 .owner = THIS_MODULE,
509 .llseek = noop_llseek,
510 };
511
512 static struct miscdevice aer_inject_device = {
513 .minor = MISC_DYNAMIC_MINOR,
514 .name = "aer_inject",
515 .fops = &aer_inject_fops,
516 };
517
aer_inject_init(void)518 static int __init aer_inject_init(void)
519 {
520 return misc_register(&aer_inject_device);
521 }
522
aer_inject_exit(void)523 static void __exit aer_inject_exit(void)
524 {
525 struct aer_error *err, *err_next;
526 unsigned long flags;
527 struct pci_bus_ops *bus_ops;
528
529 misc_deregister(&aer_inject_device);
530
531 while ((bus_ops = pci_bus_ops_pop())) {
532 pci_bus_set_ops(bus_ops->bus, bus_ops->ops);
533 kfree(bus_ops);
534 }
535
536 spin_lock_irqsave(&inject_lock, flags);
537 list_for_each_entry_safe(err, err_next, &einjected, list) {
538 list_del(&err->list);
539 kfree(err);
540 }
541 spin_unlock_irqrestore(&inject_lock, flags);
542 }
543
544 module_init(aer_inject_init);
545 module_exit(aer_inject_exit);
546
547 MODULE_DESCRIPTION("PCIe AER software error injector");
548 MODULE_LICENSE("GPL");
549