linux/drivers/pci/pcie/aer_inject.c
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   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 */
  31static bool aer_mask_override;
  32module_param(aer_mask_override, bool, 0);
  33
  34struct 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
  47struct 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
  64struct pci_bus_ops {
  65        struct list_head list;
  66        struct pci_bus *bus;
  67        struct pci_ops *ops;
  68};
  69
  70static LIST_HEAD(einjected);
  71
  72static LIST_HEAD(pci_bus_ops_list);
  73
  74/* Protect einjected and pci_bus_ops_list */
  75static DEFINE_SPINLOCK(inject_lock);
  76
  77static 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 */
  89static 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 */
 104static 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 */
 113static 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
 124static 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
 138static 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
 181static 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
 199static 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
 217static 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        }
 242out:
 243        rv = aer_inj_read(bus, devfn, where, size, val);
 244        spin_unlock_irqrestore(&inject_lock, flags);
 245        return rv;
 246}
 247
 248static 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        }
 277out:
 278        rv = aer_inj_write(bus, devfn, where, size, val);
 279        spin_unlock_irqrestore(&inject_lock, flags);
 280        return rv;
 281}
 282
 283static struct pci_ops aer_inj_pci_ops = {
 284        .read = aer_inj_read_config,
 285        .write = aer_inj_write_config,
 286};
 287
 288static 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
 297static 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;
 313out:
 314        spin_unlock_irqrestore(&inject_lock, flags);
 315        kfree(bus_ops);
 316        return 0;
 317}
 318
 319static 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        }
 479out_put:
 480        kfree(err_alloc);
 481        kfree(rperr_alloc);
 482        pci_dev_put(dev);
 483        return ret;
 484}
 485
 486static 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
 506static const struct file_operations aer_inject_fops = {
 507        .write = aer_inject_write,
 508        .owner = THIS_MODULE,
 509        .llseek = noop_llseek,
 510};
 511
 512static struct miscdevice aer_inject_device = {
 513        .minor = MISC_DYNAMIC_MINOR,
 514        .name = "aer_inject",
 515        .fops = &aer_inject_fops,
 516};
 517
 518static int __init aer_inject_init(void)
 519{
 520        return misc_register(&aer_inject_device);
 521}
 522
 523static 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
 544module_init(aer_inject_init);
 545module_exit(aer_inject_exit);
 546
 547MODULE_DESCRIPTION("PCIe AER software error injector");
 548MODULE_LICENSE("GPL");
 549