linux/drivers/pci/pcie/aer/aer_inject.c
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   1/*
   2 * PCIe AER software error injection support.
   3 *
   4 * Debuging PCIe AER code is quite difficult because it is hard to
   5 * trigger various real hardware errors. Software based error
   6 * injection can fake almost all kinds of errors with the help of a
   7 * user space helper tool aer-inject, which can be gotten from:
   8 *   http://www.kernel.org/pub/linux/utils/pci/aer-inject/
   9 *
  10 * Copyright 2009 Intel Corporation.
  11 *     Huang Ying <ying.huang@intel.com>
  12 *
  13 * This program is free software; you can redistribute it and/or
  14 * modify it under the terms of the GNU General Public License
  15 * as published by the Free Software Foundation; version 2
  16 * of the License.
  17 *
  18 */
  19
  20#include <linux/module.h>
  21#include <linux/init.h>
  22#include <linux/miscdevice.h>
  23#include <linux/pci.h>
  24#include <linux/slab.h>
  25#include <linux/fs.h>
  26#include <linux/uaccess.h>
  27#include <linux/stddef.h>
  28#include "aerdrv.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        u16 domain;
  45};
  46
  47struct aer_error {
  48        struct list_head list;
  49        u16 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, u16 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(u16 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((u16)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 = NULL;
 128
 129        spin_lock_irqsave(&inject_lock, flags);
 130        if (list_empty(&pci_bus_ops_list))
 131                bus_ops = NULL;
 132        else {
 133                struct list_head *lh = pci_bus_ops_list.next;
 134                list_del(lh);
 135                bus_ops = list_entry(lh, struct pci_bus_ops, list);
 136        }
 137        spin_unlock_irqrestore(&inject_lock, flags);
 138        return bus_ops;
 139}
 140
 141static u32 *find_pci_config_dword(struct aer_error *err, int where,
 142                                  int *prw1cs)
 143{
 144        int rw1cs = 0;
 145        u32 *target = NULL;
 146
 147        if (err->pos_cap_err == -1)
 148                return NULL;
 149
 150        switch (where - err->pos_cap_err) {
 151        case PCI_ERR_UNCOR_STATUS:
 152                target = &err->uncor_status;
 153                rw1cs = 1;
 154                break;
 155        case PCI_ERR_COR_STATUS:
 156                target = &err->cor_status;
 157                rw1cs = 1;
 158                break;
 159        case PCI_ERR_HEADER_LOG:
 160                target = &err->header_log0;
 161                break;
 162        case PCI_ERR_HEADER_LOG+4:
 163                target = &err->header_log1;
 164                break;
 165        case PCI_ERR_HEADER_LOG+8:
 166                target = &err->header_log2;
 167                break;
 168        case PCI_ERR_HEADER_LOG+12:
 169                target = &err->header_log3;
 170                break;
 171        case PCI_ERR_ROOT_STATUS:
 172                target = &err->root_status;
 173                rw1cs = 1;
 174                break;
 175        case PCI_ERR_ROOT_ERR_SRC:
 176                target = &err->source_id;
 177                break;
 178        }
 179        if (prw1cs)
 180                *prw1cs = rw1cs;
 181        return target;
 182}
 183
 184static int pci_read_aer(struct pci_bus *bus, unsigned int devfn, int where,
 185                        int size, u32 *val)
 186{
 187        u32 *sim;
 188        struct aer_error *err;
 189        unsigned long flags;
 190        struct pci_ops *ops;
 191        int domain;
 192
 193        spin_lock_irqsave(&inject_lock, flags);
 194        if (size != sizeof(u32))
 195                goto out;
 196        domain = pci_domain_nr(bus);
 197        if (domain < 0)
 198                goto out;
 199        err = __find_aer_error((u16)domain, bus->number, devfn);
 200        if (!err)
 201                goto out;
 202
 203        sim = find_pci_config_dword(err, where, NULL);
 204        if (sim) {
 205                *val = *sim;
 206                spin_unlock_irqrestore(&inject_lock, flags);
 207                return 0;
 208        }
 209out:
 210        ops = __find_pci_bus_ops(bus);
 211        spin_unlock_irqrestore(&inject_lock, flags);
 212        return ops->read(bus, devfn, where, size, val);
 213}
 214
 215static int pci_write_aer(struct pci_bus *bus, unsigned int devfn, int where,
 216                         int size, u32 val)
 217{
 218        u32 *sim;
 219        struct aer_error *err;
 220        unsigned long flags;
 221        int rw1cs;
 222        struct pci_ops *ops;
 223        int domain;
 224
 225        spin_lock_irqsave(&inject_lock, flags);
 226        if (size != sizeof(u32))
 227                goto out;
 228        domain = pci_domain_nr(bus);
 229        if (domain < 0)
 230                goto out;
 231        err = __find_aer_error((u16)domain, bus->number, devfn);
 232        if (!err)
 233                goto out;
 234
 235        sim = find_pci_config_dword(err, where, &rw1cs);
 236        if (sim) {
 237                if (rw1cs)
 238                        *sim ^= val;
 239                else
 240                        *sim = val;
 241                spin_unlock_irqrestore(&inject_lock, flags);
 242                return 0;
 243        }
 244out:
 245        ops = __find_pci_bus_ops(bus);
 246        spin_unlock_irqrestore(&inject_lock, flags);
 247        return ops->write(bus, devfn, where, size, val);
 248}
 249
 250static struct pci_ops pci_ops_aer = {
 251        .read = pci_read_aer,
 252        .write = pci_write_aer,
 253};
 254
 255static void pci_bus_ops_init(struct pci_bus_ops *bus_ops,
 256                             struct pci_bus *bus,
 257                             struct pci_ops *ops)
 258{
 259        INIT_LIST_HEAD(&bus_ops->list);
 260        bus_ops->bus = bus;
 261        bus_ops->ops = ops;
 262}
 263
 264static int pci_bus_set_aer_ops(struct pci_bus *bus)
 265{
 266        struct pci_ops *ops;
 267        struct pci_bus_ops *bus_ops;
 268        unsigned long flags;
 269
 270        bus_ops = kmalloc(sizeof(*bus_ops), GFP_KERNEL);
 271        if (!bus_ops)
 272                return -ENOMEM;
 273        ops = pci_bus_set_ops(bus, &pci_ops_aer);
 274        spin_lock_irqsave(&inject_lock, flags);
 275        if (ops == &pci_ops_aer)
 276                goto out;
 277        pci_bus_ops_init(bus_ops, bus, ops);
 278        list_add(&bus_ops->list, &pci_bus_ops_list);
 279        bus_ops = NULL;
 280out:
 281        spin_unlock_irqrestore(&inject_lock, flags);
 282        kfree(bus_ops);
 283        return 0;
 284}
 285
 286static struct pci_dev *pcie_find_root_port(struct pci_dev *dev)
 287{
 288        while (1) {
 289                if (!pci_is_pcie(dev))
 290                        break;
 291                if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT)
 292                        return dev;
 293                if (!dev->bus->self)
 294                        break;
 295                dev = dev->bus->self;
 296        }
 297        return NULL;
 298}
 299
 300static int find_aer_device_iter(struct device *device, void *data)
 301{
 302        struct pcie_device **result = data;
 303        struct pcie_device *pcie_dev;
 304
 305        if (device->bus == &pcie_port_bus_type) {
 306                pcie_dev = to_pcie_device(device);
 307                if (pcie_dev->service & PCIE_PORT_SERVICE_AER) {
 308                        *result = pcie_dev;
 309                        return 1;
 310                }
 311        }
 312        return 0;
 313}
 314
 315static int find_aer_device(struct pci_dev *dev, struct pcie_device **result)
 316{
 317        return device_for_each_child(&dev->dev, result, find_aer_device_iter);
 318}
 319
 320static int aer_inject(struct aer_error_inj *einj)
 321{
 322        struct aer_error *err, *rperr;
 323        struct aer_error *err_alloc = NULL, *rperr_alloc = NULL;
 324        struct pci_dev *dev, *rpdev;
 325        struct pcie_device *edev;
 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((int)einj->domain, einj->bus, devfn);
 333        if (!dev)
 334                return -ENODEV;
 335        rpdev = pcie_find_root_port(dev);
 336        if (!rpdev) {
 337                ret = -ENODEV;
 338                goto out_put;
 339        }
 340
 341        pos_cap_err = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
 342        if (!pos_cap_err) {
 343                ret = -EPERM;
 344                goto out_put;
 345        }
 346        pci_read_config_dword(dev, pos_cap_err + PCI_ERR_UNCOR_SEVER, &sever);
 347        pci_read_config_dword(dev, pos_cap_err + PCI_ERR_COR_MASK, &cor_mask);
 348        pci_read_config_dword(dev, pos_cap_err + PCI_ERR_UNCOR_MASK,
 349                              &uncor_mask);
 350
 351        rp_pos_cap_err = pci_find_ext_capability(rpdev, PCI_EXT_CAP_ID_ERR);
 352        if (!rp_pos_cap_err) {
 353                ret = -EPERM;
 354                goto out_put;
 355        }
 356
 357        err_alloc =  kzalloc(sizeof(struct aer_error), GFP_KERNEL);
 358        if (!err_alloc) {
 359                ret = -ENOMEM;
 360                goto out_put;
 361        }
 362        rperr_alloc =  kzalloc(sizeof(struct aer_error), GFP_KERNEL);
 363        if (!rperr_alloc) {
 364                ret = -ENOMEM;
 365                goto out_put;
 366        }
 367
 368        if (aer_mask_override) {
 369                cor_mask_orig = cor_mask;
 370                cor_mask &= !(einj->cor_status);
 371                pci_write_config_dword(dev, pos_cap_err + PCI_ERR_COR_MASK,
 372                                       cor_mask);
 373
 374                uncor_mask_orig = uncor_mask;
 375                uncor_mask &= !(einj->uncor_status);
 376                pci_write_config_dword(dev, pos_cap_err + PCI_ERR_UNCOR_MASK,
 377                                       uncor_mask);
 378        }
 379
 380        spin_lock_irqsave(&inject_lock, flags);
 381
 382        err = __find_aer_error_by_dev(dev);
 383        if (!err) {
 384                err = err_alloc;
 385                err_alloc = NULL;
 386                aer_error_init(err, einj->domain, einj->bus, devfn,
 387                               pos_cap_err);
 388                list_add(&err->list, &einjected);
 389        }
 390        err->uncor_status |= einj->uncor_status;
 391        err->cor_status |= einj->cor_status;
 392        err->header_log0 = einj->header_log0;
 393        err->header_log1 = einj->header_log1;
 394        err->header_log2 = einj->header_log2;
 395        err->header_log3 = einj->header_log3;
 396
 397        if (!aer_mask_override && einj->cor_status &&
 398            !(einj->cor_status & ~cor_mask)) {
 399                ret = -EINVAL;
 400                printk(KERN_WARNING "The correctable error(s) is masked "
 401                                "by device\n");
 402                spin_unlock_irqrestore(&inject_lock, flags);
 403                goto out_put;
 404        }
 405        if (!aer_mask_override && einj->uncor_status &&
 406            !(einj->uncor_status & ~uncor_mask)) {
 407                ret = -EINVAL;
 408                printk(KERN_WARNING "The uncorrectable error(s) is masked "
 409                                "by device\n");
 410                spin_unlock_irqrestore(&inject_lock, flags);
 411                goto out_put;
 412        }
 413
 414        rperr = __find_aer_error_by_dev(rpdev);
 415        if (!rperr) {
 416                rperr = rperr_alloc;
 417                rperr_alloc = NULL;
 418                aer_error_init(rperr, pci_domain_nr(rpdev->bus),
 419                               rpdev->bus->number, rpdev->devfn,
 420                               rp_pos_cap_err);
 421                list_add(&rperr->list, &einjected);
 422        }
 423        if (einj->cor_status) {
 424                if (rperr->root_status & PCI_ERR_ROOT_COR_RCV)
 425                        rperr->root_status |= PCI_ERR_ROOT_MULTI_COR_RCV;
 426                else
 427                        rperr->root_status |= PCI_ERR_ROOT_COR_RCV;
 428                rperr->source_id &= 0xffff0000;
 429                rperr->source_id |= (einj->bus << 8) | devfn;
 430        }
 431        if (einj->uncor_status) {
 432                if (rperr->root_status & PCI_ERR_ROOT_UNCOR_RCV)
 433                        rperr->root_status |= PCI_ERR_ROOT_MULTI_UNCOR_RCV;
 434                if (sever & einj->uncor_status) {
 435                        rperr->root_status |= PCI_ERR_ROOT_FATAL_RCV;
 436                        if (!(rperr->root_status & PCI_ERR_ROOT_UNCOR_RCV))
 437                                rperr->root_status |= PCI_ERR_ROOT_FIRST_FATAL;
 438                } else
 439                        rperr->root_status |= PCI_ERR_ROOT_NONFATAL_RCV;
 440                rperr->root_status |= PCI_ERR_ROOT_UNCOR_RCV;
 441                rperr->source_id &= 0x0000ffff;
 442                rperr->source_id |= ((einj->bus << 8) | devfn) << 16;
 443        }
 444        spin_unlock_irqrestore(&inject_lock, flags);
 445
 446        if (aer_mask_override) {
 447                pci_write_config_dword(dev, pos_cap_err + PCI_ERR_COR_MASK,
 448                                       cor_mask_orig);
 449                pci_write_config_dword(dev, pos_cap_err + PCI_ERR_UNCOR_MASK,
 450                                       uncor_mask_orig);
 451        }
 452
 453        ret = pci_bus_set_aer_ops(dev->bus);
 454        if (ret)
 455                goto out_put;
 456        ret = pci_bus_set_aer_ops(rpdev->bus);
 457        if (ret)
 458                goto out_put;
 459
 460        if (find_aer_device(rpdev, &edev)) {
 461                if (!get_service_data(edev)) {
 462                        printk(KERN_WARNING "AER service is not initialized\n");
 463                        ret = -EINVAL;
 464                        goto out_put;
 465                }
 466                aer_irq(-1, edev);
 467        }
 468        else
 469                ret = -EINVAL;
 470out_put:
 471        kfree(err_alloc);
 472        kfree(rperr_alloc);
 473        pci_dev_put(dev);
 474        return ret;
 475}
 476
 477static ssize_t aer_inject_write(struct file *filp, const char __user *ubuf,
 478                                size_t usize, loff_t *off)
 479{
 480        struct aer_error_inj einj;
 481        int ret;
 482
 483        if (!capable(CAP_SYS_ADMIN))
 484                return -EPERM;
 485        if (usize < offsetof(struct aer_error_inj, domain) ||
 486            usize > sizeof(einj))
 487                return -EINVAL;
 488
 489        memset(&einj, 0, sizeof(einj));
 490        if (copy_from_user(&einj, ubuf, usize))
 491                return -EFAULT;
 492
 493        ret = aer_inject(&einj);
 494        return ret ? ret : usize;
 495}
 496
 497static const struct file_operations aer_inject_fops = {
 498        .write = aer_inject_write,
 499        .owner = THIS_MODULE,
 500        .llseek = noop_llseek,
 501};
 502
 503static struct miscdevice aer_inject_device = {
 504        .minor = MISC_DYNAMIC_MINOR,
 505        .name = "aer_inject",
 506        .fops = &aer_inject_fops,
 507};
 508
 509static int __init aer_inject_init(void)
 510{
 511        return misc_register(&aer_inject_device);
 512}
 513
 514static void __exit aer_inject_exit(void)
 515{
 516        struct aer_error *err, *err_next;
 517        unsigned long flags;
 518        struct pci_bus_ops *bus_ops;
 519
 520        misc_deregister(&aer_inject_device);
 521
 522        while ((bus_ops = pci_bus_ops_pop())) {
 523                pci_bus_set_ops(bus_ops->bus, bus_ops->ops);
 524                kfree(bus_ops);
 525        }
 526
 527        spin_lock_irqsave(&inject_lock, flags);
 528        list_for_each_entry_safe(err, err_next, &einjected, list) {
 529                list_del(&err->list);
 530                kfree(err);
 531        }
 532        spin_unlock_irqrestore(&inject_lock, flags);
 533}
 534
 535module_init(aer_inject_init);
 536module_exit(aer_inject_exit);
 537
 538MODULE_DESCRIPTION("PCIe AER software error injector");
 539MODULE_LICENSE("GPL");
 540