1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright IBM Corporation 2001, 2005, 2006 4 * Copyright Dave Engebretsen & Todd Inglett 2001 5 * Copyright Linas Vepstas 2005, 2006 6 * Copyright 2001-2012 IBM Corporation. 7 * 8 * Please address comments and feedback to Linas Vepstas <linas@austin.ibm.com> 9 */ 10 11 #include <linux/delay.h> 12 #include <linux/sched.h> 13 #include <linux/init.h> 14 #include <linux/list.h> 15 #include <linux/pci.h> 16 #include <linux/iommu.h> 17 #include <linux/proc_fs.h> 18 #include <linux/rbtree.h> 19 #include <linux/reboot.h> 20 #include <linux/seq_file.h> 21 #include <linux/spinlock.h> 22 #include <linux/export.h> 23 #include <linux/of.h> 24 25 #include <linux/atomic.h> 26 #include <asm/debugfs.h> 27 #include <asm/eeh.h> 28 #include <asm/eeh_event.h> 29 #include <asm/io.h> 30 #include <asm/iommu.h> 31 #include <asm/machdep.h> 32 #include <asm/ppc-pci.h> 33 #include <asm/rtas.h> 34 #include <asm/pte-walk.h> 35 36 37 /** Overview: 38 * EEH, or "Enhanced Error Handling" is a PCI bridge technology for 39 * dealing with PCI bus errors that can't be dealt with within the 40 * usual PCI framework, except by check-stopping the CPU. Systems 41 * that are designed for high-availability/reliability cannot afford 42 * to crash due to a "mere" PCI error, thus the need for EEH. 43 * An EEH-capable bridge operates by converting a detected error 44 * into a "slot freeze", taking the PCI adapter off-line, making 45 * the slot behave, from the OS'es point of view, as if the slot 46 * were "empty": all reads return 0xff's and all writes are silently 47 * ignored. EEH slot isolation events can be triggered by parity 48 * errors on the address or data busses (e.g. during posted writes), 49 * which in turn might be caused by low voltage on the bus, dust, 50 * vibration, humidity, radioactivity or plain-old failed hardware. 51 * 52 * Note, however, that one of the leading causes of EEH slot 53 * freeze events are buggy device drivers, buggy device microcode, 54 * or buggy device hardware. This is because any attempt by the 55 * device to bus-master data to a memory address that is not 56 * assigned to the device will trigger a slot freeze. (The idea 57 * is to prevent devices-gone-wild from corrupting system memory). 58 * Buggy hardware/drivers will have a miserable time co-existing 59 * with EEH. 60 * 61 * Ideally, a PCI device driver, when suspecting that an isolation 62 * event has occurred (e.g. by reading 0xff's), will then ask EEH 63 * whether this is the case, and then take appropriate steps to 64 * reset the PCI slot, the PCI device, and then resume operations. 65 * However, until that day, the checking is done here, with the 66 * eeh_check_failure() routine embedded in the MMIO macros. If 67 * the slot is found to be isolated, an "EEH Event" is synthesized 68 * and sent out for processing. 69 */ 70 71 /* If a device driver keeps reading an MMIO register in an interrupt 72 * handler after a slot isolation event, it might be broken. 73 * This sets the threshold for how many read attempts we allow 74 * before printing an error message. 75 */ 76 #define EEH_MAX_FAILS 2100000 77 78 /* Time to wait for a PCI slot to report status, in milliseconds */ 79 #define PCI_BUS_RESET_WAIT_MSEC (5*60*1000) 80 81 /* 82 * EEH probe mode support, which is part of the flags, 83 * is to support multiple platforms for EEH. Some platforms 84 * like pSeries do PCI emunation based on device tree. 85 * However, other platforms like powernv probe PCI devices 86 * from hardware. The flag is used to distinguish that. 87 * In addition, struct eeh_ops::probe would be invoked for 88 * particular OF node or PCI device so that the corresponding 89 * PE would be created there. 90 */ 91 int eeh_subsystem_flags; 92 EXPORT_SYMBOL(eeh_subsystem_flags); 93 94 /* 95 * EEH allowed maximal frozen times. If one particular PE's 96 * frozen count in last hour exceeds this limit, the PE will 97 * be forced to be offline permanently. 98 */ 99 u32 eeh_max_freezes = 5; 100 101 /* 102 * Controls whether a recovery event should be scheduled when an 103 * isolated device is discovered. This is only really useful for 104 * debugging problems with the EEH core. 105 */ 106 bool eeh_debugfs_no_recover; 107 108 /* Platform dependent EEH operations */ 109 struct eeh_ops *eeh_ops = NULL; 110 111 /* Lock to avoid races due to multiple reports of an error */ 112 DEFINE_RAW_SPINLOCK(confirm_error_lock); 113 EXPORT_SYMBOL_GPL(confirm_error_lock); 114 115 /* Lock to protect passed flags */ 116 static DEFINE_MUTEX(eeh_dev_mutex); 117 118 /* Buffer for reporting pci register dumps. Its here in BSS, and 119 * not dynamically alloced, so that it ends up in RMO where RTAS 120 * can access it. 121 */ 122 #define EEH_PCI_REGS_LOG_LEN 8192 123 static unsigned char pci_regs_buf[EEH_PCI_REGS_LOG_LEN]; 124 125 /* 126 * The struct is used to maintain the EEH global statistic 127 * information. Besides, the EEH global statistics will be 128 * exported to user space through procfs 129 */ 130 struct eeh_stats { 131 u64 no_device; /* PCI device not found */ 132 u64 no_dn; /* OF node not found */ 133 u64 no_cfg_addr; /* Config address not found */ 134 u64 ignored_check; /* EEH check skipped */ 135 u64 total_mmio_ffs; /* Total EEH checks */ 136 u64 false_positives; /* Unnecessary EEH checks */ 137 u64 slot_resets; /* PE reset */ 138 }; 139 140 static struct eeh_stats eeh_stats; 141 142 static int __init eeh_setup(char *str) 143 { 144 if (!strcmp(str, "off")) 145 eeh_add_flag(EEH_FORCE_DISABLED); 146 else if (!strcmp(str, "early_log")) 147 eeh_add_flag(EEH_EARLY_DUMP_LOG); 148 149 return 1; 150 } 151 __setup("eeh=", eeh_setup); 152 153 void eeh_show_enabled(void) 154 { 155 if (eeh_has_flag(EEH_FORCE_DISABLED)) 156 pr_info("EEH: Recovery disabled by kernel parameter.\n"); 157 else if (eeh_has_flag(EEH_ENABLED)) 158 pr_info("EEH: Capable adapter found: recovery enabled.\n"); 159 else 160 pr_info("EEH: No capable adapters found: recovery disabled.\n"); 161 } 162 163 /* 164 * This routine captures assorted PCI configuration space data 165 * for the indicated PCI device, and puts them into a buffer 166 * for RTAS error logging. 167 */ 168 static size_t eeh_dump_dev_log(struct eeh_dev *edev, char *buf, size_t len) 169 { 170 struct pci_dn *pdn = eeh_dev_to_pdn(edev); 171 u32 cfg; 172 int cap, i; 173 int n = 0, l = 0; 174 char buffer[128]; 175 176 if (!pdn) { 177 pr_warn("EEH: Note: No error log for absent device.\n"); 178 return 0; 179 } 180 181 n += scnprintf(buf+n, len-n, "%04x:%02x:%02x.%01x\n", 182 pdn->phb->global_number, pdn->busno, 183 PCI_SLOT(pdn->devfn), PCI_FUNC(pdn->devfn)); 184 pr_warn("EEH: of node=%04x:%02x:%02x.%01x\n", 185 pdn->phb->global_number, pdn->busno, 186 PCI_SLOT(pdn->devfn), PCI_FUNC(pdn->devfn)); 187 188 eeh_ops->read_config(pdn, PCI_VENDOR_ID, 4, &cfg); 189 n += scnprintf(buf+n, len-n, "dev/vend:%08x\n", cfg); 190 pr_warn("EEH: PCI device/vendor: %08x\n", cfg); 191 192 eeh_ops->read_config(pdn, PCI_COMMAND, 4, &cfg); 193 n += scnprintf(buf+n, len-n, "cmd/stat:%x\n", cfg); 194 pr_warn("EEH: PCI cmd/status register: %08x\n", cfg); 195 196 /* Gather bridge-specific registers */ 197 if (edev->mode & EEH_DEV_BRIDGE) { 198 eeh_ops->read_config(pdn, PCI_SEC_STATUS, 2, &cfg); 199 n += scnprintf(buf+n, len-n, "sec stat:%x\n", cfg); 200 pr_warn("EEH: Bridge secondary status: %04x\n", cfg); 201 202 eeh_ops->read_config(pdn, PCI_BRIDGE_CONTROL, 2, &cfg); 203 n += scnprintf(buf+n, len-n, "brdg ctl:%x\n", cfg); 204 pr_warn("EEH: Bridge control: %04x\n", cfg); 205 } 206 207 /* Dump out the PCI-X command and status regs */ 208 cap = edev->pcix_cap; 209 if (cap) { 210 eeh_ops->read_config(pdn, cap, 4, &cfg); 211 n += scnprintf(buf+n, len-n, "pcix-cmd:%x\n", cfg); 212 pr_warn("EEH: PCI-X cmd: %08x\n", cfg); 213 214 eeh_ops->read_config(pdn, cap+4, 4, &cfg); 215 n += scnprintf(buf+n, len-n, "pcix-stat:%x\n", cfg); 216 pr_warn("EEH: PCI-X status: %08x\n", cfg); 217 } 218 219 /* If PCI-E capable, dump PCI-E cap 10 */ 220 cap = edev->pcie_cap; 221 if (cap) { 222 n += scnprintf(buf+n, len-n, "pci-e cap10:\n"); 223 pr_warn("EEH: PCI-E capabilities and status follow:\n"); 224 225 for (i=0; i<=8; i++) { 226 eeh_ops->read_config(pdn, cap+4*i, 4, &cfg); 227 n += scnprintf(buf+n, len-n, "%02x:%x\n", 4*i, cfg); 228 229 if ((i % 4) == 0) { 230 if (i != 0) 231 pr_warn("%s\n", buffer); 232 233 l = scnprintf(buffer, sizeof(buffer), 234 "EEH: PCI-E %02x: %08x ", 235 4*i, cfg); 236 } else { 237 l += scnprintf(buffer+l, sizeof(buffer)-l, 238 "%08x ", cfg); 239 } 240 241 } 242 243 pr_warn("%s\n", buffer); 244 } 245 246 /* If AER capable, dump it */ 247 cap = edev->aer_cap; 248 if (cap) { 249 n += scnprintf(buf+n, len-n, "pci-e AER:\n"); 250 pr_warn("EEH: PCI-E AER capability register set follows:\n"); 251 252 for (i=0; i<=13; i++) { 253 eeh_ops->read_config(pdn, cap+4*i, 4, &cfg); 254 n += scnprintf(buf+n, len-n, "%02x:%x\n", 4*i, cfg); 255 256 if ((i % 4) == 0) { 257 if (i != 0) 258 pr_warn("%s\n", buffer); 259 260 l = scnprintf(buffer, sizeof(buffer), 261 "EEH: PCI-E AER %02x: %08x ", 262 4*i, cfg); 263 } else { 264 l += scnprintf(buffer+l, sizeof(buffer)-l, 265 "%08x ", cfg); 266 } 267 } 268 269 pr_warn("%s\n", buffer); 270 } 271 272 return n; 273 } 274 275 static void *eeh_dump_pe_log(struct eeh_pe *pe, void *flag) 276 { 277 struct eeh_dev *edev, *tmp; 278 size_t *plen = flag; 279 280 eeh_pe_for_each_dev(pe, edev, tmp) 281 *plen += eeh_dump_dev_log(edev, pci_regs_buf + *plen, 282 EEH_PCI_REGS_LOG_LEN - *plen); 283 284 return NULL; 285 } 286 287 /** 288 * eeh_slot_error_detail - Generate combined log including driver log and error log 289 * @pe: EEH PE 290 * @severity: temporary or permanent error log 291 * 292 * This routine should be called to generate the combined log, which 293 * is comprised of driver log and error log. The driver log is figured 294 * out from the config space of the corresponding PCI device, while 295 * the error log is fetched through platform dependent function call. 296 */ 297 void eeh_slot_error_detail(struct eeh_pe *pe, int severity) 298 { 299 size_t loglen = 0; 300 301 /* 302 * When the PHB is fenced or dead, it's pointless to collect 303 * the data from PCI config space because it should return 304 * 0xFF's. For ER, we still retrieve the data from the PCI 305 * config space. 306 * 307 * For pHyp, we have to enable IO for log retrieval. Otherwise, 308 * 0xFF's is always returned from PCI config space. 309 * 310 * When the @severity is EEH_LOG_PERM, the PE is going to be 311 * removed. Prior to that, the drivers for devices included in 312 * the PE will be closed. The drivers rely on working IO path 313 * to bring the devices to quiet state. Otherwise, PCI traffic 314 * from those devices after they are removed is like to cause 315 * another unexpected EEH error. 316 */ 317 if (!(pe->type & EEH_PE_PHB)) { 318 if (eeh_has_flag(EEH_ENABLE_IO_FOR_LOG) || 319 severity == EEH_LOG_PERM) 320 eeh_pci_enable(pe, EEH_OPT_THAW_MMIO); 321 322 /* 323 * The config space of some PCI devices can't be accessed 324 * when their PEs are in frozen state. Otherwise, fenced 325 * PHB might be seen. Those PEs are identified with flag 326 * EEH_PE_CFG_RESTRICTED, indicating EEH_PE_CFG_BLOCKED 327 * is set automatically when the PE is put to EEH_PE_ISOLATED. 328 * 329 * Restoring BARs possibly triggers PCI config access in 330 * (OPAL) firmware and then causes fenced PHB. If the 331 * PCI config is blocked with flag EEH_PE_CFG_BLOCKED, it's 332 * pointless to restore BARs and dump config space. 333 */ 334 eeh_ops->configure_bridge(pe); 335 if (!(pe->state & EEH_PE_CFG_BLOCKED)) { 336 eeh_pe_restore_bars(pe); 337 338 pci_regs_buf[0] = 0; 339 eeh_pe_traverse(pe, eeh_dump_pe_log, &loglen); 340 } 341 } 342 343 eeh_ops->get_log(pe, severity, pci_regs_buf, loglen); 344 } 345 346 /** 347 * eeh_token_to_phys - Convert EEH address token to phys address 348 * @token: I/O token, should be address in the form 0xA.... 349 * 350 * This routine should be called to convert virtual I/O address 351 * to physical one. 352 */ 353 static inline unsigned long eeh_token_to_phys(unsigned long token) 354 { 355 pte_t *ptep; 356 unsigned long pa; 357 int hugepage_shift; 358 359 /* 360 * We won't find hugepages here(this is iomem). Hence we are not 361 * worried about _PAGE_SPLITTING/collapse. Also we will not hit 362 * page table free, because of init_mm. 363 */ 364 ptep = find_init_mm_pte(token, &hugepage_shift); 365 if (!ptep) 366 return token; 367 368 pa = pte_pfn(*ptep); 369 370 /* On radix we can do hugepage mappings for io, so handle that */ 371 if (hugepage_shift) { 372 pa <<= hugepage_shift; 373 pa |= token & ((1ul << hugepage_shift) - 1); 374 } else { 375 pa <<= PAGE_SHIFT; 376 pa |= token & (PAGE_SIZE - 1); 377 } 378 379 return pa; 380 } 381 382 /* 383 * On PowerNV platform, we might already have fenced PHB there. 384 * For that case, it's meaningless to recover frozen PE. Intead, 385 * We have to handle fenced PHB firstly. 386 */ 387 static int eeh_phb_check_failure(struct eeh_pe *pe) 388 { 389 struct eeh_pe *phb_pe; 390 unsigned long flags; 391 int ret; 392 393 if (!eeh_has_flag(EEH_PROBE_MODE_DEV)) 394 return -EPERM; 395 396 /* Find the PHB PE */ 397 phb_pe = eeh_phb_pe_get(pe->phb); 398 if (!phb_pe) { 399 pr_warn("%s Can't find PE for PHB#%x\n", 400 __func__, pe->phb->global_number); 401 return -EEXIST; 402 } 403 404 /* If the PHB has been in problematic state */ 405 eeh_serialize_lock(&flags); 406 if (phb_pe->state & EEH_PE_ISOLATED) { 407 ret = 0; 408 goto out; 409 } 410 411 /* Check PHB state */ 412 ret = eeh_ops->get_state(phb_pe, NULL); 413 if ((ret < 0) || 414 (ret == EEH_STATE_NOT_SUPPORT) || eeh_state_active(ret)) { 415 ret = 0; 416 goto out; 417 } 418 419 /* Isolate the PHB and send event */ 420 eeh_pe_mark_isolated(phb_pe); 421 eeh_serialize_unlock(flags); 422 423 pr_debug("EEH: PHB#%x failure detected, location: %s\n", 424 phb_pe->phb->global_number, eeh_pe_loc_get(phb_pe)); 425 eeh_send_failure_event(phb_pe); 426 return 1; 427 out: 428 eeh_serialize_unlock(flags); 429 return ret; 430 } 431 432 /** 433 * eeh_dev_check_failure - Check if all 1's data is due to EEH slot freeze 434 * @edev: eeh device 435 * 436 * Check for an EEH failure for the given device node. Call this 437 * routine if the result of a read was all 0xff's and you want to 438 * find out if this is due to an EEH slot freeze. This routine 439 * will query firmware for the EEH status. 440 * 441 * Returns 0 if there has not been an EEH error; otherwise returns 442 * a non-zero value and queues up a slot isolation event notification. 443 * 444 * It is safe to call this routine in an interrupt context. 445 */ 446 int eeh_dev_check_failure(struct eeh_dev *edev) 447 { 448 int ret; 449 unsigned long flags; 450 struct device_node *dn; 451 struct pci_dev *dev; 452 struct eeh_pe *pe, *parent_pe; 453 int rc = 0; 454 const char *location = NULL; 455 456 eeh_stats.total_mmio_ffs++; 457 458 if (!eeh_enabled()) 459 return 0; 460 461 if (!edev) { 462 eeh_stats.no_dn++; 463 return 0; 464 } 465 dev = eeh_dev_to_pci_dev(edev); 466 pe = eeh_dev_to_pe(edev); 467 468 /* Access to IO BARs might get this far and still not want checking. */ 469 if (!pe) { 470 eeh_stats.ignored_check++; 471 eeh_edev_dbg(edev, "Ignored check\n"); 472 return 0; 473 } 474 475 if (!pe->addr && !pe->config_addr) { 476 eeh_stats.no_cfg_addr++; 477 return 0; 478 } 479 480 /* 481 * On PowerNV platform, we might already have fenced PHB 482 * there and we need take care of that firstly. 483 */ 484 ret = eeh_phb_check_failure(pe); 485 if (ret > 0) 486 return ret; 487 488 /* 489 * If the PE isn't owned by us, we shouldn't check the 490 * state. Instead, let the owner handle it if the PE has 491 * been frozen. 492 */ 493 if (eeh_pe_passed(pe)) 494 return 0; 495 496 /* If we already have a pending isolation event for this 497 * slot, we know it's bad already, we don't need to check. 498 * Do this checking under a lock; as multiple PCI devices 499 * in one slot might report errors simultaneously, and we 500 * only want one error recovery routine running. 501 */ 502 eeh_serialize_lock(&flags); 503 rc = 1; 504 if (pe->state & EEH_PE_ISOLATED) { 505 pe->check_count++; 506 if (pe->check_count == EEH_MAX_FAILS) { 507 dn = pci_device_to_OF_node(dev); 508 if (dn) 509 location = of_get_property(dn, "ibm,loc-code", 510 NULL); 511 eeh_edev_err(edev, "%d reads ignored for recovering device at location=%s driver=%s\n", 512 pe->check_count, 513 location ? location : "unknown", 514 eeh_driver_name(dev)); 515 eeh_edev_err(edev, "Might be infinite loop in %s driver\n", 516 eeh_driver_name(dev)); 517 dump_stack(); 518 } 519 goto dn_unlock; 520 } 521 522 /* 523 * Now test for an EEH failure. This is VERY expensive. 524 * Note that the eeh_config_addr may be a parent device 525 * in the case of a device behind a bridge, or it may be 526 * function zero of a multi-function device. 527 * In any case they must share a common PHB. 528 */ 529 ret = eeh_ops->get_state(pe, NULL); 530 531 /* Note that config-io to empty slots may fail; 532 * they are empty when they don't have children. 533 * We will punt with the following conditions: Failure to get 534 * PE's state, EEH not support and Permanently unavailable 535 * state, PE is in good state. 536 */ 537 if ((ret < 0) || 538 (ret == EEH_STATE_NOT_SUPPORT) || eeh_state_active(ret)) { 539 eeh_stats.false_positives++; 540 pe->false_positives++; 541 rc = 0; 542 goto dn_unlock; 543 } 544 545 /* 546 * It should be corner case that the parent PE has been 547 * put into frozen state as well. We should take care 548 * that at first. 549 */ 550 parent_pe = pe->parent; 551 while (parent_pe) { 552 /* Hit the ceiling ? */ 553 if (parent_pe->type & EEH_PE_PHB) 554 break; 555 556 /* Frozen parent PE ? */ 557 ret = eeh_ops->get_state(parent_pe, NULL); 558 if (ret > 0 && !eeh_state_active(ret)) { 559 pe = parent_pe; 560 pr_err("EEH: Failure of PHB#%x-PE#%x will be handled at parent PHB#%x-PE#%x.\n", 561 pe->phb->global_number, pe->addr, 562 pe->phb->global_number, parent_pe->addr); 563 } 564 565 /* Next parent level */ 566 parent_pe = parent_pe->parent; 567 } 568 569 eeh_stats.slot_resets++; 570 571 /* Avoid repeated reports of this failure, including problems 572 * with other functions on this device, and functions under 573 * bridges. 574 */ 575 eeh_pe_mark_isolated(pe); 576 eeh_serialize_unlock(flags); 577 578 /* Most EEH events are due to device driver bugs. Having 579 * a stack trace will help the device-driver authors figure 580 * out what happened. So print that out. 581 */ 582 pr_debug("EEH: %s: Frozen PHB#%x-PE#%x detected\n", 583 __func__, pe->phb->global_number, pe->addr); 584 eeh_send_failure_event(pe); 585 586 return 1; 587 588 dn_unlock: 589 eeh_serialize_unlock(flags); 590 return rc; 591 } 592 593 EXPORT_SYMBOL_GPL(eeh_dev_check_failure); 594 595 /** 596 * eeh_check_failure - Check if all 1's data is due to EEH slot freeze 597 * @token: I/O address 598 * 599 * Check for an EEH failure at the given I/O address. Call this 600 * routine if the result of a read was all 0xff's and you want to 601 * find out if this is due to an EEH slot freeze event. This routine 602 * will query firmware for the EEH status. 603 * 604 * Note this routine is safe to call in an interrupt context. 605 */ 606 int eeh_check_failure(const volatile void __iomem *token) 607 { 608 unsigned long addr; 609 struct eeh_dev *edev; 610 611 /* Finding the phys addr + pci device; this is pretty quick. */ 612 addr = eeh_token_to_phys((unsigned long __force) token); 613 edev = eeh_addr_cache_get_dev(addr); 614 if (!edev) { 615 eeh_stats.no_device++; 616 return 0; 617 } 618 619 return eeh_dev_check_failure(edev); 620 } 621 EXPORT_SYMBOL(eeh_check_failure); 622 623 624 /** 625 * eeh_pci_enable - Enable MMIO or DMA transfers for this slot 626 * @pe: EEH PE 627 * 628 * This routine should be called to reenable frozen MMIO or DMA 629 * so that it would work correctly again. It's useful while doing 630 * recovery or log collection on the indicated device. 631 */ 632 int eeh_pci_enable(struct eeh_pe *pe, int function) 633 { 634 int active_flag, rc; 635 636 /* 637 * pHyp doesn't allow to enable IO or DMA on unfrozen PE. 638 * Also, it's pointless to enable them on unfrozen PE. So 639 * we have to check before enabling IO or DMA. 640 */ 641 switch (function) { 642 case EEH_OPT_THAW_MMIO: 643 active_flag = EEH_STATE_MMIO_ACTIVE | EEH_STATE_MMIO_ENABLED; 644 break; 645 case EEH_OPT_THAW_DMA: 646 active_flag = EEH_STATE_DMA_ACTIVE; 647 break; 648 case EEH_OPT_DISABLE: 649 case EEH_OPT_ENABLE: 650 case EEH_OPT_FREEZE_PE: 651 active_flag = 0; 652 break; 653 default: 654 pr_warn("%s: Invalid function %d\n", 655 __func__, function); 656 return -EINVAL; 657 } 658 659 /* 660 * Check if IO or DMA has been enabled before 661 * enabling them. 662 */ 663 if (active_flag) { 664 rc = eeh_ops->get_state(pe, NULL); 665 if (rc < 0) 666 return rc; 667 668 /* Needn't enable it at all */ 669 if (rc == EEH_STATE_NOT_SUPPORT) 670 return 0; 671 672 /* It's already enabled */ 673 if (rc & active_flag) 674 return 0; 675 } 676 677 678 /* Issue the request */ 679 rc = eeh_ops->set_option(pe, function); 680 if (rc) 681 pr_warn("%s: Unexpected state change %d on " 682 "PHB#%x-PE#%x, err=%d\n", 683 __func__, function, pe->phb->global_number, 684 pe->addr, rc); 685 686 /* Check if the request is finished successfully */ 687 if (active_flag) { 688 rc = eeh_wait_state(pe, PCI_BUS_RESET_WAIT_MSEC); 689 if (rc < 0) 690 return rc; 691 692 if (rc & active_flag) 693 return 0; 694 695 return -EIO; 696 } 697 698 return rc; 699 } 700 701 static void eeh_disable_and_save_dev_state(struct eeh_dev *edev, 702 void *userdata) 703 { 704 struct pci_dev *pdev = eeh_dev_to_pci_dev(edev); 705 struct pci_dev *dev = userdata; 706 707 /* 708 * The caller should have disabled and saved the 709 * state for the specified device 710 */ 711 if (!pdev || pdev == dev) 712 return; 713 714 /* Ensure we have D0 power state */ 715 pci_set_power_state(pdev, PCI_D0); 716 717 /* Save device state */ 718 pci_save_state(pdev); 719 720 /* 721 * Disable device to avoid any DMA traffic and 722 * interrupt from the device 723 */ 724 pci_write_config_word(pdev, PCI_COMMAND, PCI_COMMAND_INTX_DISABLE); 725 } 726 727 static void eeh_restore_dev_state(struct eeh_dev *edev, void *userdata) 728 { 729 struct pci_dn *pdn = eeh_dev_to_pdn(edev); 730 struct pci_dev *pdev = eeh_dev_to_pci_dev(edev); 731 struct pci_dev *dev = userdata; 732 733 if (!pdev) 734 return; 735 736 /* Apply customization from firmware */ 737 if (pdn && eeh_ops->restore_config) 738 eeh_ops->restore_config(pdn); 739 740 /* The caller should restore state for the specified device */ 741 if (pdev != dev) 742 pci_restore_state(pdev); 743 } 744 745 int eeh_restore_vf_config(struct pci_dn *pdn) 746 { 747 struct eeh_dev *edev = pdn_to_eeh_dev(pdn); 748 u32 devctl, cmd, cap2, aer_capctl; 749 int old_mps; 750 751 if (edev->pcie_cap) { 752 /* Restore MPS */ 753 old_mps = (ffs(pdn->mps) - 8) << 5; 754 eeh_ops->read_config(pdn, edev->pcie_cap + PCI_EXP_DEVCTL, 755 2, &devctl); 756 devctl &= ~PCI_EXP_DEVCTL_PAYLOAD; 757 devctl |= old_mps; 758 eeh_ops->write_config(pdn, edev->pcie_cap + PCI_EXP_DEVCTL, 759 2, devctl); 760 761 /* Disable Completion Timeout if possible */ 762 eeh_ops->read_config(pdn, edev->pcie_cap + PCI_EXP_DEVCAP2, 763 4, &cap2); 764 if (cap2 & PCI_EXP_DEVCAP2_COMP_TMOUT_DIS) { 765 eeh_ops->read_config(pdn, 766 edev->pcie_cap + PCI_EXP_DEVCTL2, 767 4, &cap2); 768 cap2 |= PCI_EXP_DEVCTL2_COMP_TMOUT_DIS; 769 eeh_ops->write_config(pdn, 770 edev->pcie_cap + PCI_EXP_DEVCTL2, 771 4, cap2); 772 } 773 } 774 775 /* Enable SERR and parity checking */ 776 eeh_ops->read_config(pdn, PCI_COMMAND, 2, &cmd); 777 cmd |= (PCI_COMMAND_PARITY | PCI_COMMAND_SERR); 778 eeh_ops->write_config(pdn, PCI_COMMAND, 2, cmd); 779 780 /* Enable report various errors */ 781 if (edev->pcie_cap) { 782 eeh_ops->read_config(pdn, edev->pcie_cap + PCI_EXP_DEVCTL, 783 2, &devctl); 784 devctl &= ~PCI_EXP_DEVCTL_CERE; 785 devctl |= (PCI_EXP_DEVCTL_NFERE | 786 PCI_EXP_DEVCTL_FERE | 787 PCI_EXP_DEVCTL_URRE); 788 eeh_ops->write_config(pdn, edev->pcie_cap + PCI_EXP_DEVCTL, 789 2, devctl); 790 } 791 792 /* Enable ECRC generation and check */ 793 if (edev->pcie_cap && edev->aer_cap) { 794 eeh_ops->read_config(pdn, edev->aer_cap + PCI_ERR_CAP, 795 4, &aer_capctl); 796 aer_capctl |= (PCI_ERR_CAP_ECRC_GENE | PCI_ERR_CAP_ECRC_CHKE); 797 eeh_ops->write_config(pdn, edev->aer_cap + PCI_ERR_CAP, 798 4, aer_capctl); 799 } 800 801 return 0; 802 } 803 804 /** 805 * pcibios_set_pcie_reset_state - Set PCI-E reset state 806 * @dev: pci device struct 807 * @state: reset state to enter 808 * 809 * Return value: 810 * 0 if success 811 */ 812 int pcibios_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state) 813 { 814 struct eeh_dev *edev = pci_dev_to_eeh_dev(dev); 815 struct eeh_pe *pe = eeh_dev_to_pe(edev); 816 817 if (!pe) { 818 pr_err("%s: No PE found on PCI device %s\n", 819 __func__, pci_name(dev)); 820 return -EINVAL; 821 } 822 823 switch (state) { 824 case pcie_deassert_reset: 825 eeh_ops->reset(pe, EEH_RESET_DEACTIVATE); 826 eeh_unfreeze_pe(pe); 827 if (!(pe->type & EEH_PE_VF)) 828 eeh_pe_state_clear(pe, EEH_PE_CFG_BLOCKED, true); 829 eeh_pe_dev_traverse(pe, eeh_restore_dev_state, dev); 830 eeh_pe_state_clear(pe, EEH_PE_ISOLATED, true); 831 break; 832 case pcie_hot_reset: 833 eeh_pe_mark_isolated(pe); 834 eeh_pe_state_clear(pe, EEH_PE_CFG_BLOCKED, true); 835 eeh_ops->set_option(pe, EEH_OPT_FREEZE_PE); 836 eeh_pe_dev_traverse(pe, eeh_disable_and_save_dev_state, dev); 837 if (!(pe->type & EEH_PE_VF)) 838 eeh_pe_state_mark(pe, EEH_PE_CFG_BLOCKED); 839 eeh_ops->reset(pe, EEH_RESET_HOT); 840 break; 841 case pcie_warm_reset: 842 eeh_pe_mark_isolated(pe); 843 eeh_pe_state_clear(pe, EEH_PE_CFG_BLOCKED, true); 844 eeh_ops->set_option(pe, EEH_OPT_FREEZE_PE); 845 eeh_pe_dev_traverse(pe, eeh_disable_and_save_dev_state, dev); 846 if (!(pe->type & EEH_PE_VF)) 847 eeh_pe_state_mark(pe, EEH_PE_CFG_BLOCKED); 848 eeh_ops->reset(pe, EEH_RESET_FUNDAMENTAL); 849 break; 850 default: 851 eeh_pe_state_clear(pe, EEH_PE_ISOLATED | EEH_PE_CFG_BLOCKED, true); 852 return -EINVAL; 853 }; 854 855 return 0; 856 } 857 858 /** 859 * eeh_set_pe_freset - Check the required reset for the indicated device 860 * @data: EEH device 861 * @flag: return value 862 * 863 * Each device might have its preferred reset type: fundamental or 864 * hot reset. The routine is used to collected the information for 865 * the indicated device and its children so that the bunch of the 866 * devices could be reset properly. 867 */ 868 static void eeh_set_dev_freset(struct eeh_dev *edev, void *flag) 869 { 870 struct pci_dev *dev; 871 unsigned int *freset = (unsigned int *)flag; 872 873 dev = eeh_dev_to_pci_dev(edev); 874 if (dev) 875 *freset |= dev->needs_freset; 876 } 877 878 static void eeh_pe_refreeze_passed(struct eeh_pe *root) 879 { 880 struct eeh_pe *pe; 881 int state; 882 883 eeh_for_each_pe(root, pe) { 884 if (eeh_pe_passed(pe)) { 885 state = eeh_ops->get_state(pe, NULL); 886 if (state & 887 (EEH_STATE_MMIO_ACTIVE | EEH_STATE_MMIO_ENABLED)) { 888 pr_info("EEH: Passed-through PE PHB#%x-PE#%x was thawed by reset, re-freezing for safety.\n", 889 pe->phb->global_number, pe->addr); 890 eeh_pe_set_option(pe, EEH_OPT_FREEZE_PE); 891 } 892 } 893 } 894 } 895 896 /** 897 * eeh_pe_reset_full - Complete a full reset process on the indicated PE 898 * @pe: EEH PE 899 * 900 * This function executes a full reset procedure on a PE, including setting 901 * the appropriate flags, performing a fundamental or hot reset, and then 902 * deactivating the reset status. It is designed to be used within the EEH 903 * subsystem, as opposed to eeh_pe_reset which is exported to drivers and 904 * only performs a single operation at a time. 905 * 906 * This function will attempt to reset a PE three times before failing. 907 */ 908 int eeh_pe_reset_full(struct eeh_pe *pe, bool include_passed) 909 { 910 int reset_state = (EEH_PE_RESET | EEH_PE_CFG_BLOCKED); 911 int type = EEH_RESET_HOT; 912 unsigned int freset = 0; 913 int i, state = 0, ret; 914 915 /* 916 * Determine the type of reset to perform - hot or fundamental. 917 * Hot reset is the default operation, unless any device under the 918 * PE requires a fundamental reset. 919 */ 920 eeh_pe_dev_traverse(pe, eeh_set_dev_freset, &freset); 921 922 if (freset) 923 type = EEH_RESET_FUNDAMENTAL; 924 925 /* Mark the PE as in reset state and block config space accesses */ 926 eeh_pe_state_mark(pe, reset_state); 927 928 /* Make three attempts at resetting the bus */ 929 for (i = 0; i < 3; i++) { 930 ret = eeh_pe_reset(pe, type, include_passed); 931 if (!ret) 932 ret = eeh_pe_reset(pe, EEH_RESET_DEACTIVATE, 933 include_passed); 934 if (ret) { 935 ret = -EIO; 936 pr_warn("EEH: Failure %d resetting PHB#%x-PE#%x (attempt %d)\n\n", 937 state, pe->phb->global_number, pe->addr, i + 1); 938 continue; 939 } 940 if (i) 941 pr_warn("EEH: PHB#%x-PE#%x: Successful reset (attempt %d)\n", 942 pe->phb->global_number, pe->addr, i + 1); 943 944 /* Wait until the PE is in a functioning state */ 945 state = eeh_wait_state(pe, PCI_BUS_RESET_WAIT_MSEC); 946 if (state < 0) { 947 pr_warn("EEH: Unrecoverable slot failure on PHB#%x-PE#%x", 948 pe->phb->global_number, pe->addr); 949 ret = -ENOTRECOVERABLE; 950 break; 951 } 952 if (eeh_state_active(state)) 953 break; 954 else 955 pr_warn("EEH: PHB#%x-PE#%x: Slot inactive after reset: 0x%x (attempt %d)\n", 956 pe->phb->global_number, pe->addr, state, i + 1); 957 } 958 959 /* Resetting the PE may have unfrozen child PEs. If those PEs have been 960 * (potentially) passed through to a guest, re-freeze them: 961 */ 962 if (!include_passed) 963 eeh_pe_refreeze_passed(pe); 964 965 eeh_pe_state_clear(pe, reset_state, true); 966 return ret; 967 } 968 969 /** 970 * eeh_save_bars - Save device bars 971 * @edev: PCI device associated EEH device 972 * 973 * Save the values of the device bars. Unlike the restore 974 * routine, this routine is *not* recursive. This is because 975 * PCI devices are added individually; but, for the restore, 976 * an entire slot is reset at a time. 977 */ 978 void eeh_save_bars(struct eeh_dev *edev) 979 { 980 struct pci_dn *pdn; 981 int i; 982 983 pdn = eeh_dev_to_pdn(edev); 984 if (!pdn) 985 return; 986 987 for (i = 0; i < 16; i++) 988 eeh_ops->read_config(pdn, i * 4, 4, &edev->config_space[i]); 989 990 /* 991 * For PCI bridges including root port, we need enable bus 992 * master explicitly. Otherwise, it can't fetch IODA table 993 * entries correctly. So we cache the bit in advance so that 994 * we can restore it after reset, either PHB range or PE range. 995 */ 996 if (edev->mode & EEH_DEV_BRIDGE) 997 edev->config_space[1] |= PCI_COMMAND_MASTER; 998 } 999 1000 /** 1001 * eeh_ops_register - Register platform dependent EEH operations 1002 * @ops: platform dependent EEH operations 1003 * 1004 * Register the platform dependent EEH operation callback 1005 * functions. The platform should call this function before 1006 * any other EEH operations. 1007 */ 1008 int __init eeh_ops_register(struct eeh_ops *ops) 1009 { 1010 if (!ops->name) { 1011 pr_warn("%s: Invalid EEH ops name for %p\n", 1012 __func__, ops); 1013 return -EINVAL; 1014 } 1015 1016 if (eeh_ops && eeh_ops != ops) { 1017 pr_warn("%s: EEH ops of platform %s already existing (%s)\n", 1018 __func__, eeh_ops->name, ops->name); 1019 return -EEXIST; 1020 } 1021 1022 eeh_ops = ops; 1023 1024 return 0; 1025 } 1026 1027 /** 1028 * eeh_ops_unregister - Unreigster platform dependent EEH operations 1029 * @name: name of EEH platform operations 1030 * 1031 * Unregister the platform dependent EEH operation callback 1032 * functions. 1033 */ 1034 int __exit eeh_ops_unregister(const char *name) 1035 { 1036 if (!name || !strlen(name)) { 1037 pr_warn("%s: Invalid EEH ops name\n", 1038 __func__); 1039 return -EINVAL; 1040 } 1041 1042 if (eeh_ops && !strcmp(eeh_ops->name, name)) { 1043 eeh_ops = NULL; 1044 return 0; 1045 } 1046 1047 return -EEXIST; 1048 } 1049 1050 static int eeh_reboot_notifier(struct notifier_block *nb, 1051 unsigned long action, void *unused) 1052 { 1053 eeh_clear_flag(EEH_ENABLED); 1054 return NOTIFY_DONE; 1055 } 1056 1057 static struct notifier_block eeh_reboot_nb = { 1058 .notifier_call = eeh_reboot_notifier, 1059 }; 1060 1061 /** 1062 * eeh_init - EEH initialization 1063 * 1064 * Initialize EEH by trying to enable it for all of the adapters in the system. 1065 * As a side effect we can determine here if eeh is supported at all. 1066 * Note that we leave EEH on so failed config cycles won't cause a machine 1067 * check. If a user turns off EEH for a particular adapter they are really 1068 * telling Linux to ignore errors. Some hardware (e.g. POWER5) won't 1069 * grant access to a slot if EEH isn't enabled, and so we always enable 1070 * EEH for all slots/all devices. 1071 * 1072 * The eeh-force-off option disables EEH checking globally, for all slots. 1073 * Even if force-off is set, the EEH hardware is still enabled, so that 1074 * newer systems can boot. 1075 */ 1076 static int eeh_init(void) 1077 { 1078 struct pci_controller *hose, *tmp; 1079 int ret = 0; 1080 1081 /* Register reboot notifier */ 1082 ret = register_reboot_notifier(&eeh_reboot_nb); 1083 if (ret) { 1084 pr_warn("%s: Failed to register notifier (%d)\n", 1085 __func__, ret); 1086 return ret; 1087 } 1088 1089 /* call platform initialization function */ 1090 if (!eeh_ops) { 1091 pr_warn("%s: Platform EEH operation not found\n", 1092 __func__); 1093 return -EEXIST; 1094 } else if ((ret = eeh_ops->init())) 1095 return ret; 1096 1097 /* Initialize PHB PEs */ 1098 list_for_each_entry_safe(hose, tmp, &hose_list, list_node) 1099 eeh_dev_phb_init_dynamic(hose); 1100 1101 eeh_addr_cache_init(); 1102 1103 /* Initialize EEH event */ 1104 return eeh_event_init(); 1105 } 1106 1107 core_initcall_sync(eeh_init); 1108 1109 /** 1110 * eeh_add_device_early - Enable EEH for the indicated device node 1111 * @pdn: PCI device node for which to set up EEH 1112 * 1113 * This routine must be used to perform EEH initialization for PCI 1114 * devices that were added after system boot (e.g. hotplug, dlpar). 1115 * This routine must be called before any i/o is performed to the 1116 * adapter (inluding any config-space i/o). 1117 * Whether this actually enables EEH or not for this device depends 1118 * on the CEC architecture, type of the device, on earlier boot 1119 * command-line arguments & etc. 1120 */ 1121 void eeh_add_device_early(struct pci_dn *pdn) 1122 { 1123 struct pci_controller *phb = pdn ? pdn->phb : NULL; 1124 struct eeh_dev *edev = pdn_to_eeh_dev(pdn); 1125 1126 if (!edev) 1127 return; 1128 1129 if (!eeh_has_flag(EEH_PROBE_MODE_DEVTREE)) 1130 return; 1131 1132 /* USB Bus children of PCI devices will not have BUID's */ 1133 if (NULL == phb || 1134 (eeh_has_flag(EEH_PROBE_MODE_DEVTREE) && 0 == phb->buid)) 1135 return; 1136 1137 eeh_ops->probe(pdn, NULL); 1138 } 1139 1140 /** 1141 * eeh_add_device_tree_early - Enable EEH for the indicated device 1142 * @pdn: PCI device node 1143 * 1144 * This routine must be used to perform EEH initialization for the 1145 * indicated PCI device that was added after system boot (e.g. 1146 * hotplug, dlpar). 1147 */ 1148 void eeh_add_device_tree_early(struct pci_dn *pdn) 1149 { 1150 struct pci_dn *n; 1151 1152 if (!pdn) 1153 return; 1154 1155 list_for_each_entry(n, &pdn->child_list, list) 1156 eeh_add_device_tree_early(n); 1157 eeh_add_device_early(pdn); 1158 } 1159 EXPORT_SYMBOL_GPL(eeh_add_device_tree_early); 1160 1161 /** 1162 * eeh_add_device_late - Perform EEH initialization for the indicated pci device 1163 * @dev: pci device for which to set up EEH 1164 * 1165 * This routine must be used to complete EEH initialization for PCI 1166 * devices that were added after system boot (e.g. hotplug, dlpar). 1167 */ 1168 void eeh_add_device_late(struct pci_dev *dev) 1169 { 1170 struct pci_dn *pdn; 1171 struct eeh_dev *edev; 1172 1173 if (!dev) 1174 return; 1175 1176 pdn = pci_get_pdn_by_devfn(dev->bus, dev->devfn); 1177 edev = pdn_to_eeh_dev(pdn); 1178 eeh_edev_dbg(edev, "Adding device\n"); 1179 if (edev->pdev == dev) { 1180 eeh_edev_dbg(edev, "Device already referenced!\n"); 1181 return; 1182 } 1183 1184 /* 1185 * The EEH cache might not be removed correctly because of 1186 * unbalanced kref to the device during unplug time, which 1187 * relies on pcibios_release_device(). So we have to remove 1188 * that here explicitly. 1189 */ 1190 if (edev->pdev) { 1191 eeh_rmv_from_parent_pe(edev); 1192 eeh_addr_cache_rmv_dev(edev->pdev); 1193 eeh_sysfs_remove_device(edev->pdev); 1194 1195 /* 1196 * We definitely should have the PCI device removed 1197 * though it wasn't correctly. So we needn't call 1198 * into error handler afterwards. 1199 */ 1200 edev->mode |= EEH_DEV_NO_HANDLER; 1201 1202 edev->pdev = NULL; 1203 dev->dev.archdata.edev = NULL; 1204 } 1205 1206 if (eeh_has_flag(EEH_PROBE_MODE_DEV)) 1207 eeh_ops->probe(pdn, NULL); 1208 1209 edev->pdev = dev; 1210 dev->dev.archdata.edev = edev; 1211 1212 eeh_addr_cache_insert_dev(dev); 1213 } 1214 1215 /** 1216 * eeh_add_device_tree_late - Perform EEH initialization for the indicated PCI bus 1217 * @bus: PCI bus 1218 * 1219 * This routine must be used to perform EEH initialization for PCI 1220 * devices which are attached to the indicated PCI bus. The PCI bus 1221 * is added after system boot through hotplug or dlpar. 1222 */ 1223 void eeh_add_device_tree_late(struct pci_bus *bus) 1224 { 1225 struct pci_dev *dev; 1226 1227 if (eeh_has_flag(EEH_FORCE_DISABLED)) 1228 return; 1229 list_for_each_entry(dev, &bus->devices, bus_list) { 1230 eeh_add_device_late(dev); 1231 if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) { 1232 struct pci_bus *subbus = dev->subordinate; 1233 if (subbus) 1234 eeh_add_device_tree_late(subbus); 1235 } 1236 } 1237 } 1238 EXPORT_SYMBOL_GPL(eeh_add_device_tree_late); 1239 1240 /** 1241 * eeh_add_sysfs_files - Add EEH sysfs files for the indicated PCI bus 1242 * @bus: PCI bus 1243 * 1244 * This routine must be used to add EEH sysfs files for PCI 1245 * devices which are attached to the indicated PCI bus. The PCI bus 1246 * is added after system boot through hotplug or dlpar. 1247 */ 1248 void eeh_add_sysfs_files(struct pci_bus *bus) 1249 { 1250 struct pci_dev *dev; 1251 1252 list_for_each_entry(dev, &bus->devices, bus_list) { 1253 eeh_sysfs_add_device(dev); 1254 if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) { 1255 struct pci_bus *subbus = dev->subordinate; 1256 if (subbus) 1257 eeh_add_sysfs_files(subbus); 1258 } 1259 } 1260 } 1261 EXPORT_SYMBOL_GPL(eeh_add_sysfs_files); 1262 1263 /** 1264 * eeh_remove_device - Undo EEH setup for the indicated pci device 1265 * @dev: pci device to be removed 1266 * 1267 * This routine should be called when a device is removed from 1268 * a running system (e.g. by hotplug or dlpar). It unregisters 1269 * the PCI device from the EEH subsystem. I/O errors affecting 1270 * this device will no longer be detected after this call; thus, 1271 * i/o errors affecting this slot may leave this device unusable. 1272 */ 1273 void eeh_remove_device(struct pci_dev *dev) 1274 { 1275 struct eeh_dev *edev; 1276 1277 if (!dev || !eeh_enabled()) 1278 return; 1279 edev = pci_dev_to_eeh_dev(dev); 1280 1281 /* Unregister the device with the EEH/PCI address search system */ 1282 dev_dbg(&dev->dev, "EEH: Removing device\n"); 1283 1284 if (!edev || !edev->pdev || !edev->pe) { 1285 dev_dbg(&dev->dev, "EEH: Device not referenced!\n"); 1286 return; 1287 } 1288 1289 /* 1290 * During the hotplug for EEH error recovery, we need the EEH 1291 * device attached to the parent PE in order for BAR restore 1292 * a bit later. So we keep it for BAR restore and remove it 1293 * from the parent PE during the BAR resotre. 1294 */ 1295 edev->pdev = NULL; 1296 1297 /* 1298 * eeh_sysfs_remove_device() uses pci_dev_to_eeh_dev() so we need to 1299 * remove the sysfs files before clearing dev.archdata.edev 1300 */ 1301 if (edev->mode & EEH_DEV_SYSFS) 1302 eeh_sysfs_remove_device(dev); 1303 1304 /* 1305 * We're removing from the PCI subsystem, that means 1306 * the PCI device driver can't support EEH or not 1307 * well. So we rely on hotplug completely to do recovery 1308 * for the specific PCI device. 1309 */ 1310 edev->mode |= EEH_DEV_NO_HANDLER; 1311 1312 eeh_addr_cache_rmv_dev(dev); 1313 1314 /* 1315 * The flag "in_error" is used to trace EEH devices for VFs 1316 * in error state or not. It's set in eeh_report_error(). If 1317 * it's not set, eeh_report_{reset,resume}() won't be called 1318 * for the VF EEH device. 1319 */ 1320 edev->in_error = false; 1321 dev->dev.archdata.edev = NULL; 1322 if (!(edev->pe->state & EEH_PE_KEEP)) 1323 eeh_rmv_from_parent_pe(edev); 1324 else 1325 edev->mode |= EEH_DEV_DISCONNECTED; 1326 } 1327 1328 int eeh_unfreeze_pe(struct eeh_pe *pe) 1329 { 1330 int ret; 1331 1332 ret = eeh_pci_enable(pe, EEH_OPT_THAW_MMIO); 1333 if (ret) { 1334 pr_warn("%s: Failure %d enabling IO on PHB#%x-PE#%x\n", 1335 __func__, ret, pe->phb->global_number, pe->addr); 1336 return ret; 1337 } 1338 1339 ret = eeh_pci_enable(pe, EEH_OPT_THAW_DMA); 1340 if (ret) { 1341 pr_warn("%s: Failure %d enabling DMA on PHB#%x-PE#%x\n", 1342 __func__, ret, pe->phb->global_number, pe->addr); 1343 return ret; 1344 } 1345 1346 return ret; 1347 } 1348 1349 1350 static struct pci_device_id eeh_reset_ids[] = { 1351 { PCI_DEVICE(0x19a2, 0x0710) }, /* Emulex, BE */ 1352 { PCI_DEVICE(0x10df, 0xe220) }, /* Emulex, Lancer */ 1353 { PCI_DEVICE(0x14e4, 0x1657) }, /* Broadcom BCM5719 */ 1354 { 0 } 1355 }; 1356 1357 static int eeh_pe_change_owner(struct eeh_pe *pe) 1358 { 1359 struct eeh_dev *edev, *tmp; 1360 struct pci_dev *pdev; 1361 struct pci_device_id *id; 1362 int ret; 1363 1364 /* Check PE state */ 1365 ret = eeh_ops->get_state(pe, NULL); 1366 if (ret < 0 || ret == EEH_STATE_NOT_SUPPORT) 1367 return 0; 1368 1369 /* Unfrozen PE, nothing to do */ 1370 if (eeh_state_active(ret)) 1371 return 0; 1372 1373 /* Frozen PE, check if it needs PE level reset */ 1374 eeh_pe_for_each_dev(pe, edev, tmp) { 1375 pdev = eeh_dev_to_pci_dev(edev); 1376 if (!pdev) 1377 continue; 1378 1379 for (id = &eeh_reset_ids[0]; id->vendor != 0; id++) { 1380 if (id->vendor != PCI_ANY_ID && 1381 id->vendor != pdev->vendor) 1382 continue; 1383 if (id->device != PCI_ANY_ID && 1384 id->device != pdev->device) 1385 continue; 1386 if (id->subvendor != PCI_ANY_ID && 1387 id->subvendor != pdev->subsystem_vendor) 1388 continue; 1389 if (id->subdevice != PCI_ANY_ID && 1390 id->subdevice != pdev->subsystem_device) 1391 continue; 1392 1393 return eeh_pe_reset_and_recover(pe); 1394 } 1395 } 1396 1397 ret = eeh_unfreeze_pe(pe); 1398 if (!ret) 1399 eeh_pe_state_clear(pe, EEH_PE_ISOLATED, true); 1400 return ret; 1401 } 1402 1403 /** 1404 * eeh_dev_open - Increase count of pass through devices for PE 1405 * @pdev: PCI device 1406 * 1407 * Increase count of passed through devices for the indicated 1408 * PE. In the result, the EEH errors detected on the PE won't be 1409 * reported. The PE owner will be responsible for detection 1410 * and recovery. 1411 */ 1412 int eeh_dev_open(struct pci_dev *pdev) 1413 { 1414 struct eeh_dev *edev; 1415 int ret = -ENODEV; 1416 1417 mutex_lock(&eeh_dev_mutex); 1418 1419 /* No PCI device ? */ 1420 if (!pdev) 1421 goto out; 1422 1423 /* No EEH device or PE ? */ 1424 edev = pci_dev_to_eeh_dev(pdev); 1425 if (!edev || !edev->pe) 1426 goto out; 1427 1428 /* 1429 * The PE might have been put into frozen state, but we 1430 * didn't detect that yet. The passed through PCI devices 1431 * in frozen PE won't work properly. Clear the frozen state 1432 * in advance. 1433 */ 1434 ret = eeh_pe_change_owner(edev->pe); 1435 if (ret) 1436 goto out; 1437 1438 /* Increase PE's pass through count */ 1439 atomic_inc(&edev->pe->pass_dev_cnt); 1440 mutex_unlock(&eeh_dev_mutex); 1441 1442 return 0; 1443 out: 1444 mutex_unlock(&eeh_dev_mutex); 1445 return ret; 1446 } 1447 EXPORT_SYMBOL_GPL(eeh_dev_open); 1448 1449 /** 1450 * eeh_dev_release - Decrease count of pass through devices for PE 1451 * @pdev: PCI device 1452 * 1453 * Decrease count of pass through devices for the indicated PE. If 1454 * there is no passed through device in PE, the EEH errors detected 1455 * on the PE will be reported and handled as usual. 1456 */ 1457 void eeh_dev_release(struct pci_dev *pdev) 1458 { 1459 struct eeh_dev *edev; 1460 1461 mutex_lock(&eeh_dev_mutex); 1462 1463 /* No PCI device ? */ 1464 if (!pdev) 1465 goto out; 1466 1467 /* No EEH device ? */ 1468 edev = pci_dev_to_eeh_dev(pdev); 1469 if (!edev || !edev->pe || !eeh_pe_passed(edev->pe)) 1470 goto out; 1471 1472 /* Decrease PE's pass through count */ 1473 WARN_ON(atomic_dec_if_positive(&edev->pe->pass_dev_cnt) < 0); 1474 eeh_pe_change_owner(edev->pe); 1475 out: 1476 mutex_unlock(&eeh_dev_mutex); 1477 } 1478 EXPORT_SYMBOL(eeh_dev_release); 1479 1480 #ifdef CONFIG_IOMMU_API 1481 1482 static int dev_has_iommu_table(struct device *dev, void *data) 1483 { 1484 struct pci_dev *pdev = to_pci_dev(dev); 1485 struct pci_dev **ppdev = data; 1486 1487 if (!dev) 1488 return 0; 1489 1490 if (device_iommu_mapped(dev)) { 1491 *ppdev = pdev; 1492 return 1; 1493 } 1494 1495 return 0; 1496 } 1497 1498 /** 1499 * eeh_iommu_group_to_pe - Convert IOMMU group to EEH PE 1500 * @group: IOMMU group 1501 * 1502 * The routine is called to convert IOMMU group to EEH PE. 1503 */ 1504 struct eeh_pe *eeh_iommu_group_to_pe(struct iommu_group *group) 1505 { 1506 struct pci_dev *pdev = NULL; 1507 struct eeh_dev *edev; 1508 int ret; 1509 1510 /* No IOMMU group ? */ 1511 if (!group) 1512 return NULL; 1513 1514 ret = iommu_group_for_each_dev(group, &pdev, dev_has_iommu_table); 1515 if (!ret || !pdev) 1516 return NULL; 1517 1518 /* No EEH device or PE ? */ 1519 edev = pci_dev_to_eeh_dev(pdev); 1520 if (!edev || !edev->pe) 1521 return NULL; 1522 1523 return edev->pe; 1524 } 1525 EXPORT_SYMBOL_GPL(eeh_iommu_group_to_pe); 1526 1527 #endif /* CONFIG_IOMMU_API */ 1528 1529 /** 1530 * eeh_pe_set_option - Set options for the indicated PE 1531 * @pe: EEH PE 1532 * @option: requested option 1533 * 1534 * The routine is called to enable or disable EEH functionality 1535 * on the indicated PE, to enable IO or DMA for the frozen PE. 1536 */ 1537 int eeh_pe_set_option(struct eeh_pe *pe, int option) 1538 { 1539 int ret = 0; 1540 1541 /* Invalid PE ? */ 1542 if (!pe) 1543 return -ENODEV; 1544 1545 /* 1546 * EEH functionality could possibly be disabled, just 1547 * return error for the case. And the EEH functinality 1548 * isn't expected to be disabled on one specific PE. 1549 */ 1550 switch (option) { 1551 case EEH_OPT_ENABLE: 1552 if (eeh_enabled()) { 1553 ret = eeh_pe_change_owner(pe); 1554 break; 1555 } 1556 ret = -EIO; 1557 break; 1558 case EEH_OPT_DISABLE: 1559 break; 1560 case EEH_OPT_THAW_MMIO: 1561 case EEH_OPT_THAW_DMA: 1562 case EEH_OPT_FREEZE_PE: 1563 if (!eeh_ops || !eeh_ops->set_option) { 1564 ret = -ENOENT; 1565 break; 1566 } 1567 1568 ret = eeh_pci_enable(pe, option); 1569 break; 1570 default: 1571 pr_debug("%s: Option %d out of range (%d, %d)\n", 1572 __func__, option, EEH_OPT_DISABLE, EEH_OPT_THAW_DMA); 1573 ret = -EINVAL; 1574 } 1575 1576 return ret; 1577 } 1578 EXPORT_SYMBOL_GPL(eeh_pe_set_option); 1579 1580 /** 1581 * eeh_pe_get_state - Retrieve PE's state 1582 * @pe: EEH PE 1583 * 1584 * Retrieve the PE's state, which includes 3 aspects: enabled 1585 * DMA, enabled IO and asserted reset. 1586 */ 1587 int eeh_pe_get_state(struct eeh_pe *pe) 1588 { 1589 int result, ret = 0; 1590 bool rst_active, dma_en, mmio_en; 1591 1592 /* Existing PE ? */ 1593 if (!pe) 1594 return -ENODEV; 1595 1596 if (!eeh_ops || !eeh_ops->get_state) 1597 return -ENOENT; 1598 1599 /* 1600 * If the parent PE is owned by the host kernel and is undergoing 1601 * error recovery, we should return the PE state as temporarily 1602 * unavailable so that the error recovery on the guest is suspended 1603 * until the recovery completes on the host. 1604 */ 1605 if (pe->parent && 1606 !(pe->state & EEH_PE_REMOVED) && 1607 (pe->parent->state & (EEH_PE_ISOLATED | EEH_PE_RECOVERING))) 1608 return EEH_PE_STATE_UNAVAIL; 1609 1610 result = eeh_ops->get_state(pe, NULL); 1611 rst_active = !!(result & EEH_STATE_RESET_ACTIVE); 1612 dma_en = !!(result & EEH_STATE_DMA_ENABLED); 1613 mmio_en = !!(result & EEH_STATE_MMIO_ENABLED); 1614 1615 if (rst_active) 1616 ret = EEH_PE_STATE_RESET; 1617 else if (dma_en && mmio_en) 1618 ret = EEH_PE_STATE_NORMAL; 1619 else if (!dma_en && !mmio_en) 1620 ret = EEH_PE_STATE_STOPPED_IO_DMA; 1621 else if (!dma_en && mmio_en) 1622 ret = EEH_PE_STATE_STOPPED_DMA; 1623 else 1624 ret = EEH_PE_STATE_UNAVAIL; 1625 1626 return ret; 1627 } 1628 EXPORT_SYMBOL_GPL(eeh_pe_get_state); 1629 1630 static int eeh_pe_reenable_devices(struct eeh_pe *pe, bool include_passed) 1631 { 1632 struct eeh_dev *edev, *tmp; 1633 struct pci_dev *pdev; 1634 int ret = 0; 1635 1636 eeh_pe_restore_bars(pe); 1637 1638 /* 1639 * Reenable PCI devices as the devices passed 1640 * through are always enabled before the reset. 1641 */ 1642 eeh_pe_for_each_dev(pe, edev, tmp) { 1643 pdev = eeh_dev_to_pci_dev(edev); 1644 if (!pdev) 1645 continue; 1646 1647 ret = pci_reenable_device(pdev); 1648 if (ret) { 1649 pr_warn("%s: Failure %d reenabling %s\n", 1650 __func__, ret, pci_name(pdev)); 1651 return ret; 1652 } 1653 } 1654 1655 /* The PE is still in frozen state */ 1656 if (include_passed || !eeh_pe_passed(pe)) { 1657 ret = eeh_unfreeze_pe(pe); 1658 } else 1659 pr_info("EEH: Note: Leaving passthrough PHB#%x-PE#%x frozen.\n", 1660 pe->phb->global_number, pe->addr); 1661 if (!ret) 1662 eeh_pe_state_clear(pe, EEH_PE_ISOLATED, include_passed); 1663 return ret; 1664 } 1665 1666 1667 /** 1668 * eeh_pe_reset - Issue PE reset according to specified type 1669 * @pe: EEH PE 1670 * @option: reset type 1671 * 1672 * The routine is called to reset the specified PE with the 1673 * indicated type, either fundamental reset or hot reset. 1674 * PE reset is the most important part for error recovery. 1675 */ 1676 int eeh_pe_reset(struct eeh_pe *pe, int option, bool include_passed) 1677 { 1678 int ret = 0; 1679 1680 /* Invalid PE ? */ 1681 if (!pe) 1682 return -ENODEV; 1683 1684 if (!eeh_ops || !eeh_ops->set_option || !eeh_ops->reset) 1685 return -ENOENT; 1686 1687 switch (option) { 1688 case EEH_RESET_DEACTIVATE: 1689 ret = eeh_ops->reset(pe, option); 1690 eeh_pe_state_clear(pe, EEH_PE_CFG_BLOCKED, include_passed); 1691 if (ret) 1692 break; 1693 1694 ret = eeh_pe_reenable_devices(pe, include_passed); 1695 break; 1696 case EEH_RESET_HOT: 1697 case EEH_RESET_FUNDAMENTAL: 1698 /* 1699 * Proactively freeze the PE to drop all MMIO access 1700 * during reset, which should be banned as it's always 1701 * cause recursive EEH error. 1702 */ 1703 eeh_ops->set_option(pe, EEH_OPT_FREEZE_PE); 1704 1705 eeh_pe_state_mark(pe, EEH_PE_CFG_BLOCKED); 1706 ret = eeh_ops->reset(pe, option); 1707 break; 1708 default: 1709 pr_debug("%s: Unsupported option %d\n", 1710 __func__, option); 1711 ret = -EINVAL; 1712 } 1713 1714 return ret; 1715 } 1716 EXPORT_SYMBOL_GPL(eeh_pe_reset); 1717 1718 /** 1719 * eeh_pe_configure - Configure PCI bridges after PE reset 1720 * @pe: EEH PE 1721 * 1722 * The routine is called to restore the PCI config space for 1723 * those PCI devices, especially PCI bridges affected by PE 1724 * reset issued previously. 1725 */ 1726 int eeh_pe_configure(struct eeh_pe *pe) 1727 { 1728 int ret = 0; 1729 1730 /* Invalid PE ? */ 1731 if (!pe) 1732 return -ENODEV; 1733 1734 return ret; 1735 } 1736 EXPORT_SYMBOL_GPL(eeh_pe_configure); 1737 1738 /** 1739 * eeh_pe_inject_err - Injecting the specified PCI error to the indicated PE 1740 * @pe: the indicated PE 1741 * @type: error type 1742 * @function: error function 1743 * @addr: address 1744 * @mask: address mask 1745 * 1746 * The routine is called to inject the specified PCI error, which 1747 * is determined by @type and @function, to the indicated PE for 1748 * testing purpose. 1749 */ 1750 int eeh_pe_inject_err(struct eeh_pe *pe, int type, int func, 1751 unsigned long addr, unsigned long mask) 1752 { 1753 /* Invalid PE ? */ 1754 if (!pe) 1755 return -ENODEV; 1756 1757 /* Unsupported operation ? */ 1758 if (!eeh_ops || !eeh_ops->err_inject) 1759 return -ENOENT; 1760 1761 /* Check on PCI error type */ 1762 if (type != EEH_ERR_TYPE_32 && type != EEH_ERR_TYPE_64) 1763 return -EINVAL; 1764 1765 /* Check on PCI error function */ 1766 if (func < EEH_ERR_FUNC_MIN || func > EEH_ERR_FUNC_MAX) 1767 return -EINVAL; 1768 1769 return eeh_ops->err_inject(pe, type, func, addr, mask); 1770 } 1771 EXPORT_SYMBOL_GPL(eeh_pe_inject_err); 1772 1773 static int proc_eeh_show(struct seq_file *m, void *v) 1774 { 1775 if (!eeh_enabled()) { 1776 seq_printf(m, "EEH Subsystem is globally disabled\n"); 1777 seq_printf(m, "eeh_total_mmio_ffs=%llu\n", eeh_stats.total_mmio_ffs); 1778 } else { 1779 seq_printf(m, "EEH Subsystem is enabled\n"); 1780 seq_printf(m, 1781 "no device=%llu\n" 1782 "no device node=%llu\n" 1783 "no config address=%llu\n" 1784 "check not wanted=%llu\n" 1785 "eeh_total_mmio_ffs=%llu\n" 1786 "eeh_false_positives=%llu\n" 1787 "eeh_slot_resets=%llu\n", 1788 eeh_stats.no_device, 1789 eeh_stats.no_dn, 1790 eeh_stats.no_cfg_addr, 1791 eeh_stats.ignored_check, 1792 eeh_stats.total_mmio_ffs, 1793 eeh_stats.false_positives, 1794 eeh_stats.slot_resets); 1795 } 1796 1797 return 0; 1798 } 1799 1800 #ifdef CONFIG_DEBUG_FS 1801 static int eeh_enable_dbgfs_set(void *data, u64 val) 1802 { 1803 if (val) 1804 eeh_clear_flag(EEH_FORCE_DISABLED); 1805 else 1806 eeh_add_flag(EEH_FORCE_DISABLED); 1807 1808 return 0; 1809 } 1810 1811 static int eeh_enable_dbgfs_get(void *data, u64 *val) 1812 { 1813 if (eeh_enabled()) 1814 *val = 0x1ul; 1815 else 1816 *val = 0x0ul; 1817 return 0; 1818 } 1819 1820 DEFINE_DEBUGFS_ATTRIBUTE(eeh_enable_dbgfs_ops, eeh_enable_dbgfs_get, 1821 eeh_enable_dbgfs_set, "0x%llx\n"); 1822 1823 static ssize_t eeh_force_recover_write(struct file *filp, 1824 const char __user *user_buf, 1825 size_t count, loff_t *ppos) 1826 { 1827 struct pci_controller *hose; 1828 uint32_t phbid, pe_no; 1829 struct eeh_pe *pe; 1830 char buf[20]; 1831 int ret; 1832 1833 ret = simple_write_to_buffer(buf, sizeof(buf), ppos, user_buf, count); 1834 if (!ret) 1835 return -EFAULT; 1836 1837 /* 1838 * When PE is NULL the event is a "special" event. Rather than 1839 * recovering a specific PE it forces the EEH core to scan for failed 1840 * PHBs and recovers each. This needs to be done before any device 1841 * recoveries can occur. 1842 */ 1843 if (!strncmp(buf, "hwcheck", 7)) { 1844 __eeh_send_failure_event(NULL); 1845 return count; 1846 } 1847 1848 ret = sscanf(buf, "%x:%x", &phbid, &pe_no); 1849 if (ret != 2) 1850 return -EINVAL; 1851 1852 hose = pci_find_controller_for_domain(phbid); 1853 if (!hose) 1854 return -ENODEV; 1855 1856 /* Retrieve PE */ 1857 pe = eeh_pe_get(hose, pe_no, 0); 1858 if (!pe) 1859 return -ENODEV; 1860 1861 /* 1862 * We don't do any state checking here since the detection 1863 * process is async to the recovery process. The recovery 1864 * thread *should* not break even if we schedule a recovery 1865 * from an odd state (e.g. PE removed, or recovery of a 1866 * non-isolated PE) 1867 */ 1868 __eeh_send_failure_event(pe); 1869 1870 return ret < 0 ? ret : count; 1871 } 1872 1873 static const struct file_operations eeh_force_recover_fops = { 1874 .open = simple_open, 1875 .llseek = no_llseek, 1876 .write = eeh_force_recover_write, 1877 }; 1878 1879 static ssize_t eeh_debugfs_dev_usage(struct file *filp, 1880 char __user *user_buf, 1881 size_t count, loff_t *ppos) 1882 { 1883 static const char usage[] = "input format: <domain>:<bus>:<dev>.<fn>\n"; 1884 1885 return simple_read_from_buffer(user_buf, count, ppos, 1886 usage, sizeof(usage) - 1); 1887 } 1888 1889 static ssize_t eeh_dev_check_write(struct file *filp, 1890 const char __user *user_buf, 1891 size_t count, loff_t *ppos) 1892 { 1893 uint32_t domain, bus, dev, fn; 1894 struct pci_dev *pdev; 1895 struct eeh_dev *edev; 1896 char buf[20]; 1897 int ret; 1898 1899 memset(buf, 0, sizeof(buf)); 1900 ret = simple_write_to_buffer(buf, sizeof(buf)-1, ppos, user_buf, count); 1901 if (!ret) 1902 return -EFAULT; 1903 1904 ret = sscanf(buf, "%x:%x:%x.%x", &domain, &bus, &dev, &fn); 1905 if (ret != 4) { 1906 pr_err("%s: expected 4 args, got %d\n", __func__, ret); 1907 return -EINVAL; 1908 } 1909 1910 pdev = pci_get_domain_bus_and_slot(domain, bus, (dev << 3) | fn); 1911 if (!pdev) 1912 return -ENODEV; 1913 1914 edev = pci_dev_to_eeh_dev(pdev); 1915 if (!edev) { 1916 pci_err(pdev, "No eeh_dev for this device!\n"); 1917 pci_dev_put(pdev); 1918 return -ENODEV; 1919 } 1920 1921 ret = eeh_dev_check_failure(edev); 1922 pci_info(pdev, "eeh_dev_check_failure(%04x:%02x:%02x.%01x) = %d\n", 1923 domain, bus, dev, fn, ret); 1924 1925 pci_dev_put(pdev); 1926 1927 return count; 1928 } 1929 1930 static const struct file_operations eeh_dev_check_fops = { 1931 .open = simple_open, 1932 .llseek = no_llseek, 1933 .write = eeh_dev_check_write, 1934 .read = eeh_debugfs_dev_usage, 1935 }; 1936 1937 static int eeh_debugfs_break_device(struct pci_dev *pdev) 1938 { 1939 struct resource *bar = NULL; 1940 void __iomem *mapped; 1941 u16 old, bit; 1942 int i, pos; 1943 1944 /* Do we have an MMIO BAR to disable? */ 1945 for (i = 0; i <= PCI_STD_RESOURCE_END; i++) { 1946 struct resource *r = &pdev->resource[i]; 1947 1948 if (!r->flags || !r->start) 1949 continue; 1950 if (r->flags & IORESOURCE_IO) 1951 continue; 1952 if (r->flags & IORESOURCE_UNSET) 1953 continue; 1954 1955 bar = r; 1956 break; 1957 } 1958 1959 if (!bar) { 1960 pci_err(pdev, "Unable to find Memory BAR to cause EEH with\n"); 1961 return -ENXIO; 1962 } 1963 1964 pci_err(pdev, "Going to break: %pR\n", bar); 1965 1966 if (pdev->is_virtfn) { 1967 #ifndef CONFIG_PCI_IOV 1968 return -ENXIO; 1969 #else 1970 /* 1971 * VFs don't have a per-function COMMAND register, so the best 1972 * we can do is clear the Memory Space Enable bit in the PF's 1973 * SRIOV control reg. 1974 * 1975 * Unfortunately, this requires that we have a PF (i.e doesn't 1976 * work for a passed-through VF) and it has the potential side 1977 * effect of also causing an EEH on every other VF under the 1978 * PF. Oh well. 1979 */ 1980 pdev = pdev->physfn; 1981 if (!pdev) 1982 return -ENXIO; /* passed through VFs have no PF */ 1983 1984 pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_SRIOV); 1985 pos += PCI_SRIOV_CTRL; 1986 bit = PCI_SRIOV_CTRL_MSE; 1987 #endif /* !CONFIG_PCI_IOV */ 1988 } else { 1989 bit = PCI_COMMAND_MEMORY; 1990 pos = PCI_COMMAND; 1991 } 1992 1993 /* 1994 * Process here is: 1995 * 1996 * 1. Disable Memory space. 1997 * 1998 * 2. Perform an MMIO to the device. This should result in an error 1999 * (CA / UR) being raised by the device which results in an EEH 2000 * PE freeze. Using the in_8() accessor skips the eeh detection hook 2001 * so the freeze hook so the EEH Detection machinery won't be 2002 * triggered here. This is to match the usual behaviour of EEH 2003 * where the HW will asyncronously freeze a PE and it's up to 2004 * the kernel to notice and deal with it. 2005 * 2006 * 3. Turn Memory space back on. This is more important for VFs 2007 * since recovery will probably fail if we don't. For normal 2008 * the COMMAND register is reset as a part of re-initialising 2009 * the device. 2010 * 2011 * Breaking stuff is the point so who cares if it's racy ;) 2012 */ 2013 pci_read_config_word(pdev, pos, &old); 2014 2015 mapped = ioremap(bar->start, PAGE_SIZE); 2016 if (!mapped) { 2017 pci_err(pdev, "Unable to map MMIO BAR %pR\n", bar); 2018 return -ENXIO; 2019 } 2020 2021 pci_write_config_word(pdev, pos, old & ~bit); 2022 in_8(mapped); 2023 pci_write_config_word(pdev, pos, old); 2024 2025 iounmap(mapped); 2026 2027 return 0; 2028 } 2029 2030 static ssize_t eeh_dev_break_write(struct file *filp, 2031 const char __user *user_buf, 2032 size_t count, loff_t *ppos) 2033 { 2034 uint32_t domain, bus, dev, fn; 2035 struct pci_dev *pdev; 2036 char buf[20]; 2037 int ret; 2038 2039 memset(buf, 0, sizeof(buf)); 2040 ret = simple_write_to_buffer(buf, sizeof(buf)-1, ppos, user_buf, count); 2041 if (!ret) 2042 return -EFAULT; 2043 2044 ret = sscanf(buf, "%x:%x:%x.%x", &domain, &bus, &dev, &fn); 2045 if (ret != 4) { 2046 pr_err("%s: expected 4 args, got %d\n", __func__, ret); 2047 return -EINVAL; 2048 } 2049 2050 pdev = pci_get_domain_bus_and_slot(domain, bus, (dev << 3) | fn); 2051 if (!pdev) 2052 return -ENODEV; 2053 2054 ret = eeh_debugfs_break_device(pdev); 2055 pci_dev_put(pdev); 2056 2057 if (ret < 0) 2058 return ret; 2059 2060 return count; 2061 } 2062 2063 static const struct file_operations eeh_dev_break_fops = { 2064 .open = simple_open, 2065 .llseek = no_llseek, 2066 .write = eeh_dev_break_write, 2067 .read = eeh_debugfs_dev_usage, 2068 }; 2069 2070 #endif 2071 2072 static int __init eeh_init_proc(void) 2073 { 2074 if (machine_is(pseries) || machine_is(powernv)) { 2075 proc_create_single("powerpc/eeh", 0, NULL, proc_eeh_show); 2076 #ifdef CONFIG_DEBUG_FS 2077 debugfs_create_file_unsafe("eeh_enable", 0600, 2078 powerpc_debugfs_root, NULL, 2079 &eeh_enable_dbgfs_ops); 2080 debugfs_create_u32("eeh_max_freezes", 0600, 2081 powerpc_debugfs_root, &eeh_max_freezes); 2082 debugfs_create_bool("eeh_disable_recovery", 0600, 2083 powerpc_debugfs_root, 2084 &eeh_debugfs_no_recover); 2085 debugfs_create_file_unsafe("eeh_dev_check", 0600, 2086 powerpc_debugfs_root, NULL, 2087 &eeh_dev_check_fops); 2088 debugfs_create_file_unsafe("eeh_dev_break", 0600, 2089 powerpc_debugfs_root, NULL, 2090 &eeh_dev_break_fops); 2091 debugfs_create_file_unsafe("eeh_force_recover", 0600, 2092 powerpc_debugfs_root, NULL, 2093 &eeh_force_recover_fops); 2094 eeh_cache_debugfs_init(); 2095 #endif 2096 } 2097 2098 return 0; 2099 } 2100 __initcall(eeh_init_proc); 2101