2 * Copyright IBM Corporation 2001, 2005, 2006
3 * Copyright Dave Engebretsen & Todd Inglett 2001
4 * Copyright Linas Vepstas 2005, 2006
5 * Copyright 2001-2012 IBM Corporation.
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 * Please address comments and feedback to Linas Vepstas <linas@austin.ibm.com>
24 #include <linux/delay.h>
25 #include <linux/debugfs.h>
26 #include <linux/sched.h>
27 #include <linux/init.h>
28 #include <linux/list.h>
29 #include <linux/pci.h>
30 #include <linux/iommu.h>
31 #include <linux/proc_fs.h>
32 #include <linux/rbtree.h>
33 #include <linux/reboot.h>
34 #include <linux/seq_file.h>
35 #include <linux/spinlock.h>
36 #include <linux/export.h>
39 #include <linux/atomic.h>
40 #include <asm/debug.h>
42 #include <asm/eeh_event.h>
44 #include <asm/iommu.h>
45 #include <asm/machdep.h>
46 #include <asm/ppc-pci.h>
51 * EEH, or "Extended Error Handling" is a PCI bridge technology for
52 * dealing with PCI bus errors that can't be dealt with within the
53 * usual PCI framework, except by check-stopping the CPU. Systems
54 * that are designed for high-availability/reliability cannot afford
55 * to crash due to a "mere" PCI error, thus the need for EEH.
56 * An EEH-capable bridge operates by converting a detected error
57 * into a "slot freeze", taking the PCI adapter off-line, making
58 * the slot behave, from the OS'es point of view, as if the slot
59 * were "empty": all reads return 0xff's and all writes are silently
60 * ignored. EEH slot isolation events can be triggered by parity
61 * errors on the address or data busses (e.g. during posted writes),
62 * which in turn might be caused by low voltage on the bus, dust,
63 * vibration, humidity, radioactivity or plain-old failed hardware.
65 * Note, however, that one of the leading causes of EEH slot
66 * freeze events are buggy device drivers, buggy device microcode,
67 * or buggy device hardware. This is because any attempt by the
68 * device to bus-master data to a memory address that is not
69 * assigned to the device will trigger a slot freeze. (The idea
70 * is to prevent devices-gone-wild from corrupting system memory).
71 * Buggy hardware/drivers will have a miserable time co-existing
74 * Ideally, a PCI device driver, when suspecting that an isolation
75 * event has occurred (e.g. by reading 0xff's), will then ask EEH
76 * whether this is the case, and then take appropriate steps to
77 * reset the PCI slot, the PCI device, and then resume operations.
78 * However, until that day, the checking is done here, with the
79 * eeh_check_failure() routine embedded in the MMIO macros. If
80 * the slot is found to be isolated, an "EEH Event" is synthesized
81 * and sent out for processing.
84 /* If a device driver keeps reading an MMIO register in an interrupt
85 * handler after a slot isolation event, it might be broken.
86 * This sets the threshold for how many read attempts we allow
87 * before printing an error message.
89 #define EEH_MAX_FAILS 2100000
91 /* Time to wait for a PCI slot to report status, in milliseconds */
92 #define PCI_BUS_RESET_WAIT_MSEC (5*60*1000)
95 * EEH probe mode support, which is part of the flags,
96 * is to support multiple platforms for EEH. Some platforms
97 * like pSeries do PCI emunation based on device tree.
98 * However, other platforms like powernv probe PCI devices
99 * from hardware. The flag is used to distinguish that.
100 * In addition, struct eeh_ops::probe would be invoked for
101 * particular OF node or PCI device so that the corresponding
102 * PE would be created there.
104 int eeh_subsystem_flags
;
105 EXPORT_SYMBOL(eeh_subsystem_flags
);
107 /* Platform dependent EEH operations */
108 struct eeh_ops
*eeh_ops
= NULL
;
110 /* Lock to avoid races due to multiple reports of an error */
111 DEFINE_RAW_SPINLOCK(confirm_error_lock
);
113 /* Lock to protect passed flags */
114 static DEFINE_MUTEX(eeh_dev_mutex
);
116 /* Buffer for reporting pci register dumps. Its here in BSS, and
117 * not dynamically alloced, so that it ends up in RMO where RTAS
120 #define EEH_PCI_REGS_LOG_LEN 4096
121 static unsigned char pci_regs_buf
[EEH_PCI_REGS_LOG_LEN
];
124 * The struct is used to maintain the EEH global statistic
125 * information. Besides, the EEH global statistics will be
126 * exported to user space through procfs
129 u64 no_device
; /* PCI device not found */
130 u64 no_dn
; /* OF node not found */
131 u64 no_cfg_addr
; /* Config address not found */
132 u64 ignored_check
; /* EEH check skipped */
133 u64 total_mmio_ffs
; /* Total EEH checks */
134 u64 false_positives
; /* Unnecessary EEH checks */
135 u64 slot_resets
; /* PE reset */
138 static struct eeh_stats eeh_stats
;
140 #define IS_BRIDGE(class_code) (((class_code)<<16) == PCI_BASE_CLASS_BRIDGE)
142 static int __init
eeh_setup(char *str
)
144 if (!strcmp(str
, "off"))
145 eeh_add_flag(EEH_FORCE_DISABLED
);
149 __setup("eeh=", eeh_setup
);
152 * eeh_gather_pci_data - Copy assorted PCI config space registers to buff
153 * @edev: device to report data for
154 * @buf: point to buffer in which to log
155 * @len: amount of room in buffer
157 * This routine captures assorted PCI configuration space data,
158 * and puts them into a buffer for RTAS error logging.
160 static size_t eeh_gather_pci_data(struct eeh_dev
*edev
, char *buf
, size_t len
)
162 struct device_node
*dn
= eeh_dev_to_of_node(edev
);
168 n
+= scnprintf(buf
+n
, len
-n
, "%s\n", dn
->full_name
);
169 pr_warn("EEH: of node=%s\n", dn
->full_name
);
171 eeh_ops
->read_config(dn
, PCI_VENDOR_ID
, 4, &cfg
);
172 n
+= scnprintf(buf
+n
, len
-n
, "dev/vend:%08x\n", cfg
);
173 pr_warn("EEH: PCI device/vendor: %08x\n", cfg
);
175 eeh_ops
->read_config(dn
, PCI_COMMAND
, 4, &cfg
);
176 n
+= scnprintf(buf
+n
, len
-n
, "cmd/stat:%x\n", cfg
);
177 pr_warn("EEH: PCI cmd/status register: %08x\n", cfg
);
179 /* Gather bridge-specific registers */
180 if (edev
->mode
& EEH_DEV_BRIDGE
) {
181 eeh_ops
->read_config(dn
, PCI_SEC_STATUS
, 2, &cfg
);
182 n
+= scnprintf(buf
+n
, len
-n
, "sec stat:%x\n", cfg
);
183 pr_warn("EEH: Bridge secondary status: %04x\n", cfg
);
185 eeh_ops
->read_config(dn
, PCI_BRIDGE_CONTROL
, 2, &cfg
);
186 n
+= scnprintf(buf
+n
, len
-n
, "brdg ctl:%x\n", cfg
);
187 pr_warn("EEH: Bridge control: %04x\n", cfg
);
190 /* Dump out the PCI-X command and status regs */
191 cap
= edev
->pcix_cap
;
193 eeh_ops
->read_config(dn
, cap
, 4, &cfg
);
194 n
+= scnprintf(buf
+n
, len
-n
, "pcix-cmd:%x\n", cfg
);
195 pr_warn("EEH: PCI-X cmd: %08x\n", cfg
);
197 eeh_ops
->read_config(dn
, cap
+4, 4, &cfg
);
198 n
+= scnprintf(buf
+n
, len
-n
, "pcix-stat:%x\n", cfg
);
199 pr_warn("EEH: PCI-X status: %08x\n", cfg
);
202 /* If PCI-E capable, dump PCI-E cap 10 */
203 cap
= edev
->pcie_cap
;
205 n
+= scnprintf(buf
+n
, len
-n
, "pci-e cap10:\n");
206 pr_warn("EEH: PCI-E capabilities and status follow:\n");
208 for (i
=0; i
<=8; i
++) {
209 eeh_ops
->read_config(dn
, cap
+4*i
, 4, &cfg
);
210 n
+= scnprintf(buf
+n
, len
-n
, "%02x:%x\n", 4*i
, cfg
);
214 pr_warn("%s\n", buffer
);
216 l
= scnprintf(buffer
, sizeof(buffer
),
217 "EEH: PCI-E %02x: %08x ",
220 l
+= scnprintf(buffer
+l
, sizeof(buffer
)-l
,
226 pr_warn("%s\n", buffer
);
229 /* If AER capable, dump it */
232 n
+= scnprintf(buf
+n
, len
-n
, "pci-e AER:\n");
233 pr_warn("EEH: PCI-E AER capability register set follows:\n");
235 for (i
=0; i
<=13; i
++) {
236 eeh_ops
->read_config(dn
, cap
+4*i
, 4, &cfg
);
237 n
+= scnprintf(buf
+n
, len
-n
, "%02x:%x\n", 4*i
, cfg
);
241 pr_warn("%s\n", buffer
);
243 l
= scnprintf(buffer
, sizeof(buffer
),
244 "EEH: PCI-E AER %02x: %08x ",
247 l
+= scnprintf(buffer
+l
, sizeof(buffer
)-l
,
252 pr_warn("%s\n", buffer
);
259 * eeh_slot_error_detail - Generate combined log including driver log and error log
261 * @severity: temporary or permanent error log
263 * This routine should be called to generate the combined log, which
264 * is comprised of driver log and error log. The driver log is figured
265 * out from the config space of the corresponding PCI device, while
266 * the error log is fetched through platform dependent function call.
268 void eeh_slot_error_detail(struct eeh_pe
*pe
, int severity
)
271 struct eeh_dev
*edev
, *tmp
;
274 * When the PHB is fenced or dead, it's pointless to collect
275 * the data from PCI config space because it should return
276 * 0xFF's. For ER, we still retrieve the data from the PCI
279 * For pHyp, we have to enable IO for log retrieval. Otherwise,
280 * 0xFF's is always returned from PCI config space.
282 if (!(pe
->type
& EEH_PE_PHB
)) {
283 if (eeh_has_flag(EEH_ENABLE_IO_FOR_LOG
))
284 eeh_pci_enable(pe
, EEH_OPT_THAW_MMIO
);
285 eeh_ops
->configure_bridge(pe
);
286 eeh_pe_restore_bars(pe
);
289 eeh_pe_for_each_dev(pe
, edev
, tmp
) {
290 loglen
+= eeh_gather_pci_data(edev
, pci_regs_buf
+ loglen
,
291 EEH_PCI_REGS_LOG_LEN
- loglen
);
295 eeh_ops
->get_log(pe
, severity
, pci_regs_buf
, loglen
);
299 * eeh_token_to_phys - Convert EEH address token to phys address
300 * @token: I/O token, should be address in the form 0xA....
302 * This routine should be called to convert virtual I/O address
305 static inline unsigned long eeh_token_to_phys(unsigned long token
)
312 * We won't find hugepages here, iomem
314 ptep
= find_linux_pte_or_hugepte(init_mm
.pgd
, token
, &hugepage_shift
);
317 WARN_ON(hugepage_shift
);
318 pa
= pte_pfn(*ptep
) << PAGE_SHIFT
;
320 return pa
| (token
& (PAGE_SIZE
-1));
324 * On PowerNV platform, we might already have fenced PHB there.
325 * For that case, it's meaningless to recover frozen PE. Intead,
326 * We have to handle fenced PHB firstly.
328 static int eeh_phb_check_failure(struct eeh_pe
*pe
)
330 struct eeh_pe
*phb_pe
;
334 if (!eeh_has_flag(EEH_PROBE_MODE_DEV
))
337 /* Find the PHB PE */
338 phb_pe
= eeh_phb_pe_get(pe
->phb
);
340 pr_warn("%s Can't find PE for PHB#%d\n",
341 __func__
, pe
->phb
->global_number
);
345 /* If the PHB has been in problematic state */
346 eeh_serialize_lock(&flags
);
347 if (phb_pe
->state
& EEH_PE_ISOLATED
) {
352 /* Check PHB state */
353 ret
= eeh_ops
->get_state(phb_pe
, NULL
);
355 (ret
== EEH_STATE_NOT_SUPPORT
) ||
356 (ret
& (EEH_STATE_MMIO_ACTIVE
| EEH_STATE_DMA_ACTIVE
)) ==
357 (EEH_STATE_MMIO_ACTIVE
| EEH_STATE_DMA_ACTIVE
)) {
362 /* Isolate the PHB and send event */
363 eeh_pe_state_mark(phb_pe
, EEH_PE_ISOLATED
);
364 eeh_serialize_unlock(flags
);
366 pr_err("EEH: PHB#%x failure detected, location: %s\n",
367 phb_pe
->phb
->global_number
, eeh_pe_loc_get(phb_pe
));
369 eeh_send_failure_event(phb_pe
);
373 eeh_serialize_unlock(flags
);
378 * eeh_dev_check_failure - Check if all 1's data is due to EEH slot freeze
381 * Check for an EEH failure for the given device node. Call this
382 * routine if the result of a read was all 0xff's and you want to
383 * find out if this is due to an EEH slot freeze. This routine
384 * will query firmware for the EEH status.
386 * Returns 0 if there has not been an EEH error; otherwise returns
387 * a non-zero value and queues up a slot isolation event notification.
389 * It is safe to call this routine in an interrupt context.
391 int eeh_dev_check_failure(struct eeh_dev
*edev
)
394 int active_flags
= (EEH_STATE_MMIO_ACTIVE
| EEH_STATE_DMA_ACTIVE
);
396 struct device_node
*dn
;
398 struct eeh_pe
*pe
, *parent_pe
, *phb_pe
;
400 const char *location
;
402 eeh_stats
.total_mmio_ffs
++;
411 dn
= eeh_dev_to_of_node(edev
);
412 dev
= eeh_dev_to_pci_dev(edev
);
415 /* Access to IO BARs might get this far and still not want checking. */
417 eeh_stats
.ignored_check
++;
418 pr_debug("EEH: Ignored check for %s %s\n",
419 eeh_pci_name(dev
), dn
->full_name
);
423 if (!pe
->addr
&& !pe
->config_addr
) {
424 eeh_stats
.no_cfg_addr
++;
429 * On PowerNV platform, we might already have fenced PHB
430 * there and we need take care of that firstly.
432 ret
= eeh_phb_check_failure(pe
);
437 * If the PE isn't owned by us, we shouldn't check the
438 * state. Instead, let the owner handle it if the PE has
441 if (eeh_pe_passed(pe
))
444 /* If we already have a pending isolation event for this
445 * slot, we know it's bad already, we don't need to check.
446 * Do this checking under a lock; as multiple PCI devices
447 * in one slot might report errors simultaneously, and we
448 * only want one error recovery routine running.
450 eeh_serialize_lock(&flags
);
452 if (pe
->state
& EEH_PE_ISOLATED
) {
454 if (pe
->check_count
% EEH_MAX_FAILS
== 0) {
455 location
= of_get_property(dn
, "ibm,loc-code", NULL
);
456 printk(KERN_ERR
"EEH: %d reads ignored for recovering device at "
457 "location=%s driver=%s pci addr=%s\n",
458 pe
->check_count
, location
,
459 eeh_driver_name(dev
), eeh_pci_name(dev
));
460 printk(KERN_ERR
"EEH: Might be infinite loop in %s driver\n",
461 eeh_driver_name(dev
));
468 * Now test for an EEH failure. This is VERY expensive.
469 * Note that the eeh_config_addr may be a parent device
470 * in the case of a device behind a bridge, or it may be
471 * function zero of a multi-function device.
472 * In any case they must share a common PHB.
474 ret
= eeh_ops
->get_state(pe
, NULL
);
476 /* Note that config-io to empty slots may fail;
477 * they are empty when they don't have children.
478 * We will punt with the following conditions: Failure to get
479 * PE's state, EEH not support and Permanently unavailable
480 * state, PE is in good state.
483 (ret
== EEH_STATE_NOT_SUPPORT
) ||
484 ((ret
& active_flags
) == active_flags
)) {
485 eeh_stats
.false_positives
++;
486 pe
->false_positives
++;
492 * It should be corner case that the parent PE has been
493 * put into frozen state as well. We should take care
496 parent_pe
= pe
->parent
;
498 /* Hit the ceiling ? */
499 if (parent_pe
->type
& EEH_PE_PHB
)
502 /* Frozen parent PE ? */
503 ret
= eeh_ops
->get_state(parent_pe
, NULL
);
505 (ret
& active_flags
) != active_flags
)
508 /* Next parent level */
509 parent_pe
= parent_pe
->parent
;
512 eeh_stats
.slot_resets
++;
514 /* Avoid repeated reports of this failure, including problems
515 * with other functions on this device, and functions under
518 eeh_pe_state_mark(pe
, EEH_PE_ISOLATED
);
519 eeh_serialize_unlock(flags
);
521 /* Most EEH events are due to device driver bugs. Having
522 * a stack trace will help the device-driver authors figure
523 * out what happened. So print that out.
525 phb_pe
= eeh_phb_pe_get(pe
->phb
);
526 pr_err("EEH: Frozen PHB#%x-PE#%x detected\n",
527 pe
->phb
->global_number
, pe
->addr
);
528 pr_err("EEH: PE location: %s, PHB location: %s\n",
529 eeh_pe_loc_get(pe
), eeh_pe_loc_get(phb_pe
));
532 eeh_send_failure_event(pe
);
537 eeh_serialize_unlock(flags
);
541 EXPORT_SYMBOL_GPL(eeh_dev_check_failure
);
544 * eeh_check_failure - Check if all 1's data is due to EEH slot freeze
545 * @token: I/O token, should be address in the form 0xA....
546 * @val: value, should be all 1's (XXX why do we need this arg??)
548 * Check for an EEH failure at the given token address. Call this
549 * routine if the result of a read was all 0xff's and you want to
550 * find out if this is due to an EEH slot freeze event. This routine
551 * will query firmware for the EEH status.
553 * Note this routine is safe to call in an interrupt context.
555 unsigned long eeh_check_failure(const volatile void __iomem
*token
, unsigned long val
)
558 struct eeh_dev
*edev
;
560 /* Finding the phys addr + pci device; this is pretty quick. */
561 addr
= eeh_token_to_phys((unsigned long __force
) token
);
562 edev
= eeh_addr_cache_get_dev(addr
);
564 eeh_stats
.no_device
++;
568 eeh_dev_check_failure(edev
);
572 EXPORT_SYMBOL(eeh_check_failure
);
576 * eeh_pci_enable - Enable MMIO or DMA transfers for this slot
579 * This routine should be called to reenable frozen MMIO or DMA
580 * so that it would work correctly again. It's useful while doing
581 * recovery or log collection on the indicated device.
583 int eeh_pci_enable(struct eeh_pe
*pe
, int function
)
585 int rc
, flags
= (EEH_STATE_MMIO_ACTIVE
| EEH_STATE_DMA_ACTIVE
);
588 * pHyp doesn't allow to enable IO or DMA on unfrozen PE.
589 * Also, it's pointless to enable them on unfrozen PE. So
590 * we have the check here.
592 if (function
== EEH_OPT_THAW_MMIO
||
593 function
== EEH_OPT_THAW_DMA
) {
594 rc
= eeh_ops
->get_state(pe
, NULL
);
598 /* Needn't to enable or already enabled */
599 if ((rc
== EEH_STATE_NOT_SUPPORT
) ||
600 ((rc
& flags
) == flags
))
604 rc
= eeh_ops
->set_option(pe
, function
);
606 pr_warn("%s: Unexpected state change %d on "
607 "PHB#%d-PE#%x, err=%d\n",
608 __func__
, function
, pe
->phb
->global_number
,
611 rc
= eeh_ops
->wait_state(pe
, PCI_BUS_RESET_WAIT_MSEC
);
615 if ((function
== EEH_OPT_THAW_MMIO
) &&
616 (rc
& EEH_STATE_MMIO_ENABLED
))
619 if ((function
== EEH_OPT_THAW_DMA
) &&
620 (rc
& EEH_STATE_DMA_ENABLED
))
627 * pcibios_set_pcie_slot_reset - Set PCI-E reset state
628 * @dev: pci device struct
629 * @state: reset state to enter
634 int pcibios_set_pcie_reset_state(struct pci_dev
*dev
, enum pcie_reset_state state
)
636 struct eeh_dev
*edev
= pci_dev_to_eeh_dev(dev
);
637 struct eeh_pe
*pe
= edev
->pe
;
640 pr_err("%s: No PE found on PCI device %s\n",
641 __func__
, pci_name(dev
));
646 case pcie_deassert_reset
:
647 eeh_ops
->reset(pe
, EEH_RESET_DEACTIVATE
);
650 eeh_ops
->reset(pe
, EEH_RESET_HOT
);
652 case pcie_warm_reset
:
653 eeh_ops
->reset(pe
, EEH_RESET_FUNDAMENTAL
);
663 * eeh_set_pe_freset - Check the required reset for the indicated device
665 * @flag: return value
667 * Each device might have its preferred reset type: fundamental or
668 * hot reset. The routine is used to collected the information for
669 * the indicated device and its children so that the bunch of the
670 * devices could be reset properly.
672 static void *eeh_set_dev_freset(void *data
, void *flag
)
675 unsigned int *freset
= (unsigned int *)flag
;
676 struct eeh_dev
*edev
= (struct eeh_dev
*)data
;
678 dev
= eeh_dev_to_pci_dev(edev
);
680 *freset
|= dev
->needs_freset
;
686 * eeh_reset_pe_once - Assert the pci #RST line for 1/4 second
689 * Assert the PCI #RST line for 1/4 second.
691 static void eeh_reset_pe_once(struct eeh_pe
*pe
)
693 unsigned int freset
= 0;
695 /* Determine type of EEH reset required for
696 * Partitionable Endpoint, a hot-reset (1)
697 * or a fundamental reset (3).
698 * A fundamental reset required by any device under
699 * Partitionable Endpoint trumps hot-reset.
701 eeh_pe_dev_traverse(pe
, eeh_set_dev_freset
, &freset
);
704 eeh_ops
->reset(pe
, EEH_RESET_FUNDAMENTAL
);
706 eeh_ops
->reset(pe
, EEH_RESET_HOT
);
708 eeh_ops
->reset(pe
, EEH_RESET_DEACTIVATE
);
712 * eeh_reset_pe - Reset the indicated PE
715 * This routine should be called to reset indicated device, including
716 * PE. A PE might include multiple PCI devices and sometimes PCI bridges
717 * might be involved as well.
719 int eeh_reset_pe(struct eeh_pe
*pe
)
721 int flags
= (EEH_STATE_MMIO_ACTIVE
| EEH_STATE_DMA_ACTIVE
);
724 /* Take three shots at resetting the bus */
725 for (i
=0; i
<3; i
++) {
726 eeh_reset_pe_once(pe
);
729 * EEH_PE_ISOLATED is expected to be removed after
732 rc
= eeh_ops
->wait_state(pe
, PCI_BUS_RESET_WAIT_MSEC
);
733 if ((rc
& flags
) == flags
)
737 pr_err("%s: Unrecoverable slot failure on PHB#%d-PE#%x",
738 __func__
, pe
->phb
->global_number
, pe
->addr
);
741 pr_err("EEH: bus reset %d failed on PHB#%d-PE#%x, rc=%d\n",
742 i
+1, pe
->phb
->global_number
, pe
->addr
, rc
);
749 * eeh_save_bars - Save device bars
750 * @edev: PCI device associated EEH device
752 * Save the values of the device bars. Unlike the restore
753 * routine, this routine is *not* recursive. This is because
754 * PCI devices are added individually; but, for the restore,
755 * an entire slot is reset at a time.
757 void eeh_save_bars(struct eeh_dev
*edev
)
760 struct device_node
*dn
;
764 dn
= eeh_dev_to_of_node(edev
);
766 for (i
= 0; i
< 16; i
++)
767 eeh_ops
->read_config(dn
, i
* 4, 4, &edev
->config_space
[i
]);
770 * For PCI bridges including root port, we need enable bus
771 * master explicitly. Otherwise, it can't fetch IODA table
772 * entries correctly. So we cache the bit in advance so that
773 * we can restore it after reset, either PHB range or PE range.
775 if (edev
->mode
& EEH_DEV_BRIDGE
)
776 edev
->config_space
[1] |= PCI_COMMAND_MASTER
;
780 * eeh_ops_register - Register platform dependent EEH operations
781 * @ops: platform dependent EEH operations
783 * Register the platform dependent EEH operation callback
784 * functions. The platform should call this function before
785 * any other EEH operations.
787 int __init
eeh_ops_register(struct eeh_ops
*ops
)
790 pr_warn("%s: Invalid EEH ops name for %p\n",
795 if (eeh_ops
&& eeh_ops
!= ops
) {
796 pr_warn("%s: EEH ops of platform %s already existing (%s)\n",
797 __func__
, eeh_ops
->name
, ops
->name
);
807 * eeh_ops_unregister - Unreigster platform dependent EEH operations
808 * @name: name of EEH platform operations
810 * Unregister the platform dependent EEH operation callback
813 int __exit
eeh_ops_unregister(const char *name
)
815 if (!name
|| !strlen(name
)) {
816 pr_warn("%s: Invalid EEH ops name\n",
821 if (eeh_ops
&& !strcmp(eeh_ops
->name
, name
)) {
829 static int eeh_reboot_notifier(struct notifier_block
*nb
,
830 unsigned long action
, void *unused
)
832 eeh_clear_flag(EEH_ENABLED
);
836 static struct notifier_block eeh_reboot_nb
= {
837 .notifier_call
= eeh_reboot_notifier
,
841 * eeh_init - EEH initialization
843 * Initialize EEH by trying to enable it for all of the adapters in the system.
844 * As a side effect we can determine here if eeh is supported at all.
845 * Note that we leave EEH on so failed config cycles won't cause a machine
846 * check. If a user turns off EEH for a particular adapter they are really
847 * telling Linux to ignore errors. Some hardware (e.g. POWER5) won't
848 * grant access to a slot if EEH isn't enabled, and so we always enable
849 * EEH for all slots/all devices.
851 * The eeh-force-off option disables EEH checking globally, for all slots.
852 * Even if force-off is set, the EEH hardware is still enabled, so that
853 * newer systems can boot.
857 struct pci_controller
*hose
, *tmp
;
858 struct device_node
*phb
;
863 * We have to delay the initialization on PowerNV after
864 * the PCI hierarchy tree has been built because the PEs
865 * are figured out based on PCI devices instead of device
868 if (machine_is(powernv
) && cnt
++ <= 0)
871 /* Register reboot notifier */
872 ret
= register_reboot_notifier(&eeh_reboot_nb
);
874 pr_warn("%s: Failed to register notifier (%d)\n",
879 /* call platform initialization function */
881 pr_warn("%s: Platform EEH operation not found\n",
884 } else if ((ret
= eeh_ops
->init())) {
885 pr_warn("%s: Failed to call platform init function (%d)\n",
890 /* Initialize EEH event */
891 ret
= eeh_event_init();
895 /* Enable EEH for all adapters */
896 if (eeh_has_flag(EEH_PROBE_MODE_DEVTREE
)) {
897 list_for_each_entry_safe(hose
, tmp
,
898 &hose_list
, list_node
) {
900 traverse_pci_devices(phb
, eeh_ops
->of_probe
, NULL
);
902 } else if (eeh_has_flag(EEH_PROBE_MODE_DEV
)) {
903 list_for_each_entry_safe(hose
, tmp
,
904 &hose_list
, list_node
)
905 pci_walk_bus(hose
->bus
, eeh_ops
->dev_probe
, NULL
);
907 pr_warn("%s: Invalid probe mode %x",
908 __func__
, eeh_subsystem_flags
);
913 * Call platform post-initialization. Actually, It's good chance
914 * to inform platform that EEH is ready to supply service if the
915 * I/O cache stuff has been built up.
917 if (eeh_ops
->post_init
) {
918 ret
= eeh_ops
->post_init();
924 pr_info("EEH: PCI Enhanced I/O Error Handling Enabled\n");
926 pr_warn("EEH: No capable adapters found\n");
931 core_initcall_sync(eeh_init
);
934 * eeh_add_device_early - Enable EEH for the indicated device_node
935 * @dn: device node for which to set up EEH
937 * This routine must be used to perform EEH initialization for PCI
938 * devices that were added after system boot (e.g. hotplug, dlpar).
939 * This routine must be called before any i/o is performed to the
940 * adapter (inluding any config-space i/o).
941 * Whether this actually enables EEH or not for this device depends
942 * on the CEC architecture, type of the device, on earlier boot
943 * command-line arguments & etc.
945 void eeh_add_device_early(struct device_node
*dn
)
947 struct pci_controller
*phb
;
950 * If we're doing EEH probe based on PCI device, we
951 * would delay the probe until late stage because
952 * the PCI device isn't available this moment.
954 if (!eeh_has_flag(EEH_PROBE_MODE_DEVTREE
))
957 if (!of_node_to_eeh_dev(dn
))
959 phb
= of_node_to_eeh_dev(dn
)->phb
;
961 /* USB Bus children of PCI devices will not have BUID's */
962 if (NULL
== phb
|| 0 == phb
->buid
)
965 eeh_ops
->of_probe(dn
, NULL
);
969 * eeh_add_device_tree_early - Enable EEH for the indicated device
972 * This routine must be used to perform EEH initialization for the
973 * indicated PCI device that was added after system boot (e.g.
976 void eeh_add_device_tree_early(struct device_node
*dn
)
978 struct device_node
*sib
;
980 for_each_child_of_node(dn
, sib
)
981 eeh_add_device_tree_early(sib
);
982 eeh_add_device_early(dn
);
984 EXPORT_SYMBOL_GPL(eeh_add_device_tree_early
);
987 * eeh_add_device_late - Perform EEH initialization for the indicated pci device
988 * @dev: pci device for which to set up EEH
990 * This routine must be used to complete EEH initialization for PCI
991 * devices that were added after system boot (e.g. hotplug, dlpar).
993 void eeh_add_device_late(struct pci_dev
*dev
)
995 struct device_node
*dn
;
996 struct eeh_dev
*edev
;
998 if (!dev
|| !eeh_enabled())
1001 pr_debug("EEH: Adding device %s\n", pci_name(dev
));
1003 dn
= pci_device_to_OF_node(dev
);
1004 edev
= of_node_to_eeh_dev(dn
);
1005 if (edev
->pdev
== dev
) {
1006 pr_debug("EEH: Already referenced !\n");
1011 * The EEH cache might not be removed correctly because of
1012 * unbalanced kref to the device during unplug time, which
1013 * relies on pcibios_release_device(). So we have to remove
1014 * that here explicitly.
1017 eeh_rmv_from_parent_pe(edev
);
1018 eeh_addr_cache_rmv_dev(edev
->pdev
);
1019 eeh_sysfs_remove_device(edev
->pdev
);
1020 edev
->mode
&= ~EEH_DEV_SYSFS
;
1023 * We definitely should have the PCI device removed
1024 * though it wasn't correctly. So we needn't call
1025 * into error handler afterwards.
1027 edev
->mode
|= EEH_DEV_NO_HANDLER
;
1030 dev
->dev
.archdata
.edev
= NULL
;
1034 dev
->dev
.archdata
.edev
= edev
;
1037 * We have to do the EEH probe here because the PCI device
1038 * hasn't been created yet in the early stage.
1040 if (eeh_has_flag(EEH_PROBE_MODE_DEV
))
1041 eeh_ops
->dev_probe(dev
, NULL
);
1043 eeh_addr_cache_insert_dev(dev
);
1047 * eeh_add_device_tree_late - Perform EEH initialization for the indicated PCI bus
1050 * This routine must be used to perform EEH initialization for PCI
1051 * devices which are attached to the indicated PCI bus. The PCI bus
1052 * is added after system boot through hotplug or dlpar.
1054 void eeh_add_device_tree_late(struct pci_bus
*bus
)
1056 struct pci_dev
*dev
;
1058 list_for_each_entry(dev
, &bus
->devices
, bus_list
) {
1059 eeh_add_device_late(dev
);
1060 if (dev
->hdr_type
== PCI_HEADER_TYPE_BRIDGE
) {
1061 struct pci_bus
*subbus
= dev
->subordinate
;
1063 eeh_add_device_tree_late(subbus
);
1067 EXPORT_SYMBOL_GPL(eeh_add_device_tree_late
);
1070 * eeh_add_sysfs_files - Add EEH sysfs files for the indicated PCI bus
1073 * This routine must be used to add EEH sysfs files for PCI
1074 * devices which are attached to the indicated PCI bus. The PCI bus
1075 * is added after system boot through hotplug or dlpar.
1077 void eeh_add_sysfs_files(struct pci_bus
*bus
)
1079 struct pci_dev
*dev
;
1081 list_for_each_entry(dev
, &bus
->devices
, bus_list
) {
1082 eeh_sysfs_add_device(dev
);
1083 if (dev
->hdr_type
== PCI_HEADER_TYPE_BRIDGE
) {
1084 struct pci_bus
*subbus
= dev
->subordinate
;
1086 eeh_add_sysfs_files(subbus
);
1090 EXPORT_SYMBOL_GPL(eeh_add_sysfs_files
);
1093 * eeh_remove_device - Undo EEH setup for the indicated pci device
1094 * @dev: pci device to be removed
1096 * This routine should be called when a device is removed from
1097 * a running system (e.g. by hotplug or dlpar). It unregisters
1098 * the PCI device from the EEH subsystem. I/O errors affecting
1099 * this device will no longer be detected after this call; thus,
1100 * i/o errors affecting this slot may leave this device unusable.
1102 void eeh_remove_device(struct pci_dev
*dev
)
1104 struct eeh_dev
*edev
;
1106 if (!dev
|| !eeh_enabled())
1108 edev
= pci_dev_to_eeh_dev(dev
);
1110 /* Unregister the device with the EEH/PCI address search system */
1111 pr_debug("EEH: Removing device %s\n", pci_name(dev
));
1113 if (!edev
|| !edev
->pdev
|| !edev
->pe
) {
1114 pr_debug("EEH: Not referenced !\n");
1119 * During the hotplug for EEH error recovery, we need the EEH
1120 * device attached to the parent PE in order for BAR restore
1121 * a bit later. So we keep it for BAR restore and remove it
1122 * from the parent PE during the BAR resotre.
1125 dev
->dev
.archdata
.edev
= NULL
;
1126 if (!(edev
->pe
->state
& EEH_PE_KEEP
))
1127 eeh_rmv_from_parent_pe(edev
);
1129 edev
->mode
|= EEH_DEV_DISCONNECTED
;
1132 * We're removing from the PCI subsystem, that means
1133 * the PCI device driver can't support EEH or not
1134 * well. So we rely on hotplug completely to do recovery
1135 * for the specific PCI device.
1137 edev
->mode
|= EEH_DEV_NO_HANDLER
;
1139 eeh_addr_cache_rmv_dev(dev
);
1140 eeh_sysfs_remove_device(dev
);
1141 edev
->mode
&= ~EEH_DEV_SYSFS
;
1145 * eeh_dev_open - Increase count of pass through devices for PE
1148 * Increase count of passed through devices for the indicated
1149 * PE. In the result, the EEH errors detected on the PE won't be
1150 * reported. The PE owner will be responsible for detection
1153 int eeh_dev_open(struct pci_dev
*pdev
)
1155 struct eeh_dev
*edev
;
1157 mutex_lock(&eeh_dev_mutex
);
1159 /* No PCI device ? */
1163 /* No EEH device or PE ? */
1164 edev
= pci_dev_to_eeh_dev(pdev
);
1165 if (!edev
|| !edev
->pe
)
1168 /* Increase PE's pass through count */
1169 atomic_inc(&edev
->pe
->pass_dev_cnt
);
1170 mutex_unlock(&eeh_dev_mutex
);
1174 mutex_unlock(&eeh_dev_mutex
);
1177 EXPORT_SYMBOL_GPL(eeh_dev_open
);
1180 * eeh_dev_release - Decrease count of pass through devices for PE
1183 * Decrease count of pass through devices for the indicated PE. If
1184 * there is no passed through device in PE, the EEH errors detected
1185 * on the PE will be reported and handled as usual.
1187 void eeh_dev_release(struct pci_dev
*pdev
)
1189 struct eeh_dev
*edev
;
1191 mutex_lock(&eeh_dev_mutex
);
1193 /* No PCI device ? */
1197 /* No EEH device ? */
1198 edev
= pci_dev_to_eeh_dev(pdev
);
1199 if (!edev
|| !edev
->pe
|| !eeh_pe_passed(edev
->pe
))
1202 /* Decrease PE's pass through count */
1203 atomic_dec(&edev
->pe
->pass_dev_cnt
);
1204 WARN_ON(atomic_read(&edev
->pe
->pass_dev_cnt
) < 0);
1206 mutex_unlock(&eeh_dev_mutex
);
1208 EXPORT_SYMBOL(eeh_dev_release
);
1210 #ifdef CONFIG_IOMMU_API
1212 static int dev_has_iommu_table(struct device
*dev
, void *data
)
1214 struct pci_dev
*pdev
= to_pci_dev(dev
);
1215 struct pci_dev
**ppdev
= data
;
1216 struct iommu_table
*tbl
;
1221 tbl
= get_iommu_table_base(dev
);
1222 if (tbl
&& tbl
->it_group
) {
1231 * eeh_iommu_group_to_pe - Convert IOMMU group to EEH PE
1232 * @group: IOMMU group
1234 * The routine is called to convert IOMMU group to EEH PE.
1236 struct eeh_pe
*eeh_iommu_group_to_pe(struct iommu_group
*group
)
1238 struct pci_dev
*pdev
= NULL
;
1239 struct eeh_dev
*edev
;
1242 /* No IOMMU group ? */
1246 ret
= iommu_group_for_each_dev(group
, &pdev
, dev_has_iommu_table
);
1250 /* No EEH device or PE ? */
1251 edev
= pci_dev_to_eeh_dev(pdev
);
1252 if (!edev
|| !edev
->pe
)
1257 EXPORT_SYMBOL_GPL(eeh_iommu_group_to_pe
);
1259 #endif /* CONFIG_IOMMU_API */
1262 * eeh_pe_set_option - Set options for the indicated PE
1264 * @option: requested option
1266 * The routine is called to enable or disable EEH functionality
1267 * on the indicated PE, to enable IO or DMA for the frozen PE.
1269 int eeh_pe_set_option(struct eeh_pe
*pe
, int option
)
1278 * EEH functionality could possibly be disabled, just
1279 * return error for the case. And the EEH functinality
1280 * isn't expected to be disabled on one specific PE.
1283 case EEH_OPT_ENABLE
:
1288 case EEH_OPT_DISABLE
:
1290 case EEH_OPT_THAW_MMIO
:
1291 case EEH_OPT_THAW_DMA
:
1292 if (!eeh_ops
|| !eeh_ops
->set_option
) {
1297 ret
= eeh_ops
->set_option(pe
, option
);
1300 pr_debug("%s: Option %d out of range (%d, %d)\n",
1301 __func__
, option
, EEH_OPT_DISABLE
, EEH_OPT_THAW_DMA
);
1307 EXPORT_SYMBOL_GPL(eeh_pe_set_option
);
1310 * eeh_pe_get_state - Retrieve PE's state
1313 * Retrieve the PE's state, which includes 3 aspects: enabled
1314 * DMA, enabled IO and asserted reset.
1316 int eeh_pe_get_state(struct eeh_pe
*pe
)
1318 int result
, ret
= 0;
1319 bool rst_active
, dma_en
, mmio_en
;
1325 if (!eeh_ops
|| !eeh_ops
->get_state
)
1328 result
= eeh_ops
->get_state(pe
, NULL
);
1329 rst_active
= !!(result
& EEH_STATE_RESET_ACTIVE
);
1330 dma_en
= !!(result
& EEH_STATE_DMA_ENABLED
);
1331 mmio_en
= !!(result
& EEH_STATE_MMIO_ENABLED
);
1334 ret
= EEH_PE_STATE_RESET
;
1335 else if (dma_en
&& mmio_en
)
1336 ret
= EEH_PE_STATE_NORMAL
;
1337 else if (!dma_en
&& !mmio_en
)
1338 ret
= EEH_PE_STATE_STOPPED_IO_DMA
;
1339 else if (!dma_en
&& mmio_en
)
1340 ret
= EEH_PE_STATE_STOPPED_DMA
;
1342 ret
= EEH_PE_STATE_UNAVAIL
;
1346 EXPORT_SYMBOL_GPL(eeh_pe_get_state
);
1349 * eeh_pe_reset - Issue PE reset according to specified type
1351 * @option: reset type
1353 * The routine is called to reset the specified PE with the
1354 * indicated type, either fundamental reset or hot reset.
1355 * PE reset is the most important part for error recovery.
1357 int eeh_pe_reset(struct eeh_pe
*pe
, int option
)
1365 if (!eeh_ops
|| !eeh_ops
->set_option
|| !eeh_ops
->reset
)
1369 case EEH_RESET_DEACTIVATE
:
1370 ret
= eeh_ops
->reset(pe
, option
);
1375 * The PE is still in frozen state and we need to clear
1376 * that. It's good to clear frozen state after deassert
1377 * to avoid messy IO access during reset, which might
1378 * cause recursive frozen PE.
1380 ret
= eeh_ops
->set_option(pe
, EEH_OPT_THAW_MMIO
);
1382 ret
= eeh_ops
->set_option(pe
, EEH_OPT_THAW_DMA
);
1384 eeh_pe_state_clear(pe
, EEH_PE_ISOLATED
);
1387 case EEH_RESET_FUNDAMENTAL
:
1388 ret
= eeh_ops
->reset(pe
, option
);
1391 pr_debug("%s: Unsupported option %d\n",
1398 EXPORT_SYMBOL_GPL(eeh_pe_reset
);
1401 * eeh_pe_configure - Configure PCI bridges after PE reset
1404 * The routine is called to restore the PCI config space for
1405 * those PCI devices, especially PCI bridges affected by PE
1406 * reset issued previously.
1408 int eeh_pe_configure(struct eeh_pe
*pe
)
1416 /* Restore config space for the affected devices */
1417 eeh_pe_restore_bars(pe
);
1421 EXPORT_SYMBOL_GPL(eeh_pe_configure
);
1423 static int proc_eeh_show(struct seq_file
*m
, void *v
)
1425 if (!eeh_enabled()) {
1426 seq_printf(m
, "EEH Subsystem is globally disabled\n");
1427 seq_printf(m
, "eeh_total_mmio_ffs=%llu\n", eeh_stats
.total_mmio_ffs
);
1429 seq_printf(m
, "EEH Subsystem is enabled\n");
1432 "no device node=%llu\n"
1433 "no config address=%llu\n"
1434 "check not wanted=%llu\n"
1435 "eeh_total_mmio_ffs=%llu\n"
1436 "eeh_false_positives=%llu\n"
1437 "eeh_slot_resets=%llu\n",
1438 eeh_stats
.no_device
,
1440 eeh_stats
.no_cfg_addr
,
1441 eeh_stats
.ignored_check
,
1442 eeh_stats
.total_mmio_ffs
,
1443 eeh_stats
.false_positives
,
1444 eeh_stats
.slot_resets
);
1450 static int proc_eeh_open(struct inode
*inode
, struct file
*file
)
1452 return single_open(file
, proc_eeh_show
, NULL
);
1455 static const struct file_operations proc_eeh_operations
= {
1456 .open
= proc_eeh_open
,
1458 .llseek
= seq_lseek
,
1459 .release
= single_release
,
1462 #ifdef CONFIG_DEBUG_FS
1463 static int eeh_enable_dbgfs_set(void *data
, u64 val
)
1466 eeh_clear_flag(EEH_FORCE_DISABLED
);
1468 eeh_add_flag(EEH_FORCE_DISABLED
);
1470 /* Notify the backend */
1471 if (eeh_ops
->post_init
)
1472 eeh_ops
->post_init();
1477 static int eeh_enable_dbgfs_get(void *data
, u64
*val
)
1486 DEFINE_SIMPLE_ATTRIBUTE(eeh_enable_dbgfs_ops
, eeh_enable_dbgfs_get
,
1487 eeh_enable_dbgfs_set
, "0x%llx\n");
1490 static int __init
eeh_init_proc(void)
1492 if (machine_is(pseries
) || machine_is(powernv
)) {
1493 proc_create("powerpc/eeh", 0, NULL
, &proc_eeh_operations
);
1494 #ifdef CONFIG_DEBUG_FS
1495 debugfs_create_file("eeh_enable", 0600,
1496 powerpc_debugfs_root
, NULL
,
1497 &eeh_enable_dbgfs_ops
);
1503 __initcall(eeh_init_proc
);