mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-23 17:30:02 +00:00
![Michael Ellerman](/assets/img/avatar_default.png)
The build breaks when STACKTRACE=n, eg. skiroot_defconfig:
arch/powerpc/kernel/eeh_event.c:124:23: error: implicit declaration of function 'stack_trace_save'
Fix it with some ifdefs for now.
Fixes: 25baf3d816
("powerpc/eeh: Defer printing stack trace")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
201 lines
5 KiB
C
201 lines
5 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/*
|
|
*
|
|
* Copyright (c) 2005 Linas Vepstas <linas@linas.org>
|
|
*/
|
|
|
|
#include <linux/delay.h>
|
|
#include <linux/list.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/semaphore.h>
|
|
#include <linux/pci.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/kthread.h>
|
|
#include <asm/eeh_event.h>
|
|
#include <asm/ppc-pci.h>
|
|
|
|
/** Overview:
|
|
* EEH error states may be detected within exception handlers;
|
|
* however, the recovery processing needs to occur asynchronously
|
|
* in a normal kernel context and not an interrupt context.
|
|
* This pair of routines creates an event and queues it onto a
|
|
* work-queue, where a worker thread can drive recovery.
|
|
*/
|
|
|
|
static DEFINE_SPINLOCK(eeh_eventlist_lock);
|
|
static DECLARE_COMPLETION(eeh_eventlist_event);
|
|
static LIST_HEAD(eeh_eventlist);
|
|
|
|
/**
|
|
* eeh_event_handler - Dispatch EEH events.
|
|
* @dummy - unused
|
|
*
|
|
* The detection of a frozen slot can occur inside an interrupt,
|
|
* where it can be hard to do anything about it. The goal of this
|
|
* routine is to pull these detection events out of the context
|
|
* of the interrupt handler, and re-dispatch them for processing
|
|
* at a later time in a normal context.
|
|
*/
|
|
static int eeh_event_handler(void * dummy)
|
|
{
|
|
unsigned long flags;
|
|
struct eeh_event *event;
|
|
|
|
while (!kthread_should_stop()) {
|
|
if (wait_for_completion_interruptible(&eeh_eventlist_event))
|
|
break;
|
|
|
|
/* Fetch EEH event from the queue */
|
|
spin_lock_irqsave(&eeh_eventlist_lock, flags);
|
|
event = NULL;
|
|
if (!list_empty(&eeh_eventlist)) {
|
|
event = list_entry(eeh_eventlist.next,
|
|
struct eeh_event, list);
|
|
list_del(&event->list);
|
|
}
|
|
spin_unlock_irqrestore(&eeh_eventlist_lock, flags);
|
|
if (!event)
|
|
continue;
|
|
|
|
/* We might have event without binding PE */
|
|
if (event->pe)
|
|
eeh_handle_normal_event(event->pe);
|
|
else
|
|
eeh_handle_special_event();
|
|
|
|
kfree(event);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* eeh_event_init - Start kernel thread to handle EEH events
|
|
*
|
|
* This routine is called to start the kernel thread for processing
|
|
* EEH event.
|
|
*/
|
|
int eeh_event_init(void)
|
|
{
|
|
struct task_struct *t;
|
|
int ret = 0;
|
|
|
|
t = kthread_run(eeh_event_handler, NULL, "eehd");
|
|
if (IS_ERR(t)) {
|
|
ret = PTR_ERR(t);
|
|
pr_err("%s: Failed to start EEH daemon (%d)\n",
|
|
__func__, ret);
|
|
return ret;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* eeh_send_failure_event - Generate a PCI error event
|
|
* @pe: EEH PE
|
|
*
|
|
* This routine can be called within an interrupt context;
|
|
* the actual event will be delivered in a normal context
|
|
* (from a workqueue).
|
|
*/
|
|
int __eeh_send_failure_event(struct eeh_pe *pe)
|
|
{
|
|
unsigned long flags;
|
|
struct eeh_event *event;
|
|
|
|
event = kzalloc(sizeof(*event), GFP_ATOMIC);
|
|
if (!event) {
|
|
pr_err("EEH: out of memory, event not handled\n");
|
|
return -ENOMEM;
|
|
}
|
|
event->pe = pe;
|
|
|
|
/*
|
|
* Mark the PE as recovering before inserting it in the queue.
|
|
* This prevents the PE from being free()ed by a hotplug driver
|
|
* while the PE is sitting in the event queue.
|
|
*/
|
|
if (pe) {
|
|
#ifdef CONFIG_STACKTRACE
|
|
/*
|
|
* Save the current stack trace so we can dump it from the
|
|
* event handler thread.
|
|
*/
|
|
pe->trace_entries = stack_trace_save(pe->stack_trace,
|
|
ARRAY_SIZE(pe->stack_trace), 0);
|
|
#endif /* CONFIG_STACKTRACE */
|
|
|
|
eeh_pe_state_mark(pe, EEH_PE_RECOVERING);
|
|
}
|
|
|
|
/* We may or may not be called in an interrupt context */
|
|
spin_lock_irqsave(&eeh_eventlist_lock, flags);
|
|
list_add(&event->list, &eeh_eventlist);
|
|
spin_unlock_irqrestore(&eeh_eventlist_lock, flags);
|
|
|
|
/* For EEH deamon to knick in */
|
|
complete(&eeh_eventlist_event);
|
|
|
|
return 0;
|
|
}
|
|
|
|
int eeh_send_failure_event(struct eeh_pe *pe)
|
|
{
|
|
/*
|
|
* If we've manually supressed recovery events via debugfs
|
|
* then just drop it on the floor.
|
|
*/
|
|
if (eeh_debugfs_no_recover) {
|
|
pr_err("EEH: Event dropped due to no_recover setting\n");
|
|
return 0;
|
|
}
|
|
|
|
return __eeh_send_failure_event(pe);
|
|
}
|
|
|
|
/**
|
|
* eeh_remove_event - Remove EEH event from the queue
|
|
* @pe: Event binding to the PE
|
|
* @force: Event will be removed unconditionally
|
|
*
|
|
* On PowerNV platform, we might have subsequent coming events
|
|
* is part of the former one. For that case, those subsequent
|
|
* coming events are totally duplicated and unnecessary, thus
|
|
* they should be removed.
|
|
*/
|
|
void eeh_remove_event(struct eeh_pe *pe, bool force)
|
|
{
|
|
unsigned long flags;
|
|
struct eeh_event *event, *tmp;
|
|
|
|
/*
|
|
* If we have NULL PE passed in, we have dead IOC
|
|
* or we're sure we can report all existing errors
|
|
* by the caller.
|
|
*
|
|
* With "force", the event with associated PE that
|
|
* have been isolated, the event won't be removed
|
|
* to avoid event lost.
|
|
*/
|
|
spin_lock_irqsave(&eeh_eventlist_lock, flags);
|
|
list_for_each_entry_safe(event, tmp, &eeh_eventlist, list) {
|
|
if (!force && event->pe &&
|
|
(event->pe->state & EEH_PE_ISOLATED))
|
|
continue;
|
|
|
|
if (!pe) {
|
|
list_del(&event->list);
|
|
kfree(event);
|
|
} else if (pe->type & EEH_PE_PHB) {
|
|
if (event->pe && event->pe->phb == pe->phb) {
|
|
list_del(&event->list);
|
|
kfree(event);
|
|
}
|
|
} else if (event->pe == pe) {
|
|
list_del(&event->list);
|
|
kfree(event);
|
|
}
|
|
}
|
|
spin_unlock_irqrestore(&eeh_eventlist_lock, flags);
|
|
}
|