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authorLinus Torvalds <torvalds@linux-foundation.org>2013-07-04 19:29:23 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2013-07-04 19:29:23 +0200
commit65b97fb7303050fc826e518cf67fc283da23314f (patch)
tree595e7f04d65d95a39d65bd2dcf2385b3b6ea7969 /arch/powerpc/kernel/eeh_event.c
parentMerge tag 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/... (diff)
parentpstore: Add hsize argument in write_buf call of pstore_ftrace_call (diff)
downloadlinux-65b97fb7303050fc826e518cf67fc283da23314f.tar.xz
linux-65b97fb7303050fc826e518cf67fc283da23314f.zip
Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc
Pull powerpc updates from Ben Herrenschmidt: "This is the powerpc changes for the 3.11 merge window. In addition to the usual bug fixes and small updates, the main highlights are: - Support for transparent huge pages by Aneesh Kumar for 64-bit server processors. This allows the use of 16M pages as transparent huge pages on kernels compiled with a 64K base page size. - Base VFIO support for KVM on power by Alexey Kardashevskiy - Wiring up of our nvram to the pstore infrastructure, including putting compressed oopses in there by Aruna Balakrishnaiah - Move, rework and improve our "EEH" (basically PCI error handling and recovery) infrastructure. It is no longer specific to pseries but is now usable by the new "powernv" platform as well (no hypervisor) by Gavin Shan. - I fixed some bugs in our math-emu instruction decoding and made it usable to emulate some optional FP instructions on processors with hard FP that lack them (such as fsqrt on Freescale embedded processors). - Support for Power8 "Event Based Branch" facility by Michael Ellerman. This facility allows what is basically "userspace interrupts" for performance monitor events. - A bunch of Transactional Memory vs. Signals bug fixes and HW breakpoint/watchpoint fixes by Michael Neuling. And more ... I appologize in advance if I've failed to highlight something that somebody deemed worth it." * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (156 commits) pstore: Add hsize argument in write_buf call of pstore_ftrace_call powerpc/fsl: add MPIC timer wakeup support powerpc/mpic: create mpic subsystem object powerpc/mpic: add global timer support powerpc/mpic: add irq_set_wake support powerpc/85xx: enable coreint for all the 64bit boards powerpc/8xx: Erroneous double irq_eoi() on CPM IRQ in MPC8xx powerpc/fsl: Enable CONFIG_E1000E in mpc85xx_smp_defconfig powerpc/mpic: Add get_version API both for internal and external use powerpc: Handle both new style and old style reserve maps powerpc/hw_brk: Fix off by one error when validating DAWR region end powerpc/pseries: Support compression of oops text via pstore powerpc/pseries: Re-organise the oops compression code pstore: Pass header size in the pstore write callback powerpc/powernv: Fix iommu initialization again powerpc/pseries: Inform the hypervisor we are using EBB regs powerpc/perf: Add power8 EBB support powerpc/perf: Core EBB support for 64-bit book3s powerpc/perf: Drop MMCRA from thread_struct powerpc/perf: Don't enable if we have zero events ...
Diffstat (limited to 'arch/powerpc/kernel/eeh_event.c')
-rw-r--r--arch/powerpc/kernel/eeh_event.c182
1 files changed, 182 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/eeh_event.c b/arch/powerpc/kernel/eeh_event.c
new file mode 100644
index 000000000000..d27c5afc90ae
--- /dev/null
+++ b/arch/powerpc/kernel/eeh_event.c
@@ -0,0 +1,182 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * 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 struct semaphore eeh_eventlist_sem;
+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;
+ struct eeh_pe *pe;
+
+ while (!kthread_should_stop()) {
+ if (down_interruptible(&eeh_eventlist_sem))
+ 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 */
+ pe = event->pe;
+ if (pe) {
+ eeh_pe_state_mark(pe, EEH_PE_RECOVERING);
+ pr_info("EEH: Detected PCI bus error on PHB#%d-PE#%x\n",
+ pe->phb->global_number, pe->addr);
+ eeh_handle_event(pe);
+ eeh_pe_state_clear(pe, EEH_PE_RECOVERING);
+ } else {
+ eeh_handle_event(NULL);
+ }
+
+ 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;
+
+ /* Initialize semaphore */
+ sema_init(&eeh_eventlist_sem, 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;
+
+ /* 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 */
+ up(&eeh_eventlist_sem);
+
+ return 0;
+}
+
+/**
+ * eeh_remove_event - Remove EEH event from the queue
+ * @pe: Event binding to the PE
+ *
+ * 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)
+{
+ unsigned long flags;
+ struct eeh_event *event, *tmp;
+
+ spin_lock_irqsave(&eeh_eventlist_lock, flags);
+ list_for_each_entry_safe(event, tmp, &eeh_eventlist, list) {
+ /*
+ * If we don't have valid PE passed in, that means
+ * we already have event corresponding to dead IOC
+ * and all events should be purged.
+ */
+ 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);
+}