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authorGavin Shan <shangw@linux.vnet.ibm.com>2013-06-20 13:20:52 +0800
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2013-06-20 17:05:35 +1000
commit317f06de78152e0eb0aab5881d69e4c5cdf9f1fe (patch)
tree7e3253345db6e8bab2089eee8cd268ac0c90ac9b /arch/powerpc/kernel/eeh_event.c
parenta84f273c30500c0d5816e07232e3326a61956016 (diff)
downloadlinux-317f06de78152e0eb0aab5881d69e4c5cdf9f1fe.tar.bz2
powerpc/eeh: Move common part to kernel directory
The patch moves the common part of EEH core into arch/powerpc/kernel directory so that we needn't PPC_PSERIES while compiling POWERNV platform: * Move the EEH common part into arch/powerpc/kernel * Move the functions for PCI hotplug from pSeries platform to arch/powerpc/kernel/pci-hotplug.c * Move CONFIG_EEH from arch/powerpc/platforms/pseries/Kconfig to arch/powerpc/platforms/Kconfig * Adjust makefile accordingly Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/kernel/eeh_event.c')
-rw-r--r--arch/powerpc/kernel/eeh_event.c142
1 files changed, 142 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..185bedd926df
--- /dev/null
+++ b/arch/powerpc/kernel/eeh_event.c
@@ -0,0 +1,142 @@
+/*
+ * 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/mutex.h>
+#include <linux/sched.h>
+#include <linux/pci.h>
+#include <linux/slab.h>
+#include <linux/workqueue.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.
+ */
+
+/* EEH event workqueue setup. */
+static DEFINE_SPINLOCK(eeh_eventlist_lock);
+LIST_HEAD(eeh_eventlist);
+static void eeh_thread_launcher(struct work_struct *);
+DECLARE_WORK(eeh_event_wq, eeh_thread_launcher);
+
+/* Serialize reset sequences for a given pci device */
+DEFINE_MUTEX(eeh_event_mutex);
+
+/**
+ * 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;
+
+ spin_lock_irqsave(&eeh_eventlist_lock, flags);
+ event = NULL;
+
+ /* Unqueue the event, get ready to process. */
+ 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 == NULL)
+ return 0;
+
+ /* Serialize processing of EEH events */
+ mutex_lock(&eeh_event_mutex);
+ pe = event->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);
+
+ set_current_state(TASK_INTERRUPTIBLE); /* Don't add to load average */
+ eeh_handle_event(pe);
+ eeh_pe_state_clear(pe, EEH_PE_RECOVERING);
+
+ kfree(event);
+ mutex_unlock(&eeh_event_mutex);
+
+ /* If there are no new errors after an hour, clear the counter. */
+ if (pe && pe->freeze_count > 0) {
+ msleep_interruptible(3600*1000);
+ if (pe->freeze_count > 0)
+ pe->freeze_count--;
+
+ }
+
+ return 0;
+}
+
+/**
+ * eeh_thread_launcher - Start kernel thread to handle EEH events
+ * @dummy - unused
+ *
+ * This routine is called to start the kernel thread for processing
+ * EEH event.
+ */
+static void eeh_thread_launcher(struct work_struct *dummy)
+{
+ if (IS_ERR(kthread_run(eeh_event_handler, NULL, "eehd")))
+ printk(KERN_ERR "Failed to start EEH daemon\n");
+}
+
+/**
+ * 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);
+
+ schedule_work(&eeh_event_wq);
+
+ return 0;
+}