1 files changed, 155 insertions, 0 deletions

diff --git a/arch/powerpc/platforms/pseries/eeh_event.c b/arch/powerpc/platforms/pseries/eeh_event.c
new file mode 100644
index 000000000000..92497333c2b6
--- /dev/null
+++ b/arch/powerpc/platforms/pseries/eeh_event.c
@@ -0,0 +1,155 @@
+/*
+ * eeh_event.c
+ *
+ * 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/list.h>
+#include <linux/pci.h>
+#include <asm/eeh_event.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 spinlock_t eeh_eventlist_lock = SPIN_LOCK_UNLOCKED;
+LIST_HEAD(eeh_eventlist);
+static void eeh_thread_launcher(void *);
+DECLARE_WORK(eeh_event_wq, eeh_thread_launcher, NULL);
+
+/**
+ * eeh_panic - call panic() for an eeh event that cannot be handled.
+ * The philosophy of this routine is that it is better to panic and
+ * halt the OS than it is to risk possible data corruption by
+ * oblivious device drivers that don't know better.
+ *
+ * @dev pci device that had an eeh event
+ * @reset_state current reset state of the device slot
+ */
+static void eeh_panic(struct pci_dev *dev, int reset_state)
+{
+        /*
+         * Since the panic_on_oops sysctl is used to halt the system
+         * in light of potential corruption, we can use it here.
+         */
+        if (panic_on_oops) {
+                panic("EEH: MMIO failure (%d) on device:%s\n", reset_state,
+                      pci_name(dev));
+        }
+        else {
+                printk(KERN_INFO "EEH: Ignored MMIO failure (%d) on device:%s\n",
+                       reset_state, pci_name(dev));
+        }
+}
+
+/**
+ * eeh_event_handler - dispatch EEH events.  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.
+ *
+ * @dummy - unused
+ */
+static int eeh_event_handler(void * dummy)
+{
+        unsigned long flags;
+        struct eeh_event        *event;
+
+        daemonize ("eehd");
+
+        while (1) {
+                set_current_state(TASK_INTERRUPTIBLE);
+
+                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 == NULL)
+                        break;
+
+                printk(KERN_INFO "EEH: Detected PCI bus error on device %s\n",
+                       pci_name(event->dev));
+
+                eeh_panic (event->dev, event->state);
+
+                kfree(event);
+        }
+
+        return 0;
+}
+
+/**
+ * eeh_thread_launcher
+ *
+ * @dummy - unused
+ */
+static void eeh_thread_launcher(void *dummy)
+{
+        if (kernel_thread(eeh_event_handler, NULL, CLONE_KERNEL) < 0)
+                printk(KERN_ERR "Failed to start EEH daemon\n");
+}
+
+/**
+ * eeh_send_failure_event - generate a PCI error event
+ * @dev pci device
+ *
+ * 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 device_node *dn,
+                            struct pci_dev *dev,
+                            int state,
+                            int time_unavail)
+{
+        unsigned long flags;
+        struct eeh_event *event;
+
+        event = kmalloc(sizeof(*event), GFP_ATOMIC);
+        if (event == NULL) {
+                printk (KERN_ERR "EEH: out of memory, event not handled\n");
+                return 1;
+        }
+
+        if (dev)
+                pci_dev_get(dev);
+
+        event->dn = dn;
+        event->dev = dev;
+        event->state = state;
+        event->time_unavail = time_unavail;
+
+        /* 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;
+}
+
+/********************** END OF FILE ******************************/