[PATCH] ppc64: PCI error event dispatcher

12-eeh-event-dispatcher.patch

ppc64: EEH Recovery dispatcher thread

This patch adds a mechanism to create recovery threads when an
EEH event is received.  Since an EEH freeze state may be detected
within an interrupt context, we need to get out of the interrupt
context before starting recovery. This dispatcher does this in
two steps: first, it uses a workqueue to get out, and then
lanuches a kernel thread, so that the recovery routine can
sleep for exteded periods without upseting the keventd.

A kernel thread is created with each EEH event, rather than
having one long-running daemon started at boot time.  This is
because it is anticipated that EEH events will be very rare
(very very rare, ideally) and so its pointless to cluter the
process tables with a daemon that will almost never run.

Signed-off-by: Linas Vepstas <linas@austin.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 52 insertions, 0 deletions

diff --git a/include/asm-powerpc/eeh_event.h b/include/asm-powerpc/eeh_event.h
new file mode 100644
index 000000000000..d168a30b3866
--- /dev/null
+++ b/include/asm-powerpc/eeh_event.h
@@ -0,0 +1,52 @@
+/*
+ *      eeh_event.h
+ *
+ * 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>
+ */
+
+#ifndef ASM_PPC64_EEH_EVENT_H
+#define ASM_PPC64_EEH_EVENT_H
+
+/** EEH event -- structure holding pci controller data that describes
+ *  a change in the isolation status of a PCI slot.  A pointer
+ *  to this struct is passed as the data pointer in a notify callback.
+ */
+struct eeh_event {
+        struct list_head     list;
+        struct device_node      *dn;   /* struct device node */
+        struct pci_dev       *dev;  /* affected device */
+        int                  state;
+        int time_unavail;    /* milliseconds until device might be available */
+};
+
+/**
+ * eeh_send_failure_event - generate a PCI error event
+ * @dev pci device
+ *
+ * This routine builds a PCI error event which will be delivered
+ * to all listeners on the peh_notifier_chain.
+ *
+ * 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 reset_state,
+                            int time_unavail);
+
+#endif /* ASM_PPC64_EEH_EVENT_H */