1 files changed, 91 insertions, 0 deletions

diff --git a/drivers/misc/ibmasm/heartbeat.c b/drivers/misc/ibmasm/heartbeat.c
new file mode 100644
index 000000000000..ce09309174d6
--- /dev/null
+++ b/drivers/misc/ibmasm/heartbeat.c
@@ -0,0 +1,91 @@
+
+/*
+ * IBM ASM Service Processor Device Driver
+ *
+ * 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) IBM Corporation, 2004
+ *
+ * Author: Max Asböck <amax@us.ibm.com> 
+ *
+ */
+
+#include <linux/notifier.h>
+#include "ibmasm.h"
+#include "dot_command.h"
+
+static int suspend_heartbeats = 0;
+
+/*
+ * Once the driver indicates to the service processor that it is running
+ * - see send_os_state() - the service processor sends periodic heartbeats
+ * to the driver. The driver must respond to the heartbeats or else the OS
+ * will be rebooted.
+ * In the case of a panic the interrupt handler continues to work and thus
+ * continues to respond to heartbeats, making the service processor believe
+ * the OS is still running and thus preventing a reboot.
+ * To prevent this from happening a callback is added the panic_notifier_list.
+ * Before responding to a heartbeat the driver checks if a panic has happened,
+ * if yes it suspends heartbeat, causing the service processor to reboot as
+ * expected.
+ */
+static int panic_happened(struct notifier_block *n, unsigned long val, void *v)
+{
+        suspend_heartbeats = 1;
+        return 0;
+}
+
+static struct notifier_block panic_notifier = { panic_happened, NULL, 1 };
+
+void ibmasm_register_panic_notifier(void)
+{
+        notifier_chain_register(&panic_notifier_list, &panic_notifier);
+}
+
+void ibmasm_unregister_panic_notifier(void)
+{
+        notifier_chain_unregister(&panic_notifier_list, &panic_notifier);
+}
+
+
+int ibmasm_heartbeat_init(struct service_processor *sp)
+{
+        sp->heartbeat = ibmasm_new_command(HEARTBEAT_BUFFER_SIZE);
+        if (sp->heartbeat == NULL)
+                return -ENOMEM;
+
+        return 0;
+}
+
+void ibmasm_heartbeat_exit(struct service_processor *sp)
+{
+        command_put(sp->heartbeat);
+}
+
+void ibmasm_receive_heartbeat(struct service_processor *sp,  void *message, size_t size)
+{
+        struct command *cmd = sp->heartbeat;
+        struct dot_command_header *header = (struct dot_command_header *)cmd->buffer;
+
+        if (suspend_heartbeats)
+                return;
+
+        /* return the received dot command to sender */
+        cmd->status = IBMASM_CMD_PENDING;
+        size = min(size, cmd->buffer_size);
+        memcpy(cmd->buffer, message, size);
+        header->type = sp_write;
+        ibmasm_exec_command(sp, cmd);
+}