Hardware watchdog

Here is an updated hardware watchdog patch, which should fix
everything that was raised about the previous version ...

Signed-off-by: Richard W.M. Jones <rjones@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

1 files changed, 112 insertions, 0 deletions

diff --git a/hw/wdt_ib700.c b/hw/wdt_ib700.c
new file mode 100644
index 0000000..d32aaf1
--- /dev/null
+++ b/hw/wdt_ib700.c
@@ -0,0 +1,112 @@
+/*
+ * Virtual hardware watchdog.
+ *
+ * Copyright (C) 2009 Red Hat Inc.
+ *
+ * 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
+ * USA.
+ *
+ * By Richard W.M. Jones (rjones@redhat.com).
+ */
+
+#include "qemu-common.h"
+#include "qemu-timer.h"
+#include "watchdog.h"
+#include "hw.h"
+#include "isa.h"
+#include "pc.h"
+
+/*#define IB700_DEBUG 1*/
+
+#ifdef IB700_DEBUG
+#define ib700_debug(fs,...)					\
+    fprintf(stderr,"ib700: %s: "fs,__func__,##__VA_ARGS__)
+#else
+#define ib700_debug(fs,...)
+#endif
+
+/* This is the timer.  We use a global here because the watchdog
+ * code ensures there is only one watchdog (it is located at a fixed,
+ * unchangable IO port, so there could only ever be one anyway).
+ */
+static QEMUTimer *timer = NULL;
+
+/* A write to this register enables the timer. */
+static void ib700_write_enable_reg(void *vp, uint32_t addr, uint32_t data)
+{
+    static int time_map[] = {
+        30, 28, 26, 24, 22, 20, 18, 16,
+        14, 12, 10,  8,  6,  4,  2,  0
+    };
+    int64 timeout;
+
+    ib700_debug("addr = %x, data = %x\n", addr, data);
+
+    timeout = (int64_t) time_map[data & 0xF] * ticks_per_sec;
+    qemu_mod_timer(timer, qemu_get_clock (vm_clock) + timeout);
+}
+
+/* A write (of any value) to this register disables the timer. */
+static void ib700_write_disable_reg(void *vp, uint32_t addr, uint32_t data)
+{
+    ib700_debug("addr = %x, data = %x\n", addr, data);
+
+    qemu_del_timer(timer);
+}
+
+/* This is called when the watchdog expires. */
+static void ib700_timer_expired(void *vp)
+{
+    ib700_debug("watchdog expired\n");
+
+    watchdog_perform_action();
+    qemu_del_timer(timer);
+}
+
+static void ib700_save(QEMUFile *f, void *vp)
+{
+    qemu_put_timer(f, timer);
+}
+
+static int ib700_load(QEMUFile *f, void *vp, int version)
+{
+    if (version != 0)
+        return -EINVAL;
+
+    qemu_get_timer(f, timer);
+
+    return 0;
+}
+
+/* Create and initialize a virtual IB700 during PC creation. */
+static void ib700_pc_init(PCIBus *unused)
+{
+    register_savevm("ib700_wdt", -1, 0, ib700_save, ib700_load, NULL);
+
+    register_ioport_write(0x441, 2, 1, ib700_write_disable_reg, NULL);
+    register_ioport_write(0x443, 2, 1, ib700_write_enable_reg, NULL);
+}
+
+static WatchdogTimerModel model = {
+    .wdt_name = "ib700",
+    .wdt_description = "iBASE 700",
+    .wdt_pc_init = ib700_pc_init,
+};
+
+void wdt_ib700_init(void)
+{
+    watchdog_add_model(&model);
+    timer = qemu_new_timer(vm_clock, ib700_timer_expired, NULL);
+}