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path: root/drivers/platform/x86/pvpanic.c
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Diffstat (limited to 'drivers/platform/x86/pvpanic.c')
-rw-r--r--drivers/platform/x86/pvpanic.c124
1 files changed, 124 insertions, 0 deletions
diff --git a/drivers/platform/x86/pvpanic.c b/drivers/platform/x86/pvpanic.c
new file mode 100644
index 000000000..073a90a63
--- /dev/null
+++ b/drivers/platform/x86/pvpanic.c
@@ -0,0 +1,124 @@
+/*
+ * pvpanic.c - pvpanic Device Support
+ *
+ * Copyright (C) 2013 Fujitsu.
+ *
+ * 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
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/acpi.h>
+
+MODULE_AUTHOR("Hu Tao <hutao@cn.fujitsu.com>");
+MODULE_DESCRIPTION("pvpanic device driver");
+MODULE_LICENSE("GPL");
+
+static int pvpanic_add(struct acpi_device *device);
+static int pvpanic_remove(struct acpi_device *device);
+
+static const struct acpi_device_id pvpanic_device_ids[] = {
+ { "QEMU0001", 0 },
+ { "", 0 },
+};
+MODULE_DEVICE_TABLE(acpi, pvpanic_device_ids);
+
+#define PVPANIC_PANICKED (1 << 0)
+
+static u16 port;
+
+static struct acpi_driver pvpanic_driver = {
+ .name = "pvpanic",
+ .class = "QEMU",
+ .ids = pvpanic_device_ids,
+ .ops = {
+ .add = pvpanic_add,
+ .remove = pvpanic_remove,
+ },
+ .owner = THIS_MODULE,
+};
+
+static void
+pvpanic_send_event(unsigned int event)
+{
+ outb(event, port);
+}
+
+static int
+pvpanic_panic_notify(struct notifier_block *nb, unsigned long code,
+ void *unused)
+{
+ pvpanic_send_event(PVPANIC_PANICKED);
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block pvpanic_panic_nb = {
+ .notifier_call = pvpanic_panic_notify,
+ .priority = 1, /* let this called before broken drm_fb_helper */
+};
+
+
+static acpi_status
+pvpanic_walk_resources(struct acpi_resource *res, void *context)
+{
+ switch (res->type) {
+ case ACPI_RESOURCE_TYPE_END_TAG:
+ return AE_OK;
+
+ case ACPI_RESOURCE_TYPE_IO:
+ port = res->data.io.minimum;
+ return AE_OK;
+
+ default:
+ return AE_ERROR;
+ }
+}
+
+static int pvpanic_add(struct acpi_device *device)
+{
+ acpi_status status;
+ u64 ret;
+
+ status = acpi_evaluate_integer(device->handle, "_STA", NULL,
+ &ret);
+
+ if (ACPI_FAILURE(status) || (ret & 0x0B) != 0x0B)
+ return -ENODEV;
+
+ acpi_walk_resources(device->handle, METHOD_NAME__CRS,
+ pvpanic_walk_resources, NULL);
+
+ if (!port)
+ return -ENODEV;
+
+ atomic_notifier_chain_register(&panic_notifier_list,
+ &pvpanic_panic_nb);
+
+ return 0;
+}
+
+static int pvpanic_remove(struct acpi_device *device)
+{
+
+ atomic_notifier_chain_unregister(&panic_notifier_list,
+ &pvpanic_panic_nb);
+ return 0;
+}
+
+module_acpi_driver(pvpanic_driver);