diff options
Diffstat (limited to 'drivers/platform/x86/pvpanic.c')
-rw-r--r-- | drivers/platform/x86/pvpanic.c | 124 |
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 000000000000..47ae0c47d4b5 --- /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 <acpi/acpi_bus.h> +#include <acpi/acpi_drivers.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, +}; + + +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); |