| Hu Tao | 8b10acd | 2013-05-08 11:15:32 +0800 | [diff] [blame] | 1 | /* |
| 2 | * pvpanic.c - pvpanic Device Support |
| 3 | * |
| 4 | * Copyright (C) 2013 Fujitsu. |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License as published by |
| 8 | * the Free Software Foundation; either version 2 of the License, or |
| 9 | * (at your option) any later version. |
| 10 | * |
| 11 | * This program is distributed in the hope that it will be useful, |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | * GNU General Public License for more details. |
| 15 | * |
| 16 | * You should have received a copy of the GNU General Public License |
| 17 | * along with this program; if not, write to the Free Software |
| 18 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 19 | */ |
| 20 | |
| 21 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| 22 | |
| 23 | #include <linux/kernel.h> |
| 24 | #include <linux/module.h> |
| 25 | #include <linux/init.h> |
| 26 | #include <linux/types.h> |
| 27 | #include <acpi/acpi_bus.h> |
| 28 | #include <acpi/acpi_drivers.h> |
| 29 | |
| 30 | MODULE_AUTHOR("Hu Tao <hutao@cn.fujitsu.com>"); |
| 31 | MODULE_DESCRIPTION("pvpanic device driver"); |
| 32 | MODULE_LICENSE("GPL"); |
| 33 | |
| 34 | static int pvpanic_add(struct acpi_device *device); |
| 35 | static int pvpanic_remove(struct acpi_device *device); |
| 36 | |
| 37 | static const struct acpi_device_id pvpanic_device_ids[] = { |
| 38 | { "QEMU0001", 0 }, |
| 39 | { "", 0 }, |
| 40 | }; |
| 41 | MODULE_DEVICE_TABLE(acpi, pvpanic_device_ids); |
| 42 | |
| 43 | #define PVPANIC_PANICKED (1 << 0) |
| 44 | |
| 45 | static u16 port; |
| 46 | |
| 47 | static struct acpi_driver pvpanic_driver = { |
| 48 | .name = "pvpanic", |
| 49 | .class = "QEMU", |
| 50 | .ids = pvpanic_device_ids, |
| 51 | .ops = { |
| 52 | .add = pvpanic_add, |
| 53 | .remove = pvpanic_remove, |
| 54 | }, |
| 55 | .owner = THIS_MODULE, |
| 56 | }; |
| 57 | |
| 58 | static void |
| 59 | pvpanic_send_event(unsigned int event) |
| 60 | { |
| 61 | outb(event, port); |
| 62 | } |
| 63 | |
| 64 | static int |
| 65 | pvpanic_panic_notify(struct notifier_block *nb, unsigned long code, |
| 66 | void *unused) |
| 67 | { |
| 68 | pvpanic_send_event(PVPANIC_PANICKED); |
| 69 | return NOTIFY_DONE; |
| 70 | } |
| 71 | |
| 72 | static struct notifier_block pvpanic_panic_nb = { |
| 73 | .notifier_call = pvpanic_panic_notify, |
| 74 | }; |
| 75 | |
| 76 | |
| 77 | static acpi_status |
| 78 | pvpanic_walk_resources(struct acpi_resource *res, void *context) |
| 79 | { |
| 80 | switch (res->type) { |
| 81 | case ACPI_RESOURCE_TYPE_END_TAG: |
| 82 | return AE_OK; |
| 83 | |
| 84 | case ACPI_RESOURCE_TYPE_IO: |
| 85 | port = res->data.io.minimum; |
| 86 | return AE_OK; |
| 87 | |
| 88 | default: |
| 89 | return AE_ERROR; |
| 90 | } |
| 91 | } |
| 92 | |
| 93 | static int pvpanic_add(struct acpi_device *device) |
| 94 | { |
| 95 | acpi_status status; |
| 96 | u64 ret; |
| 97 | |
| 98 | status = acpi_evaluate_integer(device->handle, "_STA", NULL, |
| 99 | &ret); |
| 100 | |
| 101 | if (ACPI_FAILURE(status) || (ret & 0x0B) != 0x0B) |
| 102 | return -ENODEV; |
| 103 | |
| 104 | acpi_walk_resources(device->handle, METHOD_NAME__CRS, |
| 105 | pvpanic_walk_resources, NULL); |
| 106 | |
| 107 | if (!port) |
| 108 | return -ENODEV; |
| 109 | |
| 110 | atomic_notifier_chain_register(&panic_notifier_list, |
| 111 | &pvpanic_panic_nb); |
| 112 | |
| 113 | return 0; |
| 114 | } |
| 115 | |
| 116 | static int pvpanic_remove(struct acpi_device *device) |
| 117 | { |
| 118 | |
| 119 | atomic_notifier_chain_unregister(&panic_notifier_list, |
| 120 | &pvpanic_panic_nb); |
| 121 | return 0; |
| 122 | } |
| 123 | |
| 124 | module_acpi_driver(pvpanic_driver); |