1 /* 2 * event.c - exporting ACPI events via procfs 3 * 4 * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com> 5 * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com> 6 * 7 */ 8 9 #include <linux/spinlock.h> 10 #include <linux/proc_fs.h> 11 #include <linux/init.h> 12 #include <linux/poll.h> 13 #include <acpi/acpi_drivers.h> 14 #include <net/netlink.h> 15 #include <net/genetlink.h> 16 17 #define _COMPONENT ACPI_SYSTEM_COMPONENT 18 ACPI_MODULE_NAME("event"); 19 20 #ifdef CONFIG_ACPI_PROC_EVENT 21 /* Global vars for handling event proc entry */ 22 static DEFINE_SPINLOCK(acpi_system_event_lock); 23 int event_is_open = 0; 24 extern struct list_head acpi_bus_event_list; 25 extern wait_queue_head_t acpi_bus_event_queue; 26 27 static int acpi_system_open_event(struct inode *inode, struct file *file) 28 { 29 spin_lock_irq(&acpi_system_event_lock); 30 31 if (event_is_open) 32 goto out_busy; 33 34 event_is_open = 1; 35 36 spin_unlock_irq(&acpi_system_event_lock); 37 return 0; 38 39 out_busy: 40 spin_unlock_irq(&acpi_system_event_lock); 41 return -EBUSY; 42 } 43 44 static ssize_t 45 acpi_system_read_event(struct file *file, char __user * buffer, size_t count, 46 loff_t * ppos) 47 { 48 int result = 0; 49 struct acpi_bus_event event; 50 static char str[ACPI_MAX_STRING]; 51 static int chars_remaining = 0; 52 static char *ptr; 53 54 if (!chars_remaining) { 55 memset(&event, 0, sizeof(struct acpi_bus_event)); 56 57 if ((file->f_flags & O_NONBLOCK) 58 && (list_empty(&acpi_bus_event_list))) 59 return -EAGAIN; 60 61 result = acpi_bus_receive_event(&event); 62 if (result) 63 return result; 64 65 chars_remaining = sprintf(str, "%s %s %08x %08x\n", 66 event.device_class ? event. 67 device_class : "<unknown>", 68 event.bus_id ? event. 69 bus_id : "<unknown>", event.type, 70 event.data); 71 ptr = str; 72 } 73 74 if (chars_remaining < count) { 75 count = chars_remaining; 76 } 77 78 if (copy_to_user(buffer, ptr, count)) 79 return -EFAULT; 80 81 *ppos += count; 82 chars_remaining -= count; 83 ptr += count; 84 85 return count; 86 } 87 88 static int acpi_system_close_event(struct inode *inode, struct file *file) 89 { 90 spin_lock_irq(&acpi_system_event_lock); 91 event_is_open = 0; 92 spin_unlock_irq(&acpi_system_event_lock); 93 return 0; 94 } 95 96 static unsigned int acpi_system_poll_event(struct file *file, poll_table * wait) 97 { 98 poll_wait(file, &acpi_bus_event_queue, wait); 99 if (!list_empty(&acpi_bus_event_list)) 100 return POLLIN | POLLRDNORM; 101 return 0; 102 } 103 104 static const struct file_operations acpi_system_event_ops = { 105 .open = acpi_system_open_event, 106 .read = acpi_system_read_event, 107 .release = acpi_system_close_event, 108 .poll = acpi_system_poll_event, 109 }; 110 #endif /* CONFIG_ACPI_PROC_EVENT */ 111 112 #ifdef CONFIG_NET 113 static unsigned int acpi_event_seqnum; 114 struct acpi_genl_event { 115 acpi_device_class device_class; 116 char bus_id[15]; 117 u32 type; 118 u32 data; 119 }; 120 121 /* attributes of acpi_genl_family */ 122 enum { 123 ACPI_GENL_ATTR_UNSPEC, 124 ACPI_GENL_ATTR_EVENT, /* ACPI event info needed by user space */ 125 __ACPI_GENL_ATTR_MAX, 126 }; 127 #define ACPI_GENL_ATTR_MAX (__ACPI_GENL_ATTR_MAX - 1) 128 129 /* commands supported by the acpi_genl_family */ 130 enum { 131 ACPI_GENL_CMD_UNSPEC, 132 ACPI_GENL_CMD_EVENT, /* kernel->user notifications for ACPI events */ 133 __ACPI_GENL_CMD_MAX, 134 }; 135 #define ACPI_GENL_CMD_MAX (__ACPI_GENL_CMD_MAX - 1) 136 137 #define ACPI_GENL_FAMILY_NAME "acpi_event" 138 #define ACPI_GENL_VERSION 0x01 139 #define ACPI_GENL_MCAST_GROUP_NAME "acpi_mc_group" 140 141 static struct genl_family acpi_event_genl_family = { 142 .id = GENL_ID_GENERATE, 143 .name = ACPI_GENL_FAMILY_NAME, 144 .version = ACPI_GENL_VERSION, 145 .maxattr = ACPI_GENL_ATTR_MAX, 146 }; 147 148 static struct genl_multicast_group acpi_event_mcgrp = { 149 .name = ACPI_GENL_MCAST_GROUP_NAME, 150 }; 151 152 int acpi_bus_generate_netlink_event(const char *device_class, 153 const char *bus_id, 154 u8 type, int data) 155 { 156 struct sk_buff *skb; 157 struct nlattr *attr; 158 struct acpi_genl_event *event; 159 void *msg_header; 160 int size; 161 int result; 162 163 /* allocate memory */ 164 size = nla_total_size(sizeof(struct acpi_genl_event)) + 165 nla_total_size(0); 166 167 skb = genlmsg_new(size, GFP_ATOMIC); 168 if (!skb) 169 return -ENOMEM; 170 171 /* add the genetlink message header */ 172 msg_header = genlmsg_put(skb, 0, acpi_event_seqnum++, 173 &acpi_event_genl_family, 0, 174 ACPI_GENL_CMD_EVENT); 175 if (!msg_header) { 176 nlmsg_free(skb); 177 return -ENOMEM; 178 } 179 180 /* fill the data */ 181 attr = 182 nla_reserve(skb, ACPI_GENL_ATTR_EVENT, 183 sizeof(struct acpi_genl_event)); 184 if (!attr) { 185 nlmsg_free(skb); 186 return -EINVAL; 187 } 188 189 event = nla_data(attr); 190 if (!event) { 191 nlmsg_free(skb); 192 return -EINVAL; 193 } 194 195 memset(event, 0, sizeof(struct acpi_genl_event)); 196 197 strcpy(event->device_class, device_class); 198 strcpy(event->bus_id, bus_id); 199 event->type = type; 200 event->data = data; 201 202 /* send multicast genetlink message */ 203 result = genlmsg_end(skb, msg_header); 204 if (result < 0) { 205 nlmsg_free(skb); 206 return result; 207 } 208 209 result = 210 genlmsg_multicast(skb, 0, acpi_event_mcgrp.id, GFP_ATOMIC); 211 if (result) 212 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 213 "Failed to send a Genetlink message!\n")); 214 return 0; 215 } 216 217 EXPORT_SYMBOL(acpi_bus_generate_netlink_event); 218 219 static int acpi_event_genetlink_init(void) 220 { 221 int result; 222 223 result = genl_register_family(&acpi_event_genl_family); 224 if (result) 225 return result; 226 227 result = genl_register_mc_group(&acpi_event_genl_family, 228 &acpi_event_mcgrp); 229 if (result) 230 genl_unregister_family(&acpi_event_genl_family); 231 232 return result; 233 } 234 235 #else 236 int acpi_bus_generate_netlink_event(const char *device_class, 237 const char *bus_id, 238 u8 type, int data) 239 { 240 return 0; 241 } 242 243 EXPORT_SYMBOL(acpi_bus_generate_netlink_event); 244 245 static int acpi_event_genetlink_init(void) 246 { 247 return -ENODEV; 248 } 249 #endif 250 251 static int __init acpi_event_init(void) 252 { 253 #ifdef CONFIG_ACPI_PROC_EVENT 254 struct proc_dir_entry *entry; 255 #endif 256 int error = 0; 257 258 if (acpi_disabled) 259 return 0; 260 261 /* create genetlink for acpi event */ 262 error = acpi_event_genetlink_init(); 263 if (error) 264 printk(KERN_WARNING PREFIX 265 "Failed to create genetlink family for ACPI event\n"); 266 267 #ifdef CONFIG_ACPI_PROC_EVENT 268 /* 'event' [R] */ 269 entry = create_proc_entry("event", S_IRUSR, acpi_root_dir); 270 if (entry) 271 entry->proc_fops = &acpi_system_event_ops; 272 else 273 return -ENODEV; 274 #endif 275 276 return 0; 277 } 278 279 fs_initcall(acpi_event_init); 280