1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * event.c - exporting ACPI events via procfs 4 * 5 * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com> 6 * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com> 7 * 8 */ 9 10 #include <linux/spinlock.h> 11 #include <linux/export.h> 12 #include <linux/proc_fs.h> 13 #include <linux/init.h> 14 #include <linux/poll.h> 15 #include <linux/gfp.h> 16 #include <linux/acpi.h> 17 #include <net/netlink.h> 18 #include <net/genetlink.h> 19 20 #include "internal.h" 21 22 /* ACPI notifier chain */ 23 static BLOCKING_NOTIFIER_HEAD(acpi_chain_head); 24 25 int acpi_notifier_call_chain(struct acpi_device *dev, u32 type, u32 data) 26 { 27 struct acpi_bus_event event; 28 29 strcpy(event.device_class, dev->pnp.device_class); 30 strcpy(event.bus_id, dev->pnp.bus_id); 31 event.type = type; 32 event.data = data; 33 return (blocking_notifier_call_chain(&acpi_chain_head, 0, (void *)&event) 34 == NOTIFY_BAD) ? -EINVAL : 0; 35 } 36 EXPORT_SYMBOL(acpi_notifier_call_chain); 37 38 int register_acpi_notifier(struct notifier_block *nb) 39 { 40 return blocking_notifier_chain_register(&acpi_chain_head, nb); 41 } 42 EXPORT_SYMBOL(register_acpi_notifier); 43 44 int unregister_acpi_notifier(struct notifier_block *nb) 45 { 46 return blocking_notifier_chain_unregister(&acpi_chain_head, nb); 47 } 48 EXPORT_SYMBOL(unregister_acpi_notifier); 49 50 #ifdef CONFIG_NET 51 static unsigned int acpi_event_seqnum; 52 struct acpi_genl_event { 53 acpi_device_class device_class; 54 char bus_id[15]; 55 u32 type; 56 u32 data; 57 }; 58 59 /* attributes of acpi_genl_family */ 60 enum { 61 ACPI_GENL_ATTR_UNSPEC, 62 ACPI_GENL_ATTR_EVENT, /* ACPI event info needed by user space */ 63 __ACPI_GENL_ATTR_MAX, 64 }; 65 #define ACPI_GENL_ATTR_MAX (__ACPI_GENL_ATTR_MAX - 1) 66 67 /* commands supported by the acpi_genl_family */ 68 enum { 69 ACPI_GENL_CMD_UNSPEC, 70 ACPI_GENL_CMD_EVENT, /* kernel->user notifications for ACPI events */ 71 __ACPI_GENL_CMD_MAX, 72 }; 73 #define ACPI_GENL_CMD_MAX (__ACPI_GENL_CMD_MAX - 1) 74 75 #define ACPI_GENL_FAMILY_NAME "acpi_event" 76 #define ACPI_GENL_VERSION 0x01 77 #define ACPI_GENL_MCAST_GROUP_NAME "acpi_mc_group" 78 79 static const struct genl_multicast_group acpi_event_mcgrps[] = { 80 { .name = ACPI_GENL_MCAST_GROUP_NAME, }, 81 }; 82 83 static struct genl_family acpi_event_genl_family __ro_after_init = { 84 .module = THIS_MODULE, 85 .name = ACPI_GENL_FAMILY_NAME, 86 .version = ACPI_GENL_VERSION, 87 .maxattr = ACPI_GENL_ATTR_MAX, 88 .mcgrps = acpi_event_mcgrps, 89 .n_mcgrps = ARRAY_SIZE(acpi_event_mcgrps), 90 }; 91 92 int acpi_bus_generate_netlink_event(const char *device_class, 93 const char *bus_id, 94 u8 type, int data) 95 { 96 struct sk_buff *skb; 97 struct nlattr *attr; 98 struct acpi_genl_event *event; 99 void *msg_header; 100 int size; 101 102 /* allocate memory */ 103 size = nla_total_size(sizeof(struct acpi_genl_event)) + 104 nla_total_size(0); 105 106 skb = genlmsg_new(size, GFP_ATOMIC); 107 if (!skb) 108 return -ENOMEM; 109 110 /* add the genetlink message header */ 111 msg_header = genlmsg_put(skb, 0, acpi_event_seqnum++, 112 &acpi_event_genl_family, 0, 113 ACPI_GENL_CMD_EVENT); 114 if (!msg_header) { 115 nlmsg_free(skb); 116 return -ENOMEM; 117 } 118 119 /* fill the data */ 120 attr = 121 nla_reserve(skb, ACPI_GENL_ATTR_EVENT, 122 sizeof(struct acpi_genl_event)); 123 if (!attr) { 124 nlmsg_free(skb); 125 return -EINVAL; 126 } 127 128 event = nla_data(attr); 129 memset(event, 0, sizeof(struct acpi_genl_event)); 130 131 strscpy(event->device_class, device_class, sizeof(event->device_class)); 132 strscpy(event->bus_id, bus_id, sizeof(event->bus_id)); 133 event->type = type; 134 event->data = data; 135 136 /* send multicast genetlink message */ 137 genlmsg_end(skb, msg_header); 138 139 genlmsg_multicast(&acpi_event_genl_family, skb, 0, 0, GFP_ATOMIC); 140 return 0; 141 } 142 143 EXPORT_SYMBOL(acpi_bus_generate_netlink_event); 144 145 static int __init acpi_event_genetlink_init(void) 146 { 147 return genl_register_family(&acpi_event_genl_family); 148 } 149 150 #else 151 int acpi_bus_generate_netlink_event(const char *device_class, 152 const char *bus_id, 153 u8 type, int data) 154 { 155 return 0; 156 } 157 158 EXPORT_SYMBOL(acpi_bus_generate_netlink_event); 159 160 static int acpi_event_genetlink_init(void) 161 { 162 return -ENODEV; 163 } 164 #endif 165 166 static int __init acpi_event_init(void) 167 { 168 int error = 0; 169 170 if (acpi_disabled) 171 return 0; 172 173 /* create genetlink for acpi event */ 174 error = acpi_event_genetlink_init(); 175 if (error) 176 printk(KERN_WARNING PREFIX 177 "Failed to create genetlink family for ACPI event\n"); 178 return 0; 179 } 180 181 fs_initcall(acpi_event_init); 182