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 #define pr_fmt(fmt) "ACPI: " fmt 11 12 #include <linux/spinlock.h> 13 #include <linux/export.h> 14 #include <linux/proc_fs.h> 15 #include <linux/init.h> 16 #include <linux/poll.h> 17 #include <linux/gfp.h> 18 #include <linux/acpi.h> 19 #include <net/netlink.h> 20 #include <net/genetlink.h> 21 22 #include "internal.h" 23 24 /* ACPI notifier chain */ 25 static BLOCKING_NOTIFIER_HEAD(acpi_chain_head); 26 27 int acpi_notifier_call_chain(struct acpi_device *dev, u32 type, u32 data) 28 { 29 struct acpi_bus_event event; 30 31 strcpy(event.device_class, dev->pnp.device_class); 32 strcpy(event.bus_id, dev->pnp.bus_id); 33 event.type = type; 34 event.data = data; 35 return (blocking_notifier_call_chain(&acpi_chain_head, 0, (void *)&event) 36 == NOTIFY_BAD) ? -EINVAL : 0; 37 } 38 EXPORT_SYMBOL(acpi_notifier_call_chain); 39 40 int register_acpi_notifier(struct notifier_block *nb) 41 { 42 return blocking_notifier_chain_register(&acpi_chain_head, nb); 43 } 44 EXPORT_SYMBOL(register_acpi_notifier); 45 46 int unregister_acpi_notifier(struct notifier_block *nb) 47 { 48 return blocking_notifier_chain_unregister(&acpi_chain_head, nb); 49 } 50 EXPORT_SYMBOL(unregister_acpi_notifier); 51 52 #ifdef CONFIG_NET 53 static unsigned int acpi_event_seqnum; 54 struct acpi_genl_event { 55 acpi_device_class device_class; 56 char bus_id[15]; 57 u32 type; 58 u32 data; 59 }; 60 61 /* attributes of acpi_genl_family */ 62 enum { 63 ACPI_GENL_ATTR_UNSPEC, 64 ACPI_GENL_ATTR_EVENT, /* ACPI event info needed by user space */ 65 __ACPI_GENL_ATTR_MAX, 66 }; 67 #define ACPI_GENL_ATTR_MAX (__ACPI_GENL_ATTR_MAX - 1) 68 69 /* commands supported by the acpi_genl_family */ 70 enum { 71 ACPI_GENL_CMD_UNSPEC, 72 ACPI_GENL_CMD_EVENT, /* kernel->user notifications for ACPI events */ 73 __ACPI_GENL_CMD_MAX, 74 }; 75 #define ACPI_GENL_CMD_MAX (__ACPI_GENL_CMD_MAX - 1) 76 77 #define ACPI_GENL_FAMILY_NAME "acpi_event" 78 #define ACPI_GENL_VERSION 0x01 79 #define ACPI_GENL_MCAST_GROUP_NAME "acpi_mc_group" 80 81 static const struct genl_multicast_group acpi_event_mcgrps[] = { 82 { .name = ACPI_GENL_MCAST_GROUP_NAME, }, 83 }; 84 85 static struct genl_family acpi_event_genl_family __ro_after_init = { 86 .module = THIS_MODULE, 87 .name = ACPI_GENL_FAMILY_NAME, 88 .version = ACPI_GENL_VERSION, 89 .maxattr = ACPI_GENL_ATTR_MAX, 90 .mcgrps = acpi_event_mcgrps, 91 .n_mcgrps = ARRAY_SIZE(acpi_event_mcgrps), 92 }; 93 94 int acpi_bus_generate_netlink_event(const char *device_class, 95 const char *bus_id, 96 u8 type, int data) 97 { 98 struct sk_buff *skb; 99 struct nlattr *attr; 100 struct acpi_genl_event *event; 101 void *msg_header; 102 int size; 103 104 /* allocate memory */ 105 size = nla_total_size(sizeof(struct acpi_genl_event)) + 106 nla_total_size(0); 107 108 skb = genlmsg_new(size, GFP_ATOMIC); 109 if (!skb) 110 return -ENOMEM; 111 112 /* add the genetlink message header */ 113 msg_header = genlmsg_put(skb, 0, acpi_event_seqnum++, 114 &acpi_event_genl_family, 0, 115 ACPI_GENL_CMD_EVENT); 116 if (!msg_header) { 117 nlmsg_free(skb); 118 return -ENOMEM; 119 } 120 121 /* fill the data */ 122 attr = 123 nla_reserve(skb, ACPI_GENL_ATTR_EVENT, 124 sizeof(struct acpi_genl_event)); 125 if (!attr) { 126 nlmsg_free(skb); 127 return -EINVAL; 128 } 129 130 event = nla_data(attr); 131 memset(event, 0, sizeof(struct acpi_genl_event)); 132 133 strscpy(event->device_class, device_class, sizeof(event->device_class)); 134 strscpy(event->bus_id, bus_id, sizeof(event->bus_id)); 135 event->type = type; 136 event->data = data; 137 138 /* send multicast genetlink message */ 139 genlmsg_end(skb, msg_header); 140 141 genlmsg_multicast(&acpi_event_genl_family, skb, 0, 0, GFP_ATOMIC); 142 return 0; 143 } 144 145 EXPORT_SYMBOL(acpi_bus_generate_netlink_event); 146 147 static int __init acpi_event_genetlink_init(void) 148 { 149 return genl_register_family(&acpi_event_genl_family); 150 } 151 152 #else 153 int acpi_bus_generate_netlink_event(const char *device_class, 154 const char *bus_id, 155 u8 type, int data) 156 { 157 return 0; 158 } 159 160 EXPORT_SYMBOL(acpi_bus_generate_netlink_event); 161 162 static int acpi_event_genetlink_init(void) 163 { 164 return -ENODEV; 165 } 166 #endif 167 168 static int __init acpi_event_init(void) 169 { 170 int error; 171 172 if (acpi_disabled) 173 return 0; 174 175 /* create genetlink for acpi event */ 176 error = acpi_event_genetlink_init(); 177 if (error) 178 pr_warn("Failed to create genetlink family for ACPI event\n"); 179 180 return 0; 181 } 182 183 fs_initcall(acpi_event_init); 184