v4.19.13 snapshot.
diff --git a/drivers/acpi/event.c b/drivers/acpi/event.c
new file mode 100644
index 0000000..5a127f3
--- /dev/null
+++ b/drivers/acpi/event.c
@@ -0,0 +1,184 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * event.c - exporting ACPI events via procfs
+ *
+ * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
+ * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
+ *
+ */
+
+#include <linux/spinlock.h>
+#include <linux/export.h>
+#include <linux/proc_fs.h>
+#include <linux/init.h>
+#include <linux/poll.h>
+#include <linux/gfp.h>
+#include <linux/acpi.h>
+#include <net/netlink.h>
+#include <net/genetlink.h>
+
+#include "internal.h"
+
+#define _COMPONENT ACPI_SYSTEM_COMPONENT
+ACPI_MODULE_NAME("event");
+
+/* ACPI notifier chain */
+static BLOCKING_NOTIFIER_HEAD(acpi_chain_head);
+
+int acpi_notifier_call_chain(struct acpi_device *dev, u32 type, u32 data)
+{
+ struct acpi_bus_event event;
+
+ strcpy(event.device_class, dev->pnp.device_class);
+ strcpy(event.bus_id, dev->pnp.bus_id);
+ event.type = type;
+ event.data = data;
+ return (blocking_notifier_call_chain(&acpi_chain_head, 0, (void *)&event)
+ == NOTIFY_BAD) ? -EINVAL : 0;
+}
+EXPORT_SYMBOL(acpi_notifier_call_chain);
+
+int register_acpi_notifier(struct notifier_block *nb)
+{
+ return blocking_notifier_chain_register(&acpi_chain_head, nb);
+}
+EXPORT_SYMBOL(register_acpi_notifier);
+
+int unregister_acpi_notifier(struct notifier_block *nb)
+{
+ return blocking_notifier_chain_unregister(&acpi_chain_head, nb);
+}
+EXPORT_SYMBOL(unregister_acpi_notifier);
+
+#ifdef CONFIG_NET
+static unsigned int acpi_event_seqnum;
+struct acpi_genl_event {
+ acpi_device_class device_class;
+ char bus_id[15];
+ u32 type;
+ u32 data;
+};
+
+/* attributes of acpi_genl_family */
+enum {
+ ACPI_GENL_ATTR_UNSPEC,
+ ACPI_GENL_ATTR_EVENT, /* ACPI event info needed by user space */
+ __ACPI_GENL_ATTR_MAX,
+};
+#define ACPI_GENL_ATTR_MAX (__ACPI_GENL_ATTR_MAX - 1)
+
+/* commands supported by the acpi_genl_family */
+enum {
+ ACPI_GENL_CMD_UNSPEC,
+ ACPI_GENL_CMD_EVENT, /* kernel->user notifications for ACPI events */
+ __ACPI_GENL_CMD_MAX,
+};
+#define ACPI_GENL_CMD_MAX (__ACPI_GENL_CMD_MAX - 1)
+
+#define ACPI_GENL_FAMILY_NAME "acpi_event"
+#define ACPI_GENL_VERSION 0x01
+#define ACPI_GENL_MCAST_GROUP_NAME "acpi_mc_group"
+
+static const struct genl_multicast_group acpi_event_mcgrps[] = {
+ { .name = ACPI_GENL_MCAST_GROUP_NAME, },
+};
+
+static struct genl_family acpi_event_genl_family __ro_after_init = {
+ .module = THIS_MODULE,
+ .name = ACPI_GENL_FAMILY_NAME,
+ .version = ACPI_GENL_VERSION,
+ .maxattr = ACPI_GENL_ATTR_MAX,
+ .mcgrps = acpi_event_mcgrps,
+ .n_mcgrps = ARRAY_SIZE(acpi_event_mcgrps),
+};
+
+int acpi_bus_generate_netlink_event(const char *device_class,
+ const char *bus_id,
+ u8 type, int data)
+{
+ struct sk_buff *skb;
+ struct nlattr *attr;
+ struct acpi_genl_event *event;
+ void *msg_header;
+ int size;
+
+ /* allocate memory */
+ size = nla_total_size(sizeof(struct acpi_genl_event)) +
+ nla_total_size(0);
+
+ skb = genlmsg_new(size, GFP_ATOMIC);
+ if (!skb)
+ return -ENOMEM;
+
+ /* add the genetlink message header */
+ msg_header = genlmsg_put(skb, 0, acpi_event_seqnum++,
+ &acpi_event_genl_family, 0,
+ ACPI_GENL_CMD_EVENT);
+ if (!msg_header) {
+ nlmsg_free(skb);
+ return -ENOMEM;
+ }
+
+ /* fill the data */
+ attr =
+ nla_reserve(skb, ACPI_GENL_ATTR_EVENT,
+ sizeof(struct acpi_genl_event));
+ if (!attr) {
+ nlmsg_free(skb);
+ return -EINVAL;
+ }
+
+ event = nla_data(attr);
+ memset(event, 0, sizeof(struct acpi_genl_event));
+
+ strcpy(event->device_class, device_class);
+ strcpy(event->bus_id, bus_id);
+ event->type = type;
+ event->data = data;
+
+ /* send multicast genetlink message */
+ genlmsg_end(skb, msg_header);
+
+ genlmsg_multicast(&acpi_event_genl_family, skb, 0, 0, GFP_ATOMIC);
+ return 0;
+}
+
+EXPORT_SYMBOL(acpi_bus_generate_netlink_event);
+
+static int __init acpi_event_genetlink_init(void)
+{
+ return genl_register_family(&acpi_event_genl_family);
+}
+
+#else
+int acpi_bus_generate_netlink_event(const char *device_class,
+ const char *bus_id,
+ u8 type, int data)
+{
+ return 0;
+}
+
+EXPORT_SYMBOL(acpi_bus_generate_netlink_event);
+
+static int acpi_event_genetlink_init(void)
+{
+ return -ENODEV;
+}
+#endif
+
+static int __init acpi_event_init(void)
+{
+ int error = 0;
+
+ if (acpi_disabled)
+ return 0;
+
+ /* create genetlink for acpi event */
+ error = acpi_event_genetlink_init();
+ if (error)
+ printk(KERN_WARNING PREFIX
+ "Failed to create genetlink family for ACPI event\n");
+ return 0;
+}
+
+fs_initcall(acpi_event_init);