ACPI: Export events via generic netlink

Upon ACPI events, send an "acpi_event" via Generic Netlink.
This is in addition to /proc/acpi/event, which remains intact for now.

Thanks to Jamal for his great help.

Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 159 insertions, 7 deletions

diff --git a/drivers/acpi/event.c b/drivers/acpi/event.c
index 3b23562e6f92..98627b02f547 100644
--- a/drivers/acpi/event.c
+++ b/drivers/acpi/event.c
@@ -11,6 +11,8 @@
 #include <linux/init.h>
 #include <linux/poll.h>
 #include <acpi/acpi_drivers.h>
+#include <net/netlink.h>
+#include <net/genetlink.h>
 
 #define _COMPONENT              ACPI_SYSTEM_COMPONENT
 ACPI_MODULE_NAME("event");
@@ -48,7 +50,6 @@ acpi_system_read_event(struct file *file, char __user * buffer, size_t count,
         static int chars_remaining = 0;
         static char *ptr;
 
-
         if (!chars_remaining) {
                 memset(&event, 0, sizeof(struct acpi_bus_event));
 
@@ -106,23 +107,174 @@ static const struct file_operations acpi_system_event_ops = {
         .poll = acpi_system_poll_event,
 };
 
+#ifdef CONFIG_NET
+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_NAME          "acpi_event"
+#define ACPI_GENL_VERSION       0x01
+
+static struct genl_family acpi_event_genl_family = {
+        .id = GENL_ID_GENERATE,
+        .name = ACPI_GENL_NAME,
+        .version = ACPI_GENL_VERSION,
+        .maxattr = ACPI_GENL_ATTR_MAX,
+};
+
+/* .doit: standard command callback */
+static int acpi_genl_cmd_event(struct sk_buff *skb, struct genl_info *info)
+{
+        struct acpi_genl_event *event = info->userhdr;
+
+        if (!event)
+                ACPI_DEBUG_PRINT((ACPI_DB_WARN, "ACPI event: NULL\n"));
+
+        return 0;
+}
+
+static struct genl_ops acpi_event_genl_ops = {
+        .cmd = ACPI_GENL_CMD_EVENT,
+        .doit = acpi_genl_cmd_event,
+};
+
+int acpi_bus_generate_genetlink_event(struct acpi_device *device,
+                                      u8 type, int data)
+{
+        struct sk_buff *skb;
+        struct nlattr *attr;
+        struct acpi_genl_event *event;
+        void *msg_header;
+        int size;
+        int result;
+
+        /* 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);
+        if (!event) {
+                nlmsg_free(skb);
+                return -EINVAL;
+        }
+
+        memset(event, 0, sizeof(struct acpi_genl_event));
+
+        strcpy(event->device_class, device->pnp.device_class);
+        strcpy(event->bus_id, device->dev.bus_id);
+        event->type = type;
+        event->data = data;
+
+        /* send multicast genetlink message */
+        result = genlmsg_end(skb, msg_header);
+        if (result < 0) {
+                nlmsg_free(skb);
+                return result;
+        }
+
+        result =
+            genlmsg_multicast(skb, 0, acpi_event_genl_family.id, GFP_ATOMIC);
+        if (result)
+                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+                                  "Failed to send a Genetlink message!\n"));
+        return 0;
+}
+EXPORT_SYMBOL(acpi_bus_generate_genetlink_event);
+
+static int acpi_event_genetlink_init(void)
+{
+        int result;
+
+        result = genl_register_family(&acpi_event_genl_family);
+        if (result)
+                return result;
+
+        result =
+            genl_register_ops(&acpi_event_genl_family, &acpi_event_genl_ops);
+        if (result)
+                genl_unregister_family(&acpi_event_genl_family);
+
+        return result;
+}
+
+#else
+int acpi_bus_generate_genetlink_event(struct acpi_device *device, u8 type,
+                                      int data)
+{
+        return 0;
+}
+EXPORT_SYMBOL(acpi_bus_generate_genetlink_event);
+
+static int acpi_event_genetlink_init(void)
+{
+        return -ENODEV;
+}
+#endif
+
 static int __init acpi_event_init(void)
 {
         struct proc_dir_entry *entry;
         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");
+
         /* 'event' [R] */
         entry = create_proc_entry("event", S_IRUSR, acpi_root_dir);
         if (entry)
                 entry->proc_fops = &acpi_system_event_ops;
-        else {
-                error = -ENODEV;
-        }
-        return error;
+        else
+                return -ENODEV;
+
+        return 0;
 }
 
-subsys_initcall(acpi_event_init);
+fs_initcall(acpi_event_init);