SCSI: add asynchronous event notification API

Originally based on a patch by Kristen Carlson Accardi @ Intel.
Copious input from James Bottomley.

Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

1 files changed, 25 insertions, 0 deletions

diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index d5057bc338ff..66e9058357e0 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -46,6 +46,22 @@ enum scsi_device_state {
                                  * to the scsi lld. */
 };
 
+enum scsi_device_event {
+        SDEV_EVT_MEDIA_CHANGE   = 1,    /* media has changed */
+
+        SDEV_EVT_LAST           = SDEV_EVT_MEDIA_CHANGE,
+        SDEV_EVT_MAXBITS        = SDEV_EVT_LAST + 1
+};
+
+struct scsi_event {
+        enum scsi_device_event  evt_type;
+        struct list_head        node;
+
+        /* put union of data structures, for non-simple event types,
+         * here
+         */
+};
+
 struct scsi_device {
         struct Scsi_Host *host;
         struct request_queue *request_queue;
@@ -127,6 +143,10 @@ struct scsi_device {
         unsigned guess_capacity:1;      /* READ_CAPACITY might be too high by 1 */
         unsigned retry_hwerror:1;       /* Retry HARDWARE_ERROR */
 
+        DECLARE_BITMAP(supported_events, SDEV_EVT_MAXBITS); /* supported events */
+        struct list_head event_list;    /* asserted events */
+        struct work_struct event_work;
+
         unsigned int device_blocked;    /* Device returned QUEUE_FULL. */
 
         unsigned int max_device_blocked; /* what device_blocked counts down from  */
@@ -275,6 +295,11 @@ extern int scsi_test_unit_ready(struct scsi_device *sdev, int timeout,
                                 int retries);
 extern int scsi_device_set_state(struct scsi_device *sdev,
                                  enum scsi_device_state state);
+extern struct scsi_event *sdev_evt_alloc(enum scsi_device_event evt_type,
+                                          gfp_t gfpflags);
+extern void sdev_evt_send(struct scsi_device *sdev, struct scsi_event *evt);
+extern void sdev_evt_send_simple(struct scsi_device *sdev,
+                          enum scsi_device_event evt_type, gfp_t gfpflags);
 extern int scsi_device_quiesce(struct scsi_device *sdev);
 extern void scsi_device_resume(struct scsi_device *sdev);
 extern void scsi_target_quiesce(struct scsi_target *);