[SCSI] async: introduce 'async_domain' type

This is in preparation for teaching async_synchronize_full() to sync all
pending async work, and not just on the async_running domain.  This
conversion is functionally equivalent, just embedding the existing list
in a new async_domain type.

The .registered attribute is used in a later patch to distinguish
between domains that want to be flushed by async_synchronize_full()
versus those that only expect async_synchronize_{full|cookie}_domain to
be used for flushing.

[jejb: add async.h to scsi_priv.h for struct async_domain]
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Tested-by: Eldad Zack <eldad@fogrefinery.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

1 files changed, 31 insertions, 4 deletions

diff --git a/include/linux/async.h b/include/linux/async.h
index 68a9530196f2..364e7ff16c08 100644
--- a/include/linux/async.h
+++ b/include/linux/async.h
@@ -9,19 +9,46 @@
  * as published by the Free Software Foundation; version 2
  * of the License.
  */
+#ifndef __ASYNC_H__
+#define __ASYNC_H__
 
 #include <linux/types.h>
 #include <linux/list.h>
 
 typedef u64 async_cookie_t;
 typedef void (async_func_ptr) (void *data, async_cookie_t cookie);
+struct async_domain {
+        struct list_head node;
+        struct list_head domain;
+        int count;
+        unsigned registered:1;
+};
+
+/*
+ * domain participates in global async_synchronize_full
+ */
+#define ASYNC_DOMAIN(_name) \
+        struct async_domain _name = { .node = LIST_HEAD_INIT(_name.node), \
+                                      .domain = LIST_HEAD_INIT(_name.domain), \
+                                      .count = 0, \
+                                      .registered = 1 }
+
+/*
+ * domain is free to go out of scope as soon as all pending work is
+ * complete, this domain does not participate in async_synchronize_full
+ */
+#define ASYNC_DOMAIN_EXCLUSIVE(_name) \
+        struct async_domain _name = { .node = LIST_HEAD_INIT(_name.node), \
+                                      .domain = LIST_HEAD_INIT(_name.domain), \
+                                      .count = 0, \
+                                      .registered = 0 }
 
 extern async_cookie_t async_schedule(async_func_ptr *ptr, void *data);
 extern async_cookie_t async_schedule_domain(async_func_ptr *ptr, void *data,
-                                            struct list_head *list);
+                                            struct async_domain *domain);
 extern void async_synchronize_full(void);
-extern void async_synchronize_full_domain(struct list_head *list);
+extern void async_synchronize_full_domain(struct async_domain *domain);
 extern void async_synchronize_cookie(async_cookie_t cookie);
 extern void async_synchronize_cookie_domain(async_cookie_t cookie,
-                                            struct list_head *list);
-
+                                            struct async_domain *domain);
+#endif