[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, 17 insertions, 18 deletions

diff --git a/kernel/async.c b/kernel/async.c
index bd0c168a3bbe..ba5491dfa991 100644
--- a/kernel/async.c
+++ b/kernel/async.c
@@ -62,7 +62,7 @@ static async_cookie_t next_cookie = 1;
 #define MAX_WORK        32768
 
 static LIST_HEAD(async_pending);
-static LIST_HEAD(async_running);
+static ASYNC_DOMAIN(async_running);
 static DEFINE_SPINLOCK(async_lock);
 
 struct async_entry {
@@ -71,7 +71,7 @@ struct async_entry {
         async_cookie_t          cookie;
         async_func_ptr          *func;
         void                    *data;
-        struct list_head        *running;
+        struct async_domain     *running;
 };
 
 static DECLARE_WAIT_QUEUE_HEAD(async_done);
@@ -82,13 +82,12 @@ static atomic_t entry_count;
 /*
  * MUST be called with the lock held!
  */
-static async_cookie_t  __lowest_in_progress(struct list_head *running)
+static async_cookie_t  __lowest_in_progress(struct async_domain *running)
 {
         struct async_entry *entry;
 
-        if (!list_empty(running)) {
-                entry = list_first_entry(running,
-                        struct async_entry, list);
+        if (!list_empty(&running->domain)) {
+                entry = list_first_entry(&running->domain, typeof(*entry), list);
                 return entry->cookie;
         }
 
@@ -99,7 +98,7 @@ static async_cookie_t  __lowest_in_progress(struct list_head *running)
         return next_cookie;     /* "infinity" value */
 }
 
-static async_cookie_t  lowest_in_progress(struct list_head *running)
+static async_cookie_t  lowest_in_progress(struct async_domain *running)
 {
         unsigned long flags;
         async_cookie_t ret;
@@ -119,10 +118,11 @@ static void async_run_entry_fn(struct work_struct *work)
                 container_of(work, struct async_entry, work);
         unsigned long flags;
         ktime_t uninitialized_var(calltime), delta, rettime;
+        struct async_domain *running = entry->running;
 
         /* 1) move self to the running queue */
         spin_lock_irqsave(&async_lock, flags);
-        list_move_tail(&entry->list, entry->running);
+        list_move_tail(&entry->list, &running->domain);
         spin_unlock_irqrestore(&async_lock, flags);
 
         /* 2) run (and print duration) */
@@ -156,7 +156,7 @@ static void async_run_entry_fn(struct work_struct *work)
         wake_up(&async_done);
 }
 
-static async_cookie_t __async_schedule(async_func_ptr *ptr, void *data, struct list_head *running)
+static async_cookie_t __async_schedule(async_func_ptr *ptr, void *data, struct async_domain *running)
 {
         struct async_entry *entry;
         unsigned long flags;
@@ -223,7 +223,7 @@ EXPORT_SYMBOL_GPL(async_schedule);
  * Note: This function may be called from atomic or non-atomic contexts.
  */
 async_cookie_t async_schedule_domain(async_func_ptr *ptr, void *data,
-                                     struct list_head *running)
+                                     struct async_domain *running)
 {
         return __async_schedule(ptr, data, running);
 }
@@ -238,20 +238,20 @@ void async_synchronize_full(void)
 {
         do {
                 async_synchronize_cookie(next_cookie);
-        } while (!list_empty(&async_running) || !list_empty(&async_pending));
+        } while (!list_empty(&async_running.domain) || !list_empty(&async_pending));
 }
 EXPORT_SYMBOL_GPL(async_synchronize_full);
 
 /**
  * async_synchronize_full_domain - synchronize all asynchronous function within a certain domain
- * @list: running list to synchronize on
+ * @domain: running list to synchronize on
  *
  * This function waits until all asynchronous function calls for the
- * synchronization domain specified by the running list @list have been done.
+ * synchronization domain specified by the running list @domain have been done.
  */
-void async_synchronize_full_domain(struct list_head *list)
+void async_synchronize_full_domain(struct async_domain *domain)
 {
-        async_synchronize_cookie_domain(next_cookie, list);
+        async_synchronize_cookie_domain(next_cookie, domain);
 }
 EXPORT_SYMBOL_GPL(async_synchronize_full_domain);
 
@@ -261,11 +261,10 @@ EXPORT_SYMBOL_GPL(async_synchronize_full_domain);
  * @running: running list to synchronize on
  *
  * This function waits until all asynchronous function calls for the
- * synchronization domain specified by the running list @list submitted
+ * synchronization domain specified by running list @running submitted
  * prior to @cookie have been done.
  */
-void async_synchronize_cookie_domain(async_cookie_t cookie,
-                                     struct list_head *running)
+void async_synchronize_cookie_domain(async_cookie_t cookie, struct async_domain *running)
 {
         ktime_t uninitialized_var(starttime), delta, endtime;