1 files changed, 57 insertions, 19 deletions

diff --git a/kernel/async.c b/kernel/async.c
index bd0c168a3bbe..9d3118384858 100644
--- a/kernel/async.c
+++ b/kernel/async.c
@@ -62,8 +62,10 @@ 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 LIST_HEAD(async_domains);
 static DEFINE_SPINLOCK(async_lock);
+static DEFINE_MUTEX(async_register_mutex);
 
 struct async_entry {
         struct list_head        list;
@@ -71,7 +73,7 @@ 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 +84,12 @@ 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 +100,7 @@ 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 +120,11 @@ 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) */
@@ -145,6 +147,8 @@ static void async_run_entry_fn(struct work_struct *work)
         /* 3) remove self from the running queue */
         spin_lock_irqsave(&async_lock, flags);
         list_del(&entry->list);
+        if (running->registered && --running->count == 0)
+                list_del_init(&running->node);
 
         /* 4) free the entry */
         kfree(entry);
@@ -156,7 +160,7 @@ 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;
@@ -187,6 +191,8 @@ static async_cookie_t __async_schedule(async_func_ptr *ptr, void *data, struct l
         spin_lock_irqsave(&async_lock, flags);
         newcookie = entry->cookie = next_cookie++;
         list_add_tail(&entry->list, &async_pending);
+        if (running->registered && running->count++ == 0)
+                list_add_tail(&running->node, &async_domains);
         atomic_inc(&entry_count);
         spin_unlock_irqrestore(&async_lock, flags);
 
@@ -223,7 +229,7 @@ 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);
 }
@@ -236,22 +242,52 @@ EXPORT_SYMBOL_GPL(async_schedule_domain);
  */
 void async_synchronize_full(void)
 {
+        mutex_lock(&async_register_mutex);
         do {
-                async_synchronize_cookie(next_cookie);
-        } while (!list_empty(&async_running) || !list_empty(&async_pending));
+                struct async_domain *domain = NULL;
+
+                spin_lock_irq(&async_lock);
+                if (!list_empty(&async_domains))
+                        domain = list_first_entry(&async_domains, typeof(*domain), node);
+                spin_unlock_irq(&async_lock);
+
+                async_synchronize_cookie_domain(next_cookie, domain);
+        } while (!list_empty(&async_domains));
+        mutex_unlock(&async_register_mutex);
 }
 EXPORT_SYMBOL_GPL(async_synchronize_full);
 
 /**
+ * async_unregister_domain - ensure no more anonymous waiters on this domain
+ * @domain: idle domain to flush out of any async_synchronize_full instances
+ *
+ * async_synchronize_{cookie|full}_domain() are not flushed since callers
+ * of these routines should know the lifetime of @domain
+ *
+ * Prefer ASYNC_DOMAIN_EXCLUSIVE() declarations over flushing
+ */
+void async_unregister_domain(struct async_domain *domain)
+{
+        mutex_lock(&async_register_mutex);
+        spin_lock_irq(&async_lock);
+        WARN_ON(!domain->registered || !list_empty(&domain->node) ||
+                !list_empty(&domain->domain));
+        domain->registered = 0;
+        spin_unlock_irq(&async_lock);
+        mutex_unlock(&async_register_mutex);
+}
+EXPORT_SYMBOL_GPL(async_unregister_domain);
+
+/**
  * 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);
 
@@ -261,14 +297,16 @@ 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;
 
+        if (!running)
+                return;
+
         if (initcall_debug && system_state == SYSTEM_BOOTING) {
                 printk(KERN_DEBUG "async_waiting @ %i\n", task_pid_nr(current));
                 starttime = ktime_get();