2 files changed, 30 insertions, 18 deletions

diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h
index 5b13dcf02714..2a7b38d87018 100644
--- a/include/linux/workqueue.h
+++ b/include/linux/workqueue.h
@@ -8,16 +8,21 @@
 #include <linux/timer.h>
 #include <linux/linkage.h>
 #include <linux/bitops.h>
+#include <asm/atomic.h>
 
 struct workqueue_struct;
 
 struct work_struct;
 typedef void (*work_func_t)(struct work_struct *work);
 
+/*
+ * The first word is the work queue pointer and the flags rolled into
+ * one
+ */
+#define work_data_bits(work) ((unsigned long *)(&(work)->data))
+
 struct work_struct {
-        /* the first word is the work queue pointer and the flags rolled into
-         * one */
-        unsigned long management;
+        atomic_long_t data;
 #define WORK_STRUCT_PENDING 0           /* T if work item pending execution */
 #define WORK_STRUCT_NOAUTOREL 1         /* F if work item automatically released on exec */
 #define WORK_STRUCT_FLAG_MASK (3UL)
@@ -26,6 +31,9 @@ struct work_struct {
         work_func_t func;
 };
 
+#define WORK_DATA_INIT(autorelease) \
+        ATOMIC_LONG_INIT((autorelease) << WORK_STRUCT_NOAUTOREL)
+
 struct delayed_work {
         struct work_struct work;
         struct timer_list timer;
@@ -36,13 +44,13 @@ struct execute_work {
 };
 
 #define __WORK_INITIALIZER(n, f) {                              \
-        .management = 0,                                        \
+        .data = WORK_DATA_INIT(0),                              \
         .entry  = { &(n).entry, &(n).entry },                   \
         .func = (f),                                            \
         }
 
 #define __WORK_INITIALIZER_NAR(n, f) {                          \
-        .management = (1 << WORK_STRUCT_NOAUTOREL),             \
+        .data = WORK_DATA_INIT(1),                              \
         .entry  = { &(n).entry, &(n).entry },                   \
         .func = (f),                                            \
         }
@@ -82,17 +90,21 @@ struct execute_work {
 
 /*
  * initialize all of a work item in one go
+ *
+ * NOTE! No point in using "atomic_long_set()": useing a direct
+ * assignment of the work data initializer allows the compiler
+ * to generate better code.
  */
 #define INIT_WORK(_work, _func)                                 \
         do {                                                    \
-                (_work)->management = 0;                        \
+                (_work)->data = (atomic_long_t) WORK_DATA_INIT(0);      \
                 INIT_LIST_HEAD(&(_work)->entry);                \
                 PREPARE_WORK((_work), (_func));                 \
         } while (0)
 
 #define INIT_WORK_NAR(_work, _func)                                     \
         do {                                                            \
-                (_work)->management = (1 << WORK_STRUCT_NOAUTOREL);     \
+                (_work)->data = (atomic_long_t) WORK_DATA_INIT(1);      \
                 INIT_LIST_HEAD(&(_work)->entry);                        \
                 PREPARE_WORK((_work), (_func));                         \
         } while (0)
@@ -114,7 +126,7 @@ struct execute_work {
  * @work: The work item in question
  */
 #define work_pending(work) \
-        test_bit(WORK_STRUCT_PENDING, &(work)->management)
+        test_bit(WORK_STRUCT_PENDING, work_data_bits(work))
 
 /**
  * delayed_work_pending - Find out whether a delayable work item is currently
@@ -143,7 +155,7 @@ struct execute_work {
  * This should also be used to release a delayed work item.
  */
 #define work_release(work) \
-        clear_bit(WORK_STRUCT_PENDING, &(work)->management)
+        clear_bit(WORK_STRUCT_PENDING, work_data_bits(work))
 
 
 extern struct workqueue_struct *__create_workqueue(const char *name,
@@ -188,7 +200,7 @@ static inline int cancel_delayed_work(struct delayed_work *work)
 
         ret = del_timer_sync(&work->timer);
         if (ret)
-                clear_bit(WORK_STRUCT_PENDING, &work->work.management);
+                work_release(&work->work);
         return ret;
 }
 
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index db49886bfae1..742cbbe49bdc 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -96,13 +96,13 @@ static inline void set_wq_data(struct work_struct *work, void *wq)
         BUG_ON(!work_pending(work));
 
         new = (unsigned long) wq | (1UL << WORK_STRUCT_PENDING);
-        new |= work->management & WORK_STRUCT_FLAG_MASK;
-        work->management = new;
+        new |= WORK_STRUCT_FLAG_MASK & *work_data_bits(work);
+        atomic_long_set(&work->data, new);
 }
 
 static inline void *get_wq_data(struct work_struct *work)
 {
-        return (void *) (work->management & WORK_STRUCT_WQ_DATA_MASK);
+        return (void *) (atomic_long_read(&work->data) & WORK_STRUCT_WQ_DATA_MASK);
 }
 
 static int __run_work(struct cpu_workqueue_struct *cwq, struct work_struct *work)
@@ -133,7 +133,7 @@ static int __run_work(struct cpu_workqueue_struct *cwq, struct work_struct *work
                 list_del_init(&work->entry);
                 spin_unlock_irqrestore(&cwq->lock, flags);
 
-                if (!test_bit(WORK_STRUCT_NOAUTOREL, &work->management))
+                if (!test_bit(WORK_STRUCT_NOAUTOREL, work_data_bits(work)))
                         work_release(work);
                 f(work);
 
@@ -206,7 +206,7 @@ int fastcall queue_work(struct workqueue_struct *wq, struct work_struct *work)
 {
         int ret = 0, cpu = get_cpu();
 
-        if (!test_and_set_bit(WORK_STRUCT_PENDING, &work->management)) {
+        if (!test_and_set_bit(WORK_STRUCT_PENDING, work_data_bits(work))) {
                 if (unlikely(is_single_threaded(wq)))
                         cpu = singlethread_cpu;
                 BUG_ON(!list_empty(&work->entry));
@@ -248,7 +248,7 @@ int fastcall queue_delayed_work(struct workqueue_struct *wq,
         if (delay == 0)
                 return queue_work(wq, work);
 
-        if (!test_and_set_bit(WORK_STRUCT_PENDING, &work->management)) {
+        if (!test_and_set_bit(WORK_STRUCT_PENDING, work_data_bits(work))) {
                 BUG_ON(timer_pending(timer));
                 BUG_ON(!list_empty(&work->entry));
 
@@ -280,7 +280,7 @@ int queue_delayed_work_on(int cpu, struct workqueue_struct *wq,
         struct timer_list *timer = &dwork->timer;
         struct work_struct *work = &dwork->work;
 
-        if (!test_and_set_bit(WORK_STRUCT_PENDING, &work->management)) {
+        if (!test_and_set_bit(WORK_STRUCT_PENDING, work_data_bits(work))) {
                 BUG_ON(timer_pending(timer));
                 BUG_ON(!list_empty(&work->entry));
 
@@ -321,7 +321,7 @@ static void run_workqueue(struct cpu_workqueue_struct *cwq)
                 spin_unlock_irqrestore(&cwq->lock, flags);
 
                 BUG_ON(get_wq_data(work) != cwq);
-                if (!test_bit(WORK_STRUCT_NOAUTOREL, &work->management))
+                if (!test_bit(WORK_STRUCT_NOAUTOREL, work_data_bits(work)))
                         work_release(work);
                 f(work);