From: Erik Gilling <konkers@xxxxxxxxxxx>
In order to allow drivers to cleanly handled teardown we need to allow them
to cancel pending async waits. To do this cleanly, we move allocation of
sync_fence_waiter to the driver calling sync_async_wait().
Cc: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxx>
Cc: Erik Gilling <konkers@xxxxxxxxxxx>
Cc: Daniel Vetter <daniel.vetter@xxxxxxxx>
Cc: Rob Clark <robclark@xxxxxxxxx>
Cc: Sumit Semwal <sumit.semwal@xxxxxxxxxx>
Cc: Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
Cc: Android Kernel Team <kernel-team@xxxxxxxxxxx>
Signed-off-by: Erik Gilling <konkers@xxxxxxxxxxx>
Signed-off-by: John Stultz <john.stultz@xxxxxxxxxx>
---
drivers/staging/android/sync.c | 46 +++++++++++++++++++++++++++-------------
drivers/staging/android/sync.h | 36 +++++++++++++++++++++++++------
2 files changed, 60 insertions(+), 22 deletions(-)
diff --git a/drivers/staging/android/sync.c b/drivers/staging/android/sync.c
index 9e35ea3..54f84d9 100644
--- a/drivers/staging/android/sync.c
+++ b/drivers/staging/android/sync.c
@@ -421,33 +421,22 @@ static void sync_fence_signal_pt(struct sync_pt *pt)
container_of(pos, struct sync_fence_waiter,
waiter_list);
- waiter->callback(fence, waiter->callback_data);
list_del(pos);
- kfree(waiter);
+ waiter->callback(fence, waiter);
}
wake_up(&fence->wq);
}
}
int sync_fence_wait_async(struct sync_fence *fence,
- void (*callback)(struct sync_fence *, void *data),
- void *callback_data)
+ struct sync_fence_waiter *waiter)
{
- struct sync_fence_waiter *waiter;
unsigned long flags;
int err = 0;
- waiter = kzalloc(sizeof(struct sync_fence_waiter), GFP_KERNEL);
- if (waiter == NULL)
- return -ENOMEM;
-
- waiter->callback = callback;
- waiter->callback_data = callback_data;
-
spin_lock_irqsave(&fence->waiter_list_lock, flags);
if (fence->status) {
- kfree(waiter);
err = fence->status;
goto out;
}
@@ -459,6 +448,34 @@ out:
return err;
}
+int sync_fence_cancel_async(struct sync_fence *fence,
+ struct sync_fence_waiter *waiter)
+{
+ struct list_head *pos;
+ struct list_head *n;
+ unsigned long flags;
+ int ret = -ENOENT;
+
+ spin_lock_irqsave(&fence->waiter_list_lock, flags);
+ /*
+ * Make sure waiter is still in waiter_list because it is possible for
+ * the waiter to be removed from the list while the callback is still
+ * pending.
+ */
+ list_for_each_safe(pos, n, &fence->waiter_list_head) {
+ struct sync_fence_waiter *list_waiter =
+ container_of(pos, struct sync_fence_waiter,
+ waiter_list);
+ if (list_waiter == waiter) {
+ list_del(pos);
+ ret = 0;
+ break;
+ }
+ }
+ spin_unlock_irqrestore(&fence->waiter_list_lock, flags);
+ return ret;
+}
+
int sync_fence_wait(struct sync_fence *fence, long timeout)
{
int err;
@@ -739,8 +756,7 @@ static void sync_print_fence(struct seq_file *s, struct sync_fence *fence)
container_of(pos, struct sync_fence_waiter,
waiter_list);
- seq_printf(s, "waiter %pF %p\n", waiter->callback,
- waiter->callback_data);
+ seq_printf(s, "waiter %pF\n", waiter->callback);
}
spin_unlock_irqrestore(&fence->waiter_list_lock, flags);
}
diff --git a/drivers/staging/android/sync.h b/drivers/staging/android/sync.h
index 4f19938..943f414 100644
--- a/drivers/staging/android/sync.h
+++ b/drivers/staging/android/sync.h
@@ -159,6 +159,10 @@ struct sync_fence {
struct list_head sync_fence_list;
};
+struct sync_fence_waiter;
+typedef void (*sync_callback_t)(struct sync_fence *fence,
+ struct sync_fence_waiter *waiter);
+
/**
* struct sync_fence_waiter - metadata for asynchronous waiter on a fence
* @waiter_list: membership in sync_fence.waiter_list_head
@@ -168,10 +172,15 @@ struct sync_fence {
struct sync_fence_waiter {
struct list_head waiter_list;
- void (*callback)(struct sync_fence *fence, void *data);
- void *callback_data;
+ sync_callback_t callback;
};
+static inline void sync_fence_waiter_init(struct sync_fence_waiter *waiter,
+ sync_callback_t callback)
+{
+ waiter->callback = callback;
+}
+
/*
* API for sync_timeline implementers
*/
@@ -284,16 +293,29 @@ void sync_fence_install(struct sync_fence *fence, int fd);
/**
* sync_fence_wait_async() - registers and async wait on the fence
* @fence: fence to wait on
- * @callback: callback
- * @callback_data data to pass to the callback
+ * @waiter: waiter callback struck
*
* Returns 1 if @fence has already signaled.
*
- * Registers a callback to be called when @fence signals or has an error
+ * Registers a callback to be called when @fence signals or has an error.
+ * @waiter should be initialized with sync_fence_waiter_init().
*/
int sync_fence_wait_async(struct sync_fence *fence,
- void (*callback)(struct sync_fence *, void *data),
- void *callback_data);
+ struct sync_fence_waiter *waiter);
+
+/**
+ * sync_fence_cancel_async() - cancels an async wait
+ * @fence: fence to wait on
+ * @waiter: waiter callback struck
+ *
+ * returns 0 if waiter was removed from fence's async waiter list.
+ * returns -ENOENT if waiter was not found on fence's async waiter list.
+ *
+ * Cancels a previously registered async wait. Will fail gracefully if
+ * @waiter was never registered or if @fence has already signaled @waiter.
+ */
+int sync_fence_cancel_async(struct sync_fence *fence,
+ struct sync_fence_waiter *waiter);
/**
* sync_fence_wait() - wait on fence
--
1.7.10.4
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