dma-buf: return index of the first signaled fence (v2)

Return the index of the first signaled fence.  This information
is useful in some APIs like Vulkan.

v2: rebase on drm-next (fence -> dma_fence)

Signed-off-by: monk.liu <monk.liu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
 [sumits: fix warnings]
Link: http://patchwork.freedesktop.org/patch/msgid/1478290570-30982-1-git-send-email-alexander.deucher@amd.com

2 files changed, 18 insertions, 6 deletions

diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c
index 3a7bf009c21c..cda40cbd8c43 100644
--- a/drivers/dma-buf/dma-fence.c
+++ b/drivers/dma-buf/dma-fence.c
@@ -403,14 +403,18 @@ out:
 EXPORT_SYMBOL(dma_fence_default_wait);
 
 static bool
-dma_fence_test_signaled_any(struct dma_fence **fences, uint32_t count)
+dma_fence_test_signaled_any(struct dma_fence **fences, uint32_t count,
+                            uint32_t *idx)
 {
         int i;
 
         for (i = 0; i < count; ++i) {
                 struct dma_fence *fence = fences[i];
-                if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags))
+                if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags)) {
+                        if (idx)
+                                *idx = i;
                         return true;
+                }
         }
         return false;
 }
@@ -422,6 +426,8 @@ dma_fence_test_signaled_any(struct dma_fence **fences, uint32_t count)
  * @count:      [in]    number of fences to wait on
  * @intr:       [in]    if true, do an interruptible wait
  * @timeout:    [in]    timeout value in jiffies, or MAX_SCHEDULE_TIMEOUT
+ * @idx:       [out]    the first signaled fence index, meaningful only on
+ *                      positive return
  *
  * Returns -EINVAL on custom fence wait implementation, -ERESTARTSYS if
  * interrupted, 0 if the wait timed out, or the remaining timeout in jiffies
@@ -433,7 +439,7 @@ dma_fence_test_signaled_any(struct dma_fence **fences, uint32_t count)
  */
 signed long
 dma_fence_wait_any_timeout(struct dma_fence **fences, uint32_t count,
-                           bool intr, signed long timeout)
+                           bool intr, signed long timeout, uint32_t *idx)
 {
         struct default_wait_cb *cb;
         signed long ret = timeout;
@@ -444,8 +450,11 @@ dma_fence_wait_any_timeout(struct dma_fence **fences, uint32_t count,
 
         if (timeout == 0) {
                 for (i = 0; i < count; ++i)
-                        if (dma_fence_is_signaled(fences[i]))
+                        if (dma_fence_is_signaled(fences[i])) {
+                                if (idx)
+                                        *idx = i;
                                 return 1;
+                        }
 
                 return 0;
         }
@@ -468,6 +477,8 @@ dma_fence_wait_any_timeout(struct dma_fence **fences, uint32_t count,
                 if (dma_fence_add_callback(fence, &cb[i].base,
                                            dma_fence_default_wait_cb)) {
                         /* This fence is already signaled */
+                        if (idx)
+                                *idx = i;
                         goto fence_rm_cb;
                 }
         }
@@ -478,7 +489,7 @@ dma_fence_wait_any_timeout(struct dma_fence **fences, uint32_t count,
                 else
                         set_current_state(TASK_UNINTERRUPTIBLE);
 
-                if (dma_fence_test_signaled_any(fences, count))
+                if (dma_fence_test_signaled_any(fences, count, idx))
                         break;
 
                 ret = schedule_timeout(ret);
diff --git a/include/linux/dma-fence.h b/include/linux/dma-fence.h
index ba60c043a5d3..fcf4b1971eba 100644
--- a/include/linux/dma-fence.h
+++ b/include/linux/dma-fence.h
@@ -382,7 +382,8 @@ signed long dma_fence_wait_timeout(struct dma_fence *,
                                    bool intr, signed long timeout);
 signed long dma_fence_wait_any_timeout(struct dma_fence **fences,
                                        uint32_t count,
-                                       bool intr, signed long timeout);
+                                       bool intr, signed long timeout,
+                                       uint32_t *idx);
 
 /**
  * dma_fence_wait - sleep until the fence gets signaled