[PATCH 1/2] dma-buf: return index of the first signaled fence (v2)

[Alex Deucher]

From: "monk.liu" <monk.liu at amd.com>

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 at amd.com>
Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
Cc: Sumit Semwal <sumit.semwal at linaro.org>
---

This is the same patch set I send out yesterday, I just
squashed the amdgpu patches together and rebased everything on
the fence -> dma_fence renaming.  This is used by our VK driver
and we are planning to use it in mesa as well.

drivers/dma-buf/dma-fence.c | 20 +++++++++++++++-----
 include/linux/dma-fence.h   |  2 +-
 2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c
index 9ef3c2f..dd00990 100644
--- a/drivers/dma-buf/dma-fence.c
+++ b/drivers/dma-buf/dma-fence.c
@@ -402,14 +402,18 @@ dma_fence_default_wait(struct dma_fence *fence, bool intr, signed long timeout)
 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;
 }
@@ -421,6 +425,7 @@ 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, meaninful only on Returns positive
  *
  * Returns -EINVAL on custom fence wait implementation, -ERESTARTSYS if
  * interrupted, 0 if the wait timed out, or the remaining timeout in jiffies
@@ -432,7 +437,7 @@ 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;
@@ -443,8 +448,11 @@ 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;
 	}
@@ -467,6 +475,8 @@ 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;
 		}
 	}
@@ -477,7 +487,7 @@ 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 ba60c04..e578fe7 100644
--- a/include/linux/dma-fence.h
+++ b/include/linux/dma-fence.h
@@ -382,7 +382,7 @@ 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
-- 
2.5.5