[RFC PATCH v1.4 08/16 1/2] drm/radeon: add timeout argument to radeon_fence_wait_seq

[Maarten Lankhorst <maarten.lankhorst@canonical.com>]

This makes it possible to wait for a specific amount of time,
rather than wait until infinity.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Reviewed-by: Christian König <deathsimple@vodafone.de>
---
  drivers/gpu/drm/radeon/radeon_fence.c | 60 +++++++++++++++++++++++------------
  1 file changed, 40 insertions(+), 20 deletions(-)

diff --git a/drivers/gpu/drm/radeon/radeon_fence.c b/drivers/gpu/drm/radeon/radeon_fence.c
index a77b1c13ea43..b25b14231421 100644
--- a/drivers/gpu/drm/radeon/radeon_fence.c
+++ b/drivers/gpu/drm/radeon/radeon_fence.c
@@ -283,28 +283,35 @@ static bool radeon_fence_any_seq_signaled(struct radeon_device *rdev, u64 *seq)
  }
  
  /**
- * radeon_fence_wait_seq - wait for a specific sequence numbers
+ * radeon_fence_wait_seq_timeout - wait for a specific sequence numbers
   *
   * @rdev: radeon device pointer
   * @target_seq: sequence number(s) we want to wait for
   * @intr: use interruptable sleep
+ * @timeout: maximum time to wait, or MAX_SCHEDULE_TIMEOUT for infinite wait
   *
   * Wait for the requested sequence number(s) to be written by any ring
   * (all asics).  Sequnce number array is indexed by ring id.
   * @intr selects whether to use interruptable (true) or non-interruptable
   * (false) sleep when waiting for the sequence number.  Helper function
   * for radeon_fence_wait_*().
- * Returns 0 if the sequence number has passed, error for all other cases.
+ * Returns remaining time if the sequence number has passed, 0 when
+ * the wait timeout, or an error for all other cases.
   * -EDEADLK is returned when a GPU lockup has been detected.
   */
-static int radeon_fence_wait_seq(struct radeon_device *rdev, u64 *target_seq,
-				 bool intr)
+static int radeon_fence_wait_seq_timeout(struct radeon_device *rdev,
+					 u64 *target_seq, bool intr,
+					 long timeout)
  {
  	uint64_t last_seq[RADEON_NUM_RINGS];
  	bool signaled;
-	int i, r;
+	int i;
  
  	while (!radeon_fence_any_seq_signaled(rdev, target_seq)) {
+		long r, waited;
+
+		waited = timeout < RADEON_FENCE_JIFFIES_TIMEOUT ?
+			 timeout : RADEON_FENCE_JIFFIES_TIMEOUT;
  
  		/* Save current sequence values, used to check for GPU lockups */
  		for (i = 0; i < RADEON_NUM_RINGS; ++i) {
@@ -319,11 +326,11 @@ static int radeon_fence_wait_seq(struct radeon_device *rdev, u64 *target_seq,
  		if (intr) {
  			r = wait_event_interruptible_timeout(rdev->fence_queue, (
  				(signaled = radeon_fence_any_seq_signaled(rdev, target_seq))
-				 || rdev->needs_reset), RADEON_FENCE_JIFFIES_TIMEOUT);
+				 || rdev->needs_reset), waited);
  		} else {
  			r = wait_event_timeout(rdev->fence_queue, (
  				(signaled = radeon_fence_any_seq_signaled(rdev, target_seq))
-				 || rdev->needs_reset), RADEON_FENCE_JIFFIES_TIMEOUT);
+				 || rdev->needs_reset), waited);
  		}
  
  		for (i = 0; i < RADEON_NUM_RINGS; ++i) {
@@ -337,6 +344,14 @@ static int radeon_fence_wait_seq(struct radeon_device *rdev, u64 *target_seq,
  		if (unlikely(r < 0))
  			return r;
  
+		timeout -= waited - r;
+
+		/*
+		 * If this is a timed wait and the wait completely timed out just return.
+		 */
+		if (!timeout)
+			break;
+
  		if (unlikely(!signaled)) {
  			if (rdev->needs_reset)
  				return -EDEADLK;
@@ -379,14 +394,14 @@ static int radeon_fence_wait_seq(struct radeon_device *rdev, u64 *target_seq,
  			}
  		}
  	}
-	return 0;
+	return timeout;
  }
  
  /**
   * radeon_fence_wait - wait for a fence to signal
   *
   * @fence: radeon fence object
- * @intr: use interruptable sleep
+ * @intr: use interruptible sleep
   *
   * Wait for the requested fence to signal (all asics).
   * @intr selects whether to use interruptable (true) or non-interruptable
@@ -396,7 +411,7 @@ static int radeon_fence_wait_seq(struct radeon_device *rdev, u64 *target_seq,
  int radeon_fence_wait(struct radeon_fence *fence, bool intr)
  {
  	uint64_t seq[RADEON_NUM_RINGS] = {};
-	int r;
+	long r;
  
  	if (fence == NULL) {
  		WARN(1, "Querying an invalid fence : %p !\n", fence);
@@ -407,9 +422,10 @@ int radeon_fence_wait(struct radeon_fence *fence, bool intr)
  	if (seq[fence->ring] == RADEON_FENCE_SIGNALED_SEQ)
  		return 0;
  
-	r = radeon_fence_wait_seq(fence->rdev, seq, intr);
-	if (r)
+	r = radeon_fence_wait_seq_timeout(fence->rdev, seq, intr, MAX_SCHEDULE_TIMEOUT);
+	if (r < 0) {
  		return r;
+	}
  
  	fence->seq = RADEON_FENCE_SIGNALED_SEQ;
  	return 0;
@@ -434,7 +450,7 @@ int radeon_fence_wait_any(struct radeon_device *rdev,
  {
  	uint64_t seq[RADEON_NUM_RINGS];
  	unsigned i, num_rings = 0;
-	int r;
+	long r;
  
  	for (i = 0; i < RADEON_NUM_RINGS; ++i) {
  		seq[i] = 0;
@@ -455,8 +471,8 @@ int radeon_fence_wait_any(struct radeon_device *rdev,
  	if (num_rings == 0)
  		return -ENOENT;
  
-	r = radeon_fence_wait_seq(rdev, seq, intr);
-	if (r) {
+	r = radeon_fence_wait_seq_timeout(rdev, seq, intr, MAX_SCHEDULE_TIMEOUT);
+	if (r < 0) {
  		return r;
  	}
  	return 0;
@@ -475,6 +491,7 @@ int radeon_fence_wait_any(struct radeon_device *rdev,
  int radeon_fence_wait_next(struct radeon_device *rdev, int ring)
  {
  	uint64_t seq[RADEON_NUM_RINGS] = {};
+	long r;
  
  	seq[ring] = atomic64_read(&rdev->fence_drv[ring].last_seq) + 1ULL;
  	if (seq[ring] >= rdev->fence_drv[ring].sync_seq[ring]) {
@@ -482,7 +499,10 @@ int radeon_fence_wait_next(struct radeon_device *rdev, int ring)
  		   already the last emited fence */
  		return -ENOENT;
  	}
-	return radeon_fence_wait_seq(rdev, seq, false);
+	r = radeon_fence_wait_seq_timeout(rdev, seq, false, MAX_SCHEDULE_TIMEOUT);
+	if (r < 0)
+		return r;
+	return 0;
  }
  
  /**
@@ -498,18 +518,18 @@ int radeon_fence_wait_next(struct radeon_device *rdev, int ring)
  int radeon_fence_wait_empty(struct radeon_device *rdev, int ring)
  {
  	uint64_t seq[RADEON_NUM_RINGS] = {};
-	int r;
+	long r;
  
  	seq[ring] = rdev->fence_drv[ring].sync_seq[ring];
  	if (!seq[ring])
  		return 0;
  
-	r = radeon_fence_wait_seq(rdev, seq, false);
-	if (r) {
+	r = radeon_fence_wait_seq_timeout(rdev, seq, false, MAX_SCHEDULE_TIMEOUT);
+	if (r < 0) {
  		if (r == -EDEADLK)
  			return -EDEADLK;
  
-		dev_err(rdev->dev, "error waiting for ring[%d] to become idle (%d)\n",
+		dev_err(rdev->dev, "error waiting for ring[%d] to become idle (%ld)\n",
  			ring, r);
  	}
  	return 0;
-- 
1.9.3