[src/trunk]: src/sys/external/bsd/drm2/dist/drm/radeon Tweak fence locking ag...

[riastradh <riastradh%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/9bca3e8352ec
branches:  trunk
changeset: 797998:9bca3e8352ec
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Wed Aug 06 12:47:13 2014 +0000

description:
Tweak fence locking again with a broader view of the code paths.

diffstat:

 sys/external/bsd/drm2/dist/drm/radeon/radeon_fence.c |  41 ++++++++++++-------
 1 files changed, 25 insertions(+), 16 deletions(-)

diffs (133 lines):

diff -r 3ffff1657088 -r 9bca3e8352ec sys/external/bsd/drm2/dist/drm/radeon/radeon_fence.c
--- a/sys/external/bsd/drm2/dist/drm/radeon/radeon_fence.c      Wed Aug 06 12:36:23 2014 +0000
+++ b/sys/external/bsd/drm2/dist/drm/radeon/radeon_fence.c      Wed Aug 06 12:47:13 2014 +0000
@@ -134,12 +134,14 @@
  * Checks the current fence value and wakes the fence queue
  * if the sequence number has increased (all asics).
  */
-void radeon_fence_process(struct radeon_device *rdev, int ring)
+static void radeon_fence_process_locked(struct radeon_device *rdev, int ring)
 {
        uint64_t seq, last_seq, last_emitted;
        unsigned count_loop = 0;
        bool wake = false;
 
+       BUG_ON(!spin_is_locked(&rdev->fence_lock));
+
        /* Note there is a scenario here for an infinite loop but it's
         * very unlikely to happen. For it to happen, the current polling
         * process need to be interrupted by another process and another
@@ -192,16 +194,20 @@
 
        if (wake)
 #ifdef __NetBSD__
-       {
-               spin_lock(&rdev->fence_lock);
                DRM_SPIN_WAKEUP_ALL(&rdev->fence_queue, &rdev->fence_lock);
-               spin_unlock(&rdev->fence_lock);
-       }
 #else
                wake_up_all(&rdev->fence_queue);
 #endif
 }
 
+void radeon_fence_process(struct radeon_device *rdev, int ring)
+{
+
+       spin_lock(&rdev->fence_lock);
+       radeon_fence_process_locked(rdev, ring);
+       spin_unlock(&rdev->fence_lock);
+}
+
 /**
  * radeon_fence_destroy - destroy a fence
  *
@@ -234,11 +240,12 @@
 static bool radeon_fence_seq_signaled(struct radeon_device *rdev,
                                      u64 seq, unsigned ring)
 {
+       BUG_ON(!spin_is_locked(&rdev->fence_lock));
        if (atomic64_read(&rdev->fence_drv[ring].last_seq) >= seq) {
                return true;
        }
        /* poll new last sequence at least once */
-       radeon_fence_process(rdev, ring);
+       radeon_fence_process_locked(rdev, ring);
        if (atomic64_read(&rdev->fence_drv[ring].last_seq) >= seq) {
                return true;
        }
@@ -283,6 +290,8 @@
 {
        unsigned i;
 
+       BUG_ON(!spin_is_locked(&rdev->fence_lock));
+
        for (i = 0; i < RADEON_NUM_RINGS; ++i) {
                if (seq[i] && radeon_fence_seq_signaled(rdev, seq[i], i))
                        return true;
@@ -312,6 +321,7 @@
        bool signaled;
        int i, r;
 
+       spin_lock(&rdev->fence_lock);
        while (!radeon_fence_any_seq_signaled(rdev, target_seq)) {
 
                /* Save current sequence values, used to check for GPU lockups */
@@ -325,7 +335,6 @@
                }
 
 #ifdef __NetBSD__
-               spin_lock(&rdev->fence_lock);
                if (intr)
                        DRM_SPIN_TIMED_WAIT_UNTIL(r, &rdev->fence_queue,
                            &rdev->fence_lock, RADEON_FENCE_JIFFIES_TIMEOUT,
@@ -338,7 +347,6 @@
                            ((signaled = radeon_fence_any_seq_signaled(rdev,
                                    target_seq))
                                || rdev->needs_reset));
-               spin_unlock(&rdev->fence_lock);
 #else
                if (intr) {
                        r = wait_event_interruptible_timeout(rdev->fence_queue, (
@@ -360,11 +368,13 @@
                }
 
                if (unlikely(r < 0))
-                       return r;
+                       goto out;
 
                if (unlikely(!signaled)) {
-                       if (rdev->needs_reset)
-                               return -EDEADLK;
+                       if (rdev->needs_reset) {
+                               r = -EDEADLK;
+                               goto out;
+                       }
 
                        /* we were interrupted for some reason and fence
                         * isn't signaled yet, resume waiting */
@@ -398,20 +408,19 @@
                                         target_seq[i], last_seq[i], i);
 
                                /* remember that we need an reset */
+                               rdev->needs_reset = true;
 #ifdef __NetBSD__
-                               spin_lock(&rdev->fence_lock);
-                               rdev->needs_reset = true;
                                DRM_SPIN_WAKEUP_ALL(&rdev->fence_queue,
                                    &rdev->fence_lock);
-                               spin_unlock(&rdev->fence_lock);
 #else
-                               rdev->needs_reset = true;
                                wake_up_all(&rdev->fence_queue);
 #endif
-                               return -EDEADLK;
+                               r = -EDEADLK;
+                               goto out;
                        }
                }
        }
+out:   spin_unlock(&rdev->fence_lock);
        return 0;
 }