1 files changed, 371 insertions, 250 deletions

diff --git a/drivers/gpu/drm/radeon/radeon_fence.c b/drivers/gpu/drm/radeon/radeon_fence.c
index 4bd36a354fbe..11f5f402d22c 100644
--- a/drivers/gpu/drm/radeon/radeon_fence.c
+++ b/drivers/gpu/drm/radeon/radeon_fence.c
@@ -63,98 +63,82 @@ static u32 radeon_fence_read(struct radeon_device *rdev, int ring)
 
 int radeon_fence_emit(struct radeon_device *rdev, struct radeon_fence *fence)
 {
-        unsigned long irq_flags;
-
-        write_lock_irqsave(&rdev->fence_lock, irq_flags);
-        if (fence->emitted) {
-                write_unlock_irqrestore(&rdev->fence_lock, irq_flags);
+        /* we are protected by the ring emission mutex */
+        if (fence->seq && fence->seq < RADEON_FENCE_NOTEMITED_SEQ) {
                 return 0;
         }
-        fence->seq = atomic_add_return(1, &rdev->fence_drv[fence->ring].seq);
-        if (!rdev->ring[fence->ring].ready)
-                /* FIXME: cp is not running assume everythings is done right
-                 * away
-                 */
-                radeon_fence_write(rdev, fence->seq, fence->ring);
-        else
-                radeon_fence_ring_emit(rdev, fence->ring, fence);
-
+        fence->seq = ++rdev->fence_drv[fence->ring].seq;
+        radeon_fence_ring_emit(rdev, fence->ring, fence);
         trace_radeon_fence_emit(rdev->ddev, fence->seq);
-        fence->emitted = true;
-        list_move_tail(&fence->list, &rdev->fence_drv[fence->ring].emitted);
-        write_unlock_irqrestore(&rdev->fence_lock, irq_flags);
         return 0;
 }
 
-static bool radeon_fence_poll_locked(struct radeon_device *rdev, int ring)
+void radeon_fence_process(struct radeon_device *rdev, int ring)
 {
-        struct radeon_fence *fence;
-        struct list_head *i, *n;
-        uint32_t seq;
+        uint64_t seq, last_seq;
+        unsigned count_loop = 0;
         bool wake = false;
-        unsigned long cjiffies;
 
-        seq = radeon_fence_read(rdev, ring);
-        if (seq != rdev->fence_drv[ring].last_seq) {
-                rdev->fence_drv[ring].last_seq = seq;
-                rdev->fence_drv[ring].last_jiffies = jiffies;
-                rdev->fence_drv[ring].last_timeout = RADEON_FENCE_JIFFIES_TIMEOUT;
-        } else {
-                cjiffies = jiffies;
-                if (time_after(cjiffies, rdev->fence_drv[ring].last_jiffies)) {
-                        cjiffies -= rdev->fence_drv[ring].last_jiffies;
-                        if (time_after(rdev->fence_drv[ring].last_timeout, cjiffies)) {
-                                /* update the timeout */
-                                rdev->fence_drv[ring].last_timeout -= cjiffies;
-                        } else {
-                                /* the 500ms timeout is elapsed we should test
-                                 * for GPU lockup
-                                 */
-                                rdev->fence_drv[ring].last_timeout = 1;
-                        }
-                } else {
-                        /* wrap around update last jiffies, we will just wait
-                         * a little longer
-                         */
-                        rdev->fence_drv[ring].last_jiffies = cjiffies;
+        /* 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
+         * process needs to update the last_seq btw the atomic read and
+         * xchg of the current process.
+         *
+         * More over for this to go in infinite loop there need to be
+         * continuously new fence signaled ie radeon_fence_read needs
+         * to return a different value each time for both the currently
+         * polling process and the other process that xchg the last_seq
+         * btw atomic read and xchg of the current process. And the
+         * value the other process set as last seq must be higher than
+         * the seq value we just read. Which means that current process
+         * need to be interrupted after radeon_fence_read and before
+         * atomic xchg.
+         *
+         * To be even more safe we count the number of time we loop and
+         * we bail after 10 loop just accepting the fact that we might
+         * have temporarly set the last_seq not to the true real last
+         * seq but to an older one.
+         */
+        last_seq = atomic64_read(&rdev->fence_drv[ring].last_seq);
+        do {
+                seq = radeon_fence_read(rdev, ring);
+                seq |= last_seq & 0xffffffff00000000LL;
+                if (seq < last_seq) {
+                        seq += 0x100000000LL;
                 }
-                return false;
-        }
-        n = NULL;
-        list_for_each(i, &rdev->fence_drv[ring].emitted) {
-                fence = list_entry(i, struct radeon_fence, list);
-                if (fence->seq == seq) {
-                        n = i;
+
+                if (seq == last_seq) {
                         break;
                 }
-        }
-        /* all fence previous to this one are considered as signaled */
-        if (n) {
-                i = n;
-                do {
-                        n = i->prev;
-                        list_move_tail(i, &rdev->fence_drv[ring].signaled);
-                        fence = list_entry(i, struct radeon_fence, list);
-                        fence->signaled = true;
-                        i = n;
-                } while (i != &rdev->fence_drv[ring].emitted);
+                /* If we loop over we don't want to return without
+                 * checking if a fence is signaled as it means that the
+                 * seq we just read is different from the previous on.
+                 */
                 wake = true;
+                last_seq = seq;
+                if ((count_loop++) > 10) {
+                        /* We looped over too many time leave with the
+                         * fact that we might have set an older fence
+                         * seq then the current real last seq as signaled
+                         * by the hw.
+                         */
+                        break;
+                }
+        } while (atomic64_xchg(&rdev->fence_drv[ring].last_seq, seq) > seq);
+
+        if (wake) {
+                rdev->fence_drv[ring].last_activity = jiffies;
+                wake_up_all(&rdev->fence_queue);
         }
-        return wake;
 }
 
 static void radeon_fence_destroy(struct kref *kref)
 {
-        unsigned long irq_flags;
-        struct radeon_fence *fence;
+        struct radeon_fence *fence;
 
         fence = container_of(kref, struct radeon_fence, kref);
-        write_lock_irqsave(&fence->rdev->fence_lock, irq_flags);
-        list_del(&fence->list);
-        fence->emitted = false;
-        write_unlock_irqrestore(&fence->rdev->fence_lock, irq_flags);
-        if (fence->semaphore)
-                radeon_semaphore_free(fence->rdev, fence->semaphore);
+        fence->seq = RADEON_FENCE_NOTEMITED_SEQ;
         kfree(fence);
 }
 
@@ -162,171 +146,342 @@ int radeon_fence_create(struct radeon_device *rdev,
                         struct radeon_fence **fence,
                         int ring)
 {
-        unsigned long irq_flags;
-
         *fence = kmalloc(sizeof(struct radeon_fence), GFP_KERNEL);
         if ((*fence) == NULL) {
                 return -ENOMEM;
         }
         kref_init(&((*fence)->kref));
         (*fence)->rdev = rdev;
-        (*fence)->emitted = false;
-        (*fence)->signaled = false;
-        (*fence)->seq = 0;
+        (*fence)->seq = RADEON_FENCE_NOTEMITED_SEQ;
         (*fence)->ring = ring;
-        (*fence)->semaphore = NULL;
-        INIT_LIST_HEAD(&(*fence)->list);
-
-        write_lock_irqsave(&rdev->fence_lock, irq_flags);
-        list_add_tail(&(*fence)->list, &rdev->fence_drv[ring].created);
-        write_unlock_irqrestore(&rdev->fence_lock, irq_flags);
         return 0;
 }
 
-bool radeon_fence_signaled(struct radeon_fence *fence)
+static bool radeon_fence_seq_signaled(struct radeon_device *rdev,
+                                      u64 seq, unsigned ring)
 {
-        unsigned long irq_flags;
-        bool signaled = false;
-
-        if (!fence)
+        if (atomic64_read(&rdev->fence_drv[ring].last_seq) >= seq) {
                 return true;
-
-        if (fence->rdev->gpu_lockup)
+        }
+        /* poll new last sequence at least once */
+        radeon_fence_process(rdev, ring);
+        if (atomic64_read(&rdev->fence_drv[ring].last_seq) >= seq) {
                 return true;
+        }
+        return false;
+}
 
-        write_lock_irqsave(&fence->rdev->fence_lock, irq_flags);
-        signaled = fence->signaled;
-        /* if we are shuting down report all fence as signaled */
-        if (fence->rdev->shutdown) {
-                signaled = true;
+bool radeon_fence_signaled(struct radeon_fence *fence)
+{
+        if (!fence) {
+                return true;
         }
-        if (!fence->emitted) {
+        if (fence->seq == RADEON_FENCE_NOTEMITED_SEQ) {
                 WARN(1, "Querying an unemitted fence : %p !\n", fence);
-                signaled = true;
+                return true;
         }
-        if (!signaled) {
-                radeon_fence_poll_locked(fence->rdev, fence->ring);
-                signaled = fence->signaled;
+        if (fence->seq == RADEON_FENCE_SIGNALED_SEQ) {
+                return true;
+        }
+        if (radeon_fence_seq_signaled(fence->rdev, fence->seq, fence->ring)) {
+                fence->seq = RADEON_FENCE_SIGNALED_SEQ;
+                return true;
         }
-        write_unlock_irqrestore(&fence->rdev->fence_lock, irq_flags);
-        return signaled;
+        return false;
+}
+
+static int radeon_fence_wait_seq(struct radeon_device *rdev, u64 target_seq,
+                                 unsigned ring, bool intr, bool lock_ring)
+{
+        unsigned long timeout, last_activity;
+        uint64_t seq;
+        unsigned i;
+        bool signaled;
+        int r;
+
+        while (target_seq > atomic64_read(&rdev->fence_drv[ring].last_seq)) {
+                if (!rdev->ring[ring].ready) {
+                        return -EBUSY;
+                }
+
+                timeout = jiffies - RADEON_FENCE_JIFFIES_TIMEOUT;
+                if (time_after(rdev->fence_drv[ring].last_activity, timeout)) {
+                        /* the normal case, timeout is somewhere before last_activity */
+                        timeout = rdev->fence_drv[ring].last_activity - timeout;
+                } else {
+                        /* either jiffies wrapped around, or no fence was signaled in the last 500ms
+                         * anyway we will just wait for the minimum amount and then check for a lockup
+                         */
+                        timeout = 1;
+                }
+                seq = atomic64_read(&rdev->fence_drv[ring].last_seq);
+                /* Save current last activity valuee, used to check for GPU lockups */
+                last_activity = rdev->fence_drv[ring].last_activity;
+
+                trace_radeon_fence_wait_begin(rdev->ddev, seq);
+                radeon_irq_kms_sw_irq_get(rdev, ring);
+                if (intr) {
+                        r = wait_event_interruptible_timeout(rdev->fence_queue,
+                                (signaled = radeon_fence_seq_signaled(rdev, target_seq, ring)),
+                                timeout);
+                } else {
+                        r = wait_event_timeout(rdev->fence_queue,
+                                (signaled = radeon_fence_seq_signaled(rdev, target_seq, ring)),
+                                timeout);
+                }
+                radeon_irq_kms_sw_irq_put(rdev, ring);
+                if (unlikely(r < 0)) {
+                        return r;
+                }
+                trace_radeon_fence_wait_end(rdev->ddev, seq);
+
+                if (unlikely(!signaled)) {
+                        /* we were interrupted for some reason and fence
+                         * isn't signaled yet, resume waiting */
+                        if (r) {
+                                continue;
+                        }
+
+                        /* check if sequence value has changed since last_activity */
+                        if (seq != atomic64_read(&rdev->fence_drv[ring].last_seq)) {
+                                continue;
+                        }
+
+                        if (lock_ring) {
+                                mutex_lock(&rdev->ring_lock);
+                        }
+
+                        /* test if somebody else has already decided that this is a lockup */
+                        if (last_activity != rdev->fence_drv[ring].last_activity) {
+                                if (lock_ring) {
+                                        mutex_unlock(&rdev->ring_lock);
+                                }
+                                continue;
+                        }
+
+                        if (radeon_ring_is_lockup(rdev, ring, &rdev->ring[ring])) {
+                                /* good news we believe it's a lockup */
+                                dev_warn(rdev->dev, "GPU lockup (waiting for 0x%016llx last fence id 0x%016llx)\n",
+                                         target_seq, seq);
+
+                                /* change last activity so nobody else think there is a lockup */
+                                for (i = 0; i < RADEON_NUM_RINGS; ++i) {
+                                        rdev->fence_drv[i].last_activity = jiffies;
+                                }
+
+                                /* mark the ring as not ready any more */
+                                rdev->ring[ring].ready = false;
+                                if (lock_ring) {
+                                        mutex_unlock(&rdev->ring_lock);
+                                }
+                                return -EDEADLK;
+                        }
+
+                        if (lock_ring) {
+                                mutex_unlock(&rdev->ring_lock);
+                        }
+                }
+        }
+        return 0;
 }
 
 int radeon_fence_wait(struct radeon_fence *fence, bool intr)
 {
-        struct radeon_device *rdev;
-        unsigned long irq_flags, timeout;
-        u32 seq;
         int r;
 
         if (fence == NULL) {
                 WARN(1, "Querying an invalid fence : %p !\n", fence);
-                return 0;
+                return -EINVAL;
         }
-        rdev = fence->rdev;
-        if (radeon_fence_signaled(fence)) {
-                return 0;
+
+        r = radeon_fence_wait_seq(fence->rdev, fence->seq,
+                                  fence->ring, intr, true);
+        if (r) {
+                return r;
         }
-        timeout = rdev->fence_drv[fence->ring].last_timeout;
-retry:
-        /* save current sequence used to check for GPU lockup */
-        seq = rdev->fence_drv[fence->ring].last_seq;
-        trace_radeon_fence_wait_begin(rdev->ddev, seq);
-        if (intr) {
-                radeon_irq_kms_sw_irq_get(rdev, fence->ring);
-                r = wait_event_interruptible_timeout(rdev->fence_drv[fence->ring].queue,
-                                radeon_fence_signaled(fence), timeout);
-                radeon_irq_kms_sw_irq_put(rdev, fence->ring);
-                if (unlikely(r < 0)) {
-                        return r;
+        fence->seq = RADEON_FENCE_SIGNALED_SEQ;
+        return 0;
+}
+
+bool radeon_fence_any_seq_signaled(struct radeon_device *rdev, u64 *seq)
+{
+        unsigned i;
+
+        for (i = 0; i < RADEON_NUM_RINGS; ++i) {
+                if (seq[i] && radeon_fence_seq_signaled(rdev, seq[i], i)) {
+                        return true;
                 }
-        } else {
-                radeon_irq_kms_sw_irq_get(rdev, fence->ring);
-                r = wait_event_timeout(rdev->fence_drv[fence->ring].queue,
-                         radeon_fence_signaled(fence), timeout);
-                radeon_irq_kms_sw_irq_put(rdev, fence->ring);
         }
-        trace_radeon_fence_wait_end(rdev->ddev, seq);
-        if (unlikely(!radeon_fence_signaled(fence))) {
-                /* we were interrupted for some reason and fence isn't
-                 * isn't signaled yet, resume wait
-                 */
-                if (r) {
-                        timeout = r;
-                        goto retry;
+        return false;
+}
+
+static int radeon_fence_wait_any_seq(struct radeon_device *rdev,
+                                     u64 *target_seq, bool intr)
+{
+        unsigned long timeout, last_activity, tmp;
+        unsigned i, ring = RADEON_NUM_RINGS;
+        bool signaled;
+        int r;
+
+        for (i = 0, last_activity = 0; i < RADEON_NUM_RINGS; ++i) {
+                if (!target_seq[i]) {
+                        continue;
+                }
+
+                /* use the most recent one as indicator */
+                if (time_after(rdev->fence_drv[i].last_activity, last_activity)) {
+                        last_activity = rdev->fence_drv[i].last_activity;
                 }
-                /* don't protect read access to rdev->fence_drv[t].last_seq
-                 * if we experiencing a lockup the value doesn't change
+
+                /* For lockup detection just pick the lowest ring we are
+                 * actively waiting for
                  */
-                if (seq == rdev->fence_drv[fence->ring].last_seq &&
-                    radeon_gpu_is_lockup(rdev, &rdev->ring[fence->ring])) {
-                        /* good news we believe it's a lockup */
-                        printk(KERN_WARNING "GPU lockup (waiting for 0x%08X last fence id 0x%08X)\n",
-                             fence->seq, seq);
-                        /* FIXME: what should we do ? marking everyone
-                         * as signaled for now
+                if (i < ring) {
+                        ring = i;
+                }
+        }
+
+        /* nothing to wait for ? */
+        if (ring == RADEON_NUM_RINGS) {
+                return 0;
+        }
+
+        while (!radeon_fence_any_seq_signaled(rdev, target_seq)) {
+                timeout = jiffies - RADEON_FENCE_JIFFIES_TIMEOUT;
+                if (time_after(last_activity, timeout)) {
+                        /* the normal case, timeout is somewhere before last_activity */
+                        timeout = last_activity - timeout;
+                } else {
+                        /* either jiffies wrapped around, or no fence was signaled in the last 500ms
+                         * anyway we will just wait for the minimum amount and then check for a lockup
                          */
-                        rdev->gpu_lockup = true;
-                        r = radeon_gpu_reset(rdev);
-                        if (r)
-                                return r;
-                        radeon_fence_write(rdev, fence->seq, fence->ring);
-                        rdev->gpu_lockup = false;
+                        timeout = 1;
+                }
+
+                trace_radeon_fence_wait_begin(rdev->ddev, target_seq[ring]);
+                for (i = 0; i < RADEON_NUM_RINGS; ++i) {
+                        if (target_seq[i]) {
+                                radeon_irq_kms_sw_irq_get(rdev, i);
+                        }
+                }
+                if (intr) {
+                        r = wait_event_interruptible_timeout(rdev->fence_queue,
+                                (signaled = radeon_fence_any_seq_signaled(rdev, target_seq)),
+                                timeout);
+                } else {
+                        r = wait_event_timeout(rdev->fence_queue,
+                                (signaled = radeon_fence_any_seq_signaled(rdev, target_seq)),
+                                timeout);
+                }
+                for (i = 0; i < RADEON_NUM_RINGS; ++i) {
+                        if (target_seq[i]) {
+                                radeon_irq_kms_sw_irq_put(rdev, i);
+                        }
+                }
+                if (unlikely(r < 0)) {
+                        return r;
+                }
+                trace_radeon_fence_wait_end(rdev->ddev, target_seq[ring]);
+
+                if (unlikely(!signaled)) {
+                        /* we were interrupted for some reason and fence
+                         * isn't signaled yet, resume waiting */
+                        if (r) {
+                                continue;
+                        }
+
+                        mutex_lock(&rdev->ring_lock);
+                        for (i = 0, tmp = 0; i < RADEON_NUM_RINGS; ++i) {
+                                if (time_after(rdev->fence_drv[i].last_activity, tmp)) {
+                                        tmp = rdev->fence_drv[i].last_activity;
+                                }
+                        }
+                        /* test if somebody else has already decided that this is a lockup */
+                        if (last_activity != tmp) {
+                                last_activity = tmp;
+                                mutex_unlock(&rdev->ring_lock);
+                                continue;
+                        }
+
+                        if (radeon_ring_is_lockup(rdev, ring, &rdev->ring[ring])) {
+                                /* good news we believe it's a lockup */
+                                dev_warn(rdev->dev, "GPU lockup (waiting for 0x%016llx)\n",
+                                         target_seq[ring]);
+
+                                /* change last activity so nobody else think there is a lockup */
+                                for (i = 0; i < RADEON_NUM_RINGS; ++i) {
+                                        rdev->fence_drv[i].last_activity = jiffies;
+                                }
+
+                                /* mark the ring as not ready any more */
+                                rdev->ring[ring].ready = false;
+                                mutex_unlock(&rdev->ring_lock);
+                                return -EDEADLK;
+                        }
+                        mutex_unlock(&rdev->ring_lock);
                 }
-                timeout = RADEON_FENCE_JIFFIES_TIMEOUT;
-                write_lock_irqsave(&rdev->fence_lock, irq_flags);
-                rdev->fence_drv[fence->ring].last_timeout = RADEON_FENCE_JIFFIES_TIMEOUT;
-                rdev->fence_drv[fence->ring].last_jiffies = jiffies;
-                write_unlock_irqrestore(&rdev->fence_lock, irq_flags);
-                goto retry;
         }
         return 0;
 }
 
-int radeon_fence_wait_next(struct radeon_device *rdev, int ring)
+int radeon_fence_wait_any(struct radeon_device *rdev,
+                          struct radeon_fence **fences,
+                          bool intr)
 {
-        unsigned long irq_flags;
-        struct radeon_fence *fence;
+        uint64_t seq[RADEON_NUM_RINGS];
+        unsigned i;
         int r;
 
-        if (rdev->gpu_lockup) {
-                return 0;
+        for (i = 0; i < RADEON_NUM_RINGS; ++i) {
+                seq[i] = 0;
+
+                if (!fences[i]) {
+                        continue;
+                }
+
+                if (fences[i]->seq == RADEON_FENCE_SIGNALED_SEQ) {
+                        /* something was allready signaled */
+                        return 0;
+                }
+
+                if (fences[i]->seq < RADEON_FENCE_NOTEMITED_SEQ) {
+                        seq[i] = fences[i]->seq;
+                }
         }
-        write_lock_irqsave(&rdev->fence_lock, irq_flags);
-        if (list_empty(&rdev->fence_drv[ring].emitted)) {
-                write_unlock_irqrestore(&rdev->fence_lock, irq_flags);
-                return 0;
+
+        r = radeon_fence_wait_any_seq(rdev, seq, intr);
+        if (r) {
+                return r;
         }
-        fence = list_entry(rdev->fence_drv[ring].emitted.next,
-                           struct radeon_fence, list);
-        radeon_fence_ref(fence);
-        write_unlock_irqrestore(&rdev->fence_lock, irq_flags);
-        r = radeon_fence_wait(fence, false);
-        radeon_fence_unref(&fence);
-        return r;
+        return 0;
 }
 
-int radeon_fence_wait_last(struct radeon_device *rdev, int ring)
+int radeon_fence_wait_next_locked(struct radeon_device *rdev, int ring)
 {
-        unsigned long irq_flags;
-        struct radeon_fence *fence;
-        int r;
-
-        if (rdev->gpu_lockup) {
-                return 0;
+        uint64_t seq;
+
+        /* We are not protected by ring lock when reading current seq but
+         * it's ok as worst case is we return to early while we could have
+         * wait.
+         */
+        seq = atomic64_read(&rdev->fence_drv[ring].last_seq) + 1ULL;
+        if (seq >= rdev->fence_drv[ring].seq) {
+                /* nothing to wait for, last_seq is
+                   already the last emited fence */
+                return -ENOENT;
         }
-        write_lock_irqsave(&rdev->fence_lock, irq_flags);
-        if (list_empty(&rdev->fence_drv[ring].emitted)) {
-                write_unlock_irqrestore(&rdev->fence_lock, irq_flags);
-                return 0;
-        }
-        fence = list_entry(rdev->fence_drv[ring].emitted.prev,
-                           struct radeon_fence, list);
-        radeon_fence_ref(fence);
-        write_unlock_irqrestore(&rdev->fence_lock, irq_flags);
-        r = radeon_fence_wait(fence, false);
-        radeon_fence_unref(&fence);
-        return r;
+        return radeon_fence_wait_seq(rdev, seq, ring, false, false);
+}
+
+int radeon_fence_wait_empty_locked(struct radeon_device *rdev, int ring)
+{
+        /* We are not protected by ring lock when reading current seq
+         * but it's ok as wait empty is call from place where no more
+         * activity can be scheduled so there won't be concurrent access
+         * to seq value.
+         */
+        return radeon_fence_wait_seq(rdev, rdev->fence_drv[ring].seq,
+                                     ring, false, false);
 }
 
 struct radeon_fence *radeon_fence_ref(struct radeon_fence *fence)
@@ -345,49 +500,27 @@ void radeon_fence_unref(struct radeon_fence **fence)
         }
 }
 
-void radeon_fence_process(struct radeon_device *rdev, int ring)
-{
-        unsigned long irq_flags;
-        bool wake;
-
-        write_lock_irqsave(&rdev->fence_lock, irq_flags);
-        wake = radeon_fence_poll_locked(rdev, ring);
-        write_unlock_irqrestore(&rdev->fence_lock, irq_flags);
-        if (wake) {
-                wake_up_all(&rdev->fence_drv[ring].queue);
-        }
-}
-
-int radeon_fence_count_emitted(struct radeon_device *rdev, int ring)
+unsigned radeon_fence_count_emitted(struct radeon_device *rdev, int ring)
 {
-        unsigned long irq_flags;
-        int not_processed = 0;
-
-        read_lock_irqsave(&rdev->fence_lock, irq_flags);
-        if (!rdev->fence_drv[ring].initialized) {
-                read_unlock_irqrestore(&rdev->fence_lock, irq_flags);
-                return 0;
+        uint64_t emitted;
+
+        /* We are not protected by ring lock when reading the last sequence
+         * but it's ok to report slightly wrong fence count here.
+         */
+        radeon_fence_process(rdev, ring);
+        emitted = rdev->fence_drv[ring].seq - atomic64_read(&rdev->fence_drv[ring].last_seq);
+        /* to avoid 32bits warp around */
+        if (emitted > 0x10000000) {
+                emitted = 0x10000000;
         }
-
-        if (!list_empty(&rdev->fence_drv[ring].emitted)) {
-                struct list_head *ptr;
-                list_for_each(ptr, &rdev->fence_drv[ring].emitted) {
-                        /* count up to 3, that's enought info */
-                        if (++not_processed >= 3)
-                                break;
-                }
-        }
-        read_unlock_irqrestore(&rdev->fence_lock, irq_flags);
-        return not_processed;
+        return (unsigned)emitted;
 }
 
 int radeon_fence_driver_start_ring(struct radeon_device *rdev, int ring)
 {
-        unsigned long irq_flags;
         uint64_t index;
         int r;
 
-        write_lock_irqsave(&rdev->fence_lock, irq_flags);
         radeon_scratch_free(rdev, rdev->fence_drv[ring].scratch_reg);
         if (rdev->wb.use_event) {
                 rdev->fence_drv[ring].scratch_reg = 0;
@@ -396,7 +529,6 @@ int radeon_fence_driver_start_ring(struct radeon_device *rdev, int ring)
                 r = radeon_scratch_get(rdev, &rdev->fence_drv[ring].scratch_reg);
                 if (r) {
                         dev_err(rdev->dev, "fence failed to get scratch register\n");
-                        write_unlock_irqrestore(&rdev->fence_lock, irq_flags);
                         return r;
                 }
                 index = RADEON_WB_SCRATCH_OFFSET +
@@ -405,11 +537,10 @@ int radeon_fence_driver_start_ring(struct radeon_device *rdev, int ring)
         }
         rdev->fence_drv[ring].cpu_addr = &rdev->wb.wb[index/4];
         rdev->fence_drv[ring].gpu_addr = rdev->wb.gpu_addr + index;
-        radeon_fence_write(rdev, atomic_read(&rdev->fence_drv[ring].seq), ring);
+        radeon_fence_write(rdev, rdev->fence_drv[ring].seq, ring);
         rdev->fence_drv[ring].initialized = true;
-        DRM_INFO("fence driver on ring %d use gpu addr 0x%08Lx and cpu addr 0x%p\n",
+        dev_info(rdev->dev, "fence driver on ring %d use gpu addr 0x%016llx and cpu addr 0x%p\n",
                  ring, rdev->fence_drv[ring].gpu_addr, rdev->fence_drv[ring].cpu_addr);
-        write_unlock_irqrestore(&rdev->fence_lock, irq_flags);
         return 0;
 }
 
@@ -418,24 +549,20 @@ static void radeon_fence_driver_init_ring(struct radeon_device *rdev, int ring)
         rdev->fence_drv[ring].scratch_reg = -1;
         rdev->fence_drv[ring].cpu_addr = NULL;
         rdev->fence_drv[ring].gpu_addr = 0;
-        atomic_set(&rdev->fence_drv[ring].seq, 0);
-        INIT_LIST_HEAD(&rdev->fence_drv[ring].created);
-        INIT_LIST_HEAD(&rdev->fence_drv[ring].emitted);
-        INIT_LIST_HEAD(&rdev->fence_drv[ring].signaled);
-        init_waitqueue_head(&rdev->fence_drv[ring].queue);
+        rdev->fence_drv[ring].seq = 0;
+        atomic64_set(&rdev->fence_drv[ring].last_seq, 0);
+        rdev->fence_drv[ring].last_activity = jiffies;
         rdev->fence_drv[ring].initialized = false;
 }
 
 int radeon_fence_driver_init(struct radeon_device *rdev)
 {
-        unsigned long irq_flags;
         int ring;
 
-        write_lock_irqsave(&rdev->fence_lock, irq_flags);
+        init_waitqueue_head(&rdev->fence_queue);
         for (ring = 0; ring < RADEON_NUM_RINGS; ring++) {
                 radeon_fence_driver_init_ring(rdev, ring);
         }
-        write_unlock_irqrestore(&rdev->fence_lock, irq_flags);
         if (radeon_debugfs_fence_init(rdev)) {
                 dev_err(rdev->dev, "fence debugfs file creation failed\n");
         }
@@ -444,19 +571,18 @@ int radeon_fence_driver_init(struct radeon_device *rdev)
 
 void radeon_fence_driver_fini(struct radeon_device *rdev)
 {
-        unsigned long irq_flags;
         int ring;
 
+        mutex_lock(&rdev->ring_lock);
         for (ring = 0; ring < RADEON_NUM_RINGS; ring++) {
                 if (!rdev->fence_drv[ring].initialized)
                         continue;
-                radeon_fence_wait_last(rdev, ring);
-                wake_up_all(&rdev->fence_drv[ring].queue);
-                write_lock_irqsave(&rdev->fence_lock, irq_flags);
+                radeon_fence_wait_empty_locked(rdev, ring);
+                wake_up_all(&rdev->fence_queue);
                 radeon_scratch_free(rdev, rdev->fence_drv[ring].scratch_reg);
-                write_unlock_irqrestore(&rdev->fence_lock, irq_flags);
                 rdev->fence_drv[ring].initialized = false;
         }
+        mutex_unlock(&rdev->ring_lock);
 }
 
 
@@ -469,7 +595,6 @@ static int radeon_debugfs_fence_info(struct seq_file *m, void *data)
         struct drm_info_node *node = (struct drm_info_node *)m->private;
         struct drm_device *dev = node->minor->dev;
         struct radeon_device *rdev = dev->dev_private;
-        struct radeon_fence *fence;
         int i;
 
         for (i = 0; i < RADEON_NUM_RINGS; ++i) {
@@ -477,14 +602,10 @@ static int radeon_debugfs_fence_info(struct seq_file *m, void *data)
                         continue;
 
                 seq_printf(m, "--- ring %d ---\n", i);
-                seq_printf(m, "Last signaled fence 0x%08X\n",
-                           radeon_fence_read(rdev, i));
-                if (!list_empty(&rdev->fence_drv[i].emitted)) {
-                        fence = list_entry(rdev->fence_drv[i].emitted.prev,
-                                           struct radeon_fence, list);
-                        seq_printf(m, "Last emitted fence %p with 0x%08X\n",
-                                   fence,  fence->seq);
-                }
+                seq_printf(m, "Last signaled fence 0x%016llx\n",
+                           (unsigned long long)atomic64_read(&rdev->fence_drv[i].last_seq));
+                seq_printf(m, "Last emitted  0x%016llx\n",
+                           rdev->fence_drv[i].seq);
         }
         return 0;
 }