drm/etnaviv: track fences by IDR instead of seqno

This moves away from using the internal seqno as the userspace fence
reference. By moving to a generic ID, we can later replace the internal
fence by something different than the etnaviv seqno fence.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>

diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem.h b/drivers/gpu/drm/etnaviv/etnaviv_gem.h
index be72a98..c309641 100644 (file)
--- a/drivers/gpu/drm/etnaviv/etnaviv_gem.h
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gem.h
@@ -104,6 +104,7 @@ struct etnaviv_gem_submit {
        struct kref refcount;
        struct etnaviv_gpu *gpu;
        struct dma_fence *out_fence, *in_fence;
+       int out_fence_id;
        struct list_head node; /* GPU active submit list */
        struct etnaviv_cmdbuf cmdbuf;
        bool runtime_resumed;

diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem_submit.c b/drivers/gpu/drm/etnaviv/etnaviv_gem_submit.c
index 1f8202b..919c8dc 100644 (file)
--- a/drivers/gpu/drm/etnaviv/etnaviv_gem_submit.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gem_submit.c
@@ -563,7 +563,7 @@ int etnaviv_ioctl_gem_submit(struct drm_device *dev, void *data,
        }
 
        args->fence_fd = out_fence_fd;
-       args->fence = submit->out_fence->seqno;
+       args->fence = submit->out_fence_id;
 
 err_submit_objects:
        etnaviv_submit_put(submit);

diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gpu.c b/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
index 72c350c..bab6a82 100644 (file)
--- a/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
@@ -1016,6 +1016,7 @@ static void hangcheck_disable(struct etnaviv_gpu *gpu)
 /* fence object management */
 struct etnaviv_fence {
        struct etnaviv_gpu *gpu;
+       int id;
        struct dma_fence base;
 };
 
@@ -1052,6 +1053,11 @@ static void etnaviv_fence_release(struct dma_fence *fence)
 {
        struct etnaviv_fence *f = to_etnaviv_fence(fence);
 
+       /* first remove from IDR, so fence can not be looked up anymore */
+       mutex_lock(&f->gpu->lock);
+       idr_remove(&f->gpu->fence_idr, f->id);
+       mutex_unlock(&f->gpu->lock);
+
        kfree_rcu(f, base.rcu);
 }
 
@@ -1078,6 +1084,11 @@ static struct dma_fence *etnaviv_gpu_fence_alloc(struct etnaviv_gpu *gpu)
        if (!f)
                return NULL;
 
+       f->id = idr_alloc_cyclic(&gpu->fence_idr, &f->base, 0, INT_MAX, GFP_KERNEL);
+       if (f->id < 0) {
+               kfree(f);
+               return NULL;
+       }
        f->gpu = gpu;
 
        dma_fence_init(&f->base, &etnaviv_fence_ops, &gpu->fence_spinlock,
@@ -1226,35 +1237,43 @@ static void retire_worker(struct work_struct *work)
 }
 
 int etnaviv_gpu_wait_fence_interruptible(struct etnaviv_gpu *gpu,
-       u32 fence, struct timespec *timeout)
+       u32 id, struct timespec *timeout)
 {
+       struct dma_fence *fence;
        int ret;
 
-       if (fence_after(fence, gpu->next_fence)) {
-               DRM_ERROR("waiting on invalid fence: %u (of %u)\n",
-                               fence, gpu->next_fence);
-               return -EINVAL;
-       }
+       /*
+        * Look up the fence and take a reference. The mutex only synchronizes
+        * the IDR lookup with the fence release. We might still find a fence
+        * whose refcount has already dropped to zero. dma_fence_get_rcu
+        * pretends we didn't find a fence in that case.
+        */
+       ret = mutex_lock_interruptible(&gpu->lock);
+       if (ret)
+               return ret;
+       fence = idr_find(&gpu->fence_idr, id);
+       if (fence)
+               fence = dma_fence_get_rcu(fence);
+       mutex_unlock(&gpu->lock);
+
+       if (!fence)
+               return 0;
 
        if (!timeout) {
                /* No timeout was requested: just test for completion */
-               ret = fence_completed(gpu, fence) ? 0 : -EBUSY;
+               ret = dma_fence_is_signaled(fence) ? 0 : -EBUSY;
        } else {
                unsigned long remaining = etnaviv_timeout_to_jiffies(timeout);
 
-               ret = wait_event_interruptible_timeout(gpu->fence_event,
-                                               fence_completed(gpu, fence),
-                                               remaining);
-               if (ret == 0) {
-                       DBG("timeout waiting for fence: %u (retired: %u completed: %u)",
-                               fence, gpu->retired_fence,
-                               gpu->completed_fence);
+               ret = dma_fence_wait_timeout(fence, true, remaining);
+               if (ret == 0)
                        ret = -ETIMEDOUT;
-               } else if (ret != -ERESTARTSYS) {
+               else if (ret != -ERESTARTSYS)
                        ret = 0;
-               }
+
        }
 
+       dma_fence_put(fence);
        return ret;
 }
 
@@ -1386,6 +1405,7 @@ int etnaviv_gpu_submit(struct etnaviv_gpu *gpu,
                ret = -ENOMEM;
                goto out_unlock;
        }
+       submit->out_fence_id = to_etnaviv_fence(submit->out_fence)->id;
 
        gpu->active_fence = submit->out_fence->seqno;
 
@@ -1490,7 +1510,6 @@ static irqreturn_t irq_handler(int irq, void *data)
                                continue;
 
                        gpu->event[event].fence = NULL;
-                       dma_fence_signal(fence);
 
                        /*
                         * Events can be processed out of order.  Eg,
@@ -1503,6 +1522,7 @@ static irqreturn_t irq_handler(int irq, void *data)
                         */
                        if (fence_after(fence->seqno, gpu->completed_fence))
                                gpu->completed_fence = fence->seqno;
+                       dma_fence_signal(fence);
 
                        event_free(gpu, event);
                }
@@ -1700,6 +1720,7 @@ static int etnaviv_gpu_bind(struct device *dev, struct device *master,
 
        gpu->drm = drm;
        gpu->fence_context = dma_fence_context_alloc(1);
+       idr_init(&gpu->fence_idr);
        spin_lock_init(&gpu->fence_spinlock);
 
        INIT_LIST_HEAD(&gpu->active_submit_list);
@@ -1751,6 +1772,7 @@ static void etnaviv_gpu_unbind(struct device *dev, struct device *master,
        }
 
        gpu->drm = NULL;
+       idr_destroy(&gpu->fence_idr);
 
        if (IS_ENABLED(CONFIG_DRM_ETNAVIV_THERMAL))
                thermal_cooling_device_unregister(gpu->cooling);

diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gpu.h b/drivers/gpu/drm/etnaviv/etnaviv_gpu.h
index 7623905..0170eb0 100644 (file)
--- a/drivers/gpu/drm/etnaviv/etnaviv_gpu.h
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gpu.h
@@ -128,6 +128,7 @@ struct etnaviv_gpu {
        u32 idle_mask;
 
        /* Fencing support */
+       struct idr fence_idr;
        u32 next_fence;
        u32 active_fence;
        u32 completed_fence;