[Intel-gfx] [PATCH 06/17] drm/i915: Extend i915_request_await_active to use all timelines

[Tvrtko Ursulin]

On 06/03/2020 13:38, Chris Wilson wrote:
> Extend i915_request_await_active() to be able to asynchronously wait on
> all the tracked timelines simultaneously.
> 
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> ---
>   drivers/gpu/drm/i915/i915_active.c | 51 +++++++++++++++++++++++-------
>   drivers/gpu/drm/i915/i915_active.h |  5 ++-
>   drivers/gpu/drm/i915/i915_vma.c    |  2 +-
>   3 files changed, 45 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_active.c b/drivers/gpu/drm/i915/i915_active.c
> index 1826de14d2da..e659688db043 100644
> --- a/drivers/gpu/drm/i915/i915_active.c
> +++ b/drivers/gpu/drm/i915/i915_active.c
> @@ -518,23 +518,52 @@ int i915_active_wait(struct i915_active *ref)
>   	return 0;
>   }
>   
> -int i915_request_await_active(struct i915_request *rq, struct i915_active *ref)
> +static int await_active(struct i915_request *rq,
> +			struct i915_active_fence *active)
> +{
> +	struct dma_fence *fence;
> +
> +	if (is_barrier(active))
> +		return 0;
> +
> +	fence = i915_active_fence_get(active);
> +	if (fence) {
> +		int err;
> +
> +		err = i915_request_await_dma_fence(rq, fence);
> +		dma_fence_put(fence);
> +		if (err < 0)
> +			return err;
> +	}
> +
> +	return 0;
> +}
> +
> +int i915_request_await_active(struct i915_request *rq,
> +			      struct i915_active *ref,
> +			      unsigned int flags)
>   {
>   	int err = 0;
>   
> +	/* We must always wait for the exclusive fence! */
>   	if (rcu_access_pointer(ref->excl.fence)) {
> -		struct dma_fence *fence;
> -
> -		rcu_read_lock();
> -		fence = dma_fence_get_rcu_safe(&ref->excl.fence);
> -		rcu_read_unlock();
> -		if (fence) {
> -			err = i915_request_await_dma_fence(rq, fence);
> -			dma_fence_put(fence);
> -		}
> +		err = await_active(rq, &ref->excl);
> +		if (err)
> +			return err;
>   	}
>   
> -	/* In the future we may choose to await on all fences */
> +	if (flags & I915_ACTIVE_AWAIT_ALL && i915_active_acquire_if_busy(ref)) {
> +		struct active_node *it, *n;
> +
> +		rbtree_postorder_for_each_entry_safe(it, n, &ref->tree, node) {
> +			err = await_active(rq, &it->base);
> +			if (err)
> +				break;
> +		}
> +		i915_active_release(ref);
> +		if (err)
> +			return err;
> +	}
>   
>   	return err;
>   }
> diff --git a/drivers/gpu/drm/i915/i915_active.h b/drivers/gpu/drm/i915/i915_active.h
> index 7e438501333e..e3c13060c4c7 100644
> --- a/drivers/gpu/drm/i915/i915_active.h
> +++ b/drivers/gpu/drm/i915/i915_active.h
> @@ -183,7 +183,10 @@ static inline bool i915_active_has_exclusive(struct i915_active *ref)
>   
>   int i915_active_wait(struct i915_active *ref);
>   
> -int i915_request_await_active(struct i915_request *rq, struct i915_active *ref);
> +int i915_request_await_active(struct i915_request *rq,
> +			      struct i915_active *ref,
> +			      unsigned int flags);
> +#define I915_ACTIVE_AWAIT_ALL BIT(0)
>   
>   int i915_active_acquire(struct i915_active *ref);
>   bool i915_active_acquire_if_busy(struct i915_active *ref);
> diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c
> index 3dde671145f7..5b3efb43a8ef 100644
> --- a/drivers/gpu/drm/i915/i915_vma.c
> +++ b/drivers/gpu/drm/i915/i915_vma.c
> @@ -1173,7 +1173,7 @@ int __i915_vma_move_to_active(struct i915_vma *vma, struct i915_request *rq)
>   	GEM_BUG_ON(!i915_vma_is_pinned(vma));
>   
>   	/* Wait for the vma to be bound before we start! */
> -	err = i915_request_await_active(rq, &vma->active);
> +	err = i915_request_await_active(rq, &vma->active, 0);
>   	if (err)
>   		return err;
>   
> 

Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>

Regards,

Tvrtko