[Intel-gfx] [PATCH 17/27] drm/i915: Replace nested subclassing with explicit subclasses

[Tvrtko Ursulin]

On 06/07/2018 07:53, Chris Wilson wrote:
> In the next patch, we will want a third distinct class of timeline that
> may overlap with the current pair of client and engine timeline classes.
> Rather than use the ad hoc markup of SINGLE_DEPTH_NESTING, initialise
> the different timeline classes with an explicit subclass.
> 
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> ---
>   drivers/gpu/drm/i915/i915_gem.c              | 2 +-
>   drivers/gpu/drm/i915/i915_request.c          | 2 +-
>   drivers/gpu/drm/i915/i915_timeline.h         | 2 ++
>   drivers/gpu/drm/i915/intel_engine_cs.c       | 1 +
>   drivers/gpu/drm/i915/selftests/mock_engine.c | 2 ++
>   5 files changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> index f516c289647c..dabe58c8ab03 100644
> --- a/drivers/gpu/drm/i915/i915_gem.c
> +++ b/drivers/gpu/drm/i915/i915_gem.c
> @@ -3091,7 +3091,7 @@ static void engine_skip_context(struct i915_request *request)
>   	GEM_BUG_ON(timeline == &engine->timeline);
>   
>   	spin_lock_irqsave(&engine->timeline.lock, flags);
> -	spin_lock_nested(&timeline->lock, SINGLE_DEPTH_NESTING);
> +	spin_lock(&timeline->lock);
>   
>   	list_for_each_entry_continue(request, &engine->timeline.requests, link)
>   		if (request->gem_context == hung_ctx)
> diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
> index 7ae08b68121e..3248369dbcfb 100644
> --- a/drivers/gpu/drm/i915/i915_request.c
> +++ b/drivers/gpu/drm/i915/i915_request.c
> @@ -503,7 +503,7 @@ static void move_to_timeline(struct i915_request *request,
>   	GEM_BUG_ON(request->timeline == &request->engine->timeline);
>   	lockdep_assert_held(&request->engine->timeline.lock);
>   
> -	spin_lock_nested(&request->timeline->lock, SINGLE_DEPTH_NESTING);
> +	spin_lock(&request->timeline->lock);
>   	list_move_tail(&request->link, &timeline->requests);
>   	spin_unlock(&request->timeline->lock);
>   }
> diff --git a/drivers/gpu/drm/i915/i915_timeline.h b/drivers/gpu/drm/i915/i915_timeline.h
> index dc2a4632faa7..a2c2c3ab5fb0 100644
> --- a/drivers/gpu/drm/i915/i915_timeline.h
> +++ b/drivers/gpu/drm/i915/i915_timeline.h
> @@ -37,6 +37,8 @@ struct i915_timeline {
>   	u32 seqno;
>   
>   	spinlock_t lock;
> +#define TIMELINE_CLIENT 0 /* default subclass */
> +#define TIMELINE_ENGINE 1
>   
>   	/**
>   	 * List of breadcrumbs associated with GPU requests currently
> diff --git a/drivers/gpu/drm/i915/intel_engine_cs.c b/drivers/gpu/drm/i915/intel_engine_cs.c
> index 478c928912c4..d9bdc674ab38 100644
> --- a/drivers/gpu/drm/i915/intel_engine_cs.c
> +++ b/drivers/gpu/drm/i915/intel_engine_cs.c
> @@ -481,6 +481,7 @@ static void intel_engine_init_execlist(struct intel_engine_cs *engine)
>   void intel_engine_setup_common(struct intel_engine_cs *engine)
>   {
>   	i915_timeline_init(engine->i915, &engine->timeline, engine->name);
> +	lockdep_set_subclass(&engine->timeline.lock, TIMELINE_ENGINE);
>   
>   	intel_engine_init_execlist(engine);
>   	intel_engine_init_hangcheck(engine);
> diff --git a/drivers/gpu/drm/i915/selftests/mock_engine.c b/drivers/gpu/drm/i915/selftests/mock_engine.c
> index c2a0451336cf..22a73da45ad5 100644
> --- a/drivers/gpu/drm/i915/selftests/mock_engine.c
> +++ b/drivers/gpu/drm/i915/selftests/mock_engine.c
> @@ -200,6 +200,8 @@ struct intel_engine_cs *mock_engine(struct drm_i915_private *i915,
>   	engine->base.submit_request = mock_submit_request;
>   
>   	i915_timeline_init(i915, &engine->base.timeline, engine->base.name);
> +	lockdep_set_subclass(&engine->base.timeline.lock, TIMELINE_ENGINE);
> +
>   	intel_engine_init_breadcrumbs(&engine->base);
>   	engine->base.breadcrumbs.mock = true; /* prevent touching HW for irqs */
>   
> 

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

Regards,

Tvrtko