drm/i915: Replace nested subclassing with explicit subclasses

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@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180706210710.16251-1-chris@chris-wilson.co.uk

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 2e05cf1..1a9dab3 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -3095,7 +3095,7 @@ 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 7ae08b6..3248369 100644 (file)
--- 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 dc2a463..a2c2c3a 100644 (file)
--- 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 e2f5628..0ac4972 100644 (file)
--- a/drivers/gpu/drm/i915/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/intel_engine_cs.c
@@ -483,6 +483,7 @@ 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 c2a0451..22a73da 100644 (file)
--- 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 */