From ae6c4574782dbfebcbf1f7e3620bcaf58ceb69e3 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Fri, 10 Nov 2017 14:26:28 +0000 Subject: [PATCH] drm/i915: Force the switch to the i915->kernel_context In the next few patches, we will have a hard requirement that we emit a context-switch to the perma-pinned i915->kernel_context (so that we can save the HW state using that context-switch). As the first context itself may be classed as a kernel context, we want to be explicit in our comparison. For an extra-layer of finesse, we can check the last unretired context on the engine; as well as the last retired context when idle. v2: verbose verbosity v3: Always force the switch, even when the engine is idle, and update the assert that this happens before suspend. Signed-off-by: Chris Wilson Cc: Joonas Lahtinen Reviewed-by: Joonas Lahtinen #v1 Reviewed-by: Mika Kuoppala Link: https://patchwork.freedesktop.org/patch/msgid/20171110142634.10551-2-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/i915_gem.c | 10 ++++++---- drivers/gpu/drm/i915/intel_engine_cs.c | 26 ++++++++++++++++++++++++-- 2 files changed, 30 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 889ae8810d5f..824515556733 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -4693,14 +4693,16 @@ void __i915_gem_object_release_unless_active(struct drm_i915_gem_object *obj) i915_gem_object_put(obj); } -static void assert_kernel_context_is_current(struct drm_i915_private *dev_priv) +static void assert_kernel_context_is_current(struct drm_i915_private *i915) { + struct i915_gem_context *kernel_context = i915->kernel_context; struct intel_engine_cs *engine; enum intel_engine_id id; - for_each_engine(engine, dev_priv, id) - GEM_BUG_ON(engine->last_retired_context && - !i915_gem_context_is_kernel(engine->last_retired_context)); + for_each_engine(engine, i915, id) { + GEM_BUG_ON(__i915_gem_active_peek(&engine->timeline->last_request)); + GEM_BUG_ON(engine->last_retired_context != kernel_context); + } } void i915_gem_sanitize(struct drm_i915_private *i915) diff --git a/drivers/gpu/drm/i915/intel_engine_cs.c b/drivers/gpu/drm/i915/intel_engine_cs.c index bded9c40dbd5..6d0b38189a7d 100644 --- a/drivers/gpu/drm/i915/intel_engine_cs.c +++ b/drivers/gpu/drm/i915/intel_engine_cs.c @@ -1596,10 +1596,32 @@ bool intel_engines_are_idle(struct drm_i915_private *dev_priv) return true; } +/** + * intel_engine_has_kernel_context: + * @engine: the engine + * + * Returns true if the last context to be executed on this engine, or has been + * executed if the engine is already idle, is the kernel context + * (#i915.kernel_context). + */ bool intel_engine_has_kernel_context(const struct intel_engine_cs *engine) { - return (!engine->last_retired_context || - i915_gem_context_is_kernel(engine->last_retired_context)); + const struct i915_gem_context * const kernel_context = + engine->i915->kernel_context; + struct drm_i915_gem_request *rq; + + lockdep_assert_held(&engine->i915->drm.struct_mutex); + + /* + * Check the last context seen by the engine. If active, it will be + * the last request that remains in the timeline. When idle, it is + * the last executed context as tracked by retirement. + */ + rq = __i915_gem_active_peek(&engine->timeline->last_request); + if (rq) + return rq->ctx == kernel_context; + else + return engine->last_retired_context == kernel_context; } void intel_engines_reset_default_submission(struct drm_i915_private *i915) -- 2.11.0