From 666424abfb863e3e51fcd35baad5f242fc69d314 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Fri, 14 Sep 2018 13:35:04 +0100 Subject: [PATCH] drm/i915/execlists: Use coherent writes into the context image That we use a WB mapping for updating the RING_TAIL register inside the context image even on !llc machines has been a source of consternation for every reader. It appears to work on bsw+, but it may just have been that we have been incredibly bad at detecting the errors. v2: With extra enthusiasm. v3: Drop force of map type for pinned default_state as by the time we pin it, the map type is always WB and doesn't conflict with the earlier use by ce->state. v4: Transfer engine->default_state from MAP_WC to MAP_WB on creation so we do not need the MAP_FORCE littered around the backends Signed-off-by: Chris Wilson Reviewed-by: Tvrtko Ursulin Link: https://patchwork.freedesktop.org/patch/msgid/20180914123504.2062-3-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/i915_drv.h | 6 ++++++ drivers/gpu/drm/i915/i915_gem.c | 4 +++- drivers/gpu/drm/i915/i915_perf.c | 3 ++- drivers/gpu/drm/i915/intel_lrc.c | 6 ++++-- 4 files changed, 15 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index ea6c6f715ca6..0509fd086130 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -3096,6 +3096,12 @@ enum i915_map_type { I915_MAP_FORCE_WC = I915_MAP_WC | I915_MAP_OVERRIDE, }; +static inline enum i915_map_type +i915_coherent_map_type(struct drm_i915_private *i915) +{ + return HAS_LLC(i915) ? I915_MAP_WB : I915_MAP_WC; +} + /** * i915_gem_object_pin_map - return a contiguous mapping of the entire object * @obj: the object to map into kernel address space diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index d276fb302d4e..e3c2492438b8 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -5418,6 +5418,8 @@ static int __intel_engines_record_defaults(struct drm_i915_private *i915) struct i915_vma *state; void *vaddr; + GEM_BUG_ON(to_intel_context(ctx, engine)->pin_count); + state = to_intel_context(ctx, engine)->state; if (!state) continue; @@ -5442,7 +5444,7 @@ static int __intel_engines_record_defaults(struct drm_i915_private *i915) /* Check we can acquire the image of the context state */ vaddr = i915_gem_object_pin_map(engine->default_state, - I915_MAP_WB); + I915_MAP_FORCE_WB); if (IS_ERR(vaddr)) { err = PTR_ERR(vaddr); goto err_active; diff --git a/drivers/gpu/drm/i915/i915_perf.c b/drivers/gpu/drm/i915/i915_perf.c index 3d7a052b4cca..664b96bb65a3 100644 --- a/drivers/gpu/drm/i915/i915_perf.c +++ b/drivers/gpu/drm/i915/i915_perf.c @@ -1707,6 +1707,7 @@ static int gen8_configure_all_contexts(struct drm_i915_private *dev_priv, const struct i915_oa_config *oa_config) { struct intel_engine_cs *engine = dev_priv->engine[RCS]; + unsigned int map_type = i915_coherent_map_type(dev_priv); struct i915_gem_context *ctx; struct i915_request *rq; int ret; @@ -1741,7 +1742,7 @@ static int gen8_configure_all_contexts(struct drm_i915_private *dev_priv, if (!ce->state) continue; - regs = i915_gem_object_pin_map(ce->state->obj, I915_MAP_WB); + regs = i915_gem_object_pin_map(ce->state->obj, map_type); if (IS_ERR(regs)) return PTR_ERR(regs); diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c index d7fcbba8e982..a51be16ddaac 100644 --- a/drivers/gpu/drm/i915/intel_lrc.c +++ b/drivers/gpu/drm/i915/intel_lrc.c @@ -1294,7 +1294,7 @@ static int __context_pin(struct i915_gem_context *ctx, struct i915_vma *vma) * on an active context (which by nature is already on the GPU). */ if (!(vma->flags & I915_VMA_GLOBAL_BIND)) { - err = i915_gem_object_set_to_gtt_domain(vma->obj, true); + err = i915_gem_object_set_to_wc_domain(vma->obj, true); if (err) return err; } @@ -1322,7 +1322,9 @@ __execlists_context_pin(struct intel_engine_cs *engine, if (ret) goto err; - vaddr = i915_gem_object_pin_map(ce->state->obj, I915_MAP_WB); + vaddr = i915_gem_object_pin_map(ce->state->obj, + i915_coherent_map_type(ctx->i915) | + I915_MAP_OVERRIDE); if (IS_ERR(vaddr)) { ret = PTR_ERR(vaddr); goto unpin_vma;