From fe0c493538f42ee1cbc4701dc6f9eb2b82d856cf Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Fri, 18 May 2018 10:02:11 +0100 Subject: [PATCH] drm/i915/execlists: Handle copying default context state for atomic reset We want to be able to reset the GPU from inside a timer callback (hardirq context). One step requires us to copy the default context state over to the guilty context, which means we need to plan in advance to have that object accessible from within an atomic context. The atomic context prevents us from pinning the object or from peeking into the shmemfs backing store (all may sleep), so we choose to pin the default_state into memory when the engine becomes active. This compromise allows us to swap out the default state when idle, when required. References: 5692251c254a ("drm/i915/lrc: Scrub the GPU state of the guilty hanging request") Signed-off-by: Chris Wilson Reviewed-by: Tvrtko Ursulin Link: https://patchwork.freedesktop.org/patch/msgid/20180518090212.5349-2-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/intel_engine_cs.c | 15 +++++++++++++++ drivers/gpu/drm/i915/intel_lrc.c | 15 ++++----------- drivers/gpu/drm/i915/intel_ringbuffer.h | 1 + 3 files changed, 20 insertions(+), 11 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_engine_cs.c b/drivers/gpu/drm/i915/intel_engine_cs.c index 8477972..0c1f084 100644 --- a/drivers/gpu/drm/i915/intel_engine_cs.c +++ b/drivers/gpu/drm/i915/intel_engine_cs.c @@ -1091,6 +1091,11 @@ void intel_engines_park(struct drm_i915_private *i915) if (engine->park) engine->park(engine); + if (engine->pinned_default_state) { + i915_gem_object_unpin_map(engine->default_state); + engine->pinned_default_state = NULL; + } + i915_gem_batch_pool_fini(&engine->batch_pool); engine->execlists.no_priolist = false; } @@ -1108,6 +1113,16 @@ void intel_engines_unpark(struct drm_i915_private *i915) enum intel_engine_id id; for_each_engine(engine, i915, id) { + void *map; + + /* Pin the default state for fast resets from atomic context. */ + map = NULL; + if (engine->default_state) + map = i915_gem_object_pin_map(engine->default_state, + I915_MAP_WB); + if (!IS_ERR_OR_NULL(map)) + engine->pinned_default_state = map; + if (engine->unpark) engine->unpark(engine); diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c index 9abd26f..46e7bf4 100644 --- a/drivers/gpu/drm/i915/intel_lrc.c +++ b/drivers/gpu/drm/i915/intel_lrc.c @@ -1965,17 +1965,10 @@ static void execlists_reset(struct intel_engine_cs *engine, * to recreate its own state. */ regs = request->hw_context->lrc_reg_state; - if (engine->default_state) { - void *defaults; - - defaults = i915_gem_object_pin_map(engine->default_state, - I915_MAP_WB); - if (!IS_ERR(defaults)) { - memcpy(regs, /* skip restoring the vanilla PPHWSP */ - defaults + LRC_STATE_PN * PAGE_SIZE, - engine->context_size - PAGE_SIZE); - i915_gem_object_unpin_map(engine->default_state); - } + if (engine->pinned_default_state) { + memcpy(regs, /* skip restoring the vanilla PPHWSP */ + engine->pinned_default_state + LRC_STATE_PN * PAGE_SIZE, + engine->context_size - PAGE_SIZE); } execlists_init_reg_state(regs, request->gem_context, engine, request->ring); diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h index 20c4e13..acef385 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.h +++ b/drivers/gpu/drm/i915/intel_ringbuffer.h @@ -342,6 +342,7 @@ struct intel_engine_cs { struct i915_timeline timeline; struct drm_i915_gem_object *default_state; + void *pinned_default_state; atomic_t irq_count; unsigned long irq_posted; -- 2.7.4