From 2c421896adb099e3a905063581f8720f6ce59638 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Fri, 15 Jan 2021 14:23:27 +0000 Subject: [PATCH] drm/i915/gt: Drop atomic for engine->fw_active tracking Since schedule-in/out is now entirely serialised by the tasklet bitlock, we do not need to worry about concurrent in/out operations and so reduce the atomic operations to plain instructions. Signed-off-by: Chris Wilson Reviewed-by: Andi Shyti Link: https://patchwork.freedesktop.org/patch/msgid/20210115142331.24458-1-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/gt/intel_engine_cs.c | 2 +- drivers/gpu/drm/i915/gt/intel_engine_types.h | 2 +- drivers/gpu/drm/i915/gt/intel_execlists_submission.c | 4 ++-- 3 files changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/i915/gt/intel_engine_cs.c b/drivers/gpu/drm/i915/gt/intel_engine_cs.c index 3fe44cd..ba8f8a8 100644 --- a/drivers/gpu/drm/i915/gt/intel_engine_cs.c +++ b/drivers/gpu/drm/i915/gt/intel_engine_cs.c @@ -1676,7 +1676,7 @@ void intel_engine_dump(struct intel_engine_cs *engine, ktime_to_ms(intel_engine_get_busy_time(engine, &dummy))); drm_printf(m, "\tForcewake: %x domains, %d active\n", - engine->fw_domain, atomic_read(&engine->fw_active)); + engine->fw_domain, READ_ONCE(engine->fw_active)); rcu_read_lock(); rq = READ_ONCE(engine->heartbeat.systole); diff --git a/drivers/gpu/drm/i915/gt/intel_engine_types.h b/drivers/gpu/drm/i915/gt/intel_engine_types.h index df62e79..75c9093 100644 --- a/drivers/gpu/drm/i915/gt/intel_engine_types.h +++ b/drivers/gpu/drm/i915/gt/intel_engine_types.h @@ -319,7 +319,7 @@ struct intel_engine_cs { * as possible. */ enum forcewake_domains fw_domain; - atomic_t fw_active; + unsigned int fw_active; unsigned long context_tag; diff --git a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c index 269492b..bb8303a 100644 --- a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c +++ b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c @@ -538,7 +538,7 @@ __execlists_schedule_in(struct i915_request *rq) ce->lrc.ccid |= engine->execlists.ccid; __intel_gt_pm_get(engine->gt); - if (engine->fw_domain && !atomic_fetch_inc(&engine->fw_active)) + if (engine->fw_domain && !engine->fw_active++) intel_uncore_forcewake_get(engine->uncore, engine->fw_domain); execlists_context_status_change(rq, INTEL_CONTEXT_SCHEDULE_IN); intel_engine_context_in(engine); @@ -645,7 +645,7 @@ static void __execlists_schedule_out(struct i915_request * const rq, lrc_update_runtime(ce); intel_engine_context_out(engine); execlists_context_status_change(rq, INTEL_CONTEXT_SCHEDULE_OUT); - if (engine->fw_domain && !atomic_dec_return(&engine->fw_active)) + if (engine->fw_domain && !--engine->fw_active) intel_uncore_forcewake_put(engine->uncore, engine->fw_domain); intel_gt_pm_put_async(engine->gt); -- 2.7.4