Commit 2c421896 authored by Chris Wilson's avatar Chris Wilson
Browse files

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: default avatarChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: default avatarAndi Shyti <andi.shyti@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210115142331.24458-1-chris@chris-wilson.co.uk
parent 0bd08049

drivers/gpu/drm/i915/gt/intel_engine_cs.c

+1 −1
Original line number Diff line number Diff line
@@ -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);

drivers/gpu/drm/i915/gt/intel_engine_types.h

+1 −1
Original line number Diff line number Diff line
@@ -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;

drivers/gpu/drm/i915/gt/intel_execlists_submission.c

+2 −2
Original line number Diff line number Diff line
@@ -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);