diff mbox series

[06/10] drm/i915/gt: Drop atomic for engine->fw_active tracking

Message ID 20210113124600.656-6-chris@chris-wilson.co.uk (mailing list archive)
State New, archived
Headers show
Series [01/10] drm/i915: Mark up protected uses of 'i915_request_completed' | expand

Commit Message

Chris Wilson Jan. 13, 2021, 12:45 p.m. UTC 
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 <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(-)

Comments

Andi Shyti Jan. 14, 2021, 3:02 a.m. UTC | #1 
Hi Chris,

On Wed, Jan 13, 2021 at 12:45:56PM +0000, Chris Wilson wrote:
> 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 <chris@chris-wilson.co.uk>

Reviewed-by: Andi Shyti <andi.shyti@intel.com>

Thanks,
Andi
diff mbox series

Patch

diff --git a/drivers/gpu/drm/i915/gt/intel_engine_cs.c b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
index 7583b6e48a9d..005ae2c54273 100644
--- a/drivers/gpu/drm/i915/gt/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
@@ -1665,7 +1665,7 @@  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 df62e793e747..75c9093b5e7f 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 e28f32661df4..d5affdda6eb8 100644
--- a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
+++ b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
@@ -539,7 +539,7 @@  __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 inline void __execlists_schedule_out(struct i915_request *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);