Re: [Intel-gfx] [PATCH 1/3] drm/i915: Add a hook for making the engines idle (parking) and unparking

[Joonas Lahtinen]

On Fri, 2017-10-20 at 22:06 +0100, Chris Wilson wrote:
> In the next patch, we will want to install a callback when the engines
> (GT as a whole) become idle and similarly when they first become busy.
> To enable that callback, first rename intel_engines_mark_idle() to the
> intel_engines_park() and provide the companion intel_engines_unpark().
> 
> Signed-off-by: Chris Wilson 
> Cc: Joonas Lahtinen 
> Cc: Tvrtko Ursulin 
> Cc: Michał Winiarski 

Reviewed-by: Joonas Lahtinen 

Regards, Joonas
-- 
Joonas Lahtinen
Open Source Technology Center
Intel Corporation
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[Intel-gfx] [PATCH 1/3] drm/i915: Add a hook for making the engines idle (parking) and unparking

[Chris Wilson]

In the next patch, we will want to install a callback when the engines
(GT as a whole) become idle and similarly when they first become busy.
To enable that callback, first rename intel_engines_mark_idle() to the
intel_engines_park() and provide the companion intel_engines_unpark().

Signed-off-by: Chris Wilson 
Cc: Joonas Lahtinen 
Cc: Tvrtko Ursulin 
Cc: Michał Winiarski 
---
 drivers/gpu/drm/i915/i915_gem.c |  2 +-
 drivers/gpu/drm/i915/i915_gem_request.c |  2 ++
 drivers/gpu/drm/i915/intel_engine_cs.c  | 33 +++--
 drivers/gpu/drm/i915/intel_lrc.c|  3 +++
 drivers/gpu/drm/i915/intel_ringbuffer.c |  5 -
 drivers/gpu/drm/i915/intel_ringbuffer.h |  6 +-
 6 files changed, 46 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 026cb52ece0b..bf350861acf7 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -3319,7 +3319,7 @@ i915_gem_idle_work_handler(struct work_struct *work)
if (wait_for(intel_engines_are_idle(dev_priv), 10))
DRM_ERROR("Timeout waiting for engines to idle\n");
 
-   intel_engines_mark_idle(dev_priv);
+   intel_engines_park(dev_priv);
i915_gem_timelines_mark_idle(dev_priv);
 
GEM_BUG_ON(!dev_priv->gt.awake);
diff --git a/drivers/gpu/drm/i915/i915_gem_request.c 
b/drivers/gpu/drm/i915/i915_gem_request.c
index d140fcf5c6a3..e0d6221022a8 100644
--- a/drivers/gpu/drm/i915/i915_gem_request.c
+++ b/drivers/gpu/drm/i915/i915_gem_request.c
@@ -259,6 +259,8 @@ static void mark_busy(struct drm_i915_private *i915)
if (INTEL_GEN(i915) >= 6)
gen6_rps_busy(i915);
 
+   intel_engines_unpark(i915);
+
queue_delayed_work(i915->wq,
   >gt.retire_work,
   round_jiffies_up_relative(HZ));
diff --git a/drivers/gpu/drm/i915/intel_engine_cs.c 
b/drivers/gpu/drm/i915/intel_engine_cs.c
index a47a9c6bea52..0213edc237fe 100644
--- a/drivers/gpu/drm/i915/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/intel_engine_cs.c
@@ -1594,19 +1594,48 @@ void intel_engines_reset_default_submission(struct 
drm_i915_private *i915)
engine->set_default_submission(engine);
 }
 
-void intel_engines_mark_idle(struct drm_i915_private *i915)
+/**
+ * intel_engines_park: called when the GT is transitioning from busy->idle
+ * @i915: the i915 device
+ *
+ * The GT is now idle and about to go to sleep (maybe never to wake again?).
+ * Time for us to tidy and put away our toys (release resources back to the
+ * system).
+ */
+void intel_engines_park(struct drm_i915_private *i915)
 {
struct intel_engine_cs *engine;
enum intel_engine_id id;
 
for_each_engine(engine, i915, id) {
+   if (engine->park)
+   engine->park(engine);
+
intel_engine_disarm_breadcrumbs(engine);
-   i915_gem_batch_pool_fini(>batch_pool);
tasklet_kill(>execlists.irq_tasklet);
+
+   i915_gem_batch_pool_fini(>batch_pool);
engine->execlists.no_priolist = false;
}
 }
 
+/**
+ * intel_engines_unpark: called when the GT is transitioning from idle->busy
+ * @i915: the i915 device
+ *
+ * The GT was idle and now about to fire up with some new user requests.
+ */
+void intel_engines_unpark(struct drm_i915_private *i915)
+{
+   struct intel_engine_cs *engine;
+   enum intel_engine_id id;
+
+   for_each_engine(engine, i915, id) {
+   if (engine->unpark)
+   engine->unpark(engine);
+   }
+}
+
 bool intel_engine_can_store_dword(struct intel_engine_cs *engine)
 {
switch (INTEL_GEN(engine->i915)) {
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 7f45dd7dc3e5..a030ca44a7ae 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -1880,6 +1880,9 @@ static void execlists_set_default_submission(struct 
intel_engine_cs *engine)
engine->cancel_requests = execlists_cancel_requests;
engine->schedule = execlists_schedule;
engine->execlists.irq_tasklet.func = intel_lrc_irq_handler;
+
+   engine->park = NULL;
+   engine->unpark = NULL;
 }
 
 static void
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c 
b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 8da1bde442dd..05e01446b00b 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -2028,12 +2028,15 @@ static void i9xx_set_default_submission(struct 
intel_engine_cs *engine)
 {
engine->submit_request = i9xx_submit_request;
engine->cancel_requests = cancel_requests;
+
+   engine->park = NULL;
+   engine->unpark = NULL;
 }
 
 static void gen6_bsd_set_default_submission(struct intel_engine_cs