[PATCH] drm/i915/gt: Register the migrate contexts with their engines

* [PATCH] drm/i915/gt: Register the migrate contexts with their engines
@ 2021-08-26  6:47 ` Thomas Hellström
  0 siblings, 0 replies; 4+ messages in thread
From: Thomas Hellström @ 2021-08-26  6:47 UTC (permalink / raw)
  To: intel-gfx, dri-devel
  Cc: Thomas Hellström, Tvrtko Ursulin, Matthew Auld,
	Maarten Lankhorst, Brost Matthew

Pinned contexts, like the migrate contexts need reset after resume
since their context image may have been lost. Also the GuC needs to
register pinned contexts.

Add a list to struct intel_engine_cs where we add all pinned contexts on
creation, and traverse that list at __engine_unpark() time to reset the
pinned contexts.

This fixes the kms_pipe_crc_basic@suspend-read-crc-pipe-a selftest for now,
but proper LMEM backup / restore is needed for full suspend functionality.
However, note that even with full LMEM backup / restore it may be
desirable to keep the reset since backing up the migrate context images
must happen using memcpy() after the migrate context has become inactive,
and for performance- and other reasons we want to avoid memcpy() from
LMEM.

Also traverse the list at guc_init_lrc_mapping() calling
guc_kernel_context_pin() for the pinned contexts, like is already done
for the kernel context.

Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Brost Matthew <matthew.brost@intel.com>
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
---
 drivers/gpu/drm/i915/gt/intel_context_types.h     |  8 ++++++++
 drivers/gpu/drm/i915/gt/intel_engine_cs.c         |  4 ++++
 drivers/gpu/drm/i915/gt/intel_engine_pm.c         |  9 +++++++++
 drivers/gpu/drm/i915/gt/intel_engine_types.h      |  7 +++++++
 drivers/gpu/drm/i915/gt/mock_engine.c             |  1 +
 drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c | 10 +++++++---
 6 files changed, 36 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_context_types.h b/drivers/gpu/drm/i915/gt/intel_context_types.h
index e54351a170e2..a63631ea0ec4 100644
--- a/drivers/gpu/drm/i915/gt/intel_context_types.h
+++ b/drivers/gpu/drm/i915/gt/intel_context_types.h
@@ -152,6 +152,14 @@ struct intel_context {
 	/** sseu: Control eu/slice partitioning */
 	struct intel_sseu sseu;
 
+	/**
+	 * pinned_contexts_link: List link for the engine's pinned contexts.
+	 * This is only used if this is a perma-pinned kernel context and
+	 * the list is assumed to only be manipulated during driver load
+	 * or unload time so no mutex protection currently.
+	 */
+	struct list_head pinned_contexts_link;
+
 	u8 wa_bb_page; /* if set, page num reserved for context workarounds */
 
 	struct {
diff --git a/drivers/gpu/drm/i915/gt/intel_engine_cs.c b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
index 332efea696a5..c606a4714904 100644
--- a/drivers/gpu/drm/i915/gt/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
@@ -320,6 +320,7 @@ static int intel_engine_setup(struct intel_gt *gt, enum intel_engine_id id)
 
 	BUILD_BUG_ON(BITS_PER_TYPE(engine->mask) < I915_NUM_ENGINES);
 
+	INIT_LIST_HEAD(&engine->pinned_contexts_list);
 	engine->id = id;
 	engine->legacy_idx = INVALID_ENGINE;
 	engine->mask = BIT(id);
@@ -875,6 +876,8 @@ intel_engine_create_pinned_context(struct intel_engine_cs *engine,
 		return ERR_PTR(err);
 	}
 
+	list_add_tail(&ce->pinned_contexts_link, &engine->pinned_contexts_list);
+
 	/*
 	 * Give our perma-pinned kernel timelines a separate lockdep class,
 	 * so that we can use them from within the normal user timelines
@@ -897,6 +900,7 @@ void intel_engine_destroy_pinned_context(struct intel_context *ce)
 	list_del(&ce->timeline->engine_link);
 	mutex_unlock(&hwsp->vm->mutex);
 
+	list_del(&ce->pinned_contexts_link);
 	intel_context_unpin(ce);
 	intel_context_put(ce);
 }
diff --git a/drivers/gpu/drm/i915/gt/intel_engine_pm.c b/drivers/gpu/drm/i915/gt/intel_engine_pm.c
index 1f07ac4e0672..3a5cbbf3e3fe 100644
--- a/drivers/gpu/drm/i915/gt/intel_engine_pm.c
+++ b/drivers/gpu/drm/i915/gt/intel_engine_pm.c
@@ -72,6 +72,15 @@ static int __engine_unpark(struct intel_wakeref *wf)
 			   READ_ONCE(*ce->timeline->hwsp_seqno));
 	}
 
+	list_for_each_entry(ce, &engine->pinned_contexts_list,
+			    pinned_contexts_link) {
+		if (ce == engine->kernel_context)
+			continue;
+
+		dbg_poison_ce(ce);
+		ce->ops->reset(ce);
+	}
+
 	if (engine->unpark)
 		engine->unpark(engine);
 
diff --git a/drivers/gpu/drm/i915/gt/intel_engine_types.h b/drivers/gpu/drm/i915/gt/intel_engine_types.h
index bfbfe53c23dd..5ae1207c363b 100644
--- a/drivers/gpu/drm/i915/gt/intel_engine_types.h
+++ b/drivers/gpu/drm/i915/gt/intel_engine_types.h
@@ -307,6 +307,13 @@ struct intel_engine_cs {
 
 	struct intel_context *kernel_context; /* pinned */
 
+	/**
+	 * pinned_contexts_list: List of pinned contexts. This list is only
+	 * assumed to be manipulated during driver load- or unload time and
+	 * does therefore not have any additional protection.
+	 */
+	struct list_head pinned_contexts_list;
+
 	intel_engine_mask_t saturated; /* submitting semaphores too late? */
 
 	struct {
diff --git a/drivers/gpu/drm/i915/gt/mock_engine.c b/drivers/gpu/drm/i915/gt/mock_engine.c
index 2c1af030310c..8a14982a9691 100644
--- a/drivers/gpu/drm/i915/gt/mock_engine.c
+++ b/drivers/gpu/drm/i915/gt/mock_engine.c
@@ -376,6 +376,7 @@ int mock_engine_init(struct intel_engine_cs *engine)
 {
 	struct intel_context *ce;
 
+	INIT_LIST_HEAD(&engine->pinned_contexts_list);
 	engine->sched_engine = i915_sched_engine_create(ENGINE_MOCK);
 	if (!engine->sched_engine)
 		return -ENOMEM;
diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
index 87d8dc8f51b9..55709206b95e 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
@@ -2385,9 +2385,13 @@ static inline void guc_init_lrc_mapping(struct intel_guc *guc)
 	 * and even it did this code would be run again.
 	 */
 
-	for_each_engine(engine, gt, id)
-		if (engine->kernel_context)
-			guc_kernel_context_pin(guc, engine->kernel_context);
+	for_each_engine(engine, gt, id) {
+		struct intel_context *ce;
+
+		list_for_each_entry(ce, &engine->pinned_contexts_list,
+				    pinned_contexts_link)
+			guc_kernel_context_pin(guc, ce);
+	}
 }
 
 static void guc_release(struct intel_engine_cs *engine)
-- 
2.31.1


^ permalink raw reply related	[flat|nested] 4+ messages in thread