[PATCH 43/52] drm/i915: Track active engines within a context

[Chris Wilson]

For use in the next patch, if we track which engines have been used by
the HW, we can reduce the work required to flush our state off the HW to
those engines.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/i915_gem_context.c | 3 +++
 drivers/gpu/drm/i915/i915_gem_context.h | 4 ++++
 drivers/gpu/drm/i915/intel_lrc.c        | 2 ++
 drivers/gpu/drm/i915/intel_ringbuffer.c | 3 +++
 4 files changed, 12 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
index ae206c3d2f7d..ef726a3bfb49 100644
--- a/drivers/gpu/drm/i915/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
@@ -210,6 +210,7 @@ static void i915_gem_context_free(struct i915_gem_context *ctx)
 
 	lockdep_assert_held(&ctx->i915->drm.struct_mutex);
 	GEM_BUG_ON(!i915_gem_context_is_closed(ctx));
+	GEM_BUG_ON(!list_empty(&ctx->active_engines));
 
 	release_hw_id(ctx);
 	i915_ppgtt_put(ctx->ppgtt);
@@ -337,6 +338,7 @@ intel_context_init(struct intel_context *ce,
 		   struct intel_engine_cs *engine)
 {
 	ce->gem_context = ctx;
+	ce->engine = engine;
 
 	INIT_LIST_HEAD(&ce->signal_link);
 	INIT_LIST_HEAD(&ce->signals);
@@ -364,6 +366,7 @@ __create_hw_context(struct drm_i915_private *dev_priv,
 	list_add_tail(&ctx->link, &dev_priv->contexts.list);
 	ctx->i915 = dev_priv;
 	ctx->sched.priority = I915_USER_PRIORITY(I915_PRIORITY_NORMAL);
+	INIT_LIST_HEAD(&ctx->active_engines);
 
 	for (n = 0; n < ARRAY_SIZE(ctx->__engine); n++)
 		intel_context_init(&ctx->__engine[n], ctx, dev_priv->engine[n]);
diff --git a/drivers/gpu/drm/i915/i915_gem_context.h b/drivers/gpu/drm/i915/i915_gem_context.h
index 902428990f34..c6a0a253e125 100644
--- a/drivers/gpu/drm/i915/i915_gem_context.h
+++ b/drivers/gpu/drm/i915/i915_gem_context.h
@@ -151,6 +151,8 @@ struct i915_gem_context {
 	atomic_t hw_id_pin_count;
 	struct list_head hw_id_link;
 
+	struct list_head active_engines;
+
 	/**
 	 * @user_handle: userspace identifier
 	 *
@@ -164,7 +166,9 @@ struct i915_gem_context {
 	/** engine: per-engine logical HW state */
 	struct intel_context {
 		struct i915_gem_context *gem_context;
+		struct intel_engine_cs *engine;
 		struct intel_engine_cs *active;
+		struct list_head active_link;
 		struct list_head signal_link;
 		struct list_head signals;
 		struct i915_vma *state;
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 78c4c7e0b45e..83d7a35b6fe8 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -1270,6 +1270,7 @@ static void execlists_context_unpin(struct intel_context *ce)
 		GEM_BUG_ON(READ_ONCE(ce->active));
 	}
 
+	list_del(&ce->active_link);
 	i915_gem_context_unpin_hw_id(ce->gem_context);
 
 	intel_ring_unpin(ce->ring);
@@ -1361,6 +1362,7 @@ __execlists_context_pin(struct intel_engine_cs *engine,
 
 	__execlists_update_reg_state(engine, ce);
 
+	list_add(&ce->active_link, &ctx->active_engines);
 	ce->state->obj->pin_global++;
 	i915_gem_context_get(ctx);
 	return ce;
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 5a0aab3dc26d..074c2f700ad1 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -1417,6 +1417,8 @@ static void __context_unpin(struct intel_context *ce)
 {
 	struct i915_vma *vma;
 
+	list_del(&ce->active_link);
+
 	vma = ce->state;
 	if (!vma)
 		return;
@@ -1529,6 +1531,7 @@ __ring_context_pin(struct intel_engine_cs *engine,
 	if (err)
 		goto err_unpin;
 
+	list_add(&ce->active_link, &ctx->active_engines);
 	i915_gem_context_get(ctx);
 
 	/* One ringbuffer to rule them all */
-- 
2.20.1