drm/i915: Push the ring creation flags to the backend

Push the ring creation flags from the outer GEM context to the inner
intel_context to avoid an unsightly back-reference from inside the
backend.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Andi Shyti <andi.shyti@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190809182518.20486-3-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/gem/i915_gem_context.c

@@ -436,8 +436,6 @@ __create_context(struct drm_i915_private *i915)
 	i915_gem_context_set_bannable(ctx);
 	i915_gem_context_set_recoverable(ctx);
 
-	ctx->ring_size = 4 * PAGE_SIZE;
-
 	for (i = 0; i < ARRAY_SIZE(ctx->hang_timestamp); i++)
 		ctx->hang_timestamp[i] = jiffies - CONTEXT_FAST_HANG_JIFFIES;
 
@@ -448,22 +446,34 @@ err_free:
 	return ERR_PTR(err);
 }
 
+static void
+context_apply_all(struct i915_gem_context *ctx,
+		  void (*fn)(struct intel_context *ce, void *data),
+		  void *data)
+{
+	struct i915_gem_engines_iter it;
+	struct intel_context *ce;
+
+	for_each_gem_engine(ce, i915_gem_context_lock_engines(ctx), it)
+		fn(ce, data);
+	i915_gem_context_unlock_engines(ctx);
+}
+
+static void __apply_ppgtt(struct intel_context *ce, void *vm)
+{
+	i915_vm_put(ce->vm);
+	ce->vm = i915_vm_get(vm);
+}
+
 static struct i915_address_space *
 __set_ppgtt(struct i915_gem_context *ctx, struct i915_address_space *vm)
 {
 	struct i915_address_space *old = ctx->vm;
-	struct i915_gem_engines_iter it;
-	struct intel_context *ce;
 
 	GEM_BUG_ON(old && i915_vm_is_4lvl(vm) != i915_vm_is_4lvl(old));
 
 	ctx->vm = i915_vm_get(vm);
-
-	for_each_gem_engine(ce, i915_gem_context_lock_engines(ctx), it) {
-		i915_vm_put(ce->vm);
-		ce->vm = i915_vm_get(vm);
-	}
-	i915_gem_context_unlock_engines(ctx);
+	context_apply_all(ctx, __apply_ppgtt, vm);
 
 	return old;
 }
@@ -560,7 +570,6 @@ i915_gem_context_create_kernel(struct drm_i915_private *i915, int prio)
 
 	i915_gem_context_clear_bannable(ctx);
 	ctx->sched.priority = I915_USER_PRIORITY(prio);
-	ctx->ring_size = PAGE_SIZE;
 
 	GEM_BUG_ON(!i915_gem_context_is_kernel(ctx));
 
@@ -1544,6 +1553,7 @@ set_engines(struct i915_gem_context *ctx,
 	for (n = 0; n < num_engines; n++) {
 		struct i915_engine_class_instance ci;
 		struct intel_engine_cs *engine;
+		struct intel_context *ce;
 
 		if (copy_from_user(&ci, &user->engines[n], sizeof(ci))) {
 			__free_engines(set.engines, n);
@@ -1566,11 +1576,13 @@ set_engines(struct i915_gem_context *ctx,
 			return -ENOENT;
 		}
 
-		set.engines->engines[n] = intel_context_create(ctx, engine);
-		if (!set.engines->engines[n]) {
+		ce = intel_context_create(ctx, engine);
+		if (IS_ERR(ce)) {
 			__free_engines(set.engines, n);
-			return -ENOMEM;
+			return PTR_ERR(ce);
 		}
+
+		set.engines->engines[n] = ce;
 	}
 	set.engines->num_engines = num_engines;
 

drivers/gpu/drm/i915/gem/i915_gem_context_types.h

@@ -169,9 +169,6 @@ struct i915_gem_context {
 
 	struct i915_sched_attr sched;
 
-	/** ring_size: size for allocating the per-engine ring buffer */
-	u32 ring_size;
-
 	/** guilty_count: How many times this context has caused a GPU hang. */
 	atomic_t guilty_count;
 	/**

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

@@ -222,6 +222,7 @@ intel_context_init(struct intel_context *ce,
 	ce->engine = engine;
 	ce->ops = engine->cops;
 	ce->sseu = engine->sseu;
+	ce->ring = __intel_context_ring_size(SZ_16K);
 
 	INIT_LIST_HEAD(&ce->signal_link);
 	INIT_LIST_HEAD(&ce->signals);

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

@@ -136,4 +136,9 @@ int intel_context_prepare_remote_request(struct intel_context *ce,
 
 struct i915_request *intel_context_create_request(struct intel_context *ce);
 
+static inline struct intel_ring *__intel_context_ring_size(u64 sz)
+{
+	return u64_to_ptr(struct intel_ring, sz);
+}
+
 #endif /* __INTEL_CONTEXT_H__ */

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

@@ -738,6 +738,8 @@ create_kernel_context(struct intel_engine_cs *engine)
 	if (IS_ERR(ce))
 		return ce;
 
+	ce->ring = __intel_context_ring_size(SZ_4K);
+
 	err = intel_context_pin(ce);
 	if (err) {
 		intel_context_put(ce);

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

@@ -3115,9 +3115,8 @@ static int __execlists_context_alloc(struct intel_context *ce,
 		goto error_deref_obj;
 	}
 
-	ring = intel_engine_create_ring(engine,
-					timeline,
-					ce->gem_context->ring_size);
+	ring = intel_engine_create_ring(engine, timeline,
+					(unsigned long)ce->ring);
 	intel_timeline_put(timeline);
 	if (IS_ERR(ring)) {
 		ret = PTR_ERR(ring);

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

@@ -2350,7 +2350,7 @@ int intel_ring_submission_init(struct intel_engine_cs *engine)
 	}
 	GEM_BUG_ON(timeline->has_initial_breadcrumb);
 
-	ring = intel_engine_create_ring(engine, timeline, 32 * PAGE_SIZE);
+	ring = intel_engine_create_ring(engine, timeline, SZ_16K);
 	intel_timeline_put(timeline);
 	if (IS_ERR(ring)) {
 		err = PTR_ERR(ring);

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

@@ -140,7 +140,7 @@ static void mock_context_destroy(struct kref *ref)
 
 	GEM_BUG_ON(intel_context_is_pinned(ce));
 
-	if (ce->ring)
+	if (test_bit(CONTEXT_ALLOC_BIT, &ce->flags))
 		mock_ring_free(ce->ring);
 
 	intel_context_fini(ce);

drivers/gpu/drm/i915/gvt/scheduler.c

@@ -1227,8 +1227,6 @@ int intel_vgpu_setup_submission(struct intel_vgpu *vgpu)
 	}
 
 	i915_gem_context_set_force_single_submission(ctx);
-	if (!USES_GUC_SUBMISSION(i915))
-		ctx->ring_size = 512 * PAGE_SIZE; /* Max ring buffer size */
 
 	i915_context_ppgtt_root_save(s, i915_vm_to_ppgtt(ctx->vm));
 
@@ -1244,6 +1242,12 @@ int intel_vgpu_setup_submission(struct intel_vgpu *vgpu)
 			goto out_shadow_ctx;
 		}
 
+		if (!USES_GUC_SUBMISSION(i915)) { /* Max ring buffer size */
+			const unsigned int ring_size = 512 * SZ_4K;
+
+			ce->ring = __intel_context_ring_size(ring_size);
+		}
+
 		ret = intel_context_pin(ce);
 		intel_context_put(ce);
 		if (ret)

drivers/gpu/drm/i915/i915_debugfs.c

@@ -324,10 +324,14 @@ static void print_context_stats(struct seq_file *m,
 
 		for_each_gem_engine(ce,
 				    i915_gem_context_lock_engines(ctx), it) {
-			if (ce->state)
-				per_file_stats(0, ce->state->obj, &kstats);
-			if (ce->ring)
+			intel_context_lock_pinned(ce);
+			if (intel_context_is_pinned(ce)) {
+				if (ce->state)
+					per_file_stats(0,
+						       ce->state->obj, &kstats);
 				per_file_stats(0, ce->ring->vma->obj, &kstats);
+			}
+			intel_context_unlock_pinned(ce);
 		}
 		i915_gem_context_unlock_engines(ctx);
 
@@ -1627,12 +1631,15 @@ static int i915_context_status(struct seq_file *m, void *unused)
 
 		for_each_gem_engine(ce,
 				    i915_gem_context_lock_engines(ctx), it) {
-			seq_printf(m, "%s: ", ce->engine->name);
-			if (ce->state)
-				describe_obj(m, ce->state->obj);
-			if (ce->ring)
+			intel_context_lock_pinned(ce);
+			if (intel_context_is_pinned(ce)) {
+				seq_printf(m, "%s: ", ce->engine->name);
+				if (ce->state)
+					describe_obj(m, ce->state->obj);
 				describe_ctx_ring(m, ce->ring);
-			seq_putc(m, '\n');
+				seq_putc(m, '\n');
+			}
+			intel_context_unlock_pinned(ce);
 		}
 		i915_gem_context_unlock_engines(ctx);