drm/i915: Record logical context support in driver caps

Avoid looking at the magical engines[RCS] to decide if the HW and driver
supports logical contexts, and instead record that knowledge during
initialisation.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180706101442.21279-1-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/i915_drv.h

@@ -2306,6 +2306,7 @@ intel_info(const struct drm_i915_private *dev_priv)
 }
 
 #define INTEL_INFO(dev_priv)	intel_info((dev_priv))
+#define DRIVER_CAPS(dev_priv)	(&(dev_priv)->caps)
 
 #define INTEL_GEN(dev_priv)	((dev_priv)->info.gen)
 #define INTEL_DEVID(dev_priv)	((dev_priv)->info.device_id)

drivers/gpu/drm/i915/i915_gem_context.c

@@ -512,8 +512,8 @@ int i915_gem_contexts_init(struct drm_i915_private *dev_priv)
 	}
 
 	DRM_DEBUG_DRIVER("%s context support initialized\n",
-			 dev_priv->engine[RCS]->context_size ? "logical" :
-			 "fake");
+			 DRIVER_CAPS(dev_priv)->has_logical_contexts ?
+			 "logical" : "fake");
 	return 0;
 }
 
@@ -720,7 +720,7 @@ int i915_gem_context_create_ioctl(struct drm_device *dev, void *data,
 	struct i915_gem_context *ctx;
 	int ret;
 
-	if (!dev_priv->engine[RCS]->context_size)
+	if (!DRIVER_CAPS(dev_priv)->has_logical_contexts)
 		return -ENODEV;
 
 	if (args->pad != 0)

drivers/gpu/drm/i915/intel_device_info.c

@@ -858,6 +858,8 @@ void intel_device_info_runtime_init(struct intel_device_info *info)
 void intel_driver_caps_print(const struct intel_driver_caps *caps,
 			     struct drm_printer *p)
 {
+	drm_printf(p, "Has logical contexts? %s\n",
+		   yesno(caps->has_logical_contexts));
 	drm_printf(p, "scheduler: %x\n", caps->scheduler);
 }
 

drivers/gpu/drm/i915/intel_device_info.h

@@ -186,6 +186,7 @@ struct intel_device_info {
 
 struct intel_driver_caps {
 	unsigned int scheduler;
+	bool has_logical_contexts:1;
 };
 
 static inline unsigned int sseu_subslice_total(const struct sseu_dev_info *sseu)

drivers/gpu/drm/i915/intel_engine_cs.c

@@ -302,6 +302,8 @@ intel_engine_setup(struct drm_i915_private *dev_priv,
 							   engine->class);
 	if (WARN_ON(engine->context_size > BIT(20)))
 		engine->context_size = 0;
+	if (engine->context_size)
+		DRIVER_CAPS(dev_priv)->has_logical_contexts = true;
 
 	/* Nothing to do here, execute in order of dependencies */
 	engine->schedule = NULL;