drm/i915: Convert i915_semaphores_is_enabled over to early sanitize

Rather than recomputing whether semaphores are enabled, we can do that
computation once during early initialisation as the i915.semaphores
module parameter is now read-only.

s/i915_semaphores_is_enabled/i915.semaphores/

v2: Add the state to the debug dmesg as well

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1469005202-9659-10-git-send-email-chris@chris-wilson.co.uk
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1469017917-15134-9-git-send-email-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/i915_debugfs.c

@@ -3220,7 +3220,7 @@ static int i915_semaphore_status(struct seq_file *m, void *unused)
 	enum intel_engine_id id;
 	int j, ret;
 
-	if (!i915_semaphore_is_enabled(dev_priv)) {
+	if (!i915.semaphores) {
 		seq_puts(m, "Semaphores are disabled\n");
 		return 0;
 	}

drivers/gpu/drm/i915/i915_drv.c

@@ -228,27 +228,6 @@ static void intel_detect_pch(struct drm_device *dev)
 	pci_dev_put(pch);
 }
 
-bool i915_semaphore_is_enabled(struct drm_i915_private *dev_priv)
-{
-	if (INTEL_GEN(dev_priv) < 6)
-		return false;
-
-	if (i915.semaphores >= 0)
-		return i915.semaphores;
-
-	/* TODO: make semaphores and Execlists play nicely together */
-	if (i915.enable_execlists)
-		return false;
-
-#ifdef CONFIG_INTEL_IOMMU
-	/* Enable semaphores on SNB when IO remapping is off */
-	if (IS_GEN6(dev_priv) && intel_iommu_gfx_mapped)
-		return false;
-#endif
-
-	return true;
-}
-
 static int i915_getparam(struct drm_device *dev, void *data,
 			 struct drm_file *file_priv)
 {
@@ -324,7 +303,7 @@ static int i915_getparam(struct drm_device *dev, void *data,
 		value = 1;
 		break;
 	case I915_PARAM_HAS_SEMAPHORES:
-		value = i915_semaphore_is_enabled(dev_priv);
+		value = i915.semaphores;
 		break;
 	case I915_PARAM_HAS_PRIME_VMAP_FLUSH:
 		value = 1;
@@ -999,6 +978,9 @@ static void intel_sanitize_options(struct drm_i915_private *dev_priv)
 	i915.enable_ppgtt =
 		intel_sanitize_enable_ppgtt(dev_priv, i915.enable_ppgtt);
 	DRM_DEBUG_DRIVER("ppgtt mode: %i\n", i915.enable_ppgtt);
+
+	i915.semaphores = intel_sanitize_semaphores(dev_priv, i915.semaphores);
+	DRM_DEBUG_DRIVER("use GPU sempahores? %s\n", yesno(i915.semaphores));
 }
 
 /**

drivers/gpu/drm/i915/i915_drv.h

@@ -2813,6 +2813,8 @@ extern int i915_resume_switcheroo(struct drm_device *dev);
 int intel_sanitize_enable_ppgtt(struct drm_i915_private *dev_priv,
 			       	int enable_ppgtt);
 
+bool intel_sanitize_semaphores(struct drm_i915_private *dev_priv, int value);
+
 /* i915_drv.c */
 void __printf(3, 4)
 __i915_printk(struct drm_i915_private *dev_priv, const char *level,
@@ -3641,7 +3643,6 @@ extern void intel_set_rps(struct drm_i915_private *dev_priv, u8 val);
 extern void intel_set_memory_cxsr(struct drm_i915_private *dev_priv,
 				  bool enable);
 
-extern bool i915_semaphore_is_enabled(struct drm_i915_private *dev_priv);
 int i915_reg_read_ioctl(struct drm_device *dev, void *data,
 			struct drm_file *file);
 

drivers/gpu/drm/i915/i915_gem.c

@@ -2856,7 +2856,7 @@ __i915_gem_object_sync(struct drm_i915_gem_object *obj,
 	if (i915_gem_request_completed(from_req))
 		return 0;
 
-	if (!i915_semaphore_is_enabled(to_i915(obj->base.dev))) {
+	if (!i915.semaphores) {
 		struct drm_i915_private *i915 = to_i915(obj->base.dev);
 		ret = __i915_wait_request(from_req,
 					  i915->mm.interruptible,
@@ -4537,6 +4537,27 @@ i915_gem_init_hw(struct drm_device *dev)
 	return ret;
 }
 
+bool intel_sanitize_semaphores(struct drm_i915_private *dev_priv, int value)
+{
+	if (INTEL_INFO(dev_priv)->gen < 6)
+		return false;
+
+	/* TODO: make semaphores and Execlists play nicely together */
+	if (i915.enable_execlists)
+		return false;
+
+	if (value >= 0)
+		return value;
+
+#ifdef CONFIG_INTEL_IOMMU
+	/* Enable semaphores on SNB when IO remapping is off */
+	if (INTEL_INFO(dev_priv)->gen == 6 && intel_iommu_gfx_mapped)
+		return false;
+#endif
+
+	return true;
+}
+
 int i915_gem_init(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = to_i915(dev);

drivers/gpu/drm/i915/i915_gem_context.c

@@ -556,7 +556,7 @@ mi_set_context(struct drm_i915_gem_request *req, u32 hw_flags)
 	u32 flags = hw_flags | MI_MM_SPACE_GTT;
 	const int num_rings =
 		/* Use an extended w/a on ivb+ if signalling from other rings */
-		i915_semaphore_is_enabled(dev_priv) ?
+		i915.semaphores ?
 		hweight32(INTEL_INFO(dev_priv)->ring_mask) - 1 :
 		0;
 	int len, ret;

drivers/gpu/drm/i915/i915_gpu_error.c

@@ -863,7 +863,7 @@ static void gen8_record_semaphore_state(struct drm_i915_private *dev_priv,
 	struct intel_engine_cs *to;
 	enum intel_engine_id id;
 
-	if (!i915_semaphore_is_enabled(dev_priv))
+	if (!i915.semaphores)
 		return;
 
 	if (!error->semaphore_obj)

drivers/gpu/drm/i915/intel_ringbuffer.c

@@ -2679,7 +2679,7 @@ static void intel_ring_init_semaphores(struct drm_i915_private *dev_priv,
 	struct drm_i915_gem_object *obj;
 	int ret, i;
 
-	if (!i915_semaphore_is_enabled(dev_priv))
+	if (!i915.semaphores)
 		return;
 
 	if (INTEL_GEN(dev_priv) >= 8 && !dev_priv->semaphore_obj) {
@@ -2700,7 +2700,7 @@ static void intel_ring_init_semaphores(struct drm_i915_private *dev_priv,
 		}
 	}
 
-	if (!i915_semaphore_is_enabled(dev_priv))
+	if (!i915.semaphores)
 		return;
 
 	if (INTEL_GEN(dev_priv) >= 8) {
@@ -2838,7 +2838,7 @@ int intel_init_render_ring_buffer(struct intel_engine_cs *engine)
 		engine->init_context = intel_rcs_ctx_init;
 		engine->add_request = gen8_render_add_request;
 		engine->flush = gen8_render_ring_flush;
-		if (i915_semaphore_is_enabled(dev_priv))
+		if (i915.semaphores)
 			engine->semaphore.signal = gen8_rcs_signal;
 	} else if (INTEL_GEN(dev_priv) >= 6) {
 		engine->init_context = intel_rcs_ctx_init;