drm/i915: Move num_plane to the intel_device_info structure

And rename it to num_sprites as this value doesn't count the primary
plane.

This limit lives with num_pipes really, and now that dev_priv->info is
writable we can put it there instead.

While at it, introduce a intel_device_info_runtime_init() where we'll be
able to gather the device info fields at run-time.

v2: rename num_plane to num_sprites (Ville Syrjälä)
v3: rebase on top of latest drm-nightly

Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com> (for v2)
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> (for v2)
Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_dma.c

@@ -1459,6 +1459,25 @@ static void i915_dump_device_info(struct drm_i915_private *dev_priv)
 #undef SEP_COMMA
 }
 
+/*
+ * Determine various intel_device_info fields at runtime.
+ *
+ * Use it when either:
+ *   - it's judged too laborious to fill n static structures with the limit
+ *     when a simple if statement does the job,
+ *   - run-time checks (eg read fuse/strap registers) are needed.
+ */
+static void intel_device_info_runtime_init(struct drm_device *dev)
+{
+	struct intel_device_info *info;
+
+	info = (struct intel_device_info *)&to_i915(dev)->info;
+
+	info->num_sprites = 1;
+	if (IS_VALLEYVIEW(dev))
+		info->num_sprites = 2;
+}
+
 /**
  * i915_driver_load - setup chip and create an initial config
  * @dev: DRM device
@@ -1638,9 +1657,7 @@ int i915_driver_load(struct drm_device *dev, unsigned long flags)
 	if (!IS_I945G(dev) && !IS_I945GM(dev))
 		pci_enable_msi(dev->pdev);
 
-	dev_priv->num_plane = 1;
-	if (IS_VALLEYVIEW(dev))
-		dev_priv->num_plane = 2;
+	intel_device_info_runtime_init(dev);
 
 	if (INTEL_INFO(dev)->num_pipes) {
 		ret = drm_vblank_init(dev, INTEL_INFO(dev)->num_pipes);

drivers/gpu/drm/i915/i915_drv.h

@@ -79,7 +79,7 @@ enum plane {
 };
 #define plane_name(p) ((p) + 'A')
 
-#define sprite_name(p, s) ((p) * dev_priv->num_plane + (s) + 'A')
+#define sprite_name(p, s) ((p) * INTEL_INFO(dev)->num_sprites + (s) + 'A')
 
 enum port {
 	PORT_A = 0,
@@ -530,6 +530,7 @@ struct intel_uncore {
 struct intel_device_info {
 	u32 display_mmio_offset;
 	u8 num_pipes:3;
+	u8 num_sprites:2;
 	u8 gen;
 	u8 ring_mask; /* Rings supported by the HW */
 	DEV_INFO_FOR_EACH_FLAG(DEFINE_FLAG, SEP_SEMICOLON);
@@ -1450,8 +1451,6 @@ typedef struct drm_i915_private {
 	u32 hpd_event_bits;
 	struct timer_list hotplug_reenable_timer;
 
-	int num_plane;
-
 	struct i915_fbc fbc;
 	struct intel_opregion opregion;
 	struct intel_vbt_data vbt;

drivers/gpu/drm/i915/intel_display.c

@@ -1189,7 +1189,7 @@ static void assert_sprites_disabled(struct drm_i915_private *dev_priv,
 	u32 val;
 
 	if (IS_VALLEYVIEW(dev)) {
-		for (i = 0; i < dev_priv->num_plane; i++) {
+		for (i = 0; i < INTEL_INFO(dev)->num_sprites; i++) {
 			reg = SPCNTR(pipe, i);
 			val = I915_READ(reg);
 			WARN((val & SP_ENABLE),
@@ -11038,7 +11038,7 @@ void intel_modeset_init(struct drm_device *dev)
 
 	for_each_pipe(i) {
 		intel_crtc_init(dev, i);
-		for (j = 0; j < dev_priv->num_plane; j++) {
+		for (j = 0; j < INTEL_INFO(dev)->num_sprites; j++) {
 			ret = intel_plane_init(dev, i, j);
 			if (ret)
 				DRM_DEBUG_KMS("pipe %c sprite %c init failed: %d\n",