drm/i915/fbc: Polish the skl+ FBC stride override handling

Polish the FBC stride override stuff:
- just call it override_cfb_stride since it'll be used on
  more gens later
- Use REG_BIT() & co. for the registers and give everything
  CHICKEN_ prefix since glk+ will have a different register
  for this
- Use intel_de_rmw() for the RMW
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210702204603.596-5-ville.syrjala@linux.intel.comReviewed-by: Jani Nikula <jani.nikula@intel.com>

drivers/gpu/drm/i915/display/intel_fbc.c

@@ -306,14 +306,15 @@ static void gen7_fbc_activate(struct drm_i915_private *dev_priv)
 
 	/* Display WA #0529: skl, kbl, bxt. */
 	if (DISPLAY_VER(dev_priv) == 9) {
-		u32 val = intel_de_read(dev_priv, CHICKEN_MISC_4);
+		u32 val = 0;
 
-		val &= ~(FBC_STRIDE_OVERRIDE | FBC_STRIDE_MASK);
+		if (params->override_cfb_stride)
+			val |= CHICKEN_FBC_STRIDE_OVERRIDE |
+				CHICKEN_FBC_STRIDE(params->override_cfb_stride);
 
-		if (params->gen9_wa_cfb_stride)
-			val |= FBC_STRIDE_OVERRIDE | params->gen9_wa_cfb_stride;
-
-		intel_de_write(dev_priv, CHICKEN_MISC_4, val);
+		intel_de_rmw(dev_priv, CHICKEN_MISC_4,
+			     CHICKEN_FBC_STRIDE_OVERRIDE |
+			     CHICKEN_FBC_STRIDE_MASK, val);
 	}
 
 	dpfc_ctl = 0;
@@ -749,7 +750,7 @@ static bool intel_fbc_cfb_size_changed(struct drm_i915_private *dev_priv)
 		fbc->compressed_fb.size * fbc->limit;
 }
 
-static u16 intel_fbc_gen9_wa_cfb_stride(struct drm_i915_private *dev_priv)
+static u16 intel_fbc_override_cfb_stride(struct drm_i915_private *dev_priv)
 {
 	struct intel_fbc *fbc = &dev_priv->fbc;
 	struct intel_fbc_state_cache *cache = &fbc->state_cache;
@@ -761,11 +762,11 @@ static u16 intel_fbc_gen9_wa_cfb_stride(struct drm_i915_private *dev_priv)
 		return 0;
 }
 
-static bool intel_fbc_gen9_wa_cfb_stride_changed(struct drm_i915_private *dev_priv)
+static bool intel_fbc_override_cfb_stride_changed(struct drm_i915_private *dev_priv)
 {
 	struct intel_fbc *fbc = &dev_priv->fbc;
 
-	return fbc->params.gen9_wa_cfb_stride != intel_fbc_gen9_wa_cfb_stride(dev_priv);
+	return fbc->params.override_cfb_stride != intel_fbc_override_cfb_stride(dev_priv);
 }
 
 static bool intel_fbc_can_enable(struct drm_i915_private *dev_priv)
@@ -950,7 +951,7 @@ static void intel_fbc_get_reg_params(struct intel_crtc *crtc,
 
 	params->cfb_size = intel_fbc_calculate_cfb_size(dev_priv, cache);
 
-	params->gen9_wa_cfb_stride = cache->gen9_wa_cfb_stride;
+	params->override_cfb_stride = cache->override_cfb_stride;
 
 	params->plane_visible = cache->plane.visible;
 }
@@ -984,7 +985,7 @@ static bool intel_fbc_can_flip_nuke(const struct intel_crtc_state *crtc_state)
 	if (params->cfb_size != intel_fbc_calculate_cfb_size(dev_priv, cache))
 		return false;
 
-	if (params->gen9_wa_cfb_stride != cache->gen9_wa_cfb_stride)
+	if (params->override_cfb_stride != cache->override_cfb_stride)
 		return false;
 
 	return true;
@@ -1258,7 +1259,7 @@ static void intel_fbc_enable(struct intel_atomic_state *state,
 	if (fbc->crtc) {
 		if (fbc->crtc != crtc ||
 		    (!intel_fbc_cfb_size_changed(dev_priv) &&
-		     !intel_fbc_gen9_wa_cfb_stride_changed(dev_priv)))
+		     !intel_fbc_override_cfb_stride_changed(dev_priv)))
 			goto out;
 
 		__intel_fbc_disable(dev_priv);
@@ -1280,7 +1281,7 @@ static void intel_fbc_enable(struct intel_atomic_state *state,
 		goto out;
 	}
 
-	cache->gen9_wa_cfb_stride = intel_fbc_gen9_wa_cfb_stride(dev_priv);
+	cache->override_cfb_stride = intel_fbc_override_cfb_stride(dev_priv);
 
 	drm_dbg_kms(&dev_priv->drm, "Enabling FBC on pipe %c\n",
 		    pipe_name(crtc->pipe));

drivers/gpu/drm/i915/i915_drv.h

@@ -454,7 +454,7 @@ struct intel_fbc {
 		} fb;
 
 		unsigned int fence_y_offset;
-		u16 gen9_wa_cfb_stride;
+		u16 override_cfb_stride;
 		u16 interval;
 		s8 fence_id;
 		bool psr2_active;
@@ -481,7 +481,7 @@ struct intel_fbc {
 
 		int cfb_size;
 		unsigned int fence_y_offset;
-		u16 gen9_wa_cfb_stride;
+		u16 override_cfb_stride;
 		u16 interval;
 		s8 fence_id;
 		bool plane_visible;

drivers/gpu/drm/i915/i915_reg.h

@@ -8176,8 +8176,9 @@ enum {
 #define  GLK_CL0_PWR_DOWN	(1 << 10)
 
 #define CHICKEN_MISC_4		_MMIO(0x4208c)
-#define   FBC_STRIDE_OVERRIDE	(1 << 13)
-#define   FBC_STRIDE_MASK	0x1FFF
+#define   CHICKEN_FBC_STRIDE_OVERRIDE	REG_BIT(13)
+#define   CHICKEN_FBC_STRIDE_MASK	REG_GENMASK(12, 0)
+#define   CHICKEN_FBC_STRIDE(x)		REG_FIELD_PREP(CHICKEN_FBC_STRIDE_MASK, (x))
 
 #define _CHICKEN_PIPESL_1_A	0x420b0
 #define _CHICKEN_PIPESL_1_B	0x420b4