drm/i915: Mask reserved bits in display/sprite address registers

The purpose of this patch is to avoid zeroing the lower 12 reserved bits
of surface base address registers (framebuffer & sprite).  There are bits
in that range that may occasionally be set by BIOS or by other components.

Signed-off-by: Armin Reese <armin.c.reese@intel.com>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_irq.c

@@ -1368,7 +1368,8 @@ static void i915_pageflip_stall_check(struct drm_device *dev, int pipe)
 	obj = work->pending_flip_obj;
 	if (INTEL_INFO(dev)->gen >= 4) {
 		int dspsurf = DSPSURF(intel_crtc->plane);
-		stall_detected = I915_READ(dspsurf) == obj->gtt_offset;
+		stall_detected = I915_HI_DISPBASE(I915_READ(dspsurf)) ==
+					obj->gtt_offset;
 	} else {
 		int dspaddr = DSPADDR(intel_crtc->plane);
 		stall_detected = I915_READ(dspaddr) == (obj->gtt_offset +

drivers/gpu/drm/i915/i915_reg.h

@@ -2869,6 +2869,13 @@
 #define DSPSURF(plane) _PIPE(plane, _DSPASURF, _DSPBSURF)
 #define DSPTILEOFF(plane) _PIPE(plane, _DSPATILEOFF, _DSPBTILEOFF)
 
+/* Display/Sprite base address macros */
+#define DISP_BASEADDR_MASK	(0xfffff000)
+#define I915_LO_DISPBASE(val)	(val & ~DISP_BASEADDR_MASK)
+#define I915_HI_DISPBASE(val)	(val & DISP_BASEADDR_MASK)
+#define I915_MODIFY_DISPBASE(reg, gfx_addr) \
+		(I915_WRITE(reg, gfx_addr | I915_LO_DISPBASE(I915_READ(reg))))
+
 /* VBIOS flags */
 #define SWF00			0x71410
 #define SWF01			0x71414

drivers/gpu/drm/i915/intel_display.c

@@ -2236,7 +2236,7 @@ static int i9xx_update_plane(struct drm_crtc *crtc, struct drm_framebuffer *fb,
 		      Start, Offset, x, y, fb->pitches[0]);
 	I915_WRITE(DSPSTRIDE(plane), fb->pitches[0]);
 	if (INTEL_INFO(dev)->gen >= 4) {
-		I915_WRITE(DSPSURF(plane), Start);
+		I915_MODIFY_DISPBASE(DSPSURF(plane), Start);
 		I915_WRITE(DSPTILEOFF(plane), (y << 16) | x);
 		I915_WRITE(DSPADDR(plane), Offset);
 	} else
@@ -2316,7 +2316,7 @@ static int ironlake_update_plane(struct drm_crtc *crtc,
 	DRM_DEBUG_KMS("Writing base %08lX %08lX %d %d %d\n",
 		      Start, Offset, x, y, fb->pitches[0]);
 	I915_WRITE(DSPSTRIDE(plane), fb->pitches[0]);
-	I915_WRITE(DSPSURF(plane), Start);
+	I915_MODIFY_DISPBASE(DSPSURF(plane), Start);
 	I915_WRITE(DSPTILEOFF(plane), (y << 16) | x);
 	I915_WRITE(DSPADDR(plane), Offset);
 	POSTING_READ(reg);

drivers/gpu/drm/i915/intel_sprite.c

@@ -133,7 +133,7 @@ ivb_update_plane(struct drm_plane *plane, struct drm_framebuffer *fb,
 	I915_WRITE(SPRSIZE(pipe), (crtc_h << 16) | crtc_w);
 	I915_WRITE(SPRSCALE(pipe), sprscale);
 	I915_WRITE(SPRCTL(pipe), sprctl);
-	I915_WRITE(SPRSURF(pipe), obj->gtt_offset);
+	I915_MODIFY_DISPBASE(SPRSURF(pipe), obj->gtt_offset);
 	POSTING_READ(SPRSURF(pipe));
 }
 
@@ -149,7 +149,7 @@ ivb_disable_plane(struct drm_plane *plane)
 	/* Can't leave the scaler enabled... */
 	I915_WRITE(SPRSCALE(pipe), 0);
 	/* Activate double buffered register update */
-	I915_WRITE(SPRSURF(pipe), 0);
+	I915_MODIFY_DISPBASE(SPRSURF(pipe), 0);
 	POSTING_READ(SPRSURF(pipe));
 }
 
@@ -291,7 +291,7 @@ ilk_update_plane(struct drm_plane *plane, struct drm_framebuffer *fb,
 	I915_WRITE(DVSSIZE(pipe), (crtc_h << 16) | crtc_w);
 	I915_WRITE(DVSSCALE(pipe), dvsscale);
 	I915_WRITE(DVSCNTR(pipe), dvscntr);
-	I915_WRITE(DVSSURF(pipe), obj->gtt_offset);
+	I915_MODIFY_DISPBASE(DVSSURF(pipe), obj->gtt_offset);
 	POSTING_READ(DVSSURF(pipe));
 }
 
@@ -307,7 +307,7 @@ ilk_disable_plane(struct drm_plane *plane)
 	/* Disable the scaler */
 	I915_WRITE(DVSSCALE(pipe), 0);
 	/* Flush double buffered register updates */
-	I915_WRITE(DVSSURF(pipe), 0);
+	I915_MODIFY_DISPBASE(DVSSURF(pipe), 0);
 	POSTING_READ(DVSSURF(pipe));
 }