drm/i915: adjust framebuffer base address on gen4+

The tileoffset register only supports a limited offset in x/y of 4096,
so for giant screen configuration with a shared fb we wrap around.

Fix this by computing a linear offset in tiles (pages) and only use
the tileoffset register to offset within the tile.

Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 38 insertions, 9 deletions

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index f8c24123dde0..ca1068bc892f 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -1973,6 +1973,22 @@ void intel_unpin_fb_obj(struct drm_i915_gem_object *obj)
         i915_gem_object_unpin(obj);
 }
 
+/* Computes the linear offset to the base tile and adjusts x, y. bytes per pixel
+ * is assumed to be a power-of-two. */
+static unsigned long gen4_compute_dspaddr_offset_xtiled(int *x, int *y,
+                                                        unsigned int bpp,
+                                                        unsigned int pitch)
+{
+        int tile_rows, tiles;
+
+        tile_rows = *y / 8;
+        *y %= 8;
+        tiles = *x / (512/bpp);
+        *x %= 512/bpp;
+
+        return tile_rows * pitch * 8 + tiles * 4096;
+}
+
 static int i9xx_update_plane(struct drm_crtc *crtc, struct drm_framebuffer *fb,
                              int x, int y)
 {
@@ -2031,16 +2047,22 @@ static int i9xx_update_plane(struct drm_crtc *crtc, struct drm_framebuffer *fb,
 
         linear_offset = y * fb->pitches[0] + x * (fb->bits_per_pixel / 8);
 
-        if (INTEL_INFO(dev)->gen >= 4)
-                intel_crtc->dspaddr_offset = 0;
-        else
+        if (INTEL_INFO(dev)->gen >= 4) {
+                intel_crtc->dspaddr_offset =
+                        gen4_compute_dspaddr_offset_xtiled(&x, &y,
+                                                           fb->bits_per_pixel / 8,
+                                                           fb->pitches[0]);
+                linear_offset -= intel_crtc->dspaddr_offset;
+        } else {
                 intel_crtc->dspaddr_offset = linear_offset;
+        }
 
         DRM_DEBUG_KMS("Writing base %08X %08lX %d %d %d\n",
                       obj->gtt_offset, linear_offset, x, y, fb->pitches[0]);
         I915_WRITE(DSPSTRIDE(plane), fb->pitches[0]);
         if (INTEL_INFO(dev)->gen >= 4) {
-                I915_MODIFY_DISPBASE(DSPSURF(plane), obj->gtt_offset);
+                I915_MODIFY_DISPBASE(DSPSURF(plane),
+                                     obj->gtt_offset + intel_crtc->dspaddr_offset);
                 I915_WRITE(DSPTILEOFF(plane), (y << 16) | x);
                 I915_WRITE(DSPLINOFF(plane), linear_offset);
         } else
@@ -2115,12 +2137,17 @@ static int ironlake_update_plane(struct drm_crtc *crtc,
         I915_WRITE(reg, dspcntr);
 
         linear_offset = y * fb->pitches[0] + x * (fb->bits_per_pixel / 8);
-        intel_crtc->dspaddr_offset = 0;
+        intel_crtc->dspaddr_offset =
+                gen4_compute_dspaddr_offset_xtiled(&x, &y,
+                                                   fb->bits_per_pixel / 8,
+                                                   fb->pitches[0]);
+        linear_offset -= intel_crtc->dspaddr_offset;
 
         DRM_DEBUG_KMS("Writing base %08X %08lX %d %d %d\n",
                       obj->gtt_offset, linear_offset, x, y, fb->pitches[0]);
         I915_WRITE(DSPSTRIDE(plane), fb->pitches[0]);
-        I915_MODIFY_DISPBASE(DSPSURF(plane), obj->gtt_offset);
+        I915_MODIFY_DISPBASE(DSPSURF(plane),
+                             obj->gtt_offset + intel_crtc->dspaddr_offset);
         I915_WRITE(DSPTILEOFF(plane), (y << 16) | x);
         I915_WRITE(DSPLINOFF(plane), linear_offset);
         POSTING_READ(reg);
@@ -6299,7 +6326,9 @@ static int intel_gen4_queue_flip(struct drm_device *dev,
         intel_ring_emit(ring, MI_DISPLAY_FLIP |
                         MI_DISPLAY_FLIP_PLANE(intel_crtc->plane));
         intel_ring_emit(ring, fb->pitches[0]);
-        intel_ring_emit(ring, obj->gtt_offset | obj->tiling_mode);
+        intel_ring_emit(ring,
+                        (obj->gtt_offset + intel_crtc->dspaddr_offset) |
+                        obj->tiling_mode);
 
         /* XXX Enabling the panel-fitter across page-flip is so far
          * untested on non-native modes, so ignore it for now.
@@ -6339,7 +6368,7 @@ static int intel_gen6_queue_flip(struct drm_device *dev,
         intel_ring_emit(ring, MI_DISPLAY_FLIP |
                         MI_DISPLAY_FLIP_PLANE(intel_crtc->plane));
         intel_ring_emit(ring, fb->pitches[0] | obj->tiling_mode);
-        intel_ring_emit(ring, obj->gtt_offset);
+        intel_ring_emit(ring, obj->gtt_offset + intel_crtc->dspaddr_offset);
 
         /* Contrary to the suggestions in the documentation,
          * "Enable Panel Fitter" does not seem to be required when page
@@ -6402,7 +6431,7 @@ static int intel_gen7_queue_flip(struct drm_device *dev,
 
         intel_ring_emit(ring, MI_DISPLAY_FLIP_I915 | plane_bit);
         intel_ring_emit(ring, (fb->pitches[0] | obj->tiling_mode));
-        intel_ring_emit(ring, (obj->gtt_offset));
+        intel_ring_emit(ring, obj->gtt_offset + intel_crtc->dspaddr_offset);
         intel_ring_emit(ring, (MI_NOOP));
         intel_ring_advance(ring);
         return 0;