+/* Parameters have changed, update FBC info */
+static void i8xx_enable_fbc(struct drm_crtc *crtc, unsigned long interval)
+{
+ struct drm_device *dev = crtc->dev;
+ struct drm_i915_private *dev_priv = dev->dev_private;
+ struct drm_framebuffer *fb = crtc->fb;
+ struct intel_framebuffer *intel_fb = to_intel_framebuffer(fb);
+ struct drm_i915_gem_object *obj_priv = intel_fb->obj->driver_private;
+ struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
+ int plane, i;
+ u32 fbc_ctl, fbc_ctl2;
+
+ dev_priv->cfb_pitch = dev_priv->cfb_size / FBC_LL_SIZE;
+
+ if (fb->pitch < dev_priv->cfb_pitch)
+ dev_priv->cfb_pitch = fb->pitch;
+
+ /* FBC_CTL wants 64B units */
+ dev_priv->cfb_pitch = (dev_priv->cfb_pitch / 64) - 1;
+ dev_priv->cfb_fence = obj_priv->fence_reg;
+ dev_priv->cfb_plane = intel_crtc->plane;
+ plane = dev_priv->cfb_plane == 0 ? FBC_CTL_PLANEA : FBC_CTL_PLANEB;
+
+ /* Clear old tags */
+ for (i = 0; i < (FBC_LL_SIZE / 32) + 1; i++)
+ I915_WRITE(FBC_TAG + (i * 4), 0);
+
+ /* Set it up... */
+ fbc_ctl2 = FBC_CTL_FENCE_DBL | FBC_CTL_IDLE_IMM | plane;
+ if (obj_priv->tiling_mode != I915_TILING_NONE)
+ fbc_ctl2 |= FBC_CTL_CPU_FENCE;
+ I915_WRITE(FBC_CONTROL2, fbc_ctl2);
+ I915_WRITE(FBC_FENCE_OFF, crtc->y);
+
+ /* enable it... */
+ fbc_ctl = FBC_CTL_EN | FBC_CTL_PERIODIC;
+ fbc_ctl |= (dev_priv->cfb_pitch & 0xff) << FBC_CTL_STRIDE_SHIFT;
+ fbc_ctl |= (interval & 0x2fff) << FBC_CTL_INTERVAL_SHIFT;
+ if (obj_priv->tiling_mode != I915_TILING_NONE)
+ fbc_ctl |= dev_priv->cfb_fence;
+ I915_WRITE(FBC_CONTROL, fbc_ctl);
+
+ DRM_DEBUG("enabled FBC, pitch %ld, yoff %d, plane %d, ",
+ dev_priv->cfb_pitch, crtc->y, dev_priv->cfb_plane);
+}
+
+void i8xx_disable_fbc(struct drm_device *dev)
+{
+ struct drm_i915_private *dev_priv = dev->dev_private;
+ u32 fbc_ctl;
+
+ /* Disable compression */
+ fbc_ctl = I915_READ(FBC_CONTROL);
+ fbc_ctl &= ~FBC_CTL_EN;
+ I915_WRITE(FBC_CONTROL, fbc_ctl);
+
+ /* Wait for compressing bit to clear */
+ while (I915_READ(FBC_STATUS) & FBC_STAT_COMPRESSING)
+ ; /* nothing */
+
+ intel_wait_for_vblank(dev);
+
+ DRM_DEBUG("disabled FBC\n");
+}
+
+static bool i8xx_fbc_enabled(struct drm_crtc *crtc)
+{
+ struct drm_device *dev = crtc->dev;
+ struct drm_i915_private *dev_priv = dev->dev_private;
+
+ return I915_READ(FBC_CONTROL) & FBC_CTL_EN;
+}
+
+/**
+ * intel_update_fbc - enable/disable FBC as needed
+ * @crtc: CRTC to point the compressor at
+ * @mode: mode in use
+ *
+ * Set up the framebuffer compression hardware at mode set time. We
+ * enable it if possible:
+ * - plane A only (on pre-965)
+ * - no pixel mulitply/line duplication
+ * - no alpha buffer discard
+ * - no dual wide
+ * - framebuffer <= 2048 in width, 1536 in height
+ *
+ * We can't assume that any compression will take place (worst case),
+ * so the compressed buffer has to be the same size as the uncompressed
+ * one. It also must reside (along with the line length buffer) in
+ * stolen memory.
+ *
+ * We need to enable/disable FBC on a global basis.
+ */
+static void intel_update_fbc(struct drm_crtc *crtc,
+ struct drm_display_mode *mode)
+{
+ struct drm_device *dev = crtc->dev;
+ struct drm_i915_private *dev_priv = dev->dev_private;
+ struct drm_framebuffer *fb = crtc->fb;
+ struct intel_framebuffer *intel_fb;
+ struct drm_i915_gem_object *obj_priv;
+ struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
+ int plane = intel_crtc->plane;
+
+ if (!i915_powersave)
+ return;
+
+ if (!crtc->fb)
+ return;
+
+ intel_fb = to_intel_framebuffer(fb);
+ obj_priv = intel_fb->obj->driver_private;
+
+ /*
+ * If FBC is already on, we just have to verify that we can
+ * keep it that way...
+ * Need to disable if:
+ * - changing FBC params (stride, fence, mode)
+ * - new fb is too large to fit in compressed buffer
+ * - going to an unsupported config (interlace, pixel multiply, etc.)
+ */
+ if (intel_fb->obj->size > dev_priv->cfb_size) {
+ DRM_DEBUG("framebuffer too large, disabling compression\n");
+ goto out_disable;
+ }
+ if ((mode->flags & DRM_MODE_FLAG_INTERLACE) ||
+ (mode->flags & DRM_MODE_FLAG_DBLSCAN)) {
+ DRM_DEBUG("mode incompatible with compression, disabling\n");
+ goto out_disable;
+ }
+ if ((mode->hdisplay > 2048) ||
+ (mode->vdisplay > 1536)) {
+ DRM_DEBUG("mode too large for compression, disabling\n");
+ goto out_disable;
+ }
+ if (IS_I9XX(dev) && plane != 0) {
+ DRM_DEBUG("plane not 0, disabling compression\n");
+ goto out_disable;
+ }
+ if (obj_priv->tiling_mode != I915_TILING_X) {
+ DRM_DEBUG("framebuffer not tiled, disabling compression\n");
+ goto out_disable;
+ }
+
+ if (i8xx_fbc_enabled(crtc)) {
+ /* We can re-enable it in this case, but need to update pitch */
+ if (fb->pitch > dev_priv->cfb_pitch)
+ i8xx_disable_fbc(dev);
+ if (obj_priv->fence_reg != dev_priv->cfb_fence)
+ i8xx_disable_fbc(dev);
+ if (plane != dev_priv->cfb_plane)
+ i8xx_disable_fbc(dev);
+ }
+
+ if (!i8xx_fbc_enabled(crtc)) {
+ /* Now try to turn it back on if possible */
+ i8xx_enable_fbc(crtc, 500);
+ }
+
+ return;
+
+out_disable:
+ DRM_DEBUG("unsupported config, disabling FBC\n");
+ /* Multiple disables should be harmless */
+ if (i8xx_fbc_enabled(crtc))
+ i8xx_disable_fbc(dev);
+}
+