+static bool multiple_pipes_ok(struct drm_i915_private *dev_priv)
+{
+ enum pipe pipe;
+ int n_pipes = 0;
+ struct drm_crtc *crtc;
+
+ if (INTEL_INFO(dev_priv)->gen > 4)
+ return true;
+
+ for_each_pipe(dev_priv, pipe) {
+ crtc = dev_priv->pipe_to_crtc_mapping[pipe];
+
+ if (intel_crtc_active(crtc) &&
+ to_intel_plane_state(crtc->primary->state)->visible)
+ n_pipes++;
+ }
+
+ return (n_pipes < 2);
+}
+
+static int find_compression_threshold(struct drm_i915_private *dev_priv,
+ struct drm_mm_node *node,
+ int size,
+ int fb_cpp)
+{
+ int compression_threshold = 1;
+ int ret;
+ u64 end;
+
+ /* The FBC hardware for BDW/SKL doesn't have access to the stolen
+ * reserved range size, so it always assumes the maximum (8mb) is used.
+ * If we enable FBC using a CFB on that memory range we'll get FIFO
+ * underruns, even if that range is not reserved by the BIOS. */
+ if (IS_BROADWELL(dev_priv) || IS_SKYLAKE(dev_priv))
+ end = dev_priv->gtt.stolen_size - 8 * 1024 * 1024;
+ else
+ end = dev_priv->gtt.stolen_usable_size;
+
+ /* HACK: This code depends on what we will do in *_enable_fbc. If that
+ * code changes, this code needs to change as well.
+ *
+ * The enable_fbc code will attempt to use one of our 2 compression
+ * thresholds, therefore, in that case, we only have 1 resort.
+ */
+
+ /* Try to over-allocate to reduce reallocations and fragmentation. */
+ ret = i915_gem_stolen_insert_node_in_range(dev_priv, node, size <<= 1,
+ 4096, 0, end);
+ if (ret == 0)
+ return compression_threshold;
+
+again:
+ /* HW's ability to limit the CFB is 1:4 */
+ if (compression_threshold > 4 ||
+ (fb_cpp == 2 && compression_threshold == 2))
+ return 0;
+
+ ret = i915_gem_stolen_insert_node_in_range(dev_priv, node, size >>= 1,
+ 4096, 0, end);
+ if (ret && INTEL_INFO(dev_priv)->gen <= 4) {
+ return 0;
+ } else if (ret) {
+ compression_threshold <<= 1;
+ goto again;
+ } else {
+ return compression_threshold;
+ }
+}
+
+static int intel_fbc_alloc_cfb(struct drm_i915_private *dev_priv, int size,
+ int fb_cpp)
+{
+ struct drm_mm_node *uninitialized_var(compressed_llb);
+ int ret;
+
+ ret = find_compression_threshold(dev_priv, &dev_priv->fbc.compressed_fb,
+ size, fb_cpp);
+ if (!ret)
+ goto err_llb;
+ else if (ret > 1) {
+ DRM_INFO("Reducing the compressed framebuffer size. This may lead to less power savings than a non-reduced-size. Try to increase stolen memory size if available in BIOS.\n");
+
+ }
+
+ dev_priv->fbc.threshold = ret;
+
+ if (INTEL_INFO(dev_priv)->gen >= 5)
+ I915_WRITE(ILK_DPFC_CB_BASE, dev_priv->fbc.compressed_fb.start);
+ else if (IS_GM45(dev_priv)) {
+ I915_WRITE(DPFC_CB_BASE, dev_priv->fbc.compressed_fb.start);
+ } else {
+ compressed_llb = kzalloc(sizeof(*compressed_llb), GFP_KERNEL);
+ if (!compressed_llb)
+ goto err_fb;
+
+ ret = i915_gem_stolen_insert_node(dev_priv, compressed_llb,
+ 4096, 4096);
+ if (ret)
+ goto err_fb;
+
+ dev_priv->fbc.compressed_llb = compressed_llb;
+
+ I915_WRITE(FBC_CFB_BASE,
+ dev_priv->mm.stolen_base + dev_priv->fbc.compressed_fb.start);
+ I915_WRITE(FBC_LL_BASE,
+ dev_priv->mm.stolen_base + compressed_llb->start);
+ }
+
+ dev_priv->fbc.uncompressed_size = size;
+
+ DRM_DEBUG_KMS("reserved %llu bytes of contiguous stolen space for FBC, threshold: %d\n",
+ dev_priv->fbc.compressed_fb.size,
+ dev_priv->fbc.threshold);
+
+ return 0;
+
+err_fb:
+ kfree(compressed_llb);
+ i915_gem_stolen_remove_node(dev_priv, &dev_priv->fbc.compressed_fb);
+err_llb:
+ pr_info_once("drm: not enough stolen space for compressed buffer (need %d more bytes), disabling. Hint: you may be able to increase stolen memory size in the BIOS to avoid this.\n", size);
+ return -ENOSPC;
+}
+
+static void __intel_fbc_cleanup_cfb(struct drm_i915_private *dev_priv)
+{
+ if (dev_priv->fbc.uncompressed_size == 0)
+ return;
+
+ i915_gem_stolen_remove_node(dev_priv, &dev_priv->fbc.compressed_fb);
+
+ if (dev_priv->fbc.compressed_llb) {
+ i915_gem_stolen_remove_node(dev_priv,
+ dev_priv->fbc.compressed_llb);
+ kfree(dev_priv->fbc.compressed_llb);
+ }
+
+ dev_priv->fbc.uncompressed_size = 0;
+}
+
+void intel_fbc_cleanup_cfb(struct drm_i915_private *dev_priv)
+{
+ if (!fbc_supported(dev_priv))
+ return;
+
+ mutex_lock(&dev_priv->fbc.lock);
+ __intel_fbc_cleanup_cfb(dev_priv);
+ mutex_unlock(&dev_priv->fbc.lock);
+}
+
+/*
+ * For SKL+, the plane source size used by the hardware is based on the value we
+ * write to the PLANE_SIZE register. For BDW-, the hardware looks at the value
+ * we wrote to PIPESRC.
+ */
+static void intel_fbc_get_plane_source_size(struct intel_crtc *crtc,
+ int *width, int *height)
+{
+ struct intel_plane_state *plane_state =
+ to_intel_plane_state(crtc->base.primary->state);
+ int w, h;
+
+ if (intel_rotation_90_or_270(plane_state->base.rotation)) {
+ w = drm_rect_height(&plane_state->src) >> 16;
+ h = drm_rect_width(&plane_state->src) >> 16;
+ } else {
+ w = drm_rect_width(&plane_state->src) >> 16;
+ h = drm_rect_height(&plane_state->src) >> 16;
+ }
+
+ if (width)
+ *width = w;
+ if (height)
+ *height = h;
+}
+
+static int intel_fbc_calculate_cfb_size(struct intel_crtc *crtc)
+{
+ struct drm_i915_private *dev_priv = crtc->base.dev->dev_private;
+ struct drm_framebuffer *fb = crtc->base.primary->fb;
+ int lines;
+
+ intel_fbc_get_plane_source_size(crtc, NULL, &lines);
+ if (INTEL_INFO(dev_priv)->gen >= 7)
+ lines = min(lines, 2048);
+
+ return lines * fb->pitches[0];
+}
+
+static int intel_fbc_setup_cfb(struct intel_crtc *crtc)
+{
+ struct drm_i915_private *dev_priv = crtc->base.dev->dev_private;
+ struct drm_framebuffer *fb = crtc->base.primary->fb;
+ int size, cpp;
+
+ size = intel_fbc_calculate_cfb_size(crtc);
+ cpp = drm_format_plane_cpp(fb->pixel_format, 0);
+
+ if (size <= dev_priv->fbc.uncompressed_size)
+ return 0;
+
+ /* Release any current block */
+ __intel_fbc_cleanup_cfb(dev_priv);
+
+ return intel_fbc_alloc_cfb(dev_priv, size, cpp);
+}
+
+static bool stride_is_valid(struct drm_i915_private *dev_priv,
+ unsigned int stride)
+{
+ /* These should have been caught earlier. */
+ WARN_ON(stride < 512);
+ WARN_ON((stride & (64 - 1)) != 0);
+
+ /* Below are the additional FBC restrictions. */
+
+ if (IS_GEN2(dev_priv) || IS_GEN3(dev_priv))
+ return stride == 4096 || stride == 8192;
+
+ if (IS_GEN4(dev_priv) && !IS_G4X(dev_priv) && stride < 2048)
+ return false;
+
+ if (stride > 16384)
+ return false;
+
+ return true;
+}
+
+static bool pixel_format_is_valid(struct drm_framebuffer *fb)
+{
+ struct drm_device *dev = fb->dev;
+ struct drm_i915_private *dev_priv = dev->dev_private;
+
+ switch (fb->pixel_format) {
+ case DRM_FORMAT_XRGB8888:
+ case DRM_FORMAT_XBGR8888:
+ return true;
+ case DRM_FORMAT_XRGB1555:
+ case DRM_FORMAT_RGB565:
+ /* 16bpp not supported on gen2 */
+ if (IS_GEN2(dev))
+ return false;
+ /* WaFbcOnly1to1Ratio:ctg */
+ if (IS_G4X(dev_priv))
+ return false;
+ return true;
+ default:
+ return false;
+ }
+}
+
+/*
+ * For some reason, the hardware tracking starts looking at whatever we
+ * programmed as the display plane base address register. It does not look at
+ * the X and Y offset registers. That's why we look at the crtc->adjusted{x,y}
+ * variables instead of just looking at the pipe/plane size.
+ */
+static bool intel_fbc_hw_tracking_covers_screen(struct intel_crtc *crtc)
+{
+ struct drm_i915_private *dev_priv = crtc->base.dev->dev_private;
+ unsigned int effective_w, effective_h, max_w, max_h;
+
+ if (INTEL_INFO(dev_priv)->gen >= 8 || IS_HASWELL(dev_priv)) {
+ max_w = 4096;
+ max_h = 4096;
+ } else if (IS_G4X(dev_priv) || INTEL_INFO(dev_priv)->gen >= 5) {
+ max_w = 4096;
+ max_h = 2048;
+ } else {
+ max_w = 2048;
+ max_h = 1536;
+ }
+
+ intel_fbc_get_plane_source_size(crtc, &effective_w, &effective_h);
+ effective_w += crtc->adjusted_x;
+ effective_h += crtc->adjusted_y;
+
+ return effective_w <= max_w && effective_h <= max_h;
+}
+