2 * Copyright © 2014 Intel Corporation
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21 * DEALINGS IN THE SOFTWARE.
25 * DOC: Frame Buffer Compression (FBC)
27 * FBC tries to save memory bandwidth (and so power consumption) by
28 * compressing the amount of memory used by the display. It is total
29 * transparent to user space and completely handled in the kernel.
31 * The benefits of FBC are mostly visible with solid backgrounds and
32 * variation-less patterns. It comes from keeping the memory footprint small
33 * and having fewer memory pages opened and accessed for refreshing the display.
35 * i915 is responsible to reserve stolen memory for FBC and configure its
36 * offset on proper registers. The hardware takes care of all
37 * compress/decompress. However there are many known cases where we have to
38 * forcibly disable it to allow proper screen updates.
41 #include "intel_drv.h"
44 static inline bool fbc_supported(struct drm_i915_private *dev_priv)
46 return HAS_FBC(dev_priv);
49 static inline bool no_fbc_on_multiple_pipes(struct drm_i915_private *dev_priv)
51 return INTEL_GEN(dev_priv) <= 3;
55 * In some platforms where the CRTC's x:0/y:0 coordinates doesn't match the
56 * frontbuffer's x:0/y:0 coordinates we lie to the hardware about the plane's
57 * origin so the x and y offsets can actually fit the registers. As a
58 * consequence, the fence doesn't really start exactly at the display plane
59 * address we program because it starts at the real start of the buffer, so we
60 * have to take this into consideration here.
62 static unsigned int get_crtc_fence_y_offset(struct intel_fbc *fbc)
64 return fbc->state_cache.plane.y - fbc->state_cache.plane.adjusted_y;
68 * For SKL+, the plane source size used by the hardware is based on the value we
69 * write to the PLANE_SIZE register. For BDW-, the hardware looks at the value
70 * we wrote to PIPESRC.
72 static void intel_fbc_get_plane_source_size(struct intel_fbc_state_cache *cache,
73 int *width, int *height)
76 *width = cache->plane.src_w;
78 *height = cache->plane.src_h;
81 static int intel_fbc_calculate_cfb_size(struct drm_i915_private *dev_priv,
82 struct intel_fbc_state_cache *cache)
86 intel_fbc_get_plane_source_size(cache, NULL, &lines);
87 if (IS_GEN7(dev_priv))
88 lines = min(lines, 2048);
89 else if (INTEL_GEN(dev_priv) >= 8)
90 lines = min(lines, 2560);
92 /* Hardware needs the full buffer stride, not just the active area. */
93 return lines * cache->fb.stride;
96 static void i8xx_fbc_deactivate(struct drm_i915_private *dev_priv)
100 /* Disable compression */
101 fbc_ctl = I915_READ(FBC_CONTROL);
102 if ((fbc_ctl & FBC_CTL_EN) == 0)
105 fbc_ctl &= ~FBC_CTL_EN;
106 I915_WRITE(FBC_CONTROL, fbc_ctl);
108 /* Wait for compressing bit to clear */
109 if (intel_wait_for_register(dev_priv,
110 FBC_STATUS, FBC_STAT_COMPRESSING, 0,
112 DRM_DEBUG_KMS("FBC idle timed out\n");
117 static void i8xx_fbc_activate(struct drm_i915_private *dev_priv)
119 struct intel_fbc_reg_params *params = &dev_priv->fbc.params;
124 /* Note: fbc.threshold == 1 for i8xx */
125 cfb_pitch = params->cfb_size / FBC_LL_SIZE;
126 if (params->fb.stride < cfb_pitch)
127 cfb_pitch = params->fb.stride;
129 /* FBC_CTL wants 32B or 64B units */
130 if (IS_GEN2(dev_priv))
131 cfb_pitch = (cfb_pitch / 32) - 1;
133 cfb_pitch = (cfb_pitch / 64) - 1;
136 for (i = 0; i < (FBC_LL_SIZE / 32) + 1; i++)
137 I915_WRITE(FBC_TAG(i), 0);
139 if (IS_GEN4(dev_priv)) {
143 fbc_ctl2 = FBC_CTL_FENCE_DBL | FBC_CTL_IDLE_IMM | FBC_CTL_CPU_FENCE;
144 fbc_ctl2 |= FBC_CTL_PLANE(params->crtc.i9xx_plane);
145 I915_WRITE(FBC_CONTROL2, fbc_ctl2);
146 I915_WRITE(FBC_FENCE_OFF, params->crtc.fence_y_offset);
150 fbc_ctl = I915_READ(FBC_CONTROL);
151 fbc_ctl &= 0x3fff << FBC_CTL_INTERVAL_SHIFT;
152 fbc_ctl |= FBC_CTL_EN | FBC_CTL_PERIODIC;
153 if (IS_I945GM(dev_priv))
154 fbc_ctl |= FBC_CTL_C3_IDLE; /* 945 needs special SR handling */
155 fbc_ctl |= (cfb_pitch & 0xff) << FBC_CTL_STRIDE_SHIFT;
156 fbc_ctl |= params->vma->fence->id;
157 I915_WRITE(FBC_CONTROL, fbc_ctl);
160 static bool i8xx_fbc_is_active(struct drm_i915_private *dev_priv)
162 return I915_READ(FBC_CONTROL) & FBC_CTL_EN;
165 static void g4x_fbc_activate(struct drm_i915_private *dev_priv)
167 struct intel_fbc_reg_params *params = &dev_priv->fbc.params;
170 dpfc_ctl = DPFC_CTL_PLANE(params->crtc.i9xx_plane) | DPFC_SR_EN;
171 if (params->fb.format->cpp[0] == 2)
172 dpfc_ctl |= DPFC_CTL_LIMIT_2X;
174 dpfc_ctl |= DPFC_CTL_LIMIT_1X;
176 if (params->flags & PLANE_HAS_FENCE) {
177 dpfc_ctl |= DPFC_CTL_FENCE_EN | params->vma->fence->id;
178 I915_WRITE(DPFC_FENCE_YOFF, params->crtc.fence_y_offset);
180 I915_WRITE(DPFC_FENCE_YOFF, 0);
184 I915_WRITE(DPFC_CONTROL, dpfc_ctl | DPFC_CTL_EN);
187 static void g4x_fbc_deactivate(struct drm_i915_private *dev_priv)
191 /* Disable compression */
192 dpfc_ctl = I915_READ(DPFC_CONTROL);
193 if (dpfc_ctl & DPFC_CTL_EN) {
194 dpfc_ctl &= ~DPFC_CTL_EN;
195 I915_WRITE(DPFC_CONTROL, dpfc_ctl);
199 static bool g4x_fbc_is_active(struct drm_i915_private *dev_priv)
201 return I915_READ(DPFC_CONTROL) & DPFC_CTL_EN;
204 /* This function forces a CFB recompression through the nuke operation. */
205 static void intel_fbc_recompress(struct drm_i915_private *dev_priv)
207 I915_WRITE(MSG_FBC_REND_STATE, FBC_REND_NUKE);
208 POSTING_READ(MSG_FBC_REND_STATE);
211 static void ilk_fbc_activate(struct drm_i915_private *dev_priv)
213 struct intel_fbc_reg_params *params = &dev_priv->fbc.params;
215 int threshold = dev_priv->fbc.threshold;
217 dpfc_ctl = DPFC_CTL_PLANE(params->crtc.i9xx_plane);
218 if (params->fb.format->cpp[0] == 2)
224 dpfc_ctl |= DPFC_CTL_LIMIT_4X;
227 dpfc_ctl |= DPFC_CTL_LIMIT_2X;
230 dpfc_ctl |= DPFC_CTL_LIMIT_1X;
234 if (params->flags & PLANE_HAS_FENCE) {
235 dpfc_ctl |= DPFC_CTL_FENCE_EN;
236 if (IS_GEN5(dev_priv))
237 dpfc_ctl |= params->vma->fence->id;
238 if (IS_GEN6(dev_priv)) {
239 I915_WRITE(SNB_DPFC_CTL_SA,
240 SNB_CPU_FENCE_ENABLE |
241 params->vma->fence->id);
242 I915_WRITE(DPFC_CPU_FENCE_OFFSET,
243 params->crtc.fence_y_offset);
246 if (IS_GEN6(dev_priv)) {
247 I915_WRITE(SNB_DPFC_CTL_SA, 0);
248 I915_WRITE(DPFC_CPU_FENCE_OFFSET, 0);
252 I915_WRITE(ILK_DPFC_FENCE_YOFF, params->crtc.fence_y_offset);
253 I915_WRITE(ILK_FBC_RT_BASE,
254 i915_ggtt_offset(params->vma) | ILK_FBC_RT_VALID);
256 I915_WRITE(ILK_DPFC_CONTROL, dpfc_ctl | DPFC_CTL_EN);
258 intel_fbc_recompress(dev_priv);
261 static void ilk_fbc_deactivate(struct drm_i915_private *dev_priv)
265 /* Disable compression */
266 dpfc_ctl = I915_READ(ILK_DPFC_CONTROL);
267 if (dpfc_ctl & DPFC_CTL_EN) {
268 dpfc_ctl &= ~DPFC_CTL_EN;
269 I915_WRITE(ILK_DPFC_CONTROL, dpfc_ctl);
273 static bool ilk_fbc_is_active(struct drm_i915_private *dev_priv)
275 return I915_READ(ILK_DPFC_CONTROL) & DPFC_CTL_EN;
278 static void gen7_fbc_activate(struct drm_i915_private *dev_priv)
280 struct intel_fbc_reg_params *params = &dev_priv->fbc.params;
282 int threshold = dev_priv->fbc.threshold;
284 /* Display WA #0529: skl, kbl, bxt. */
285 if (IS_GEN9(dev_priv) && !IS_GEMINILAKE(dev_priv)) {
286 u32 val = I915_READ(CHICKEN_MISC_4);
288 val &= ~(FBC_STRIDE_OVERRIDE | FBC_STRIDE_MASK);
290 if (i915_gem_object_get_tiling(params->vma->obj) !=
292 val |= FBC_STRIDE_OVERRIDE | params->gen9_wa_cfb_stride;
294 I915_WRITE(CHICKEN_MISC_4, val);
298 if (IS_IVYBRIDGE(dev_priv))
299 dpfc_ctl |= IVB_DPFC_CTL_PLANE(params->crtc.i9xx_plane);
301 if (params->fb.format->cpp[0] == 2)
307 dpfc_ctl |= DPFC_CTL_LIMIT_4X;
310 dpfc_ctl |= DPFC_CTL_LIMIT_2X;
313 dpfc_ctl |= DPFC_CTL_LIMIT_1X;
317 if (params->flags & PLANE_HAS_FENCE) {
318 dpfc_ctl |= IVB_DPFC_CTL_FENCE_EN;
319 I915_WRITE(SNB_DPFC_CTL_SA,
320 SNB_CPU_FENCE_ENABLE |
321 params->vma->fence->id);
322 I915_WRITE(DPFC_CPU_FENCE_OFFSET, params->crtc.fence_y_offset);
324 I915_WRITE(SNB_DPFC_CTL_SA,0);
325 I915_WRITE(DPFC_CPU_FENCE_OFFSET, 0);
328 if (dev_priv->fbc.false_color)
329 dpfc_ctl |= FBC_CTL_FALSE_COLOR;
331 if (IS_IVYBRIDGE(dev_priv)) {
332 /* WaFbcAsynchFlipDisableFbcQueue:ivb */
333 I915_WRITE(ILK_DISPLAY_CHICKEN1,
334 I915_READ(ILK_DISPLAY_CHICKEN1) |
336 } else if (IS_HASWELL(dev_priv) || IS_BROADWELL(dev_priv)) {
337 /* WaFbcAsynchFlipDisableFbcQueue:hsw,bdw */
338 I915_WRITE(CHICKEN_PIPESL_1(params->crtc.pipe),
339 I915_READ(CHICKEN_PIPESL_1(params->crtc.pipe)) |
343 I915_WRITE(ILK_DPFC_CONTROL, dpfc_ctl | DPFC_CTL_EN);
345 intel_fbc_recompress(dev_priv);
348 static bool intel_fbc_hw_is_active(struct drm_i915_private *dev_priv)
350 if (INTEL_GEN(dev_priv) >= 5)
351 return ilk_fbc_is_active(dev_priv);
352 else if (IS_GM45(dev_priv))
353 return g4x_fbc_is_active(dev_priv);
355 return i8xx_fbc_is_active(dev_priv);
358 static void intel_fbc_hw_activate(struct drm_i915_private *dev_priv)
360 struct intel_fbc *fbc = &dev_priv->fbc;
364 if (INTEL_GEN(dev_priv) >= 7)
365 gen7_fbc_activate(dev_priv);
366 else if (INTEL_GEN(dev_priv) >= 5)
367 ilk_fbc_activate(dev_priv);
368 else if (IS_GM45(dev_priv))
369 g4x_fbc_activate(dev_priv);
371 i8xx_fbc_activate(dev_priv);
374 static void intel_fbc_hw_deactivate(struct drm_i915_private *dev_priv)
376 struct intel_fbc *fbc = &dev_priv->fbc;
380 if (INTEL_GEN(dev_priv) >= 5)
381 ilk_fbc_deactivate(dev_priv);
382 else if (IS_GM45(dev_priv))
383 g4x_fbc_deactivate(dev_priv);
385 i8xx_fbc_deactivate(dev_priv);
389 * intel_fbc_is_active - Is FBC active?
390 * @dev_priv: i915 device instance
392 * This function is used to verify the current state of FBC.
394 * FIXME: This should be tracked in the plane config eventually
395 * instead of queried at runtime for most callers.
397 bool intel_fbc_is_active(struct drm_i915_private *dev_priv)
399 return dev_priv->fbc.active;
402 static void intel_fbc_deactivate(struct drm_i915_private *dev_priv,
405 struct intel_fbc *fbc = &dev_priv->fbc;
407 WARN_ON(!mutex_is_locked(&fbc->lock));
410 intel_fbc_hw_deactivate(dev_priv);
412 fbc->no_fbc_reason = reason;
415 static bool multiple_pipes_ok(struct intel_crtc *crtc,
416 struct intel_plane_state *plane_state)
418 struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
419 struct intel_fbc *fbc = &dev_priv->fbc;
420 enum pipe pipe = crtc->pipe;
422 /* Don't even bother tracking anything we don't need. */
423 if (!no_fbc_on_multiple_pipes(dev_priv))
426 if (plane_state->base.visible)
427 fbc->visible_pipes_mask |= (1 << pipe);
429 fbc->visible_pipes_mask &= ~(1 << pipe);
431 return (fbc->visible_pipes_mask & ~(1 << pipe)) != 0;
434 static int find_compression_threshold(struct drm_i915_private *dev_priv,
435 struct drm_mm_node *node,
439 int compression_threshold = 1;
443 /* The FBC hardware for BDW/SKL doesn't have access to the stolen
444 * reserved range size, so it always assumes the maximum (8mb) is used.
445 * If we enable FBC using a CFB on that memory range we'll get FIFO
446 * underruns, even if that range is not reserved by the BIOS. */
447 if (IS_BROADWELL(dev_priv) || IS_GEN9_BC(dev_priv))
448 end = resource_size(&dev_priv->dsm) - 8 * 1024 * 1024;
452 /* HACK: This code depends on what we will do in *_enable_fbc. If that
453 * code changes, this code needs to change as well.
455 * The enable_fbc code will attempt to use one of our 2 compression
456 * thresholds, therefore, in that case, we only have 1 resort.
459 /* Try to over-allocate to reduce reallocations and fragmentation. */
460 ret = i915_gem_stolen_insert_node_in_range(dev_priv, node, size <<= 1,
463 return compression_threshold;
466 /* HW's ability to limit the CFB is 1:4 */
467 if (compression_threshold > 4 ||
468 (fb_cpp == 2 && compression_threshold == 2))
471 ret = i915_gem_stolen_insert_node_in_range(dev_priv, node, size >>= 1,
473 if (ret && INTEL_GEN(dev_priv) <= 4) {
476 compression_threshold <<= 1;
479 return compression_threshold;
483 static int intel_fbc_alloc_cfb(struct intel_crtc *crtc)
485 struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
486 struct intel_fbc *fbc = &dev_priv->fbc;
487 struct drm_mm_node *uninitialized_var(compressed_llb);
488 int size, fb_cpp, ret;
490 WARN_ON(drm_mm_node_allocated(&fbc->compressed_fb));
492 size = intel_fbc_calculate_cfb_size(dev_priv, &fbc->state_cache);
493 fb_cpp = fbc->state_cache.fb.format->cpp[0];
495 ret = find_compression_threshold(dev_priv, &fbc->compressed_fb,
500 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");
504 fbc->threshold = ret;
506 if (INTEL_GEN(dev_priv) >= 5)
507 I915_WRITE(ILK_DPFC_CB_BASE, fbc->compressed_fb.start);
508 else if (IS_GM45(dev_priv)) {
509 I915_WRITE(DPFC_CB_BASE, fbc->compressed_fb.start);
511 compressed_llb = kzalloc(sizeof(*compressed_llb), GFP_KERNEL);
515 ret = i915_gem_stolen_insert_node(dev_priv, compressed_llb,
520 fbc->compressed_llb = compressed_llb;
522 GEM_BUG_ON(range_overflows_t(u64, dev_priv->dsm.start,
523 fbc->compressed_fb.start,
525 GEM_BUG_ON(range_overflows_t(u64, dev_priv->dsm.start,
526 fbc->compressed_llb->start,
528 I915_WRITE(FBC_CFB_BASE,
529 dev_priv->dsm.start + fbc->compressed_fb.start);
530 I915_WRITE(FBC_LL_BASE,
531 dev_priv->dsm.start + compressed_llb->start);
534 DRM_DEBUG_KMS("reserved %llu bytes of contiguous stolen space for FBC, threshold: %d\n",
535 fbc->compressed_fb.size, fbc->threshold);
540 kfree(compressed_llb);
541 i915_gem_stolen_remove_node(dev_priv, &fbc->compressed_fb);
543 if (drm_mm_initialized(&dev_priv->mm.stolen))
544 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);
548 static void __intel_fbc_cleanup_cfb(struct drm_i915_private *dev_priv)
550 struct intel_fbc *fbc = &dev_priv->fbc;
552 if (drm_mm_node_allocated(&fbc->compressed_fb))
553 i915_gem_stolen_remove_node(dev_priv, &fbc->compressed_fb);
555 if (fbc->compressed_llb) {
556 i915_gem_stolen_remove_node(dev_priv, fbc->compressed_llb);
557 kfree(fbc->compressed_llb);
561 void intel_fbc_cleanup_cfb(struct drm_i915_private *dev_priv)
563 struct intel_fbc *fbc = &dev_priv->fbc;
565 if (!fbc_supported(dev_priv))
568 mutex_lock(&fbc->lock);
569 __intel_fbc_cleanup_cfb(dev_priv);
570 mutex_unlock(&fbc->lock);
573 static bool stride_is_valid(struct drm_i915_private *dev_priv,
576 /* This should have been caught earlier. */
577 if (WARN_ON_ONCE((stride & (64 - 1)) != 0))
580 /* Below are the additional FBC restrictions. */
584 if (IS_GEN2(dev_priv) || IS_GEN3(dev_priv))
585 return stride == 4096 || stride == 8192;
587 if (IS_GEN4(dev_priv) && !IS_G4X(dev_priv) && stride < 2048)
596 static bool pixel_format_is_valid(struct drm_i915_private *dev_priv,
597 uint32_t pixel_format)
599 switch (pixel_format) {
600 case DRM_FORMAT_XRGB8888:
601 case DRM_FORMAT_XBGR8888:
603 case DRM_FORMAT_XRGB1555:
604 case DRM_FORMAT_RGB565:
605 /* 16bpp not supported on gen2 */
606 if (IS_GEN2(dev_priv))
608 /* WaFbcOnly1to1Ratio:ctg */
609 if (IS_G4X(dev_priv))
618 * For some reason, the hardware tracking starts looking at whatever we
619 * programmed as the display plane base address register. It does not look at
620 * the X and Y offset registers. That's why we look at the crtc->adjusted{x,y}
621 * variables instead of just looking at the pipe/plane size.
623 static bool intel_fbc_hw_tracking_covers_screen(struct intel_crtc *crtc)
625 struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
626 struct intel_fbc *fbc = &dev_priv->fbc;
627 unsigned int effective_w, effective_h, max_w, max_h;
629 if (INTEL_GEN(dev_priv) >= 8 || IS_HASWELL(dev_priv)) {
632 } else if (IS_G4X(dev_priv) || INTEL_GEN(dev_priv) >= 5) {
640 intel_fbc_get_plane_source_size(&fbc->state_cache, &effective_w,
642 effective_w += fbc->state_cache.plane.adjusted_x;
643 effective_h += fbc->state_cache.plane.adjusted_y;
645 return effective_w <= max_w && effective_h <= max_h;
648 static void intel_fbc_update_state_cache(struct intel_crtc *crtc,
649 struct intel_crtc_state *crtc_state,
650 struct intel_plane_state *plane_state)
652 struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
653 struct intel_fbc *fbc = &dev_priv->fbc;
654 struct intel_fbc_state_cache *cache = &fbc->state_cache;
655 struct drm_framebuffer *fb = plane_state->base.fb;
660 cache->crtc.mode_flags = crtc_state->base.adjusted_mode.flags;
661 if (IS_HASWELL(dev_priv) || IS_BROADWELL(dev_priv))
662 cache->crtc.hsw_bdw_pixel_rate = crtc_state->pixel_rate;
664 cache->plane.rotation = plane_state->base.rotation;
666 * Src coordinates are already rotated by 270 degrees for
667 * the 90/270 degree plane rotation cases (to match the
668 * GTT mapping), hence no need to account for rotation here.
670 cache->plane.src_w = drm_rect_width(&plane_state->base.src) >> 16;
671 cache->plane.src_h = drm_rect_height(&plane_state->base.src) >> 16;
672 cache->plane.visible = plane_state->base.visible;
673 cache->plane.adjusted_x = plane_state->color_plane[0].x;
674 cache->plane.adjusted_y = plane_state->color_plane[0].y;
675 cache->plane.y = plane_state->base.src.y1 >> 16;
677 cache->plane.pixel_blend_mode = plane_state->base.pixel_blend_mode;
679 if (!cache->plane.visible)
682 cache->fb.format = fb->format;
683 cache->fb.stride = fb->pitches[0];
685 cache->vma = plane_state->vma;
686 cache->flags = plane_state->flags;
687 if (WARN_ON(cache->flags & PLANE_HAS_FENCE && !cache->vma->fence))
688 cache->flags &= ~PLANE_HAS_FENCE;
691 static bool intel_fbc_can_activate(struct intel_crtc *crtc)
693 struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
694 struct intel_fbc *fbc = &dev_priv->fbc;
695 struct intel_fbc_state_cache *cache = &fbc->state_cache;
697 /* We don't need to use a state cache here since this information is
698 * global for all CRTC.
700 if (fbc->underrun_detected) {
701 fbc->no_fbc_reason = "underrun detected";
706 fbc->no_fbc_reason = "primary plane not visible";
710 if (cache->crtc.mode_flags & DRM_MODE_FLAG_INTERLACE) {
711 fbc->no_fbc_reason = "incompatible mode";
715 if (!intel_fbc_hw_tracking_covers_screen(crtc)) {
716 fbc->no_fbc_reason = "mode too large for compression";
720 /* The use of a CPU fence is mandatory in order to detect writes
721 * by the CPU to the scanout and trigger updates to the FBC.
723 * Note that is possible for a tiled surface to be unmappable (and
724 * so have no fence associated with it) due to aperture constaints
725 * at the time of pinning.
727 * FIXME with 90/270 degree rotation we should use the fence on
728 * the normal GTT view (the rotated view doesn't even have a
729 * fence). Would need changes to the FBC fence Y offset as well.
730 * For now this will effecively disable FBC with 90/270 degree
733 if (!(cache->flags & PLANE_HAS_FENCE)) {
734 fbc->no_fbc_reason = "framebuffer not tiled or fenced";
737 if (INTEL_GEN(dev_priv) <= 4 && !IS_G4X(dev_priv) &&
738 cache->plane.rotation != DRM_MODE_ROTATE_0) {
739 fbc->no_fbc_reason = "rotation unsupported";
743 if (!stride_is_valid(dev_priv, cache->fb.stride)) {
744 fbc->no_fbc_reason = "framebuffer stride not supported";
748 if (!pixel_format_is_valid(dev_priv, cache->fb.format->format)) {
749 fbc->no_fbc_reason = "pixel format is invalid";
753 if (cache->plane.pixel_blend_mode != DRM_MODE_BLEND_PIXEL_NONE &&
754 cache->fb.format->has_alpha) {
755 fbc->no_fbc_reason = "per-pixel alpha blending is incompatible with FBC";
759 /* WaFbcExceedCdClockThreshold:hsw,bdw */
760 if ((IS_HASWELL(dev_priv) || IS_BROADWELL(dev_priv)) &&
761 cache->crtc.hsw_bdw_pixel_rate >= dev_priv->cdclk.hw.cdclk * 95 / 100) {
762 fbc->no_fbc_reason = "pixel rate is too big";
766 /* It is possible for the required CFB size change without a
767 * crtc->disable + crtc->enable since it is possible to change the
768 * stride without triggering a full modeset. Since we try to
769 * over-allocate the CFB, there's a chance we may keep FBC enabled even
770 * if this happens, but if we exceed the current CFB size we'll have to
771 * disable FBC. Notice that it would be possible to disable FBC, wait
772 * for a frame, free the stolen node, then try to reenable FBC in case
773 * we didn't get any invalidate/deactivate calls, but this would require
774 * a lot of tracking just for a specific case. If we conclude it's an
775 * important case, we can implement it later. */
776 if (intel_fbc_calculate_cfb_size(dev_priv, &fbc->state_cache) >
777 fbc->compressed_fb.size * fbc->threshold) {
778 fbc->no_fbc_reason = "CFB requirements changed";
783 * Work around a problem on GEN9+ HW, where enabling FBC on a plane
784 * having a Y offset that isn't divisible by 4 causes FIFO underrun
785 * and screen flicker.
787 if (IS_GEN(dev_priv, 9, 10) &&
788 (fbc->state_cache.plane.adjusted_y & 3)) {
789 fbc->no_fbc_reason = "plane Y offset is misaligned";
796 static bool intel_fbc_can_enable(struct drm_i915_private *dev_priv)
798 struct intel_fbc *fbc = &dev_priv->fbc;
800 if (intel_vgpu_active(dev_priv)) {
801 fbc->no_fbc_reason = "VGPU is active";
805 if (!i915_modparams.enable_fbc) {
806 fbc->no_fbc_reason = "disabled per module param or by default";
810 if (fbc->underrun_detected) {
811 fbc->no_fbc_reason = "underrun detected";
818 static void intel_fbc_get_reg_params(struct intel_crtc *crtc,
819 struct intel_fbc_reg_params *params)
821 struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
822 struct intel_fbc *fbc = &dev_priv->fbc;
823 struct intel_fbc_state_cache *cache = &fbc->state_cache;
825 /* Since all our fields are integer types, use memset here so the
826 * comparison function can rely on memcmp because the padding will be
828 memset(params, 0, sizeof(*params));
830 params->vma = cache->vma;
831 params->flags = cache->flags;
833 params->crtc.pipe = crtc->pipe;
834 params->crtc.i9xx_plane = to_intel_plane(crtc->base.primary)->i9xx_plane;
835 params->crtc.fence_y_offset = get_crtc_fence_y_offset(fbc);
837 params->fb.format = cache->fb.format;
838 params->fb.stride = cache->fb.stride;
840 params->cfb_size = intel_fbc_calculate_cfb_size(dev_priv, cache);
842 if (IS_GEN9(dev_priv) && !IS_GEMINILAKE(dev_priv))
843 params->gen9_wa_cfb_stride = DIV_ROUND_UP(cache->plane.src_w,
844 32 * fbc->threshold) * 8;
847 void intel_fbc_pre_update(struct intel_crtc *crtc,
848 struct intel_crtc_state *crtc_state,
849 struct intel_plane_state *plane_state)
851 struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
852 struct intel_fbc *fbc = &dev_priv->fbc;
853 const char *reason = "update pending";
855 if (!fbc_supported(dev_priv))
858 mutex_lock(&fbc->lock);
860 if (!multiple_pipes_ok(crtc, plane_state)) {
861 reason = "more than one pipe active";
865 if (!fbc->enabled || fbc->crtc != crtc)
868 intel_fbc_update_state_cache(crtc, crtc_state, plane_state);
869 fbc->flip_pending = true;
872 intel_fbc_deactivate(dev_priv, reason);
874 mutex_unlock(&fbc->lock);
878 * __intel_fbc_disable - disable FBC
879 * @dev_priv: i915 device instance
881 * This is the low level function that actually disables FBC. Callers should
884 static void __intel_fbc_disable(struct drm_i915_private *dev_priv)
886 struct intel_fbc *fbc = &dev_priv->fbc;
887 struct intel_crtc *crtc = fbc->crtc;
889 WARN_ON(!mutex_is_locked(&fbc->lock));
890 WARN_ON(!fbc->enabled);
891 WARN_ON(fbc->active);
893 DRM_DEBUG_KMS("Disabling FBC on pipe %c\n", pipe_name(crtc->pipe));
895 __intel_fbc_cleanup_cfb(dev_priv);
897 fbc->enabled = false;
901 static void __intel_fbc_post_update(struct intel_crtc *crtc)
903 struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
904 struct intel_fbc *fbc = &dev_priv->fbc;
906 WARN_ON(!mutex_is_locked(&fbc->lock));
908 if (!fbc->enabled || fbc->crtc != crtc)
911 fbc->flip_pending = false;
912 WARN_ON(fbc->active);
914 if (!i915_modparams.enable_fbc) {
915 intel_fbc_deactivate(dev_priv, "disabled at runtime per module param");
916 __intel_fbc_disable(dev_priv);
921 intel_fbc_get_reg_params(crtc, &fbc->params);
923 if (!intel_fbc_can_activate(crtc))
926 if (!fbc->busy_bits) {
927 intel_fbc_deactivate(dev_priv, "FBC enabled (active or scheduled)");
928 intel_fbc_hw_activate(dev_priv);
930 intel_fbc_deactivate(dev_priv, "frontbuffer write");
933 void intel_fbc_post_update(struct intel_crtc *crtc)
935 struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
936 struct intel_fbc *fbc = &dev_priv->fbc;
938 if (!fbc_supported(dev_priv))
941 mutex_lock(&fbc->lock);
942 __intel_fbc_post_update(crtc);
943 mutex_unlock(&fbc->lock);
946 static unsigned int intel_fbc_get_frontbuffer_bit(struct intel_fbc *fbc)
949 return to_intel_plane(fbc->crtc->base.primary)->frontbuffer_bit;
951 return fbc->possible_framebuffer_bits;
954 void intel_fbc_invalidate(struct drm_i915_private *dev_priv,
955 unsigned int frontbuffer_bits,
956 enum fb_op_origin origin)
958 struct intel_fbc *fbc = &dev_priv->fbc;
960 if (!fbc_supported(dev_priv))
963 if (origin == ORIGIN_GTT || origin == ORIGIN_FLIP)
966 mutex_lock(&fbc->lock);
968 fbc->busy_bits |= intel_fbc_get_frontbuffer_bit(fbc) & frontbuffer_bits;
970 if (fbc->enabled && fbc->busy_bits)
971 intel_fbc_deactivate(dev_priv, "frontbuffer write");
973 mutex_unlock(&fbc->lock);
976 void intel_fbc_flush(struct drm_i915_private *dev_priv,
977 unsigned int frontbuffer_bits, enum fb_op_origin origin)
979 struct intel_fbc *fbc = &dev_priv->fbc;
981 if (!fbc_supported(dev_priv))
984 mutex_lock(&fbc->lock);
986 fbc->busy_bits &= ~frontbuffer_bits;
988 if (origin == ORIGIN_GTT || origin == ORIGIN_FLIP)
991 if (!fbc->busy_bits && fbc->enabled &&
992 (frontbuffer_bits & intel_fbc_get_frontbuffer_bit(fbc))) {
994 intel_fbc_recompress(dev_priv);
995 else if (!fbc->flip_pending)
996 __intel_fbc_post_update(fbc->crtc);
1000 mutex_unlock(&fbc->lock);
1004 * intel_fbc_choose_crtc - select a CRTC to enable FBC on
1005 * @dev_priv: i915 device instance
1006 * @state: the atomic state structure
1008 * This function looks at the proposed state for CRTCs and planes, then chooses
1009 * which pipe is going to have FBC by setting intel_crtc_state->enable_fbc to
1012 * Later, intel_fbc_enable is going to look for state->enable_fbc and then maybe
1013 * enable FBC for the chosen CRTC. If it does, it will set dev_priv->fbc.crtc.
1015 void intel_fbc_choose_crtc(struct drm_i915_private *dev_priv,
1016 struct intel_atomic_state *state)
1018 struct intel_fbc *fbc = &dev_priv->fbc;
1019 struct intel_plane *plane;
1020 struct intel_plane_state *plane_state;
1021 bool crtc_chosen = false;
1024 mutex_lock(&fbc->lock);
1026 /* Does this atomic commit involve the CRTC currently tied to FBC? */
1028 !intel_atomic_get_new_crtc_state(state, fbc->crtc))
1031 if (!intel_fbc_can_enable(dev_priv))
1034 /* Simply choose the first CRTC that is compatible and has a visible
1035 * plane. We could go for fancier schemes such as checking the plane
1036 * size, but this would just affect the few platforms that don't tie FBC
1037 * to pipe or plane A. */
1038 for_each_new_intel_plane_in_state(state, plane, plane_state, i) {
1039 struct intel_crtc_state *crtc_state;
1040 struct intel_crtc *crtc = to_intel_crtc(plane_state->base.crtc);
1042 if (!plane->has_fbc)
1045 if (!plane_state->base.visible)
1048 crtc_state = intel_atomic_get_new_crtc_state(state, crtc);
1050 crtc_state->enable_fbc = true;
1056 fbc->no_fbc_reason = "no suitable CRTC for FBC";
1059 mutex_unlock(&fbc->lock);
1063 * intel_fbc_enable: tries to enable FBC on the CRTC
1065 * @crtc_state: corresponding &drm_crtc_state for @crtc
1066 * @plane_state: corresponding &drm_plane_state for the primary plane of @crtc
1068 * This function checks if the given CRTC was chosen for FBC, then enables it if
1069 * possible. Notice that it doesn't activate FBC. It is valid to call
1070 * intel_fbc_enable multiple times for the same pipe without an
1071 * intel_fbc_disable in the middle, as long as it is deactivated.
1073 void intel_fbc_enable(struct intel_crtc *crtc,
1074 struct intel_crtc_state *crtc_state,
1075 struct intel_plane_state *plane_state)
1077 struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
1078 struct intel_fbc *fbc = &dev_priv->fbc;
1080 if (!fbc_supported(dev_priv))
1083 mutex_lock(&fbc->lock);
1086 WARN_ON(fbc->crtc == NULL);
1087 if (fbc->crtc == crtc) {
1088 WARN_ON(!crtc_state->enable_fbc);
1089 WARN_ON(fbc->active);
1094 if (!crtc_state->enable_fbc)
1097 WARN_ON(fbc->active);
1098 WARN_ON(fbc->crtc != NULL);
1100 intel_fbc_update_state_cache(crtc, crtc_state, plane_state);
1101 if (intel_fbc_alloc_cfb(crtc)) {
1102 fbc->no_fbc_reason = "not enough stolen memory";
1106 DRM_DEBUG_KMS("Enabling FBC on pipe %c\n", pipe_name(crtc->pipe));
1107 fbc->no_fbc_reason = "FBC enabled but not active yet\n";
1109 fbc->enabled = true;
1112 mutex_unlock(&fbc->lock);
1116 * intel_fbc_disable - disable FBC if it's associated with crtc
1119 * This function disables FBC if it's associated with the provided CRTC.
1121 void intel_fbc_disable(struct intel_crtc *crtc)
1123 struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
1124 struct intel_fbc *fbc = &dev_priv->fbc;
1126 if (!fbc_supported(dev_priv))
1129 WARN_ON(crtc->active);
1131 mutex_lock(&fbc->lock);
1132 if (fbc->crtc == crtc)
1133 __intel_fbc_disable(dev_priv);
1134 mutex_unlock(&fbc->lock);
1138 * intel_fbc_global_disable - globally disable FBC
1139 * @dev_priv: i915 device instance
1141 * This function disables FBC regardless of which CRTC is associated with it.
1143 void intel_fbc_global_disable(struct drm_i915_private *dev_priv)
1145 struct intel_fbc *fbc = &dev_priv->fbc;
1147 if (!fbc_supported(dev_priv))
1150 mutex_lock(&fbc->lock);
1152 WARN_ON(fbc->crtc->active);
1153 __intel_fbc_disable(dev_priv);
1155 mutex_unlock(&fbc->lock);
1158 static void intel_fbc_underrun_work_fn(struct work_struct *work)
1160 struct drm_i915_private *dev_priv =
1161 container_of(work, struct drm_i915_private, fbc.underrun_work);
1162 struct intel_fbc *fbc = &dev_priv->fbc;
1164 mutex_lock(&fbc->lock);
1166 /* Maybe we were scheduled twice. */
1167 if (fbc->underrun_detected || !fbc->enabled)
1170 DRM_DEBUG_KMS("Disabling FBC due to FIFO underrun.\n");
1171 fbc->underrun_detected = true;
1173 intel_fbc_deactivate(dev_priv, "FIFO underrun");
1175 mutex_unlock(&fbc->lock);
1179 * intel_fbc_reset_underrun - reset FBC fifo underrun status.
1180 * @dev_priv: i915 device instance
1182 * See intel_fbc_handle_fifo_underrun_irq(). For automated testing we
1183 * want to re-enable FBC after an underrun to increase test coverage.
1185 int intel_fbc_reset_underrun(struct drm_i915_private *dev_priv)
1189 cancel_work_sync(&dev_priv->fbc.underrun_work);
1191 ret = mutex_lock_interruptible(&dev_priv->fbc.lock);
1195 if (dev_priv->fbc.underrun_detected) {
1196 DRM_DEBUG_KMS("Re-allowing FBC after fifo underrun\n");
1197 dev_priv->fbc.no_fbc_reason = "FIFO underrun cleared";
1200 dev_priv->fbc.underrun_detected = false;
1201 mutex_unlock(&dev_priv->fbc.lock);
1207 * intel_fbc_handle_fifo_underrun_irq - disable FBC when we get a FIFO underrun
1208 * @dev_priv: i915 device instance
1210 * Without FBC, most underruns are harmless and don't really cause too many
1211 * problems, except for an annoying message on dmesg. With FBC, underruns can
1212 * become black screens or even worse, especially when paired with bad
1213 * watermarks. So in order for us to be on the safe side, completely disable FBC
1214 * in case we ever detect a FIFO underrun on any pipe. An underrun on any pipe
1215 * already suggests that watermarks may be bad, so try to be as safe as
1218 * This function is called from the IRQ handler.
1220 void intel_fbc_handle_fifo_underrun_irq(struct drm_i915_private *dev_priv)
1222 struct intel_fbc *fbc = &dev_priv->fbc;
1224 if (!fbc_supported(dev_priv))
1227 /* There's no guarantee that underrun_detected won't be set to true
1228 * right after this check and before the work is scheduled, but that's
1229 * not a problem since we'll check it again under the work function
1230 * while FBC is locked. This check here is just to prevent us from
1231 * unnecessarily scheduling the work, and it relies on the fact that we
1232 * never switch underrun_detect back to false after it's true. */
1233 if (READ_ONCE(fbc->underrun_detected))
1236 schedule_work(&fbc->underrun_work);
1240 * intel_fbc_init_pipe_state - initialize FBC's CRTC visibility tracking
1241 * @dev_priv: i915 device instance
1243 * The FBC code needs to track CRTC visibility since the older platforms can't
1244 * have FBC enabled while multiple pipes are used. This function does the
1245 * initial setup at driver load to make sure FBC is matching the real hardware.
1247 void intel_fbc_init_pipe_state(struct drm_i915_private *dev_priv)
1249 struct intel_crtc *crtc;
1251 /* Don't even bother tracking anything if we don't need. */
1252 if (!no_fbc_on_multiple_pipes(dev_priv))
1255 for_each_intel_crtc(&dev_priv->drm, crtc)
1256 if (intel_crtc_active(crtc) &&
1257 crtc->base.primary->state->visible)
1258 dev_priv->fbc.visible_pipes_mask |= (1 << crtc->pipe);
1262 * The DDX driver changes its behavior depending on the value it reads from
1263 * i915.enable_fbc, so sanitize it by translating the default value into either
1264 * 0 or 1 in order to allow it to know what's going on.
1266 * Notice that this is done at driver initialization and we still allow user
1267 * space to change the value during runtime without sanitizing it again. IGT
1268 * relies on being able to change i915.enable_fbc at runtime.
1270 static int intel_sanitize_fbc_option(struct drm_i915_private *dev_priv)
1272 if (i915_modparams.enable_fbc >= 0)
1273 return !!i915_modparams.enable_fbc;
1275 if (!HAS_FBC(dev_priv))
1278 if (IS_BROADWELL(dev_priv) || INTEL_GEN(dev_priv) >= 9)
1284 static bool need_fbc_vtd_wa(struct drm_i915_private *dev_priv)
1286 /* WaFbcTurnOffFbcWhenHyperVisorIsUsed:skl,bxt */
1287 if (intel_vtd_active() &&
1288 (IS_SKYLAKE(dev_priv) || IS_BROXTON(dev_priv))) {
1289 DRM_INFO("Disabling framebuffer compression (FBC) to prevent screen flicker with VT-d enabled\n");
1297 * intel_fbc_init - Initialize FBC
1298 * @dev_priv: the i915 device
1300 * This function might be called during PM init process.
1302 void intel_fbc_init(struct drm_i915_private *dev_priv)
1304 struct intel_fbc *fbc = &dev_priv->fbc;
1306 INIT_WORK(&fbc->underrun_work, intel_fbc_underrun_work_fn);
1307 mutex_init(&fbc->lock);
1308 fbc->enabled = false;
1309 fbc->active = false;
1311 if (need_fbc_vtd_wa(dev_priv))
1312 mkwrite_device_info(dev_priv)->display.has_fbc = false;
1314 i915_modparams.enable_fbc = intel_sanitize_fbc_option(dev_priv);
1315 DRM_DEBUG_KMS("Sanitized enable_fbc value: %d\n",
1316 i915_modparams.enable_fbc);
1318 if (!HAS_FBC(dev_priv)) {
1319 fbc->no_fbc_reason = "unsupported by this chipset";
1323 /* This value was pulled out of someone's hat */
1324 if (INTEL_GEN(dev_priv) <= 4 && !IS_GM45(dev_priv))
1325 I915_WRITE(FBC_CONTROL, 500 << FBC_CTL_INTERVAL_SHIFT);
1327 /* We still don't have any sort of hardware state readout for FBC, so
1328 * deactivate it in case the BIOS activated it to make sure software
1329 * matches the hardware state. */
1330 if (intel_fbc_hw_is_active(dev_priv))
1331 intel_fbc_hw_deactivate(dev_priv);