1/*
2 * Copyright © 2014 Intel Corporation
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
21 * DEALINGS IN THE SOFTWARE.
22 */
23
24/**
25 * DOC: Frame Buffer Compression (FBC)
26 *
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.
30 *
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.
34 *
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.
39 */
40
41#include "intel_drv.h"
42#include "i915_drv.h"
43
44static void i8xx_fbc_disable(struct drm_device *dev)
45{
46	struct drm_i915_private *dev_priv = dev->dev_private;
47	u32 fbc_ctl;
48
49	dev_priv->fbc.enabled = false;
50
51	/* Disable compression */
52	fbc_ctl = I915_READ(FBC_CONTROL);
53	if ((fbc_ctl & FBC_CTL_EN) == 0)
54		return;
55
56	fbc_ctl &= ~FBC_CTL_EN;
57	I915_WRITE(FBC_CONTROL, fbc_ctl);
58
59	/* Wait for compressing bit to clear */
60	if (wait_for((I915_READ(FBC_STATUS) & FBC_STAT_COMPRESSING) == 0, 10)) {
61		DRM_DEBUG_KMS("FBC idle timed out\n");
62		return;
63	}
64
65	DRM_DEBUG_KMS("disabled FBC\n");
66}
67
68static void i8xx_fbc_enable(struct drm_crtc *crtc)
69{
70	struct drm_device *dev = crtc->dev;
71	struct drm_i915_private *dev_priv = dev->dev_private;
72	struct drm_framebuffer *fb = crtc->primary->fb;
73	struct drm_i915_gem_object *obj = intel_fb_obj(fb);
74	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
75	int cfb_pitch;
76	int i;
77	u32 fbc_ctl;
78
79	dev_priv->fbc.enabled = true;
80
81	/* Note: fbc.threshold == 1 for i8xx */
82	cfb_pitch = dev_priv->fbc.uncompressed_size / FBC_LL_SIZE;
83	if (fb->pitches[0] < cfb_pitch)
84		cfb_pitch = fb->pitches[0];
85
86	/* FBC_CTL wants 32B or 64B units */
87	if (IS_GEN2(dev))
88		cfb_pitch = (cfb_pitch / 32) - 1;
89	else
90		cfb_pitch = (cfb_pitch / 64) - 1;
91
92	/* Clear old tags */
93	for (i = 0; i < (FBC_LL_SIZE / 32) + 1; i++)
94		I915_WRITE(FBC_TAG + (i * 4), 0);
95
96	if (IS_GEN4(dev)) {
97		u32 fbc_ctl2;
98
99		/* Set it up... */
100		fbc_ctl2 = FBC_CTL_FENCE_DBL | FBC_CTL_IDLE_IMM | FBC_CTL_CPU_FENCE;
101		fbc_ctl2 |= FBC_CTL_PLANE(intel_crtc->plane);
102		I915_WRITE(FBC_CONTROL2, fbc_ctl2);
103		I915_WRITE(FBC_FENCE_OFF, crtc->y);
104	}
105
106	/* enable it... */
107	fbc_ctl = I915_READ(FBC_CONTROL);
108	fbc_ctl &= 0x3fff << FBC_CTL_INTERVAL_SHIFT;
109	fbc_ctl |= FBC_CTL_EN | FBC_CTL_PERIODIC;
110	if (IS_I945GM(dev))
111		fbc_ctl |= FBC_CTL_C3_IDLE; /* 945 needs special SR handling */
112	fbc_ctl |= (cfb_pitch & 0xff) << FBC_CTL_STRIDE_SHIFT;
113	fbc_ctl |= obj->fence_reg;
114	I915_WRITE(FBC_CONTROL, fbc_ctl);
115
116	DRM_DEBUG_KMS("enabled FBC, pitch %d, yoff %d, plane %c\n",
117		      cfb_pitch, crtc->y, plane_name(intel_crtc->plane));
118}
119
120static bool i8xx_fbc_enabled(struct drm_device *dev)
121{
122	struct drm_i915_private *dev_priv = dev->dev_private;
123
124	return I915_READ(FBC_CONTROL) & FBC_CTL_EN;
125}
126
127static void g4x_fbc_enable(struct drm_crtc *crtc)
128{
129	struct drm_device *dev = crtc->dev;
130	struct drm_i915_private *dev_priv = dev->dev_private;
131	struct drm_framebuffer *fb = crtc->primary->fb;
132	struct drm_i915_gem_object *obj = intel_fb_obj(fb);
133	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
134	u32 dpfc_ctl;
135
136	dev_priv->fbc.enabled = true;
137
138	dpfc_ctl = DPFC_CTL_PLANE(intel_crtc->plane) | DPFC_SR_EN;
139	if (drm_format_plane_cpp(fb->pixel_format, 0) == 2)
140		dpfc_ctl |= DPFC_CTL_LIMIT_2X;
141	else
142		dpfc_ctl |= DPFC_CTL_LIMIT_1X;
143	dpfc_ctl |= DPFC_CTL_FENCE_EN | obj->fence_reg;
144
145	I915_WRITE(DPFC_FENCE_YOFF, crtc->y);
146
147	/* enable it... */
148	I915_WRITE(DPFC_CONTROL, dpfc_ctl | DPFC_CTL_EN);
149
150	DRM_DEBUG_KMS("enabled fbc on plane %c\n", plane_name(intel_crtc->plane));
151}
152
153static void g4x_fbc_disable(struct drm_device *dev)
154{
155	struct drm_i915_private *dev_priv = dev->dev_private;
156	u32 dpfc_ctl;
157
158	dev_priv->fbc.enabled = false;
159
160	/* Disable compression */
161	dpfc_ctl = I915_READ(DPFC_CONTROL);
162	if (dpfc_ctl & DPFC_CTL_EN) {
163		dpfc_ctl &= ~DPFC_CTL_EN;
164		I915_WRITE(DPFC_CONTROL, dpfc_ctl);
165
166		DRM_DEBUG_KMS("disabled FBC\n");
167	}
168}
169
170static bool g4x_fbc_enabled(struct drm_device *dev)
171{
172	struct drm_i915_private *dev_priv = dev->dev_private;
173
174	return I915_READ(DPFC_CONTROL) & DPFC_CTL_EN;
175}
176
177static void intel_fbc_nuke(struct drm_i915_private *dev_priv)
178{
179	I915_WRITE(MSG_FBC_REND_STATE, FBC_REND_NUKE);
180	POSTING_READ(MSG_FBC_REND_STATE);
181}
182
183static void ilk_fbc_enable(struct drm_crtc *crtc)
184{
185	struct drm_device *dev = crtc->dev;
186	struct drm_i915_private *dev_priv = dev->dev_private;
187	struct drm_framebuffer *fb = crtc->primary->fb;
188	struct drm_i915_gem_object *obj = intel_fb_obj(fb);
189	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
190	u32 dpfc_ctl;
191
192	dev_priv->fbc.enabled = true;
193
194	dpfc_ctl = DPFC_CTL_PLANE(intel_crtc->plane);
195	if (drm_format_plane_cpp(fb->pixel_format, 0) == 2)
196		dev_priv->fbc.threshold++;
197
198	switch (dev_priv->fbc.threshold) {
199	case 4:
200	case 3:
201		dpfc_ctl |= DPFC_CTL_LIMIT_4X;
202		break;
203	case 2:
204		dpfc_ctl |= DPFC_CTL_LIMIT_2X;
205		break;
206	case 1:
207		dpfc_ctl |= DPFC_CTL_LIMIT_1X;
208		break;
209	}
210	dpfc_ctl |= DPFC_CTL_FENCE_EN;
211	if (IS_GEN5(dev))
212		dpfc_ctl |= obj->fence_reg;
213
214	I915_WRITE(ILK_DPFC_FENCE_YOFF, crtc->y);
215	I915_WRITE(ILK_FBC_RT_BASE, i915_gem_obj_ggtt_offset(obj) | ILK_FBC_RT_VALID);
216	/* enable it... */
217	I915_WRITE(ILK_DPFC_CONTROL, dpfc_ctl | DPFC_CTL_EN);
218
219	if (IS_GEN6(dev)) {
220		I915_WRITE(SNB_DPFC_CTL_SA,
221			   SNB_CPU_FENCE_ENABLE | obj->fence_reg);
222		I915_WRITE(DPFC_CPU_FENCE_OFFSET, crtc->y);
223	}
224
225	intel_fbc_nuke(dev_priv);
226
227	DRM_DEBUG_KMS("enabled fbc on plane %c\n", plane_name(intel_crtc->plane));
228}
229
230static void ilk_fbc_disable(struct drm_device *dev)
231{
232	struct drm_i915_private *dev_priv = dev->dev_private;
233	u32 dpfc_ctl;
234
235	dev_priv->fbc.enabled = false;
236
237	/* Disable compression */
238	dpfc_ctl = I915_READ(ILK_DPFC_CONTROL);
239	if (dpfc_ctl & DPFC_CTL_EN) {
240		dpfc_ctl &= ~DPFC_CTL_EN;
241		I915_WRITE(ILK_DPFC_CONTROL, dpfc_ctl);
242
243		DRM_DEBUG_KMS("disabled FBC\n");
244	}
245}
246
247static bool ilk_fbc_enabled(struct drm_device *dev)
248{
249	struct drm_i915_private *dev_priv = dev->dev_private;
250
251	return I915_READ(ILK_DPFC_CONTROL) & DPFC_CTL_EN;
252}
253
254static void gen7_fbc_enable(struct drm_crtc *crtc)
255{
256	struct drm_device *dev = crtc->dev;
257	struct drm_i915_private *dev_priv = dev->dev_private;
258	struct drm_framebuffer *fb = crtc->primary->fb;
259	struct drm_i915_gem_object *obj = intel_fb_obj(fb);
260	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
261	u32 dpfc_ctl;
262
263	dev_priv->fbc.enabled = true;
264
265	dpfc_ctl = IVB_DPFC_CTL_PLANE(intel_crtc->plane);
266	if (drm_format_plane_cpp(fb->pixel_format, 0) == 2)
267		dev_priv->fbc.threshold++;
268
269	switch (dev_priv->fbc.threshold) {
270	case 4:
271	case 3:
272		dpfc_ctl |= DPFC_CTL_LIMIT_4X;
273		break;
274	case 2:
275		dpfc_ctl |= DPFC_CTL_LIMIT_2X;
276		break;
277	case 1:
278		dpfc_ctl |= DPFC_CTL_LIMIT_1X;
279		break;
280	}
281
282	dpfc_ctl |= IVB_DPFC_CTL_FENCE_EN;
283
284	if (dev_priv->fbc.false_color)
285		dpfc_ctl |= FBC_CTL_FALSE_COLOR;
286
287	I915_WRITE(ILK_DPFC_CONTROL, dpfc_ctl | DPFC_CTL_EN);
288
289	if (IS_IVYBRIDGE(dev)) {
290		/* WaFbcAsynchFlipDisableFbcQueue:ivb */
291		I915_WRITE(ILK_DISPLAY_CHICKEN1,
292			   I915_READ(ILK_DISPLAY_CHICKEN1) |
293			   ILK_FBCQ_DIS);
294	} else {
295		/* WaFbcAsynchFlipDisableFbcQueue:hsw,bdw */
296		I915_WRITE(CHICKEN_PIPESL_1(intel_crtc->pipe),
297			   I915_READ(CHICKEN_PIPESL_1(intel_crtc->pipe)) |
298			   HSW_FBCQ_DIS);
299	}
300
301	I915_WRITE(SNB_DPFC_CTL_SA,
302		   SNB_CPU_FENCE_ENABLE | obj->fence_reg);
303	I915_WRITE(DPFC_CPU_FENCE_OFFSET, crtc->y);
304
305	intel_fbc_nuke(dev_priv);
306
307	DRM_DEBUG_KMS("enabled fbc on plane %c\n", plane_name(intel_crtc->plane));
308}
309
310/**
311 * intel_fbc_enabled - Is FBC enabled?
312 * @dev: the drm_device
313 *
314 * This function is used to verify the current state of FBC.
315 * FIXME: This should be tracked in the plane config eventually
316 *        instead of queried at runtime for most callers.
317 */
318bool intel_fbc_enabled(struct drm_device *dev)
319{
320	struct drm_i915_private *dev_priv = dev->dev_private;
321
322	return dev_priv->fbc.enabled;
323}
324
325static void intel_fbc_work_fn(struct work_struct *__work)
326{
327	struct intel_fbc_work *work =
328		container_of(to_delayed_work(__work),
329			     struct intel_fbc_work, work);
330	struct drm_device *dev = work->crtc->dev;
331	struct drm_i915_private *dev_priv = dev->dev_private;
332
333	mutex_lock(&dev->struct_mutex);
334	if (work == dev_priv->fbc.fbc_work) {
335		/* Double check that we haven't switched fb without cancelling
336		 * the prior work.
337		 */
338		if (work->crtc->primary->fb == work->fb) {
339			dev_priv->display.enable_fbc(work->crtc);
340
341			dev_priv->fbc.crtc = to_intel_crtc(work->crtc);
342			dev_priv->fbc.fb_id = work->crtc->primary->fb->base.id;
343			dev_priv->fbc.y = work->crtc->y;
344		}
345
346		dev_priv->fbc.fbc_work = NULL;
347	}
348	mutex_unlock(&dev->struct_mutex);
349
350	kfree(work);
351}
352
353static void intel_fbc_cancel_work(struct drm_i915_private *dev_priv)
354{
355	if (dev_priv->fbc.fbc_work == NULL)
356		return;
357
358	DRM_DEBUG_KMS("cancelling pending FBC enable\n");
359
360	/* Synchronisation is provided by struct_mutex and checking of
361	 * dev_priv->fbc.fbc_work, so we can perform the cancellation
362	 * entirely asynchronously.
363	 */
364	if (cancel_delayed_work(&dev_priv->fbc.fbc_work->work))
365		/* tasklet was killed before being run, clean up */
366		kfree(dev_priv->fbc.fbc_work);
367
368	/* Mark the work as no longer wanted so that if it does
369	 * wake-up (because the work was already running and waiting
370	 * for our mutex), it will discover that is no longer
371	 * necessary to run.
372	 */
373	dev_priv->fbc.fbc_work = NULL;
374}
375
376static void intel_fbc_enable(struct drm_crtc *crtc)
377{
378	struct intel_fbc_work *work;
379	struct drm_device *dev = crtc->dev;
380	struct drm_i915_private *dev_priv = dev->dev_private;
381
382	if (!dev_priv->display.enable_fbc)
383		return;
384
385	intel_fbc_cancel_work(dev_priv);
386
387	work = kzalloc(sizeof(*work), GFP_KERNEL);
388	if (work == NULL) {
389		DRM_ERROR("Failed to allocate FBC work structure\n");
390		dev_priv->display.enable_fbc(crtc);
391		return;
392	}
393
394	work->crtc = crtc;
395	work->fb = crtc->primary->fb;
396	INIT_DELAYED_WORK(&work->work, intel_fbc_work_fn);
397
398	dev_priv->fbc.fbc_work = work;
399
400	/* Delay the actual enabling to let pageflipping cease and the
401	 * display to settle before starting the compression. Note that
402	 * this delay also serves a second purpose: it allows for a
403	 * vblank to pass after disabling the FBC before we attempt
404	 * to modify the control registers.
405	 *
406	 * A more complicated solution would involve tracking vblanks
407	 * following the termination of the page-flipping sequence
408	 * and indeed performing the enable as a co-routine and not
409	 * waiting synchronously upon the vblank.
410	 *
411	 * WaFbcWaitForVBlankBeforeEnable:ilk,snb
412	 */
413	schedule_delayed_work(&work->work, msecs_to_jiffies(50));
414}
415
416/**
417 * intel_fbc_disable - disable FBC
418 * @dev: the drm_device
419 *
420 * This function disables FBC.
421 */
422void intel_fbc_disable(struct drm_device *dev)
423{
424	struct drm_i915_private *dev_priv = dev->dev_private;
425
426	intel_fbc_cancel_work(dev_priv);
427
428	if (!dev_priv->display.disable_fbc)
429		return;
430
431	dev_priv->display.disable_fbc(dev);
432	dev_priv->fbc.crtc = NULL;
433}
434
435static bool set_no_fbc_reason(struct drm_i915_private *dev_priv,
436			      enum no_fbc_reason reason)
437{
438	if (dev_priv->fbc.no_fbc_reason == reason)
439		return false;
440
441	dev_priv->fbc.no_fbc_reason = reason;
442	return true;
443}
444
445static struct drm_crtc *intel_fbc_find_crtc(struct drm_i915_private *dev_priv)
446{
447	struct drm_crtc *crtc = NULL, *tmp_crtc;
448	enum pipe pipe;
449	bool pipe_a_only = false, one_pipe_only = false;
450
451	if (IS_HASWELL(dev_priv) || INTEL_INFO(dev_priv)->gen >= 8)
452		pipe_a_only = true;
453	else if (INTEL_INFO(dev_priv)->gen <= 4)
454		one_pipe_only = true;
455
456	for_each_pipe(dev_priv, pipe) {
457		tmp_crtc = dev_priv->pipe_to_crtc_mapping[pipe];
458
459		if (intel_crtc_active(tmp_crtc) &&
460		    to_intel_crtc(tmp_crtc)->primary_enabled) {
461			if (one_pipe_only && crtc) {
462				if (set_no_fbc_reason(dev_priv, FBC_MULTIPLE_PIPES))
463					DRM_DEBUG_KMS("more than one pipe active, disabling compression\n");
464				return NULL;
465			}
466			crtc = tmp_crtc;
467		}
468
469		if (pipe_a_only)
470			break;
471	}
472
473	if (!crtc || crtc->primary->fb == NULL) {
474		if (set_no_fbc_reason(dev_priv, FBC_NO_OUTPUT))
475			DRM_DEBUG_KMS("no output, disabling\n");
476		return NULL;
477	}
478
479	return crtc;
480}
481
482/**
483 * intel_fbc_update - enable/disable FBC as needed
484 * @dev: the drm_device
485 *
486 * Set up the framebuffer compression hardware at mode set time.  We
487 * enable it if possible:
488 *   - plane A only (on pre-965)
489 *   - no pixel mulitply/line duplication
490 *   - no alpha buffer discard
491 *   - no dual wide
492 *   - framebuffer <= max_hdisplay in width, max_vdisplay in height
493 *
494 * We can't assume that any compression will take place (worst case),
495 * so the compressed buffer has to be the same size as the uncompressed
496 * one.  It also must reside (along with the line length buffer) in
497 * stolen memory.
498 *
499 * We need to enable/disable FBC on a global basis.
500 */
501void intel_fbc_update(struct drm_device *dev)
502{
503	struct drm_i915_private *dev_priv = dev->dev_private;
504	struct drm_crtc *crtc = NULL;
505	struct intel_crtc *intel_crtc;
506	struct drm_framebuffer *fb;
507	struct drm_i915_gem_object *obj;
508	const struct drm_display_mode *adjusted_mode;
509	unsigned int max_width, max_height;
510
511	if (!HAS_FBC(dev))
512		return;
513
514	/* disable framebuffer compression in vGPU */
515	if (intel_vgpu_active(dev))
516		i915.enable_fbc = 0;
517
518	if (i915.enable_fbc < 0) {
519		if (set_no_fbc_reason(dev_priv, FBC_CHIP_DEFAULT))
520			DRM_DEBUG_KMS("disabled per chip default\n");
521		goto out_disable;
522	}
523
524	if (!i915.enable_fbc) {
525		if (set_no_fbc_reason(dev_priv, FBC_MODULE_PARAM))
526			DRM_DEBUG_KMS("fbc disabled per module param\n");
527		goto out_disable;
528	}
529
530	/*
531	 * If FBC is already on, we just have to verify that we can
532	 * keep it that way...
533	 * Need to disable if:
534	 *   - more than one pipe is active
535	 *   - changing FBC params (stride, fence, mode)
536	 *   - new fb is too large to fit in compressed buffer
537	 *   - going to an unsupported config (interlace, pixel multiply, etc.)
538	 */
539	crtc = intel_fbc_find_crtc(dev_priv);
540	if (!crtc)
541		goto out_disable;
542
543	intel_crtc = to_intel_crtc(crtc);
544	fb = crtc->primary->fb;
545	obj = intel_fb_obj(fb);
546	adjusted_mode = &intel_crtc->config->base.adjusted_mode;
547
548	if ((adjusted_mode->flags & DRM_MODE_FLAG_INTERLACE) ||
549	    (adjusted_mode->flags & DRM_MODE_FLAG_DBLSCAN)) {
550		if (set_no_fbc_reason(dev_priv, FBC_UNSUPPORTED_MODE))
551			DRM_DEBUG_KMS("mode incompatible with compression, "
552				      "disabling\n");
553		goto out_disable;
554	}
555
556	if (INTEL_INFO(dev)->gen >= 8 || IS_HASWELL(dev)) {
557		max_width = 4096;
558		max_height = 4096;
559	} else if (IS_G4X(dev) || INTEL_INFO(dev)->gen >= 5) {
560		max_width = 4096;
561		max_height = 2048;
562	} else {
563		max_width = 2048;
564		max_height = 1536;
565	}
566	if (intel_crtc->config->pipe_src_w > max_width ||
567	    intel_crtc->config->pipe_src_h > max_height) {
568		if (set_no_fbc_reason(dev_priv, FBC_MODE_TOO_LARGE))
569			DRM_DEBUG_KMS("mode too large for compression, disabling\n");
570		goto out_disable;
571	}
572	if ((INTEL_INFO(dev)->gen < 4 || HAS_DDI(dev)) &&
573	    intel_crtc->plane != PLANE_A) {
574		if (set_no_fbc_reason(dev_priv, FBC_BAD_PLANE))
575			DRM_DEBUG_KMS("plane not A, disabling compression\n");
576		goto out_disable;
577	}
578
579	/* The use of a CPU fence is mandatory in order to detect writes
580	 * by the CPU to the scanout and trigger updates to the FBC.
581	 */
582	if (obj->tiling_mode != I915_TILING_X ||
583	    obj->fence_reg == I915_FENCE_REG_NONE) {
584		if (set_no_fbc_reason(dev_priv, FBC_NOT_TILED))
585			DRM_DEBUG_KMS("framebuffer not tiled or fenced, disabling compression\n");
586		goto out_disable;
587	}
588	if (INTEL_INFO(dev)->gen <= 4 && !IS_G4X(dev) &&
589	    crtc->primary->state->rotation != BIT(DRM_ROTATE_0)) {
590		if (set_no_fbc_reason(dev_priv, FBC_UNSUPPORTED_MODE))
591			DRM_DEBUG_KMS("Rotation unsupported, disabling\n");
592		goto out_disable;
593	}
594
595	/* If the kernel debugger is active, always disable compression */
596	if (in_dbg_master())
597		goto out_disable;
598
599	if (i915_gem_stolen_setup_compression(dev, obj->base.size,
600					      drm_format_plane_cpp(fb->pixel_format, 0))) {
601		if (set_no_fbc_reason(dev_priv, FBC_STOLEN_TOO_SMALL))
602			DRM_DEBUG_KMS("framebuffer too large, disabling compression\n");
603		goto out_disable;
604	}
605
606	/* If the scanout has not changed, don't modify the FBC settings.
607	 * Note that we make the fundamental assumption that the fb->obj
608	 * cannot be unpinned (and have its GTT offset and fence revoked)
609	 * without first being decoupled from the scanout and FBC disabled.
610	 */
611	if (dev_priv->fbc.crtc == intel_crtc &&
612	    dev_priv->fbc.fb_id == fb->base.id &&
613	    dev_priv->fbc.y == crtc->y)
614		return;
615
616	if (intel_fbc_enabled(dev)) {
617		/* We update FBC along two paths, after changing fb/crtc
618		 * configuration (modeswitching) and after page-flipping
619		 * finishes. For the latter, we know that not only did
620		 * we disable the FBC at the start of the page-flip
621		 * sequence, but also more than one vblank has passed.
622		 *
623		 * For the former case of modeswitching, it is possible
624		 * to switch between two FBC valid configurations
625		 * instantaneously so we do need to disable the FBC
626		 * before we can modify its control registers. We also
627		 * have to wait for the next vblank for that to take
628		 * effect. However, since we delay enabling FBC we can
629		 * assume that a vblank has passed since disabling and
630		 * that we can safely alter the registers in the deferred
631		 * callback.
632		 *
633		 * In the scenario that we go from a valid to invalid
634		 * and then back to valid FBC configuration we have
635		 * no strict enforcement that a vblank occurred since
636		 * disabling the FBC. However, along all current pipe
637		 * disabling paths we do need to wait for a vblank at
638		 * some point. And we wait before enabling FBC anyway.
639		 */
640		DRM_DEBUG_KMS("disabling active FBC for update\n");
641		intel_fbc_disable(dev);
642	}
643
644	intel_fbc_enable(crtc);
645	dev_priv->fbc.no_fbc_reason = FBC_OK;
646	return;
647
648out_disable:
649	/* Multiple disables should be harmless */
650	if (intel_fbc_enabled(dev)) {
651		DRM_DEBUG_KMS("unsupported config, disabling FBC\n");
652		intel_fbc_disable(dev);
653	}
654	i915_gem_stolen_cleanup_compression(dev);
655}
656
657void intel_fbc_invalidate(struct drm_i915_private *dev_priv,
658			  unsigned int frontbuffer_bits,
659			  enum fb_op_origin origin)
660{
661	struct drm_device *dev = dev_priv->dev;
662	unsigned int fbc_bits;
663
664	if (origin == ORIGIN_GTT)
665		return;
666
667	if (dev_priv->fbc.enabled)
668		fbc_bits = INTEL_FRONTBUFFER_PRIMARY(dev_priv->fbc.crtc->pipe);
669	else if (dev_priv->fbc.fbc_work)
670		fbc_bits = INTEL_FRONTBUFFER_PRIMARY(
671			to_intel_crtc(dev_priv->fbc.fbc_work->crtc)->pipe);
672	else
673		fbc_bits = dev_priv->fbc.possible_framebuffer_bits;
674
675	dev_priv->fbc.busy_bits |= (fbc_bits & frontbuffer_bits);
676
677	if (dev_priv->fbc.busy_bits)
678		intel_fbc_disable(dev);
679}
680
681void intel_fbc_flush(struct drm_i915_private *dev_priv,
682		     unsigned int frontbuffer_bits)
683{
684	struct drm_device *dev = dev_priv->dev;
685
686	if (!dev_priv->fbc.busy_bits)
687		return;
688
689	dev_priv->fbc.busy_bits &= ~frontbuffer_bits;
690
691	if (!dev_priv->fbc.busy_bits)
692		intel_fbc_update(dev);
693}
694
695/**
696 * intel_fbc_init - Initialize FBC
697 * @dev_priv: the i915 device
698 *
699 * This function might be called during PM init process.
700 */
701void intel_fbc_init(struct drm_i915_private *dev_priv)
702{
703	enum pipe pipe;
704
705	if (!HAS_FBC(dev_priv)) {
706		dev_priv->fbc.enabled = false;
707		dev_priv->fbc.no_fbc_reason = FBC_UNSUPPORTED;
708		return;
709	}
710
711	for_each_pipe(dev_priv, pipe) {
712		dev_priv->fbc.possible_framebuffer_bits |=
713				INTEL_FRONTBUFFER_PRIMARY(pipe);
714
715		if (IS_HASWELL(dev_priv) || INTEL_INFO(dev_priv)->gen >= 8)
716			break;
717	}
718
719	if (INTEL_INFO(dev_priv)->gen >= 7) {
720		dev_priv->display.fbc_enabled = ilk_fbc_enabled;
721		dev_priv->display.enable_fbc = gen7_fbc_enable;
722		dev_priv->display.disable_fbc = ilk_fbc_disable;
723	} else if (INTEL_INFO(dev_priv)->gen >= 5) {
724		dev_priv->display.fbc_enabled = ilk_fbc_enabled;
725		dev_priv->display.enable_fbc = ilk_fbc_enable;
726		dev_priv->display.disable_fbc = ilk_fbc_disable;
727	} else if (IS_GM45(dev_priv)) {
728		dev_priv->display.fbc_enabled = g4x_fbc_enabled;
729		dev_priv->display.enable_fbc = g4x_fbc_enable;
730		dev_priv->display.disable_fbc = g4x_fbc_disable;
731	} else {
732		dev_priv->display.fbc_enabled = i8xx_fbc_enabled;
733		dev_priv->display.enable_fbc = i8xx_fbc_enable;
734		dev_priv->display.disable_fbc = i8xx_fbc_disable;
735
736		/* This value was pulled out of someone's hat */
737		I915_WRITE(FBC_CONTROL, 500 << FBC_CTL_INTERVAL_SHIFT);
738	}
739
740	dev_priv->fbc.enabled = dev_priv->display.fbc_enabled(dev_priv->dev);
741}
742