xref: /netbsd-src/sys/external/bsd/drm2/dist/drm/i915/display/intel_fbc.c (revision 2a8c33eaff5adddac3ef2c5cb48ee67ef6d5d6dc)
1 /*	$NetBSD: intel_fbc.c,v 1.3 2021/12/19 12:32:15 riastradh Exp $	*/
2 
3 /*
4  * Copyright © 2014 Intel Corporation
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a
7  * copy of this software and associated documentation files (the "Software"),
8  * to deal in the Software without restriction, including without limitation
9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
10  * and/or sell copies of the Software, and to permit persons to whom the
11  * Software is furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice (including the next
14  * paragraph) shall be included in all copies or substantial portions of the
15  * Software.
16  *
17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
20  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
22  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
23  * DEALINGS IN THE SOFTWARE.
24  */
25 
26 /**
27  * DOC: Frame Buffer Compression (FBC)
28  *
29  * FBC tries to save memory bandwidth (and so power consumption) by
30  * compressing the amount of memory used by the display. It is total
31  * transparent to user space and completely handled in the kernel.
32  *
33  * The benefits of FBC are mostly visible with solid backgrounds and
34  * variation-less patterns. It comes from keeping the memory footprint small
35  * and having fewer memory pages opened and accessed for refreshing the display.
36  *
37  * i915 is responsible to reserve stolen memory for FBC and configure its
38  * offset on proper registers. The hardware takes care of all
39  * compress/decompress. However there are many known cases where we have to
40  * forcibly disable it to allow proper screen updates.
41  */
42 
43 #include <sys/cdefs.h>
44 __KERNEL_RCSID(0, "$NetBSD: intel_fbc.c,v 1.3 2021/12/19 12:32:15 riastradh Exp $");
45 
46 #include <drm/drm_fourcc.h>
47 
48 #include "i915_drv.h"
49 #include "intel_display_types.h"
50 #include "intel_fbc.h"
51 #include "intel_frontbuffer.h"
52 
53 #include <linux/nbsd-namespace.h>
54 
fbc_supported(struct drm_i915_private * dev_priv)55 static inline bool fbc_supported(struct drm_i915_private *dev_priv)
56 {
57 	return HAS_FBC(dev_priv);
58 }
59 
60 /*
61  * In some platforms where the CRTC's x:0/y:0 coordinates doesn't match the
62  * frontbuffer's x:0/y:0 coordinates we lie to the hardware about the plane's
63  * origin so the x and y offsets can actually fit the registers. As a
64  * consequence, the fence doesn't really start exactly at the display plane
65  * address we program because it starts at the real start of the buffer, so we
66  * have to take this into consideration here.
67  */
get_crtc_fence_y_offset(struct intel_fbc * fbc)68 static unsigned int get_crtc_fence_y_offset(struct intel_fbc *fbc)
69 {
70 	return fbc->state_cache.plane.y - fbc->state_cache.plane.adjusted_y;
71 }
72 
73 /*
74  * For SKL+, the plane source size used by the hardware is based on the value we
75  * write to the PLANE_SIZE register. For BDW-, the hardware looks at the value
76  * we wrote to PIPESRC.
77  */
intel_fbc_get_plane_source_size(const struct intel_fbc_state_cache * cache,int * width,int * height)78 static void intel_fbc_get_plane_source_size(const struct intel_fbc_state_cache *cache,
79 					    int *width, int *height)
80 {
81 	if (width)
82 		*width = cache->plane.src_w;
83 	if (height)
84 		*height = cache->plane.src_h;
85 }
86 
intel_fbc_calculate_cfb_size(struct drm_i915_private * dev_priv,const struct intel_fbc_state_cache * cache)87 static int intel_fbc_calculate_cfb_size(struct drm_i915_private *dev_priv,
88 					const struct intel_fbc_state_cache *cache)
89 {
90 	int lines;
91 
92 	intel_fbc_get_plane_source_size(cache, NULL, &lines);
93 	if (IS_GEN(dev_priv, 7))
94 		lines = min(lines, 2048);
95 	else if (INTEL_GEN(dev_priv) >= 8)
96 		lines = min(lines, 2560);
97 
98 	/* Hardware needs the full buffer stride, not just the active area. */
99 	return lines * cache->fb.stride;
100 }
101 
i8xx_fbc_deactivate(struct drm_i915_private * dev_priv)102 static void i8xx_fbc_deactivate(struct drm_i915_private *dev_priv)
103 {
104 	u32 fbc_ctl;
105 
106 	/* Disable compression */
107 	fbc_ctl = I915_READ(FBC_CONTROL);
108 	if ((fbc_ctl & FBC_CTL_EN) == 0)
109 		return;
110 
111 	fbc_ctl &= ~FBC_CTL_EN;
112 	I915_WRITE(FBC_CONTROL, fbc_ctl);
113 
114 	/* Wait for compressing bit to clear */
115 	if (intel_de_wait_for_clear(dev_priv, FBC_STATUS,
116 				    FBC_STAT_COMPRESSING, 10)) {
117 		DRM_DEBUG_KMS("FBC idle timed out\n");
118 		return;
119 	}
120 }
121 
i8xx_fbc_activate(struct drm_i915_private * dev_priv)122 static void i8xx_fbc_activate(struct drm_i915_private *dev_priv)
123 {
124 	struct intel_fbc_reg_params *params = &dev_priv->fbc.params;
125 	int cfb_pitch;
126 	int i;
127 	u32 fbc_ctl;
128 
129 	/* Note: fbc.threshold == 1 for i8xx */
130 	cfb_pitch = params->cfb_size / FBC_LL_SIZE;
131 	if (params->fb.stride < cfb_pitch)
132 		cfb_pitch = params->fb.stride;
133 
134 	/* FBC_CTL wants 32B or 64B units */
135 	if (IS_GEN(dev_priv, 2))
136 		cfb_pitch = (cfb_pitch / 32) - 1;
137 	else
138 		cfb_pitch = (cfb_pitch / 64) - 1;
139 
140 	/* Clear old tags */
141 	for (i = 0; i < (FBC_LL_SIZE / 32) + 1; i++)
142 		I915_WRITE(FBC_TAG(i), 0);
143 
144 	if (IS_GEN(dev_priv, 4)) {
145 		u32 fbc_ctl2;
146 
147 		/* Set it up... */
148 		fbc_ctl2 = FBC_CTL_FENCE_DBL | FBC_CTL_IDLE_IMM;
149 		fbc_ctl2 |= FBC_CTL_PLANE(params->crtc.i9xx_plane);
150 		if (params->fence_id >= 0)
151 			fbc_ctl2 |= FBC_CTL_CPU_FENCE;
152 		I915_WRITE(FBC_CONTROL2, fbc_ctl2);
153 		I915_WRITE(FBC_FENCE_OFF, params->crtc.fence_y_offset);
154 	}
155 
156 	/* enable it... */
157 	fbc_ctl = I915_READ(FBC_CONTROL);
158 	fbc_ctl &= 0x3fff << FBC_CTL_INTERVAL_SHIFT;
159 	fbc_ctl |= FBC_CTL_EN | FBC_CTL_PERIODIC;
160 	if (IS_I945GM(dev_priv))
161 		fbc_ctl |= FBC_CTL_C3_IDLE; /* 945 needs special SR handling */
162 	fbc_ctl |= (cfb_pitch & 0xff) << FBC_CTL_STRIDE_SHIFT;
163 	if (params->fence_id >= 0)
164 		fbc_ctl |= params->fence_id;
165 	I915_WRITE(FBC_CONTROL, fbc_ctl);
166 }
167 
i8xx_fbc_is_active(struct drm_i915_private * dev_priv)168 static bool i8xx_fbc_is_active(struct drm_i915_private *dev_priv)
169 {
170 	return I915_READ(FBC_CONTROL) & FBC_CTL_EN;
171 }
172 
g4x_fbc_activate(struct drm_i915_private * dev_priv)173 static void g4x_fbc_activate(struct drm_i915_private *dev_priv)
174 {
175 	struct intel_fbc_reg_params *params = &dev_priv->fbc.params;
176 	u32 dpfc_ctl;
177 
178 	dpfc_ctl = DPFC_CTL_PLANE(params->crtc.i9xx_plane) | DPFC_SR_EN;
179 	if (params->fb.format->cpp[0] == 2)
180 		dpfc_ctl |= DPFC_CTL_LIMIT_2X;
181 	else
182 		dpfc_ctl |= DPFC_CTL_LIMIT_1X;
183 
184 	if (params->fence_id >= 0) {
185 		dpfc_ctl |= DPFC_CTL_FENCE_EN | params->fence_id;
186 		I915_WRITE(DPFC_FENCE_YOFF, params->crtc.fence_y_offset);
187 	} else {
188 		I915_WRITE(DPFC_FENCE_YOFF, 0);
189 	}
190 
191 	/* enable it... */
192 	I915_WRITE(DPFC_CONTROL, dpfc_ctl | DPFC_CTL_EN);
193 }
194 
g4x_fbc_deactivate(struct drm_i915_private * dev_priv)195 static void g4x_fbc_deactivate(struct drm_i915_private *dev_priv)
196 {
197 	u32 dpfc_ctl;
198 
199 	/* Disable compression */
200 	dpfc_ctl = I915_READ(DPFC_CONTROL);
201 	if (dpfc_ctl & DPFC_CTL_EN) {
202 		dpfc_ctl &= ~DPFC_CTL_EN;
203 		I915_WRITE(DPFC_CONTROL, dpfc_ctl);
204 	}
205 }
206 
g4x_fbc_is_active(struct drm_i915_private * dev_priv)207 static bool g4x_fbc_is_active(struct drm_i915_private *dev_priv)
208 {
209 	return I915_READ(DPFC_CONTROL) & DPFC_CTL_EN;
210 }
211 
212 /* This function forces a CFB recompression through the nuke operation. */
intel_fbc_recompress(struct drm_i915_private * dev_priv)213 static void intel_fbc_recompress(struct drm_i915_private *dev_priv)
214 {
215 	I915_WRITE(MSG_FBC_REND_STATE, FBC_REND_NUKE);
216 	POSTING_READ(MSG_FBC_REND_STATE);
217 }
218 
ilk_fbc_activate(struct drm_i915_private * dev_priv)219 static void ilk_fbc_activate(struct drm_i915_private *dev_priv)
220 {
221 	struct intel_fbc_reg_params *params = &dev_priv->fbc.params;
222 	u32 dpfc_ctl;
223 	int threshold = dev_priv->fbc.threshold;
224 
225 	dpfc_ctl = DPFC_CTL_PLANE(params->crtc.i9xx_plane);
226 	if (params->fb.format->cpp[0] == 2)
227 		threshold++;
228 
229 	switch (threshold) {
230 	case 4:
231 	case 3:
232 		dpfc_ctl |= DPFC_CTL_LIMIT_4X;
233 		break;
234 	case 2:
235 		dpfc_ctl |= DPFC_CTL_LIMIT_2X;
236 		break;
237 	case 1:
238 		dpfc_ctl |= DPFC_CTL_LIMIT_1X;
239 		break;
240 	}
241 
242 	if (params->fence_id >= 0) {
243 		dpfc_ctl |= DPFC_CTL_FENCE_EN;
244 		if (IS_GEN(dev_priv, 5))
245 			dpfc_ctl |= params->fence_id;
246 		if (IS_GEN(dev_priv, 6)) {
247 			I915_WRITE(SNB_DPFC_CTL_SA,
248 				   SNB_CPU_FENCE_ENABLE |
249 				   params->fence_id);
250 			I915_WRITE(DPFC_CPU_FENCE_OFFSET,
251 				   params->crtc.fence_y_offset);
252 		}
253 	} else {
254 		if (IS_GEN(dev_priv, 6)) {
255 			I915_WRITE(SNB_DPFC_CTL_SA, 0);
256 			I915_WRITE(DPFC_CPU_FENCE_OFFSET, 0);
257 		}
258 	}
259 
260 	I915_WRITE(ILK_DPFC_FENCE_YOFF, params->crtc.fence_y_offset);
261 	/* enable it... */
262 	I915_WRITE(ILK_DPFC_CONTROL, dpfc_ctl | DPFC_CTL_EN);
263 
264 	intel_fbc_recompress(dev_priv);
265 }
266 
ilk_fbc_deactivate(struct drm_i915_private * dev_priv)267 static void ilk_fbc_deactivate(struct drm_i915_private *dev_priv)
268 {
269 	u32 dpfc_ctl;
270 
271 	/* Disable compression */
272 	dpfc_ctl = I915_READ(ILK_DPFC_CONTROL);
273 	if (dpfc_ctl & DPFC_CTL_EN) {
274 		dpfc_ctl &= ~DPFC_CTL_EN;
275 		I915_WRITE(ILK_DPFC_CONTROL, dpfc_ctl);
276 	}
277 }
278 
ilk_fbc_is_active(struct drm_i915_private * dev_priv)279 static bool ilk_fbc_is_active(struct drm_i915_private *dev_priv)
280 {
281 	return I915_READ(ILK_DPFC_CONTROL) & DPFC_CTL_EN;
282 }
283 
gen7_fbc_activate(struct drm_i915_private * dev_priv)284 static void gen7_fbc_activate(struct drm_i915_private *dev_priv)
285 {
286 	struct intel_fbc_reg_params *params = &dev_priv->fbc.params;
287 	u32 dpfc_ctl;
288 	int threshold = dev_priv->fbc.threshold;
289 
290 	/* Display WA #0529: skl, kbl, bxt. */
291 	if (IS_GEN9_BC(dev_priv) || IS_BROXTON(dev_priv)) {
292 		u32 val = I915_READ(CHICKEN_MISC_4);
293 
294 		val &= ~(FBC_STRIDE_OVERRIDE | FBC_STRIDE_MASK);
295 
296 		if (params->gen9_wa_cfb_stride)
297 			val |= FBC_STRIDE_OVERRIDE | params->gen9_wa_cfb_stride;
298 
299 		I915_WRITE(CHICKEN_MISC_4, val);
300 	}
301 
302 	dpfc_ctl = 0;
303 	if (IS_IVYBRIDGE(dev_priv))
304 		dpfc_ctl |= IVB_DPFC_CTL_PLANE(params->crtc.i9xx_plane);
305 
306 	if (params->fb.format->cpp[0] == 2)
307 		threshold++;
308 
309 	switch (threshold) {
310 	case 4:
311 	case 3:
312 		dpfc_ctl |= DPFC_CTL_LIMIT_4X;
313 		break;
314 	case 2:
315 		dpfc_ctl |= DPFC_CTL_LIMIT_2X;
316 		break;
317 	case 1:
318 		dpfc_ctl |= DPFC_CTL_LIMIT_1X;
319 		break;
320 	}
321 
322 	if (params->fence_id >= 0) {
323 		dpfc_ctl |= IVB_DPFC_CTL_FENCE_EN;
324 		I915_WRITE(SNB_DPFC_CTL_SA,
325 			   SNB_CPU_FENCE_ENABLE |
326 			   params->fence_id);
327 		I915_WRITE(DPFC_CPU_FENCE_OFFSET, params->crtc.fence_y_offset);
328 	} else {
329 		I915_WRITE(SNB_DPFC_CTL_SA,0);
330 		I915_WRITE(DPFC_CPU_FENCE_OFFSET, 0);
331 	}
332 
333 	if (dev_priv->fbc.false_color)
334 		dpfc_ctl |= FBC_CTL_FALSE_COLOR;
335 
336 	if (IS_IVYBRIDGE(dev_priv)) {
337 		/* WaFbcAsynchFlipDisableFbcQueue:ivb */
338 		I915_WRITE(ILK_DISPLAY_CHICKEN1,
339 			   I915_READ(ILK_DISPLAY_CHICKEN1) |
340 			   ILK_FBCQ_DIS);
341 	} else if (IS_HASWELL(dev_priv) || IS_BROADWELL(dev_priv)) {
342 		/* WaFbcAsynchFlipDisableFbcQueue:hsw,bdw */
343 		I915_WRITE(CHICKEN_PIPESL_1(params->crtc.pipe),
344 			   I915_READ(CHICKEN_PIPESL_1(params->crtc.pipe)) |
345 			   HSW_FBCQ_DIS);
346 	}
347 
348 	if (INTEL_GEN(dev_priv) >= 11)
349 		/* Wa_1409120013:icl,ehl,tgl */
350 		I915_WRITE(ILK_DPFC_CHICKEN, ILK_DPFC_CHICKEN_COMP_DUMMY_PIXEL);
351 
352 	I915_WRITE(ILK_DPFC_CONTROL, dpfc_ctl | DPFC_CTL_EN);
353 
354 	intel_fbc_recompress(dev_priv);
355 }
356 
intel_fbc_hw_is_active(struct drm_i915_private * dev_priv)357 static bool intel_fbc_hw_is_active(struct drm_i915_private *dev_priv)
358 {
359 	if (INTEL_GEN(dev_priv) >= 5)
360 		return ilk_fbc_is_active(dev_priv);
361 	else if (IS_GM45(dev_priv))
362 		return g4x_fbc_is_active(dev_priv);
363 	else
364 		return i8xx_fbc_is_active(dev_priv);
365 }
366 
intel_fbc_hw_activate(struct drm_i915_private * dev_priv)367 static void intel_fbc_hw_activate(struct drm_i915_private *dev_priv)
368 {
369 	struct intel_fbc *fbc = &dev_priv->fbc;
370 
371 	fbc->active = true;
372 	fbc->activated = true;
373 
374 	if (INTEL_GEN(dev_priv) >= 7)
375 		gen7_fbc_activate(dev_priv);
376 	else if (INTEL_GEN(dev_priv) >= 5)
377 		ilk_fbc_activate(dev_priv);
378 	else if (IS_GM45(dev_priv))
379 		g4x_fbc_activate(dev_priv);
380 	else
381 		i8xx_fbc_activate(dev_priv);
382 }
383 
intel_fbc_hw_deactivate(struct drm_i915_private * dev_priv)384 static void intel_fbc_hw_deactivate(struct drm_i915_private *dev_priv)
385 {
386 	struct intel_fbc *fbc = &dev_priv->fbc;
387 
388 	fbc->active = false;
389 
390 	if (INTEL_GEN(dev_priv) >= 5)
391 		ilk_fbc_deactivate(dev_priv);
392 	else if (IS_GM45(dev_priv))
393 		g4x_fbc_deactivate(dev_priv);
394 	else
395 		i8xx_fbc_deactivate(dev_priv);
396 }
397 
398 /**
399  * intel_fbc_is_active - Is FBC active?
400  * @dev_priv: i915 device instance
401  *
402  * This function is used to verify the current state of FBC.
403  *
404  * FIXME: This should be tracked in the plane config eventually
405  * instead of queried at runtime for most callers.
406  */
intel_fbc_is_active(struct drm_i915_private * dev_priv)407 bool intel_fbc_is_active(struct drm_i915_private *dev_priv)
408 {
409 	return dev_priv->fbc.active;
410 }
411 
intel_fbc_deactivate(struct drm_i915_private * dev_priv,const char * reason)412 static void intel_fbc_deactivate(struct drm_i915_private *dev_priv,
413 				 const char *reason)
414 {
415 	struct intel_fbc *fbc = &dev_priv->fbc;
416 
417 	WARN_ON(!mutex_is_locked(&fbc->lock));
418 
419 	if (fbc->active)
420 		intel_fbc_hw_deactivate(dev_priv);
421 
422 	fbc->no_fbc_reason = reason;
423 }
424 
find_compression_threshold(struct drm_i915_private * dev_priv,struct drm_mm_node * node,unsigned int size,unsigned int fb_cpp)425 static int find_compression_threshold(struct drm_i915_private *dev_priv,
426 				      struct drm_mm_node *node,
427 				      unsigned int size,
428 				      unsigned int fb_cpp)
429 {
430 	int compression_threshold = 1;
431 	int ret;
432 	u64 end;
433 
434 	/* The FBC hardware for BDW/SKL doesn't have access to the stolen
435 	 * reserved range size, so it always assumes the maximum (8mb) is used.
436 	 * If we enable FBC using a CFB on that memory range we'll get FIFO
437 	 * underruns, even if that range is not reserved by the BIOS. */
438 	if (IS_BROADWELL(dev_priv) || IS_GEN9_BC(dev_priv))
439 		end = resource_size(&dev_priv->dsm) - 8 * 1024 * 1024;
440 	else
441 		end = U64_MAX;
442 
443 	/* HACK: This code depends on what we will do in *_enable_fbc. If that
444 	 * code changes, this code needs to change as well.
445 	 *
446 	 * The enable_fbc code will attempt to use one of our 2 compression
447 	 * thresholds, therefore, in that case, we only have 1 resort.
448 	 */
449 
450 	/* Try to over-allocate to reduce reallocations and fragmentation. */
451 	ret = i915_gem_stolen_insert_node_in_range(dev_priv, node, size <<= 1,
452 						   4096, 0, end);
453 	if (ret == 0)
454 		return compression_threshold;
455 
456 again:
457 	/* HW's ability to limit the CFB is 1:4 */
458 	if (compression_threshold > 4 ||
459 	    (fb_cpp == 2 && compression_threshold == 2))
460 		return 0;
461 
462 	ret = i915_gem_stolen_insert_node_in_range(dev_priv, node, size >>= 1,
463 						   4096, 0, end);
464 	if (ret && INTEL_GEN(dev_priv) <= 4) {
465 		return 0;
466 	} else if (ret) {
467 		compression_threshold <<= 1;
468 		goto again;
469 	} else {
470 		return compression_threshold;
471 	}
472 }
473 
intel_fbc_alloc_cfb(struct drm_i915_private * dev_priv,unsigned int size,unsigned int fb_cpp)474 static int intel_fbc_alloc_cfb(struct drm_i915_private *dev_priv,
475 			       unsigned int size, unsigned int fb_cpp)
476 {
477 	struct intel_fbc *fbc = &dev_priv->fbc;
478 	struct drm_mm_node *uninitialized_var(compressed_llb);
479 	int ret;
480 
481 	WARN_ON(drm_mm_node_allocated(&fbc->compressed_fb));
482 
483 	ret = find_compression_threshold(dev_priv, &fbc->compressed_fb,
484 					 size, fb_cpp);
485 	if (!ret)
486 		goto err_llb;
487 	else if (ret > 1) {
488 		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");
489 
490 	}
491 
492 	fbc->threshold = ret;
493 
494 	if (INTEL_GEN(dev_priv) >= 5)
495 		I915_WRITE(ILK_DPFC_CB_BASE, fbc->compressed_fb.start);
496 	else if (IS_GM45(dev_priv)) {
497 		I915_WRITE(DPFC_CB_BASE, fbc->compressed_fb.start);
498 	} else {
499 		compressed_llb = kzalloc(sizeof(*compressed_llb), GFP_KERNEL);
500 		if (!compressed_llb)
501 			goto err_fb;
502 
503 		ret = i915_gem_stolen_insert_node(dev_priv, compressed_llb,
504 						  4096, 4096);
505 		if (ret)
506 			goto err_fb;
507 
508 		fbc->compressed_llb = compressed_llb;
509 
510 		GEM_BUG_ON(range_overflows_t(u64, dev_priv->dsm.start,
511 					     fbc->compressed_fb.start,
512 					     U32_MAX));
513 		GEM_BUG_ON(range_overflows_t(u64, dev_priv->dsm.start,
514 					     fbc->compressed_llb->start,
515 					     U32_MAX));
516 		I915_WRITE(FBC_CFB_BASE,
517 			   dev_priv->dsm.start + fbc->compressed_fb.start);
518 		I915_WRITE(FBC_LL_BASE,
519 			   dev_priv->dsm.start + compressed_llb->start);
520 	}
521 
522 	DRM_DEBUG_KMS("reserved %"PRIu64" bytes of contiguous stolen space for FBC, threshold: %d\n",
523 		      fbc->compressed_fb.size, fbc->threshold);
524 
525 	return 0;
526 
527 err_fb:
528 	kfree(compressed_llb);
529 	i915_gem_stolen_remove_node(dev_priv, &fbc->compressed_fb);
530 err_llb:
531 	if (drm_mm_initialized(&dev_priv->mm.stolen))
532 		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);
533 	return -ENOSPC;
534 }
535 
__intel_fbc_cleanup_cfb(struct drm_i915_private * dev_priv)536 static void __intel_fbc_cleanup_cfb(struct drm_i915_private *dev_priv)
537 {
538 	struct intel_fbc *fbc = &dev_priv->fbc;
539 
540 	if (drm_mm_node_allocated(&fbc->compressed_fb))
541 		i915_gem_stolen_remove_node(dev_priv, &fbc->compressed_fb);
542 
543 	if (fbc->compressed_llb) {
544 		i915_gem_stolen_remove_node(dev_priv, fbc->compressed_llb);
545 		kfree(fbc->compressed_llb);
546 	}
547 }
548 
intel_fbc_cleanup_cfb(struct drm_i915_private * dev_priv)549 void intel_fbc_cleanup_cfb(struct drm_i915_private *dev_priv)
550 {
551 	struct intel_fbc *fbc = &dev_priv->fbc;
552 
553 	if (!fbc_supported(dev_priv))
554 		return;
555 
556 	mutex_lock(&fbc->lock);
557 	__intel_fbc_cleanup_cfb(dev_priv);
558 	mutex_unlock(&fbc->lock);
559 }
560 
stride_is_valid(struct drm_i915_private * dev_priv,unsigned int stride)561 static bool stride_is_valid(struct drm_i915_private *dev_priv,
562 			    unsigned int stride)
563 {
564 	/* This should have been caught earlier. */
565 	if (WARN_ON_ONCE((stride & (64 - 1)) != 0))
566 		return false;
567 
568 	/* Below are the additional FBC restrictions. */
569 	if (stride < 512)
570 		return false;
571 
572 	if (IS_GEN(dev_priv, 2) || IS_GEN(dev_priv, 3))
573 		return stride == 4096 || stride == 8192;
574 
575 	if (IS_GEN(dev_priv, 4) && !IS_G4X(dev_priv) && stride < 2048)
576 		return false;
577 
578 	if (stride > 16384)
579 		return false;
580 
581 	return true;
582 }
583 
pixel_format_is_valid(struct drm_i915_private * dev_priv,u32 pixel_format)584 static bool pixel_format_is_valid(struct drm_i915_private *dev_priv,
585 				  u32 pixel_format)
586 {
587 	switch (pixel_format) {
588 	case DRM_FORMAT_XRGB8888:
589 	case DRM_FORMAT_XBGR8888:
590 		return true;
591 	case DRM_FORMAT_XRGB1555:
592 	case DRM_FORMAT_RGB565:
593 		/* 16bpp not supported on gen2 */
594 		if (IS_GEN(dev_priv, 2))
595 			return false;
596 		/* WaFbcOnly1to1Ratio:ctg */
597 		if (IS_G4X(dev_priv))
598 			return false;
599 		return true;
600 	default:
601 		return false;
602 	}
603 }
604 
605 /*
606  * For some reason, the hardware tracking starts looking at whatever we
607  * programmed as the display plane base address register. It does not look at
608  * the X and Y offset registers. That's why we look at the crtc->adjusted{x,y}
609  * variables instead of just looking at the pipe/plane size.
610  */
intel_fbc_hw_tracking_covers_screen(struct intel_crtc * crtc)611 static bool intel_fbc_hw_tracking_covers_screen(struct intel_crtc *crtc)
612 {
613 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
614 	struct intel_fbc *fbc = &dev_priv->fbc;
615 	unsigned int effective_w, effective_h, max_w, max_h;
616 
617 	if (INTEL_GEN(dev_priv) >= 10 || IS_GEMINILAKE(dev_priv)) {
618 		max_w = 5120;
619 		max_h = 4096;
620 	} else if (INTEL_GEN(dev_priv) >= 8 || IS_HASWELL(dev_priv)) {
621 		max_w = 4096;
622 		max_h = 4096;
623 	} else if (IS_G4X(dev_priv) || INTEL_GEN(dev_priv) >= 5) {
624 		max_w = 4096;
625 		max_h = 2048;
626 	} else {
627 		max_w = 2048;
628 		max_h = 1536;
629 	}
630 
631 	intel_fbc_get_plane_source_size(&fbc->state_cache, &effective_w,
632 					&effective_h);
633 	effective_w += fbc->state_cache.plane.adjusted_x;
634 	effective_h += fbc->state_cache.plane.adjusted_y;
635 
636 	return effective_w <= max_w && effective_h <= max_h;
637 }
638 
intel_fbc_update_state_cache(struct intel_crtc * crtc,const struct intel_crtc_state * crtc_state,const struct intel_plane_state * plane_state)639 static void intel_fbc_update_state_cache(struct intel_crtc *crtc,
640 					 const struct intel_crtc_state *crtc_state,
641 					 const struct intel_plane_state *plane_state)
642 {
643 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
644 	struct intel_fbc *fbc = &dev_priv->fbc;
645 	struct intel_fbc_state_cache *cache = &fbc->state_cache;
646 	struct drm_framebuffer *fb = plane_state->hw.fb;
647 
648 	cache->plane.visible = plane_state->uapi.visible;
649 	if (!cache->plane.visible)
650 		return;
651 
652 	cache->crtc.mode_flags = crtc_state->hw.adjusted_mode.flags;
653 	if (IS_HASWELL(dev_priv) || IS_BROADWELL(dev_priv))
654 		cache->crtc.hsw_bdw_pixel_rate = crtc_state->pixel_rate;
655 
656 	cache->plane.rotation = plane_state->hw.rotation;
657 	/*
658 	 * Src coordinates are already rotated by 270 degrees for
659 	 * the 90/270 degree plane rotation cases (to match the
660 	 * GTT mapping), hence no need to account for rotation here.
661 	 */
662 	cache->plane.src_w = drm_rect_width(&plane_state->uapi.src) >> 16;
663 	cache->plane.src_h = drm_rect_height(&plane_state->uapi.src) >> 16;
664 	cache->plane.adjusted_x = plane_state->color_plane[0].x;
665 	cache->plane.adjusted_y = plane_state->color_plane[0].y;
666 	cache->plane.y = plane_state->uapi.src.y1 >> 16;
667 
668 	cache->plane.pixel_blend_mode = plane_state->hw.pixel_blend_mode;
669 
670 	cache->fb.format = fb->format;
671 	cache->fb.stride = fb->pitches[0];
672 
673 	WARN_ON(plane_state->flags & PLANE_HAS_FENCE &&
674 		!plane_state->vma->fence);
675 
676 	if (plane_state->flags & PLANE_HAS_FENCE &&
677 	    plane_state->vma->fence)
678 		cache->fence_id = plane_state->vma->fence->id;
679 	else
680 		cache->fence_id = -1;
681 }
682 
intel_fbc_cfb_size_changed(struct drm_i915_private * dev_priv)683 static bool intel_fbc_cfb_size_changed(struct drm_i915_private *dev_priv)
684 {
685 	struct intel_fbc *fbc = &dev_priv->fbc;
686 
687 	return intel_fbc_calculate_cfb_size(dev_priv, &fbc->state_cache) >
688 		fbc->compressed_fb.size * fbc->threshold;
689 }
690 
intel_fbc_can_activate(struct intel_crtc * crtc)691 static bool intel_fbc_can_activate(struct intel_crtc *crtc)
692 {
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;
696 
697 	if (!cache->plane.visible) {
698 		fbc->no_fbc_reason = "primary plane not visible";
699 		return false;
700 	}
701 
702 	/* We don't need to use a state cache here since this information is
703 	 * global for all CRTC.
704 	 */
705 	if (fbc->underrun_detected) {
706 		fbc->no_fbc_reason = "underrun detected";
707 		return false;
708 	}
709 
710 	if (cache->crtc.mode_flags & DRM_MODE_FLAG_INTERLACE) {
711 		fbc->no_fbc_reason = "incompatible mode";
712 		return false;
713 	}
714 
715 	if (!intel_fbc_hw_tracking_covers_screen(crtc)) {
716 		fbc->no_fbc_reason = "mode too large for compression";
717 		return false;
718 	}
719 
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.
722 	 *
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.
726 	 *
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
731 	 * rotation.
732 	 */
733 	if (cache->fence_id < 0) {
734 		fbc->no_fbc_reason = "framebuffer not tiled or fenced";
735 		return false;
736 	}
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";
740 		return false;
741 	}
742 
743 	if (!stride_is_valid(dev_priv, cache->fb.stride)) {
744 		fbc->no_fbc_reason = "framebuffer stride not supported";
745 		return false;
746 	}
747 
748 	if (!pixel_format_is_valid(dev_priv, cache->fb.format->format)) {
749 		fbc->no_fbc_reason = "pixel format is invalid";
750 		return false;
751 	}
752 
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";
756 		return false;
757 	}
758 
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";
763 		return false;
764 	}
765 
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_cfb_size_changed(dev_priv)) {
777 		fbc->no_fbc_reason = "CFB requirements changed";
778 		return false;
779 	}
780 
781 	/*
782 	 * Work around a problem on GEN9+ HW, where enabling FBC on a plane
783 	 * having a Y offset that isn't divisible by 4 causes FIFO underrun
784 	 * and screen flicker.
785 	 */
786 	if (INTEL_GEN(dev_priv) >= 9 &&
787 	    (fbc->state_cache.plane.adjusted_y & 3)) {
788 		fbc->no_fbc_reason = "plane Y offset is misaligned";
789 		return false;
790 	}
791 
792 	return true;
793 }
794 
intel_fbc_can_enable(struct drm_i915_private * dev_priv)795 static bool intel_fbc_can_enable(struct drm_i915_private *dev_priv)
796 {
797 	struct intel_fbc *fbc = &dev_priv->fbc;
798 
799 	if (intel_vgpu_active(dev_priv)) {
800 		fbc->no_fbc_reason = "VGPU is active";
801 		return false;
802 	}
803 
804 	if (!i915_modparams.enable_fbc) {
805 		fbc->no_fbc_reason = "disabled per module param or by default";
806 		return false;
807 	}
808 
809 	if (fbc->underrun_detected) {
810 		fbc->no_fbc_reason = "underrun detected";
811 		return false;
812 	}
813 
814 	return true;
815 }
816 
intel_fbc_get_reg_params(struct intel_crtc * crtc,struct intel_fbc_reg_params * params)817 static void intel_fbc_get_reg_params(struct intel_crtc *crtc,
818 				     struct intel_fbc_reg_params *params)
819 {
820 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
821 	struct intel_fbc *fbc = &dev_priv->fbc;
822 	struct intel_fbc_state_cache *cache = &fbc->state_cache;
823 
824 	/* Since all our fields are integer types, use memset here so the
825 	 * comparison function can rely on memcmp because the padding will be
826 	 * zero. */
827 	memset(params, 0, sizeof(*params));
828 
829 	params->fence_id = cache->fence_id;
830 
831 	params->crtc.pipe = crtc->pipe;
832 	params->crtc.i9xx_plane = to_intel_plane(crtc->base.primary)->i9xx_plane;
833 	params->crtc.fence_y_offset = get_crtc_fence_y_offset(fbc);
834 
835 	params->fb.format = cache->fb.format;
836 	params->fb.stride = cache->fb.stride;
837 
838 	params->cfb_size = intel_fbc_calculate_cfb_size(dev_priv, cache);
839 
840 	params->gen9_wa_cfb_stride = cache->gen9_wa_cfb_stride;
841 
842 	params->plane_visible = cache->plane.visible;
843 }
844 
intel_fbc_can_flip_nuke(const struct intel_crtc_state * crtc_state)845 static bool intel_fbc_can_flip_nuke(const struct intel_crtc_state *crtc_state)
846 {
847 	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
848 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
849 	const struct intel_fbc *fbc = &dev_priv->fbc;
850 	const struct intel_fbc_state_cache *cache = &fbc->state_cache;
851 	const struct intel_fbc_reg_params *params = &fbc->params;
852 
853 	if (drm_atomic_crtc_needs_modeset(&crtc_state->uapi))
854 		return false;
855 
856 	if (!params->plane_visible)
857 		return false;
858 
859 	if (!intel_fbc_can_activate(crtc))
860 		return false;
861 
862 	if (params->fb.format != cache->fb.format)
863 		return false;
864 
865 	if (params->fb.stride != cache->fb.stride)
866 		return false;
867 
868 	if (params->cfb_size != intel_fbc_calculate_cfb_size(dev_priv, cache))
869 		return false;
870 
871 	if (params->gen9_wa_cfb_stride != cache->gen9_wa_cfb_stride)
872 		return false;
873 
874 	return true;
875 }
876 
intel_fbc_pre_update(struct intel_crtc * crtc,const struct intel_crtc_state * crtc_state,const struct intel_plane_state * plane_state)877 bool intel_fbc_pre_update(struct intel_crtc *crtc,
878 			  const struct intel_crtc_state *crtc_state,
879 			  const struct intel_plane_state *plane_state)
880 {
881 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
882 	struct intel_fbc *fbc = &dev_priv->fbc;
883 	const char *reason = "update pending";
884 	bool need_vblank_wait = false;
885 
886 	if (!fbc_supported(dev_priv))
887 		return need_vblank_wait;
888 
889 	mutex_lock(&fbc->lock);
890 
891 	if (fbc->crtc != crtc)
892 		goto unlock;
893 
894 	intel_fbc_update_state_cache(crtc, crtc_state, plane_state);
895 	fbc->flip_pending = true;
896 
897 	if (!intel_fbc_can_flip_nuke(crtc_state)) {
898 		intel_fbc_deactivate(dev_priv, reason);
899 
900 		/*
901 		 * Display WA #1198: glk+
902 		 * Need an extra vblank wait between FBC disable and most plane
903 		 * updates. Bspec says this is only needed for plane disable, but
904 		 * that is not true. Touching most plane registers will cause the
905 		 * corruption to appear. Also SKL/derivatives do not seem to be
906 		 * affected.
907 		 *
908 		 * TODO: could optimize this a bit by sampling the frame
909 		 * counter when we disable FBC (if it was already done earlier)
910 		 * and skipping the extra vblank wait before the plane update
911 		 * if at least one frame has already passed.
912 		 */
913 		if (fbc->activated &&
914 		    (INTEL_GEN(dev_priv) >= 10 || IS_GEMINILAKE(dev_priv)))
915 			need_vblank_wait = true;
916 		fbc->activated = false;
917 	}
918 unlock:
919 	mutex_unlock(&fbc->lock);
920 
921 	return need_vblank_wait;
922 }
923 
924 /**
925  * __intel_fbc_disable - disable FBC
926  * @dev_priv: i915 device instance
927  *
928  * This is the low level function that actually disables FBC. Callers should
929  * grab the FBC lock.
930  */
__intel_fbc_disable(struct drm_i915_private * dev_priv)931 static void __intel_fbc_disable(struct drm_i915_private *dev_priv)
932 {
933 	struct intel_fbc *fbc = &dev_priv->fbc;
934 	struct intel_crtc *crtc = fbc->crtc;
935 
936 	WARN_ON(!mutex_is_locked(&fbc->lock));
937 	WARN_ON(!fbc->crtc);
938 	WARN_ON(fbc->active);
939 
940 	DRM_DEBUG_KMS("Disabling FBC on pipe %c\n", pipe_name(crtc->pipe));
941 
942 	__intel_fbc_cleanup_cfb(dev_priv);
943 
944 	fbc->crtc = NULL;
945 }
946 
__intel_fbc_post_update(struct intel_crtc * crtc)947 static void __intel_fbc_post_update(struct intel_crtc *crtc)
948 {
949 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
950 	struct intel_fbc *fbc = &dev_priv->fbc;
951 
952 	WARN_ON(!mutex_is_locked(&fbc->lock));
953 
954 	if (fbc->crtc != crtc)
955 		return;
956 
957 	fbc->flip_pending = false;
958 
959 	if (!i915_modparams.enable_fbc) {
960 		intel_fbc_deactivate(dev_priv, "disabled at runtime per module param");
961 		__intel_fbc_disable(dev_priv);
962 
963 		return;
964 	}
965 
966 	intel_fbc_get_reg_params(crtc, &fbc->params);
967 
968 	if (!intel_fbc_can_activate(crtc))
969 		return;
970 
971 	if (!fbc->busy_bits)
972 		intel_fbc_hw_activate(dev_priv);
973 	else
974 		intel_fbc_deactivate(dev_priv, "frontbuffer write");
975 }
976 
intel_fbc_post_update(struct intel_crtc * crtc)977 void intel_fbc_post_update(struct intel_crtc *crtc)
978 {
979 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
980 	struct intel_fbc *fbc = &dev_priv->fbc;
981 
982 	if (!fbc_supported(dev_priv))
983 		return;
984 
985 	mutex_lock(&fbc->lock);
986 	__intel_fbc_post_update(crtc);
987 	mutex_unlock(&fbc->lock);
988 }
989 
intel_fbc_get_frontbuffer_bit(struct intel_fbc * fbc)990 static unsigned int intel_fbc_get_frontbuffer_bit(struct intel_fbc *fbc)
991 {
992 	if (fbc->crtc)
993 		return to_intel_plane(fbc->crtc->base.primary)->frontbuffer_bit;
994 	else
995 		return fbc->possible_framebuffer_bits;
996 }
997 
intel_fbc_invalidate(struct drm_i915_private * dev_priv,unsigned int frontbuffer_bits,enum fb_op_origin origin)998 void intel_fbc_invalidate(struct drm_i915_private *dev_priv,
999 			  unsigned int frontbuffer_bits,
1000 			  enum fb_op_origin origin)
1001 {
1002 	struct intel_fbc *fbc = &dev_priv->fbc;
1003 
1004 	if (!fbc_supported(dev_priv))
1005 		return;
1006 
1007 	if (origin == ORIGIN_GTT || origin == ORIGIN_FLIP)
1008 		return;
1009 
1010 	mutex_lock(&fbc->lock);
1011 
1012 	fbc->busy_bits |= intel_fbc_get_frontbuffer_bit(fbc) & frontbuffer_bits;
1013 
1014 	if (fbc->crtc && fbc->busy_bits)
1015 		intel_fbc_deactivate(dev_priv, "frontbuffer write");
1016 
1017 	mutex_unlock(&fbc->lock);
1018 }
1019 
intel_fbc_flush(struct drm_i915_private * dev_priv,unsigned int frontbuffer_bits,enum fb_op_origin origin)1020 void intel_fbc_flush(struct drm_i915_private *dev_priv,
1021 		     unsigned int frontbuffer_bits, enum fb_op_origin origin)
1022 {
1023 	struct intel_fbc *fbc = &dev_priv->fbc;
1024 
1025 	if (!fbc_supported(dev_priv))
1026 		return;
1027 
1028 	mutex_lock(&fbc->lock);
1029 
1030 	fbc->busy_bits &= ~frontbuffer_bits;
1031 
1032 	if (origin == ORIGIN_GTT || origin == ORIGIN_FLIP)
1033 		goto out;
1034 
1035 	if (!fbc->busy_bits && fbc->crtc &&
1036 	    (frontbuffer_bits & intel_fbc_get_frontbuffer_bit(fbc))) {
1037 		if (fbc->active)
1038 			intel_fbc_recompress(dev_priv);
1039 		else if (!fbc->flip_pending)
1040 			__intel_fbc_post_update(fbc->crtc);
1041 	}
1042 
1043 out:
1044 	mutex_unlock(&fbc->lock);
1045 }
1046 
1047 /**
1048  * intel_fbc_choose_crtc - select a CRTC to enable FBC on
1049  * @dev_priv: i915 device instance
1050  * @state: the atomic state structure
1051  *
1052  * This function looks at the proposed state for CRTCs and planes, then chooses
1053  * which pipe is going to have FBC by setting intel_crtc_state->enable_fbc to
1054  * true.
1055  *
1056  * Later, intel_fbc_enable is going to look for state->enable_fbc and then maybe
1057  * enable FBC for the chosen CRTC. If it does, it will set dev_priv->fbc.crtc.
1058  */
intel_fbc_choose_crtc(struct drm_i915_private * dev_priv,struct intel_atomic_state * state)1059 void intel_fbc_choose_crtc(struct drm_i915_private *dev_priv,
1060 			   struct intel_atomic_state *state)
1061 {
1062 	struct intel_fbc *fbc = &dev_priv->fbc;
1063 	struct intel_plane *plane;
1064 	struct intel_plane_state *plane_state;
1065 	bool crtc_chosen = false;
1066 	int i;
1067 
1068 	mutex_lock(&fbc->lock);
1069 
1070 	/* Does this atomic commit involve the CRTC currently tied to FBC? */
1071 	if (fbc->crtc &&
1072 	    !intel_atomic_get_new_crtc_state(state, fbc->crtc))
1073 		goto out;
1074 
1075 	if (!intel_fbc_can_enable(dev_priv))
1076 		goto out;
1077 
1078 	/* Simply choose the first CRTC that is compatible and has a visible
1079 	 * plane. We could go for fancier schemes such as checking the plane
1080 	 * size, but this would just affect the few platforms that don't tie FBC
1081 	 * to pipe or plane A. */
1082 	for_each_new_intel_plane_in_state(state, plane, plane_state, i) {
1083 		struct intel_crtc_state *crtc_state;
1084 		struct intel_crtc *crtc = to_intel_crtc(plane_state->hw.crtc);
1085 
1086 		if (!plane->has_fbc)
1087 			continue;
1088 
1089 		if (!plane_state->uapi.visible)
1090 			continue;
1091 
1092 		crtc_state = intel_atomic_get_new_crtc_state(state, crtc);
1093 
1094 		crtc_state->enable_fbc = true;
1095 		crtc_chosen = true;
1096 		break;
1097 	}
1098 
1099 	if (!crtc_chosen)
1100 		fbc->no_fbc_reason = "no suitable CRTC for FBC";
1101 
1102 out:
1103 	mutex_unlock(&fbc->lock);
1104 }
1105 
1106 /**
1107  * intel_fbc_enable: tries to enable FBC on the CRTC
1108  * @crtc: the CRTC
1109  * @crtc_state: corresponding &drm_crtc_state for @crtc
1110  * @plane_state: corresponding &drm_plane_state for the primary plane of @crtc
1111  *
1112  * This function checks if the given CRTC was chosen for FBC, then enables it if
1113  * possible. Notice that it doesn't activate FBC. It is valid to call
1114  * intel_fbc_enable multiple times for the same pipe without an
1115  * intel_fbc_disable in the middle, as long as it is deactivated.
1116  */
intel_fbc_enable(struct intel_crtc * crtc,const struct intel_crtc_state * crtc_state,const struct intel_plane_state * plane_state)1117 void intel_fbc_enable(struct intel_crtc *crtc,
1118 		      const struct intel_crtc_state *crtc_state,
1119 		      const struct intel_plane_state *plane_state)
1120 {
1121 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
1122 	struct intel_fbc *fbc = &dev_priv->fbc;
1123 	struct intel_fbc_state_cache *cache = &fbc->state_cache;
1124 	const struct drm_framebuffer *fb = plane_state->hw.fb;
1125 
1126 	if (!fbc_supported(dev_priv))
1127 		return;
1128 
1129 	mutex_lock(&fbc->lock);
1130 
1131 	if (fbc->crtc) {
1132 		if (fbc->crtc != crtc ||
1133 		    !intel_fbc_cfb_size_changed(dev_priv))
1134 			goto out;
1135 
1136 		__intel_fbc_disable(dev_priv);
1137 	}
1138 
1139 	WARN_ON(fbc->active);
1140 
1141 	intel_fbc_update_state_cache(crtc, crtc_state, plane_state);
1142 
1143 	/* FIXME crtc_state->enable_fbc lies :( */
1144 	if (!cache->plane.visible)
1145 		goto out;
1146 
1147 	if (intel_fbc_alloc_cfb(dev_priv,
1148 				intel_fbc_calculate_cfb_size(dev_priv, cache),
1149 				fb->format->cpp[0])) {
1150 		cache->plane.visible = false;
1151 		fbc->no_fbc_reason = "not enough stolen memory";
1152 		goto out;
1153 	}
1154 
1155 	if ((IS_GEN9_BC(dev_priv) || IS_BROXTON(dev_priv)) &&
1156 	    fb->modifier != I915_FORMAT_MOD_X_TILED)
1157 		cache->gen9_wa_cfb_stride =
1158 			DIV_ROUND_UP(cache->plane.src_w, 32 * fbc->threshold) * 8;
1159 	else
1160 		cache->gen9_wa_cfb_stride = 0;
1161 
1162 	DRM_DEBUG_KMS("Enabling FBC on pipe %c\n", pipe_name(crtc->pipe));
1163 	fbc->no_fbc_reason = "FBC enabled but not active yet\n";
1164 
1165 	fbc->crtc = crtc;
1166 out:
1167 	mutex_unlock(&fbc->lock);
1168 }
1169 
1170 /**
1171  * intel_fbc_disable - disable FBC if it's associated with crtc
1172  * @crtc: the CRTC
1173  *
1174  * This function disables FBC if it's associated with the provided CRTC.
1175  */
intel_fbc_disable(struct intel_crtc * crtc)1176 void intel_fbc_disable(struct intel_crtc *crtc)
1177 {
1178 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
1179 	struct intel_fbc *fbc = &dev_priv->fbc;
1180 
1181 	if (!fbc_supported(dev_priv))
1182 		return;
1183 
1184 	mutex_lock(&fbc->lock);
1185 	if (fbc->crtc == crtc)
1186 		__intel_fbc_disable(dev_priv);
1187 	mutex_unlock(&fbc->lock);
1188 }
1189 
1190 /**
1191  * intel_fbc_global_disable - globally disable FBC
1192  * @dev_priv: i915 device instance
1193  *
1194  * This function disables FBC regardless of which CRTC is associated with it.
1195  */
intel_fbc_global_disable(struct drm_i915_private * dev_priv)1196 void intel_fbc_global_disable(struct drm_i915_private *dev_priv)
1197 {
1198 	struct intel_fbc *fbc = &dev_priv->fbc;
1199 
1200 	if (!fbc_supported(dev_priv))
1201 		return;
1202 
1203 	mutex_lock(&fbc->lock);
1204 	if (fbc->crtc) {
1205 		WARN_ON(fbc->crtc->active);
1206 		__intel_fbc_disable(dev_priv);
1207 	}
1208 	mutex_unlock(&fbc->lock);
1209 }
1210 
intel_fbc_underrun_work_fn(struct work_struct * work)1211 static void intel_fbc_underrun_work_fn(struct work_struct *work)
1212 {
1213 	struct drm_i915_private *dev_priv =
1214 		container_of(work, struct drm_i915_private, fbc.underrun_work);
1215 	struct intel_fbc *fbc = &dev_priv->fbc;
1216 
1217 	mutex_lock(&fbc->lock);
1218 
1219 	/* Maybe we were scheduled twice. */
1220 	if (fbc->underrun_detected || !fbc->crtc)
1221 		goto out;
1222 
1223 	DRM_DEBUG_KMS("Disabling FBC due to FIFO underrun.\n");
1224 	fbc->underrun_detected = true;
1225 
1226 	intel_fbc_deactivate(dev_priv, "FIFO underrun");
1227 out:
1228 	mutex_unlock(&fbc->lock);
1229 }
1230 
1231 /*
1232  * intel_fbc_reset_underrun - reset FBC fifo underrun status.
1233  * @dev_priv: i915 device instance
1234  *
1235  * See intel_fbc_handle_fifo_underrun_irq(). For automated testing we
1236  * want to re-enable FBC after an underrun to increase test coverage.
1237  */
intel_fbc_reset_underrun(struct drm_i915_private * dev_priv)1238 int intel_fbc_reset_underrun(struct drm_i915_private *dev_priv)
1239 {
1240 	int ret;
1241 
1242 	cancel_work_sync(&dev_priv->fbc.underrun_work);
1243 
1244 	ret = mutex_lock_interruptible(&dev_priv->fbc.lock);
1245 	if (ret)
1246 		return ret;
1247 
1248 	if (dev_priv->fbc.underrun_detected) {
1249 		DRM_DEBUG_KMS("Re-allowing FBC after fifo underrun\n");
1250 		dev_priv->fbc.no_fbc_reason = "FIFO underrun cleared";
1251 	}
1252 
1253 	dev_priv->fbc.underrun_detected = false;
1254 	mutex_unlock(&dev_priv->fbc.lock);
1255 
1256 	return 0;
1257 }
1258 
1259 /**
1260  * intel_fbc_handle_fifo_underrun_irq - disable FBC when we get a FIFO underrun
1261  * @dev_priv: i915 device instance
1262  *
1263  * Without FBC, most underruns are harmless and don't really cause too many
1264  * problems, except for an annoying message on dmesg. With FBC, underruns can
1265  * become black screens or even worse, especially when paired with bad
1266  * watermarks. So in order for us to be on the safe side, completely disable FBC
1267  * in case we ever detect a FIFO underrun on any pipe. An underrun on any pipe
1268  * already suggests that watermarks may be bad, so try to be as safe as
1269  * possible.
1270  *
1271  * This function is called from the IRQ handler.
1272  */
intel_fbc_handle_fifo_underrun_irq(struct drm_i915_private * dev_priv)1273 void intel_fbc_handle_fifo_underrun_irq(struct drm_i915_private *dev_priv)
1274 {
1275 	struct intel_fbc *fbc = &dev_priv->fbc;
1276 
1277 	if (!fbc_supported(dev_priv))
1278 		return;
1279 
1280 	/* There's no guarantee that underrun_detected won't be set to true
1281 	 * right after this check and before the work is scheduled, but that's
1282 	 * not a problem since we'll check it again under the work function
1283 	 * while FBC is locked. This check here is just to prevent us from
1284 	 * unnecessarily scheduling the work, and it relies on the fact that we
1285 	 * never switch underrun_detect back to false after it's true. */
1286 	if (READ_ONCE(fbc->underrun_detected))
1287 		return;
1288 
1289 	schedule_work(&fbc->underrun_work);
1290 }
1291 
1292 /*
1293  * The DDX driver changes its behavior depending on the value it reads from
1294  * i915.enable_fbc, so sanitize it by translating the default value into either
1295  * 0 or 1 in order to allow it to know what's going on.
1296  *
1297  * Notice that this is done at driver initialization and we still allow user
1298  * space to change the value during runtime without sanitizing it again. IGT
1299  * relies on being able to change i915.enable_fbc at runtime.
1300  */
intel_sanitize_fbc_option(struct drm_i915_private * dev_priv)1301 static int intel_sanitize_fbc_option(struct drm_i915_private *dev_priv)
1302 {
1303 	if (i915_modparams.enable_fbc >= 0)
1304 		return !!i915_modparams.enable_fbc;
1305 
1306 	if (!HAS_FBC(dev_priv))
1307 		return 0;
1308 
1309 	if (IS_BROADWELL(dev_priv) || INTEL_GEN(dev_priv) >= 9)
1310 		return 1;
1311 
1312 	return 0;
1313 }
1314 
need_fbc_vtd_wa(struct drm_i915_private * dev_priv)1315 static bool need_fbc_vtd_wa(struct drm_i915_private *dev_priv)
1316 {
1317 	/* WaFbcTurnOffFbcWhenHyperVisorIsUsed:skl,bxt */
1318 	if (intel_vtd_active() &&
1319 	    (IS_SKYLAKE(dev_priv) || IS_BROXTON(dev_priv))) {
1320 		DRM_INFO("Disabling framebuffer compression (FBC) to prevent screen flicker with VT-d enabled\n");
1321 		return true;
1322 	}
1323 
1324 	return false;
1325 }
1326 
1327 /**
1328  * intel_fbc_init - Initialize FBC
1329  * @dev_priv: the i915 device
1330  *
1331  * This function might be called during PM init process.
1332  */
intel_fbc_init(struct drm_i915_private * dev_priv)1333 void intel_fbc_init(struct drm_i915_private *dev_priv)
1334 {
1335 	struct intel_fbc *fbc = &dev_priv->fbc;
1336 
1337 	INIT_WORK(&fbc->underrun_work, intel_fbc_underrun_work_fn);
1338 	mutex_init(&fbc->lock);
1339 	fbc->active = false;
1340 
1341 	if (!drm_mm_initialized(&dev_priv->mm.stolen))
1342 		mkwrite_device_info(dev_priv)->display.has_fbc = false;
1343 
1344 	if (need_fbc_vtd_wa(dev_priv))
1345 		mkwrite_device_info(dev_priv)->display.has_fbc = false;
1346 
1347 	i915_modparams.enable_fbc = intel_sanitize_fbc_option(dev_priv);
1348 	DRM_DEBUG_KMS("Sanitized enable_fbc value: %d\n",
1349 		      i915_modparams.enable_fbc);
1350 
1351 	if (!HAS_FBC(dev_priv)) {
1352 		fbc->no_fbc_reason = "unsupported by this chipset";
1353 		return;
1354 	}
1355 
1356 	/* This value was pulled out of someone's hat */
1357 	if (INTEL_GEN(dev_priv) <= 4 && !IS_GM45(dev_priv))
1358 		I915_WRITE(FBC_CONTROL, 500 << FBC_CTL_INTERVAL_SHIFT);
1359 
1360 	/* We still don't have any sort of hardware state readout for FBC, so
1361 	 * deactivate it in case the BIOS activated it to make sure software
1362 	 * matches the hardware state. */
1363 	if (intel_fbc_hw_is_active(dev_priv))
1364 		intel_fbc_hw_deactivate(dev_priv);
1365 }
1366 
1367 void
intel_fbc_cleanup(struct drm_i915_private * dev_priv)1368 intel_fbc_cleanup(struct drm_i915_private *dev_priv)
1369 {
1370 	struct intel_fbc *fbc = &dev_priv->fbc;
1371 
1372 	mutex_destroy(&fbc->lock);
1373 }
1374