xref: /openbmc/linux/drivers/gpu/drm/amd/display/dc/dsc/dc_dsc.c (revision 1da37801a8b0fffb024fea594c7f1d7867ed8aa0)
1 /*
2  * Copyright 2019 Advanced Micro Devices, Inc.
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 shall be included in
12  * all copies or substantial portions of the Software.
13  *
14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
17  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
18  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
19  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
20  * OTHER DEALINGS IN THE SOFTWARE.
21  *
22  * Author: AMD
23  */
24 
25 #include "dc_hw_types.h"
26 #include "dsc.h"
27 #include <drm/drm_dp_helper.h>
28 
29 struct dc_dsc_policy {
30 	bool use_min_slices_h;
31 	int max_slices_h; // Maximum available if 0
32 	int min_sice_height; // Must not be less than 8
33 	int max_target_bpp;
34 	int min_target_bpp; // Minimum target bits per pixel
35 };
36 
37 const struct dc_dsc_policy dsc_policy = {
38 	.use_min_slices_h = true, // DSC Policy: Use minimum number of slices that fits the pixel clock
39 	.max_slices_h = 0, // DSC Policy: Use max available slices (in our case 4 for or 8, depending on the mode)
40 	.min_sice_height = 108, // DSC Policy: Use slice height recommended by VESA DSC Spreadsheet user guide
41 	.max_target_bpp = 16,
42 	.min_target_bpp = 8,
43 };
44 
45 
46 /* This module's internal functions */
47 
48 static uint32_t dc_dsc_bandwidth_in_kbps_from_timing(
49 	const struct dc_crtc_timing *timing)
50 {
51 	uint32_t bits_per_channel = 0;
52 	uint32_t kbps;
53 
54 	if (timing->flags.DSC) {
55 		kbps = (timing->pix_clk_100hz * timing->dsc_cfg.bits_per_pixel);
56 		kbps = kbps / 160 + ((kbps % 160) ? 1 : 0);
57 		return kbps;
58 	}
59 
60 	switch (timing->display_color_depth) {
61 	case COLOR_DEPTH_666:
62 		bits_per_channel = 6;
63 		break;
64 	case COLOR_DEPTH_888:
65 		bits_per_channel = 8;
66 		break;
67 	case COLOR_DEPTH_101010:
68 		bits_per_channel = 10;
69 		break;
70 	case COLOR_DEPTH_121212:
71 		bits_per_channel = 12;
72 		break;
73 	case COLOR_DEPTH_141414:
74 		bits_per_channel = 14;
75 		break;
76 	case COLOR_DEPTH_161616:
77 		bits_per_channel = 16;
78 		break;
79 	default:
80 		break;
81 	}
82 
83 	ASSERT(bits_per_channel != 0);
84 
85 	kbps = timing->pix_clk_100hz / 10;
86 	kbps *= bits_per_channel;
87 
88 	if (timing->flags.Y_ONLY != 1) {
89 		/*Only YOnly make reduce bandwidth by 1/3 compares to RGB*/
90 		kbps *= 3;
91 		if (timing->pixel_encoding == PIXEL_ENCODING_YCBCR420)
92 			kbps /= 2;
93 		else if (timing->pixel_encoding == PIXEL_ENCODING_YCBCR422)
94 			kbps = kbps * 2 / 3;
95 	}
96 
97 	return kbps;
98 
99 }
100 
101 static bool dsc_buff_block_size_from_dpcd(int dpcd_buff_block_size, int *buff_block_size)
102 {
103 
104 	switch (dpcd_buff_block_size) {
105 	case DP_DSC_RC_BUF_BLK_SIZE_1:
106 		*buff_block_size = 1024;
107 		break;
108 	case DP_DSC_RC_BUF_BLK_SIZE_4:
109 		*buff_block_size = 4 * 1024;
110 		break;
111 	case DP_DSC_RC_BUF_BLK_SIZE_16:
112 		*buff_block_size = 16 * 1024;
113 		break;
114 	case DP_DSC_RC_BUF_BLK_SIZE_64:
115 		*buff_block_size = 64 * 1024;
116 		break;
117 	default: {
118 			dm_error("%s: DPCD DSC buffer size not recognized.\n", __func__);
119 			return false;
120 		}
121 	}
122 
123 	return true;
124 }
125 
126 
127 static bool dsc_line_buff_depth_from_dpcd(int dpcd_line_buff_bit_depth, int *line_buff_bit_depth)
128 {
129 	if (0 <= dpcd_line_buff_bit_depth && dpcd_line_buff_bit_depth <= 7)
130 		*line_buff_bit_depth = dpcd_line_buff_bit_depth + 9;
131 	else if (dpcd_line_buff_bit_depth == 8)
132 		*line_buff_bit_depth = 8;
133 	else {
134 		dm_error("%s: DPCD DSC buffer depth not recognized.\n", __func__);
135 		return false;
136 	}
137 
138 	return true;
139 }
140 
141 
142 static bool dsc_throughput_from_dpcd(int dpcd_throughput, int *throughput)
143 {
144 	switch (dpcd_throughput) {
145 	case DP_DSC_THROUGHPUT_MODE_0_UPSUPPORTED:
146 		*throughput = 0;
147 		break;
148 	case DP_DSC_THROUGHPUT_MODE_0_170:
149 		*throughput = 170;
150 		break;
151 	case DP_DSC_THROUGHPUT_MODE_0_340:
152 		*throughput = 340;
153 		break;
154 	case DP_DSC_THROUGHPUT_MODE_0_400:
155 		*throughput = 400;
156 		break;
157 	case DP_DSC_THROUGHPUT_MODE_0_450:
158 		*throughput = 450;
159 		break;
160 	case DP_DSC_THROUGHPUT_MODE_0_500:
161 		*throughput = 500;
162 		break;
163 	case DP_DSC_THROUGHPUT_MODE_0_550:
164 		*throughput = 550;
165 		break;
166 	case DP_DSC_THROUGHPUT_MODE_0_600:
167 		*throughput = 600;
168 		break;
169 	case DP_DSC_THROUGHPUT_MODE_0_650:
170 		*throughput = 650;
171 		break;
172 	case DP_DSC_THROUGHPUT_MODE_0_700:
173 		*throughput = 700;
174 		break;
175 	case DP_DSC_THROUGHPUT_MODE_0_750:
176 		*throughput = 750;
177 		break;
178 	case DP_DSC_THROUGHPUT_MODE_0_800:
179 		*throughput = 800;
180 		break;
181 	case DP_DSC_THROUGHPUT_MODE_0_850:
182 		*throughput = 850;
183 		break;
184 	case DP_DSC_THROUGHPUT_MODE_0_900:
185 		*throughput = 900;
186 		break;
187 	case DP_DSC_THROUGHPUT_MODE_0_950:
188 		*throughput = 950;
189 		break;
190 	case DP_DSC_THROUGHPUT_MODE_0_1000:
191 		*throughput = 1000;
192 		break;
193 	default: {
194 			dm_error("%s: DPCD DSC throughput mode not recognized.\n", __func__);
195 			return false;
196 		}
197 	}
198 
199 	return true;
200 }
201 
202 
203 static bool dsc_bpp_increment_div_from_dpcd(int bpp_increment_dpcd, uint32_t *bpp_increment_div)
204 {
205 
206 	switch (bpp_increment_dpcd) {
207 	case 0:
208 		*bpp_increment_div = 16;
209 		break;
210 	case 1:
211 		*bpp_increment_div = 8;
212 		break;
213 	case 2:
214 		*bpp_increment_div = 4;
215 		break;
216 	case 3:
217 		*bpp_increment_div = 2;
218 		break;
219 	case 4:
220 		*bpp_increment_div = 1;
221 		break;
222 	default: {
223 		dm_error("%s: DPCD DSC bits-per-pixel increment not recognized.\n", __func__);
224 		return false;
225 	}
226 	}
227 
228 	return true;
229 }
230 
231 static void get_dsc_enc_caps(
232 	const struct display_stream_compressor *dsc,
233 	struct dsc_enc_caps *dsc_enc_caps,
234 	int pixel_clock_100Hz)
235 {
236 	// This is a static HW query, so we can use any DSC
237 
238 	memset(dsc_enc_caps, 0, sizeof(struct dsc_enc_caps));
239 	if (dsc)
240 		dsc->funcs->dsc_get_enc_caps(dsc_enc_caps, pixel_clock_100Hz);
241 }
242 
243 /* Returns 'false' if no intersection was found for at least one capablity.
244  * It also implicitly validates some sink caps against invalid value of zero.
245  */
246 static bool intersect_dsc_caps(
247 	const struct dsc_dec_dpcd_caps *dsc_sink_caps,
248 	const struct dsc_enc_caps *dsc_enc_caps,
249 	enum dc_pixel_encoding pixel_encoding,
250 	struct dsc_enc_caps *dsc_common_caps)
251 {
252 	int32_t max_slices;
253 	int32_t total_sink_throughput;
254 
255 	memset(dsc_common_caps, 0, sizeof(struct dsc_enc_caps));
256 
257 	dsc_common_caps->dsc_version = min(dsc_sink_caps->dsc_version, dsc_enc_caps->dsc_version);
258 	if (!dsc_common_caps->dsc_version)
259 		return false;
260 
261 	dsc_common_caps->slice_caps.bits.NUM_SLICES_1 = dsc_sink_caps->slice_caps1.bits.NUM_SLICES_1 && dsc_enc_caps->slice_caps.bits.NUM_SLICES_1;
262 	dsc_common_caps->slice_caps.bits.NUM_SLICES_2 = dsc_sink_caps->slice_caps1.bits.NUM_SLICES_2 && dsc_enc_caps->slice_caps.bits.NUM_SLICES_2;
263 	dsc_common_caps->slice_caps.bits.NUM_SLICES_4 = dsc_sink_caps->slice_caps1.bits.NUM_SLICES_4 && dsc_enc_caps->slice_caps.bits.NUM_SLICES_4;
264 	dsc_common_caps->slice_caps.bits.NUM_SLICES_8 = dsc_sink_caps->slice_caps1.bits.NUM_SLICES_8 && dsc_enc_caps->slice_caps.bits.NUM_SLICES_8;
265 	if (!dsc_common_caps->slice_caps.raw)
266 		return false;
267 
268 	dsc_common_caps->lb_bit_depth = min(dsc_sink_caps->lb_bit_depth, dsc_enc_caps->lb_bit_depth);
269 	if (!dsc_common_caps->lb_bit_depth)
270 		return false;
271 
272 	dsc_common_caps->is_block_pred_supported = dsc_sink_caps->is_block_pred_supported && dsc_enc_caps->is_block_pred_supported;
273 
274 	dsc_common_caps->color_formats.raw = dsc_sink_caps->color_formats.raw & dsc_enc_caps->color_formats.raw;
275 	if (!dsc_common_caps->color_formats.raw)
276 		return false;
277 
278 	dsc_common_caps->color_depth.raw = dsc_sink_caps->color_depth.raw & dsc_enc_caps->color_depth.raw;
279 	if (!dsc_common_caps->color_depth.raw)
280 		return false;
281 
282 	max_slices = 0;
283 	if (dsc_common_caps->slice_caps.bits.NUM_SLICES_1)
284 		max_slices = 1;
285 
286 	if (dsc_common_caps->slice_caps.bits.NUM_SLICES_2)
287 		max_slices = 2;
288 
289 	if (dsc_common_caps->slice_caps.bits.NUM_SLICES_4)
290 		max_slices = 4;
291 
292 	total_sink_throughput = max_slices * dsc_sink_caps->throughput_mode_0_mps;
293 	if (pixel_encoding == PIXEL_ENCODING_YCBCR422 || pixel_encoding == PIXEL_ENCODING_YCBCR420)
294 		total_sink_throughput = max_slices * dsc_sink_caps->throughput_mode_1_mps;
295 
296 	dsc_common_caps->max_total_throughput_mps = min(total_sink_throughput, dsc_enc_caps->max_total_throughput_mps);
297 
298 	dsc_common_caps->max_slice_width = min(dsc_sink_caps->max_slice_width, dsc_enc_caps->max_slice_width);
299 	if (!dsc_common_caps->max_slice_width)
300 		return false;
301 
302 	dsc_common_caps->bpp_increment_div = min(dsc_sink_caps->bpp_increment_div, dsc_enc_caps->bpp_increment_div);
303 
304 	// TODO DSC: Remove this workaround for N422 and 420 once it's fixed, or move it to get_dsc_encoder_caps()
305 	if (pixel_encoding == PIXEL_ENCODING_YCBCR422 || pixel_encoding == PIXEL_ENCODING_YCBCR420)
306 		dsc_common_caps->bpp_increment_div = min(dsc_common_caps->bpp_increment_div, (uint32_t)8);
307 
308 	return true;
309 }
310 
311 static inline uint32_t dsc_div_by_10_round_up(uint32_t value)
312 {
313 	return (value + 9) / 10;
314 }
315 
316 static inline uint32_t calc_dsc_bpp_x16(uint32_t stream_bandwidth_kbps, uint32_t pix_clk_100hz, uint32_t bpp_increment_div)
317 {
318 	uint32_t dsc_target_bpp_x16;
319 	float f_dsc_target_bpp;
320 	float f_stream_bandwidth_100bps = stream_bandwidth_kbps * 10.0f;
321 	uint32_t precision = bpp_increment_div; // bpp_increment_div is actually precision
322 
323 	f_dsc_target_bpp = f_stream_bandwidth_100bps / pix_clk_100hz;
324 
325 	// Round down to the nearest precision stop to bring it into DSC spec range
326 	dsc_target_bpp_x16 = (uint32_t)(f_dsc_target_bpp * precision);
327 	dsc_target_bpp_x16 = (dsc_target_bpp_x16 * 16) / precision;
328 
329 	return dsc_target_bpp_x16;
330 }
331 
332 /* Get DSC bandwidth range based on [min_bpp, max_bpp] target bitrate range, and timing's pixel clock
333  * and uncompressed bandwidth.
334  */
335 static void get_dsc_bandwidth_range(
336 		const uint32_t min_bpp,
337 		const uint32_t max_bpp,
338 		const struct dsc_enc_caps *dsc_caps,
339 		const struct dc_crtc_timing *timing,
340 		struct dc_dsc_bw_range *range)
341 {
342 	/* native stream bandwidth */
343 	range->stream_kbps = dc_dsc_bandwidth_in_kbps_from_timing(timing);
344 
345 	/* max dsc target bpp */
346 	range->max_kbps = dsc_div_by_10_round_up(max_bpp * timing->pix_clk_100hz);
347 	range->max_target_bpp_x16 = max_bpp * 16;
348 	if (range->max_kbps > range->stream_kbps) {
349 		/* max dsc target bpp is capped to native bandwidth */
350 		range->max_kbps = range->stream_kbps;
351 		range->max_target_bpp_x16 = calc_dsc_bpp_x16(range->stream_kbps, timing->pix_clk_100hz, dsc_caps->bpp_increment_div);
352 	}
353 
354 	/* min dsc target bpp */
355 	range->min_kbps = dsc_div_by_10_round_up(min_bpp * timing->pix_clk_100hz);
356 	range->min_target_bpp_x16 = min_bpp * 16;
357 	if (range->min_kbps > range->max_kbps) {
358 		/* min dsc target bpp is capped to max dsc bandwidth*/
359 		range->min_kbps = range->max_kbps;
360 		range->min_target_bpp_x16 = range->max_target_bpp_x16;
361 	}
362 }
363 
364 
365 /* Decides if DSC should be used and calculates target bpp if it should, applying DSC policy.
366  *
367  * Returns:
368  *     - 'true' if DSC was required by policy and was successfully applied
369  *     - 'false' if DSC was not necessary (e.g. if uncompressed stream fits 'target_bandwidth_kbps'),
370  *        or if it couldn't be applied based on DSC policy.
371  */
372 static bool decide_dsc_target_bpp_x16(
373 		const struct dc_dsc_policy *policy,
374 		const struct dsc_enc_caps *dsc_common_caps,
375 		const int target_bandwidth_kbps,
376 		const struct dc_crtc_timing *timing,
377 		int *target_bpp_x16)
378 {
379 	bool should_use_dsc = false;
380 	struct dc_dsc_bw_range range;
381 
382 	memset(&range, 0, sizeof(range));
383 
384 	get_dsc_bandwidth_range(policy->min_target_bpp, policy->max_target_bpp,
385 			dsc_common_caps, timing, &range);
386 	if (target_bandwidth_kbps >= range.stream_kbps) {
387 		/* enough bandwidth without dsc */
388 		*target_bpp_x16 = 0;
389 		should_use_dsc = false;
390 	} else if (target_bandwidth_kbps >= range.max_kbps) {
391 		/* use max target bpp allowed */
392 		*target_bpp_x16 = range.max_target_bpp_x16;
393 		should_use_dsc = true;
394 	} else if (target_bandwidth_kbps >= range.min_kbps) {
395 		/* use target bpp that can take entire target bandwidth */
396 		*target_bpp_x16 = calc_dsc_bpp_x16(target_bandwidth_kbps, timing->pix_clk_100hz, dsc_common_caps->bpp_increment_div);
397 		should_use_dsc = true;
398 	} else {
399 		/* not enough bandwidth to fulfill minimum requirement */
400 		*target_bpp_x16 = 0;
401 		should_use_dsc = false;
402 	}
403 
404 	return should_use_dsc;
405 }
406 
407 #define MIN_AVAILABLE_SLICES_SIZE  4
408 
409 static int get_available_dsc_slices(union dsc_enc_slice_caps slice_caps, int *available_slices)
410 {
411 	int idx = 0;
412 
413 	memset(available_slices, -1, MIN_AVAILABLE_SLICES_SIZE);
414 
415 	if (slice_caps.bits.NUM_SLICES_1)
416 		available_slices[idx++] = 1;
417 
418 	if (slice_caps.bits.NUM_SLICES_2)
419 		available_slices[idx++] = 2;
420 
421 	if (slice_caps.bits.NUM_SLICES_4)
422 		available_slices[idx++] = 4;
423 
424 	if (slice_caps.bits.NUM_SLICES_8)
425 		available_slices[idx++] = 8;
426 
427 	return idx;
428 }
429 
430 
431 static int get_max_dsc_slices(union dsc_enc_slice_caps slice_caps)
432 {
433 	int max_slices = 0;
434 	int available_slices[MIN_AVAILABLE_SLICES_SIZE];
435 	int end_idx = get_available_dsc_slices(slice_caps, &available_slices[0]);
436 
437 	if (end_idx > 0)
438 		max_slices = available_slices[end_idx - 1];
439 
440 	return max_slices;
441 }
442 
443 
444 // Increment sice number in available sice numbers stops if possible, or just increment if not
445 static int inc_num_slices(union dsc_enc_slice_caps slice_caps, int num_slices)
446 {
447 	// Get next bigger num slices available in common caps
448 	int available_slices[MIN_AVAILABLE_SLICES_SIZE];
449 	int end_idx;
450 	int i;
451 	int new_num_slices = num_slices;
452 
453 	end_idx = get_available_dsc_slices(slice_caps, &available_slices[0]);
454 	if (end_idx == 0) {
455 		// No available slices found
456 		new_num_slices++;
457 		return new_num_slices;
458 	}
459 
460 	// Numbers of slices found - get the next bigger number
461 	for (i = 0; i < end_idx; i++) {
462 		if (new_num_slices < available_slices[i]) {
463 			new_num_slices = available_slices[i];
464 			break;
465 		}
466 	}
467 
468 	if (new_num_slices == num_slices) // No biger number of slices found
469 		new_num_slices++;
470 
471 	return new_num_slices;
472 }
473 
474 
475 // Decrement sice number in available sice numbers stops if possible, or just decrement if not. Stop at zero.
476 static int dec_num_slices(union dsc_enc_slice_caps slice_caps, int num_slices)
477 {
478 	// Get next bigger num slices available in common caps
479 	int available_slices[MIN_AVAILABLE_SLICES_SIZE];
480 	int end_idx;
481 	int i;
482 	int new_num_slices = num_slices;
483 
484 	end_idx = get_available_dsc_slices(slice_caps, &available_slices[0]);
485 	if (end_idx == 0 && new_num_slices > 0) {
486 		// No numbers of slices found
487 		new_num_slices++;
488 		return new_num_slices;
489 	}
490 
491 	// Numbers of slices found - get the next smaller number
492 	for (i = end_idx - 1; i >= 0; i--) {
493 		if (new_num_slices > available_slices[i]) {
494 			new_num_slices = available_slices[i];
495 			break;
496 		}
497 	}
498 
499 	if (new_num_slices == num_slices) {
500 		// No smaller number of slices found
501 		new_num_slices--;
502 		if (new_num_slices < 0)
503 			new_num_slices = 0;
504 	}
505 
506 	return new_num_slices;
507 }
508 
509 
510 // Choose next bigger number of slices if the requested number of slices is not available
511 static int fit_num_slices_up(union dsc_enc_slice_caps slice_caps, int num_slices)
512 {
513 	// Get next bigger num slices available in common caps
514 	int available_slices[MIN_AVAILABLE_SLICES_SIZE];
515 	int end_idx;
516 	int i;
517 	int new_num_slices = num_slices;
518 
519 	end_idx = get_available_dsc_slices(slice_caps, &available_slices[0]);
520 	if (end_idx == 0) {
521 		// No available slices found
522 		new_num_slices++;
523 		return new_num_slices;
524 	}
525 
526 	// Numbers of slices found - get the equal or next bigger number
527 	for (i = 0; i < end_idx; i++) {
528 		if (new_num_slices <= available_slices[i]) {
529 			new_num_slices = available_slices[i];
530 			break;
531 		}
532 	}
533 
534 	return new_num_slices;
535 }
536 
537 
538 /* Attempts to set DSC configuration for the stream, applying DSC policy.
539  * Returns 'true' if successful or 'false' if not.
540  *
541  * Parameters:
542  *
543  * dsc_sink_caps       - DSC sink decoder capabilities (from DPCD)
544  *
545  * dsc_enc_caps        - DSC encoder capabilities
546  *
547  * target_bandwidth_kbps  - Target bandwidth to fit the stream into.
548  *                          If 0, do not calculate target bpp.
549  *
550  * timing              - The stream timing to fit into 'target_bandwidth_kbps' or apply
551  *                       maximum compression to, if 'target_badwidth == 0'
552  *
553  * dsc_cfg             - DSC configuration to use if it was possible to come up with
554  *                       one for the given inputs.
555  *                       The target bitrate after DSC can be calculated by multiplying
556  *                       dsc_cfg.bits_per_pixel (in U6.4 format) by pixel rate, e.g.
557  *
558  *                       dsc_stream_bitrate_kbps = (int)ceil(timing->pix_clk_khz * dsc_cfg.bits_per_pixel / 16.0);
559  */
560 static bool setup_dsc_config(
561 		const struct dsc_dec_dpcd_caps *dsc_sink_caps,
562 		const struct dsc_enc_caps *dsc_enc_caps,
563 		int target_bandwidth_kbps,
564 		const struct dc_crtc_timing *timing,
565 		int min_slice_height_override,
566 		struct dc_dsc_config *dsc_cfg)
567 {
568 	struct dsc_enc_caps dsc_common_caps;
569 	int max_slices_h;
570 	int min_slices_h;
571 	int num_slices_h;
572 	int pic_width;
573 	int slice_width;
574 	int target_bpp;
575 	int sink_per_slice_throughput_mps;
576 	int branch_max_throughput_mps = 0;
577 	bool is_dsc_possible = false;
578 	int pic_height;
579 	int slice_height;
580 
581 	memset(dsc_cfg, 0, sizeof(struct dc_dsc_config));
582 
583 	pic_width = timing->h_addressable + timing->h_border_left + timing->h_border_right;
584 	pic_height = timing->v_addressable + timing->v_border_top + timing->v_border_bottom;
585 
586 	if (!dsc_sink_caps->is_dsc_supported)
587 		goto done;
588 
589 	if (dsc_sink_caps->branch_max_line_width && dsc_sink_caps->branch_max_line_width < pic_width)
590 		goto done;
591 
592 	// Intersect decoder with encoder DSC caps and validate DSC settings
593 	is_dsc_possible = intersect_dsc_caps(dsc_sink_caps, dsc_enc_caps, timing->pixel_encoding, &dsc_common_caps);
594 	if (!is_dsc_possible)
595 		goto done;
596 
597 	if (target_bandwidth_kbps > 0) {
598 		is_dsc_possible = decide_dsc_target_bpp_x16(&dsc_policy, &dsc_common_caps, target_bandwidth_kbps, timing, &target_bpp);
599 		dsc_cfg->bits_per_pixel = target_bpp;
600 	}
601 	if (!is_dsc_possible)
602 		goto done;
603 
604 	sink_per_slice_throughput_mps = 0;
605 
606 	// Validate available DSC settings against the mode timing
607 
608 	// Validate color format (and pick up the throughput values)
609 	dsc_cfg->ycbcr422_simple = false;
610 	switch (timing->pixel_encoding)	{
611 	case PIXEL_ENCODING_RGB:
612 		is_dsc_possible = (bool)dsc_common_caps.color_formats.bits.RGB;
613 		sink_per_slice_throughput_mps = dsc_sink_caps->throughput_mode_0_mps;
614 		branch_max_throughput_mps = dsc_sink_caps->branch_overall_throughput_0_mps;
615 		break;
616 	case PIXEL_ENCODING_YCBCR444:
617 		is_dsc_possible = (bool)dsc_common_caps.color_formats.bits.YCBCR_444;
618 		sink_per_slice_throughput_mps = dsc_sink_caps->throughput_mode_0_mps;
619 		branch_max_throughput_mps = dsc_sink_caps->branch_overall_throughput_0_mps;
620 		break;
621 	case PIXEL_ENCODING_YCBCR422:
622 		is_dsc_possible = (bool)dsc_common_caps.color_formats.bits.YCBCR_NATIVE_422;
623 		sink_per_slice_throughput_mps = dsc_sink_caps->throughput_mode_1_mps;
624 		branch_max_throughput_mps = dsc_sink_caps->branch_overall_throughput_1_mps;
625 		if (!is_dsc_possible) {
626 			is_dsc_possible = (bool)dsc_common_caps.color_formats.bits.YCBCR_SIMPLE_422;
627 			dsc_cfg->ycbcr422_simple = is_dsc_possible;
628 			sink_per_slice_throughput_mps = dsc_sink_caps->throughput_mode_0_mps;
629 		}
630 		break;
631 	case PIXEL_ENCODING_YCBCR420:
632 		is_dsc_possible = (bool)dsc_common_caps.color_formats.bits.YCBCR_NATIVE_420;
633 		sink_per_slice_throughput_mps = dsc_sink_caps->throughput_mode_1_mps;
634 		branch_max_throughput_mps = dsc_sink_caps->branch_overall_throughput_1_mps;
635 		break;
636 	default:
637 		is_dsc_possible = false;
638 	}
639 
640 	// Validate branch's maximum throughput
641 	if (branch_max_throughput_mps && dsc_div_by_10_round_up(timing->pix_clk_100hz) > branch_max_throughput_mps * 1000)
642 		is_dsc_possible = false;
643 
644 	if (!is_dsc_possible)
645 		goto done;
646 
647 	// Color depth
648 	switch (timing->display_color_depth) {
649 	case COLOR_DEPTH_888:
650 		is_dsc_possible = (bool)dsc_common_caps.color_depth.bits.COLOR_DEPTH_8_BPC;
651 		break;
652 	case COLOR_DEPTH_101010:
653 		is_dsc_possible = (bool)dsc_common_caps.color_depth.bits.COLOR_DEPTH_10_BPC;
654 		break;
655 	case COLOR_DEPTH_121212:
656 		is_dsc_possible = (bool)dsc_common_caps.color_depth.bits.COLOR_DEPTH_12_BPC;
657 		break;
658 	default:
659 		is_dsc_possible = false;
660 	}
661 
662 	if (!is_dsc_possible)
663 		goto done;
664 
665 	// Slice width (i.e. number of slices per line)
666 	max_slices_h = get_max_dsc_slices(dsc_common_caps.slice_caps);
667 
668 	while (max_slices_h > 0) {
669 		if (pic_width % max_slices_h == 0)
670 			break;
671 
672 		max_slices_h = dec_num_slices(dsc_common_caps.slice_caps, max_slices_h);
673 	}
674 
675 	is_dsc_possible = (dsc_common_caps.max_slice_width > 0);
676 	if (!is_dsc_possible)
677 		goto done;
678 
679 	min_slices_h = pic_width / dsc_common_caps.max_slice_width;
680 	if (pic_width % dsc_common_caps.max_slice_width)
681 		min_slices_h++;
682 
683 	min_slices_h = fit_num_slices_up(dsc_common_caps.slice_caps, min_slices_h);
684 
685 	while (min_slices_h <= max_slices_h) {
686 		int pix_clk_per_slice_khz = dsc_div_by_10_round_up(timing->pix_clk_100hz) / min_slices_h;
687 		if (pix_clk_per_slice_khz <= sink_per_slice_throughput_mps * 1000)
688 			break;
689 
690 		min_slices_h = inc_num_slices(dsc_common_caps.slice_caps, min_slices_h);
691 	}
692 
693 	if (pic_width % min_slices_h != 0)
694 		min_slices_h = 0; // DSC TODO: Maybe try increasing the number of slices first?
695 
696 	is_dsc_possible = (min_slices_h <= max_slices_h);
697 	if (!is_dsc_possible)
698 		goto done;
699 
700 	if (dsc_policy.use_min_slices_h) {
701 		if (min_slices_h > 0)
702 			num_slices_h = min_slices_h;
703 		else if (max_slices_h > 0) { // Fall back to max slices if min slices is not working out
704 			if (dsc_policy.max_slices_h)
705 				num_slices_h = min(dsc_policy.max_slices_h, max_slices_h);
706 			else
707 				num_slices_h = max_slices_h;
708 		} else
709 			is_dsc_possible = false;
710 	} else {
711 		if (max_slices_h > 0) {
712 			if (dsc_policy.max_slices_h)
713 				num_slices_h = min(dsc_policy.max_slices_h, max_slices_h);
714 			else
715 				num_slices_h = max_slices_h;
716 		} else if (min_slices_h > 0) // Fall back to min slices if max slices is not possible
717 			num_slices_h = min_slices_h;
718 		else
719 			is_dsc_possible = false;
720 	}
721 
722 	if (!is_dsc_possible)
723 		goto done;
724 
725 	dsc_cfg->num_slices_h = num_slices_h;
726 	slice_width = pic_width / num_slices_h;
727 
728 	is_dsc_possible = slice_width <= dsc_common_caps.max_slice_width;
729 	if (!is_dsc_possible)
730 		goto done;
731 
732 	// Slice height (i.e. number of slices per column): start with policy and pick the first one that height is divisible by.
733 	// For 4:2:0 make sure the slice height is divisible by 2 as well.
734 	if (min_slice_height_override == 0)
735 		slice_height = min(dsc_policy.min_sice_height, pic_height);
736 	else
737 		slice_height = min(min_slice_height_override, pic_height);
738 
739 	while (slice_height < pic_height && (pic_height % slice_height != 0 ||
740 		(timing->pixel_encoding == PIXEL_ENCODING_YCBCR420 && slice_height % 2 != 0)))
741 		slice_height++;
742 
743 	if (timing->pixel_encoding == PIXEL_ENCODING_YCBCR420) // For the case when pic_height < dsc_policy.min_sice_height
744 		is_dsc_possible = (slice_height % 2 == 0);
745 
746 	if (!is_dsc_possible)
747 		goto done;
748 
749 	dsc_cfg->num_slices_v = pic_height/slice_height;
750 
751 	// Final decission: can we do DSC or not?
752 	if (is_dsc_possible) {
753 		// Fill out the rest of DSC settings
754 		dsc_cfg->block_pred_enable = dsc_common_caps.is_block_pred_supported;
755 		dsc_cfg->linebuf_depth = dsc_common_caps.lb_bit_depth;
756 		dsc_cfg->version_minor = (dsc_common_caps.dsc_version & 0xf0) >> 4;
757 	}
758 
759 done:
760 	if (!is_dsc_possible)
761 		memset(dsc_cfg, 0, sizeof(struct dc_dsc_config));
762 
763 	return is_dsc_possible;
764 }
765 
766 bool dc_dsc_parse_dsc_dpcd(const uint8_t *dpcd_dsc_basic_data, const uint8_t *dpcd_dsc_ext_data, struct dsc_dec_dpcd_caps *dsc_sink_caps)
767 {
768 	if (!dpcd_dsc_basic_data)
769 		return false;
770 
771 	dsc_sink_caps->is_dsc_supported = (dpcd_dsc_basic_data[DP_DSC_SUPPORT - DP_DSC_SUPPORT] & DP_DSC_DECOMPRESSION_IS_SUPPORTED) != 0;
772 	if (!dsc_sink_caps->is_dsc_supported)
773 		return false;
774 
775 	dsc_sink_caps->dsc_version = dpcd_dsc_basic_data[DP_DSC_REV - DP_DSC_SUPPORT];
776 
777 	{
778 		int buff_block_size;
779 		int buff_size;
780 
781 		if (!dsc_buff_block_size_from_dpcd(dpcd_dsc_basic_data[DP_DSC_RC_BUF_BLK_SIZE - DP_DSC_SUPPORT], &buff_block_size))
782 			return false;
783 
784 		buff_size = dpcd_dsc_basic_data[DP_DSC_RC_BUF_SIZE - DP_DSC_SUPPORT] + 1;
785 		dsc_sink_caps->rc_buffer_size = buff_size * buff_block_size;
786 	}
787 
788 	dsc_sink_caps->slice_caps1.raw = dpcd_dsc_basic_data[DP_DSC_SLICE_CAP_1 - DP_DSC_SUPPORT];
789 	if (!dsc_line_buff_depth_from_dpcd(dpcd_dsc_basic_data[DP_DSC_LINE_BUF_BIT_DEPTH - DP_DSC_SUPPORT], &dsc_sink_caps->lb_bit_depth))
790 		return false;
791 
792 	dsc_sink_caps->is_block_pred_supported =
793 		(dpcd_dsc_basic_data[DP_DSC_BLK_PREDICTION_SUPPORT - DP_DSC_SUPPORT] & DP_DSC_BLK_PREDICTION_IS_SUPPORTED) != 0;
794 
795 	dsc_sink_caps->edp_max_bits_per_pixel =
796 		dpcd_dsc_basic_data[DP_DSC_MAX_BITS_PER_PIXEL_LOW - DP_DSC_SUPPORT] |
797 		dpcd_dsc_basic_data[DP_DSC_MAX_BITS_PER_PIXEL_HI - DP_DSC_SUPPORT] << 8;
798 
799 	dsc_sink_caps->color_formats.raw = dpcd_dsc_basic_data[DP_DSC_DEC_COLOR_FORMAT_CAP - DP_DSC_SUPPORT];
800 	dsc_sink_caps->color_depth.raw = dpcd_dsc_basic_data[DP_DSC_DEC_COLOR_DEPTH_CAP - DP_DSC_SUPPORT];
801 
802 	{
803 		int dpcd_throughput = dpcd_dsc_basic_data[DP_DSC_PEAK_THROUGHPUT - DP_DSC_SUPPORT];
804 
805 		if (!dsc_throughput_from_dpcd(dpcd_throughput & DP_DSC_THROUGHPUT_MODE_0_MASK, &dsc_sink_caps->throughput_mode_0_mps))
806 			return false;
807 
808 		dpcd_throughput = (dpcd_throughput & DP_DSC_THROUGHPUT_MODE_1_MASK) >> DP_DSC_THROUGHPUT_MODE_1_SHIFT;
809 		if (!dsc_throughput_from_dpcd(dpcd_throughput, &dsc_sink_caps->throughput_mode_1_mps))
810 			return false;
811 	}
812 
813 	dsc_sink_caps->max_slice_width = dpcd_dsc_basic_data[DP_DSC_MAX_SLICE_WIDTH - DP_DSC_SUPPORT] * 320;
814 	dsc_sink_caps->slice_caps2.raw = dpcd_dsc_basic_data[DP_DSC_SLICE_CAP_2 - DP_DSC_SUPPORT];
815 
816 	if (!dsc_bpp_increment_div_from_dpcd(dpcd_dsc_basic_data[DP_DSC_BITS_PER_PIXEL_INC - DP_DSC_SUPPORT], &dsc_sink_caps->bpp_increment_div))
817 		return false;
818 
819 	/* Extended caps */
820 	if (dpcd_dsc_ext_data == NULL) { // Extended DPCD DSC data can be null, e.g. because it doesn't apply to SST
821 		dsc_sink_caps->branch_overall_throughput_0_mps = 0;
822 		dsc_sink_caps->branch_overall_throughput_1_mps = 0;
823 		dsc_sink_caps->branch_max_line_width = 0;
824 		return true;
825 	}
826 
827 	dsc_sink_caps->branch_overall_throughput_0_mps = dpcd_dsc_ext_data[DP_DSC_BRANCH_OVERALL_THROUGHPUT_0 - DP_DSC_BRANCH_OVERALL_THROUGHPUT_0];
828 	if (dsc_sink_caps->branch_overall_throughput_0_mps == 0)
829 		dsc_sink_caps->branch_overall_throughput_0_mps = 0;
830 	else if (dsc_sink_caps->branch_overall_throughput_0_mps == 1)
831 		dsc_sink_caps->branch_overall_throughput_0_mps = 680;
832 	else {
833 		dsc_sink_caps->branch_overall_throughput_0_mps *= 50;
834 		dsc_sink_caps->branch_overall_throughput_0_mps += 600;
835 	}
836 
837 	dsc_sink_caps->branch_overall_throughput_1_mps = dpcd_dsc_ext_data[DP_DSC_BRANCH_OVERALL_THROUGHPUT_1 - DP_DSC_BRANCH_OVERALL_THROUGHPUT_0];
838 	if (dsc_sink_caps->branch_overall_throughput_1_mps == 0)
839 		dsc_sink_caps->branch_overall_throughput_1_mps = 0;
840 	else if (dsc_sink_caps->branch_overall_throughput_1_mps == 1)
841 		dsc_sink_caps->branch_overall_throughput_1_mps = 680;
842 	else {
843 		dsc_sink_caps->branch_overall_throughput_1_mps *= 50;
844 		dsc_sink_caps->branch_overall_throughput_1_mps += 600;
845 	}
846 
847 	dsc_sink_caps->branch_max_line_width = dpcd_dsc_ext_data[DP_DSC_BRANCH_MAX_LINE_WIDTH - DP_DSC_BRANCH_OVERALL_THROUGHPUT_0] * 320;
848 	ASSERT(dsc_sink_caps->branch_max_line_width == 0 || dsc_sink_caps->branch_max_line_width >= 5120);
849 
850 	return true;
851 }
852 
853 
854 /* If DSC is possbile, get DSC bandwidth range based on [min_bpp, max_bpp] target bitrate range and
855  * timing's pixel clock and uncompressed bandwidth.
856  * If DSC is not possible, leave '*range' untouched.
857  */
858 bool dc_dsc_compute_bandwidth_range(
859 		const struct display_stream_compressor *dsc,
860 		const uint32_t dsc_min_slice_height_override,
861 		const uint32_t min_bpp,
862 		const uint32_t max_bpp,
863 		const struct dsc_dec_dpcd_caps *dsc_sink_caps,
864 		const struct dc_crtc_timing *timing,
865 		struct dc_dsc_bw_range *range)
866 {
867 	bool is_dsc_possible = false;
868 	struct dsc_enc_caps dsc_enc_caps;
869 	struct dsc_enc_caps dsc_common_caps;
870 	struct dc_dsc_config config;
871 
872 	get_dsc_enc_caps(dsc, &dsc_enc_caps, timing->pix_clk_100hz);
873 
874 	is_dsc_possible = intersect_dsc_caps(dsc_sink_caps, &dsc_enc_caps,
875 			timing->pixel_encoding, &dsc_common_caps);
876 
877 	if (is_dsc_possible)
878 		is_dsc_possible = setup_dsc_config(dsc_sink_caps, &dsc_enc_caps, 0, timing,
879 				dsc_min_slice_height_override, &config);
880 
881 	if (is_dsc_possible)
882 		get_dsc_bandwidth_range(min_bpp, max_bpp, &dsc_common_caps, timing, range);
883 
884 	return is_dsc_possible;
885 }
886 
887 bool dc_dsc_compute_config(
888 		const struct display_stream_compressor *dsc,
889 		const struct dsc_dec_dpcd_caps *dsc_sink_caps,
890 		const uint32_t dsc_min_slice_height_override,
891 		uint32_t target_bandwidth_kbps,
892 		const struct dc_crtc_timing *timing,
893 		struct dc_dsc_config *dsc_cfg)
894 {
895 	bool is_dsc_possible = false;
896 	struct dsc_enc_caps dsc_enc_caps;
897 
898 	get_dsc_enc_caps(dsc, &dsc_enc_caps, timing->pix_clk_100hz);
899 	is_dsc_possible = setup_dsc_config(dsc_sink_caps,
900 			&dsc_enc_caps,
901 			target_bandwidth_kbps,
902 			timing, dsc_min_slice_height_override, dsc_cfg);
903 	return is_dsc_possible;
904 }
905