kernel/drivers/gpu/drm/amd/display/dc/dsc/dc_dsc.c
2024-07-22 17:22:30 +08:00

1103 lines
35 KiB
C

/*
* Copyright 2019 Advanced Micro Devices, Inc.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*
* Author: AMD
*/
#include <drm/drm_dsc.h>
#include "dc_hw_types.h"
#include "dsc.h"
#include <drm/drm_dp_helper.h>
#include "dc.h"
#include "rc_calc.h"
#include "fixed31_32.h"
/* This module's internal functions */
/* default DSC policy target bitrate limit is 16bpp */
static uint32_t dsc_policy_max_target_bpp_limit = 16;
/* default DSC policy enables DSC only when needed */
static bool dsc_policy_enable_dsc_when_not_needed;
static bool dsc_policy_disable_dsc_stream_overhead;
/* Forward Declerations */
static void get_dsc_bandwidth_range(
const uint32_t min_bpp_x16,
const uint32_t max_bpp_x16,
const uint32_t num_slices_h,
const struct dsc_enc_caps *dsc_caps,
const struct dc_crtc_timing *timing,
struct dc_dsc_bw_range *range);
static uint32_t compute_bpp_x16_from_target_bandwidth(
const uint32_t bandwidth_in_kbps,
const struct dc_crtc_timing *timing,
const uint32_t num_slices_h,
const uint32_t bpp_increment_div,
const bool is_dp);
static void get_dsc_enc_caps(
const struct display_stream_compressor *dsc,
struct dsc_enc_caps *dsc_enc_caps,
int pixel_clock_100Hz);
static bool intersect_dsc_caps(
const struct dsc_dec_dpcd_caps *dsc_sink_caps,
const struct dsc_enc_caps *dsc_enc_caps,
enum dc_pixel_encoding pixel_encoding,
struct dsc_enc_caps *dsc_common_caps);
static bool setup_dsc_config(
const struct dsc_dec_dpcd_caps *dsc_sink_caps,
const struct dsc_enc_caps *dsc_enc_caps,
int target_bandwidth_kbps,
const struct dc_crtc_timing *timing,
int min_slice_height_override,
int max_dsc_target_bpp_limit_override_x16,
struct dc_dsc_config *dsc_cfg);
static struct fixed31_32 compute_dsc_max_bandwidth_overhead(
const struct dc_crtc_timing *timing,
const int num_slices_h,
const bool is_dp);
static bool dsc_buff_block_size_from_dpcd(int dpcd_buff_block_size, int *buff_block_size)
{
switch (dpcd_buff_block_size) {
case DP_DSC_RC_BUF_BLK_SIZE_1:
*buff_block_size = 1024;
break;
case DP_DSC_RC_BUF_BLK_SIZE_4:
*buff_block_size = 4 * 1024;
break;
case DP_DSC_RC_BUF_BLK_SIZE_16:
*buff_block_size = 16 * 1024;
break;
case DP_DSC_RC_BUF_BLK_SIZE_64:
*buff_block_size = 64 * 1024;
break;
default: {
dm_error("%s: DPCD DSC buffer size not recognized.\n", __func__);
return false;
}
}
return true;
}
static bool dsc_line_buff_depth_from_dpcd(int dpcd_line_buff_bit_depth, int *line_buff_bit_depth)
{
if (0 <= dpcd_line_buff_bit_depth && dpcd_line_buff_bit_depth <= 7)
*line_buff_bit_depth = dpcd_line_buff_bit_depth + 9;
else if (dpcd_line_buff_bit_depth == 8)
*line_buff_bit_depth = 8;
else {
dm_error("%s: DPCD DSC buffer depth not recognized.\n", __func__);
return false;
}
return true;
}
static bool dsc_throughput_from_dpcd(int dpcd_throughput, int *throughput)
{
switch (dpcd_throughput) {
case DP_DSC_THROUGHPUT_MODE_0_UNSUPPORTED:
*throughput = 0;
break;
case DP_DSC_THROUGHPUT_MODE_0_170:
*throughput = 170;
break;
case DP_DSC_THROUGHPUT_MODE_0_340:
*throughput = 340;
break;
case DP_DSC_THROUGHPUT_MODE_0_400:
*throughput = 400;
break;
case DP_DSC_THROUGHPUT_MODE_0_450:
*throughput = 450;
break;
case DP_DSC_THROUGHPUT_MODE_0_500:
*throughput = 500;
break;
case DP_DSC_THROUGHPUT_MODE_0_550:
*throughput = 550;
break;
case DP_DSC_THROUGHPUT_MODE_0_600:
*throughput = 600;
break;
case DP_DSC_THROUGHPUT_MODE_0_650:
*throughput = 650;
break;
case DP_DSC_THROUGHPUT_MODE_0_700:
*throughput = 700;
break;
case DP_DSC_THROUGHPUT_MODE_0_750:
*throughput = 750;
break;
case DP_DSC_THROUGHPUT_MODE_0_800:
*throughput = 800;
break;
case DP_DSC_THROUGHPUT_MODE_0_850:
*throughput = 850;
break;
case DP_DSC_THROUGHPUT_MODE_0_900:
*throughput = 900;
break;
case DP_DSC_THROUGHPUT_MODE_0_950:
*throughput = 950;
break;
case DP_DSC_THROUGHPUT_MODE_0_1000:
*throughput = 1000;
break;
default: {
dm_error("%s: DPCD DSC throughput mode not recognized.\n", __func__);
return false;
}
}
return true;
}
static bool dsc_bpp_increment_div_from_dpcd(uint8_t bpp_increment_dpcd, uint32_t *bpp_increment_div)
{
// Mask bpp increment dpcd field to avoid reading other fields
bpp_increment_dpcd &= 0x7;
switch (bpp_increment_dpcd) {
case 0:
*bpp_increment_div = 16;
break;
case 1:
*bpp_increment_div = 8;
break;
case 2:
*bpp_increment_div = 4;
break;
case 3:
*bpp_increment_div = 2;
break;
case 4:
*bpp_increment_div = 1;
break;
default: {
dm_error("%s: DPCD DSC bits-per-pixel increment not recognized.\n", __func__);
return false;
}
}
return true;
}
bool dc_dsc_parse_dsc_dpcd(const struct dc *dc,
const uint8_t *dpcd_dsc_basic_data,
const uint8_t *dpcd_dsc_branch_decoder_caps,
struct dsc_dec_dpcd_caps *dsc_sink_caps)
{
if (!dpcd_dsc_basic_data)
return false;
dsc_sink_caps->is_dsc_supported =
(dpcd_dsc_basic_data[DP_DSC_SUPPORT - DP_DSC_SUPPORT] & DP_DSC_DECOMPRESSION_IS_SUPPORTED) != 0;
if (!dsc_sink_caps->is_dsc_supported)
return false;
dsc_sink_caps->dsc_version = dpcd_dsc_basic_data[DP_DSC_REV - DP_DSC_SUPPORT];
{
int buff_block_size;
int buff_size;
if (!dsc_buff_block_size_from_dpcd(dpcd_dsc_basic_data[DP_DSC_RC_BUF_BLK_SIZE - DP_DSC_SUPPORT],
&buff_block_size))
return false;
buff_size = dpcd_dsc_basic_data[DP_DSC_RC_BUF_SIZE - DP_DSC_SUPPORT] + 1;
dsc_sink_caps->rc_buffer_size = buff_size * buff_block_size;
}
dsc_sink_caps->slice_caps1.raw = dpcd_dsc_basic_data[DP_DSC_SLICE_CAP_1 - DP_DSC_SUPPORT];
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))
return false;
dsc_sink_caps->is_block_pred_supported =
(dpcd_dsc_basic_data[DP_DSC_BLK_PREDICTION_SUPPORT - DP_DSC_SUPPORT] &
DP_DSC_BLK_PREDICTION_IS_SUPPORTED) != 0;
dsc_sink_caps->edp_max_bits_per_pixel =
dpcd_dsc_basic_data[DP_DSC_MAX_BITS_PER_PIXEL_LOW - DP_DSC_SUPPORT] |
dpcd_dsc_basic_data[DP_DSC_MAX_BITS_PER_PIXEL_HI - DP_DSC_SUPPORT] << 8;
dsc_sink_caps->color_formats.raw = dpcd_dsc_basic_data[DP_DSC_DEC_COLOR_FORMAT_CAP - DP_DSC_SUPPORT];
dsc_sink_caps->color_depth.raw = dpcd_dsc_basic_data[DP_DSC_DEC_COLOR_DEPTH_CAP - DP_DSC_SUPPORT];
{
int dpcd_throughput = dpcd_dsc_basic_data[DP_DSC_PEAK_THROUGHPUT - DP_DSC_SUPPORT];
if (!dsc_throughput_from_dpcd(dpcd_throughput & DP_DSC_THROUGHPUT_MODE_0_MASK,
&dsc_sink_caps->throughput_mode_0_mps))
return false;
dpcd_throughput = (dpcd_throughput & DP_DSC_THROUGHPUT_MODE_1_MASK) >> DP_DSC_THROUGHPUT_MODE_1_SHIFT;
if (!dsc_throughput_from_dpcd(dpcd_throughput, &dsc_sink_caps->throughput_mode_1_mps))
return false;
}
dsc_sink_caps->max_slice_width = dpcd_dsc_basic_data[DP_DSC_MAX_SLICE_WIDTH - DP_DSC_SUPPORT] * 320;
dsc_sink_caps->slice_caps2.raw = dpcd_dsc_basic_data[DP_DSC_SLICE_CAP_2 - DP_DSC_SUPPORT];
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))
return false;
if (dc->debug.dsc_bpp_increment_div) {
/* dsc_bpp_increment_div should onl be 1, 2, 4, 8 or 16, but rather than rejecting invalid values,
* we'll accept all and get it into range. This also makes the above check against 0 redundant,
* but that one stresses out the override will be only used if it's not 0.
*/
if (dc->debug.dsc_bpp_increment_div >= 1)
dsc_sink_caps->bpp_increment_div = 1;
if (dc->debug.dsc_bpp_increment_div >= 2)
dsc_sink_caps->bpp_increment_div = 2;
if (dc->debug.dsc_bpp_increment_div >= 4)
dsc_sink_caps->bpp_increment_div = 4;
if (dc->debug.dsc_bpp_increment_div >= 8)
dsc_sink_caps->bpp_increment_div = 8;
if (dc->debug.dsc_bpp_increment_div >= 16)
dsc_sink_caps->bpp_increment_div = 16;
}
/* Extended caps */
if (dpcd_dsc_branch_decoder_caps == NULL) { // branch decoder DPCD DSC data can be null for non branch device
dsc_sink_caps->branch_overall_throughput_0_mps = 0;
dsc_sink_caps->branch_overall_throughput_1_mps = 0;
dsc_sink_caps->branch_max_line_width = 0;
return true;
}
dsc_sink_caps->branch_overall_throughput_0_mps =
dpcd_dsc_branch_decoder_caps[DP_DSC_BRANCH_OVERALL_THROUGHPUT_0 - DP_DSC_BRANCH_OVERALL_THROUGHPUT_0];
if (dsc_sink_caps->branch_overall_throughput_0_mps == 0)
dsc_sink_caps->branch_overall_throughput_0_mps = 0;
else if (dsc_sink_caps->branch_overall_throughput_0_mps == 1)
dsc_sink_caps->branch_overall_throughput_0_mps = 680;
else {
dsc_sink_caps->branch_overall_throughput_0_mps *= 50;
dsc_sink_caps->branch_overall_throughput_0_mps += 600;
}
dsc_sink_caps->branch_overall_throughput_1_mps =
dpcd_dsc_branch_decoder_caps[DP_DSC_BRANCH_OVERALL_THROUGHPUT_1 - DP_DSC_BRANCH_OVERALL_THROUGHPUT_0];
if (dsc_sink_caps->branch_overall_throughput_1_mps == 0)
dsc_sink_caps->branch_overall_throughput_1_mps = 0;
else if (dsc_sink_caps->branch_overall_throughput_1_mps == 1)
dsc_sink_caps->branch_overall_throughput_1_mps = 680;
else {
dsc_sink_caps->branch_overall_throughput_1_mps *= 50;
dsc_sink_caps->branch_overall_throughput_1_mps += 600;
}
dsc_sink_caps->branch_max_line_width =
dpcd_dsc_branch_decoder_caps[DP_DSC_BRANCH_MAX_LINE_WIDTH - DP_DSC_BRANCH_OVERALL_THROUGHPUT_0] * 320;
ASSERT(dsc_sink_caps->branch_max_line_width == 0 || dsc_sink_caps->branch_max_line_width >= 5120);
dsc_sink_caps->is_dp = true;
return true;
}
/* If DSC is possbile, get DSC bandwidth range based on [min_bpp, max_bpp] target bitrate range and
* timing's pixel clock and uncompressed bandwidth.
* If DSC is not possible, leave '*range' untouched.
*/
bool dc_dsc_compute_bandwidth_range(
const struct display_stream_compressor *dsc,
uint32_t dsc_min_slice_height_override,
uint32_t min_bpp_x16,
uint32_t max_bpp_x16,
const struct dsc_dec_dpcd_caps *dsc_sink_caps,
const struct dc_crtc_timing *timing,
struct dc_dsc_bw_range *range)
{
bool is_dsc_possible = false;
struct dsc_enc_caps dsc_enc_caps;
struct dsc_enc_caps dsc_common_caps;
struct dc_dsc_config config;
get_dsc_enc_caps(dsc, &dsc_enc_caps, timing->pix_clk_100hz);
is_dsc_possible = intersect_dsc_caps(dsc_sink_caps, &dsc_enc_caps,
timing->pixel_encoding, &dsc_common_caps);
if (is_dsc_possible)
is_dsc_possible = setup_dsc_config(dsc_sink_caps, &dsc_enc_caps, 0, timing,
dsc_min_slice_height_override, max_bpp_x16, &config);
if (is_dsc_possible)
get_dsc_bandwidth_range(min_bpp_x16, max_bpp_x16,
config.num_slices_h, &dsc_common_caps, timing, range);
return is_dsc_possible;
}
static void get_dsc_enc_caps(
const struct display_stream_compressor *dsc,
struct dsc_enc_caps *dsc_enc_caps,
int pixel_clock_100Hz)
{
// This is a static HW query, so we can use any DSC
memset(dsc_enc_caps, 0, sizeof(struct dsc_enc_caps));
if (dsc) {
if (!dsc->ctx->dc->debug.disable_dsc)
dsc->funcs->dsc_get_enc_caps(dsc_enc_caps, pixel_clock_100Hz);
if (dsc->ctx->dc->debug.native422_support)
dsc_enc_caps->color_formats.bits.YCBCR_NATIVE_422 = 1;
}
}
/* Returns 'false' if no intersection was found for at least one capability.
* It also implicitly validates some sink caps against invalid value of zero.
*/
static bool intersect_dsc_caps(
const struct dsc_dec_dpcd_caps *dsc_sink_caps,
const struct dsc_enc_caps *dsc_enc_caps,
enum dc_pixel_encoding pixel_encoding,
struct dsc_enc_caps *dsc_common_caps)
{
int32_t max_slices;
int32_t total_sink_throughput;
memset(dsc_common_caps, 0, sizeof(struct dsc_enc_caps));
dsc_common_caps->dsc_version = min(dsc_sink_caps->dsc_version, dsc_enc_caps->dsc_version);
if (!dsc_common_caps->dsc_version)
return false;
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;
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;
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;
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;
if (!dsc_common_caps->slice_caps.raw)
return false;
dsc_common_caps->lb_bit_depth = min(dsc_sink_caps->lb_bit_depth, dsc_enc_caps->lb_bit_depth);
if (!dsc_common_caps->lb_bit_depth)
return false;
dsc_common_caps->is_block_pred_supported =
dsc_sink_caps->is_block_pred_supported && dsc_enc_caps->is_block_pred_supported;
dsc_common_caps->color_formats.raw = dsc_sink_caps->color_formats.raw & dsc_enc_caps->color_formats.raw;
if (!dsc_common_caps->color_formats.raw)
return false;
dsc_common_caps->color_depth.raw = dsc_sink_caps->color_depth.raw & dsc_enc_caps->color_depth.raw;
if (!dsc_common_caps->color_depth.raw)
return false;
max_slices = 0;
if (dsc_common_caps->slice_caps.bits.NUM_SLICES_1)
max_slices = 1;
if (dsc_common_caps->slice_caps.bits.NUM_SLICES_2)
max_slices = 2;
if (dsc_common_caps->slice_caps.bits.NUM_SLICES_4)
max_slices = 4;
total_sink_throughput = max_slices * dsc_sink_caps->throughput_mode_0_mps;
if (pixel_encoding == PIXEL_ENCODING_YCBCR422 || pixel_encoding == PIXEL_ENCODING_YCBCR420)
total_sink_throughput = max_slices * dsc_sink_caps->throughput_mode_1_mps;
dsc_common_caps->max_total_throughput_mps = min(total_sink_throughput, dsc_enc_caps->max_total_throughput_mps);
dsc_common_caps->max_slice_width = min(dsc_sink_caps->max_slice_width, dsc_enc_caps->max_slice_width);
if (!dsc_common_caps->max_slice_width)
return false;
dsc_common_caps->bpp_increment_div = min(dsc_sink_caps->bpp_increment_div, dsc_enc_caps->bpp_increment_div);
// TODO DSC: Remove this workaround for N422 and 420 once it's fixed, or move it to get_dsc_encoder_caps()
if (pixel_encoding == PIXEL_ENCODING_YCBCR422 || pixel_encoding == PIXEL_ENCODING_YCBCR420)
dsc_common_caps->bpp_increment_div = min(dsc_common_caps->bpp_increment_div, (uint32_t)8);
dsc_common_caps->is_dp = dsc_sink_caps->is_dp;
return true;
}
static inline uint32_t dsc_div_by_10_round_up(uint32_t value)
{
return (value + 9) / 10;
}
static struct fixed31_32 compute_dsc_max_bandwidth_overhead(
const struct dc_crtc_timing *timing,
const int num_slices_h,
const bool is_dp)
{
struct fixed31_32 max_dsc_overhead;
struct fixed31_32 refresh_rate;
if (dsc_policy_disable_dsc_stream_overhead || !is_dp)
return dc_fixpt_from_int(0);
/* use target bpp that can take entire target bandwidth */
refresh_rate = dc_fixpt_from_int(timing->pix_clk_100hz);
refresh_rate = dc_fixpt_div_int(refresh_rate, timing->h_total);
refresh_rate = dc_fixpt_div_int(refresh_rate, timing->v_total);
refresh_rate = dc_fixpt_mul_int(refresh_rate, 100);
max_dsc_overhead = dc_fixpt_from_int(num_slices_h);
max_dsc_overhead = dc_fixpt_mul_int(max_dsc_overhead, timing->v_total);
max_dsc_overhead = dc_fixpt_mul_int(max_dsc_overhead, 256);
max_dsc_overhead = dc_fixpt_div_int(max_dsc_overhead, 1000);
max_dsc_overhead = dc_fixpt_mul(max_dsc_overhead, refresh_rate);
return max_dsc_overhead;
}
static uint32_t compute_bpp_x16_from_target_bandwidth(
const uint32_t bandwidth_in_kbps,
const struct dc_crtc_timing *timing,
const uint32_t num_slices_h,
const uint32_t bpp_increment_div,
const bool is_dp)
{
struct fixed31_32 overhead_in_kbps;
struct fixed31_32 effective_bandwidth_in_kbps;
struct fixed31_32 bpp_x16;
overhead_in_kbps = compute_dsc_max_bandwidth_overhead(
timing, num_slices_h, is_dp);
effective_bandwidth_in_kbps = dc_fixpt_from_int(bandwidth_in_kbps);
effective_bandwidth_in_kbps = dc_fixpt_sub(effective_bandwidth_in_kbps,
overhead_in_kbps);
bpp_x16 = dc_fixpt_mul_int(effective_bandwidth_in_kbps, 10);
bpp_x16 = dc_fixpt_div_int(bpp_x16, timing->pix_clk_100hz);
bpp_x16 = dc_fixpt_from_int(dc_fixpt_floor(dc_fixpt_mul_int(bpp_x16, bpp_increment_div)));
bpp_x16 = dc_fixpt_div_int(bpp_x16, bpp_increment_div);
bpp_x16 = dc_fixpt_mul_int(bpp_x16, 16);
return dc_fixpt_floor(bpp_x16);
}
/* Get DSC bandwidth range based on [min_bpp, max_bpp] target bitrate range, and timing's pixel clock
* and uncompressed bandwidth.
*/
static void get_dsc_bandwidth_range(
const uint32_t min_bpp_x16,
const uint32_t max_bpp_x16,
const uint32_t num_slices_h,
const struct dsc_enc_caps *dsc_caps,
const struct dc_crtc_timing *timing,
struct dc_dsc_bw_range *range)
{
/* native stream bandwidth */
range->stream_kbps = dc_bandwidth_in_kbps_from_timing(timing);
/* max dsc target bpp */
range->max_kbps = dc_dsc_stream_bandwidth_in_kbps(timing,
max_bpp_x16, num_slices_h, dsc_caps->is_dp);
range->max_target_bpp_x16 = max_bpp_x16;
if (range->max_kbps > range->stream_kbps) {
/* max dsc target bpp is capped to native bandwidth */
range->max_kbps = range->stream_kbps;
range->max_target_bpp_x16 = compute_bpp_x16_from_target_bandwidth(
range->max_kbps, timing, num_slices_h,
dsc_caps->bpp_increment_div,
dsc_caps->is_dp);
}
/* min dsc target bpp */
range->min_kbps = dc_dsc_stream_bandwidth_in_kbps(timing,
min_bpp_x16, num_slices_h, dsc_caps->is_dp);
range->min_target_bpp_x16 = min_bpp_x16;
if (range->min_kbps > range->max_kbps) {
/* min dsc target bpp is capped to max dsc bandwidth*/
range->min_kbps = range->max_kbps;
range->min_target_bpp_x16 = range->max_target_bpp_x16;
}
}
/* Decides if DSC should be used and calculates target bpp if it should, applying DSC policy.
*
* Returns:
* - 'true' if DSC was required by policy and was successfully applied
* - 'false' if DSC was not necessary (e.g. if uncompressed stream fits 'target_bandwidth_kbps'),
* or if it couldn't be applied based on DSC policy.
*/
static bool decide_dsc_target_bpp_x16(
const struct dc_dsc_policy *policy,
const struct dsc_enc_caps *dsc_common_caps,
const int target_bandwidth_kbps,
const struct dc_crtc_timing *timing,
const int num_slices_h,
int *target_bpp_x16)
{
bool should_use_dsc = false;
struct dc_dsc_bw_range range;
memset(&range, 0, sizeof(range));
get_dsc_bandwidth_range(policy->min_target_bpp * 16, policy->max_target_bpp * 16,
num_slices_h, dsc_common_caps, timing, &range);
if (!policy->enable_dsc_when_not_needed && target_bandwidth_kbps >= range.stream_kbps) {
/* enough bandwidth without dsc */
*target_bpp_x16 = 0;
should_use_dsc = false;
} else if (policy->preferred_bpp_x16 > 0 &&
policy->preferred_bpp_x16 <= range.max_target_bpp_x16 &&
policy->preferred_bpp_x16 >= range.min_target_bpp_x16) {
*target_bpp_x16 = policy->preferred_bpp_x16;
should_use_dsc = true;
} else if (target_bandwidth_kbps >= range.max_kbps) {
/* use max target bpp allowed */
*target_bpp_x16 = range.max_target_bpp_x16;
should_use_dsc = true;
} else if (target_bandwidth_kbps >= range.min_kbps) {
/* use target bpp that can take entire target bandwidth */
*target_bpp_x16 = compute_bpp_x16_from_target_bandwidth(
target_bandwidth_kbps, timing, num_slices_h,
dsc_common_caps->bpp_increment_div,
dsc_common_caps->is_dp);
should_use_dsc = true;
} else {
/* not enough bandwidth to fulfill minimum requirement */
*target_bpp_x16 = 0;
should_use_dsc = false;
}
return should_use_dsc;
}
#define MIN_AVAILABLE_SLICES_SIZE 4
static int get_available_dsc_slices(union dsc_enc_slice_caps slice_caps, int *available_slices)
{
int idx = 0;
memset(available_slices, -1, MIN_AVAILABLE_SLICES_SIZE);
if (slice_caps.bits.NUM_SLICES_1)
available_slices[idx++] = 1;
if (slice_caps.bits.NUM_SLICES_2)
available_slices[idx++] = 2;
if (slice_caps.bits.NUM_SLICES_4)
available_slices[idx++] = 4;
if (slice_caps.bits.NUM_SLICES_8)
available_slices[idx++] = 8;
return idx;
}
static int get_max_dsc_slices(union dsc_enc_slice_caps slice_caps)
{
int max_slices = 0;
int available_slices[MIN_AVAILABLE_SLICES_SIZE];
int end_idx = get_available_dsc_slices(slice_caps, &available_slices[0]);
if (end_idx > 0)
max_slices = available_slices[end_idx - 1];
return max_slices;
}
// Increment sice number in available sice numbers stops if possible, or just increment if not
static int inc_num_slices(union dsc_enc_slice_caps slice_caps, int num_slices)
{
// Get next bigger num slices available in common caps
int available_slices[MIN_AVAILABLE_SLICES_SIZE];
int end_idx;
int i;
int new_num_slices = num_slices;
end_idx = get_available_dsc_slices(slice_caps, &available_slices[0]);
if (end_idx == 0) {
// No available slices found
new_num_slices++;
return new_num_slices;
}
// Numbers of slices found - get the next bigger number
for (i = 0; i < end_idx; i++) {
if (new_num_slices < available_slices[i]) {
new_num_slices = available_slices[i];
break;
}
}
if (new_num_slices == num_slices) // No biger number of slices found
new_num_slices++;
return new_num_slices;
}
// Decrement sice number in available sice numbers stops if possible, or just decrement if not. Stop at zero.
static int dec_num_slices(union dsc_enc_slice_caps slice_caps, int num_slices)
{
// Get next bigger num slices available in common caps
int available_slices[MIN_AVAILABLE_SLICES_SIZE];
int end_idx;
int i;
int new_num_slices = num_slices;
end_idx = get_available_dsc_slices(slice_caps, &available_slices[0]);
if (end_idx == 0 && new_num_slices > 0) {
// No numbers of slices found
new_num_slices++;
return new_num_slices;
}
// Numbers of slices found - get the next smaller number
for (i = end_idx - 1; i >= 0; i--) {
if (new_num_slices > available_slices[i]) {
new_num_slices = available_slices[i];
break;
}
}
if (new_num_slices == num_slices) {
// No smaller number of slices found
new_num_slices--;
if (new_num_slices < 0)
new_num_slices = 0;
}
return new_num_slices;
}
// Choose next bigger number of slices if the requested number of slices is not available
static int fit_num_slices_up(union dsc_enc_slice_caps slice_caps, int num_slices)
{
// Get next bigger num slices available in common caps
int available_slices[MIN_AVAILABLE_SLICES_SIZE];
int end_idx;
int i;
int new_num_slices = num_slices;
end_idx = get_available_dsc_slices(slice_caps, &available_slices[0]);
if (end_idx == 0) {
// No available slices found
new_num_slices++;
return new_num_slices;
}
// Numbers of slices found - get the equal or next bigger number
for (i = 0; i < end_idx; i++) {
if (new_num_slices <= available_slices[i]) {
new_num_slices = available_slices[i];
break;
}
}
return new_num_slices;
}
/* Attempts to set DSC configuration for the stream, applying DSC policy.
* Returns 'true' if successful or 'false' if not.
*
* Parameters:
*
* dsc_sink_caps - DSC sink decoder capabilities (from DPCD)
*
* dsc_enc_caps - DSC encoder capabilities
*
* target_bandwidth_kbps - Target bandwidth to fit the stream into.
* If 0, do not calculate target bpp.
*
* timing - The stream timing to fit into 'target_bandwidth_kbps' or apply
* maximum compression to, if 'target_badwidth == 0'
*
* dsc_cfg - DSC configuration to use if it was possible to come up with
* one for the given inputs.
* The target bitrate after DSC can be calculated by multiplying
* dsc_cfg.bits_per_pixel (in U6.4 format) by pixel rate, e.g.
*
* dsc_stream_bitrate_kbps = (int)ceil(timing->pix_clk_khz * dsc_cfg.bits_per_pixel / 16.0);
*/
static bool setup_dsc_config(
const struct dsc_dec_dpcd_caps *dsc_sink_caps,
const struct dsc_enc_caps *dsc_enc_caps,
int target_bandwidth_kbps,
const struct dc_crtc_timing *timing,
int min_slice_height_override,
int max_dsc_target_bpp_limit_override_x16,
struct dc_dsc_config *dsc_cfg)
{
struct dsc_enc_caps dsc_common_caps;
int max_slices_h;
int min_slices_h;
int num_slices_h;
int pic_width;
int slice_width;
int target_bpp;
int sink_per_slice_throughput_mps;
int branch_max_throughput_mps = 0;
bool is_dsc_possible = false;
int pic_height;
int slice_height;
struct dc_dsc_policy policy;
memset(dsc_cfg, 0, sizeof(struct dc_dsc_config));
dc_dsc_get_policy_for_timing(timing, max_dsc_target_bpp_limit_override_x16, &policy);
pic_width = timing->h_addressable + timing->h_border_left + timing->h_border_right;
pic_height = timing->v_addressable + timing->v_border_top + timing->v_border_bottom;
if (!dsc_sink_caps->is_dsc_supported)
goto done;
if (dsc_sink_caps->branch_max_line_width && dsc_sink_caps->branch_max_line_width < pic_width)
goto done;
// Intersect decoder with encoder DSC caps and validate DSC settings
is_dsc_possible = intersect_dsc_caps(dsc_sink_caps, dsc_enc_caps, timing->pixel_encoding, &dsc_common_caps);
if (!is_dsc_possible)
goto done;
sink_per_slice_throughput_mps = 0;
// Validate available DSC settings against the mode timing
// Validate color format (and pick up the throughput values)
dsc_cfg->ycbcr422_simple = false;
switch (timing->pixel_encoding) {
case PIXEL_ENCODING_RGB:
is_dsc_possible = (bool)dsc_common_caps.color_formats.bits.RGB;
sink_per_slice_throughput_mps = dsc_sink_caps->throughput_mode_0_mps;
branch_max_throughput_mps = dsc_sink_caps->branch_overall_throughput_0_mps;
break;
case PIXEL_ENCODING_YCBCR444:
is_dsc_possible = (bool)dsc_common_caps.color_formats.bits.YCBCR_444;
sink_per_slice_throughput_mps = dsc_sink_caps->throughput_mode_0_mps;
branch_max_throughput_mps = dsc_sink_caps->branch_overall_throughput_0_mps;
break;
case PIXEL_ENCODING_YCBCR422:
is_dsc_possible = (bool)dsc_common_caps.color_formats.bits.YCBCR_NATIVE_422;
sink_per_slice_throughput_mps = dsc_sink_caps->throughput_mode_1_mps;
branch_max_throughput_mps = dsc_sink_caps->branch_overall_throughput_1_mps;
if (!is_dsc_possible) {
is_dsc_possible = (bool)dsc_common_caps.color_formats.bits.YCBCR_SIMPLE_422;
dsc_cfg->ycbcr422_simple = is_dsc_possible;
sink_per_slice_throughput_mps = dsc_sink_caps->throughput_mode_0_mps;
}
break;
case PIXEL_ENCODING_YCBCR420:
is_dsc_possible = (bool)dsc_common_caps.color_formats.bits.YCBCR_NATIVE_420;
sink_per_slice_throughput_mps = dsc_sink_caps->throughput_mode_1_mps;
branch_max_throughput_mps = dsc_sink_caps->branch_overall_throughput_1_mps;
break;
default:
is_dsc_possible = false;
}
// Validate branch's maximum throughput
if (branch_max_throughput_mps && dsc_div_by_10_round_up(timing->pix_clk_100hz) > branch_max_throughput_mps * 1000)
is_dsc_possible = false;
if (!is_dsc_possible)
goto done;
// Color depth
switch (timing->display_color_depth) {
case COLOR_DEPTH_888:
is_dsc_possible = (bool)dsc_common_caps.color_depth.bits.COLOR_DEPTH_8_BPC;
break;
case COLOR_DEPTH_101010:
is_dsc_possible = (bool)dsc_common_caps.color_depth.bits.COLOR_DEPTH_10_BPC;
break;
case COLOR_DEPTH_121212:
is_dsc_possible = (bool)dsc_common_caps.color_depth.bits.COLOR_DEPTH_12_BPC;
break;
default:
is_dsc_possible = false;
}
if (!is_dsc_possible)
goto done;
// Slice width (i.e. number of slices per line)
max_slices_h = get_max_dsc_slices(dsc_common_caps.slice_caps);
while (max_slices_h > 0) {
if (pic_width % max_slices_h == 0)
break;
max_slices_h = dec_num_slices(dsc_common_caps.slice_caps, max_slices_h);
}
is_dsc_possible = (dsc_common_caps.max_slice_width > 0);
if (!is_dsc_possible)
goto done;
min_slices_h = pic_width / dsc_common_caps.max_slice_width;
if (pic_width % dsc_common_caps.max_slice_width)
min_slices_h++;
min_slices_h = fit_num_slices_up(dsc_common_caps.slice_caps, min_slices_h);
while (min_slices_h <= max_slices_h) {
int pix_clk_per_slice_khz = dsc_div_by_10_round_up(timing->pix_clk_100hz) / min_slices_h;
if (pix_clk_per_slice_khz <= sink_per_slice_throughput_mps * 1000)
break;
min_slices_h = inc_num_slices(dsc_common_caps.slice_caps, min_slices_h);
}
if (pic_width % min_slices_h != 0)
min_slices_h = 0; // DSC TODO: Maybe try increasing the number of slices first?
is_dsc_possible = (min_slices_h <= max_slices_h);
if (!is_dsc_possible)
goto done;
if (policy.use_min_slices_h) {
if (min_slices_h > 0)
num_slices_h = min_slices_h;
else if (max_slices_h > 0) { // Fall back to max slices if min slices is not working out
if (policy.max_slices_h)
num_slices_h = min(policy.max_slices_h, max_slices_h);
else
num_slices_h = max_slices_h;
} else
is_dsc_possible = false;
} else {
if (max_slices_h > 0) {
if (policy.max_slices_h)
num_slices_h = min(policy.max_slices_h, max_slices_h);
else
num_slices_h = max_slices_h;
} else if (min_slices_h > 0) // Fall back to min slices if max slices is not possible
num_slices_h = min_slices_h;
else
is_dsc_possible = false;
}
if (!is_dsc_possible)
goto done;
dsc_cfg->num_slices_h = num_slices_h;
slice_width = pic_width / num_slices_h;
is_dsc_possible = slice_width <= dsc_common_caps.max_slice_width;
if (!is_dsc_possible)
goto done;
// Slice height (i.e. number of slices per column): start with policy and pick the first one that height is divisible by.
// For 4:2:0 make sure the slice height is divisible by 2 as well.
if (min_slice_height_override == 0)
slice_height = min(policy.min_slice_height, pic_height);
else
slice_height = min(min_slice_height_override, pic_height);
while (slice_height < pic_height && (pic_height % slice_height != 0 ||
(timing->pixel_encoding == PIXEL_ENCODING_YCBCR420 && slice_height % 2 != 0)))
slice_height++;
if (timing->pixel_encoding == PIXEL_ENCODING_YCBCR420) // For the case when pic_height < dsc_policy.min_sice_height
is_dsc_possible = (slice_height % 2 == 0);
if (!is_dsc_possible)
goto done;
if (slice_height > 0) {
dsc_cfg->num_slices_v = pic_height / slice_height;
} else {
is_dsc_possible = false;
goto done;
}
if (target_bandwidth_kbps > 0) {
is_dsc_possible = decide_dsc_target_bpp_x16(
&policy,
&dsc_common_caps,
target_bandwidth_kbps,
timing,
num_slices_h,
&target_bpp);
dsc_cfg->bits_per_pixel = target_bpp;
}
if (!is_dsc_possible)
goto done;
// Final decission: can we do DSC or not?
if (is_dsc_possible) {
// Fill out the rest of DSC settings
dsc_cfg->block_pred_enable = dsc_common_caps.is_block_pred_supported;
dsc_cfg->linebuf_depth = dsc_common_caps.lb_bit_depth;
dsc_cfg->version_minor = (dsc_common_caps.dsc_version & 0xf0) >> 4;
dsc_cfg->is_dp = dsc_sink_caps->is_dp;
}
done:
if (!is_dsc_possible)
memset(dsc_cfg, 0, sizeof(struct dc_dsc_config));
return is_dsc_possible;
}
bool dc_dsc_compute_config(
const struct display_stream_compressor *dsc,
const struct dsc_dec_dpcd_caps *dsc_sink_caps,
uint32_t dsc_min_slice_height_override,
uint32_t max_target_bpp_limit_override,
uint32_t target_bandwidth_kbps,
const struct dc_crtc_timing *timing,
struct dc_dsc_config *dsc_cfg)
{
bool is_dsc_possible = false;
struct dsc_enc_caps dsc_enc_caps;
get_dsc_enc_caps(dsc, &dsc_enc_caps, timing->pix_clk_100hz);
is_dsc_possible = setup_dsc_config(dsc_sink_caps,
&dsc_enc_caps,
target_bandwidth_kbps,
timing, dsc_min_slice_height_override,
max_target_bpp_limit_override * 16, dsc_cfg);
return is_dsc_possible;
}
uint32_t dc_dsc_stream_bandwidth_in_kbps(const struct dc_crtc_timing *timing,
uint32_t bpp_x16, uint32_t num_slices_h, bool is_dp)
{
struct fixed31_32 overhead_in_kbps;
struct fixed31_32 bpp;
struct fixed31_32 actual_bandwidth_in_kbps;
overhead_in_kbps = compute_dsc_max_bandwidth_overhead(
timing, num_slices_h, is_dp);
bpp = dc_fixpt_from_fraction(bpp_x16, 16);
actual_bandwidth_in_kbps = dc_fixpt_from_fraction(timing->pix_clk_100hz, 10);
actual_bandwidth_in_kbps = dc_fixpt_mul(actual_bandwidth_in_kbps, bpp);
actual_bandwidth_in_kbps = dc_fixpt_add(actual_bandwidth_in_kbps, overhead_in_kbps);
return dc_fixpt_ceil(actual_bandwidth_in_kbps);
}
void dc_dsc_get_policy_for_timing(const struct dc_crtc_timing *timing,
uint32_t max_target_bpp_limit_override_x16,
struct dc_dsc_policy *policy)
{
uint32_t bpc = 0;
policy->min_target_bpp = 0;
policy->max_target_bpp = 0;
/* DSC Policy: Use minimum number of slices that fits the pixel clock */
policy->use_min_slices_h = true;
/* DSC Policy: Use max available slices
* (in our case 4 for or 8, depending on the mode)
*/
policy->max_slices_h = 0;
/* DSC Policy: Use slice height recommended
* by VESA DSC Spreadsheet user guide
*/
policy->min_slice_height = 108;
/* DSC Policy: follow DP specs with an internal upper limit to 16 bpp
* for better interoperability
*/
switch (timing->display_color_depth) {
case COLOR_DEPTH_888:
bpc = 8;
break;
case COLOR_DEPTH_101010:
bpc = 10;
break;
case COLOR_DEPTH_121212:
bpc = 12;
break;
default:
return;
}
switch (timing->pixel_encoding) {
case PIXEL_ENCODING_RGB:
case PIXEL_ENCODING_YCBCR444:
case PIXEL_ENCODING_YCBCR422: /* assume no YCbCr422 native support */
/* DP specs limits to 8 */
policy->min_target_bpp = 8;
/* DP specs limits to 3 x bpc */
policy->max_target_bpp = 3 * bpc;
break;
case PIXEL_ENCODING_YCBCR420:
/* DP specs limits to 6 */
policy->min_target_bpp = 6;
/* DP specs limits to 1.5 x bpc assume bpc is an even number */
policy->max_target_bpp = bpc * 3 / 2;
break;
default:
return;
}
policy->preferred_bpp_x16 = timing->dsc_fixed_bits_per_pixel_x16;
/* internal upper limit, default 16 bpp */
if (policy->max_target_bpp > dsc_policy_max_target_bpp_limit)
policy->max_target_bpp = dsc_policy_max_target_bpp_limit;
/* apply override */
if (max_target_bpp_limit_override_x16 && policy->max_target_bpp > max_target_bpp_limit_override_x16 / 16)
policy->max_target_bpp = max_target_bpp_limit_override_x16 / 16;
/* enable DSC when not needed, default false */
if (dsc_policy_enable_dsc_when_not_needed)
policy->enable_dsc_when_not_needed = dsc_policy_enable_dsc_when_not_needed;
else
policy->enable_dsc_when_not_needed = false;
}
void dc_dsc_policy_set_max_target_bpp_limit(uint32_t limit)
{
dsc_policy_max_target_bpp_limit = limit;
}
void dc_dsc_policy_set_enable_dsc_when_not_needed(bool enable)
{
dsc_policy_enable_dsc_when_not_needed = enable;
}
void dc_dsc_policy_set_disable_dsc_stream_overhead(bool disable)
{
dsc_policy_disable_dsc_stream_overhead = disable;
}