On 2022-06-08 12:48, sunpeng.li@xxxxxxx wrote:
> From: Leo Li <sunpeng.li@xxxxxxx>
>
> [Why]
>
> There is a theoretical problem in prior patches for reducing the stack
> size of *update_bw_bounding_box() functions.
>
> By modifying the soc.clock_limits[n] struct directly, this can cause
> unintended behavior as the for loop attempts to swap rows in
> clock_limits[n]. A temporary struct is still required to make sure we
> stay functinoally equivalent.
>
> [How]
>
> Add a temporary clock_limits table to the SOC struct, and use it when
> swapping rows.
>
> Signed-off-by: Leo Li <sunpeng.li@xxxxxxx>
> ---
> .../drm/amd/display/dc/dml/dcn20/dcn20_fpu.c | 33 +++++-----
> .../amd/display/dc/dml/dcn301/dcn301_fpu.c | 36 ++++++-----
> .../drm/amd/display/dc/dml/dcn31/dcn31_fpu.c | 64 +++++++++++--------
> .../amd/display/dc/dml/display_mode_structs.h | 5 ++
> 4 files changed, 82 insertions(+), 56 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/display/dc/dml/dcn20/dcn20_fpu.c b/drivers/gpu/drm/amd/display/dc/dml/dcn20/dcn20_fpu.c
> index c2fec0d85da4..e247b2270b1d 100644
> --- a/drivers/gpu/drm/amd/display/dc/dml/dcn20/dcn20_fpu.c
> +++ b/drivers/gpu/drm/amd/display/dc/dml/dcn20/dcn20_fpu.c
> @@ -2015,9 +2015,8 @@ void dcn21_update_bw_bounding_box(struct dc *dc, struct clk_bw_params *bw_params
>
> ASSERT(clk_table->num_entries);
> /* Copy dcn2_1_soc.clock_limits to clock_limits to avoid copying over null states later */
> - for (i = 0; i < dcn2_1_soc.num_states + 1; i++) {
> - dcn2_1_soc.clock_limits[i] = dcn2_1_soc.clock_limits[i];
> - }
Hmm, this for loop didn't make sense. I gave my RB for the previous patch too quickly.
> + memcpy(&dcn2_1_soc._clock_tmp, &dcn2_1_soc.clock_limits,
> + sizeof(dcn2_1_soc.clock_limits));
>
> for (i = 0; i < clk_table->num_entries; i++) {
> /* loop backwards*/
> @@ -2032,22 +2031,26 @@ void dcn21_update_bw_bounding_box(struct dc *dc, struct clk_bw_params *bw_params
> if (i == 1)
> k++;
>
> - dcn2_1_soc.clock_limits[k].state = k;
> - dcn2_1_soc.clock_limits[k].dcfclk_mhz = clk_table->entries[i].dcfclk_mhz;
> - dcn2_1_soc.clock_limits[k].fabricclk_mhz = clk_table->entries[i].fclk_mhz;
> - dcn2_1_soc.clock_limits[k].socclk_mhz = clk_table->entries[i].socclk_mhz;
> - dcn2_1_soc.clock_limits[k].dram_speed_mts = clk_table->entries[i].memclk_mhz * 2;
> + dcn2_1_soc._clock_tmp[k].state = k;
> + dcn2_1_soc._clock_tmp[k].dcfclk_mhz = clk_table->entries[i].dcfclk_mhz;
> + dcn2_1_soc._clock_tmp[k].fabricclk_mhz = clk_table->entries[i].fclk_mhz;
> + dcn2_1_soc._clock_tmp[k].socclk_mhz = clk_table->entries[i].socclk_mhz;
> + dcn2_1_soc._clock_tmp[k].dram_speed_mts = clk_table->entries[i].memclk_mhz * 2;
>
> - dcn2_1_soc.clock_limits[k].dispclk_mhz = dcn2_1_soc.clock_limits[closest_clk_lvl].dispclk_mhz;
> - dcn2_1_soc.clock_limits[k].dppclk_mhz = dcn2_1_soc.clock_limits[closest_clk_lvl].dppclk_mhz;
> - dcn2_1_soc.clock_limits[k].dram_bw_per_chan_gbps = dcn2_1_soc.clock_limits[closest_clk_lvl].dram_bw_per_chan_gbps;
> - dcn2_1_soc.clock_limits[k].dscclk_mhz = dcn2_1_soc.clock_limits[closest_clk_lvl].dscclk_mhz;
> - dcn2_1_soc.clock_limits[k].dtbclk_mhz = dcn2_1_soc.clock_limits[closest_clk_lvl].dtbclk_mhz;
> - dcn2_1_soc.clock_limits[k].phyclk_d18_mhz = dcn2_1_soc.clock_limits[closest_clk_lvl].phyclk_d18_mhz;
> - dcn2_1_soc.clock_limits[k].phyclk_mhz = dcn2_1_soc.clock_limits[closest_clk_lvl].phyclk_mhz;
> + dcn2_1_soc._clock_tmp[k].dispclk_mhz = dcn2_1_soc.clock_limits[closest_clk_lvl].dispclk_mhz;
> + dcn2_1_soc._clock_tmp[k].dppclk_mhz = dcn2_1_soc.clock_limits[closest_clk_lvl].dppclk_mhz;
> + dcn2_1_soc._clock_tmp[k].dram_bw_per_chan_gbps = dcn2_1_soc.clock_limits[closest_clk_lvl].dram_bw_per_chan_gbps;
> + dcn2_1_soc._clock_tmp[k].dscclk_mhz = dcn2_1_soc.clock_limits[closest_clk_lvl].dscclk_mhz;
> + dcn2_1_soc._clock_tmp[k].dtbclk_mhz = dcn2_1_soc.clock_limits[closest_clk_lvl].dtbclk_mhz;
> + dcn2_1_soc._clock_tmp[k].phyclk_d18_mhz = dcn2_1_soc.clock_limits[closest_clk_lvl].phyclk_d18_mhz;
> + dcn2_1_soc._clock_tmp[k].phyclk_mhz = dcn2_1_soc.clock_limits[closest_clk_lvl].phyclk_mhz;
>
I see why we need a tmp array and agree that we shouldn't allocate it inside DML
functions.
Reviewed-by: Harry Wentland <harry.wentland@xxxxxxx>
Harry
> k++;
> }
> +
> + memcpy(&dcn2_1_soc.clock_limits, &dcn2_1_soc._clock_tmp,
> + sizeof(dcn2_1_soc.clock_limits));
> +
> if (clk_table->num_entries) {
> dcn2_1_soc.num_states = clk_table->num_entries + 1;
> /* fill in min DF PState */
> diff --git a/drivers/gpu/drm/amd/display/dc/dml/dcn301/dcn301_fpu.c b/drivers/gpu/drm/amd/display/dc/dml/dcn301/dcn301_fpu.c
> index 62cf283d9f41..e4863f0bf0f6 100644
> --- a/drivers/gpu/drm/amd/display/dc/dml/dcn301/dcn301_fpu.c
> +++ b/drivers/gpu/drm/amd/display/dc/dml/dcn301/dcn301_fpu.c
> @@ -254,6 +254,9 @@ void dcn301_update_bw_bounding_box(struct dc *dc, struct clk_bw_params *bw_param
>
> dc_assert_fp_enabled();
>
> + memcpy(&dcn3_01_soc._clock_tmp, &dcn3_01_soc.clock_limits,
> + sizeof(dcn3_01_soc.clock_limits));
> +
> /* Default clock levels are used for diags, which may lead to overclocking. */
> if (!IS_DIAG_DC(dc->ctx->dce_environment)) {
> dcn3_01_ip.max_num_otg = pool->base.res_cap->num_timing_generator;
> @@ -270,29 +273,32 @@ void dcn301_update_bw_bounding_box(struct dc *dc, struct clk_bw_params *bw_param
> }
> }
>
> - dcn3_01_soc.clock_limits[i].state = i;
> - dcn3_01_soc.clock_limits[i].dcfclk_mhz = clk_table->entries[i].dcfclk_mhz;
> - dcn3_01_soc.clock_limits[i].fabricclk_mhz = clk_table->entries[i].fclk_mhz;
> - dcn3_01_soc.clock_limits[i].socclk_mhz = clk_table->entries[i].socclk_mhz;
> - dcn3_01_soc.clock_limits[i].dram_speed_mts = clk_table->entries[i].memclk_mhz * 2;
> -
> - dcn3_01_soc.clock_limits[i].dispclk_mhz = dcn3_01_soc.clock_limits[closest_clk_lvl].dispclk_mhz;
> - dcn3_01_soc.clock_limits[i].dppclk_mhz = dcn3_01_soc.clock_limits[closest_clk_lvl].dppclk_mhz;
> - dcn3_01_soc.clock_limits[i].dram_bw_per_chan_gbps = dcn3_01_soc.clock_limits[closest_clk_lvl].dram_bw_per_chan_gbps;
> - dcn3_01_soc.clock_limits[i].dscclk_mhz = dcn3_01_soc.clock_limits[closest_clk_lvl].dscclk_mhz;
> - dcn3_01_soc.clock_limits[i].dtbclk_mhz = dcn3_01_soc.clock_limits[closest_clk_lvl].dtbclk_mhz;
> - dcn3_01_soc.clock_limits[i].phyclk_d18_mhz = dcn3_01_soc.clock_limits[closest_clk_lvl].phyclk_d18_mhz;
> - dcn3_01_soc.clock_limits[i].phyclk_mhz = dcn3_01_soc.clock_limits[closest_clk_lvl].phyclk_mhz;
> + dcn3_01_soc._clock_tmp[i].state = i;
> + dcn3_01_soc._clock_tmp[i].dcfclk_mhz = clk_table->entries[i].dcfclk_mhz;
> + dcn3_01_soc._clock_tmp[i].fabricclk_mhz = clk_table->entries[i].fclk_mhz;
> + dcn3_01_soc._clock_tmp[i].socclk_mhz = clk_table->entries[i].socclk_mhz;
> + dcn3_01_soc._clock_tmp[i].dram_speed_mts = clk_table->entries[i].memclk_mhz * 2;
> +
> + dcn3_01_soc._clock_tmp[i].dispclk_mhz = dcn3_01_soc.clock_limits[closest_clk_lvl].dispclk_mhz;
> + dcn3_01_soc._clock_tmp[i].dppclk_mhz = dcn3_01_soc.clock_limits[closest_clk_lvl].dppclk_mhz;
> + dcn3_01_soc._clock_tmp[i].dram_bw_per_chan_gbps = dcn3_01_soc.clock_limits[closest_clk_lvl].dram_bw_per_chan_gbps;
> + dcn3_01_soc._clock_tmp[i].dscclk_mhz = dcn3_01_soc.clock_limits[closest_clk_lvl].dscclk_mhz;
> + dcn3_01_soc._clock_tmp[i].dtbclk_mhz = dcn3_01_soc.clock_limits[closest_clk_lvl].dtbclk_mhz;
> + dcn3_01_soc._clock_tmp[i].phyclk_d18_mhz = dcn3_01_soc.clock_limits[closest_clk_lvl].phyclk_d18_mhz;
> + dcn3_01_soc._clock_tmp[i].phyclk_mhz = dcn3_01_soc.clock_limits[closest_clk_lvl].phyclk_mhz;
> }
>
> if (clk_table->num_entries) {
> dcn3_01_soc.num_states = clk_table->num_entries;
> /* duplicate last level */
> - dcn3_01_soc.clock_limits[dcn3_01_soc.num_states] = dcn3_01_soc.clock_limits[dcn3_01_soc.num_states - 1];
> - dcn3_01_soc.clock_limits[dcn3_01_soc.num_states].state = dcn3_01_soc.num_states;
> + dcn3_01_soc._clock_tmp[dcn3_01_soc.num_states] = dcn3_01_soc.clock_limits[dcn3_01_soc.num_states - 1];
> + dcn3_01_soc._clock_tmp[dcn3_01_soc.num_states].state = dcn3_01_soc.num_states;
> }
> }
>
> + memcpy(&dcn3_01_soc.clock_limits, &dcn3_01_soc._clock_tmp,
> + sizeof(dcn3_01_soc.clock_limits));
> +
> dcn3_01_soc.dispclk_dppclk_vco_speed_mhz = dc->clk_mgr->dentist_vco_freq_khz / 1000.0;
> dc->dml.soc.dispclk_dppclk_vco_speed_mhz = dc->clk_mgr->dentist_vco_freq_khz / 1000.0;
>
> diff --git a/drivers/gpu/drm/amd/display/dc/dml/dcn31/dcn31_fpu.c b/drivers/gpu/drm/amd/display/dc/dml/dcn31/dcn31_fpu.c
> index 6da702923226..7be3476989ce 100644
> --- a/drivers/gpu/drm/amd/display/dc/dml/dcn31/dcn31_fpu.c
> +++ b/drivers/gpu/drm/amd/display/dc/dml/dcn31/dcn31_fpu.c
> @@ -580,6 +580,9 @@ void dcn31_update_bw_bounding_box(struct dc *dc, struct clk_bw_params *bw_params
>
> dc_assert_fp_enabled();
>
> + memcpy(&dcn3_1_soc._clock_tmp, &dcn3_1_soc.clock_limits,
> + sizeof(dcn3_1_soc.clock_limits));
> +
> // Default clock levels are used for diags, which may lead to overclocking.
> if (!IS_DIAG_DC(dc->ctx->dce_environment)) {
> int max_dispclk_mhz = 0, max_dppclk_mhz = 0;
> @@ -607,32 +610,35 @@ void dcn31_update_bw_bounding_box(struct dc *dc, struct clk_bw_params *bw_params
> }
> }
>
> - dcn3_1_soc.clock_limits[i].state = i;
> + dcn3_1_soc._clock_tmp[i].state = i;
>
> /* Clocks dependent on voltage level. */
> - dcn3_1_soc.clock_limits[i].dcfclk_mhz = clk_table->entries[i].dcfclk_mhz;
> - dcn3_1_soc.clock_limits[i].fabricclk_mhz = clk_table->entries[i].fclk_mhz;
> - dcn3_1_soc.clock_limits[i].socclk_mhz = clk_table->entries[i].socclk_mhz;
> - dcn3_1_soc.clock_limits[i].dram_speed_mts = clk_table->entries[i].memclk_mhz * 2 * clk_table->entries[i].wck_ratio;
> + dcn3_1_soc._clock_tmp[i].dcfclk_mhz = clk_table->entries[i].dcfclk_mhz;
> + dcn3_1_soc._clock_tmp[i].fabricclk_mhz = clk_table->entries[i].fclk_mhz;
> + dcn3_1_soc._clock_tmp[i].socclk_mhz = clk_table->entries[i].socclk_mhz;
> + dcn3_1_soc._clock_tmp[i].dram_speed_mts = clk_table->entries[i].memclk_mhz * 2 * clk_table->entries[i].wck_ratio;
>
> /* Clocks independent of voltage level. */
> - dcn3_1_soc.clock_limits[i].dispclk_mhz = max_dispclk_mhz ? max_dispclk_mhz :
> + dcn3_1_soc._clock_tmp[i].dispclk_mhz = max_dispclk_mhz ? max_dispclk_mhz :
> dcn3_1_soc.clock_limits[closest_clk_lvl].dispclk_mhz;
>
> - dcn3_1_soc.clock_limits[i].dppclk_mhz = max_dppclk_mhz ? max_dppclk_mhz :
> + dcn3_1_soc._clock_tmp[i].dppclk_mhz = max_dppclk_mhz ? max_dppclk_mhz :
> dcn3_1_soc.clock_limits[closest_clk_lvl].dppclk_mhz;
>
> - dcn3_1_soc.clock_limits[i].dram_bw_per_chan_gbps = dcn3_1_soc.clock_limits[closest_clk_lvl].dram_bw_per_chan_gbps;
> - dcn3_1_soc.clock_limits[i].dscclk_mhz = dcn3_1_soc.clock_limits[closest_clk_lvl].dscclk_mhz;
> - dcn3_1_soc.clock_limits[i].dtbclk_mhz = dcn3_1_soc.clock_limits[closest_clk_lvl].dtbclk_mhz;
> - dcn3_1_soc.clock_limits[i].phyclk_d18_mhz = dcn3_1_soc.clock_limits[closest_clk_lvl].phyclk_d18_mhz;
> - dcn3_1_soc.clock_limits[i].phyclk_mhz = dcn3_1_soc.clock_limits[closest_clk_lvl].phyclk_mhz;
> + dcn3_1_soc._clock_tmp[i].dram_bw_per_chan_gbps = dcn3_1_soc.clock_limits[closest_clk_lvl].dram_bw_per_chan_gbps;
> + dcn3_1_soc._clock_tmp[i].dscclk_mhz = dcn3_1_soc.clock_limits[closest_clk_lvl].dscclk_mhz;
> + dcn3_1_soc._clock_tmp[i].dtbclk_mhz = dcn3_1_soc.clock_limits[closest_clk_lvl].dtbclk_mhz;
> + dcn3_1_soc._clock_tmp[i].phyclk_d18_mhz = dcn3_1_soc.clock_limits[closest_clk_lvl].phyclk_d18_mhz;
> + dcn3_1_soc._clock_tmp[i].phyclk_mhz = dcn3_1_soc.clock_limits[closest_clk_lvl].phyclk_mhz;
> }
> if (clk_table->num_entries) {
> dcn3_1_soc.num_states = clk_table->num_entries;
> }
> }
>
> + memcpy(&dcn3_1_soc.clock_limits, &dcn3_1_soc._clock_tmp,
> + sizeof(dcn3_1_soc.clock_limits));
> +
> dcn3_1_soc.dispclk_dppclk_vco_speed_mhz = dc->clk_mgr->dentist_vco_freq_khz / 1000.0;
> dc->dml.soc.dispclk_dppclk_vco_speed_mhz = dc->clk_mgr->dentist_vco_freq_khz / 1000.0;
>
> @@ -705,6 +711,9 @@ void dcn316_update_bw_bounding_box(struct dc *dc, struct clk_bw_params *bw_param
>
> dc_assert_fp_enabled();
>
> + memcpy(&dcn3_16_soc._clock_tmp, &dcn3_16_soc.clock_limits,
> + sizeof(dcn3_16_soc.clock_limits));
> +
> // Default clock levels are used for diags, which may lead to overclocking.
> if (!IS_DIAG_DC(dc->ctx->dce_environment)) {
>
> @@ -736,37 +745,40 @@ void dcn316_update_bw_bounding_box(struct dc *dc, struct clk_bw_params *bw_param
> closest_clk_lvl = dcn3_16_soc.num_states - 1;
> }
>
> - dcn3_16_soc.clock_limits[i].state = i;
> + dcn3_16_soc._clock_tmp[i].state = i;
>
> /* Clocks dependent on voltage level. */
> - dcn3_16_soc.clock_limits[i].dcfclk_mhz = clk_table->entries[i].dcfclk_mhz;
> + dcn3_16_soc._clock_tmp[i].dcfclk_mhz = clk_table->entries[i].dcfclk_mhz;
> if (clk_table->num_entries == 1 &&
> - dcn3_16_soc.clock_limits[i].dcfclk_mhz < dcn3_16_soc.clock_limits[closest_clk_lvl].dcfclk_mhz) {
> + dcn3_16_soc._clock_tmp[i].dcfclk_mhz < dcn3_16_soc.clock_limits[closest_clk_lvl].dcfclk_mhz) {
> /*SMU fix not released yet*/
> - dcn3_16_soc.clock_limits[i].dcfclk_mhz = dcn3_16_soc.clock_limits[closest_clk_lvl].dcfclk_mhz;
> + dcn3_16_soc._clock_tmp[i].dcfclk_mhz = dcn3_16_soc.clock_limits[closest_clk_lvl].dcfclk_mhz;
> }
> - dcn3_16_soc.clock_limits[i].fabricclk_mhz = clk_table->entries[i].fclk_mhz;
> - dcn3_16_soc.clock_limits[i].socclk_mhz = clk_table->entries[i].socclk_mhz;
> - dcn3_16_soc.clock_limits[i].dram_speed_mts = clk_table->entries[i].memclk_mhz * 2 * clk_table->entries[i].wck_ratio;
> + dcn3_16_soc._clock_tmp[i].fabricclk_mhz = clk_table->entries[i].fclk_mhz;
> + dcn3_16_soc._clock_tmp[i].socclk_mhz = clk_table->entries[i].socclk_mhz;
> + dcn3_16_soc._clock_tmp[i].dram_speed_mts = clk_table->entries[i].memclk_mhz * 2 * clk_table->entries[i].wck_ratio;
>
> /* Clocks independent of voltage level. */
> - dcn3_16_soc.clock_limits[i].dispclk_mhz = max_dispclk_mhz ? max_dispclk_mhz :
> + dcn3_16_soc._clock_tmp[i].dispclk_mhz = max_dispclk_mhz ? max_dispclk_mhz :
> dcn3_16_soc.clock_limits[closest_clk_lvl].dispclk_mhz;
>
> - dcn3_16_soc.clock_limits[i].dppclk_mhz = max_dppclk_mhz ? max_dppclk_mhz :
> + dcn3_16_soc._clock_tmp[i].dppclk_mhz = max_dppclk_mhz ? max_dppclk_mhz :
> dcn3_16_soc.clock_limits[closest_clk_lvl].dppclk_mhz;
>
> - dcn3_16_soc.clock_limits[i].dram_bw_per_chan_gbps = dcn3_16_soc.clock_limits[closest_clk_lvl].dram_bw_per_chan_gbps;
> - dcn3_16_soc.clock_limits[i].dscclk_mhz = dcn3_16_soc.clock_limits[closest_clk_lvl].dscclk_mhz;
> - dcn3_16_soc.clock_limits[i].dtbclk_mhz = dcn3_16_soc.clock_limits[closest_clk_lvl].dtbclk_mhz;
> - dcn3_16_soc.clock_limits[i].phyclk_d18_mhz = dcn3_16_soc.clock_limits[closest_clk_lvl].phyclk_d18_mhz;
> - dcn3_16_soc.clock_limits[i].phyclk_mhz = dcn3_16_soc.clock_limits[closest_clk_lvl].phyclk_mhz;
> + dcn3_16_soc._clock_tmp[i].dram_bw_per_chan_gbps = dcn3_16_soc.clock_limits[closest_clk_lvl].dram_bw_per_chan_gbps;
> + dcn3_16_soc._clock_tmp[i].dscclk_mhz = dcn3_16_soc.clock_limits[closest_clk_lvl].dscclk_mhz;
> + dcn3_16_soc._clock_tmp[i].dtbclk_mhz = dcn3_16_soc.clock_limits[closest_clk_lvl].dtbclk_mhz;
> + dcn3_16_soc._clock_tmp[i].phyclk_d18_mhz = dcn3_16_soc.clock_limits[closest_clk_lvl].phyclk_d18_mhz;
> + dcn3_16_soc._clock_tmp[i].phyclk_mhz = dcn3_16_soc.clock_limits[closest_clk_lvl].phyclk_mhz;
> }
> if (clk_table->num_entries) {
> dcn3_16_soc.num_states = clk_table->num_entries;
> }
> }
>
> + memcpy(&dcn3_16_soc.clock_limits, &dcn3_16_soc._clock_tmp,
> + sizeof(dcn3_16_soc.clock_limits));
> +
> if (max_dispclk_mhz) {
> dcn3_16_soc.dispclk_dppclk_vco_speed_mhz = max_dispclk_mhz * 2;
> dc->dml.soc.dispclk_dppclk_vco_speed_mhz = max_dispclk_mhz * 2;
> diff --git a/drivers/gpu/drm/amd/display/dc/dml/display_mode_structs.h b/drivers/gpu/drm/amd/display/dc/dml/display_mode_structs.h
> index 74afa10e70f8..2bdf60846762 100644
> --- a/drivers/gpu/drm/amd/display/dc/dml/display_mode_structs.h
> +++ b/drivers/gpu/drm/amd/display/dc/dml/display_mode_structs.h
> @@ -161,6 +161,11 @@ struct _vcs_dpi_voltage_scaling_st {
>
> struct _vcs_dpi_soc_bounding_box_st {
> struct _vcs_dpi_voltage_scaling_st clock_limits[DC__VOLTAGE_STATES];
> + /*
> + * This is a temporary stash for updating @clock_limits with the PMFW
> + * clock table. Do not use outside of *update_bw_boudning_box functions.
> + */
> + struct _vcs_dpi_voltage_scaling_st _clock_tmp[DC__VOLTAGE_STATES];
> unsigned int num_states;
> double sr_exit_time_us;
> double sr_enter_plus_exit_time_us;
