drm/amd/display: Use pre-allocated temp struct for bounding box update

[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@amd.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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];
-	}
+	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;
 
 		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 */

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;
 

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;

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;