drm/amd/display: Fix index may exceed array range within fpu_update_bw_bounding_box

[Why]
Coverity reports OVERRUN warning. soc.num_states could
be 40. But array range of bw_params->clk_table.entries is 8.

[How]
Assert if soc.num_states greater than 8.
Reviewed-by: Alex Hung <alex.hung@amd.com>
Acked-by: Tom Chung <chiahsuan.chung@amd.com>
Signed-off-by: Hersen Wu <hersenxs.wu@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/dml/dcn302/dcn302_fpu.c

@@ -304,6 +304,16 @@ void dcn302_fpu_update_bw_bounding_box(struct dc *dc, struct clk_bw_params *bw_p
 			dram_speed_mts[num_states++] = bw_params->clk_table.entries[j++].memclk_mhz * 16;
 		}
 
+		/* bw_params->clk_table.entries[MAX_NUM_DPM_LVL].
+		 * MAX_NUM_DPM_LVL is 8.
+		 * dcn3_02_soc.clock_limits[DC__VOLTAGE_STATES].
+		 * DC__VOLTAGE_STATES is 40.
+		 */
+		if (num_states > MAX_NUM_DPM_LVL) {
+			ASSERT(0);
+			return;
+		}
+
 		dcn3_02_soc.num_states = num_states;
 		for (i = 0; i < dcn3_02_soc.num_states; i++) {
 			dcn3_02_soc.clock_limits[i].state = i;

drivers/gpu/drm/amd/display/dc/dml/dcn303/dcn303_fpu.c

@@ -310,6 +310,16 @@ void dcn303_fpu_update_bw_bounding_box(struct dc *dc, struct clk_bw_params *bw_p
 			dram_speed_mts[num_states++] = bw_params->clk_table.entries[j++].memclk_mhz * 16;
 		}
 
+		/* bw_params->clk_table.entries[MAX_NUM_DPM_LVL].
+		 * MAX_NUM_DPM_LVL is 8.
+		 * dcn3_02_soc.clock_limits[DC__VOLTAGE_STATES].
+		 * DC__VOLTAGE_STATES is 40.
+		 */
+		if (num_states > MAX_NUM_DPM_LVL) {
+			ASSERT(0);
+			return;
+		}
+
 		dcn3_03_soc.num_states = num_states;
 		for (i = 0; i < dcn3_03_soc.num_states; i++) {
 			dcn3_03_soc.clock_limits[i].state = i;

drivers/gpu/drm/amd/display/dc/dml/dcn32/dcn32_fpu.c

@@ -3232,6 +3232,16 @@ void dcn32_update_bw_bounding_box_fpu(struct dc *dc, struct clk_bw_params *bw_pa
 				dram_speed_mts[num_states++] = bw_params->clk_table.entries[j++].memclk_mhz * 16;
 			}
 
+			/* bw_params->clk_table.entries[MAX_NUM_DPM_LVL].
+			 * MAX_NUM_DPM_LVL is 8.
+			 * dcn3_02_soc.clock_limits[DC__VOLTAGE_STATES].
+			 * DC__VOLTAGE_STATES is 40.
+			 */
+			if (num_states > MAX_NUM_DPM_LVL) {
+				ASSERT(0);
+				return;
+			}
+
 			dcn3_2_soc.num_states = num_states;
 			for (i = 0; i < dcn3_2_soc.num_states; i++) {
 				dcn3_2_soc.clock_limits[i].state = i;

drivers/gpu/drm/amd/display/dc/dml/dcn321/dcn321_fpu.c

@@ -803,6 +803,16 @@ void dcn321_update_bw_bounding_box_fpu(struct dc *dc, struct clk_bw_params *bw_p
 			dram_speed_mts[num_states++] = bw_params->clk_table.entries[j++].memclk_mhz * 16;
 		}
 
+		/* bw_params->clk_table.entries[MAX_NUM_DPM_LVL].
+		 * MAX_NUM_DPM_LVL is 8.
+		 * dcn3_02_soc.clock_limits[DC__VOLTAGE_STATES].
+		 * DC__VOLTAGE_STATES is 40.
+		 */
+		if (num_states > MAX_NUM_DPM_LVL) {
+			ASSERT(0);
+			return;
+		}
+
 		dcn3_21_soc.num_states = num_states;
 		for (i = 0; i < dcn3_21_soc.num_states; i++) {
 			dcn3_21_soc.clock_limits[i].state = i;