From: Evan Quan <evan.quan@amd.com>
Date: Wed, 3 Jan 2018 10:28:10 +0800
Subject: drm/amd/powerplay: use ffs/fls instead of implementing our own
Git-commit: 10cd19c87736c1354ef7c175729433b73a988fb1
Patch-mainline: v4.17-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

Signed-off-by: Evan Quan <evan.quan@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/amd/powerplay/hwmgr/vega10_hwmgr.c |   27 +++------------------
 1 file changed, 4 insertions(+), 23 deletions(-)

--- a/drivers/gpu/drm/amd/powerplay/hwmgr/vega10_hwmgr.c
+++ b/drivers/gpu/drm/amd/powerplay/hwmgr/vega10_hwmgr.c
@@ -4492,7 +4492,6 @@ static int vega10_force_clock_level(stru
 		enum pp_clock_type type, uint32_t mask)
 {
 	struct vega10_hwmgr *data = (struct vega10_hwmgr *)(hwmgr->backend);
-	int i;
 
 	if (hwmgr->request_dpm_level & (AMD_DPM_FORCED_LEVEL_AUTO |
 				AMD_DPM_FORCED_LEVEL_LOW |
@@ -4501,17 +4500,8 @@ static int vega10_force_clock_level(stru
 
 	switch (type) {
 	case PP_SCLK:
-		for (i = 0; i < 32; i++) {
-			if (mask & (1 << i))
-				break;
-		}
-		data->smc_state_table.gfx_boot_level = i;
-
-		for (i = 31; i >= 0; i--) {
-			if (mask & (1 << i))
-				break;
-		}
-		data->smc_state_table.gfx_max_level = i;
+		data->smc_state_table.gfx_boot_level = mask ? (ffs(mask) - 1) : 0;
+		data->smc_state_table.gfx_max_level = mask ? (fls(mask) - 1) : 0;
 
 		PP_ASSERT_WITH_CODE(!vega10_upload_dpm_bootup_level(hwmgr),
 			"Failed to upload boot level to lowest!",
@@ -4523,17 +4513,8 @@ static int vega10_force_clock_level(stru
 		break;
 
 	case PP_MCLK:
-		for (i = 0; i < 32; i++) {
-			if (mask & (1 << i))
-				break;
-		}
-		data->smc_state_table.mem_boot_level = i;
-
-		for (i = 31; i >= 0; i--) {
-			if (mask & (1 << i))
-				break;
-		}
-		data->smc_state_table.mem_max_level = i;
+		data->smc_state_table.mem_boot_level = mask ? (ffs(mask) - 1) : 0;
+		data->smc_state_table.mem_max_level = mask ? (fls(mask) - 1) : 0;
 
 		PP_ASSERT_WITH_CODE(!vega10_upload_dpm_bootup_level(hwmgr),
 			"Failed to upload boot level to lowest!",