drm/amdgpu/powerplay/smu10: add support for gpu busy query (v2)

Was added in newer versions of the firmware.  Add support
for it.

v2: return an error in SMU error, drop needless break.
Reviewed-by: Evan Quan <evan.quan@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/pm/inc/rv_ppsmc.h

@@ -84,6 +84,7 @@
 #define PPSMC_MSG_PowerGateMmHub                0x35
 #define PPSMC_MSG_SetRccPfcPmeRestoreRegister   0x36
 #define PPSMC_MSG_GpuChangeState                0x37
+#define PPSMC_MSG_GetGfxBusy                    0x3D
 #define PPSMC_Message_Count                     0x42
 
 typedef uint16_t PPSMC_Result;

drivers/gpu/drm/amd/pm/powerplay/hwmgr/smu10_hwmgr.c

@@ -1261,9 +1261,21 @@ static int smu10_read_sensor(struct pp_hwmgr *hwmgr, int idx,
 			  void *value, int *size)
 {
 	struct smu10_hwmgr *smu10_data = (struct smu10_hwmgr *)(hwmgr->backend);
-	uint32_t sclk, mclk;
+	struct amdgpu_device *adev = hwmgr->adev;
+	uint32_t sclk, mclk, activity_percent;
+	bool has_gfx_busy;
 	int ret = 0;
 
+	/* GetGfxBusy support was added on RV SMU FW 30.85.00 and PCO 4.30.59 */
+	if ((adev->apu_flags & AMD_APU_IS_PICASSO) &&
+	    (hwmgr->smu_version >= 0x41e3b))
+		has_gfx_busy = true;
+	else if ((adev->apu_flags & AMD_APU_IS_RAVEN) &&
+		 (hwmgr->smu_version >= 0x1e5500))
+		has_gfx_busy = true;
+	else
+		has_gfx_busy = false;
+
 	switch (idx) {
 	case AMDGPU_PP_SENSOR_GFX_SCLK:
 		smum_send_msg_to_smc(hwmgr, PPSMC_MSG_GetGfxclkFrequency, &sclk);
@@ -1284,6 +1296,20 @@ static int smu10_read_sensor(struct pp_hwmgr *hwmgr, int idx,
 		*(uint32_t *)value =  smu10_data->vcn_power_gated ? 0 : 1;
 		*size = 4;
 		break;
+	case AMDGPU_PP_SENSOR_GPU_LOAD:
+		if (has_gfx_busy) {
+			ret = smum_send_msg_to_smc(hwmgr,
+						   PPSMC_MSG_GetGfxBusy,
+						   &activity_percent);
+			if (!ret)
+				activity_percent = activity_percent > 100 ? 100 : activity_percent;
+			else
+				return -EIO;
+			*((uint32_t *)value) = activity_percent;
+			return 0;
+		} else {
+			return -EOPNOTSUPP;
+		}
 	default:
 		ret = -EOPNOTSUPP;
 		break;