drm/amdgpu: add reset_ras_error_count function for MMHUB

MMHUB ras error counters are dirty ones after cold reboot
Read operation is needed to reset them to 0

Signed-off-by: Hawking Zhang <[e-mail]>
Reviewed-by: Alex Deucher <[e-mail]>
Reviewed-by: Tao Zhou <[e-mail]>
Reviewed-by: Guchun Chen <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>

drivers/gpu/drm/amd/amdgpu/amdgpu_mmhub.h

···
 	int (*ras_late_init)(struct amdgpu_device *adev);
 	void (*query_ras_error_count)(struct amdgpu_device *adev,
 					void *ras_error_status);
+	void (*reset_ras_error_count)(struct amdgpu_device *adev);
 };
 
 struct amdgpu_mmhub {

drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c

···
 		}
 	}
 
+	if (adev->mmhub.funcs && adev->mmhub.funcs->reset_ras_error_count)
+		adev->mmhub.funcs->reset_ras_error_count(adev);
+
 	r = amdgpu_gmc_ras_late_init(adev);
 	if (r)
 		return r;

drivers/gpu/drm/amd/amdgpu/mmhub_v1_0.c

···
 	err_data->ue_count += ded_count;
 }
 
+static void mmhub_v1_0_reset_ras_error_count(struct amdgpu_device *adev)
+{
+	uint32_t i;
+
+	/* read back edc counter registers to reset the counters to 0 */
+	if (amdgpu_ras_is_supported(adev, AMDGPU_RAS_BLOCK__MMHUB)) {
+		for (i = 0; i < ARRAY_SIZE(mmhub_v1_0_edc_cnt_regs); i++)
+			RREG32(SOC15_REG_ENTRY_OFFSET(mmhub_v1_0_edc_cnt_regs[i]));
+	}
+}
+
 const struct amdgpu_mmhub_funcs mmhub_v1_0_funcs = {
 	.ras_late_init = amdgpu_mmhub_ras_late_init,
 	.query_ras_error_count = mmhub_v1_0_query_ras_error_count,
+	.reset_ras_error_count = mmhub_v1_0_reset_ras_error_count,
 };

drivers/gpu/drm/amd/amdgpu/mmhub_v9_4.c

···
 	err_data->ue_count += ded_count;
 }
 
+static void mmhub_v9_4_reset_ras_error_count(struct amdgpu_device *adev)
+{
+	uint32_t i;
+
+	/* read back edc counter registers to reset the counters to 0 */
+	if (amdgpu_ras_is_supported(adev, AMDGPU_RAS_BLOCK__MMHUB)) {
+		for (i = 0; i < ARRAY_SIZE(mmhub_v9_4_edc_cnt_regs); i++)
+			RREG32(SOC15_REG_ENTRY_OFFSET(mmhub_v9_4_edc_cnt_regs[i]));
+	}
+}
+
 const struct amdgpu_mmhub_funcs mmhub_v9_4_funcs = {
 	.ras_late_init = amdgpu_mmhub_ras_late_init,
 	.query_ras_error_count = mmhub_v9_4_query_ras_error_count,
+	.reset_ras_error_count = mmhub_v9_4_reset_ras_error_count,
 };