drm/amd/pm: Add VCN reset support check capability

This change introduces infrastructure to check whether VCN reset
is supported by the SMU firmware. Key changes include:

1. Added new functions to query VCN reset support:
- amdgpu_dpm_reset_vcn_is_supported()
- smu_reset_vcn_is_supported()
- pptable_funcs.reset_vcn_is_supported callback

2. Implemented proper locking in the DPM layer with mutex protection

3. Maintained consistency with existing SDMA reset support checks

The new capability allows callers to check for VCN reset support
before attempting the operation, preventing unnecessary attempts
on unsupported platforms.

v2: clean up debug info(Alex)

Suggested-by: Alex Deucher <[e-mail]>
Signed-off-by: Ruili Ji <[e-mail]>
Signed-off-by: Jesse Zhang <[e-mail]>
Reviewed-by: Lijo Lazar <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>

drivers/gpu/drm/amd/pm/amdgpu_dpm.c

···
 	return ret;
 }
 
+bool amdgpu_dpm_reset_vcn_is_supported(struct amdgpu_device *adev)
+{
+	struct smu_context *smu = adev->powerplay.pp_handle;
+	bool ret;
+
+	if (!is_support_sw_smu(adev))
+		return false;
+
+	mutex_lock(&adev->pm.mutex);
+	ret = smu_reset_vcn_is_supported(smu);
+	mutex_unlock(&adev->pm.mutex);
+
+	return ret;
+}
+
 int amdgpu_dpm_get_dpm_freq_range(struct amdgpu_device *adev,
 				  enum pp_clock_type type,
 				  uint32_t *min,

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

···
 int amdgpu_dpm_reset_sdma(struct amdgpu_device *adev, uint32_t inst_mask);
 bool amdgpu_dpm_reset_sdma_is_supported(struct amdgpu_device *adev);
 int amdgpu_dpm_reset_vcn(struct amdgpu_device *adev, uint32_t inst_mask);
+bool amdgpu_dpm_reset_vcn_is_supported(struct amdgpu_device *adev);
 bool amdgpu_dpm_is_temp_metrics_supported(struct amdgpu_device *adev,
 					  enum smu_temp_metric_type type);
 

drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c

···
 	return ret;
 }
 
+bool smu_reset_vcn_is_supported(struct smu_context *smu)
+{
+	bool ret = false;
+
+	if (smu->ppt_funcs && smu->ppt_funcs->reset_vcn_is_supported)
+		ret = smu->ppt_funcs->reset_vcn_is_supported(smu);
+
+	return ret;
+}
+
 int smu_reset_vcn(struct smu_context *smu, uint32_t inst_mask)
 {
 	if (smu->ppt_funcs && smu->ppt_funcs->dpm_reset_vcn)

drivers/gpu/drm/amd/pm/swsmu/inc/amdgpu_smu.h

···
 	 * @reset_vcn: message SMU to soft reset vcn instance.
 	 */
 	int (*dpm_reset_vcn)(struct smu_context *smu, uint32_t inst_mask);
+	/**
+	 * @reset_vcn_is_supported: Check if support resets vcn.
+	 */
+	bool (*reset_vcn_is_supported)(struct smu_context *smu);
 
 	/**
 	 * @get_ecc_table:  message SMU to get ECC INFO table.
···
 int smu_reset_sdma(struct smu_context *smu, uint32_t inst_mask);
 bool smu_reset_sdma_is_supported(struct smu_context *smu);
 int smu_reset_vcn(struct smu_context *smu, uint32_t inst_mask);
+bool smu_reset_vcn_is_supported(struct smu_context *smu);
 int smu_set_pm_policy(struct smu_context *smu, enum pp_pm_policy p_type,
 		      int level);
 ssize_t smu_get_pm_policy_info(struct smu_context *smu,