srvgrp-base.adoc

Service Groups

A service group is a collection of services which are logically grouped according to the functionality they provide. For example, all voltage related services/messages are collectively referred to as Voltage Service Group.

This specification defines standard service groups and services with provision to add more service groups as per requirement in the future.

Following table lists the service group

Table 1. Service Groups

Service Group ID	Service Group Name
0x00001	BASE
0x00002	SYSTEM_RESET
0x00003	SYSTEM_SUSPEND
0x00004	HART_STATE_MANAGEMENT
0x00005	CPPC
0x00006	VOLTAGE
0x00007	CLOCK
0x00008	DEVICE_POWER
0x00009	PERFORMANCE
0x0000A	MM_SERVICE
0x0000B	RAS_AGENT
0x0000B - 0x7FFFF	Reserved for Future Use
0x80000 - 0xFFFFF	Implementation Specific Service Groups

Note	The services listed in each service group do not follow any sequence and are not defined in any specific order. It’s possible that any particular service in any service group inherently requires to be called first before other defined services before that.

Service Group - BASE (servicegroup_id: 0x00001)

Base service group is mandatory and provides services for:

• Initial handshaking between the Application processor and Platform micro-controller.

• Querying the message framework implementation version information.

• Discovering the implementation and version of a specific service group or any specific service in any service group.

• Gathering allowed system information from the firmware.

• Status of the transport and if the Platform Microcontroller is ready for accepting messages.

Below table lists the services in this group:

Table 2. Base Services

Service ID	Service Name	Request Type
0x01	ENABLE_NOTIFICATION	NORMAL_REQUEST
0x02	GET_IMPLEMENTATION_VERSION	NORMAL_REQUEST
0x03	GET_IMPLEMENTATION_ID	NORMAL_REQUEST
0x04	GET_SPEC_VERSION	NORMAL_REQUEST
0x05	GET_HW_INFO	NORMAL_REQUEST
0x06	PROBE_SERVICE_GROUP	NORMAL_REQUEST
0x07	GET_BASE_ATTRIBUTES	NORMAL_REQUEST
0x08	SET_MSI	NORMAL_REQUEST

Base Notifications

Platform Microcontroller can send asynchronous notifications to AP via this service. There can be multiple types of events classified in the Base service group which can be combined into a single message as depicted in Figure 3.5. If Platform Microcontroller has multiple events for the same type, Platform Microcontroller can send the single instance of that event that was received last.

Table 3. Base Service Group Events

Event ID	Event Name	Event Data	Description
0x001	REQUEST_HANDLE_ERROR	NA	This event indicates that the Platform Microcontroller is unable to serve the message requests anymore and this event may send the list of messages which the Platform Microcontroller was processing when the failure took place. No event data is necessary for this notification

Service: ENABLE_NOTIFICATION

This service allows AP to subscribe to Base service group notifications.
Platform can optionally support notifications of errors which might occur in the platform. PuC can send these notification messages to AP if they are implemented and AP has subscribed to these. Events supported are described above in Base Notifications.

Table 4. Request Data

Word	Name	Type	Description
0	EVENT_ID	uint32	Event to be subscribed for notification.

Table 5. Response Data

Word	Name	Type	Description
0	STATUS	int32	Return Status Code Error Code Description RPMI_SUCCESS Notifications are subscribed successfully. RPMI_ERROR_NOT_FOUND EVENT_ID is not supported or invalid. RPMI_ERROR_NOT_SUPPORTED Notifications not supported. Other errors [table_error_codes]

Service: GET_IMPLEMENTATION_VERSION

Get the implementation version of the message framework from Platform Microcontroller. Versioning is also done for the spec but it’s possible that for a single version of spec there may be multiple implementation versions and based on that any lowest supported implementation version can be mandated to ensure the stability and support. Version returned using this service is a 32-Bit composite number which contains both Major and Minor numbers.

Request Data

• NA

Table 6. Response Data

Word	Name	Type	Description
0	STATUS	int32	Return Status Code Error Code Description RPMI_SUCCESS Implementation version returned successfully. Other errors [table_error_codes]
1	VERSION	uint32	Implementation Version Bits Description [31:16] Major Number [15:0] Minor Number

Service: GET_IMPLEMENTATION_ID

Get the RPMI Implementation ID assigned to the Operating system or Firmware or any other software host which implements the RPMI specification.

Request Data

• NA

Table 7. Response Data

Word	Name	Type	Description
0	STATUS	int32	Return Status Code Error Code Description RPMI_SUCCESS Implementation ID returned successfully. Other errors [table_error_codes]
1	IMPL_ID	uint32	Implementation ID

Service: GET_SPEC_VERSION

Get version of the implemented RPMI specification

Request Data

• NA

Table 8. Response Data

Word	Name	Type	Description
0	STATUS	int32	Return Status Code Error Code Description RPMI_SUCCESS RPMI specification version returned successfully. Other errors [table_error_codes]
1	VERSION	uint32	RPMI Specification Version Bits Description [31:16] Major Number [15:0] Minor Number

Service: GET_HW_INFO

This service is used to retrieve the Vendor ID and Name of the Vendor having a RPMI implementation on PuC. Each vendor will be assigned a unique Vendor ID.

Request Data

• NA

Table 9. Response Data

Word	Name	Type	Description
0	STATUS	int32	Return Status Code Error Code Description RPMI_SUCCESS Vendor info returned successfully. Other errors [table_error_codes]
1	VENDOR_ID	uint32	Vendor Identifier Bits Description [31:16] SUB_VENDOR_ID (optional) It is an additional numeric value used to further differentiate between different sub-vendors or product lines within the same hardware vendor. 0x0: Not Supported [15:0] VENDOR_ID Hardware Vendor ID is a numeric value that uniquely identifies the manufacturer or vendor of the hardware platform or device.
2	HW_ID_LEN	uint32	HW_ID field length in bytes.
3	HW_ID	uint8[HW_ID_LEN]	Hardware Identifier String Up to HW_ID_LEN bytes NULL terminated ASCII string. It can be used to convey details such as the specific product model, revision, or configuration of the hardware.

Service: PROBE_SERVICE_GROUP

Probe the implementation of any service group by its service group id. Except BASE, rest of the service groups are optional but if a service group is implemented then it has to be implemented completely with all services in that group. The notifications in that service group are still optional which will be implemented by the PuC.

Table 10. Request Data

Word	Name	Type	Description
0	SERVICEGROUP_ID	uint32	24 bit ID assigned to each service group.

Table 11. Response Data

Word	Name	Type	Description
0	STATUS	int32	Return Status Code Error Code Description RPMI_SUCCESS Service completed successfully. Status of Service group represented by SERVICEGROUP_ID is identified by field SERVICE_GROUP_STATUS. Other errors [table_error_codes]
1	SERVICE_GROUP_STATUS	uint32	Service group implementation status. 0: Service group not implemented by platform. 1: Service group implemented by platform.

Service: GET_BASE_ATTRIBUTES

This service is used to discover additional features supported by the base service group.

Request Data

• NA

Table 12. Response Data

Word	Name	Type	Description
0	STATUS	int32	Return Status Code Error Code Description RPMI_SUCCESS Attributes returned successfully. Other errors [table_error_codes]
1	FLAGS0	uint32	Vendor Identifier Bits Description [31] EVENT_NOTIFICATION 0b0: Notifications are not supported 0b1: Notifications are supported [30] MSI 0b0: Not Supported 0b1: Supported [29:0] Reserved
2	FLAGS1	uint32	Reserved, initialized to 0
3	FLAGS2	uint32	Reserved, initialized to 0
4	FLAGS3	uint32	Reserved, initialized to 0

Service: SET_MSI

Configure the MSI address and data which the Platform Microcontroller can use as a doorbell to AP.

The PuC to AP MSI can be used for both sending MSI or injecting wired interrupts. If the MSI target address is IMSIC then AP will take MSI whereas if the MSI target address is "setipnum" of APLIC then AP will take wired interrupt.

In case of platforms with PLIC, the platform need to provide a MMIO register to inject a edge-triggered interrupt.

Table 13. Request Data

Word	Name	Type	Description
0	MSI_ADDRESS_LOW	uint32	Lower 32 bit of MSI address
1	MSI_ADDRESS_HIGH	uint32	Higher 32 bit of MSI address
2	MSI_DATA	uint32	32 bit MSI data

Table 14. Response Data

Word	Name	Type	Description
0	STATUS	int32	Return Status Code Error Code Description RPMI_SUCCESS MSI address and data are configured successfully. RPMI_ERROR_NOT_SUPPORTED MSI not supported. Implementation must use base attributes to discover this capability and then use this service.. Other errors [table_error_codes]