1 /* 2 * Copyright (c) 2020-2023, Arm Limited and Contributors. All rights reserved. 3 * 4 * SPDX-License-Identifier: BSD-3-Clause 5 */ 6 7 #ifndef RPC_INTERFACE_H 8 #define RPC_INTERFACE_H 9 10 #include "rpc_status.h" 11 #include "rpc_uuid.h" 12 #include <stddef.h> 13 #include <stdint.h> 14 15 #ifdef EXPORT_PUBLIC_INTERFACE_RPC_SERVICE 16 #define RPC_SERVICE_EXPORTED __attribute__((__visibility__("default"))) 17 #else 18 #define RPC_SERVICE_EXPORTED 19 #endif 20 21 #ifdef __cplusplus 22 extern "C" { 23 #endif 24 25 /** 26 * @brief RPC buffer 27 * 28 * Describes an RPC buffer by its data pointer, size and the used data length. 29 */ 30 struct rpc_buffer { 31 uint8_t *data; 32 size_t data_length; 33 size_t size; 34 }; 35 36 /** 37 * @brief RPC request 38 * 39 * The service should select the requested function by the opcode field. The call's request and 40 * response parameter buffer is accessible via the request and response rpc_buffers. The response's 41 * size must be indicated by the service through setting the data_length field of the response. 42 * The services can identify the caller via the source_id and client_id fields. 43 */ 44 struct rpc_request { 45 uint16_t source_id; /** Call source ID (i.e. FF-A source ID) */ 46 uint8_t interface_id; /** Service interface ID */ 47 uint16_t opcode; /** Opcode of the required function */ 48 uint32_t client_id; /** Client ID for further caller identification */ 49 service_status_t service_status; /** Service specific status code */ 50 struct rpc_buffer request; /** Request buffer */ 51 struct rpc_buffer response; /** Response buffer */ 52 }; 53 54 /** 55 * @brief RPC service interface 56 * 57 * An endpoint (i.e. secure partition) can implement multiple services which are identified by their 58 * service UUID. Once an endpoint receives an RPC call, it selects the matching 59 * rpc_service_interface instance, builds the rpc_request structure and calls the interface's 60 * receive function. 61 * If the service is not able to parse the request (invalid opcode, request or response buffer) 62 * it should return an rpc_status_t value indicating the issue with the RPC request. Otherwise it 63 * must return RPC_SUCCESS. 64 * Service level status codes should be passed in a service specific way. 65 */ 66 struct rpc_service_interface { 67 void *context; 68 struct rpc_uuid uuid; 69 70 rpc_status_t (*receive)(void *context, struct rpc_request *request); 71 }; 72 73 /** 74 * @brief Call the receive function of the RPC interface. 75 * 76 * @param service The service instance 77 * @param request RPC request 78 * @return rpc_status_t 79 */ 80 RPC_SERVICE_EXPORTED 81 rpc_status_t rpc_service_receive(struct rpc_service_interface *service, 82 struct rpc_request *request); 83 84 #ifdef __cplusplus 85 } 86 #endif 87 88 #endif /* RPC_INTERFACE_H */ 89