1 /* 2 * Copyright (c) 2013-2016, ARM Limited and Contributors. All rights reserved. 3 * 4 * SPDX-License-Identifier: BSD-3-Clause 5 */ 6 7 #include <assert.h> 8 #include <debug.h> 9 #include <errno.h> 10 #include <runtime_svc.h> 11 #include <string.h> 12 13 /******************************************************************************* 14 * The 'rt_svc_descs' array holds the runtime service descriptors exported by 15 * services by placing them in the 'rt_svc_descs' linker section. 16 * The 'rt_svc_descs_indices' array holds the index of a descriptor in the 17 * 'rt_svc_descs' array. When an SMC arrives, the OEN[29:24] bits and the call 18 * type[31] bit in the function id are combined to get an index into the 19 * 'rt_svc_descs_indices' array. This gives the index of the descriptor in the 20 * 'rt_svc_descs' array which contains the SMC handler. 21 ******************************************************************************/ 22 #define RT_SVC_DESCS_START ((uintptr_t) (&__RT_SVC_DESCS_START__)) 23 #define RT_SVC_DESCS_END ((uintptr_t) (&__RT_SVC_DESCS_END__)) 24 uint8_t rt_svc_descs_indices[MAX_RT_SVCS]; 25 static rt_svc_desc_t *rt_svc_descs; 26 27 #define RT_SVC_DECS_NUM ((RT_SVC_DESCS_END - RT_SVC_DESCS_START)\ 28 / sizeof(rt_svc_desc_t)) 29 30 /******************************************************************************* 31 * Function to invoke the registered `handle` corresponding to the smc_fid. 32 ******************************************************************************/ 33 uintptr_t handle_runtime_svc(uint32_t smc_fid, 34 void *cookie, 35 void *handle, 36 unsigned int flags) 37 { 38 u_register_t x1, x2, x3, x4; 39 int index, idx; 40 const rt_svc_desc_t *rt_svc_descs; 41 42 assert(handle); 43 idx = get_unique_oen_from_smc_fid(smc_fid); 44 assert(idx >= 0 && idx < MAX_RT_SVCS); 45 46 index = rt_svc_descs_indices[idx]; 47 if (index < 0 || index >= RT_SVC_DECS_NUM) 48 SMC_RET1(handle, SMC_UNK); 49 50 rt_svc_descs = (rt_svc_desc_t *) RT_SVC_DESCS_START; 51 52 get_smc_params_from_ctx(handle, x1, x2, x3, x4); 53 54 return rt_svc_descs[index].handle(smc_fid, x1, x2, x3, x4, cookie, 55 handle, flags); 56 } 57 58 /******************************************************************************* 59 * Simple routine to sanity check a runtime service descriptor before using it 60 ******************************************************************************/ 61 static int32_t validate_rt_svc_desc(const rt_svc_desc_t *desc) 62 { 63 if (desc == NULL) 64 return -EINVAL; 65 66 if (desc->start_oen > desc->end_oen) 67 return -EINVAL; 68 69 if (desc->end_oen >= OEN_LIMIT) 70 return -EINVAL; 71 72 if (desc->call_type != SMC_TYPE_FAST && desc->call_type != SMC_TYPE_STD) 73 return -EINVAL; 74 75 /* A runtime service having no init or handle function doesn't make sense */ 76 if (desc->init == NULL && desc->handle == NULL) 77 return -EINVAL; 78 79 return 0; 80 } 81 82 /******************************************************************************* 83 * This function calls the initialisation routine in the descriptor exported by 84 * a runtime service. Once a descriptor has been validated, its start & end 85 * owning entity numbers and the call type are combined to form a unique oen. 86 * The unique oen is used as an index into the 'rt_svc_descs_indices' array. 87 * The index of the runtime service descriptor is stored at this index. 88 ******************************************************************************/ 89 void runtime_svc_init(void) 90 { 91 int rc = 0, index, start_idx, end_idx; 92 93 /* Assert the number of descriptors detected are less than maximum indices */ 94 assert((RT_SVC_DESCS_END >= RT_SVC_DESCS_START) && 95 (RT_SVC_DECS_NUM < MAX_RT_SVCS)); 96 97 /* If no runtime services are implemented then simply bail out */ 98 if (RT_SVC_DECS_NUM == 0) 99 return; 100 101 /* Initialise internal variables to invalid state */ 102 memset(rt_svc_descs_indices, -1, sizeof(rt_svc_descs_indices)); 103 104 rt_svc_descs = (rt_svc_desc_t *) RT_SVC_DESCS_START; 105 for (index = 0; index < RT_SVC_DECS_NUM; index++) { 106 rt_svc_desc_t *service = &rt_svc_descs[index]; 107 108 /* 109 * An invalid descriptor is an error condition since it is 110 * difficult to predict the system behaviour in the absence 111 * of this service. 112 */ 113 rc = validate_rt_svc_desc(service); 114 if (rc) { 115 ERROR("Invalid runtime service descriptor %p\n", 116 (void *) service); 117 panic(); 118 } 119 120 /* 121 * The runtime service may have separate rt_svc_desc_t 122 * for its fast smc and standard smc. Since the service itself 123 * need to be initialized only once, only one of them will have 124 * an initialisation routine defined. Call the initialisation 125 * routine for this runtime service, if it is defined. 126 */ 127 if (service->init) { 128 rc = service->init(); 129 if (rc) { 130 ERROR("Error initializing runtime service %s\n", 131 service->name); 132 continue; 133 } 134 } 135 136 /* 137 * Fill the indices corresponding to the start and end 138 * owning entity numbers with the index of the 139 * descriptor which will handle the SMCs for this owning 140 * entity range. 141 */ 142 start_idx = get_unique_oen(rt_svc_descs[index].start_oen, 143 service->call_type); 144 assert(start_idx < MAX_RT_SVCS); 145 end_idx = get_unique_oen(rt_svc_descs[index].end_oen, 146 service->call_type); 147 assert(end_idx < MAX_RT_SVCS); 148 for (; start_idx <= end_idx; start_idx++) 149 rt_svc_descs_indices[start_idx] = index; 150 } 151 } 152