1 /* 2 * Copyright (c) 2013-2018, 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 uint8_t rt_svc_descs_indices[MAX_RT_SVCS]; 23 24 #define RT_SVC_DECS_NUM ((RT_SVC_DESCS_END - RT_SVC_DESCS_START)\ 25 / sizeof(rt_svc_desc_t)) 26 27 /******************************************************************************* 28 * Function to invoke the registered `handle` corresponding to the smc_fid in 29 * AArch32 mode. 30 ******************************************************************************/ 31 #if SMCCC_MAJOR_VERSION == 1 32 uintptr_t handle_runtime_svc(uint32_t smc_fid, 33 void *cookie, 34 void *handle, 35 unsigned int flags) 36 { 37 u_register_t x1, x2, x3, x4; 38 int index; 39 unsigned int 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 < MAX_RT_SVCS); 45 46 index = rt_svc_descs_indices[idx]; 47 if (index < 0 || index >= (int)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 #endif /* SMCCC_MAJOR_VERSION */ 58 59 /******************************************************************************* 60 * Simple routine to sanity check a runtime service descriptor before using it 61 ******************************************************************************/ 62 static int32_t validate_rt_svc_desc(const rt_svc_desc_t *desc) 63 { 64 if (desc == NULL) 65 return -EINVAL; 66 67 if (desc->start_oen > desc->end_oen) 68 return -EINVAL; 69 70 if (desc->end_oen >= OEN_LIMIT) 71 return -EINVAL; 72 73 #if SMCCC_MAJOR_VERSION == 1 74 if ((desc->call_type != SMC_TYPE_FAST) && 75 (desc->call_type != SMC_TYPE_YIELD)) 76 return -EINVAL; 77 #elif SMCCC_MAJOR_VERSION == 2 78 if (desc->is_vendor > 1U) 79 return -EINVAL; 80 #endif /* SMCCC_MAJOR_VERSION */ 81 82 /* A runtime service having no init or handle function doesn't make sense */ 83 if ((desc->init == NULL) && (desc->handle == NULL)) 84 return -EINVAL; 85 86 return 0; 87 } 88 89 /******************************************************************************* 90 * This function calls the initialisation routine in the descriptor exported by 91 * a runtime service. Once a descriptor has been validated, its start & end 92 * owning entity numbers and the call type are combined to form a unique oen. 93 * The unique oen is used as an index into the 'rt_svc_descs_indices' array. 94 * The index of the runtime service descriptor is stored at this index. 95 ******************************************************************************/ 96 void runtime_svc_init(void) 97 { 98 int rc = 0; 99 unsigned int index, start_idx, end_idx; 100 rt_svc_desc_t *rt_svc_descs; 101 102 /* Assert the number of descriptors detected are less than maximum indices */ 103 assert((RT_SVC_DESCS_END >= RT_SVC_DESCS_START) && 104 (RT_SVC_DECS_NUM < MAX_RT_SVCS)); 105 106 /* If no runtime services are implemented then simply bail out */ 107 if (RT_SVC_DECS_NUM == 0U) 108 return; 109 110 /* Initialise internal variables to invalid state */ 111 memset(rt_svc_descs_indices, -1, sizeof(rt_svc_descs_indices)); 112 113 rt_svc_descs = (rt_svc_desc_t *) RT_SVC_DESCS_START; 114 for (index = 0; index < RT_SVC_DECS_NUM; index++) { 115 rt_svc_desc_t *service = &rt_svc_descs[index]; 116 117 /* 118 * An invalid descriptor is an error condition since it is 119 * difficult to predict the system behaviour in the absence 120 * of this service. 121 */ 122 rc = validate_rt_svc_desc(service); 123 if (rc) { 124 ERROR("Invalid runtime service descriptor %p\n", 125 (void *) service); 126 panic(); 127 } 128 129 /* 130 * The runtime service may have separate rt_svc_desc_t 131 * for its fast smc and yielding smc. Since the service itself 132 * need to be initialized only once, only one of them will have 133 * an initialisation routine defined. Call the initialisation 134 * routine for this runtime service, if it is defined. 135 */ 136 if (service->init) { 137 rc = service->init(); 138 if (rc) { 139 ERROR("Error initializing runtime service %s\n", 140 service->name); 141 continue; 142 } 143 } 144 145 /* 146 * Fill the indices corresponding to the start and end 147 * owning entity numbers with the index of the 148 * descriptor which will handle the SMCs for this owning 149 * entity range. 150 */ 151 #if SMCCC_MAJOR_VERSION == 1 152 start_idx = get_unique_oen(service->start_oen, 153 service->call_type); 154 end_idx = get_unique_oen(service->end_oen, 155 service->call_type); 156 #elif SMCCC_MAJOR_VERSION == 2 157 start_idx = get_rt_desc_idx(service->start_oen, 158 service->is_vendor); 159 end_idx = get_rt_desc_idx(service->end_oen, 160 service->is_vendor); 161 #endif 162 assert(start_idx <= end_idx); 163 assert(end_idx < MAX_RT_SVCS); 164 for (; start_idx <= end_idx; start_idx++) 165 rt_svc_descs_indices[start_idx] = index; 166 } 167 } 168