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 static rt_svc_desc_t *rt_svc_descs; 24 25 #define RT_SVC_DECS_NUM ((RT_SVC_DESCS_END - RT_SVC_DESCS_START)\ 26 / sizeof(rt_svc_desc_t)) 27 28 /******************************************************************************* 29 * Function to invoke the registered `handle` corresponding to the smc_fid in 30 * AArch32 mode. 31 ******************************************************************************/ 32 #if SMCCC_MAJOR_VERSION == 1 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; 40 unsigned int idx; 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; 100 101 /* Assert the number of descriptors detected are less than maximum indices */ 102 assert((RT_SVC_DESCS_END >= RT_SVC_DESCS_START) && 103 (RT_SVC_DECS_NUM < MAX_RT_SVCS)); 104 105 /* If no runtime services are implemented then simply bail out */ 106 if (RT_SVC_DECS_NUM == 0U) 107 return; 108 109 /* Initialise internal variables to invalid state */ 110 memset(rt_svc_descs_indices, -1, sizeof(rt_svc_descs_indices)); 111 112 rt_svc_descs = (rt_svc_desc_t *) RT_SVC_DESCS_START; 113 for (index = 0; index < RT_SVC_DECS_NUM; index++) { 114 rt_svc_desc_t *service = &rt_svc_descs[index]; 115 116 /* 117 * An invalid descriptor is an error condition since it is 118 * difficult to predict the system behaviour in the absence 119 * of this service. 120 */ 121 rc = validate_rt_svc_desc(service); 122 if (rc) { 123 ERROR("Invalid runtime service descriptor %p\n", 124 (void *) service); 125 panic(); 126 } 127 128 /* 129 * The runtime service may have separate rt_svc_desc_t 130 * for its fast smc and yielding smc. Since the service itself 131 * need to be initialized only once, only one of them will have 132 * an initialisation routine defined. Call the initialisation 133 * routine for this runtime service, if it is defined. 134 */ 135 if (service->init) { 136 rc = service->init(); 137 if (rc) { 138 ERROR("Error initializing runtime service %s\n", 139 service->name); 140 continue; 141 } 142 } 143 144 /* 145 * Fill the indices corresponding to the start and end 146 * owning entity numbers with the index of the 147 * descriptor which will handle the SMCs for this owning 148 * entity range. 149 */ 150 #if SMCCC_MAJOR_VERSION == 1 151 start_idx = get_unique_oen(service->start_oen, 152 service->call_type); 153 end_idx = get_unique_oen(service->end_oen, 154 service->call_type); 155 #elif SMCCC_MAJOR_VERSION == 2 156 start_idx = get_rt_desc_idx(service->start_oen, 157 service->is_vendor); 158 end_idx = get_rt_desc_idx(service->end_oen, 159 service->is_vendor); 160 #endif 161 assert(start_idx <= end_idx); 162 assert(end_idx < MAX_RT_SVCS); 163 for (; start_idx <= end_idx; start_idx++) 164 rt_svc_descs_indices[start_idx] = index; 165 } 166 } 167