1 /* 2 * Copyright (c) 2013-2019, ARM Limited and Contributors. All rights reserved. 3 * 4 * SPDX-License-Identifier: BSD-3-Clause 5 */ 6 7 #include <assert.h> 8 #include <errno.h> 9 #include <string.h> 10 11 #include <common/debug.h> 12 #include <common/runtime_svc.h> 13 14 /******************************************************************************* 15 * The 'rt_svc_descs' array holds the runtime service descriptors exported by 16 * services by placing them in the 'rt_svc_descs' linker section. 17 * The 'rt_svc_descs_indices' array holds the index of a descriptor in the 18 * 'rt_svc_descs' array. When an SMC arrives, the OEN[29:24] bits and the call 19 * type[31] bit in the function id are combined to get an index into the 20 * 'rt_svc_descs_indices' array. This gives the index of the descriptor in the 21 * 'rt_svc_descs' array which contains the SMC handler. 22 ******************************************************************************/ 23 uint8_t rt_svc_descs_indices[MAX_RT_SVCS]; 24 25 #define RT_SVC_DECS_NUM ((RT_SVC_DESCS_END - RT_SVC_DESCS_START)\ 26 / sizeof(rt_svc_desc_t)) 27 28 static bool get_handler_for_smc_fid(uint32_t smc_fid, rt_svc_handle_t *handler) 29 { 30 unsigned int index; 31 unsigned int idx; 32 const rt_svc_desc_t *rt_svc_descs; 33 34 idx = get_unique_oen_from_smc_fid(smc_fid); 35 assert(idx < MAX_RT_SVCS); 36 index = rt_svc_descs_indices[idx]; 37 38 if (index >= RT_SVC_DECS_NUM) 39 return false; 40 41 rt_svc_descs = (rt_svc_desc_t *) RT_SVC_DESCS_START; 42 assert(handler != NULL); 43 *handler = rt_svc_descs[index].handle; 44 assert(*handler != NULL); 45 46 return true; 47 } 48 49 /******************************************************************************* 50 * Function to invoke the registered `handle` corresponding to the smc_fid in 51 * AArch32 mode. 52 ******************************************************************************/ 53 uintptr_t handle_runtime_svc(uint32_t smc_fid, 54 void *cookie, 55 void *handle, 56 unsigned int flags) 57 { 58 u_register_t x1, x2, x3, x4; 59 rt_svc_handle_t handler; 60 61 assert(handle != NULL); 62 63 if (!get_handler_for_smc_fid(smc_fid, &handler)) { 64 SMC_RET1(handle, SMC_UNK); 65 } 66 67 get_smc_params_from_ctx(handle, x1, x2, x3, x4); 68 69 return handler(smc_fid, x1, x2, x3, x4, cookie, handle, flags); 70 } 71 72 /******************************************************************************* 73 * Simple routine to sanity check a runtime service descriptor before using it 74 ******************************************************************************/ 75 static int32_t validate_rt_svc_desc(const rt_svc_desc_t *desc) 76 { 77 if (desc == NULL) { 78 return -EINVAL; 79 } 80 if (desc->start_oen > desc->end_oen) { 81 return -EINVAL; 82 } 83 if (desc->end_oen >= OEN_LIMIT) { 84 return -EINVAL; 85 } 86 if ((desc->call_type != SMC_TYPE_FAST) && 87 (desc->call_type != SMC_TYPE_YIELD)) { 88 return -EINVAL; 89 } 90 /* A runtime service having no init or handle function doesn't make sense */ 91 if ((desc->init == NULL) && (desc->handle == NULL)) { 92 return -EINVAL; 93 } 94 return 0; 95 } 96 97 /******************************************************************************* 98 * This function calls the initialisation routine in the descriptor exported by 99 * a runtime service. Once a descriptor has been validated, its start & end 100 * owning entity numbers and the call type are combined to form a unique oen. 101 * The unique oen is used as an index into the 'rt_svc_descs_indices' array. 102 * The index of the runtime service descriptor is stored at this index. 103 ******************************************************************************/ 104 void __init runtime_svc_init(void) 105 { 106 int rc = 0; 107 uint8_t index, start_idx, end_idx; 108 rt_svc_desc_t *rt_svc_descs; 109 110 /* Assert the number of descriptors detected are less than maximum indices */ 111 assert((RT_SVC_DESCS_END >= RT_SVC_DESCS_START) && 112 (RT_SVC_DECS_NUM < MAX_RT_SVCS)); 113 114 /* If no runtime services are implemented then simply bail out */ 115 if (RT_SVC_DECS_NUM == 0U) { 116 return; 117 } 118 /* Initialise internal variables to invalid state */ 119 (void)memset(rt_svc_descs_indices, -1, sizeof(rt_svc_descs_indices)); 120 121 rt_svc_descs = (rt_svc_desc_t *) RT_SVC_DESCS_START; 122 for (index = 0U; index < RT_SVC_DECS_NUM; index++) { 123 rt_svc_desc_t *service = &rt_svc_descs[index]; 124 125 /* 126 * An invalid descriptor is an error condition since it is 127 * difficult to predict the system behaviour in the absence 128 * of this service. 129 */ 130 rc = validate_rt_svc_desc(service); 131 if (rc != 0) { 132 ERROR("Invalid runtime service descriptor %p\n", 133 (void *) service); 134 panic(); 135 } 136 137 /* 138 * The runtime service may have separate rt_svc_desc_t 139 * for its fast smc and yielding smc. Since the service itself 140 * need to be initialized only once, only one of them will have 141 * an initialisation routine defined. Call the initialisation 142 * routine for this runtime service, if it is defined. 143 */ 144 if (service->init != NULL) { 145 rc = service->init(); 146 if (rc != 0) { 147 ERROR("Error initializing runtime service %s\n", 148 service->name); 149 continue; 150 } 151 } 152 153 /* 154 * Fill the indices corresponding to the start and end 155 * owning entity numbers with the index of the 156 * descriptor which will handle the SMCs for this owning 157 * entity range. 158 */ 159 start_idx = (uint8_t)get_unique_oen(service->start_oen, 160 service->call_type); 161 end_idx = (uint8_t)get_unique_oen(service->end_oen, 162 service->call_type); 163 assert(start_idx <= end_idx); 164 assert(end_idx < MAX_RT_SVCS); 165 for (; start_idx <= end_idx; start_idx++) { 166 rt_svc_descs_indices[start_idx] = index; 167 } 168 } 169 } 170