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 /******************************************************************************* 29 * Function to invoke the registered `handle` corresponding to the smc_fid in 30 * AArch32 mode. 31 ******************************************************************************/ 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 unsigned int index; 39 unsigned int idx; 40 const rt_svc_desc_t *rt_svc_descs; 41 42 assert(handle != NULL); 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 >= 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) && 73 (desc->call_type != SMC_TYPE_YIELD)) 74 return -EINVAL; 75 76 /* A runtime service having no init or handle function doesn't make sense */ 77 if ((desc->init == NULL) && (desc->handle == NULL)) 78 return -EINVAL; 79 80 return 0; 81 } 82 83 /******************************************************************************* 84 * This function calls the initialisation routine in the descriptor exported by 85 * a runtime service. Once a descriptor has been validated, its start & end 86 * owning entity numbers and the call type are combined to form a unique oen. 87 * The unique oen is used as an index into the 'rt_svc_descs_indices' array. 88 * The index of the runtime service descriptor is stored at this index. 89 ******************************************************************************/ 90 void __init runtime_svc_init(void) 91 { 92 int rc = 0; 93 uint8_t index, start_idx, end_idx; 94 rt_svc_desc_t *rt_svc_descs; 95 96 /* Assert the number of descriptors detected are less than maximum indices */ 97 assert((RT_SVC_DESCS_END >= RT_SVC_DESCS_START) && 98 (RT_SVC_DECS_NUM < MAX_RT_SVCS)); 99 100 /* If no runtime services are implemented then simply bail out */ 101 if (RT_SVC_DECS_NUM == 0U) 102 return; 103 104 /* Initialise internal variables to invalid state */ 105 (void)memset(rt_svc_descs_indices, -1, sizeof(rt_svc_descs_indices)); 106 107 rt_svc_descs = (rt_svc_desc_t *) RT_SVC_DESCS_START; 108 for (index = 0U; index < RT_SVC_DECS_NUM; index++) { 109 rt_svc_desc_t *service = &rt_svc_descs[index]; 110 111 /* 112 * An invalid descriptor is an error condition since it is 113 * difficult to predict the system behaviour in the absence 114 * of this service. 115 */ 116 rc = validate_rt_svc_desc(service); 117 if (rc != 0) { 118 ERROR("Invalid runtime service descriptor %p\n", 119 (void *) service); 120 panic(); 121 } 122 123 /* 124 * The runtime service may have separate rt_svc_desc_t 125 * for its fast smc and yielding smc. Since the service itself 126 * need to be initialized only once, only one of them will have 127 * an initialisation routine defined. Call the initialisation 128 * routine for this runtime service, if it is defined. 129 */ 130 if (service->init != NULL) { 131 rc = service->init(); 132 if (rc != 0) { 133 ERROR("Error initializing runtime service %s\n", 134 service->name); 135 continue; 136 } 137 } 138 139 /* 140 * Fill the indices corresponding to the start and end 141 * owning entity numbers with the index of the 142 * descriptor which will handle the SMCs for this owning 143 * entity range. 144 */ 145 start_idx = (uint8_t)get_unique_oen(service->start_oen, 146 service->call_type); 147 end_idx = (uint8_t)get_unique_oen(service->end_oen, 148 service->call_type); 149 assert(start_idx <= end_idx); 150 assert(end_idx < MAX_RT_SVCS); 151 for (; start_idx <= end_idx; start_idx++) 152 rt_svc_descs_indices[start_idx] = index; 153 } 154 } 155