1 /* 2 * Copyright (c) 2013-2017, 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; 40 unsigned int idx; 41 const rt_svc_desc_t *rt_svc_descs; 42 43 assert(handle); 44 idx = get_unique_oen_from_smc_fid(smc_fid); 45 assert(idx < MAX_RT_SVCS); 46 47 index = rt_svc_descs_indices[idx]; 48 if (index < 0 || index >= (int)RT_SVC_DECS_NUM) 49 SMC_RET1(handle, SMC_UNK); 50 51 rt_svc_descs = (rt_svc_desc_t *) RT_SVC_DESCS_START; 52 53 get_smc_params_from_ctx(handle, x1, x2, x3, x4); 54 55 return rt_svc_descs[index].handle(smc_fid, x1, x2, x3, x4, cookie, 56 handle, flags); 57 } 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 (desc->call_type != SMC_TYPE_FAST && 74 desc->call_type != SMC_TYPE_YIELD) 75 return -EINVAL; 76 77 /* A runtime service having no init or handle function doesn't make sense */ 78 if (desc->init == NULL && desc->handle == NULL) 79 return -EINVAL; 80 81 return 0; 82 } 83 84 /******************************************************************************* 85 * This function calls the initialisation routine in the descriptor exported by 86 * a runtime service. Once a descriptor has been validated, its start & end 87 * owning entity numbers and the call type are combined to form a unique oen. 88 * The unique oen is used as an index into the 'rt_svc_descs_indices' array. 89 * The index of the runtime service descriptor is stored at this index. 90 ******************************************************************************/ 91 void runtime_svc_init(void) 92 { 93 int rc = 0; 94 unsigned int index, start_idx, end_idx; 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 == 0) 102 return; 103 104 /* Initialise internal variables to invalid state */ 105 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 = 0; 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) { 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) { 131 rc = service->init(); 132 if (rc) { 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 = get_unique_oen(rt_svc_descs[index].start_oen, 146 service->call_type); 147 assert(start_idx < MAX_RT_SVCS); 148 end_idx = get_unique_oen(rt_svc_descs[index].end_oen, 149 service->call_type); 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
