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, 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 >= 0 && idx < MAX_RT_SVCS); 45 46 index = rt_svc_descs_indices[idx]; 47 if (index < 0 || 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 runtime_svc_init(void) 91 { 92 int rc = 0, index, start_idx, end_idx; 93 94 /* Assert the number of descriptors detected are less than maximum indices */ 95 assert((RT_SVC_DESCS_END >= RT_SVC_DESCS_START) && 96 (RT_SVC_DECS_NUM < MAX_RT_SVCS)); 97 98 /* If no runtime services are implemented then simply bail out */ 99 if (RT_SVC_DECS_NUM == 0) 100 return; 101 102 /* Initialise internal variables to invalid state */ 103 memset(rt_svc_descs_indices, -1, sizeof(rt_svc_descs_indices)); 104 105 rt_svc_descs = (rt_svc_desc_t *) RT_SVC_DESCS_START; 106 for (index = 0; index < RT_SVC_DECS_NUM; index++) { 107 rt_svc_desc_t *service = &rt_svc_descs[index]; 108 109 /* 110 * An invalid descriptor is an error condition since it is 111 * difficult to predict the system behaviour in the absence 112 * of this service. 113 */ 114 rc = validate_rt_svc_desc(service); 115 if (rc) { 116 ERROR("Invalid runtime service descriptor %p\n", 117 (void *) service); 118 panic(); 119 } 120 121 /* 122 * The runtime service may have separate rt_svc_desc_t 123 * for its fast smc and yielding smc. Since the service itself 124 * need to be initialized only once, only one of them will have 125 * an initialisation routine defined. Call the initialisation 126 * routine for this runtime service, if it is defined. 127 */ 128 if (service->init) { 129 rc = service->init(); 130 if (rc) { 131 ERROR("Error initializing runtime service %s\n", 132 service->name); 133 continue; 134 } 135 } 136 137 /* 138 * Fill the indices corresponding to the start and end 139 * owning entity numbers with the index of the 140 * descriptor which will handle the SMCs for this owning 141 * entity range. 142 */ 143 start_idx = get_unique_oen(rt_svc_descs[index].start_oen, 144 service->call_type); 145 assert(start_idx < MAX_RT_SVCS); 146 end_idx = get_unique_oen(rt_svc_descs[index].end_oen, 147 service->call_type); 148 assert(end_idx < MAX_RT_SVCS); 149 for (; start_idx <= end_idx; start_idx++) 150 rt_svc_descs_indices[start_idx] = index; 151 } 152 } 153