1 /* 2 * Copyright (c) 2013-2017, ARM Limited and Contributors. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions are met: 6 * 7 * Redistributions of source code must retain the above copyright notice, this 8 * list of conditions and the following disclaimer. 9 * 10 * Redistributions in binary form must reproduce the above copyright notice, 11 * this list of conditions and the following disclaimer in the documentation 12 * and/or other materials provided with the distribution. 13 * 14 * Neither the name of ARM nor the names of its contributors may be used 15 * to endorse or promote products derived from this software without specific 16 * prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 19 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE 22 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 28 * POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31 #include <assert.h> 32 #include <debug.h> 33 #include <errno.h> 34 #include <runtime_svc.h> 35 #include <string.h> 36 37 /******************************************************************************* 38 * The 'rt_svc_descs' array holds the runtime service descriptors exported by 39 * services by placing them in the 'rt_svc_descs' linker section. 40 * The 'rt_svc_descs_indices' array holds the index of a descriptor in the 41 * 'rt_svc_descs' array. When an SMC arrives, the OEN[29:24] bits and the call 42 * type[31] bit in the function id are combined to get an index into the 43 * 'rt_svc_descs_indices' array. This gives the index of the descriptor in the 44 * 'rt_svc_descs' array which contains the SMC handler. 45 ******************************************************************************/ 46 #define RT_SVC_DESCS_START ((uintptr_t) (&__RT_SVC_DESCS_START__)) 47 #define RT_SVC_DESCS_END ((uintptr_t) (&__RT_SVC_DESCS_END__)) 48 uint8_t rt_svc_descs_indices[MAX_RT_SVCS]; 49 static rt_svc_desc_t *rt_svc_descs; 50 51 #define RT_SVC_DECS_NUM ((RT_SVC_DESCS_END - RT_SVC_DESCS_START)\ 52 / sizeof(rt_svc_desc_t)) 53 54 /******************************************************************************* 55 * Function to invoke the registered `handle` corresponding to the smc_fid. 56 ******************************************************************************/ 57 uintptr_t handle_runtime_svc(uint32_t smc_fid, 58 void *cookie, 59 void *handle, 60 unsigned int flags) 61 { 62 u_register_t x1, x2, x3, x4; 63 int index, idx; 64 const rt_svc_desc_t *rt_svc_descs; 65 66 assert(handle); 67 idx = get_unique_oen_from_smc_fid(smc_fid); 68 assert(idx >= 0 && idx < MAX_RT_SVCS); 69 70 index = rt_svc_descs_indices[idx]; 71 if (index < 0 || index >= RT_SVC_DECS_NUM) 72 SMC_RET1(handle, SMC_UNK); 73 74 rt_svc_descs = (rt_svc_desc_t *) RT_SVC_DESCS_START; 75 76 get_smc_params_from_ctx(handle, x1, x2, x3, x4); 77 78 return rt_svc_descs[index].handle(smc_fid, x1, x2, x3, x4, cookie, 79 handle, flags); 80 } 81 82 /******************************************************************************* 83 * Simple routine to sanity check a runtime service descriptor before using it 84 ******************************************************************************/ 85 static int32_t validate_rt_svc_desc(const rt_svc_desc_t *desc) 86 { 87 if (desc == NULL) 88 return -EINVAL; 89 90 if (desc->start_oen > desc->end_oen) 91 return -EINVAL; 92 93 if (desc->end_oen >= OEN_LIMIT) 94 return -EINVAL; 95 96 if (desc->call_type != SMC_TYPE_FAST && 97 desc->call_type != SMC_TYPE_YIELD) 98 return -EINVAL; 99 100 /* A runtime service having no init or handle function doesn't make sense */ 101 if (desc->init == NULL && desc->handle == NULL) 102 return -EINVAL; 103 104 return 0; 105 } 106 107 /******************************************************************************* 108 * This function calls the initialisation routine in the descriptor exported by 109 * a runtime service. Once a descriptor has been validated, its start & end 110 * owning entity numbers and the call type are combined to form a unique oen. 111 * The unique oen is used as an index into the 'rt_svc_descs_indices' array. 112 * The index of the runtime service descriptor is stored at this index. 113 ******************************************************************************/ 114 void runtime_svc_init(void) 115 { 116 int rc = 0, index, start_idx, end_idx; 117 118 /* Assert the number of descriptors detected are less than maximum indices */ 119 assert((RT_SVC_DESCS_END >= RT_SVC_DESCS_START) && 120 (RT_SVC_DECS_NUM < MAX_RT_SVCS)); 121 122 /* If no runtime services are implemented then simply bail out */ 123 if (RT_SVC_DECS_NUM == 0) 124 return; 125 126 /* Initialise internal variables to invalid state */ 127 memset(rt_svc_descs_indices, -1, sizeof(rt_svc_descs_indices)); 128 129 rt_svc_descs = (rt_svc_desc_t *) RT_SVC_DESCS_START; 130 for (index = 0; index < RT_SVC_DECS_NUM; index++) { 131 rt_svc_desc_t *service = &rt_svc_descs[index]; 132 133 /* 134 * An invalid descriptor is an error condition since it is 135 * difficult to predict the system behaviour in the absence 136 * of this service. 137 */ 138 rc = validate_rt_svc_desc(service); 139 if (rc) { 140 ERROR("Invalid runtime service descriptor %p\n", 141 (void *) service); 142 panic(); 143 } 144 145 /* 146 * The runtime service may have separate rt_svc_desc_t 147 * for its fast smc and yielding smc. Since the service itself 148 * need to be initialized only once, only one of them will have 149 * an initialisation routine defined. Call the initialisation 150 * routine for this runtime service, if it is defined. 151 */ 152 if (service->init) { 153 rc = service->init(); 154 if (rc) { 155 ERROR("Error initializing runtime service %s\n", 156 service->name); 157 continue; 158 } 159 } 160 161 /* 162 * Fill the indices corresponding to the start and end 163 * owning entity numbers with the index of the 164 * descriptor which will handle the SMCs for this owning 165 * entity range. 166 */ 167 start_idx = get_unique_oen(rt_svc_descs[index].start_oen, 168 service->call_type); 169 assert(start_idx < MAX_RT_SVCS); 170 end_idx = get_unique_oen(rt_svc_descs[index].end_oen, 171 service->call_type); 172 assert(end_idx < MAX_RT_SVCS); 173 for (; start_idx <= end_idx; start_idx++) 174 rt_svc_descs_indices[start_idx] = index; 175 } 176 } 177