1 /* 2 * Copyright (c) 2013-2017, ARM Limited and Contributors. All rights reserved. 3 * 4 * SPDX-License-Identifier: BSD-3-Clause 5 */ 6 7 8 /******************************************************************************* 9 * This is the Secure Payload Dispatcher (SPD). The dispatcher is meant to be a 10 * plug-in component to the Secure Monitor, registered as a runtime service. The 11 * SPD is expected to be a functional extension of the Secure Payload (SP) that 12 * executes in Secure EL1. The Secure Monitor will delegate all SMCs targeting 13 * the Trusted OS/Applications range to the dispatcher. The SPD will either 14 * handle the request locally or delegate it to the Secure Payload. It is also 15 * responsible for initialising and maintaining communication with the SP. 16 ******************************************************************************/ 17 #include <arch_helpers.h> 18 #include <assert.h> 19 #include <bl31.h> 20 #include <bl_common.h> 21 #include <context_mgmt.h> 22 #include <debug.h> 23 #include <errno.h> 24 #include <platform.h> 25 #include <runtime_svc.h> 26 #include <stddef.h> 27 #include <uuid.h> 28 #include "opteed_private.h" 29 #include "teesmc_opteed.h" 30 #include "teesmc_opteed_macros.h" 31 32 33 /******************************************************************************* 34 * Address of the entrypoint vector table in OPTEE. It is 35 * initialised once on the primary core after a cold boot. 36 ******************************************************************************/ 37 optee_vectors_t *optee_vectors; 38 39 /******************************************************************************* 40 * Array to keep track of per-cpu OPTEE state 41 ******************************************************************************/ 42 optee_context_t opteed_sp_context[OPTEED_CORE_COUNT]; 43 uint32_t opteed_rw; 44 45 static int32_t opteed_init(void); 46 47 /******************************************************************************* 48 * This function is the handler registered for S-EL1 interrupts by the 49 * OPTEED. It validates the interrupt and upon success arranges entry into 50 * the OPTEE at 'optee_fiq_entry()' for handling the interrupt. 51 ******************************************************************************/ 52 static uint64_t opteed_sel1_interrupt_handler(uint32_t id, 53 uint32_t flags, 54 void *handle, 55 void *cookie) 56 { 57 uint32_t linear_id; 58 optee_context_t *optee_ctx; 59 60 /* Check the security state when the exception was generated */ 61 assert(get_interrupt_src_ss(flags) == NON_SECURE); 62 63 /* Sanity check the pointer to this cpu's context */ 64 assert(handle == cm_get_context(NON_SECURE)); 65 66 /* Save the non-secure context before entering the OPTEE */ 67 cm_el1_sysregs_context_save(NON_SECURE); 68 69 /* Get a reference to this cpu's OPTEE context */ 70 linear_id = plat_my_core_pos(); 71 optee_ctx = &opteed_sp_context[linear_id]; 72 assert(&optee_ctx->cpu_ctx == cm_get_context(SECURE)); 73 74 cm_set_elr_el3(SECURE, (uint64_t)&optee_vectors->fiq_entry); 75 cm_el1_sysregs_context_restore(SECURE); 76 cm_set_next_eret_context(SECURE); 77 78 /* 79 * Tell the OPTEE that it has to handle an FIQ (synchronously). 80 * Also the instruction in normal world where the interrupt was 81 * generated is passed for debugging purposes. It is safe to 82 * retrieve this address from ELR_EL3 as the secure context will 83 * not take effect until el3_exit(). 84 */ 85 SMC_RET1(&optee_ctx->cpu_ctx, read_elr_el3()); 86 } 87 88 /******************************************************************************* 89 * OPTEE Dispatcher setup. The OPTEED finds out the OPTEE entrypoint and type 90 * (aarch32/aarch64) if not already known and initialises the context for entry 91 * into OPTEE for its initialization. 92 ******************************************************************************/ 93 int32_t opteed_setup(void) 94 { 95 entry_point_info_t *optee_ep_info; 96 uint32_t linear_id; 97 uint64_t opteed_pageable_part; 98 uint64_t opteed_mem_limit; 99 100 linear_id = plat_my_core_pos(); 101 102 /* 103 * Get information about the Secure Payload (BL32) image. Its 104 * absence is a critical failure. TODO: Add support to 105 * conditionally include the SPD service 106 */ 107 optee_ep_info = bl31_plat_get_next_image_ep_info(SECURE); 108 if (!optee_ep_info) { 109 WARN("No OPTEE provided by BL2 boot loader, Booting device" 110 " without OPTEE initialization. SMC`s destined for OPTEE" 111 " will return SMC_UNK\n"); 112 return 1; 113 } 114 115 /* 116 * If there's no valid entry point for SP, we return a non-zero value 117 * signalling failure initializing the service. We bail out without 118 * registering any handlers 119 */ 120 if (!optee_ep_info->pc) 121 return 1; 122 123 /* 124 * We could inspect the SP image and determine it's execution 125 * state i.e whether AArch32 or AArch64. 126 */ 127 opteed_rw = optee_ep_info->args.arg0; 128 opteed_pageable_part = optee_ep_info->args.arg1; 129 opteed_mem_limit = optee_ep_info->args.arg2; 130 131 opteed_init_optee_ep_state(optee_ep_info, 132 opteed_rw, 133 optee_ep_info->pc, 134 opteed_pageable_part, 135 opteed_mem_limit, 136 &opteed_sp_context[linear_id]); 137 138 /* 139 * All OPTEED initialization done. Now register our init function with 140 * BL31 for deferred invocation 141 */ 142 bl31_register_bl32_init(&opteed_init); 143 144 return 0; 145 } 146 147 /******************************************************************************* 148 * This function passes control to the OPTEE image (BL32) for the first time 149 * on the primary cpu after a cold boot. It assumes that a valid secure 150 * context has already been created by opteed_setup() which can be directly 151 * used. It also assumes that a valid non-secure context has been 152 * initialised by PSCI so it does not need to save and restore any 153 * non-secure state. This function performs a synchronous entry into 154 * OPTEE. OPTEE passes control back to this routine through a SMC. 155 ******************************************************************************/ 156 static int32_t opteed_init(void) 157 { 158 uint32_t linear_id = plat_my_core_pos(); 159 optee_context_t *optee_ctx = &opteed_sp_context[linear_id]; 160 entry_point_info_t *optee_entry_point; 161 uint64_t rc; 162 163 /* 164 * Get information about the OPTEE (BL32) image. Its 165 * absence is a critical failure. 166 */ 167 optee_entry_point = bl31_plat_get_next_image_ep_info(SECURE); 168 assert(optee_entry_point); 169 170 cm_init_my_context(optee_entry_point); 171 172 /* 173 * Arrange for an entry into OPTEE. It will be returned via 174 * OPTEE_ENTRY_DONE case 175 */ 176 rc = opteed_synchronous_sp_entry(optee_ctx); 177 assert(rc != 0); 178 179 return rc; 180 } 181 182 183 /******************************************************************************* 184 * This function is responsible for handling all SMCs in the Trusted OS/App 185 * range from the non-secure state as defined in the SMC Calling Convention 186 * Document. It is also responsible for communicating with the Secure 187 * payload to delegate work and return results back to the non-secure 188 * state. Lastly it will also return any information that OPTEE needs to do 189 * the work assigned to it. 190 ******************************************************************************/ 191 uint64_t opteed_smc_handler(uint32_t smc_fid, 192 uint64_t x1, 193 uint64_t x2, 194 uint64_t x3, 195 uint64_t x4, 196 void *cookie, 197 void *handle, 198 uint64_t flags) 199 { 200 cpu_context_t *ns_cpu_context; 201 uint32_t linear_id = plat_my_core_pos(); 202 optee_context_t *optee_ctx = &opteed_sp_context[linear_id]; 203 uint64_t rc; 204 205 /* 206 * Determine which security state this SMC originated from 207 */ 208 209 if (is_caller_non_secure(flags)) { 210 /* 211 * This is a fresh request from the non-secure client. 212 * The parameters are in x1 and x2. Figure out which 213 * registers need to be preserved, save the non-secure 214 * state and send the request to the secure payload. 215 */ 216 assert(handle == cm_get_context(NON_SECURE)); 217 218 cm_el1_sysregs_context_save(NON_SECURE); 219 220 /* 221 * We are done stashing the non-secure context. Ask the 222 * OPTEE to do the work now. 223 */ 224 225 /* 226 * Verify if there is a valid context to use, copy the 227 * operation type and parameters to the secure context 228 * and jump to the fast smc entry point in the secure 229 * payload. Entry into S-EL1 will take place upon exit 230 * from this function. 231 */ 232 assert(&optee_ctx->cpu_ctx == cm_get_context(SECURE)); 233 234 /* Set appropriate entry for SMC. 235 * We expect OPTEE to manage the PSTATE.I and PSTATE.F 236 * flags as appropriate. 237 */ 238 if (GET_SMC_TYPE(smc_fid) == SMC_TYPE_FAST) { 239 cm_set_elr_el3(SECURE, (uint64_t) 240 &optee_vectors->fast_smc_entry); 241 } else { 242 cm_set_elr_el3(SECURE, (uint64_t) 243 &optee_vectors->yield_smc_entry); 244 } 245 246 cm_el1_sysregs_context_restore(SECURE); 247 cm_set_next_eret_context(SECURE); 248 249 write_ctx_reg(get_gpregs_ctx(&optee_ctx->cpu_ctx), 250 CTX_GPREG_X4, 251 read_ctx_reg(get_gpregs_ctx(handle), 252 CTX_GPREG_X4)); 253 write_ctx_reg(get_gpregs_ctx(&optee_ctx->cpu_ctx), 254 CTX_GPREG_X5, 255 read_ctx_reg(get_gpregs_ctx(handle), 256 CTX_GPREG_X5)); 257 write_ctx_reg(get_gpregs_ctx(&optee_ctx->cpu_ctx), 258 CTX_GPREG_X6, 259 read_ctx_reg(get_gpregs_ctx(handle), 260 CTX_GPREG_X6)); 261 /* Propagate hypervisor client ID */ 262 write_ctx_reg(get_gpregs_ctx(&optee_ctx->cpu_ctx), 263 CTX_GPREG_X7, 264 read_ctx_reg(get_gpregs_ctx(handle), 265 CTX_GPREG_X7)); 266 267 SMC_RET4(&optee_ctx->cpu_ctx, smc_fid, x1, x2, x3); 268 } 269 270 /* 271 * Returning from OPTEE 272 */ 273 274 switch (smc_fid) { 275 /* 276 * OPTEE has finished initialising itself after a cold boot 277 */ 278 case TEESMC_OPTEED_RETURN_ENTRY_DONE: 279 /* 280 * Stash the OPTEE entry points information. This is done 281 * only once on the primary cpu 282 */ 283 assert(optee_vectors == NULL); 284 optee_vectors = (optee_vectors_t *) x1; 285 286 if (optee_vectors) { 287 set_optee_pstate(optee_ctx->state, OPTEE_PSTATE_ON); 288 289 /* 290 * OPTEE has been successfully initialized. 291 * Register power management hooks with PSCI 292 */ 293 psci_register_spd_pm_hook(&opteed_pm); 294 295 /* 296 * Register an interrupt handler for S-EL1 interrupts 297 * when generated during code executing in the 298 * non-secure state. 299 */ 300 flags = 0; 301 set_interrupt_rm_flag(flags, NON_SECURE); 302 rc = register_interrupt_type_handler(INTR_TYPE_S_EL1, 303 opteed_sel1_interrupt_handler, 304 flags); 305 if (rc) 306 panic(); 307 } 308 309 /* 310 * OPTEE reports completion. The OPTEED must have initiated 311 * the original request through a synchronous entry into 312 * OPTEE. Jump back to the original C runtime context. 313 */ 314 opteed_synchronous_sp_exit(optee_ctx, x1); 315 316 317 /* 318 * These function IDs is used only by OP-TEE to indicate it has 319 * finished: 320 * 1. turning itself on in response to an earlier psci 321 * cpu_on request 322 * 2. resuming itself after an earlier psci cpu_suspend 323 * request. 324 */ 325 case TEESMC_OPTEED_RETURN_ON_DONE: 326 case TEESMC_OPTEED_RETURN_RESUME_DONE: 327 328 329 /* 330 * These function IDs is used only by the SP to indicate it has 331 * finished: 332 * 1. suspending itself after an earlier psci cpu_suspend 333 * request. 334 * 2. turning itself off in response to an earlier psci 335 * cpu_off request. 336 */ 337 case TEESMC_OPTEED_RETURN_OFF_DONE: 338 case TEESMC_OPTEED_RETURN_SUSPEND_DONE: 339 case TEESMC_OPTEED_RETURN_SYSTEM_OFF_DONE: 340 case TEESMC_OPTEED_RETURN_SYSTEM_RESET_DONE: 341 342 /* 343 * OPTEE reports completion. The OPTEED must have initiated the 344 * original request through a synchronous entry into OPTEE. 345 * Jump back to the original C runtime context, and pass x1 as 346 * return value to the caller 347 */ 348 opteed_synchronous_sp_exit(optee_ctx, x1); 349 350 /* 351 * OPTEE is returning from a call or being preempted from a call, in 352 * either case execution should resume in the normal world. 353 */ 354 case TEESMC_OPTEED_RETURN_CALL_DONE: 355 /* 356 * This is the result from the secure client of an 357 * earlier request. The results are in x0-x3. Copy it 358 * into the non-secure context, save the secure state 359 * and return to the non-secure state. 360 */ 361 assert(handle == cm_get_context(SECURE)); 362 cm_el1_sysregs_context_save(SECURE); 363 364 /* Get a reference to the non-secure context */ 365 ns_cpu_context = cm_get_context(NON_SECURE); 366 assert(ns_cpu_context); 367 368 /* Restore non-secure state */ 369 cm_el1_sysregs_context_restore(NON_SECURE); 370 cm_set_next_eret_context(NON_SECURE); 371 372 SMC_RET4(ns_cpu_context, x1, x2, x3, x4); 373 374 /* 375 * OPTEE has finished handling a S-EL1 FIQ interrupt. Execution 376 * should resume in the normal world. 377 */ 378 case TEESMC_OPTEED_RETURN_FIQ_DONE: 379 /* Get a reference to the non-secure context */ 380 ns_cpu_context = cm_get_context(NON_SECURE); 381 assert(ns_cpu_context); 382 383 /* 384 * Restore non-secure state. There is no need to save the 385 * secure system register context since OPTEE was supposed 386 * to preserve it during S-EL1 interrupt handling. 387 */ 388 cm_el1_sysregs_context_restore(NON_SECURE); 389 cm_set_next_eret_context(NON_SECURE); 390 391 SMC_RET0((uint64_t) ns_cpu_context); 392 393 default: 394 panic(); 395 } 396 } 397 398 /* Define an OPTEED runtime service descriptor for fast SMC calls */ 399 DECLARE_RT_SVC( 400 opteed_fast, 401 402 OEN_TOS_START, 403 OEN_TOS_END, 404 SMC_TYPE_FAST, 405 opteed_setup, 406 opteed_smc_handler 407 ); 408 409 /* Define an OPTEED runtime service descriptor for yielding SMC calls */ 410 DECLARE_RT_SVC( 411 opteed_std, 412 413 OEN_TOS_START, 414 OEN_TOS_END, 415 SMC_TYPE_YIELD, 416 NULL, 417 opteed_smc_handler 418 ); 419