1/* 2 * Copyright (c) 2016, Linaro Limited 3 * Copyright (c) 2014, STMicroelectronics International N.V. 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions are met: 8 * 9 * 1. Redistributions of source code must retain the above copyright notice, 10 * this list of conditions and the following disclaimer. 11 * 12 * 2. Redistributions in binary form must reproduce the above copyright notice, 13 * this list of conditions and the following disclaimer in the documentation 14 * and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 17 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE 20 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 26 * POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29#include <asm.S> 30#include <arm.h> 31#include <arm32_macros.S> 32#include <sm/teesmc.h> 33#include <sm/teesmc_opteed_macros.h> 34#include <sm/teesmc_opteed.h> 35#include <kernel/abort.h> 36#include <kernel/thread_defs.h> 37#include <kernel/unwind.h> 38 39 .section .text.thread_asm 40 41LOCAL_FUNC vector_std_smc_entry , : 42UNWIND( .fnstart) 43UNWIND( .cantunwind) 44 push {r0-r7} 45 mov r0, sp 46 bl thread_handle_std_smc 47 /* 48 * Normally thread_handle_std_smc() should return via 49 * thread_exit(), thread_rpc(), but if thread_handle_std_smc() 50 * hasn't switched stack (error detected) it will do a normal "C" 51 * return. 52 */ 53 pop {r1-r8} 54 ldr r0, =TEESMC_OPTEED_RETURN_CALL_DONE 55 smc #0 56 b . /* SMC should not return */ 57UNWIND( .fnend) 58END_FUNC vector_std_smc_entry 59 60LOCAL_FUNC vector_fast_smc_entry , : 61UNWIND( .fnstart) 62UNWIND( .cantunwind) 63 push {r0-r7} 64 mov r0, sp 65 bl thread_handle_fast_smc 66 pop {r1-r8} 67 ldr r0, =TEESMC_OPTEED_RETURN_CALL_DONE 68 smc #0 69 b . /* SMC should not return */ 70UNWIND( .fnend) 71END_FUNC vector_fast_smc_entry 72 73LOCAL_FUNC vector_fiq_entry , : 74UNWIND( .fnstart) 75UNWIND( .cantunwind) 76 /* Secure Monitor received a FIQ and passed control to us. */ 77 bl thread_check_canaries 78 ldr lr, =thread_fiq_handler_ptr 79 ldr lr, [lr] 80 blx lr 81 mov r1, r0 82 ldr r0, =TEESMC_OPTEED_RETURN_FIQ_DONE 83 smc #0 84 b . /* SMC should not return */ 85UNWIND( .fnend) 86END_FUNC vector_fiq_entry 87 88LOCAL_FUNC vector_cpu_on_entry , : 89UNWIND( .fnstart) 90UNWIND( .cantunwind) 91 ldr lr, =thread_cpu_on_handler_ptr 92 ldr lr, [lr] 93 blx lr 94 mov r1, r0 95 ldr r0, =TEESMC_OPTEED_RETURN_ON_DONE 96 smc #0 97 b . /* SMC should not return */ 98UNWIND( .fnend) 99END_FUNC vector_cpu_on_entry 100 101LOCAL_FUNC vector_cpu_off_entry , : 102UNWIND( .fnstart) 103UNWIND( .cantunwind) 104 ldr lr, =thread_cpu_off_handler_ptr 105 ldr lr, [lr] 106 blx lr 107 mov r1, r0 108 ldr r0, =TEESMC_OPTEED_RETURN_OFF_DONE 109 smc #0 110 b . /* SMC should not return */ 111UNWIND( .fnend) 112END_FUNC vector_cpu_off_entry 113 114LOCAL_FUNC vector_cpu_suspend_entry , : 115UNWIND( .fnstart) 116UNWIND( .cantunwind) 117 ldr lr, =thread_cpu_suspend_handler_ptr 118 ldr lr, [lr] 119 blx lr 120 mov r1, r0 121 ldr r0, =TEESMC_OPTEED_RETURN_SUSPEND_DONE 122 smc #0 123 b . /* SMC should not return */ 124UNWIND( .fnend) 125END_FUNC vector_cpu_suspend_entry 126 127LOCAL_FUNC vector_cpu_resume_entry , : 128UNWIND( .fnstart) 129UNWIND( .cantunwind) 130 ldr lr, =thread_cpu_resume_handler_ptr 131 ldr lr, [lr] 132 blx lr 133 mov r1, r0 134 ldr r0, =TEESMC_OPTEED_RETURN_RESUME_DONE 135 smc #0 136 b . /* SMC should not return */ 137UNWIND( .fnend) 138END_FUNC vector_cpu_resume_entry 139 140LOCAL_FUNC vector_system_off_entry , : 141UNWIND( .fnstart) 142UNWIND( .cantunwind) 143 ldr lr, =thread_system_off_handler_ptr 144 ldr lr, [lr] 145 blx lr 146 mov r1, r0 147 ldr r0, =TEESMC_OPTEED_RETURN_SYSTEM_OFF_DONE 148 smc #0 149 b . /* SMC should not return */ 150UNWIND( .fnend) 151END_FUNC vector_system_off_entry 152 153LOCAL_FUNC vector_system_reset_entry , : 154UNWIND( .fnstart) 155UNWIND( .cantunwind) 156 ldr lr, =thread_system_reset_handler_ptr 157 ldr lr, [lr] 158 blx lr 159 mov r1, r0 160 ldr r0, =TEESMC_OPTEED_RETURN_SYSTEM_RESET_DONE 161 smc #0 162 b . /* SMC should not return */ 163UNWIND( .fnend) 164END_FUNC vector_system_reset_entry 165 166/* 167 * Vector table supplied to ARM Trusted Firmware (ARM-TF) at 168 * initialization. Also used when compiled with the internal monitor, but 169 * the cpu_*_entry and system_*_entry are not used then. 170 * 171 * Note that ARM-TF depends on the layout of this vector table, any change 172 * in layout has to be synced with ARM-TF. This layout must also be kept in 173 * sync with sm_entry_vector in sm.c 174 */ 175FUNC thread_vector_table , : 176UNWIND( .fnstart) 177UNWIND( .cantunwind) 178 b vector_std_smc_entry 179 b vector_fast_smc_entry 180 b vector_cpu_on_entry 181 b vector_cpu_off_entry 182 b vector_cpu_resume_entry 183 b vector_cpu_suspend_entry 184 b vector_fiq_entry 185 b vector_system_off_entry 186 b vector_system_reset_entry 187UNWIND( .fnend) 188END_FUNC thread_vector_table 189 190FUNC thread_set_abt_sp , : 191UNWIND( .fnstart) 192UNWIND( .cantunwind) 193 mrs r1, cpsr 194 cps #CPSR_MODE_ABT 195 mov sp, r0 196 msr cpsr, r1 197 bx lr 198UNWIND( .fnend) 199END_FUNC thread_set_abt_sp 200 201FUNC thread_set_irq_sp , : 202UNWIND( .fnstart) 203UNWIND( .cantunwind) 204 mrs r1, cpsr 205 cps #CPSR_MODE_IRQ 206 mov sp, r0 207 msr cpsr, r1 208 bx lr 209UNWIND( .fnend) 210END_FUNC thread_set_irq_sp 211 212FUNC thread_set_fiq_sp , : 213UNWIND( .fnstart) 214UNWIND( .cantunwind) 215 mrs r1, cpsr 216 cps #CPSR_MODE_FIQ 217 mov sp, r0 218 msr cpsr, r1 219 bx lr 220UNWIND( .fnend) 221END_FUNC thread_set_fiq_sp 222 223/* void thread_resume(struct thread_ctx_regs *regs) */ 224FUNC thread_resume , : 225UNWIND( .fnstart) 226UNWIND( .cantunwind) 227 add r12, r0, #(13 * 4) /* Restore registers r0-r12 later */ 228 229 cps #CPSR_MODE_SYS 230 ldm r12!, {sp, lr} 231 232 cps #CPSR_MODE_SVC 233 ldm r12!, {r1, sp, lr} 234 msr spsr_fsxc, r1 235 236 cps #CPSR_MODE_SVC 237 ldm r12, {r1, r2} 238 push {r1, r2} 239 240 ldm r0, {r0-r12} 241 242 /* Restore CPSR and jump to the instruction to resume at */ 243 rfefd sp! 244UNWIND( .fnend) 245END_FUNC thread_resume 246 247/* 248 * Disables IRQ and FIQ and saves state of thread, returns original 249 * CPSR. 250 */ 251LOCAL_FUNC thread_save_state , : 252UNWIND( .fnstart) 253UNWIND( .cantunwind) 254 push {r12, lr} 255 /* 256 * Uses stack for temporary storage, while storing needed 257 * context in the thread context struct. 258 */ 259 260 mrs r12, cpsr 261 262 cpsid aif /* Disable Async abort, IRQ and FIQ */ 263 264 push {r4-r7} 265 push {r0-r3} 266 267 mov r5, r12 /* Save CPSR in a preserved register */ 268 mrs r6, cpsr /* Save current CPSR */ 269 270 bl thread_get_ctx_regs 271 272 pop {r1-r4} /* r0-r3 pushed above */ 273 stm r0!, {r1-r4} 274 pop {r1-r4} /* r4-r7 pushed above */ 275 stm r0!, {r1-r4} 276 stm r0!, {r8-r11} 277 278 pop {r12, lr} 279 stm r0!, {r12} 280 281 cps #CPSR_MODE_SYS 282 stm r0!, {sp, lr} 283 284 cps #CPSR_MODE_SVC 285 mrs r1, spsr 286 stm r0!, {r1, sp, lr} 287 288 msr cpsr, r6 /* Restore mode */ 289 290 mov r0, r5 /* Return original CPSR */ 291 bx lr 292UNWIND( .fnend) 293END_FUNC thread_save_state 294 295FUNC thread_std_smc_entry , : 296UNWIND( .fnstart) 297UNWIND( .cantunwind) 298 /* Pass r0-r7 in a struct thread_smc_args */ 299 push {r0-r7} 300 mov r0, sp 301 bl __thread_std_smc_entry 302 /* 303 * Load the returned r0-r3 into preserved registers and skip the 304 * "returned" r4-r7 since they will not be returned to normal 305 * world. 306 */ 307 pop {r4-r7} 308 add sp, #(4 * 4) 309 310 /* Disable interrupts before switching to temporary stack */ 311 cpsid if 312 bl thread_get_tmp_sp 313 mov sp, r0 314 315 bl thread_state_free 316 317 ldr r0, =TEESMC_OPTEED_RETURN_CALL_DONE 318 mov r1, r4 319 mov r2, r5 320 mov r3, r6 321 mov r4, r7 322 smc #0 323 b . /* SMC should not return */ 324UNWIND( .fnend) 325END_FUNC thread_std_smc_entry 326 327 328/* void thread_rpc(uint32_t rv[THREAD_RPC_NUM_ARGS]) */ 329FUNC thread_rpc , : 330UNWIND( .fnstart) 331 push {lr} 332UNWIND( .save {lr}) 333 push {r0} 334UNWIND( .save {r0}) 335 336 bl thread_save_state 337 mov r4, r0 /* Save original CPSR */ 338 339 /* 340 * Switch to temporary stack and SVC mode. Save CPSR to resume into. 341 */ 342 bl thread_get_tmp_sp 343 ldr r5, [sp] /* Get pointer to rv[] */ 344 cps #CPSR_MODE_SVC /* Change to SVC mode */ 345 mov sp, r0 /* Switch to tmp stack */ 346 347 mov r0, #THREAD_FLAGS_COPY_ARGS_ON_RETURN 348 mov r1, r4 /* CPSR to restore */ 349 ldr r2, =.thread_rpc_return 350 bl thread_state_suspend 351 mov r4, r0 /* Supply thread index */ 352 ldr r0, =TEESMC_OPTEED_RETURN_CALL_DONE 353 ldm r5, {r1-r3} /* Load rv[] into r0-r2 */ 354 smc #0 355 b . /* SMC should not return */ 356 357.thread_rpc_return: 358 /* 359 * At this point has the stack pointer been restored to the value 360 * it had when thread_save_state() was called above. 361 * 362 * Jumps here from thread_resume above when RPC has returned. The 363 * IRQ and FIQ bits are restored to what they where when this 364 * function was originally entered. 365 */ 366 pop {r12} /* Get pointer to rv[] */ 367 stm r12, {r0-r2} /* Store r0-r2 into rv[] */ 368 pop {pc} 369UNWIND( .fnend) 370END_FUNC thread_rpc 371 372LOCAL_FUNC thread_fiq_handler , : 373UNWIND( .fnstart) 374UNWIND( .cantunwind) 375 /* FIQ has a +4 offset for lr compared to preferred return address */ 376 sub lr, lr, #4 377 push {r0-r12, lr} 378 bl thread_check_canaries 379 ldr lr, =thread_fiq_handler_ptr 380 ldr lr, [lr] 381 blx lr 382 pop {r0-r12, lr} 383 movs pc, lr 384UNWIND( .fnend) 385END_FUNC thread_fiq_handler 386 387LOCAL_FUNC thread_irq_handler , : 388UNWIND( .fnstart) 389UNWIND( .cantunwind) 390 /* 391 * IRQ mode is set up to use tmp stack so FIQ has to be 392 * disabled before touching the stack. We can also assign 393 * SVC sp from IRQ sp to get SVC mode into the state we 394 * need when doing the SMC below. 395 */ 396 cpsid f /* Disable FIQ also */ 397 sub lr, lr, #4 398 push {lr} 399 push {r12} 400 401 bl thread_save_state 402 403 mov r0, #THREAD_FLAGS_EXIT_ON_IRQ 404 mrs r1, spsr 405 pop {r12} 406 pop {r2} 407 blx thread_state_suspend 408 mov r4, r0 /* Supply thread index */ 409 410 /* 411 * Switch to SVC mode and copy current stack pointer as it already 412 * is the tmp stack. 413 */ 414 mov r0, sp 415 cps #CPSR_MODE_SVC 416 mov sp, r0 417 418 ldr r0, =TEESMC_OPTEED_RETURN_CALL_DONE 419 ldr r1, =TEESMC_RETURN_RPC_IRQ 420 mov r2, #0 421 mov r3, #0 422 /* r4 is already filled in above */ 423 smc #0 424 b . /* SMC should not return */ 425UNWIND( .fnend) 426END_FUNC thread_irq_handler 427 428FUNC thread_init_vbar , : 429UNWIND( .fnstart) 430 /* Set vector (VBAR) */ 431 ldr r0, =thread_vect_table 432 write_vbar r0 433 bx lr 434UNWIND( .fnend) 435END_FUNC thread_init_vbar 436 437/* 438 * Below are low level routines handling entry and return from user mode. 439 * 440 * thread_enter_user_mode() saves all that registers user mode can change 441 * so kernel mode can restore needed registers when resuming execution 442 * after the call to thread_enter_user_mode() has returned. 443 * thread_enter_user_mode() doesn't return directly since it enters user 444 * mode instead, it's thread_unwind_user_mode() that does the 445 * returning by restoring the registers saved by thread_enter_user_mode(). 446 * 447 * There's three ways for thread_enter_user_mode() to return to caller, 448 * user TA calls utee_return, user TA calls utee_panic or through an abort. 449 * 450 * Calls to utee_return or utee_panic are handled as: 451 * thread_svc_handler() -> tee_svc_handler() -> tee_svc_do_call() which 452 * calls syscall_return() or syscall_panic(). 453 * 454 * These function calls returns normally except thread_svc_handler() which 455 * which is an exception handling routine so it reads return address and 456 * SPSR to restore from the stack. syscall_return() and syscall_panic() 457 * changes return address and SPSR used by thread_svc_handler() to instead of 458 * returning into user mode as with other syscalls it returns into 459 * thread_unwind_user_mode() in kernel mode instead. When 460 * thread_svc_handler() returns the stack pointer at the point where 461 * thread_enter_user_mode() left it so this is where 462 * thread_unwind_user_mode() can operate. 463 * 464 * Aborts are handled in a similar way but by thread_abort_handler() 465 * instead, when the pager sees that it's an abort from user mode that 466 * can't be handled it updates SPSR and return address used by 467 * thread_abort_handler() to return into thread_unwind_user_mode() 468 * instead. 469 */ 470 471/* 472 * uint32_t __thread_enter_user_mode(unsigned long a0, unsigned long a1, 473 * unsigned long a2, unsigned long a3, unsigned long user_sp, 474 * unsigned long user_func, unsigned long spsr, 475 * uint32_t *exit_status0, uint32_t *exit_status1) 476 * 477 */ 478FUNC __thread_enter_user_mode , : 479UNWIND( .fnstart) 480UNWIND( .cantunwind) 481 /* 482 * Save all registers to allow syscall_return() to resume execution 483 * as if this function would have returned. This is also used in 484 * syscall_panic(). 485 * 486 * If stack usage of this function is changed 487 * thread_unwind_user_mode() has to be updated. 488 */ 489 push {r4-r12,lr} 490 491 ldr r4, [sp, #(10 * 0x4)] /* user stack pointer */ 492 ldr r5, [sp, #(11 * 0x4)] /* user function */ 493 ldr r6, [sp, #(12 * 0x4)] /* spsr */ 494 495 /* 496 * Set the saved Processors Status Register to user mode to allow 497 * entry of user mode through movs below. 498 */ 499 msr spsr_cxsf, r6 500 501 /* 502 * Save old user sp and set new user sp. 503 */ 504 cps #CPSR_MODE_SYS 505 mov r6, sp 506 mov sp, r4 507 cps #CPSR_MODE_SVC 508 push {r6} 509 510 /* 511 * Don't allow return from this function, return is done through 512 * thread_unwind_user_mode() below. 513 */ 514 mov lr, #0 515 /* Call the user function with its arguments */ 516 movs pc, r5 517UNWIND( .fnend) 518END_FUNC __thread_enter_user_mode 519 520/* 521 * void thread_unwind_user_mode(uint32_t ret, uint32_t exit_status0, 522 * uint32_t exit_status1); 523 * See description in thread.h 524 */ 525FUNC thread_unwind_user_mode , : 526UNWIND( .fnstart) 527UNWIND( .cantunwind) 528 ldr ip, [sp, #(14 * 0x4)] /* &ctx->panicked */ 529 str r1, [ip] 530 ldr ip, [sp, #(15 * 0x4)] /* &ctx->panic_code */ 531 str r2, [ip] 532 533 /* Restore old user sp */ 534 pop {r4} 535 cps #CPSR_MODE_SYS 536 mov sp, r4 537 cps #CPSR_MODE_SVC 538 539 pop {r4-r12,pc} /* Match the push in thread_enter_user_mode()*/ 540UNWIND( .fnend) 541END_FUNC thread_unwind_user_mode 542 543LOCAL_FUNC thread_abort_handler , : 544thread_abort_handler: 545thread_und_handler: 546UNWIND( .fnstart) 547UNWIND( .cantunwind) 548 /* 549 * Switch to abort mode to use that stack instead. 550 */ 551 cps #CPSR_MODE_ABT 552 push {r0-r11, ip} 553 cps #CPSR_MODE_UND 554 mrs r0, spsr 555 tst r0, #CPSR_T 556 subne r1, lr, #2 557 subeq r1, lr, #4 558 cps #CPSR_MODE_ABT 559 push {r0, r1} 560 msr spsr_fsxc, r0 /* In case some code reads spsr directly */ 561 mov r0, #ABORT_TYPE_UNDEF 562 b .thread_abort_generic 563 564thread_dabort_handler: 565 push {r0-r11, ip} 566 sub r1, lr, #8 567 mrs r0, spsr 568 push {r0, r1} 569 mov r0, #ABORT_TYPE_DATA 570 b .thread_abort_generic 571 572thread_pabort_handler: 573 push {r0-r11, ip} 574 sub r1, lr, #4 575 mrs r0, spsr 576 push {r0, r1} 577 mov r0, #ABORT_TYPE_PREFETCH 578 b .thread_abort_generic 579 580.thread_abort_generic: 581 cps #CPSR_MODE_SYS 582 mov r1, sp 583 mov r2, lr 584 cps #CPSR_MODE_ABT 585 push {r1-r3} 586 mov r1, sp 587 bl abort_handler 588 pop {r1-r3} 589 cps #CPSR_MODE_SYS 590 mov sp, r1 591 mov lr, r2 592 cps #CPSR_MODE_ABT 593 pop {r0, r1} 594 mov lr, r1 595 msr spsr_fsxc, r0 596 pop {r0-r11, ip} 597 movs pc, lr 598UNWIND( .fnend) 599END_FUNC thread_abort_handler 600 601LOCAL_FUNC thread_svc_handler , : 602UNWIND( .fnstart) 603UNWIND( .cantunwind) 604 push {r0-r7, lr} 605 mrs r0, spsr 606 push {r0} 607 mov r0, sp 608 bl tee_svc_handler 609 pop {r0} 610 msr spsr_fsxc, r0 611 pop {r0-r7, lr} 612 movs pc, lr 613UNWIND( .fnend) 614END_FUNC thread_svc_handler 615 616 .align 5 617LOCAL_FUNC thread_vect_table , : 618UNWIND( .fnstart) 619UNWIND( .cantunwind) 620 b . /* Reset */ 621 b thread_und_handler /* Undefined instruction */ 622 b thread_svc_handler /* System call */ 623 b thread_pabort_handler /* Prefetch abort */ 624 b thread_dabort_handler /* Data abort */ 625 b . /* Reserved */ 626 b thread_irq_handler /* IRQ */ 627 b thread_fiq_handler /* FIQ */ 628UNWIND( .fnend) 629END_FUNC thread_vect_table 630