1 /* SPDX-License-Identifier: GPL-2.0+ */ 2 /* 3 * (C) Copyright 2008 - 2013 Tensilica Inc. 4 * (C) Copyright 2014 - 2016 Cadence Design Systems Inc. 5 */ 6 7 #include <config.h> 8 #include <asm/asmmacro.h> 9 #include <asm/cacheasm.h> 10 #include <asm/regs.h> 11 #include <asm/arch/tie.h> 12 #include <asm-offsets.h> 13 14 /* 15 * Offsets into the the pt_regs struture. 16 * Make sure these always match with the structure defined in ptrace.h! 17 */ 18 19 #define PT_PC 0 20 #define PT_PS 4 21 #define PT_DEPC 8 22 #define PT_EXCCAUSE 12 23 #define PT_EXCVADDR 16 24 #define PT_DEBUGCAUSE 20 25 #define PT_WMASK 24 26 #define PT_LBEG 28 27 #define PT_LEND 32 28 #define PT_LCOUNT 36 29 #define PT_SAR 40 30 #define PT_WINDOWBASE 44 31 #define PT_WINDOWSTART 48 32 #define PT_SYSCALL 52 33 #define PT_ICOUNTLEVEL 56 34 #define PT_RESERVED 60 35 #define PT_AREG 64 36 #define PT_SIZE (64 + 64) 37 38 /* 39 * Cache attributes are different for full MMU and region protection. 40 */ 41 42 #if XCHAL_HAVE_PTP_MMU 43 #define CA_WRITEBACK (0x7) 44 #else 45 #define CA_WRITEBACK (0x4) 46 #endif 47 48 /* 49 * Reset vector. 50 * Only a trampoline to jump to _start 51 * (Note that we have to mark the section writable as the section contains 52 * a relocatable literal) 53 */ 54 55 .section .ResetVector.text, "awx" 56 .global _ResetVector 57 _ResetVector: 58 59 j 1f 60 .align 4 61 2: .long _start 62 1: l32r a2, 2b 63 jx a2 64 65 66 /* 67 * Processor initialization. We still run in rom space. 68 * 69 * NOTE: Running in ROM 70 * For Xtensa, we currently don't allow to run some code from ROM but 71 * unpack the data immediately to memory. This requires, for example, 72 * that DDR has been set up before running U-Boot. (See also comments 73 * inline for ways to change it) 74 */ 75 76 .section .reset.text, "ax" 77 .global _start 78 .align 4 79 _start: 80 /* Keep a0 = 0 for various initializations */ 81 82 movi a0, 0 83 84 /* 85 * For full MMU cores, put page table at unmapped virtual address. 86 * This ensures that accesses outside the static maps result 87 * in miss exceptions rather than random behaviour. 88 */ 89 90 #if XCHAL_HAVE_PTP_MMU 91 wsr a0, PTEVADDR 92 #endif 93 94 /* Disable dbreak debug exceptions */ 95 96 #if XCHAL_HAVE_DEBUG && XCHAL_NUM_DBREAK > 0 97 .set _index, 0 98 .rept XCHAL_NUM_DBREAK 99 wsr a0, DBREAKC + _index 100 .set _index, _index + 1 101 .endr 102 #endif 103 104 /* Reset windowbase and windowstart */ 105 106 #if XCHAL_HAVE_WINDOWED 107 movi a3, 1 108 wsr a3, windowstart 109 wsr a0, windowbase 110 rsync 111 movi a0, 0 /* windowbase might have changed */ 112 #endif 113 114 /* 115 * Vecbase in bitstream may differ from header files 116 * set or check it. 117 */ 118 119 #if XCHAL_HAVE_VECBASE 120 movi a3, XCHAL_VECBASE_RESET_VADDR /* VECBASE reset value */ 121 wsr a3, VECBASE 122 #endif 123 124 #if XCHAL_HAVE_LOOPS 125 /* Disable loops */ 126 127 wsr a0, LCOUNT 128 #endif 129 130 /* Set PS.WOE = 0, PS.EXCM = 0 (for loop), PS.INTLEVEL = EXCM level */ 131 132 #if XCHAL_HAVE_XEA1 133 movi a2, 1 134 #else 135 movi a2, XCHAL_EXCM_LEVEL 136 #endif 137 wsr a2, PS 138 rsync 139 140 /* Unlock and invalidate caches */ 141 142 ___unlock_dcache_all a2, a3 143 ___invalidate_dcache_all a2, a3 144 ___unlock_icache_all a2, a3 145 ___invalidate_icache_all a2, a3 146 147 isync 148 149 /* Unpack data sections */ 150 151 movi a2, __reloc_table_start 152 movi a3, __reloc_table_end 153 154 1: beq a2, a3, 3f # no more entries? 155 l32i a4, a2, 0 # start destination (in RAM) 156 l32i a5, a2, 4 # end destination (in RAM) 157 l32i a6, a2, 8 # start source (in ROM) 158 addi a2, a2, 12 # next entry 159 beq a4, a5, 1b # skip, empty entry 160 beq a4, a6, 1b # skip, source and destination are the same 161 162 /* If there's memory protection option with 512MB TLB regions and 163 * cache attributes in TLB entries and caching is not inhibited, 164 * enable data/instruction cache for relocated image. 165 */ 166 #if XCHAL_HAVE_SPANNING_WAY && \ 167 (!defined(CONFIG_SYS_DCACHE_OFF) || \ 168 !defined(CONFIG_SYS_ICACHE_OFF)) 169 srli a7, a4, 29 170 slli a7, a7, 29 171 addi a7, a7, XCHAL_SPANNING_WAY 172 #ifndef CONFIG_SYS_DCACHE_OFF 173 rdtlb1 a8, a7 174 srli a8, a8, 4 175 slli a8, a8, 4 176 addi a8, a8, CA_WRITEBACK 177 wdtlb a8, a7 178 #endif 179 #ifndef CONFIG_SYS_ICACHE_OFF 180 ritlb1 a8, a7 181 srli a8, a8, 4 182 slli a8, a8, 4 183 addi a8, a8, CA_WRITEBACK 184 witlb a8, a7 185 #endif 186 isync 187 #endif 188 189 2: l32i a7, a6, 0 190 addi a6, a6, 4 191 s32i a7, a4, 0 192 addi a4, a4, 4 193 bltu a4, a5, 2b 194 j 1b 195 196 3: /* All code and initalized data segments have been copied */ 197 198 /* Setup PS, PS.WOE = 1, PS.EXCM = 0, PS.INTLEVEL = EXCM level. */ 199 200 #if __XTENSA_CALL0_ABI__ 201 movi a2, XCHAL_EXCM_LEVEL 202 #else 203 movi a2, (1<<PS_WOE_BIT) | XCHAL_EXCM_LEVEL 204 #endif 205 wsr a2, PS 206 rsync 207 208 /* Writeback */ 209 210 ___flush_dcache_all a2, a3 211 212 #ifdef __XTENSA_WINDOWED_ABI__ 213 /* 214 * In windowed ABI caller and call target need to be within the same 215 * gigabyte. Put the rest of the code into the text segment and jump 216 * there. 217 */ 218 219 movi a4, .Lboard_init_code 220 jx a4 221 222 .text 223 .align 4 224 .Lboard_init_code: 225 #endif 226 227 movi a0, 0 228 movi sp, (XTENSA_SYS_TEXT_ADDR - 16) & 0xfffffff0 229 230 #ifdef CONFIG_DEBUG_UART 231 movi a4, debug_uart_init 232 #ifdef __XTENSA_CALL0_ABI__ 233 callx0 a4 234 #else 235 callx4 a4 236 #endif 237 #endif 238 239 movi a4, board_init_f_alloc_reserve 240 241 #ifdef __XTENSA_CALL0_ABI__ 242 mov a2, sp 243 callx0 a4 244 mov sp, a2 245 #else 246 mov a6, sp 247 callx4 a4 248 movsp sp, a6 249 #endif 250 251 movi a4, board_init_f_init_reserve 252 253 #ifdef __XTENSA_CALL0_ABI__ 254 callx0 a4 255 #else 256 callx4 a4 257 #endif 258 259 /* 260 * Call board initialization routine (never returns). 261 */ 262 263 movi a4, board_init_f 264 265 #ifdef __XTENSA_CALL0_ABI__ 266 movi a2, 0 267 callx0 a4 268 #else 269 movi a6, 0 270 callx4 a4 271 #endif 272 /* Never Returns */ 273 ill 274 275 /* 276 * void relocate_code (addr_sp, gd, addr_moni) 277 * 278 * This "function" does not return, instead it continues in RAM 279 * after relocating the monitor code. 280 * 281 * a2 = addr_sp 282 * a3 = gd 283 * a4 = destination address 284 */ 285 .text 286 .globl relocate_code 287 .align 4 288 relocate_code: 289 abi_entry 290 291 #ifdef __XTENSA_CALL0_ABI__ 292 mov a1, a2 293 mov a2, a3 294 mov a3, a4 295 movi a0, board_init_r 296 callx0 a0 297 #else 298 /* We can't movsp here, because the chain of stack frames may cross 299 * the now reserved memory. We need to toss all window frames except 300 * the current, create new pristine stack frame and start from scratch. 301 */ 302 rsr a0, windowbase 303 ssl a0 304 movi a0, 1 305 sll a0, a0 306 wsr a0, windowstart 307 rsync 308 309 movi a0, 0 310 311 /* Reserve 16-byte save area */ 312 addi sp, a2, -16 313 mov a6, a3 314 mov a7, a4 315 movi a4, board_init_r 316 callx4 a4 317 #endif 318 ill 319 320 #if XCHAL_HAVE_EXCEPTIONS 321 322 /* 323 * Exception vectors. 324 * 325 * Various notes: 326 * - We currently don't use the user exception vector (PS.UM is always 0), 327 * but do define such a vector, just in case. They both jump to the 328 * same exception handler, though. 329 * - We currently only save the bare minimum number of registers: 330 * a0...a15, sar, loop-registers, exception register (epc1, excvaddr, 331 * exccause, depc) 332 * - WINDOWSTART is only saved to identify if registers have been spilled 333 * to the wrong stack (exception stack) while executing the exception 334 * handler. 335 */ 336 337 .section .KernelExceptionVector.text, "ax" 338 .global _KernelExceptionVector 339 _KernelExceptionVector: 340 341 wsr a2, EXCSAVE1 342 movi a2, ExceptionHandler 343 jx a2 344 345 .section .UserExceptionVector.text, "ax" 346 .global _UserExceptionVector 347 _UserExceptionVector: 348 349 wsr a2, EXCSAVE1 350 movi a2, ExceptionHandler 351 jx a2 352 353 #if !XCHAL_HAVE_XEA1 354 .section .DoubleExceptionVector.text, "ax" 355 .global _DoubleExceptionVector 356 _DoubleExceptionVector: 357 358 #ifdef __XTENSA_CALL0_ABI__ 359 wsr a0, EXCSAVE1 360 movi a0, hang # report and ask user to reset board 361 callx0 a0 362 #else 363 wsr a4, EXCSAVE1 364 movi a4, hang # report and ask user to reset board 365 callx4 a4 366 #endif 367 #endif 368 /* Does not return here */ 369 370 371 .text 372 .align 4 373 ExceptionHandler: 374 375 rsr a2, EXCCAUSE # find handler 376 377 #if XCHAL_HAVE_WINDOWED 378 /* Special case for alloca handler */ 379 380 bnei a2, 5, 1f # jump if not alloca exception 381 382 addi a1, a1, -16 - 4 # create a small stack frame 383 s32i a3, a1, 0 # and save a3 (a2 still in excsave1) 384 movi a2, fast_alloca_exception 385 jx a2 # jump to fast_alloca_exception 386 #endif 387 /* All other exceptions go here: */ 388 389 /* Create ptrace stack and save a0...a3 */ 390 391 1: addi a2, a1, - PT_SIZE - 16 392 s32i a0, a2, PT_AREG + 0 * 4 393 s32i a1, a2, PT_AREG + 1 * 4 394 s32i a3, a2, PT_AREG + 3 * 4 395 rsr a3, EXCSAVE1 396 s32i a3, a2, PT_AREG + 2 * 4 397 mov a1, a2 398 399 /* Save remaining AR registers */ 400 401 s32i a4, a1, PT_AREG + 4 * 4 402 s32i a5, a1, PT_AREG + 5 * 4 403 s32i a6, a1, PT_AREG + 6 * 4 404 s32i a7, a1, PT_AREG + 7 * 4 405 s32i a8, a1, PT_AREG + 8 * 4 406 s32i a9, a1, PT_AREG + 9 * 4 407 s32i a10, a1, PT_AREG + 10 * 4 408 s32i a11, a1, PT_AREG + 11 * 4 409 s32i a12, a1, PT_AREG + 12 * 4 410 s32i a13, a1, PT_AREG + 13 * 4 411 s32i a14, a1, PT_AREG + 14 * 4 412 s32i a15, a1, PT_AREG + 15 * 4 413 414 /* Save SRs */ 415 416 #if XCHAL_HAVE_WINDOWED 417 rsr a2, WINDOWSTART 418 s32i a2, a1, PT_WINDOWSTART 419 #endif 420 421 rsr a2, SAR 422 rsr a3, EPC1 423 rsr a4, EXCVADDR 424 s32i a2, a1, PT_SAR 425 s32i a3, a1, PT_PC 426 s32i a4, a1, PT_EXCVADDR 427 428 #if XCHAL_HAVE_LOOPS 429 movi a2, 0 430 rsr a3, LBEG 431 xsr a2, LCOUNT 432 s32i a3, a1, PT_LBEG 433 rsr a3, LEND 434 s32i a2, a1, PT_LCOUNT 435 s32i a3, a1, PT_LEND 436 #endif 437 438 /* Set up C environment and call registered handler */ 439 /* Setup stack, PS.WOE = 1, PS.EXCM = 0, PS.INTLEVEL = EXCM level. */ 440 441 rsr a2, EXCCAUSE 442 #if XCHAL_HAVE_XEA1 443 movi a3, (1<<PS_WOE_BIT) | 1 444 #elif __XTENSA_CALL0_ABI__ 445 movi a3, XCHAL_EXCM_LEVEL 446 #else 447 movi a3, (1<<PS_WOE_BIT) | XCHAL_EXCM_LEVEL 448 #endif 449 xsr a3, PS 450 rsync 451 s32i a2, a1, PT_EXCCAUSE 452 s32i a3, a1, PT_PS 453 454 movi a0, exc_table 455 addx4 a0, a2, a0 456 l32i a0, a0, 0 457 #ifdef __XTENSA_CALL0_ABI__ 458 mov a2, a1 # Provide stack frame as only argument 459 callx0 a0 460 l32i a3, a1, PT_PS 461 #else 462 mov a6, a1 # Provide stack frame as only argument 463 callx4 a0 464 #endif 465 466 /* Restore PS and go to exception mode (PS.EXCM=1) */ 467 468 wsr a3, PS 469 470 /* Restore SR registers */ 471 472 #if XCHAL_HAVE_LOOPS 473 l32i a2, a1, PT_LBEG 474 l32i a3, a1, PT_LEND 475 l32i a4, a1, PT_LCOUNT 476 wsr a2, LBEG 477 wsr a3, LEND 478 wsr a4, LCOUNT 479 #endif 480 481 l32i a2, a1, PT_SAR 482 l32i a3, a1, PT_PC 483 wsr a2, SAR 484 wsr a3, EPC1 485 486 #if XCHAL_HAVE_WINDOWED 487 /* Do we need to simulate a MOVSP? */ 488 489 l32i a2, a1, PT_WINDOWSTART 490 addi a3, a2, -1 491 and a2, a2, a3 492 beqz a2, 1f # Skip if regs were spilled before exc. 493 494 rsr a2, WINDOWSTART 495 addi a3, a2, -1 496 and a2, a2, a3 497 bnez a2, 1f # Skip if registers aren't spilled now 498 499 addi a2, a1, -16 500 l32i a4, a2, 0 501 l32i a5, a2, 4 502 s32i a4, a1, PT_SIZE + 0 503 s32i a5, a1, PT_SIZE + 4 504 l32i a4, a2, 8 505 l32i a5, a2, 12 506 s32i a4, a1, PT_SIZE + 8 507 s32i a5, a1, PT_SIZE + 12 508 #endif 509 510 /* Restore address register */ 511 512 1: l32i a15, a1, PT_AREG + 15 * 4 513 l32i a14, a1, PT_AREG + 14 * 4 514 l32i a13, a1, PT_AREG + 13 * 4 515 l32i a12, a1, PT_AREG + 12 * 4 516 l32i a11, a1, PT_AREG + 11 * 4 517 l32i a10, a1, PT_AREG + 10 * 4 518 l32i a9, a1, PT_AREG + 9 * 4 519 l32i a8, a1, PT_AREG + 8 * 4 520 l32i a7, a1, PT_AREG + 7 * 4 521 l32i a6, a1, PT_AREG + 6 * 4 522 l32i a5, a1, PT_AREG + 5 * 4 523 l32i a4, a1, PT_AREG + 4 * 4 524 l32i a3, a1, PT_AREG + 3 * 4 525 l32i a2, a1, PT_AREG + 2 * 4 526 l32i a0, a1, PT_AREG + 0 * 4 527 528 l32i a1, a1, PT_AREG + 1 * 4 # Remove ptrace stack frame 529 530 rfe 531 532 #endif /* XCHAL_HAVE_EXCEPTIONS */ 533 534 #if XCHAL_HAVE_WINDOWED 535 536 /* 537 * Window overflow and underflow handlers. 538 * The handlers must be 64 bytes apart, first starting with the underflow 539 * handlers underflow-4 to underflow-12, then the overflow handlers 540 * overflow-4 to overflow-12. 541 * 542 * Note: We rerun the underflow handlers if we hit an exception, so 543 * we try to access any page that would cause a page fault early. 544 */ 545 546 .section .WindowVectors.text, "ax" 547 548 /* 4-Register Window Overflow Vector (Handler) */ 549 550 .align 64 551 .global _WindowOverflow4 552 _WindowOverflow4: 553 s32e a0, a5, -16 554 s32e a1, a5, -12 555 s32e a2, a5, -8 556 s32e a3, a5, -4 557 rfwo 558 559 560 /* 4-Register Window Underflow Vector (Handler) */ 561 562 .align 64 563 .global _WindowUnderflow4 564 _WindowUnderflow4: 565 l32e a0, a5, -16 566 l32e a1, a5, -12 567 l32e a2, a5, -8 568 l32e a3, a5, -4 569 rfwu 570 571 /* 572 * a0: a0 573 * a1: new stack pointer = a1 - 16 - 4 574 * a2: available, saved in excsave1 575 * a3: available, saved on stack *a1 576 */ 577 578 /* 15*/ .byte 0xff 579 580 fast_alloca_exception: /* must be at _WindowUnderflow4 + 16 */ 581 582 /* 16*/ rsr a2, PS 583 /* 19*/ rsr a3, WINDOWBASE 584 /* 22*/ extui a2, a2, PS_OWB_SHIFT, PS_OWB_SHIFT 585 /* 25*/ xor a2, a2, a3 586 /* 28*/ rsr a3, PS 587 /* 31*/ slli a2, a2, PS_OWB_SHIFT 588 /* 34*/ xor a2, a3, a2 589 /* 37*/ wsr a2, PS 590 591 /* 40*/ _l32i a3, a1, 0 592 /* 43*/ addi a1, a1, 16 + 4 593 /* 46*/ rsr a2, EXCSAVE1 594 595 /* 49*/ rotw -1 596 /* 52*/ _bbci.l a4, 31, _WindowUnderflow4 /* 0x: call4 */ 597 /* 55*/ rotw -1 598 /* 58*/ _bbci.l a8, 30, _WindowUnderflow8 /* 10: call8 */ 599 /* 61*/ _j __WindowUnderflow12 /* 11: call12 */ 600 /* 64*/ 601 602 /* 8-Register Window Overflow Vector (Handler) */ 603 604 .align 64 605 .global _WindowOverflow8 606 _WindowOverflow8: 607 s32e a0, a9, -16 608 l32e a0, a1, -12 609 s32e a2, a9, -8 610 s32e a1, a9, -12 611 s32e a3, a9, -4 612 s32e a4, a0, -32 613 s32e a5, a0, -28 614 s32e a6, a0, -24 615 s32e a7, a0, -20 616 rfwo 617 618 /* 8-Register Window Underflow Vector (Handler) */ 619 620 .align 64 621 .global _WindowUnderflow8 622 _WindowUnderflow8: 623 l32e a1, a9, -12 624 l32e a0, a9, -16 625 l32e a7, a1, -12 626 l32e a2, a9, -8 627 l32e a4, a7, -32 628 l32e a3, a9, -4 629 l32e a5, a7, -28 630 l32e a6, a7, -24 631 l32e a7, a7, -20 632 rfwu 633 634 /* 12-Register Window Overflow Vector (Handler) */ 635 636 .align 64 637 .global _WindowOverflow12 638 _WindowOverflow12: 639 s32e a0, a13, -16 640 l32e a0, a1, -12 641 s32e a1, a13, -12 642 s32e a2, a13, -8 643 s32e a3, a13, -4 644 s32e a4, a0, -48 645 s32e a5, a0, -44 646 s32e a6, a0, -40 647 s32e a7, a0, -36 648 s32e a8, a0, -32 649 s32e a9, a0, -28 650 s32e a10, a0, -24 651 s32e a11, a0, -20 652 rfwo 653 654 /* 12-Register Window Underflow Vector (Handler) */ 655 656 .org _WindowOverflow12 + 64 - 3 657 __WindowUnderflow12: 658 rotw -1 659 .global _WindowUnderflow12 660 _WindowUnderflow12: 661 l32e a1, a13, -12 662 l32e a0, a13, -16 663 l32e a11, a1, -12 664 l32e a2, a13, -8 665 l32e a4, a11, -48 666 l32e a8, a11, -32 667 l32e a3, a13, -4 668 l32e a5, a11, -44 669 l32e a6, a11, -40 670 l32e a7, a11, -36 671 l32e a9, a11, -28 672 l32e a10, a11, -24 673 l32e a11, a11, -20 674 rfwu 675 676 #endif /* XCHAL_HAVE_WINDOWED */ 677
