1/* SPDX-License-Identifier: GPL-2.0-or-later */ 2/* 3 * PowerPC version 4 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) 5 * 6 * Rewritten by Cort Dougan (cort@cs.nmt.edu) for PReP 7 * Copyright (C) 1996 Cort Dougan <cort@cs.nmt.edu> 8 * Adapted for Power Macintosh by Paul Mackerras. 9 * Low-level exception handlers and MMU support 10 * rewritten by Paul Mackerras. 11 * Copyright (C) 1996 Paul Mackerras. 12 * 13 * Adapted for 64bit PowerPC by Dave Engebretsen, Peter Bergner, and 14 * Mike Corrigan {engebret|bergner|mikejc}@us.ibm.com 15 * 16 * This file contains the entry point for the 64-bit kernel along 17 * with some early initialization code common to all 64-bit powerpc 18 * variants. 19 */ 20 21#include <linux/threads.h> 22#include <linux/init.h> 23#include <asm/reg.h> 24#include <asm/page.h> 25#include <asm/mmu.h> 26#include <asm/ppc_asm.h> 27#include <asm/head-64.h> 28#include <asm/asm-offsets.h> 29#include <asm/bug.h> 30#include <asm/cputable.h> 31#include <asm/setup.h> 32#include <asm/hvcall.h> 33#include <asm/thread_info.h> 34#include <asm/firmware.h> 35#include <asm/page_64.h> 36#include <asm/irqflags.h> 37#include <asm/kvm_book3s_asm.h> 38#include <asm/ptrace.h> 39#include <asm/hw_irq.h> 40#include <asm/cputhreads.h> 41#include <asm/ppc-opcode.h> 42#include <asm/export.h> 43#include <asm/feature-fixups.h> 44 45/* The physical memory is laid out such that the secondary processor 46 * spin code sits at 0x0000...0x00ff. On server, the vectors follow 47 * using the layout described in exceptions-64s.S 48 */ 49 50/* 51 * Entering into this code we make the following assumptions: 52 * 53 * For pSeries or server processors: 54 * 1. The MMU is off & open firmware is running in real mode. 55 * 2. The primary CPU enters at __start. 56 * 3. If the RTAS supports "query-cpu-stopped-state", then secondary 57 * CPUs will enter as directed by "start-cpu" RTAS call, which is 58 * generic_secondary_smp_init, with PIR in r3. 59 * 4. Else the secondary CPUs will enter at secondary_hold (0x60) as 60 * directed by the "start-cpu" RTS call, with PIR in r3. 61 * -or- For OPAL entry: 62 * 1. The MMU is off, processor in HV mode. 63 * 2. The primary CPU enters at 0 with device-tree in r3, OPAL base 64 * in r8, and entry in r9 for debugging purposes. 65 * 3. Secondary CPUs enter as directed by OPAL_START_CPU call, which 66 * is at generic_secondary_smp_init, with PIR in r3. 67 * 68 * For Book3E processors: 69 * 1. The MMU is on running in AS0 in a state defined in ePAPR 70 * 2. The kernel is entered at __start 71 */ 72 73OPEN_FIXED_SECTION(first_256B, 0x0, 0x100) 74USE_FIXED_SECTION(first_256B) 75 /* 76 * Offsets are relative from the start of fixed section, and 77 * first_256B starts at 0. Offsets are a bit easier to use here 78 * than the fixed section entry macros. 79 */ 80 . = 0x0 81_GLOBAL(__start) 82 /* NOP this out unconditionally */ 83BEGIN_FTR_SECTION 84 FIXUP_ENDIAN 85 b __start_initialization_multiplatform 86END_FTR_SECTION(0, 1) 87 88 /* Catch branch to 0 in real mode */ 89 trap 90 91 /* Secondary processors spin on this value until it becomes non-zero. 92 * When non-zero, it contains the real address of the function the cpu 93 * should jump to. 94 */ 95 .balign 8 96 .globl __secondary_hold_spinloop 97__secondary_hold_spinloop: 98 .8byte 0x0 99 100 /* Secondary processors write this value with their cpu # */ 101 /* after they enter the spin loop immediately below. */ 102 .globl __secondary_hold_acknowledge 103__secondary_hold_acknowledge: 104 .8byte 0x0 105 106#ifdef CONFIG_RELOCATABLE 107 /* This flag is set to 1 by a loader if the kernel should run 108 * at the loaded address instead of the linked address. This 109 * is used by kexec-tools to keep the the kdump kernel in the 110 * crash_kernel region. The loader is responsible for 111 * observing the alignment requirement. 112 */ 113 114#ifdef CONFIG_RELOCATABLE_TEST 115#define RUN_AT_LOAD_DEFAULT 1 /* Test relocation, do not copy to 0 */ 116#else 117#define RUN_AT_LOAD_DEFAULT 0x72756e30 /* "run0" -- relocate to 0 by default */ 118#endif 119 120 /* Do not move this variable as kexec-tools knows about it. */ 121 . = 0x5c 122 .globl __run_at_load 123__run_at_load: 124DEFINE_FIXED_SYMBOL(__run_at_load) 125 .long RUN_AT_LOAD_DEFAULT 126#endif 127 128 . = 0x60 129/* 130 * The following code is used to hold secondary processors 131 * in a spin loop after they have entered the kernel, but 132 * before the bulk of the kernel has been relocated. This code 133 * is relocated to physical address 0x60 before prom_init is run. 134 * All of it must fit below the first exception vector at 0x100. 135 * Use .globl here not _GLOBAL because we want __secondary_hold 136 * to be the actual text address, not a descriptor. 137 */ 138 .globl __secondary_hold 139__secondary_hold: 140 FIXUP_ENDIAN 141#ifndef CONFIG_PPC_BOOK3E 142 mfmsr r24 143 ori r24,r24,MSR_RI 144 mtmsrd r24 /* RI on */ 145#endif 146 /* Grab our physical cpu number */ 147 mr r24,r3 148 /* stash r4 for book3e */ 149 mr r25,r4 150 151 /* Tell the master cpu we're here */ 152 /* Relocation is off & we are located at an address less */ 153 /* than 0x100, so only need to grab low order offset. */ 154 std r24,(ABS_ADDR(__secondary_hold_acknowledge))(0) 155 sync 156 157 li r26,0 158#ifdef CONFIG_PPC_BOOK3E 159 tovirt(r26,r26) 160#endif 161 /* All secondary cpus wait here until told to start. */ 162100: ld r12,(ABS_ADDR(__secondary_hold_spinloop))(r26) 163 cmpdi 0,r12,0 164 beq 100b 165 166#if defined(CONFIG_SMP) || defined(CONFIG_KEXEC_CORE) 167#ifdef CONFIG_PPC_BOOK3E 168 tovirt(r12,r12) 169#endif 170 mtctr r12 171 mr r3,r24 172 /* 173 * it may be the case that other platforms have r4 right to 174 * begin with, this gives us some safety in case it is not 175 */ 176#ifdef CONFIG_PPC_BOOK3E 177 mr r4,r25 178#else 179 li r4,0 180#endif 181 /* Make sure that patched code is visible */ 182 isync 183 bctr 184#else 1850: trap 186 EMIT_BUG_ENTRY 0b, __FILE__, __LINE__, 0 187#endif 188CLOSE_FIXED_SECTION(first_256B) 189 190/* This value is used to mark exception frames on the stack. */ 191 .section ".toc","aw" 192exception_marker: 193 .tc ID_72656773_68657265[TC],0x7265677368657265 194 .previous 195 196/* 197 * On server, we include the exception vectors code here as it 198 * relies on absolute addressing which is only possible within 199 * this compilation unit 200 */ 201#ifdef CONFIG_PPC_BOOK3S 202#include "exceptions-64s.S" 203#else 204OPEN_TEXT_SECTION(0x100) 205#endif 206 207USE_TEXT_SECTION() 208 209#ifdef CONFIG_PPC_BOOK3E 210/* 211 * The booting_thread_hwid holds the thread id we want to boot in cpu 212 * hotplug case. It is set by cpu hotplug code, and is invalid by default. 213 * The thread id is the same as the initial value of SPRN_PIR[THREAD_ID] 214 * bit field. 215 */ 216 .globl booting_thread_hwid 217booting_thread_hwid: 218 .long INVALID_THREAD_HWID 219 .align 3 220/* 221 * start a thread in the same core 222 * input parameters: 223 * r3 = the thread physical id 224 * r4 = the entry point where thread starts 225 */ 226_GLOBAL(book3e_start_thread) 227 LOAD_REG_IMMEDIATE(r5, MSR_KERNEL) 228 cmpwi r3, 0 229 beq 10f 230 cmpwi r3, 1 231 beq 11f 232 /* If the thread id is invalid, just exit. */ 233 b 13f 23410: 235 MTTMR(TMRN_IMSR0, 5) 236 MTTMR(TMRN_INIA0, 4) 237 b 12f 23811: 239 MTTMR(TMRN_IMSR1, 5) 240 MTTMR(TMRN_INIA1, 4) 24112: 242 isync 243 li r6, 1 244 sld r6, r6, r3 245 mtspr SPRN_TENS, r6 24613: 247 blr 248 249/* 250 * stop a thread in the same core 251 * input parameter: 252 * r3 = the thread physical id 253 */ 254_GLOBAL(book3e_stop_thread) 255 cmpwi r3, 0 256 beq 10f 257 cmpwi r3, 1 258 beq 10f 259 /* If the thread id is invalid, just exit. */ 260 b 13f 26110: 262 li r4, 1 263 sld r4, r4, r3 264 mtspr SPRN_TENC, r4 26513: 266 blr 267 268_GLOBAL(fsl_secondary_thread_init) 269 mfspr r4,SPRN_BUCSR 270 271 /* Enable branch prediction */ 272 lis r3,BUCSR_INIT@h 273 ori r3,r3,BUCSR_INIT@l 274 mtspr SPRN_BUCSR,r3 275 isync 276 277 /* 278 * Fix PIR to match the linear numbering in the device tree. 279 * 280 * On e6500, the reset value of PIR uses the low three bits for 281 * the thread within a core, and the upper bits for the core 282 * number. There are two threads per core, so shift everything 283 * but the low bit right by two bits so that the cpu numbering is 284 * continuous. 285 * 286 * If the old value of BUCSR is non-zero, this thread has run 287 * before. Thus, we assume we are coming from kexec or a similar 288 * scenario, and PIR is already set to the correct value. This 289 * is a bit of a hack, but there are limited opportunities for 290 * getting information into the thread and the alternatives 291 * seemed like they'd be overkill. We can't tell just by looking 292 * at the old PIR value which state it's in, since the same value 293 * could be valid for one thread out of reset and for a different 294 * thread in Linux. 295 */ 296 297 mfspr r3, SPRN_PIR 298 cmpwi r4,0 299 bne 1f 300 rlwimi r3, r3, 30, 2, 30 301 mtspr SPRN_PIR, r3 3021: 303#endif 304 305_GLOBAL(generic_secondary_thread_init) 306 mr r24,r3 307 308 /* turn on 64-bit mode */ 309 bl enable_64b_mode 310 311 /* get a valid TOC pointer, wherever we're mapped at */ 312 bl relative_toc 313 tovirt(r2,r2) 314 315#ifdef CONFIG_PPC_BOOK3E 316 /* Book3E initialization */ 317 mr r3,r24 318 bl book3e_secondary_thread_init 319#endif 320 b generic_secondary_common_init 321 322/* 323 * On pSeries and most other platforms, secondary processors spin 324 * in the following code. 325 * At entry, r3 = this processor's number (physical cpu id) 326 * 327 * On Book3E, r4 = 1 to indicate that the initial TLB entry for 328 * this core already exists (setup via some other mechanism such 329 * as SCOM before entry). 330 */ 331_GLOBAL(generic_secondary_smp_init) 332 FIXUP_ENDIAN 333 mr r24,r3 334 mr r25,r4 335 336 /* turn on 64-bit mode */ 337 bl enable_64b_mode 338 339 /* get a valid TOC pointer, wherever we're mapped at */ 340 bl relative_toc 341 tovirt(r2,r2) 342 343#ifdef CONFIG_PPC_BOOK3E 344 /* Book3E initialization */ 345 mr r3,r24 346 mr r4,r25 347 bl book3e_secondary_core_init 348 349/* 350 * After common core init has finished, check if the current thread is the 351 * one we wanted to boot. If not, start the specified thread and stop the 352 * current thread. 353 */ 354 LOAD_REG_ADDR(r4, booting_thread_hwid) 355 lwz r3, 0(r4) 356 li r5, INVALID_THREAD_HWID 357 cmpw r3, r5 358 beq 20f 359 360 /* 361 * The value of booting_thread_hwid has been stored in r3, 362 * so make it invalid. 363 */ 364 stw r5, 0(r4) 365 366 /* 367 * Get the current thread id and check if it is the one we wanted. 368 * If not, start the one specified in booting_thread_hwid and stop 369 * the current thread. 370 */ 371 mfspr r8, SPRN_TIR 372 cmpw r3, r8 373 beq 20f 374 375 /* start the specified thread */ 376 LOAD_REG_ADDR(r5, fsl_secondary_thread_init) 377 ld r4, 0(r5) 378 bl book3e_start_thread 379 380 /* stop the current thread */ 381 mr r3, r8 382 bl book3e_stop_thread 38310: 384 b 10b 38520: 386#endif 387 388generic_secondary_common_init: 389 /* Set up a paca value for this processor. Since we have the 390 * physical cpu id in r24, we need to search the pacas to find 391 * which logical id maps to our physical one. 392 */ 393#ifndef CONFIG_SMP 394 b kexec_wait /* wait for next kernel if !SMP */ 395#else 396 LOAD_REG_ADDR(r8, paca_ptrs) /* Load paca_ptrs pointe */ 397 ld r8,0(r8) /* Get base vaddr of array */ 398 LOAD_REG_ADDR(r7, nr_cpu_ids) /* Load nr_cpu_ids address */ 399 lwz r7,0(r7) /* also the max paca allocated */ 400 li r5,0 /* logical cpu id */ 4011: 402 sldi r9,r5,3 /* get paca_ptrs[] index from cpu id */ 403 ldx r13,r9,r8 /* r13 = paca_ptrs[cpu id] */ 404 lhz r6,PACAHWCPUID(r13) /* Load HW procid from paca */ 405 cmpw r6,r24 /* Compare to our id */ 406 beq 2f 407 addi r5,r5,1 408 cmpw r5,r7 /* Check if more pacas exist */ 409 blt 1b 410 411 mr r3,r24 /* not found, copy phys to r3 */ 412 b kexec_wait /* next kernel might do better */ 413 4142: SET_PACA(r13) 415#ifdef CONFIG_PPC_BOOK3E 416 addi r12,r13,PACA_EXTLB /* and TLB exc frame in another */ 417 mtspr SPRN_SPRG_TLB_EXFRAME,r12 418#endif 419 420 /* From now on, r24 is expected to be logical cpuid */ 421 mr r24,r5 422 423 /* See if we need to call a cpu state restore handler */ 424 LOAD_REG_ADDR(r23, cur_cpu_spec) 425 ld r23,0(r23) 426 ld r12,CPU_SPEC_RESTORE(r23) 427 cmpdi 0,r12,0 428 beq 3f 429#ifdef PPC64_ELF_ABI_v1 430 ld r12,0(r12) 431#endif 432 mtctr r12 433 bctrl 434 4353: LOAD_REG_ADDR(r3, spinning_secondaries) /* Decrement spinning_secondaries */ 436 lwarx r4,0,r3 437 subi r4,r4,1 438 stwcx. r4,0,r3 439 bne 3b 440 isync 441 4424: HMT_LOW 443 lbz r23,PACAPROCSTART(r13) /* Test if this processor should */ 444 /* start. */ 445 cmpwi 0,r23,0 446 beq 4b /* Loop until told to go */ 447 448 sync /* order paca.run and cur_cpu_spec */ 449 isync /* In case code patching happened */ 450 451 /* Create a temp kernel stack for use before relocation is on. */ 452 ld r1,PACAEMERGSP(r13) 453 subi r1,r1,STACK_FRAME_OVERHEAD 454 455 b __secondary_start 456#endif /* SMP */ 457 458/* 459 * Turn the MMU off. 460 * Assumes we're mapped EA == RA if the MMU is on. 461 */ 462#ifdef CONFIG_PPC_BOOK3S 463__mmu_off: 464 mfmsr r3 465 andi. r0,r3,MSR_IR|MSR_DR 466 beqlr 467 mflr r4 468 andc r3,r3,r0 469 mtspr SPRN_SRR0,r4 470 mtspr SPRN_SRR1,r3 471 sync 472 rfid 473 b . /* prevent speculative execution */ 474#endif 475 476 477/* 478 * Here is our main kernel entry point. We support currently 2 kind of entries 479 * depending on the value of r5. 480 * 481 * r5 != NULL -> OF entry, we go to prom_init, "legacy" parameter content 482 * in r3...r7 483 * 484 * r5 == NULL -> kexec style entry. r3 is a physical pointer to the 485 * DT block, r4 is a physical pointer to the kernel itself 486 * 487 */ 488__start_initialization_multiplatform: 489 /* Make sure we are running in 64 bits mode */ 490 bl enable_64b_mode 491 492 /* Get TOC pointer (current runtime address) */ 493 bl relative_toc 494 495 /* find out where we are now */ 496 bcl 20,31,$+4 4970: mflr r26 /* r26 = runtime addr here */ 498 addis r26,r26,(_stext - 0b)@ha 499 addi r26,r26,(_stext - 0b)@l /* current runtime base addr */ 500 501 /* 502 * Are we booted from a PROM Of-type client-interface ? 503 */ 504 cmpldi cr0,r5,0 505 beq 1f 506 b __boot_from_prom /* yes -> prom */ 5071: 508 /* Save parameters */ 509 mr r31,r3 510 mr r30,r4 511#ifdef CONFIG_PPC_EARLY_DEBUG_OPAL 512 /* Save OPAL entry */ 513 mr r28,r8 514 mr r29,r9 515#endif 516 517#ifdef CONFIG_PPC_BOOK3E 518 bl start_initialization_book3e 519 b __after_prom_start 520#else 521 /* Setup some critical 970 SPRs before switching MMU off */ 522 mfspr r0,SPRN_PVR 523 srwi r0,r0,16 524 cmpwi r0,0x39 /* 970 */ 525 beq 1f 526 cmpwi r0,0x3c /* 970FX */ 527 beq 1f 528 cmpwi r0,0x44 /* 970MP */ 529 beq 1f 530 cmpwi r0,0x45 /* 970GX */ 531 bne 2f 5321: bl __cpu_preinit_ppc970 5332: 534 535 /* Switch off MMU if not already off */ 536 bl __mmu_off 537 b __after_prom_start 538#endif /* CONFIG_PPC_BOOK3E */ 539 540__REF 541__boot_from_prom: 542#ifdef CONFIG_PPC_OF_BOOT_TRAMPOLINE 543 /* Save parameters */ 544 mr r31,r3 545 mr r30,r4 546 mr r29,r5 547 mr r28,r6 548 mr r27,r7 549 550 /* 551 * Align the stack to 16-byte boundary 552 * Depending on the size and layout of the ELF sections in the initial 553 * boot binary, the stack pointer may be unaligned on PowerMac 554 */ 555 rldicr r1,r1,0,59 556 557#ifdef CONFIG_RELOCATABLE 558 /* Relocate code for where we are now */ 559 mr r3,r26 560 bl relocate 561#endif 562 563 /* Restore parameters */ 564 mr r3,r31 565 mr r4,r30 566 mr r5,r29 567 mr r6,r28 568 mr r7,r27 569 570 /* Do all of the interaction with OF client interface */ 571 mr r8,r26 572 bl prom_init 573#endif /* #CONFIG_PPC_OF_BOOT_TRAMPOLINE */ 574 575 /* We never return. We also hit that trap if trying to boot 576 * from OF while CONFIG_PPC_OF_BOOT_TRAMPOLINE isn't selected */ 577 trap 578 .previous 579 580__after_prom_start: 581#ifdef CONFIG_RELOCATABLE 582 /* process relocations for the final address of the kernel */ 583 lis r25,PAGE_OFFSET@highest /* compute virtual base of kernel */ 584 sldi r25,r25,32 585#if defined(CONFIG_PPC_BOOK3E) 586 tovirt(r26,r26) /* on booke, we already run at PAGE_OFFSET */ 587#endif 588 lwz r7,(FIXED_SYMBOL_ABS_ADDR(__run_at_load))(r26) 589#if defined(CONFIG_PPC_BOOK3E) 590 tophys(r26,r26) 591#endif 592 cmplwi cr0,r7,1 /* flagged to stay where we are ? */ 593 bne 1f 594 add r25,r25,r26 5951: mr r3,r25 596 bl relocate 597#if defined(CONFIG_PPC_BOOK3E) 598 /* IVPR needs to be set after relocation. */ 599 bl init_core_book3e 600#endif 601#endif 602 603/* 604 * We need to run with _stext at physical address PHYSICAL_START. 605 * This will leave some code in the first 256B of 606 * real memory, which are reserved for software use. 607 * 608 * Note: This process overwrites the OF exception vectors. 609 */ 610 li r3,0 /* target addr */ 611#ifdef CONFIG_PPC_BOOK3E 612 tovirt(r3,r3) /* on booke, we already run at PAGE_OFFSET */ 613#endif 614 mr. r4,r26 /* In some cases the loader may */ 615#if defined(CONFIG_PPC_BOOK3E) 616 tovirt(r4,r4) 617#endif 618 beq 9f /* have already put us at zero */ 619 li r6,0x100 /* Start offset, the first 0x100 */ 620 /* bytes were copied earlier. */ 621 622#ifdef CONFIG_RELOCATABLE 623/* 624 * Check if the kernel has to be running as relocatable kernel based on the 625 * variable __run_at_load, if it is set the kernel is treated as relocatable 626 * kernel, otherwise it will be moved to PHYSICAL_START 627 */ 628#if defined(CONFIG_PPC_BOOK3E) 629 tovirt(r26,r26) /* on booke, we already run at PAGE_OFFSET */ 630#endif 631 lwz r7,(FIXED_SYMBOL_ABS_ADDR(__run_at_load))(r26) 632 cmplwi cr0,r7,1 633 bne 3f 634 635#ifdef CONFIG_PPC_BOOK3E 636 LOAD_REG_ADDR(r5, __end_interrupts) 637 LOAD_REG_ADDR(r11, _stext) 638 sub r5,r5,r11 639#else 640 /* just copy interrupts */ 641 LOAD_REG_IMMEDIATE_SYM(r5, r11, FIXED_SYMBOL_ABS_ADDR(__end_interrupts)) 642#endif 643 b 5f 6443: 645#endif 646 /* # bytes of memory to copy */ 647 lis r5,(ABS_ADDR(copy_to_here))@ha 648 addi r5,r5,(ABS_ADDR(copy_to_here))@l 649 650 bl copy_and_flush /* copy the first n bytes */ 651 /* this includes the code being */ 652 /* executed here. */ 653 /* Jump to the copy of this code that we just made */ 654 addis r8,r3,(ABS_ADDR(4f))@ha 655 addi r12,r8,(ABS_ADDR(4f))@l 656 mtctr r12 657 bctr 658 659.balign 8 660p_end: .8byte _end - copy_to_here 661 6624: 663 /* 664 * Now copy the rest of the kernel up to _end, add 665 * _end - copy_to_here to the copy limit and run again. 666 */ 667 addis r8,r26,(ABS_ADDR(p_end))@ha 668 ld r8,(ABS_ADDR(p_end))@l(r8) 669 add r5,r5,r8 6705: bl copy_and_flush /* copy the rest */ 671 6729: b start_here_multiplatform 673 674/* 675 * Copy routine used to copy the kernel to start at physical address 0 676 * and flush and invalidate the caches as needed. 677 * r3 = dest addr, r4 = source addr, r5 = copy limit, r6 = start offset 678 * on exit, r3, r4, r5 are unchanged, r6 is updated to be >= r5. 679 * 680 * Note: this routine *only* clobbers r0, r6 and lr 681 */ 682_GLOBAL(copy_and_flush) 683 addi r5,r5,-8 684 addi r6,r6,-8 6854: li r0,8 /* Use the smallest common */ 686 /* denominator cache line */ 687 /* size. This results in */ 688 /* extra cache line flushes */ 689 /* but operation is correct. */ 690 /* Can't get cache line size */ 691 /* from NACA as it is being */ 692 /* moved too. */ 693 694 mtctr r0 /* put # words/line in ctr */ 6953: addi r6,r6,8 /* copy a cache line */ 696 ldx r0,r6,r4 697 stdx r0,r6,r3 698 bdnz 3b 699 dcbst r6,r3 /* write it to memory */ 700 sync 701 icbi r6,r3 /* flush the icache line */ 702 cmpld 0,r6,r5 703 blt 4b 704 sync 705 addi r5,r5,8 706 addi r6,r6,8 707 isync 708 blr 709 710.align 8 711copy_to_here: 712 713#ifdef CONFIG_SMP 714#ifdef CONFIG_PPC_PMAC 715/* 716 * On PowerMac, secondary processors starts from the reset vector, which 717 * is temporarily turned into a call to one of the functions below. 718 */ 719 .section ".text"; 720 .align 2 ; 721 722 .globl __secondary_start_pmac_0 723__secondary_start_pmac_0: 724 /* NB the entries for cpus 0, 1, 2 must each occupy 8 bytes. */ 725 li r24,0 726 b 1f 727 li r24,1 728 b 1f 729 li r24,2 730 b 1f 731 li r24,3 7321: 733 734_GLOBAL(pmac_secondary_start) 735 /* turn on 64-bit mode */ 736 bl enable_64b_mode 737 738 li r0,0 739 mfspr r3,SPRN_HID4 740 rldimi r3,r0,40,23 /* clear bit 23 (rm_ci) */ 741 sync 742 mtspr SPRN_HID4,r3 743 isync 744 sync 745 slbia 746 747 /* get TOC pointer (real address) */ 748 bl relative_toc 749 tovirt(r2,r2) 750 751 /* Copy some CPU settings from CPU 0 */ 752 bl __restore_cpu_ppc970 753 754 /* pSeries do that early though I don't think we really need it */ 755 mfmsr r3 756 ori r3,r3,MSR_RI 757 mtmsrd r3 /* RI on */ 758 759 /* Set up a paca value for this processor. */ 760 LOAD_REG_ADDR(r4,paca_ptrs) /* Load paca pointer */ 761 ld r4,0(r4) /* Get base vaddr of paca_ptrs array */ 762 sldi r5,r24,3 /* get paca_ptrs[] index from cpu id */ 763 ldx r13,r5,r4 /* r13 = paca_ptrs[cpu id] */ 764 SET_PACA(r13) /* Save vaddr of paca in an SPRG*/ 765 766 /* Mark interrupts soft and hard disabled (they might be enabled 767 * in the PACA when doing hotplug) 768 */ 769 li r0,IRQS_DISABLED 770 stb r0,PACAIRQSOFTMASK(r13) 771 li r0,PACA_IRQ_HARD_DIS 772 stb r0,PACAIRQHAPPENED(r13) 773 774 /* Create a temp kernel stack for use before relocation is on. */ 775 ld r1,PACAEMERGSP(r13) 776 subi r1,r1,STACK_FRAME_OVERHEAD 777 778 b __secondary_start 779 780#endif /* CONFIG_PPC_PMAC */ 781 782/* 783 * This function is called after the master CPU has released the 784 * secondary processors. The execution environment is relocation off. 785 * The paca for this processor has the following fields initialized at 786 * this point: 787 * 1. Processor number 788 * 2. Segment table pointer (virtual address) 789 * On entry the following are set: 790 * r1 = stack pointer (real addr of temp stack) 791 * r24 = cpu# (in Linux terms) 792 * r13 = paca virtual address 793 * SPRG_PACA = paca virtual address 794 */ 795 .section ".text"; 796 .align 2 ; 797 798 .globl __secondary_start 799__secondary_start: 800 /* Set thread priority to MEDIUM */ 801 HMT_MEDIUM 802 803 /* 804 * Do early setup for this CPU, in particular initialising the MMU so we 805 * can turn it on below. This is a call to C, which is OK, we're still 806 * running on the emergency stack. 807 */ 808 bl early_setup_secondary 809 810 /* 811 * The primary has initialized our kernel stack for us in the paca, grab 812 * it and put it in r1. We must *not* use it until we turn on the MMU 813 * below, because it may not be inside the RMO. 814 */ 815 ld r1, PACAKSAVE(r13) 816 817 /* Clear backchain so we get nice backtraces */ 818 li r7,0 819 mtlr r7 820 821 /* Mark interrupts soft and hard disabled (they might be enabled 822 * in the PACA when doing hotplug) 823 */ 824 li r7,IRQS_DISABLED 825 stb r7,PACAIRQSOFTMASK(r13) 826 li r0,PACA_IRQ_HARD_DIS 827 stb r0,PACAIRQHAPPENED(r13) 828 829 /* enable MMU and jump to start_secondary */ 830 LOAD_REG_ADDR(r3, start_secondary_prolog) 831 LOAD_REG_IMMEDIATE(r4, MSR_KERNEL) 832 833 mtspr SPRN_SRR0,r3 834 mtspr SPRN_SRR1,r4 835 RFI 836 b . /* prevent speculative execution */ 837 838/* 839 * Running with relocation on at this point. All we want to do is 840 * zero the stack back-chain pointer and get the TOC virtual address 841 * before going into C code. 842 */ 843start_secondary_prolog: 844 ld r2,PACATOC(r13) 845 li r3,0 846 std r3,0(r1) /* Zero the stack frame pointer */ 847 bl start_secondary 848 b . 849/* 850 * Reset stack pointer and call start_secondary 851 * to continue with online operation when woken up 852 * from cede in cpu offline. 853 */ 854_GLOBAL(start_secondary_resume) 855 ld r1,PACAKSAVE(r13) /* Reload kernel stack pointer */ 856 li r3,0 857 std r3,0(r1) /* Zero the stack frame pointer */ 858 bl start_secondary 859 b . 860#endif 861 862/* 863 * This subroutine clobbers r11 and r12 864 */ 865enable_64b_mode: 866 mfmsr r11 /* grab the current MSR */ 867#ifdef CONFIG_PPC_BOOK3E 868 oris r11,r11,0x8000 /* CM bit set, we'll set ICM later */ 869 mtmsr r11 870#else /* CONFIG_PPC_BOOK3E */ 871 li r12,(MSR_64BIT | MSR_ISF)@highest 872 sldi r12,r12,48 873 or r11,r11,r12 874 mtmsrd r11 875 isync 876#endif 877 blr 878 879/* 880 * This puts the TOC pointer into r2, offset by 0x8000 (as expected 881 * by the toolchain). It computes the correct value for wherever we 882 * are running at the moment, using position-independent code. 883 * 884 * Note: The compiler constructs pointers using offsets from the 885 * TOC in -mcmodel=medium mode. After we relocate to 0 but before 886 * the MMU is on we need our TOC to be a virtual address otherwise 887 * these pointers will be real addresses which may get stored and 888 * accessed later with the MMU on. We use tovirt() at the call 889 * sites to handle this. 890 */ 891_GLOBAL(relative_toc) 892 mflr r0 893 bcl 20,31,$+4 8940: mflr r11 895 ld r2,(p_toc - 0b)(r11) 896 add r2,r2,r11 897 mtlr r0 898 blr 899 900.balign 8 901p_toc: .8byte __toc_start + 0x8000 - 0b 902 903/* 904 * This is where the main kernel code starts. 905 */ 906__REF 907start_here_multiplatform: 908 /* set up the TOC */ 909 bl relative_toc 910 tovirt(r2,r2) 911 912 /* Clear out the BSS. It may have been done in prom_init, 913 * already but that's irrelevant since prom_init will soon 914 * be detached from the kernel completely. Besides, we need 915 * to clear it now for kexec-style entry. 916 */ 917 LOAD_REG_ADDR(r11,__bss_stop) 918 LOAD_REG_ADDR(r8,__bss_start) 919 sub r11,r11,r8 /* bss size */ 920 addi r11,r11,7 /* round up to an even double word */ 921 srdi. r11,r11,3 /* shift right by 3 */ 922 beq 4f 923 addi r8,r8,-8 924 li r0,0 925 mtctr r11 /* zero this many doublewords */ 9263: stdu r0,8(r8) 927 bdnz 3b 9284: 929 930#ifdef CONFIG_PPC_EARLY_DEBUG_OPAL 931 /* Setup OPAL entry */ 932 LOAD_REG_ADDR(r11, opal) 933 std r28,0(r11); 934 std r29,8(r11); 935#endif 936 937#ifndef CONFIG_PPC_BOOK3E 938 mfmsr r6 939 ori r6,r6,MSR_RI 940 mtmsrd r6 /* RI on */ 941#endif 942 943#ifdef CONFIG_RELOCATABLE 944 /* Save the physical address we're running at in kernstart_addr */ 945 LOAD_REG_ADDR(r4, kernstart_addr) 946 clrldi r0,r25,2 947 std r0,0(r4) 948#endif 949 950 /* set up a stack pointer */ 951 LOAD_REG_ADDR(r3,init_thread_union) 952 LOAD_REG_IMMEDIATE(r1,THREAD_SIZE) 953 add r1,r3,r1 954 li r0,0 955 stdu r0,-STACK_FRAME_OVERHEAD(r1) 956 957 /* 958 * Do very early kernel initializations, including initial hash table 959 * and SLB setup before we turn on relocation. 960 */ 961 962 /* Restore parameters passed from prom_init/kexec */ 963 mr r3,r31 964 LOAD_REG_ADDR(r12, DOTSYM(early_setup)) 965 mtctr r12 966 bctrl /* also sets r13 and SPRG_PACA */ 967 968 LOAD_REG_ADDR(r3, start_here_common) 969 ld r4,PACAKMSR(r13) 970 mtspr SPRN_SRR0,r3 971 mtspr SPRN_SRR1,r4 972 RFI 973 b . /* prevent speculative execution */ 974 975 /* This is where all platforms converge execution */ 976 977start_here_common: 978 /* relocation is on at this point */ 979 std r1,PACAKSAVE(r13) 980 981 /* Load the TOC (virtual address) */ 982 ld r2,PACATOC(r13) 983 984 /* Mark interrupts soft and hard disabled (they might be enabled 985 * in the PACA when doing hotplug) 986 */ 987 li r0,IRQS_DISABLED 988 stb r0,PACAIRQSOFTMASK(r13) 989 li r0,PACA_IRQ_HARD_DIS 990 stb r0,PACAIRQHAPPENED(r13) 991 992 /* Generic kernel entry */ 993 bl start_kernel 994 995 /* Not reached */ 996 trap 997 EMIT_BUG_ENTRY 0b, __FILE__, __LINE__, 0 998 .previous 999 1000/* 1001 * We put a few things here that have to be page-aligned. 1002 * This stuff goes at the beginning of the bss, which is page-aligned. 1003 */ 1004 .section ".bss" 1005/* 1006 * pgd dir should be aligned to PGD_TABLE_SIZE which is 64K. 1007 * We will need to find a better way to fix this 1008 */ 1009 .align 16 1010 1011 .globl swapper_pg_dir 1012swapper_pg_dir: 1013 .space PGD_TABLE_SIZE 1014 1015 .globl empty_zero_page 1016empty_zero_page: 1017 .space PAGE_SIZE 1018EXPORT_SYMBOL(empty_zero_page) 1019