1/* 2 * Kernel execution entry point code. 3 * 4 * Copyright (c) 1995-1996 Gary Thomas <gdt@linuxppc.org> 5 * Initial PowerPC version. 6 * Copyright (c) 1996 Cort Dougan <cort@cs.nmt.edu> 7 * Rewritten for PReP 8 * Copyright (c) 1996 Paul Mackerras <paulus@cs.anu.edu.au> 9 * Low-level exception handers, MMU support, and rewrite. 10 * Copyright (c) 1997 Dan Malek <dmalek@jlc.net> 11 * PowerPC 8xx modifications. 12 * Copyright (c) 1998-1999 TiVo, Inc. 13 * PowerPC 403GCX modifications. 14 * Copyright (c) 1999 Grant Erickson <grant@lcse.umn.edu> 15 * PowerPC 403GCX/405GP modifications. 16 * Copyright 2000 MontaVista Software Inc. 17 * PPC405 modifications 18 * PowerPC 403GCX/405GP modifications. 19 * Author: MontaVista Software, Inc. 20 * frank_rowand@mvista.com or source@mvista.com 21 * debbie_chu@mvista.com 22 * Copyright 2002-2004 MontaVista Software, Inc. 23 * PowerPC 44x support, Matt Porter <mporter@kernel.crashing.org> 24 * Copyright 2004 Freescale Semiconductor, Inc 25 * PowerPC e500 modifications, Kumar Gala <galak@kernel.crashing.org> 26 * 27 * This program is free software; you can redistribute it and/or modify it 28 * under the terms of the GNU General Public License as published by the 29 * Free Software Foundation; either version 2 of the License, or (at your 30 * option) any later version. 31 */ 32 33#include <linux/init.h> 34#include <linux/threads.h> 35#include <asm/processor.h> 36#include <asm/page.h> 37#include <asm/mmu.h> 38#include <asm/pgtable.h> 39#include <asm/cputable.h> 40#include <asm/thread_info.h> 41#include <asm/ppc_asm.h> 42#include <asm/asm-offsets.h> 43#include <asm/cache.h> 44#include <asm/ptrace.h> 45#include <asm/export.h> 46#include "head_booke.h" 47 48/* As with the other PowerPC ports, it is expected that when code 49 * execution begins here, the following registers contain valid, yet 50 * optional, information: 51 * 52 * r3 - Board info structure pointer (DRAM, frequency, MAC address, etc.) 53 * r4 - Starting address of the init RAM disk 54 * r5 - Ending address of the init RAM disk 55 * r6 - Start of kernel command line string (e.g. "mem=128") 56 * r7 - End of kernel command line string 57 * 58 */ 59 __HEAD 60_ENTRY(_stext); 61_ENTRY(_start); 62 /* 63 * Reserve a word at a fixed location to store the address 64 * of abatron_pteptrs 65 */ 66 nop 67 68 /* Translate device tree address to physical, save in r30/r31 */ 69 bl get_phys_addr 70 mr r30,r3 71 mr r31,r4 72 73 li r25,0 /* phys kernel start (low) */ 74 li r24,0 /* CPU number */ 75 li r23,0 /* phys kernel start (high) */ 76 77#ifdef CONFIG_RELOCATABLE 78 LOAD_REG_ADDR_PIC(r3, _stext) /* Get our current runtime base */ 79 80 /* Translate _stext address to physical, save in r23/r25 */ 81 bl get_phys_addr 82 mr r23,r3 83 mr r25,r4 84 85 bl 0f 860: mflr r8 87 addis r3,r8,(is_second_reloc - 0b)@ha 88 lwz r19,(is_second_reloc - 0b)@l(r3) 89 90 /* Check if this is the second relocation. */ 91 cmpwi r19,1 92 bne 1f 93 94 /* 95 * For the second relocation, we already get the real memstart_addr 96 * from device tree. So we will map PAGE_OFFSET to memstart_addr, 97 * then the virtual address of start kernel should be: 98 * PAGE_OFFSET + (kernstart_addr - memstart_addr) 99 * Since the offset between kernstart_addr and memstart_addr should 100 * never be beyond 1G, so we can just use the lower 32bit of them 101 * for the calculation. 102 */ 103 lis r3,PAGE_OFFSET@h 104 105 addis r4,r8,(kernstart_addr - 0b)@ha 106 addi r4,r4,(kernstart_addr - 0b)@l 107 lwz r5,4(r4) 108 109 addis r6,r8,(memstart_addr - 0b)@ha 110 addi r6,r6,(memstart_addr - 0b)@l 111 lwz r7,4(r6) 112 113 subf r5,r7,r5 114 add r3,r3,r5 115 b 2f 116 1171: 118 /* 119 * We have the runtime (virutal) address of our base. 120 * We calculate our shift of offset from a 64M page. 121 * We could map the 64M page we belong to at PAGE_OFFSET and 122 * get going from there. 123 */ 124 lis r4,KERNELBASE@h 125 ori r4,r4,KERNELBASE@l 126 rlwinm r6,r25,0,0x3ffffff /* r6 = PHYS_START % 64M */ 127 rlwinm r5,r4,0,0x3ffffff /* r5 = KERNELBASE % 64M */ 128 subf r3,r5,r6 /* r3 = r6 - r5 */ 129 add r3,r4,r3 /* Required Virtual Address */ 130 1312: bl relocate 132 133 /* 134 * For the second relocation, we already set the right tlb entries 135 * for the kernel space, so skip the code in fsl_booke_entry_mapping.S 136 */ 137 cmpwi r19,1 138 beq set_ivor 139#endif 140 141/* We try to not make any assumptions about how the boot loader 142 * setup or used the TLBs. We invalidate all mappings from the 143 * boot loader and load a single entry in TLB1[0] to map the 144 * first 64M of kernel memory. Any boot info passed from the 145 * bootloader needs to live in this first 64M. 146 * 147 * Requirement on bootloader: 148 * - The page we're executing in needs to reside in TLB1 and 149 * have IPROT=1. If not an invalidate broadcast could 150 * evict the entry we're currently executing in. 151 * 152 * r3 = Index of TLB1 were executing in 153 * r4 = Current MSR[IS] 154 * r5 = Index of TLB1 temp mapping 155 * 156 * Later in mapin_ram we will correctly map lowmem, and resize TLB1[0] 157 * if needed 158 */ 159 160_ENTRY(__early_start) 161 162#define ENTRY_MAPPING_BOOT_SETUP 163#include "fsl_booke_entry_mapping.S" 164#undef ENTRY_MAPPING_BOOT_SETUP 165 166set_ivor: 167 /* Establish the interrupt vector offsets */ 168 SET_IVOR(0, CriticalInput); 169 SET_IVOR(1, MachineCheck); 170 SET_IVOR(2, DataStorage); 171 SET_IVOR(3, InstructionStorage); 172 SET_IVOR(4, ExternalInput); 173 SET_IVOR(5, Alignment); 174 SET_IVOR(6, Program); 175 SET_IVOR(7, FloatingPointUnavailable); 176 SET_IVOR(8, SystemCall); 177 SET_IVOR(9, AuxillaryProcessorUnavailable); 178 SET_IVOR(10, Decrementer); 179 SET_IVOR(11, FixedIntervalTimer); 180 SET_IVOR(12, WatchdogTimer); 181 SET_IVOR(13, DataTLBError); 182 SET_IVOR(14, InstructionTLBError); 183 SET_IVOR(15, DebugCrit); 184 185 /* Establish the interrupt vector base */ 186 lis r4,interrupt_base@h /* IVPR only uses the high 16-bits */ 187 mtspr SPRN_IVPR,r4 188 189 /* Setup the defaults for TLB entries */ 190 li r2,(MAS4_TSIZED(BOOK3E_PAGESZ_4K))@l 191#ifdef CONFIG_E200 192 oris r2,r2,MAS4_TLBSELD(1)@h 193#endif 194 mtspr SPRN_MAS4, r2 195 196#if 0 197 /* Enable DOZE */ 198 mfspr r2,SPRN_HID0 199 oris r2,r2,HID0_DOZE@h 200 mtspr SPRN_HID0, r2 201#endif 202 203#if !defined(CONFIG_BDI_SWITCH) 204 /* 205 * The Abatron BDI JTAG debugger does not tolerate others 206 * mucking with the debug registers. 207 */ 208 lis r2,DBCR0_IDM@h 209 mtspr SPRN_DBCR0,r2 210 isync 211 /* clear any residual debug events */ 212 li r2,-1 213 mtspr SPRN_DBSR,r2 214#endif 215 216#ifdef CONFIG_SMP 217 /* Check to see if we're the second processor, and jump 218 * to the secondary_start code if so 219 */ 220 LOAD_REG_ADDR_PIC(r24, boot_cpuid) 221 lwz r24, 0(r24) 222 cmpwi r24, -1 223 mfspr r24,SPRN_PIR 224 bne __secondary_start 225#endif 226 227 /* 228 * This is where the main kernel code starts. 229 */ 230 231 /* ptr to current */ 232 lis r2,init_task@h 233 ori r2,r2,init_task@l 234 235 /* ptr to current thread */ 236 addi r4,r2,THREAD /* init task's THREAD */ 237 mtspr SPRN_SPRG_THREAD,r4 238 239 /* stack */ 240 lis r1,init_thread_union@h 241 ori r1,r1,init_thread_union@l 242 li r0,0 243 stwu r0,THREAD_SIZE-STACK_FRAME_OVERHEAD(r1) 244 245 CURRENT_THREAD_INFO(r22, r1) 246 stw r24, TI_CPU(r22) 247 248 bl early_init 249 250#ifdef CONFIG_RELOCATABLE 251 mr r3,r30 252 mr r4,r31 253#ifdef CONFIG_PHYS_64BIT 254 mr r5,r23 255 mr r6,r25 256#else 257 mr r5,r25 258#endif 259 bl relocate_init 260#endif 261 262#ifdef CONFIG_DYNAMIC_MEMSTART 263 lis r3,kernstart_addr@ha 264 la r3,kernstart_addr@l(r3) 265#ifdef CONFIG_PHYS_64BIT 266 stw r23,0(r3) 267 stw r25,4(r3) 268#else 269 stw r25,0(r3) 270#endif 271#endif 272 273/* 274 * Decide what sort of machine this is and initialize the MMU. 275 */ 276 mr r3,r30 277 mr r4,r31 278 bl machine_init 279 bl MMU_init 280 281 /* Setup PTE pointers for the Abatron bdiGDB */ 282 lis r6, swapper_pg_dir@h 283 ori r6, r6, swapper_pg_dir@l 284 lis r5, abatron_pteptrs@h 285 ori r5, r5, abatron_pteptrs@l 286 lis r4, KERNELBASE@h 287 ori r4, r4, KERNELBASE@l 288 stw r5, 0(r4) /* Save abatron_pteptrs at a fixed location */ 289 stw r6, 0(r5) 290 291 /* Let's move on */ 292 lis r4,start_kernel@h 293 ori r4,r4,start_kernel@l 294 lis r3,MSR_KERNEL@h 295 ori r3,r3,MSR_KERNEL@l 296 mtspr SPRN_SRR0,r4 297 mtspr SPRN_SRR1,r3 298 rfi /* change context and jump to start_kernel */ 299 300/* Macros to hide the PTE size differences 301 * 302 * FIND_PTE -- walks the page tables given EA & pgdir pointer 303 * r10 -- EA of fault 304 * r11 -- PGDIR pointer 305 * r12 -- free 306 * label 2: is the bailout case 307 * 308 * if we find the pte (fall through): 309 * r11 is low pte word 310 * r12 is pointer to the pte 311 * r10 is the pshift from the PGD, if we're a hugepage 312 */ 313#ifdef CONFIG_PTE_64BIT 314#ifdef CONFIG_HUGETLB_PAGE 315#define FIND_PTE \ 316 rlwinm r12, r10, 13, 19, 29; /* Compute pgdir/pmd offset */ \ 317 lwzx r11, r12, r11; /* Get pgd/pmd entry */ \ 318 rlwinm. r12, r11, 0, 0, 20; /* Extract pt base address */ \ 319 blt 1000f; /* Normal non-huge page */ \ 320 beq 2f; /* Bail if no table */ \ 321 oris r11, r11, PD_HUGE@h; /* Put back address bit */ \ 322 andi. r10, r11, HUGEPD_SHIFT_MASK@l; /* extract size field */ \ 323 xor r12, r10, r11; /* drop size bits from pointer */ \ 324 b 1001f; \ 3251000: rlwimi r12, r10, 23, 20, 28; /* Compute pte address */ \ 326 li r10, 0; /* clear r10 */ \ 3271001: lwz r11, 4(r12); /* Get pte entry */ 328#else 329#define FIND_PTE \ 330 rlwinm r12, r10, 13, 19, 29; /* Compute pgdir/pmd offset */ \ 331 lwzx r11, r12, r11; /* Get pgd/pmd entry */ \ 332 rlwinm. r12, r11, 0, 0, 20; /* Extract pt base address */ \ 333 beq 2f; /* Bail if no table */ \ 334 rlwimi r12, r10, 23, 20, 28; /* Compute pte address */ \ 335 lwz r11, 4(r12); /* Get pte entry */ 336#endif /* HUGEPAGE */ 337#else /* !PTE_64BIT */ 338#define FIND_PTE \ 339 rlwimi r11, r10, 12, 20, 29; /* Create L1 (pgdir/pmd) address */ \ 340 lwz r11, 0(r11); /* Get L1 entry */ \ 341 rlwinm. r12, r11, 0, 0, 19; /* Extract L2 (pte) base address */ \ 342 beq 2f; /* Bail if no table */ \ 343 rlwimi r12, r10, 22, 20, 29; /* Compute PTE address */ \ 344 lwz r11, 0(r12); /* Get Linux PTE */ 345#endif 346 347/* 348 * Interrupt vector entry code 349 * 350 * The Book E MMUs are always on so we don't need to handle 351 * interrupts in real mode as with previous PPC processors. In 352 * this case we handle interrupts in the kernel virtual address 353 * space. 354 * 355 * Interrupt vectors are dynamically placed relative to the 356 * interrupt prefix as determined by the address of interrupt_base. 357 * The interrupt vectors offsets are programmed using the labels 358 * for each interrupt vector entry. 359 * 360 * Interrupt vectors must be aligned on a 16 byte boundary. 361 * We align on a 32 byte cache line boundary for good measure. 362 */ 363 364interrupt_base: 365 /* Critical Input Interrupt */ 366 CRITICAL_EXCEPTION(0x0100, CRITICAL, CriticalInput, unknown_exception) 367 368 /* Machine Check Interrupt */ 369#ifdef CONFIG_E200 370 /* no RFMCI, MCSRRs on E200 */ 371 CRITICAL_EXCEPTION(0x0200, MACHINE_CHECK, MachineCheck, \ 372 machine_check_exception) 373#else 374 MCHECK_EXCEPTION(0x0200, MachineCheck, machine_check_exception) 375#endif 376 377 /* Data Storage Interrupt */ 378 START_EXCEPTION(DataStorage) 379 NORMAL_EXCEPTION_PROLOG(DATA_STORAGE) 380 mfspr r5,SPRN_ESR /* Grab the ESR, save it, pass arg3 */ 381 stw r5,_ESR(r11) 382 mfspr r4,SPRN_DEAR /* Grab the DEAR, save it, pass arg2 */ 383 andis. r10,r5,(ESR_ILK|ESR_DLK)@h 384 bne 1f 385 EXC_XFER_LITE(0x0300, handle_page_fault) 3861: 387 addi r3,r1,STACK_FRAME_OVERHEAD 388 EXC_XFER_EE_LITE(0x0300, CacheLockingException) 389 390 /* Instruction Storage Interrupt */ 391 INSTRUCTION_STORAGE_EXCEPTION 392 393 /* External Input Interrupt */ 394 EXCEPTION(0x0500, EXTERNAL, ExternalInput, do_IRQ, EXC_XFER_LITE) 395 396 /* Alignment Interrupt */ 397 ALIGNMENT_EXCEPTION 398 399 /* Program Interrupt */ 400 PROGRAM_EXCEPTION 401 402 /* Floating Point Unavailable Interrupt */ 403#ifdef CONFIG_PPC_FPU 404 FP_UNAVAILABLE_EXCEPTION 405#else 406#ifdef CONFIG_E200 407 /* E200 treats 'normal' floating point instructions as FP Unavail exception */ 408 EXCEPTION(0x0800, FP_UNAVAIL, FloatingPointUnavailable, \ 409 program_check_exception, EXC_XFER_EE) 410#else 411 EXCEPTION(0x0800, FP_UNAVAIL, FloatingPointUnavailable, \ 412 unknown_exception, EXC_XFER_EE) 413#endif 414#endif 415 416 /* System Call Interrupt */ 417 START_EXCEPTION(SystemCall) 418 NORMAL_EXCEPTION_PROLOG(SYSCALL) 419 EXC_XFER_EE_LITE(0x0c00, DoSyscall) 420 421 /* Auxiliary Processor Unavailable Interrupt */ 422 EXCEPTION(0x2900, AP_UNAVAIL, AuxillaryProcessorUnavailable, \ 423 unknown_exception, EXC_XFER_EE) 424 425 /* Decrementer Interrupt */ 426 DECREMENTER_EXCEPTION 427 428 /* Fixed Internal Timer Interrupt */ 429 /* TODO: Add FIT support */ 430 EXCEPTION(0x3100, FIT, FixedIntervalTimer, \ 431 unknown_exception, EXC_XFER_EE) 432 433 /* Watchdog Timer Interrupt */ 434#ifdef CONFIG_BOOKE_WDT 435 CRITICAL_EXCEPTION(0x3200, WATCHDOG, WatchdogTimer, WatchdogException) 436#else 437 CRITICAL_EXCEPTION(0x3200, WATCHDOG, WatchdogTimer, unknown_exception) 438#endif 439 440 /* Data TLB Error Interrupt */ 441 START_EXCEPTION(DataTLBError) 442 mtspr SPRN_SPRG_WSCRATCH0, r10 /* Save some working registers */ 443 mfspr r10, SPRN_SPRG_THREAD 444 stw r11, THREAD_NORMSAVE(0)(r10) 445#ifdef CONFIG_KVM_BOOKE_HV 446BEGIN_FTR_SECTION 447 mfspr r11, SPRN_SRR1 448END_FTR_SECTION_IFSET(CPU_FTR_EMB_HV) 449#endif 450 stw r12, THREAD_NORMSAVE(1)(r10) 451 stw r13, THREAD_NORMSAVE(2)(r10) 452 mfcr r13 453 stw r13, THREAD_NORMSAVE(3)(r10) 454 DO_KVM BOOKE_INTERRUPT_DTLB_MISS SPRN_SRR1 455START_BTB_FLUSH_SECTION 456 mfspr r11, SPRN_SRR1 457 andi. r10,r11,MSR_PR 458 beq 1f 459 BTB_FLUSH(r10) 4601: 461END_BTB_FLUSH_SECTION 462 mfspr r10, SPRN_DEAR /* Get faulting address */ 463 464 /* If we are faulting a kernel address, we have to use the 465 * kernel page tables. 466 */ 467 lis r11, PAGE_OFFSET@h 468 cmplw 5, r10, r11 469 blt 5, 3f 470 lis r11, swapper_pg_dir@h 471 ori r11, r11, swapper_pg_dir@l 472 473 mfspr r12,SPRN_MAS1 /* Set TID to 0 */ 474 rlwinm r12,r12,0,16,1 475 mtspr SPRN_MAS1,r12 476 477 b 4f 478 479 /* Get the PGD for the current thread */ 4803: 481 mfspr r11,SPRN_SPRG_THREAD 482 lwz r11,PGDIR(r11) 483 4844: 485 /* Mask of required permission bits. Note that while we 486 * do copy ESR:ST to _PAGE_RW position as trying to write 487 * to an RO page is pretty common, we don't do it with 488 * _PAGE_DIRTY. We could do it, but it's a fairly rare 489 * event so I'd rather take the overhead when it happens 490 * rather than adding an instruction here. We should measure 491 * whether the whole thing is worth it in the first place 492 * as we could avoid loading SPRN_ESR completely in the first 493 * place... 494 * 495 * TODO: Is it worth doing that mfspr & rlwimi in the first 496 * place or can we save a couple of instructions here ? 497 */ 498 mfspr r12,SPRN_ESR 499#ifdef CONFIG_PTE_64BIT 500 li r13,_PAGE_PRESENT 501 oris r13,r13,_PAGE_ACCESSED@h 502#else 503 li r13,_PAGE_PRESENT|_PAGE_ACCESSED 504#endif 505 rlwimi r13,r12,11,29,29 506 507 FIND_PTE 508 andc. r13,r13,r11 /* Check permission */ 509 510#ifdef CONFIG_PTE_64BIT 511#ifdef CONFIG_SMP 512 subf r13,r11,r12 /* create false data dep */ 513 lwzx r13,r11,r13 /* Get upper pte bits */ 514#else 515 lwz r13,0(r12) /* Get upper pte bits */ 516#endif 517#endif 518 519 bne 2f /* Bail if permission/valid mismach */ 520 521 /* Jump to common tlb load */ 522 b finish_tlb_load 5232: 524 /* The bailout. Restore registers to pre-exception conditions 525 * and call the heavyweights to help us out. 526 */ 527 mfspr r10, SPRN_SPRG_THREAD 528 lwz r11, THREAD_NORMSAVE(3)(r10) 529 mtcr r11 530 lwz r13, THREAD_NORMSAVE(2)(r10) 531 lwz r12, THREAD_NORMSAVE(1)(r10) 532 lwz r11, THREAD_NORMSAVE(0)(r10) 533 mfspr r10, SPRN_SPRG_RSCRATCH0 534 b DataStorage 535 536 /* Instruction TLB Error Interrupt */ 537 /* 538 * Nearly the same as above, except we get our 539 * information from different registers and bailout 540 * to a different point. 541 */ 542 START_EXCEPTION(InstructionTLBError) 543 mtspr SPRN_SPRG_WSCRATCH0, r10 /* Save some working registers */ 544 mfspr r10, SPRN_SPRG_THREAD 545 stw r11, THREAD_NORMSAVE(0)(r10) 546#ifdef CONFIG_KVM_BOOKE_HV 547BEGIN_FTR_SECTION 548 mfspr r11, SPRN_SRR1 549END_FTR_SECTION_IFSET(CPU_FTR_EMB_HV) 550#endif 551 stw r12, THREAD_NORMSAVE(1)(r10) 552 stw r13, THREAD_NORMSAVE(2)(r10) 553 mfcr r13 554 stw r13, THREAD_NORMSAVE(3)(r10) 555 DO_KVM BOOKE_INTERRUPT_ITLB_MISS SPRN_SRR1 556START_BTB_FLUSH_SECTION 557 mfspr r11, SPRN_SRR1 558 andi. r10,r11,MSR_PR 559 beq 1f 560 BTB_FLUSH(r10) 5611: 562END_BTB_FLUSH_SECTION 563 564 mfspr r10, SPRN_SRR0 /* Get faulting address */ 565 566 /* If we are faulting a kernel address, we have to use the 567 * kernel page tables. 568 */ 569 lis r11, PAGE_OFFSET@h 570 cmplw 5, r10, r11 571 blt 5, 3f 572 lis r11, swapper_pg_dir@h 573 ori r11, r11, swapper_pg_dir@l 574 575 mfspr r12,SPRN_MAS1 /* Set TID to 0 */ 576 rlwinm r12,r12,0,16,1 577 mtspr SPRN_MAS1,r12 578 579 /* Make up the required permissions for kernel code */ 580#ifdef CONFIG_PTE_64BIT 581 li r13,_PAGE_PRESENT | _PAGE_BAP_SX 582 oris r13,r13,_PAGE_ACCESSED@h 583#else 584 li r13,_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_EXEC 585#endif 586 b 4f 587 588 /* Get the PGD for the current thread */ 5893: 590 mfspr r11,SPRN_SPRG_THREAD 591 lwz r11,PGDIR(r11) 592 593 /* Make up the required permissions for user code */ 594#ifdef CONFIG_PTE_64BIT 595 li r13,_PAGE_PRESENT | _PAGE_BAP_UX 596 oris r13,r13,_PAGE_ACCESSED@h 597#else 598 li r13,_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_EXEC 599#endif 600 6014: 602 FIND_PTE 603 andc. r13,r13,r11 /* Check permission */ 604 605#ifdef CONFIG_PTE_64BIT 606#ifdef CONFIG_SMP 607 subf r13,r11,r12 /* create false data dep */ 608 lwzx r13,r11,r13 /* Get upper pte bits */ 609#else 610 lwz r13,0(r12) /* Get upper pte bits */ 611#endif 612#endif 613 614 bne 2f /* Bail if permission mismach */ 615 616 /* Jump to common TLB load point */ 617 b finish_tlb_load 618 6192: 620 /* The bailout. Restore registers to pre-exception conditions 621 * and call the heavyweights to help us out. 622 */ 623 mfspr r10, SPRN_SPRG_THREAD 624 lwz r11, THREAD_NORMSAVE(3)(r10) 625 mtcr r11 626 lwz r13, THREAD_NORMSAVE(2)(r10) 627 lwz r12, THREAD_NORMSAVE(1)(r10) 628 lwz r11, THREAD_NORMSAVE(0)(r10) 629 mfspr r10, SPRN_SPRG_RSCRATCH0 630 b InstructionStorage 631 632/* Define SPE handlers for e200 and e500v2 */ 633#ifdef CONFIG_SPE 634 /* SPE Unavailable */ 635 START_EXCEPTION(SPEUnavailable) 636 NORMAL_EXCEPTION_PROLOG(SPE_UNAVAIL) 637 beq 1f 638 bl load_up_spe 639 b fast_exception_return 6401: addi r3,r1,STACK_FRAME_OVERHEAD 641 EXC_XFER_EE_LITE(0x2010, KernelSPE) 642#elif defined(CONFIG_SPE_POSSIBLE) 643 EXCEPTION(0x2020, SPE_UNAVAIL, SPEUnavailable, \ 644 unknown_exception, EXC_XFER_EE) 645#endif /* CONFIG_SPE_POSSIBLE */ 646 647 /* SPE Floating Point Data */ 648#ifdef CONFIG_SPE 649 EXCEPTION(0x2030, SPE_FP_DATA, SPEFloatingPointData, 650 SPEFloatingPointException, EXC_XFER_EE) 651 652 /* SPE Floating Point Round */ 653 EXCEPTION(0x2050, SPE_FP_ROUND, SPEFloatingPointRound, \ 654 SPEFloatingPointRoundException, EXC_XFER_EE) 655#elif defined(CONFIG_SPE_POSSIBLE) 656 EXCEPTION(0x2040, SPE_FP_DATA, SPEFloatingPointData, 657 unknown_exception, EXC_XFER_EE) 658 EXCEPTION(0x2050, SPE_FP_ROUND, SPEFloatingPointRound, \ 659 unknown_exception, EXC_XFER_EE) 660#endif /* CONFIG_SPE_POSSIBLE */ 661 662 663 /* Performance Monitor */ 664 EXCEPTION(0x2060, PERFORMANCE_MONITOR, PerformanceMonitor, \ 665 performance_monitor_exception, EXC_XFER_STD) 666 667 EXCEPTION(0x2070, DOORBELL, Doorbell, doorbell_exception, EXC_XFER_STD) 668 669 CRITICAL_EXCEPTION(0x2080, DOORBELL_CRITICAL, \ 670 CriticalDoorbell, unknown_exception) 671 672 /* Debug Interrupt */ 673 DEBUG_DEBUG_EXCEPTION 674 DEBUG_CRIT_EXCEPTION 675 676 GUEST_DOORBELL_EXCEPTION 677 678 CRITICAL_EXCEPTION(0, GUEST_DBELL_CRIT, CriticalGuestDoorbell, \ 679 unknown_exception) 680 681 /* Hypercall */ 682 EXCEPTION(0, HV_SYSCALL, Hypercall, unknown_exception, EXC_XFER_EE) 683 684 /* Embedded Hypervisor Privilege */ 685 EXCEPTION(0, HV_PRIV, Ehvpriv, unknown_exception, EXC_XFER_EE) 686 687interrupt_end: 688 689/* 690 * Local functions 691 */ 692 693/* 694 * Both the instruction and data TLB miss get to this 695 * point to load the TLB. 696 * r10 - tsize encoding (if HUGETLB_PAGE) or available to use 697 * r11 - TLB (info from Linux PTE) 698 * r12 - available to use 699 * r13 - upper bits of PTE (if PTE_64BIT) or available to use 700 * CR5 - results of addr >= PAGE_OFFSET 701 * MAS0, MAS1 - loaded with proper value when we get here 702 * MAS2, MAS3 - will need additional info from Linux PTE 703 * Upon exit, we reload everything and RFI. 704 */ 705finish_tlb_load: 706#ifdef CONFIG_HUGETLB_PAGE 707 cmpwi 6, r10, 0 /* check for huge page */ 708 beq 6, finish_tlb_load_cont /* !huge */ 709 710 /* Alas, we need more scratch registers for hugepages */ 711 mfspr r12, SPRN_SPRG_THREAD 712 stw r14, THREAD_NORMSAVE(4)(r12) 713 stw r15, THREAD_NORMSAVE(5)(r12) 714 stw r16, THREAD_NORMSAVE(6)(r12) 715 stw r17, THREAD_NORMSAVE(7)(r12) 716 717 /* Get the next_tlbcam_idx percpu var */ 718#ifdef CONFIG_SMP 719 lwz r12, THREAD_INFO-THREAD(r12) 720 lwz r15, TI_CPU(r12) 721 lis r14, __per_cpu_offset@h 722 ori r14, r14, __per_cpu_offset@l 723 rlwinm r15, r15, 2, 0, 29 724 lwzx r16, r14, r15 725#else 726 li r16, 0 727#endif 728 lis r17, next_tlbcam_idx@h 729 ori r17, r17, next_tlbcam_idx@l 730 add r17, r17, r16 /* r17 = *next_tlbcam_idx */ 731 lwz r15, 0(r17) /* r15 = next_tlbcam_idx */ 732 733 lis r14, MAS0_TLBSEL(1)@h /* select TLB1 (TLBCAM) */ 734 rlwimi r14, r15, 16, 4, 15 /* next_tlbcam_idx entry */ 735 mtspr SPRN_MAS0, r14 736 737 /* Extract TLB1CFG(NENTRY) */ 738 mfspr r16, SPRN_TLB1CFG 739 andi. r16, r16, 0xfff 740 741 /* Update next_tlbcam_idx, wrapping when necessary */ 742 addi r15, r15, 1 743 cmpw r15, r16 744 blt 100f 745 lis r14, tlbcam_index@h 746 ori r14, r14, tlbcam_index@l 747 lwz r15, 0(r14) 748100: stw r15, 0(r17) 749 750 /* 751 * Calc MAS1_TSIZE from r10 (which has pshift encoded) 752 * tlb_enc = (pshift - 10). 753 */ 754 subi r15, r10, 10 755 mfspr r16, SPRN_MAS1 756 rlwimi r16, r15, 7, 20, 24 757 mtspr SPRN_MAS1, r16 758 759 /* copy the pshift for use later */ 760 mr r14, r10 761 762 /* fall through */ 763 764#endif /* CONFIG_HUGETLB_PAGE */ 765 766 /* 767 * We set execute, because we don't have the granularity to 768 * properly set this at the page level (Linux problem). 769 * Many of these bits are software only. Bits we don't set 770 * here we (properly should) assume have the appropriate value. 771 */ 772finish_tlb_load_cont: 773#ifdef CONFIG_PTE_64BIT 774 rlwinm r12, r11, 32-2, 26, 31 /* Move in perm bits */ 775 andi. r10, r11, _PAGE_DIRTY 776 bne 1f 777 li r10, MAS3_SW | MAS3_UW 778 andc r12, r12, r10 7791: rlwimi r12, r13, 20, 0, 11 /* grab RPN[32:43] */ 780 rlwimi r12, r11, 20, 12, 19 /* grab RPN[44:51] */ 7812: mtspr SPRN_MAS3, r12 782BEGIN_MMU_FTR_SECTION 783 srwi r10, r13, 12 /* grab RPN[12:31] */ 784 mtspr SPRN_MAS7, r10 785END_MMU_FTR_SECTION_IFSET(MMU_FTR_BIG_PHYS) 786#else 787 li r10, (_PAGE_EXEC | _PAGE_PRESENT) 788 mr r13, r11 789 rlwimi r10, r11, 31, 29, 29 /* extract _PAGE_DIRTY into SW */ 790 and r12, r11, r10 791 andi. r10, r11, _PAGE_USER /* Test for _PAGE_USER */ 792 slwi r10, r12, 1 793 or r10, r10, r12 794 iseleq r12, r12, r10 795 rlwimi r13, r12, 0, 20, 31 /* Get RPN from PTE, merge w/ perms */ 796 mtspr SPRN_MAS3, r13 797#endif 798 799 mfspr r12, SPRN_MAS2 800#ifdef CONFIG_PTE_64BIT 801 rlwimi r12, r11, 32-19, 27, 31 /* extract WIMGE from pte */ 802#else 803 rlwimi r12, r11, 26, 27, 31 /* extract WIMGE from pte */ 804#endif 805#ifdef CONFIG_HUGETLB_PAGE 806 beq 6, 3f /* don't mask if page isn't huge */ 807 li r13, 1 808 slw r13, r13, r14 809 subi r13, r13, 1 810 rlwinm r13, r13, 0, 0, 19 /* bottom bits used for WIMGE/etc */ 811 andc r12, r12, r13 /* mask off ea bits within the page */ 812#endif 8133: mtspr SPRN_MAS2, r12 814 815#ifdef CONFIG_E200 816 /* Round robin TLB1 entries assignment */ 817 mfspr r12, SPRN_MAS0 818 819 /* Extract TLB1CFG(NENTRY) */ 820 mfspr r11, SPRN_TLB1CFG 821 andi. r11, r11, 0xfff 822 823 /* Extract MAS0(NV) */ 824 andi. r13, r12, 0xfff 825 addi r13, r13, 1 826 cmpw 0, r13, r11 827 addi r12, r12, 1 828 829 /* check if we need to wrap */ 830 blt 7f 831 832 /* wrap back to first free tlbcam entry */ 833 lis r13, tlbcam_index@ha 834 lwz r13, tlbcam_index@l(r13) 835 rlwimi r12, r13, 0, 20, 31 8367: 837 mtspr SPRN_MAS0,r12 838#endif /* CONFIG_E200 */ 839 840tlb_write_entry: 841 tlbwe 842 843 /* Done...restore registers and get out of here. */ 844 mfspr r10, SPRN_SPRG_THREAD 845#ifdef CONFIG_HUGETLB_PAGE 846 beq 6, 8f /* skip restore for 4k page faults */ 847 lwz r14, THREAD_NORMSAVE(4)(r10) 848 lwz r15, THREAD_NORMSAVE(5)(r10) 849 lwz r16, THREAD_NORMSAVE(6)(r10) 850 lwz r17, THREAD_NORMSAVE(7)(r10) 851#endif 8528: lwz r11, THREAD_NORMSAVE(3)(r10) 853 mtcr r11 854 lwz r13, THREAD_NORMSAVE(2)(r10) 855 lwz r12, THREAD_NORMSAVE(1)(r10) 856 lwz r11, THREAD_NORMSAVE(0)(r10) 857 mfspr r10, SPRN_SPRG_RSCRATCH0 858 rfi /* Force context change */ 859 860#ifdef CONFIG_SPE 861/* Note that the SPE support is closely modeled after the AltiVec 862 * support. Changes to one are likely to be applicable to the 863 * other! */ 864_GLOBAL(load_up_spe) 865/* 866 * Disable SPE for the task which had SPE previously, 867 * and save its SPE registers in its thread_struct. 868 * Enables SPE for use in the kernel on return. 869 * On SMP we know the SPE units are free, since we give it up every 870 * switch. -- Kumar 871 */ 872 mfmsr r5 873 oris r5,r5,MSR_SPE@h 874 mtmsr r5 /* enable use of SPE now */ 875 isync 876 /* enable use of SPE after return */ 877 oris r9,r9,MSR_SPE@h 878 mfspr r5,SPRN_SPRG_THREAD /* current task's THREAD (phys) */ 879 li r4,1 880 li r10,THREAD_ACC 881 stw r4,THREAD_USED_SPE(r5) 882 evlddx evr4,r10,r5 883 evmra evr4,evr4 884 REST_32EVRS(0,r10,r5,THREAD_EVR0) 885 blr 886 887/* 888 * SPE unavailable trap from kernel - print a message, but let 889 * the task use SPE in the kernel until it returns to user mode. 890 */ 891KernelSPE: 892 lwz r3,_MSR(r1) 893 oris r3,r3,MSR_SPE@h 894 stw r3,_MSR(r1) /* enable use of SPE after return */ 895#ifdef CONFIG_PRINTK 896 lis r3,87f@h 897 ori r3,r3,87f@l 898 mr r4,r2 /* current */ 899 lwz r5,_NIP(r1) 900 bl printk 901#endif 902 b ret_from_except 903#ifdef CONFIG_PRINTK 90487: .string "SPE used in kernel (task=%p, pc=%x) \n" 905#endif 906 .align 4,0 907 908#endif /* CONFIG_SPE */ 909 910/* 911 * Translate the effec addr in r3 to phys addr. The phys addr will be put 912 * into r3(higher 32bit) and r4(lower 32bit) 913 */ 914get_phys_addr: 915 mfmsr r8 916 mfspr r9,SPRN_PID 917 rlwinm r9,r9,16,0x3fff0000 /* turn PID into MAS6[SPID] */ 918 rlwimi r9,r8,28,0x00000001 /* turn MSR[DS] into MAS6[SAS] */ 919 mtspr SPRN_MAS6,r9 920 921 tlbsx 0,r3 /* must succeed */ 922 923 mfspr r8,SPRN_MAS1 924 mfspr r12,SPRN_MAS3 925 rlwinm r9,r8,25,0x1f /* r9 = log2(page size) */ 926 li r10,1024 927 slw r10,r10,r9 /* r10 = page size */ 928 addi r10,r10,-1 929 and r11,r3,r10 /* r11 = page offset */ 930 andc r4,r12,r10 /* r4 = page base */ 931 or r4,r4,r11 /* r4 = devtree phys addr */ 932#ifdef CONFIG_PHYS_64BIT 933 mfspr r3,SPRN_MAS7 934#endif 935 blr 936 937/* 938 * Global functions 939 */ 940 941#ifdef CONFIG_E200 942/* Adjust or setup IVORs for e200 */ 943_GLOBAL(__setup_e200_ivors) 944 li r3,DebugDebug@l 945 mtspr SPRN_IVOR15,r3 946 li r3,SPEUnavailable@l 947 mtspr SPRN_IVOR32,r3 948 li r3,SPEFloatingPointData@l 949 mtspr SPRN_IVOR33,r3 950 li r3,SPEFloatingPointRound@l 951 mtspr SPRN_IVOR34,r3 952 sync 953 blr 954#endif 955 956#ifdef CONFIG_E500 957#ifndef CONFIG_PPC_E500MC 958/* Adjust or setup IVORs for e500v1/v2 */ 959_GLOBAL(__setup_e500_ivors) 960 li r3,DebugCrit@l 961 mtspr SPRN_IVOR15,r3 962 li r3,SPEUnavailable@l 963 mtspr SPRN_IVOR32,r3 964 li r3,SPEFloatingPointData@l 965 mtspr SPRN_IVOR33,r3 966 li r3,SPEFloatingPointRound@l 967 mtspr SPRN_IVOR34,r3 968 li r3,PerformanceMonitor@l 969 mtspr SPRN_IVOR35,r3 970 sync 971 blr 972#else 973/* Adjust or setup IVORs for e500mc */ 974_GLOBAL(__setup_e500mc_ivors) 975 li r3,DebugDebug@l 976 mtspr SPRN_IVOR15,r3 977 li r3,PerformanceMonitor@l 978 mtspr SPRN_IVOR35,r3 979 li r3,Doorbell@l 980 mtspr SPRN_IVOR36,r3 981 li r3,CriticalDoorbell@l 982 mtspr SPRN_IVOR37,r3 983 sync 984 blr 985 986/* setup ehv ivors for */ 987_GLOBAL(__setup_ehv_ivors) 988 li r3,GuestDoorbell@l 989 mtspr SPRN_IVOR38,r3 990 li r3,CriticalGuestDoorbell@l 991 mtspr SPRN_IVOR39,r3 992 li r3,Hypercall@l 993 mtspr SPRN_IVOR40,r3 994 li r3,Ehvpriv@l 995 mtspr SPRN_IVOR41,r3 996 sync 997 blr 998#endif /* CONFIG_PPC_E500MC */ 999#endif /* CONFIG_E500 */ 1000 1001#ifdef CONFIG_SPE 1002/* 1003 * extern void __giveup_spe(struct task_struct *prev) 1004 * 1005 */ 1006_GLOBAL(__giveup_spe) 1007 addi r3,r3,THREAD /* want THREAD of task */ 1008 lwz r5,PT_REGS(r3) 1009 cmpi 0,r5,0 1010 SAVE_32EVRS(0, r4, r3, THREAD_EVR0) 1011 evxor evr6, evr6, evr6 /* clear out evr6 */ 1012 evmwumiaa evr6, evr6, evr6 /* evr6 <- ACC = 0 * 0 + ACC */ 1013 li r4,THREAD_ACC 1014 evstddx evr6, r4, r3 /* save off accumulator */ 1015 beq 1f 1016 lwz r4,_MSR-STACK_FRAME_OVERHEAD(r5) 1017 lis r3,MSR_SPE@h 1018 andc r4,r4,r3 /* disable SPE for previous task */ 1019 stw r4,_MSR-STACK_FRAME_OVERHEAD(r5) 10201: 1021 blr 1022#endif /* CONFIG_SPE */ 1023 1024/* 1025 * extern void abort(void) 1026 * 1027 * At present, this routine just applies a system reset. 1028 */ 1029_GLOBAL(abort) 1030 li r13,0 1031 mtspr SPRN_DBCR0,r13 /* disable all debug events */ 1032 isync 1033 mfmsr r13 1034 ori r13,r13,MSR_DE@l /* Enable Debug Events */ 1035 mtmsr r13 1036 isync 1037 mfspr r13,SPRN_DBCR0 1038 lis r13,(DBCR0_IDM|DBCR0_RST_CHIP)@h 1039 mtspr SPRN_DBCR0,r13 1040 isync 1041 1042_GLOBAL(set_context) 1043 1044#ifdef CONFIG_BDI_SWITCH 1045 /* Context switch the PTE pointer for the Abatron BDI2000. 1046 * The PGDIR is the second parameter. 1047 */ 1048 lis r5, abatron_pteptrs@h 1049 ori r5, r5, abatron_pteptrs@l 1050 stw r4, 0x4(r5) 1051#endif 1052 mtspr SPRN_PID,r3 1053 isync /* Force context change */ 1054 blr 1055 1056#ifdef CONFIG_SMP 1057/* When we get here, r24 needs to hold the CPU # */ 1058 .globl __secondary_start 1059__secondary_start: 1060 LOAD_REG_ADDR_PIC(r3, tlbcam_index) 1061 lwz r3,0(r3) 1062 mtctr r3 1063 li r26,0 /* r26 safe? */ 1064 1065 bl switch_to_as1 1066 mr r27,r3 /* tlb entry */ 1067 /* Load each CAM entry */ 10681: mr r3,r26 1069 bl loadcam_entry 1070 addi r26,r26,1 1071 bdnz 1b 1072 mr r3,r27 /* tlb entry */ 1073 LOAD_REG_ADDR_PIC(r4, memstart_addr) 1074 lwz r4,0(r4) 1075 mr r5,r25 /* phys kernel start */ 1076 rlwinm r5,r5,0,~0x3ffffff /* aligned 64M */ 1077 subf r4,r5,r4 /* memstart_addr - phys kernel start */ 1078 li r5,0 /* no device tree */ 1079 li r6,0 /* not boot cpu */ 1080 bl restore_to_as0 1081 1082 1083 lis r3,__secondary_hold_acknowledge@h 1084 ori r3,r3,__secondary_hold_acknowledge@l 1085 stw r24,0(r3) 1086 1087 li r3,0 1088 mr r4,r24 /* Why? */ 1089 bl call_setup_cpu 1090 1091 /* get current_thread_info and current */ 1092 lis r1,secondary_ti@ha 1093 lwz r1,secondary_ti@l(r1) 1094 lwz r2,TI_TASK(r1) 1095 1096 /* stack */ 1097 addi r1,r1,THREAD_SIZE-STACK_FRAME_OVERHEAD 1098 li r0,0 1099 stw r0,0(r1) 1100 1101 /* ptr to current thread */ 1102 addi r4,r2,THREAD /* address of our thread_struct */ 1103 mtspr SPRN_SPRG_THREAD,r4 1104 1105 /* Setup the defaults for TLB entries */ 1106 li r4,(MAS4_TSIZED(BOOK3E_PAGESZ_4K))@l 1107 mtspr SPRN_MAS4,r4 1108 1109 /* Jump to start_secondary */ 1110 lis r4,MSR_KERNEL@h 1111 ori r4,r4,MSR_KERNEL@l 1112 lis r3,start_secondary@h 1113 ori r3,r3,start_secondary@l 1114 mtspr SPRN_SRR0,r3 1115 mtspr SPRN_SRR1,r4 1116 sync 1117 rfi 1118 sync 1119 1120 .globl __secondary_hold_acknowledge 1121__secondary_hold_acknowledge: 1122 .long -1 1123#endif 1124 1125/* 1126 * Create a tlb entry with the same effective and physical address as 1127 * the tlb entry used by the current running code. But set the TS to 1. 1128 * Then switch to the address space 1. It will return with the r3 set to 1129 * the ESEL of the new created tlb. 1130 */ 1131_GLOBAL(switch_to_as1) 1132 mflr r5 1133 1134 /* Find a entry not used */ 1135 mfspr r3,SPRN_TLB1CFG 1136 andi. r3,r3,0xfff 1137 mfspr r4,SPRN_PID 1138 rlwinm r4,r4,16,0x3fff0000 /* turn PID into MAS6[SPID] */ 1139 mtspr SPRN_MAS6,r4 11401: lis r4,0x1000 /* Set MAS0(TLBSEL) = 1 */ 1141 addi r3,r3,-1 1142 rlwimi r4,r3,16,4,15 /* Setup MAS0 = TLBSEL | ESEL(r3) */ 1143 mtspr SPRN_MAS0,r4 1144 tlbre 1145 mfspr r4,SPRN_MAS1 1146 andis. r4,r4,MAS1_VALID@h 1147 bne 1b 1148 1149 /* Get the tlb entry used by the current running code */ 1150 bl 0f 11510: mflr r4 1152 tlbsx 0,r4 1153 1154 mfspr r4,SPRN_MAS1 1155 ori r4,r4,MAS1_TS /* Set the TS = 1 */ 1156 mtspr SPRN_MAS1,r4 1157 1158 mfspr r4,SPRN_MAS0 1159 rlwinm r4,r4,0,~MAS0_ESEL_MASK 1160 rlwimi r4,r3,16,4,15 /* Setup MAS0 = TLBSEL | ESEL(r3) */ 1161 mtspr SPRN_MAS0,r4 1162 tlbwe 1163 isync 1164 sync 1165 1166 mfmsr r4 1167 ori r4,r4,MSR_IS | MSR_DS 1168 mtspr SPRN_SRR0,r5 1169 mtspr SPRN_SRR1,r4 1170 sync 1171 rfi 1172 1173/* 1174 * Restore to the address space 0 and also invalidate the tlb entry created 1175 * by switch_to_as1. 1176 * r3 - the tlb entry which should be invalidated 1177 * r4 - __pa(PAGE_OFFSET in AS1) - __pa(PAGE_OFFSET in AS0) 1178 * r5 - device tree virtual address. If r4 is 0, r5 is ignored. 1179 * r6 - boot cpu 1180*/ 1181_GLOBAL(restore_to_as0) 1182 mflr r0 1183 1184 bl 0f 11850: mflr r9 1186 addi r9,r9,1f - 0b 1187 1188 /* 1189 * We may map the PAGE_OFFSET in AS0 to a different physical address, 1190 * so we need calculate the right jump and device tree address based 1191 * on the offset passed by r4. 1192 */ 1193 add r9,r9,r4 1194 add r5,r5,r4 1195 add r0,r0,r4 1196 11972: mfmsr r7 1198 li r8,(MSR_IS | MSR_DS) 1199 andc r7,r7,r8 1200 1201 mtspr SPRN_SRR0,r9 1202 mtspr SPRN_SRR1,r7 1203 sync 1204 rfi 1205 1206 /* Invalidate the temporary tlb entry for AS1 */ 12071: lis r9,0x1000 /* Set MAS0(TLBSEL) = 1 */ 1208 rlwimi r9,r3,16,4,15 /* Setup MAS0 = TLBSEL | ESEL(r3) */ 1209 mtspr SPRN_MAS0,r9 1210 tlbre 1211 mfspr r9,SPRN_MAS1 1212 rlwinm r9,r9,0,2,31 /* Clear MAS1 Valid and IPPROT */ 1213 mtspr SPRN_MAS1,r9 1214 tlbwe 1215 isync 1216 1217 cmpwi r4,0 1218 cmpwi cr1,r6,0 1219 cror eq,4*cr1+eq,eq 1220 bne 3f /* offset != 0 && is_boot_cpu */ 1221 mtlr r0 1222 blr 1223 1224 /* 1225 * The PAGE_OFFSET will map to a different physical address, 1226 * jump to _start to do another relocation again. 1227 */ 12283: mr r3,r5 1229 bl _start 1230 1231/* 1232 * We put a few things here that have to be page-aligned. This stuff 1233 * goes at the beginning of the data segment, which is page-aligned. 1234 */ 1235 .data 1236 .align 12 1237 .globl sdata 1238sdata: 1239 .globl empty_zero_page 1240empty_zero_page: 1241 .space 4096 1242EXPORT_SYMBOL(empty_zero_page) 1243 .globl swapper_pg_dir 1244swapper_pg_dir: 1245 .space PGD_TABLE_SIZE 1246 1247/* 1248 * Room for two PTE pointers, usually the kernel and current user pointers 1249 * to their respective root page table. 1250 */ 1251abatron_pteptrs: 1252 .space 8 1253