diff options
Diffstat (limited to 'arch/powerpc/kernel/head_40x.S')
| -rw-r--r-- | arch/powerpc/kernel/head_40x.S | 721 |
1 files changed, 0 insertions, 721 deletions
diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S deleted file mode 100644 index 9fc90410b385..000000000000 --- a/arch/powerpc/kernel/head_40x.S +++ /dev/null @@ -1,721 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0-or-later */ -/* - * Copyright (c) 1995-1996 Gary Thomas <gdt@linuxppc.org> - * Initial PowerPC version. - * Copyright (c) 1996 Cort Dougan <cort@cs.nmt.edu> - * Rewritten for PReP - * Copyright (c) 1996 Paul Mackerras <paulus@cs.anu.edu.au> - * Low-level exception handers, MMU support, and rewrite. - * Copyright (c) 1997 Dan Malek <dmalek@jlc.net> - * PowerPC 8xx modifications. - * Copyright (c) 1998-1999 TiVo, Inc. - * PowerPC 403GCX modifications. - * Copyright (c) 1999 Grant Erickson <grant@lcse.umn.edu> - * PowerPC 403GCX/405GP modifications. - * Copyright 2000 MontaVista Software Inc. - * PPC405 modifications - * PowerPC 403GCX/405GP modifications. - * Author: MontaVista Software, Inc. - * frank_rowand@mvista.com or source@mvista.com - * debbie_chu@mvista.com - * - * Module name: head_4xx.S - * - * Description: - * Kernel execution entry point code. - */ - -#include <linux/init.h> -#include <linux/pgtable.h> -#include <linux/sizes.h> -#include <linux/linkage.h> - -#include <asm/processor.h> -#include <asm/page.h> -#include <asm/mmu.h> -#include <asm/cputable.h> -#include <asm/thread_info.h> -#include <asm/ppc_asm.h> -#include <asm/asm-offsets.h> -#include <asm/ptrace.h> - -#include "head_32.h" - -/* As with the other PowerPC ports, it is expected that when code - * execution begins here, the following registers contain valid, yet - * optional, information: - * - * r3 - Board info structure pointer (DRAM, frequency, MAC address, etc.) - * r4 - Starting address of the init RAM disk - * r5 - Ending address of the init RAM disk - * r6 - Start of kernel command line string (e.g. "mem=96m") - * r7 - End of kernel command line string - * - * This is all going to change RSN when we add bi_recs....... -- Dan - */ - __HEAD -_GLOBAL(_stext); -_GLOBAL(_start); - - mr r31,r3 /* save device tree ptr */ - - /* We have to turn on the MMU right away so we get cache modes - * set correctly. - */ - bl initial_mmu - -/* We now have the lower 16 Meg mapped into TLB entries, and the caches - * ready to work. - */ -turn_on_mmu: - lis r0,MSR_KERNEL@h - ori r0,r0,MSR_KERNEL@l - mtspr SPRN_SRR1,r0 - lis r0,start_here@h - ori r0,r0,start_here@l - mtspr SPRN_SRR0,r0 - rfi /* enables MMU */ - b . /* prevent prefetch past rfi */ - -/* - * This area is used for temporarily saving registers during the - * critical exception prolog. - */ - . = 0xc0 -crit_save: -_GLOBAL(crit_r10) - .space 4 -_GLOBAL(crit_r11) - .space 4 -_GLOBAL(crit_srr0) - .space 4 -_GLOBAL(crit_srr1) - .space 4 -_GLOBAL(crit_r1) - .space 4 -_GLOBAL(crit_dear) - .space 4 -_GLOBAL(crit_esr) - .space 4 - -/* - * Exception prolog for critical exceptions. This is a little different - * from the normal exception prolog above since a critical exception - * can potentially occur at any point during normal exception processing. - * Thus we cannot use the same SPRG registers as the normal prolog above. - * Instead we use a couple of words of memory at low physical addresses. - * This is OK since we don't support SMP on these processors. - */ -.macro CRITICAL_EXCEPTION_PROLOG trapno name - stw r10,crit_r10@l(0) /* save two registers to work with */ - stw r11,crit_r11@l(0) - mfspr r10,SPRN_SRR0 - mfspr r11,SPRN_SRR1 - stw r10,crit_srr0@l(0) - stw r11,crit_srr1@l(0) - mfspr r10,SPRN_DEAR - mfspr r11,SPRN_ESR - stw r10,crit_dear@l(0) - stw r11,crit_esr@l(0) - mfcr r10 /* save CR in r10 for now */ - mfspr r11,SPRN_SRR3 /* check whether user or kernel */ - andi. r11,r11,MSR_PR - lis r11,(critirq_ctx-PAGE_OFFSET)@ha - lwz r11,(critirq_ctx-PAGE_OFFSET)@l(r11) - beq 1f - /* COMING FROM USER MODE */ - mfspr r11,SPRN_SPRG_THREAD /* if from user, start at top of */ - lwz r11,TASK_STACK-THREAD(r11) /* this thread's kernel stack */ -1: stw r1,crit_r1@l(0) - addi r1,r11,THREAD_SIZE-INT_FRAME_SIZE /* Alloc an excpt frm */ - LOAD_REG_IMMEDIATE(r11, MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE)) /* re-enable MMU */ - mtspr SPRN_SRR1, r11 - lis r11, 1f@h - ori r11, r11, 1f@l - mtspr SPRN_SRR0, r11 - rfi - - .text -1: -\name\()_virt: - lwz r11,crit_r1@l(0) - stw r11,GPR1(r1) - stw r11,0(r1) - mr r11,r1 - stw r10,_CCR(r11) /* save various registers */ - stw r12,GPR12(r11) - stw r9,GPR9(r11) - mflr r10 - stw r10,_LINK(r11) - lis r9,PAGE_OFFSET@ha - lwz r10,crit_r10@l(r9) - lwz r12,crit_r11@l(r9) - stw r10,GPR10(r11) - stw r12,GPR11(r11) - lwz r12,crit_dear@l(r9) - lwz r9,crit_esr@l(r9) - stw r12,_DEAR(r11) /* since they may have had stuff */ - stw r9,_ESR(r11) /* exception was taken */ - mfspr r12,SPRN_SRR2 - mfspr r9,SPRN_SRR3 - rlwinm r9,r9,0,14,12 /* clear MSR_WE (necessary?) */ - COMMON_EXCEPTION_PROLOG_END \trapno + 2 -_ASM_NOKPROBE_SYMBOL(\name\()_virt) -.endm - - /* - * State at this point: - * r9 saved in stack frame, now saved SRR3 & ~MSR_WE - * r10 saved in crit_r10 and in stack frame, trashed - * r11 saved in crit_r11 and in stack frame, - * now phys stack/exception frame pointer - * r12 saved in stack frame, now saved SRR2 - * CR saved in stack frame, CR0.EQ = !SRR3.PR - * LR, DEAR, ESR in stack frame - * r1 saved in stack frame, now virt stack/excframe pointer - * r0, r3-r8 saved in stack frame - */ - -/* - * Exception vectors. - */ -#define CRITICAL_EXCEPTION(n, label, hdlr) \ - START_EXCEPTION(n, label); \ - CRITICAL_EXCEPTION_PROLOG n label; \ - prepare_transfer_to_handler; \ - bl hdlr; \ - b ret_from_crit_exc - -/* - * 0x0100 - Critical Interrupt Exception - */ - CRITICAL_EXCEPTION(0x0100, CriticalInterrupt, unknown_exception) - -/* - * 0x0200 - Machine Check Exception - */ - CRITICAL_EXCEPTION(0x0200, MachineCheck, machine_check_exception) - -/* - * 0x0300 - Data Storage Exception - * This happens for just a few reasons. U0 set (but we don't do that), - * or zone protection fault (user violation, write to protected page). - * The other Data TLB exceptions bail out to this point - * if they can't resolve the lightweight TLB fault. - */ - START_EXCEPTION(0x0300, DataStorage) - EXCEPTION_PROLOG 0x300 DataStorage handle_dar_dsisr=1 - prepare_transfer_to_handler - bl do_page_fault - b interrupt_return - -/* - * 0x0400 - Instruction Storage Exception - * This is caused by a fetch from non-execute or guarded pages. - */ - START_EXCEPTION(0x0400, InstructionAccess) - EXCEPTION_PROLOG 0x400 InstructionAccess - li r5,0 - stw r5, _ESR(r11) /* Zero ESR */ - stw r12, _DEAR(r11) /* SRR0 as DEAR */ - prepare_transfer_to_handler - bl do_page_fault - b interrupt_return - -/* 0x0500 - External Interrupt Exception */ - EXCEPTION(0x0500, HardwareInterrupt, do_IRQ) - -/* 0x0600 - Alignment Exception */ - START_EXCEPTION(0x0600, Alignment) - EXCEPTION_PROLOG 0x600 Alignment handle_dar_dsisr=1 - prepare_transfer_to_handler - bl alignment_exception - REST_NVGPRS(r1) - b interrupt_return - -/* 0x0700 - Program Exception */ - START_EXCEPTION(0x0700, ProgramCheck) - EXCEPTION_PROLOG 0x700 ProgramCheck handle_dar_dsisr=1 - prepare_transfer_to_handler - bl program_check_exception - REST_NVGPRS(r1) - b interrupt_return - - EXCEPTION(0x0800, Trap_08, unknown_exception) - EXCEPTION(0x0900, Trap_09, unknown_exception) - EXCEPTION(0x0A00, Trap_0A, unknown_exception) - EXCEPTION(0x0B00, Trap_0B, unknown_exception) - -/* 0x0C00 - System Call Exception */ - START_EXCEPTION(0x0C00, SystemCall) - SYSCALL_ENTRY 0xc00 -/* Trap_0D is commented out to get more space for system call exception */ - -/* EXCEPTION(0x0D00, Trap_0D, unknown_exception) */ - EXCEPTION(0x0E00, Trap_0E, unknown_exception) - EXCEPTION(0x0F00, Trap_0F, unknown_exception) - -/* 0x1000 - Programmable Interval Timer (PIT) Exception */ - START_EXCEPTION(0x1000, DecrementerTrap) - b Decrementer - -/* 0x1010 - Fixed Interval Timer (FIT) Exception */ - START_EXCEPTION(0x1010, FITExceptionTrap) - b FITException - -/* 0x1020 - Watchdog Timer (WDT) Exception */ - START_EXCEPTION(0x1020, WDTExceptionTrap) - b WDTException - -/* 0x1100 - Data TLB Miss Exception - * As the name implies, translation is not in the MMU, so search the - * page tables and fix it. The only purpose of this function is to - * load TLB entries from the page table if they exist. - */ - START_EXCEPTION(0x1100, DTLBMiss) - mtspr SPRN_SPRG_SCRATCH5, r10 /* Save some working registers */ - mtspr SPRN_SPRG_SCRATCH6, r11 - mtspr SPRN_SPRG_SCRATCH3, r12 - mtspr SPRN_SPRG_SCRATCH4, r9 - mfcr r12 - mfspr r9, SPRN_PID - rlwimi r12, r9, 0, 0xff - mfspr r10, SPRN_DEAR /* Get faulting address */ - - /* If we are faulting a kernel address, we have to use the - * kernel page tables. - */ - lis r11, PAGE_OFFSET@h - cmplw r10, r11 - blt+ 3f - lis r11, swapper_pg_dir@h - ori r11, r11, swapper_pg_dir@l - li r9, 0 - mtspr SPRN_PID, r9 /* TLB will have 0 TID */ - b 4f - - /* Get the PGD for the current thread. - */ -3: - mfspr r11,SPRN_SPRG_THREAD - lwz r11,PGDIR(r11) -#ifdef CONFIG_PPC_KUAP - rlwinm. r9, r9, 0, 0xff - beq 5f /* Kuap fault */ -#endif -4: - tophys(r11, r11) - rlwimi r11, r10, 12, 20, 29 /* Create L1 (pgdir/pmd) address */ - lwz r11, 0(r11) /* Get L1 entry */ - andi. r9, r11, _PMD_PRESENT /* Check if it points to a PTE page */ - beq 2f /* Bail if no table */ - - rlwimi r11, r10, 22, 20, 29 /* Compute PTE address */ - lwz r11, 0(r11) /* Get Linux PTE */ - li r9, _PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_READ - andc. r9, r9, r11 /* Check permission */ - bne 5f - - rlwinm r9, r11, 1, _PAGE_WRITE /* dirty => w */ - and r9, r9, r11 /* hwwrite = dirty & w */ - rlwimi r11, r9, 0, _PAGE_WRITE /* replace w by hwwrite */ - - /* Create TLB tag. This is the faulting address plus a static - * set of bits. These are size, valid, E, U0. - */ - li r9, 0x00c0 - rlwimi r10, r9, 0, 20, 31 - - b finish_tlb_load - -2: /* Check for possible large-page pmd entry */ - rlwinm. r9, r11, 2, 22, 24 - beq 5f - - /* Create TLB tag. This is the faulting address, plus a static - * set of bits (valid, E, U0) plus the size from the PMD. - */ - ori r9, r9, 0x40 - rlwimi r10, r9, 0, 20, 31 - - b finish_tlb_load - -5: - /* The bailout. Restore registers to pre-exception conditions - * and call the heavyweights to help us out. - */ - mtspr SPRN_PID, r12 - mtcrf 0x80, r12 - mfspr r9, SPRN_SPRG_SCRATCH4 - mfspr r12, SPRN_SPRG_SCRATCH3 - mfspr r11, SPRN_SPRG_SCRATCH6 - mfspr r10, SPRN_SPRG_SCRATCH5 - b DataStorage - -/* 0x1200 - Instruction TLB Miss Exception - * Nearly the same as above, except we get our information from different - * registers and bailout to a different point. - */ - START_EXCEPTION(0x1200, ITLBMiss) - mtspr SPRN_SPRG_SCRATCH5, r10 /* Save some working registers */ - mtspr SPRN_SPRG_SCRATCH6, r11 - mtspr SPRN_SPRG_SCRATCH3, r12 - mtspr SPRN_SPRG_SCRATCH4, r9 - mfcr r12 - mfspr r9, SPRN_PID - rlwimi r12, r9, 0, 0xff - mfspr r10, SPRN_SRR0 /* Get faulting address */ - - /* If we are faulting a kernel address, we have to use the - * kernel page tables. - */ - lis r11, PAGE_OFFSET@h - cmplw r10, r11 - blt+ 3f - lis r11, swapper_pg_dir@h - ori r11, r11, swapper_pg_dir@l - li r9, 0 - mtspr SPRN_PID, r9 /* TLB will have 0 TID */ - b 4f - - /* Get the PGD for the current thread. - */ -3: - mfspr r11,SPRN_SPRG_THREAD - lwz r11,PGDIR(r11) -#ifdef CONFIG_PPC_KUAP - rlwinm. r9, r9, 0, 0xff - beq 5f /* Kuap fault */ -#endif -4: - tophys(r11, r11) - rlwimi r11, r10, 12, 20, 29 /* Create L1 (pgdir/pmd) address */ - lwz r11, 0(r11) /* Get L1 entry */ - andi. r9, r11, _PMD_PRESENT /* Check if it points to a PTE page */ - beq 2f /* Bail if no table */ - - rlwimi r11, r10, 22, 20, 29 /* Compute PTE address */ - lwz r11, 0(r11) /* Get Linux PTE */ - li r9, _PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_EXEC - andc. r9, r9, r11 /* Check permission */ - bne 5f - - rlwinm r9, r11, 1, _PAGE_WRITE /* dirty => w */ - and r9, r9, r11 /* hwwrite = dirty & w */ - rlwimi r11, r9, 0, _PAGE_WRITE /* replace w by hwwrite */ - - /* Create TLB tag. This is the faulting address plus a static - * set of bits. These are size, valid, E, U0. - */ - li r9, 0x00c0 - rlwimi r10, r9, 0, 20, 31 - - b finish_tlb_load - -2: /* Check for possible large-page pmd entry */ - rlwinm. r9, r11, 2, 22, 24 - beq 5f - - /* Create TLB tag. This is the faulting address, plus a static - * set of bits (valid, E, U0) plus the size from the PMD. - */ - ori r9, r9, 0x40 - rlwimi r10, r9, 0, 20, 31 - - b finish_tlb_load - -5: - /* The bailout. Restore registers to pre-exception conditions - * and call the heavyweights to help us out. - */ - mtspr SPRN_PID, r12 - mtcrf 0x80, r12 - mfspr r9, SPRN_SPRG_SCRATCH4 - mfspr r12, SPRN_SPRG_SCRATCH3 - mfspr r11, SPRN_SPRG_SCRATCH6 - mfspr r10, SPRN_SPRG_SCRATCH5 - b InstructionAccess - - EXCEPTION(0x1300, Trap_13, unknown_exception) - EXCEPTION(0x1400, Trap_14, unknown_exception) - EXCEPTION(0x1500, Trap_15, unknown_exception) - EXCEPTION(0x1600, Trap_16, unknown_exception) - EXCEPTION(0x1700, Trap_17, unknown_exception) - EXCEPTION(0x1800, Trap_18, unknown_exception) - EXCEPTION(0x1900, Trap_19, unknown_exception) - EXCEPTION(0x1A00, Trap_1A, unknown_exception) - EXCEPTION(0x1B00, Trap_1B, unknown_exception) - EXCEPTION(0x1C00, Trap_1C, unknown_exception) - EXCEPTION(0x1D00, Trap_1D, unknown_exception) - EXCEPTION(0x1E00, Trap_1E, unknown_exception) - EXCEPTION(0x1F00, Trap_1F, unknown_exception) - -/* Check for a single step debug exception while in an exception - * handler before state has been saved. This is to catch the case - * where an instruction that we are trying to single step causes - * an exception (eg ITLB/DTLB miss) and thus the first instruction of - * the exception handler generates a single step debug exception. - * - * If we get a debug trap on the first instruction of an exception handler, - * we reset the MSR_DE in the _exception handler's_ MSR (the debug trap is - * a critical exception, so we are using SPRN_CSRR1 to manipulate the MSR). - * The exception handler was handling a non-critical interrupt, so it will - * save (and later restore) the MSR via SPRN_SRR1, which will still have - * the MSR_DE bit set. - */ - /* 0x2000 - Debug Exception */ - START_EXCEPTION(0x2000, DebugTrap) - CRITICAL_EXCEPTION_PROLOG 0x2000 DebugTrap - - /* - * If this is a single step or branch-taken exception in an - * exception entry sequence, it was probably meant to apply to - * the code where the exception occurred (since exception entry - * doesn't turn off DE automatically). We simulate the effect - * of turning off DE on entry to an exception handler by turning - * off DE in the SRR3 value and clearing the debug status. - */ - mfspr r10,SPRN_DBSR /* check single-step/branch taken */ - andis. r10,r10,DBSR_IC@h - beq+ 2f - - andi. r10,r9,MSR_IR|MSR_PR /* check supervisor + MMU off */ - beq 1f /* branch and fix it up */ - - mfspr r10,SPRN_SRR2 /* Faulting instruction address */ - cmplwi r10,0x2100 - bgt+ 2f /* address above exception vectors */ - - /* here it looks like we got an inappropriate debug exception. */ -1: rlwinm r9,r9,0,~MSR_DE /* clear DE in the SRR3 value */ - lis r10,DBSR_IC@h /* clear the IC event */ - mtspr SPRN_DBSR,r10 - /* restore state and get out */ - lwz r10,_CCR(r11) - lwz r0,GPR0(r11) - lwz r1,GPR1(r11) - mtcrf 0x80,r10 - mtspr SPRN_SRR2,r12 - mtspr SPRN_SRR3,r9 - lwz r9,GPR9(r11) - lwz r12,GPR12(r11) - lwz r10,crit_r10@l(0) - lwz r11,crit_r11@l(0) - rfci - b . - - /* continue normal handling for a critical exception... */ -2: mfspr r4,SPRN_DBSR - stw r4,_ESR(r11) /* DebugException takes DBSR in _ESR */ - prepare_transfer_to_handler - bl DebugException - b ret_from_crit_exc - - /* Programmable Interval Timer (PIT) Exception. (from 0x1000) */ - __HEAD -Decrementer: - EXCEPTION_PROLOG 0x1000 Decrementer - lis r0,TSR_PIS@h - mtspr SPRN_TSR,r0 /* Clear the PIT exception */ - prepare_transfer_to_handler - bl timer_interrupt - b interrupt_return - - /* Fixed Interval Timer (FIT) Exception. (from 0x1010) */ - __HEAD -FITException: - EXCEPTION_PROLOG 0x1010 FITException - prepare_transfer_to_handler - bl unknown_exception - b interrupt_return - - /* Watchdog Timer (WDT) Exception. (from 0x1020) */ - __HEAD -WDTException: - CRITICAL_EXCEPTION_PROLOG 0x1020 WDTException - prepare_transfer_to_handler - bl WatchdogException - b ret_from_crit_exc - -/* Other PowerPC processors, namely those derived from the 6xx-series - * have vectors from 0x2100 through 0x2F00 defined, but marked as reserved. - * However, for the 4xx-series processors these are neither defined nor - * reserved. - */ - - __HEAD - /* Damn, I came up one instruction too many to fit into the - * exception space :-). Both the instruction and data TLB - * miss get to this point to load the TLB. - * r10 - TLB_TAG value - * r11 - Linux PTE - * r9 - available to use - * PID - loaded with proper value when we get here - * Upon exit, we reload everything and RFI. - * Actually, it will fit now, but oh well.....a common place - * to load the TLB. - */ -tlb_4xx_index: - .long 0 -finish_tlb_load: - /* - * Clear out the software-only bits in the PTE to generate the - * TLB_DATA value. These are the bottom 2 bits of the RPM, the - * 4 bits of the zone field, and M. - */ - li r9, 0x0cf2 - andc r11, r11, r9 - rlwimi r11, r10, 8, 24, 27 /* Copy 4 upper address bit into zone */ - - /* load the next available TLB index. */ - lwz r9, tlb_4xx_index@l(0) - addi r9, r9, 1 - andi. r9, r9, PPC40X_TLB_SIZE - 1 - stw r9, tlb_4xx_index@l(0) - - tlbwe r11, r9, TLB_DATA /* Load TLB LO */ - tlbwe r10, r9, TLB_TAG /* Load TLB HI */ - - /* Done...restore registers and get out of here. - */ - mtspr SPRN_PID, r12 - mtcrf 0x80, r12 - mfspr r9, SPRN_SPRG_SCRATCH4 - mfspr r12, SPRN_SPRG_SCRATCH3 - mfspr r11, SPRN_SPRG_SCRATCH6 - mfspr r10, SPRN_SPRG_SCRATCH5 - rfi /* Should sync shadow TLBs */ - b . /* prevent prefetch past rfi */ - -/* This is where the main kernel code starts. - */ -start_here: - - /* ptr to current */ - lis r2,init_task@h - ori r2,r2,init_task@l - - /* ptr to phys current thread */ - tophys(r4,r2) - addi r4,r4,THREAD /* init task's THREAD */ - mtspr SPRN_SPRG_THREAD,r4 - - /* stack */ - lis r1,init_thread_union@ha - addi r1,r1,init_thread_union@l - li r0,0 - stwu r0,THREAD_SIZE-STACK_FRAME_MIN_SIZE(r1) - - bl early_init /* We have to do this with MMU on */ - -/* - * Decide what sort of machine this is and initialize the MMU. - */ -#ifdef CONFIG_KASAN - bl kasan_early_init -#endif - li r3,0 - mr r4,r31 - bl machine_init - bl MMU_init - -/* Go back to running unmapped so we can load up new values - * and change to using our exception vectors. - * On the 4xx, all we have to do is invalidate the TLB to clear - * the old 16M byte TLB mappings. - */ - lis r4,2f@h - ori r4,r4,2f@l - tophys(r4,r4) - lis r3,(MSR_KERNEL & ~(MSR_IR|MSR_DR))@h - ori r3,r3,(MSR_KERNEL & ~(MSR_IR|MSR_DR))@l - mtspr SPRN_SRR0,r4 - mtspr SPRN_SRR1,r3 - rfi - b . /* prevent prefetch past rfi */ - -/* Load up the kernel context */ -2: - sync /* Flush to memory before changing TLB */ - tlbia - isync /* Flush shadow TLBs */ - - /* set up the PTE pointers for the Abatron bdiGDB. - */ - lis r6, swapper_pg_dir@h - ori r6, r6, swapper_pg_dir@l - lis r5, abatron_pteptrs@h - ori r5, r5, abatron_pteptrs@l - stw r5, 0xf0(0) /* Must match your Abatron config file */ - tophys(r5,r5) - stw r6, 0(r5) - -/* Now turn on the MMU for real! */ - lis r4,MSR_KERNEL@h - ori r4,r4,MSR_KERNEL@l - lis r3,start_kernel@h - ori r3,r3,start_kernel@l - mtspr SPRN_SRR0,r3 - mtspr SPRN_SRR1,r4 - rfi /* enable MMU and jump to start_kernel */ - b . /* prevent prefetch past rfi */ - -/* Set up the initial MMU state so we can do the first level of - * kernel initialization. This maps the first 32 MBytes of memory 1:1 - * virtual to physical and more importantly sets the cache mode. - */ -SYM_FUNC_START_LOCAL(initial_mmu) - tlbia /* Invalidate all TLB entries */ - isync - - /* We should still be executing code at physical address 0x0000xxxx - * at this point. However, start_here is at virtual address - * 0xC000xxxx. So, set up a TLB mapping to cover this once - * translation is enabled. - */ - - lis r3,KERNELBASE@h /* Load the kernel virtual address */ - ori r3,r3,KERNELBASE@l - tophys(r4,r3) /* Load the kernel physical address */ - - iccci r0,r3 /* Invalidate the i-cache before use */ - - /* Load the kernel PID. - */ - li r0,0 - mtspr SPRN_PID,r0 - sync - - /* Configure and load one entry into TLB slots 63 */ - clrrwi r4,r4,10 /* Mask off the real page number */ - ori r4,r4,(TLB_WR | TLB_EX) /* Set the write and execute bits */ - - clrrwi r3,r3,10 /* Mask off the effective page number */ - ori r3,r3,(TLB_VALID | TLB_PAGESZ(PAGESZ_16M)) - - li r0,63 /* TLB slot 63 */ - - tlbwe r4,r0,TLB_DATA /* Load the data portion of the entry */ - tlbwe r3,r0,TLB_TAG /* Load the tag portion of the entry */ - - li r0,62 /* TLB slot 62 */ - addis r4,r4,SZ_16M@h - addis r3,r3,SZ_16M@h - tlbwe r4,r0,TLB_DATA /* Load the data portion of the entry */ - tlbwe r3,r0,TLB_TAG /* Load the tag portion of the entry */ - - isync - - /* Establish the exception vector base - */ - lis r4,KERNELBASE@h /* EVPR only uses the high 16-bits */ - tophys(r0,r4) /* Use the physical address */ - mtspr SPRN_EVPR,r0 - - blr -SYM_FUNC_END(initial_mmu) - -_GLOBAL(abort) - mfspr r13,SPRN_DBCR0 - oris r13,r13,DBCR0_RST_SYSTEM@h - mtspr SPRN_DBCR0,r13 |