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Diffstat (limited to 'arch/powerpc/kernel/head_8xx.S')
| -rw-r--r-- | arch/powerpc/kernel/head_8xx.S | 848 |
1 files changed, 848 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S new file mode 100644 index 000000000..a61b4ff3b --- /dev/null +++ b/arch/powerpc/kernel/head_8xx.S @@ -0,0 +1,848 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * PowerPC version + * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) + * Rewritten by Cort Dougan (cort@cs.nmt.edu) for PReP + * Copyright (C) 1996 Cort Dougan <cort@cs.nmt.edu> + * Low-level exception handlers and MMU support + * rewritten by Paul Mackerras. + * Copyright (C) 1996 Paul Mackerras. + * MPC8xx modifications by Dan Malek + * Copyright (C) 1997 Dan Malek (dmalek@jlc.net). + * + * This file contains low-level support and setup for PowerPC 8xx + * embedded processors, including trap and interrupt dispatch. + */ + +#include <linux/init.h> +#include <linux/magic.h> +#include <linux/pgtable.h> +#include <linux/sizes.h> +#include <asm/processor.h> +#include <asm/page.h> +#include <asm/mmu.h> +#include <asm/cache.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 <asm/export.h> +#include <asm/code-patching-asm.h> + +#include "head_32.h" + +.macro compare_to_kernel_boundary scratch, addr +#if CONFIG_TASK_SIZE <= 0x80000000 && CONFIG_PAGE_OFFSET >= 0x80000000 +/* By simply checking Address >= 0x80000000, we know if its a kernel address */ + not. \scratch, \addr +#else + rlwinm \scratch, \addr, 16, 0xfff8 + cmpli cr0, \scratch, PAGE_OFFSET@h +#endif +.endm + +/* + * We need an ITLB miss handler for kernel addresses if: + * - Either we have modules + * - Or we have not pinned the first 8M + */ +#if defined(CONFIG_MODULES) || !defined(CONFIG_PIN_TLB_TEXT) || \ + defined(CONFIG_DEBUG_PAGEALLOC) +#define ITLB_MISS_KERNEL 1 +#endif + +/* + * Value for the bits that have fixed value in RPN entries. + * Also used for tagging DAR for DTLBerror. + */ +#define RPN_PATTERN 0x00f0 + +#define PAGE_SHIFT_512K 19 +#define PAGE_SHIFT_8M 23 + + __HEAD +_ENTRY(_stext); +_ENTRY(_start); + +/* MPC8xx + * This port was done on an MBX board with an 860. Right now I only + * support an ELF compressed (zImage) boot from EPPC-Bug because the + * code there loads up some registers before calling us: + * r3: ptr to board info data + * r4: initrd_start or if no initrd then 0 + * r5: initrd_end - unused if r4 is 0 + * r6: Start of command line string + * r7: End of command line string + * + * I decided to use conditional compilation instead of checking PVR and + * adding more processor specific branches around code I don't need. + * Since this is an embedded processor, I also appreciate any memory + * savings I can get. + * + * The MPC8xx does not have any BATs, but it supports large page sizes. + * We first initialize the MMU to support 8M byte pages, then load one + * entry into each of the instruction and data TLBs to map the first + * 8M 1:1. I also mapped an additional I/O space 1:1 so we can get to + * the "internal" processor registers before MMU_init is called. + * + * -- Dan + */ + .globl __start +__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 8 Meg mapped into TLB entries, and the caches + * ready to work. + */ + +turn_on_mmu: + mfmsr r0 + ori r0,r0,MSR_DR|MSR_IR + mtspr SPRN_SRR1,r0 + lis r0,start_here@h + ori r0,r0,start_here@l + mtspr SPRN_SRR0,r0 + rfi /* enables MMU */ + + +#ifdef CONFIG_PERF_EVENTS + .align 4 + + .globl itlb_miss_counter +itlb_miss_counter: + .space 4 + + .globl dtlb_miss_counter +dtlb_miss_counter: + .space 4 + + .globl instruction_counter +instruction_counter: + .space 4 +#endif + +/* System reset */ + EXCEPTION(0x100, Reset, system_reset_exception, EXC_XFER_STD) + +/* Machine check */ + . = 0x200 +MachineCheck: + EXCEPTION_PROLOG handle_dar_dsisr=1 + save_dar_dsisr_on_stack r4, r5, r11 + li r6, RPN_PATTERN + mtspr SPRN_DAR, r6 /* Tag DAR, to be used in DTLB Error */ + addi r3,r1,STACK_FRAME_OVERHEAD + EXC_XFER_STD(0x200, machine_check_exception) + +/* External interrupt */ + EXCEPTION(0x500, HardwareInterrupt, do_IRQ, EXC_XFER_LITE) + +/* Alignment exception */ + . = 0x600 +Alignment: + EXCEPTION_PROLOG handle_dar_dsisr=1 + save_dar_dsisr_on_stack r4, r5, r11 + li r6, RPN_PATTERN + mtspr SPRN_DAR, r6 /* Tag DAR, to be used in DTLB Error */ + addi r3,r1,STACK_FRAME_OVERHEAD + b .Lalignment_exception_ool + +/* Program check exception */ + EXCEPTION(0x700, ProgramCheck, program_check_exception, EXC_XFER_STD) + +/* Decrementer */ + EXCEPTION(0x900, Decrementer, timer_interrupt, EXC_XFER_LITE) + + /* With VMAP_STACK there's not enough room for this at 0x600 */ + . = 0xa00 +.Lalignment_exception_ool: + EXC_XFER_STD(0x600, alignment_exception) + +/* System call */ + . = 0xc00 +SystemCall: + SYSCALL_ENTRY 0xc00 + +/* Single step - not used on 601 */ + EXCEPTION(0xd00, SingleStep, single_step_exception, EXC_XFER_STD) + +/* On the MPC8xx, this is a software emulation interrupt. It occurs + * for all unimplemented and illegal instructions. + */ + EXCEPTION(0x1000, SoftEmu, emulation_assist_interrupt, EXC_XFER_STD) + + . = 0x1100 +/* + * For the MPC8xx, this is a software tablewalk to load the instruction + * TLB. The task switch loads the M_TWB register with the pointer to the first + * level table. + * If we discover there is no second level table (value is zero) or if there + * is an invalid pte, we load that into the TLB, which causes another fault + * into the TLB Error interrupt where we can handle such problems. + * We have to use the MD_xxx registers for the tablewalk because the + * equivalent MI_xxx registers only perform the attribute functions. + */ + +#ifdef CONFIG_8xx_CPU15 +#define INVALIDATE_ADJACENT_PAGES_CPU15(addr) \ + addi addr, addr, PAGE_SIZE; \ + tlbie addr; \ + addi addr, addr, -(PAGE_SIZE << 1); \ + tlbie addr; \ + addi addr, addr, PAGE_SIZE +#else +#define INVALIDATE_ADJACENT_PAGES_CPU15(addr) +#endif + +InstructionTLBMiss: + mtspr SPRN_SPRG_SCRATCH0, r10 + mtspr SPRN_SPRG_SCRATCH1, r11 + + /* If we are faulting a kernel address, we have to use the + * kernel page tables. + */ + mfspr r10, SPRN_SRR0 /* Get effective address of fault */ + INVALIDATE_ADJACENT_PAGES_CPU15(r10) + mtspr SPRN_MD_EPN, r10 +#ifdef ITLB_MISS_KERNEL + mfcr r11 + compare_to_kernel_boundary r10, r10 +#endif + mfspr r10, SPRN_M_TWB /* Get level 1 table */ +#ifdef ITLB_MISS_KERNEL + blt+ 3f + rlwinm r10, r10, 0, 20, 31 + oris r10, r10, (swapper_pg_dir - PAGE_OFFSET)@ha +3: + mtcr r11 +#endif + lwz r11, (swapper_pg_dir-PAGE_OFFSET)@l(r10) /* Get level 1 entry */ + mtspr SPRN_MD_TWC, r11 + mfspr r10, SPRN_MD_TWC + lwz r10, 0(r10) /* Get the pte */ + rlwimi r11, r10, 0, _PAGE_GUARDED | _PAGE_ACCESSED + rlwimi r11, r10, 32 - 9, _PMD_PAGE_512K + mtspr SPRN_MI_TWC, r11 + /* The Linux PTE won't go exactly into the MMU TLB. + * Software indicator bits 20 and 23 must be clear. + * Software indicator bits 22, 24, 25, 26, and 27 must be + * set. All other Linux PTE bits control the behavior + * of the MMU. + */ + rlwinm r10, r10, 0, ~0x0f00 /* Clear bits 20-23 */ + rlwimi r10, r10, 4, 0x0400 /* Copy _PAGE_EXEC into bit 21 */ + ori r10, r10, RPN_PATTERN | 0x200 /* Set 22 and 24-27 */ + mtspr SPRN_MI_RPN, r10 /* Update TLB entry */ + + /* Restore registers */ +0: mfspr r10, SPRN_SPRG_SCRATCH0 + mfspr r11, SPRN_SPRG_SCRATCH1 + rfi + patch_site 0b, patch__itlbmiss_exit_1 + +#ifdef CONFIG_PERF_EVENTS + patch_site 0f, patch__itlbmiss_perf +0: lwz r10, (itlb_miss_counter - PAGE_OFFSET)@l(0) + addi r10, r10, 1 + stw r10, (itlb_miss_counter - PAGE_OFFSET)@l(0) + mfspr r10, SPRN_SPRG_SCRATCH0 + mfspr r11, SPRN_SPRG_SCRATCH1 + rfi +#endif + + . = 0x1200 +DataStoreTLBMiss: + mtspr SPRN_DAR, r10 + mtspr SPRN_M_TW, r11 + mfcr r11 + + /* If we are faulting a kernel address, we have to use the + * kernel page tables. + */ + mfspr r10, SPRN_MD_EPN + compare_to_kernel_boundary r10, r10 + mfspr r10, SPRN_M_TWB /* Get level 1 table */ + blt+ 3f + rlwinm r10, r10, 0, 20, 31 + oris r10, r10, (swapper_pg_dir - PAGE_OFFSET)@ha +3: + mtcr r11 + lwz r11, (swapper_pg_dir-PAGE_OFFSET)@l(r10) /* Get level 1 entry */ + + mtspr SPRN_MD_TWC, r11 + mfspr r10, SPRN_MD_TWC + lwz r10, 0(r10) /* Get the pte */ + + /* Insert Guarded and Accessed flags into the TWC from the Linux PTE. + * It is bit 27 of both the Linux PTE and the TWC (at least + * I got that right :-). It will be better when we can put + * this into the Linux pgd/pmd and load it in the operation + * above. + */ + rlwimi r11, r10, 0, _PAGE_GUARDED | _PAGE_ACCESSED + rlwimi r11, r10, 32 - 9, _PMD_PAGE_512K + mtspr SPRN_MD_TWC, r11 + + /* The Linux PTE won't go exactly into the MMU TLB. + * Software indicator bits 24, 25, 26, and 27 must be + * set. All other Linux PTE bits control the behavior + * of the MMU. + */ + li r11, RPN_PATTERN + rlwimi r10, r11, 0, 24, 27 /* Set 24-27 */ + mtspr SPRN_MD_RPN, r10 /* Update TLB entry */ + + /* Restore registers */ + +0: mfspr r10, SPRN_DAR + mtspr SPRN_DAR, r11 /* Tag DAR */ + mfspr r11, SPRN_M_TW + rfi + patch_site 0b, patch__dtlbmiss_exit_1 + +#ifdef CONFIG_PERF_EVENTS + patch_site 0f, patch__dtlbmiss_perf +0: lwz r10, (dtlb_miss_counter - PAGE_OFFSET)@l(0) + addi r10, r10, 1 + stw r10, (dtlb_miss_counter - PAGE_OFFSET)@l(0) + mfspr r10, SPRN_DAR + mtspr SPRN_DAR, r11 /* Tag DAR */ + mfspr r11, SPRN_M_TW + rfi +#endif + +/* This is an instruction TLB error on the MPC8xx. This could be due + * to many reasons, such as executing guarded memory or illegal instruction + * addresses. There is nothing to do but handle a big time error fault. + */ + . = 0x1300 +InstructionTLBError: + EXCEPTION_PROLOG + mr r4,r12 + andis. r5,r9,DSISR_SRR1_MATCH_32S@h /* Filter relevant SRR1 bits */ + andis. r10,r9,SRR1_ISI_NOPT@h + beq+ .Litlbie + tlbie r4 + /* 0x400 is InstructionAccess exception, needed by bad_page_fault() */ +.Litlbie: + stw r4, _DAR(r11) + EXC_XFER_LITE(0x400, handle_page_fault) + +/* This is the data TLB error on the MPC8xx. This could be due to + * many reasons, including a dirty update to a pte. We bail out to + * a higher level function that can handle it. + */ + . = 0x1400 +DataTLBError: + EXCEPTION_PROLOG_0 handle_dar_dsisr=1 + mfspr r11, SPRN_DAR + cmpwi cr1, r11, RPN_PATTERN + beq- cr1, FixupDAR /* must be a buggy dcbX, icbi insn. */ +DARFixed:/* Return from dcbx instruction bug workaround */ +#ifdef CONFIG_VMAP_STACK + li r11, RPN_PATTERN + mtspr SPRN_DAR, r11 /* Tag DAR, to be used in DTLB Error */ +#endif + EXCEPTION_PROLOG_1 + EXCEPTION_PROLOG_2 handle_dar_dsisr=1 + get_and_save_dar_dsisr_on_stack r4, r5, r11 + andis. r10,r5,DSISR_NOHPTE@h + beq+ .Ldtlbie + tlbie r4 +.Ldtlbie: +#ifndef CONFIG_VMAP_STACK + li r10,RPN_PATTERN + mtspr SPRN_DAR,r10 /* Tag DAR, to be used in DTLB Error */ +#endif + /* 0x300 is DataAccess exception, needed by bad_page_fault() */ + EXC_XFER_LITE(0x300, handle_page_fault) + +stack_overflow: + vmap_stack_overflow_exception + +/* On the MPC8xx, these next four traps are used for development + * support of breakpoints and such. Someday I will get around to + * using them. + */ +do_databreakpoint: + EXCEPTION_PROLOG_1 + EXCEPTION_PROLOG_2 handle_dar_dsisr=1 + addi r3,r1,STACK_FRAME_OVERHEAD + mfspr r4,SPRN_BAR + stw r4,_DAR(r11) +#ifdef CONFIG_VMAP_STACK + lwz r5,_DSISR(r11) +#else + mfspr r5,SPRN_DSISR +#endif + EXC_XFER_STD(0x1c00, do_break) + + . = 0x1c00 +DataBreakpoint: + EXCEPTION_PROLOG_0 handle_dar_dsisr=1 + mfspr r11, SPRN_SRR0 + cmplwi cr1, r11, (.Ldtlbie - PAGE_OFFSET)@l + cmplwi cr7, r11, (.Litlbie - PAGE_OFFSET)@l + cror 4*cr1+eq, 4*cr1+eq, 4*cr7+eq + bne cr1, do_databreakpoint + mtcr r10 + mfspr r10, SPRN_SPRG_SCRATCH0 + mfspr r11, SPRN_SPRG_SCRATCH1 + rfi + +#ifdef CONFIG_PERF_EVENTS + . = 0x1d00 +InstructionBreakpoint: + mtspr SPRN_SPRG_SCRATCH0, r10 + lwz r10, (instruction_counter - PAGE_OFFSET)@l(0) + addi r10, r10, -1 + stw r10, (instruction_counter - PAGE_OFFSET)@l(0) + lis r10, 0xffff + ori r10, r10, 0x01 + mtspr SPRN_COUNTA, r10 + mfspr r10, SPRN_SPRG_SCRATCH0 + rfi +#else + EXCEPTION(0x1d00, Trap_1d, unknown_exception, EXC_XFER_STD) +#endif + EXCEPTION(0x1e00, Trap_1e, unknown_exception, EXC_XFER_STD) + EXCEPTION(0x1f00, Trap_1f, unknown_exception, EXC_XFER_STD) + + . = 0x2000 + +/* This is the procedure to calculate the data EA for buggy dcbx,dcbi instructions + * by decoding the registers used by the dcbx instruction and adding them. + * DAR is set to the calculated address. + */ +FixupDAR:/* Entry point for dcbx workaround. */ + mtspr SPRN_M_TW, r10 + /* fetch instruction from memory. */ + mfspr r10, SPRN_SRR0 + mtspr SPRN_MD_EPN, r10 + rlwinm r11, r10, 16, 0xfff8 + cmpli cr1, r11, PAGE_OFFSET@h + mfspr r11, SPRN_M_TWB /* Get level 1 table */ + blt+ cr1, 3f + + /* create physical page address from effective address */ + tophys(r11, r10) + mfspr r11, SPRN_M_TWB /* Get level 1 table */ + rlwinm r11, r11, 0, 20, 31 + oris r11, r11, (swapper_pg_dir - PAGE_OFFSET)@ha +3: + lwz r11, (swapper_pg_dir-PAGE_OFFSET)@l(r11) /* Get the level 1 entry */ + mtspr SPRN_MD_TWC, r11 + mtcrf 0x01, r11 + mfspr r11, SPRN_MD_TWC + lwz r11, 0(r11) /* Get the pte */ + bt 28,200f /* bit 28 = Large page (8M) */ + /* concat physical page address(r11) and page offset(r10) */ + rlwimi r11, r10, 0, 32 - PAGE_SHIFT, 31 +201: lwz r11,0(r11) +/* Check if it really is a dcbx instruction. */ +/* dcbt and dcbtst does not generate DTLB Misses/Errors, + * no need to include them here */ + xoris r10, r11, 0x7c00 /* check if major OP code is 31 */ + rlwinm r10, r10, 0, 21, 5 + cmpwi cr1, r10, 2028 /* Is dcbz? */ + beq+ cr1, 142f + cmpwi cr1, r10, 940 /* Is dcbi? */ + beq+ cr1, 142f + cmpwi cr1, r10, 108 /* Is dcbst? */ + beq+ cr1, 144f /* Fix up store bit! */ + cmpwi cr1, r10, 172 /* Is dcbf? */ + beq+ cr1, 142f + cmpwi cr1, r10, 1964 /* Is icbi? */ + beq+ cr1, 142f +141: mfspr r10,SPRN_M_TW + b DARFixed /* Nope, go back to normal TLB processing */ + +200: + /* concat physical page address(r11) and page offset(r10) */ + rlwimi r11, r10, 0, 32 - PAGE_SHIFT_8M, 31 + b 201b + +144: mfspr r10, SPRN_DSISR + rlwinm r10, r10,0,7,5 /* Clear store bit for buggy dcbst insn */ + mtspr SPRN_DSISR, r10 +142: /* continue, it was a dcbx, dcbi instruction. */ + mfctr r10 + mtdar r10 /* save ctr reg in DAR */ + rlwinm r10, r11, 24, 24, 28 /* offset into jump table for reg RB */ + addi r10, r10, 150f@l /* add start of table */ + mtctr r10 /* load ctr with jump address */ + xor r10, r10, r10 /* sum starts at zero */ + bctr /* jump into table */ +150: + add r10, r10, r0 ;b 151f + add r10, r10, r1 ;b 151f + add r10, r10, r2 ;b 151f + add r10, r10, r3 ;b 151f + add r10, r10, r4 ;b 151f + add r10, r10, r5 ;b 151f + add r10, r10, r6 ;b 151f + add r10, r10, r7 ;b 151f + add r10, r10, r8 ;b 151f + add r10, r10, r9 ;b 151f + mtctr r11 ;b 154f /* r10 needs special handling */ + mtctr r11 ;b 153f /* r11 needs special handling */ + add r10, r10, r12 ;b 151f + add r10, r10, r13 ;b 151f + add r10, r10, r14 ;b 151f + add r10, r10, r15 ;b 151f + add r10, r10, r16 ;b 151f + add r10, r10, r17 ;b 151f + add r10, r10, r18 ;b 151f + add r10, r10, r19 ;b 151f + add r10, r10, r20 ;b 151f + add r10, r10, r21 ;b 151f + add r10, r10, r22 ;b 151f + add r10, r10, r23 ;b 151f + add r10, r10, r24 ;b 151f + add r10, r10, r25 ;b 151f + add r10, r10, r26 ;b 151f + add r10, r10, r27 ;b 151f + add r10, r10, r28 ;b 151f + add r10, r10, r29 ;b 151f + add r10, r10, r30 ;b 151f + add r10, r10, r31 +151: + rlwinm r11,r11,19,24,28 /* offset into jump table for reg RA */ + cmpwi cr1, r11, 0 + beq cr1, 152f /* if reg RA is zero, don't add it */ + addi r11, r11, 150b@l /* add start of table */ + mtctr r11 /* load ctr with jump address */ + rlwinm r11,r11,0,16,10 /* make sure we don't execute this more than once */ + bctr /* jump into table */ +152: + mfdar r11 + mtctr r11 /* restore ctr reg from DAR */ +#ifdef CONFIG_VMAP_STACK + mfspr r11, SPRN_SPRG_THREAD + stw r10, DAR(r11) + mfspr r10, SPRN_DSISR + stw r10, DSISR(r11) +#else + mtdar r10 /* save fault EA to DAR */ +#endif + mfspr r10,SPRN_M_TW + b DARFixed /* Go back to normal TLB handling */ + + /* special handling for r10,r11 since these are modified already */ +153: mfspr r11, SPRN_SPRG_SCRATCH1 /* load r11 from SPRN_SPRG_SCRATCH1 */ + add r10, r10, r11 /* add it */ + mfctr r11 /* restore r11 */ + b 151b +154: mfspr r11, SPRN_SPRG_SCRATCH0 /* load r10 from SPRN_SPRG_SCRATCH0 */ + add r10, r10, r11 /* add it */ + mfctr r11 /* restore r11 */ + b 151b + +/* + * 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 + lis r0, STACK_END_MAGIC@h + ori r0, r0, STACK_END_MAGIC@l + stw r0, 0(r1) + li r0,0 + stwu r0,THREAD_SIZE-STACK_FRAME_OVERHEAD(r1) + + lis r6, swapper_pg_dir@ha + tophys(r6,r6) + mtspr SPRN_M_TWB, r6 + + 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 8xx, all we have to do is invalidate the TLB to clear + * the old 8M byte TLB mappings and load the page table base register. + */ + /* The right way to do this would be to track it down through + * init's THREAD like the context switch code does, but this is + * easier......until someone changes init's static structures. + */ + lis r4,2f@h + ori r4,r4,2f@l + tophys(r4,r4) + li r3,MSR_KERNEL & ~(MSR_IR|MSR_DR) + mtspr SPRN_SRR0,r4 + mtspr SPRN_SRR1,r3 + rfi +/* Load up the kernel context */ +2: +#ifdef CONFIG_PIN_TLB_IMMR + lis r0, MD_TWAM@h + oris r0, r0, 0x1f00 + mtspr SPRN_MD_CTR, r0 + LOAD_REG_IMMEDIATE(r0, VIRT_IMMR_BASE | MD_EVALID) + tlbie r0 + mtspr SPRN_MD_EPN, r0 + LOAD_REG_IMMEDIATE(r0, MD_SVALID | MD_PS512K | MD_GUARDED) + mtspr SPRN_MD_TWC, r0 + mfspr r0, SPRN_IMMR + rlwinm r0, r0, 0, 0xfff80000 + ori r0, r0, 0xf0 | _PAGE_DIRTY | _PAGE_SPS | _PAGE_SH | \ + _PAGE_NO_CACHE | _PAGE_PRESENT + mtspr SPRN_MD_RPN, r0 + lis r0, (MD_TWAM | MD_RSV4I)@h + mtspr SPRN_MD_CTR, r0 +#endif +#ifndef CONFIG_PIN_TLB_TEXT + li r0, 0 + mtspr SPRN_MI_CTR, r0 +#endif +#if !defined(CONFIG_PIN_TLB_DATA) && !defined(CONFIG_PIN_TLB_IMMR) + lis r0, MD_TWAM@h + mtspr SPRN_MD_CTR, r0 +#endif + tlbia /* Clear all TLB entries */ + sync /* wait for tlbia/tlbie to finish */ + + /* set up the PTE pointers for the Abatron bdiGDB. + */ + lis r5, abatron_pteptrs@h + ori r5, r5, abatron_pteptrs@l + stw r5, 0xf0(0) /* Must match your Abatron config file */ + tophys(r5,r5) + lis r6, swapper_pg_dir@h + ori r6, r6, swapper_pg_dir@l + stw r6, 0(r5) + +/* Now turn on the MMU for real! */ + li r4,MSR_KERNEL + 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 */ + +/* Set up the initial MMU state so we can do the first level of + * kernel initialization. This maps the first 8 MBytes of memory 1:1 + * virtual to physical. Also, set the cache mode since that is defined + * by TLB entries and perform any additional mapping (like of the IMMR). + * If configured to pin some TLBs, we pin the first 8 Mbytes of kernel, + * 24 Mbytes of data, and the 512k IMMR space. Anything not covered by + * these mappings is mapped by page tables. + */ +initial_mmu: + li r8, 0 + mtspr SPRN_MI_CTR, r8 /* remove PINNED ITLB entries */ + lis r10, MD_TWAM@h + mtspr SPRN_MD_CTR, r10 /* remove PINNED DTLB entries */ + + tlbia /* Invalidate all TLB entries */ + + lis r8, MI_APG_INIT@h /* Set protection modes */ + ori r8, r8, MI_APG_INIT@l + mtspr SPRN_MI_AP, r8 + lis r8, MD_APG_INIT@h + ori r8, r8, MD_APG_INIT@l + mtspr SPRN_MD_AP, r8 + + /* Map the lower RAM (up to 32 Mbytes) into the ITLB and DTLB */ + lis r8, MI_RSV4I@h + ori r8, r8, 0x1c00 + oris r12, r10, MD_RSV4I@h + ori r12, r12, 0x1c00 + li r9, 4 /* up to 4 pages of 8M */ + mtctr r9 + lis r9, KERNELBASE@h /* Create vaddr for TLB */ + li r10, MI_PS8MEG | _PMD_ACCESSED | MI_SVALID + li r11, MI_BOOTINIT /* Create RPN for address 0 */ +1: + mtspr SPRN_MI_CTR, r8 /* Set instruction MMU control */ + addi r8, r8, 0x100 + ori r0, r9, MI_EVALID /* Mark it valid */ + mtspr SPRN_MI_EPN, r0 + mtspr SPRN_MI_TWC, r10 + mtspr SPRN_MI_RPN, r11 /* Store TLB entry */ + mtspr SPRN_MD_CTR, r12 + addi r12, r12, 0x100 + mtspr SPRN_MD_EPN, r0 + mtspr SPRN_MD_TWC, r10 + mtspr SPRN_MD_RPN, r11 + addis r9, r9, 0x80 + addis r11, r11, 0x80 + + bdnz 1b + + /* Since the cache is enabled according to the information we + * just loaded into the TLB, invalidate and enable the caches here. + * We should probably check/set other modes....later. + */ + lis r8, IDC_INVALL@h + mtspr SPRN_IC_CST, r8 + mtspr SPRN_DC_CST, r8 + lis r8, IDC_ENABLE@h + mtspr SPRN_IC_CST, r8 + mtspr SPRN_DC_CST, r8 + /* Disable debug mode entry on breakpoints */ + mfspr r8, SPRN_DER +#ifdef CONFIG_PERF_EVENTS + rlwinm r8, r8, 0, ~0xc +#else + rlwinm r8, r8, 0, ~0x8 +#endif + mtspr SPRN_DER, r8 + blr + +#ifdef CONFIG_PIN_TLB +_GLOBAL(mmu_pin_tlb) + lis r9, (1f - PAGE_OFFSET)@h + ori r9, r9, (1f - PAGE_OFFSET)@l + mfmsr r10 + mflr r11 + li r12, MSR_KERNEL & ~(MSR_IR | MSR_DR | MSR_RI) + rlwinm r0, r10, 0, ~MSR_RI + rlwinm r0, r0, 0, ~MSR_EE + mtmsr r0 + isync + .align 4 + mtspr SPRN_SRR0, r9 + mtspr SPRN_SRR1, r12 + rfi +1: + li r5, 0 + lis r6, MD_TWAM@h + mtspr SPRN_MI_CTR, r5 + mtspr SPRN_MD_CTR, r6 + tlbia + +#ifdef CONFIG_PIN_TLB_TEXT + LOAD_REG_IMMEDIATE(r5, 28 << 8) + LOAD_REG_IMMEDIATE(r6, PAGE_OFFSET) + LOAD_REG_IMMEDIATE(r7, MI_SVALID | MI_PS8MEG | _PMD_ACCESSED) + LOAD_REG_IMMEDIATE(r8, 0xf0 | _PAGE_RO | _PAGE_SPS | _PAGE_SH | _PAGE_PRESENT) + LOAD_REG_ADDR(r9, _sinittext) + li r0, 4 + mtctr r0 + +2: ori r0, r6, MI_EVALID + mtspr SPRN_MI_CTR, r5 + mtspr SPRN_MI_EPN, r0 + mtspr SPRN_MI_TWC, r7 + mtspr SPRN_MI_RPN, r8 + addi r5, r5, 0x100 + addis r6, r6, SZ_8M@h + addis r8, r8, SZ_8M@h + cmplw r6, r9 + bdnzt lt, 2b + lis r0, MI_RSV4I@h + mtspr SPRN_MI_CTR, r0 +#endif + LOAD_REG_IMMEDIATE(r5, 28 << 8 | MD_TWAM) +#ifdef CONFIG_PIN_TLB_DATA + LOAD_REG_IMMEDIATE(r6, PAGE_OFFSET) + LOAD_REG_IMMEDIATE(r7, MI_SVALID | MI_PS8MEG | _PMD_ACCESSED) + li r8, 0 +#ifdef CONFIG_PIN_TLB_IMMR + li r0, 3 +#else + li r0, 4 +#endif + mtctr r0 + cmpwi r4, 0 + beq 4f + LOAD_REG_ADDR(r9, _sinittext) + +2: ori r0, r6, MD_EVALID + ori r12, r8, 0xf0 | _PAGE_RO | _PAGE_SPS | _PAGE_SH | _PAGE_PRESENT + mtspr SPRN_MD_CTR, r5 + mtspr SPRN_MD_EPN, r0 + mtspr SPRN_MD_TWC, r7 + mtspr SPRN_MD_RPN, r12 + addi r5, r5, 0x100 + addis r6, r6, SZ_8M@h + addis r8, r8, SZ_8M@h + cmplw r6, r9 + bdnzt lt, 2b +4: +2: ori r0, r6, MD_EVALID + ori r12, r8, 0xf0 | _PAGE_DIRTY | _PAGE_SPS | _PAGE_SH | _PAGE_PRESENT + mtspr SPRN_MD_CTR, r5 + mtspr SPRN_MD_EPN, r0 + mtspr SPRN_MD_TWC, r7 + mtspr SPRN_MD_RPN, r12 + addi r5, r5, 0x100 + addis r6, r6, SZ_8M@h + addis r8, r8, SZ_8M@h + cmplw r6, r3 + bdnzt lt, 2b +#endif +#ifdef CONFIG_PIN_TLB_IMMR + LOAD_REG_IMMEDIATE(r0, VIRT_IMMR_BASE | MD_EVALID) + LOAD_REG_IMMEDIATE(r7, MD_SVALID | MD_PS512K | MD_GUARDED | _PMD_ACCESSED) + mfspr r8, SPRN_IMMR + rlwinm r8, r8, 0, 0xfff80000 + ori r8, r8, 0xf0 | _PAGE_DIRTY | _PAGE_SPS | _PAGE_SH | \ + _PAGE_NO_CACHE | _PAGE_PRESENT + mtspr SPRN_MD_CTR, r5 + mtspr SPRN_MD_EPN, r0 + mtspr SPRN_MD_TWC, r7 + mtspr SPRN_MD_RPN, r8 +#endif +#if defined(CONFIG_PIN_TLB_IMMR) || defined(CONFIG_PIN_TLB_DATA) + lis r0, (MD_RSV4I | MD_TWAM)@h + mtspr SPRN_MD_CTR, r0 +#endif + mtspr SPRN_SRR1, r10 + mtspr SPRN_SRR0, r11 + rfi +#endif /* CONFIG_PIN_TLB */ + +/* + * We put a few things here that have to be page-aligned. + * This stuff goes at the beginning of the data segment, + * which is page-aligned. + */ + .data + .globl sdata +sdata: + .globl empty_zero_page + .align PAGE_SHIFT +empty_zero_page: + .space PAGE_SIZE +EXPORT_SYMBOL(empty_zero_page) + + .globl swapper_pg_dir +swapper_pg_dir: + .space PGD_TABLE_SIZE + +/* Room for two PTE table poiners, usually the kernel and current user + * pointer to their respective root page table (pgdir). + */ + .globl abatron_pteptrs +abatron_pteptrs: + .space 8 |