| /* 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 <linux/linkage.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/code-patching-asm.h> |
| #include <asm/interrupt.h> |
| |
| /* |
| * Value for the bits that have fixed value in RPN entries. |
| * Also used for tagging DAR for DTLBerror. |
| */ |
| #define RPN_PATTERN 0x00f0 |
| |
| #include "head_32.h" |
| |
| #define PAGE_SHIFT_512K 19 |
| #define PAGE_SHIFT_8M 23 |
| |
| __HEAD |
| _GLOBAL(_stext); |
| _GLOBAL(_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(INTERRUPT_SYSTEM_RESET, Reset, system_reset_exception) |
| |
| /* Machine check */ |
| START_EXCEPTION(INTERRUPT_MACHINE_CHECK, MachineCheck) |
| EXCEPTION_PROLOG INTERRUPT_MACHINE_CHECK MachineCheck handle_dar_dsisr=1 |
| prepare_transfer_to_handler |
| bl machine_check_exception |
| b interrupt_return |
| |
| /* External interrupt */ |
| EXCEPTION(INTERRUPT_EXTERNAL, HardwareInterrupt, do_IRQ) |
| |
| /* Alignment exception */ |
| START_EXCEPTION(INTERRUPT_ALIGNMENT, Alignment) |
| EXCEPTION_PROLOG INTERRUPT_ALIGNMENT Alignment handle_dar_dsisr=1 |
| prepare_transfer_to_handler |
| bl alignment_exception |
| REST_NVGPRS(r1) |
| b interrupt_return |
| |
| /* Program check exception */ |
| START_EXCEPTION(INTERRUPT_PROGRAM, ProgramCheck) |
| EXCEPTION_PROLOG INTERRUPT_PROGRAM ProgramCheck |
| prepare_transfer_to_handler |
| bl program_check_exception |
| REST_NVGPRS(r1) |
| b interrupt_return |
| |
| /* Decrementer */ |
| EXCEPTION(INTERRUPT_DECREMENTER, Decrementer, timer_interrupt) |
| |
| /* System call */ |
| START_EXCEPTION(INTERRUPT_SYSCALL, SystemCall) |
| SYSCALL_ENTRY INTERRUPT_SYSCALL |
| |
| /* Single step - not used on 601 */ |
| EXCEPTION(INTERRUPT_TRACE, SingleStep, single_step_exception) |
| |
| /* On the MPC8xx, this is a software emulation interrupt. It occurs |
| * for all unimplemented and illegal instructions. |
| */ |
| START_EXCEPTION(INTERRUPT_SOFT_EMU_8xx, SoftEmu) |
| EXCEPTION_PROLOG INTERRUPT_SOFT_EMU_8xx SoftEmu |
| prepare_transfer_to_handler |
| bl emulation_assist_interrupt |
| REST_NVGPRS(r1) |
| b interrupt_return |
| |
| /* |
| * 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, tmp) \ |
| addi tmp, addr, PAGE_SIZE; \ |
| tlbie tmp; \ |
| addi tmp, addr, -PAGE_SIZE; \ |
| tlbie tmp |
| #else |
| #define INVALIDATE_ADJACENT_PAGES_CPU15(addr, tmp) |
| #endif |
| |
| START_EXCEPTION(INTERRUPT_INST_TLB_MISS_8xx, InstructionTLBMiss) |
| mtspr SPRN_SPRG_SCRATCH2, r10 |
| mtspr SPRN_M_TW, 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, r11) |
| mtspr SPRN_MD_EPN, r10 |
| mfspr r10, SPRN_M_TWB /* Get level 1 table */ |
| 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_SCRATCH2 |
| mfspr r11, SPRN_M_TW |
| 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_SCRATCH2 |
| mfspr r11, SPRN_M_TW |
| rfi |
| #endif |
| |
| START_EXCEPTION(INTERRUPT_DATA_TLB_MISS_8xx, DataStoreTLBMiss) |
| mtspr SPRN_SPRG_SCRATCH2, r10 |
| mtspr SPRN_M_TW, r11 |
| |
| /* If we are faulting a kernel address, we have to use the |
| * kernel page tables. |
| */ |
| mfspr r10, SPRN_MD_EPN |
| mfspr r10, SPRN_M_TWB /* Get level 1 table */ |
| 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 */ |
| mtspr SPRN_DAR, r11 /* Tag DAR */ |
| |
| /* Restore registers */ |
| |
| 0: mfspr r10, SPRN_SPRG_SCRATCH2 |
| 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_SPRG_SCRATCH2 |
| 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. |
| */ |
| START_EXCEPTION(INTERRUPT_INST_TLB_ERROR_8xx, InstructionTLBError) |
| /* 0x400 is InstructionAccess exception, needed by bad_page_fault() */ |
| EXCEPTION_PROLOG INTERRUPT_INST_STORAGE InstructionTLBError |
| andis. r5,r9,DSISR_SRR1_MATCH_32S@h /* Filter relevant SRR1 bits */ |
| andis. r10,r9,SRR1_ISI_NOPT@h |
| beq+ .Litlbie |
| tlbie r12 |
| .Litlbie: |
| stw r12, _DAR(r11) |
| stw r5, _DSISR(r11) |
| prepare_transfer_to_handler |
| bl do_page_fault |
| b interrupt_return |
| |
| /* 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. |
| */ |
| START_EXCEPTION(INTERRUPT_DATA_TLB_ERROR_8xx, 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 */ |
| mfspr r11, SPRN_DSISR |
| rlwinm r11, r11, 0, DSISR_NOHPTE |
| cmpwi cr1, r11, 0 |
| beq+ cr1, .Ldtlbie |
| mfspr r11, SPRN_DAR |
| tlbie r11 |
| rlwinm r11, r11, 16, 0xffff |
| cmplwi cr1, r11, TASK_SIZE@h |
| bge- cr1, FixupPGD |
| .Ldtlbie: |
| EXCEPTION_PROLOG_1 |
| /* 0x300 is DataAccess exception, needed by bad_page_fault() */ |
| EXCEPTION_PROLOG_2 INTERRUPT_DATA_STORAGE DataTLBError handle_dar_dsisr=1 |
| prepare_transfer_to_handler |
| bl do_page_fault |
| b interrupt_return |
| |
| #ifdef CONFIG_VMAP_STACK |
| vmap_stack_overflow_exception |
| #endif |
| |
| /* On the MPC8xx, these next four traps are used for development |
| * support of breakpoints and such. Someday I will get around to |
| * using them. |
| */ |
| START_EXCEPTION(INTERRUPT_DATA_BREAKPOINT_8xx, 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, 1f |
| mtcr r10 |
| mfspr r10, SPRN_SPRG_SCRATCH0 |
| mfspr r11, SPRN_SPRG_SCRATCH1 |
| rfi |
| |
| 1: EXCEPTION_PROLOG_1 |
| EXCEPTION_PROLOG_2 INTERRUPT_DATA_BREAKPOINT_8xx DataBreakpoint handle_dar_dsisr=1 |
| mfspr r4,SPRN_BAR |
| stw r4,_DAR(r11) |
| prepare_transfer_to_handler |
| bl do_break |
| REST_NVGPRS(r1) |
| b interrupt_return |
| |
| #ifdef CONFIG_PERF_EVENTS |
| START_EXCEPTION(INTERRUPT_INST_BREAKPOINT_8xx, 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(INTERRUPT_INST_BREAKPOINT_8xx, Trap_1d, unknown_exception) |
| #endif |
| EXCEPTION(0x1e00, Trap_1e, unknown_exception) |
| EXCEPTION(0x1f00, Trap_1f, unknown_exception) |
| |
| __HEAD |
| . = 0x2000 |
| |
| FixupPGD: |
| mtspr SPRN_M_TW, r10 |
| mfspr r10, SPRN_DAR |
| mtspr SPRN_MD_EPN, r10 |
| mfspr r11, SPRN_M_TWB /* Get level 1 table */ |
| lwz r10, (swapper_pg_dir - PAGE_OFFSET)@l(r11) /* Get the level 1 entry */ |
| cmpwi cr1, r10, 0 |
| bne cr1, 1f |
| |
| rlwinm r10, r11, 0, 20, 31 |
| oris r10, r10, (swapper_pg_dir - PAGE_OFFSET)@ha |
| lwz r10, (swapper_pg_dir - PAGE_OFFSET)@l(r10) /* Get the level 1 entry */ |
| cmpwi cr1, r10, 0 |
| beq cr1, 1f |
| stw r10, (swapper_pg_dir - PAGE_OFFSET)@l(r11) /* Set the level 1 entry */ |
| mfspr r10, SPRN_M_TW |
| mtcr r10 |
| mfspr r10, SPRN_SPRG_SCRATCH0 |
| mfspr r11, SPRN_SPRG_SCRATCH1 |
| rfi |
| 1: |
| mfspr r10, SPRN_M_TW |
| b .Ldtlbie |
| |
| /* 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, TASK_SIZE@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 */ |
| rlwinm r11, r11, 0, ~_PMD_PAGE_8M |
| mtspr SPRN_MD_TWC, r11 |
| mfspr r11, SPRN_MD_TWC |
| lwz r11, 0(r11) /* Get the pte */ |
| /* concat physical page address(r11) and page offset(r10) */ |
| rlwimi r11, r10, 0, 32 - PAGE_SHIFT, 31 |
| 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 */ |
| |
| 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 |
| mtdar r10 |
| mtctr r11 /* restore ctr reg from DAR */ |
| mfspr r11, SPRN_SPRG_THREAD |
| stw r10, DAR(r11) |
| mfspr r10, SPRN_DSISR |
| stw r10, DSISR(r11) |
| 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_MIN_SIZE(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. |
| */ |
| SYM_FUNC_START_LOCAL(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 |
| SYM_FUNC_END(initial_mmu) |
| |
| #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 |
