| /* |
| * OpenRISC head.S |
| * |
| * Linux architectural port borrowing liberally from similar works of |
| * others. All original copyrights apply as per the original source |
| * declaration. |
| * |
| * Modifications for the OpenRISC architecture: |
| * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com> |
| * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se> |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version |
| * 2 of the License, or (at your option) any later version. |
| */ |
| |
| #include <linux/linkage.h> |
| #include <linux/threads.h> |
| #include <linux/errno.h> |
| #include <linux/init.h> |
| #include <asm/processor.h> |
| #include <asm/page.h> |
| #include <asm/mmu.h> |
| #include <asm/pgtable.h> |
| #include <asm/cache.h> |
| #include <asm/spr_defs.h> |
| #include <asm/asm-offsets.h> |
| |
| #define tophys(rd,rs) \ |
| l.movhi rd,hi(-KERNELBASE) ;\ |
| l.add rd,rd,rs |
| |
| #define CLEAR_GPR(gpr) \ |
| l.or gpr,r0,r0 |
| |
| #define LOAD_SYMBOL_2_GPR(gpr,symbol) \ |
| l.movhi gpr,hi(symbol) ;\ |
| l.ori gpr,gpr,lo(symbol) |
| |
| |
| #define UART_BASE_ADD 0x90000000 |
| |
| #define EXCEPTION_SR (SPR_SR_DME | SPR_SR_IME | SPR_SR_DCE | SPR_SR_ICE | SPR_SR_SM) |
| #define SYSCALL_SR (SPR_SR_DME | SPR_SR_IME | SPR_SR_DCE | SPR_SR_ICE | SPR_SR_IEE | SPR_SR_TEE | SPR_SR_SM) |
| |
| /* ============================================[ tmp store locations ]=== */ |
| |
| /* |
| * emergency_print temporary stores |
| */ |
| #define EMERGENCY_PRINT_STORE_GPR4 l.sw 0x20(r0),r4 |
| #define EMERGENCY_PRINT_LOAD_GPR4 l.lwz r4,0x20(r0) |
| |
| #define EMERGENCY_PRINT_STORE_GPR5 l.sw 0x24(r0),r5 |
| #define EMERGENCY_PRINT_LOAD_GPR5 l.lwz r5,0x24(r0) |
| |
| #define EMERGENCY_PRINT_STORE_GPR6 l.sw 0x28(r0),r6 |
| #define EMERGENCY_PRINT_LOAD_GPR6 l.lwz r6,0x28(r0) |
| |
| #define EMERGENCY_PRINT_STORE_GPR7 l.sw 0x2c(r0),r7 |
| #define EMERGENCY_PRINT_LOAD_GPR7 l.lwz r7,0x2c(r0) |
| |
| #define EMERGENCY_PRINT_STORE_GPR8 l.sw 0x30(r0),r8 |
| #define EMERGENCY_PRINT_LOAD_GPR8 l.lwz r8,0x30(r0) |
| |
| #define EMERGENCY_PRINT_STORE_GPR9 l.sw 0x34(r0),r9 |
| #define EMERGENCY_PRINT_LOAD_GPR9 l.lwz r9,0x34(r0) |
| |
| |
| /* |
| * TLB miss handlers temorary stores |
| */ |
| #define EXCEPTION_STORE_GPR9 l.sw 0x10(r0),r9 |
| #define EXCEPTION_LOAD_GPR9 l.lwz r9,0x10(r0) |
| |
| #define EXCEPTION_STORE_GPR2 l.sw 0x64(r0),r2 |
| #define EXCEPTION_LOAD_GPR2 l.lwz r2,0x64(r0) |
| |
| #define EXCEPTION_STORE_GPR3 l.sw 0x68(r0),r3 |
| #define EXCEPTION_LOAD_GPR3 l.lwz r3,0x68(r0) |
| |
| #define EXCEPTION_STORE_GPR4 l.sw 0x6c(r0),r4 |
| #define EXCEPTION_LOAD_GPR4 l.lwz r4,0x6c(r0) |
| |
| #define EXCEPTION_STORE_GPR5 l.sw 0x70(r0),r5 |
| #define EXCEPTION_LOAD_GPR5 l.lwz r5,0x70(r0) |
| |
| #define EXCEPTION_STORE_GPR6 l.sw 0x74(r0),r6 |
| #define EXCEPTION_LOAD_GPR6 l.lwz r6,0x74(r0) |
| |
| |
| /* |
| * EXCEPTION_HANDLE temporary stores |
| */ |
| |
| #define EXCEPTION_T_STORE_GPR30 l.sw 0x78(r0),r30 |
| #define EXCEPTION_T_LOAD_GPR30(reg) l.lwz reg,0x78(r0) |
| |
| #define EXCEPTION_T_STORE_GPR10 l.sw 0x7c(r0),r10 |
| #define EXCEPTION_T_LOAD_GPR10(reg) l.lwz reg,0x7c(r0) |
| |
| #define EXCEPTION_T_STORE_SP l.sw 0x80(r0),r1 |
| #define EXCEPTION_T_LOAD_SP(reg) l.lwz reg,0x80(r0) |
| |
| /* |
| * For UNHANLDED_EXCEPTION |
| */ |
| |
| #define EXCEPTION_T_STORE_GPR31 l.sw 0x84(r0),r31 |
| #define EXCEPTION_T_LOAD_GPR31(reg) l.lwz reg,0x84(r0) |
| |
| /* =========================================================[ macros ]=== */ |
| |
| |
| #define GET_CURRENT_PGD(reg,t1) \ |
| LOAD_SYMBOL_2_GPR(reg,current_pgd) ;\ |
| tophys (t1,reg) ;\ |
| l.lwz reg,0(t1) |
| |
| |
| /* |
| * DSCR: this is a common hook for handling exceptions. it will save |
| * the needed registers, set up stack and pointer to current |
| * then jump to the handler while enabling MMU |
| * |
| * PRMS: handler - a function to jump to. it has to save the |
| * remaining registers to kernel stack, call |
| * appropriate arch-independant exception handler |
| * and finaly jump to ret_from_except |
| * |
| * PREQ: unchanged state from the time exception happened |
| * |
| * POST: SAVED the following registers original value |
| * to the new created exception frame pointed to by r1 |
| * |
| * r1 - ksp pointing to the new (exception) frame |
| * r4 - EEAR exception EA |
| * r10 - current pointing to current_thread_info struct |
| * r12 - syscall 0, since we didn't come from syscall |
| * r13 - temp it actually contains new SR, not needed anymore |
| * r31 - handler address of the handler we'll jump to |
| * |
| * handler has to save remaining registers to the exception |
| * ksp frame *before* tainting them! |
| * |
| * NOTE: this function is not reentrant per se. reentrancy is guaranteed |
| * by processor disabling all exceptions/interrupts when exception |
| * accours. |
| * |
| * OPTM: no need to make it so wasteful to extract ksp when in user mode |
| */ |
| |
| #define EXCEPTION_HANDLE(handler) \ |
| EXCEPTION_T_STORE_GPR30 ;\ |
| l.mfspr r30,r0,SPR_ESR_BASE ;\ |
| l.andi r30,r30,SPR_SR_SM ;\ |
| l.sfeqi r30,0 ;\ |
| EXCEPTION_T_STORE_GPR10 ;\ |
| l.bnf 2f /* kernel_mode */ ;\ |
| EXCEPTION_T_STORE_SP /* delay slot */ ;\ |
| 1: /* user_mode: */ ;\ |
| LOAD_SYMBOL_2_GPR(r1,current_thread_info_set) ;\ |
| tophys (r30,r1) ;\ |
| /* r10: current_thread_info */ ;\ |
| l.lwz r10,0(r30) ;\ |
| tophys (r30,r10) ;\ |
| l.lwz r1,(TI_KSP)(r30) ;\ |
| /* fall through */ ;\ |
| 2: /* kernel_mode: */ ;\ |
| /* create new stack frame, save only needed gprs */ ;\ |
| /* r1: KSP, r10: current, r4: EEAR, r31: __pa(KSP) */ ;\ |
| /* r12: temp, syscall indicator */ ;\ |
| l.addi r1,r1,-(INT_FRAME_SIZE) ;\ |
| /* r1 is KSP, r30 is __pa(KSP) */ ;\ |
| tophys (r30,r1) ;\ |
| l.sw PT_GPR12(r30),r12 ;\ |
| l.mfspr r12,r0,SPR_EPCR_BASE ;\ |
| l.sw PT_PC(r30),r12 ;\ |
| l.mfspr r12,r0,SPR_ESR_BASE ;\ |
| l.sw PT_SR(r30),r12 ;\ |
| /* save r30 */ ;\ |
| EXCEPTION_T_LOAD_GPR30(r12) ;\ |
| l.sw PT_GPR30(r30),r12 ;\ |
| /* save r10 as was prior to exception */ ;\ |
| EXCEPTION_T_LOAD_GPR10(r12) ;\ |
| l.sw PT_GPR10(r30),r12 ;\ |
| /* save PT_SP as was prior to exception */ ;\ |
| EXCEPTION_T_LOAD_SP(r12) ;\ |
| l.sw PT_SP(r30),r12 ;\ |
| /* save exception r4, set r4 = EA */ ;\ |
| l.sw PT_GPR4(r30),r4 ;\ |
| l.mfspr r4,r0,SPR_EEAR_BASE ;\ |
| /* r12 == 1 if we come from syscall */ ;\ |
| CLEAR_GPR(r12) ;\ |
| /* ----- turn on MMU ----- */ ;\ |
| l.ori r30,r0,(EXCEPTION_SR) ;\ |
| l.mtspr r0,r30,SPR_ESR_BASE ;\ |
| /* r30: EA address of handler */ ;\ |
| LOAD_SYMBOL_2_GPR(r30,handler) ;\ |
| l.mtspr r0,r30,SPR_EPCR_BASE ;\ |
| l.rfe |
| |
| /* |
| * this doesn't work |
| * |
| * |
| * #ifdef CONFIG_JUMP_UPON_UNHANDLED_EXCEPTION |
| * #define UNHANDLED_EXCEPTION(handler) \ |
| * l.ori r3,r0,0x1 ;\ |
| * l.mtspr r0,r3,SPR_SR ;\ |
| * l.movhi r3,hi(0xf0000100) ;\ |
| * l.ori r3,r3,lo(0xf0000100) ;\ |
| * l.jr r3 ;\ |
| * l.nop 1 |
| * |
| * #endif |
| */ |
| |
| /* DSCR: this is the same as EXCEPTION_HANDLE(), we are just |
| * a bit more carefull (if we have a PT_SP or current pointer |
| * corruption) and set them up from 'current_set' |
| * |
| */ |
| #define UNHANDLED_EXCEPTION(handler) \ |
| EXCEPTION_T_STORE_GPR31 ;\ |
| EXCEPTION_T_STORE_GPR10 ;\ |
| EXCEPTION_T_STORE_SP ;\ |
| /* temporary store r3, r9 into r1, r10 */ ;\ |
| l.addi r1,r3,0x0 ;\ |
| l.addi r10,r9,0x0 ;\ |
| /* the string referenced by r3 must be low enough */ ;\ |
| l.jal _emergency_print ;\ |
| l.ori r3,r0,lo(_string_unhandled_exception) ;\ |
| l.mfspr r3,r0,SPR_NPC ;\ |
| l.jal _emergency_print_nr ;\ |
| l.andi r3,r3,0x1f00 ;\ |
| /* the string referenced by r3 must be low enough */ ;\ |
| l.jal _emergency_print ;\ |
| l.ori r3,r0,lo(_string_epc_prefix) ;\ |
| l.jal _emergency_print_nr ;\ |
| l.mfspr r3,r0,SPR_EPCR_BASE ;\ |
| l.jal _emergency_print ;\ |
| l.ori r3,r0,lo(_string_nl) ;\ |
| /* end of printing */ ;\ |
| l.addi r3,r1,0x0 ;\ |
| l.addi r9,r10,0x0 ;\ |
| /* extract current, ksp from current_set */ ;\ |
| LOAD_SYMBOL_2_GPR(r1,_unhandled_stack_top) ;\ |
| LOAD_SYMBOL_2_GPR(r10,init_thread_union) ;\ |
| /* create new stack frame, save only needed gprs */ ;\ |
| /* r1: KSP, r10: current, r31: __pa(KSP) */ ;\ |
| /* r12: temp, syscall indicator, r13 temp */ ;\ |
| l.addi r1,r1,-(INT_FRAME_SIZE) ;\ |
| /* r1 is KSP, r31 is __pa(KSP) */ ;\ |
| tophys (r31,r1) ;\ |
| l.sw PT_GPR12(r31),r12 ;\ |
| l.mfspr r12,r0,SPR_EPCR_BASE ;\ |
| l.sw PT_PC(r31),r12 ;\ |
| l.mfspr r12,r0,SPR_ESR_BASE ;\ |
| l.sw PT_SR(r31),r12 ;\ |
| /* save r31 */ ;\ |
| EXCEPTION_T_LOAD_GPR31(r12) ;\ |
| l.sw PT_GPR31(r31),r12 ;\ |
| /* save r10 as was prior to exception */ ;\ |
| EXCEPTION_T_LOAD_GPR10(r12) ;\ |
| l.sw PT_GPR10(r31),r12 ;\ |
| /* save PT_SP as was prior to exception */ ;\ |
| EXCEPTION_T_LOAD_SP(r12) ;\ |
| l.sw PT_SP(r31),r12 ;\ |
| l.sw PT_GPR13(r31),r13 ;\ |
| /* --> */ ;\ |
| /* save exception r4, set r4 = EA */ ;\ |
| l.sw PT_GPR4(r31),r4 ;\ |
| l.mfspr r4,r0,SPR_EEAR_BASE ;\ |
| /* r12 == 1 if we come from syscall */ ;\ |
| CLEAR_GPR(r12) ;\ |
| /* ----- play a MMU trick ----- */ ;\ |
| l.ori r31,r0,(EXCEPTION_SR) ;\ |
| l.mtspr r0,r31,SPR_ESR_BASE ;\ |
| /* r31: EA address of handler */ ;\ |
| LOAD_SYMBOL_2_GPR(r31,handler) ;\ |
| l.mtspr r0,r31,SPR_EPCR_BASE ;\ |
| l.rfe |
| |
| /* =====================================================[ exceptions] === */ |
| |
| /* ---[ 0x100: RESET exception ]----------------------------------------- */ |
| .org 0x100 |
| /* Jump to .init code at _start which lives in the .head section |
| * and will be discarded after boot. |
| */ |
| LOAD_SYMBOL_2_GPR(r4, _start) |
| tophys (r3,r4) /* MMU disabled */ |
| l.jr r3 |
| l.nop |
| |
| /* ---[ 0x200: BUS exception ]------------------------------------------- */ |
| .org 0x200 |
| _dispatch_bus_fault: |
| EXCEPTION_HANDLE(_bus_fault_handler) |
| |
| /* ---[ 0x300: Data Page Fault exception ]------------------------------- */ |
| .org 0x300 |
| _dispatch_do_dpage_fault: |
| // totaly disable timer interrupt |
| // l.mtspr r0,r0,SPR_TTMR |
| // DEBUG_TLB_PROBE(0x300) |
| // EXCEPTION_DEBUG_VALUE_ER_ENABLED(0x300) |
| EXCEPTION_HANDLE(_data_page_fault_handler) |
| |
| /* ---[ 0x400: Insn Page Fault exception ]------------------------------- */ |
| .org 0x400 |
| _dispatch_do_ipage_fault: |
| // totaly disable timer interrupt |
| // l.mtspr r0,r0,SPR_TTMR |
| // DEBUG_TLB_PROBE(0x400) |
| // EXCEPTION_DEBUG_VALUE_ER_ENABLED(0x400) |
| EXCEPTION_HANDLE(_insn_page_fault_handler) |
| |
| /* ---[ 0x500: Timer exception ]----------------------------------------- */ |
| .org 0x500 |
| EXCEPTION_HANDLE(_timer_handler) |
| |
| /* ---[ 0x600: Aligment exception ]-------------------------------------- */ |
| .org 0x600 |
| EXCEPTION_HANDLE(_alignment_handler) |
| |
| /* ---[ 0x700: Illegal insn exception ]---------------------------------- */ |
| .org 0x700 |
| EXCEPTION_HANDLE(_illegal_instruction_handler) |
| |
| /* ---[ 0x800: External interrupt exception ]---------------------------- */ |
| .org 0x800 |
| EXCEPTION_HANDLE(_external_irq_handler) |
| |
| /* ---[ 0x900: DTLB miss exception ]------------------------------------- */ |
| .org 0x900 |
| l.j boot_dtlb_miss_handler |
| l.nop |
| |
| /* ---[ 0xa00: ITLB miss exception ]------------------------------------- */ |
| .org 0xa00 |
| l.j boot_itlb_miss_handler |
| l.nop |
| |
| /* ---[ 0xb00: Range exception ]----------------------------------------- */ |
| .org 0xb00 |
| UNHANDLED_EXCEPTION(_vector_0xb00) |
| |
| /* ---[ 0xc00: Syscall exception ]--------------------------------------- */ |
| .org 0xc00 |
| EXCEPTION_HANDLE(_sys_call_handler) |
| |
| /* ---[ 0xd00: Trap exception ]------------------------------------------ */ |
| .org 0xd00 |
| UNHANDLED_EXCEPTION(_vector_0xd00) |
| |
| /* ---[ 0xe00: Trap exception ]------------------------------------------ */ |
| .org 0xe00 |
| // UNHANDLED_EXCEPTION(_vector_0xe00) |
| EXCEPTION_HANDLE(_trap_handler) |
| |
| /* ---[ 0xf00: Reserved exception ]-------------------------------------- */ |
| .org 0xf00 |
| UNHANDLED_EXCEPTION(_vector_0xf00) |
| |
| /* ---[ 0x1000: Reserved exception ]------------------------------------- */ |
| .org 0x1000 |
| UNHANDLED_EXCEPTION(_vector_0x1000) |
| |
| /* ---[ 0x1100: Reserved exception ]------------------------------------- */ |
| .org 0x1100 |
| UNHANDLED_EXCEPTION(_vector_0x1100) |
| |
| /* ---[ 0x1200: Reserved exception ]------------------------------------- */ |
| .org 0x1200 |
| UNHANDLED_EXCEPTION(_vector_0x1200) |
| |
| /* ---[ 0x1300: Reserved exception ]------------------------------------- */ |
| .org 0x1300 |
| UNHANDLED_EXCEPTION(_vector_0x1300) |
| |
| /* ---[ 0x1400: Reserved exception ]------------------------------------- */ |
| .org 0x1400 |
| UNHANDLED_EXCEPTION(_vector_0x1400) |
| |
| /* ---[ 0x1500: Reserved exception ]------------------------------------- */ |
| .org 0x1500 |
| UNHANDLED_EXCEPTION(_vector_0x1500) |
| |
| /* ---[ 0x1600: Reserved exception ]------------------------------------- */ |
| .org 0x1600 |
| UNHANDLED_EXCEPTION(_vector_0x1600) |
| |
| /* ---[ 0x1700: Reserved exception ]------------------------------------- */ |
| .org 0x1700 |
| UNHANDLED_EXCEPTION(_vector_0x1700) |
| |
| /* ---[ 0x1800: Reserved exception ]------------------------------------- */ |
| .org 0x1800 |
| UNHANDLED_EXCEPTION(_vector_0x1800) |
| |
| /* ---[ 0x1900: Reserved exception ]------------------------------------- */ |
| .org 0x1900 |
| UNHANDLED_EXCEPTION(_vector_0x1900) |
| |
| /* ---[ 0x1a00: Reserved exception ]------------------------------------- */ |
| .org 0x1a00 |
| UNHANDLED_EXCEPTION(_vector_0x1a00) |
| |
| /* ---[ 0x1b00: Reserved exception ]------------------------------------- */ |
| .org 0x1b00 |
| UNHANDLED_EXCEPTION(_vector_0x1b00) |
| |
| /* ---[ 0x1c00: Reserved exception ]------------------------------------- */ |
| .org 0x1c00 |
| UNHANDLED_EXCEPTION(_vector_0x1c00) |
| |
| /* ---[ 0x1d00: Reserved exception ]------------------------------------- */ |
| .org 0x1d00 |
| UNHANDLED_EXCEPTION(_vector_0x1d00) |
| |
| /* ---[ 0x1e00: Reserved exception ]------------------------------------- */ |
| .org 0x1e00 |
| UNHANDLED_EXCEPTION(_vector_0x1e00) |
| |
| /* ---[ 0x1f00: Reserved exception ]------------------------------------- */ |
| .org 0x1f00 |
| UNHANDLED_EXCEPTION(_vector_0x1f00) |
| |
| .org 0x2000 |
| /* ===================================================[ kernel start ]=== */ |
| |
| /* .text*/ |
| |
| /* This early stuff belongs in HEAD, but some of the functions below definitely |
| * don't... */ |
| |
| __HEAD |
| .global _start |
| _start: |
| /* |
| * ensure a deterministic start |
| */ |
| |
| l.ori r3,r0,0x1 |
| l.mtspr r0,r3,SPR_SR |
| |
| CLEAR_GPR(r1) |
| CLEAR_GPR(r2) |
| CLEAR_GPR(r3) |
| CLEAR_GPR(r4) |
| CLEAR_GPR(r5) |
| CLEAR_GPR(r6) |
| CLEAR_GPR(r7) |
| CLEAR_GPR(r8) |
| CLEAR_GPR(r9) |
| CLEAR_GPR(r10) |
| CLEAR_GPR(r11) |
| CLEAR_GPR(r12) |
| CLEAR_GPR(r13) |
| CLEAR_GPR(r14) |
| CLEAR_GPR(r15) |
| CLEAR_GPR(r16) |
| CLEAR_GPR(r17) |
| CLEAR_GPR(r18) |
| CLEAR_GPR(r19) |
| CLEAR_GPR(r20) |
| CLEAR_GPR(r21) |
| CLEAR_GPR(r22) |
| CLEAR_GPR(r23) |
| CLEAR_GPR(r24) |
| CLEAR_GPR(r25) |
| CLEAR_GPR(r26) |
| CLEAR_GPR(r27) |
| CLEAR_GPR(r28) |
| CLEAR_GPR(r29) |
| CLEAR_GPR(r30) |
| CLEAR_GPR(r31) |
| |
| /* |
| * set up initial ksp and current |
| */ |
| LOAD_SYMBOL_2_GPR(r1,init_thread_union+0x2000) // setup kernel stack |
| LOAD_SYMBOL_2_GPR(r10,init_thread_union) // setup current |
| tophys (r31,r10) |
| l.sw TI_KSP(r31), r1 |
| |
| l.ori r4,r0,0x0 |
| |
| |
| /* |
| * .data contains initialized data, |
| * .bss contains uninitialized data - clear it up |
| */ |
| clear_bss: |
| LOAD_SYMBOL_2_GPR(r24, __bss_start) |
| LOAD_SYMBOL_2_GPR(r26, _end) |
| tophys(r28,r24) |
| tophys(r30,r26) |
| CLEAR_GPR(r24) |
| CLEAR_GPR(r26) |
| 1: |
| l.sw (0)(r28),r0 |
| l.sfltu r28,r30 |
| l.bf 1b |
| l.addi r28,r28,4 |
| |
| enable_ic: |
| l.jal _ic_enable |
| l.nop |
| |
| enable_dc: |
| l.jal _dc_enable |
| l.nop |
| |
| flush_tlb: |
| /* |
| * I N V A L I D A T E T L B e n t r i e s |
| */ |
| LOAD_SYMBOL_2_GPR(r5,SPR_DTLBMR_BASE(0)) |
| LOAD_SYMBOL_2_GPR(r6,SPR_ITLBMR_BASE(0)) |
| l.addi r7,r0,128 /* Maximum number of sets */ |
| 1: |
| l.mtspr r5,r0,0x0 |
| l.mtspr r6,r0,0x0 |
| |
| l.addi r5,r5,1 |
| l.addi r6,r6,1 |
| l.sfeq r7,r0 |
| l.bnf 1b |
| l.addi r7,r7,-1 |
| |
| |
| /* The MMU needs to be enabled before or32_early_setup is called */ |
| |
| enable_mmu: |
| /* |
| * enable dmmu & immu |
| * SR[5] = 0, SR[6] = 0, 6th and 7th bit of SR set to 0 |
| */ |
| l.mfspr r30,r0,SPR_SR |
| l.movhi r28,hi(SPR_SR_DME | SPR_SR_IME) |
| l.ori r28,r28,lo(SPR_SR_DME | SPR_SR_IME) |
| l.or r30,r30,r28 |
| l.mtspr r0,r30,SPR_SR |
| l.nop |
| l.nop |
| l.nop |
| l.nop |
| l.nop |
| l.nop |
| l.nop |
| l.nop |
| l.nop |
| l.nop |
| l.nop |
| l.nop |
| l.nop |
| l.nop |
| l.nop |
| l.nop |
| |
| // reset the simulation counters |
| l.nop 5 |
| |
| LOAD_SYMBOL_2_GPR(r24, or32_early_setup) |
| l.jalr r24 |
| l.nop |
| |
| clear_regs: |
| /* |
| * clear all GPRS to increase determinism |
| */ |
| CLEAR_GPR(r2) |
| CLEAR_GPR(r3) |
| CLEAR_GPR(r4) |
| CLEAR_GPR(r5) |
| CLEAR_GPR(r6) |
| CLEAR_GPR(r7) |
| CLEAR_GPR(r8) |
| CLEAR_GPR(r9) |
| CLEAR_GPR(r11) |
| CLEAR_GPR(r12) |
| CLEAR_GPR(r13) |
| CLEAR_GPR(r14) |
| CLEAR_GPR(r15) |
| CLEAR_GPR(r16) |
| CLEAR_GPR(r17) |
| CLEAR_GPR(r18) |
| CLEAR_GPR(r19) |
| CLEAR_GPR(r20) |
| CLEAR_GPR(r21) |
| CLEAR_GPR(r22) |
| CLEAR_GPR(r23) |
| CLEAR_GPR(r24) |
| CLEAR_GPR(r25) |
| CLEAR_GPR(r26) |
| CLEAR_GPR(r27) |
| CLEAR_GPR(r28) |
| CLEAR_GPR(r29) |
| CLEAR_GPR(r30) |
| CLEAR_GPR(r31) |
| |
| jump_start_kernel: |
| /* |
| * jump to kernel entry (start_kernel) |
| */ |
| LOAD_SYMBOL_2_GPR(r30, start_kernel) |
| l.jr r30 |
| l.nop |
| |
| /* ========================================[ cache ]=== */ |
| |
| /* aligment here so we don't change memory offsets with |
| * memory controler defined |
| */ |
| .align 0x2000 |
| |
| _ic_enable: |
| /* Check if IC present and skip enabling otherwise */ |
| l.mfspr r24,r0,SPR_UPR |
| l.andi r26,r24,SPR_UPR_ICP |
| l.sfeq r26,r0 |
| l.bf 9f |
| l.nop |
| |
| /* Disable IC */ |
| l.mfspr r6,r0,SPR_SR |
| l.addi r5,r0,-1 |
| l.xori r5,r5,SPR_SR_ICE |
| l.and r5,r6,r5 |
| l.mtspr r0,r5,SPR_SR |
| |
| /* Establish cache block size |
| If BS=0, 16; |
| If BS=1, 32; |
| r14 contain block size |
| */ |
| l.mfspr r24,r0,SPR_ICCFGR |
| l.andi r26,r24,SPR_ICCFGR_CBS |
| l.srli r28,r26,7 |
| l.ori r30,r0,16 |
| l.sll r14,r30,r28 |
| |
| /* Establish number of cache sets |
| r16 contains number of cache sets |
| r28 contains log(# of cache sets) |
| */ |
| l.andi r26,r24,SPR_ICCFGR_NCS |
| l.srli r28,r26,3 |
| l.ori r30,r0,1 |
| l.sll r16,r30,r28 |
| |
| /* Invalidate IC */ |
| l.addi r6,r0,0 |
| l.sll r5,r14,r28 |
| // l.mul r5,r14,r16 |
| // l.trap 1 |
| // l.addi r5,r0,IC_SIZE |
| 1: |
| l.mtspr r0,r6,SPR_ICBIR |
| l.sfne r6,r5 |
| l.bf 1b |
| l.add r6,r6,r14 |
| // l.addi r6,r6,IC_LINE |
| |
| /* Enable IC */ |
| l.mfspr r6,r0,SPR_SR |
| l.ori r6,r6,SPR_SR_ICE |
| l.mtspr r0,r6,SPR_SR |
| l.nop |
| l.nop |
| l.nop |
| l.nop |
| l.nop |
| l.nop |
| l.nop |
| l.nop |
| l.nop |
| l.nop |
| 9: |
| l.jr r9 |
| l.nop |
| |
| _dc_enable: |
| /* Check if DC present and skip enabling otherwise */ |
| l.mfspr r24,r0,SPR_UPR |
| l.andi r26,r24,SPR_UPR_DCP |
| l.sfeq r26,r0 |
| l.bf 9f |
| l.nop |
| |
| /* Disable DC */ |
| l.mfspr r6,r0,SPR_SR |
| l.addi r5,r0,-1 |
| l.xori r5,r5,SPR_SR_DCE |
| l.and r5,r6,r5 |
| l.mtspr r0,r5,SPR_SR |
| |
| /* Establish cache block size |
| If BS=0, 16; |
| If BS=1, 32; |
| r14 contain block size |
| */ |
| l.mfspr r24,r0,SPR_DCCFGR |
| l.andi r26,r24,SPR_DCCFGR_CBS |
| l.srli r28,r26,7 |
| l.ori r30,r0,16 |
| l.sll r14,r30,r28 |
| |
| /* Establish number of cache sets |
| r16 contains number of cache sets |
| r28 contains log(# of cache sets) |
| */ |
| l.andi r26,r24,SPR_DCCFGR_NCS |
| l.srli r28,r26,3 |
| l.ori r30,r0,1 |
| l.sll r16,r30,r28 |
| |
| /* Invalidate DC */ |
| l.addi r6,r0,0 |
| l.sll r5,r14,r28 |
| 1: |
| l.mtspr r0,r6,SPR_DCBIR |
| l.sfne r6,r5 |
| l.bf 1b |
| l.add r6,r6,r14 |
| |
| /* Enable DC */ |
| l.mfspr r6,r0,SPR_SR |
| l.ori r6,r6,SPR_SR_DCE |
| l.mtspr r0,r6,SPR_SR |
| 9: |
| l.jr r9 |
| l.nop |
| |
| /* ===============================================[ page table masks ]=== */ |
| |
| /* bit 4 is used in hardware as write back cache bit. we never use this bit |
| * explicitly, so we can reuse it as _PAGE_FILE bit and mask it out when |
| * writing into hardware pte's |
| */ |
| |
| #define DTLB_UP_CONVERT_MASK 0x3fa |
| #define ITLB_UP_CONVERT_MASK 0x3a |
| |
| /* for SMP we'd have (this is a bit subtle, CC must be always set |
| * for SMP, but since we have _PAGE_PRESENT bit always defined |
| * we can just modify the mask) |
| */ |
| #define DTLB_SMP_CONVERT_MASK 0x3fb |
| #define ITLB_SMP_CONVERT_MASK 0x3b |
| |
| /* ---[ boot dtlb miss handler ]----------------------------------------- */ |
| |
| boot_dtlb_miss_handler: |
| |
| /* mask for DTLB_MR register: - (0) sets V (valid) bit, |
| * - (31-12) sets bits belonging to VPN (31-12) |
| */ |
| #define DTLB_MR_MASK 0xfffff001 |
| |
| /* mask for DTLB_TR register: - (2) sets CI (cache inhibit) bit, |
| * - (4) sets A (access) bit, |
| * - (5) sets D (dirty) bit, |
| * - (8) sets SRE (superuser read) bit |
| * - (9) sets SWE (superuser write) bit |
| * - (31-12) sets bits belonging to VPN (31-12) |
| */ |
| #define DTLB_TR_MASK 0xfffff332 |
| |
| /* These are for masking out the VPN/PPN value from the MR/TR registers... |
| * it's not the same as the PFN */ |
| #define VPN_MASK 0xfffff000 |
| #define PPN_MASK 0xfffff000 |
| |
| |
| EXCEPTION_STORE_GPR6 |
| |
| #if 0 |
| l.mfspr r6,r0,SPR_ESR_BASE // |
| l.andi r6,r6,SPR_SR_SM // are we in kernel mode ? |
| l.sfeqi r6,0 // r6 == 0x1 --> SM |
| l.bf exit_with_no_dtranslation // |
| l.nop |
| #endif |
| |
| /* this could be optimized by moving storing of |
| * non r6 registers here, and jumping r6 restore |
| * if not in supervisor mode |
| */ |
| |
| EXCEPTION_STORE_GPR2 |
| EXCEPTION_STORE_GPR3 |
| EXCEPTION_STORE_GPR4 |
| EXCEPTION_STORE_GPR5 |
| |
| l.mfspr r4,r0,SPR_EEAR_BASE // get the offending EA |
| |
| immediate_translation: |
| CLEAR_GPR(r6) |
| |
| l.srli r3,r4,0xd // r3 <- r4 / 8192 (sets are relative to page size (8Kb) NOT VPN size (4Kb) |
| |
| l.mfspr r6, r0, SPR_DMMUCFGR |
| l.andi r6, r6, SPR_DMMUCFGR_NTS |
| l.srli r6, r6, SPR_DMMUCFGR_NTS_OFF |
| l.ori r5, r0, 0x1 |
| l.sll r5, r5, r6 // r5 = number DMMU sets |
| l.addi r6, r5, -1 // r6 = nsets mask |
| l.and r2, r3, r6 // r2 <- r3 % NSETS_MASK |
| |
| l.or r6,r6,r4 // r6 <- r4 |
| l.ori r6,r6,~(VPN_MASK) // r6 <- VPN :VPN .xfff - clear up lo(r6) to 0x**** *fff |
| l.movhi r5,hi(DTLB_MR_MASK) // r5 <- ffff:0000.x000 |
| l.ori r5,r5,lo(DTLB_MR_MASK) // r5 <- ffff:1111.x001 - apply DTLB_MR_MASK |
| l.and r5,r5,r6 // r5 <- VPN :VPN .x001 - we have DTLBMR entry |
| l.mtspr r2,r5,SPR_DTLBMR_BASE(0) // set DTLBMR |
| |
| /* set up DTLB with no translation for EA <= 0xbfffffff */ |
| LOAD_SYMBOL_2_GPR(r6,0xbfffffff) |
| l.sfgeu r6,r4 // flag if r6 >= r4 (if 0xbfffffff >= EA) |
| l.bf 1f // goto out |
| l.and r3,r4,r4 // delay slot :: 24 <- r4 (if flag==1) |
| |
| tophys(r3,r4) // r3 <- PA |
| 1: |
| l.ori r3,r3,~(PPN_MASK) // r3 <- PPN :PPN .xfff - clear up lo(r6) to 0x**** *fff |
| l.movhi r5,hi(DTLB_TR_MASK) // r5 <- ffff:0000.x000 |
| l.ori r5,r5,lo(DTLB_TR_MASK) // r5 <- ffff:1111.x330 - apply DTLB_MR_MASK |
| l.and r5,r5,r3 // r5 <- PPN :PPN .x330 - we have DTLBTR entry |
| l.mtspr r2,r5,SPR_DTLBTR_BASE(0) // set DTLBTR |
| |
| EXCEPTION_LOAD_GPR6 |
| EXCEPTION_LOAD_GPR5 |
| EXCEPTION_LOAD_GPR4 |
| EXCEPTION_LOAD_GPR3 |
| EXCEPTION_LOAD_GPR2 |
| |
| l.rfe // SR <- ESR, PC <- EPC |
| |
| exit_with_no_dtranslation: |
| /* EA out of memory or not in supervisor mode */ |
| EXCEPTION_LOAD_GPR6 |
| EXCEPTION_LOAD_GPR4 |
| l.j _dispatch_bus_fault |
| |
| /* ---[ boot itlb miss handler ]----------------------------------------- */ |
| |
| boot_itlb_miss_handler: |
| |
| /* mask for ITLB_MR register: - sets V (valid) bit, |
| * - sets bits belonging to VPN (15-12) |
| */ |
| #define ITLB_MR_MASK 0xfffff001 |
| |
| /* mask for ITLB_TR register: - sets A (access) bit, |
| * - sets SXE (superuser execute) bit |
| * - sets bits belonging to VPN (15-12) |
| */ |
| #define ITLB_TR_MASK 0xfffff050 |
| |
| /* |
| #define VPN_MASK 0xffffe000 |
| #define PPN_MASK 0xffffe000 |
| */ |
| |
| |
| |
| EXCEPTION_STORE_GPR2 |
| EXCEPTION_STORE_GPR3 |
| EXCEPTION_STORE_GPR4 |
| EXCEPTION_STORE_GPR5 |
| EXCEPTION_STORE_GPR6 |
| |
| #if 0 |
| l.mfspr r6,r0,SPR_ESR_BASE // |
| l.andi r6,r6,SPR_SR_SM // are we in kernel mode ? |
| l.sfeqi r6,0 // r6 == 0x1 --> SM |
| l.bf exit_with_no_itranslation |
| l.nop |
| #endif |
| |
| |
| l.mfspr r4,r0,SPR_EEAR_BASE // get the offending EA |
| |
| earlyearly: |
| CLEAR_GPR(r6) |
| |
| l.srli r3,r4,0xd // r3 <- r4 / 8192 (sets are relative to page size (8Kb) NOT VPN size (4Kb) |
| |
| l.mfspr r6, r0, SPR_IMMUCFGR |
| l.andi r6, r6, SPR_IMMUCFGR_NTS |
| l.srli r6, r6, SPR_IMMUCFGR_NTS_OFF |
| l.ori r5, r0, 0x1 |
| l.sll r5, r5, r6 // r5 = number IMMU sets from IMMUCFGR |
| l.addi r6, r5, -1 // r6 = nsets mask |
| l.and r2, r3, r6 // r2 <- r3 % NSETS_MASK |
| |
| l.or r6,r6,r4 // r6 <- r4 |
| l.ori r6,r6,~(VPN_MASK) // r6 <- VPN :VPN .xfff - clear up lo(r6) to 0x**** *fff |
| l.movhi r5,hi(ITLB_MR_MASK) // r5 <- ffff:0000.x000 |
| l.ori r5,r5,lo(ITLB_MR_MASK) // r5 <- ffff:1111.x001 - apply ITLB_MR_MASK |
| l.and r5,r5,r6 // r5 <- VPN :VPN .x001 - we have ITLBMR entry |
| l.mtspr r2,r5,SPR_ITLBMR_BASE(0) // set ITLBMR |
| |
| /* |
| * set up ITLB with no translation for EA <= 0x0fffffff |
| * |
| * we need this for head.S mapping (EA = PA). if we move all functions |
| * which run with mmu enabled into entry.S, we might be able to eliminate this. |
| * |
| */ |
| LOAD_SYMBOL_2_GPR(r6,0x0fffffff) |
| l.sfgeu r6,r4 // flag if r6 >= r4 (if 0xb0ffffff >= EA) |
| l.bf 1f // goto out |
| l.and r3,r4,r4 // delay slot :: 24 <- r4 (if flag==1) |
| |
| tophys(r3,r4) // r3 <- PA |
| 1: |
| l.ori r3,r3,~(PPN_MASK) // r3 <- PPN :PPN .xfff - clear up lo(r6) to 0x**** *fff |
| l.movhi r5,hi(ITLB_TR_MASK) // r5 <- ffff:0000.x000 |
| l.ori r5,r5,lo(ITLB_TR_MASK) // r5 <- ffff:1111.x050 - apply ITLB_MR_MASK |
| l.and r5,r5,r3 // r5 <- PPN :PPN .x050 - we have ITLBTR entry |
| l.mtspr r2,r5,SPR_ITLBTR_BASE(0) // set ITLBTR |
| |
| EXCEPTION_LOAD_GPR6 |
| EXCEPTION_LOAD_GPR5 |
| EXCEPTION_LOAD_GPR4 |
| EXCEPTION_LOAD_GPR3 |
| EXCEPTION_LOAD_GPR2 |
| |
| l.rfe // SR <- ESR, PC <- EPC |
| |
| exit_with_no_itranslation: |
| EXCEPTION_LOAD_GPR4 |
| EXCEPTION_LOAD_GPR6 |
| l.j _dispatch_bus_fault |
| l.nop |
| |
| /* ====================================================================== */ |
| /* |
| * Stuff below here shouldn't go into .head section... maybe this stuff |
| * can be moved to entry.S ??? |
| */ |
| |
| /* ==============================================[ DTLB miss handler ]=== */ |
| |
| /* |
| * Comments: |
| * Exception handlers are entered with MMU off so the following handler |
| * needs to use physical addressing |
| * |
| */ |
| |
| .text |
| ENTRY(dtlb_miss_handler) |
| EXCEPTION_STORE_GPR2 |
| EXCEPTION_STORE_GPR3 |
| EXCEPTION_STORE_GPR4 |
| EXCEPTION_STORE_GPR5 |
| EXCEPTION_STORE_GPR6 |
| /* |
| * get EA of the miss |
| */ |
| l.mfspr r2,r0,SPR_EEAR_BASE |
| /* |
| * pmd = (pmd_t *)(current_pgd + pgd_index(daddr)); |
| */ |
| GET_CURRENT_PGD(r3,r5) // r3 is current_pgd, r5 is temp |
| l.srli r4,r2,0x18 // >> PAGE_SHIFT + (PAGE_SHIFT - 2) |
| l.slli r4,r4,0x2 // to get address << 2 |
| l.add r5,r4,r3 // r4 is pgd_index(daddr) |
| /* |
| * if (pmd_none(*pmd)) |
| * goto pmd_none: |
| */ |
| tophys (r4,r5) |
| l.lwz r3,0x0(r4) // get *pmd value |
| l.sfne r3,r0 |
| l.bnf d_pmd_none |
| l.andi r3,r3,~PAGE_MASK //0x1fff // ~PAGE_MASK |
| /* |
| * if (pmd_bad(*pmd)) |
| * pmd_clear(pmd) |
| * goto pmd_bad: |
| */ |
| // l.sfeq r3,r0 // check *pmd value |
| // l.bf d_pmd_good |
| l.addi r3,r0,0xffffe000 // PAGE_MASK |
| // l.j d_pmd_bad |
| // l.sw 0x0(r4),r0 // clear pmd |
| d_pmd_good: |
| /* |
| * pte = *pte_offset(pmd, daddr); |
| */ |
| l.lwz r4,0x0(r4) // get **pmd value |
| l.and r4,r4,r3 // & PAGE_MASK |
| l.srli r5,r2,0xd // >> PAGE_SHIFT, r2 == EEAR |
| l.andi r3,r5,0x7ff // (1UL << PAGE_SHIFT - 2) - 1 |
| l.slli r3,r3,0x2 // to get address << 2 |
| l.add r3,r3,r4 |
| l.lwz r2,0x0(r3) // this is pte at last |
| /* |
| * if (!pte_present(pte)) |
| */ |
| l.andi r4,r2,0x1 |
| l.sfne r4,r0 // is pte present |
| l.bnf d_pte_not_present |
| l.addi r3,r0,0xffffe3fa // PAGE_MASK | DTLB_UP_CONVERT_MASK |
| /* |
| * fill DTLB TR register |
| */ |
| l.and r4,r2,r3 // apply the mask |
| // Determine number of DMMU sets |
| l.mfspr r6, r0, SPR_DMMUCFGR |
| l.andi r6, r6, SPR_DMMUCFGR_NTS |
| l.srli r6, r6, SPR_DMMUCFGR_NTS_OFF |
| l.ori r3, r0, 0x1 |
| l.sll r3, r3, r6 // r3 = number DMMU sets DMMUCFGR |
| l.addi r6, r3, -1 // r6 = nsets mask |
| l.and r5, r5, r6 // calc offset: & (NUM_TLB_ENTRIES-1) |
| //NUM_TLB_ENTRIES |
| l.mtspr r5,r4,SPR_DTLBTR_BASE(0) |
| /* |
| * fill DTLB MR register |
| */ |
| l.mfspr r2,r0,SPR_EEAR_BASE |
| l.addi r3,r0,0xffffe000 // PAGE_MASK |
| l.and r4,r2,r3 // apply PAGE_MASK to EA (__PHX__ do we really need this?) |
| l.ori r4,r4,0x1 // set hardware valid bit: DTBL_MR entry |
| l.mtspr r5,r4,SPR_DTLBMR_BASE(0) |
| |
| EXCEPTION_LOAD_GPR2 |
| EXCEPTION_LOAD_GPR3 |
| EXCEPTION_LOAD_GPR4 |
| EXCEPTION_LOAD_GPR5 |
| EXCEPTION_LOAD_GPR6 |
| l.rfe |
| d_pmd_bad: |
| l.nop 1 |
| EXCEPTION_LOAD_GPR2 |
| EXCEPTION_LOAD_GPR3 |
| EXCEPTION_LOAD_GPR4 |
| EXCEPTION_LOAD_GPR5 |
| EXCEPTION_LOAD_GPR6 |
| l.rfe |
| d_pmd_none: |
| d_pte_not_present: |
| EXCEPTION_LOAD_GPR2 |
| EXCEPTION_LOAD_GPR3 |
| EXCEPTION_LOAD_GPR4 |
| EXCEPTION_LOAD_GPR5 |
| EXCEPTION_LOAD_GPR6 |
| l.j _dispatch_do_dpage_fault |
| l.nop |
| |
| /* ==============================================[ ITLB miss handler ]=== */ |
| ENTRY(itlb_miss_handler) |
| EXCEPTION_STORE_GPR2 |
| EXCEPTION_STORE_GPR3 |
| EXCEPTION_STORE_GPR4 |
| EXCEPTION_STORE_GPR5 |
| EXCEPTION_STORE_GPR6 |
| /* |
| * get EA of the miss |
| */ |
| l.mfspr r2,r0,SPR_EEAR_BASE |
| |
| /* |
| * pmd = (pmd_t *)(current_pgd + pgd_index(daddr)); |
| * |
| */ |
| GET_CURRENT_PGD(r3,r5) // r3 is current_pgd, r5 is temp |
| l.srli r4,r2,0x18 // >> PAGE_SHIFT + (PAGE_SHIFT - 2) |
| l.slli r4,r4,0x2 // to get address << 2 |
| l.add r5,r4,r3 // r4 is pgd_index(daddr) |
| /* |
| * if (pmd_none(*pmd)) |
| * goto pmd_none: |
| */ |
| tophys (r4,r5) |
| l.lwz r3,0x0(r4) // get *pmd value |
| l.sfne r3,r0 |
| l.bnf i_pmd_none |
| l.andi r3,r3,0x1fff // ~PAGE_MASK |
| /* |
| * if (pmd_bad(*pmd)) |
| * pmd_clear(pmd) |
| * goto pmd_bad: |
| */ |
| |
| // l.sfeq r3,r0 // check *pmd value |
| // l.bf i_pmd_good |
| l.addi r3,r0,0xffffe000 // PAGE_MASK |
| // l.j i_pmd_bad |
| // l.sw 0x0(r4),r0 // clear pmd |
| |
| i_pmd_good: |
| /* |
| * pte = *pte_offset(pmd, iaddr); |
| * |
| */ |
| l.lwz r4,0x0(r4) // get **pmd value |
| l.and r4,r4,r3 // & PAGE_MASK |
| l.srli r5,r2,0xd // >> PAGE_SHIFT, r2 == EEAR |
| l.andi r3,r5,0x7ff // (1UL << PAGE_SHIFT - 2) - 1 |
| l.slli r3,r3,0x2 // to get address << 2 |
| l.add r3,r3,r4 |
| l.lwz r2,0x0(r3) // this is pte at last |
| /* |
| * if (!pte_present(pte)) |
| * |
| */ |
| l.andi r4,r2,0x1 |
| l.sfne r4,r0 // is pte present |
| l.bnf i_pte_not_present |
| l.addi r3,r0,0xffffe03a // PAGE_MASK | ITLB_UP_CONVERT_MASK |
| /* |
| * fill ITLB TR register |
| */ |
| l.and r4,r2,r3 // apply the mask |
| l.andi r3,r2,0x7c0 // _PAGE_EXEC | _PAGE_SRE | _PAGE_SWE | _PAGE_URE | _PAGE_UWE |
| // l.andi r3,r2,0x400 // _PAGE_EXEC |
| l.sfeq r3,r0 |
| l.bf itlb_tr_fill //_workaround |
| // Determine number of IMMU sets |
| l.mfspr r6, r0, SPR_IMMUCFGR |
| l.andi r6, r6, SPR_IMMUCFGR_NTS |
| l.srli r6, r6, SPR_IMMUCFGR_NTS_OFF |
| l.ori r3, r0, 0x1 |
| l.sll r3, r3, r6 // r3 = number IMMU sets IMMUCFGR |
| l.addi r6, r3, -1 // r6 = nsets mask |
| l.and r5, r5, r6 // calc offset: & (NUM_TLB_ENTRIES-1) |
| |
| /* |
| * __PHX__ :: fixme |
| * we should not just blindly set executable flags, |
| * but it does help with ping. the clean way would be to find out |
| * (and fix it) why stack doesn't have execution permissions |
| */ |
| |
| itlb_tr_fill_workaround: |
| l.ori r4,r4,0xc0 // | (SPR_ITLBTR_UXE | ITLBTR_SXE) |
| itlb_tr_fill: |
| l.mtspr r5,r4,SPR_ITLBTR_BASE(0) |
| /* |
| * fill DTLB MR register |
| */ |
| l.mfspr r2,r0,SPR_EEAR_BASE |
| l.addi r3,r0,0xffffe000 // PAGE_MASK |
| l.and r4,r2,r3 // apply PAGE_MASK to EA (__PHX__ do we really need this?) |
| l.ori r4,r4,0x1 // set hardware valid bit: DTBL_MR entry |
| l.mtspr r5,r4,SPR_ITLBMR_BASE(0) |
| |
| EXCEPTION_LOAD_GPR2 |
| EXCEPTION_LOAD_GPR3 |
| EXCEPTION_LOAD_GPR4 |
| EXCEPTION_LOAD_GPR5 |
| EXCEPTION_LOAD_GPR6 |
| l.rfe |
| |
| i_pmd_bad: |
| l.nop 1 |
| EXCEPTION_LOAD_GPR2 |
| EXCEPTION_LOAD_GPR3 |
| EXCEPTION_LOAD_GPR4 |
| EXCEPTION_LOAD_GPR5 |
| EXCEPTION_LOAD_GPR6 |
| l.rfe |
| i_pmd_none: |
| i_pte_not_present: |
| EXCEPTION_LOAD_GPR2 |
| EXCEPTION_LOAD_GPR3 |
| EXCEPTION_LOAD_GPR4 |
| EXCEPTION_LOAD_GPR5 |
| EXCEPTION_LOAD_GPR6 |
| l.j _dispatch_do_ipage_fault |
| l.nop |
| |
| /* ==============================================[ boot tlb handlers ]=== */ |
| |
| |
| /* =================================================[ debugging aids ]=== */ |
| |
| .align 64 |
| _immu_trampoline: |
| .space 64 |
| _immu_trampoline_top: |
| |
| #define TRAMP_SLOT_0 (0x0) |
| #define TRAMP_SLOT_1 (0x4) |
| #define TRAMP_SLOT_2 (0x8) |
| #define TRAMP_SLOT_3 (0xc) |
| #define TRAMP_SLOT_4 (0x10) |
| #define TRAMP_SLOT_5 (0x14) |
| #define TRAMP_FRAME_SIZE (0x18) |
| |
| ENTRY(_immu_trampoline_workaround) |
| // r2 EEA |
| // r6 is physical EEA |
| tophys(r6,r2) |
| |
| LOAD_SYMBOL_2_GPR(r5,_immu_trampoline) |
| tophys (r3,r5) // r3 is trampoline (physical) |
| |
| LOAD_SYMBOL_2_GPR(r4,0x15000000) |
| l.sw TRAMP_SLOT_0(r3),r4 |
| l.sw TRAMP_SLOT_1(r3),r4 |
| l.sw TRAMP_SLOT_4(r3),r4 |
| l.sw TRAMP_SLOT_5(r3),r4 |
| |
| // EPC = EEA - 0x4 |
| l.lwz r4,0x0(r6) // load op @ EEA + 0x0 (fc address) |
| l.sw TRAMP_SLOT_3(r3),r4 // store it to _immu_trampoline_data |
| l.lwz r4,-0x4(r6) // load op @ EEA - 0x4 (f8 address) |
| l.sw TRAMP_SLOT_2(r3),r4 // store it to _immu_trampoline_data |
| |
| l.srli r5,r4,26 // check opcode for write access |
| l.sfeqi r5,0 // l.j |
| l.bf 0f |
| l.sfeqi r5,0x11 // l.jr |
| l.bf 1f |
| l.sfeqi r5,1 // l.jal |
| l.bf 2f |
| l.sfeqi r5,0x12 // l.jalr |
| l.bf 3f |
| l.sfeqi r5,3 // l.bnf |
| l.bf 4f |
| l.sfeqi r5,4 // l.bf |
| l.bf 5f |
| 99: |
| l.nop |
| l.j 99b // should never happen |
| l.nop 1 |
| |
| // r2 is EEA |
| // r3 is trampoline address (physical) |
| // r4 is instruction |
| // r6 is physical(EEA) |
| // |
| // r5 |
| |
| 2: // l.jal |
| |
| /* 19 20 aa aa l.movhi r9,0xaaaa |
| * a9 29 bb bb l.ori r9,0xbbbb |
| * |
| * where 0xaaaabbbb is EEA + 0x4 shifted right 2 |
| */ |
| |
| l.addi r6,r2,0x4 // this is 0xaaaabbbb |
| |
| // l.movhi r9,0xaaaa |
| l.ori r5,r0,0x1920 // 0x1920 == l.movhi r9 |
| l.sh (TRAMP_SLOT_0+0x0)(r3),r5 |
| l.srli r5,r6,16 |
| l.sh (TRAMP_SLOT_0+0x2)(r3),r5 |
| |
| // l.ori r9,0xbbbb |
| l.ori r5,r0,0xa929 // 0xa929 == l.ori r9 |
| l.sh (TRAMP_SLOT_1+0x0)(r3),r5 |
| l.andi r5,r6,0xffff |
| l.sh (TRAMP_SLOT_1+0x2)(r3),r5 |
| |
| /* falthrough, need to set up new jump offset */ |
| |
| |
| 0: // l.j |
| l.slli r6,r4,6 // original offset shifted left 6 - 2 |
| // l.srli r6,r6,6 // original offset shifted right 2 |
| |
| l.slli r4,r2,4 // old jump position: EEA shifted left 4 |
| // l.srli r4,r4,6 // old jump position: shifted right 2 |
| |
| l.addi r5,r3,0xc // new jump position (physical) |
| l.slli r5,r5,4 // new jump position: shifted left 4 |
| |
| // calculate new jump offset |
| // new_off = old_off + (old_jump - new_jump) |
| |
| l.sub r5,r4,r5 // old_jump - new_jump |
| l.add r5,r6,r5 // orig_off + (old_jump - new_jump) |
| l.srli r5,r5,6 // new offset shifted right 2 |
| |
| // r5 is new jump offset |
| // l.j has opcode 0x0... |
| l.sw TRAMP_SLOT_2(r3),r5 // write it back |
| |
| l.j trampoline_out |
| l.nop |
| |
| /* ----------------------------- */ |
| |
| 3: // l.jalr |
| |
| /* 19 20 aa aa l.movhi r9,0xaaaa |
| * a9 29 bb bb l.ori r9,0xbbbb |
| * |
| * where 0xaaaabbbb is EEA + 0x4 shifted right 2 |
| */ |
| |
| l.addi r6,r2,0x4 // this is 0xaaaabbbb |
| |
| // l.movhi r9,0xaaaa |
| l.ori r5,r0,0x1920 // 0x1920 == l.movhi r9 |
| l.sh (TRAMP_SLOT_0+0x0)(r3),r5 |
| l.srli r5,r6,16 |
| l.sh (TRAMP_SLOT_0+0x2)(r3),r5 |
| |
| // l.ori r9,0xbbbb |
| l.ori r5,r0,0xa929 // 0xa929 == l.ori r9 |
| l.sh (TRAMP_SLOT_1+0x0)(r3),r5 |
| l.andi r5,r6,0xffff |
| l.sh (TRAMP_SLOT_1+0x2)(r3),r5 |
| |
| l.lhz r5,(TRAMP_SLOT_2+0x0)(r3) // load hi part of jump instruction |
| l.andi r5,r5,0x3ff // clear out opcode part |
| l.ori r5,r5,0x4400 // opcode changed from l.jalr -> l.jr |
| l.sh (TRAMP_SLOT_2+0x0)(r3),r5 // write it back |
| |
| /* falthrough */ |
| |
| 1: // l.jr |
| l.j trampoline_out |
| l.nop |
| |
| /* ----------------------------- */ |
| |
| 4: // l.bnf |
| 5: // l.bf |
| l.slli r6,r4,6 // original offset shifted left 6 - 2 |
| // l.srli r6,r6,6 // original offset shifted right 2 |
| |
| l.slli r4,r2,4 // old jump position: EEA shifted left 4 |
| // l.srli r4,r4,6 // old jump position: shifted right 2 |
| |
| l.addi r5,r3,0xc // new jump position (physical) |
| l.slli r5,r5,4 // new jump position: shifted left 4 |
| |
| // calculate new jump offset |
| // new_off = old_off + (old_jump - new_jump) |
| |
| l.add r6,r6,r4 // (orig_off + old_jump) |
| l.sub r6,r6,r5 // (orig_off + old_jump) - new_jump |
| l.srli r6,r6,6 // new offset shifted right 2 |
| |
| // r6 is new jump offset |
| l.lwz r4,(TRAMP_SLOT_2+0x0)(r3) // load jump instruction |
| l.srli r4,r4,16 |
| l.andi r4,r4,0xfc00 // get opcode part |
| l.slli r4,r4,16 |
| l.or r6,r4,r6 // l.b(n)f new offset |
| l.sw TRAMP_SLOT_2(r3),r6 // write it back |
| |
| /* we need to add l.j to EEA + 0x8 */ |
| tophys (r4,r2) // may not be needed (due to shifts down_ |
| l.addi r4,r4,(0x8 - 0x8) // jump target = r2 + 0x8 (compensate for 0x8) |
| // jump position = r5 + 0x8 (0x8 compensated) |
| l.sub r4,r4,r5 // jump offset = target - new_position + 0x8 |
| |
| l.slli r4,r4,4 // the amount of info in imediate of jump |
| l.srli r4,r4,6 // jump instruction with offset |
| l.sw TRAMP_SLOT_4(r3),r4 // write it to 4th slot |
| |
| /* fallthrough */ |
| |
| trampoline_out: |
| // set up new EPC to point to our trampoline code |
| LOAD_SYMBOL_2_GPR(r5,_immu_trampoline) |
| l.mtspr r0,r5,SPR_EPCR_BASE |
| |
| // immu_trampoline is (4x) CACHE_LINE aligned |
| // and only 6 instructions long, |
| // so we need to invalidate only 2 lines |
| |
| /* Establish cache block size |
| If BS=0, 16; |
| If BS=1, 32; |
| r14 contain block size |
| */ |
| l.mfspr r21,r0,SPR_ICCFGR |
| l.andi r21,r21,SPR_ICCFGR_CBS |
| l.srli r21,r21,7 |
| l.ori r23,r0,16 |
| l.sll r14,r23,r21 |
| |
| l.mtspr r0,r5,SPR_ICBIR |
| l.add r5,r5,r14 |
| l.mtspr r0,r5,SPR_ICBIR |
| |
| l.jr r9 |
| l.nop |
| |
| |
| /* |
| * DSCR: prints a string referenced by r3. |
| * |
| * PRMS: r3 - address of the first character of null |
| * terminated string to be printed |
| * |
| * PREQ: UART at UART_BASE_ADD has to be initialized |
| * |
| * POST: caller should be aware that r3, r9 are changed |
| */ |
| ENTRY(_emergency_print) |
| EMERGENCY_PRINT_STORE_GPR4 |
| EMERGENCY_PRINT_STORE_GPR5 |
| EMERGENCY_PRINT_STORE_GPR6 |
| EMERGENCY_PRINT_STORE_GPR7 |
| 2: |
| l.lbz r7,0(r3) |
| l.sfeq r7,r0 |
| l.bf 9f |
| l.nop |
| |
| // putc: |
| l.movhi r4,hi(UART_BASE_ADD) |
| |
| l.addi r6,r0,0x20 |
| 1: l.lbz r5,5(r4) |
| l.andi r5,r5,0x20 |
| l.sfeq r5,r6 |
| l.bnf 1b |
| l.nop |
| |
| l.sb 0(r4),r7 |
| |
| l.addi r6,r0,0x60 |
| 1: l.lbz r5,5(r4) |
| l.andi r5,r5,0x60 |
| l.sfeq r5,r6 |
| l.bnf 1b |
| l.nop |
| |
| /* next character */ |
| l.j 2b |
| l.addi r3,r3,0x1 |
| |
| 9: |
| EMERGENCY_PRINT_LOAD_GPR7 |
| EMERGENCY_PRINT_LOAD_GPR6 |
| EMERGENCY_PRINT_LOAD_GPR5 |
| EMERGENCY_PRINT_LOAD_GPR4 |
| l.jr r9 |
| l.nop |
| |
| ENTRY(_emergency_print_nr) |
| EMERGENCY_PRINT_STORE_GPR4 |
| EMERGENCY_PRINT_STORE_GPR5 |
| EMERGENCY_PRINT_STORE_GPR6 |
| EMERGENCY_PRINT_STORE_GPR7 |
| EMERGENCY_PRINT_STORE_GPR8 |
| |
| l.addi r8,r0,32 // shift register |
| |
| 1: /* remove leading zeros */ |
| l.addi r8,r8,-0x4 |
| l.srl r7,r3,r8 |
| l.andi r7,r7,0xf |
| |
| /* don't skip the last zero if number == 0x0 */ |
| l.sfeqi r8,0x4 |
| l.bf 2f |
| l.nop |
| |
| l.sfeq r7,r0 |
| l.bf 1b |
| l.nop |
| |
| 2: |
| l.srl r7,r3,r8 |
| |
| l.andi r7,r7,0xf |
| l.sflts r8,r0 |
| l.bf 9f |
| |
| l.sfgtui r7,0x9 |
| l.bnf 8f |
| l.nop |
| l.addi r7,r7,0x27 |
| |
| 8: |
| l.addi r7,r7,0x30 |
| // putc: |
| l.movhi r4,hi(UART_BASE_ADD) |
| |
| l.addi r6,r0,0x20 |
| 1: l.lbz r5,5(r4) |
| l.andi r5,r5,0x20 |
| l.sfeq r5,r6 |
| l.bnf 1b |
| l.nop |
| |
| l.sb 0(r4),r7 |
| |
| l.addi r6,r0,0x60 |
| 1: l.lbz r5,5(r4) |
| l.andi r5,r5,0x60 |
| l.sfeq r5,r6 |
| l.bnf 1b |
| l.nop |
| |
| /* next character */ |
| l.j 2b |
| l.addi r8,r8,-0x4 |
| |
| 9: |
| EMERGENCY_PRINT_LOAD_GPR8 |
| EMERGENCY_PRINT_LOAD_GPR7 |
| EMERGENCY_PRINT_LOAD_GPR6 |
| EMERGENCY_PRINT_LOAD_GPR5 |
| EMERGENCY_PRINT_LOAD_GPR4 |
| l.jr r9 |
| l.nop |
| |
| |
| /* |
| * This should be used for debugging only. |
| * It messes up the Linux early serial output |
| * somehow, so use it sparingly and essentially |
| * only if you need to debug something that goes wrong |
| * before Linux gets the early serial going. |
| * |
| * Furthermore, you'll have to make sure you set the |
| * UART_DEVISOR correctly according to the system |
| * clock rate. |
| * |
| * |
| */ |
| |
| |
| |
| #define SYS_CLK 20000000 |
| //#define SYS_CLK 1843200 |
| #define OR32_CONSOLE_BAUD 115200 |
| #define UART_DIVISOR SYS_CLK/(16*OR32_CONSOLE_BAUD) |
| |
| ENTRY(_early_uart_init) |
| l.movhi r3,hi(UART_BASE_ADD) |
| |
| l.addi r4,r0,0x7 |
| l.sb 0x2(r3),r4 |
| |
| l.addi r4,r0,0x0 |
| l.sb 0x1(r3),r4 |
| |
| l.addi r4,r0,0x3 |
| l.sb 0x3(r3),r4 |
| |
| l.lbz r5,3(r3) |
| l.ori r4,r5,0x80 |
| l.sb 0x3(r3),r4 |
| l.addi r4,r0,((UART_DIVISOR>>8) & 0x000000ff) |
| l.sb UART_DLM(r3),r4 |
| l.addi r4,r0,((UART_DIVISOR) & 0x000000ff) |
| l.sb UART_DLL(r3),r4 |
| l.sb 0x3(r3),r5 |
| |
| l.jr r9 |
| l.nop |
| |
| _string_copying_linux: |
| .string "\n\n\n\n\n\rCopying Linux... \0" |
| |
| _string_ok_booting: |
| .string "Ok, booting the kernel.\n\r\0" |
| |
| _string_unhandled_exception: |
| .string "\n\rRunarunaround: Unhandled exception 0x\0" |
| |
| _string_epc_prefix: |
| .string ": EPC=0x\0" |
| |
| _string_nl: |
| .string "\n\r\0" |
| |
| .global _string_esr_irq_bug |
| _string_esr_irq_bug: |
| .string "\n\rESR external interrupt bug, for details look into entry.S\n\r\0" |
| |
| |
| |
| /* ========================================[ page aligned structures ]=== */ |
| |
| /* |
| * .data section should be page aligned |
| * (look into arch/or32/kernel/vmlinux.lds) |
| */ |
| .section .data,"aw" |
| .align 8192 |
| .global empty_zero_page |
| empty_zero_page: |
| .space 8192 |
| |
| .global swapper_pg_dir |
| swapper_pg_dir: |
| .space 8192 |
| |
| .global _unhandled_stack |
| _unhandled_stack: |
| .space 8192 |
| _unhandled_stack_top: |
| |
| /* ============================================================[ EOF ]=== */ |