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Diffstat (limited to 'arch/openrisc/kernel/head.S')
| -rw-r--r-- | arch/openrisc/kernel/head.S | 1607 |
1 files changed, 1607 insertions, 0 deletions
diff --git a/arch/openrisc/kernel/head.S b/arch/openrisc/kernel/head.S new file mode 100644 index 000000000000..c75018d22644 --- /dev/null +++ b/arch/openrisc/kernel/head.S @@ -0,0 +1,1607 @@ +/* + * 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 ]=== */ |