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Diffstat (limited to '')
| -rw-r--r-- | arch/ppc/kernel/head_4xx.S | 1021 |
1 files changed, 0 insertions, 1021 deletions
diff --git a/arch/ppc/kernel/head_4xx.S b/arch/ppc/kernel/head_4xx.S deleted file mode 100644 index 51da157a629e..000000000000 --- a/arch/ppc/kernel/head_4xx.S +++ /dev/null @@ -1,1021 +0,0 @@ -/* - * Copyright (c) 1995-1996 Gary Thomas <gdt@linuxppc.org> - * Initial PowerPC version. - * Copyright (c) 1996 Cort Dougan <cort@cs.nmt.edu> - * Rewritten for PReP - * Copyright (c) 1996 Paul Mackerras <paulus@cs.anu.edu.au> - * Low-level exception handers, MMU support, and rewrite. - * Copyright (c) 1997 Dan Malek <dmalek@jlc.net> - * PowerPC 8xx modifications. - * Copyright (c) 1998-1999 TiVo, Inc. - * PowerPC 403GCX modifications. - * Copyright (c) 1999 Grant Erickson <grant@lcse.umn.edu> - * PowerPC 403GCX/405GP modifications. - * Copyright 2000 MontaVista Software Inc. - * PPC405 modifications - * PowerPC 403GCX/405GP modifications. - * Author: MontaVista Software, Inc. - * frank_rowand@mvista.com or source@mvista.com - * debbie_chu@mvista.com - * - * - * Module name: head_4xx.S - * - * Description: - * Kernel execution entry point code. - * - * 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 <asm/processor.h> -#include <asm/page.h> -#include <asm/mmu.h> -#include <asm/pgtable.h> -#include <asm/ibm4xx.h> -#include <asm/cputable.h> -#include <asm/thread_info.h> -#include <asm/ppc_asm.h> -#include <asm/asm-offsets.h> - -/* As with the other PowerPC ports, it is expected that when code - * execution begins here, the following registers contain valid, yet - * optional, information: - * - * r3 - Board info structure pointer (DRAM, frequency, MAC address, etc.) - * r4 - Starting address of the init RAM disk - * r5 - Ending address of the init RAM disk - * r6 - Start of kernel command line string (e.g. "mem=96m") - * r7 - End of kernel command line string - * - * This is all going to change RSN when we add bi_recs....... -- Dan - */ - .text -_GLOBAL(_stext) -_GLOBAL(_start) - - /* Save parameters we are passed. - */ - mr r31,r3 - mr r30,r4 - mr r29,r5 - mr r28,r6 - mr r27,r7 - - /* We have to turn on the MMU right away so we get cache modes - * set correctly. - */ - bl initial_mmu - -/* We now have the lower 16 Meg mapped into TLB entries, and the caches - * ready to work. - */ -turn_on_mmu: - lis r0,MSR_KERNEL@h - ori r0,r0,MSR_KERNEL@l - mtspr SPRN_SRR1,r0 - lis r0,start_here@h - ori r0,r0,start_here@l - mtspr SPRN_SRR0,r0 - SYNC - rfi /* enables MMU */ - b . /* prevent prefetch past rfi */ - -/* - * This area is used for temporarily saving registers during the - * critical exception prolog. - */ - . = 0xc0 -crit_save: -_GLOBAL(crit_r10) - .space 4 -_GLOBAL(crit_r11) - .space 4 - -/* - * Exception vector entry code. This code runs with address translation - * turned off (i.e. using physical addresses). We assume SPRG3 has the - * physical address of the current task thread_struct. - * Note that we have to have decremented r1 before we write to any fields - * of the exception frame, since a critical interrupt could occur at any - * time, and it will write to the area immediately below the current r1. - */ -#define NORMAL_EXCEPTION_PROLOG \ - mtspr SPRN_SPRG0,r10; /* save two registers to work with */\ - mtspr SPRN_SPRG1,r11; \ - mtspr SPRN_SPRG2,r1; \ - mfcr r10; /* save CR in r10 for now */\ - mfspr r11,SPRN_SRR1; /* check whether user or kernel */\ - andi. r11,r11,MSR_PR; \ - beq 1f; \ - mfspr r1,SPRN_SPRG3; /* if from user, start at top of */\ - lwz r1,THREAD_INFO-THREAD(r1); /* this thread's kernel stack */\ - addi r1,r1,THREAD_SIZE; \ -1: subi r1,r1,INT_FRAME_SIZE; /* Allocate an exception frame */\ - tophys(r11,r1); \ - stw r10,_CCR(r11); /* save various registers */\ - stw r12,GPR12(r11); \ - stw r9,GPR9(r11); \ - mfspr r10,SPRN_SPRG0; \ - stw r10,GPR10(r11); \ - mfspr r12,SPRN_SPRG1; \ - stw r12,GPR11(r11); \ - mflr r10; \ - stw r10,_LINK(r11); \ - mfspr r10,SPRN_SPRG2; \ - mfspr r12,SPRN_SRR0; \ - stw r10,GPR1(r11); \ - mfspr r9,SPRN_SRR1; \ - stw r10,0(r11); \ - rlwinm r9,r9,0,14,12; /* clear MSR_WE (necessary?) */\ - stw r0,GPR0(r11); \ - SAVE_4GPRS(3, r11); \ - SAVE_2GPRS(7, r11) - -/* - * Exception prolog for critical exceptions. This is a little different - * from the normal exception prolog above since a critical exception - * can potentially occur at any point during normal exception processing. - * Thus we cannot use the same SPRG registers as the normal prolog above. - * Instead we use a couple of words of memory at low physical addresses. - * This is OK since we don't support SMP on these processors. - */ -#define CRITICAL_EXCEPTION_PROLOG \ - stw r10,crit_r10@l(0); /* save two registers to work with */\ - stw r11,crit_r11@l(0); \ - mfcr r10; /* save CR in r10 for now */\ - mfspr r11,SPRN_SRR3; /* check whether user or kernel */\ - andi. r11,r11,MSR_PR; \ - lis r11,critical_stack_top@h; \ - ori r11,r11,critical_stack_top@l; \ - beq 1f; \ - /* COMING FROM USER MODE */ \ - mfspr r11,SPRN_SPRG3; /* if from user, start at top of */\ - lwz r11,THREAD_INFO-THREAD(r11); /* this thread's kernel stack */\ - addi r11,r11,THREAD_SIZE; \ -1: subi r11,r11,INT_FRAME_SIZE; /* Allocate an exception frame */\ - tophys(r11,r11); \ - stw r10,_CCR(r11); /* save various registers */\ - stw r12,GPR12(r11); \ - stw r9,GPR9(r11); \ - mflr r10; \ - stw r10,_LINK(r11); \ - mfspr r12,SPRN_DEAR; /* save DEAR and ESR in the frame */\ - stw r12,_DEAR(r11); /* since they may have had stuff */\ - mfspr r9,SPRN_ESR; /* in them at the point where the */\ - stw r9,_ESR(r11); /* exception was taken */\ - mfspr r12,SPRN_SRR2; \ - stw r1,GPR1(r11); \ - mfspr r9,SPRN_SRR3; \ - stw r1,0(r11); \ - tovirt(r1,r11); \ - rlwinm r9,r9,0,14,12; /* clear MSR_WE (necessary?) */\ - stw r0,GPR0(r11); \ - SAVE_4GPRS(3, r11); \ - SAVE_2GPRS(7, r11) - - /* - * State at this point: - * r9 saved in stack frame, now saved SRR3 & ~MSR_WE - * r10 saved in crit_r10 and in stack frame, trashed - * r11 saved in crit_r11 and in stack frame, - * now phys stack/exception frame pointer - * r12 saved in stack frame, now saved SRR2 - * CR saved in stack frame, CR0.EQ = !SRR3.PR - * LR, DEAR, ESR in stack frame - * r1 saved in stack frame, now virt stack/excframe pointer - * r0, r3-r8 saved in stack frame - */ - -/* - * Exception vectors. - */ -#define START_EXCEPTION(n, label) \ - . = n; \ -label: - -#define EXCEPTION(n, label, hdlr, xfer) \ - START_EXCEPTION(n, label); \ - NORMAL_EXCEPTION_PROLOG; \ - addi r3,r1,STACK_FRAME_OVERHEAD; \ - xfer(n, hdlr) - -#define CRITICAL_EXCEPTION(n, label, hdlr) \ - START_EXCEPTION(n, label); \ - CRITICAL_EXCEPTION_PROLOG; \ - addi r3,r1,STACK_FRAME_OVERHEAD; \ - EXC_XFER_TEMPLATE(hdlr, n+2, (MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE)), \ - NOCOPY, crit_transfer_to_handler, \ - ret_from_crit_exc) - -#define EXC_XFER_TEMPLATE(hdlr, trap, msr, copyee, tfer, ret) \ - li r10,trap; \ - stw r10,TRAP(r11); \ - lis r10,msr@h; \ - ori r10,r10,msr@l; \ - copyee(r10, r9); \ - bl tfer; \ - .long hdlr; \ - .long ret - -#define COPY_EE(d, s) rlwimi d,s,0,16,16 -#define NOCOPY(d, s) - -#define EXC_XFER_STD(n, hdlr) \ - EXC_XFER_TEMPLATE(hdlr, n, MSR_KERNEL, NOCOPY, transfer_to_handler_full, \ - ret_from_except_full) - -#define EXC_XFER_LITE(n, hdlr) \ - EXC_XFER_TEMPLATE(hdlr, n+1, MSR_KERNEL, NOCOPY, transfer_to_handler, \ - ret_from_except) - -#define EXC_XFER_EE(n, hdlr) \ - EXC_XFER_TEMPLATE(hdlr, n, MSR_KERNEL, COPY_EE, transfer_to_handler_full, \ - ret_from_except_full) - -#define EXC_XFER_EE_LITE(n, hdlr) \ - EXC_XFER_TEMPLATE(hdlr, n+1, MSR_KERNEL, COPY_EE, transfer_to_handler, \ - ret_from_except) - - -/* - * 0x0100 - Critical Interrupt Exception - */ - CRITICAL_EXCEPTION(0x0100, CriticalInterrupt, unknown_exception) - -/* - * 0x0200 - Machine Check Exception - */ - CRITICAL_EXCEPTION(0x0200, MachineCheck, machine_check_exception) - -/* - * 0x0300 - Data Storage Exception - * This happens for just a few reasons. U0 set (but we don't do that), - * or zone protection fault (user violation, write to protected page). - * If this is just an update of modified status, we do that quickly - * and exit. Otherwise, we call heavywight functions to do the work. - */ - START_EXCEPTION(0x0300, DataStorage) - mtspr SPRN_SPRG0, r10 /* Save some working registers */ - mtspr SPRN_SPRG1, r11 -#ifdef CONFIG_403GCX - stw r12, 0(r0) - stw r9, 4(r0) - mfcr r11 - mfspr r12, SPRN_PID - stw r11, 8(r0) - stw r12, 12(r0) -#else - mtspr SPRN_SPRG4, r12 - mtspr SPRN_SPRG5, r9 - mfcr r11 - mfspr r12, SPRN_PID - mtspr SPRN_SPRG7, r11 - mtspr SPRN_SPRG6, r12 -#endif - - /* First, check if it was a zone fault (which means a user - * tried to access a kernel or read-protected page - always - * a SEGV). All other faults here must be stores, so no - * need to check ESR_DST as well. */ - mfspr r10, SPRN_ESR - andis. r10, r10, ESR_DIZ@h - bne 2f - - mfspr r10, SPRN_DEAR /* Get faulting address */ - - /* If we are faulting a kernel address, we have to use the - * kernel page tables. - */ - lis r11, TASK_SIZE@h - cmplw r10, r11 - blt+ 3f - lis r11, swapper_pg_dir@h - ori r11, r11, swapper_pg_dir@l - li r9, 0 - mtspr SPRN_PID, r9 /* TLB will have 0 TID */ - b 4f - - /* Get the PGD for the current thread. - */ -3: - mfspr r11,SPRN_SPRG3 - lwz r11,PGDIR(r11) -4: - tophys(r11, r11) - rlwimi r11, r10, 12, 20, 29 /* Create L1 (pgdir/pmd) address */ - lwz r11, 0(r11) /* Get L1 entry */ - rlwinm. r12, r11, 0, 0, 19 /* Extract L2 (pte) base address */ - beq 2f /* Bail if no table */ - - rlwimi r12, r10, 22, 20, 29 /* Compute PTE address */ - lwz r11, 0(r12) /* Get Linux PTE */ - - andi. r9, r11, _PAGE_RW /* Is it writeable? */ - beq 2f /* Bail if not */ - - /* Update 'changed'. - */ - ori r11, r11, _PAGE_DIRTY|_PAGE_ACCESSED|_PAGE_HWWRITE - stw r11, 0(r12) /* Update Linux page table */ - - /* Most of the Linux PTE is ready to load into the TLB LO. - * We set ZSEL, where only the LS-bit determines user access. - * We set execute, because we don't have the granularity to - * properly set this at the page level (Linux problem). - * If shared is set, we cause a zero PID->TID load. - * Many of these bits are software only. Bits we don't set - * here we (properly should) assume have the appropriate value. - */ - li r12, 0x0ce2 - andc r11, r11, r12 /* Make sure 20, 21 are zero */ - - /* find the TLB index that caused the fault. It has to be here. - */ - tlbsx r9, 0, r10 - - tlbwe r11, r9, TLB_DATA /* Load TLB LO */ - - /* Done...restore registers and get out of here. - */ -#ifdef CONFIG_403GCX - lwz r12, 12(r0) - lwz r11, 8(r0) - mtspr SPRN_PID, r12 - mtcr r11 - lwz r9, 4(r0) - lwz r12, 0(r0) -#else - mfspr r12, SPRN_SPRG6 - mfspr r11, SPRN_SPRG7 - mtspr SPRN_PID, r12 - mtcr r11 - mfspr r9, SPRN_SPRG5 - mfspr r12, SPRN_SPRG4 -#endif - mfspr r11, SPRN_SPRG1 - mfspr r10, SPRN_SPRG0 - PPC405_ERR77_SYNC - rfi /* Should sync shadow TLBs */ - b . /* prevent prefetch past rfi */ - -2: - /* The bailout. Restore registers to pre-exception conditions - * and call the heavyweights to help us out. - */ -#ifdef CONFIG_403GCX - lwz r12, 12(r0) - lwz r11, 8(r0) - mtspr SPRN_PID, r12 - mtcr r11 - lwz r9, 4(r0) - lwz r12, 0(r0) -#else - mfspr r12, SPRN_SPRG6 - mfspr r11, SPRN_SPRG7 - mtspr SPRN_PID, r12 - mtcr r11 - mfspr r9, SPRN_SPRG5 - mfspr r12, SPRN_SPRG4 -#endif - mfspr r11, SPRN_SPRG1 - mfspr r10, SPRN_SPRG0 - b DataAccess - -/* - * 0x0400 - Instruction Storage Exception - * This is caused by a fetch from non-execute or guarded pages. - */ - START_EXCEPTION(0x0400, InstructionAccess) - NORMAL_EXCEPTION_PROLOG - mr r4,r12 /* Pass SRR0 as arg2 */ - li r5,0 /* Pass zero as arg3 */ - EXC_XFER_EE_LITE(0x400, handle_page_fault) - -/* 0x0500 - External Interrupt Exception */ - EXCEPTION(0x0500, HardwareInterrupt, do_IRQ, EXC_XFER_LITE) - -/* 0x0600 - Alignment Exception */ - START_EXCEPTION(0x0600, Alignment) - NORMAL_EXCEPTION_PROLOG - mfspr r4,SPRN_DEAR /* Grab the DEAR and save it */ - stw r4,_DEAR(r11) - addi r3,r1,STACK_FRAME_OVERHEAD - EXC_XFER_EE(0x600, alignment_exception) - -/* 0x0700 - Program Exception */ - START_EXCEPTION(0x0700, ProgramCheck) - NORMAL_EXCEPTION_PROLOG - mfspr r4,SPRN_ESR /* Grab the ESR and save it */ - stw r4,_ESR(r11) - addi r3,r1,STACK_FRAME_OVERHEAD - EXC_XFER_STD(0x700, program_check_exception) - - EXCEPTION(0x0800, Trap_08, unknown_exception, EXC_XFER_EE) - EXCEPTION(0x0900, Trap_09, unknown_exception, EXC_XFER_EE) - EXCEPTION(0x0A00, Trap_0A, unknown_exception, EXC_XFER_EE) - EXCEPTION(0x0B00, Trap_0B, unknown_exception, EXC_XFER_EE) - -/* 0x0C00 - System Call Exception */ - START_EXCEPTION(0x0C00, SystemCall) - NORMAL_EXCEPTION_PROLOG - EXC_XFER_EE_LITE(0xc00, DoSyscall) - - EXCEPTION(0x0D00, Trap_0D, unknown_exception, EXC_XFER_EE) - EXCEPTION(0x0E00, Trap_0E, unknown_exception, EXC_XFER_EE) - EXCEPTION(0x0F00, Trap_0F, unknown_exception, EXC_XFER_EE) - -/* 0x1000 - Programmable Interval Timer (PIT) Exception */ - START_EXCEPTION(0x1000, Decrementer) - NORMAL_EXCEPTION_PROLOG - lis r0,TSR_PIS@h - mtspr SPRN_TSR,r0 /* Clear the PIT exception */ - addi r3,r1,STACK_FRAME_OVERHEAD - EXC_XFER_LITE(0x1000, timer_interrupt) - -#if 0 -/* NOTE: - * FIT and WDT handlers are not implemented yet. - */ - -/* 0x1010 - Fixed Interval Timer (FIT) Exception -*/ - STND_EXCEPTION(0x1010, FITException, unknown_exception) - -/* 0x1020 - Watchdog Timer (WDT) Exception -*/ -#ifdef CONFIG_BOOKE_WDT - CRITICAL_EXCEPTION(0x1020, WDTException, WatchdogException) -#else - CRITICAL_EXCEPTION(0x1020, WDTException, unknown_exception) -#endif -#endif - -/* 0x1100 - Data TLB Miss Exception - * As the name implies, translation is not in the MMU, so search the - * page tables and fix it. The only purpose of this function is to - * load TLB entries from the page table if they exist. - */ - START_EXCEPTION(0x1100, DTLBMiss) - mtspr SPRN_SPRG0, r10 /* Save some working registers */ - mtspr SPRN_SPRG1, r11 -#ifdef CONFIG_403GCX - stw r12, 0(r0) - stw r9, 4(r0) - mfcr r11 - mfspr r12, SPRN_PID - stw r11, 8(r0) - stw r12, 12(r0) -#else - mtspr SPRN_SPRG4, r12 - mtspr SPRN_SPRG5, r9 - mfcr r11 - mfspr r12, SPRN_PID - mtspr SPRN_SPRG7, r11 - mtspr SPRN_SPRG6, r12 -#endif - mfspr r10, SPRN_DEAR /* Get faulting address */ - - /* If we are faulting a kernel address, we have to use the - * kernel page tables. - */ - lis r11, TASK_SIZE@h - cmplw r10, r11 - blt+ 3f - lis r11, swapper_pg_dir@h - ori r11, r11, swapper_pg_dir@l - li r9, 0 - mtspr SPRN_PID, r9 /* TLB will have 0 TID */ - b 4f - - /* Get the PGD for the current thread. - */ -3: - mfspr r11,SPRN_SPRG3 - lwz r11,PGDIR(r11) -4: - tophys(r11, r11) - rlwimi r11, r10, 12, 20, 29 /* Create L1 (pgdir/pmd) address */ - lwz r12, 0(r11) /* Get L1 entry */ - andi. r9, r12, _PMD_PRESENT /* Check if it points to a PTE page */ - beq 2f /* Bail if no table */ - - rlwimi r12, r10, 22, 20, 29 /* Compute PTE address */ - lwz r11, 0(r12) /* Get Linux PTE */ - andi. r9, r11, _PAGE_PRESENT - beq 5f - - ori r11, r11, _PAGE_ACCESSED - stw r11, 0(r12) - - /* Create TLB tag. This is the faulting address plus a static - * set of bits. These are size, valid, E, U0. - */ - li r12, 0x00c0 - rlwimi r10, r12, 0, 20, 31 - - b finish_tlb_load - -2: /* Check for possible large-page pmd entry */ - rlwinm. r9, r12, 2, 22, 24 - beq 5f - - /* Create TLB tag. This is the faulting address, plus a static - * set of bits (valid, E, U0) plus the size from the PMD. - */ - ori r9, r9, 0x40 - rlwimi r10, r9, 0, 20, 31 - mr r11, r12 - - b finish_tlb_load - -5: - /* The bailout. Restore registers to pre-exception conditions - * and call the heavyweights to help us out. - */ -#ifdef CONFIG_403GCX - lwz r12, 12(r0) - lwz r11, 8(r0) - mtspr SPRN_PID, r12 - mtcr r11 - lwz r9, 4(r0) - lwz r12, 0(r0) -#else - mfspr r12, SPRN_SPRG6 - mfspr r11, SPRN_SPRG7 - mtspr SPRN_PID, r12 - mtcr r11 - mfspr r9, SPRN_SPRG5 - mfspr r12, SPRN_SPRG4 -#endif - mfspr r11, SPRN_SPRG1 - mfspr r10, SPRN_SPRG0 - b DataAccess - -/* 0x1200 - Instruction TLB Miss Exception - * Nearly the same as above, except we get our information from different - * registers and bailout to a different point. - */ - START_EXCEPTION(0x1200, ITLBMiss) - mtspr SPRN_SPRG0, r10 /* Save some working registers */ - mtspr SPRN_SPRG1, r11 -#ifdef CONFIG_403GCX - stw r12, 0(r0) - stw r9, 4(r0) - mfcr r11 - mfspr r12, SPRN_PID - stw r11, 8(r0) - stw r12, 12(r0) -#else - mtspr SPRN_SPRG4, r12 - mtspr SPRN_SPRG5, r9 - mfcr r11 - mfspr r12, SPRN_PID - mtspr SPRN_SPRG7, r11 - mtspr SPRN_SPRG6, r12 -#endif - mfspr r10, SPRN_SRR0 /* Get faulting address */ - - /* If we are faulting a kernel address, we have to use the - * kernel page tables. - */ - lis r11, TASK_SIZE@h - cmplw r10, r11 - blt+ 3f - lis r11, swapper_pg_dir@h - ori r11, r11, swapper_pg_dir@l - li r9, 0 - mtspr SPRN_PID, r9 /* TLB will have 0 TID */ - b 4f - - /* Get the PGD for the current thread. - */ -3: - mfspr r11,SPRN_SPRG3 - lwz r11,PGDIR(r11) -4: - tophys(r11, r11) - rlwimi r11, r10, 12, 20, 29 /* Create L1 (pgdir/pmd) address */ - lwz r12, 0(r11) /* Get L1 entry */ - andi. r9, r12, _PMD_PRESENT /* Check if it points to a PTE page */ - beq 2f /* Bail if no table */ - - rlwimi r12, r10, 22, 20, 29 /* Compute PTE address */ - lwz r11, 0(r12) /* Get Linux PTE */ - andi. r9, r11, _PAGE_PRESENT - beq 5f - - ori r11, r11, _PAGE_ACCESSED - stw r11, 0(r12) - - /* Create TLB tag. This is the faulting address plus a static - * set of bits. These are size, valid, E, U0. - */ - li r12, 0x00c0 - rlwimi r10, r12, 0, 20, 31 - - b finish_tlb_load - -2: /* Check for possible large-page pmd entry */ - rlwinm. r9, r12, 2, 22, 24 - beq 5f - - /* Create TLB tag. This is the faulting address, plus a static - * set of bits (valid, E, U0) plus the size from the PMD. - */ - ori r9, r9, 0x40 - rlwimi r10, r9, 0, 20, 31 - mr r11, r12 - - b finish_tlb_load - -5: - /* The bailout. Restore registers to pre-exception conditions - * and call the heavyweights to help us out. - */ -#ifdef CONFIG_403GCX - lwz r12, 12(r0) - lwz r11, 8(r0) - mtspr SPRN_PID, r12 - mtcr r11 - lwz r9, 4(r0) - lwz r12, 0(r0) -#else - mfspr r12, SPRN_SPRG6 - mfspr r11, SPRN_SPRG7 - mtspr SPRN_PID, r12 - mtcr r11 - mfspr r9, SPRN_SPRG5 - mfspr r12, SPRN_SPRG4 -#endif - mfspr r11, SPRN_SPRG1 - mfspr r10, SPRN_SPRG0 - b InstructionAccess - - EXCEPTION(0x1300, Trap_13, unknown_exception, EXC_XFER_EE) - EXCEPTION(0x1400, Trap_14, unknown_exception, EXC_XFER_EE) - EXCEPTION(0x1500, Trap_15, unknown_exception, EXC_XFER_EE) - EXCEPTION(0x1600, Trap_16, unknown_exception, EXC_XFER_EE) -#ifdef CONFIG_IBM405_ERR51 - /* 405GP errata 51 */ - START_EXCEPTION(0x1700, Trap_17) - b DTLBMiss -#else - EXCEPTION(0x1700, Trap_17, unknown_exception, EXC_XFER_EE) -#endif - EXCEPTION(0x1800, Trap_18, unknown_exception, EXC_XFER_EE) - EXCEPTION(0x1900, Trap_19, unknown_exception, EXC_XFER_EE) - EXCEPTION(0x1A00, Trap_1A, unknown_exception, EXC_XFER_EE) - EXCEPTION(0x1B00, Trap_1B, unknown_exception, EXC_XFER_EE) - EXCEPTION(0x1C00, Trap_1C, unknown_exception, EXC_XFER_EE) - EXCEPTION(0x1D00, Trap_1D, unknown_exception, EXC_XFER_EE) - EXCEPTION(0x1E00, Trap_1E, unknown_exception, EXC_XFER_EE) - EXCEPTION(0x1F00, Trap_1F, unknown_exception, EXC_XFER_EE) - -/* Check for a single step debug exception while in an exception - * handler before state has been saved. This is to catch the case - * where an instruction that we are trying to single step causes - * an exception (eg ITLB/DTLB miss) and thus the first instruction of - * the exception handler generates a single step debug exception. - * - * If we get a debug trap on the first instruction of an exception handler, - * we reset the MSR_DE in the _exception handler's_ MSR (the debug trap is - * a critical exception, so we are using SPRN_CSRR1 to manipulate the MSR). - * The exception handler was handling a non-critical interrupt, so it will - * save (and later restore) the MSR via SPRN_SRR1, which will still have - * the MSR_DE bit set. - */ - /* 0x2000 - Debug Exception */ - START_EXCEPTION(0x2000, DebugTrap) - CRITICAL_EXCEPTION_PROLOG - - /* - * If this is a single step or branch-taken exception in an - * exception entry sequence, it was probably meant to apply to - * the code where the exception occurred (since exception entry - * doesn't turn off DE automatically). We simulate the effect - * of turning off DE on entry to an exception handler by turning - * off DE in the SRR3 value and clearing the debug status. - */ - mfspr r10,SPRN_DBSR /* check single-step/branch taken */ - andis. r10,r10,DBSR_IC@h - beq+ 2f - - andi. r10,r9,MSR_IR|MSR_PR /* check supervisor + MMU off */ - beq 1f /* branch and fix it up */ - - mfspr r10,SPRN_SRR2 /* Faulting instruction address */ - cmplwi r10,0x2100 - bgt+ 2f /* address above exception vectors */ - - /* here it looks like we got an inappropriate debug exception. */ -1: rlwinm r9,r9,0,~MSR_DE /* clear DE in the SRR3 value */ - lis r10,DBSR_IC@h /* clear the IC event */ - mtspr SPRN_DBSR,r10 - /* restore state and get out */ - lwz r10,_CCR(r11) - lwz r0,GPR0(r11) - lwz r1,GPR1(r11) - mtcrf 0x80,r10 - mtspr SPRN_SRR2,r12 - mtspr SPRN_SRR3,r9 - lwz r9,GPR9(r11) - lwz r12,GPR12(r11) - lwz r10,crit_r10@l(0) - lwz r11,crit_r11@l(0) - PPC405_ERR77_SYNC - rfci - b . - - /* continue normal handling for a critical exception... */ -2: mfspr r4,SPRN_DBSR - addi r3,r1,STACK_FRAME_OVERHEAD - EXC_XFER_TEMPLATE(DebugException, 0x2002, \ - (MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE)), \ - NOCOPY, crit_transfer_to_handler, ret_from_crit_exc) - -/* - * The other Data TLB exceptions bail out to this point - * if they can't resolve the lightweight TLB fault. - */ -DataAccess: - NORMAL_EXCEPTION_PROLOG - mfspr r5,SPRN_ESR /* Grab the ESR, save it, pass arg3 */ - stw r5,_ESR(r11) - mfspr r4,SPRN_DEAR /* Grab the DEAR, save it, pass arg2 */ - EXC_XFER_EE_LITE(0x300, handle_page_fault) - -/* Other PowerPC processors, namely those derived from the 6xx-series - * have vectors from 0x2100 through 0x2F00 defined, but marked as reserved. - * However, for the 4xx-series processors these are neither defined nor - * reserved. - */ - - /* Damn, I came up one instruction too many to fit into the - * exception space :-). Both the instruction and data TLB - * miss get to this point to load the TLB. - * r10 - TLB_TAG value - * r11 - Linux PTE - * r12, r9 - avilable to use - * PID - loaded with proper value when we get here - * Upon exit, we reload everything and RFI. - * Actually, it will fit now, but oh well.....a common place - * to load the TLB. - */ -tlb_4xx_index: - .long 0 -finish_tlb_load: - /* load the next available TLB index. - */ - lwz r9, tlb_4xx_index@l(0) - addi r9, r9, 1 - andi. r9, r9, (PPC4XX_TLB_SIZE-1) - stw r9, tlb_4xx_index@l(0) - -6: - /* - * Clear out the software-only bits in the PTE to generate the - * TLB_DATA value. These are the bottom 2 bits of the RPM, the - * top 3 bits of the zone field, and M. - */ - li r12, 0x0ce2 - andc r11, r11, r12 - - tlbwe r11, r9, TLB_DATA /* Load TLB LO */ - tlbwe r10, r9, TLB_TAG /* Load TLB HI */ - - /* Done...restore registers and get out of here. - */ -#ifdef CONFIG_403GCX - lwz r12, 12(r0) - lwz r11, 8(r0) - mtspr SPRN_PID, r12 - mtcr r11 - lwz r9, 4(r0) - lwz r12, 0(r0) -#else - mfspr r12, SPRN_SPRG6 - mfspr r11, SPRN_SPRG7 - mtspr SPRN_PID, r12 - mtcr r11 - mfspr r9, SPRN_SPRG5 - mfspr r12, SPRN_SPRG4 -#endif - mfspr r11, SPRN_SPRG1 - mfspr r10, SPRN_SPRG0 - PPC405_ERR77_SYNC - rfi /* Should sync shadow TLBs */ - b . /* prevent prefetch past rfi */ - -/* extern void giveup_fpu(struct task_struct *prev) - * - * The PowerPC 4xx family of processors do not have an FPU, so this just - * returns. - */ -_GLOBAL(giveup_fpu) - blr - -/* 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_SPRG3,r4 - - /* stack */ - lis r1,init_thread_union@ha - addi r1,r1,init_thread_union@l - li r0,0 - stwu r0,THREAD_SIZE-STACK_FRAME_OVERHEAD(r1) - - bl early_init /* We have to do this with MMU on */ - -/* - * Decide what sort of machine this is and initialize the MMU. - */ - mr r3,r31 - mr r4,r30 - mr r5,r29 - mr r6,r28 - mr r7,r27 - bl machine_init - bl MMU_init - -/* Go back to running unmapped so we can load up new values - * and change to using our exception vectors. - * On the 4xx, all we have to do is invalidate the TLB to clear - * the old 16M byte TLB mappings. - */ - lis r4,2f@h - ori r4,r4,2f@l - tophys(r4,r4) - lis r3,(MSR_KERNEL & ~(MSR_IR|MSR_DR))@h - ori r3,r3,(MSR_KERNEL & ~(MSR_IR|MSR_DR))@l - mtspr SPRN_SRR0,r4 - mtspr SPRN_SRR1,r3 - rfi - b . /* prevent prefetch past rfi */ - -/* Load up the kernel context */ -2: - sync /* Flush to memory before changing TLB */ - tlbia - isync /* Flush shadow TLBs */ - - /* set up the PTE pointers for the Abatron bdiGDB. - */ - lis r6, swapper_pg_dir@h - ori r6, r6, swapper_pg_dir@l - lis r5, abatron_pteptrs@h - ori r5, r5, abatron_pteptrs@l - stw r5, 0xf0(r0) /* Must match your Abatron config file */ - tophys(r5,r5) - stw r6, 0(r5) - -/* Now turn on the MMU for real! */ - lis r4,MSR_KERNEL@h - ori r4,r4,MSR_KERNEL@l - lis r3,start_kernel@h - ori r3,r3,start_kernel@l - mtspr SPRN_SRR0,r3 - mtspr SPRN_SRR1,r4 - rfi /* enable MMU and jump to start_kernel */ - b . /* prevent prefetch past rfi */ - -/* Set up the initial MMU state so we can do the first level of - * kernel initialization. This maps the first 16 MBytes of memory 1:1 - * virtual to physical and more importantly sets the cache mode. - */ -initial_mmu: - tlbia /* Invalidate all TLB entries */ - isync - - /* We should still be executing code at physical address 0x0000xxxx - * at this point. However, start_here is at virtual address - * 0xC000xxxx. So, set up a TLB mapping to cover this once - * translation is enabled. - */ - - lis r3,KERNELBASE@h /* Load the kernel virtual address */ - ori r3,r3,KERNELBASE@l - tophys(r4,r3) /* Load the kernel physical address */ - - iccci r0,r3 /* Invalidate the i-cache before use */ - - /* Load the kernel PID. - */ - li r0,0 - mtspr SPRN_PID,r0 - sync - - /* Configure and load two entries into TLB slots 62 and 63. - * In case we are pinning TLBs, these are reserved in by the - * other TLB functions. If not reserving, then it doesn't - * matter where they are loaded. - */ - clrrwi r4,r4,10 /* Mask off the real page number */ - ori r4,r4,(TLB_WR | TLB_EX) /* Set the write and execute bits */ - - clrrwi r3,r3,10 /* Mask off the effective page number */ - ori r3,r3,(TLB_VALID | TLB_PAGESZ(PAGESZ_16M)) - - li r0,63 /* TLB slot 63 */ - - tlbwe r4,r0,TLB_DATA /* Load the data portion of the entry */ - tlbwe r3,r0,TLB_TAG /* Load the tag portion of the entry */ - -#if defined(CONFIG_SERIAL_TEXT_DEBUG) && defined(SERIAL_DEBUG_IO_BASE) - - /* Load a TLB entry for the UART, so that ppc4xx_progress() can use - * the UARTs nice and early. We use a 4k real==virtual mapping. */ - - lis r3,SERIAL_DEBUG_IO_BASE@h - ori r3,r3,SERIAL_DEBUG_IO_BASE@l - mr r4,r3 - clrrwi r4,r4,12 - ori r4,r4,(TLB_WR|TLB_I|TLB_M|TLB_G) - - clrrwi r3,r3,12 - ori r3,r3,(TLB_VALID | TLB_PAGESZ(PAGESZ_4K)) - - li r0,0 /* TLB slot 0 */ - tlbwe r4,r0,TLB_DATA - tlbwe r3,r0,TLB_TAG -#endif /* CONFIG_SERIAL_DEBUG_TEXT && SERIAL_DEBUG_IO_BASE */ - - isync - - /* Establish the exception vector base - */ - lis r4,KERNELBASE@h /* EVPR only uses the high 16-bits */ - tophys(r0,r4) /* Use the physical address */ - mtspr SPRN_EVPR,r0 - - blr - -_GLOBAL(abort) - mfspr r13,SPRN_DBCR0 - oris r13,r13,DBCR0_RST_SYSTEM@h - mtspr SPRN_DBCR0,r13 - -_GLOBAL(set_context) - -#ifdef CONFIG_BDI_SWITCH - /* Context switch the PTE pointer for the Abatron BDI2000. - * The PGDIR is the second parameter. - */ - lis r5, KERNELBASE@h - lwz r5, 0xf0(r5) - stw r4, 0x4(r5) -#endif - sync - mtspr SPRN_PID,r3 - isync /* Need an isync to flush shadow */ - /* TLBs after changing PID */ - blr - -/* We put a few things here that have to be page-aligned. This stuff - * goes at the beginning of the data segment, which is page-aligned. - */ - .data - .align 12 - .globl sdata -sdata: - .globl empty_zero_page -empty_zero_page: - .space 4096 - .globl swapper_pg_dir -swapper_pg_dir: - .space 4096 - - -/* Stack for handling critical exceptions from kernel mode */ - .section .bss - .align 12 -exception_stack_bottom: - .space 4096 -critical_stack_top: - .globl exception_stack_top -exception_stack_top: - -/* This space gets a copy of optional info passed to us by the bootstrap - * which is used to pass parameters into the kernel like root=/dev/sda1, etc. - */ - .globl cmd_line -cmd_line: - .space 512 - -/* Room for two PTE pointers, usually the kernel and current user pointers - * to their respective root page table. - */ -abatron_pteptrs: - .space 8 |