446957ba51
Signed-off-by: Adam Buchbinder <adam.buchbinder@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
1277 lines
33 KiB
ArmAsm
1277 lines
33 KiB
ArmAsm
/*
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* Kernel execution entry point code.
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*
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* Copyright (c) 1995-1996 Gary Thomas <gdt@linuxppc.org>
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* Initial PowerPC version.
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* Copyright (c) 1996 Cort Dougan <cort@cs.nmt.edu>
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* Rewritten for PReP
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* Copyright (c) 1996 Paul Mackerras <paulus@cs.anu.edu.au>
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* Low-level exception handers, MMU support, and rewrite.
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* Copyright (c) 1997 Dan Malek <dmalek@jlc.net>
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* PowerPC 8xx modifications.
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* Copyright (c) 1998-1999 TiVo, Inc.
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* PowerPC 403GCX modifications.
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* Copyright (c) 1999 Grant Erickson <grant@lcse.umn.edu>
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* PowerPC 403GCX/405GP modifications.
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* Copyright 2000 MontaVista Software Inc.
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* PPC405 modifications
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* PowerPC 403GCX/405GP modifications.
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* Author: MontaVista Software, Inc.
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* frank_rowand@mvista.com or source@mvista.com
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* debbie_chu@mvista.com
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* Copyright 2002-2005 MontaVista Software, Inc.
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* PowerPC 44x support, Matt Porter <mporter@kernel.crashing.org>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation; either version 2 of the License, or (at your
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* option) any later version.
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*/
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#include <linux/init.h>
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#include <asm/processor.h>
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#include <asm/page.h>
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#include <asm/mmu.h>
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#include <asm/pgtable.h>
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#include <asm/cputable.h>
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#include <asm/thread_info.h>
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#include <asm/ppc_asm.h>
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#include <asm/asm-offsets.h>
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#include <asm/ptrace.h>
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#include <asm/synch.h>
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#include "head_booke.h"
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/* As with the other PowerPC ports, it is expected that when code
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* execution begins here, the following registers contain valid, yet
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* optional, information:
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*
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* r3 - Board info structure pointer (DRAM, frequency, MAC address, etc.)
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* r4 - Starting address of the init RAM disk
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* r5 - Ending address of the init RAM disk
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* r6 - Start of kernel command line string (e.g. "mem=128")
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* r7 - End of kernel command line string
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*
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*/
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__HEAD
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_ENTRY(_stext);
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_ENTRY(_start);
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/*
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* Reserve a word at a fixed location to store the address
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* of abatron_pteptrs
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*/
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nop
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mr r31,r3 /* save device tree ptr */
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li r24,0 /* CPU number */
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#ifdef CONFIG_RELOCATABLE
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/*
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* Relocate ourselves to the current runtime address.
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* This is called only by the Boot CPU.
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* "relocate" is called with our current runtime virutal
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* address.
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* r21 will be loaded with the physical runtime address of _stext
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*/
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bl 0f /* Get our runtime address */
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0: mflr r21 /* Make it accessible */
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addis r21,r21,(_stext - 0b)@ha
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addi r21,r21,(_stext - 0b)@l /* Get our current runtime base */
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/*
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* We have the runtime (virutal) address of our base.
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* We calculate our shift of offset from a 256M page.
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* We could map the 256M page we belong to at PAGE_OFFSET and
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* get going from there.
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*/
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lis r4,KERNELBASE@h
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ori r4,r4,KERNELBASE@l
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rlwinm r6,r21,0,4,31 /* r6 = PHYS_START % 256M */
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rlwinm r5,r4,0,4,31 /* r5 = KERNELBASE % 256M */
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subf r3,r5,r6 /* r3 = r6 - r5 */
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add r3,r4,r3 /* Required Virutal Address */
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bl relocate
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#endif
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bl init_cpu_state
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/*
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* This is where the main kernel code starts.
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*/
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/* ptr to current */
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lis r2,init_task@h
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ori r2,r2,init_task@l
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/* ptr to current thread */
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addi r4,r2,THREAD /* init task's THREAD */
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mtspr SPRN_SPRG_THREAD,r4
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/* stack */
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lis r1,init_thread_union@h
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ori r1,r1,init_thread_union@l
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li r0,0
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stwu r0,THREAD_SIZE-STACK_FRAME_OVERHEAD(r1)
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bl early_init
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#ifdef CONFIG_RELOCATABLE
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/*
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* Relocatable kernel support based on processing of dynamic
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* relocation entries.
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*
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* r25 will contain RPN/ERPN for the start address of memory
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* r21 will contain the current offset of _stext
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*/
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lis r3,kernstart_addr@ha
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la r3,kernstart_addr@l(r3)
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/*
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* Compute the kernstart_addr.
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* kernstart_addr => (r6,r8)
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* kernstart_addr & ~0xfffffff => (r6,r7)
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*/
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rlwinm r6,r25,0,28,31 /* ERPN. Bits 32-35 of Address */
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rlwinm r7,r25,0,0,3 /* RPN - assuming 256 MB page size */
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rlwinm r8,r21,0,4,31 /* r8 = (_stext & 0xfffffff) */
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or r8,r7,r8 /* Compute the lower 32bit of kernstart_addr */
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/* Store kernstart_addr */
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stw r6,0(r3) /* higher 32bit */
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stw r8,4(r3) /* lower 32bit */
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/*
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* Compute the virt_phys_offset :
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* virt_phys_offset = stext.run - kernstart_addr
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*
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* stext.run = (KERNELBASE & ~0xfffffff) + (kernstart_addr & 0xfffffff)
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* When we relocate, we have :
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*
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* (kernstart_addr & 0xfffffff) = (stext.run & 0xfffffff)
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*
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* hence:
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* virt_phys_offset = (KERNELBASE & ~0xfffffff) - (kernstart_addr & ~0xfffffff)
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*
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*/
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/* KERNELBASE&~0xfffffff => (r4,r5) */
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li r4, 0 /* higer 32bit */
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lis r5,KERNELBASE@h
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rlwinm r5,r5,0,0,3 /* Align to 256M, lower 32bit */
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/*
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* 64bit subtraction.
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*/
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subfc r5,r7,r5
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subfe r4,r6,r4
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/* Store virt_phys_offset */
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lis r3,virt_phys_offset@ha
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la r3,virt_phys_offset@l(r3)
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stw r4,0(r3)
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stw r5,4(r3)
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#elif defined(CONFIG_DYNAMIC_MEMSTART)
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/*
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* Mapping based, page aligned dynamic kernel loading.
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*
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* r25 will contain RPN/ERPN for the start address of memory
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*
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* Add the difference between KERNELBASE and PAGE_OFFSET to the
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* start of physical memory to get kernstart_addr.
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*/
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lis r3,kernstart_addr@ha
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la r3,kernstart_addr@l(r3)
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lis r4,KERNELBASE@h
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ori r4,r4,KERNELBASE@l
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lis r5,PAGE_OFFSET@h
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ori r5,r5,PAGE_OFFSET@l
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subf r4,r5,r4
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rlwinm r6,r25,0,28,31 /* ERPN */
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rlwinm r7,r25,0,0,3 /* RPN - assuming 256 MB page size */
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add r7,r7,r4
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stw r6,0(r3)
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stw r7,4(r3)
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#endif
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/*
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* Decide what sort of machine this is and initialize the MMU.
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*/
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li r3,0
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mr r4,r31
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bl machine_init
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bl MMU_init
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/* Setup PTE pointers for the Abatron bdiGDB */
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lis r6, swapper_pg_dir@h
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ori r6, r6, swapper_pg_dir@l
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lis r5, abatron_pteptrs@h
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ori r5, r5, abatron_pteptrs@l
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lis r4, KERNELBASE@h
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ori r4, r4, KERNELBASE@l
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stw r5, 0(r4) /* Save abatron_pteptrs at a fixed location */
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stw r6, 0(r5)
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/* Clear the Machine Check Syndrome Register */
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li r0,0
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mtspr SPRN_MCSR,r0
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/* Let's move on */
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lis r4,start_kernel@h
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ori r4,r4,start_kernel@l
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lis r3,MSR_KERNEL@h
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ori r3,r3,MSR_KERNEL@l
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mtspr SPRN_SRR0,r4
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mtspr SPRN_SRR1,r3
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rfi /* change context and jump to start_kernel */
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/*
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* Interrupt vector entry code
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*
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* The Book E MMUs are always on so we don't need to handle
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* interrupts in real mode as with previous PPC processors. In
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* this case we handle interrupts in the kernel virtual address
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* space.
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*
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* Interrupt vectors are dynamically placed relative to the
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* interrupt prefix as determined by the address of interrupt_base.
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* The interrupt vectors offsets are programmed using the labels
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* for each interrupt vector entry.
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*
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* Interrupt vectors must be aligned on a 16 byte boundary.
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* We align on a 32 byte cache line boundary for good measure.
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*/
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interrupt_base:
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/* Critical Input Interrupt */
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CRITICAL_EXCEPTION(0x0100, CRITICAL, CriticalInput, unknown_exception)
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/* Machine Check Interrupt */
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CRITICAL_EXCEPTION(0x0200, MACHINE_CHECK, MachineCheck, \
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machine_check_exception)
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MCHECK_EXCEPTION(0x0210, MachineCheckA, machine_check_exception)
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/* Data Storage Interrupt */
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DATA_STORAGE_EXCEPTION
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/* Instruction Storage Interrupt */
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INSTRUCTION_STORAGE_EXCEPTION
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/* External Input Interrupt */
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EXCEPTION(0x0500, BOOKE_INTERRUPT_EXTERNAL, ExternalInput, \
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do_IRQ, EXC_XFER_LITE)
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/* Alignment Interrupt */
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ALIGNMENT_EXCEPTION
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/* Program Interrupt */
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PROGRAM_EXCEPTION
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/* Floating Point Unavailable Interrupt */
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#ifdef CONFIG_PPC_FPU
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FP_UNAVAILABLE_EXCEPTION
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#else
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EXCEPTION(0x2010, BOOKE_INTERRUPT_FP_UNAVAIL, \
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FloatingPointUnavailable, unknown_exception, EXC_XFER_EE)
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#endif
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/* System Call Interrupt */
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START_EXCEPTION(SystemCall)
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NORMAL_EXCEPTION_PROLOG(BOOKE_INTERRUPT_SYSCALL)
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EXC_XFER_EE_LITE(0x0c00, DoSyscall)
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/* Auxiliary Processor Unavailable Interrupt */
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EXCEPTION(0x2020, BOOKE_INTERRUPT_AP_UNAVAIL, \
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AuxillaryProcessorUnavailable, unknown_exception, EXC_XFER_EE)
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/* Decrementer Interrupt */
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DECREMENTER_EXCEPTION
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/* Fixed Internal Timer Interrupt */
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/* TODO: Add FIT support */
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EXCEPTION(0x1010, BOOKE_INTERRUPT_FIT, FixedIntervalTimer, \
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unknown_exception, EXC_XFER_EE)
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/* Watchdog Timer Interrupt */
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/* TODO: Add watchdog support */
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#ifdef CONFIG_BOOKE_WDT
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CRITICAL_EXCEPTION(0x1020, WATCHDOG, WatchdogTimer, WatchdogException)
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#else
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CRITICAL_EXCEPTION(0x1020, WATCHDOG, WatchdogTimer, unknown_exception)
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#endif
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/* Data TLB Error Interrupt */
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START_EXCEPTION(DataTLBError44x)
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mtspr SPRN_SPRG_WSCRATCH0, r10 /* Save some working registers */
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mtspr SPRN_SPRG_WSCRATCH1, r11
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mtspr SPRN_SPRG_WSCRATCH2, r12
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mtspr SPRN_SPRG_WSCRATCH3, r13
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mfcr r11
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mtspr SPRN_SPRG_WSCRATCH4, r11
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mfspr r10, SPRN_DEAR /* Get faulting address */
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/* If we are faulting a kernel address, we have to use the
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* kernel page tables.
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*/
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lis r11, PAGE_OFFSET@h
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cmplw r10, r11
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blt+ 3f
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lis r11, swapper_pg_dir@h
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ori r11, r11, swapper_pg_dir@l
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mfspr r12,SPRN_MMUCR
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rlwinm r12,r12,0,0,23 /* Clear TID */
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b 4f
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/* Get the PGD for the current thread */
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3:
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mfspr r11,SPRN_SPRG_THREAD
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lwz r11,PGDIR(r11)
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/* Load PID into MMUCR TID */
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mfspr r12,SPRN_MMUCR
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mfspr r13,SPRN_PID /* Get PID */
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rlwimi r12,r13,0,24,31 /* Set TID */
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4:
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mtspr SPRN_MMUCR,r12
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/* Mask of required permission bits. Note that while we
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* do copy ESR:ST to _PAGE_RW position as trying to write
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* to an RO page is pretty common, we don't do it with
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* _PAGE_DIRTY. We could do it, but it's a fairly rare
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* event so I'd rather take the overhead when it happens
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* rather than adding an instruction here. We should measure
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* whether the whole thing is worth it in the first place
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* as we could avoid loading SPRN_ESR completely in the first
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* place...
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*
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* TODO: Is it worth doing that mfspr & rlwimi in the first
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* place or can we save a couple of instructions here ?
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*/
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mfspr r12,SPRN_ESR
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li r13,_PAGE_PRESENT|_PAGE_ACCESSED
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rlwimi r13,r12,10,30,30
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/* Load the PTE */
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/* Compute pgdir/pmd offset */
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rlwinm r12, r10, PPC44x_PGD_OFF_SHIFT, PPC44x_PGD_OFF_MASK_BIT, 29
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lwzx r11, r12, r11 /* Get pgd/pmd entry */
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rlwinm. r12, r11, 0, 0, 20 /* Extract pt base address */
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beq 2f /* Bail if no table */
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/* Compute pte address */
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rlwimi r12, r10, PPC44x_PTE_ADD_SHIFT, PPC44x_PTE_ADD_MASK_BIT, 28
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lwz r11, 0(r12) /* Get high word of pte entry */
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lwz r12, 4(r12) /* Get low word of pte entry */
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lis r10,tlb_44x_index@ha
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andc. r13,r13,r12 /* Check permission */
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/* Load the next available TLB index */
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lwz r13,tlb_44x_index@l(r10)
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bne 2f /* Bail if permission mismach */
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/* Increment, rollover, and store TLB index */
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addi r13,r13,1
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/* Compare with watermark (instruction gets patched) */
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.globl tlb_44x_patch_hwater_D
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tlb_44x_patch_hwater_D:
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cmpwi 0,r13,1 /* reserve entries */
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ble 5f
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li r13,0
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5:
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/* Store the next available TLB index */
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stw r13,tlb_44x_index@l(r10)
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/* Re-load the faulting address */
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mfspr r10,SPRN_DEAR
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/* Jump to common tlb load */
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b finish_tlb_load_44x
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2:
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/* The bailout. Restore registers to pre-exception conditions
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* and call the heavyweights to help us out.
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*/
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mfspr r11, SPRN_SPRG_RSCRATCH4
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mtcr r11
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mfspr r13, SPRN_SPRG_RSCRATCH3
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mfspr r12, SPRN_SPRG_RSCRATCH2
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mfspr r11, SPRN_SPRG_RSCRATCH1
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mfspr r10, SPRN_SPRG_RSCRATCH0
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b DataStorage
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/* Instruction TLB Error Interrupt */
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/*
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* Nearly the same as above, except we get our
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* information from different registers and bailout
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* to a different point.
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*/
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START_EXCEPTION(InstructionTLBError44x)
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mtspr SPRN_SPRG_WSCRATCH0, r10 /* Save some working registers */
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mtspr SPRN_SPRG_WSCRATCH1, r11
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mtspr SPRN_SPRG_WSCRATCH2, r12
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mtspr SPRN_SPRG_WSCRATCH3, r13
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mfcr r11
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mtspr SPRN_SPRG_WSCRATCH4, r11
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mfspr r10, SPRN_SRR0 /* Get faulting address */
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/* If we are faulting a kernel address, we have to use the
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* kernel page tables.
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*/
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lis r11, PAGE_OFFSET@h
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cmplw r10, r11
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blt+ 3f
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lis r11, swapper_pg_dir@h
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ori r11, r11, swapper_pg_dir@l
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mfspr r12,SPRN_MMUCR
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rlwinm r12,r12,0,0,23 /* Clear TID */
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b 4f
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/* Get the PGD for the current thread */
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3:
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mfspr r11,SPRN_SPRG_THREAD
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lwz r11,PGDIR(r11)
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/* Load PID into MMUCR TID */
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mfspr r12,SPRN_MMUCR
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mfspr r13,SPRN_PID /* Get PID */
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rlwimi r12,r13,0,24,31 /* Set TID */
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4:
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mtspr SPRN_MMUCR,r12
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/* Make up the required permissions */
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li r13,_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_EXEC
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/* Compute pgdir/pmd offset */
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rlwinm r12, r10, PPC44x_PGD_OFF_SHIFT, PPC44x_PGD_OFF_MASK_BIT, 29
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lwzx r11, r12, r11 /* Get pgd/pmd entry */
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rlwinm. r12, r11, 0, 0, 20 /* Extract pt base address */
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beq 2f /* Bail if no table */
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/* Compute pte address */
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rlwimi r12, r10, PPC44x_PTE_ADD_SHIFT, PPC44x_PTE_ADD_MASK_BIT, 28
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lwz r11, 0(r12) /* Get high word of pte entry */
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lwz r12, 4(r12) /* Get low word of pte entry */
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lis r10,tlb_44x_index@ha
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andc. r13,r13,r12 /* Check permission */
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/* Load the next available TLB index */
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lwz r13,tlb_44x_index@l(r10)
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bne 2f /* Bail if permission mismach */
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/* Increment, rollover, and store TLB index */
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addi r13,r13,1
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/* Compare with watermark (instruction gets patched) */
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.globl tlb_44x_patch_hwater_I
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tlb_44x_patch_hwater_I:
|
|
cmpwi 0,r13,1 /* reserve entries */
|
|
ble 5f
|
|
li r13,0
|
|
5:
|
|
/* Store the next available TLB index */
|
|
stw r13,tlb_44x_index@l(r10)
|
|
|
|
/* Re-load the faulting address */
|
|
mfspr r10,SPRN_SRR0
|
|
|
|
/* Jump to common TLB load point */
|
|
b finish_tlb_load_44x
|
|
|
|
2:
|
|
/* The bailout. Restore registers to pre-exception conditions
|
|
* and call the heavyweights to help us out.
|
|
*/
|
|
mfspr r11, SPRN_SPRG_RSCRATCH4
|
|
mtcr r11
|
|
mfspr r13, SPRN_SPRG_RSCRATCH3
|
|
mfspr r12, SPRN_SPRG_RSCRATCH2
|
|
mfspr r11, SPRN_SPRG_RSCRATCH1
|
|
mfspr r10, SPRN_SPRG_RSCRATCH0
|
|
b InstructionStorage
|
|
|
|
/*
|
|
* Both the instruction and data TLB miss get to this
|
|
* point to load the TLB.
|
|
* r10 - EA of fault
|
|
* r11 - PTE high word value
|
|
* r12 - PTE low word value
|
|
* r13 - TLB index
|
|
* MMUCR - loaded with proper value when we get here
|
|
* Upon exit, we reload everything and RFI.
|
|
*/
|
|
finish_tlb_load_44x:
|
|
/* Combine RPN & ERPN an write WS 0 */
|
|
rlwimi r11,r12,0,0,31-PAGE_SHIFT
|
|
tlbwe r11,r13,PPC44x_TLB_XLAT
|
|
|
|
/*
|
|
* Create WS1. This is the faulting address (EPN),
|
|
* page size, and valid flag.
|
|
*/
|
|
li r11,PPC44x_TLB_VALID | PPC44x_TLBE_SIZE
|
|
/* Insert valid and page size */
|
|
rlwimi r10,r11,0,PPC44x_PTE_ADD_MASK_BIT,31
|
|
tlbwe r10,r13,PPC44x_TLB_PAGEID /* Write PAGEID */
|
|
|
|
/* And WS 2 */
|
|
li r10,0xf85 /* Mask to apply from PTE */
|
|
rlwimi r10,r12,29,30,30 /* DIRTY -> SW position */
|
|
and r11,r12,r10 /* Mask PTE bits to keep */
|
|
andi. r10,r12,_PAGE_USER /* User page ? */
|
|
beq 1f /* nope, leave U bits empty */
|
|
rlwimi r11,r11,3,26,28 /* yes, copy S bits to U */
|
|
1: tlbwe r11,r13,PPC44x_TLB_ATTRIB /* Write ATTRIB */
|
|
|
|
/* Done...restore registers and get out of here.
|
|
*/
|
|
mfspr r11, SPRN_SPRG_RSCRATCH4
|
|
mtcr r11
|
|
mfspr r13, SPRN_SPRG_RSCRATCH3
|
|
mfspr r12, SPRN_SPRG_RSCRATCH2
|
|
mfspr r11, SPRN_SPRG_RSCRATCH1
|
|
mfspr r10, SPRN_SPRG_RSCRATCH0
|
|
rfi /* Force context change */
|
|
|
|
/* TLB error interrupts for 476
|
|
*/
|
|
#ifdef CONFIG_PPC_47x
|
|
START_EXCEPTION(DataTLBError47x)
|
|
mtspr SPRN_SPRG_WSCRATCH0,r10 /* Save some working registers */
|
|
mtspr SPRN_SPRG_WSCRATCH1,r11
|
|
mtspr SPRN_SPRG_WSCRATCH2,r12
|
|
mtspr SPRN_SPRG_WSCRATCH3,r13
|
|
mfcr r11
|
|
mtspr SPRN_SPRG_WSCRATCH4,r11
|
|
mfspr r10,SPRN_DEAR /* Get faulting address */
|
|
|
|
/* If we are faulting a kernel address, we have to use the
|
|
* kernel page tables.
|
|
*/
|
|
lis r11,PAGE_OFFSET@h
|
|
cmplw cr0,r10,r11
|
|
blt+ 3f
|
|
lis r11,swapper_pg_dir@h
|
|
ori r11,r11, swapper_pg_dir@l
|
|
li r12,0 /* MMUCR = 0 */
|
|
b 4f
|
|
|
|
/* Get the PGD for the current thread and setup MMUCR */
|
|
3: mfspr r11,SPRN_SPRG3
|
|
lwz r11,PGDIR(r11)
|
|
mfspr r12,SPRN_PID /* Get PID */
|
|
4: mtspr SPRN_MMUCR,r12 /* Set MMUCR */
|
|
|
|
/* Mask of required permission bits. Note that while we
|
|
* do copy ESR:ST to _PAGE_RW position as trying to write
|
|
* to an RO page is pretty common, we don't do it with
|
|
* _PAGE_DIRTY. We could do it, but it's a fairly rare
|
|
* event so I'd rather take the overhead when it happens
|
|
* rather than adding an instruction here. We should measure
|
|
* whether the whole thing is worth it in the first place
|
|
* as we could avoid loading SPRN_ESR completely in the first
|
|
* place...
|
|
*
|
|
* TODO: Is it worth doing that mfspr & rlwimi in the first
|
|
* place or can we save a couple of instructions here ?
|
|
*/
|
|
mfspr r12,SPRN_ESR
|
|
li r13,_PAGE_PRESENT|_PAGE_ACCESSED
|
|
rlwimi r13,r12,10,30,30
|
|
|
|
/* Load the PTE */
|
|
/* Compute pgdir/pmd offset */
|
|
rlwinm r12,r10,PPC44x_PGD_OFF_SHIFT,PPC44x_PGD_OFF_MASK_BIT,29
|
|
lwzx r11,r12,r11 /* Get pgd/pmd entry */
|
|
|
|
/* Word 0 is EPN,V,TS,DSIZ */
|
|
li r12,PPC47x_TLB0_VALID | PPC47x_TLBE_SIZE
|
|
rlwimi r10,r12,0,32-PAGE_SHIFT,31 /* Insert valid and page size*/
|
|
li r12,0
|
|
tlbwe r10,r12,0
|
|
|
|
/* XXX can we do better ? Need to make sure tlbwe has established
|
|
* latch V bit in MMUCR0 before the PTE is loaded further down */
|
|
#ifdef CONFIG_SMP
|
|
isync
|
|
#endif
|
|
|
|
rlwinm. r12,r11,0,0,20 /* Extract pt base address */
|
|
/* Compute pte address */
|
|
rlwimi r12,r10,PPC44x_PTE_ADD_SHIFT,PPC44x_PTE_ADD_MASK_BIT,28
|
|
beq 2f /* Bail if no table */
|
|
lwz r11,0(r12) /* Get high word of pte entry */
|
|
|
|
/* XXX can we do better ? maybe insert a known 0 bit from r11 into the
|
|
* bottom of r12 to create a data dependency... We can also use r10
|
|
* as destination nowadays
|
|
*/
|
|
#ifdef CONFIG_SMP
|
|
lwsync
|
|
#endif
|
|
lwz r12,4(r12) /* Get low word of pte entry */
|
|
|
|
andc. r13,r13,r12 /* Check permission */
|
|
|
|
/* Jump to common tlb load */
|
|
beq finish_tlb_load_47x
|
|
|
|
2: /* The bailout. Restore registers to pre-exception conditions
|
|
* and call the heavyweights to help us out.
|
|
*/
|
|
mfspr r11,SPRN_SPRG_RSCRATCH4
|
|
mtcr r11
|
|
mfspr r13,SPRN_SPRG_RSCRATCH3
|
|
mfspr r12,SPRN_SPRG_RSCRATCH2
|
|
mfspr r11,SPRN_SPRG_RSCRATCH1
|
|
mfspr r10,SPRN_SPRG_RSCRATCH0
|
|
b DataStorage
|
|
|
|
/* Instruction TLB Error Interrupt */
|
|
/*
|
|
* Nearly the same as above, except we get our
|
|
* information from different registers and bailout
|
|
* to a different point.
|
|
*/
|
|
START_EXCEPTION(InstructionTLBError47x)
|
|
mtspr SPRN_SPRG_WSCRATCH0,r10 /* Save some working registers */
|
|
mtspr SPRN_SPRG_WSCRATCH1,r11
|
|
mtspr SPRN_SPRG_WSCRATCH2,r12
|
|
mtspr SPRN_SPRG_WSCRATCH3,r13
|
|
mfcr r11
|
|
mtspr SPRN_SPRG_WSCRATCH4,r11
|
|
mfspr r10,SPRN_SRR0 /* Get faulting address */
|
|
|
|
/* If we are faulting a kernel address, we have to use the
|
|
* kernel page tables.
|
|
*/
|
|
lis r11,PAGE_OFFSET@h
|
|
cmplw cr0,r10,r11
|
|
blt+ 3f
|
|
lis r11,swapper_pg_dir@h
|
|
ori r11,r11, swapper_pg_dir@l
|
|
li r12,0 /* MMUCR = 0 */
|
|
b 4f
|
|
|
|
/* Get the PGD for the current thread and setup MMUCR */
|
|
3: mfspr r11,SPRN_SPRG_THREAD
|
|
lwz r11,PGDIR(r11)
|
|
mfspr r12,SPRN_PID /* Get PID */
|
|
4: mtspr SPRN_MMUCR,r12 /* Set MMUCR */
|
|
|
|
/* Make up the required permissions */
|
|
li r13,_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_EXEC
|
|
|
|
/* Load PTE */
|
|
/* Compute pgdir/pmd offset */
|
|
rlwinm r12,r10,PPC44x_PGD_OFF_SHIFT,PPC44x_PGD_OFF_MASK_BIT,29
|
|
lwzx r11,r12,r11 /* Get pgd/pmd entry */
|
|
|
|
/* Word 0 is EPN,V,TS,DSIZ */
|
|
li r12,PPC47x_TLB0_VALID | PPC47x_TLBE_SIZE
|
|
rlwimi r10,r12,0,32-PAGE_SHIFT,31 /* Insert valid and page size*/
|
|
li r12,0
|
|
tlbwe r10,r12,0
|
|
|
|
/* XXX can we do better ? Need to make sure tlbwe has established
|
|
* latch V bit in MMUCR0 before the PTE is loaded further down */
|
|
#ifdef CONFIG_SMP
|
|
isync
|
|
#endif
|
|
|
|
rlwinm. r12,r11,0,0,20 /* Extract pt base address */
|
|
/* Compute pte address */
|
|
rlwimi r12,r10,PPC44x_PTE_ADD_SHIFT,PPC44x_PTE_ADD_MASK_BIT,28
|
|
beq 2f /* Bail if no table */
|
|
|
|
lwz r11,0(r12) /* Get high word of pte entry */
|
|
/* XXX can we do better ? maybe insert a known 0 bit from r11 into the
|
|
* bottom of r12 to create a data dependency... We can also use r10
|
|
* as destination nowadays
|
|
*/
|
|
#ifdef CONFIG_SMP
|
|
lwsync
|
|
#endif
|
|
lwz r12,4(r12) /* Get low word of pte entry */
|
|
|
|
andc. r13,r13,r12 /* Check permission */
|
|
|
|
/* Jump to common TLB load point */
|
|
beq finish_tlb_load_47x
|
|
|
|
2: /* The bailout. Restore registers to pre-exception conditions
|
|
* and call the heavyweights to help us out.
|
|
*/
|
|
mfspr r11, SPRN_SPRG_RSCRATCH4
|
|
mtcr r11
|
|
mfspr r13, SPRN_SPRG_RSCRATCH3
|
|
mfspr r12, SPRN_SPRG_RSCRATCH2
|
|
mfspr r11, SPRN_SPRG_RSCRATCH1
|
|
mfspr r10, SPRN_SPRG_RSCRATCH0
|
|
b InstructionStorage
|
|
|
|
/*
|
|
* Both the instruction and data TLB miss get to this
|
|
* point to load the TLB.
|
|
* r10 - free to use
|
|
* r11 - PTE high word value
|
|
* r12 - PTE low word value
|
|
* r13 - free to use
|
|
* MMUCR - loaded with proper value when we get here
|
|
* Upon exit, we reload everything and RFI.
|
|
*/
|
|
finish_tlb_load_47x:
|
|
/* Combine RPN & ERPN an write WS 1 */
|
|
rlwimi r11,r12,0,0,31-PAGE_SHIFT
|
|
tlbwe r11,r13,1
|
|
|
|
/* And make up word 2 */
|
|
li r10,0xf85 /* Mask to apply from PTE */
|
|
rlwimi r10,r12,29,30,30 /* DIRTY -> SW position */
|
|
and r11,r12,r10 /* Mask PTE bits to keep */
|
|
andi. r10,r12,_PAGE_USER /* User page ? */
|
|
beq 1f /* nope, leave U bits empty */
|
|
rlwimi r11,r11,3,26,28 /* yes, copy S bits to U */
|
|
1: tlbwe r11,r13,2
|
|
|
|
/* Done...restore registers and get out of here.
|
|
*/
|
|
mfspr r11, SPRN_SPRG_RSCRATCH4
|
|
mtcr r11
|
|
mfspr r13, SPRN_SPRG_RSCRATCH3
|
|
mfspr r12, SPRN_SPRG_RSCRATCH2
|
|
mfspr r11, SPRN_SPRG_RSCRATCH1
|
|
mfspr r10, SPRN_SPRG_RSCRATCH0
|
|
rfi
|
|
|
|
#endif /* CONFIG_PPC_47x */
|
|
|
|
/* Debug Interrupt */
|
|
/*
|
|
* This statement needs to exist at the end of the IVPR
|
|
* definition just in case you end up taking a debug
|
|
* exception within another exception.
|
|
*/
|
|
DEBUG_CRIT_EXCEPTION
|
|
|
|
interrupt_end:
|
|
|
|
/*
|
|
* Global functions
|
|
*/
|
|
|
|
/*
|
|
* Adjust the machine check IVOR on 440A cores
|
|
*/
|
|
_GLOBAL(__fixup_440A_mcheck)
|
|
li r3,MachineCheckA@l
|
|
mtspr SPRN_IVOR1,r3
|
|
sync
|
|
blr
|
|
|
|
_GLOBAL(set_context)
|
|
|
|
#ifdef CONFIG_BDI_SWITCH
|
|
/* Context switch the PTE pointer for the Abatron BDI2000.
|
|
* The PGDIR is the second parameter.
|
|
*/
|
|
lis r5, abatron_pteptrs@h
|
|
ori r5, r5, abatron_pteptrs@l
|
|
stw r4, 0x4(r5)
|
|
#endif
|
|
mtspr SPRN_PID,r3
|
|
isync /* Force context change */
|
|
blr
|
|
|
|
/*
|
|
* Init CPU state. This is called at boot time or for secondary CPUs
|
|
* to setup initial TLB entries, setup IVORs, etc...
|
|
*
|
|
*/
|
|
_GLOBAL(init_cpu_state)
|
|
mflr r22
|
|
#ifdef CONFIG_PPC_47x
|
|
/* We use the PVR to differentiate 44x cores from 476 */
|
|
mfspr r3,SPRN_PVR
|
|
srwi r3,r3,16
|
|
cmplwi cr0,r3,PVR_476FPE@h
|
|
beq head_start_47x
|
|
cmplwi cr0,r3,PVR_476@h
|
|
beq head_start_47x
|
|
cmplwi cr0,r3,PVR_476_ISS@h
|
|
beq head_start_47x
|
|
#endif /* CONFIG_PPC_47x */
|
|
|
|
/*
|
|
* In case the firmware didn't do it, we apply some workarounds
|
|
* that are good for all 440 core variants here
|
|
*/
|
|
mfspr r3,SPRN_CCR0
|
|
rlwinm r3,r3,0,0,27 /* disable icache prefetch */
|
|
isync
|
|
mtspr SPRN_CCR0,r3
|
|
isync
|
|
sync
|
|
|
|
/*
|
|
* Set up the initial MMU state for 44x
|
|
*
|
|
* We are still executing code at the virtual address
|
|
* mappings set by the firmware for the base of RAM.
|
|
*
|
|
* We first invalidate all TLB entries but the one
|
|
* we are running from. We then load the KERNELBASE
|
|
* mappings so we can begin to use kernel addresses
|
|
* natively and so the interrupt vector locations are
|
|
* permanently pinned (necessary since Book E
|
|
* implementations always have translation enabled).
|
|
*
|
|
* TODO: Use the known TLB entry we are running from to
|
|
* determine which physical region we are located
|
|
* in. This can be used to determine where in RAM
|
|
* (on a shared CPU system) or PCI memory space
|
|
* (on a DRAMless system) we are located.
|
|
* For now, we assume a perfect world which means
|
|
* we are located at the base of DRAM (physical 0).
|
|
*/
|
|
|
|
/*
|
|
* Search TLB for entry that we are currently using.
|
|
* Invalidate all entries but the one we are using.
|
|
*/
|
|
/* Load our current PID->MMUCR TID and MSR IS->MMUCR STS */
|
|
mfspr r3,SPRN_PID /* Get PID */
|
|
mfmsr r4 /* Get MSR */
|
|
andi. r4,r4,MSR_IS@l /* TS=1? */
|
|
beq wmmucr /* If not, leave STS=0 */
|
|
oris r3,r3,PPC44x_MMUCR_STS@h /* Set STS=1 */
|
|
wmmucr: mtspr SPRN_MMUCR,r3 /* Put MMUCR */
|
|
sync
|
|
|
|
bl invstr /* Find our address */
|
|
invstr: mflr r5 /* Make it accessible */
|
|
tlbsx r23,0,r5 /* Find entry we are in */
|
|
li r4,0 /* Start at TLB entry 0 */
|
|
li r3,0 /* Set PAGEID inval value */
|
|
1: cmpw r23,r4 /* Is this our entry? */
|
|
beq skpinv /* If so, skip the inval */
|
|
tlbwe r3,r4,PPC44x_TLB_PAGEID /* If not, inval the entry */
|
|
skpinv: addi r4,r4,1 /* Increment */
|
|
cmpwi r4,64 /* Are we done? */
|
|
bne 1b /* If not, repeat */
|
|
isync /* If so, context change */
|
|
|
|
/*
|
|
* Configure and load pinned entry into TLB slot 63.
|
|
*/
|
|
#ifdef CONFIG_NONSTATIC_KERNEL
|
|
/*
|
|
* In case of a NONSTATIC_KERNEL we reuse the TLB XLAT
|
|
* entries of the initial mapping set by the boot loader.
|
|
* The XLAT entry is stored in r25
|
|
*/
|
|
|
|
/* Read the XLAT entry for our current mapping */
|
|
tlbre r25,r23,PPC44x_TLB_XLAT
|
|
|
|
lis r3,KERNELBASE@h
|
|
ori r3,r3,KERNELBASE@l
|
|
|
|
/* Use our current RPN entry */
|
|
mr r4,r25
|
|
#else
|
|
|
|
lis r3,PAGE_OFFSET@h
|
|
ori r3,r3,PAGE_OFFSET@l
|
|
|
|
/* Kernel is at the base of RAM */
|
|
li r4, 0 /* Load the kernel physical address */
|
|
#endif
|
|
|
|
/* Load the kernel PID = 0 */
|
|
li r0,0
|
|
mtspr SPRN_PID,r0
|
|
sync
|
|
|
|
/* Initialize MMUCR */
|
|
li r5,0
|
|
mtspr SPRN_MMUCR,r5
|
|
sync
|
|
|
|
/* pageid fields */
|
|
clrrwi r3,r3,10 /* Mask off the effective page number */
|
|
ori r3,r3,PPC44x_TLB_VALID | PPC44x_TLB_256M
|
|
|
|
/* xlat fields */
|
|
clrrwi r4,r4,10 /* Mask off the real page number */
|
|
/* ERPN is 0 for first 4GB page */
|
|
|
|
/* attrib fields */
|
|
/* Added guarded bit to protect against speculative loads/stores */
|
|
li r5,0
|
|
ori r5,r5,(PPC44x_TLB_SW | PPC44x_TLB_SR | PPC44x_TLB_SX | PPC44x_TLB_G)
|
|
|
|
li r0,63 /* TLB slot 63 */
|
|
|
|
tlbwe r3,r0,PPC44x_TLB_PAGEID /* Load the pageid fields */
|
|
tlbwe r4,r0,PPC44x_TLB_XLAT /* Load the translation fields */
|
|
tlbwe r5,r0,PPC44x_TLB_ATTRIB /* Load the attrib/access fields */
|
|
|
|
/* Force context change */
|
|
mfmsr r0
|
|
mtspr SPRN_SRR1, r0
|
|
lis r0,3f@h
|
|
ori r0,r0,3f@l
|
|
mtspr SPRN_SRR0,r0
|
|
sync
|
|
rfi
|
|
|
|
/* If necessary, invalidate original entry we used */
|
|
3: cmpwi r23,63
|
|
beq 4f
|
|
li r6,0
|
|
tlbwe r6,r23,PPC44x_TLB_PAGEID
|
|
isync
|
|
|
|
4:
|
|
#ifdef CONFIG_PPC_EARLY_DEBUG_44x
|
|
/* Add UART mapping for early debug. */
|
|
|
|
/* pageid fields */
|
|
lis r3,PPC44x_EARLY_DEBUG_VIRTADDR@h
|
|
ori r3,r3,PPC44x_TLB_VALID|PPC44x_TLB_TS|PPC44x_TLB_64K
|
|
|
|
/* xlat fields */
|
|
lis r4,CONFIG_PPC_EARLY_DEBUG_44x_PHYSLOW@h
|
|
ori r4,r4,CONFIG_PPC_EARLY_DEBUG_44x_PHYSHIGH
|
|
|
|
/* attrib fields */
|
|
li r5,(PPC44x_TLB_SW|PPC44x_TLB_SR|PPC44x_TLB_I|PPC44x_TLB_G)
|
|
li r0,62 /* TLB slot 0 */
|
|
|
|
tlbwe r3,r0,PPC44x_TLB_PAGEID
|
|
tlbwe r4,r0,PPC44x_TLB_XLAT
|
|
tlbwe r5,r0,PPC44x_TLB_ATTRIB
|
|
|
|
/* Force context change */
|
|
isync
|
|
#endif /* CONFIG_PPC_EARLY_DEBUG_44x */
|
|
|
|
/* Establish the interrupt vector offsets */
|
|
SET_IVOR(0, CriticalInput);
|
|
SET_IVOR(1, MachineCheck);
|
|
SET_IVOR(2, DataStorage);
|
|
SET_IVOR(3, InstructionStorage);
|
|
SET_IVOR(4, ExternalInput);
|
|
SET_IVOR(5, Alignment);
|
|
SET_IVOR(6, Program);
|
|
SET_IVOR(7, FloatingPointUnavailable);
|
|
SET_IVOR(8, SystemCall);
|
|
SET_IVOR(9, AuxillaryProcessorUnavailable);
|
|
SET_IVOR(10, Decrementer);
|
|
SET_IVOR(11, FixedIntervalTimer);
|
|
SET_IVOR(12, WatchdogTimer);
|
|
SET_IVOR(13, DataTLBError44x);
|
|
SET_IVOR(14, InstructionTLBError44x);
|
|
SET_IVOR(15, DebugCrit);
|
|
|
|
b head_start_common
|
|
|
|
|
|
#ifdef CONFIG_PPC_47x
|
|
|
|
#ifdef CONFIG_SMP
|
|
|
|
/* Entry point for secondary 47x processors */
|
|
_GLOBAL(start_secondary_47x)
|
|
mr r24,r3 /* CPU number */
|
|
|
|
bl init_cpu_state
|
|
|
|
/* Now we need to bolt the rest of kernel memory which
|
|
* is done in C code. We must be careful because our task
|
|
* struct or our stack can (and will probably) be out
|
|
* of reach of the initial 256M TLB entry, so we use a
|
|
* small temporary stack in .bss for that. This works
|
|
* because only one CPU at a time can be in this code
|
|
*/
|
|
lis r1,temp_boot_stack@h
|
|
ori r1,r1,temp_boot_stack@l
|
|
addi r1,r1,1024-STACK_FRAME_OVERHEAD
|
|
li r0,0
|
|
stw r0,0(r1)
|
|
bl mmu_init_secondary
|
|
|
|
/* Now we can get our task struct and real stack pointer */
|
|
|
|
/* Get current_thread_info and current */
|
|
lis r1,secondary_ti@ha
|
|
lwz r1,secondary_ti@l(r1)
|
|
lwz r2,TI_TASK(r1)
|
|
|
|
/* Current stack pointer */
|
|
addi r1,r1,THREAD_SIZE-STACK_FRAME_OVERHEAD
|
|
li r0,0
|
|
stw r0,0(r1)
|
|
|
|
/* Kernel stack for exception entry in SPRG3 */
|
|
addi r4,r2,THREAD /* init task's THREAD */
|
|
mtspr SPRN_SPRG3,r4
|
|
|
|
b start_secondary
|
|
|
|
#endif /* CONFIG_SMP */
|
|
|
|
/*
|
|
* Set up the initial MMU state for 44x
|
|
*
|
|
* We are still executing code at the virtual address
|
|
* mappings set by the firmware for the base of RAM.
|
|
*/
|
|
|
|
head_start_47x:
|
|
/* Load our current PID->MMUCR TID and MSR IS->MMUCR STS */
|
|
mfspr r3,SPRN_PID /* Get PID */
|
|
mfmsr r4 /* Get MSR */
|
|
andi. r4,r4,MSR_IS@l /* TS=1? */
|
|
beq 1f /* If not, leave STS=0 */
|
|
oris r3,r3,PPC47x_MMUCR_STS@h /* Set STS=1 */
|
|
1: mtspr SPRN_MMUCR,r3 /* Put MMUCR */
|
|
sync
|
|
|
|
/* Find the entry we are running from */
|
|
bl 1f
|
|
1: mflr r23
|
|
tlbsx r23,0,r23
|
|
tlbre r24,r23,0
|
|
tlbre r25,r23,1
|
|
tlbre r26,r23,2
|
|
|
|
/*
|
|
* Cleanup time
|
|
*/
|
|
|
|
/* Initialize MMUCR */
|
|
li r5,0
|
|
mtspr SPRN_MMUCR,r5
|
|
sync
|
|
|
|
clear_all_utlb_entries:
|
|
|
|
#; Set initial values.
|
|
|
|
addis r3,0,0x8000
|
|
addi r4,0,0
|
|
addi r5,0,0
|
|
b clear_utlb_entry
|
|
|
|
#; Align the loop to speed things up.
|
|
|
|
.align 6
|
|
|
|
clear_utlb_entry:
|
|
|
|
tlbwe r4,r3,0
|
|
tlbwe r5,r3,1
|
|
tlbwe r5,r3,2
|
|
addis r3,r3,0x2000
|
|
cmpwi r3,0
|
|
bne clear_utlb_entry
|
|
addis r3,0,0x8000
|
|
addis r4,r4,0x100
|
|
cmpwi r4,0
|
|
bne clear_utlb_entry
|
|
|
|
#; Restore original entry.
|
|
|
|
oris r23,r23,0x8000 /* specify the way */
|
|
tlbwe r24,r23,0
|
|
tlbwe r25,r23,1
|
|
tlbwe r26,r23,2
|
|
|
|
/*
|
|
* Configure and load pinned entry into TLB for the kernel core
|
|
*/
|
|
|
|
lis r3,PAGE_OFFSET@h
|
|
ori r3,r3,PAGE_OFFSET@l
|
|
|
|
/* Load the kernel PID = 0 */
|
|
li r0,0
|
|
mtspr SPRN_PID,r0
|
|
sync
|
|
|
|
/* Word 0 */
|
|
clrrwi r3,r3,12 /* Mask off the effective page number */
|
|
ori r3,r3,PPC47x_TLB0_VALID | PPC47x_TLB0_256M
|
|
|
|
/* Word 1 - use r25. RPN is the same as the original entry */
|
|
|
|
/* Word 2 */
|
|
li r5,0
|
|
ori r5,r5,PPC47x_TLB2_S_RWX
|
|
#ifdef CONFIG_SMP
|
|
ori r5,r5,PPC47x_TLB2_M
|
|
#endif
|
|
|
|
/* We write to way 0 and bolted 0 */
|
|
lis r0,0x8800
|
|
tlbwe r3,r0,0
|
|
tlbwe r25,r0,1
|
|
tlbwe r5,r0,2
|
|
|
|
/*
|
|
* Configure SSPCR, ISPCR and USPCR for now to search everything, we can fix
|
|
* them up later
|
|
*/
|
|
LOAD_REG_IMMEDIATE(r3, 0x9abcdef0)
|
|
mtspr SPRN_SSPCR,r3
|
|
mtspr SPRN_USPCR,r3
|
|
LOAD_REG_IMMEDIATE(r3, 0x12345670)
|
|
mtspr SPRN_ISPCR,r3
|
|
|
|
/* Force context change */
|
|
mfmsr r0
|
|
mtspr SPRN_SRR1, r0
|
|
lis r0,3f@h
|
|
ori r0,r0,3f@l
|
|
mtspr SPRN_SRR0,r0
|
|
sync
|
|
rfi
|
|
|
|
/* Invalidate original entry we used */
|
|
3:
|
|
rlwinm r24,r24,0,21,19 /* clear the "valid" bit */
|
|
tlbwe r24,r23,0
|
|
addi r24,0,0
|
|
tlbwe r24,r23,1
|
|
tlbwe r24,r23,2
|
|
isync /* Clear out the shadow TLB entries */
|
|
|
|
#ifdef CONFIG_PPC_EARLY_DEBUG_44x
|
|
/* Add UART mapping for early debug. */
|
|
|
|
/* Word 0 */
|
|
lis r3,PPC44x_EARLY_DEBUG_VIRTADDR@h
|
|
ori r3,r3,PPC47x_TLB0_VALID | PPC47x_TLB0_TS | PPC47x_TLB0_1M
|
|
|
|
/* Word 1 */
|
|
lis r4,CONFIG_PPC_EARLY_DEBUG_44x_PHYSLOW@h
|
|
ori r4,r4,CONFIG_PPC_EARLY_DEBUG_44x_PHYSHIGH
|
|
|
|
/* Word 2 */
|
|
li r5,(PPC47x_TLB2_S_RW | PPC47x_TLB2_IMG)
|
|
|
|
/* Bolted in way 0, bolt slot 5, we -hope- we don't hit the same
|
|
* congruence class as the kernel, we need to make sure of it at
|
|
* some point
|
|
*/
|
|
lis r0,0x8d00
|
|
tlbwe r3,r0,0
|
|
tlbwe r4,r0,1
|
|
tlbwe r5,r0,2
|
|
|
|
/* Force context change */
|
|
isync
|
|
#endif /* CONFIG_PPC_EARLY_DEBUG_44x */
|
|
|
|
/* Establish the interrupt vector offsets */
|
|
SET_IVOR(0, CriticalInput);
|
|
SET_IVOR(1, MachineCheckA);
|
|
SET_IVOR(2, DataStorage);
|
|
SET_IVOR(3, InstructionStorage);
|
|
SET_IVOR(4, ExternalInput);
|
|
SET_IVOR(5, Alignment);
|
|
SET_IVOR(6, Program);
|
|
SET_IVOR(7, FloatingPointUnavailable);
|
|
SET_IVOR(8, SystemCall);
|
|
SET_IVOR(9, AuxillaryProcessorUnavailable);
|
|
SET_IVOR(10, Decrementer);
|
|
SET_IVOR(11, FixedIntervalTimer);
|
|
SET_IVOR(12, WatchdogTimer);
|
|
SET_IVOR(13, DataTLBError47x);
|
|
SET_IVOR(14, InstructionTLBError47x);
|
|
SET_IVOR(15, DebugCrit);
|
|
|
|
/* We configure icbi to invalidate 128 bytes at a time since the
|
|
* current 32-bit kernel code isn't too happy with icache != dcache
|
|
* block size. We also disable the BTAC as this can cause errors
|
|
* in some circumstances (see IBM Erratum 47).
|
|
*/
|
|
mfspr r3,SPRN_CCR0
|
|
oris r3,r3,0x0020
|
|
ori r3,r3,0x0040
|
|
mtspr SPRN_CCR0,r3
|
|
isync
|
|
|
|
#endif /* CONFIG_PPC_47x */
|
|
|
|
/*
|
|
* Here we are back to code that is common between 44x and 47x
|
|
*
|
|
* We proceed to further kernel initialization and return to the
|
|
* main kernel entry
|
|
*/
|
|
head_start_common:
|
|
/* Establish the interrupt vector base */
|
|
lis r4,interrupt_base@h /* IVPR only uses the high 16-bits */
|
|
mtspr SPRN_IVPR,r4
|
|
|
|
/*
|
|
* If the kernel was loaded at a non-zero 256 MB page, we need to
|
|
* mask off the most significant 4 bits to get the relative address
|
|
* from the start of physical memory
|
|
*/
|
|
rlwinm r22,r22,0,4,31
|
|
addis r22,r22,PAGE_OFFSET@h
|
|
mtlr r22
|
|
isync
|
|
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 PAGE_SHIFT
|
|
.globl sdata
|
|
sdata:
|
|
.globl empty_zero_page
|
|
empty_zero_page:
|
|
.space PAGE_SIZE
|
|
|
|
/*
|
|
* To support >32-bit physical addresses, we use an 8KB pgdir.
|
|
*/
|
|
.globl swapper_pg_dir
|
|
swapper_pg_dir:
|
|
.space PGD_TABLE_SIZE
|
|
|
|
/*
|
|
* Room for two PTE pointers, usually the kernel and current user pointers
|
|
* to their respective root page table.
|
|
*/
|
|
abatron_pteptrs:
|
|
.space 8
|
|
|
|
#ifdef CONFIG_SMP
|
|
.align 12
|
|
temp_boot_stack:
|
|
.space 1024
|
|
#endif /* CONFIG_SMP */
|