mirror of https://gitee.com/openkylin/linux.git
121 lines
3.1 KiB
C
121 lines
3.1 KiB
C
/*
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* Modifications by Matt Porter (mporter@mvista.com) to support
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* PPC44x Book E processors.
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*
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* This file contains the routines for initializing the MMU
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* on the 4xx series of chips.
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* -- paulus
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*
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* Derived from arch/ppc/mm/init.c:
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* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
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*
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* Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
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* and Cort Dougan (PReP) (cort@cs.nmt.edu)
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* Copyright (C) 1996 Paul Mackerras
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* Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk).
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*
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* Derived from "arch/i386/mm/init.c"
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* Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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*/
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#include <linux/config.h>
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#include <linux/signal.h>
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#include <linux/sched.h>
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#include <linux/kernel.h>
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#include <linux/errno.h>
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#include <linux/string.h>
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#include <linux/types.h>
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#include <linux/ptrace.h>
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#include <linux/mman.h>
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#include <linux/mm.h>
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#include <linux/swap.h>
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#include <linux/stddef.h>
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#include <linux/vmalloc.h>
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#include <linux/init.h>
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#include <linux/delay.h>
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#include <linux/highmem.h>
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#include <asm/pgalloc.h>
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#include <asm/prom.h>
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#include <asm/io.h>
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#include <asm/mmu_context.h>
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#include <asm/pgtable.h>
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#include <asm/mmu.h>
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#include <asm/uaccess.h>
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#include <asm/smp.h>
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#include <asm/bootx.h>
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#include <asm/machdep.h>
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#include <asm/setup.h>
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#include "mmu_decl.h"
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extern char etext[], _stext[];
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/* Used by the 44x TLB replacement exception handler.
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* Just needed it declared someplace.
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*/
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unsigned int tlb_44x_index = 0;
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unsigned int tlb_44x_hwater = 62;
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/*
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* "Pins" a 256MB TLB entry in AS0 for kernel lowmem
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*/
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static void __init
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ppc44x_pin_tlb(int slot, unsigned int virt, unsigned int phys)
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{
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unsigned long attrib = 0;
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__asm__ __volatile__("\
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clrrwi %2,%2,10\n\
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ori %2,%2,%4\n\
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clrrwi %1,%1,10\n\
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li %0,0\n\
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ori %0,%0,%5\n\
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tlbwe %2,%3,%6\n\
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tlbwe %1,%3,%7\n\
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tlbwe %0,%3,%8"
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:
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: "r" (attrib), "r" (phys), "r" (virt), "r" (slot),
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"i" (PPC44x_TLB_VALID | PPC44x_TLB_256M),
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"i" (PPC44x_TLB_SW | PPC44x_TLB_SR | PPC44x_TLB_SX | PPC44x_TLB_G),
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"i" (PPC44x_TLB_PAGEID),
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"i" (PPC44x_TLB_XLAT),
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"i" (PPC44x_TLB_ATTRIB));
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}
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/*
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* MMU_init_hw does the chip-specific initialization of the MMU hardware.
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*/
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void __init MMU_init_hw(void)
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{
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flush_instruction_cache();
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}
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unsigned long __init mmu_mapin_ram(void)
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{
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unsigned int pinned_tlbs = 1;
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int i;
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/* Determine number of entries necessary to cover lowmem */
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pinned_tlbs = (unsigned int)
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(_ALIGN(total_lowmem, PPC44x_PIN_SIZE) >> PPC44x_PIN_SHIFT);
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/* Write upper watermark to save location */
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tlb_44x_hwater = PPC44x_LOW_SLOT - pinned_tlbs;
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/* If necessary, set additional pinned TLBs */
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if (pinned_tlbs > 1)
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for (i = (PPC44x_LOW_SLOT-(pinned_tlbs-1)); i < PPC44x_LOW_SLOT; i++) {
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unsigned int phys_addr = (PPC44x_LOW_SLOT-i) * PPC44x_PIN_SIZE;
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ppc44x_pin_tlb(i, phys_addr+PAGE_OFFSET, phys_addr);
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}
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return total_lowmem;
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}
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