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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 | /* * Modifications by Matt Porter (mporter@mvista.com) to support * PPC44x Book E processors. * * This file contains the routines for initializing the MMU * on the 4xx series of chips. * -- paulus * * Derived from arch/ppc/mm/init.c: * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) * * Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au) * and Cort Dougan (PReP) (cort@cs.nmt.edu) * Copyright (C) 1996 Paul Mackerras * Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk). * * Derived from "arch/i386/mm/init.c" * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. * */ #include <linux/config.h> #include <linux/signal.h> #include <linux/sched.h> #include <linux/kernel.h> #include <linux/errno.h> #include <linux/string.h> #include <linux/types.h> #include <linux/ptrace.h> #include <linux/mman.h> #include <linux/mm.h> #include <linux/swap.h> #include <linux/stddef.h> #include <linux/vmalloc.h> #include <linux/init.h> #include <linux/delay.h> #include <linux/bootmem.h> #include <linux/highmem.h> #include <asm/pgalloc.h> #include <asm/prom.h> #include <asm/io.h> #include <asm/mmu_context.h> #include <asm/pgtable.h> #include <asm/mmu.h> #include <asm/uaccess.h> #include <asm/smp.h> #include <asm/bootx.h> #include <asm/machdep.h> #include <asm/setup.h> #include "mmu_decl.h" #include "mem_pieces.h" extern char etext[], _stext[]; extern struct mem_pieces phys_avail; /* Used by the 44x TLB replacement exception handler. * Just needed it declared someplace. */ unsigned int tlb_44x_index = 0; unsigned int tlb_44x_hwater = 62; /* * "Pins" a 256MB TLB entry in AS0 for kernel lowmem */ static void __init ppc44x_pin_tlb(int slot, unsigned int virt, unsigned int phys) { unsigned long attrib; __asm__ __volatile__("\ clrrwi %2,%2,10\n\ ori %2,%2,%4\n\ clrrwi %1,%1,10\n\ li %0,0\n\ ori %0,%0,%5\n\ tlbwe %2,%3,%6\n\ tlbwe %1,%3,%7\n\ tlbwe %0,%3,%8" : : "r" (attrib), "r" (phys), "r" (virt), "r" (slot), "i" (PPC44x_TLB_VALID | PPC44x_TLB_256M), "i" (PPC44x_TLB_SW | PPC44x_TLB_SR | PPC44x_TLB_SX | PPC44x_TLB_G), "i" (PPC44x_TLB_PAGEID), "i" (PPC44x_TLB_XLAT), "i" (PPC44x_TLB_ATTRIB)); } /* * MMU_init_hw does the chip-specific initialization of the MMU hardware. */ void __init MMU_init_hw(void) { flush_instruction_cache(); } unsigned long __init mmu_mapin_ram(void) { unsigned int pinned_tlbs = 1; int i; /* * If lowmem is not on a pin tlb entry size boundary, * then reserve the last page of system memory. This * eliminates the possibility of a speculative dcache * fetch past the end of system memory that would * result in a machine check exception. */ if (total_lowmem | (PPC44x_PIN_SIZE - 1)) mem_pieces_remove(&phys_avail, total_lowmem - PAGE_SIZE, PAGE_SIZE, 1); /* Determine number of entries necessary to cover lowmem */ pinned_tlbs = (unsigned int) (_ALIGN(total_lowmem, PPC44x_PIN_SIZE) >> PPC44x_PIN_SHIFT); /* Write upper watermark to save location */ tlb_44x_hwater = PPC44x_LOW_SLOT - pinned_tlbs; /* If necessary, set additional pinned TLBs */ if (pinned_tlbs > 1) for (i = (PPC44x_LOW_SLOT-(pinned_tlbs-1)); i < PPC44x_LOW_SLOT; i++) { unsigned int phys_addr = (PPC44x_LOW_SLOT-i) * PPC44x_PIN_SIZE; ppc44x_pin_tlb(i, phys_addr+PAGE_OFFSET, phys_addr); } return total_lowmem; } |