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/*
* PowerPC version
* 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
* PPC44x/36-bit changes by Matt Porter (mporter@mvista.com)
*
* 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/module.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/mm.h>
#include <linux/stddef.h>
#include <linux/init.h>
#include <linux/bootmem.h>
#include <linux/highmem.h>
#include <linux/initrd.h>
#include <linux/pagemap.h>
#include <linux/memblock.h>
#include <linux/gfp.h>
#include <asm/pgalloc.h>
#include <asm/prom.h>
#include <asm/io.h>
#include <asm/pgtable.h>
#include <asm/mmu.h>
#include <asm/smp.h>
#include <asm/machdep.h>
#include <asm/btext.h>
#include <asm/tlb.h>
#include <asm/sections.h>
#include <asm/system.h>
#include "mmu_decl.h"
#if defined(CONFIG_KERNEL_START_BOOL) || defined(CONFIG_LOWMEM_SIZE_BOOL)
/* The amount of lowmem must be within 0xF0000000 - KERNELBASE. */
#if (CONFIG_LOWMEM_SIZE > (0xF0000000 - PAGE_OFFSET))
#error "You must adjust CONFIG_LOWMEM_SIZE or CONFIG_START_KERNEL"
#endif
#endif
#define MAX_LOW_MEM CONFIG_LOWMEM_SIZE
phys_addr_t total_memory;
phys_addr_t total_lowmem;
phys_addr_t memstart_addr = (phys_addr_t)~0ull;
EXPORT_SYMBOL(memstart_addr);
phys_addr_t kernstart_addr;
EXPORT_SYMBOL(kernstart_addr);
phys_addr_t lowmem_end_addr;
int boot_mapsize;
#ifdef CONFIG_PPC_PMAC
unsigned long agp_special_page;
EXPORT_SYMBOL(agp_special_page);
#endif
void MMU_init(void);
/* XXX should be in current.h -- paulus */
extern struct task_struct *current_set[NR_CPUS];
/*
* this tells the system to map all of ram with the segregs
* (i.e. page tables) instead of the bats.
* -- Cort
*/
int __map_without_bats;
int __map_without_ltlbs;
/*
* This tells the system to allow ioremapping memory marked as reserved.
*/
int __allow_ioremap_reserved;
/* max amount of low RAM to map in */
unsigned long __max_low_memory = MAX_LOW_MEM;
/*
* Check for command-line options that affect what MMU_init will do.
*/
void MMU_setup(void)
{
/* Check for nobats option (used in mapin_ram). */
if (strstr(cmd_line, "nobats")) {
__map_without_bats = 1;
}
if (strstr(cmd_line, "noltlbs")) {
__map_without_ltlbs = 1;
}
#ifdef CONFIG_DEBUG_PAGEALLOC
__map_without_bats = 1;
__map_without_ltlbs = 1;
#endif
}
/*
* MMU_init sets up the basic memory mappings for the kernel,
* including both RAM and possibly some I/O regions,
* and sets up the page tables and the MMU hardware ready to go.
*/
void __init MMU_init(void)
{
if (ppc_md.progress)
ppc_md.progress("MMU:enter", 0x111);
/* parse args from command line */
MMU_setup();
if (memblock.memory.cnt > 1) {
#ifndef CONFIG_WII
memblock.memory.cnt = 1;
memblock_analyze();
printk(KERN_WARNING "Only using first contiguous memory region");
#else
wii_memory_fixups();
#endif
}
total_lowmem = total_memory = memblock_end_of_DRAM() - memstart_addr;
lowmem_end_addr = memstart_addr + total_lowmem;
#ifdef CONFIG_FSL_BOOKE
/* Freescale Book-E parts expect lowmem to be mapped by fixed TLB
* entries, so we need to adjust lowmem to match the amount we can map
* in the fixed entries */
adjust_total_lowmem();
#endif /* CONFIG_FSL_BOOKE */
if (total_lowmem > __max_low_memory) {
total_lowmem = __max_low_memory;
lowmem_end_addr = memstart_addr + total_lowmem;
#ifndef CONFIG_HIGHMEM
total_memory = total_lowmem;
memblock_enforce_memory_limit(total_lowmem);
memblock_analyze();
#endif /* CONFIG_HIGHMEM */
}
/* Initialize the MMU hardware */
if (ppc_md.progress)
ppc_md.progress("MMU:hw init", 0x300);
MMU_init_hw();
/* Map in all of RAM starting at KERNELBASE */
if (ppc_md.progress)
ppc_md.progress("MMU:mapin", 0x301);
mapin_ram();
/* Initialize early top-down ioremap allocator */
ioremap_bot = IOREMAP_TOP;
/* Map in I/O resources */
if (ppc_md.progress)
ppc_md.progress("MMU:setio", 0x302);
if (ppc_md.progress)
ppc_md.progress("MMU:exit", 0x211);
/* From now on, btext is no longer BAT mapped if it was at all */
#ifdef CONFIG_BOOTX_TEXT
btext_unmap();
#endif
/* Shortly after that, the entire linear mapping will be available */
memblock_set_current_limit(lowmem_end_addr);
}
/* This is only called until mem_init is done. */
void __init *early_get_page(void)
{
if (init_bootmem_done)
return alloc_bootmem_pages(PAGE_SIZE);
else
return __va(memblock_alloc(PAGE_SIZE, PAGE_SIZE));
}
/* Free up now-unused memory */
static void free_sec(unsigned long start, unsigned long end, const char *name)
{
unsigned long cnt = 0;
while (start < end) {
ClearPageReserved(virt_to_page(start));
init_page_count(virt_to_page(start));
free_page(start);
cnt++;
start += PAGE_SIZE;
}
if (cnt) {
printk(" %ldk %s", cnt << (PAGE_SHIFT - 10), name);
totalram_pages += cnt;
}
}
void free_initmem(void)
{
#define FREESEC(TYPE) \
free_sec((unsigned long)(&__ ## TYPE ## _begin), \
(unsigned long)(&__ ## TYPE ## _end), \
#TYPE);
printk ("Freeing unused kernel memory:");
FREESEC(init);
printk("\n");
ppc_md.progress = NULL;
#undef FREESEC
}
#ifdef CONFIG_8xx /* No 8xx specific .c file to put that in ... */
void setup_initial_memory_limit(phys_addr_t first_memblock_base,
phys_addr_t first_memblock_size)
{
/* We don't currently support the first MEMBLOCK not mapping 0
* physical on those processors
*/
BUG_ON(first_memblock_base != 0);
/* 8xx can only access 8MB at the moment */
memblock_set_current_limit(min_t(u64, first_memblock_size, 0x00800000));
}
#endif /* CONFIG_8xx */
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