257 lines
6.1 KiB
C
257 lines
6.1 KiB
C
/*
|
|
* 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
|
|
* Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk).
|
|
* 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/config.h>
|
|
#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 <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/smp.h>
|
|
#include <asm/machdep.h>
|
|
#include <asm/btext.h>
|
|
#include <asm/tlb.h>
|
|
#include <asm/prom.h>
|
|
#include <asm/lmb.h>
|
|
#include <asm/sections.h>
|
|
|
|
#include "mmu_decl.h"
|
|
|
|
#if defined(CONFIG_KERNEL_START_BOOL) || defined(CONFIG_LOWMEM_SIZE_BOOL)
|
|
/* The ammount of lowmem must be within 0xF0000000 - KERNELBASE. */
|
|
#if (CONFIG_LOWMEM_SIZE > (0xF0000000 - KERNELBASE))
|
|
#error "You must adjust CONFIG_LOWMEM_SIZE or CONFIG_START_KERNEL"
|
|
#endif
|
|
#endif
|
|
#define MAX_LOW_MEM CONFIG_LOWMEM_SIZE
|
|
|
|
DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
|
|
|
|
unsigned long total_memory;
|
|
unsigned long total_lowmem;
|
|
|
|
unsigned long ppc_memstart;
|
|
unsigned long ppc_memoffset = PAGE_OFFSET;
|
|
|
|
int boot_mapsize;
|
|
#ifdef CONFIG_PPC_PMAC
|
|
unsigned long agp_special_page;
|
|
EXPORT_SYMBOL(agp_special_page);
|
|
#endif
|
|
|
|
#ifdef CONFIG_HIGHMEM
|
|
pte_t *kmap_pte;
|
|
pgprot_t kmap_prot;
|
|
|
|
EXPORT_SYMBOL(kmap_prot);
|
|
EXPORT_SYMBOL(kmap_pte);
|
|
#endif
|
|
|
|
void MMU_init(void);
|
|
|
|
/* XXX should be in current.h -- paulus */
|
|
extern struct task_struct *current_set[NR_CPUS];
|
|
|
|
extern int init_bootmem_done;
|
|
|
|
/*
|
|
* 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;
|
|
|
|
/* max amount of low RAM to map in */
|
|
unsigned long __max_low_memory = MAX_LOW_MEM;
|
|
|
|
/*
|
|
* limit of what is accessible with initial MMU setup -
|
|
* 256MB usually, but only 16MB on 601.
|
|
*/
|
|
unsigned long __initial_memory_limit = 0x10000000;
|
|
|
|
/*
|
|
* 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;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 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);
|
|
|
|
/* 601 can only access 16MB at the moment */
|
|
if (PVR_VER(mfspr(SPRN_PVR)) == 1)
|
|
__initial_memory_limit = 0x01000000;
|
|
|
|
/* parse args from command line */
|
|
MMU_setup();
|
|
|
|
if (lmb.memory.cnt > 1) {
|
|
lmb.memory.cnt = 1;
|
|
lmb_analyze();
|
|
printk(KERN_WARNING "Only using first contiguous memory region");
|
|
}
|
|
|
|
total_memory = lmb_end_of_DRAM();
|
|
total_lowmem = total_memory;
|
|
|
|
#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;
|
|
#ifndef CONFIG_HIGHMEM
|
|
total_memory = total_lowmem;
|
|
lmb_enforce_memory_limit(total_lowmem);
|
|
lmb_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();
|
|
|
|
#ifdef CONFIG_HIGHMEM
|
|
ioremap_base = PKMAP_BASE;
|
|
#else
|
|
ioremap_base = 0xfe000000UL; /* for now, could be 0xfffff000 */
|
|
#endif /* CONFIG_HIGHMEM */
|
|
ioremap_bot = ioremap_base;
|
|
|
|
/* Map in I/O resources */
|
|
if (ppc_md.progress)
|
|
ppc_md.progress("MMU:setio", 0x302);
|
|
if (ppc_md.setup_io_mappings)
|
|
ppc_md.setup_io_mappings();
|
|
|
|
/* Initialize the context management stuff */
|
|
mmu_context_init();
|
|
|
|
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
|
|
}
|
|
|
|
/* This is only called until mem_init is done. */
|
|
void __init *early_get_page(void)
|
|
{
|
|
void *p;
|
|
|
|
if (init_bootmem_done) {
|
|
p = alloc_bootmem_pages(PAGE_SIZE);
|
|
} else {
|
|
p = __va(lmb_alloc_base(PAGE_SIZE, PAGE_SIZE,
|
|
__initial_memory_limit));
|
|
}
|
|
return p;
|
|
}
|
|
|
|
/* 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_BLK_DEV_INITRD
|
|
void free_initrd_mem(unsigned long start, unsigned long end)
|
|
{
|
|
if (start < end)
|
|
printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
|
|
for (; start < end; start += PAGE_SIZE) {
|
|
ClearPageReserved(virt_to_page(start));
|
|
init_page_count(virt_to_page(start));
|
|
free_page(start);
|
|
totalram_pages++;
|
|
}
|
|
}
|
|
#endif
|