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* linux/arch/arm/mm/init.c
*
* Copyright (C) 1995-1999 Russell King
*/
#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/swapctl.h>
#include <linux/smp.h>
#include <linux/init.h>
#include <linux/bootmem.h>
#ifdef CONFIG_BLK_DEV_INITRD
#include <linux/blk.h>
#endif
#include <asm/system.h>
#include <asm/segment.h>
#include <asm/pgalloc.h>
#include <asm/dma.h>
#include <asm/hardware.h>
#include <asm/setup.h>
#include "map.h"
static unsigned long totalram_pages;
pgd_t swapper_pg_dir[PTRS_PER_PGD];
/*
* empty_bad_page is the page that is used for page faults when
* linux is out-of-memory. Older versions of linux just did a
* do_exit(), but using this instead means there is less risk
* for a process dying in kernel mode, possibly leaving a inode
* unused etc..
*
* empty_bad_pte_table is the accompanying page-table: it is
* initialized to point to BAD_PAGE entries.
*
* empty_zero_page is a special page that is used for
* zero-initialized data and COW.
*/
struct page *empty_zero_page;
struct page *empty_bad_page;
pte_t *empty_bad_pte_table;
pte_t *get_bad_pte_table(void)
{
pte_t v;
int i;
v = pte_mkdirty(mk_pte(empty_bad_page, PAGE_SHARED));
for (i = 0; i < PTRS_PER_PTE; i++)
set_pte(empty_bad_pte_table + i, v);
return empty_bad_pte_table;
}
void __handle_bad_pmd(pmd_t *pmd)
{
pmd_ERROR(*pmd);
#ifdef CONFIG_DEBUG_ERRORS
__backtrace();
#endif
set_pmd(pmd, mk_user_pmd(get_bad_pte_table()));
}
void __handle_bad_pmd_kernel(pmd_t *pmd)
{
pmd_ERROR(*pmd);
#ifdef CONFIG_DEBUG_ERRORS
__backtrace();
#endif
set_pmd(pmd, mk_kernel_pmd(get_bad_pte_table()));
}
#ifndef CONFIG_NO_PGT_CACHE
struct pgtable_cache_struct quicklists;
int do_check_pgt_cache(int low, int high)
{
int freed = 0;
if(pgtable_cache_size > high) {
do {
if(pgd_quicklist) {
free_pgd_slow(get_pgd_fast());
freed++;
}
if(pmd_quicklist) {
free_pmd_slow(get_pmd_fast());
freed++;
}
if(pte_quicklist) {
free_pte_slow(get_pte_fast());
freed++;
}
} while(pgtable_cache_size > low);
}
return freed;
}
#else
int do_check_pgt_cache(int low, int high)
{
return 0;
}
#endif
void show_mem(void)
{
int free = 0, total = 0, reserved = 0;
int shared = 0, cached = 0;
struct page *page, *end;
printk("Mem-info:\n");
show_free_areas();
printk("Free swap: %6dkB\n",nr_swap_pages<<(PAGE_SHIFT-10));
page = mem_map;
end = mem_map + max_mapnr;
do {
if (PageSkip(page)) {
page = page->next_hash;
if (page == NULL)
break;
}
total++;
if (PageReserved(page))
reserved++;
else if (PageSwapCache(page))
cached++;
else if (!page_count(page))
free++;
else
shared += atomic_read(&page->count) - 1;
page++;
} while (page < end);
printk("%d pages of RAM\n", total);
printk("%d free pages\n", free);
printk("%d reserved pages\n", reserved);
printk("%d pages shared\n", shared);
printk("%d pages swap cached\n", cached);
#ifndef CONFIG_NO_PGT_CACHE
printk("%ld page tables cached\n", pgtable_cache_size);
#endif
show_buffers();
}
/*
* paging_init() sets up the page tables...
*/
void __init paging_init(void)
{
void *zero_page, *bad_page, *bad_table;
unsigned long zone_size[MAX_NR_ZONES];
int i;
#ifdef CONFIG_CPU_32
#define TABLE_OFFSET (PTRS_PER_PTE)
#else
#define TABLE_OFFSET 0
#endif
#define TABLE_SIZE ((TABLE_OFFSET + PTRS_PER_PTE) * sizeof(void *))
/*
* allocate what we need for the bad pages
*/
zero_page = alloc_bootmem_low_pages(PAGE_SIZE);
bad_page = alloc_bootmem_low_pages(PAGE_SIZE);
bad_table = alloc_bootmem_low_pages(TABLE_SIZE);
/*
* initialise the page tables
*/
pagetable_init();
flush_tlb_all();
/*
* Initialise the zones and mem_map
*/
for (i = 0; i < MAX_NR_ZONES; i++)
zone_size[i] = 0;
/*
* Calculate the size of the zones. On ARM, we don't have
* any problems with DMA or highmem, so all memory is
* allocated to the DMA zone.
*/
for (i = 0; i < meminfo.nr_banks; i++) {
if (meminfo.bank[i].size) {
unsigned int end;
end = (meminfo.bank[i].start - PHYS_OFFSET +
meminfo.bank[i].size) >> PAGE_SHIFT;
if (zone_size[0] < end)
zone_size[0] = end;
}
}
free_area_init(zone_size);
/*
* finish off the bad pages once
* the mem_map is initialised
*/
memzero(zero_page, PAGE_SIZE);
memzero(bad_page, PAGE_SIZE);
empty_zero_page = mem_map + MAP_NR(zero_page);
empty_bad_page = mem_map + MAP_NR(bad_page);
empty_bad_pte_table = ((pte_t *)bad_table) + TABLE_OFFSET;
}
static inline void free_unused_mem_map(void)
{
struct page *page, *end;
end = mem_map + max_mapnr;
for (page = mem_map; page < end; page++) {
unsigned long low, high;
if (!PageSkip(page))
continue;
low = PAGE_ALIGN((unsigned long)(page + 1));
if (page->next_hash < page)
high = ((unsigned long)end) & PAGE_MASK;
else
high = ((unsigned long)page->next_hash) & PAGE_MASK;
while (low < high) {
ClearPageReserved(mem_map + MAP_NR(low));
low += PAGE_SIZE;
}
}
}
/*
* mem_init() marks the free areas in the mem_map and tells us how much
* memory is free. This is done after various parts of the system have
* claimed their memory after the kernel image.
*/
void __init mem_init(void)
{
extern char __init_begin, __init_end, _text, _etext, _end;
unsigned int codepages, datapages, initpages;
int i;
codepages = &_etext - &_text;
datapages = &_end - &_etext;
initpages = &__init_end - &__init_begin;
max_mapnr = max_low_pfn;
high_memory = (void *)__va(PHYS_OFFSET + max_low_pfn * PAGE_SIZE);
/*
* We may have non-contiguous memory. Setup the PageSkip stuff,
* and mark the areas of mem_map which can be freed
*/
if (meminfo.nr_banks != 1)
create_memmap_holes();
/* this will put all unused low memory onto the freelists */
totalram_pages += free_all_bootmem();
/*
* Since our memory may not be contiguous, calculate the
* real number of pages we have in this system
*/
printk("Memory:");
num_physpages = 0;
for (i = 0; i < meminfo.nr_banks; i++) {
num_physpages += meminfo.bank[i].size >> PAGE_SHIFT;
printk(" %ldMB", meminfo.bank[i].size >> 20);
}
printk(" = %luMB total\n", num_physpages >> (20 - PAGE_SHIFT));
printk("Memory: %luKB available (%dK code, %dK data, %dK init)\n",
(unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
codepages >> 10, datapages >> 10, initpages >> 10);
if (PAGE_SIZE >= 16384 && num_physpages <= 128) {
extern int sysctl_overcommit_memory;
/*
* On a machine this small we won't get
* anywhere without overcommit, so turn
* it on by default.
*/
sysctl_overcommit_memory = 1;
}
}
static inline void free_area(unsigned long addr, unsigned long end, char *s)
{
unsigned int size = (end - addr) >> 10;
struct page *page = mem_map + MAP_NR(addr);
for (; addr < end; addr += PAGE_SIZE, page ++) {
ClearPageReserved(page);
set_page_count(page, 1);
free_page(addr);
totalram_pages++;
}
if (size)
printk(" %dk %s", size, s);
}
void free_initmem(void)
{
extern char __init_begin, __init_end;
printk("Freeing unused kernel memory:");
free_area((unsigned long)(&__init_begin),
(unsigned long)(&__init_end),
"init");
#ifdef CONFIG_FOOTBRIDGE
{
extern int __netwinder_begin, __netwinder_end,
__ebsa285_begin, __ebsa285_end;
if (!machine_is_netwinder())
free_area((unsigned long)(&__netwinder_begin),
(unsigned long)(&__netwinder_end),
"netwinder");
if (!machine_is_ebsa285() && !machine_is_cats() &&
!machine_is_co285())
free_area((unsigned long)(&__ebsa285_begin),
(unsigned long)(&__ebsa285_end),
"ebsa285/cats");
}
#endif
printk("\n");
}
#ifdef CONFIG_BLK_DEV_INITRD
void free_initrd_mem(unsigned long start, unsigned long end)
{
unsigned long addr;
for (addr = start; addr < end; addr += PAGE_SIZE) {
ClearPageReserved(mem_map + MAP_NR(addr));
set_page_count(mem_map+MAP_NR(addr), 1);
free_page(addr);
totalram_pages++;
}
printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
}
#endif
void si_meminfo(struct sysinfo *val)
{
val->totalram = totalram_pages;
val->sharedram = 0;
val->freeram = nr_free_pages();
val->bufferram = atomic_read(&buffermem_pages);
val->totalhigh = 0;
val->freehigh = 0;
val->mem_unit = PAGE_SIZE;
}
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