init.c
/*
* linux/arch/arm26/mm/init.c
*
* Copyright (C) 1995-2002 Russell King
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#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/smp.h>
#include <linux/init.h>
#include <linux/initrd.h>
#include <linux/bootmem.h>
#include <linux/blkdev.h>
#include <linux/pfn.h>
#include <asm/segment.h>
#include <asm/mach-types.h>
#include <asm/dma.h>
#include <asm/hardware.h>
#include <asm/setup.h>
#include <asm/tlb.h>
#include <asm/map.h>
#define TABLE_SIZE PTRS_PER_PTE * sizeof(pte_t))
struct mmu_gather mmu_gathers[NR_CPUS];
extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
extern char _stext, _text, _etext, _end, __init_begin, __init_end;
#ifdef CONFIG_XIP_KERNEL
extern char _endtext, _sdata;
#endif
extern unsigned long phys_initrd_start;
extern unsigned long phys_initrd_size;
/*
* The sole use of this is to pass memory configuration
* data from paging_init to mem_init.
*/
static struct meminfo meminfo __initdata = { 0, };
/*
* empty_zero_page is a special page that is used for
* zero-initialized data and COW.
*/
struct page *empty_zero_page;
void show_mem(void)
{
int free = 0, total = 0, reserved = 0;
int shared = 0, cached = 0, slab = 0;
struct page *page, *end;
printk("Mem-info:\n");
show_free_areas();
printk("Free swap: %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
page = NODE_MEM_MAP(0);
end = page + NODE_DATA(0)->node_spanned_pages;
do {
total++;
if (PageReserved(page))
reserved++;
else if (PageSwapCache(page))
cached++;
else if (PageSlab(page))
slab++;
else if (!page_count(page))
free++;
else
shared += page_count(page) - 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 slab pages\n", slab);
printk("%d pages shared\n", shared);
printk("%d pages swap cached\n", cached);
}
struct node_info {
unsigned int start;
unsigned int end;
int bootmap_pages;
};
/*
* FIXME: We really want to avoid allocating the bootmap bitmap
* over the top of the initrd. Hopefully, this is located towards
* the start of a bank, so if we allocate the bootmap bitmap at
* the end, we won't clash.
*/
static unsigned int __init
find_bootmap_pfn(struct meminfo *mi, unsigned int bootmap_pages)
{
unsigned int start_pfn, bootmap_pfn;
unsigned int start, end;
start_pfn = PFN_UP((unsigned long)&_end);
bootmap_pfn = 0;
/* ARM26 machines only have one node */
if (mi->bank->node != 0)
BUG();
start = PFN_UP(mi->bank->start);
end = PFN_DOWN(mi->bank->size + mi->bank->start);
if (start < start_pfn)
start = start_pfn;
if (end <= start)
BUG();
if (end - start >= bootmap_pages)
bootmap_pfn = start;
else
BUG();
return bootmap_pfn;
}
/*
* Scan the memory info structure and pull out:
* - the end of memory
* - the number of nodes
* - the pfn range of each node
* - the number of bootmem bitmap pages
*/
static void __init
find_memend_and_nodes(struct meminfo *mi, struct node_info *np)
{
unsigned int memend_pfn = 0;
nodes_clear(node_online_map);
node_set_online(0);
np->bootmap_pages = 0;
if (mi->bank->size == 0) {
BUG();
}
/*
* Get the start and end pfns for this bank
*/
np->start = PFN_UP(mi->bank->start);
np->end = PFN_DOWN(mi->bank->start + mi->bank->size);
if (memend_pfn < np->end)
memend_pfn = np->end;
/*
* Calculate the number of pages we require to
* store the bootmem bitmaps.
*/
np->bootmap_pages = bootmem_bootmap_pages(np->end - np->start);
/*
* This doesn't seem to be used by the Linux memory
* manager any more. If we can get rid of it, we
* also get rid of some of the stuff above as well.
*/
max_low_pfn = memend_pfn - PFN_DOWN(PHYS_OFFSET);
max_pfn = memend_pfn - PFN_DOWN(PHYS_OFFSET);
mi->end = memend_pfn << PAGE_SHIFT;
}
/*
* Initialise the bootmem allocator for all nodes. This is called
* early during the architecture specific initialisation.
*/
void __init bootmem_init(struct meminfo *mi)
{
struct node_info node_info;
unsigned int bootmap_pfn;
pg_data_t *pgdat = NODE_DATA(0);
find_memend_and_nodes(mi, &node_info);
bootmap_pfn = find_bootmap_pfn(mi, node_info.bootmap_pages);
/*
* Note that node 0 must always have some pages.
*/
if (node_info.end == 0)
BUG();
/*
* Initialise the bootmem allocator.
*/
init_bootmem_node(pgdat, bootmap_pfn, node_info.start, node_info.end);
/*
* Register all available RAM in this node with the bootmem allocator.
*/
free_bootmem_node(pgdat, mi->bank->start, mi->bank->size);
/*
* Register the kernel text and data with bootmem.
* Note: with XIP we dont register .text since
* its in ROM.
*/
#ifdef CONFIG_XIP_KERNEL
reserve_bootmem_node(pgdat, __pa(&_sdata), &_end - &_sdata);
#else
reserve_bootmem_node(pgdat, __pa(&_stext), &_end - &_stext);
#endif
/*
* And don't forget to reserve the allocator bitmap,
* which will be freed later.
*/
reserve_bootmem_node(pgdat, bootmap_pfn << PAGE_SHIFT,
node_info.bootmap_pages << PAGE_SHIFT);
/*
* These should likewise go elsewhere. They pre-reserve
* the screen memory region at the start of main system
* memory. FIXME - screen RAM is not 512K!
*/
reserve_bootmem_node(pgdat, 0x02000000, 0x00080000);
#ifdef CONFIG_BLK_DEV_INITRD
initrd_start = phys_initrd_start;
initrd_end = initrd_start + phys_initrd_size;
/* Achimedes machines only have one node, so initrd is in node 0 */
#ifdef CONFIG_XIP_KERNEL
/* Only reserve initrd space if it is in RAM */
if(initrd_start && initrd_start < 0x03000000){
#else
if(initrd_start){
#endif
reserve_bootmem_node(pgdat, __pa(initrd_start),
initrd_end - initrd_start);
}
#endif /* CONFIG_BLK_DEV_INITRD */
}
/*
* paging_init() sets up the page tables, initialises the zone memory
* maps, and sets up the zero page, bad page and bad page tables.
*/
void __init paging_init(struct meminfo *mi)
{
void *zero_page;
unsigned long zone_size[MAX_NR_ZONES];
unsigned long zhole_size[MAX_NR_ZONES];
struct bootmem_data *bdata;
pg_data_t *pgdat;
int i;
memcpy(&meminfo, mi, sizeof(meminfo));
/*
* allocate the zero page. Note that we count on this going ok.
*/
zero_page = alloc_bootmem_low_pages(PAGE_SIZE);
/*
* initialise the page tables.
*/
memtable_init(mi);
flush_tlb_all();
/*
* initialise the zones in node 0 (archimedes have only 1 node)
*/
for (i = 0; i < MAX_NR_ZONES; i++) {
zone_size[i] = 0;
zhole_size[i] = 0;
}
pgdat = NODE_DATA(0);
bdata = pgdat->bdata;
zone_size[0] = bdata->node_low_pfn -
(bdata->node_boot_start >> PAGE_SHIFT);
if (!zone_size[0])
BUG();
pgdat->node_mem_map = NULL;
free_area_init_node(0, pgdat, zone_size,
bdata->node_boot_start >> PAGE_SHIFT, zhole_size);
/*
* finish off the bad pages once
* the mem_map is initialised
*/
memzero(zero_page, PAGE_SIZE);
empty_zero_page = virt_to_page(zero_page);
}
static inline void free_area(unsigned long addr, unsigned long end, char *s)
{
unsigned int size = (end - addr) >> 10;
for (; addr < end; addr += PAGE_SIZE) {
struct page *page = virt_to_page(addr);
ClearPageReserved(page);
init_page_count(page);
free_page(addr);
totalram_pages++;
}
if (size && s)
printk(KERN_INFO "Freeing %s memory: %dK\n", s, 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)
{
unsigned int codepages, datapages, initpages;
pg_data_t *pgdat = NODE_DATA(0);
extern int sysctl_overcommit_memory;
/* Note: data pages includes BSS */
#ifdef CONFIG_XIP_KERNEL
codepages = &_endtext - &_text;
datapages = &_end - &_sdata;
#else
codepages = &_etext - &_text;
datapages = &_end - &_etext;
#endif
initpages = &__init_end - &__init_begin;
high_memory = (void *)__va(meminfo.end);
max_mapnr = virt_to_page(high_memory) - mem_map;
/* this will put all unused low memory onto the freelists */
if (pgdat->node_spanned_pages != 0)
totalram_pages += free_all_bootmem_node(pgdat);
num_physpages = meminfo.bank[0].size >> PAGE_SHIFT;
printk(KERN_INFO "Memory: %luMB total\n", num_physpages >> (20 - PAGE_SHIFT));
printk(KERN_NOTICE "Memory: %luKB available (%dK code, "
"%dK data, %dK init)\n",
(unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
codepages >> 10, datapages >> 10, initpages >> 10);
/*
* Turn on overcommit on tiny machines
*/
if (PAGE_SIZE >= 16384 && num_physpages <= 128) {
sysctl_overcommit_memory = OVERCOMMIT_ALWAYS;
printk("Turning on overcommit\n");
}
}
void free_initmem(void){
#ifndef CONFIG_XIP_KERNEL
free_area((unsigned long)(&__init_begin),
(unsigned long)(&__init_end),
"init");
#endif
}
#ifdef CONFIG_BLK_DEV_INITRD
static int keep_initrd;
void free_initrd_mem(unsigned long start, unsigned long end)
{
#ifdef CONFIG_XIP_KERNEL
/* Only bin initrd if it is in RAM... */
if(!keep_initrd && start < 0x03000000)
#else
if (!keep_initrd)
#endif
free_area(start, end, "initrd");
}
static int __init keepinitrd_setup(char *__unused)
{
keep_initrd = 1;
return 1;
}
__setup("keepinitrd", keepinitrd_setup);
#endif
