linux-sg2042/arch/xtensa/mm/init.c

329 lines
7.6 KiB
C

/*
* arch/xtensa/mm/init.c
*
* Derived from MIPS, PPC.
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2001 - 2005 Tensilica Inc.
*
* Chris Zankel <chris@zankel.net>
* Joe Taylor <joe@tensilica.com, joetylr@yahoo.com>
* Marc Gauthier
* Kevin Chea
*/
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/bootmem.h>
#include <linux/swap.h>
#include <linux/mman.h>
#include <linux/nodemask.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <asm/pgtable.h>
#include <asm/bootparam.h>
#include <asm/mmu_context.h>
#include <asm/tlb.h>
#include <asm/page.h>
#include <asm/pgalloc.h>
DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
/* References to section boundaries */
extern char _ftext, _etext, _fdata, _edata, _rodata_end;
extern char __init_begin, __init_end;
/*
* mem_reserve(start, end, must_exist)
*
* Reserve some memory from the memory pool.
*
* Parameters:
* start Start of region,
* end End of region,
* must_exist Must exist in memory pool.
*
* Returns:
* 0 (memory area couldn't be mapped)
* -1 (success)
*/
int __init mem_reserve(unsigned long start, unsigned long end, int must_exist)
{
int i;
if (start == end)
return 0;
start = start & PAGE_MASK;
end = PAGE_ALIGN(end);
for (i = 0; i < sysmem.nr_banks; i++)
if (start < sysmem.bank[i].end
&& end >= sysmem.bank[i].start)
break;
if (i == sysmem.nr_banks) {
if (must_exist)
printk (KERN_WARNING "mem_reserve: [0x%0lx, 0x%0lx) "
"not in any region!\n", start, end);
return 0;
}
if (start > sysmem.bank[i].start) {
if (end < sysmem.bank[i].end) {
/* split entry */
if (sysmem.nr_banks >= SYSMEM_BANKS_MAX)
panic("meminfo overflow\n");
sysmem.bank[sysmem.nr_banks].start = end;
sysmem.bank[sysmem.nr_banks].end = sysmem.bank[i].end;
sysmem.nr_banks++;
}
sysmem.bank[i].end = start;
} else {
if (end < sysmem.bank[i].end)
sysmem.bank[i].start = end;
else {
/* remove entry */
sysmem.nr_banks--;
sysmem.bank[i].start = sysmem.bank[sysmem.nr_banks].start;
sysmem.bank[i].end = sysmem.bank[sysmem.nr_banks].end;
}
}
return -1;
}
/*
* Initialize the bootmem system and give it all the memory we have available.
*/
void __init bootmem_init(void)
{
unsigned long pfn;
unsigned long bootmap_start, bootmap_size;
int i;
max_low_pfn = max_pfn = 0;
min_low_pfn = ~0;
for (i=0; i < sysmem.nr_banks; i++) {
pfn = PAGE_ALIGN(sysmem.bank[i].start) >> PAGE_SHIFT;
if (pfn < min_low_pfn)
min_low_pfn = pfn;
pfn = PAGE_ALIGN(sysmem.bank[i].end - 1) >> PAGE_SHIFT;
if (pfn > max_pfn)
max_pfn = pfn;
}
if (min_low_pfn > max_pfn)
panic("No memory found!\n");
max_low_pfn = max_pfn < MAX_MEM_PFN >> PAGE_SHIFT ?
max_pfn : MAX_MEM_PFN >> PAGE_SHIFT;
/* Find an area to use for the bootmem bitmap. */
bootmap_size = bootmem_bootmap_pages(max_low_pfn) << PAGE_SHIFT;
bootmap_start = ~0;
for (i=0; i<sysmem.nr_banks; i++)
if (sysmem.bank[i].end - sysmem.bank[i].start >= bootmap_size) {
bootmap_start = sysmem.bank[i].start;
break;
}
if (bootmap_start == ~0UL)
panic("Cannot find %ld bytes for bootmap\n", bootmap_size);
/* Reserve the bootmem bitmap area */
mem_reserve(bootmap_start, bootmap_start + bootmap_size, 1);
bootmap_size = init_bootmem_node(NODE_DATA(0), min_low_pfn,
bootmap_start >> PAGE_SHIFT,
max_low_pfn);
/* Add all remaining memory pieces into the bootmem map */
for (i=0; i<sysmem.nr_banks; i++)
free_bootmem(sysmem.bank[i].start,
sysmem.bank[i].end - sysmem.bank[i].start);
}
void __init paging_init(void)
{
unsigned long zones_size[MAX_NR_ZONES];
int i;
/* All pages are DMA-able, so we put them all in the DMA zone. */
zones_size[ZONE_DMA] = max_low_pfn;
for (i = 1; i < MAX_NR_ZONES; i++)
zones_size[i] = 0;
#ifdef CONFIG_HIGHMEM
zones_size[ZONE_HIGHMEM] = max_pfn - max_low_pfn;
#endif
/* Initialize the kernel's page tables. */
memset(swapper_pg_dir, 0, PAGE_SIZE);
free_area_init(zones_size);
}
/*
* Flush the mmu and reset associated register to default values.
*/
void __init init_mmu (void)
{
/* Writing zeros to the <t>TLBCFG special registers ensure
* that valid values exist in the register. For existing
* PGSZID<w> fields, zero selects the first element of the
* page-size array. For nonexistent PGSZID<w> fields, zero is
* the best value to write. Also, when changing PGSZID<w>
* fields, the corresponding TLB must be flushed.
*/
set_itlbcfg_register (0);
set_dtlbcfg_register (0);
flush_tlb_all ();
/* Set rasid register to a known value. */
set_rasid_register (ASID_USER_FIRST);
/* Set PTEVADDR special register to the start of the page
* table, which is in kernel mappable space (ie. not
* statically mapped). This register's value is undefined on
* reset.
*/
set_ptevaddr_register (PGTABLE_START);
}
/*
* Initialize memory pages.
*/
void __init mem_init(void)
{
unsigned long codesize, reservedpages, datasize, initsize;
unsigned long highmemsize, tmp, ram;
max_mapnr = num_physpages = max_low_pfn;
high_memory = (void *) __va(max_mapnr << PAGE_SHIFT);
highmemsize = 0;
#ifdef CONFIG_HIGHMEM
#error HIGHGMEM not implemented in init.c
#endif
totalram_pages += free_all_bootmem();
reservedpages = ram = 0;
for (tmp = 0; tmp < max_low_pfn; tmp++) {
ram++;
if (PageReserved(mem_map+tmp))
reservedpages++;
}
codesize = (unsigned long) &_etext - (unsigned long) &_ftext;
datasize = (unsigned long) &_edata - (unsigned long) &_fdata;
initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin;
printk("Memory: %luk/%luk available (%ldk kernel code, %ldk reserved, "
"%ldk data, %ldk init %ldk highmem)\n",
(unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
ram << (PAGE_SHIFT-10),
codesize >> 10,
reservedpages << (PAGE_SHIFT-10),
datasize >> 10,
initsize >> 10,
highmemsize >> 10);
}
void
free_reserved_mem(void *start, void *end)
{
for (; start < end; start += PAGE_SIZE) {
ClearPageReserved(virt_to_page(start));
init_page_count(virt_to_page(start));
free_page((unsigned long)start);
totalram_pages++;
}
}
#ifdef CONFIG_BLK_DEV_INITRD
extern int initrd_is_mapped;
void free_initrd_mem(unsigned long start, unsigned long end)
{
if (initrd_is_mapped) {
free_reserved_mem((void*)start, (void*)end);
printk ("Freeing initrd memory: %ldk freed\n",(end-start)>>10);
}
}
#endif
void free_initmem(void)
{
free_reserved_mem(&__init_begin, &__init_end);
printk("Freeing unused kernel memory: %dk freed\n",
(&__init_end - &__init_begin) >> 10);
}
void show_mem(void)
{
int i, free = 0, total = 0, reserved = 0;
int shared = 0, cached = 0;
printk("Mem-info:\n");
show_free_areas();
printk("Free swap: %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
i = max_mapnr;
while (i-- > 0) {
total++;
if (PageReserved(mem_map+i))
reserved++;
else if (PageSwapCache(mem_map+i))
cached++;
else if (!page_count(mem_map + i))
free++;
else
shared += page_count(mem_map + i) - 1;
}
printk("%d pages of RAM\n", total);
printk("%d reserved pages\n", reserved);
printk("%d pages shared\n", shared);
printk("%d pages swap cached\n",cached);
printk("%d free pages\n", free);
}
struct kmem_cache *pgtable_cache __read_mostly;
static void pgd_ctor(void *addr, struct kmem_cache *cache, unsigned long flags)
{
pte_t* ptep = (pte_t*)addr;
int i;
for (i = 0; i < 1024; i++, ptep++)
pte_clear(NULL, 0, ptep);
}
void __init pgtable_cache_init(void)
{
pgtable_cache = kmem_cache_create("pgd",
PAGE_SIZE, PAGE_SIZE,
SLAB_HWCACHE_ALIGN,
pgd_ctor);
}