kernel-ark/arch/arm/mm/init.c
Russell King 6bf7bd6967 [ARM] Fix mm initialisation with write buffered write allocate caches
It seems that without the extra tlb flush, we may end up faulting
during the early kernel initialisation because the TLB can't see
the updated page tables.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-11-02 14:11:35 +00:00

690 lines
17 KiB
C

/*
* linux/arch/arm/mm/init.c
*
* Copyright (C) 1995-2005 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/config.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/ptrace.h>
#include <linux/swap.h>
#include <linux/init.h>
#include <linux/bootmem.h>
#include <linux/mman.h>
#include <linux/nodemask.h>
#include <linux/initrd.h>
#include <asm/mach-types.h>
#include <asm/hardware.h>
#include <asm/setup.h>
#include <asm/tlb.h>
#include <asm/mach/arch.h>
#include <asm/mach/map.h>
#define TABLE_SIZE (2 * PTRS_PER_PTE * sizeof(pte_t))
DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
extern void _stext, _text, _etext, __data_start, _end, __init_begin, __init_end;
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, node;
printk("Mem-info:\n");
show_free_areas();
printk("Free swap: %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
for_each_online_node(node) {
struct page *page, *end;
page = NODE_MEM_MAP(node);
end = page + NODE_DATA(node)->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);
}
static inline pmd_t *pmd_off(pgd_t *pgd, unsigned long virt)
{
return pmd_offset(pgd, virt);
}
static inline pmd_t *pmd_off_k(unsigned long virt)
{
return pmd_off(pgd_offset_k(virt), virt);
}
#define for_each_nodebank(iter,mi,no) \
for (iter = 0; iter < mi->nr_banks; iter++) \
if (mi->bank[iter].node == no)
/*
* 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(int node, struct meminfo *mi, unsigned int bootmap_pages)
{
unsigned int start_pfn, bank, bootmap_pfn;
start_pfn = PAGE_ALIGN(__pa(&_end)) >> PAGE_SHIFT;
bootmap_pfn = 0;
for_each_nodebank(bank, mi, node) {
unsigned int start, end;
start = mi->bank[bank].start >> PAGE_SHIFT;
end = (mi->bank[bank].size +
mi->bank[bank].start) >> PAGE_SHIFT;
if (end < start_pfn)
continue;
if (start < start_pfn)
start = start_pfn;
if (end <= start)
continue;
if (end - start >= bootmap_pages) {
bootmap_pfn = start;
break;
}
}
if (bootmap_pfn == 0)
BUG();
return bootmap_pfn;
}
static int __init check_initrd(struct meminfo *mi)
{
int initrd_node = -2;
#ifdef CONFIG_BLK_DEV_INITRD
unsigned long end = phys_initrd_start + phys_initrd_size;
/*
* Make sure that the initrd is within a valid area of
* memory.
*/
if (phys_initrd_size) {
unsigned int i;
initrd_node = -1;
for (i = 0; i < mi->nr_banks; i++) {
unsigned long bank_end;
bank_end = mi->bank[i].start + mi->bank[i].size;
if (mi->bank[i].start <= phys_initrd_start &&
end <= bank_end)
initrd_node = mi->bank[i].node;
}
}
if (initrd_node == -1) {
printk(KERN_ERR "initrd (0x%08lx - 0x%08lx) extends beyond "
"physical memory - disabling initrd\n",
phys_initrd_start, end);
phys_initrd_start = phys_initrd_size = 0;
}
#endif
return initrd_node;
}
/*
* Reserve the various regions of node 0
*/
static __init void reserve_node_zero(pg_data_t *pgdat)
{
unsigned long res_size = 0;
/*
* Register the kernel text and data with bootmem.
* Note that this can only be in node 0.
*/
#ifdef CONFIG_XIP_KERNEL
reserve_bootmem_node(pgdat, __pa(&__data_start), &_end - &__data_start);
#else
reserve_bootmem_node(pgdat, __pa(&_stext), &_end - &_stext);
#endif
/*
* Reserve the page tables. These are already in use,
* and can only be in node 0.
*/
reserve_bootmem_node(pgdat, __pa(swapper_pg_dir),
PTRS_PER_PGD * sizeof(pgd_t));
/*
* Hmm... This should go elsewhere, but we really really need to
* stop things allocating the low memory; ideally we need a better
* implementation of GFP_DMA which does not assume that DMA-able
* memory starts at zero.
*/
if (machine_is_integrator() || machine_is_cintegrator())
res_size = __pa(swapper_pg_dir) - PHYS_OFFSET;
/*
* These should likewise go elsewhere. They pre-reserve the
* screen memory region at the start of main system memory.
*/
if (machine_is_edb7211())
res_size = 0x00020000;
if (machine_is_p720t())
res_size = 0x00014000;
#ifdef CONFIG_SA1111
/*
* Because of the SA1111 DMA bug, we want to preserve our
* precious DMA-able memory...
*/
res_size = __pa(swapper_pg_dir) - PHYS_OFFSET;
#endif
if (res_size)
reserve_bootmem_node(pgdat, PHYS_OFFSET, res_size);
}
void __init build_mem_type_table(void);
void __init create_mapping(struct map_desc *md);
static unsigned long __init
bootmem_init_node(int node, int initrd_node, struct meminfo *mi)
{
unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES];
unsigned long start_pfn, end_pfn, boot_pfn;
unsigned int boot_pages;
pg_data_t *pgdat;
int i;
start_pfn = -1UL;
end_pfn = 0;
/*
* Calculate the pfn range, and map the memory banks for this node.
*/
for_each_nodebank(i, mi, node) {
unsigned long start, end;
struct map_desc map;
start = mi->bank[i].start >> PAGE_SHIFT;
end = (mi->bank[i].start + mi->bank[i].size) >> PAGE_SHIFT;
if (start_pfn > start)
start_pfn = start;
if (end_pfn < end)
end_pfn = end;
map.pfn = __phys_to_pfn(mi->bank[i].start);
map.virtual = __phys_to_virt(mi->bank[i].start);
map.length = mi->bank[i].size;
map.type = MT_MEMORY;
create_mapping(&map);
}
/*
* If there is no memory in this node, ignore it.
*/
if (end_pfn == 0)
return end_pfn;
/*
* Allocate the bootmem bitmap page.
*/
boot_pages = bootmem_bootmap_pages(end_pfn - start_pfn);
boot_pfn = find_bootmap_pfn(node, mi, boot_pages);
/*
* Initialise the bootmem allocator for this node, handing the
* memory banks over to bootmem.
*/
node_set_online(node);
pgdat = NODE_DATA(node);
init_bootmem_node(pgdat, boot_pfn, start_pfn, end_pfn);
for_each_nodebank(i, mi, node)
free_bootmem_node(pgdat, mi->bank[i].start, mi->bank[i].size);
/*
* Reserve the bootmem bitmap for this node.
*/
reserve_bootmem_node(pgdat, boot_pfn << PAGE_SHIFT,
boot_pages << PAGE_SHIFT);
#ifdef CONFIG_BLK_DEV_INITRD
/*
* If the initrd is in this node, reserve its memory.
*/
if (node == initrd_node) {
reserve_bootmem_node(pgdat, phys_initrd_start,
phys_initrd_size);
initrd_start = __phys_to_virt(phys_initrd_start);
initrd_end = initrd_start + phys_initrd_size;
}
#endif
/*
* Finally, reserve any node zero regions.
*/
if (node == 0)
reserve_node_zero(pgdat);
/*
* initialise the zones within this node.
*/
memset(zone_size, 0, sizeof(zone_size));
memset(zhole_size, 0, sizeof(zhole_size));
/*
* The size of this node has already been determined. If we need
* to do anything fancy with the allocation of this memory to the
* zones, now is the time to do it.
*/
zone_size[0] = end_pfn - start_pfn;
/*
* For each bank in this node, calculate the size of the holes.
* holes = node_size - sum(bank_sizes_in_node)
*/
zhole_size[0] = zone_size[0];
for_each_nodebank(i, mi, node)
zhole_size[0] -= mi->bank[i].size >> PAGE_SHIFT;
/*
* Adjust the sizes according to any special requirements for
* this machine type.
*/
arch_adjust_zones(node, zone_size, zhole_size);
free_area_init_node(node, pgdat, zone_size, start_pfn, zhole_size);
return end_pfn;
}
static void __init bootmem_init(struct meminfo *mi)
{
unsigned long addr, memend_pfn = 0;
int node, initrd_node, i;
/*
* Invalidate the node number for empty or invalid memory banks
*/
for (i = 0; i < mi->nr_banks; i++)
if (mi->bank[i].size == 0 || mi->bank[i].node >= MAX_NUMNODES)
mi->bank[i].node = -1;
memcpy(&meminfo, mi, sizeof(meminfo));
/*
* Clear out all the mappings below the kernel image.
*/
for (addr = 0; addr < MODULE_START; addr += PGDIR_SIZE)
pmd_clear(pmd_off_k(addr));
#ifdef CONFIG_XIP_KERNEL
/* The XIP kernel is mapped in the module area -- skip over it */
addr = ((unsigned long)&_etext + PGDIR_SIZE - 1) & PGDIR_MASK;
#endif
for ( ; addr < PAGE_OFFSET; addr += PGDIR_SIZE)
pmd_clear(pmd_off_k(addr));
/*
* Clear out all the kernel space mappings, except for the first
* memory bank, up to the end of the vmalloc region.
*/
for (addr = __phys_to_virt(mi->bank[0].start + mi->bank[0].size);
addr < VMALLOC_END; addr += PGDIR_SIZE)
pmd_clear(pmd_off_k(addr));
/*
* Locate which node contains the ramdisk image, if any.
*/
initrd_node = check_initrd(mi);
/*
* Run through each node initialising the bootmem allocator.
*/
for_each_node(node) {
unsigned long end_pfn;
end_pfn = bootmem_init_node(node, initrd_node, mi);
/*
* Remember the highest memory PFN.
*/
if (end_pfn > memend_pfn)
memend_pfn = end_pfn;
}
high_memory = __va(memend_pfn << PAGE_SHIFT);
/*
* This doesn't seem to be used by the Linux memory manager any
* more, but is used by ll_rw_block. If we can get rid of it, we
* also get rid of some of the stuff above as well.
*
* Note: max_low_pfn and max_pfn reflect the number of _pages_ in
* the system, not the maximum PFN.
*/
max_pfn = max_low_pfn = memend_pfn - PHYS_PFN_OFFSET;
}
/*
* Set up device the mappings. Since we clear out the page tables for all
* mappings above VMALLOC_END, we will remove any debug device mappings.
* This means you have to be careful how you debug this function, or any
* called function. (Do it by code inspection!)
*/
static void __init devicemaps_init(struct machine_desc *mdesc)
{
struct map_desc map;
unsigned long addr;
void *vectors;
for (addr = VMALLOC_END; addr; addr += PGDIR_SIZE)
pmd_clear(pmd_off_k(addr));
/*
* Map the kernel if it is XIP.
* It is always first in the modulearea.
*/
#ifdef CONFIG_XIP_KERNEL
map.pfn = __phys_to_pfn(CONFIG_XIP_PHYS_ADDR & PGDIR_MASK);
map.virtual = MODULE_START;
map.length = ((unsigned long)&_etext - map.virtual + ~PGDIR_MASK) & PGDIR_MASK;
map.type = MT_ROM;
create_mapping(&map);
#endif
/*
* Map the cache flushing regions.
*/
#ifdef FLUSH_BASE
map.pfn = __phys_to_pfn(FLUSH_BASE_PHYS);
map.virtual = FLUSH_BASE;
map.length = PGDIR_SIZE;
map.type = MT_CACHECLEAN;
create_mapping(&map);
#endif
#ifdef FLUSH_BASE_MINICACHE
map.pfn = __phys_to_pfn(FLUSH_BASE_PHYS + PGDIR_SIZE);
map.virtual = FLUSH_BASE_MINICACHE;
map.length = PGDIR_SIZE;
map.type = MT_MINICLEAN;
create_mapping(&map);
#endif
flush_cache_all();
local_flush_tlb_all();
vectors = alloc_bootmem_low_pages(PAGE_SIZE);
BUG_ON(!vectors);
/*
* Create a mapping for the machine vectors at the high-vectors
* location (0xffff0000). If we aren't using high-vectors, also
* create a mapping at the low-vectors virtual address.
*/
map.pfn = __phys_to_pfn(virt_to_phys(vectors));
map.virtual = 0xffff0000;
map.length = PAGE_SIZE;
map.type = MT_HIGH_VECTORS;
create_mapping(&map);
if (!vectors_high()) {
map.virtual = 0;
map.type = MT_LOW_VECTORS;
create_mapping(&map);
}
/*
* Ask the machine support to map in the statically mapped devices.
*/
if (mdesc->map_io)
mdesc->map_io();
/*
* Finally flush the tlb again - this ensures that we're in a
* consistent state wrt the writebuffer if the writebuffer needs
* draining. After this point, we can start to touch devices
* again.
*/
local_flush_tlb_all();
}
/*
* 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, struct machine_desc *mdesc)
{
void *zero_page;
build_mem_type_table();
bootmem_init(mi);
devicemaps_init(mdesc);
top_pmd = pmd_off_k(0xffff0000);
/*
* allocate the zero page. Note that we count on this going ok.
*/
zero_page = alloc_bootmem_low_pages(PAGE_SIZE);
memzero(zero_page, PAGE_SIZE);
empty_zero_page = virt_to_page(zero_page);
flush_dcache_page(empty_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);
set_page_count(page, 1);
free_page(addr);
totalram_pages++;
}
if (size && s)
printk(KERN_INFO "Freeing %s memory: %dK\n", s, size);
}
static inline void
free_memmap(int node, unsigned long start_pfn, unsigned long end_pfn)
{
struct page *start_pg, *end_pg;
unsigned long pg, pgend;
/*
* Convert start_pfn/end_pfn to a struct page pointer.
*/
start_pg = pfn_to_page(start_pfn);
end_pg = pfn_to_page(end_pfn);
/*
* Convert to physical addresses, and
* round start upwards and end downwards.
*/
pg = PAGE_ALIGN(__pa(start_pg));
pgend = __pa(end_pg) & PAGE_MASK;
/*
* If there are free pages between these,
* free the section of the memmap array.
*/
if (pg < pgend)
free_bootmem_node(NODE_DATA(node), pg, pgend - pg);
}
/*
* The mem_map array can get very big. Free the unused area of the memory map.
*/
static void __init free_unused_memmap_node(int node, struct meminfo *mi)
{
unsigned long bank_start, prev_bank_end = 0;
unsigned int i;
/*
* [FIXME] This relies on each bank being in address order. This
* may not be the case, especially if the user has provided the
* information on the command line.
*/
for_each_nodebank(i, mi, node) {
bank_start = mi->bank[i].start >> PAGE_SHIFT;
if (bank_start < prev_bank_end) {
printk(KERN_ERR "MEM: unordered memory banks. "
"Not freeing memmap.\n");
break;
}
/*
* If we had a previous bank, and there is a space
* between the current bank and the previous, free it.
*/
if (prev_bank_end && prev_bank_end != bank_start)
free_memmap(node, prev_bank_end, bank_start);
prev_bank_end = (mi->bank[i].start +
mi->bank[i].size) >> PAGE_SHIFT;
}
}
/*
* 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;
int i, node;
codepages = &_etext - &_text;
datapages = &_end - &__data_start;
initpages = &__init_end - &__init_begin;
#ifndef CONFIG_DISCONTIGMEM
max_mapnr = virt_to_page(high_memory) - mem_map;
#endif
/* this will put all unused low memory onto the freelists */
for_each_online_node(node) {
pg_data_t *pgdat = NODE_DATA(node);
free_unused_memmap_node(node, &meminfo);
if (pgdat->node_spanned_pages != 0)
totalram_pages += free_all_bootmem_node(pgdat);
}
#ifdef CONFIG_SA1111
/* now that our DMA memory is actually so designated, we can free it */
free_area(PAGE_OFFSET, (unsigned long)swapper_pg_dir, NULL);
#endif
/*
* Since our memory may not be contiguous, calculate the
* real number of pages we have in this system
*/
printk(KERN_INFO "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(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);
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 = OVERCOMMIT_ALWAYS;
}
}
void free_initmem(void)
{
if (!machine_is_integrator() && !machine_is_cintegrator()) {
free_area((unsigned long)(&__init_begin),
(unsigned long)(&__init_end),
"init");
}
}
#ifdef CONFIG_BLK_DEV_INITRD
static int keep_initrd;
void free_initrd_mem(unsigned long start, unsigned long end)
{
if (!keep_initrd)
free_area(start, end, "initrd");
}
static int __init keepinitrd_setup(char *__unused)
{
keep_initrd = 1;
return 1;
}
__setup("keepinitrd", keepinitrd_setup);
#endif