linux/arch/arm/mm/init.c
Russell King dde5828f56 ARM: Fix broken highmem support
Currently, highmem is selectable, and you can request an increased
vmalloc area.  However, none of this has any effect on the memory
layout since a patch in the highmem series was accidentally dropped.
Moreover, even if you did want highmem, all memory would still be
registered as lowmem, possibly resulting in overflow of the available
virtual mapping space.

The highmem boundary is determined by the highest allowed beginning
of the vmalloc area, which depends on its configurable minimum size
(see commit 60296c71f6 for details on
this).

We should create mappings and initialize bootmem only for low memory,
while the zone allocator must still be told about highmem.

Currently, memory nodes which are completely located in high memory
are not supported.  This is not a huge limitation since systems
relying on highmem support are unlikely to have discontiguous memory
with large holes.

[ A similar patch was meant to be merged before commit 5f0fbf9eca
  and be available  in Linux v2.6.30, however some git rebase screw-up
  of mine dropped the first commit of the series, and that goofage
  escaped testing somehow as well. -- Nico ]

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Reviewed-by: Nicolas Pitre <nico@marvell.com>
2009-08-15 12:36:00 +01:00

610 lines
14 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/kernel.h>
#include <linux/errno.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 <linux/highmem.h>
#include <asm/mach-types.h>
#include <asm/sections.h>
#include <asm/setup.h>
#include <asm/sizes.h>
#include <asm/tlb.h>
#include <asm/mach/arch.h>
#include <asm/mach/map.h>
#include "mm.h"
static unsigned long phys_initrd_start __initdata = 0;
static unsigned long phys_initrd_size __initdata = 0;
static void __init early_initrd(char **p)
{
unsigned long start, size;
start = memparse(*p, p);
if (**p == ',') {
size = memparse((*p) + 1, p);
phys_initrd_start = start;
phys_initrd_size = size;
}
}
__early_param("initrd=", early_initrd);
static int __init parse_tag_initrd(const struct tag *tag)
{
printk(KERN_WARNING "ATAG_INITRD is deprecated; "
"please update your bootloader.\n");
phys_initrd_start = __virt_to_phys(tag->u.initrd.start);
phys_initrd_size = tag->u.initrd.size;
return 0;
}
__tagtable(ATAG_INITRD, parse_tag_initrd);
static int __init parse_tag_initrd2(const struct tag *tag)
{
phys_initrd_start = tag->u.initrd.start;
phys_initrd_size = tag->u.initrd.size;
return 0;
}
__tagtable(ATAG_INITRD2, parse_tag_initrd2);
/*
* This keeps memory configuration data used by a couple memory
* initialization functions, as well as show_mem() for the skipping
* of holes in the memory map. It is populated by arm_add_memory().
*/
struct meminfo meminfo;
void show_mem(void)
{
int free = 0, total = 0, reserved = 0;
int shared = 0, cached = 0, slab = 0, node, i;
struct meminfo * mi = &meminfo;
printk("Mem-info:\n");
show_free_areas();
for_each_online_node(node) {
pg_data_t *n = NODE_DATA(node);
struct page *map = pgdat_page_nr(n, 0) - n->node_start_pfn;
for_each_nodebank (i,mi,node) {
struct membank *bank = &mi->bank[i];
unsigned int pfn1, pfn2;
struct page *page, *end;
pfn1 = bank_pfn_start(bank);
pfn2 = bank_pfn_end(bank);
page = map + pfn1;
end = map + pfn2;
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 void __init find_node_limits(int node, struct meminfo *mi,
unsigned long *min, unsigned long *max_low, unsigned long *max_high)
{
int i;
*min = -1UL;
*max_low = *max_high = 0;
for_each_nodebank(i, mi, node) {
struct membank *bank = &mi->bank[i];
unsigned long start, end;
start = bank_pfn_start(bank);
end = bank_pfn_end(bank);
if (*min > start)
*min = start;
if (*max_high < end)
*max_high = end;
if (bank->highmem)
continue;
if (*max_low < end)
*max_low = end;
}
}
/*
* 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, i, bootmap_pfn;
start_pfn = PAGE_ALIGN(__pa(_end)) >> PAGE_SHIFT;
bootmap_pfn = 0;
for_each_nodebank(i, mi, node) {
struct membank *bank = &mi->bank[i];
unsigned int start, end;
start = bank_pfn_start(bank);
end = bank_pfn_end(bank);
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++) {
struct membank *bank = &mi->bank[i];
if (bank_phys_start(bank) <= phys_initrd_start &&
end <= bank_phys_end(bank))
initrd_node = bank->node;
}
}
if (initrd_node == -1) {
printk(KERN_ERR "INITRD: 0x%08lx+0x%08lx extends beyond "
"physical memory - disabling initrd\n",
phys_initrd_start, phys_initrd_size);
phys_initrd_start = phys_initrd_size = 0;
}
#endif
return initrd_node;
}
static inline void map_memory_bank(struct membank *bank)
{
#ifdef CONFIG_MMU
struct map_desc map;
map.pfn = bank_pfn_start(bank);
map.virtual = __phys_to_virt(bank_phys_start(bank));
map.length = bank_phys_size(bank);
map.type = MT_MEMORY;
create_mapping(&map);
#endif
}
static void __init bootmem_init_node(int node, struct meminfo *mi,
unsigned long start_pfn, unsigned long end_pfn)
{
unsigned long boot_pfn;
unsigned int boot_pages;
pg_data_t *pgdat;
int i;
/*
* Map the memory banks for this node.
*/
for_each_nodebank(i, mi, node) {
struct membank *bank = &mi->bank[i];
if (!bank->highmem)
map_memory_bank(bank);
}
/*
* 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) {
struct membank *bank = &mi->bank[i];
if (!bank->highmem)
free_bootmem_node(pgdat, bank_phys_start(bank), bank_phys_size(bank));
memory_present(node, bank_pfn_start(bank), bank_pfn_end(bank));
}
/*
* Reserve the bootmem bitmap for this node.
*/
reserve_bootmem_node(pgdat, boot_pfn << PAGE_SHIFT,
boot_pages << PAGE_SHIFT, BOOTMEM_DEFAULT);
}
static void __init bootmem_reserve_initrd(int node)
{
#ifdef CONFIG_BLK_DEV_INITRD
pg_data_t *pgdat = NODE_DATA(node);
int res;
res = reserve_bootmem_node(pgdat, phys_initrd_start,
phys_initrd_size, BOOTMEM_EXCLUSIVE);
if (res == 0) {
initrd_start = __phys_to_virt(phys_initrd_start);
initrd_end = initrd_start + phys_initrd_size;
} else {
printk(KERN_ERR
"INITRD: 0x%08lx+0x%08lx overlaps in-use "
"memory region - disabling initrd\n",
phys_initrd_start, phys_initrd_size);
}
#endif
}
static void __init bootmem_free_node(int node, struct meminfo *mi)
{
unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES];
unsigned long min, max_low, max_high;
int i;
find_node_limits(node, mi, &min, &max_low, &max_high);
/*
* initialise the zones within this node.
*/
memset(zone_size, 0, sizeof(zone_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] = max_low - min;
#ifdef CONFIG_HIGHMEM
zone_size[ZONE_HIGHMEM] = max_high - max_low;
#endif
/*
* For each bank in this node, calculate the size of the holes.
* holes = node_size - sum(bank_sizes_in_node)
*/
memcpy(zhole_size, zone_size, sizeof(zhole_size));
for_each_nodebank(i, mi, node) {
int idx = 0;
#ifdef CONFIG_HIGHMEM
if (mi->bank[i].highmem)
idx = ZONE_HIGHMEM;
#endif
zhole_size[idx] -= bank_pfn_size(&mi->bank[i]);
}
/*
* 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, zone_size, min, zhole_size);
}
void __init bootmem_init(void)
{
struct meminfo *mi = &meminfo;
unsigned long min, max_low, max_high;
int node, initrd_node;
/*
* Locate which node contains the ramdisk image, if any.
*/
initrd_node = check_initrd(mi);
max_low = max_high = 0;
/*
* Run through each node initialising the bootmem allocator.
*/
for_each_node(node) {
unsigned long node_low, node_high;
find_node_limits(node, mi, &min, &node_low, &node_high);
if (node_low > max_low)
max_low = node_low;
if (node_high > max_high)
max_high = node_high;
/*
* If there is no memory in this node, ignore it.
* (We can't have nodes which have no lowmem)
*/
if (node_low == 0)
continue;
bootmem_init_node(node, mi, min, node_low);
/*
* Reserve any special node zero regions.
*/
if (node == 0)
reserve_node_zero(NODE_DATA(node));
/*
* If the initrd is in this node, reserve its memory.
*/
if (node == initrd_node)
bootmem_reserve_initrd(node);
}
/*
* sparse_init() needs the bootmem allocator up and running.
*/
sparse_init();
/*
* Now free memory in each node - free_area_init_node needs
* the sparse mem_map arrays initialized by sparse_init()
* for memmap_init_zone(), otherwise all PFNs are invalid.
*/
for_each_node(node)
bootmem_free_node(node, mi);
high_memory = __va((max_low << PAGE_SHIFT) - 1) + 1;
/*
* 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_low_pfn = max_low - PHYS_PFN_OFFSET;
max_pfn = max_high - PHYS_PFN_OFFSET;
}
static inline int free_area(unsigned long pfn, unsigned long end, char *s)
{
unsigned int pages = 0, size = (end - pfn) << (PAGE_SHIFT - 10);
for (; pfn < end; pfn++) {
struct page *page = pfn_to_page(pfn);
ClearPageReserved(page);
init_page_count(page);
__free_page(page);
pages++;
}
if (size && s)
printk(KERN_INFO "Freeing %s memory: %dK\n", s, size);
return pages;
}
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) {
struct membank *bank = &mi->bank[i];
bank_start = bank_pfn_start(bank);
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 = bank_pfn_end(bank);
}
}
/*
* 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 codesize, datasize, initsize;
int i, node;
#ifndef CONFIG_DISCONTIGMEM
max_mapnr = pfn_to_page(max_pfn + PHYS_PFN_OFFSET) - 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 */
totalram_pages += free_area(PHYS_PFN_OFFSET,
__phys_to_pfn(__pa(swapper_pg_dir)), NULL);
#endif
#ifdef CONFIG_HIGHMEM
/* set highmem page free */
for_each_online_node(node) {
for_each_nodebank (i, &meminfo, node) {
unsigned long start = bank_pfn_start(&meminfo.bank[i]);
unsigned long end = bank_pfn_end(&meminfo.bank[i]);
if (start >= max_low_pfn + PHYS_PFN_OFFSET)
totalhigh_pages += free_area(start, end, NULL);
}
}
totalram_pages += totalhigh_pages;
#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 += bank_pfn_size(&meminfo.bank[i]);
printk(" %ldMB", bank_phys_size(&meminfo.bank[i]) >> 20);
}
printk(" = %luMB total\n", num_physpages >> (20 - PAGE_SHIFT));
codesize = _etext - _text;
datasize = _end - _data;
initsize = __init_end - __init_begin;
printk(KERN_NOTICE "Memory: %luKB available (%dK code, "
"%dK data, %dK init, %luK highmem)\n",
(unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
codesize >> 10, datasize >> 10, initsize >> 10,
(unsigned long) (totalhigh_pages << (PAGE_SHIFT-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())
totalram_pages += free_area(__phys_to_pfn(__pa(__init_begin)),
__phys_to_pfn(__pa(__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)
totalram_pages += free_area(__phys_to_pfn(__pa(start)),
__phys_to_pfn(__pa(end)),
"initrd");
}
static int __init keepinitrd_setup(char *__unused)
{
keep_initrd = 1;
return 1;
}
__setup("keepinitrd", keepinitrd_setup);
#endif