- 根目录:
- arch
- xtensa
- mm
- init.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.
* Copyright (C) 2014 Cadence Design Systems 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/gfp.h>
#include <linux/highmem.h>
#include <linux/swap.h>
#include <linux/mman.h>
#include <linux/nodemask.h>
#include <linux/mm.h>
#include <asm/bootparam.h>
#include <asm/page.h>
#include <asm/sections.h>
#include <asm/sysmem.h>
struct sysmem_info sysmem __initdata;
static void __init sysmem_dump(void)
{
unsigned i;
pr_debug("Sysmem:\n");
for (i = 0; i < sysmem.nr_banks; ++i)
pr_debug(" 0x%08lx - 0x%08lx (%ldK)\n",
sysmem.bank[i].start, sysmem.bank[i].end,
(sysmem.bank[i].end - sysmem.bank[i].start) >> 10);
}
/*
* Find bank with maximal .start such that bank.start <= start
*/
static inline struct meminfo * __init find_bank(unsigned long start)
{
unsigned i;
struct meminfo *it = NULL;
for (i = 0; i < sysmem.nr_banks; ++i)
if (sysmem.bank[i].start <= start)
it = sysmem.bank + i;
else
break;
return it;
}
/*
* Move all memory banks starting at 'from' to a new place at 'to',
* adjust nr_banks accordingly.
* Both 'from' and 'to' must be inside the sysmem.bank.
*
* Returns: 0 (success), -ENOMEM (not enough space in the sysmem.bank).
*/
static int __init move_banks(struct meminfo *to, struct meminfo *from)
{
unsigned n = sysmem.nr_banks - (from - sysmem.bank);
if (to > from && to - from + sysmem.nr_banks > SYSMEM_BANKS_MAX)
return -ENOMEM;
if (to != from)
memmove(to, from, n * sizeof(struct meminfo));
sysmem.nr_banks += to - from;
return 0;
}
/*
* Add new bank to sysmem. Resulting sysmem is the union of bytes of the
* original sysmem and the new bank.
*
* Returns: 0 (success), < 0 (error)
*/
int __init add_sysmem_bank(unsigned long start, unsigned long end)
{
unsigned i;
struct meminfo *it = NULL;
unsigned long sz;
unsigned long bank_sz = 0;
if (start == end ||
(start < end) != (PAGE_ALIGN(start) < (end & PAGE_MASK))) {
pr_warn("Ignoring small memory bank 0x%08lx size: %ld bytes\n",
start, end - start);
return -EINVAL;
}
start = PAGE_ALIGN(start);
end &= PAGE_MASK;
sz = end - start;
it = find_bank(start);
if (it)
bank_sz = it->end - it->start;
if (it && bank_sz >= start - it->start) {
if (end - it->start > bank_sz)
it->end = end;
else
return 0;
} else {
if (!it)
it = sysmem.bank;
else
++it;
if (it - sysmem.bank < sysmem.nr_banks &&
it->start - start <= sz) {
it->start = start;
if (it->end - it->start < sz)
it->end = end;
else
return 0;
} else {
if (move_banks(it + 1, it) < 0) {
pr_warn("Ignoring memory bank 0x%08lx size %ld bytes\n",
start, end - start);
return -EINVAL;
}
it->start = start;
it->end = end;
return 0;
}
}
sz = it->end - it->start;
for (i = it + 1 - sysmem.bank; i < sysmem.nr_banks; ++i)
if (sysmem.bank[i].start - it->start <= sz) {
if (sz < sysmem.bank[i].end - it->start)
it->end = sysmem.bank[i].end;
} else {
break;
}
move_banks(it + 1, sysmem.bank + i);
return 0;
}
/*
* mem_reserve(start, end, must_exist)
*
* Reserve some memory from the memory pool.
* If must_exist is set and a part of the region being reserved does not exist
* memory map is not altered.
*
* Parameters:
* start Start of region,
* end End of region,
* must_exist Must exist in memory pool.
*
* Returns:
* 0 (success)
* < 0 (error)
*/
int __init mem_reserve(unsigned long start, unsigned long end, int must_exist)
{
struct meminfo *it;
struct meminfo *rm = NULL;
unsigned long sz;
unsigned long bank_sz = 0;
start = start & PAGE_MASK;
end = PAGE_ALIGN(end);
sz = end - start;
if (!sz)
return -EINVAL;
it = find_bank(start);
if (it)
bank_sz = it->end - it->start;
if ((!it || end - it->start > bank_sz) && must_exist) {
pr_warn("mem_reserve: [0x%0lx, 0x%0lx) not in any region!\n",
start, end);
return -EINVAL;
}
if (it && start - it->start <= bank_sz) {
if (start == it->start) {
if (end - it->start < bank_sz) {
it->start = end;
return 0;
} else {
rm = it;
}
} else {
it->end = start;
if (end - it->start < bank_sz)
return add_sysmem_bank(end,
it->start + bank_sz);
++it;
}
}
if (!it)
it = sysmem.bank;
for (; it < sysmem.bank + sysmem.nr_banks; ++it) {
if (it->end - start <= sz) {
if (!rm)
rm = it;
} else {
if (it->start - start < sz)
it->start = end;
break;
}
}
if (rm)
move_banks(rm, it);
return 0;
}
/*
* Initialize the bootmem system and give it all low memory we have available.
*/
void __init bootmem_init(void)
{
unsigned long pfn;
unsigned long bootmap_start, bootmap_size;
int i;
/* Reserve all memory below PLATFORM_DEFAULT_MEM_START, as memory
* accounting doesn't work for pages below that address.
*
* If PLATFORM_DEFAULT_MEM_START is zero reserve page at address 0:
* successfull allocations should never return NULL.
*/
if (PLATFORM_DEFAULT_MEM_START)
mem_reserve(0, PLATFORM_DEFAULT_MEM_START, 0);
else
mem_reserve(0, 1, 0);
sysmem_dump();
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 - min_low_pfn);
bootmap_size <<= 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),
bootmap_start >> PAGE_SHIFT,
min_low_pfn,
max_low_pfn);
/* Add all remaining memory pieces into the bootmem map */
for (i = 0; i < sysmem.nr_banks; i++) {
if (sysmem.bank[i].start >> PAGE_SHIFT < max_low_pfn) {
unsigned long end = min(max_low_pfn << PAGE_SHIFT,
sysmem.bank[i].end);
free_bootmem(sysmem.bank[i].start,
end - sysmem.bank[i].start);
}
}
}
void __init zones_init(void)
{
/* All pages are DMA-able, so we put them all in the DMA zone. */
unsigned long zones_size[MAX_NR_ZONES] = {
[ZONE_DMA] = max_low_pfn - ARCH_PFN_OFFSET,
#ifdef CONFIG_HIGHMEM
[ZONE_HIGHMEM] = max_pfn - max_low_pfn,
#endif
};
free_area_init_node(0, zones_size, ARCH_PFN_OFFSET, NULL);
}
/*
* Initialize memory pages.
*/
void __init mem_init(void)
{
#ifdef CONFIG_HIGHMEM
unsigned long tmp;
reset_all_zones_managed_pages();
for (tmp = max_low_pfn; tmp < max_pfn; tmp++)
free_highmem_page(pfn_to_page(tmp));
#endif
max_mapnr = max_pfn - ARCH_PFN_OFFSET;
high_memory = (void *)__va(max_low_pfn << PAGE_SHIFT);
free_all_bootmem();
mem_init_print_info(NULL);
pr_info("virtual kernel memory layout:\n"
#ifdef CONFIG_HIGHMEM
" pkmap : 0x%08lx - 0x%08lx (%5lu kB)\n"
" fixmap : 0x%08lx - 0x%08lx (%5lu kB)\n"
#endif
#ifdef CONFIG_MMU
" vmalloc : 0x%08x - 0x%08x (%5u MB)\n"
#endif
" lowmem : 0x%08lx - 0x%08lx (%5lu MB)\n",
#ifdef CONFIG_HIGHMEM
PKMAP_BASE, PKMAP_BASE + LAST_PKMAP * PAGE_SIZE,
(LAST_PKMAP*PAGE_SIZE) >> 10,
FIXADDR_START, FIXADDR_TOP,
(FIXADDR_TOP - FIXADDR_START) >> 10,
#endif
#ifdef CONFIG_MMU
VMALLOC_START, VMALLOC_END,
(VMALLOC_END - VMALLOC_START) >> 20,
PAGE_OFFSET, PAGE_OFFSET +
(max_low_pfn - min_low_pfn) * PAGE_SIZE,
#else
min_low_pfn * PAGE_SIZE, max_low_pfn * PAGE_SIZE,
#endif
((max_low_pfn - min_low_pfn) * PAGE_SIZE) >> 20);
}
#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_area((void *)start, (void *)end, -1, "initrd");
}
#endif
void free_initmem(void)
{
free_initmem_default(-1);
}
static void __init parse_memmap_one(char *p)
{
char *oldp;
unsigned long start_at, mem_size;
if (!p)
return;
oldp = p;
mem_size = memparse(p, &p);
if (p == oldp)
return;
switch (*p) {
case '@':
start_at = memparse(p + 1, &p);
add_sysmem_bank(start_at, start_at + mem_size);
break;
case '$':
start_at = memparse(p + 1, &p);
mem_reserve(start_at, start_at + mem_size, 0);
break;
case 0:
mem_reserve(mem_size, 0, 0);
break;
default:
pr_warn("Unrecognized memmap syntax: %s\n", p);
break;
}
}
static int __init parse_memmap_opt(char *str)
{
while (str) {
char *k = strchr(str, ',');
if (k)
*k++ = 0;
parse_memmap_one(str);
str = k;
}
return 0;
}
early_param("memmap", parse_memmap_opt);