linux/arch/arm64/mm/init.c
Will Deacon f483a853b0 arm64: mm: fix booting on systems with no memory below 4GB
Booting on a system with all of its memory above the 4GB boundary breaks
for two reasons:

	(1) We still try to create a non-empty DMA32 zone
	(2) no-bootmem limits allocations to 0xffffffff

This patch fixes these issues for ARM64.

Tested-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2012-11-08 16:06:21 +00:00

435 lines
11 KiB
C

/*
* Based on arch/arm/mm/init.c
*
* Copyright (C) 1995-2005 Russell King
* Copyright (C) 2012 ARM Ltd.
*
* 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/kernel.h>
#include <linux/export.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/gfp.h>
#include <linux/memblock.h>
#include <linux/sort.h>
#include <linux/of_fdt.h>
#include <asm/prom.h>
#include <asm/sections.h>
#include <asm/setup.h>
#include <asm/sizes.h>
#include <asm/tlb.h>
#include "mm.h"
static unsigned long phys_initrd_start __initdata = 0;
static unsigned long phys_initrd_size __initdata = 0;
phys_addr_t memstart_addr __read_mostly = 0;
void __init early_init_dt_setup_initrd_arch(unsigned long start,
unsigned long end)
{
phys_initrd_start = start;
phys_initrd_size = end - start;
}
static int __init early_initrd(char *p)
{
unsigned long start, size;
char *endp;
start = memparse(p, &endp);
if (*endp == ',') {
size = memparse(endp + 1, NULL);
phys_initrd_start = start;
phys_initrd_size = size;
}
return 0;
}
early_param("initrd", early_initrd);
#define MAX_DMA32_PFN ((4UL * 1024 * 1024 * 1024) >> PAGE_SHIFT)
static void __init zone_sizes_init(unsigned long min, unsigned long max)
{
struct memblock_region *reg;
unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES];
unsigned long max_dma32 = min;
memset(zone_size, 0, sizeof(zone_size));
#ifdef CONFIG_ZONE_DMA32
/* 4GB maximum for 32-bit only capable devices */
max_dma32 = min(max, MAX_DMA32_PFN);
zone_size[ZONE_DMA32] = max(min, max_dma32) - min;
#endif
zone_size[ZONE_NORMAL] = max - max_dma32;
memcpy(zhole_size, zone_size, sizeof(zhole_size));
for_each_memblock(memory, reg) {
unsigned long start = memblock_region_memory_base_pfn(reg);
unsigned long end = memblock_region_memory_end_pfn(reg);
if (start >= max)
continue;
#ifdef CONFIG_ZONE_DMA32
if (start < max_dma32) {
unsigned long dma_end = min(end, max_dma32);
zhole_size[ZONE_DMA32] -= dma_end - start;
}
#endif
if (end > max_dma32) {
unsigned long normal_end = min(end, max);
unsigned long normal_start = max(start, max_dma32);
zhole_size[ZONE_NORMAL] -= normal_end - normal_start;
}
}
free_area_init_node(0, zone_size, min, zhole_size);
}
#ifdef CONFIG_HAVE_ARCH_PFN_VALID
int pfn_valid(unsigned long pfn)
{
return memblock_is_memory(pfn << PAGE_SHIFT);
}
EXPORT_SYMBOL(pfn_valid);
#endif
#ifndef CONFIG_SPARSEMEM
static void arm64_memory_present(void)
{
}
#else
static void arm64_memory_present(void)
{
struct memblock_region *reg;
for_each_memblock(memory, reg)
memory_present(0, memblock_region_memory_base_pfn(reg),
memblock_region_memory_end_pfn(reg));
}
#endif
void __init arm64_memblock_init(void)
{
u64 *reserve_map, base, size;
/* Register the kernel text, kernel data and initrd with memblock */
memblock_reserve(__pa(_text), _end - _text);
#ifdef CONFIG_BLK_DEV_INITRD
if (phys_initrd_size) {
memblock_reserve(phys_initrd_start, phys_initrd_size);
/* Now convert initrd to virtual addresses */
initrd_start = __phys_to_virt(phys_initrd_start);
initrd_end = initrd_start + phys_initrd_size;
}
#endif
/*
* Reserve the page tables. These are already in use,
* and can only be in node 0.
*/
memblock_reserve(__pa(swapper_pg_dir), SWAPPER_DIR_SIZE);
memblock_reserve(__pa(idmap_pg_dir), IDMAP_DIR_SIZE);
/* Reserve the dtb region */
memblock_reserve(virt_to_phys(initial_boot_params),
be32_to_cpu(initial_boot_params->totalsize));
/*
* Process the reserve map. This will probably overlap the initrd
* and dtb locations which are already reserved, but overlapping
* doesn't hurt anything
*/
reserve_map = ((void*)initial_boot_params) +
be32_to_cpu(initial_boot_params->off_mem_rsvmap);
while (1) {
base = be64_to_cpup(reserve_map++);
size = be64_to_cpup(reserve_map++);
if (!size)
break;
memblock_reserve(base, size);
}
memblock_allow_resize();
memblock_dump_all();
}
void __init bootmem_init(void)
{
unsigned long min, max;
min = PFN_UP(memblock_start_of_DRAM());
max = PFN_DOWN(memblock_end_of_DRAM());
/*
* Sparsemem tries to allocate bootmem in memory_present(), so must be
* done after the fixed reservations.
*/
arm64_memory_present();
sparse_init();
zone_sizes_init(min, max);
high_memory = __va((max << PAGE_SHIFT) - 1) + 1;
max_pfn = max_low_pfn = max;
}
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)
pr_info("Freeing %s memory: %dK\n", s, size);
return pages;
}
/*
* Poison init memory with an undefined instruction (0x0).
*/
static inline void poison_init_mem(void *s, size_t count)
{
memset(s, 0, count);
}
#ifndef CONFIG_SPARSEMEM_VMEMMAP
static inline void free_memmap(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 - 1) + 1;
end_pg = pfn_to_page(end_pfn - 1) + 1;
/*
* Convert to physical addresses, and round start upwards and end
* downwards.
*/
pg = (unsigned long)PAGE_ALIGN(__pa(start_pg));
pgend = (unsigned long)__pa(end_pg) & PAGE_MASK;
/*
* If there are free pages between these, free the section of the
* memmap array.
*/
if (pg < pgend)
free_bootmem(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(void)
{
unsigned long start, prev_end = 0;
struct memblock_region *reg;
for_each_memblock(memory, reg) {
start = __phys_to_pfn(reg->base);
#ifdef CONFIG_SPARSEMEM
/*
* Take care not to free memmap entries that don't exist due
* to SPARSEMEM sections which aren't present.
*/
start = min(start, ALIGN(prev_end, PAGES_PER_SECTION));
#endif
/*
* If we had a previous bank, and there is a space between the
* current bank and the previous, free it.
*/
if (prev_end && prev_end < start)
free_memmap(prev_end, start);
/*
* Align up here since the VM subsystem insists that the
* memmap entries are valid from the bank end aligned to
* MAX_ORDER_NR_PAGES.
*/
prev_end = ALIGN(start + __phys_to_pfn(reg->size),
MAX_ORDER_NR_PAGES);
}
#ifdef CONFIG_SPARSEMEM
if (!IS_ALIGNED(prev_end, PAGES_PER_SECTION))
free_memmap(prev_end, ALIGN(prev_end, PAGES_PER_SECTION));
#endif
}
#endif /* !CONFIG_SPARSEMEM_VMEMMAP */
/*
* 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 long reserved_pages, free_pages;
struct memblock_region *reg;
arm64_swiotlb_init();
max_mapnr = pfn_to_page(max_pfn + PHYS_PFN_OFFSET) - mem_map;
#ifndef CONFIG_SPARSEMEM_VMEMMAP
/* this will put all unused low memory onto the freelists */
free_unused_memmap();
#endif
totalram_pages += free_all_bootmem();
reserved_pages = free_pages = 0;
for_each_memblock(memory, reg) {
unsigned int pfn1, pfn2;
struct page *page, *end;
pfn1 = __phys_to_pfn(reg->base);
pfn2 = pfn1 + __phys_to_pfn(reg->size);
page = pfn_to_page(pfn1);
end = pfn_to_page(pfn2 - 1) + 1;
do {
if (PageReserved(page))
reserved_pages++;
else if (!page_count(page))
free_pages++;
page++;
} while (page < end);
}
/*
* Since our memory may not be contiguous, calculate the real number
* of pages we have in this system.
*/
pr_info("Memory:");
num_physpages = 0;
for_each_memblock(memory, reg) {
unsigned long pages = memblock_region_memory_end_pfn(reg) -
memblock_region_memory_base_pfn(reg);
num_physpages += pages;
printk(" %ldMB", pages >> (20 - PAGE_SHIFT));
}
printk(" = %luMB total\n", num_physpages >> (20 - PAGE_SHIFT));
pr_notice("Memory: %luk/%luk available, %luk reserved\n",
nr_free_pages() << (PAGE_SHIFT-10),
free_pages << (PAGE_SHIFT-10),
reserved_pages << (PAGE_SHIFT-10));
#define MLK(b, t) b, t, ((t) - (b)) >> 10
#define MLM(b, t) b, t, ((t) - (b)) >> 20
#define MLK_ROUNDUP(b, t) b, t, DIV_ROUND_UP(((t) - (b)), SZ_1K)
pr_notice("Virtual kernel memory layout:\n"
" vmalloc : 0x%16lx - 0x%16lx (%6ld MB)\n"
#ifdef CONFIG_SPARSEMEM_VMEMMAP
" vmemmap : 0x%16lx - 0x%16lx (%6ld MB)\n"
#endif
" modules : 0x%16lx - 0x%16lx (%6ld MB)\n"
" memory : 0x%16lx - 0x%16lx (%6ld MB)\n"
" .init : 0x%p" " - 0x%p" " (%6ld kB)\n"
" .text : 0x%p" " - 0x%p" " (%6ld kB)\n"
" .data : 0x%p" " - 0x%p" " (%6ld kB)\n",
MLM(VMALLOC_START, VMALLOC_END),
#ifdef CONFIG_SPARSEMEM_VMEMMAP
MLM((unsigned long)virt_to_page(PAGE_OFFSET),
(unsigned long)virt_to_page(high_memory)),
#endif
MLM(MODULES_VADDR, MODULES_END),
MLM(PAGE_OFFSET, (unsigned long)high_memory),
MLK_ROUNDUP(__init_begin, __init_end),
MLK_ROUNDUP(_text, _etext),
MLK_ROUNDUP(_sdata, _edata));
#undef MLK
#undef MLM
#undef MLK_ROUNDUP
/*
* Check boundaries twice: Some fundamental inconsistencies can be
* detected at build time already.
*/
#ifdef CONFIG_COMPAT
BUILD_BUG_ON(TASK_SIZE_32 > TASK_SIZE_64);
#endif
BUILD_BUG_ON(TASK_SIZE_64 > MODULES_VADDR);
BUG_ON(TASK_SIZE_64 > MODULES_VADDR);
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)
{
poison_init_mem(__init_begin, __init_end - __init_begin);
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) {
poison_init_mem((void *)start, PAGE_ALIGN(end) - start);
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