OpenCloudOS-Kernel/arch/arm64/mm/init.c

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/*
* 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 <linux/dma-mapping.h>
#include <linux/dma-contiguous.h>
#include <linux/efi.h>
#include <linux/swiotlb.h>
#include <asm/boot.h>
#include <asm/fixmap.h>
#include <asm/kasan.h>
#include <asm/kernel-pgtable.h>
arm64: Fix overlapping VA allocations PCI IO space was intended to be 16MiB, at 32MiB below MODULES_VADDR, but commit d1e6dc91b532d3d3 ("arm64: Add architectural support for PCI") extended this to cover the full 32MiB. The final 8KiB of this 32MiB is also allocated for the fixmap, allowing for potential clashes between the two. This change was masked by assumptions in mem_init and the page table dumping code, which assumed the I/O space to be 16MiB long through seaparte hard-coded definitions. This patch changes the definition of the PCI I/O space allocation to live in asm/memory.h, along with the other VA space allocations. As the fixmap allocation depends on the number of fixmap entries, this is moved below the PCI I/O space allocation. Both the fixmap and PCI I/O space are guarded with 2MB of padding. Sites assuming the I/O space was 16MiB are moved over use new PCI_IO_{START,END} definitions, which will keep in sync with the size of the IO space (now restored to 16MiB). As a useful side effect, the use of the new PCI_IO_{START,END} definitions prevents a build issue in the dumping code due to a (now redundant) missing include of io.h for PCI_IOBASE. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Kees Cook <keescook@chromium.org> Cc: Laura Abbott <lauraa@codeaurora.org> Cc: Liviu Dudau <liviu.dudau@arm.com> Cc: Steve Capper <steve.capper@linaro.org> Cc: Will Deacon <will.deacon@arm.com> [catalin.marinas@arm.com: reorder FIXADDR and PCI_IO address_markers_idx enum] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-01-23 02:20:35 +08:00
#include <asm/memory.h>
#include <asm/numa.h>
#include <asm/sections.h>
#include <asm/setup.h>
#include <asm/sizes.h>
#include <asm/tlb.h>
#include <asm/alternative.h>
#include "mm.h"
/*
* We need to be able to catch inadvertent references to memstart_addr
* that occur (potentially in generic code) before arm64_memblock_init()
* executes, which assigns it its actual value. So use a default value
* that cannot be mistaken for a real physical address.
*/
s64 memstart_addr __read_mostly = -1;
phys_addr_t arm64_dma_phys_limit __read_mostly;
#ifdef CONFIG_BLK_DEV_INITRD
static int __init early_initrd(char *p)
{
unsigned long start, size;
char *endp;
start = memparse(p, &endp);
if (*endp == ',') {
size = memparse(endp + 1, NULL);
initrd_start = start;
initrd_end = start + size;
}
return 0;
}
early_param("initrd", early_initrd);
#endif
/*
* Return the maximum physical address for ZONE_DMA (DMA_BIT_MASK(32)). It
* currently assumes that for memory starting above 4G, 32-bit devices will
* use a DMA offset.
*/
static phys_addr_t __init max_zone_dma_phys(void)
{
phys_addr_t offset = memblock_start_of_DRAM() & GENMASK_ULL(63, 32);
return min(offset + (1ULL << 32), memblock_end_of_DRAM());
}
#ifdef CONFIG_NUMA
static void __init zone_sizes_init(unsigned long min, unsigned long max)
{
unsigned long max_zone_pfns[MAX_NR_ZONES] = {0};
if (IS_ENABLED(CONFIG_ZONE_DMA))
max_zone_pfns[ZONE_DMA] = PFN_DOWN(max_zone_dma_phys());
max_zone_pfns[ZONE_NORMAL] = max;
free_area_init_nodes(max_zone_pfns);
}
#else
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_dma = min;
memset(zone_size, 0, sizeof(zone_size));
/* 4GB maximum for 32-bit only capable devices */
#ifdef CONFIG_ZONE_DMA
max_dma = PFN_DOWN(arm64_dma_phys_limit);
zone_size[ZONE_DMA] = max_dma - min;
#endif
zone_size[ZONE_NORMAL] = max - max_dma;
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_DMA
if (start < max_dma) {
unsigned long dma_end = min(end, max_dma);
zhole_size[ZONE_DMA] -= dma_end - start;
}
#endif
if (end > max_dma) {
unsigned long normal_end = min(end, max);
unsigned long normal_start = max(start, max_dma);
zhole_size[ZONE_NORMAL] -= normal_end - normal_start;
}
}
free_area_init_node(0, zone_size, min, zhole_size);
}
#endif /* CONFIG_NUMA */
#ifdef CONFIG_HAVE_ARCH_PFN_VALID
int pfn_valid(unsigned long pfn)
{
return memblock_is_map_memory(pfn << PAGE_SHIFT);
}
EXPORT_SYMBOL(pfn_valid);
#endif
#ifndef CONFIG_SPARSEMEM
static void __init arm64_memory_present(void)
{
}
#else
static void __init arm64_memory_present(void)
{
struct memblock_region *reg;
for_each_memblock(memory, reg) {
int nid = memblock_get_region_node(reg);
memory_present(nid, memblock_region_memory_base_pfn(reg),
memblock_region_memory_end_pfn(reg));
}
}
#endif
static phys_addr_t memory_limit = (phys_addr_t)ULLONG_MAX;
/*
* Limit the memory size that was specified via FDT.
*/
static int __init early_mem(char *p)
{
if (!p)
return 1;
memory_limit = memparse(p, &p) & PAGE_MASK;
pr_notice("Memory limited to %lldMB\n", memory_limit >> 20);
return 0;
}
early_param("mem", early_mem);
void __init arm64_memblock_init(void)
{
const s64 linear_region_size = -(s64)PAGE_OFFSET;
/*
* Ensure that the linear region takes up exactly half of the kernel
* virtual address space. This way, we can distinguish a linear address
* from a kernel/module/vmalloc address by testing a single bit.
*/
BUILD_BUG_ON(linear_region_size != BIT(VA_BITS - 1));
/*
* Select a suitable value for the base of physical memory.
*/
memstart_addr = round_down(memblock_start_of_DRAM(),
ARM64_MEMSTART_ALIGN);
/*
* Remove the memory that we will not be able to cover with the
* linear mapping. Take care not to clip the kernel which may be
* high in memory.
*/
memblock_remove(max_t(u64, memstart_addr + linear_region_size, __pa(_end)),
ULLONG_MAX);
if (memstart_addr + linear_region_size < memblock_end_of_DRAM()) {
/* ensure that memstart_addr remains sufficiently aligned */
memstart_addr = round_up(memblock_end_of_DRAM() - linear_region_size,
ARM64_MEMSTART_ALIGN);
memblock_remove(0, memstart_addr);
}
/*
* Apply the memory limit if it was set. Since the kernel may be loaded
* high up in memory, add back the kernel region that must be accessible
* via the linear mapping.
*/
if (memory_limit != (phys_addr_t)ULLONG_MAX) {
arm64:acpi: fix the acpi alignment exception when 'mem=' specified When booting an ACPI enabled kernel with 'mem=x', there is the possibility that ACPI data regions from the firmware will lie above the memory limit. Ordinarily these will be removed by memblock_enforce_memory_limit(.). Unfortunately, this means that these regions will then be mapped by acpi_os_ioremap(.) as device memory (instead of normal) thus unaligned accessess will then provoke alignment faults. In this patch we adopt memblock_mem_limit_remove_map instead, and this preserves these ACPI data regions (marked NOMAP) thus ensuring that these regions are not mapped as device memory. For example, below is an alignment exception observed on ARM platform when booting the kernel with 'acpi=on mem=8G': ... Unable to handle kernel paging request at virtual address ffff0000080521e7 pgd = ffff000008aa0000 [ffff0000080521e7] *pgd=000000801fffe003, *pud=000000801fffd003, *pmd=000000801fffc003, *pte=00e80083ff1c1707 Internal error: Oops: 96000021 [#1] PREEMPT SMP Modules linked in: CPU: 1 PID: 1 Comm: swapper/0 Not tainted 4.7.0-rc3-next-20160616+ #172 Hardware name: AMD Overdrive/Supercharger/Default string, BIOS ROD1001A 02/09/2016 task: ffff800001ef0000 ti: ffff800001ef8000 task.ti: ffff800001ef8000 PC is at acpi_ns_lookup+0x520/0x734 LR is at acpi_ns_lookup+0x4a4/0x734 pc : [<ffff0000083b8b10>] lr : [<ffff0000083b8a94>] pstate: 60000045 sp : ffff800001efb8b0 x29: ffff800001efb8c0 x28: 000000000000001b x27: 0000000000000001 x26: 0000000000000000 x25: ffff800001efb9e8 x24: ffff000008a10000 x23: 0000000000000001 x22: 0000000000000001 x21: ffff000008724000 x20: 000000000000001b x19: ffff0000080521e7 x18: 000000000000000d x17: 00000000000038ff x16: 0000000000000002 x15: 0000000000000007 x14: 0000000000007fff x13: ffffff0000000000 x12: 0000000000000018 x11: 000000001fffd200 x10: 00000000ffffff76 x9 : 000000000000005f x8 : ffff000008725fa8 x7 : ffff000008a8df70 x6 : ffff000008a8df70 x5 : ffff000008a8d000 x4 : 0000000000000010 x3 : 0000000000000010 x2 : 000000000000000c x1 : 0000000000000006 x0 : 0000000000000000 ... acpi_ns_lookup+0x520/0x734 acpi_ds_load1_begin_op+0x174/0x4fc acpi_ps_build_named_op+0xf8/0x220 acpi_ps_create_op+0x208/0x33c acpi_ps_parse_loop+0x204/0x838 acpi_ps_parse_aml+0x1bc/0x42c acpi_ns_one_complete_parse+0x1e8/0x22c acpi_ns_parse_table+0x8c/0x128 acpi_ns_load_table+0xc0/0x1e8 acpi_tb_load_namespace+0xf8/0x2e8 acpi_load_tables+0x7c/0x110 acpi_init+0x90/0x2c0 do_one_initcall+0x38/0x12c kernel_init_freeable+0x148/0x1ec kernel_init+0x10/0xec ret_from_fork+0x10/0x40 Code: b9009fbc 2a00037b 36380057 3219037b (b9400260) ---[ end trace 03381e5eb0a24de4 ]--- Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b With 'efi=debug', we can see those ACPI regions loaded by firmware on that board as: efi: 0x0083ff185000-0x0083ff1b4fff [Reserved | | | | | | | | |WB|WT|WC|UC]* efi: 0x0083ff1b5000-0x0083ff1c2fff [ACPI Reclaim Memory| | | | | | | | |WB|WT|WC|UC]* efi: 0x0083ff223000-0x0083ff224fff [ACPI Memory NVS | | | | | | | | |WB|WT|WC|UC]* Link: http://lkml.kernel.org/r/1468475036-5852-3-git-send-email-dennis.chen@arm.com Acked-by: Steve Capper <steve.capper@arm.com> Signed-off-by: Dennis Chen <dennis.chen@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Tang Chen <tangchen@cn.fujitsu.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Rafael J. Wysocki <rafael@kernel.org> Cc: Will Deacon <will.deacon@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Kaly Xin <kaly.xin@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-29 06:48:29 +08:00
memblock_mem_limit_remove_map(memory_limit);
memblock_add(__pa(_text), (u64)(_end - _text));
}
if (IS_ENABLED(CONFIG_BLK_DEV_INITRD) && initrd_start) {
/*
* Add back the memory we just removed if it results in the
* initrd to become inaccessible via the linear mapping.
* Otherwise, this is a no-op
*/
u64 base = initrd_start & PAGE_MASK;
u64 size = PAGE_ALIGN(initrd_end) - base;
/*
* We can only add back the initrd memory if we don't end up
* with more memory than we can address via the linear mapping.
* It is up to the bootloader to position the kernel and the
* initrd reasonably close to each other (i.e., within 32 GB of
* each other) so that all granule/#levels combinations can
* always access both.
*/
if (WARN(base < memblock_start_of_DRAM() ||
base + size > memblock_start_of_DRAM() +
linear_region_size,
"initrd not fully accessible via the linear mapping -- please check your bootloader ...\n")) {
initrd_start = 0;
} else {
memblock_remove(base, size); /* clear MEMBLOCK_ flags */
memblock_add(base, size);
memblock_reserve(base, size);
}
}
if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) {
extern u16 memstart_offset_seed;
u64 range = linear_region_size -
(memblock_end_of_DRAM() - memblock_start_of_DRAM());
/*
* If the size of the linear region exceeds, by a sufficient
* margin, the size of the region that the available physical
* memory spans, randomize the linear region as well.
*/
if (memstart_offset_seed > 0 && range >= ARM64_MEMSTART_ALIGN) {
range = range / ARM64_MEMSTART_ALIGN + 1;
memstart_addr -= ARM64_MEMSTART_ALIGN *
((range * memstart_offset_seed) >> 16);
}
}
/*
* Register the kernel text, kernel data, initrd, and initial
* pagetables with memblock.
*/
memblock_reserve(__pa(_text), _end - _text);
#ifdef CONFIG_BLK_DEV_INITRD
if (initrd_start) {
memblock_reserve(initrd_start, initrd_end - initrd_start);
/* the generic initrd code expects virtual addresses */
initrd_start = __phys_to_virt(initrd_start);
initrd_end = __phys_to_virt(initrd_end);
}
#endif
early_init_fdt_scan_reserved_mem();
/* 4GB maximum for 32-bit only capable devices */
if (IS_ENABLED(CONFIG_ZONE_DMA))
arm64_dma_phys_limit = max_zone_dma_phys();
else
arm64_dma_phys_limit = PHYS_MASK + 1;
dma_contiguous_reserve(arm64_dma_phys_limit);
memblock_allow_resize();
}
void __init bootmem_init(void)
{
unsigned long min, max;
min = PFN_UP(memblock_start_of_DRAM());
max = PFN_DOWN(memblock_end_of_DRAM());
early_memtest(min << PAGE_SHIFT, max << PAGE_SHIFT);
max_pfn = max_low_pfn = max;
arm64_numa_init();
/*
* 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;
memblock_dump_all();
}
#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(__phys_to_pfn(reg->base + 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)
{
if (swiotlb_force || max_pfn > (arm64_dma_phys_limit >> PAGE_SHIFT))
swiotlb_init(1);
set_max_mapnr(pfn_to_page(max_pfn) - mem_map);
#ifndef CONFIG_SPARSEMEM_VMEMMAP
free_unused_memmap();
#endif
/* this will put all unused low memory onto the freelists */
mm: concentrate modification of totalram_pages into the mm core Concentrate code to modify totalram_pages into the mm core, so the arch memory initialized code doesn't need to take care of it. With these changes applied, only following functions from mm core modify global variable totalram_pages: free_bootmem_late(), free_all_bootmem(), free_all_bootmem_node(), adjust_managed_page_count(). With this patch applied, it will be much more easier for us to keep totalram_pages and zone->managed_pages in consistence. Signed-off-by: Jiang Liu <jiang.liu@huawei.com> Acked-by: David Howells <dhowells@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: <sworddragon2@aol.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Jianguo Wu <wujianguo@huawei.com> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Michel Lespinasse <walken@google.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@redhat.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Tang Chen <tangchen@cn.fujitsu.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wen Congyang <wency@cn.fujitsu.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Russell King <rmk@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-04 06:03:24 +08:00
free_all_bootmem();
mem_init_print_info(NULL);
#define MLK(b, t) b, t, ((t) - (b)) >> 10
#define MLM(b, t) b, t, ((t) - (b)) >> 20
#define MLG(b, t) b, t, ((t) - (b)) >> 30
#define MLK_ROUNDUP(b, t) b, t, DIV_ROUND_UP(((t) - (b)), SZ_1K)
pr_notice("Virtual kernel memory layout:\n");
#ifdef CONFIG_KASAN
pr_cont(" kasan : 0x%16lx - 0x%16lx (%6ld GB)\n",
MLG(KASAN_SHADOW_START, KASAN_SHADOW_END));
#endif
pr_cont(" modules : 0x%16lx - 0x%16lx (%6ld MB)\n",
MLM(MODULES_VADDR, MODULES_END));
pr_cont(" vmalloc : 0x%16lx - 0x%16lx (%6ld GB)\n",
MLG(VMALLOC_START, VMALLOC_END));
pr_cont(" .text : 0x%p" " - 0x%p" " (%6ld KB)\n",
MLK_ROUNDUP(_text, _etext));
pr_cont(" .rodata : 0x%p" " - 0x%p" " (%6ld KB)\n",
MLK_ROUNDUP(__start_rodata, __init_begin));
pr_cont(" .init : 0x%p" " - 0x%p" " (%6ld KB)\n",
MLK_ROUNDUP(__init_begin, __init_end));
pr_cont(" .data : 0x%p" " - 0x%p" " (%6ld KB)\n",
MLK_ROUNDUP(_sdata, _edata));
pr_cont(" .bss : 0x%p" " - 0x%p" " (%6ld KB)\n",
MLK_ROUNDUP(__bss_start, __bss_stop));
pr_cont(" fixed : 0x%16lx - 0x%16lx (%6ld KB)\n",
MLK(FIXADDR_START, FIXADDR_TOP));
pr_cont(" PCI I/O : 0x%16lx - 0x%16lx (%6ld MB)\n",
MLM(PCI_IO_START, PCI_IO_END));
#ifdef CONFIG_SPARSEMEM_VMEMMAP
pr_cont(" vmemmap : 0x%16lx - 0x%16lx (%6ld GB maximum)\n",
MLG(VMEMMAP_START, VMEMMAP_START + VMEMMAP_SIZE));
pr_cont(" 0x%16lx - 0x%16lx (%6ld MB actual)\n",
MLM((unsigned long)phys_to_page(memblock_start_of_DRAM()),
(unsigned long)virt_to_page(high_memory)));
#endif
pr_cont(" memory : 0x%16lx - 0x%16lx (%6ld MB)\n",
MLM(__phys_to_virt(memblock_start_of_DRAM()),
(unsigned long)high_memory));
#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
/*
* Make sure we chose the upper bound of sizeof(struct page)
* correctly.
*/
BUILD_BUG_ON(sizeof(struct page) > (1 << STRUCT_PAGE_MAX_SHIFT));
if (PAGE_SIZE >= 16384 && get_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)
{
free_reserved_area(__va(__pa(__init_begin)), __va(__pa(__init_end)),
0, "unused kernel");
fixup_init();
}
#ifdef CONFIG_BLK_DEV_INITRD
static int keep_initrd __initdata;
void __init free_initrd_mem(unsigned long start, unsigned long end)
{
if (!keep_initrd)
free_reserved_area((void *)start, (void *)end, 0, "initrd");
}
static int __init keepinitrd_setup(char *__unused)
{
keep_initrd = 1;
return 1;
}
__setup("keepinitrd", keepinitrd_setup);
#endif
/*
* Dump out memory limit information on panic.
*/
static int dump_mem_limit(struct notifier_block *self, unsigned long v, void *p)
{
if (memory_limit != (phys_addr_t)ULLONG_MAX) {
pr_emerg("Memory Limit: %llu MB\n", memory_limit >> 20);
} else {
pr_emerg("Memory Limit: none\n");
}
return 0;
}
static struct notifier_block mem_limit_notifier = {
.notifier_call = dump_mem_limit,
};
static int __init register_mem_limit_dumper(void)
{
atomic_notifier_chain_register(&panic_notifier_list,
&mem_limit_notifier);
return 0;
}
__initcall(register_mem_limit_dumper);