arch/nios2/mm/init.c

Source file repositories/reference/linux-study-clean/arch/nios2/mm/init.c

File Facts

System
Linux kernel
Corpus path
arch/nios2/mm/init.c
Extension
.c
Size
4033 bytes
Lines
155
Domain
Architecture Layer
Bucket
arch/nios2
Inferred role
Architecture Layer: implementation source
Status
source implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/ptrace.h>
#include <linux/mman.h>
#include <linux/mm.h>
#include <linux/init.h>
#include <linux/pagemap.h>
#include <linux/memblock.h>
#include <linux/slab.h>
#include <linux/binfmts.h>
#include <linux/execmem.h>

#include <asm/setup.h>
#include <asm/page.h>
#include <asm/sections.h>
#include <asm/tlb.h>
#include <asm/mmu_context.h>
#include <asm/cpuinfo.h>
#include <asm/processor.h>

pgd_t *pgd_current;

void __init arch_zone_limits_init(unsigned long *max_zone_pfns)
{
	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
}

/*
 * paging_init() continues the virtual memory environment setup which
 * was begun by the code in arch/head.S.
 * The parameters are pointers to where to stick the starting and ending
 * addresses of available kernel virtual memory.
 */
void __init paging_init(void)
{
	pagetable_init();
	pgd_current = swapper_pg_dir;

	flush_dcache_range((unsigned long)empty_zero_page,
			(unsigned long)empty_zero_page + PAGE_SIZE);
}

void __init mmu_init(void)
{
	flush_tlb_all();
}

pgd_t swapper_pg_dir[PTRS_PER_PGD] __aligned(PAGE_SIZE);
pte_t invalid_pte_table[PTRS_PER_PTE] __aligned(PAGE_SIZE);
static struct page *kuser_page[1];
static struct vm_special_mapping vdso_mapping = {
	.name = "[vdso]",
	.pages = kuser_page,
};

static int alloc_kuser_page(void)
{
	extern char __kuser_helper_start[], __kuser_helper_end[];
	int kuser_sz = __kuser_helper_end - __kuser_helper_start;
	unsigned long vpage;

	vpage = get_zeroed_page(GFP_ATOMIC);
	if (!vpage)
		return -ENOMEM;

	/* Copy kuser helpers */
	memcpy((void *)vpage, __kuser_helper_start, kuser_sz);

	flush_icache_range(vpage, vpage + KUSER_SIZE);
	kuser_page[0] = virt_to_page(vpage);

	return 0;
}
arch_initcall(alloc_kuser_page);

int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
{
	struct mm_struct *mm = current->mm;
	struct vm_area_struct *vma;

	mmap_write_lock(mm);

	/* Map kuser helpers to user space address */
	vma = _install_special_mapping(mm, KUSER_BASE, KUSER_SIZE,
				      VM_READ | VM_EXEC | VM_MAYREAD |
				      VM_MAYEXEC, &vdso_mapping);

Annotation

Implementation Notes