arch/loongarch/mm/pgtable.c

Source file repositories/reference/linux-study-clean/arch/loongarch/mm/pgtable.c

File Facts

System
Linux kernel
Corpus path
arch/loongarch/mm/pgtable.c
Extension
.c
Size
3672 bytes
Lines
184
Domain
Architecture Layer
Bucket
arch/loongarch
Inferred role
Architecture Layer: exported/initcall integration point
Status
integration 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

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
 */
#include <linux/init.h>
#include <linux/export.h>
#include <linux/mm.h>
#include <asm/fixmap.h>
#include <asm/pgalloc.h>
#include <asm/pgtable.h>
#include <asm/tlbflush.h>

struct page *dmw_virt_to_page(unsigned long kaddr)
{
	return phys_to_page(__pa(kaddr));
}
EXPORT_SYMBOL(dmw_virt_to_page);

struct page *tlb_virt_to_page(unsigned long kaddr)
{
	return phys_to_page(pfn_to_phys(pte_pfn(*virt_to_kpte(kaddr))));
}
EXPORT_SYMBOL(tlb_virt_to_page);

pgd_t *pgd_alloc(struct mm_struct *mm)
{
	pgd_t *init, *ret;

	ret = __pgd_alloc(mm, 0);
	if (ret) {
		init = pgd_offset(&init_mm, 0UL);
		pgd_init(ret);
		memcpy(ret + USER_PTRS_PER_PGD, init + USER_PTRS_PER_PGD,
		       (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
	}

	return ret;
}
EXPORT_SYMBOL_GPL(pgd_alloc);

void pgd_init(void *addr)
{
	unsigned long *p, *end;
	unsigned long entry;

#if !defined(__PAGETABLE_PUD_FOLDED)
	entry = (unsigned long)invalid_pud_table;
#elif !defined(__PAGETABLE_PMD_FOLDED)
	entry = (unsigned long)invalid_pmd_table;
#else
	entry = (unsigned long)invalid_pte_table;
#endif

	p = (unsigned long *)addr;
	end = p + PTRS_PER_PGD;

	do {
		p[0] = entry;
		p[1] = entry;
		p[2] = entry;
		p[3] = entry;
		p[4] = entry;
		p += 8;
		p[-3] = entry;
		p[-2] = entry;
		p[-1] = entry;
	} while (p != end);
}
EXPORT_SYMBOL_GPL(pgd_init);

#ifndef __PAGETABLE_PMD_FOLDED
void pmd_init(void *addr)
{
	unsigned long *p, *end;
	unsigned long pagetable = (unsigned long)invalid_pte_table;

	p = (unsigned long *)addr;
	end = p + PTRS_PER_PMD;

	do {
		p[0] = pagetable;
		p[1] = pagetable;
		p[2] = pagetable;
		p[3] = pagetable;
		p[4] = pagetable;
		p += 8;
		p[-3] = pagetable;
		p[-2] = pagetable;
		p[-1] = pagetable;
	} while (p != end);

Annotation

Implementation Notes