mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-15 00:04:15 +08:00
4574815abf
As very well explained in commit20a004e7b0("arm64: mm: Use READ_ONCE/WRITE_ONCE when accessing page tables"), an architecture whose page table walker can modify the PTE in parallel must use READ_ONCE()/ WRITE_ONCE() macro to avoid any compiler transformation. So apply that to LoongArch which is such an architecture, in order to avoid potential problems. Similar to commitedf9556472("riscv: Use accessors to page table entries instead of direct dereference"). Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
147 lines
2.9 KiB
C
147 lines
2.9 KiB
C
// 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/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 = NULL;
|
|
struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL & ~__GFP_HIGHMEM, 0);
|
|
|
|
if (ptdesc) {
|
|
ret = (pgd_t *)ptdesc_address(ptdesc);
|
|
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);
|
|
}
|
|
EXPORT_SYMBOL_GPL(pmd_init);
|
|
#endif
|
|
|
|
#ifndef __PAGETABLE_PUD_FOLDED
|
|
void pud_init(void *addr)
|
|
{
|
|
unsigned long *p, *end;
|
|
unsigned long pagetable = (unsigned long)invalid_pmd_table;
|
|
|
|
p = (unsigned long *)addr;
|
|
end = p + PTRS_PER_PUD;
|
|
|
|
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);
|
|
}
|
|
EXPORT_SYMBOL_GPL(pud_init);
|
|
#endif
|
|
|
|
pmd_t mk_pmd(struct page *page, pgprot_t prot)
|
|
{
|
|
pmd_t pmd;
|
|
|
|
pmd_val(pmd) = (page_to_pfn(page) << PFN_PTE_SHIFT) | pgprot_val(prot);
|
|
|
|
return pmd;
|
|
}
|
|
|
|
void set_pmd_at(struct mm_struct *mm, unsigned long addr,
|
|
pmd_t *pmdp, pmd_t pmd)
|
|
{
|
|
WRITE_ONCE(*pmdp, pmd);
|
|
flush_tlb_all();
|
|
}
|
|
|
|
void __init pagetable_init(void)
|
|
{
|
|
/* Initialize the entire pgd. */
|
|
pgd_init(swapper_pg_dir);
|
|
pgd_init(invalid_pg_dir);
|
|
#ifndef __PAGETABLE_PUD_FOLDED
|
|
pud_init(invalid_pud_table);
|
|
#endif
|
|
#ifndef __PAGETABLE_PMD_FOLDED
|
|
pmd_init(invalid_pmd_table);
|
|
#endif
|
|
}
|