예제 #1
0
파일: efi_64.c 프로젝트: EMFPGA/linux_media
void __init efi_call_phys_epilog(pgd_t *save_pgd)
{
	/*
	 * After the lock is released, the original page table is restored.
	 */
	int pgd_idx, i;
	int nr_pgds;
	pgd_t *pgd;
	p4d_t *p4d;
	pud_t *pud;

	if (!efi_enabled(EFI_OLD_MEMMAP)) {
		write_cr3((unsigned long)save_pgd);
		__flush_tlb_all();
		return;
	}

	nr_pgds = DIV_ROUND_UP((max_pfn << PAGE_SHIFT) , PGDIR_SIZE);

	for (pgd_idx = 0; pgd_idx < nr_pgds; pgd_idx++) {
		pgd = pgd_offset_k(pgd_idx * PGDIR_SIZE);
		set_pgd(pgd_offset_k(pgd_idx * PGDIR_SIZE), save_pgd[pgd_idx]);

		if (!(pgd_val(*pgd) & _PAGE_PRESENT))
			continue;

		for (i = 0; i < PTRS_PER_P4D; i++) {
			p4d = p4d_offset(pgd,
					 pgd_idx * PGDIR_SIZE + i * P4D_SIZE);

			if (!(p4d_val(*p4d) & _PAGE_PRESENT))
				continue;

			pud = (pud_t *)p4d_page_vaddr(*p4d);
			pud_free(&init_mm, pud);
		}

		p4d = (p4d_t *)pgd_page_vaddr(*pgd);
		p4d_free(&init_mm, p4d);
	}

	kfree(save_pgd);

	__flush_tlb_all();
	early_code_mapping_set_exec(0);
}
예제 #2
0
/*
 * The VSYSCALL page is the only user-accessible page in the kernel address
 * range.  Normally, the kernel page tables can have _PAGE_USER clear, but
 * the tables covering VSYSCALL_ADDR need _PAGE_USER set if vsyscalls
 * are enabled.
 *
 * Some day we may create a "minimal" vsyscall mode in which we emulate
 * vsyscalls but leave the page not present.  If so, we skip calling
 * this.
 */
void __init set_vsyscall_pgtable_user_bits(pgd_t *root)
{
	pgd_t *pgd;
	p4d_t *p4d;
	pud_t *pud;
	pmd_t *pmd;

	pgd = pgd_offset_pgd(root, VSYSCALL_ADDR);
	set_pgd(pgd, __pgd(pgd_val(*pgd) | _PAGE_USER));
	p4d = p4d_offset(pgd, VSYSCALL_ADDR);
#if CONFIG_PGTABLE_LEVELS >= 5
	set_p4d(p4d, __p4d(p4d_val(*p4d) | _PAGE_USER));
#endif
	pud = pud_offset(p4d, VSYSCALL_ADDR);
	set_pud(pud, __pud(pud_val(*pud) | _PAGE_USER));
	pmd = pmd_offset(pud, VSYSCALL_ADDR);
	set_pmd(pmd, __pmd(pmd_val(*pmd) | _PAGE_USER));
}