/arch/unicore32/mm/pgd.c
C | 102 lines | 63 code | 17 blank | 22 comment | 7 complexity | 257a1e1fe35ab9136cd1cb344145b299 MD5 | raw file
Possible License(s): GPL-2.0, LGPL-2.0, AGPL-1.0
1/* 2 * linux/arch/unicore32/mm/pgd.c 3 * 4 * Code specific to PKUnity SoC and UniCore ISA 5 * 6 * Copyright (C) 2001-2010 GUAN Xue-tao 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License version 2 as 10 * published by the Free Software Foundation. 11 */ 12#include <linux/mm.h> 13#include <linux/gfp.h> 14#include <linux/highmem.h> 15 16#include <asm/pgalloc.h> 17#include <asm/page.h> 18#include <asm/tlbflush.h> 19 20#include "mm.h" 21 22#define FIRST_KERNEL_PGD_NR (FIRST_USER_PGD_NR + USER_PTRS_PER_PGD) 23 24/* 25 * need to get a 4k page for level 1 26 */ 27pgd_t *get_pgd_slow(struct mm_struct *mm) 28{ 29 pgd_t *new_pgd, *init_pgd; 30 pmd_t *new_pmd, *init_pmd; 31 pte_t *new_pte, *init_pte; 32 33 new_pgd = (pgd_t *)__get_free_pages(GFP_KERNEL, 0); 34 if (!new_pgd) 35 goto no_pgd; 36 37 memset(new_pgd, 0, FIRST_KERNEL_PGD_NR * sizeof(pgd_t)); 38 39 /* 40 * Copy over the kernel and IO PGD entries 41 */ 42 init_pgd = pgd_offset_k(0); 43 memcpy(new_pgd + FIRST_KERNEL_PGD_NR, init_pgd + FIRST_KERNEL_PGD_NR, 44 (PTRS_PER_PGD - FIRST_KERNEL_PGD_NR) * sizeof(pgd_t)); 45 46 clean_dcache_area(new_pgd, PTRS_PER_PGD * sizeof(pgd_t)); 47 48 if (!vectors_high()) { 49 /* 50 * On UniCore, first page must always be allocated since it 51 * contains the machine vectors. 52 */ 53 new_pmd = pmd_alloc(mm, (pud_t *)new_pgd, 0); 54 if (!new_pmd) 55 goto no_pmd; 56 57 new_pte = pte_alloc_map(mm, NULL, new_pmd, 0); 58 if (!new_pte) 59 goto no_pte; 60 61 init_pmd = pmd_offset((pud_t *)init_pgd, 0); 62 init_pte = pte_offset_map(init_pmd, 0); 63 set_pte(new_pte, *init_pte); 64 pte_unmap(init_pte); 65 pte_unmap(new_pte); 66 } 67 68 return new_pgd; 69 70no_pte: 71 pmd_free(mm, new_pmd); 72no_pmd: 73 free_pages((unsigned long)new_pgd, 0); 74no_pgd: 75 return NULL; 76} 77 78void free_pgd_slow(struct mm_struct *mm, pgd_t *pgd) 79{ 80 pmd_t *pmd; 81 pgtable_t pte; 82 83 if (!pgd) 84 return; 85 86 /* pgd is always present and good */ 87 pmd = pmd_off(pgd, 0); 88 if (pmd_none(*pmd)) 89 goto free; 90 if (pmd_bad(*pmd)) { 91 pmd_ERROR(*pmd); 92 pmd_clear(pmd); 93 goto free; 94 } 95 96 pte = pmd_pgtable(*pmd); 97 pmd_clear(pmd); 98 pte_free(mm, pte); 99 pmd_free(mm, pmd); 100free: 101 free_pages((unsigned long) pgd, 0); 102}