175 lines
3.7 KiB
C
175 lines
3.7 KiB
C
/*
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* linux/arch/arm/mm/pgd.c
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*
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* Copyright (C) 1998-2005 Russell King
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/mm.h>
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#include <linux/gfp.h>
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#include <linux/highmem.h>
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#include <linux/slab.h>
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#include <asm/cp15.h>
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#include <asm/pgalloc.h>
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#include <asm/page.h>
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#include <asm/tlbflush.h>
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#include "mm.h"
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#ifdef CONFIG_ARM_LPAE
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#define __pgd_alloc() kmalloc(PTRS_PER_PGD * sizeof(pgd_t), GFP_KERNEL)
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#define __pgd_free(pgd) kfree(pgd)
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#else
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#define __pgd_alloc() (pgd_t *)__get_free_pages(GFP_KERNEL, 2)
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#define __pgd_free(pgd) free_pages((unsigned long)pgd, 2)
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#endif
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/*
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* need to get a 16k page for level 1
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*/
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pgd_t *pgd_alloc(struct mm_struct *mm)
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{
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pgd_t *new_pgd, *init_pgd;
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pud_t *new_pud, *init_pud;
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pmd_t *new_pmd, *init_pmd;
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pte_t *new_pte, *init_pte;
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new_pgd = __pgd_alloc();
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if (!new_pgd)
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goto no_pgd;
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memset(new_pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
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/*
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* Copy over the kernel and IO PGD entries
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*/
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init_pgd = pgd_offset_k(0);
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memcpy(new_pgd + USER_PTRS_PER_PGD, init_pgd + USER_PTRS_PER_PGD,
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(PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
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clean_dcache_area(new_pgd, PTRS_PER_PGD * sizeof(pgd_t));
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#ifdef CONFIG_ARM_LPAE
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/*
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* Allocate PMD table for modules and pkmap mappings.
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*/
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new_pud = pud_alloc(mm, new_pgd + pgd_index(MODULES_VADDR),
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MODULES_VADDR);
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if (!new_pud)
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goto no_pud;
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new_pmd = pmd_alloc(mm, new_pud, 0);
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if (!new_pmd)
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goto no_pmd;
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#endif
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if (!vectors_high()) {
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/*
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* On ARM, first page must always be allocated since it
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* contains the machine vectors. The vectors are always high
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* with LPAE.
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*/
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new_pud = pud_alloc(mm, new_pgd, 0);
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if (!new_pud)
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goto no_pud;
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new_pmd = pmd_alloc(mm, new_pud, 0);
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if (!new_pmd)
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goto no_pmd;
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new_pte = pte_alloc_map(mm, new_pmd, 0);
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if (!new_pte)
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goto no_pte;
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#ifndef CONFIG_ARM_LPAE
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/*
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* Modify the PTE pointer to have the correct domain. This
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* needs to be the vectors domain to avoid the low vectors
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* being unmapped.
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*/
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pmd_val(*new_pmd) &= ~PMD_DOMAIN_MASK;
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pmd_val(*new_pmd) |= PMD_DOMAIN(DOMAIN_VECTORS);
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#endif
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init_pud = pud_offset(init_pgd, 0);
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init_pmd = pmd_offset(init_pud, 0);
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init_pte = pte_offset_map(init_pmd, 0);
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set_pte_ext(new_pte + 0, init_pte[0], 0);
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set_pte_ext(new_pte + 1, init_pte[1], 0);
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pte_unmap(init_pte);
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pte_unmap(new_pte);
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}
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return new_pgd;
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no_pte:
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pmd_free(mm, new_pmd);
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mm_dec_nr_pmds(mm);
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no_pmd:
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pud_free(mm, new_pud);
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no_pud:
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__pgd_free(new_pgd);
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no_pgd:
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return NULL;
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}
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void pgd_free(struct mm_struct *mm, pgd_t *pgd_base)
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{
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pgd_t *pgd;
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pud_t *pud;
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pmd_t *pmd;
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pgtable_t pte;
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if (!pgd_base)
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return;
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pgd = pgd_base + pgd_index(0);
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if (pgd_none_or_clear_bad(pgd))
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goto no_pgd;
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pud = pud_offset(pgd, 0);
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if (pud_none_or_clear_bad(pud))
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goto no_pud;
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pmd = pmd_offset(pud, 0);
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if (pmd_none_or_clear_bad(pmd))
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goto no_pmd;
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pte = pmd_pgtable(*pmd);
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pmd_clear(pmd);
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pte_free(mm, pte);
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atomic_long_dec(&mm->nr_ptes);
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no_pmd:
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pud_clear(pud);
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pmd_free(mm, pmd);
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mm_dec_nr_pmds(mm);
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no_pud:
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pgd_clear(pgd);
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pud_free(mm, pud);
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no_pgd:
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#ifdef CONFIG_ARM_LPAE
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/*
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* Free modules/pkmap or identity pmd tables.
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*/
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for (pgd = pgd_base; pgd < pgd_base + PTRS_PER_PGD; pgd++) {
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if (pgd_none_or_clear_bad(pgd))
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continue;
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if (pgd_val(*pgd) & L_PGD_SWAPPER)
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continue;
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pud = pud_offset(pgd, 0);
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if (pud_none_or_clear_bad(pud))
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continue;
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pmd = pmd_offset(pud, 0);
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pud_clear(pud);
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pmd_free(mm, pmd);
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mm_dec_nr_pmds(mm);
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pgd_clear(pgd);
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pud_free(mm, pud);
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}
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#endif
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__pgd_free(pgd_base);
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}
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