pgalloc.h

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/*
 *  arch/arm/include/asm/pgalloc.h
 *
 *  Copyright (C) 2000-2001 Russell King
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#ifndef _ASMARM_PGALLOC_H
#define _ASMARM_PGALLOC_H

#include <linux/pagemap.h>

#include <asm/domain.h>
#include <asm/pgtable-hwdef.h>
#include <asm/processor.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>

#define check_pgt_cache()       do { } while (0)

#ifdef CONFIG_MMU

#define _PAGE_USER_TABLE    (PMD_TYPE_TABLE | PMD_BIT4 | PMD_DOMAIN(DOMAIN_USER))
#define _PAGE_KERNEL_TABLE  (PMD_TYPE_TABLE | PMD_BIT4 | PMD_DOMAIN(DOMAIN_KERNEL))

#ifdef CONFIG_ARM_LPAE

static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long addr)
{
    return (pmd_t *)get_zeroed_page(GFP_KERNEL | __GFP_REPEAT);
}

static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
{
    BUG_ON((unsigned long)pmd & (PAGE_SIZE-1));
    free_page((unsigned long)pmd);
}

static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
{
    set_pud(pud, __pud(__pa(pmd) | PMD_TYPE_TABLE));
}

#else   /* !CONFIG_ARM_LPAE */

/*
 * Since we have only two-level page tables, these are trivial
 */
#define pmd_alloc_one(mm,addr)      ({ BUG(); ((pmd_t *)2); })
#define pmd_free(mm, pmd)       do { } while (0)
#define pud_populate(mm,pmd,pte)    BUG()

#endif  /* CONFIG_ARM_LPAE */

extern pgd_t *pgd_alloc(struct mm_struct *mm);
extern void pgd_free(struct mm_struct *mm, pgd_t *pgd);

#define PGALLOC_GFP (GFP_KERNEL | __GFP_NOTRACK | __GFP_REPEAT | __GFP_ZERO)

static inline void clean_pte_table(pte_t *pte)
{
    clean_dcache_area(pte + PTE_HWTABLE_PTRS, PTE_HWTABLE_SIZE);
}

/*
 * Allocate one PTE table.
 *
 * This actually allocates two hardware PTE tables, but we wrap this up
 * into one table thus:
 *
 *  +------------+
 *  | Linux pt 0 |
 *  +------------+
 *  | Linux pt 1 |
 *  +------------+
 *  |  h/w pt 0  |
 *  +------------+
 *  |  h/w pt 1  |
 *  +------------+
 */
static inline pte_t *
pte_alloc_one_kernel(struct mm_struct *mm, unsigned long addr)
{
    pte_t *pte;

    pte = (pte_t *)__get_free_page(PGALLOC_GFP);
    if (pte)
        clean_pte_table(pte);

    return pte;
}

static inline pgtable_t
pte_alloc_one(struct mm_struct *mm, unsigned long addr)
{
    struct page *pte;

#ifdef CONFIG_HIGHPTE
    pte = alloc_pages(PGALLOC_GFP | __GFP_HIGHMEM, 0);
#else
    pte = alloc_pages(PGALLOC_GFP, 0);
#endif
    if (pte) {
        if (!PageHighMem(pte))
            clean_pte_table(page_address(pte));
        pgtable_page_ctor(pte);
    }

    return pte;
}

/*
 * Free one PTE table.
 */
static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
{
    if (pte)
        free_page((unsigned long)pte);
}

static inline void pte_free(struct mm_struct *mm, pgtable_t pte)
{
    pgtable_page_dtor(pte);
    __free_page(pte);
}

static inline void __pmd_populate(pmd_t *pmdp, phys_addr_t pte,
                  pmdval_t prot)
{
    pmdval_t pmdval = (pte + PTE_HWTABLE_OFF) | prot;
    pmdp[0] = __pmd(pmdval);
#ifndef CONFIG_ARM_LPAE
    pmdp[1] = __pmd(pmdval + 256 * sizeof(pte_t));
#endif
    flush_pmd_entry(pmdp);
}

/*
 * Populate the pmdp entry with a pointer to the pte.  This pmd is part
 * of the mm address space.
 *
 * Ensure that we always set both PMD entries.
 */
static inline void
pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmdp, pte_t *ptep)
{
    /*
     * The pmd must be loaded with the physical address of the PTE table
     */
    __pmd_populate(pmdp, __pa(ptep), _PAGE_KERNEL_TABLE);
}

static inline void
pmd_populate(struct mm_struct *mm, pmd_t *pmdp, pgtable_t ptep)
{
    __pmd_populate(pmdp, page_to_phys(ptep), _PAGE_USER_TABLE);
}
#define pmd_pgtable(pmd) pmd_page(pmd)

#endif /* CONFIG_MMU */

#endif