pgalloc.h

来自「this SRC packet is the headfiles that MI」· C头文件 代码 · 共 181 行

/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 1994 - 2001 by Ralf Baechle
 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
 */
#ifndef _ASM_PGALLOC_H
#define _ASM_PGALLOC_H

#include <linux/config.h>
#include <linux/mm.h>

/* TLB flushing:
 *
 *  - flush_tlb_all() flushes all processes TLB entries
 *  - flush_tlb_mm(mm) flushes the specified mm context TLB entries
 *  - flush_tlb_page(mm, vmaddr) flushes a single page
 *  - flush_tlb_range(mm, start, end) flushes a range of pages
 */
extern void flush_tlb_all(void);
extern void flush_tlb_mm(struct mm_struct *mm);
extern void flush_tlb_range(struct mm_struct *mm, unsigned long start,
			       unsigned long end);
extern void flush_tlb_page(struct vm_area_struct *vma, unsigned long page);

extern inline void flush_tlb_pgtables(struct mm_struct *mm,
                                      unsigned long start, unsigned long end)
{
	/* Nothing to do on MIPS.  */
}


/*
 * Allocate and free page tables.
 */

#define pgd_quicklist (current_cpu_data.pgd_quick)
#define pmd_quicklist ((unsigned long *)0)
#define pte_quicklist (current_cpu_data.pte_quick)
#define pgtable_cache_size (current_cpu_data.pgtable_cache_sz)

#define pmd_populate(mm, pmd, pte)	pmd_set(pmd, pte)

/*
 * Initialize new page directory with pointers to invalid ptes
 */
extern void pgd_init(unsigned long page);

extern __inline__ pgd_t *get_pgd_slow(void)
{
	pgd_t *ret = (pgd_t *)__get_free_page(GFP_KERNEL), *init;

	if (ret) {
		init = pgd_offset(&init_mm, 0);
		pgd_init((unsigned long)ret);
		memcpy (ret + USER_PTRS_PER_PGD, init + USER_PTRS_PER_PGD,
			(PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
	}
	return ret;
}

extern __inline__ pgd_t *get_pgd_fast(void)
{
	unsigned long *ret;

	if((ret = pgd_quicklist) != NULL) {
		pgd_quicklist = (unsigned long *)(*ret);
		ret[0] = ret[1];
		pgtable_cache_size--;
	} else
		ret = (unsigned long *)get_pgd_slow();
	return (pgd_t *)ret;
}

extern __inline__ void free_pgd_fast(pgd_t *pgd)
{
	*(unsigned long *)pgd = (unsigned long) pgd_quicklist;
	pgd_quicklist = (unsigned long *) pgd;
	pgtable_cache_size++;
}

extern __inline__ void free_pgd_slow(pgd_t *pgd)
{
	free_page((unsigned long)pgd);
}

extern pte_t *get_pte_slow(pmd_t *pmd, unsigned long address_preadjusted);

extern __inline__ pte_t *get_pte_fast(void)
{
	unsigned long *ret;

	if((ret = (unsigned long *)pte_quicklist) != NULL) {
		pte_quicklist = (unsigned long *)(*ret);
		ret[0] = ret[1];
		pgtable_cache_size--;
	}
	return (pte_t *)ret;
}

extern __inline__ void free_pte_fast(pte_t *pte)
{
	*(unsigned long *)pte = (unsigned long) pte_quicklist;
	pte_quicklist = (unsigned long *) pte;
	pgtable_cache_size++;
}

extern __inline__ void free_pte_slow(pte_t *pte)
{
	free_page((unsigned long)pte);
}

/* We don't use pmd cache, so these are dummy routines */
extern __inline__ pmd_t *get_pmd_fast(void)
{
	return (pmd_t *)0;
}

extern __inline__ void free_pmd_fast(pmd_t *pmd)
{
}

extern __inline__ void free_pmd_slow(pmd_t *pmd)
{
}

extern void __bad_pte(pmd_t *pmd);

static inline pte_t *pte_alloc_one(struct mm_struct *mm, unsigned long address)
{
	pte_t *pte;

	pte = (pte_t *) __get_free_page(GFP_KERNEL);
	if (pte)
		clear_page(pte);
	return pte;
}

static inline pte_t *pte_alloc_one_fast(struct mm_struct *mm, unsigned long address)
{
	unsigned long *ret;

	if ((ret = (unsigned long *)pte_quicklist) != NULL) {
		pte_quicklist = (unsigned long *)(*ret);
		ret[0] = ret[1];
		pgtable_cache_size--;
	}
	return (pte_t *)ret;
}

extern __inline__ void pte_free_fast(pte_t *pte)
{
	*(unsigned long *)pte = (unsigned long) pte_quicklist;
	pte_quicklist = (unsigned long *) pte;
	pgtable_cache_size++;
}

extern __inline__ void pte_free_slow(pte_t *pte)
{
	free_page((unsigned long)pte);
}

#define pte_free(pte)           pte_free_slow(pte)
#define pgd_free(pgd)           free_pgd_fast(pgd)
#define pgd_alloc(mm)           get_pgd_fast()

/*
 * allocating and freeing a pmd is trivial: the 1-entry pmd is
 * inside the pgd, so has no extra memory associated with it.
 */
#define pmd_alloc_one_fast(mm, addr)	({ BUG(); ((pmd_t *)1); })
#define pmd_alloc_one(mm, addr)		({ BUG(); ((pmd_t *)2); })
#define pmd_free(x)			do { } while (0)
#define pgd_populate(mm, pmd, pte)	BUG()

extern int do_check_pgt_cache(int, int);

#endif /* _ASM_PGALLOC_H */