include/asm-um/pgalloc.h

/* 
 * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
 * Derived from include/asm-i386/pgalloc.h and include/asm-i386/pgtable.h
 * Licensed under the GPL
 */

#ifndef __UM_PGALLOC_H
#define __UM_PGALLOC_H

#include "linux/config.h"
#include "linux/mm.h"
#include "asm/fixmap.h"
#include "choose-mode.h"

#define pgd_quicklist (current_cpu_data.pgd_quick)
#define pmd_quicklist (current_cpu_data.pmd_quick)
#define pte_quicklist (current_cpu_data.pte_quick)
#define pgtable_cache_size (current_cpu_data.pgtable_cache_sz)

#define pmd_populate(mm, pmd, pte) set_pmd(pmd, __pmd(_PAGE_TABLE + __pa(pte)))

/*
 * Allocate and free page tables.
 */

static inline pgd_t *get_pgd_slow_tt(void)
{
	pgd_t *pgd = (pgd_t *)__get_free_page(GFP_KERNEL);

	if (pgd) {
		memset(pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
		memcpy(pgd + USER_PTRS_PER_PGD, 
		       swapper_pg_dir + USER_PTRS_PER_PGD, 
		       (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
	}
	return pgd;
}

static inline pgd_t *get_pgd_slow_skas(void)
{
	pgd_t *pgd = (pgd_t *)__get_free_page(GFP_KERNEL);

	if (pgd)
		memset(pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
	return pgd;
}

static inline pgd_t *get_pgd_slow(void)
{
	return(CHOOSE_MODE(get_pgd_slow_tt(), get_pgd_slow_skas()));
}

static inline pgd_t *get_pgd_fast(void)
{
	unsigned long *ret;

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

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

static inline void free_pgd_slow(pgd_t *pgd)
{
	free_page((unsigned long)pgd);
}

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;

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

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

static inline void pte_free_slow(pte_t *pte)
{
	free_page((unsigned long)pte);
}

#define pte_free(pte)           pte_free_fast(pte)
#define pgd_free(pgd)           free_pgd_slow(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_slow(x)		do { } while (0)
#define pmd_free_fast(x)		do { } while (0)
#define pmd_free(x)			do { } while (0)
#define pgd_populate(mm, pmd, pte)	BUG()

/*
 * TLB flushing:
 *
 *  - flush_tlb() flushes the current mm struct TLBs
 *  - flush_tlb_all() flushes all processes TLBs
 *  - flush_tlb_mm(mm) flushes the specified mm context TLB's
 *  - flush_tlb_page(vma, vmaddr) flushes one page
 *  - flush_tlb_kernel_vm() flushes the kernel vm area
 *  - flush_tlb_range(mm, start, end) flushes a range of pages
 *  - flush_tlb_pgtables(mm, start, end) flushes a range of page tables
 */

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 vmaddr);
extern void flush_tlb_kernel_vm(void);

static inline void flush_tlb_pgtables(struct mm_struct *mm,
				      unsigned long start, unsigned long end)
{
}

#endif
/*
 * Overrides for Emacs so that we follow Linus's tabbing style.
 * Emacs will notice this stuff at the end of the file and automatically
 * adjust the settings for this buffer only.  This must remain at the end
 * of the file.
 * ---------------------------------------------------------------------------
 * Local variables:
 * c-file-style: "linux"
 * End:
 */