[deliverable/linux.git] / include / asm-arm / tlb.h

/*
 *  linux/include/asm-arm/tlb.h
 *
 *  Copyright (C) 2002 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.
 *
 *  Experimentation shows that on a StrongARM, it appears to be faster
 *  to use the "invalidate whole tlb" rather than "invalidate single
 *  tlb" for this.
 *
 *  This appears true for both the process fork+exit case, as well as
 *  the munmap-large-area case.
 */
#ifndef __ASMARM_TLB_H
#define __ASMARM_TLB_H

#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
#include <asm/pgalloc.h>

/*
 * TLB handling.  This allows us to remove pages from the page
 * tables, and efficiently handle the TLB issues.
 */
struct mmu_gather {
	struct mm_struct	*mm;
	unsigned int		freed;
	unsigned int		fullmm;

	unsigned int		flushes;
	unsigned int		avoided_flushes;
};

DECLARE_PER_CPU(struct mmu_gather, mmu_gathers);

static inline struct mmu_gather *
tlb_gather_mmu(struct mm_struct *mm, unsigned int full_mm_flush)
{
	struct mmu_gather *tlb = &get_cpu_var(mmu_gathers);

	tlb->mm = mm;
	tlb->freed = 0;
	tlb->fullmm = full_mm_flush;

	return tlb;
}

static inline void
tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end)
{
	struct mm_struct *mm = tlb->mm;
	unsigned long freed = tlb->freed;
	int rss = get_mm_counter(mm, rss);

	if (rss < freed)
		freed = rss;
	add_mm_counter(mm, rss, -freed);

	if (tlb->fullmm)
		flush_tlb_mm(mm);

	/* keep the page table cache within bounds */
	check_pgt_cache();

	put_cpu_var(mmu_gathers);
}

#define tlb_remove_tlb_entry(tlb,ptep,address)	do { } while (0)

/*
 * In the case of tlb vma handling, we can optimise these away in the
 * case where we're doing a full MM flush.  When we're doing a munmap,
 * the vmas are adjusted to only cover the region to be torn down.
 */
static inline void
tlb_start_vma(struct mmu_gather *tlb, struct vm_area_struct *vma)
{
	if (!tlb->fullmm)
		flush_cache_range(vma, vma->vm_start, vma->vm_end);
}

static inline void
tlb_end_vma(struct mmu_gather *tlb, struct vm_area_struct *vma)
{
	if (!tlb->fullmm)
		flush_tlb_range(vma, vma->vm_start, vma->vm_end);
}

#define tlb_remove_page(tlb,page)	free_page_and_swap_cache(page)
#define pte_free_tlb(tlb,ptep)		pte_free(ptep)
#define pmd_free_tlb(tlb,pmdp)		pmd_free(pmdp)

#define tlb_migrate_finish(mm)		do { } while (0)

#endif
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/include/asm-arm/tlb.h
	3	*
	4	* Copyright (C) 2002 Russell King
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License version 2 as
	8	* published by the Free Software Foundation.
	9	*
	10	* Experimentation shows that on a StrongARM, it appears to be faster
	11	* to use the "invalidate whole tlb" rather than "invalidate single
	12	* tlb" for this.
	13	*
	14	* This appears true for both the process fork+exit case, as well as
	15	* the munmap-large-area case.
	16	*/
	17	#ifndef __ASMARM_TLB_H
	18	#define __ASMARM_TLB_H
	19
	20	#include <asm/cacheflush.h>
	21	#include <asm/tlbflush.h>
	22	#include <asm/pgalloc.h>
	23
	24	/*
	25	* TLB handling. This allows us to remove pages from the page
	26	* tables, and efficiently handle the TLB issues.
	27	*/
	28	struct mmu_gather {
	29	struct mm_struct *mm;
	30	unsigned int freed;
	31	unsigned int fullmm;
	32
	33	unsigned int flushes;
	34	unsigned int avoided_flushes;
	35	};
	36
	37	DECLARE_PER_CPU(struct mmu_gather, mmu_gathers);
	38
	39	static inline struct mmu_gather *
	40	tlb_gather_mmu(struct mm_struct *mm, unsigned int full_mm_flush)
	41	{
15a23ffa	42	struct mmu_gather *tlb = &get_cpu_var(mmu_gathers);
1da177e4 LT	43
	44	tlb->mm = mm;
	45	tlb->freed = 0;
	46	tlb->fullmm = full_mm_flush;
	47
	48	return tlb;
	49	}
	50
	51	static inline void
	52	tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end)
	53	{
	54	struct mm_struct *mm = tlb->mm;
	55	unsigned long freed = tlb->freed;
	56	int rss = get_mm_counter(mm, rss);
	57
	58	if (rss < freed)
	59	freed = rss;
	60	add_mm_counter(mm, rss, -freed);
	61
	62	if (tlb->fullmm)
	63	flush_tlb_mm(mm);
	64
	65	/* keep the page table cache within bounds */
	66	check_pgt_cache();
15a23ffa HD	67
15a23ffa HD	68	put_cpu_var(mmu_gathers);
1da177e4 LT	69	}
1da177e4 LT	70
1da177e4 LT	71	#define tlb_remove_tlb_entry(tlb,ptep,address) do { } while (0)
	72
	73	/*
	74	* In the case of tlb vma handling, we can optimise these away in the
	75	* case where we're doing a full MM flush. When we're doing a munmap,
	76	* the vmas are adjusted to only cover the region to be torn down.
	77	*/
	78	static inline void
	79	tlb_start_vma(struct mmu_gather tlb, struct vm_area_struct vma)
	80	{
	81	if (!tlb->fullmm)
	82	flush_cache_range(vma, vma->vm_start, vma->vm_end);
	83	}
	84
	85	static inline void
	86	tlb_end_vma(struct mmu_gather tlb, struct vm_area_struct vma)
	87	{
	88	if (!tlb->fullmm)
	89	flush_tlb_range(vma, vma->vm_start, vma->vm_end);
	90	}
	91
	92	#define tlb_remove_page(tlb,page) free_page_and_swap_cache(page)
	93	#define pte_free_tlb(tlb,ptep) pte_free(ptep)
	94	#define pmd_free_tlb(tlb,pmdp) pmd_free(pmdp)
	95
	96	#define tlb_migrate_finish(mm) do { } while (0)
	97
	98	#endif