kernel-ark/include/asm-arm/tlb.h
Hugh Dickins 4d6ddfa924 [PATCH] mm: tlb_is_full_mm was obscure
tlb_is_full_mm?  What does that mean?  The TLB is full?  No, it means that the
mm's last user has gone and the whole mm is being torn down.  And it's an
inline function because sparc64 uses a different (slightly better)
"tlb_frozen" name for the flag others call "fullmm".

And now the ptep_get_and_clear_full macro used in zap_pte_range refers
directly to tlb->fullmm, which would be wrong for sparc64.  Rather than
correct that, I'd prefer to scrap tlb_is_full_mm altogether, and change
sparc64 to just use the same poor name as everyone else - is that okay?

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-29 21:40:37 -07:00

99 lines
2.4 KiB
C

/*
* 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