Commit 0b4e273f authored by Jeff Dike's avatar Jeff Dike Committed by Linus Torvalds
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uml: customize tlb.h



Customize the hooks in tlb.h to optimize TLB flushing some more.

Add start and end fields to tlb_gather_mmu, which are used to limit
the address space range scanned when a region is unmapped.

The interfaces which just free page tables, without actually changing
mappings, don't need to cause a TLB flush.
Signed-off-by: default avatarJeff Dike <jdike@linux.intel.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 909e90d3
......@@ -193,18 +193,18 @@ static inline int update_pte_range(pmd_t *pmd, unsigned long addr,
if (!pte_young(*pte)) {
r = 0;
w = 0;
} else if (!pte_dirty(*pte)) {
} else if (!pte_dirty(*pte))
w = 0;
}
prot = ((r ? UM_PROT_READ : 0) | (w ? UM_PROT_WRITE : 0) |
(x ? UM_PROT_EXEC : 0));
if (hvc->force || pte_newpage(*pte)) {
if (pte_present(*pte))
ret = add_mmap(addr, pte_val(*pte) & PAGE_MASK,
PAGE_SIZE, prot, hvc);
else ret = add_munmap(addr, PAGE_SIZE, hvc);
}
else if (pte_newprot(*pte))
else
ret = add_munmap(addr, PAGE_SIZE, hvc);
} else if (pte_newprot(*pte))
ret = add_mprotect(addr, PAGE_SIZE, prot, hvc);
*pte = pte_mkuptodate(*pte);
} while (pte++, addr += PAGE_SIZE, ((addr < end) && !ret));
......@@ -500,7 +500,8 @@ void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
else fix_range(vma->vm_mm, start, end, 0);
}
void flush_tlb_mm(struct mm_struct *mm)
void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start,
unsigned long end)
{
/*
* Don't bother flushing if this address space is about to be
......@@ -509,7 +510,17 @@ void flush_tlb_mm(struct mm_struct *mm)
if (atomic_read(&mm->mm_users) == 0)
return;
fix_range(mm, 0, TASK_SIZE, 0);
fix_range(mm, start, end, 0);
}
void flush_tlb_mm(struct mm_struct *mm)
{
struct vm_area_struct *vma = mm->mmap;
while (vma != NULL) {
fix_range(mm, vma->vm_start, vma->vm_end, 0);
vma = vma->vm_next;
}
}
void force_flush_all(void)
......
#ifndef __UM_TLB_H
#define __UM_TLB_H
#include <asm/arch/tlb.h>
#include <linux/swap.h>
#include <asm/percpu.h>
#include <asm/pgalloc.h>
#include <asm/tlbflush.h>
#define tlb_start_vma(tlb, vma) do { } while (0)
#define tlb_end_vma(tlb, vma) do { } while (0)
#define tlb_flush(tlb) flush_tlb_mm((tlb)->mm)
/* struct mmu_gather is an opaque type used by the mm code for passing around
* any data needed by arch specific code for tlb_remove_page.
*/
struct mmu_gather {
struct mm_struct *mm;
unsigned int need_flush; /* Really unmapped some ptes? */
unsigned long start;
unsigned long end;
unsigned int fullmm; /* non-zero means full mm flush */
};
/* Users of the generic TLB shootdown code must declare this storage space. */
DECLARE_PER_CPU(struct mmu_gather, mmu_gathers);
static inline void __tlb_remove_tlb_entry(struct mmu_gather *tlb, pte_t *ptep,
unsigned long address)
{
if (tlb->start > address)
tlb->start = address;
if (tlb->end < address + PAGE_SIZE)
tlb->end = address + PAGE_SIZE;
}
static inline void init_tlb_gather(struct mmu_gather *tlb)
{
tlb->need_flush = 0;
tlb->start = TASK_SIZE;
tlb->end = 0;
if (tlb->fullmm) {
tlb->start = 0;
tlb->end = TASK_SIZE;
}
}
/* tlb_gather_mmu
* Return a pointer to an initialized struct mmu_gather.
*/
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->fullmm = full_mm_flush;
init_tlb_gather(tlb);
return tlb;
}
extern void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start,
unsigned long end);
static inline void
tlb_flush_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end)
{
if (!tlb->need_flush)
return;
flush_tlb_mm_range(tlb->mm, tlb->start, tlb->end);
init_tlb_gather(tlb);
}
/* tlb_finish_mmu
* Called at the end of the shootdown operation to free up any resources
* that were required.
*/
static inline void
tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end)
{
tlb_flush_mmu(tlb, start, end);
/* keep the page table cache within bounds */
check_pgt_cache();
put_cpu_var(mmu_gathers);
}
/* tlb_remove_page
* Must perform the equivalent to __free_pte(pte_get_and_clear(ptep)),
* while handling the additional races in SMP caused by other CPUs
* caching valid mappings in their TLBs.
*/
static inline void tlb_remove_page(struct mmu_gather *tlb, struct page *page)
{
tlb->need_flush = 1;
free_page_and_swap_cache(page);
return;
}
/**
* tlb_remove_tlb_entry - remember a pte unmapping for later tlb invalidation.
*
* Record the fact that pte's were really umapped in ->need_flush, so we can
* later optimise away the tlb invalidate. This helps when userspace is
* unmapping already-unmapped pages, which happens quite a lot.
*/
#define tlb_remove_tlb_entry(tlb, ptep, address) \
do { \
tlb->need_flush = 1; \
__tlb_remove_tlb_entry(tlb, ptep, address); \
} while (0)
#define pte_free_tlb(tlb, ptep) __pte_free_tlb(tlb, ptep)
#define pud_free_tlb(tlb, pudp) __pud_free_tlb(tlb, pudp)
#define pmd_free_tlb(tlb, pmdp) __pmd_free_tlb(tlb, pmdp)
#define tlb_migrate_finish(mm) do {} while (0)
#endif
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