arm64: Convert asm/tlb.h to generic mmu_gather

Over the past couple of years, the generic mmu_gather gained range
tracking - 597e1c3580 (mm/mmu_gather: enable tlb flush range in generic
mmu_gather), 2b047252d0 (Fix TLB gather virtual address range
invalidation corner cases) - and tlb_fast_mode() has been removed -
29eb77825c (arch, mm: Remove tlb_fast_mode()).

The new mmu_gather structure is now suitable for arm64 and this patch
converts the arch asm/tlb.h to the generic code. One functional
difference is the shift_arg_pages() case where previously the code was
flushing the full mm (no tlb_start_vma call) but now it flushes the
range given to tlb_gather_mmu() (possibly slightly more efficient
previously).

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
This commit is contained in:
Catalin Marinas 2014-02-11 15:22:01 +00:00
parent 22bd1c91fe
commit 020c1427f3

View File

@ -19,115 +19,44 @@
#ifndef __ASM_TLB_H
#define __ASM_TLB_H
#include <linux/pagemap.h>
#include <linux/swap.h>
#include <asm/pgalloc.h>
#include <asm/tlbflush.h>
#define MMU_GATHER_BUNDLE 8
#include <asm-generic/tlb.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 fullmm;
struct vm_area_struct *vma;
unsigned long start, end;
unsigned long range_start;
unsigned long range_end;
unsigned int nr;
unsigned int max;
struct page **pages;
struct page *local[MMU_GATHER_BUNDLE];
};
/*
* This is unnecessarily complex. There's three ways the TLB shootdown
* code is used:
* There's three ways the TLB shootdown code is used:
* 1. Unmapping a range of vmas. See zap_page_range(), unmap_region().
* tlb->fullmm = 0, and tlb_start_vma/tlb_end_vma will be called.
* tlb->vma will be non-NULL.
* 2. Unmapping all vmas. See exit_mmap().
* tlb->fullmm = 1, and tlb_start_vma/tlb_end_vma will be called.
* tlb->vma will be non-NULL. Additionally, page tables will be freed.
* Page tables will be freed.
* 3. Unmapping argument pages. See shift_arg_pages().
* tlb->fullmm = 0, but tlb_start_vma/tlb_end_vma will not be called.
* tlb->vma will be NULL.
*/
static inline void tlb_flush(struct mmu_gather *tlb)
{
if (tlb->fullmm || !tlb->vma)
if (tlb->fullmm) {
flush_tlb_mm(tlb->mm);
else if (tlb->range_end > 0) {
flush_tlb_range(tlb->vma, tlb->range_start, tlb->range_end);
tlb->range_start = TASK_SIZE;
tlb->range_end = 0;
} else if (tlb->end > 0) {
struct vm_area_struct vma = { .vm_mm = tlb->mm, };
flush_tlb_range(&vma, tlb->start, tlb->end);
tlb->start = TASK_SIZE;
tlb->end = 0;
}
}
static inline void tlb_add_flush(struct mmu_gather *tlb, unsigned long addr)
{
if (!tlb->fullmm) {
if (addr < tlb->range_start)
tlb->range_start = addr;
if (addr + PAGE_SIZE > tlb->range_end)
tlb->range_end = addr + PAGE_SIZE;
tlb->start = min(tlb->start, addr);
tlb->end = max(tlb->end, addr + PAGE_SIZE);
}
}
static inline void __tlb_alloc_page(struct mmu_gather *tlb)
{
unsigned long addr = __get_free_pages(GFP_NOWAIT | __GFP_NOWARN, 0);
if (addr) {
tlb->pages = (void *)addr;
tlb->max = PAGE_SIZE / sizeof(struct page *);
}
}
static inline void tlb_flush_mmu(struct mmu_gather *tlb)
{
tlb_flush(tlb);
free_pages_and_swap_cache(tlb->pages, tlb->nr);
tlb->nr = 0;
if (tlb->pages == tlb->local)
__tlb_alloc_page(tlb);
}
static inline void
tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm, unsigned long start, unsigned long end)
{
tlb->mm = mm;
tlb->fullmm = !(start | (end+1));
tlb->start = start;
tlb->end = end;
tlb->vma = NULL;
tlb->max = ARRAY_SIZE(tlb->local);
tlb->pages = tlb->local;
tlb->nr = 0;
__tlb_alloc_page(tlb);
}
static inline void
tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end)
{
tlb_flush_mmu(tlb);
/* keep the page table cache within bounds */
check_pgt_cache();
if (tlb->pages != tlb->local)
free_pages((unsigned long)tlb->pages, 0);
}
/*
* Memorize the range for the TLB flush.
*/
static inline void
tlb_remove_tlb_entry(struct mmu_gather *tlb, pte_t *ptep, unsigned long addr)
static inline void __tlb_remove_tlb_entry(struct mmu_gather *tlb, pte_t *ptep,
unsigned long addr)
{
tlb_add_flush(tlb, addr);
}
@ -137,38 +66,24 @@ tlb_remove_tlb_entry(struct mmu_gather *tlb, pte_t *ptep, unsigned long addr)
* 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)
static inline void tlb_start_vma(struct mmu_gather *tlb,
struct vm_area_struct *vma)
{
if (!tlb->fullmm) {
tlb->vma = vma;
tlb->range_start = TASK_SIZE;
tlb->range_end = 0;
tlb->start = TASK_SIZE;
tlb->end = 0;
}
}
static inline void
tlb_end_vma(struct mmu_gather *tlb, struct vm_area_struct *vma)
static inline void tlb_end_vma(struct mmu_gather *tlb,
struct vm_area_struct *vma)
{
if (!tlb->fullmm)
tlb_flush(tlb);
}
static inline int __tlb_remove_page(struct mmu_gather *tlb, struct page *page)
{
tlb->pages[tlb->nr++] = page;
VM_BUG_ON(tlb->nr > tlb->max);
return tlb->max - tlb->nr;
}
static inline void tlb_remove_page(struct mmu_gather *tlb, struct page *page)
{
if (!__tlb_remove_page(tlb, page))
tlb_flush_mmu(tlb);
}
static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t pte,
unsigned long addr)
unsigned long addr)
{
pgtable_page_dtor(pte);
tlb_add_flush(tlb, addr);
@ -184,16 +99,5 @@ static inline void __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmdp,
}
#endif
#define pte_free_tlb(tlb, ptep, addr) __pte_free_tlb(tlb, ptep, addr)
#define pmd_free_tlb(tlb, pmdp, addr) __pmd_free_tlb(tlb, pmdp, addr)
#define pud_free_tlb(tlb, pudp, addr) pud_free((tlb)->mm, pudp)
#define tlb_migrate_finish(mm) do { } while (0)
static inline void
tlb_remove_pmd_tlb_entry(struct mmu_gather *tlb, pmd_t *pmdp, unsigned long addr)
{
tlb_add_flush(tlb, addr);
}
#endif