[RFC PATCH V4 5/7] arm64: Convert asm/tlb.h to generic mmu_gather
Steve Capper
steve.capper at linaro.org
Fri Mar 28 11:01:30 EDT 2014
From: Catalin Marinas <catalin.marinas at arm.com>
Over the past couple of years, the generic mmu_gather gained range
tracking - 597e1c3580b7 (mm/mmu_gather: enable tlb flush range in generic
mmu_gather), 2b047252d087 (Fix TLB gather virtual address range
invalidation corner cases) - and tlb_fast_mode() has been removed -
29eb77825cc7 (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 at arm.com>
Cc: Peter Zijlstra <peterz at infradead.org>
Signed-off-by: Steve Capper <steve.capper at linaro.org>
---
I think Catalin already has this patch in his upstream tree, it's
included in this series for the sake of completeness.
---
arch/arm64/include/asm/tlb.h | 136 +++++++------------------------------------
1 file changed, 20 insertions(+), 116 deletions(-)
diff --git a/arch/arm64/include/asm/tlb.h b/arch/arm64/include/asm/tlb.h
index 717031a..72cadf5 100644
--- a/arch/arm64/include/asm/tlb.h
+++ b/arch/arm64/include/asm/tlb.h
@@ -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
-
-/*
- * 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];
-};
+#include <asm-generic/tlb.h>
/*
- * 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;
- }
-}
-
-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 *);
+ tlb->start = min(tlb->start, addr);
+ tlb->end = max(tlb->end, addr + PAGE_SIZE);
}
}
-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
--
1.8.1.4
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