arm/tlb: Convert to generic mmu_gather
Generic mmu_gather provides everything that ARM needs: - range tracking - RCU table free - VM_EXEC tracking - VIPT cache flushing The one notable curiosity is the 'funny' range tracking for classical ARM in __pte_free_tlb(). No change in behavior intended. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Will Deacon <will.deacon@arm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Nick Piggin <npiggin@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@surriel.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Peter Zijlstra
Ingo Molnar
parent
96bc9567cb
commit
b78180b97d
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@ -33,270 +33,42 @@
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#include <asm/pgalloc.h>
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#include <asm/tlbflush.h>
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#define MMU_GATHER_BUNDLE 8
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#ifdef CONFIG_HAVE_RCU_TABLE_FREE
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static inline void __tlb_remove_table(void *_table)
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{
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free_page_and_swap_cache((struct page *)_table);
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}
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struct mmu_table_batch {
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struct rcu_head rcu;
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unsigned int nr;
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void *tables[0];
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};
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#include <asm-generic/tlb.h>
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#define MAX_TABLE_BATCH \
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((PAGE_SIZE - sizeof(struct mmu_table_batch)) / sizeof(void *))
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extern void tlb_table_flush(struct mmu_gather *tlb);
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extern void tlb_remove_table(struct mmu_gather *tlb, void *table);
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#define tlb_remove_entry(tlb, entry) tlb_remove_table(tlb, entry)
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#else
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#define tlb_remove_entry(tlb, entry) tlb_remove_page(tlb, entry)
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#endif /* CONFIG_HAVE_RCU_TABLE_FREE */
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/*
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* TLB handling. This allows us to remove pages from the page
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* tables, and efficiently handle the TLB issues.
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*/
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struct mmu_gather {
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struct mm_struct *mm;
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#ifdef CONFIG_HAVE_RCU_TABLE_FREE
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struct mmu_table_batch *batch;
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unsigned int need_flush;
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#ifndef CONFIG_HAVE_RCU_TABLE_FREE
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#define tlb_remove_table(tlb, entry) tlb_remove_page(tlb, entry)
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#endif
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unsigned int fullmm;
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struct vm_area_struct *vma;
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unsigned long start, end;
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unsigned long range_start;
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unsigned long range_end;
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unsigned int nr;
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unsigned int max;
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struct page **pages;
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struct page *local[MMU_GATHER_BUNDLE];
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};
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DECLARE_PER_CPU(struct mmu_gather, mmu_gathers);
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/*
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* This is unnecessarily complex. There's three ways the TLB shootdown
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* code is used:
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* 1. Unmapping a range of vmas. See zap_page_range(), unmap_region().
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* tlb->fullmm = 0, and tlb_start_vma/tlb_end_vma will be called.
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* tlb->vma will be non-NULL.
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* 2. Unmapping all vmas. See exit_mmap().
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* tlb->fullmm = 1, and tlb_start_vma/tlb_end_vma will be called.
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* tlb->vma will be non-NULL. Additionally, page tables will be freed.
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* 3. Unmapping argument pages. See shift_arg_pages().
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* tlb->fullmm = 0, but tlb_start_vma/tlb_end_vma will not be called.
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* tlb->vma will be NULL.
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*/
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static inline void tlb_flush(struct mmu_gather *tlb)
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{
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if (tlb->fullmm || !tlb->vma)
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flush_tlb_mm(tlb->mm);
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else if (tlb->range_end > 0) {
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flush_tlb_range(tlb->vma, tlb->range_start, tlb->range_end);
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tlb->range_start = TASK_SIZE;
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tlb->range_end = 0;
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}
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}
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static inline void tlb_add_flush(struct mmu_gather *tlb, unsigned long addr)
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{
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if (!tlb->fullmm) {
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if (addr < tlb->range_start)
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tlb->range_start = addr;
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if (addr + PAGE_SIZE > tlb->range_end)
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tlb->range_end = addr + PAGE_SIZE;
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}
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}
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static inline void __tlb_alloc_page(struct mmu_gather *tlb)
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{
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unsigned long addr = __get_free_pages(GFP_NOWAIT | __GFP_NOWARN, 0);
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if (addr) {
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tlb->pages = (void *)addr;
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tlb->max = PAGE_SIZE / sizeof(struct page *);
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}
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}
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static inline void tlb_flush_mmu_tlbonly(struct mmu_gather *tlb)
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{
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tlb_flush(tlb);
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#ifdef CONFIG_HAVE_RCU_TABLE_FREE
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tlb_table_flush(tlb);
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#endif
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}
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static inline void tlb_flush_mmu_free(struct mmu_gather *tlb)
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{
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free_pages_and_swap_cache(tlb->pages, tlb->nr);
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tlb->nr = 0;
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if (tlb->pages == tlb->local)
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__tlb_alloc_page(tlb);
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}
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static inline void tlb_flush_mmu(struct mmu_gather *tlb)
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{
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tlb_flush_mmu_tlbonly(tlb);
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tlb_flush_mmu_free(tlb);
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}
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static inline void
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arch_tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm,
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unsigned long start, unsigned long end)
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{
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tlb->mm = mm;
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tlb->fullmm = !(start | (end+1));
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tlb->start = start;
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tlb->end = end;
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tlb->vma = NULL;
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tlb->max = ARRAY_SIZE(tlb->local);
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tlb->pages = tlb->local;
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tlb->nr = 0;
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__tlb_alloc_page(tlb);
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#ifdef CONFIG_HAVE_RCU_TABLE_FREE
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tlb->batch = NULL;
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#endif
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}
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static inline void
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arch_tlb_finish_mmu(struct mmu_gather *tlb,
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unsigned long start, unsigned long end, bool force)
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{
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if (force) {
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tlb->range_start = start;
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tlb->range_end = end;
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}
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tlb_flush_mmu(tlb);
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/* keep the page table cache within bounds */
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check_pgt_cache();
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if (tlb->pages != tlb->local)
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free_pages((unsigned long)tlb->pages, 0);
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}
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/*
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* Memorize the range for the TLB flush.
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*/
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static inline void
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tlb_remove_tlb_entry(struct mmu_gather *tlb, pte_t *ptep, unsigned long addr)
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{
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tlb_add_flush(tlb, addr);
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}
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#define tlb_remove_huge_tlb_entry(h, tlb, ptep, address) \
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tlb_remove_tlb_entry(tlb, ptep, address)
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/*
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* In the case of tlb vma handling, we can optimise these away in the
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* case where we're doing a full MM flush. When we're doing a munmap,
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* the vmas are adjusted to only cover the region to be torn down.
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*/
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static inline void
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tlb_start_vma(struct mmu_gather *tlb, struct vm_area_struct *vma)
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{
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if (!tlb->fullmm) {
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flush_cache_range(vma, vma->vm_start, vma->vm_end);
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tlb->vma = vma;
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tlb->range_start = TASK_SIZE;
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tlb->range_end = 0;
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}
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}
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static inline void
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tlb_end_vma(struct mmu_gather *tlb, struct vm_area_struct *vma)
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{
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if (!tlb->fullmm)
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tlb_flush(tlb);
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}
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static inline bool __tlb_remove_page(struct mmu_gather *tlb, struct page *page)
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{
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tlb->pages[tlb->nr++] = page;
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VM_WARN_ON(tlb->nr > tlb->max);
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if (tlb->nr == tlb->max)
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return true;
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return false;
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}
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static inline void tlb_remove_page(struct mmu_gather *tlb, struct page *page)
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{
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if (__tlb_remove_page(tlb, page))
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tlb_flush_mmu(tlb);
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}
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static inline bool __tlb_remove_page_size(struct mmu_gather *tlb,
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struct page *page, int page_size)
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{
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return __tlb_remove_page(tlb, page);
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}
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static inline void tlb_remove_page_size(struct mmu_gather *tlb,
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struct page *page, int page_size)
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{
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return tlb_remove_page(tlb, page);
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}
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static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t pte,
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unsigned long addr)
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__pte_free_tlb(struct mmu_gather *tlb, pgtable_t pte, unsigned long addr)
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{
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pgtable_page_dtor(pte);
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#ifdef CONFIG_ARM_LPAE
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tlb_add_flush(tlb, addr);
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#else
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#ifndef CONFIG_ARM_LPAE
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/*
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* With the classic ARM MMU, a pte page has two corresponding pmd
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* entries, each covering 1MB.
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*/
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addr &= PMD_MASK;
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tlb_add_flush(tlb, addr + SZ_1M - PAGE_SIZE);
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tlb_add_flush(tlb, addr + SZ_1M);
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addr = (addr & PMD_MASK) + SZ_1M;
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__tlb_adjust_range(tlb, addr - PAGE_SIZE, 2 * PAGE_SIZE);
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#endif
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tlb_remove_entry(tlb, pte);
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}
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static inline void __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmdp,
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unsigned long addr)
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{
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#ifdef CONFIG_ARM_LPAE
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tlb_add_flush(tlb, addr);
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tlb_remove_entry(tlb, virt_to_page(pmdp));
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#endif
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tlb_remove_table(tlb, pte);
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}
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static inline void
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tlb_remove_pmd_tlb_entry(struct mmu_gather *tlb, pmd_t *pmdp, unsigned long addr)
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__pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmdp, unsigned long addr)
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{
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tlb_add_flush(tlb, addr);
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}
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#ifdef CONFIG_ARM_LPAE
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struct page *page = virt_to_page(pmdp);
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#define pte_free_tlb(tlb, ptep, addr) __pte_free_tlb(tlb, ptep, addr)
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#define pmd_free_tlb(tlb, pmdp, addr) __pmd_free_tlb(tlb, pmdp, addr)
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#define pud_free_tlb(tlb, pudp, addr) pud_free((tlb)->mm, pudp)
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#define tlb_migrate_finish(mm) do { } while (0)
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static inline void tlb_change_page_size(struct mmu_gather *tlb,
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unsigned int page_size)
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{
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}
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static inline void tlb_flush_remove_tables(struct mm_struct *mm)
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{
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}
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static inline void tlb_flush_remove_tables_local(void *arg)
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{
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tlb_remove_table(tlb, page);
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#endif
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}
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#endif /* CONFIG_MMU */
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