1#ifndef __UM_TLB_H
  2#define __UM_TLB_H
  3
  4#include <linux/pagemap.h>
  5#include <linux/swap.h>
  6#include <asm/percpu.h>
  7#include <asm/pgalloc.h>
  8#include <asm/tlbflush.h>
  9
 10#define tlb_start_vma(tlb, vma) do { } while (0)
 11#define tlb_end_vma(tlb, vma) do { } while (0)
 12#define tlb_flush(tlb) flush_tlb_mm((tlb)->mm)
 13
 14/* struct mmu_gather is an opaque type used by the mm code for passing around
 15 * any data needed by arch specific code for tlb_remove_page.
 16 */
 17struct mmu_gather {
 18	struct mm_struct	*mm;
 19	unsigned int		need_flush; /* Really unmapped some ptes? */
 20	unsigned long		start;
 21	unsigned long		end;
 22	unsigned int		fullmm; /* non-zero means full mm flush */
 23};
 24
 25static inline void __tlb_remove_tlb_entry(struct mmu_gather *tlb, pte_t *ptep,
 26					  unsigned long address)
 27{
 28	if (tlb->start > address)
 29		tlb->start = address;
 30	if (tlb->end < address + PAGE_SIZE)
 31		tlb->end = address + PAGE_SIZE;
 32}
 33
 34static inline void init_tlb_gather(struct mmu_gather *tlb)
 35{
 36	tlb->need_flush = 0;
 37
 38	tlb->start = TASK_SIZE;
 39	tlb->end = 0;
 40
 41	if (tlb->fullmm) {
 42		tlb->start = 0;
 43		tlb->end = TASK_SIZE;
 44	}
 45}
 46
 47static inline void
 48tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm, unsigned int full_mm_flush)
 49{
 50	tlb->mm = mm;
 51	tlb->fullmm = full_mm_flush;
 52
 53	init_tlb_gather(tlb);
 54}
 55
 56extern void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start,
 57			       unsigned long end);
 58
 59static inline void
 60tlb_flush_mmu(struct mmu_gather *tlb)
 61{
 62	if (!tlb->need_flush)
 63		return;
 64
 65	flush_tlb_mm_range(tlb->mm, tlb->start, tlb->end);
 66	init_tlb_gather(tlb);
 67}
 68
 69/* tlb_finish_mmu
 70 *	Called at the end of the shootdown operation to free up any resources
 71 *	that were required.
 72 */
 73static inline void
 74tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end)
 75{
 76	tlb_flush_mmu(tlb);
 77
 78	/* keep the page table cache within bounds */
 79	check_pgt_cache();
 80}
 81
 82/* tlb_remove_page
 83 *	Must perform the equivalent to __free_pte(pte_get_and_clear(ptep)),
 84 *	while handling the additional races in SMP caused by other CPUs
 85 *	caching valid mappings in their TLBs.
 86 */
 87static inline int __tlb_remove_page(struct mmu_gather *tlb, struct page *page)
 88{
 89	tlb->need_flush = 1;
 90	free_page_and_swap_cache(page);
 91	return 1; /* avoid calling tlb_flush_mmu */
 92}
 93
 94static inline void tlb_remove_page(struct mmu_gather *tlb, struct page *page)
 95{
 96	__tlb_remove_page(tlb, page);
 97}
 98
 99/**
100 * tlb_remove_tlb_entry - remember a pte unmapping for later tlb invalidation.
101 *
102 * Record the fact that pte's were really umapped in ->need_flush, so we can
103 * later optimise away the tlb invalidate.   This helps when userspace is
104 * unmapping already-unmapped pages, which happens quite a lot.
105 */
106#define tlb_remove_tlb_entry(tlb, ptep, address)		\
107	do {							\
108		tlb->need_flush = 1;				\
109		__tlb_remove_tlb_entry(tlb, ptep, address);	\
110	} while (0)
111
112#define pte_free_tlb(tlb, ptep, addr) __pte_free_tlb(tlb, ptep, addr)
113
114#define pud_free_tlb(tlb, pudp, addr) __pud_free_tlb(tlb, pudp, addr)
115
116#define pmd_free_tlb(tlb, pmdp, addr) __pmd_free_tlb(tlb, pmdp, addr)
117
118#define tlb_migrate_finish(mm) do {} while (0)
119
120#endif