1/* SPDX-License-Identifier: GPL-2.0 */
 2#ifndef __UM_TLB_H
 3#define __UM_TLB_H
 4
 5#include <linux/mm.h>
 6
 
 
 7#include <asm/tlbflush.h>
 8#include <asm/cacheflush.h>
 9#include <asm-generic/tlb.h>
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
10
11#endif

 
  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 long start, unsigned long end)
 49{
 50	tlb->mm = mm;
 51	tlb->start = start;
 52	tlb->end = end;
 53	tlb->fullmm = !(start | (end+1));
 54
 55	init_tlb_gather(tlb);
 56}
 57
 58extern void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start,
 59			       unsigned long end);
 60
 61static inline void
 62tlb_flush_mmu_tlbonly(struct mmu_gather *tlb)
 63{
 64	flush_tlb_mm_range(tlb->mm, tlb->start, tlb->end);
 65}
 66
 67static inline void
 68tlb_flush_mmu_free(struct mmu_gather *tlb)
 69{
 70	init_tlb_gather(tlb);
 71}
 72
 73static inline void
 74tlb_flush_mmu(struct mmu_gather *tlb)
 75{
 76	if (!tlb->need_flush)
 77		return;
 78
 79	tlb_flush_mmu_tlbonly(tlb);
 80	tlb_flush_mmu_free(tlb);
 81}
 82
 83/* tlb_finish_mmu
 84 *	Called at the end of the shootdown operation to free up any resources
 85 *	that were required.
 86 */
 87static inline void
 88tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end)
 89{
 90	tlb_flush_mmu(tlb);
 91
 92	/* keep the page table cache within bounds */
 93	check_pgt_cache();
 94}
 95
 96/* tlb_remove_page
 97 *	Must perform the equivalent to __free_pte(pte_get_and_clear(ptep)),
 98 *	while handling the additional races in SMP caused by other CPUs
 99 *	caching valid mappings in their TLBs.
100 */
101static inline int __tlb_remove_page(struct mmu_gather *tlb, struct page *page)
102{
103	tlb->need_flush = 1;
104	free_page_and_swap_cache(page);
105	return 1; /* avoid calling tlb_flush_mmu */
106}
107
108static inline void tlb_remove_page(struct mmu_gather *tlb, struct page *page)
109{
110	__tlb_remove_page(tlb, page);
111}
112
113/**
114 * tlb_remove_tlb_entry - remember a pte unmapping for later tlb invalidation.
115 *
116 * Record the fact that pte's were really umapped in ->need_flush, so we can
117 * later optimise away the tlb invalidate.   This helps when userspace is
118 * unmapping already-unmapped pages, which happens quite a lot.
119 */
120#define tlb_remove_tlb_entry(tlb, ptep, address)		\
121	do {							\
122		tlb->need_flush = 1;				\
123		__tlb_remove_tlb_entry(tlb, ptep, address);	\
124	} while (0)
125
126#define pte_free_tlb(tlb, ptep, addr) __pte_free_tlb(tlb, ptep, addr)
127
128#define pud_free_tlb(tlb, pudp, addr) __pud_free_tlb(tlb, pudp, addr)
129
130#define pmd_free_tlb(tlb, pmdp, addr) __pmd_free_tlb(tlb, pmdp, addr)
131
132#define tlb_migrate_finish(mm) do {} while (0)
133
134#endif