include/asm-generic/tlb.h

/* include/asm-generic/tlb.h
 *
 *	Generic TLB shootdown code
 *
 * Copyright 2001 Red Hat, Inc.
 * Based on code from mm/memory.c Copyright Linus Torvalds and others.
 *
 * Copyright 2011 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */
#ifndef _ASM_GENERIC__TLB_H
#define _ASM_GENERIC__TLB_H

#include <linux/swap.h>
#include <asm/pgalloc.h>
#include <asm/tlbflush.h>

#ifdef CONFIG_HAVE_RCU_TABLE_FREE
struct mmu_table_batch {
	struct rcu_head		rcu;
	unsigned int		nr;
	void			*tables[0];
};

#define MAX_TABLE_BATCH		\
	((PAGE_SIZE - sizeof(struct mmu_table_batch)) / sizeof(void *))

extern void tlb_table_flush(struct mmu_gather *tlb);
extern void tlb_remove_table(struct mmu_gather *tlb, void *table);

#endif

#define MMU_GATHER_BUNDLE	8

struct mmu_gather_batch {
	struct mmu_gather_batch	*next;
	unsigned int		nr;
	unsigned int		max;
	struct page		*pages[0];
};

#define MAX_GATHER_BATCH	\
	((PAGE_SIZE - sizeof(struct mmu_gather_batch)) / sizeof(void *))

struct mmu_gather {
	struct mm_struct	*mm;
#ifdef CONFIG_HAVE_RCU_TABLE_FREE
	struct mmu_table_batch	*batch;
#endif
	unsigned int		need_flush : 1,	
				fast_mode  : 1; 

	unsigned int		fullmm;

	struct mmu_gather_batch *active;
	struct mmu_gather_batch	local;
	struct page		*__pages[MMU_GATHER_BUNDLE];
};

#define HAVE_GENERIC_MMU_GATHER

static inline int tlb_fast_mode(struct mmu_gather *tlb)
{
#ifdef CONFIG_SMP
	return tlb->fast_mode;
#else
	return 1;
#endif
}

void tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm, bool fullmm);
void tlb_flush_mmu(struct mmu_gather *tlb);
void tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end);
int __tlb_remove_page(struct mmu_gather *tlb, struct page *page);

static inline void tlb_remove_page(struct mmu_gather *tlb, struct page *page)
{
	if (!__tlb_remove_page(tlb, page))
		tlb_flush_mmu(tlb);
}

#define tlb_remove_tlb_entry(tlb, ptep, address)		\
	do {							\
		tlb->need_flush = 1;				\
		__tlb_remove_tlb_entry(tlb, ptep, address);	\
	} while (0)

#ifndef __tlb_remove_pmd_tlb_entry
#define __tlb_remove_pmd_tlb_entry(tlb, pmdp, address) do {} while (0)
#endif

#define tlb_remove_pmd_tlb_entry(tlb, pmdp, address)		\
	do {							\
		tlb->need_flush = 1;				\
		__tlb_remove_pmd_tlb_entry(tlb, pmdp, address);	\
	} while (0)

#define pte_free_tlb(tlb, ptep, address)			\
	do {							\
		tlb->need_flush = 1;				\
		__pte_free_tlb(tlb, ptep, address);		\
	} while (0)

#ifndef __ARCH_HAS_4LEVEL_HACK
#define pud_free_tlb(tlb, pudp, address)			\
	do {							\
		tlb->need_flush = 1;				\
		__pud_free_tlb(tlb, pudp, address);		\
	} while (0)
#endif

#define pmd_free_tlb(tlb, pmdp, address)			\
	do {							\
		tlb->need_flush = 1;				\
		__pmd_free_tlb(tlb, pmdp, address);		\
	} while (0)

#define tlb_migrate_finish(mm) do {} while (0)

#endif