126 lines
3.4 KiB
C
126 lines
3.4 KiB
C
#ifndef _LINUX_RMAP_H
|
|
#define _LINUX_RMAP_H
|
|
/*
|
|
* Declarations for Reverse Mapping functions in mm/rmap.c
|
|
*/
|
|
|
|
#include <linux/list.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/spinlock.h>
|
|
|
|
/*
|
|
* The anon_vma heads a list of private "related" vmas, to scan if
|
|
* an anonymous page pointing to this anon_vma needs to be unmapped:
|
|
* the vmas on the list will be related by forking, or by splitting.
|
|
*
|
|
* Since vmas come and go as they are split and merged (particularly
|
|
* in mprotect), the mapping field of an anonymous page cannot point
|
|
* directly to a vma: instead it points to an anon_vma, on whose list
|
|
* the related vmas can be easily linked or unlinked.
|
|
*
|
|
* After unlinking the last vma on the list, we must garbage collect
|
|
* the anon_vma object itself: we're guaranteed no page can be
|
|
* pointing to this anon_vma once its vma list is empty.
|
|
*/
|
|
struct anon_vma {
|
|
spinlock_t lock; /* Serialize access to vma list */
|
|
struct list_head head; /* List of private "related" vmas */
|
|
};
|
|
|
|
#ifdef CONFIG_MMU
|
|
|
|
extern kmem_cache_t *anon_vma_cachep;
|
|
|
|
static inline struct anon_vma *anon_vma_alloc(void)
|
|
{
|
|
return kmem_cache_alloc(anon_vma_cachep, SLAB_KERNEL);
|
|
}
|
|
|
|
static inline void anon_vma_free(struct anon_vma *anon_vma)
|
|
{
|
|
kmem_cache_free(anon_vma_cachep, anon_vma);
|
|
}
|
|
|
|
static inline void anon_vma_lock(struct vm_area_struct *vma)
|
|
{
|
|
struct anon_vma *anon_vma = vma->anon_vma;
|
|
if (anon_vma)
|
|
spin_lock(&anon_vma->lock);
|
|
}
|
|
|
|
static inline void anon_vma_unlock(struct vm_area_struct *vma)
|
|
{
|
|
struct anon_vma *anon_vma = vma->anon_vma;
|
|
if (anon_vma)
|
|
spin_unlock(&anon_vma->lock);
|
|
}
|
|
|
|
/*
|
|
* anon_vma helper functions.
|
|
*/
|
|
void anon_vma_init(void); /* create anon_vma_cachep */
|
|
int anon_vma_prepare(struct vm_area_struct *);
|
|
void __anon_vma_merge(struct vm_area_struct *, struct vm_area_struct *);
|
|
void anon_vma_unlink(struct vm_area_struct *);
|
|
void anon_vma_link(struct vm_area_struct *);
|
|
void __anon_vma_link(struct vm_area_struct *);
|
|
|
|
/*
|
|
* rmap interfaces called when adding or removing pte of page
|
|
*/
|
|
void page_add_anon_rmap(struct page *, struct vm_area_struct *, unsigned long);
|
|
void page_add_new_anon_rmap(struct page *, struct vm_area_struct *, unsigned long);
|
|
void page_add_file_rmap(struct page *);
|
|
void page_remove_rmap(struct page *);
|
|
|
|
/**
|
|
* page_dup_rmap - duplicate pte mapping to a page
|
|
* @page: the page to add the mapping to
|
|
*
|
|
* For copy_page_range only: minimal extract from page_add_rmap,
|
|
* avoiding unnecessary tests (already checked) so it's quicker.
|
|
*/
|
|
static inline void page_dup_rmap(struct page *page)
|
|
{
|
|
atomic_inc(&page->_mapcount);
|
|
}
|
|
|
|
/*
|
|
* Called from mm/vmscan.c to handle paging out
|
|
*/
|
|
int page_referenced(struct page *, int is_locked);
|
|
int try_to_unmap(struct page *, int ignore_refs);
|
|
void remove_from_swap(struct page *page);
|
|
|
|
/*
|
|
* Called from mm/filemap_xip.c to unmap empty zero page
|
|
*/
|
|
pte_t *page_check_address(struct page *, struct mm_struct *,
|
|
unsigned long, spinlock_t **);
|
|
|
|
/*
|
|
* Used by swapoff to help locate where page is expected in vma.
|
|
*/
|
|
unsigned long page_address_in_vma(struct page *, struct vm_area_struct *);
|
|
|
|
#else /* !CONFIG_MMU */
|
|
|
|
#define anon_vma_init() do {} while (0)
|
|
#define anon_vma_prepare(vma) (0)
|
|
#define anon_vma_link(vma) do {} while (0)
|
|
|
|
#define page_referenced(page,l) TestClearPageReferenced(page)
|
|
#define try_to_unmap(page, refs) SWAP_FAIL
|
|
|
|
#endif /* CONFIG_MMU */
|
|
|
|
/*
|
|
* Return values of try_to_unmap
|
|
*/
|
|
#define SWAP_SUCCESS 0
|
|
#define SWAP_AGAIN 1
|
|
#define SWAP_FAIL 2
|
|
|
|
#endif /* _LINUX_RMAP_H */
|