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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _MM_SWAP_H
#define _MM_SWAP_H
#ifdef CONFIG_SWAP
#include <linux/blk_types.h> /* for bio_end_io_t */
/* linux/mm/page_io.c */
int sio_pool_init(void);
struct swap_iocb;
int swap_readpage(struct page *page, bool do_poll,
struct swap_iocb **plug);
void __swap_read_unplug(struct swap_iocb *plug);
static inline void swap_read_unplug(struct swap_iocb *plug)
{
if (unlikely(plug))
__swap_read_unplug(plug);
}
void swap_write_unplug(struct swap_iocb *sio);
int swap_writepage(struct page *page, struct writeback_control *wbc);
void end_swap_bio_write(struct bio *bio);
int __swap_writepage(struct page *page, struct writeback_control *wbc,
bio_end_io_t end_write_func);
/* linux/mm/swap_state.c */
/* One swap address space for each 64M swap space */
#define SWAP_ADDRESS_SPACE_SHIFT 14
#define SWAP_ADDRESS_SPACE_PAGES (1 << SWAP_ADDRESS_SPACE_SHIFT)
extern struct address_space *swapper_spaces[];
#define swap_address_space(entry) \
(&swapper_spaces[swp_type(entry)][swp_offset(entry) \
>> SWAP_ADDRESS_SPACE_SHIFT])
void show_swap_cache_info(void);
bool add_to_swap(struct folio *folio);
void *get_shadow_from_swap_cache(swp_entry_t entry);
int add_to_swap_cache(struct page *page, swp_entry_t entry,
gfp_t gfp, void **shadowp);
void __delete_from_swap_cache(struct page *page,
swp_entry_t entry, void *shadow);
void delete_from_swap_cache(struct page *page);
void clear_shadow_from_swap_cache(int type, unsigned long begin,
unsigned long end);
void free_swap_cache(struct page *page);
struct page *lookup_swap_cache(swp_entry_t entry,
struct vm_area_struct *vma,
unsigned long addr);
struct page *find_get_incore_page(struct address_space *mapping, pgoff_t index);
struct page *read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
struct vm_area_struct *vma,
unsigned long addr,
bool do_poll,
struct swap_iocb **plug);
struct page *__read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
struct vm_area_struct *vma,
unsigned long addr,
bool *new_page_allocated);
struct page *swap_cluster_readahead(swp_entry_t entry, gfp_t flag,
struct vm_fault *vmf);
struct page *swapin_readahead(swp_entry_t entry, gfp_t flag,
struct vm_fault *vmf);
static inline unsigned int folio_swap_flags(struct folio *folio)
{
return page_swap_info(&folio->page)->flags;
}
#else /* CONFIG_SWAP */
struct swap_iocb;
static inline int swap_readpage(struct page *page, bool do_poll,
struct swap_iocb **plug)
{
return 0;
}
static inline void swap_write_unplug(struct swap_iocb *sio)
{
}
static inline struct address_space *swap_address_space(swp_entry_t entry)
{
return NULL;
}
static inline void free_swap_cache(struct page *page)
{
}
static inline void show_swap_cache_info(void)
{
}
static inline struct page *swap_cluster_readahead(swp_entry_t entry,
gfp_t gfp_mask, struct vm_fault *vmf)
{
return NULL;
}
static inline struct page *swapin_readahead(swp_entry_t swp, gfp_t gfp_mask,
struct vm_fault *vmf)
{
return NULL;
}
static inline int swap_writepage(struct page *p, struct writeback_control *wbc)
{
return 0;
}
static inline struct page *lookup_swap_cache(swp_entry_t swp,
struct vm_area_struct *vma,
unsigned long addr)
{
return NULL;
}
static inline
struct page *find_get_incore_page(struct address_space *mapping, pgoff_t index)
{
return find_get_page(mapping, index);
}
static inline bool add_to_swap(struct folio *folio)
{
return false;
}
static inline void *get_shadow_from_swap_cache(swp_entry_t entry)
{
return NULL;
}
static inline int add_to_swap_cache(struct page *page, swp_entry_t entry,
gfp_t gfp_mask, void **shadowp)
{
return -1;
}
static inline void __delete_from_swap_cache(struct page *page,
swp_entry_t entry, void *shadow)
{
}
static inline void delete_from_swap_cache(struct page *page)
{
}
static inline void clear_shadow_from_swap_cache(int type, unsigned long begin,
unsigned long end)
{
}
static inline unsigned int folio_swap_flags(struct folio *folio)
{
return 0;
}
#endif /* CONFIG_SWAP */
#endif /* _MM_SWAP_H */
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