[linux.git] / mm / swap.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _MM_SWAP_H
#define _MM_SWAP_H

struct mempolicy;

#ifdef CONFIG_SWAP
#include <linux/swapops.h> /* for swp_offset */
#include <linux/blk_types.h> /* for bio_end_io_t */

/* linux/mm/page_io.c */
int sio_pool_init(void);
struct swap_iocb;
void swap_read_folio(struct folio *folio, 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 __swap_writepage(struct folio *folio, struct writeback_control *wbc);

/* 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)
#define SWAP_ADDRESS_SPACE_MASK		(SWAP_ADDRESS_SPACE_PAGES - 1)
extern struct address_space *swapper_spaces[];
#define swap_address_space(entry)			    \
	(&swapper_spaces[swp_type(entry)][swp_offset(entry) \
		>> SWAP_ADDRESS_SPACE_SHIFT])

/*
 * Return the swap device position of the swap entry.
 */
static inline loff_t swap_dev_pos(swp_entry_t entry)
{
	return ((loff_t)swp_offset(entry)) << PAGE_SHIFT;
}

/*
 * Return the swap cache index of the swap entry.
 */
static inline pgoff_t swap_cache_index(swp_entry_t entry)
{
	BUILD_BUG_ON((SWP_OFFSET_MASK | SWAP_ADDRESS_SPACE_MASK) != SWP_OFFSET_MASK);
	return swp_offset(entry) & SWAP_ADDRESS_SPACE_MASK;
}

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 folio *folio, swp_entry_t entry,
		      gfp_t gfp, void **shadowp);
void __delete_from_swap_cache(struct folio *folio,
			      swp_entry_t entry, void *shadow);
void delete_from_swap_cache(struct folio *folio);
void clear_shadow_from_swap_cache(int type, unsigned long begin,
				  unsigned long end);
void swapcache_clear(struct swap_info_struct *si, swp_entry_t entry);
struct folio *swap_cache_get_folio(swp_entry_t entry,
		struct vm_area_struct *vma, unsigned long addr);
struct folio *filemap_get_incore_folio(struct address_space *mapping,
		pgoff_t index);

struct folio *read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
		struct vm_area_struct *vma, unsigned long addr,
		struct swap_iocb **plug);
struct folio *__read_swap_cache_async(swp_entry_t entry, gfp_t gfp_flags,
		struct mempolicy *mpol, pgoff_t ilx, bool *new_page_allocated,
		bool skip_if_exists);
struct folio *swap_cluster_readahead(swp_entry_t entry, gfp_t flag,
		struct mempolicy *mpol, pgoff_t ilx);
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 swp_swap_info(folio->swap)->flags;
}
#else /* CONFIG_SWAP */
struct swap_iocb;
static inline void swap_read_folio(struct folio *folio, struct swap_iocb **plug)
{
}
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 pgoff_t swap_cache_index(swp_entry_t entry)
{
	return 0;
}

static inline void show_swap_cache_info(void)
{
}

static inline struct folio *swap_cluster_readahead(swp_entry_t entry,
			gfp_t gfp_mask, struct mempolicy *mpol, pgoff_t ilx)
{
	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 void swapcache_clear(struct swap_info_struct *si, swp_entry_t entry)
{
}

static inline struct folio *swap_cache_get_folio(swp_entry_t entry,
		struct vm_area_struct *vma, unsigned long addr)
{
	return NULL;
}

static inline
struct folio *filemap_get_incore_folio(struct address_space *mapping,
		pgoff_t index)
{
	return filemap_get_folio(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 folio *folio, swp_entry_t entry,
					gfp_t gfp_mask, void **shadowp)
{
	return -1;
}

static inline void __delete_from_swap_cache(struct folio *folio,
					swp_entry_t entry, void *shadow)
{
}

static inline void delete_from_swap_cache(struct folio *folio)
{
}

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 */
Commit	Line	Data
014bb1de N	1	/* SPDX-License-Identifier: GPL-2.0 */
	2	#ifndef _MM_SWAP_H
	3	#define _MM_SWAP_H
	4
ddc1a5cb HD	5	struct mempolicy;
ddc1a5cb HD	6
014bb1de	7	#ifdef CONFIG_SWAP
545ebe71	8	#include <linux/swapops.h> /* for swp_offset */
014bb1de N	9	#include <linux/blk_types.h> /* for bio_end_io_t */
	10
	11	/* linux/mm/page_io.c */
e1209d3a	12	int sio_pool_init(void);
5169b844	13	struct swap_iocb;
b2d1f38b	14	void swap_read_folio(struct folio folio, struct swap_iocb *plug);
5169b844 N	15	void __swap_read_unplug(struct swap_iocb *plug);
	16	static inline void swap_read_unplug(struct swap_iocb *plug)
	17	{
	18	if (unlikely(plug))
	19	__swap_read_unplug(plug);
	20	}
2282679f	21	void swap_write_unplug(struct swap_iocb *sio);
014bb1de	22	int swap_writepage(struct page page, struct writeback_control wbc);
b99b4e0d	23	void __swap_writepage(struct folio folio, struct writeback_control wbc);
014bb1de N	24
	25	/* linux/mm/swap_state.c */
	26	/* One swap address space for each 64M swap space */
	27	#define SWAP_ADDRESS_SPACE_SHIFT 14
	28	#define SWAP_ADDRESS_SPACE_PAGES (1 << SWAP_ADDRESS_SPACE_SHIFT)
7aad25b4	29	#define SWAP_ADDRESS_SPACE_MASK (SWAP_ADDRESS_SPACE_PAGES - 1)
014bb1de N	30	extern struct address_space *swapper_spaces[];
	31	#define swap_address_space(entry) \
	32	(&swapper_spaces[swp_type(entry)][swp_offset(entry) \
	33	>> SWAP_ADDRESS_SPACE_SHIFT])
	34
545ebe71 KS	35	/*
	36	* Return the swap device position of the swap entry.
	37	*/
	38	static inline loff_t swap_dev_pos(swp_entry_t entry)
	39	{
	40	return ((loff_t)swp_offset(entry)) << PAGE_SHIFT;
	41	}
	42
7aad25b4 KS	43	/*
	44	* Return the swap cache index of the swap entry.
	45	*/
	46	static inline pgoff_t swap_cache_index(swp_entry_t entry)
	47	{
	48	BUILD_BUG_ON((SWP_OFFSET_MASK \| SWAP_ADDRESS_SPACE_MASK) != SWP_OFFSET_MASK);
	49	return swp_offset(entry) & SWAP_ADDRESS_SPACE_MASK;
	50	}
	51
014bb1de	52	void show_swap_cache_info(void);
09c02e56	53	bool add_to_swap(struct folio *folio);
014bb1de	54	void *get_shadow_from_swap_cache(swp_entry_t entry);
a4c366f0	55	int add_to_swap_cache(struct folio *folio, swp_entry_t entry,
014bb1de	56	gfp_t gfp, void **shadowp);
ceff9d33	57	void __delete_from_swap_cache(struct folio *folio,
014bb1de	58	swp_entry_t entry, void *shadow);
75fa68a5	59	void delete_from_swap_cache(struct folio *folio);
014bb1de N	60	void clear_shadow_from_swap_cache(int type, unsigned long begin,
014bb1de N	61	unsigned long end);
13ddaf26	62	void swapcache_clear(struct swap_info_struct *si, swp_entry_t entry);
c9edc242 MWO	63	struct folio *swap_cache_get_folio(swp_entry_t entry,
c9edc242 MWO	64	struct vm_area_struct *vma, unsigned long addr);
524984ff MWO	65	struct folio filemap_get_incore_folio(struct address_space mapping,
524984ff MWO	66	pgoff_t index);
014bb1de	67
6e03492e MWO	68	struct folio *read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
	69	struct vm_area_struct *vma, unsigned long addr,
	70	struct swap_iocb **plug);
96c7b0b4 MWO	71	struct folio *__read_swap_cache_async(swp_entry_t entry, gfp_t gfp_flags,
	72	struct mempolicy mpol, pgoff_t ilx, bool new_page_allocated,
	73	bool skip_if_exists);
a4575c41 MWO	74	struct folio *swap_cluster_readahead(swp_entry_t entry, gfp_t flag,
a4575c41 MWO	75	struct mempolicy *mpol, pgoff_t ilx);
014bb1de N	76	struct page *swapin_readahead(swp_entry_t entry, gfp_t flag,
	77	struct vm_fault *vmf);
	78
b98c359f	79	static inline unsigned int folio_swap_flags(struct folio *folio)
d791ea67	80	{
69fe7d67	81	return swp_swap_info(folio->swap)->flags;
d791ea67	82	}
014bb1de	83	#else /* CONFIG_SWAP */
5169b844	84	struct swap_iocb;
b2d1f38b	85	static inline void swap_read_folio(struct folio folio, struct swap_iocb *plug)
014bb1de	86	{
014bb1de	87	}
2282679f N	88	static inline void swap_write_unplug(struct swap_iocb *sio)
	89	{
	90	}
014bb1de N	91
	92	static inline struct address_space *swap_address_space(swp_entry_t entry)
	93	{
	94	return NULL;
	95	}
	96
7aad25b4 KS	97	static inline pgoff_t swap_cache_index(swp_entry_t entry)
	98	{
	99	return 0;
	100	}
	101
014bb1de N	102	static inline void show_swap_cache_info(void)
	103	{
	104	}
	105
a4575c41	106	static inline struct folio *swap_cluster_readahead(swp_entry_t entry,
ddc1a5cb	107	gfp_t gfp_mask, struct mempolicy *mpol, pgoff_t ilx)
014bb1de N	108	{
	109	return NULL;
	110	}
	111
	112	static inline struct page *swapin_readahead(swp_entry_t swp, gfp_t gfp_mask,
	113	struct vm_fault *vmf)
	114	{
	115	return NULL;
	116	}
	117
	118	static inline int swap_writepage(struct page p, struct writeback_control wbc)
	119	{
	120	return 0;
	121	}
	122
13ddaf26 KS	123	static inline void swapcache_clear(struct swap_info_struct *si, swp_entry_t entry)
	124	{
	125	}
	126
c9edc242 MWO	127	static inline struct folio *swap_cache_get_folio(swp_entry_t entry,
	128	struct vm_area_struct *vma, unsigned long addr)
	129	{
	130	return NULL;
	131	}
	132
014bb1de	133	static inline
524984ff MWO	134	struct folio filemap_get_incore_folio(struct address_space mapping,
524984ff MWO	135	pgoff_t index)
014bb1de	136	{
524984ff	137	return filemap_get_folio(mapping, index);
014bb1de N	138	}
014bb1de N	139
09c02e56	140	static inline bool add_to_swap(struct folio *folio)
014bb1de	141	{
09c02e56	142	return false;
014bb1de N	143	}
	144
	145	static inline void *get_shadow_from_swap_cache(swp_entry_t entry)
	146	{
	147	return NULL;
	148	}
	149
a4c366f0	150	static inline int add_to_swap_cache(struct folio *folio, swp_entry_t entry,
014bb1de N	151	gfp_t gfp_mask, void **shadowp)
	152	{
	153	return -1;
	154	}
	155
ceff9d33	156	static inline void __delete_from_swap_cache(struct folio *folio,
014bb1de N	157	swp_entry_t entry, void *shadow)
	158	{
	159	}
	160
75fa68a5	161	static inline void delete_from_swap_cache(struct folio *folio)
014bb1de N	162	{
	163	}
	164
	165	static inline void clear_shadow_from_swap_cache(int type, unsigned long begin,
	166	unsigned long end)
	167	{
	168	}
	169
b98c359f	170	static inline unsigned int folio_swap_flags(struct folio *folio)
d791ea67 N	171	{
	172	return 0;
	173	}
014bb1de N	174	#endif /* CONFIG_SWAP */
014bb1de N	175	#endif /* _MM_SWAP_H */