[linux-2.6-block.git] / fs / squashfs / page_actor.h

/* SPDX-License-Identifier: GPL-2.0-only */
#ifndef PAGE_ACTOR_H
#define PAGE_ACTOR_H
/*
 * Copyright (c) 2013
 * Phillip Lougher <phillip@squashfs.org.uk>
 */

#ifndef CONFIG_SQUASHFS_FILE_DIRECT
struct squashfs_page_actor {
	void	**page;
	int	pages;
	int	length;
	int	next_page;
};

static inline struct squashfs_page_actor *squashfs_page_actor_init(void **page,
	int pages, int length)
{
	struct squashfs_page_actor *actor = kmalloc(sizeof(*actor), GFP_KERNEL);

	if (actor == NULL)
		return NULL;

	actor->length = length ? : pages * PAGE_SIZE;
	actor->page = page;
	actor->pages = pages;
	actor->next_page = 0;
	return actor;
}

static inline void *squashfs_first_page(struct squashfs_page_actor *actor)
{
	actor->next_page = 1;
	return actor->page[0];
}

static inline void *squashfs_next_page(struct squashfs_page_actor *actor)
{
	return actor->next_page == actor->pages ? NULL :
		actor->page[actor->next_page++];
}

static inline void squashfs_finish_page(struct squashfs_page_actor *actor)
{
	/* empty */
}
#else
struct squashfs_page_actor {
	union {
		void		**buffer;
		struct page	**page;
	};
	void	*pageaddr;
	void    *(*squashfs_first_page)(struct squashfs_page_actor *);
	void    *(*squashfs_next_page)(struct squashfs_page_actor *);
	void    (*squashfs_finish_page)(struct squashfs_page_actor *);
	int	pages;
	int	length;
	int	next_page;
};

extern struct squashfs_page_actor *squashfs_page_actor_init(void **, int, int);
extern struct squashfs_page_actor *squashfs_page_actor_init_special(struct page
							 **, int, int);
static inline void *squashfs_first_page(struct squashfs_page_actor *actor)
{
	return actor->squashfs_first_page(actor);
}
static inline void *squashfs_next_page(struct squashfs_page_actor *actor)
{
	return actor->squashfs_next_page(actor);
}
static inline void squashfs_finish_page(struct squashfs_page_actor *actor)
{
	actor->squashfs_finish_page(actor);
}
#endif
#endif
Commit	Line	Data
20c8ccb1	1	/* SPDX-License-Identifier: GPL-2.0-only */
846b730e PL	2	#ifndef PAGE_ACTOR_H
	3	#define PAGE_ACTOR_H
	4	/*
	5	* Copyright (c) 2013
	6	* Phillip Lougher <phillip@squashfs.org.uk>
846b730e PL	7	*/
846b730e PL	8
0d455c12	9	#ifndef CONFIG_SQUASHFS_FILE_DIRECT
846b730e PL	10	struct squashfs_page_actor {
	11	void **page;
	12	int pages;
	13	int length;
	14	int next_page;
	15	};
	16
	17	static inline struct squashfs_page_actor squashfs_page_actor_init(void *page,
	18	int pages, int length)
	19	{
	20	struct squashfs_page_actor actor = kmalloc(sizeof(actor), GFP_KERNEL);
	21
	22	if (actor == NULL)
	23	return NULL;
	24
09cbfeaf	25	actor->length = length ? : pages * PAGE_SIZE;
846b730e PL	26	actor->page = page;
	27	actor->pages = pages;
	28	actor->next_page = 0;
	29	return actor;
	30	}
	31
	32	static inline void squashfs_first_page(struct squashfs_page_actor actor)
	33	{
	34	actor->next_page = 1;
	35	return actor->page[0];
	36	}
	37
	38	static inline void squashfs_next_page(struct squashfs_page_actor actor)
	39	{
	40	return actor->next_page == actor->pages ? NULL :
	41	actor->page[actor->next_page++];
	42	}
	43
	44	static inline void squashfs_finish_page(struct squashfs_page_actor *actor)
	45	{
	46	/* empty */
	47	}
0d455c12 PL	48	#else
	49	struct squashfs_page_actor {
	50	union {
	51	void **buffer;
	52	struct page **page;
	53	};
	54	void *pageaddr;
	55	void (squashfs_first_page)(struct squashfs_page_actor *);
	56	void (squashfs_next_page)(struct squashfs_page_actor *);
	57	void (squashfs_finish_page)(struct squashfs_page_actor );
	58	int pages;
	59	int length;
	60	int next_page;
	61	};
	62
	63	extern struct squashfs_page_actor squashfs_page_actor_init(void *, int, int);
	64	extern struct squashfs_page_actor *squashfs_page_actor_init_special(struct page
	65	**, int, int);
	66	static inline void squashfs_first_page(struct squashfs_page_actor actor)
	67	{
	68	return actor->squashfs_first_page(actor);
	69	}
	70	static inline void squashfs_next_page(struct squashfs_page_actor actor)
	71	{
	72	return actor->squashfs_next_page(actor);
	73	}
	74	static inline void squashfs_finish_page(struct squashfs_page_actor *actor)
	75	{
	76	actor->squashfs_finish_page(actor);
	77	}
	78	#endif
846b730e	79	#endif