[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / staging / ramzswap / xvmalloc_int.h

/*
 * xvmalloc memory allocator
 *
 * Copyright (C) 2008, 2009, 2010  Nitin Gupta
 *
 * This code is released using a dual license strategy: BSD/GPL
 * You can choose the licence that better fits your requirements.
 *
 * Released under the terms of 3-clause BSD License
 * Released under the terms of GNU General Public License Version 2.0
 */

#ifndef _XV_MALLOC_INT_H_
#define _XV_MALLOC_INT_H_

#include <linux/kernel.h>
#include <linux/types.h>

/* User configurable params */

/* Must be power of two */
#define XV_ALIGN_SHIFT	2
#define XV_ALIGN	(1 << XV_ALIGN_SHIFT)
#define XV_ALIGN_MASK	(XV_ALIGN - 1)

/* This must be greater than sizeof(link_free) */
#define XV_MIN_ALLOC_SIZE	32
#define XV_MAX_ALLOC_SIZE	(PAGE_SIZE - XV_ALIGN)

/* Free lists are separated by FL_DELTA bytes */
#define FL_DELTA_SHIFT	3
#define FL_DELTA	(1 << FL_DELTA_SHIFT)
#define FL_DELTA_MASK	(FL_DELTA - 1)
#define NUM_FREE_LISTS	((XV_MAX_ALLOC_SIZE - XV_MIN_ALLOC_SIZE) \
				/ FL_DELTA + 1)

#define MAX_FLI		DIV_ROUND_UP(NUM_FREE_LISTS, BITS_PER_LONG)

/* End of user params */

enum blockflags {
	BLOCK_FREE,
	PREV_FREE,
	__NR_BLOCKFLAGS,
};

#define FLAGS_MASK	XV_ALIGN_MASK
#define PREV_MASK	(~FLAGS_MASK)

struct freelist_entry {
	struct page *page;
	u16 offset;
	u16 pad;
};

struct link_free {
	struct page *prev_page;
	struct page *next_page;
	u16 prev_offset;
	u16 next_offset;
};

struct block_header {
	union {
		/* This common header must be XV_ALIGN bytes */
		u8 common[XV_ALIGN];
		struct {
			u16 size;
			u16 prev;
		};
	};
	struct link_free link;
};

struct xv_pool {
	ulong flbitmap;
	ulong slbitmap[MAX_FLI];
	spinlock_t lock;

	struct freelist_entry freelist[NUM_FREE_LISTS];

	/* stats */
	u64 total_pages;
};

#endif
Commit	Line	Data
644bf7b5 NG	1	/*
	2	* xvmalloc memory allocator
	3	*
1130ebba	4	* Copyright (C) 2008, 2009, 2010 Nitin Gupta
644bf7b5 NG	5	*
	6	* This code is released using a dual license strategy: BSD/GPL
	7	* You can choose the licence that better fits your requirements.
	8	*
	9	* Released under the terms of 3-clause BSD License
	10	* Released under the terms of GNU General Public License Version 2.0
	11	*/
	12
	13	#ifndef _XV_MALLOC_INT_H_
	14	#define _XV_MALLOC_INT_H_
	15
	16	#include <linux/kernel.h>
	17	#include <linux/types.h>
	18
	19	/* User configurable params */
	20
	21	/* Must be power of two */
	22	#define XV_ALIGN_SHIFT 2
	23	#define XV_ALIGN (1 << XV_ALIGN_SHIFT)
	24	#define XV_ALIGN_MASK (XV_ALIGN - 1)
	25
	26	/* This must be greater than sizeof(link_free) */
	27	#define XV_MIN_ALLOC_SIZE 32
	28	#define XV_MAX_ALLOC_SIZE (PAGE_SIZE - XV_ALIGN)
	29
	30	/* Free lists are separated by FL_DELTA bytes */
	31	#define FL_DELTA_SHIFT 3
	32	#define FL_DELTA (1 << FL_DELTA_SHIFT)
	33	#define FL_DELTA_MASK (FL_DELTA - 1)
	34	#define NUM_FREE_LISTS ((XV_MAX_ALLOC_SIZE - XV_MIN_ALLOC_SIZE) \
	35	/ FL_DELTA + 1)
	36
	37	#define MAX_FLI DIV_ROUND_UP(NUM_FREE_LISTS, BITS_PER_LONG)
	38
	39	/* End of user params */
	40
	41	enum blockflags {
	42	BLOCK_FREE,
	43	PREV_FREE,
	44	__NR_BLOCKFLAGS,
	45	};
	46
	47	#define FLAGS_MASK XV_ALIGN_MASK
	48	#define PREV_MASK (~FLAGS_MASK)
	49
	50	struct freelist_entry {
	51	struct page *page;
	52	u16 offset;
	53	u16 pad;
	54	};
	55
	56	struct link_free {
	57	struct page *prev_page;
	58	struct page *next_page;
	59	u16 prev_offset;
	60	u16 next_offset;
	61	};
	62
	63	struct block_header {
	64	union {
ef4ffb7a	65	/* This common header must be XV_ALIGN bytes */
644bf7b5 NG	66	u8 common[XV_ALIGN];
	67	struct {
	68	u16 size;
	69	u16 prev;
	70	};
	71	};
	72	struct link_free link;
	73	};
	74
	75	struct xv_pool {
	76	ulong flbitmap;
	77	ulong slbitmap[MAX_FLI];
	78	spinlock_t lock;
	79
	80	struct freelist_entry freelist[NUM_FREE_LISTS];
	81
	82	/* stats */
	83	u64 total_pages;
	84	};
	85
	86	#endif