/*

 * libhugetlbfs - Easy use of Linux hugepages

 * Copyright (C) 2005-2006 David Gibson & Adam Litke, IBM Corporation.

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public License

 * as published by the Free Software Foundation; either version 2.1 of

 * the License, or (at your option) any later version.

 *

 * This library is distributed in the hope that it will be useful, but

 * WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with this library; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA

 */

/*

 * This file should only contain definitions of functions, data types, and

 * constants which are part of the published libhugetlfs API.  Functions

 * exported here must also be listed in version.lds.

 */

#ifndef _HUGETLBFS_H

#define _HUGETLBFS_H

#define HUGETLBFS_MAGIC	0x958458f6

long gethugepagesize(void);

int gethugepagesizes(long pagesizes[], int n_elem);

int getpagesizes(long pagesizes[], int n_elem);

int hugetlbfs_test_path(const char *mount);

const char *hugetlbfs_find_path(void);

const char *hugetlbfs_find_path_for_size(long page_size);

int hugetlbfs_unlinked_fd(void);

int hugetlbfs_unlinked_fd_for_size(long page_size);

#define PF_LINUX_HUGETLB	0x100000

/*

 * Direct hugepage allocation flags and types

 *

 * GHP_DEFAULT - Use the default hugepage size to back the region

 */

typedef unsigned long ghp_t;

#define GHP_DEFAULT	((ghp_t)0x01UL)

#define GHP_MASK	(GHP_DEFAULT)

/* Direct alloc functions for hugepages */

void *get_huge_pages(size_t len, ghp_t flags);

void free_huge_pages(void *ptr);

/*

 * Region alloc flags and types

 *

 * GHR_DEFAULT  - Use a combination of flags deemed to be a sensible default

 * 		  by the current implementation of the library

 * GHR_FALLBACK - Use the default hugepage size if possible but fallback to

 * 		  smaller pages if necessary

 * GHR_STRICT   - Use hugepages of some size or return NULL

 * GHP_COLOR    - Use bytes wasted due to alignment to offset the buffer

 *		  by a random cache line. This gives better average

 *		  performance with many buffers

 */

typedef unsigned long ghr_t;

#define GHR_STRICT	((ghr_t)0x10000000U)

#define GHR_FALLBACK	((ghr_t)0x20000000U)

#define GHR_COLOR	((ghr_t)0x40000000U)

#define GHR_DEFAULT	(GHR_FALLBACK|GHR_COLOR)

#define GHR_MASK	(GHR_FALLBACK|GHR_STRICT|GHR_COLOR)

/* Allocation functions for regions backed by hugepages */

void *get_hugepage_region(size_t len, ghr_t flags);

void free_hugepage_region(void *ptr);

#endif /* _HUGETLBFS_H */