/*
 * Copyright (c) 2000-2003,2005 Silicon Graphics, Inc.
 * All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it would be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write the Free Software Foundation,
 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
#ifndef __XFS_RTALLOC_H__
#define __XFS_RTALLOC_H__

struct xfs_mount;
struct xfs_trans;

/* Min and max rt extent sizes, specified in bytes */
#define XFS_MAX_RTEXTSIZE       (1024 * 1024 * 1024)    /* 1GB */
#define XFS_DFL_RTEXTSIZE       (64 * 1024)             /* 64kB */
#define XFS_MIN_RTEXTSIZE       (4 * 1024)              /* 4kB */

/*
 * Constants for bit manipulations.
 */
#define XFS_NBBYLOG     3               /* log2(NBBY) */
#define XFS_WORDLOG     2               /* log2(sizeof(xfs_rtword_t)) */
#define XFS_NBWORDLOG   (XFS_NBBYLOG + XFS_WORDLOG)
#define XFS_NBWORD      (1 << XFS_NBWORDLOG)
#define XFS_WORDMASK    ((1 << XFS_WORDLOG) - 1)

#define XFS_BLOCKSIZE(mp)       ((mp)->m_sb.sb_blocksize)
#define XFS_BLOCKMASK(mp)       ((mp)->m_blockmask)
#define XFS_BLOCKWSIZE(mp)      ((mp)->m_blockwsize)
#define XFS_BLOCKWMASK(mp)      ((mp)->m_blockwmask)

/*
 * Summary and bit manipulation macros.
 */
#define XFS_SUMOFFS(mp,ls,bb)   ((int)((ls) * (mp)->m_sb.sb_rbmblocks + (bb)))
#define XFS_SUMOFFSTOBLOCK(mp,s)        \
        (((s) * (uint)sizeof(xfs_suminfo_t)) >> (mp)->m_sb.sb_blocklog)
#define XFS_SUMPTR(mp,bp,so)    \
        ((xfs_suminfo_t *)((bp)->b_addr + \
                (((so) * (uint)sizeof(xfs_suminfo_t)) & XFS_BLOCKMASK(mp))))

#define XFS_BITTOBLOCK(mp,bi)   ((bi) >> (mp)->m_blkbit_log)
#define XFS_BLOCKTOBIT(mp,bb)   ((bb) << (mp)->m_blkbit_log)
#define XFS_BITTOWORD(mp,bi)    \
        ((int)(((bi) >> XFS_NBWORDLOG) & XFS_BLOCKWMASK(mp)))

#define XFS_RTMIN(a,b)  ((a) < (b) ? (a) : (b))
#define XFS_RTMAX(a,b)  ((a) > (b) ? (a) : (b))

#define XFS_RTLOBIT(w)  xfs_lowbit32(w)
#define XFS_RTHIBIT(w)  xfs_highbit32(w)

#if XFS_BIG_BLKNOS
#define XFS_RTBLOCKLOG(b)       xfs_highbit64(b)
#else
#define XFS_RTBLOCKLOG(b)       xfs_highbit32(b)
#endif


#ifdef __KERNEL__

#ifdef CONFIG_XFS_RT
/*
 * Function prototypes for exported functions.
 */

/*
 * Allocate an extent in the realtime subvolume, with the usual allocation
 * parameters.  The length units are all in realtime extents, as is the
 * result block number.
 */
int                                     /* error */
xfs_rtallocate_extent(
        struct xfs_trans        *tp,    /* transaction pointer */
        xfs_rtblock_t           bno,    /* starting block number to allocate */
        xfs_extlen_t            minlen, /* minimum length to allocate */
        xfs_extlen_t            maxlen, /* maximum length to allocate */
        xfs_extlen_t            *len,   /* out: actual length allocated */
        xfs_alloctype_t         type,   /* allocation type XFS_ALLOCTYPE... */
        int                     wasdel, /* was a delayed allocation extent */
        xfs_extlen_t            prod,   /* extent product factor */
        xfs_rtblock_t           *rtblock); /* out: start block allocated */

/*
 * Free an extent in the realtime subvolume.  Length is expressed in
 * realtime extents, as is the block number.
 */
int                                     /* error */
xfs_rtfree_extent(
        struct xfs_trans        *tp,    /* transaction pointer */
        xfs_rtblock_t           bno,    /* starting block number to free */
        xfs_extlen_t            len);   /* length of extent freed */

/*
 * Initialize realtime fields in the mount structure.
 */
int                                     /* error */
xfs_rtmount_init(
        struct xfs_mount        *mp);   /* file system mount structure */
void
xfs_rtunmount_inodes(
        struct xfs_mount        *mp);

/*
 * Get the bitmap and summary inodes into the mount structure
 * at mount time.
 */
int                                     /* error */
xfs_rtmount_inodes(
        struct xfs_mount        *mp);   /* file system mount structure */

/*
 * Pick an extent for allocation at the start of a new realtime file.
 * Use the sequence number stored in the atime field of the bitmap inode.
 * Translate this to a fraction of the rtextents, and return the product
 * of rtextents and the fraction.
 * The fraction sequence is 0, 1/2, 1/4, 3/4, 1/8, ..., 7/8, 1/16, ...
 */
int                                     /* error */
xfs_rtpick_extent(
        struct xfs_mount        *mp,    /* file system mount point */
        struct xfs_trans        *tp,    /* transaction pointer */
        xfs_extlen_t            len,    /* allocation length (rtextents) */
        xfs_rtblock_t           *pick); /* result rt extent */

/*
 * Grow the realtime area of the filesystem.
 */
int
xfs_growfs_rt(
        struct xfs_mount        *mp,    /* file system mount structure */
        xfs_growfs_rt_t         *in);   /* user supplied growfs struct */

#else
# define xfs_rtallocate_extent(t,b,min,max,l,a,f,p,rb)  (ENOSYS)
# define xfs_rtfree_extent(t,b,l)                       (ENOSYS)
# define xfs_rtpick_extent(m,t,l,rb)                    (ENOSYS)
# define xfs_growfs_rt(mp,in)                           (ENOSYS)
static inline int               /* error */
xfs_rtmount_init(
        xfs_mount_t     *mp)    /* file system mount structure */
{
        if (mp->m_sb.sb_rblocks == 0)
                return 0;

        xfs_warn(mp, "Not built with CONFIG_XFS_RT");
        return ENOSYS;
}
# define xfs_rtmount_inodes(m)  (((mp)->m_sb.sb_rblocks == 0)? 0 : (ENOSYS))
# define xfs_rtunmount_inodes(m)
#endif  /* CONFIG_XFS_RT */

#endif  /* __KERNEL__ */

#endif  /* __XFS_RTALLOC_H__ */