/*

   *   Copyright (C) International Business Machines Corp., 2000-2002

   *
   *   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; either version 2 of the License, or

   *   (at your option) any later version.

   *

   *   This program 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 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 to the Free Software

   *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
   */
  #ifndef	_H_JFS_DMAP
  #define _H_JFS_DMAP
  
  #include "jfs_txnmgr.h"
  
  #define BMAPVERSION	1	/* version number */
  #define	TREESIZE	(256+64+16+4+1)	/* size of a dmap tree */
  #define	LEAFIND		(64+16+4+1)	/* index of 1st leaf of a dmap tree */
  #define LPERDMAP	256	/* num leaves per dmap tree */
  #define L2LPERDMAP	8	/* l2 number of leaves per dmap tree */
  #define	DBWORD		32	/* # of blks covered by a map word */
  #define	L2DBWORD	5	/* l2 # of blks covered by a mword */

  #define BUDMIN		L2DBWORD	/* max free string in a map word */

  #define BPERDMAP	(LPERDMAP * DBWORD)	/* num of blks per dmap */
  #define L2BPERDMAP	13	/* l2 num of blks per dmap */
  #define CTLTREESIZE	(1024+256+64+16+4+1)	/* size of a dmapctl tree */
  #define CTLLEAFIND	(256+64+16+4+1)	/* idx of 1st leaf of a dmapctl tree */
  #define LPERCTL		1024	/* num of leaves per dmapctl tree */
  #define L2LPERCTL	10	/* l2 num of leaves per dmapctl tree */
  #define	ROOT		0	/* index of the root of a tree */
  #define	NOFREE		((s8) -1)	/* no blocks free */
  #define	MAXAG		128	/* max number of allocation groups */
  #define L2MAXAG		7	/* l2 max num of AG */
  #define L2MINAGSZ	25	/* l2 of minimum AG size in bytes */
  #define	BMAPBLKNO	0	/* lblkno of bmap within the map */
  
  /*
   * maximum l2 number of disk blocks at the various dmapctl levels.
   */
  #define	L2MAXL0SIZE	(L2BPERDMAP + 1 * L2LPERCTL)
  #define	L2MAXL1SIZE	(L2BPERDMAP + 2 * L2LPERCTL)
  #define	L2MAXL2SIZE	(L2BPERDMAP + 3 * L2LPERCTL)
  
  /*
   * maximum number of disk blocks at the various dmapctl levels.
   */
  #define	MAXL0SIZE	((s64)1 << L2MAXL0SIZE)
  #define	MAXL1SIZE	((s64)1 << L2MAXL1SIZE)
  #define	MAXL2SIZE	((s64)1 << L2MAXL2SIZE)
  
  #define	MAXMAPSIZE	MAXL2SIZE	/* maximum aggregate map size */

  /*

   * determine the maximum free string for four (lower level) nodes
   * of the tree.
   */

  static inline signed char TREEMAX(signed char *cp)

  {
  	signed char tmp1, tmp2;
  
  	tmp1 = max(*(cp+2), *(cp+3));
  	tmp2 = max(*(cp), *(cp+1));
  
  	return max(tmp1, tmp2);
  }
  
  /*
   * convert disk block number to the logical block number of the dmap
   * describing the disk block.  s is the log2(number of logical blocks per page)
   *
   * The calculation figures out how many logical pages are in front of the dmap.
   *	- the number of dmaps preceding it
   *	- the number of L0 pages preceding its L0 page
   *	- the number of L1 pages preceding its L1 page
   *	- 3 is added to account for the L2, L1, and L0 page for this dmap
   *	- 1 is added to account for the control page of the map.
   */
  #define BLKTODMAP(b,s)    \

  	((((b) >> 13) + ((b) >> 23) + ((b) >> 33) + 3 + 1) << (s))

  
  /*
   * convert disk block number to the logical block number of the LEVEL 0
   * dmapctl describing the disk block.  s is the log2(number of logical blocks
   * per page)
   *
   * The calculation figures out how many logical pages are in front of the L0.
   *	- the number of dmap pages preceding it
   *	- the number of L0 pages preceding it
   *	- the number of L1 pages preceding its L1 page
   *	- 2 is added to account for the L2, and L1 page for this L0
   *	- 1 is added to account for the control page of the map.
   */
  #define BLKTOL0(b,s)      \

  	(((((b) >> 23) << 10) + ((b) >> 23) + ((b) >> 33) + 2 + 1) << (s))

  
  /*
   * convert disk block number to the logical block number of the LEVEL 1
   * dmapctl describing the disk block.  s is the log2(number of logical blocks
   * per page)
   *
   * The calculation figures out how many logical pages are in front of the L1.
   *	- the number of dmap pages preceding it
   *	- the number of L0 pages preceding it
   *	- the number of L1 pages preceding it
   *	- 1 is added to account for the L2 page
   *	- 1 is added to account for the control page of the map.
   */
  #define BLKTOL1(b,s)      \
       (((((b) >> 33) << 20) + (((b) >> 33) << 10) + ((b) >> 33) + 1 + 1) << (s))
  
  /*
   * convert disk block number to the logical block number of the dmapctl
   * at the specified level which describes the disk block.
   */
  #define BLKTOCTL(b,s,l)   \

  	(((l) == 2) ? 1 : ((l) == 1) ? BLKTOL1((b),(s)) : BLKTOL0((b),(s)))

  /*

   * convert aggregate map size to the zero origin dmapctl level of the
   * top dmapctl.
   */
  #define	BMAPSZTOLEV(size)	\
  	(((size) <= MAXL0SIZE) ? 0 : ((size) <= MAXL1SIZE) ? 1 : 2)
  
  /* convert disk block number to allocation group number.
   */
  #define BLKTOAG(b,sbi)	((b) >> ((sbi)->bmap->db_agl2size))
  
  /* convert allocation group number to starting disk block
   * number.
   */
  #define AGTOBLK(a,ip)	\
  	((s64)(a) << (JFS_SBI((ip)->i_sb)->bmap->db_agl2size))
  
  /*
   *	dmap summary tree
   *
   * dmaptree must be consistent with dmapctl.
   */
  struct dmaptree {

  	__le32 nleafs;		/* 4: number of tree leafs	*/
  	__le32 l2nleafs;	/* 4: l2 number of tree leafs	*/
  	__le32 leafidx;		/* 4: index of first tree leaf	*/
  	__le32 height;		/* 4: height of the tree	*/

  	s8 budmin;		/* 1: min l2 tree leaf value to combine */

  	s8 stree[TREESIZE];	/* TREESIZE: tree		*/
  	u8 pad[2];		/* 2: pad to word boundary	*/
  };				/* - 360 -			*/

  
  /*
   *	dmap page per 8K blocks bitmap
   */
  struct dmap {

  	__le32 nblocks;		/* 4: num blks covered by this dmap	*/
  	__le32 nfree;		/* 4: num of free blks in this dmap	*/
  	__le64 start;		/* 8: starting blkno for this dmap	*/
  	struct dmaptree tree;	/* 360: dmap tree			*/
  	u8 pad[1672];		/* 1672: pad to 2048 bytes		*/
  	__le32 wmap[LPERDMAP];	/* 1024: bits of the working map	*/
  	__le32 pmap[LPERDMAP];	/* 1024: bits of the persistent map	*/
  };				/* - 4096 -				*/

  
  /*
   *	disk map control page per level.
   *
   * dmapctl must be consistent with dmaptree.
   */
  struct dmapctl {

  	__le32 nleafs;		/* 4: number of tree leafs	*/
  	__le32 l2nleafs;	/* 4: l2 number of tree leafs	*/
  	__le32 leafidx;		/* 4: index of the first tree leaf	*/
  	__le32 height;		/* 4: height of tree		*/
  	s8 budmin;		/* 1: minimum l2 tree leaf value	*/
  	s8 stree[CTLTREESIZE];	/* CTLTREESIZE: dmapctl tree	*/
  	u8 pad[2714];		/* 2714: pad to 4096		*/
  };				/* - 4096 -			*/

  
  /*
   *	common definition for dmaptree within dmap and dmapctl
   */
  typedef union dmtree {
  	struct dmaptree t1;
  	struct dmapctl t2;
  } dmtree_t;
  
  /* macros for accessing fields within dmtree */
  #define	dmt_nleafs	t1.nleafs

  #define	dmt_l2nleafs	t1.l2nleafs
  #define	dmt_leafidx	t1.leafidx
  #define	dmt_height	t1.height
  #define	dmt_budmin	t1.budmin
  #define	dmt_stree	t1.stree

  /*

   *	on-disk aggregate disk allocation map descriptor.
   */
  struct dbmap_disk {

  	__le64 dn_mapsize;	/* 8: number of blocks in aggregate	*/
  	__le64 dn_nfree;	/* 8: num free blks in aggregate map	*/
  	__le32 dn_l2nbperpage;	/* 4: number of blks per page		*/
  	__le32 dn_numag;	/* 4: total number of ags		*/
  	__le32 dn_maxlevel;	/* 4: number of active ags		*/
  	__le32 dn_maxag;	/* 4: max active alloc group number	*/
  	__le32 dn_agpref;	/* 4: preferred alloc group (hint)	*/
  	__le32 dn_aglevel;	/* 4: dmapctl level holding the AG	*/

  	__le32 dn_agheight;	/* 4: height in dmapctl of the AG	*/

  	__le32 dn_agwidth;	/* 4: width in dmapctl of the AG	*/
  	__le32 dn_agstart;	/* 4: start tree index at AG height	*/
  	__le32 dn_agl2size;	/* 4: l2 num of blks per alloc group	*/
  	__le64 dn_agfree[MAXAG];/* 8*MAXAG: per AG free count		*/
  	__le64 dn_agsize;	/* 8: num of blks per alloc group	*/
  	s8 dn_maxfreebud;	/* 1: max free buddy system		*/
  	u8 pad[3007];		/* 3007: pad to 4096			*/
  };				/* - 4096 -				*/

  
  struct dbmap {

  	s64 dn_mapsize;		/* number of blocks in aggregate	*/
  	s64 dn_nfree;		/* num free blks in aggregate map	*/
  	int dn_l2nbperpage;	/* number of blks per page		*/
  	int dn_numag;		/* total number of ags			*/
  	int dn_maxlevel;	/* number of active ags			*/
  	int dn_maxag;		/* max active alloc group number	*/
  	int dn_agpref;		/* preferred alloc group (hint)		*/
  	int dn_aglevel;		/* dmapctl level holding the AG		*/

  	int dn_agheight;	/* height in dmapctl of the AG		*/

  	int dn_agwidth;		/* width in dmapctl of the AG		*/
  	int dn_agstart;		/* start tree index at AG height	*/
  	int dn_agl2size;	/* l2 num of blks per alloc group	*/
  	s64 dn_agfree[MAXAG];	/* per AG free count			*/
  	s64 dn_agsize;		/* num of blks per alloc group		*/
  	signed char dn_maxfreebud;	/* max free buddy system	*/
  };				/* - 4096 -				*/

  /*

   *	in-memory aggregate disk allocation map descriptor.
   */
  struct bmap {
  	struct dbmap db_bmap;		/* on-disk aggregate map descriptor */
  	struct inode *db_ipbmap;	/* ptr to aggregate map incore inode */

  	struct mutex db_bmaplock;	/* aggregate map lock */

  	atomic_t db_active[MAXAG];	/* count of active, open files in AG */
  	u32 *db_DBmap;
  };
  
  /* macros for accessing fields within in-memory aggregate map descriptor */
  #define	db_mapsize	db_bmap.dn_mapsize
  #define	db_nfree	db_bmap.dn_nfree
  #define	db_agfree	db_bmap.dn_agfree
  #define	db_agsize	db_bmap.dn_agsize
  #define	db_agl2size	db_bmap.dn_agl2size
  #define	db_agwidth	db_bmap.dn_agwidth

  #define	db_agheight	db_bmap.dn_agheight

  #define	db_agstart	db_bmap.dn_agstart
  #define	db_numag	db_bmap.dn_numag
  #define	db_maxlevel	db_bmap.dn_maxlevel
  #define	db_aglevel	db_bmap.dn_aglevel
  #define	db_agpref	db_bmap.dn_agpref
  #define	db_maxag	db_bmap.dn_maxag
  #define	db_maxfreebud	db_bmap.dn_maxfreebud
  #define	db_l2nbperpage	db_bmap.dn_l2nbperpage
  
  /*
   * macros for various conversions needed by the allocators.
   * blkstol2(), cntlz(), and cnttz() are operating system dependent functions.
   */
  /* convert number of blocks to log2 number of blocks, rounding up to
   * the next log2 value if blocks is not a l2 multiple.
   */
  #define	BLKSTOL2(d)		(blkstol2(d))
  
  /* convert number of leafs to log2 leaf value */
  #define	NLSTOL2BSZ(n)		(31 - cntlz((n)) + BUDMIN)
  
  /* convert leaf index to log2 leaf value */
  #define	LITOL2BSZ(n,m,b)	((((n) == 0) ? (m) : cnttz((n))) + (b))
  
  /* convert a block number to a dmap control leaf index */
  #define BLKTOCTLLEAF(b,m)	\
  	(((b) & (((s64)1 << ((m) + L2LPERCTL)) - 1)) >> (m))
  
  /* convert log2 leaf value to buddy size */
  #define	BUDSIZE(s,m)		(1 << ((s) - (m)))
  
  /*
   *	external references.
   */
  extern int dbMount(struct inode *ipbmap);
  
  extern int dbUnmount(struct inode *ipbmap, int mounterror);
  
  extern int dbFree(struct inode *ipbmap, s64 blkno, s64 nblocks);
  
  extern int dbUpdatePMap(struct inode *ipbmap,
  			int free, s64 blkno, s64 nblocks, struct tblock * tblk);
  
  extern int dbNextAG(struct inode *ipbmap);
  
  extern int dbAlloc(struct inode *ipbmap, s64 hint, s64 nblocks, s64 * results);
  
  extern int dbReAlloc(struct inode *ipbmap,
  		     s64 blkno, s64 nblocks, s64 addnblocks, s64 * results);
  
  extern int dbSync(struct inode *ipbmap);
  extern int dbAllocBottomUp(struct inode *ip, s64 blkno, s64 nblocks);
  extern int dbExtendFS(struct inode *ipbmap, s64 blkno, s64 nblocks);
  extern void dbFinalizeBmap(struct inode *ipbmap);
  extern s64 dbMapFileSizeToMapSize(struct inode *ipbmap);
  #endif				/* _H_JFS_DMAP */