/*

 *  GRUB  --  GRand Unified Bootloader

 *  Copyright (C) 1999,2000,2001,2002,2003,2004  Free Software Foundation, Inc.

 *

 *  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., 675 Mass Ave, Cambridge, MA 02139, USA.

 */

/*

 * Use is subject to license terms.

 */

#ifndef _SYS_SPA_H

#define	_SYS_SPA_H

/*

 * General-purpose 32-bit and 64-bit bitfield encodings.

 */

#define	BF32_DECODE(x, low, len)	P2PHASE((x) >> (low), 1U << (len))

#define	BF64_DECODE(x, low, len)	P2PHASE((x) >> (low), 1ULL << (len))

#define	BF32_ENCODE(x, low, len)	(P2PHASE((x), 1U << (len)) << (low))

#define	BF64_ENCODE(x, low, len)	(P2PHASE((x), 1ULL << (len)) << (low))

#define	BF32_GET(x, low, len)		BF32_DECODE(x, low, len)

#define	BF64_GET(x, low, len)		BF64_DECODE(x, low, len)

#define	BF32_SET(x, low, len, val)	\

	((x) ^= BF32_ENCODE((x >> low) ^ (val), low, len))

#define	BF64_SET(x, low, len, val)	\

	((x) ^= BF64_ENCODE((x >> low) ^ (val), low, len))

#define	BF32_GET_SB(x, low, len, shift, bias)	\

	((BF32_GET(x, low, len) + (bias)) << (shift))

#define	BF64_GET_SB(x, low, len, shift, bias)	\

	((BF64_GET(x, low, len) + (bias)) << (shift))

#define	BF32_SET_SB(x, low, len, shift, bias, val)	\

	BF32_SET(x, low, len, ((val) >> (shift)) - (bias))

#define	BF64_SET_SB(x, low, len, shift, bias, val)	\

	BF64_SET(x, low, len, ((val) >> (shift)) - (bias))

/*

 * We currently support nine block sizes, from 512 bytes to 128K.

 * We could go higher, but the benefits are near-zero and the cost

 * of COWing a giant block to modify one byte would become excessive.

 */

#define	SPA_MINBLOCKSHIFT	9

#define	SPA_MAXBLOCKSHIFT	17

#define	SPA_MINBLOCKSIZE	(1ULL << SPA_MINBLOCKSHIFT)

#define	SPA_MAXBLOCKSIZE	(1ULL << SPA_MAXBLOCKSHIFT)

#define	SPA_BLOCKSIZES		(SPA_MAXBLOCKSHIFT - SPA_MINBLOCKSHIFT + 1)

/*

 * The DVA size encodings for LSIZE and PSIZE support blocks up to 32MB.

 * The ASIZE encoding should be at least 64 times larger (6 more bits)

 * to support up to 4-way RAID-Z mirror mode with worst-case gang block

 * overhead, three DVAs per bp, plus one more bit in case we do anything

 * else that expands the ASIZE.

 */

#define	SPA_LSIZEBITS		16	/* LSIZE up to 32M (2^16 * 512)	*/

#define	SPA_PSIZEBITS		16	/* PSIZE up to 32M (2^16 * 512)	*/

#define	SPA_ASIZEBITS		24	/* ASIZE up to 64 times larger	*/

/*

 * All SPA data is represented by 128-bit data virtual addresses (DVAs).

 * The members of the dva_t should be considered opaque outside the SPA.

 */

typedef struct dva {

	uint64_t	dva_word[2];

} dva_t;

/*

 * Each block has a 256-bit checksum -- strong enough for cryptographic hashes.

 */

typedef struct zio_cksum {

	uint64_t	zc_word[4];

} zio_cksum_t;

/*

 * Each block is described by its DVAs, time of birth, checksum, etc.

 * The word-by-word, bit-by-bit layout of the blkptr is as follows:

 *

 *	64	56	48	40	32	24	16	8	0

 *	+-------+-------+-------+-------+-------+-------+-------+-------+

 * 0	|		vdev1		| GRID  |	  ASIZE		|

 *	+-------+-------+-------+-------+-------+-------+-------+-------+

 * 1	|G|			 offset1				|

 *	+-------+-------+-------+-------+-------+-------+-------+-------+

 * 2	|		vdev2		| GRID  |	  ASIZE		|

 *	+-------+-------+-------+-------+-------+-------+-------+-------+

 * 3	|G|			 offset2				|

 *	+-------+-------+-------+-------+-------+-------+-------+-------+

 * 4	|		vdev3		| GRID  |	  ASIZE		|

 *	+-------+-------+-------+-------+-------+-------+-------+-------+

 * 5	|G|			 offset3				|

 *	+-------+-------+-------+-------+-------+-------+-------+-------+

 *	+-------+-------+-------+-------+-------+-------+-------+-------+

 * 7	|			padding					|

 *	+-------+-------+-------+-------+-------+-------+-------+-------+

 * 8	|			padding					|

 *	+-------+-------+-------+-------+-------+-------+-------+-------+

 *	+-------+-------+-------+-------+-------+-------+-------+-------+

 *	+-------+-------+-------+-------+-------+-------+-------+-------+

 * b	|			fill count				|

 *	+-------+-------+-------+-------+-------+-------+-------+-------+

 * c	|			checksum[0]				|

 *	+-------+-------+-------+-------+-------+-------+-------+-------+

 * d	|			checksum[1]				|

 *	+-------+-------+-------+-------+-------+-------+-------+-------+

 * e	|			checksum[2]				|

 *	+-------+-------+-------+-------+-------+-------+-------+-------+

 * f	|			checksum[3]				|

 *	+-------+-------+-------+-------+-------+-------+-------+-------+

 *

 * Legend:

 *

 * vdev		virtual device ID

 * offset	offset into virtual device

 * LSIZE	logical size

 * PSIZE	physical size (after compression)

 * ASIZE	allocated size (including RAID-Z parity and gang block headers)

 * GRID		RAID-Z layout information (reserved for future use)

 * cksum	checksum function

 * comp		compression function

 * G		gang block indicator

 * type		DMU object type

 * fill count	number of non-zero blocks under this bp

 * checksum[4]	256-bit checksum of the data this bp describes

 */

#define	SPA_BLKPTRSHIFT	7		/* blkptr_t is 128 bytes	*/

#define	SPA_DVAS_PER_BP	3		/* Number of DVAs in a bp	*/

/*

 * Macros to get and set fields in a bp or DVA.

 */

#define	DVA_GET_ASIZE(dva)	\

	BF64_GET_SB((dva)->dva_word[0], 0, 24, SPA_MINBLOCKSHIFT, 0)

#define	DVA_SET_ASIZE(dva, x)	\

	BF64_SET_SB((dva)->dva_word[0], 0, 24, SPA_MINBLOCKSHIFT, 0, x)

#define	DVA_GET_GRID(dva)	BF64_GET((dva)->dva_word[0], 24, 8)

#define	DVA_SET_GRID(dva, x)	BF64_SET((dva)->dva_word[0], 24, 8, x)

#define	DVA_GET_VDEV(dva)	BF64_GET((dva)->dva_word[0], 32, 32)

#define	DVA_SET_VDEV(dva, x)	BF64_SET((dva)->dva_word[0], 32, 32, x)

#define	DVA_GET_OFFSET(dva)	\

	BF64_GET_SB((dva)->dva_word[1], 0, 63, SPA_MINBLOCKSHIFT, 0)

#define	DVA_SET_OFFSET(dva, x)	\

	BF64_SET_SB((dva)->dva_word[1], 0, 63, SPA_MINBLOCKSHIFT, 0, x)

#define	DVA_GET_GANG(dva)	BF64_GET((dva)->dva_word[1], 63, 1)

#define	DVA_SET_GANG(dva, x)	BF64_SET((dva)->dva_word[1], 63, 1, x)

#define	BP_GET_LSIZE(bp)	\

#define	BP_SET_LSIZE(bp, x)	\

	BF64_SET_SB((bp)->blk_prop, 0, 16, SPA_MINBLOCKSHIFT, 1, x)

#define	BP_GET_PSIZE(bp)	\

	BF64_GET_SB((bp)->blk_prop, 16, 16, SPA_MINBLOCKSHIFT, 1)

#define	BP_SET_PSIZE(bp, x)	\

	BF64_SET_SB((bp)->blk_prop, 16, 16, SPA_MINBLOCKSHIFT, 1, x)

#define	BP_GET_ASIZE(bp)	\

	(DVA_GET_ASIZE(&(bp)->blk_dva[0]) + DVA_GET_ASIZE(&(bp)->blk_dva[1]) + \

		DVA_GET_ASIZE(&(bp)->blk_dva[2]))

#define	BP_GET_UCSIZE(bp) \

	((BP_GET_LEVEL(bp) > 0 || dmu_ot[BP_GET_TYPE(bp)].ot_metadata) ? \

	BP_GET_PSIZE(bp) : BP_GET_LSIZE(bp));

#define	BP_GET_NDVAS(bp)	\

	(!!DVA_GET_ASIZE(&(bp)->blk_dva[0]) + \

	!!DVA_GET_ASIZE(&(bp)->blk_dva[1]) + \

	!!DVA_GET_ASIZE(&(bp)->blk_dva[2]))

#define	BP_COUNT_GANG(bp)	\

	(DVA_GET_GANG(&(bp)->blk_dva[0]) + \

	DVA_GET_GANG(&(bp)->blk_dva[1]) + \

	DVA_GET_GANG(&(bp)->blk_dva[2]))

#define	DVA_EQUAL(dva1, dva2)	\

	((dva1)->dva_word[1] == (dva2)->dva_word[1] && \

	(dva1)->dva_word[0] == (dva2)->dva_word[0])

#define	ZIO_CHECKSUM_EQUAL(zc1, zc2) \

	(0 == (((zc1).zc_word[0] - (zc2).zc_word[0]) | \

	((zc1).zc_word[1] - (zc2).zc_word[1]) | \

	((zc1).zc_word[2] - (zc2).zc_word[2]) | \

	((zc1).zc_word[3] - (zc2).zc_word[3])))

#define	DVA_IS_VALID(dva)	(DVA_GET_ASIZE(dva) != 0)

#define	ZIO_SET_CHECKSUM(zcp, w0, w1, w2, w3)	\

{						\

	(zcp)->zc_word[0] = w0;			\

	(zcp)->zc_word[1] = w1;			\

	(zcp)->zc_word[2] = w2;			\

	(zcp)->zc_word[3] = w3;			\

}

#define	BP_IDENTITY(bp)		(&(bp)->blk_dva[0])

#define	BP_IS_GANG(bp)		DVA_GET_GANG(BP_IDENTITY(bp))

#define	BP_IS_HOLE(bp)		((bp)->blk_birth == 0)

#define	BP_ZERO(bp)				\

{						\

	(bp)->blk_dva[0].dva_word[0] = 0;	\

	(bp)->blk_dva[0].dva_word[1] = 0;	\

	(bp)->blk_dva[1].dva_word[0] = 0;	\

	(bp)->blk_dva[1].dva_word[1] = 0;	\

	(bp)->blk_dva[2].dva_word[0] = 0;	\

	(bp)->blk_dva[2].dva_word[1] = 0;	\

	(bp)->blk_prop = 0;			\

	(bp)->blk_pad[0] = 0;			\

	(bp)->blk_pad[1] = 0;			\

	(bp)->blk_birth = 0;			\

	(bp)->blk_fill = 0;			\

	ZIO_SET_CHECKSUM(&(bp)->blk_cksum, 0, 0, 0, 0);	\

}

/*

 * Note: the byteorder is either 0 or -1, both of which are palindromes.

 * This simplifies the endianness handling a bit.

 */

#ifdef _BIG_ENDIAN

#define	ZFS_HOST_BYTEORDER	(0ULL)

#else

#define	ZFS_HOST_BYTEORDER	(-1ULL)

#endif

#define	BP_SHOULD_BYTESWAP(bp)	(BP_GET_BYTEORDER(bp) != ZFS_HOST_BYTEORDER)

#define	BP_SPRINTF_LEN	320

#endif	/* _SYS_SPA_H */