/*
   *  GRUB  --  GRand Unified Bootloader
   *  Copyright (C) 1999,2000,2001,2002,2003,2004  Free Software Foundation, Inc.
   *
   * SPDX-License-Identifier:	GPL-2.0+
   */
  /*
   * Copyright (c) 2008, 2011, Oracle and/or its affiliates. All rights reserved.
   */
  
  #ifndef ZFS_SPA_HEADER
  #define	ZFS_SPA_HEADER 1
  
  
  /*
   * 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)
  
  /*
   * Size of block to hold the configuration data (a packed nvlist)
   */
  #define	SPA_CONFIG_BLOCKSIZE	(1 << 14)
  
  /*
   * 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				|
   *	+-------+-------+-------+-------+-------+-------+-------+-------+
   * 6	|BDX|lvl| type	| cksum | comp	|	  PSIZE	|	  LSIZE	|
   *	+-------+-------+-------+-------+-------+-------+-------+-------+
   * 7	|			padding					|
   *	+-------+-------+-------+-------+-------+-------+-------+-------+
   * 8	|			padding					|
   *	+-------+-------+-------+-------+-------+-------+-------+-------+
   * 9	|			physical birth txg			|
   *	+-------+-------+-------+-------+-------+-------+-------+-------+
   * a	|			logical birth txg			|
   *	+-------+-------+-------+-------+-------+-------+-------+-------+
   * 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
   * B		byteorder (endianness)
   * D		dedup
   * X		unused
   * lvl		level of indirection
   * type		DMU object type
   * phys birth	txg of block allocation; zero if same as logical birth txg
   * log. birth	transaction group in which the block was logically born
   * 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	*/
  
  typedef struct blkptr {
  	dva_t		blk_dva[SPA_DVAS_PER_BP]; /* Data Virtual Addresses */
  	uint64_t	blk_prop;	/* size, compression, type, etc		*/
  	uint64_t	blk_pad[2];	/* Extra space for the future		*/
  	uint64_t	blk_phys_birth;	/* txg when block was allocated		*/
  	uint64_t	blk_birth;	/* transaction group at birth		*/
  	uint64_t	blk_fill;	/* fill count				*/
  	zio_cksum_t	blk_cksum;	/* 256-bit checksum			*/
  } blkptr_t;
  
  /*
   * 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_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)										\
  	BF64_GET_SB((bp)->blk_prop, 0, 16, SPA_MINBLOCKSHIFT, 1)
  #define	BP_SET_LSIZE(bp, x)										\
  	BF64_SET_SB((bp)->blk_prop, 0, 16, SPA_MINBLOCKSHIFT, 1, x)
  
  #define	BP_GET_COMPRESS(bp)		BF64_GET((bp)->blk_prop, 32, 8)
  #define	BP_SET_COMPRESS(bp, x)		BF64_SET((bp)->blk_prop, 32, 8, x)
  
  #define	BP_GET_CHECKSUM(bp)		BF64_GET((bp)->blk_prop, 40, 8)
  #define	BP_SET_CHECKSUM(bp, x)		BF64_SET((bp)->blk_prop, 40, 8, x)
  
  #define	BP_GET_TYPE(bp)			BF64_GET((bp)->blk_prop, 48, 8)
  #define	BP_SET_TYPE(bp, x)		BF64_SET((bp)->blk_prop, 48, 8, x)
  
  #define	BP_GET_LEVEL(bp)		BF64_GET((bp)->blk_prop, 56, 5)
  #define	BP_SET_LEVEL(bp, x)		BF64_SET((bp)->blk_prop, 56, 5, x)
  
  #define	BP_GET_PROP_BIT_61(bp)		BF64_GET((bp)->blk_prop, 61, 1)
  #define	BP_SET_PROP_BIT_61(bp, x)	BF64_SET((bp)->blk_prop, 61, 1, x)
  
  #define	BP_GET_DEDUP(bp)		BF64_GET((bp)->blk_prop, 62, 1)
  #define	BP_SET_DEDUP(bp, x)		BF64_SET((bp)->blk_prop, 62, 1, x)
  
  #define	BP_GET_BYTEORDER(bp)		(0 - BF64_GET((bp)->blk_prop, 63, 1))
  #define	BP_SET_BYTEORDER(bp, x)		BF64_SET((bp)->blk_prop, 63, 1, x)
  
  #define	BP_PHYSICAL_BIRTH(bp)										\
  	((bp)->blk_phys_birth ? (bp)->blk_phys_birth : (bp)->blk_birth)
  
  #define	BP_SET_BIRTH(bp, logical, physical)								\
  	{																	\
  		(bp)->blk_birth = (logical);									\
  		(bp)->blk_phys_birth = ((logical) == (physical) ? 0 : (physical)); \
  	}
  
  #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	BP_EQUAL(bp1, bp2)									\
  	(BP_PHYSICAL_BIRTH(bp1) == BP_PHYSICAL_BIRTH(bp2) &&	\
  	 DVA_EQUAL(&(bp1)->blk_dva[0], &(bp2)->blk_dva[0]) &&	\
  	 DVA_EQUAL(&(bp1)->blk_dva[1], &(bp2)->blk_dva[1]) &&	\
  	 DVA_EQUAL(&(bp1)->blk_dva[2], &(bp2)->blk_dva[2]))
  
  #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)
  
  /* BP_IS_RAIDZ(bp) assumes no block compression */
  #define	BP_IS_RAIDZ(bp)		(DVA_GET_ASIZE(&(bp)->blk_dva[0]) > \
  							 BP_GET_PSIZE(bp))
  
  #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_phys_birth = 0;						\
  		(bp)->blk_birth = 0;							\
  		(bp)->blk_fill = 0;								\
  		ZIO_SET_CHECKSUM(&(bp)->blk_cksum, 0, 0, 0, 0);	\
  	}
  
  #define	BP_SPRINTF_LEN	320
  
  #endif	/* ! ZFS_SPA_HEADER */