zfs: Add ZFS filesystem support

U-Boot port is based on sources forked from GRUB-0.97 by Sun in 2004,
which can be found here:
http://src.opensolaris.org/source/xref/onnv/onnv-gate/usr/src/grub/grub-0.97/stage2/zfs-include/zfs.h

Released by Sun for GRUB under the license:
  *  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.

GRUB official releases include ZFS in version:
ftp://alpha.gnu.org/gnu/grub/grub-1.99~rc1.tar.gz

And patched against GRUB Bazaar repository for ashift fixes (4KB HDDs)
more conveniently found at github:
https://github.com/pendor/grub-zfs/commit/e7b6ef3ac3b9685ac4c394c897b1d4221b7381f1

Signed-off-by: Jorgen Lundman <lundman@lundman.net>
diff --git a/include/zfs/spa.h b/include/zfs/spa.h
new file mode 100644
index 0000000..360cf89
--- /dev/null
+++ b/include/zfs/spa.h
@@ -0,0 +1,292 @@
+/*
+ *  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.
+ */
+/*
+ * 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 */