Prefix zfs internal endian checks with _ZFS

FreeBSD defines _BIG_ENDIAN BIG_ENDIAN _LITTLE_ENDIAN
LITTLE_ENDIAN on every architecture. Trying to do
cross builds whilst hiding this from ZFS has proven
extremely cumbersome.

Reviewed-by: Ryan Moeller <[email protected]>
Reviewed-by: Brian Behlendorf <[email protected]>
Signed-off-by: Matt Macy <[email protected]>
Closes #10621 

23 files changed, 99 insertions, 240 deletions

diff --git a/config/Rules.am b/config/Rules.am
index c6dce34b0..b02511a05 100644
--- a/config/Rules.am
+++ b/config/Rules.am
@@ -32,7 +32,6 @@ if BUILD_FREEBSD
 AM_CFLAGS += -fPIC -Werror -Wno-unknown-pragmas -Wno-enum-conversion
 AM_CFLAGS += -include $(top_srcdir)/include/os/freebsd/spl/sys/ccompile.h
 AM_CFLAGS += -I/usr/include -I/usr/local/include
-AM_CFLAGS += -D_MACHINE_ENDIAN_H_
 endif
 
 AM_CPPFLAGS  = -D_GNU_SOURCE
diff --git a/include/os/freebsd/spl/sys/Makefile.am b/include/os/freebsd/spl/sys/Makefile.am
index 7803d1af3..7d82e2d6d 100644
--- a/include/os/freebsd/spl/sys/Makefile.am
+++ b/include/os/freebsd/spl/sys/Makefile.am
@@ -14,7 +14,6 @@ KERNEL_H = \
 	dirent.h \
 	disp.h \
 	dkio.h \
-	endian.h \
 	extdirent.h \
 	file.h \
 	freebsd_rwlock.h \
diff --git a/include/os/freebsd/spl/sys/byteorder.h b/include/os/freebsd/spl/sys/byteorder.h
index 79ae848c7..fd6b0269d 100644
--- a/include/os/freebsd/spl/sys/byteorder.h
+++ b/include/os/freebsd/spl/sys/byteorder.h
@@ -60,7 +60,7 @@
 /*
  * Macros to convert from a specific byte order to/from native byte order
  */
-#if BYTE_ORDER == BIG_ENDIAN
+#if BYTE_ORDER == _BIG_ENDIAN
 #define	BE_8(x)		BMASK_8(x)
 #define	BE_16(x)	BMASK_16(x)
 #define	BE_32(x)	BMASK_32(x)
@@ -80,7 +80,7 @@
 #define	BE_64(x)	BSWAP_64(x)
 #endif
 
-#if BYTE_ORDER == BIG_ENDIAN
+#if BYTE_ORDER == _BIG_ENDIAN
 #define	htonll(x)	BMASK_64(x)
 #define	ntohll(x)	BMASK_64(x)
 #else
diff --git a/include/os/freebsd/spl/sys/endian.h b/include/os/freebsd/spl/sys/endian.h
deleted file mode 100644
index 4de4b8829..000000000
--- a/include/os/freebsd/spl/sys/endian.h
+++ /dev/null
@@ -1,42 +0,0 @@
-/*
- * Copyright (c) 2020 iXsystems, Inc.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in the
- *    documentation and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
- * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- *
- * $FreeBSD$
- */
-
-
-#ifndef _SPL_SYS_ENDIAN_H_
-#define	_SPL_SYS_ENDIAN_H_
-
-#undef _MACHINE_ENDIAN_H_
-#include_next<sys/endian.h>
-
-#if BYTE_ORDER == LITTLE_ENDIAN
-#undef _BIG_ENDIAN
-#undef BIG_ENDIAN
-#define	BIG_ENDIAN 4321
-#endif
-
-#endif /*  _SPL_SYS_ENDIAN_H_ */
diff --git a/include/os/freebsd/spl/sys/isa_defs.h b/include/os/freebsd/spl/sys/isa_defs.h
index 863c2447f..399d510b5 100644
--- a/include/os/freebsd/spl/sys/isa_defs.h
+++ b/include/os/freebsd/spl/sys/isa_defs.h
@@ -27,6 +27,7 @@
 
 #ifndef	_SYS_ISA_DEFS_H
 #define	_SYS_ISA_DEFS_H
+#include <sys/endian.h>
 
 /*
  * This header file serves to group a set of well known defines and to
@@ -696,6 +697,14 @@ extern "C" {
 #error "Both _ILP32 and _LP64 are defined"
 #endif
 
+#if BYTE_ORDER == _BIG_ENDIAN
+#define	_ZFS_BIG_ENDIAN
+#elif BYTE_ORDER == _LITTLE_ENDIAN
+#define	_ZFS_LITTLE_ENDIAN
+#else
+#error "unknown byte order"
+#endif
+
 #ifdef	__cplusplus
 }
 #endif
diff --git a/include/os/linux/spl/sys/byteorder.h b/include/os/linux/spl/sys/byteorder.h
index 477707996..70847edbc 100644
--- a/include/os/linux/spl/sys/byteorder.h
+++ b/include/os/linux/spl/sys/byteorder.h
@@ -26,6 +26,15 @@
 #define	_SPL_BYTEORDER_H
 
 #include <asm/byteorder.h>
+
+#if defined(__BIG_ENDIAN) && !defined(_ZFS_BIG_ENDIAN)
+#define	_ZFS_BIG_ENDIAN
+#endif
+
+#if defined(__LITTLE_ENDIAN) && !defined(_ZFS_LITTLE_ENDIAN)
+#define	_ZFS_LITTLE_ENDIAN
+#endif
+
 #include <sys/isa_defs.h>
 
 #define	BSWAP_8(x)	((x) & 0xff)
@@ -49,7 +58,7 @@
 #define	BE_IN32(xa) \
 	(((uint32_t)BE_IN16(xa) << 16) | BE_IN16((uint8_t *)(xa)+2))
 
-#ifdef _BIG_ENDIAN
+#ifdef _ZFS_BIG_ENDIAN
 static __inline__ uint64_t
 htonll(uint64_t n)
 {
diff --git a/include/os/linux/spl/sys/isa_defs.h b/include/os/linux/spl/sys/isa_defs.h
index c19943b85..af064e567 100644
--- a/include/os/linux/spl/sys/isa_defs.h
+++ b/include/os/linux/spl/sys/isa_defs.h
@@ -117,9 +117,9 @@
 #endif
 
 #if defined(__ARMEL__) || defined(__AARCH64EL__)
-#define	_LITTLE_ENDIAN
+#define	_ZFS_LITTLE_ENDIAN
 #else
-#define	_BIG_ENDIAN
+#define	_ZFS_BIG_ENDIAN
 #endif
 
 /*
@@ -149,7 +149,7 @@
 #endif
 #endif
 
-#define	_BIG_ENDIAN
+#define	_ZFS_BIG_ENDIAN
 #define	_SUNOS_VTOC_16
 #define	_ALIGNMENT_REQUIRED	1
 
@@ -165,7 +165,7 @@
 #endif
 #endif
 
-#define	_BIG_ENDIAN
+#define	_ZFS_BIG_ENDIAN
 
 /*
  * Illumos doesn't define _ALIGNMENT_REQUIRED for s390, so default to 1
@@ -177,9 +177,9 @@
 #elif defined(__mips__)
 
 #if defined(__MIPSEB__)
-#define	_BIG_ENDIAN
+#define	_ZFS_BIG_ENDIAN
 #elif defined(__MIPSEL__)
-#define	_LITTLE_ENDIAN
+#define	_ZFS_LITTLE_ENDIAN
 #else
 #error MIPS no endian specified
 #endif
@@ -211,7 +211,7 @@
 #define	__rv64g__
 #endif
 
-#define	_LITTLE_ENDIAN
+#define	_ZFS_LITTLE_ENDIAN
 
 #define	_SUNOS_VTOC_16
 
@@ -243,20 +243,12 @@
 #define	HAVE_EFFICIENT_UNALIGNED_ACCESS
 #endif
 
-#if defined(__LITTLE_ENDIAN) && !defined(_LITTLE_ENDIAN)
-#define	_LITTLE_ENDIAN __LITTLE_ENDIAN
+#if defined(_ZFS_LITTLE_ENDIAN) && defined(_ZFS_BIG_ENDIAN)
+#error "Both _ZFS_LITTLE_ENDIAN and _ZFS_BIG_ENDIAN are defined"
 #endif
 
-#if defined(__BIG_ENDIAN) && !defined(_BIG_ENDIAN)
-#define	_BIG_ENDIAN __BIG_ENDIAN
-#endif
-
-#if defined(_LITTLE_ENDIAN) && defined(_BIG_ENDIAN)
-#error "Both _LITTLE_ENDIAN and _BIG_ENDIAN are defined"
-#endif
-
-#if !defined(_LITTLE_ENDIAN) && !defined(_BIG_ENDIAN)
-#error "Neither _LITTLE_ENDIAN or _BIG_ENDIAN are defined"
+#if !defined(_ZFS_LITTLE_ENDIAN) && !defined(_ZFS_BIG_ENDIAN)
+#error "Neither _ZFS_LITTLE_ENDIAN or _ZFS_BIG_ENDIAN are defined"
 #endif
 
 #endif	/* _SPL_ISA_DEFS_H */
diff --git a/include/sys/spa.h b/include/sys/spa.h
index 9b96eb1f8..f0f77cd85 100644
--- a/include/sys/spa.h
+++ b/include/sys/spa.h
@@ -600,7 +600,7 @@ _NOTE(CONSTCOND) } while (0)
 	ZIO_SET_CHECKSUM(&(bp)->blk_cksum, 0, 0, 0, 0);	\
 }
 
-#ifdef _BIG_ENDIAN
+#ifdef _ZFS_BIG_ENDIAN
 #define	ZFS_HOST_BYTEORDER	(0ULL)
 #else
 #define	ZFS_HOST_BYTEORDER	(1ULL)
diff --git a/lib/libspl/include/os/freebsd/sys/byteorder.h b/lib/libspl/include/os/freebsd/sys/byteorder.h
index 74649cc4e..cd692d361 100644
--- a/lib/libspl/include/os/freebsd/sys/byteorder.h
+++ b/lib/libspl/include/os/freebsd/sys/byteorder.h
@@ -40,91 +40,8 @@
 #ifndef _SYS_BYTEORDER_H
 #define	_SYS_BYTEORDER_H
 
-/*
- * XXX FIXME
- * on FreeBSD _BIG_ENDIAN is defined on all architectures so we have
- * to exclude _MACHINE_ENDIAN_H_ and define the bulk of it here
- */
-
-#include <sys/cdefs.h>
-#include <sys/_types.h>
-
-/*
- * Define the order of 32-bit words in 64-bit words.
- */
-#define	_QUAD_HIGHWORD 1
-#define	_QUAD_LOWWORD 0
-
-/*
- * Definitions for byte order, according to byte significance from low
- * address to high.
- */
-#undef _LITTLE_ENDIAN
-/* LSB first: i386, vax */
-#define	_LITTLE_ENDIAN	1234
-/* LSB first in word, MSW first in long */
-#define	_PDP_ENDIAN		3412
-
-#define	_BYTE_ORDER		_LITTLE_ENDIAN
-
-/*
- * Deprecated variants that don't have enough underscores to be useful in more
- * strict namespaces.
- */
-#if __BSD_VISIBLE
-#define	LITTLE_ENDIAN	_LITTLE_ENDIAN
-#define	PDP_ENDIAN		_PDP_ENDIAN
-#define	BYTE_ORDER		_BYTE_ORDER
-#endif
-
-#define	__bswap16_gen(x)	(__uint16_t)((x) << 8 | (x) >> 8)
-#define	__bswap32_gen(x)                \
-	(((__uint32_t)__bswap16((x) & 0xffff) << 16) | __bswap16((x) >> 16))
-#define	__bswap64_gen(x)                \
-	(((__uint64_t)__bswap32((x) & 0xffffffff) << 32) | __bswap32((x) >> 32))
-
-#ifdef __GNUCLIKE_BUILTIN_CONSTANT_P
-#define	__bswap16(x)                            \
-	((__uint16_t)(__builtin_constant_p(x) ? \
-	__bswap16_gen((__uint16_t)(x)) : __bswap16_var(x)))
-#define	__bswap32(x)                    \
-	(__builtin_constant_p(x) ?      \
-	__bswap32_gen((__uint32_t)(x)) : __bswap32_var(x))
-#define	__bswap64(x)                    \
-	(__builtin_constant_p(x) ?      \
-	__bswap64_gen((__uint64_t)(x)) : __bswap64_var(x))
-#else
-/* XXX these are broken for use in static initializers. */
-#define	__bswap16(x)    __bswap16_var(x)
-#define	__bswap32(x)    __bswap32_var(x)
-#define	__bswap64(x)    __bswap64_var(x)
-#endif
-
-/* These are defined as functions to avoid multiple evaluation of x. */
-
-static __inline __uint16_t
-__bswap16_var(__uint16_t _x)
-{
-
-	return (__bswap16_gen(_x));
-}
-
-static __inline __uint32_t
-__bswap32_var(__uint32_t _x)
-{
-
-#ifdef __GNUCLIKE_ASM
-	__asm("bswap %0" : "+r" (_x));
-	return (_x);
-#else
-	return (__bswap32_gen(_x));
-#endif
-}
-#define	__htonl(x)	__bswap32(x)
-#define	__htons(x)	__bswap16(x)
-#define	__ntohl(x)	__bswap32(x)
-#define	__ntohs(x)	__bswap16(x)
-
+#include <sys/endian.h>
+#include <netinet/in.h>
 #include <sys/isa_defs.h>
 #include <sys/int_types.h>
 
@@ -140,42 +57,6 @@ extern "C" {
 /*
  * macros for conversion between host and (internet) network byte order
  */
-
-#if defined(_BIG_ENDIAN) && !defined(ntohl) && !defined(__lint)
-/* big-endian */
-#if defined(_BIG_ENDIAN) && (defined(__amd64__) || defined(__amd64))
-#error "incompatible ENDIAN / ARCH combination"
-#endif
-#define	ntohl(x)	(x)
-#define	ntohs(x)	(x)
-#define	htonl(x)	(x)
-#define	htons(x)	(x)
-
-#elif !defined(ntohl) /* little-endian */
-
-#ifndef	_IN_PORT_T
-#define	_IN_PORT_T
-typedef uint16_t in_port_t;
-#endif
-
-#ifndef	_IN_ADDR_T
-#define	_IN_ADDR_T
-typedef uint32_t in_addr_t;
-#endif
-
-#if !defined(_XPG4_2) || defined(__EXTENSIONS__) || defined(_XPG5)
-extern	uint32_t htonl(uint32_t);
-extern	uint16_t htons(uint16_t);
-extern 	uint32_t ntohl(uint32_t);
-extern	uint16_t ntohs(uint16_t);
-#else
-extern	in_addr_t htonl(in_addr_t);
-extern	in_port_t htons(in_port_t);
-extern 	in_addr_t ntohl(in_addr_t);
-extern	in_port_t ntohs(in_port_t);
-#endif	/* !defined(_XPG4_2) || defined(__EXTENSIONS__) || defined(_XPG5) */
-#endif
-
 #if !defined(_XPG4_2) || defined(__EXTENSIONS__)
 
 /*
@@ -194,7 +75,7 @@ extern	in_port_t ntohs(in_port_t);
 /*
  * Macros to convert from a specific byte order to/from native byte order
  */
-#ifdef _BIG_ENDIAN
+#ifdef _ZFS_BIG_ENDIAN
 #define	BE_8(x)		BMASK_8(x)
 #define	BE_16(x)	BMASK_16(x)
 #define	BE_32(x)	BMASK_32(x)
@@ -214,7 +95,7 @@ extern	in_port_t ntohs(in_port_t);
 #define	BE_64(x)	BSWAP_64(x)
 #endif
 
-#ifdef _BIG_ENDIAN
+#ifdef _ZFS_BIG_ENDIAN
 static __inline__ uint64_t
 htonll(uint64_t n)
 {
diff --git a/lib/libspl/include/os/freebsd/sys/zfs_context_os.h b/lib/libspl/include/os/freebsd/sys/zfs_context_os.h
index 25b5a47df..f5a136d22 100644
--- a/lib/libspl/include/os/freebsd/sys/zfs_context_os.h
+++ b/lib/libspl/include/os/freebsd/sys/zfs_context_os.h
@@ -29,10 +29,6 @@
 #ifndef ZFS_CONTEXT_OS_H_
 #define	ZFS_CONTEXT_OS_H_
 
-#if BYTE_ORDER != BIG_ENDIAN
-#undef _BIG_ENDIAN
-#endif
-
 #define	ZFS_EXPORTS_PATH	"/etc/zfs/exports"
 
 #endif
diff --git a/lib/libspl/include/os/linux/sys/byteorder.h b/lib/libspl/include/os/linux/sys/byteorder.h
index 72d40b164..d5ee3e26f 100644
--- a/lib/libspl/include/os/linux/sys/byteorder.h
+++ b/lib/libspl/include/os/linux/sys/byteorder.h
@@ -40,16 +40,14 @@
 #ifndef _SYS_BYTEORDER_H
 #define	_SYS_BYTEORDER_H
 
-
-
-#include <sys/isa_defs.h>
-#include <sys/int_types.h>
-
 #if defined(__GNUC__) && defined(_ASM_INLINES) && \
 	(defined(__i386) || defined(__amd64))
 #include <asm/byteorder.h>
 #endif
 
+#include <sys/isa_defs.h>
+#include <sys/int_types.h>
+
 #ifdef	__cplusplus
 extern "C" {
 #endif
@@ -58,7 +56,7 @@ extern "C" {
  * macros for conversion between host and (internet) network byte order
  */
 
-#if defined(_BIG_ENDIAN) && !defined(ntohl) && !defined(__lint)
+#if defined(_ZFS_BIG_ENDIAN) && !defined(ntohl) && !defined(__lint)
 /* big-endian */
 #define	ntohl(x)	(x)
 #define	ntohs(x)	(x)
@@ -108,7 +106,7 @@ extern	in_port_t ntohs(in_port_t);
 /*
  * Macros to convert from a specific byte order to/from native byte order
  */
-#ifdef _BIG_ENDIAN
+#ifdef _ZFS_BIG_ENDIAN
 #define	BE_8(x)		BMASK_8(x)
 #define	BE_16(x)	BMASK_16(x)
 #define	BE_32(x)	BMASK_32(x)
@@ -128,7 +126,7 @@ extern	in_port_t ntohs(in_port_t);
 #define	BE_64(x)	BSWAP_64(x)
 #endif
 
-#ifdef _BIG_ENDIAN
+#ifdef _ZFS_BIG_ENDIAN
 static __inline__ uint64_t
 htonll(uint64_t n)
 {
diff --git a/lib/libspl/include/sys/isa_defs.h b/lib/libspl/include/sys/isa_defs.h
index 4d2d909f3..6f242ea77 100644
--- a/lib/libspl/include/sys/isa_defs.h
+++ b/lib/libspl/include/sys/isa_defs.h
@@ -54,8 +54,8 @@ extern "C" {
 #endif
 #endif
 
-#if !defined(_LITTLE_ENDIAN)
-#define	_LITTLE_ENDIAN
+#if !defined(_ZFS_LITTLE_ENDIAN)
+#define	_ZFS_LITTLE_ENDIAN
 #endif
 
 #define	_SUNOS_VTOC_16
@@ -76,8 +76,8 @@ extern "C" {
 #define	_ILP32
 #endif
 
-#if !defined(_LITTLE_ENDIAN)
-#define	_LITTLE_ENDIAN
+#if !defined(_ZFS_LITTLE_ENDIAN)
+#define	_ZFS_LITTLE_ENDIAN
 #endif
 
 #define	_SUNOS_VTOC_16
@@ -107,6 +107,24 @@ extern "C" {
 #define	_SUNOS_VTOC_16
 #define	HAVE_EFFICIENT_UNALIGNED_ACCESS
 
+#if defined(__BYTE_ORDER)
+#if defined(__BIG_ENDIAN) && __BYTE_ORDER == __BIG_ENDIAN
+#define	_ZFS_BIG_ENDIAN
+#elif defined(__LITTLE_ENDIAN) && __BYTE_ORDER == __LITTLE_ENDIAN
+#define	_ZFS_LITTLE_ENDIAN
+#endif
+#elif defined(_BYTE_ORDER)
+#if defined(_BIG_ENDIAN) && _BYTE_ORDER == _BIG_ENDIAN
+#define	_ZFS_BIG_ENDIAN
+#elif defined(_LITTLE_ENDIAN) && _BYTE_ORDER == _LITTLE_ENDIAN
+#define	_ZFS_LITTLE_ENDIAN
+#endif
+#elif defined(_BIG_ENDIAN) && !defined(_LITTLE_ENDIAN)
+#define	_ZFS_BIG_ENDIAN
+#elif defined(_LITTLE_ENDIAN) && !defined(_BIG_ENDIAN)
+#define	_ZFS_LITTLE_ENDIAN
+#endif
+
 /* arm arch specific defines */
 #elif defined(__arm) || defined(__arm__) || defined(__aarch64__)
 
@@ -129,9 +147,9 @@ extern "C" {
 #endif
 
 #if defined(__ARMEL__) || defined(__AARCH64EL__)
-#define	_LITTLE_ENDIAN
+#define	_ZFS_LITTLE_ENDIAN
 #else
-#define	_BIG_ENDIAN
+#define	_ZFS_BIG_ENDIAN
 #endif
 
 #define	_SUNOS_VTOC_16
@@ -151,7 +169,7 @@ extern "C" {
 #define	__sparc__
 #endif
 
-#define	_BIG_ENDIAN
+#define	_ZFS_BIG_ENDIAN
 #define	_SUNOS_VTOC_16
 
 #if defined(__arch64__)
@@ -176,16 +194,16 @@ extern "C" {
 #endif
 #endif
 
-#define	_BIG_ENDIAN
+#define	_ZFS_BIG_ENDIAN
 #define	_SUNOS_VTOC_16
 
 /* MIPS arch specific defines */
 #elif defined(__mips__)
 
 #if defined(__MIPSEB__)
-#define	_BIG_ENDIAN
+#define	_ZFS_BIG_ENDIAN
 #elif defined(__MIPSEL__)
-#define	_LITTLE_ENDIAN
+#define	_ZFS_LITTLE_ENDIAN
 #else
 #error MIPS no endian specified
 #endif
@@ -198,7 +216,7 @@ extern "C" {
 
 /*
  * RISC-V arch specific defines
- * only RV64G (including atomic) LP64 is supported yetxi
+ * only RV64G (including atomic) LP64 is supported yet
  */
 #elif defined(__riscv) && defined(_LP64) && _LP64 && \
 	defined(__riscv_atomic) && __riscv_atomic
@@ -211,7 +229,7 @@ extern "C" {
 #define	__rv64g__
 #endif
 
-#define	_LITTLE_ENDIAN
+#define	_ZFS_LITTLE_ENDIAN
 
 #define	_SUNOS_VTOC_16
 
@@ -231,12 +249,12 @@ extern "C" {
 #error "Neither _ILP32 or _LP64 are defined"
 #endif
 
-#if defined(_LITTLE_ENDIAN) && defined(_BIG_ENDIAN)
-#error "Both _LITTLE_ENDIAN and _BIG_ENDIAN are defined"
+#if defined(_ZFS_LITTLE_ENDIAN) && defined(_ZFS_BIG_ENDIAN)
+#error "Both _ZFS_LITTLE_ENDIAN and _ZFS_BIG_ENDIAN are defined"
 #endif
 
-#if !defined(_LITTLE_ENDIAN) && !defined(_BIG_ENDIAN)
-#error "Neither _LITTLE_ENDIAN nor _BIG_ENDIAN are defined"
+#if !defined(_ZFS_LITTLE_ENDIAN) && !defined(_ZFS_BIG_ENDIAN)
+#error "Neither _ZFS_LITTLE_ENDIAN nor _ZFS_BIG_ENDIAN are defined"
 #endif
 
 #ifdef  __cplusplus
diff --git a/module/Makefile.bsd b/module/Makefile.bsd
index 517054b0e..76889770c 100644
--- a/module/Makefile.bsd
+++ b/module/Makefile.bsd
@@ -29,7 +29,7 @@ CFLAGS+= -include ${INCDIR}/os/freebsd/spl/sys/ccompile.h
 
 CFLAGS+= -D__KERNEL__ -DFREEBSD_NAMECACHE -DBUILDING_ZFS  -D__BSD_VISIBLE=1
 CFLAGS+= -DHAVE_UIO_ZEROCOPY -DWITHOUT_NETDUMP -D__KERNEL -D_SYS_CONDVAR_H_
-CFLAGS+= -D_SYS_VMEM_H_ -D_MACHINE_ENDIAN_H_ -DKDTRACE_HOOKS -DSMP
+CFLAGS+= -D_SYS_VMEM_H_ -DKDTRACE_HOOKS -DSMP
 
 .if ${MACHINE_ARCH} == "amd64"
 CFLAGS+= -DHAVE_AVX2 -DHAVE_AVX -D__x86_64 -DHAVE_SSE2 -DHAVE_AVX512F -DHAVE_SSSE3
diff --git a/module/icp/algs/aes/aes_impl_generic.c b/module/icp/algs/aes/aes_impl_generic.c
index a3b75dbf3..427c096c6 100644
--- a/module/icp/algs/aes/aes_impl_generic.c
+++ b/module/icp/algs/aes/aes_impl_generic.c
@@ -1233,7 +1233,7 @@ const aes_impl_ops_t aes_generic_impl = {
 	.encrypt = &aes_generic_encrypt,
 	.decrypt = &aes_generic_decrypt,
 	.is_supported = &aes_generic_will_work,
-#if defined(_LITTLE_ENDIAN)
+#if defined(_ZFS_LITTLE_ENDIAN)
 	.needs_byteswap = B_TRUE,
 #else
 	.needs_byteswap = B_FALSE,
diff --git a/module/icp/algs/edonr/edonr_byteorder.h b/module/icp/algs/edonr/edonr_byteorder.h
index 532dfd743..2b5d48287 100644
--- a/module/icp/algs/edonr/edonr_byteorder.h
+++ b/module/icp/algs/edonr/edonr_byteorder.h
@@ -52,10 +52,10 @@
 #endif /* __BYTE_ORDER || BYTE_ORDER */
 
 #if !defined(MACHINE_IS_BIG_ENDIAN) && !defined(MACHINE_IS_LITTLE_ENDIAN)
-#if defined(_BIG_ENDIAN) || defined(_MIPSEB)
+#if defined(_ZFS_BIG_ENDIAN) || defined(_MIPSEB)
 #define	MACHINE_IS_BIG_ENDIAN
 #endif
-#if defined(_LITTLE_ENDIAN) || defined(_MIPSEL)
+#if defined(_ZFS_LITTLE_ENDIAN) || defined(_MIPSEL)
 #define	MACHINE_IS_LITTLE_ENDIAN
 #endif
 #endif /* !MACHINE_IS_BIG_ENDIAN && !MACHINE_IS_LITTLE_ENDIAN */
diff --git a/module/icp/algs/modes/ccm.c b/module/icp/algs/modes/ccm.c
index c927f0897..5d6507c49 100644
--- a/module/icp/algs/modes/ccm.c
+++ b/module/icp/algs/modes/ccm.c
@@ -107,13 +107,13 @@ ccm_mode_encrypt_contiguous_blocks(ccm_ctx_t *ctx, char *data, size_t length,
 		 * Increment counter. Counter bits are confined
 		 * to the bottom 64 bits of the counter block.
 		 */
-#ifdef _LITTLE_ENDIAN
+#ifdef _ZFS_LITTLE_ENDIAN
 		counter = ntohll(ctx->ccm_cb[1] & ctx->ccm_counter_mask);
 		counter = htonll(counter + 1);
 #else
 		counter = ctx->ccm_cb[1] & ctx->ccm_counter_mask;
 		counter++;
-#endif	/* _LITTLE_ENDIAN */
+#endif	/* _ZFS_LITTLE_ENDIAN */
 		counter &= ctx->ccm_counter_mask;
 		ctx->ccm_cb[1] =
 		    (ctx->ccm_cb[1] & ~(ctx->ccm_counter_mask)) | counter;
@@ -458,13 +458,13 @@ ccm_mode_decrypt_contiguous_blocks(ccm_ctx_t *ctx, char *data, size_t length,
 		 * Increment counter.
 		 * Counter bits are confined to the bottom 64 bits
 		 */
-#ifdef _LITTLE_ENDIAN
+#ifdef _ZFS_LITTLE_ENDIAN
 		counter = ntohll(ctx->ccm_cb[1] & ctx->ccm_counter_mask);
 		counter = htonll(counter + 1);
 #else
 		counter = ctx->ccm_cb[1] & ctx->ccm_counter_mask;
 		counter++;
-#endif	/* _LITTLE_ENDIAN */
+#endif	/* _ZFS_LITTLE_ENDIAN */
 		counter &= ctx->ccm_counter_mask;
 		ctx->ccm_cb[1] =
 		    (ctx->ccm_cb[1] & ~(ctx->ccm_counter_mask)) | counter;
@@ -684,7 +684,7 @@ ccm_format_initial_blocks(uchar_t *nonce, ulong_t nonceSize,
 		mask |= (1ULL << q);
 	}
 
-#ifdef _LITTLE_ENDIAN
+#ifdef _ZFS_LITTLE_ENDIAN
 	mask = htonll(mask);
 #endif
 	aes_ctx->ccm_counter_mask = mask;
diff --git a/module/icp/algs/sha1/sha1.c b/module/icp/algs/sha1/sha1.c
index e4b7a0c8c..da34222c8 100644
--- a/module/icp/algs/sha1/sha1.c
+++ b/module/icp/algs/sha1/sha1.c
@@ -226,16 +226,14 @@ typedef uint32_t sha1word;
  * careful programming can guarantee this for us.
  */
 
-#if	defined(_BIG_ENDIAN)
+#if	defined(_ZFS_BIG_ENDIAN)
 #define	LOAD_BIG_32(addr)	(*(uint32_t *)(addr))
 
 #elif	defined(HAVE_HTONL)
 #define	LOAD_BIG_32(addr) htonl(*((uint32_t *)(addr)))
 
 #else
-/* little endian -- will work on big endian, but slowly */
-#define	LOAD_BIG_32(addr)	\
-	(((addr)[0] << 24) | ((addr)[1] << 16) | ((addr)[2] << 8) | (addr)[3])
+#define	LOAD_BIG_32(addr)	BE_32(*((uint32_t *)(addr)))
 #endif	/* _BIG_ENDIAN */
 
 /*
diff --git a/module/icp/algs/sha2/sha2.c b/module/icp/algs/sha2/sha2.c
index 05a2e6ad1..75f6a3c1a 100644
--- a/module/icp/algs/sha2/sha2.c
+++ b/module/icp/algs/sha2/sha2.c
@@ -43,7 +43,7 @@
 
 #define	_RESTRICT_KYWD
 
-#ifdef _LITTLE_ENDIAN
+#ifdef _ZFS_LITTLE_ENDIAN
 #include <sys/byteorder.h>
 #define	HAVE_HTONL
 #endif
@@ -123,7 +123,7 @@ static uint8_t PADDING[128] = { 0x80, /* all zeros */ };
  * careful programming can guarantee this for us.
  */
 
-#if	defined(_BIG_ENDIAN)
+#if	defined(_ZFS_BIG_ENDIAN)
 #define	LOAD_BIG_32(addr)	(*(uint32_t *)(addr))
 #define	LOAD_BIG_64(addr)	(*(uint64_t *)(addr))
 
diff --git a/module/icp/algs/skein/skein_port.h b/module/icp/algs/skein/skein_port.h
index 417ed7c4b..ce4353082 100644
--- a/module/icp/algs/skein/skein_port.h
+++ b/module/icp/algs/skein/skein_port.h
@@ -44,7 +44,7 @@
 
 #include <sys/isa_defs.h>	/* get endianness selection */
 
-#if	defined(_BIG_ENDIAN)
+#if	defined(_ZFS_BIG_ENDIAN)
 /* here for big-endian CPUs */
 #define	SKEIN_NEED_SWAP   (1)
 #else
diff --git a/module/nvpair/nvpair.c b/module/nvpair/nvpair.c
index 6c0261f08..20a58802f 100644
--- a/module/nvpair/nvpair.c
+++ b/module/nvpair/nvpair.c
@@ -2555,11 +2555,13 @@ nvlist_common(nvlist_t *nvl, char *buf, size_t *buflen, int encoding,
 	int err = 0;
 	nvstream_t nvs;
 	int nvl_endian;
-#ifdef	_LITTLE_ENDIAN
+#if defined(_ZFS_LITTLE_ENDIAN)
 	int host_endian = 1;
-#else
+#elif defined(_ZFS_BIG_ENDIAN)
 	int host_endian = 0;
-#endif	/* _LITTLE_ENDIAN */
+#else
+#error "No endian defined!"
+#endif	/* _ZFS_LITTLE_ENDIAN */
 	nvs_header_t *nvh;
 
 	if (buflen == NULL || nvl == NULL ||
diff --git a/module/unicode/uconv.c b/module/unicode/uconv.c
index d812d5f96..fe84979d0 100644
--- a/module/unicode/uconv.c
+++ b/module/unicode/uconv.c
@@ -69,7 +69,7 @@
 #define	UCONV_OUT_ENDIAN_MASKS	(UCONV_OUT_BIG_ENDIAN | UCONV_OUT_LITTLE_ENDIAN)
 
 /* Native and reversed endian macros. */
-#ifdef	_BIG_ENDIAN
+#ifdef	_ZFS_BIG_ENDIAN
 #define	UCONV_IN_NAT_ENDIAN	UCONV_IN_BIG_ENDIAN
 #define	UCONV_IN_REV_ENDIAN	UCONV_IN_LITTLE_ENDIAN
 #define	UCONV_OUT_NAT_ENDIAN	UCONV_OUT_BIG_ENDIAN
diff --git a/module/zfs/lz4.c b/module/zfs/lz4.c
index 52e527b02..4b46e6948 100644
--- a/module/zfs/lz4.c
+++ b/module/zfs/lz4.c
@@ -208,7 +208,7 @@ lz4_decompress_zfs(void *s_start, void *d_start, size_t s_len,
  * Little Endian or Big Endian?
  * Note: overwrite the below #define if you know your architecture endianness.
  */
-#if defined(_BIG_ENDIAN)
+#if defined(_ZFS_BIG_ENDIAN)
 #define	LZ4_BIG_ENDIAN 1
 #else
 /*
diff --git a/module/zfs/vdev_raidz_math_powerpc_altivec.c b/module/zfs/vdev_raidz_math_powerpc_altivec.c
index 88f2646ae..1db2c4cd3 100644
--- a/module/zfs/vdev_raidz_math_powerpc_altivec.c
+++ b/module/zfs/vdev_raidz_math_powerpc_altivec.c
@@ -225,7 +225,7 @@ const raidz_impl_ops_t vdev_raidz_powerpc_altivec_impl = {
 
 
 #if defined(__powerpc__)
-#if defined(_LITTLE_ENDIAN) && _LITTLE_ENDIAN
+#if defined(_ZFS_LITTLE_ENDIAN) && _LITTLE_ENDIAN
 /* BEGIN CSTYLED */
 const uint8_t
 __attribute__((aligned(256))) gf_clmul_mod_lt[4*256][16] = {