Index: sys/arch/amd64/include/endian.h
===================================================================
RCS file: /mount/openbsd/cvs/src/sys/arch/amd64/include/endian.h,v
diff -u -p -u -p -r1.8 endian.h
--- sys/arch/amd64/include/endian.h	7 May 2024 14:26:48 -0000	1.8
+++ sys/arch/amd64/include/endian.h	14 May 2024 23:02:16 -0000
@@ -27,6 +27,34 @@
 #ifndef _MACHINE_ENDIAN_H_
 #define _MACHINE_ENDIAN_H_
 
+#ifndef __FROM_SYS__ENDIAN
+#include <sys/_types.h>
+#endif
+
+static __inline __uint16_t
+__swap16md(__uint16_t _x)
+{
+	__asm ("rorw $8, %w0" : "+r" (_x));
+	return (_x);
+}
+
+static __inline __uint32_t
+__swap32md(__uint32_t _x)
+{
+	__asm ("bswap %0" : "+r" (_x));
+	return (_x);
+}
+
+static __inline __uint64_t
+__swap64md(__uint64_t _x)
+{
+	__asm ("bswapq %0" : "+r" (_x));
+	return (_x);
+}
+
+/* Tell sys/endian.h we have MD variants of the swap macros.  */
+#define __HAVE_MD_SWAP
+
 #define _BYTE_ORDER _LITTLE_ENDIAN
 
 #ifndef __FROM_SYS__ENDIAN
Index: sys/arch/arm/include/endian.h
===================================================================
RCS file: /mount/openbsd/cvs/src/sys/arch/arm/include/endian.h,v
diff -u -p -u -p -r1.12 endian.h
--- sys/arch/arm/include/endian.h	7 May 2024 14:26:48 -0000	1.12
+++ sys/arch/arm/include/endian.h	14 May 2024 23:02:16 -0000
@@ -19,11 +19,48 @@
 #ifndef _ARM_ENDIAN_H_
 #define _ARM_ENDIAN_H_
 
+#ifndef __FROM_SYS__ENDIAN
+#include <sys/_types.h>
+#endif
+
+static __inline __uint16_t
+__swap16md(__uint16_t _x)
+{
+	__uint16_t _rv;
+
+	__asm ("rev16 %0, %1" : "=r" (_rv) : "r" (_x));
+
+	return (_rv);
+}
+
+static __inline __uint32_t
+__swap32md(__uint32_t _x)
+{
+	__uint32_t _rv;
+
+	__asm ("rev %0, %1" : "=r" (_rv) : "r" (_x));
+
+	return (_rv);
+}
+
+static __inline __uint64_t
+__swap64md(__uint64_t _x)
+{
+	__uint64_t _rv;
+
+	_rv = (__uint64_t)__swap32md(_x >> 32) |
+	    (__uint64_t)__swap32md(_x) << 32;
+
+	return (_rv);
+}
+
+/* Tell sys/endian.h we have MD variants of the swap macros.  */
+#define __HAVE_MD_SWAP
+
 #define _BYTE_ORDER _LITTLE_ENDIAN
 #define	__STRICT_ALIGNMENT
 
 #ifndef __FROM_SYS__ENDIAN
 #include <sys/endian.h>
 #endif
-
 #endif /* _ARM_ENDIAN_H_ */
Index: sys/arch/arm64/include/endian.h
===================================================================
RCS file: /mount/openbsd/cvs/src/sys/arch/arm64/include/endian.h,v
diff -u -p -u -p -r1.4 endian.h
--- sys/arch/arm64/include/endian.h	7 May 2024 14:26:48 -0000	1.4
+++ sys/arch/arm64/include/endian.h	14 May 2024 23:02:16 -0000
@@ -19,11 +19,48 @@
 #ifndef _MACHINE_ENDIAN_H_
 #define _MACHINE_ENDIAN_H_
 
+#ifndef __FROM_SYS__ENDIAN
+#include <sys/_types.h>
+#endif
+
+static __inline __uint16_t
+__swap16md(__uint16_t _x)
+{
+        __uint16_t _rv;
+
+        __asm ("rev16 %w0, %w1" : "=r" (_rv) : "r"(_x));
+
+	return (_rv);
+}
+
+static __inline __uint32_t
+__swap32md(__uint32_t _x)
+{
+        __uint32_t _rv;
+
+        __asm ("rev %w0, %w1" : "=r" (_rv) : "r"(_x));
+
+        return (_rv);
+}
+
+static __inline __uint64_t
+__swap64md(__uint64_t _x)
+{
+        __uint64_t _rv;
+
+        __asm ("rev %x0, %x1" : "=r" (_rv) : "r"(_x));
+
+        return (_rv);
+}
+
+/* Tell sys/endian.h we have MD variants of the swap macros.  */
+#define __HAVE_MD_SWAP
+
+
 #define _BYTE_ORDER _LITTLE_ENDIAN
 #define	__STRICT_ALIGNMENT
 
 #ifndef __FROM_SYS__ENDIAN
 #include <sys/endian.h>
 #endif
-
 #endif /* _MACHINE_ENDIAN_H_ */
Index: sys/arch/i386/include/endian.h
===================================================================
RCS file: /mount/openbsd/cvs/src/sys/arch/i386/include/endian.h,v
diff -u -p -u -p -r1.20 endian.h
--- sys/arch/i386/include/endian.h	7 May 2024 14:26:48 -0000	1.20
+++ sys/arch/i386/include/endian.h	14 May 2024 23:02:16 -0000
@@ -27,6 +27,34 @@
 #ifndef _MACHINE_ENDIAN_H_
 #define _MACHINE_ENDIAN_H_
 
+#ifndef __FROM_SYS__ENDIAN
+#include <sys/_types.h>
+#endif
+
+static __inline __uint16_t
+__swap16md(__uint16_t _x)
+{
+	__asm ("rorw $8, %w0" : "+r" (_x));
+	return (_x);
+}
+
+static __inline __uint32_t
+__swap32md(__uint32_t _x)
+{
+	__asm ("bswap %0" : "+r" (_x));
+	return (_x);
+}
+
+static __inline __uint64_t
+__swap64md(__uint64_t _x)
+{
+	return ((__uint64_t)__swap32md(_x >> 32) |
+	    (__uint64_t)__swap32md(_x & 0xffffffff) << 32);
+}
+
+/* Tell sys/endian.h we have MD variants of the swap macros.  */
+#define __HAVE_MD_SWAP
+
 #define _BYTE_ORDER _LITTLE_ENDIAN
 
 #ifndef __FROM_SYS__ENDIAN
Index: sys/arch/powerpc/include/endian.h
===================================================================
RCS file: /mount/openbsd/cvs/src/sys/arch/powerpc/include/endian.h,v
diff -u -p -u -p -r1.22 endian.h
--- sys/arch/powerpc/include/endian.h	7 May 2024 14:26:48 -0000	1.22
+++ sys/arch/powerpc/include/endian.h	14 May 2024 23:02:16 -0000
@@ -27,6 +27,72 @@
 #ifndef _POWERPC_ENDIAN_H_
 #define _POWERPC_ENDIAN_H_
 
+#ifdef _KERNEL
+
+static inline __uint16_t
+__mswap16(volatile const __uint16_t *m)
+{
+	__uint16_t v;
+
+	__asm("lhbrx %0, 0, %1"
+	    : "=r" (v)
+            : "r" (m), "m" (*m));
+
+	return (v);
+}
+
+static inline __uint32_t
+__mswap32(volatile const __uint32_t *m)
+{
+	__uint32_t v;
+
+	__asm("lwbrx %0, 0, %1"
+	    : "=r" (v)
+            : "r" (m), "m" (*m));
+
+	return (v);
+}
+
+static inline __uint64_t
+__mswap64(volatile const __uint64_t *m)
+{
+	__uint32_t *a = (__uint32_t *)m;
+	__uint64_t v;
+
+	v = (__uint64_t)__mswap32(a + 1) << 32 |
+	    (__uint64_t)__mswap32(a);
+
+	return (v);
+}
+
+static inline void
+__swapm16(volatile __uint16_t *m, __uint16_t v)
+{
+	__asm("sthbrx %1, 0, %2"
+	    : "=m" (*m)
+	    : "r" (v), "r" (m));
+}
+
+static inline void
+__swapm32(volatile __uint32_t *m, __uint32_t v)
+{
+	__asm("stwbrx %1, 0, %2"
+	    : "=m" (*m)
+	    : "r" (v), "r" (m));
+}
+
+static inline void
+__swapm64(volatile __uint64_t *m, __uint64_t v)
+{
+	__uint32_t *a = (__uint32_t *)m;
+
+	__swapm32(a + 1, v >> 32);
+	__swapm32(a, v);
+}
+
+#define __HAVE_MD_SWAPIO
+#endif /* _KERNEL */
+
 #undef _BIG_ENDIAN	/* XXX - gcc may define _BIG_ENDIAN too */
 #define _BYTE_ORDER _BIG_ENDIAN
 
Index: sys/arch/powerpc64/include/endian.h
===================================================================
RCS file: /mount/openbsd/cvs/src/sys/arch/powerpc64/include/endian.h,v
diff -u -p -u -p -r1.3 endian.h
--- sys/arch/powerpc64/include/endian.h	7 May 2024 14:26:48 -0000	1.3
+++ sys/arch/powerpc64/include/endian.h	14 May 2024 23:02:16 -0000
@@ -27,6 +27,71 @@
 #ifndef _MACHINE_ENDIAN_H_
 #define _MACHINE_ENDIAN_H_
 
+#ifdef _KERNEL
+
+static inline __uint16_t
+__mswap16(volatile const __uint16_t *m)
+{
+	__uint16_t v;
+
+	__asm("lhbrx %0, 0, %1"
+	    : "=r" (v)
+	    : "r" (m), "m" (*m));
+
+	return (v);
+}
+
+static inline __uint32_t
+__mswap32(volatile const __uint32_t *m)
+{
+	__uint32_t v;
+
+	__asm("lwbrx %0, 0, %1"
+	    : "=r" (v)
+	    : "r" (m), "m" (*m));
+
+	return (v);
+}
+
+static inline __uint64_t
+__mswap64(volatile const __uint64_t *m)
+{
+	__uint64_t v;
+
+	__asm("ldbrx %0, 0, %1"
+	    : "=r" (v)
+	    : "r" (m), "m" (*m));
+
+	return (v);
+}
+
+static inline void
+__swapm16(volatile __uint16_t *m, __uint16_t v)
+{
+	__asm("sthbrx %1, 0, %2"
+	    : "=m" (*m)
+	    : "r" (v), "r" (m));
+}
+
+static inline void
+__swapm32(volatile __uint32_t *m, __uint32_t v)
+{
+	__asm("stwbrx %1, 0, %2"
+	    : "=m" (*m)
+	    : "r" (v), "r" (m));
+}
+
+static inline void
+__swapm64(volatile __uint64_t *m, __uint64_t v)
+{
+	__asm("stdbrx %1, 0, %2"
+	    : "=m" (*m)
+	    : "r" (v), "r" (m));
+}
+
+#define __HAVE_MD_SWAPIO
+#endif /* _KERNEL */
+
 #undef _BIG_ENDIAN	/* XXX - gcc may define _BIG_ENDIAN too */
 #define _BYTE_ORDER _BIG_ENDIAN