backout 5876 sys/regset.h pollutes name space

backout commit 21227944c2bcc086121a5428f3f9d2496ba646f5.

44 files changed, 801 insertions, 672 deletions

diff --git a/usr/src/cmd/csh/i386/signal.c b/usr/src/cmd/csh/i386/signal.c
index 59b3eb54e4..d023a9bd88 100644
--- a/usr/src/cmd/csh/i386/signal.c
+++ b/usr/src/cmd/csh/i386/signal.c
@@ -12,6 +12,8 @@
  * specifies the terms and conditions for redistribution.
  */
 
+#pragma ident	"%Z%%M%	%I%	%E% SMI"
+
 /*
  * 4.3BSD signal compatibility functions
  *
@@ -26,7 +28,6 @@
 #include <sys/types.h>
 #include <sys/siginfo.h>
 #include <sys/ucontext.h>
-#include <sys/regset.h>
 #include <signal.h>
 #include "signal.h"
 #include <errno.h>
diff --git a/usr/src/cmd/csh/sparc/signal.c b/usr/src/cmd/csh/sparc/signal.c
index cac56044fa..9502940859 100644
--- a/usr/src/cmd/csh/sparc/signal.c
+++ b/usr/src/cmd/csh/sparc/signal.c
@@ -12,6 +12,8 @@
  * specifies the terms and conditions for redistribution.
  */
 
+#pragma ident	"%Z%%M%	%I%	%E% SMI"
+
 /*
  * 4.3BSD signal compatibility functions
  *
@@ -26,7 +28,6 @@
 #include <sys/types.h>
 #include <sys/siginfo.h>
 #include <sys/ucontext.h>
-#include <sys/regset.h>
 #include <signal.h>
 #include "signal.h"
 #include <errno.h>
diff --git a/usr/src/cmd/mdb/intel/mdb/proc_amd64dep.c b/usr/src/cmd/mdb/intel/mdb/proc_amd64dep.c
index c11e08ba0d..ed61bade77 100644
--- a/usr/src/cmd/mdb/intel/mdb/proc_amd64dep.c
+++ b/usr/src/cmd/mdb/intel/mdb/proc_amd64dep.c
@@ -448,7 +448,7 @@ pt_fpregs(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
 	mdb_tgt_t *t = mdb.m_target;
 	mdb_tgt_tid_t tid;
 	prfpregset_t fprs;
-	struct _fpchip_state fps;
+	struct fpchip_state fps;
 	char buf[256];
 	uint_t top;
 	int i;
diff --git a/usr/src/cmd/mdb/sparc/kmdb/kmdb_makecontext.c b/usr/src/cmd/mdb/sparc/kmdb/kmdb_makecontext.c
index 0a7f46f5d1..1d3781f1e9 100644
--- a/usr/src/cmd/mdb/sparc/kmdb/kmdb_makecontext.c
+++ b/usr/src/cmd/mdb/sparc/kmdb/kmdb_makecontext.c
@@ -24,6 +24,8 @@
  * Use is subject to license terms.
  */
 
+#pragma ident	"%Z%%M%	%I%	%E% SMI"
+
 /*
  * Context-saving routine used for pipelines.  Designed for use only
  * with kmdb_setcontext, and with the assumption that func() will never
@@ -34,7 +36,6 @@
 #include <ucontext.h>
 #include <sys/types.h>
 #include <sys/stack.h>
-#include <sys/regset.h>
 
 #include <kmdb/kmdb_context_impl.h>
 #include <mdb/mdb_kreg.h>
diff --git a/usr/src/lib/libc/amd64/gen/makectxt.c b/usr/src/lib/libc/amd64/gen/makectxt.c
index c8fd3c7742..5b2ce15313 100644
--- a/usr/src/lib/libc/amd64/gen/makectxt.c
+++ b/usr/src/lib/libc/amd64/gen/makectxt.c
@@ -27,13 +27,14 @@
 /*	Copyright (c) 1988 AT&T	*/
 /*	  All Rights Reserved  	*/
 
+#pragma ident	"%Z%%M%	%I%	%E% SMI"
+
 #pragma weak _makecontext = makecontext
 
 #include "lint.h"
 #include <stdarg.h>
 #include <ucontext.h>
 #include <sys/stack.h>
-#include <sys/regset.h>
 
 /*
  * The ucontext_t that the user passes in must have been primed with a
diff --git a/usr/src/lib/libc/amd64/gen/siglongjmp.c b/usr/src/lib/libc/amd64/gen/siglongjmp.c
index 6637c19625..07a89b485f 100644
--- a/usr/src/lib/libc/amd64/gen/siglongjmp.c
+++ b/usr/src/lib/libc/amd64/gen/siglongjmp.c
@@ -24,12 +24,13 @@
  * Use is subject to license terms.
  */
 
+#pragma ident	"%Z%%M%	%I%	%E% SMI"
+
 #pragma weak _siglongjmp = siglongjmp
 
 #include "lint.h"
 #include <sys/types.h>
 #include <sys/ucontext.h>
-#include <sys/regset.h>
 #include <setjmp.h>
 #include <ucontext.h>
 
diff --git a/usr/src/lib/libc/i386/gen/makectxt.c b/usr/src/lib/libc/i386/gen/makectxt.c
index 1e6f995d84..d72a67a481 100644
--- a/usr/src/lib/libc/i386/gen/makectxt.c
+++ b/usr/src/lib/libc/i386/gen/makectxt.c
@@ -27,12 +27,13 @@
 /*	Copyright (c) 1988 AT&T	*/
 /*	  All Rights Reserved  	*/
 
+#pragma ident	"%Z%%M%	%I%	%E% SMI"
+
 #pragma weak _makecontext = makecontext
 
 #include "lint.h"
 #include <stdarg.h>
 #include <ucontext.h>
-#include <sys/regset.h>
 #include <sys/stack.h>
 
 /*
diff --git a/usr/src/lib/libc/i386/gen/siglongjmp.c b/usr/src/lib/libc/i386/gen/siglongjmp.c
index 17261b3efd..ea23fcf749 100644
--- a/usr/src/lib/libc/i386/gen/siglongjmp.c
+++ b/usr/src/lib/libc/i386/gen/siglongjmp.c
@@ -28,12 +28,13 @@
 /*	Copyright (c) 1988 AT&T	*/
 /*	  All Rights Reserved  	*/
 
+#pragma ident	"%Z%%M%	%I%	%E% SMI"
+
 #pragma weak _siglongjmp = siglongjmp
 
 #include "lint.h"
 #include <sys/types.h>
 #include <sys/ucontext.h>
-#include <sys/regset.h>
 #include <setjmp.h>
 #include <ucontext.h>
 
diff --git a/usr/src/lib/libc/port/threads/sigaction.c b/usr/src/lib/libc/port/threads/sigaction.c
index 571e211f97..8e9df7ab60 100644
--- a/usr/src/lib/libc/port/threads/sigaction.c
+++ b/usr/src/lib/libc/port/threads/sigaction.c
@@ -208,7 +208,7 @@ call_user_handler(int sig, siginfo_t *sip, ucontext_t *ucp)
 
 		if (--fp->fpu_qcnt > 0) {
 			unsigned char i;
-			struct _fq *fqp;
+			struct fq *fqp;
 
 			fqp = fp->fpu_q;
 			for (i = 0; i < fp->fpu_qcnt; i++)
diff --git a/usr/src/lib/libc/sparc/gen/makectxt.c b/usr/src/lib/libc/sparc/gen/makectxt.c
index fa5725525e..7519bdabcb 100644
--- a/usr/src/lib/libc/sparc/gen/makectxt.c
+++ b/usr/src/lib/libc/sparc/gen/makectxt.c
@@ -27,6 +27,8 @@
 /*	Copyright (c) 1988 AT&T	*/
 /*	  All Rights Reserved  	*/
 
+#pragma ident	"%Z%%M%	%I%	%E% SMI"
+
 #pragma weak _makecontext = makecontext
 #pragma weak ___makecontext_v2 = __makecontext_v2
 
@@ -36,7 +38,6 @@
 #include <sys/ucontext.h>
 #include <sys/stack.h>
 #include <sys/frame.h>
-#include <sys/regset.h>
 
 /*
  * The ucontext_t that the user passes in must have been primed with a
diff --git a/usr/src/lib/libc/sparc/gen/siglongjmp.c b/usr/src/lib/libc/sparc/gen/siglongjmp.c
index 90b406cf8d..83a640397d 100644
--- a/usr/src/lib/libc/sparc/gen/siglongjmp.c
+++ b/usr/src/lib/libc/sparc/gen/siglongjmp.c
@@ -27,13 +27,14 @@
 /*	Copyright (c) 1988 AT&T	*/
 /*	  All Rights Reserved  	*/
 
+#pragma ident	"%Z%%M%	%I%	%E% SMI"
+
 #pragma weak _siglongjmp = siglongjmp
 
 #include "lint.h"
 #include <sys/types.h>
 #include <sys/stack.h>
 #include <sys/frame.h>
-#include <sys/regset.h>
 #include <memory.h>
 #include <ucontext.h>
 #include <setjmp.h>
diff --git a/usr/src/lib/libc/sparcv9/gen/makectxt.c b/usr/src/lib/libc/sparcv9/gen/makectxt.c
index fa5725525e..7519bdabcb 100644
--- a/usr/src/lib/libc/sparcv9/gen/makectxt.c
+++ b/usr/src/lib/libc/sparcv9/gen/makectxt.c
@@ -27,6 +27,8 @@
 /*	Copyright (c) 1988 AT&T	*/
 /*	  All Rights Reserved  	*/
 
+#pragma ident	"%Z%%M%	%I%	%E% SMI"
+
 #pragma weak _makecontext = makecontext
 #pragma weak ___makecontext_v2 = __makecontext_v2
 
@@ -36,7 +38,6 @@
 #include <sys/ucontext.h>
 #include <sys/stack.h>
 #include <sys/frame.h>
-#include <sys/regset.h>
 
 /*
  * The ucontext_t that the user passes in must have been primed with a
diff --git a/usr/src/lib/libc/sparcv9/gen/siglongjmp.c b/usr/src/lib/libc/sparcv9/gen/siglongjmp.c
index 424942966f..5d4ca06426 100644
--- a/usr/src/lib/libc/sparcv9/gen/siglongjmp.c
+++ b/usr/src/lib/libc/sparcv9/gen/siglongjmp.c
@@ -32,7 +32,6 @@
 #include <sys/types.h>
 #include <sys/stack.h>
 #include <sys/frame.h>
-#include <sys/regset.h>
 #include <memory.h>
 #include <ucontext.h>
 #include <setjmp.h>
diff --git a/usr/src/lib/libm/common/m9x/__fex_hdlr.c b/usr/src/lib/libm/common/m9x/__fex_hdlr.c
index 5b7ac8d933..7732d0a9fe 100644
--- a/usr/src/lib/libm/common/m9x/__fex_hdlr.c
+++ b/usr/src/lib/libm/common/m9x/__fex_hdlr.c
@@ -40,7 +40,6 @@
 #include <sunmath.h>
 #endif
 #include <fenv.h>
-#include <sys/regset.h>
 #include "fex_handler.h"
 #include "fenv_inlines.h"
 
diff --git a/usr/src/lib/libm/common/m9x/__fex_i386.c b/usr/src/lib/libm/common/m9x/__fex_i386.c
index 5743bd414e..c6ffa593be 100644
--- a/usr/src/lib/libm/common/m9x/__fex_i386.c
+++ b/usr/src/lib/libm/common/m9x/__fex_i386.c
@@ -40,7 +40,6 @@
 #include <sunmath.h>
 #endif
 #include <fenv.h>
-#include <sys/regset.h>
 #include "fex_handler.h"
 #include "fenv_inlines.h"
 
diff --git a/usr/src/lib/libm/common/m9x/__fex_sse.c b/usr/src/lib/libm/common/m9x/__fex_sse.c
index e679e71929..df83dff212 100644
--- a/usr/src/lib/libm/common/m9x/__fex_sse.c
+++ b/usr/src/lib/libm/common/m9x/__fex_sse.c
@@ -34,7 +34,6 @@
 #else
 #include <sys/ieeefp.h>
 #endif
-#include <sys/regset.h>
 #include "fex_handler.h"
 #include "fenv_inlines.h"
 
diff --git a/usr/src/lib/libm/common/m9x/fex_log.c b/usr/src/lib/libm/common/m9x/fex_log.c
index 6a8e759cc0..336358da4c 100644
--- a/usr/src/lib/libm/common/m9x/fex_log.c
+++ b/usr/src/lib/libm/common/m9x/fex_log.c
@@ -39,7 +39,6 @@
 #include <string.h>
 #include <signal.h>
 #include <ucontext.h>
-#include <sys/regset.h>
 #include <sys/frame.h>
 #include <fenv.h>
 #include <sys/ieeefp.h>
diff --git a/usr/src/lib/libproc/common/P32ton.c b/usr/src/lib/libproc/common/P32ton.c
index acb52058c9..78219550c8 100644
--- a/usr/src/lib/libproc/common/P32ton.c
+++ b/usr/src/lib/libproc/common/P32ton.c
@@ -24,6 +24,8 @@
  * Use is subject to license terms.
  */
 
+#pragma ident	"%Z%%M%	%I%	%E% SMI"
+
 #include <sys/types.h>
 #include <sys/mkdev.h>
 #include <sys/regset.h>
@@ -265,7 +267,7 @@ prfpregset_32_to_n(const prfpregset32_t *src, prfpregset_t *dst)
 #elif defined(__amd64)
 
 	struct _fpstate32 *src32 = (struct _fpstate32 *)src;
-	struct _fpchip_state *dst64 = (struct _fpchip_state *)dst;
+	struct fpchip_state *dst64 = (struct fpchip_state *)dst;
 	int i;
 
 	(void) memcpy(dst64->st, src32->_st, sizeof (src32->_st));
@@ -596,7 +598,7 @@ prfpregset_n_to_32(const prfpregset_t *src, prfpregset32_t *dst)
 #elif defined(__amd64)
 
 	struct _fpstate32 *dst32 = (struct _fpstate32 *)dst;
-	struct _fpchip_state *src64 = (struct _fpchip_state *)src;
+	struct fpchip_state *src64 = (struct fpchip_state *)src;
 	uint32_t top;
 	int i;
 
diff --git a/usr/src/pkg/manifests/system-header.mf b/usr/src/pkg/manifests/system-header.mf
index f4f92a63e0..08f0b19416 100644
--- a/usr/src/pkg/manifests/system-header.mf
+++ b/usr/src/pkg/manifests/system-header.mf
@@ -1219,7 +1219,6 @@ $(i386_ONLY)file path=usr/include/sys/mc_amd.h
 $(i386_ONLY)file path=usr/include/sys/mc_intel.h
 $(i386_ONLY)file path=usr/include/sys/mca_amd.h
 $(i386_ONLY)file path=usr/include/sys/mca_x86.h
-file path=usr/include/sys/mcontext.h
 file path=usr/include/sys/md4.h
 file path=usr/include/sys/md5.h
 file path=usr/include/sys/md5_consts.h
diff --git a/usr/src/uts/common/sys/core.h b/usr/src/uts/common/sys/core.h
index 543ed5fada..28ee6faaff 100644
--- a/usr/src/uts/common/sys/core.h
+++ b/usr/src/uts/common/sys/core.h
@@ -20,8 +20,6 @@
  * CDDL HEADER END
  */
 /*
- * Copyright 2015 Nexenta Systems, Inc.  All rights reserved.
- *
  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
  */
@@ -29,6 +27,8 @@
 #ifndef	_SYS_CORE_H
 #define	_SYS_CORE_H
 
+#pragma ident	"%Z%%M%	%I%	%E% SMI"
+
 #ifndef _KERNEL
 #include <sys/reg.h>
 #endif /* _KERNEL */
@@ -63,9 +63,9 @@ struct core {
 	int	c_dsize;		/* Data size (bytes) */
 	int	c_ssize;		/* Stack size (bytes) */
 	char	c_cmdname[CORE_NAMELEN + 1]; /* Command name */
-	struct	_fpu	c_fpu;		/* external FPU state */
+	struct	fpu c_fpu;		/* external FPU state */
 #if defined(__sparc)
-	struct	_fq c_fpu_q[_MAXFPQ];	/* fpu exception queue */
+	struct	fq c_fpu_q[MAXFPQ];	/* fpu exception queue */
 #endif
 	int	c_ucode;		/* Exception no. from u_code */
 };
diff --git a/usr/src/uts/common/sys/prsystm.h b/usr/src/uts/common/sys/prsystm.h
index 6f5d4b914f..ebded76dce 100644
--- a/usr/src/uts/common/sys/prsystm.h
+++ b/usr/src/uts/common/sys/prsystm.h
@@ -108,9 +108,9 @@ extern int  pr_watch_emul(struct regs *, caddr_t, enum seg_rw);
 extern void pr_free_watched_pages(proc_t *);
 extern int  pr_allstopped(proc_t *, int);
 #if defined(__sparc)
-struct _gwindows;
+struct gwindows;
 extern	int	prnwindows(klwp_t *);
-extern	void	prgetwindows(klwp_t *, struct _gwindows *);
+extern	void	prgetwindows(klwp_t *, struct gwindows *);
 #if defined(__sparcv9) /* 32-bit adb macros should not see these defs */
 extern	void	prgetasregs(klwp_t *, asrset_t);
 extern	void	prsetasregs(klwp_t *, asrset_t);
diff --git a/usr/src/uts/intel/ia32/os/archdep.c b/usr/src/uts/intel/ia32/os/archdep.c
index 2a33f306c2..d83b16d673 100644
--- a/usr/src/uts/intel/ia32/os/archdep.c
+++ b/usr/src/uts/intel/ia32/os/archdep.c
@@ -193,7 +193,7 @@ fpregset_to_fxsave(const fpregset_t *fp, struct fxsave_state *fx)
 #if defined(__amd64)
 	bcopy(fp, fx, sizeof (*fx));
 #else
-	const struct _fpchip_state *fc = &fp->fp_reg_set.fpchip_state;
+	const struct fpchip_state *fc = &fp->fp_reg_set.fpchip_state;
 
 	fnsave_to_fxsave((const struct fnsave_state *)fc, fx);
 	fx->fx_mxcsr = fc->mxcsr;
@@ -214,7 +214,7 @@ fxsave_to_fpregset(const struct fxsave_state *fx, fpregset_t *fp)
 #if defined(__amd64)
 	bcopy(fx, fp, sizeof (*fx));
 #else
-	struct _fpchip_state *fc = &fp->fp_reg_set.fpchip_state;
+	struct fpchip_state *fc = &fp->fp_reg_set.fpchip_state;
 
 	fxsave_to_fnsave(fx, (struct fnsave_state *)fc);
 	fc->mxcsr = fx->fx_mxcsr;
diff --git a/usr/src/uts/intel/ia32/os/fpu.c b/usr/src/uts/intel/ia32/os/fpu.c
index dc3e286ad5..b7022cf0e5 100644
--- a/usr/src/uts/intel/ia32/os/fpu.c
+++ b/usr/src/uts/intel/ia32/os/fpu.c
@@ -416,7 +416,7 @@ fpnoextflt(struct regs *rp)
 	ASSERT(sizeof (struct xsave_state) >= AVX_XSAVE_SIZE);
 
 #if defined(__i386)
-	ASSERT(sizeof (struct _fpu) == sizeof (struct __old_fpu));
+	ASSERT(sizeof (struct fpu) == sizeof (struct __old_fpu));
 #endif	/* __i386 */
 #endif	/* !__lint */
 
diff --git a/usr/src/uts/intel/sys/Makefile b/usr/src/uts/intel/sys/Makefile
index 5cfbdec4fc..192ada41a5 100644
--- a/usr/src/uts/intel/sys/Makefile
+++ b/usr/src/uts/intel/sys/Makefile
@@ -56,7 +56,6 @@ HDRS	=			\
 	mc_intel.h		\
 	mca_amd.h		\
 	mca_x86.h		\
-	mcontext.h		\
 	mutex_impl.h		\
 	obpdefs.h		\
 	old_procfs.h		\
diff --git a/usr/src/uts/intel/sys/fp.h b/usr/src/uts/intel/sys/fp.h
index 3373484dec..4956e2d318 100644
--- a/usr/src/uts/intel/sys/fp.h
+++ b/usr/src/uts/intel/sys/fp.h
@@ -19,8 +19,6 @@
  * CDDL HEADER END
  */
 /*
- * Copyright 2015 Nexenta Systems, Inc.  All rights reserved.
- *
  * Copyright (c) 1992, 2010, Oracle and/or its affiliates. All rights reserved.
  */
 
@@ -170,91 +168,6 @@ extern "C" {
 	"\20\20fz\17ru\16rd\15pm\14um\13om\12zm\11dm"	\
 	"\10im\7daz\6pe\5ue\4oe\3ze\2de\1ie"
 
-/*
- * This structure is written to memory by an 'fnsave' instruction
- */
-struct fnsave_state {
-	uint16_t	f_fcw;
-	uint16_t	__f_ign0;
-	uint16_t	f_fsw;
-	uint16_t	__f_ign1;
-	uint16_t	f_ftw;
-	uint16_t	__f_ign2;
-	uint32_t	f_eip;
-	uint16_t	f_cs;
-	uint16_t	f_fop;
-	uint32_t	f_dp;
-	uint16_t	f_ds;
-	uint16_t	__f_ign3;
-	union {
-		uint16_t fpr_16[5];	/* 80-bits of x87 state */
-	} f_st[8];
-};	/* 108 bytes */
-
-/*
- * This structure is written to memory by an 'fxsave' instruction
- * Note the variant behaviour of this instruction between long mode
- * and legacy environments!
- */
-struct fxsave_state {
-	uint16_t	fx_fcw;
-	uint16_t	fx_fsw;
-	uint16_t	fx_fctw;	/* compressed tag word */
-	uint16_t	fx_fop;
-#if defined(__amd64)
-	uint64_t	fx_rip;
-	uint64_t	fx_rdp;
-#else
-	uint32_t	fx_eip;
-	uint16_t	fx_cs;
-	uint16_t	__fx_ign0;
-	uint32_t	fx_dp;
-	uint16_t	fx_ds;
-	uint16_t	__fx_ign1;
-#endif
-	uint32_t	fx_mxcsr;
-	uint32_t	fx_mxcsr_mask;
-	union {
-		uint16_t fpr_16[5];	/* 80-bits of x87 state */
-		u_longlong_t fpr_mmx;	/* 64-bit mmx register */
-		uint32_t __fpr_pad[4];	/* (pad out to 128-bits) */
-	} fx_st[8];
-#if defined(__amd64)
-	upad128_t	fx_xmm[16];	/* 128-bit registers */
-	upad128_t	__fx_ign2[6];
-#else
-	upad128_t	fx_xmm[8];	/* 128-bit registers */
-	upad128_t	__fx_ign2[14];
-#endif
-};	/* 512 bytes */
-
-/*
- * This structure is written to memory by an 'xsave' instruction.
- * First 512 byte is compatible with the format of an 'fxsave' area.
- */
-struct xsave_state {
-	struct fxsave_state	xs_fxsave;
-	uint64_t		xs_xstate_bv;	/* 512 */
-	uint64_t		xs_rsv_mbz[2];
-	uint64_t		xs_reserved[5];
-	upad128_t		xs_ymm[16];	/* avx - 576 */
-};	/* 832 bytes, asserted in fpnoextflt() */
-
-/*
- * Kernel's FPU save area
- */
-typedef struct {
-	union _kfpu_u {
-		struct fxsave_state kfpu_fx;
-#if defined(__i386)
-		struct fnsave_state kfpu_fn;
-#endif
-		struct xsave_state kfpu_xs;
-	} kfpu_u;
-	uint32_t kfpu_status;		/* saved at #mf exception */
-	uint32_t kfpu_xstatus;		/* saved at #xm exception */
-} kfpu_t;
-
 extern int fp_kind;		/* kind of fp support			*/
 extern int fp_save_mech;	/* fp save/restore mechanism		*/
 extern int fpu_exists;		/* FPU hw exists			*/
@@ -275,6 +188,9 @@ extern void fpxsave_ctxt(void *);
 extern void xsave_ctxt(void *);
 extern void (*fpsave_ctxt)(void *);
 
+struct fnsave_state;
+struct fxsave_state;
+struct xsave_state;
 extern void fxsave_insn(struct fxsave_state *);
 extern void fpsave(struct fnsave_state *);
 extern void fprestore(struct fnsave_state *);
diff --git a/usr/src/uts/intel/sys/mcontext.h b/usr/src/uts/intel/sys/mcontext.h
deleted file mode 100644
index 23d0aba364..0000000000
--- a/usr/src/uts/intel/sys/mcontext.h
+++ /dev/null
@@ -1,191 +0,0 @@
-/*
- * CDDL HEADER START
- *
- * The contents of this file are subject to the terms of the
- * Common Development and Distribution License (the "License").
- * You may not use this file except in compliance with the License.
- *
- * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
- * or http://www.opensolaris.org/os/licensing.
- * See the License for the specific language governing permissions
- * and limitations under the License.
- *
- * When distributing Covered Code, include this CDDL HEADER in each
- * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
- * If applicable, add the following below this CDDL HEADER, with the
- * fields enclosed by brackets "[]" replaced with your own identifying
- * information: Portions Copyright [yyyy] [name of copyright owner]
- *
- * CDDL HEADER END
- */
-/*
- * Copyright 2015 Nexenta Systems, Inc.  All rights reserved.
- *
- * Copyright (c) 1989, 2010, Oracle and/or its affiliates. All rights reserved.
- */
-/*	Copyright (c) 1990, 1991 UNIX System Laboratories, Inc. */
-
-/*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T		*/
-/*	All Rights Reserved	*/
-
-/*
- * Essential struct definitions for mcontext_t needed by ucontext.h
- * These were formerly in regset.h, which now includes this file.
- */
-
-#ifndef	_SYS_MCONTEXT_H
-#define	_SYS_MCONTEXT_H
-
-#include <sys/feature_tests.h>
-
-#if !defined(_ASM)
-#include <sys/types.h>
-#endif
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-/*
- * A gregset_t is defined as an array type for compatibility with the reference
- * source. This is important due to differences in the way the C language
- * treats arrays and structures as parameters.
- */
-#if defined(__amd64)
-#define	_NGREG	28
-#else
-#define	_NGREG	19
-#endif
-
-#if !defined(_ASM)
-
-#if defined(_LP64) || defined(_I32LPx)
-typedef long	greg_t;
-#else
-typedef int	greg_t;
-#endif
-
-#if defined(_SYSCALL32)
-
-typedef int32_t greg32_t;
-typedef int64_t	greg64_t;
-
-#endif	/* _SYSCALL32 */
-
-typedef greg_t	gregset_t[_NGREG];
-
-#if defined(_SYSCALL32)
-
-#define	_NGREG32	19
-#define	_NGREG64	28
-
-typedef greg32_t gregset32_t[_NGREG32];
-typedef	greg64_t gregset64_t[_NGREG64];
-
-#endif	/* _SYSCALL32 */
-
-/*
- * Floating point definitions.
- */
-
-#if defined(__amd64)
-
-typedef struct _fpu {
-	union {
-		struct _fpchip_state {
-			uint16_t cw;
-			uint16_t sw;
-			uint8_t  fctw;
-			uint8_t  __fx_rsvd;
-			uint16_t fop;
-			uint64_t rip;
-			uint64_t rdp;
-			uint32_t mxcsr;
-			uint32_t mxcsr_mask;
-			union {
-				uint16_t fpr_16[5];
-				upad128_t __fpr_pad;
-			} st[8];
-			upad128_t xmm[16];
-			upad128_t __fx_ign2[6];
-			uint32_t status;	/* sw at exception */
-			uint32_t xstatus;	/* mxcsr at exception */
-		} fpchip_state;
-		uint32_t	f_fpregs[130];
-	} fp_reg_set;
-} fpregset_t;
-
-#else	/* __i386 */
-
-/*
- * This definition of the floating point structure is binary
- * compatible with the Intel386 psABI definition, and source
- * compatible with that specification for x87-style floating point.
- * It also allows SSE/SSE2 state to be accessed on machines that
- * possess such hardware capabilities.
- */
-typedef struct _fpu {
-	union {
-		struct _fpchip_state {
-			uint32_t state[27];	/* 287/387 saved state */
-			uint32_t status;	/* saved at exception */
-			uint32_t mxcsr;		/* SSE control and status */
-			uint32_t xstatus;	/* SSE mxcsr at exception */
-			uint32_t __pad[2];	/* align to 128-bits */
-			upad128_t xmm[8];	/* %xmm0-%xmm7 */
-		} fpchip_state;
-		struct _fp_emul_space {		/* for emulator(s) */
-			uint8_t	fp_emul[246];
-			uint8_t	fp_epad[2];
-		} fp_emul_space;
-		uint32_t	f_fpregs[95];	/* union of the above */
-	} fp_reg_set;
-} fpregset_t;
-
-#endif	/* __i386 */
-
-#if defined(_SYSCALL32)
-
-/* Kernel view of user i386 fpu structure */
-
-typedef struct fpu32 {
-	union {
-		struct fpchip32_state {
-			uint32_t state[27];	/* 287/387 saved state */
-			uint32_t status;	/* saved at exception */
-			uint32_t mxcsr;		/* SSE control and status */
-			uint32_t xstatus;	/* SSE mxcsr at exception */
-			uint32_t __pad[2];	/* align to 128-bits */
-			uint32_t xmm[8][4];	/* %xmm0-%xmm7 */
-		} fpchip_state;
-		uint32_t	f_fpregs[95];	/* union of the above */
-	} fp_reg_set;
-} fpregset32_t;
-
-#endif	/* _SYSCALL32 */
-
-/*
- * Structure mcontext defines the complete hardware machine state.
- * (This structure is specified in the i386 ABI suppl.)
- */
-typedef struct {
-	gregset_t	gregs;		/* general register set */
-	fpregset_t	fpregs;		/* floating point register set */
-} mcontext_t;
-
-#if defined(_SYSCALL32)
-
-typedef struct {
-	gregset32_t	gregs;		/* general register set */
-	fpregset32_t	fpregs;		/* floating point register set */
-} mcontext32_t;
-
-#endif	/* _SYSCALL32 */
-
-#endif	/* _ASM */
-
-#ifdef	__cplusplus
-}
-#endif
-
-#endif	/* _SYS_MCONTEXT_H */
diff --git a/usr/src/uts/intel/sys/pcb.h b/usr/src/uts/intel/sys/pcb.h
index defd116eba..3a690bd980 100644
--- a/usr/src/uts/intel/sys/pcb.h
+++ b/usr/src/uts/intel/sys/pcb.h
@@ -28,9 +28,6 @@
 
 #include <sys/regset.h>
 #include <sys/segments.h>
-#ifndef _ASM
-#include <sys/fp.h>	/* kfpu_t */
-#endif
 
 #ifdef	__cplusplus
 extern "C" {
diff --git a/usr/src/uts/intel/sys/procfs_isa.h b/usr/src/uts/intel/sys/procfs_isa.h
index 5af0386d9b..b7a6cc3582 100644
--- a/usr/src/uts/intel/sys/procfs_isa.h
+++ b/usr/src/uts/intel/sys/procfs_isa.h
@@ -27,6 +27,8 @@
 #ifndef _SYS_PROCFS_ISA_H
 #define	_SYS_PROCFS_ISA_H
 
+#pragma ident	"%Z%%M%	%I%	%E% SMI"
+
 /*
  * Instruction Set Architecture specific component of <sys/procfs.h>
  * i386 version
@@ -67,7 +69,7 @@ typedef	uchar_t instr_t;
 #define	NPRGREG		_NGREG
 #define	prgreg_t	greg_t
 #define	prgregset_t	gregset_t
-#define	prfpregset	_fpu
+#define	prfpregset	fpu
 #define	prfpregset_t	fpregset_t
 
 #if defined(_SYSCALL32)
@@ -85,7 +87,7 @@ typedef	uchar_t		instr32_t;
 #define	NPRGREG32	_NGREG
 #define	prgreg32_t	greg_t
 #define	prgregset32_t	gregset_t
-#define	prfpregset32	_fpu
+#define	prfpregset32	fpu
 #define	prfpregset32_t	fpregset_t
 #endif
 #endif	/* _SYSCALL32 */
diff --git a/usr/src/uts/intel/sys/regset.h b/usr/src/uts/intel/sys/regset.h
index 12b8f9e888..5436ae0be3 100644
--- a/usr/src/uts/intel/sys/regset.h
+++ b/usr/src/uts/intel/sys/regset.h
@@ -19,8 +19,6 @@
  * CDDL HEADER END
  */
 /*
- * Copyright 2015 Nexenta Systems, Inc.  All rights reserved.
- *
  * Copyright (c) 1989, 2010, Oracle and/or its affiliates. All rights reserved.
  */
 /*	Copyright (c) 1990, 1991 UNIX System Laboratories, Inc. */
@@ -36,12 +34,13 @@
 #if !defined(_ASM)
 #include <sys/types.h>
 #endif
-#include <sys/mcontext.h>
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
+#if !defined(_XPG4_2) || defined(__EXTENSIONS__)
+
 /*
  * The names and offsets defined here should be specified by the
  * AMD64 ABI suppl.
@@ -135,16 +134,181 @@ extern "C" {
 
 #endif	/* __i386 */
 
+#endif	/* !defined(_XPG4_2) || defined(__EXTENSIONS__) */
+
+/*
+ * A gregset_t is defined as an array type for compatibility with the reference
+ * source. This is important due to differences in the way the C language
+ * treats arrays and structures as parameters.
+ */
+#if defined(__amd64)
+#define	_NGREG	28
+#else
+#define	_NGREG	19
+#endif
+#if !defined(_XPG4_2) || defined(__EXTENSIONS__)
 #define	NGREG	_NGREG
+#endif
 
 #if !defined(_ASM)
 
-#ifdef	__i386
+#if defined(_LP64) || defined(_I32LPx)
+typedef long	greg_t;
+#else
+typedef int	greg_t;
+#endif
+
+#if defined(_SYSCALL32)
+
+typedef int32_t greg32_t;
+typedef int64_t	greg64_t;
+
+#endif	/* _SYSCALL32 */
+
+typedef greg_t	gregset_t[_NGREG];
+
+#if defined(_SYSCALL32)
+
+#define	_NGREG32	19
+#define	_NGREG64	28
+
+typedef greg32_t gregset32_t[_NGREG32];
+typedef	greg64_t gregset64_t[_NGREG64];
+
+#endif	/* _SYSCALL32 */
+
+#if !defined(_XPG4_2) || defined(__EXTENSIONS__)
+
+/*
+ * Floating point definitions.
+ */
+
+/*
+ * This structure is written to memory by an 'fnsave' instruction
+ */
+struct fnsave_state {
+	uint16_t	f_fcw;
+	uint16_t	__f_ign0;
+	uint16_t	f_fsw;
+	uint16_t	__f_ign1;
+	uint16_t	f_ftw;
+	uint16_t	__f_ign2;
+	uint32_t	f_eip;
+	uint16_t	f_cs;
+	uint16_t	f_fop;
+	uint32_t	f_dp;
+	uint16_t	f_ds;
+	uint16_t	__f_ign3;
+	union {
+		uint16_t fpr_16[5];	/* 80-bits of x87 state */
+	} f_st[8];
+};	/* 108 bytes */
+
+/*
+ * This structure is written to memory by an 'fxsave' instruction
+ * Note the variant behaviour of this instruction between long mode
+ * and legacy environments!
+ */
+struct fxsave_state {
+	uint16_t	fx_fcw;
+	uint16_t	fx_fsw;
+	uint16_t	fx_fctw;	/* compressed tag word */
+	uint16_t	fx_fop;
+#if defined(__amd64)
+	uint64_t	fx_rip;
+	uint64_t	fx_rdp;
+#else
+	uint32_t	fx_eip;
+	uint16_t	fx_cs;
+	uint16_t	__fx_ign0;
+	uint32_t	fx_dp;
+	uint16_t	fx_ds;
+	uint16_t	__fx_ign1;
+#endif
+	uint32_t	fx_mxcsr;
+	uint32_t	fx_mxcsr_mask;
+	union {
+		uint16_t fpr_16[5];	/* 80-bits of x87 state */
+		u_longlong_t fpr_mmx;	/* 64-bit mmx register */
+		uint32_t __fpr_pad[4];	/* (pad out to 128-bits) */
+	} fx_st[8];
+#if defined(__amd64)
+	upad128_t	fx_xmm[16];	/* 128-bit registers */
+	upad128_t	__fx_ign2[6];
+#else
+	upad128_t	fx_xmm[8];	/* 128-bit registers */
+	upad128_t	__fx_ign2[14];
+#endif
+};	/* 512 bytes */
+
+/*
+ * This structure is written to memory by an 'xsave' instruction.
+ * First 512 byte is compatible with the format of an 'fxsave' area.
+ */
+struct xsave_state {
+	struct fxsave_state	xs_fxsave;
+	uint64_t		xs_xstate_bv;	/* 512 */
+	uint64_t		xs_rsv_mbz[2];
+	uint64_t		xs_reserved[5];
+	upad128_t		xs_ymm[16];	/* avx - 576 */
+};	/* 832 bytes, asserted in fpnoextflt() */
+
+#if defined(__amd64)
+
+typedef struct fpu {
+	union {
+		struct fpchip_state {
+			uint16_t cw;
+			uint16_t sw;
+			uint8_t  fctw;
+			uint8_t  __fx_rsvd;
+			uint16_t fop;
+			uint64_t rip;
+			uint64_t rdp;
+			uint32_t mxcsr;
+			uint32_t mxcsr_mask;
+			union {
+				uint16_t fpr_16[5];
+				upad128_t __fpr_pad;
+			} st[8];
+			upad128_t xmm[16];
+			upad128_t __fx_ign2[6];
+			uint32_t status;	/* sw at exception */
+			uint32_t xstatus;	/* mxcsr at exception */
+		} fpchip_state;
+		uint32_t	f_fpregs[130];
+	} fp_reg_set;
+} fpregset_t;
+
+#else	/* __i386 */
+
+/*
+ * This definition of the floating point structure is binary
+ * compatible with the Intel386 psABI definition, and source
+ * compatible with that specification for x87-style floating point.
+ * It also allows SSE/SSE2 state to be accessed on machines that
+ * possess such hardware capabilities.
+ */
+typedef struct fpu {
+	union {
+		struct fpchip_state {
+			uint32_t state[27];	/* 287/387 saved state */
+			uint32_t status;	/* saved at exception */
+			uint32_t mxcsr;		/* SSE control and status */
+			uint32_t xstatus;	/* SSE mxcsr at exception */
+			uint32_t __pad[2];	/* align to 128-bits */
+			upad128_t xmm[8];	/* %xmm0-%xmm7 */
+		} fpchip_state;
+		struct fp_emul_space {		/* for emulator(s) */
+			uint8_t	fp_emul[246];
+			uint8_t	fp_epad[2];
+		} fp_emul_space;
+		uint32_t	f_fpregs[95];	/* union of the above */
+	} fp_reg_set;
+} fpregset_t;
+
 /*
  * (This structure definition is specified in the i386 ABI supplement)
- * It's likely we can just get rid of the struct __old_fpu or maybe
- * move it to $SRC/uts/intel/ia32/os/fpu.c which appears to be the
- * only place that uses it.  See: www.illumos.org/issues/6284
  */
 typedef struct __old_fpu {
 	union {
@@ -163,19 +327,74 @@ typedef struct __old_fpu {
 	} fp_reg_set;
 	long    	f_wregs[33];		/* saved weitek state */
 } __old_fpregset_t;
+
 #endif	/* __i386 */
 
+#if defined(_SYSCALL32)
+
+/* Kernel view of user i386 fpu structure */
+
+typedef struct fpu32 {
+	union {
+		struct fpchip32_state {
+			uint32_t state[27];	/* 287/387 saved state */
+			uint32_t status;	/* saved at exception */
+			uint32_t mxcsr;		/* SSE control and status */
+			uint32_t xstatus;	/* SSE mxcsr at exception */
+			uint32_t __pad[2];	/* align to 128-bits */
+			uint32_t xmm[8][4];	/* %xmm0-%xmm7 */
+		} fpchip_state;
+		uint32_t	f_fpregs[95];	/* union of the above */
+	} fp_reg_set;
+} fpregset32_t;
+
+#endif	/* _SYSCALL32 */
+
+/*
+ * Kernel's FPU save area
+ */
+typedef struct {
+	union _kfpu_u {
+		struct fxsave_state kfpu_fx;
+#if defined(__i386)
+		struct fnsave_state kfpu_fn;
+#endif
+		struct xsave_state kfpu_xs;
+	} kfpu_u;
+	uint32_t kfpu_status;		/* saved at #mf exception */
+	uint32_t kfpu_xstatus;		/* saved at #xm exception */
+} kfpu_t;
+
 #if defined(__amd64)
-#define	_NDEBUGREG	16
+#define	NDEBUGREG	16
 #else
-#define	_NDEBUGREG	8
+#define	NDEBUGREG	8
 #endif
 
 typedef struct dbregset {
-	unsigned long	debugreg[_NDEBUGREG];
+	unsigned long	debugreg[NDEBUGREG];
 } dbregset_t;
 
+/*
+ * Structure mcontext defines the complete hardware machine state.
+ * (This structure is specified in the i386 ABI suppl.)
+ */
+typedef struct {
+	gregset_t	gregs;		/* general register set */
+	fpregset_t	fpregs;		/* floating point register set */
+} mcontext_t;
+
+#if defined(_SYSCALL32)
+
+typedef struct {
+	gregset32_t	gregs;		/* general register set */
+	fpregset32_t	fpregs;		/* floating point register set */
+} mcontext32_t;
+
+#endif	/* _SYSCALL32 */
+
 #endif	/* _ASM */
+#endif /* !defined(_XPG4_2) || defined(__EXTENSIONS__) */
 
 /*
  * The version of privregs.h that is used on implementations that run on
@@ -201,6 +420,80 @@ typedef struct dbregset {
 #include <sys/privregs.h>
 #endif	/* __i386 (!_KERNEL && !_XPG4_2 || __EXTENSIONS__) */
 
+/*
+ * The following is here for XPG4.2 standards compliance.
+ * regset.h is included in ucontext.h for the definition of
+ * mcontext_t, all of which breaks XPG4.2 namespace.
+ */
+
+#if defined(_XPG4_2) && !defined(__EXTENSIONS__) && !defined(_ASM)
+
+/*
+ * The following is here for UNIX 95 compliance (XPG Issue 4, Version 2
+ * System Interfaces and Headers). The structures included here are identical
+ * to those visible elsewhere in this header except that the structure
+ * element names have been changed in accordance with the X/Open namespace
+ * rules.  Specifically, depending on the name and scope, the names have
+ * been prepended with a single or double underscore (_ or __).  See the
+ * structure definitions in the non-X/Open namespace for more detailed
+ * comments describing each of these structures.
+ */
+
+#if defined(__amd64)
+
+typedef struct __fpu {
+	union {
+		struct __fpchip_state {
+			uint16_t __fx_cw;
+			uint16_t __fx_sw;
+			uint16_t __fx_ctw;
+			uint16_t __fx_op;
+			uint64_t __fx_rip;
+			uint64_t __fx_rdp;
+			uint32_t __fx_mxcsr;
+			uint32_t __fx_mxcsr_mask;
+			union {
+				uint16_t __fpr_16[5];
+				upad128_t __fpr_pad;
+			} __fx_st[8];
+			upad128_t __fx_xmm[16];
+			upad128_t __fx_ign2[6];
+			uint32_t __status;
+			uint32_t __xstatus;
+		} __fpchip_state;
+		uint32_t	__f_fpregs[130];
+	} __fp_reg_set;
+} fpregset_t;
+
+#else	/* __i386 */
+
+typedef struct __fpu {
+	union {
+		struct __fpchip_state {
+			uint32_t __state[27];	/* 287/387 saved state */
+			uint32_t __status;	/* saved at exception */
+			uint32_t __mxcsr;	/* SSE control and status */
+			uint32_t __xstatus;	/* SSE mxcsr at exception */
+			uint32_t __pad[2];	/* align to 128-bits */
+			upad128_t __xmm[8];	/* %xmm0-%xmm7 */
+		} __fpchip_state;
+		struct __fp_emul_space {	/* for emulator(s) */
+			uint8_t	 __fp_emul[246];
+			uint8_t	 __fp_epad[2];
+		} __fp_emul_space;
+		uint32_t	__f_fpregs[95];	/* union of the above */
+	} __fp_reg_set;
+} fpregset_t;
+
+#endif	/* __i386 */
+
+typedef struct {
+	gregset_t	__gregs;	/* general register set */
+	fpregset_t	__fpregs;	/* floating point register set */
+} mcontext_t;
+
+#endif /* _XPG4_2 && !__EXTENSIONS__ && !_ASM */
+
 #ifdef	__cplusplus
 }
 #endif
diff --git a/usr/src/uts/intel/sys/ucontext.h b/usr/src/uts/intel/sys/ucontext.h
index 5f64fa9393..acd6ddc99e 100644
--- a/usr/src/uts/intel/sys/ucontext.h
+++ b/usr/src/uts/intel/sys/ucontext.h
@@ -20,8 +20,6 @@
  */
 
 /*
- * Copyright 2015 Nexenta Systems, Inc.  All rights reserved.
- *
  * Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
  */
@@ -35,7 +33,7 @@
 #include <sys/feature_tests.h>
 
 #include <sys/types.h>
-#include <sys/mcontext.h>
+#include <sys/regset.h>
 #if !defined(_XPG4_2) || defined(__EXTENSIONS__)
 #include <sys/signal.h>
 #endif
diff --git a/usr/src/uts/sparc/fpu/fpu_simulator.c b/usr/src/uts/sparc/fpu/fpu_simulator.c
index 16393bc9d1..aeafdc515d 100644
--- a/usr/src/uts/sparc/fpu/fpu_simulator.c
+++ b/usr/src/uts/sparc/fpu/fpu_simulator.c
@@ -29,7 +29,6 @@
 #include <sys/fpu/globals.h>
 #include <sys/fpu/fpusystm.h>
 #include <sys/proc.h>
-#include <sys/regset.h>
 #include <sys/signal.h>
 #include <sys/siginfo.h>
 #include <sys/thread.h>
diff --git a/usr/src/uts/sparc/sys/Makefile b/usr/src/uts/sparc/sys/Makefile
index 975639fa06..1ae69ac3cc 100644
--- a/usr/src/uts/sparc/sys/Makefile
+++ b/usr/src/uts/sparc/sys/Makefile
@@ -22,6 +22,8 @@
 # Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 # Use is subject to license terms.
 #
+#ident	"%Z%%M%	%I%	%E% SMI"
+#
 
 include ../../../Makefile.master
 
@@ -39,7 +41,6 @@ HDRS=  \
 	machlock.h	\
 	machsig.h	\
 	machtypes.h	\
-	mcontext.h	\
 	old_procfs.h	\
 	pcb.h		\
 	procfs_isa.h	\
diff --git a/usr/src/uts/sparc/sys/fpu/fpu_simulator.h b/usr/src/uts/sparc/sys/fpu/fpu_simulator.h
index 0087877f55..4d83a2c795 100644
--- a/usr/src/uts/sparc/sys/fpu/fpu_simulator.h
+++ b/usr/src/uts/sparc/sys/fpu/fpu_simulator.h
@@ -455,7 +455,7 @@ extern enum ftt_type fp_emulator(
 	fp_inst_type	*pinst,    /* Pointer to FPU instruction to simulate. */
 	struct regs	*pregs,    /* Pointer to PCB image of registers. */
 	struct rwindow	*pwindow,  /* Pointer to locals and ins. */
-	struct _fpu	*pfpu);	   /* Pointer to FPU register block. */
+	struct fpu	*pfpu);	   /* Pointer to FPU register block. */
 
 /*
  * fp_traps handles passing exception conditions to the kernel.
diff --git a/usr/src/uts/sparc/sys/fpu/fpusystm.h b/usr/src/uts/sparc/sys/fpu/fpusystm.h
index cf178fa87f..6b013aa52d 100644
--- a/usr/src/uts/sparc/sys/fpu/fpusystm.h
+++ b/usr/src/uts/sparc/sys/fpu/fpusystm.h
@@ -27,6 +27,8 @@
 #ifndef _SYS_FPU_FPUSYSTM_H
 #define	_SYS_FPU_FPUSYSTM_H
 
+#pragma ident	"%Z%%M%	%I%	%E% SMI"
+
 /*
  * ISA-dependent FPU interfaces
  */
@@ -37,7 +39,7 @@ extern "C" {
 
 #ifdef _KERNEL
 
-struct _fpu;
+struct fpu;
 struct regs;
 
 #if !defined(DEBUG) && !defined(NEED_FPU_EXISTS)
diff --git a/usr/src/uts/sparc/sys/mcontext.h b/usr/src/uts/sparc/sys/mcontext.h
deleted file mode 100644
index f35d0c1d22..0000000000
--- a/usr/src/uts/sparc/sys/mcontext.h
+++ /dev/null
@@ -1,304 +0,0 @@
-/*
- * CDDL HEADER START
- *
- * The contents of this file are subject to the terms of the
- * Common Development and Distribution License (the "License").
- * You may not use this file except in compliance with the License.
- *
- * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
- * or http://www.opensolaris.org/os/licensing.
- * See the License for the specific language governing permissions
- * and limitations under the License.
- *
- * When distributing Covered Code, include this CDDL HEADER in each
- * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
- * If applicable, add the following below this CDDL HEADER, with the
- * fields enclosed by brackets "[]" replaced with your own identifying
- * information: Portions Copyright [yyyy] [name of copyright owner]
- *
- * CDDL HEADER END
- */
-/*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
-/*	All Rights Reserved	*/
-
-
-/*
- * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
- * Use is subject to license terms.
- *
- * Copyright 2015 Nexenta Systems, Inc.  All rights reserved.
- */
-
-/*
- * Essential struct definitions for mcontext_t needed by ucontext.h
- * These were formerly in regset.h, which now includes this file.
- */
-
-#ifndef	_SYS_MCONTEXT_H
-#define	_SYS_MCONTEXT_H
-
-#include <sys/feature_tests.h>
-
-#if !defined(_ASM)
-#include <sys/int_types.h>
-#endif
-
-#ifdef	__cplusplus
-extern "C" {
-#endif
-
-/*
- * A gregset_t is defined as an array type for compatibility with the reference
- * source. This is important due to differences in the way the C language
- * treats arrays and structures as parameters.
- *
- * Note that NGREG is really (sizeof (struct regs) / sizeof (greg_t)),
- * but that the SPARC V8 ABI defines it absolutely to be 19.
- */
-#if defined(__sparcv9)
-#define	_NGREG	21
-#else	/* __sparcv9 */
-#define	_NGREG	19
-#endif	/* __sparcv9 */
-
-#ifndef	_ASM
-
-#if defined(_LP64) || defined(_I32LPx)
-typedef long	greg_t;
-#else
-typedef int	greg_t;
-#endif
-
-#if defined(_SYSCALL32)
-
-typedef int32_t greg32_t;
-typedef int64_t greg64_t;
-
-#endif	/* _SYSCALL32 */
-
-typedef greg_t	gregset_t[_NGREG];
-
-#if defined(_SYSCALL32)
-
-#define	_NGREG32	19
-#define	_NGREG64	21
-
-typedef	greg32_t gregset32_t[_NGREG32];
-typedef greg64_t gregset64_t[_NGREG64];
-
-#endif	/* _SYSCALL32 */
-
-/*
- * Floating point definitions.
- */
-
-#define	_MAXFPQ	16	/* max # of fpu queue entries currently supported */
-
-/*
- * struct _fq defines the minimal format of a floating point instruction queue
- * entry. The size of entries in the floating point queue are implementation
- * dependent. The union FQu is guarenteed to be the first field in any ABI
- * conformant system implementation. Any additional fields provided by an
- * implementation should not be used applications designed to be ABI conformant.
- */
-
-struct _fpq {
-	unsigned int *fpq_addr;		/* address */
-	unsigned int fpq_instr;		/* instruction */
-};
-
-struct _fq {
-	union {				/* FPU inst/addr queue */
-		double whole;
-		struct _fpq fpq;
-	} FQu;
-};
-
-#if defined(_SYSCALL32)
-
-struct fpq32 {
-	caddr32_t	fpq_addr;	/* address */
-	uint32_t	fpq_instr;	/* instruction */
-};
-
-struct fq32 {
-	union {				/* FPU inst/addr queue */
-		double whole;
-		struct fpq32 fpq;
-	} FQu;
-};
-
-#endif	/* _SYSCALL32 */
-
-/*
- * struct fpu is the floating point processor state. struct fpu is the sum
- * total of all possible floating point state which includes the state of
- * external floating point hardware, fpa registers, etc..., if it exists.
- *
- * A floating point instuction queue may or may not be associated with
- * the floating point processor state. If a queue does exist, the field
- * fpu_q will point to an array of fpu_qcnt entries where each entry is
- * fpu_q_entrysize long. fpu_q_entry has a lower bound of sizeof (union FQu)
- * and no upper bound. If no floating point queue entries are associated
- * with the processor state, fpu_qcnt will be zeo and fpu_q will be NULL.
- */
-
-#if defined(__sparcv9)
-
-struct _fpu {
-	union {					/* FPU floating point regs */
-		uint32_t	fpu_regs[32];	/* 32 singles */
-		double		fpu_dregs[32];	/* 32 doubles */
-		long double	fpu_qregs[16];	/* 16 quads */
-	} fpu_fr;
-	struct _fq	*fpu_q;			/* ptr to array of FQ entries */
-	uint64_t	fpu_fsr;		/* FPU status register */
-	uint8_t		fpu_qcnt;		/* # of entries in saved FQ */
-	uint8_t		fpu_q_entrysize;	/* # of bytes per FQ entry */
-	uint8_t		fpu_en;			/* flag specifying fpu in use */
-};
-
-#else	/* __sparcv9 */
-
-struct _fpu {
-	union {					/* FPU floating point regs */
-		uint32_t	fpu_regs[32];	/* 32 singles */
-		double		fpu_dregs[16];	/* 16 doubles */
-	} fpu_fr;
-	struct _fq	*fpu_q;			/* ptr to array of FQ entries */
-	uint32_t	fpu_fsr;		/* FPU status register */
-	uint8_t		fpu_qcnt;		/* # of entries in saved FQ */
-	uint8_t		fpu_q_entrysize;	/* # of bytes per FQ entry */
-	uint8_t		fpu_en;			/* flag signifying fpu in use */
-};
-
-#endif	/* __sparcv9 */
-
-typedef struct _fpu	fpregset_t;
-
-#if defined(_SYSCALL32)
-
-/* Kernel view of user sparcv7/v8 fpu structure */
-
-struct fpu32 {
-	union {					/* FPU floating point regs */
-		uint32_t	fpu_regs[32];	/* 32 singles */
-		double		fpu_dregs[16];	/* 16 doubles */
-	} fpu_fr;
-	caddr32_t	fpu_q;			/* ptr to array of FQ entries */
-	uint32_t	fpu_fsr;		/* FPU status register */
-	uint8_t		fpu_qcnt;		/* # of entries in saved FQ */
-	uint8_t		fpu_q_entrysize;	/* # of bytes per FQ entry */
-	uint8_t		fpu_en;			/* flag signifying fpu in use */
-};
-
-typedef struct fpu32	fpregset32_t;
-
-#endif	/* _SYSCALL32 */
-
-#if defined(_KERNEL) || defined(_KMDB)
-/*
- * The ABI uses struct fpu, so we use this to describe the kernel's view of the
- * fpu.
- */
-typedef struct {
-	union _fpu_fr {				/* V9 FPU floating point regs */
-		uint32_t	fpu_regs[32];	/* 32 singles */
-		uint64_t	fpu_dregs[32];	/* 32 doubles */
-		long double	fpu_qregs[16];	/* 16 quads */
-	} fpu_fr;
-	uint64_t	fpu_fsr;		/* FPU status register */
-	uint32_t	 fpu_fprs;		/* fprs register */
-	struct _fq	*fpu_q;
-	uint8_t		fpu_qcnt;
-	uint8_t		fpu_q_entrysize;
-	uint8_t		fpu_en;			/* flag signifying fpu in use */
-} kfpu_t;
-#endif /* _KERNEL || _KMDB */
-
-/*
- * The following structure is for associating extra register state with
- * the ucontext structure and is kept within the uc_mcontext filler area.
- *
- * If (xrs_id == XRS_ID) then the xrs_ptr field is a valid pointer to
- * extra register state. The exact format of the extra register state
- * pointed to by xrs_ptr is platform-dependent.
- *
- * Note: a platform may or may not manage extra register state.
- */
-typedef struct {
-	unsigned int	xrs_id;		/* indicates xrs_ptr validity */
-	caddr_t		xrs_ptr;	/* ptr to extra reg state */
-} xrs_t;
-
-#define	_XRS_ID			0x78727300	/* the string "xrs" */
-
-#if defined(_SYSCALL32)
-
-typedef	struct {
-	uint32_t	xrs_id;		/* indicates xrs_ptr validity */
-	caddr32_t	xrs_ptr;	/* ptr to extra reg state */
-} xrs32_t;
-
-#endif	/* _SYSCALL32 */
-
-#if defined(__sparcv9)
-
-/*
- * Ancillary State Registers
- *
- * The SPARC V9 architecture defines 25 ASRs, numbered from 7 through 31.
- * ASRs 16 through 31 are available to user programs, though the meaning
- * and content of these registers is implementation dependent.
- */
-typedef	int64_t	asrset_t[16];	/* %asr16 - > %asr31 */
-
-#endif	/* __sparcv9 */
-
-/*
- * Structure mcontext defines the complete hardware machine state. If
- * the field `gwins' is non NULL, it points to a save area for register
- * window frames. If `gwins' is NULL, the register windows were saved
- * on the user's stack.
- *
- * The filler of 21 longs is historical (now filler[19] plus the xrs_t
- * field). The value was selected to provide binary compatibility with
- * statically linked ICL binaries. It is in the ABI (do not change). It
- * actually appears in the ABI as a single filler of 44 is in the field
- * uc_filler of struct ucontext. It is split here so that ucontext.h can
- * (hopefully) remain architecture independent.
- *
- * Note that 2 longs of the filler are used to hold extra register state info.
- */
-typedef struct {
-	gregset_t	gregs;	/* general register set */
-	struct _gwindows *gwins; /* POSSIBLE pointer to register windows */
-	fpregset_t	fpregs;	/* floating point register set */
-	xrs_t		xrs;	/* POSSIBLE extra register state association */
-#if defined(__sparcv9)
-	asrset_t	asrs;		/* ancillary registers */
-	long		filler[4];	/* room for expansion */
-#else	/* __sparcv9 */
-	long		filler[19];
-#endif	/* __sparcv9 */
-} mcontext_t;
-
-#if defined(_SYSCALL32)
-
-typedef struct {
-	gregset32_t	gregs;	/* general register set */
-	caddr32_t	gwins;	/* POSSIBLE pointer to register windows */
-	fpregset32_t	fpregs;	/* floating point register set */
-	xrs32_t		xrs;	/* POSSIBLE extra register state association */
-	int32_t		filler[19];
-} mcontext32_t;
-
-#endif /* _SYSCALL32 */
-
-#endif	/* _ASM */
-
-#ifdef	__cplusplus
-}
-#endif
-
-#endif	/* _SYS_MCONTEXT_H */
diff --git a/usr/src/uts/sparc/sys/procfs_isa.h b/usr/src/uts/sparc/sys/procfs_isa.h
index 4c9ffec7c1..a1c98655b5 100644
--- a/usr/src/uts/sparc/sys/procfs_isa.h
+++ b/usr/src/uts/sparc/sys/procfs_isa.h
@@ -27,6 +27,8 @@
 #ifndef _SYS_PROCFS_ISA_H
 #define	_SYS_PROCFS_ISA_H
 
+#pragma ident	"%Z%%M%	%I%	%E% SMI"
+
 /*
  * Instruction Set Architecture specific component of <sys/procfs.h>
  * sparc v8/v9 version
@@ -167,7 +169,7 @@ typedef struct prfpregset {
 	uint8_t	pr_q_entrysize;		/* # of bytes per FQ entry */
 	uint8_t	pr_en;			/* flag signifying fpu in use */
 	char	pr_pad[13];		/* ensure sizeof(prfpregset)%16 == 0 */
-	struct _fq pr_q[16];		/* contains the FQ array */
+	struct fq pr_q[16];		/* contains the FQ array */
 } prfpregset_t;
 #else
 typedef struct prfpregset {
@@ -180,7 +182,7 @@ typedef struct prfpregset {
 	uint8_t	pr_qcnt;		/* # of entries in saved FQ */
 	uint8_t	pr_q_entrysize;		/* # of bytes per FQ entry */
 	uint8_t	pr_en;			/* flag signifying fpu in use */
-	struct _fq pr_q[32];		/* contains the FQ array */
+	struct fq pr_q[32];		/* contains the FQ array */
 } prfpregset_t;
 #endif	/* __sparcv9 */
 
diff --git a/usr/src/uts/sparc/sys/regset.h b/usr/src/uts/sparc/sys/regset.h
index cebf5939a3..26e7119a38 100644
--- a/usr/src/uts/sparc/sys/regset.h
+++ b/usr/src/uts/sparc/sys/regset.h
@@ -23,8 +23,6 @@
 
 
 /*
- * Copyright 2015 Nexenta Systems, Inc.  All rights reserved.
- *
  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
  */
@@ -32,12 +30,13 @@
 #ifndef	_SYS_REGSET_H
 #define	_SYS_REGSET_H
 
+#pragma ident	"%Z%%M%	%I%	%E% SMI"	/* SVr4.0 1.1	*/
+
 #include <sys/feature_tests.h>
 
 #if !defined(_ASM)
 #include <sys/int_types.h>
 #endif
-#include <sys/mcontext.h>
 
 #ifdef	__cplusplus
 extern "C" {
@@ -47,6 +46,8 @@ extern "C" {
  * Location of the users' stored registers relative to R0.
  * Usage is as an index into a gregset_t array or as u.u_ar0[XX].
  */
+#if !defined(_XPG4_2) || defined(__EXTENSIONS__)
+
 #if defined(__sparcv9)
 #define	REG_CCR (0)
 #if defined(_SYSCALL32)
@@ -86,12 +87,53 @@ extern "C" {
 #define	REG_SP	REG_O6
 #define	REG_R0	REG_O0
 #define	REG_R1	REG_O1
+#endif /* !defined(_XPG4_2) || defined(__EXTENSIONS__) */
+
+/*
+ * A gregset_t is defined as an array type for compatibility with the reference
+ * source. This is important due to differences in the way the C language
+ * treats arrays and structures as parameters.
+ *
+ * Note that NGREG is really (sizeof (struct regs) / sizeof (greg_t)),
+ * but that the SPARC V8 ABI defines it absolutely to be 19.
+ */
+#if defined(__sparcv9)
+#define	_NGREG	21
+#else	/* __sparcv9 */
+#define	_NGREG	19
+#endif	/* __sparcv9 */
+#if !defined(_XPG4_2) || defined(__EXTENSIONS__)
+#define	NGREG	_NGREG
+#endif
 
 #ifndef	_ASM
 
-#define	NGREG	_NGREG
-#define	MAXFPQ	_MAXFPQ
+#if defined(_LP64) || defined(_I32LPx)
+typedef long	greg_t;
+#else
+typedef int	greg_t;
+#endif
+
+#if defined(_SYSCALL32)
+
+typedef int32_t greg32_t;
+typedef int64_t greg64_t;
+
+#endif	/* _SYSCALL32 */
+
+typedef greg_t	gregset_t[_NGREG];
+
+#if defined(_SYSCALL32)
 
+#define	_NGREG32	19
+#define	_NGREG64	21
+
+typedef	greg32_t gregset32_t[_NGREG32];
+typedef greg64_t gregset64_t[_NGREG64];
+
+#endif	/* _SYSCALL32 */
+
+#if !defined(_XPG4_2) || defined(__EXTENSIONS__)
 /*
  * The following structures define how a register window can appear on the
  * stack. This structure is available (when required) through the `gwins'
@@ -101,7 +143,7 @@ extern "C" {
  */
 #define	SPARC_MAXREGWINDOW	31	/* max windows in SPARC arch. */
 
-struct	rwindow {
+struct rwindow {
 	greg_t	rw_local[8];		/* locals */
 	greg_t	rw_in[8];		/* ins */
 };
@@ -128,7 +170,7 @@ extern	void	rwindow_32ton(struct rwindow32 *, struct rwindow *);
 #define	rw_fp	rw_in[6]		/* frame pointer */
 #define	rw_rtn	rw_in[7]		/* return address */
 
-typedef struct _gwindows {
+typedef struct gwindows {
 	int		wbcnt;
 	greg_t		*spbuf[SPARC_MAXREGWINDOW];
 	struct rwindow	wbuf[SPARC_MAXREGWINDOW];
@@ -150,6 +192,62 @@ typedef struct gwindows64 {
 
 #endif	/* _SYSCALL32 */
 
+
+/*
+ * Floating point definitions.
+ */
+
+#define	MAXFPQ	16	/* max # of fpu queue entries currently supported */
+
+/*
+ * struct fq defines the minimal format of a floating point instruction queue
+ * entry. The size of entries in the floating point queue are implementation
+ * dependent. The union FQu is guarenteed to be the first field in any ABI
+ * conformant system implementation. Any additional fields provided by an
+ * implementation should not be used applications designed to be ABI conformant.
+ */
+
+struct fpq {
+	unsigned int *fpq_addr;		/* address */
+	unsigned int fpq_instr;		/* instruction */
+};
+
+struct fq {
+	union {				/* FPU inst/addr queue */
+		double whole;
+		struct fpq fpq;
+	} FQu;
+};
+
+#if defined(_SYSCALL32)
+
+struct fpq32 {
+	caddr32_t	fpq_addr;	/* address */
+	uint32_t	fpq_instr;	/* instruction */
+};
+
+struct fq32 {
+	union {				/* FPU inst/addr queue */
+		double whole;
+		struct fpq32 fpq;
+	} FQu;
+};
+
+#endif	/* _SYSCALL32 */
+
+/*
+ * struct fpu is the floating point processor state. struct fpu is the sum
+ * total of all possible floating point state which includes the state of
+ * external floating point hardware, fpa registers, etc..., if it exists.
+ *
+ * A floating point instuction queue may or may not be associated with
+ * the floating point processor state. If a queue does exist, the field
+ * fpu_q will point to an array of fpu_qcnt entries where each entry is
+ * fpu_q_entrysize long. fpu_q_entry has a lower bound of sizeof (union FQu)
+ * and no upper bound. If no floating point queue entries are associated
+ * with the processor state, fpu_qcnt will be zeo and fpu_q will be NULL.
+ */
+
 /*
  * The following #define's are obsolete and may be removed in a future release.
  * The corresponding integer types should be used instead (i.e. uint64_t).
@@ -160,9 +258,160 @@ typedef struct gwindows64 {
 #define	V9_FPU_FSR_TYPE		uint64_t
 #define	V9_FPU_FPRS_TYPE	uint32_t
 
-#define	XRS_ID			_XRS_ID
+#if defined(__sparcv9)
+
+struct fpu {
+	union {					/* FPU floating point regs */
+		uint32_t	fpu_regs[32];	/* 32 singles */
+		double		fpu_dregs[32];	/* 32 doubles */
+		long double	fpu_qregs[16];	/* 16 quads */
+	} fpu_fr;
+	struct fq	*fpu_q;			/* ptr to array of FQ entries */
+	uint64_t	fpu_fsr;		/* FPU status register */
+	uint8_t		fpu_qcnt;		/* # of entries in saved FQ */
+	uint8_t		fpu_q_entrysize;	/* # of bytes per FQ entry */
+	uint8_t		fpu_en;			/* flag specifying fpu in use */
+};
+
+#else	/* __sparcv9 */
+
+struct fpu {
+	union {					/* FPU floating point regs */
+		uint32_t	fpu_regs[32];	/* 32 singles */
+		double		fpu_dregs[16];	/* 16 doubles */
+	} fpu_fr;
+	struct fq	*fpu_q;			/* ptr to array of FQ entries */
+	uint32_t	fpu_fsr;		/* FPU status register */
+	uint8_t		fpu_qcnt;		/* # of entries in saved FQ */
+	uint8_t		fpu_q_entrysize;	/* # of bytes per FQ entry */
+	uint8_t		fpu_en;			/* flag signifying fpu in use */
+};
+
+#endif	/* __sparcv9 */
+
+typedef struct fpu	fpregset_t;
+
+#if defined(_SYSCALL32)
+
+/* Kernel view of user sparcv7/v8 fpu structure */
+
+struct fpu32 {
+	union {					/* FPU floating point regs */
+		uint32_t	fpu_regs[32];	/* 32 singles */
+		double		fpu_dregs[16];	/* 16 doubles */
+	} fpu_fr;
+	caddr32_t	fpu_q;			/* ptr to array of FQ entries */
+	uint32_t	fpu_fsr;		/* FPU status register */
+	uint8_t		fpu_qcnt;		/* # of entries in saved FQ */
+	uint8_t		fpu_q_entrysize;	/* # of bytes per FQ entry */
+	uint8_t		fpu_en;			/* flag signifying fpu in use */
+};
+
+typedef struct fpu32	fpregset32_t;
+
+#endif	/* _SYSCALL32 */
 
-#endif	/* !_ASM */
+#if defined(_KERNEL) || defined(_KMDB)
+/*
+ * The ABI uses struct fpu, so we use this to describe the kernel's view of the
+ * fpu.
+ */
+typedef struct {
+	union _fpu_fr {				/* V9 FPU floating point regs */
+		uint32_t	fpu_regs[32];	/* 32 singles */
+		uint64_t	fpu_dregs[32];	/* 32 doubles */
+		long double	fpu_qregs[16];	/* 16 quads */
+	} fpu_fr;
+	uint64_t	fpu_fsr;		/* FPU status register */
+	uint32_t	 fpu_fprs;		/* fprs register */
+	struct fq	*fpu_q;
+	uint8_t		fpu_qcnt;
+	uint8_t		fpu_q_entrysize;
+	uint8_t		fpu_en;			/* flag signifying fpu in use */
+} kfpu_t;
+#endif /* _KERNEL || _KMDB */
+
+/*
+ * The following structure is for associating extra register state with
+ * the ucontext structure and is kept within the uc_mcontext filler area.
+ *
+ * If (xrs_id == XRS_ID) then the xrs_ptr field is a valid pointer to
+ * extra register state. The exact format of the extra register state
+ * pointed to by xrs_ptr is platform-dependent.
+ *
+ * Note: a platform may or may not manage extra register state.
+ */
+typedef struct {
+	unsigned int	xrs_id;		/* indicates xrs_ptr validity */
+	caddr_t		xrs_ptr;	/* ptr to extra reg state */
+} xrs_t;
+
+#define	XRS_ID			0x78727300	/* the string "xrs" */
+
+#if defined(_SYSCALL32)
+
+typedef	struct {
+	uint32_t	xrs_id;		/* indicates xrs_ptr validity */
+	caddr32_t	xrs_ptr;	/* ptr to extra reg state */
+} xrs32_t;
+
+#endif	/* _SYSCALL32 */
+
+#if defined(__sparcv9)
+
+/*
+ * Ancillary State Registers
+ *
+ * The SPARC V9 architecture defines 25 ASRs, numbered from 7 through 31.
+ * ASRs 16 through 31 are available to user programs, though the meaning
+ * and content of these registers is implementation dependent.
+ */
+typedef	int64_t	asrset_t[16];	/* %asr16 - > %asr31 */
+
+#endif	/* __sparcv9 */
+
+/*
+ * Structure mcontext defines the complete hardware machine state. If
+ * the field `gwins' is non NULL, it points to a save area for register
+ * window frames. If `gwins' is NULL, the register windows were saved
+ * on the user's stack.
+ *
+ * The filler of 21 longs is historical (now filler[19] plus the xrs_t
+ * field). The value was selected to provide binary compatibility with
+ * statically linked ICL binaries. It is in the ABI (do not change). It
+ * actually appears in the ABI as a single filler of 44 is in the field
+ * uc_filler of struct ucontext. It is split here so that ucontext.h can
+ * (hopefully) remain architecture independent.
+ *
+ * Note that 2 longs of the filler are used to hold extra register state info.
+ */
+typedef struct {
+	gregset_t	gregs;	/* general register set */
+	gwindows_t	*gwins;	/* POSSIBLE pointer to register windows */
+	fpregset_t	fpregs;	/* floating point register set */
+	xrs_t		xrs;	/* POSSIBLE extra register state association */
+#if defined(__sparcv9)
+	asrset_t	asrs;		/* ancillary registers */
+	long		filler[4];	/* room for expansion */
+#else	/* __sparcv9 */
+	long		filler[19];
+#endif	/* __sparcv9 */
+} mcontext_t;
+
+#if defined(_SYSCALL32)
+
+typedef struct {
+	gregset32_t	gregs;	/* general register set */
+	caddr32_t	gwins;	/* POSSIBLE pointer to register windows */
+	fpregset32_t	fpregs;	/* floating point register set */
+	xrs32_t		xrs;	/* POSSIBLE extra register state association */
+	int32_t		filler[19];
+} mcontext32_t;
+
+#endif /* _SYSCALL32 */
+
+#endif /* !defined(_XPG4_2) || defined(__EXTENSIONS__) */
+#endif	/* _ASM */
 
 /*
  * The version of privregs.h that is used on implementations that run
@@ -179,7 +428,7 @@ typedef struct gwindows64 {
  * 'struct regs' to match the content of a 32-bit core file, or a ucontext_t.
  *
  * Note that the ucontext_t actually describes the general registers in
- * terms of the gregset_t data type, as described in mcontex.h.  Note also
+ * terms of the gregset_t data type, as described in this file.  Note also
  * that the core file content is defined by core(4) in terms of data types
  * defined by procfs -- see proc(4).
  */
@@ -189,6 +438,164 @@ typedef struct gwindows64 {
 #endif	/* !_KERNEL && !_XPG4_2 || __EXTENSIONS__ */
 #endif	/* __sparcv9 */
 
+/*
+ * The following is here for XPG4.2 standards compliance.
+ * regset.h is included in ucontext.h for the definition of
+ * mcontext_t, all of which breaks XPG4.2 namespace.
+ */
+
+#if defined(_XPG4_2) && !defined(__EXTENSIONS__)
+/*
+ * The following is here for UNIX 95 compliance (XPG Issue 4, Version 2
+ * System Interfaces and Headers. The structures included here are identical
+ * to those visible elsewhere in this header except that the structure
+ * element names have been changed in accordance with the X/Open namespace
+ * rules.  Specifically, depending on the name and scope, the names have
+ * been prepended with a single or double underscore (_ or __).  See the
+ * structure definitions in the non-X/Open namespace for more detailed
+ * comments describing each of these structures.
+ */
+
+#ifndef	_ASM
+
+/*
+ * The following structures define how a register window can appear on the
+ * stack.
+ */
+#define	_SPARC_MAXREGWINDOW	31		/* max windows in SPARC arch. */
+
+struct	__rwindow {
+	greg_t	__rw_local[8];		/* locals */
+	greg_t	__rw_in[8];		/* ins */
+};
+
+#define	__rw_fp		__rw_in[6]		/* frame pointer */
+#define	__rw_rtn	__rw_in[7]		/* return address */
+
+struct __gwindows {
+	int		__wbcnt;
+	greg_t		*__spbuf[_SPARC_MAXREGWINDOW];
+	struct __rwindow	__wbuf[_SPARC_MAXREGWINDOW];
+};
+
+typedef struct __gwindows	gwindows_t;
+
+/*
+ * The fq structure defines the minimal format of a floating point
+ * instruction queue entry.
+ */
+
+struct __fpq {
+	unsigned int *__fpq_addr;	/* address */
+	unsigned int __fpq_instr;	/* instruction */
+};
+
+struct __fq {
+	union {				/* FPU inst/addr queue */
+		double __whole;
+		struct __fpq __fpq;
+	} _FQu;
+};
+
+/*
+ * The fpu structure is the floating point processor state.
+ */
+
+/*
+ * The following #define's are obsolete and may be removed in a future release.
+ * The corresponding integer types should be used instead (i.e. uint64_t).
+ */
+#define	_FPU_REGS_TYPE		uint32_t
+#define	_FPU_DREGS_TYPE		uint64_t
+#define	_V7_FPU_FSR_TYPE	uint32_t
+#define	_V9_FPU_FSR_TYPE	uint64_t
+#define	_V9_FPU_FPRS_TYPE	uint32_t
+
+#if defined(__sparcv9)
+
+/*
+ * SPARC Version 9 floating point
+ */
+
+struct __fpu {
+	union {					/* FPU floating point regs */
+		uint32_t	__fpu_regs[32];		/* 32 singles */
+		double		__fpu_dregs[32];	/* 32 doubles */
+		long double	__fpu_qregs[16];	/* 16 quads */
+	} __fpu_fr;
+	struct __fq	*__fpu_q;		/* ptr to array of FQ entries */
+	uint64_t	__fpu_fsr;	/* FPU status register */
+	uint8_t		__fpu_qcnt;		/* # of entries in saved FQ */
+	uint8_t		__fpu_q_entrysize;	/* # of bytes per FQ entry */
+	uint8_t		__fpu_en;		/* flag signifying fpu in use */
+};
+
+#else	/* __sparcv9 */
+
+/*
+ * SPARC Version 7 and 8 floating point
+ */
+
+struct __fpu {
+	union {					/* FPU floating point regs */
+		uint32_t	__fpu_regs[32];		/* 32 singles */
+		double		__fpu_dregs[16];	/* 16 doubles */
+	} __fpu_fr;
+	struct __fq	*__fpu_q;		/* ptr to array of FQ entries */
+	uint32_t	__fpu_fsr;	/* FPU status register */
+	uint8_t		__fpu_qcnt;		/* # of entries in saved FQ */
+	uint8_t		__fpu_q_entrysize;	/* # of bytes per FQ entry */
+	uint8_t		__fpu_en;		/* flag signifying fpu in use */
+};
+
+#endif	/* __sparcv9 */
+
+typedef struct __fpu	fpregset_t;
+
+/*
+ * The xrs_t structure is for associating extra register state with
+ * the ucontext structure and is kept within the uc_mcontext filler area.
+ */
+typedef struct {
+	unsigned int	__xrs_id;	/* indicates xrs_ptr validity */
+	caddr_t		__xrs_ptr;	/* ptr to extra reg state */
+} xrs_t;
+
+#define	_XRS_ID			0x78727300	/* the string "xrs" */
+
+#if defined(__sparcv9)
+
+/*
+ * Ancillary State Registers
+ *
+ * The SPARC V9 architecture defines 25 ASRs, numbered from 7 through 31.
+ * ASRs 16 through 31 are available to user programs, though the meaning
+ * and content of these registers is implementation dependent.
+ */
+typedef	int64_t	asrset_t[16];	/* %asr16 - > %asr31 */
+
+#endif	/* __sparcv9 */
+
+/*
+ * Structure mcontext defines the complete hardware machine state.
+ */
+typedef struct {
+	gregset_t	__gregs; /* general register set */
+	gwindows_t	*__gwins; /* POSSIBLE pointer to register windows */
+	fpregset_t	__fpregs; /* floating point register set */
+	xrs_t		__xrs;	/* POSSIBLE extra register state association */
+#if defined(__sparcv9)
+	asrset_t	__asrs;		/* ancillary registers */
+	long		__filler[4];	/* room for expansion */
+#else	/* __sparcv9 */
+	long		__filler[19];
+#endif	/* __sparcv9 */
+} mcontext_t;
+
+#endif	/* _ASM */
+#endif /* defined(_XPG4_2) && !defined(__EXTENSIONS__) */
+
+
 #ifdef	__cplusplus
 }
 #endif
diff --git a/usr/src/uts/sparc/sys/ucontext.h b/usr/src/uts/sparc/sys/ucontext.h
index 35eff287af..e0cfea55bd 100644
--- a/usr/src/uts/sparc/sys/ucontext.h
+++ b/usr/src/uts/sparc/sys/ucontext.h
@@ -20,8 +20,6 @@
  */
 
 /*
- * Copyright 2015 Nexenta Systems, Inc.  All rights reserved.
- *
  * Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
  */
@@ -35,7 +33,7 @@
 #include <sys/feature_tests.h>
 
 #include <sys/types.h>
-#include <sys/mcontext.h>
+#include <sys/regset.h>
 #if !defined(_XPG4_2) || defined(__EXTENSIONS__)
 #include <sys/signal.h>
 #endif
@@ -107,7 +105,7 @@ typedef struct ucontext32 {
 
 #ifdef _KERNEL
 extern void ucontext_32ton(const ucontext32_t *, ucontext_t *,
-    const struct fq32 *, struct _fq *);
+    const struct fq32 *, struct fq *);
 extern void fpuregset_nto32(const fpregset_t *, fpregset32_t *, struct fq32 *);
 #endif
 
diff --git a/usr/src/uts/sparc/syscall/getcontext.c b/usr/src/uts/sparc/syscall/getcontext.c
index c9adb54b86..437eef5e1a 100644
--- a/usr/src/uts/sparc/syscall/getcontext.c
+++ b/usr/src/uts/sparc/syscall/getcontext.c
@@ -176,7 +176,7 @@ int
 getsetcontext(int flag, void *arg)
 {
 	ucontext_t uc;
-	struct _fq fpu_q[MAXFPQ]; /* to hold floating queue */
+	struct fq fpu_q[MAXFPQ]; /* to hold floating queue */
 	fpregset_t *fpp;
 	gwindows_t *gwin = NULL;	/* to hold windows */
 	caddr_t xregs = NULL;
@@ -214,7 +214,7 @@ getsetcontext(int flag, void *arg)
 		 * a later setcontext(2).
 		 */
 		uc.uc_mcontext.fpregs.fpu_qcnt = 0;
-		uc.uc_mcontext.fpregs.fpu_q = (struct _fq *)NULL;
+		uc.uc_mcontext.fpregs.fpu_q = (struct fq *)NULL;
 
 		if (copyout(&uc, arg, sizeof (ucontext_t)))
 			return (set_errno(EFAULT));
@@ -255,7 +255,7 @@ getsetcontext(int flag, void *arg)
 			if ((fpp->fpu_q) && (fpp->fpu_qcnt)) {
 				if (fpp->fpu_qcnt > MAXFPQ ||
 				    fpp->fpu_q_entrysize <= 0 ||
-				    fpp->fpu_q_entrysize > sizeof (struct _fq))
+				    fpp->fpu_q_entrysize > sizeof (struct fq))
 					return (set_errno(EINVAL));
 				if (copyin(fpp->fpu_q, fpu_q,
 				    fpp->fpu_qcnt * fpp->fpu_q_entrysize))
@@ -424,7 +424,7 @@ getsetcontext32(int flag, void *arg)
 {
 	ucontext32_t uc;
 	ucontext_t   ucnat;
-	struct _fq fpu_qnat[MAXFPQ]; /* to hold "native" floating queue */
+	struct fq fpu_qnat[MAXFPQ]; /* to hold "native" floating queue */
 	struct fq32 fpu_q[MAXFPQ]; /* to hold 32 bit floating queue */
 	fpregset32_t *fpp;
 	gwindows32_t *gwin = NULL;	/* to hold windows */
diff --git a/usr/src/uts/sparc/v7/sys/machpcb.h b/usr/src/uts/sparc/v7/sys/machpcb.h
index f0b76ee7a6..a964018519 100644
--- a/usr/src/uts/sparc/v7/sys/machpcb.h
+++ b/usr/src/uts/sparc/v7/sys/machpcb.h
@@ -26,6 +26,8 @@
 #ifndef _SYS_MACHPCB_H
 #define	_SYS_MACHPCB_H
 
+#pragma ident	"%Z%%M%	%I%	%E% SMI"
+
 #include <sys/stack.h>
 #include <sys/regset.h>
 #include <sys/privregs.h>
@@ -69,8 +71,8 @@ typedef struct machpcb {
 	int	mpcb_uwm;	/* user window mask */
 	int	mpcb_swm;	/* shared user/kernel window mask */
 	int	mpcb_wbcnt;	/* number of saved windows in pcb_wbuf */
-	struct	_fpu mpcb_fpu;	/* fpu state */
-	struct	_fq mpcb_fpu_q[_MAXFPQ]; /* fpu exception queue */
+	struct	fpu mpcb_fpu;	/* fpu state */
+	struct	fq mpcb_fpu_q[MAXFPQ]; /* fpu exception queue */
 	int	mpcb_flags;	/* various state flags */
 	int	mpcb_wocnt;	/* window overflow count */
 	int	mpcb_wucnt;	/* window underflow count */
diff --git a/usr/src/uts/sparc/v9/fpu/fpu.c b/usr/src/uts/sparc/v9/fpu/fpu.c
index a84612e030..a341eb120d 100644
--- a/usr/src/uts/sparc/v9/fpu/fpu.c
+++ b/usr/src/uts/sparc/v9/fpu/fpu.c
@@ -24,6 +24,8 @@
  * Use is subject to license terms.
  */
 
+#pragma ident	"%Z%%M%	%I%	%E% SMI"
+
 #include <sys/types.h>
 #include <sys/param.h>
 #include <sys/signal.h>
@@ -289,7 +291,7 @@ fp_disabled(struct regs *rp)
 		}
 		if (ftt = fp_emulator(&fpsd, (fp_inst_type *)rp->r_pc,
 		    rp, (ulong_t *)rp->r_sp, fp)) {
-			fp->fpu_q_entrysize = sizeof (struct _fpq);
+			fp->fpu_q_entrysize = sizeof (struct fpq);
 			fp_traps(&fpsd, ftt, rp);
 		}
 	}
@@ -318,7 +320,7 @@ void
 fp_runq(struct regs *rp)
 {
 	kfpu_t *fp = lwptofpu(curthread->t_lwp);
-	struct _fq *fqp = fp->fpu_q;
+	struct fq *fqp = fp->fpu_q;
 	fp_simd_type fpsd;
 	uint64_t gsr = get_gsr(fp);
 
@@ -343,7 +345,7 @@ fp_runq(struct regs *rp)
 			 */
 			if (fqp != fp->fpu_q) {
 				int i;
-				struct _fq *fqdp;
+				struct fq *fqdp;
 
 				/*
 				 * We need to normalize the floating queue so
@@ -357,7 +359,7 @@ fp_runq(struct regs *rp)
 				}
 				fqp = fp->fpu_q;
 			}
-			fp->fpu_q_entrysize = sizeof (struct _fpq);
+			fp->fpu_q_entrysize = sizeof (struct fpq);
 
 			/*
 			 * fpu_simulator uses the fp registers directly but it
@@ -465,14 +467,14 @@ fp_precise(struct regs *rp)
 		 * problem for a restorecontext of a v8 fp queue on a
 		 * v9 system, which seems like the .000000001% case (on v9)!
 		 */
-		struct _fpq *pfpq = &fp->fpu_q->FQu.fpq;
+		struct fpq *pfpq = &fp->fpu_q->FQu.fpq;
 		fp_simd_type	fpsd;
 		int fptrap;
 
 		pfpq->fpq_addr = (uint_t *)rp->r_pc;
 		pfpq->fpq_instr = kluge.i;
 		fp->fpu_qcnt = 1;
-		fp->fpu_q_entrysize = sizeof (struct _fpq);
+		fp->fpu_q_entrysize = sizeof (struct fpq);
 
 		kpreempt_disable();
 		(void) flush_user_windows_to_stack(NULL);
diff --git a/usr/src/uts/sparc/v9/os/v9dep.c b/usr/src/uts/sparc/v9/os/v9dep.c
index f54dab4f5d..751837788e 100644
--- a/usr/src/uts/sparc/v9/os/v9dep.c
+++ b/usr/src/uts/sparc/v9/os/v9dep.c
@@ -73,7 +73,7 @@ static uint_t mkpsr(uint64_t tstate, uint32_t fprs);
 
 #ifdef _SYSCALL32_IMPL
 static void fpuregset_32ton(const fpregset32_t *src, fpregset_t *dest,
-    const struct fq32 *sfq, struct _fq *dfq);
+    const struct fq32 *sfq, struct fq *dfq);
 #endif /* _SYSCALL32_IMPL */
 
 /*
@@ -122,7 +122,7 @@ setfpregs(klwp_t *lwp, fpregset_t *fp)
 		 */
 		if (fp->fpu_qcnt > MAXFPQ) 	/* plug security holes */
 			fp->fpu_qcnt = MAXFPQ;
-		fp->fpu_q_entrysize = sizeof (struct _fq);
+		fp->fpu_q_entrysize = sizeof (struct fq);
 
 		/*
 		 * For v9 kernel, copy all of the fp regs.
@@ -1098,7 +1098,7 @@ sendsig(int sig, k_siginfo_t *sip, void (*hdlr)())
 		sulword_noerr(&fp->uc.uc_mcontext.gwins, (ulong_t)NULL);
 
 	if (fpq_size != 0) {
-		struct _fq *fqp = (struct _fq *)sp;
+		struct fq *fqp = (struct fq *)sp;
 		sulword_noerr(&fp->uc.uc_mcontext.fpregs.fpu_q, (ulong_t)fqp);
 		copyout_noerr(mpcb->mpcb_fpu_q, fqp, fpq_size);
 
@@ -1730,7 +1730,7 @@ fpuregset_nto32(const fpregset_t *src, fpregset32_t *dest, struct fq32 *dfq)
 	dest->fpu_en = src->fpu_en;
 
 	if ((src->fpu_qcnt) && (dfq != NULL)) {
-		struct _fq *sfq = src->fpu_q;
+		struct fq *sfq = src->fpu_q;
 		for (i = 0; i < src->fpu_qcnt; i++, dfq++, sfq++) {
 			dfq->FQu.fpq.fpq_addr =
 			    (caddr32_t)(uintptr_t)sfq->FQu.fpq.fpq_addr;
@@ -1748,7 +1748,7 @@ fpuregset_nto32(const fpregset_t *src, fpregset32_t *dest, struct fq32 *dfq)
  */
 static void
 fpuregset_32ton(const fpregset32_t *src, fpregset_t *dest,
-    const struct fq32 *sfq, struct _fq *dfq)
+    const struct fq32 *sfq, struct fq *dfq)
 {
 	int i;
 
@@ -1758,7 +1758,7 @@ fpuregset_32ton(const fpregset32_t *src, fpregset_t *dest,
 	dest->fpu_q = dfq;
 	dest->fpu_fsr = (uint64_t)src->fpu_fsr;
 	if ((dest->fpu_qcnt = src->fpu_qcnt) > 0)
-		dest->fpu_q_entrysize = sizeof (struct _fpq);
+		dest->fpu_q_entrysize = sizeof (struct fpq);
 	else
 		dest->fpu_q_entrysize = 0;
 	dest->fpu_en = src->fpu_en;
@@ -1774,7 +1774,7 @@ fpuregset_32ton(const fpregset32_t *src, fpregset_t *dest,
 
 void
 ucontext_32ton(const ucontext32_t *src, ucontext_t *dest,
-    const struct fq32 *sfq, struct _fq *dfq)
+    const struct fq32 *sfq, struct fq *dfq)
 {
 	int i;
 
diff --git a/usr/src/uts/sparc/v9/sys/machpcb.h b/usr/src/uts/sparc/v9/sys/machpcb.h
index e4b1972d8a..298dae5100 100644
--- a/usr/src/uts/sparc/v9/sys/machpcb.h
+++ b/usr/src/uts/sparc/v9/sys/machpcb.h
@@ -72,7 +72,7 @@ typedef struct machpcb {
 	int	mpcb_wbcnt;	/* number of saved windows in pcb_wbuf */
 	uint_t	mpcb_wstate;	/* per-lwp %wstate */
 	kfpu_t	*mpcb_fpu; /* fpu state */
-	struct	_fq mpcb_fpu_q[_MAXFPQ]; /* fpu exception queue */
+	struct	fq mpcb_fpu_q[MAXFPQ]; /* fpu exception queue */
 	caddr_t	mpcb_illexcaddr; /* address of last illegal instruction */
 	uint_t	mpcb_illexcinsn; /* last illegal instruction */
 	uint_t	mpcb_illexccnt; /* count of illegal instruction attempts */
diff --git a/usr/src/uts/sun4/os/trap.c b/usr/src/uts/sun4/os/trap.c
index 094620625a..654b83c953 100644
--- a/usr/src/uts/sun4/os/trap.c
+++ b/usr/src/uts/sun4/os/trap.c
@@ -1366,7 +1366,7 @@ fpu_trap(struct regs *rp, caddr_t addr, uint32_t type, uint32_t code)
 	int mstate;
 	char *badaddr;
 	kfpu_t *fp;
-	struct _fpq *pfpq;
+	struct fpq *pfpq;
 	uint32_t inst;
 	utrap_handler_t *utrapp;
 
@@ -1431,7 +1431,7 @@ fpu_trap(struct regs *rp, caddr_t addr, uint32_t type, uint32_t code)
 			pfpq->fpq_addr = (uint32_t *)rp->r_pc;
 			pfpq->fpq_instr = inst;
 			fp->fpu_qcnt = 1;
-			fp->fpu_q_entrysize = sizeof (struct _fpq);
+			fp->fpu_q_entrysize = sizeof (struct fpq);
 #ifdef SF_V9_TABLE_28
 			/*
 			 * Spitfire and blackbird followed the SPARC V9 manual