Merge the fueword(9) and casueword(9). In particular,

MFC r273783:
Add fueword(9) and casueword(9) functions.
MFC note: ia64 is handled like arm, with NO_FUEWORD define.

MFC r273784:
Replace some calls to fuword() by fueword() with proper error checking.

MFC r273785:
Convert kern_umtx.c to use fueword() and casueword().
MFC note: the sys__umtx_lock and sys__umtx_unlock syscalls are not
converted, they are removed from HEAD, and not used.  The do_sem2*()
family is not yet merged to stable/10, corresponding chunk will be
merged after do_sem2* are committed.

MFC r273788 (by jkim):
Actually install casuword(9) to fix build.

MFC r273911:
Add type qualifier volatile to the base (userspace) address argument
of fuword(9) and suword(9).

4 files changed, 171 insertions, 19 deletions

diff --git a/share/man/man9/Makefile b/share/man/man9/Makefile
index 66e0027..c7140e2 100644
--- a/share/man/man9/Makefile
+++ b/share/man/man9/Makefile
@@ -46,6 +46,7 @@ MAN=	accept_filter.9 \
 	BUS_SETUP_INTR.9 \
 	bus_space.9 \
 	byteorder.9 \
+	casuword.9 \
 	cd.9 \
 	condvar.9 \
 	config_intrhook.9 \
@@ -566,6 +567,9 @@ MLINKS+=condvar.9 cv_broadcast.9 \
 MLINKS+=config_intrhook.9 config_intrhook_disestablish.9 \
 	config_intrhook.9 config_intrhook_establish.9
 MLINKS+=contigmalloc.9 contigfree.9
+MLINKS+=casuword.9 casueword.9 \
+	casuword.9 casueword32.9 \
+	casuword.9 casuword32.9
 MLINKS+=copy.9 copyin.9 \
 	copy.9 copyin_nofault.9 \
 	copy.9 copyinstr.9 \
@@ -668,7 +672,10 @@ MLINKS+=fetch.9 fubyte.9 \
 	fetch.9 fuword.9 \
 	fetch.9 fuword16.9 \
 	fetch.9 fuword32.9 \
-	fetch.9 fuword64.9
+	fetch.9 fuword64.9 \
+	fetch.9 fueword.9 \
+	fetch.9 fueword32.9 \
+	fetch.9 fueword64.9
 MLINKS+=fpu_kern.9 fpu_kern_alloc_ctx.9 \
 	fpu_kern.9 fpu_kern_free_ctx.9 \
 	fpu_kern.9 fpu_kern_enter.9 \
diff --git a/share/man/man9/casuword.9 b/share/man/man9/casuword.9
new file mode 100644
index 0000000..34a0f1d
--- /dev/null
+++ b/share/man/man9/casuword.9
@@ -0,0 +1,95 @@
+.\" Copyright (c) 2014 The FreeBSD Foundation
+.\" All rights reserved.
+.\"
+.\" Part of this documentation was written by
+.\" Konstantin Belousov <kib@FreeBSD.org> under sponsorship
+.\" from the FreeBSD Foundation.
+.\"
+.\" 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.
+.\"
+.\" $FreeBSD$
+.\"
+.Dd October 21, 2014
+.Dt CASU 9
+.Os
+.Sh NAME
+.Nm casueword ,
+.Nm casueword32 ,
+.Nm casuword ,
+.Nm casuword32
+.Nd fetch, compare and store data from user-space
+.Sh SYNOPSIS
+.In sys/types.h
+.In sys/systm.h
+.Ft int
+.Fn casueword "volatile u_long *base" "u_long oldval" "u_long *oldvalp" "u_long newval"
+.Ft int
+.Fn casueword32 "volatile uint32_t *base" "uint32_t oldval" "uint32_t *oldvalp" "uint32_t newval"
+.Ft u_long
+.Fn casuword "volatile u_long *base" "u_long oldval" "u_long newval"
+.Ft uint32_t
+.Fn casuword32 "volatile uint32_t *base" "uint32_t oldval" "uint32_t newval"
+.Sh DESCRIPTION
+The
+.Nm
+functions are designed to perform atomic compare-and-swap operation on
+the value in the usermode memory of the current process.
+.Pp
+The
+.Nm
+routines reads the value from user memory with address
+.Pa base ,
+and compare the value read with
+.Pa oldval .
+If the values are equal,
+.Pa newval
+is written to the
+.Pa *base .
+In case of
+.Fn casueword32
+and
+.Fn casueword ,
+old value is stored into the (kernel-mode) variable pointed by
+.Pa *oldvalp .
+The userspace value must be naturally aligned.
+.Pp
+The callers of
+.Fn casuword
+and
+.Fn casuword32
+functions cannot distinguish between -1 read from
+userspace and function failure.
+.Sh RETURN VALUES
+The
+.Fn casuword
+and
+.Fn casuword32
+functions return the data fetched or -1 on failure.
+The
+.Fn casueword
+and
+.Fn casueword32
+functions return 0 on success and -1 on failure.
+.Sh SEE ALSO
+.Xr atomic 9 ,
+.Xr fetch 9 ,
+.Xr store 9
diff --git a/share/man/man9/fetch.9 b/share/man/man9/fetch.9
index ccf6866..1d46784 100644
--- a/share/man/man9/fetch.9
+++ b/share/man/man9/fetch.9
@@ -34,7 +34,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd October 5, 2009
+.Dd October 29, 2014
 .Dt FETCH 9
 .Os
 .Sh NAME
@@ -44,43 +44,56 @@
 .Nm fuword ,
 .Nm fuword16 ,
 .Nm fuword32 ,
-.Nm fuword64
+.Nm fuword64 ,
+.Nm fueword ,
+.Nm fueword32 ,
+.Nm fueword64
 .Nd fetch data from user-space
 .Sh SYNOPSIS
 .In sys/types.h
-.In sys/time.h
 .In sys/systm.h
 .Ft int
-.Fn fubyte "const void *base"
+.Fn fubyte "volatile const void *base"
 .Ft long
-.Fn fuword "const void *base"
+.Fn fuword "volatile const void *base"
 .Ft int
-.Fn fuword16 "void *base"
+.Fn fuword16 "volatile const void *base"
 .Ft int32_t
-.Fn fuword32 "const void *base"
+.Fn fuword32 "volatile const void *base"
 .Ft int64_t
-.Fn fuword64 "const void *base"
+.Fn fuword64 "volatile const void *base"
+.Ft long
+.Fn fueword "volatile const void *base" "long *val"
+.Ft int32_t
+.Fn fueword32 "volatile const void *base" "int32_t *val"
+.Ft int64_t
+.Fn fueword64 "volatile const void *base" "int64_t *val"
 .In sys/resourcevar.h
 .Ft int
 .Fn fuswintr "void *base"
 .Sh DESCRIPTION
 The
 .Nm
-functions are designed to copy small amounts of data from user-space.
+functions are designed to copy small amounts of data from user-space
+of the current process.
+If read is successful, it is performed atomically.
+The data read must be naturally aligned.
 .Pp
 The
 .Nm
 routines provide the following functionality:
-.Bl -tag -width "fuswintr()"
+.Bl -tag -width "fueword32()"
 .It Fn fubyte
 Fetches a byte of data from the user-space address
 .Pa base .
+The byte read is zero-extended into the results variable.
 .It Fn fuword
-Fetches a word of data from the user-space address
+Fetches a word of data (long) from the user-space address
 .Pa base .
 .It Fn fuword16
 Fetches 16 bits of data from the user-space address
 .Pa base .
+The half-word read is zero-extended into the results variable.
 .It Fn fuword32
 Fetches 32 bits of data from the user-space address
 .Pa base .
@@ -91,11 +104,46 @@ Fetches 64 bits of data from the user-space address
 Fetches a short word of data from the user-space address
 .Pa base .
 This function is safe to call during an interrupt context.
+.It Fn fueword
+Fetches a word of data (long) from the user-space address
+.Pa base
+and stores the result in the variable pointed by
+.Pa val .
+.It Fn fueword32
+Fetches 32 bits of data from the user-space address
+.Pa base
+and stores the result in the variable pointed by
+.Pa val .
+.It Fn fueword64
+Fetches 64 bits of data from the user-space address
+.Pa base
+and stores the result in the variable pointed by
+.Pa val .
 .El
+.Pp
+The callers of
+.Fn fuword ,
+.Fn fuword32
+and
+.Fn fuword64
+functions cannot distinguish between -1 read from
+userspace and function failure.
 .Sh RETURN VALUES
 The
-.Nm
+.Fn fubyte ,
+.Fn fuword ,
+.Fn fuword16 ,
+.Fn fuword32 ,
+.Fn fuword64 ,
+and
+.Fn fuswintr
 functions return the data fetched or -1 on failure.
+The
+.Fn fueword ,
+.Fn fueword32
+and
+.Fn fueword64
+functions return 0 on success and -1 on failure.
 .Sh SEE ALSO
 .Xr copy 9 ,
 .Xr store 9
diff --git a/share/man/man9/store.9 b/share/man/man9/store.9
index d333eff..cc442f2 100644
--- a/share/man/man9/store.9
+++ b/share/man/man9/store.9
@@ -34,7 +34,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd October 5, 2009
+.Dd October 29, 2014
 .Dt STORE 9
 .Os
 .Sh NAME
@@ -48,15 +48,15 @@
 .In sys/time.h
 .In sys/systm.h
 .Ft int
-.Fn subyte "void *base" "int byte"
+.Fn subyte "volatile void *base" "int byte"
 .Ft int
-.Fn suword "void *base" "long word"
+.Fn suword "volatile void *base" "long word"
 .Ft int
-.Fn suword16 "void *base" "int word"
+.Fn suword16 "volatile void *base" "int word"
 .Ft int
-.Fn suword32 "void *base" "int32_t word"
+.Fn suword32 "volatile void *base" "int32_t word"
 .Ft int
-.Fn suword64 "void *base" "int64_t word"
+.Fn suword64 "volatile void *base" "int64_t word"
 .In sys/resourcevar.h
 .Ft int
 .Fn suswintr "void *base" "int word"
@@ -64,6 +64,8 @@
 The
 .Nm
 functions are designed to copy small amounts of data to user-space.
+If write is successful, it is performed atomically.
+The data written must be naturally aligned.
 .Pp
 The
 .Nm