freebsd-skq/sys/i386/linux/linux_support.s
kib cdee790df9 Move futex support code from <arch>/support.s into linux compat directory.
Implement all futex atomic operations in assembler to not depend on the
fuword() that does not allow to distinguish between -1 and failure return.
Correctly return 0 from atomic operations on success.

In collaboration with:	rdivacky
Tested by:	Scot Hetzel <swhetzel gmail com>, Milos Vyletel <mvyletel mzm cz>
Sponsored by:	Google SoC 2007
2007-05-23 08:33:06 +00:00

128 lines
3.3 KiB
ArmAsm

/*-
* Copyright (c) 2006,2007 Konstantin Belousov
* 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.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
*
* $FreeBSD$
*/
#include "linux_assym.h" /* system definitions */
#include <machine/asmacros.h> /* miscellaneous asm macros */
#include "assym.s"
futex_fault_decx:
movl PCPU(CURPCB),%ecx
futex_fault:
movl $0,PCB_ONFAULT(%ecx)
movl $-EFAULT,%eax
ret
ENTRY(futex_xchgl)
movl PCPU(CURPCB),%ecx
movl $futex_fault,PCB_ONFAULT(%ecx)
movl 4(%esp),%eax
movl 8(%esp),%edx
cmpl $VM_MAXUSER_ADDRESS-4,%edx
ja futex_fault
xchgl %eax,(%edx)
movl 12(%esp),%edx
movl %eax,(%edx)
xorl %eax,%eax
movl %eax,PCB_ONFAULT(%ecx)
ret
ENTRY(futex_addl)
movl PCPU(CURPCB),%ecx
movl $futex_fault,PCB_ONFAULT(%ecx)
movl 4(%esp),%eax
movl 8(%esp),%edx
cmpl $VM_MAXUSER_ADDRESS-4,%edx
ja futex_fault
#ifdef SMP
lock
#endif
xaddl %eax,(%edx)
movl 12(%esp),%edx
movl %eax,(%edx)
xorl %eax,%eax
movl %eax,PCB_ONFAULT(%ecx)
ret
ENTRY(futex_orl)
movl PCPU(CURPCB),%ecx
movl $futex_fault_decx,PCB_ONFAULT(%ecx)
movl 8(%esp),%edx
cmpl $VM_MAXUSER_ADDRESS-4,%edx
ja futex_fault
movl (%edx),%eax
1: movl %eax,%ecx
orl 4(%esp),%ecx
#ifdef SMP
lock
#endif
cmpxchgl %ecx,(%edx)
jnz 1b
futex_tail:
movl 12(%esp),%edx
movl %eax,(%edx)
xorl %eax,%eax
movl PCPU(CURPCB),%ecx
movl %eax,PCB_ONFAULT(%ecx)
ret
ENTRY(futex_andl)
movl PCPU(CURPCB),%ecx
movl $futex_fault_decx,PCB_ONFAULT(%ecx)
movl 8(%esp),%edx
cmpl $VM_MAXUSER_ADDRESS-4,%edx
ja futex_fault
movl (%edx),%eax
1: movl %eax,%ecx
andl 4(%esp),%ecx
#ifdef SMP
lock
#endif
cmpxchgl %ecx,(%edx)
jnz 1b
jmp futex_tail
ENTRY(futex_xorl)
movl PCPU(CURPCB),%ecx
movl $futex_fault_decx,PCB_ONFAULT(%ecx)
movl 8(%esp),%edx
cmpl $VM_MAXUSER_ADDRESS-4,%edx
ja futex_fault
movl (%edx),%eax
1: movl %eax,%ecx
xorl 4(%esp),%ecx
#ifdef SMP
lock
#endif
cmpxchgl %ecx,(%edx)
jnz 1b
jmp futex_tail