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/* Assembler macros for 64 bit S/390.
Copyright (C) 2001 Free Software Foundation, Inc.
Contributed by Martin Schwidefsky (schwidefsky@de.ibm.com).
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#ifndef _LINUX_S390_SYSDEP_H
#define _LINUX_S390_SYSEDP_H
#include <sysdeps/s390/s390-64/sysdep.h>
#include <sysdeps/unix/sysdep.h>
/* For Linux we can use the system call table in the header file
/usr/include/asm/unistd.h
of the kernel. But these symbols do not follow the SYS_* syntax
so we have to redefine the `SYS_ify' macro here. */
/* In newer 2.1 kernels __NR_syscall is missing so we define it here. */
#define __NR_syscall 0
#undef SYS_ify
#define SYS_ify(syscall_name) __NR_##syscall_name
/* ELF-like local names start with `.L'. */
#undef L
#define L(name) .L##name
#ifdef __ASSEMBLER__
/* Linux uses a negative return value to indicate syscall errors, unlike
most Unices, which use the condition codes' carry flag.
Since version 2.1 the return value of a system call might be negative
even if the call succeeded. E.g., the `lseek' system call might return
a large offset. Therefore we must not anymore test for < 0, but test
for a real error by making sure the value in gpr2 is a real error
number. Linus said he will make sure the no syscall returns a value
in -1 .. -4095 as a valid result so we can savely test with -4095. */
#define SYSCALL_ERROR_LABEL 0f
#undef PSEUDO
#define PSEUDO(name, syscall_name, args) \
.text; \
ENTRY (name) \
DO_CALL (args, syscall_name); \
lghi %r4,-4095 ; \
clgr %r2,%r4 ; \
jnl SYSCALL_ERROR_LABEL ; \
L(pseudo_end):
#undef PSEUDO_END
#define PSEUDO_END(name) \
SYSCALL_ERROR_HANDLER; \
END (name)
#ifndef _LIBC_REENTRANT
#ifndef PIC
#define SYSCALL_ERROR_HANDLER \
0: lcr %r2,%r2 ; \
larl %r1,errno ; \
st %r2,0(%r1) ; \
lghi %r2,-1 ; \
br %r14
#else
#define SYSCALL_ERROR_HANDLER \
0: larl %r1,_GLOBAL_OFFSET_TABLE_ ; \
lg %r1,errno@GOT(%r1) ; \
lcr %r2,%r2 ; \
st %r2,0(%r1) ; \
lghi %r2,-1 ; \
br %r14
#endif /* PIC */
#else
#define SYSCALL_ERROR_HANDLER \
0: jg __syscall_error@PLT
#endif /* _LIBC_REENTRANT */
/* Linux takes system call arguments in registers:
syscall number 1 call-clobbered
arg 1 2 call-clobbered
arg 2 3 call-clobbered
arg 3 4 call-clobbered
arg 4 5 call-clobbered
arg 5 6 call-saved
(Of course a function with say 3 arguments does not have entries for
arguments 4 and 5.)
S390 does not need to do ANY stack operations to get its parameters
right.
*/
#define DO_CALL(args, syscall) \
svc SYS_ify (syscall)
#define ret \
br 14
#endif /* __ASSEMBLER__ */
#undef INLINE_SYSCALL
#define INLINE_SYSCALL(name, nr, args...) \
({ \
DECLARGS_##nr(args) \
int err; \
asm volatile ( \
LOADARGS_##nr \
"svc %b1\n\t" \
"lgr %0,%%r2\n\t" \
: "=d" (err) \
: "I" (__NR_##name) ASMFMT_##nr \
: "memory", "cc", "2", "3", "4", "5", "6"); \
if (err >= 0xfffff001) \
{ \
__set_errno(-err); \
err = -1; \
} \
(int) err; })
#define DECLARGS_0()
#define DECLARGS_1(arg1) \
unsigned long gpr2 = (unsigned long) (arg1);
#define DECLARGS_2(arg1, arg2) \
DECLARGS_1(arg1) \
unsigned long gpr3 = (unsigned long) (arg2);
#define DECLARGS_3(arg1, arg2, arg3) \
DECLARGS_2(arg1, arg2) \
unsigned long gpr4 = (unsigned long) (arg3);
#define DECLARGS_4(arg1, arg2, arg3, arg4) \
DECLARGS_3(arg1, arg2, arg3) \
unsigned long gpr5 = (unsigned long) (arg4);
#define DECLARGS_5(arg1, arg2, arg3, arg4, arg5) \
DECLARGS_4(arg1, arg2, arg3, arg4) \
unsigned long gpr6 = (unsigned long) (arg5);
#define LOADARGS_0
#define LOADARGS_1 "LG 2,%2\n\t"
#define LOADARGS_2 LOADARGS_1 "LG 3,%3\n\t"
#define LOADARGS_3 LOADARGS_2 "LG 4,%4\n\t"
#define LOADARGS_4 LOADARGS_3 "LG 5,%5\n\t"
#define LOADARGS_5 LOADARGS_4 "LG 6,%6\n\t"
#define ASMFMT_0
#define ASMFMT_1 , "m" (gpr2)
#define ASMFMT_2 , "m" (gpr2), "m" (gpr3)
#define ASMFMT_3 , "m" (gpr2), "m" (gpr3), "m" (gpr4)
#define ASMFMT_4 , "m" (gpr2), "m" (gpr3), "m" (gpr4), "m" (gpr5)
#define ASMFMT_5 , "m" (gpr2), "m" (gpr3), "m" (gpr4), "m" (gpr5), "m" (gpr6)
#endif /* _LINUX_S390_SYSDEP_H */
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