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/* Assembler macros for CRIS.
Copyright (C) 1999, 2001 Free Software Foundation, Inc.
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. */
#include <asm/unistd.h>
#include <sysdeps/cris/sysdep.h>
#include <sys/syscall.h>
#include "config.h"
#undef SYS_ify
#define SYS_ify(syscall_name) (__NR_##syscall_name)
#ifdef __ASSEMBLER__
/* 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. */
#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
/* 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 %eax
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 safely
test with -4095. */
/* Syscall wrappers consist of
#include <sysdep.h>
PSEUDO (...)
ret
PSEUDO_END (...)
which expand to the following. */
/* Linux takes system call arguments in registers:
syscall number R9
arg 1 R10
arg 2 R11
arg 3 R12
arg 4 R13
arg 5 MOF
arg 6 SRP
The compiler calls us by the C convention:
syscall number in the DO_CALL macro
arg 1 R10
arg 2 R11
arg 3 R12
arg 4 R13
arg 5 [SP]
arg 6 [SP + 4]
*/
/* Note that we use "bhs", since we want to match
(unsigned) -4096 .. 0xffffffff. Using "ble" would match
-4096 .. -2**31. */
#define PSEUDO(name, syscall_name, args) \
ENTRY (name) @ \
DOARGS_##args @ \
movu.w SYS_ify (syscall_name),$r9 @ \
break 13 @ \
cmps.w -4096,$r10 @ \
bhs 0f @ \
nop @ \
UNDOARGS_return_##args
/* Ouch! We have to remember not to use "ret" in assembly-code.
("Luckily", mnemonics are case-insensitive.)
Note that we assume usage is exactly:
PSEUDO (...)
ret
PSEUDO_END (...)
so we can put all payload into PSEUDO (except for error handling). */
#define ret
#define PSEUDO_END(name) \
0: @ \
SETUP_PIC @ \
PLTJUMP (syscall_error) @ \
END (name)
#define DOARGS_0
#define DOARGS_1
#define DOARGS_2
#define DOARGS_3
#define DOARGS_4
#define DOARGS_5 \
move [$sp],$mof
/* To avoid allocating stack-space, we re-use the arg 5 (MOF) entry by
storing SRP into it. If called with too-few arguments, we will crash,
but that will happen in the general case too. */
#define DOARGS_6 \
DOARGS_5 @ \
move $srp,[$sp] @ \
move [$sp+4],$srp
#define UNDOARGS_return_0 \
Ret @ \
nop
#define UNDOARGS_return_1 UNDOARGS_return_0
#define UNDOARGS_return_2 UNDOARGS_return_0
#define UNDOARGS_return_3 UNDOARGS_return_0
#define UNDOARGS_return_4 UNDOARGS_return_0
#define UNDOARGS_return_5 UNDOARGS_return_0
/* We assume the following code will be "ret" and "PSEUDO_END". */
#define UNDOARGS_return_return_6 \
jump [$sp]
#else /* not __ASSEMBLER__ */
#undef INLINE_SYSCALL
#define INLINE_SYSCALL(name, nr, args...) \
({ \
unsigned long __sys_res; \
register unsigned long __res asm ("r10"); \
LOAD_ARGS_c_##nr (args) \
register unsigned long __callno asm ("r9") \
= SYS_ify (name); \
asm volatile (LOAD_ARGS_asm_##nr (args) \
"break 13" \
: "=r" (__res) \
: ASM_ARGS_##nr (args) \
: ASM_CLOBBER_##nr); \
__sys_res = __res; \
\
if (__sys_res >= (unsigned long) -4096) \
{ \
__set_errno (- __sys_res); \
__sys_res = (unsigned long) -1; \
} \
__sys_res; \
})
#define LOAD_ARGS_c_0()
#define LOAD_ARGS_asm_0()
#define ASM_CLOBBER_0 "memory"
#define ASM_ARGS_0() "r" (__callno)
#define LOAD_ARGS_c_1(r10) \
LOAD_ARGS_c_0() \
register unsigned long __r10 __asm__ ("r10") = (unsigned long) (r10);
#define LOAD_ARGS_asm_1(r10) LOAD_ARGS_asm_0 ()
#define ASM_CLOBBER_1 ASM_CLOBBER_0
#define ASM_ARGS_1(r10) ASM_ARGS_0 (), "0" (__r10)
#define LOAD_ARGS_c_2(r10, r11) \
LOAD_ARGS_c_1(r10) \
register unsigned long __r11 __asm__ ("r11") = (unsigned long) (r11);
#define LOAD_ARGS_asm_2(r10, r11) LOAD_ARGS_asm_1 (r10)
#define ASM_CLOBBER_2 ASM_CLOBBER_1
#define ASM_ARGS_2(r10, r11) ASM_ARGS_1 (r10), "r" (__r11)
#define LOAD_ARGS_c_3(r10, r11, r12) \
LOAD_ARGS_c_2(r10, r11) \
register unsigned long __r12 __asm__ ("r12") = (unsigned long) (r12);
#define LOAD_ARGS_asm_3(r10, r11, r12) LOAD_ARGS_asm_2 (r10, r11)
#define ASM_CLOBBER_3 ASM_CLOBBER_2
#define ASM_ARGS_3(r10, r11, r12) ASM_ARGS_2 (r10, r11), "r" (__r12)
#define LOAD_ARGS_c_4(r10, r11, r12, r13) \
LOAD_ARGS_c_3(r10, r11, r12) \
register unsigned long __r13 __asm__ ("r13") = (unsigned long) (r13);
#define LOAD_ARGS_asm_4(r10, r11, r12, r13) LOAD_ARGS_asm_3 (r10, r11, r12)
#define ASM_CLOBBER_4 ASM_CLOBBER_3
#define ASM_ARGS_4(r10, r11, r12, r13) ASM_ARGS_3 (r10, r11, r12), "r" (__r13)
#define LOAD_ARGS_c_5(r10, r11, r12, r13, mof) \
LOAD_ARGS_c_4(r10, r11, r12, r13)
#define LOAD_ARGS_asm_5(r10, r11, r12, r13, mof) \
LOAD_ARGS_asm_4 (r10, r11, r12, r13) "move %5,$mof\n\t"
#define ASM_CLOBBER_5 ASM_CLOBBER_4
#define ASM_ARGS_5(r10, r11, r12, r13, mof) \
ASM_ARGS_4 (r10, r11, r12, r13), "g" (mof)
#define LOAD_ARGS_c_6(r10, r11, r12, r13, mof, srp) \
LOAD_ARGS_c_5(r10, r11, r12, r13, mof)
#define LOAD_ARGS_asm_6(r10, r11, r12, r13, mof, srp) \
LOAD_ARGS_asm_5(r10, r11, r12, r13, mof) \
"move %6,$srp\n\t"
#define ASM_CLOBBER_6 ASM_CLOBBER_5, "srp"
#define ASM_ARGS_6(r10, r11, r12, r13, mof, srp) \
ASM_ARGS_5 (r10, r11, r12, r13, mof), "g" (srp)
#endif /* not __ASSEMBLER__ */
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