/* Copyright (C) 2000,01,02,03 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 Lesser General Public License as published by the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with the GNU C Library; 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_SYSDEP_H #include #include /* 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 #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 (syscall_name, args); \ lhi %r4,-4095 ; \ clr %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 ; \ basr %r1,0 ; \ 1: l %r1,2f-1b(%r1) \ st %r2,0(%r1) \ lhi %r2,-1 \ br %r14 \ 2: .long errno #else #define SYSCALL_ERROR_HANDLER \ 0: basr %r1,0 ; \ 1: al %r1,2f-1b(%r1) ; \ l %r1,errno@GOT12(%r1) ; \ lcr %r2,%r2 ; \ st %r2,0(%r1) ; \ lhi %r2,-1 ; \ br %r14 ; \ 2: .long _GLOBAL_OFFSET_TABLE_-1b #endif /* PIC */ #else #define SYSCALL_ERROR_HANDLER \ 0: basr %r1,0 ; \ 1: al %r1,2f-1b(%r1) ; \ br %r1 ; \ 2: .long __syscall_error@PLT-1b #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(syscall, args) \ svc SYS_ify (syscall) #define ret \ br 14 #endif /* __ASSEMBLER__ */ #undef INLINE_SYSCALL #define INLINE_SYSCALL(name, nr, args...) \ ({ \ unsigned int _ret = INTERNAL_SYSCALL (name, , nr, args); \ if (__builtin_expect (INTERNAL_SYSCALL_ERROR_P (_ret, ), 0)) \ { \ __set_errno (INTERNAL_SYSCALL_ERRNO (_ret, )); \ _ret = 0xffffffff; \ } \ (int) _ret; }) #undef INTERNAL_SYSCALL_DECL #define INTERNAL_SYSCALL_DECL(err) do { } while (0) #undef INTERNAL_SYSCALL #define INTERNAL_SYSCALL(name, err, nr, args...) \ ({ \ DECLARGS_##nr(args) \ register int _ret asm("2"); \ asm volatile ( \ "svc %b1\n\t" \ : "=d" (_ret) \ : "i" (__NR_##name) ASMFMT_##nr \ : "memory" ); \ _ret; }) #undef INTERNAL_SYSCALL_ERROR_P #define INTERNAL_SYSCALL_ERROR_P(val, err) \ ((unsigned int) (val) >= 0xfffff001u) #undef INTERNAL_SYSCALL_ERRNO #define INTERNAL_SYSCALL_ERRNO(val, err) (-(val)) #define DECLARGS_0() #define DECLARGS_1(arg1) \ register unsigned long gpr2 asm ("2") = (unsigned long)(arg1); #define DECLARGS_2(arg1, arg2) \ DECLARGS_1(arg1) \ register unsigned long gpr3 asm ("3") = (unsigned long)(arg2); #define DECLARGS_3(arg1, arg2, arg3) \ DECLARGS_2(arg1, arg2) \ register unsigned long gpr4 asm ("4") = (unsigned long)(arg3); #define DECLARGS_4(arg1, arg2, arg3, arg4) \ DECLARGS_3(arg1, arg2, arg3) \ register unsigned long gpr5 asm ("5") = (unsigned long)(arg4); #define DECLARGS_5(arg1, arg2, arg3, arg4, arg5) \ DECLARGS_4(arg1, arg2, arg3, arg4) \ register unsigned long gpr6 asm ("6") = (unsigned long)(arg5); #define ASMFMT_0 #define ASMFMT_1 , "0" (gpr2) #define ASMFMT_2 , "0" (gpr2), "d" (gpr3) #define ASMFMT_3 , "0" (gpr2), "d" (gpr3), "d" (gpr4) #define ASMFMT_4 , "0" (gpr2), "d" (gpr3), "d" (gpr4), "d" (gpr5) #define ASMFMT_5 , "0" (gpr2), "d" (gpr3), "d" (gpr4), "d" (gpr5), "d" (gpr6) #endif /* _LINUX_S390_SYSDEP_H */