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s390/syscall: provide generic system call functions

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Provide generic system call functions which should be used whenever a
system call needs to be done from user space. The only in-kernel code
is vdso, which will be converted with a follow on patch.

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
This commit is contained in:
Heiko Carstens 2021-07-13 16:21:07 +02:00
parent b84d0c417a
commit 91f05c2744
1 changed files with 59 additions and 0 deletions
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59
arch/s390/include/asm/syscall.h
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@ -104,4 +104,63 @@ static inline bool arch_syscall_is_vdso_sigreturn(struct pt_regs *regs)
return false;
}
#define SYSCALL_FMT_0
#define SYSCALL_FMT_1 , "0" (r2)
#define SYSCALL_FMT_2 , "d" (r3) SYSCALL_FMT_1
#define SYSCALL_FMT_3 , "d" (r4) SYSCALL_FMT_2
#define SYSCALL_FMT_4 , "d" (r5) SYSCALL_FMT_3
#define SYSCALL_FMT_5 , "d" (r6) SYSCALL_FMT_4
#define SYSCALL_FMT_6 , "d" (r7) SYSCALL_FMT_5
#define SYSCALL_PARM_0
#define SYSCALL_PARM_1 , long arg1
#define SYSCALL_PARM_2 SYSCALL_PARM_1, long arg2
#define SYSCALL_PARM_3 SYSCALL_PARM_2, long arg3
#define SYSCALL_PARM_4 SYSCALL_PARM_3, long arg4
#define SYSCALL_PARM_5 SYSCALL_PARM_4, long arg5
#define SYSCALL_PARM_6 SYSCALL_PARM_5, long arg6
#define SYSCALL_REGS_0
#define SYSCALL_REGS_1 \
register long r2 asm("2") = arg1
#define SYSCALL_REGS_2 \
SYSCALL_REGS_1; \
register long r3 asm("3") = arg2
#define SYSCALL_REGS_3 \
SYSCALL_REGS_2; \
register long r4 asm("4") = arg3
#define SYSCALL_REGS_4 \
SYSCALL_REGS_3; \
register long r5 asm("5") = arg4
#define SYSCALL_REGS_5 \
SYSCALL_REGS_4; \
register long r6 asm("6") = arg5
#define SYSCALL_REGS_6 \
SYSCALL_REGS_5; \
register long r7 asm("7") = arg6
#define GENERATE_SYSCALL_FUNC(nr) \
static __always_inline \
long syscall##nr(unsigned long syscall SYSCALL_PARM_##nr) \
{ \
register unsigned long r1 asm ("1") = syscall; \
register long rc asm ("2"); \
SYSCALL_REGS_##nr; \
\
asm volatile ( \
" svc 0\n" \
: "=d" (rc) \
: "d" (r1) SYSCALL_FMT_##nr \
: "memory"); \
return rc; \
}
GENERATE_SYSCALL_FUNC(0)
GENERATE_SYSCALL_FUNC(1)
GENERATE_SYSCALL_FUNC(2)
GENERATE_SYSCALL_FUNC(3)
GENERATE_SYSCALL_FUNC(4)
GENERATE_SYSCALL_FUNC(5)
GENERATE_SYSCALL_FUNC(6)
#endif /* _ASM_SYSCALL_H */