Commit 91f05c27 authored by Heiko Carstens's avatar Heiko Carstens
Browse files

s390/syscall: provide generic system call functions 



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: default avatarSven Schnelle <svens@linux.ibm.com>
Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
parent b84d0c41

arch/s390/include/asm/syscall.h

+59 −0
Original line number Diff line number Diff line
@@ -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 */