From: Jan Kiszka <jan.kis...@siemens.com>
Converting them into inline functions helps to avoid clobbering of w8.
Without this, the compiler may squeeze function calls between the setup
of __scno in w8 and the actually submission of the syscall. Seen with
the smokey y2038 testcase.
Signed-off-by: Jan Kiszka <jan.kis...@siemens.com>
---
Close to an out-of-line version, possibly even better.
I'm not sure, though, if that pattern buys us anything on 32-bit arm.
Problem there remains the usage conflict of r7 which static inline may
not resolve.
.../arch/arm64/include/asm/xenomai/syscall.h | 115 ++++++++++--------
1 file changed, 61 insertions(+), 54 deletions(-)
diff --git a/lib/cobalt/arch/arm64/include/asm/xenomai/syscall.h
b/lib/cobalt/arch/arm64/include/asm/xenomai/syscall.h
index d2dfda6846..d896977125 100644
--- a/lib/cobalt/arch/arm64/include/asm/xenomai/syscall.h
+++ b/lib/cobalt/arch/arm64/include/asm/xenomai/syscall.h
@@ -1,5 +1,6 @@
/*
* Copyright (C) 2015 Philippe Gerum <r...@xenomai.org>.
+ * Copyright (C) Siemens AG, 2021
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
@@ -22,76 +23,82 @@
#include <errno.h>
#include <cobalt/uapi/syscall.h>
-#define __emit_asmdecl0
\
- register unsigned int __scno __asm__ ("w8"); \
- register unsigned long __res __asm__ ("x0")
-#define __emit_asmdecl1
\
- __emit_asmdecl0; register unsigned long __x0 __asm__ ("x0")
-#define __emit_asmdecl2
\
- __emit_asmdecl1; register unsigned long __x1 __asm__ ("x1")
-#define __emit_asmdecl3
\
- __emit_asmdecl2; register unsigned long __x2 __asm__ ("x2")
-#define __emit_asmdecl4
\
- __emit_asmdecl3; register unsigned long __x3 __asm__ ("x3")
-#define __emit_asmdecl5
\
- __emit_asmdecl4; register unsigned long __x4 __asm__ ("x4")
-
-#define __load_asminput0(__op) \
- __scno = (unsigned int)__xn_syscode(__op)
-#define __load_asminput1(__op, __a1) \
- __load_asminput0(__op); \
- __x0 = (unsigned long)(__a1)
-#define __load_asminput2(__op, __a1, __a2) \
- __load_asminput1(__op, __a1); \
- __x1 = (unsigned long)(__a2)
-#define __load_asminput3(__op, __a1, __a2, __a3) \
- __load_asminput2(__op, __a1, __a2); \
- __x2 = (unsigned long)(__a3)
-#define __load_asminput4(__op, __a1, __a2, __a3, __a4) \
- __load_asminput3(__op, __a1, __a2, __a3); \
- __x3 = (unsigned long)(__a4)
-#define __load_asminput5(__op, __a1, __a2, __a3, __a4, __a5) \
- __load_asminput4(__op, __a1, __a2, __a3, __a4); \
- __x4 = (unsigned long)(__a5)
+#define __xn_syscall_args0
+#define __xn_syscall_args1 , unsigned long __a1
+#define __xn_syscall_args2 __xn_syscall_args1, unsigned long __a2
+#define __xn_syscall_args3 __xn_syscall_args2, unsigned long __a3
+#define __xn_syscall_args4 __xn_syscall_args3, unsigned long __a4
+#define __xn_syscall_args5 __xn_syscall_args4, unsigned long __a5
#define __emit_syscall0(__args...) \
+ register unsigned int __scno __asm__("w8") = __xn_syscode(__op); \
+ register unsigned long __res __asm__("x0"); \
__asm__ __volatile__ ( \
"svc 0;\n\t" \
: "=r" (__res) \
: "r" (__scno), ##__args \
: "cc", "memory"); \
- __res
-#define __emit_syscall1(__a1, __args...) \
+ return __res
+#define __emit_syscall1(__args...) \
+ register unsigned long __x0 __asm__("x0") = __a1; \
__emit_syscall0("r" (__x0), ##__args)
-#define __emit_syscall2(__a1, __a2, __args...) \
- __emit_syscall1(__a1, "r" (__x1), ##__args)
-#define __emit_syscall3(__a1, __a2, __a3, __args...) \
- __emit_syscall2(__a1, __a2, "r" (__x2), ##__args)
-#define __emit_syscall4(__a1, __a2, __a3, __a4, __args...) \
- __emit_syscall3(__a1, __a2, __a3, "r" (__x3), ##__args)
-#define __emit_syscall5(__a1, __a2, __a3, __a4, __a5, __args...) \
- __emit_syscall4(__a1, __a2, __a3, __a4, "r" (__x4), ##__args)
+#define __emit_syscall2(__args...) \
+ register unsigned long __x1 __asm__("x1") = __a2; \
+ __emit_syscall1("r" (__x1), ##__args)
+#define __emit_syscall3(__args...) \
+ register unsigned long __x2 __asm__("x2") = __a3; \
+ __emit_syscall2("r" (__x2), ##__args)
+#define __emit_syscall4(__args...) \
+ register unsigned long __x3 __asm__("x3") = __a4; \
+ __emit_syscall3("r" (__x3), ##__args)
+#define __emit_syscall5(__args...) \
+ register unsigned long __x4 __asm__("x4") = __a5; \
+ __emit_syscall4("r" (__x4), ##__args)
+
+#define DEFINE_XENOMAI_SYSCALL(__argnr)
\
+static inline long __attribute__((always_inline)) \
+__xenomai_do_syscall##__argnr(unsigned int __op
\
+ __xn_syscall_args##__argnr) \
+{ \
+ __emit_syscall##__argnr(); \
+}
-#define XENOMAI_DO_SYSCALL(__argnr, __op, __args...) \
- ({ \
- __emit_asmdecl##__argnr; \
- __load_asminput##__argnr(__op, ##__args); \
- __emit_syscall##__argnr(__args); \
- })
+DEFINE_XENOMAI_SYSCALL(0)
+DEFINE_XENOMAI_SYSCALL(1)
+DEFINE_XENOMAI_SYSCALL(2)
+DEFINE_XENOMAI_SYSCALL(3)
+DEFINE_XENOMAI_SYSCALL(4)
+DEFINE_XENOMAI_SYSCALL(5)
#define XENOMAI_SYSCALL0(__op) \
- XENOMAI_DO_SYSCALL(0, __op)
+ __xenomai_do_syscall0(__op)
#define XENOMAI_SYSCALL1(__op, __a1) \
- XENOMAI_DO_SYSCALL(1, __op, __a1)
+ __xenomai_do_syscall1(__op, \
+ (unsigned long)__a1)
#define XENOMAI_SYSCALL2(__op, __a1, __a2) \
- XENOMAI_DO_SYSCALL(2, __op, __a1, __a2)
+ __xenomai_do_syscall2(__op, \
+ (unsigned long)__a1, \
+ (unsigned long)__a2)
#define XENOMAI_SYSCALL3(__op, __a1, __a2, __a3) \
- XENOMAI_DO_SYSCALL(3, __op, __a1, __a2, __a3)
+ __xenomai_do_syscall3(__op, \
+ (unsigned long)__a1, \
+ (unsigned long)__a2, \
+ (unsigned long)__a3)
#define XENOMAI_SYSCALL4(__op, __a1, __a2, __a3, __a4) \
- XENOMAI_DO_SYSCALL(4, __op, __a1, __a2, __a3, __a4)
+ __xenomai_do_syscall4(__op, \
+ (unsigned long)__a1, \
+ (unsigned long)__a2, \
+ (unsigned long)__a3, \
+ (unsigned long)__a4)
#define XENOMAI_SYSCALL5(__op, __a1, __a2, __a3, __a4, __a5) \
- XENOMAI_DO_SYSCALL(5, __op, __a1, __a2, __a3, __a4, __a5)
+ __xenomai_do_syscall5(__op, \
+ (unsigned long)__a1, \
+ (unsigned long)__a2, \
+ (unsigned long)__a3, \
+ (unsigned long)__a4, \
+ (unsigned long)__a5)
#define XENOMAI_SYSBIND(__breq) \
- XENOMAI_DO_SYSCALL(1, sc_cobalt_bind, __breq)
+ __xenomai_do_syscall1(sc_cobalt_bind, \
+ (unsigned long)__breq)
#endif /* !_LIB_COBALT_ARM64_SYSCALL_H */
--
2.31.1
