asm-generic: add generic versions of common headers

These are all kernel internal interfaces that get copied
around a lot. In most cases, architectures can provide
their own optimized versions, but these generic versions
can work as well.

I have tried to use the most common contents of each
header to allow existing architectures to migrate easily.

Thanks to Remis for suggesting a number of cleanups.

Signed-off-by: Remis Lima Baima <remis.developer@googlemail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

include/asm-generic/syscalls.h

@@ -0,0 +1,60 @@
+#ifndef __ASM_GENERIC_SYSCALLS_H
+#define __ASM_GENERIC_SYSCALLS_H
+
+#include <linux/compiler.h>
+#include <linux/linkage.h>
+
+/*
+ * Calling conventions for these system calls can differ, so
+ * it's possible to override them.
+ */
+#ifndef sys_clone
+asmlinkage long sys_clone(unsigned long clone_flags, unsigned long newsp,
+			void __user *parent_tid, void __user *child_tid,
+			struct pt_regs *regs);
+#endif
+
+#ifndef sys_fork
+asmlinkage long sys_fork(struct pt_regs *regs);
+#endif
+
+#ifndef sys_vfork
+asmlinkage long sys_vfork(struct pt_regs *regs);
+#endif
+
+#ifndef sys_execve
+asmlinkage long sys_execve(char __user *filename, char __user * __user *argv,
+			char __user * __user *envp, struct pt_regs *regs);
+#endif
+
+#ifndef sys_mmap2
+asmlinkage long sys_mmap2(unsigned long addr, unsigned long len,
+			unsigned long prot, unsigned long flags,
+			unsigned long fd, unsigned long pgoff);
+#endif
+
+#ifndef sys_mmap
+asmlinkage long sys_mmap(unsigned long addr, unsigned long len,
+			unsigned long prot, unsigned long flags,
+			unsigned long fd, off_t pgoff);
+#endif
+
+#ifndef sys_sigaltstack
+asmlinkage long sys_sigaltstack(const stack_t __user *, stack_t __user *,
+			struct pt_regs *);
+#endif
+
+#ifndef sys_rt_sigreturn
+asmlinkage long sys_rt_sigreturn(struct pt_regs *regs);
+#endif
+
+#ifndef sys_rt_sigsuspend
+asmlinkage long sys_rt_sigsuspend(sigset_t __user *unewset, size_t sigsetsize);
+#endif
+
+#ifndef sys_rt_sigaction
+asmlinkage long sys_rt_sigaction(int sig, const struct sigaction __user *act,
+			 struct sigaction __user *oact, size_t sigsetsize);
+#endif
+
+#endif /* __ASM_GENERIC_SYSCALLS_H */