arch/tile: eliminate pt_regs trampolines for syscalls

Using the new current_pt_regs() model, we can remove some trampolines
from assembly code and call directly to the C syscall implementations.
rt_sigreturn() and clone() still need some assembly wrapping, but no
longer are passed a pt_regs pointer.  sigaltstack() and the
tilepro-specific cmpxchg_badaddr() syscalls are now just straight C.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>

2 files changed, 16 insertions, 12 deletions

diff --git a/arch/tile/include/asm/compat.h b/arch/tile/include/asm/compat.h
index 3bcf1b94b563..ca61fb4296b3 100644
--- a/arch/tile/include/asm/compat.h
+++ b/arch/tile/include/asm/compat.h
@@ -280,10 +280,9 @@ long compat_sys_rt_sigaction(int sig, struct compat_sigaction __user *act,
 			     size_t sigsetsize);
 long compat_sys_rt_sigqueueinfo(int pid, int sig,
 				struct compat_siginfo __user *uinfo);
-long compat_sys_rt_sigreturn(struct pt_regs *);
+long compat_sys_rt_sigreturn(void);
 long compat_sys_sigaltstack(const struct compat_sigaltstack __user *uss_ptr,
-			    struct compat_sigaltstack __user *uoss_ptr,
-			    struct pt_regs *);
+			    struct compat_sigaltstack __user *uoss_ptr);
 long compat_sys_truncate64(char __user *filename, u32 dummy, u32 low, u32 high);
 long compat_sys_ftruncate64(unsigned int fd, u32 dummy, u32 low, u32 high);
 long compat_sys_pread64(unsigned int fd, char __user *ubuf, size_t count,
@@ -300,9 +299,7 @@ long compat_sys_fallocate(int fd, int mode,
 long compat_sys_sched_rr_get_interval(compat_pid_t pid,
 				      struct compat_timespec __user *interval);
 
-/* These are the intvec_64.S trampolines. */
-long _compat_sys_sigaltstack(const struct compat_sigaltstack __user *uss_ptr,
-			    struct compat_sigaltstack __user *uoss_ptr);
+/* Assembly trampoline to avoid clobbering r0. */
 long _compat_sys_rt_sigreturn(void);
 
 #endif /* _ASM_TILE_COMPAT_H */
diff --git a/arch/tile/include/asm/syscalls.h b/arch/tile/include/asm/syscalls.h
index 0d52992f8e05..369696d63e7b 100644
--- a/arch/tile/include/asm/syscalls.h
+++ b/arch/tile/include/asm/syscalls.h
@@ -51,8 +51,7 @@ long sys_cacheflush(unsigned long addr, unsigned long len,
 
 #ifndef __tilegx__
 /* mm/fault.c */
-long sys_cmpxchg_badaddr(unsigned long address, struct pt_regs *);
-long _sys_cmpxchg_badaddr(unsigned long address);
+long sys_cmpxchg_badaddr(unsigned long address);
 #endif
 
 #ifdef CONFIG_COMPAT
@@ -63,15 +62,23 @@ long sys_truncate64(const char __user *path, loff_t length);
 long sys_ftruncate64(unsigned int fd, loff_t length);
 #endif
 
-/* These are the intvec*.S trampolines. */
-long _sys_sigaltstack(const stack_t __user *, stack_t __user *);
-long _sys_rt_sigreturn(void);
-long _sys_clone(unsigned long clone_flags, unsigned long newsp,
+/* Provide versions of standard syscalls that use current_pt_regs(). */
+long sys_clone(unsigned long clone_flags, unsigned long newsp,
 		void __user *parent_tid, void __user *child_tid);
 long sys_execve(const char __user *filename,
 		 const char __user *const __user *argv,
 		 const char __user *const __user *envp);
+long sys_rt_sigreturn(void);
+long sys_sigaltstack(const stack_t __user *, stack_t __user *);
+#define sys_clone sys_clone
 #define sys_execve sys_execve
+#define sys_rt_sigreturn sys_rt_sigreturn
+#define sys_sigaltstack sys_sigaltstack
+
+/* These are the intvec*.S trampolines. */
+long _sys_rt_sigreturn(void);
+long _sys_clone(unsigned long clone_flags, unsigned long newsp,
+		void __user *parent_tid, void __user *child_tid);
 
 #include <asm-generic/syscalls.h>