nios2: convert to generic syscall table

The uapi/asm/unistd_32.h and asm/syscall_table_32.h headers can now be
generated from scripts/syscall.tbl, which makes this consistent with
the other architectures that have their own syscall.tbl.

nios2 has one extra system call that gets added to scripts/syscall.tbl.

The time32, stat64, and rlimit entries in the syscall_abis_32
line are for system calls that were part of the generic ABI when
arch/nios2 got added but are no longer enabled by default for new
architectures.

Both the user visible side of asm/unistd.h and the internal syscall
table in the kernel should have the same effective contents after this.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

arch/nios2/include/asm/Kbuild

@@ -1,4 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0
+syscall-y += syscall_table_32.h
+
 generic-y += cmpxchg.h
 generic-y += extable.h
 generic-y += kvm_para.h

arch/nios2/include/asm/unistd.h

@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+#ifndef __ASM_UNISTD_H
+#define __ASM_UNISTD_H
+
+#include <uapi/asm/unistd.h>
+
+#define __ARCH_WANT_STAT64
+#define __ARCH_WANT_SET_GET_RLIMIT
+
+#define __ARCH_BROKEN_SYS_CLONE3
+
+#endif

arch/nios2/include/uapi/asm/Kbuild

@@ -1,2 +1,4 @@
 # SPDX-License-Identifier: GPL-2.0
+syscall-y += unistd_32.h
+
 generic-y += ucontext.h

arch/nios2/include/uapi/asm/unistd.h

@@ -16,18 +16,4 @@
  *
  */
 
- #define sys_mmap2 sys_mmap_pgoff
-
-#define __ARCH_WANT_RENAMEAT
-#define __ARCH_WANT_STAT64
-#define __ARCH_WANT_SET_GET_RLIMIT
-#define __ARCH_WANT_TIME32_SYSCALLS
-
-#define __ARCH_BROKEN_SYS_CLONE3
-
-/* Use the standard ABI for syscalls */
-#include <asm-generic/unistd.h>
-
-/* Additional Nios II specific syscalls. */
-#define __NR_cacheflush (__NR_arch_specific_syscall)
-__SYSCALL(__NR_cacheflush, sys_cacheflush)
+#include <asm/unistd_32.h>

arch/nios2/kernel/Makefile.syscalls

@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0
+
+syscall_abis_32 += nios2 time32 stat64 renameat rlimit

arch/nios2/kernel/syscall_table.c

@@ -9,10 +9,12 @@
 
 #include <asm/syscalls.h>
 
-#undef __SYSCALL
 #define __SYSCALL(nr, call) [nr] = (call),
+#define __SYSCALL_WITH_COMPAT(nr, native, compat)        __SYSCALL(nr, native)
+
+#define sys_mmap2 sys_mmap_pgoff
 
 void *sys_call_table[__NR_syscalls] = {
 	[0 ... __NR_syscalls-1] = sys_ni_syscall,
-#include <asm/unistd.h>
+#include <asm/syscall_table_32.h>
 };

scripts/syscall.tbl

@@ -297,6 +297,8 @@
 244	csky	set_thread_area			sys_set_thread_area
 245	csky	cacheflush			sys_cacheflush
 
+244	nios2	cacheflush			sys_cacheflush
+
 260	time32	wait4				sys_wait4			compat_sys_wait4
 260	64	wait4				sys_wait4
 261	common	prlimit64			sys_prlimit64