arc: 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.

arc has a couple of architecture specific system calls, which I add to the
generic table. This for some reason includes the deprecated sys_sysfs()
syscall that was presumably added by accident.

The time32, renameat, stat64 and rlimit entries in the syscall_abis_32
entry are for system calls that were part of the generic ABI when arch/arc
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/arc/include/asm/Kbuild

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

arch/arc/include/asm/unistd.h

@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+#ifndef _ASM_ARC_UNISTD_H
+#define _ASM_ARC_UNISTD_H
+
+#include <uapi/asm/unistd.h>
+
+#define __ARCH_WANT_STAT64
+#define __ARCH_WANT_SYS_CLONE
+#define __ARCH_WANT_SYS_VFORK
+#define __ARCH_WANT_SYS_FORK
+
+#define NR_syscalls __NR_syscalls
+
+#endif

arch/arc/include/uapi/asm/Kbuild

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

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

@@ -7,45 +7,4 @@
  * published by the Free Software Foundation.
  */
 
-/******** no-legacy-syscalls-ABI *******/
+#include <asm/unistd_32.h>
-
-/*
- * Non-typical guard macro to enable inclusion twice in ARCH sys.c
- * That is how the Generic syscall wrapper generator works
- */
-#if !defined(_UAPI_ASM_ARC_UNISTD_H) || defined(__SYSCALL)
-#define _UAPI_ASM_ARC_UNISTD_H
-
-#define __ARCH_WANT_RENAMEAT
-#define __ARCH_WANT_STAT64
-#define __ARCH_WANT_SET_GET_RLIMIT
-#define __ARCH_WANT_SYS_EXECVE
-#define __ARCH_WANT_SYS_CLONE
-#define __ARCH_WANT_SYS_VFORK
-#define __ARCH_WANT_SYS_FORK
-#define __ARCH_WANT_TIME32_SYSCALLS
-
-#define sys_mmap2 sys_mmap_pgoff
-
-#include <asm-generic/unistd.h>
-
-#define NR_syscalls	__NR_syscalls
-
-/* Generic syscall (fs/filesystems.c - lost in asm-generic/unistd.h */
-#define __NR_sysfs		(__NR_arch_specific_syscall + 3)
-
-/* ARC specific syscall */
-#define __NR_cacheflush		(__NR_arch_specific_syscall + 0)
-#define __NR_arc_settls		(__NR_arch_specific_syscall + 1)
-#define __NR_arc_gettls		(__NR_arch_specific_syscall + 2)
-#define __NR_arc_usr_cmpxchg	(__NR_arch_specific_syscall + 4)
-
-__SYSCALL(__NR_cacheflush, sys_cacheflush)
-__SYSCALL(__NR_arc_settls, sys_arc_settls)
-__SYSCALL(__NR_arc_gettls, sys_arc_gettls)
-__SYSCALL(__NR_arc_usr_cmpxchg, sys_arc_usr_cmpxchg)
-__SYSCALL(__NR_sysfs, sys_sysfs)
-
-#undef __SYSCALL
-
-#endif

arch/arc/kernel/Makefile.syscalls

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

arch/arc/kernel/sys.c

@@ -8,11 +8,12 @@
 
 #define sys_clone	sys_clone_wrapper
 #define sys_clone3	sys_clone3_wrapper
+#define sys_mmap2	sys_mmap_pgoff
 
-#undef __SYSCALL
 #define __SYSCALL(nr, call) [nr] = (call),
+#define __SYSCALL_WITH_COMPAT(nr, native, compat)  __SYSCALL(nr, native)
 
 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

@@ -288,6 +288,11 @@
 243	time32	recvmmsg			sys_recvmmsg_time32		compat_sys_recvmmsg_time32
 243	64	recvmmsg			sys_recvmmsg
 # Architectures may provide up to 16 syscalls of their own between 244 and 259
+244	arc	cacheflush			sys_cacheflush
+245	arc	arc_settls			sys_arc_settls
+246	arc	arc_gettls			sys_arc_gettls
+247	arc	sysfs				sys_sysfs
+248	arc	arc_usr_cmpxchg			sys_arc_usr_cmpxchg
 260	time32	wait4				sys_wait4			compat_sys_wait4
 260	64	wait4				sys_wait4
 261	common	prlimit64			sys_prlimit64