s390/syscalls: Switch to generic system call table generation

The s390 syscall.tbl format differs slightly from most others, and
therefore requires an s390 specific system call table generation
script.

With compat support gone use the opportunity to switch to generic
system call table generation. The abi for all 64 bit system calls is
now common, since there is no need to specify if system call entry
points are only for 64 bit anymore.

Furthermore create the system call table in C instead of assembler
code in order to get type checking for all system call functions
contained within the table.

Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

Author: hcahca

arch/s390/Makefile

@@ -134,10 +134,9 @@ zfcpdump:
 	$(Q)$(MAKE) $(build)=$(boot) $(boot)/$@
 
 archheaders:
-	$(Q)$(MAKE) $(build)=$(syscalls) uapi
+	$(Q)$(MAKE) $(build)=$(syscalls) all
 
 archprepare:
-	$(Q)$(MAKE) $(build)=$(syscalls) kapi
 	$(Q)$(MAKE) $(build)=$(tools) kapi $(extra_tools)
 ifeq ($(KBUILD_EXTMOD),)
 # We need to generate vdso-offsets.h before compiling certain files in kernel/.

arch/s390/include/asm/unistd.h

@@ -8,7 +8,8 @@
 #define _ASM_S390_UNISTD_H_
 
 #include <uapi/asm/unistd.h>
-#include <asm/unistd_nr.h>
+
+#define NR_syscalls (__NR_syscalls)
 
 #define __ARCH_WANT_NEW_STAT
 #define __ARCH_WANT_OLD_READDIR

arch/s390/kernel/entry.S

@@ -606,11 +606,3 @@ SYM_DATA_START_LOCAL(daton_psw)
 	.quad	PSW_KERNEL_BITS
 	.quad	.Ldaton
 SYM_DATA_END(daton_psw)
-
-	.section .rodata, "a"
-	.balign	8
-#define SYSCALL(esame,emu)	.quad __s390x_ ## esame
-SYM_DATA_START(sys_call_table)
-#include <asm/syscall_table.h>
-SYM_DATA_END(sys_call_table)
-#undef SYSCALL

arch/s390/kernel/syscall.c

@@ -39,6 +39,16 @@
 
 #include "entry.h"
 
+#define __SYSCALL(nr, sym) long __s390x_##sym(struct pt_regs *);
+#include <asm/syscall_table.h>
+#undef __SYSCALL
+
+#define __SYSCALL(nr, sym) [nr] = (__s390x_##sym),
+const sys_call_ptr_t sys_call_table[__NR_syscalls] = {
+#include <asm/syscall_table.h>
+};
+#undef __SYSCALL
+
 #ifdef CONFIG_SYSVIPC
 /*
  * sys_ipc() is the de-multiplexer for the SysV IPC calls.

arch/s390/kernel/syscalls/Makefile

@@ -1,48 +1,32 @@
 # SPDX-License-Identifier: GPL-2.0
+kapi := arch/$(SRCARCH)/include/generated/asm
+uapi := arch/$(SRCARCH)/include/generated/uapi/asm
 
-gen	:= arch/$(ARCH)/include/generated
-kapi	:= $(gen)/asm
-uapi	:= $(gen)/uapi/asm
-
-syscall	:= $(src)/syscall.tbl
-systbl	:= $(src)/syscalltbl
-
-gen-y := $(kapi)/syscall_table.h
-kapi-hdrs-y := $(kapi)/unistd_nr.h
-uapi-hdrs-y := $(uapi)/unistd_32.h
-uapi-hdrs-y += $(uapi)/unistd_64.h
-
-targets += $(addprefix ../../../../,$(gen-y) $(kapi-hdrs-y) $(uapi-hdrs-y))
-
-PHONY += kapi uapi
-
-kapi:	$(gen-y) $(kapi-hdrs-y)
-uapi:	$(uapi-hdrs-y)
-
-
-# Create output directory if not already present
 $(shell mkdir -p $(uapi) $(kapi))
 
-quiet_cmd_syshdr = SYSHDR  $@
-      cmd_syshdr = $(CONFIG_SHELL) '$(systbl)' -H -a $(syshdr_abi_$(basetarget)) -f "$@" < $< > $@
-
-quiet_cmd_sysnr = SYSNR   $@
-      cmd_sysnr = $(CONFIG_SHELL) '$(systbl)' -N -a $(sysnr_abi_$(basetarget)) < $< > $@
+syscall := $(src)/syscall.tbl
+syshdr := $(srctree)/scripts/syscallhdr.sh
+systbl := $(srctree)/scripts/syscalltbl.sh
 
-quiet_cmd_syscalls = SYSTBL  $@
-      cmd_syscalls = $(CONFIG_SHELL) '$(systbl)' -S < $< > $@
+quiet_cmd_syshdr = SYSHDR  $@
+      cmd_syshdr = $(CONFIG_SHELL) $(syshdr) --emit-nr --abis common,$* $< $@
 
-syshdr_abi_unistd_32 := common,32
-$(uapi)/unistd_32.h: $(syscall) $(systbl) FORCE
-	$(call if_changed,syshdr)
+quiet_cmd_systbl = SYSTBL  $@
+      cmd_systbl = $(CONFIG_SHELL) $(systbl) --abis common,$* $< $@
 
-syshdr_abi_unistd_64 := common,64
-$(uapi)/unistd_64.h: $(syscall) $(systbl) FORCE
+$(uapi)/unistd_%.h: $(syscall) $(syshdr) FORCE
 	$(call if_changed,syshdr)
 
 $(kapi)/syscall_table.h: $(syscall) $(systbl) FORCE
-	$(call if_changed,syscalls)
+	$(call if_changed,systbl)
+
+uapisyshdr-y		+= unistd_64.h
+kapisyshdr-y		+= syscall_table.h
+
+uapisyshdr-y	:= $(addprefix $(uapi)/, $(uapisyshdr-y))
+kapisyshdr-y	:= $(addprefix $(kapi)/, $(kapisyshdr-y))
+targets		+= $(addprefix ../../../../, $(uapisyshdr-y) $(kapisyshdr-y))
 
-sysnr_abi_unistd_nr := common,32,64
-$(kapi)/unistd_nr.h: $(syscall) $(systbl) FORCE
-	$(call if_changed,sysnr)
+PHONY += all
+all: $(uapisyshdr-y) $(kapisyshdr-y)
+	@: