ARM: convert to generated system call tables

Convert ARM to use a similar mechanism to x86 to generate the unistd.h
system call numbers and the various kernel system call tables.  This
means that rather than having to edit three places (asm/unistd.h for
the total number of system calls, uapi/asm/unistd.h for the system call
numbers, and arch/arm/kernel/calls.S for the call table) we have only
one place to edit, making the process much more simple.

The scripts have knowledge of the table padding requirements, so there's
no need to worry about __NR_syscalls not fitting within the immediate
constant field of ALU instructions anymore.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

arch/arm/Makefile

@@ -311,6 +311,9 @@ all:	$(KBUILD_IMAGE) $(KBUILD_DTBS)
 
 boot := arch/arm/boot
 
+archheaders:
+	$(Q)$(MAKE) $(build)=arch/arm/tools uapi
+
 archprepare:
 	$(Q)$(MAKE) $(build)=arch/arm/tools kapi
 

arch/arm/include/asm/Kbuild

@@ -41,3 +41,4 @@ generic-y += trace_clock.h
 generic-y += unaligned.h
 
 generated-y += mach-types.h
+generated-y += unistd-nr.h

arch/arm/include/asm/unistd.h

@@ -14,12 +14,7 @@
 #define __ASM_ARM_UNISTD_H
 
 #include <uapi/asm/unistd.h>
-
-/*
- * This may need to be greater than __NR_last_syscall+1 in order to
- * account for the padding in the syscall table
- */
-#define __NR_syscalls  (396)
+#include <asm/unistd-nr.h>
 
 #define __ARCH_WANT_STAT64
 #define __ARCH_WANT_SYS_GETHOSTNAME
@@ -52,4 +47,23 @@
 #define __IGNORE_fadvise64_64
 #define __IGNORE_migrate_pages
 
+#ifdef __ARM_EABI__
+/*
+ * The following syscalls are obsolete and no longer available for EABI:
+ *  __NR_time
+ *  __NR_umount
+ *  __NR_stime
+ *  __NR_alarm
+ *  __NR_utime
+ *  __NR_getrlimit
+ *  __NR_select
+ *  __NR_readdir
+ *  __NR_mmap
+ *  __NR_socketcall
+ *  __NR_syscall
+ *  __NR_ipc
+ */
+#define __IGNORE_getrlimit
+#endif
+
 #endif /* __ASM_ARM_UNISTD_H */

arch/arm/include/uapi/asm/Kbuild

@@ -18,3 +18,6 @@ header-y += stat.h
 header-y += statfs.h
 header-y += swab.h
 header-y += unistd.h
+genhdr-y += unistd-common.h
+genhdr-y += unistd-oabi.h
+genhdr-y += unistd-eabi.h

arch/arm/kernel/entry-common.S

@@ -12,6 +12,11 @@
 #include <asm/unistd.h>
 #include <asm/ftrace.h>
 #include <asm/unwind.h>
+#ifdef CONFIG_AEABI
+#include <asm/unistd-oabi.h>
+#endif
+
+	.equ	NR_syscalls, __NR_syscalls
 
 #ifdef CONFIG_NEED_RET_TO_USER
 #include <mach/entry-macro.S>
@@ -120,21 +125,6 @@ ENTRY(ret_from_fork)
 	b	ret_slow_syscall
 ENDPROC(ret_from_fork)
 
-	.equ NR_syscalls,0
-#define CALL(x) .equ NR_syscalls,NR_syscalls+1
-#include "calls.S"
-
-/*
- * Ensure that the system call table is equal to __NR_syscalls,
- * which is the value the rest of the system sees
- */
-.ifne NR_syscalls - __NR_syscalls
-.error "__NR_syscalls is not equal to the size of the syscall table"
-.endif
-
-#undef CALL
-#define CALL(x) .long x
-
 /*=============================================================================
  * SWI handler
  *-----------------------------------------------------------------------------
@@ -291,22 +281,48 @@ __cr_alignment:
 #endif
 	.ltorg
 
+	.macro	syscall_table_start, sym
+	.equ	__sys_nr, 0
+	.type	\sym, #object
+ENTRY(\sym)
+	.endm
+
+	.macro	syscall, nr, func
+	.ifgt	__sys_nr - \nr
+	.error	"Duplicated/unorded system call entry"
+	.endif
+	.rept	\nr - __sys_nr
+	.long	sys_ni_syscall
+	.endr
+	.long	\func
+	.equ	__sys_nr, \nr + 1
+	.endm
+
+	.macro	syscall_table_end, sym
+	.ifgt	__sys_nr - __NR_syscalls
+	.error	"System call table too big"
+	.endif
+	.rept	__NR_syscalls - __sys_nr
+	.long	sys_ni_syscall
+	.endr
+	.size	\sym, . - \sym
+	.endm
+
+#define NATIVE(nr, func) syscall nr, func
+
 /*
  * This is the syscall table declaration for native ABI syscalls.
  * With EABI a couple syscalls are obsolete and defined as sys_ni_syscall.
  */
-#define ABI(native, compat) native
+	syscall_table_start sys_call_table
+#define COMPAT(nr, native, compat) syscall nr, native
 #ifdef CONFIG_AEABI
-#define OBSOLETE(syscall) sys_ni_syscall
+#include <calls-eabi.S>
 #else
-#define OBSOLETE(syscall) syscall
+#include <calls-oabi.S>
 #endif
-
-	.type	sys_call_table, #object
-ENTRY(sys_call_table)
-#include "calls.S"
-#undef ABI
-#undef OBSOLETE
+#undef COMPAT
+	syscall_table_end sys_call_table
 
 /*============================================================================
  * Special system call wrappers
@@ -407,14 +423,10 @@ ENDPROC(sys_oabi_readahead)
  * Let's declare a second syscall table for old ABI binaries
  * using the compatibility syscall entries.
  */
-#define ABI(native, compat) compat
-#define OBSOLETE(syscall) syscall
-
-	.type	sys_oabi_call_table, #object
-ENTRY(sys_oabi_call_table)
-#include "calls.S"
-#undef ABI
-#undef OBSOLETE
+	syscall_table_start sys_oabi_call_table
+#define COMPAT(nr, native, compat) syscall nr, compat
+#include <calls-oabi.S>
+	syscall_table_end sys_oabi_call_table
 
 #endif
 

arch/arm/tools/Makefile

@@ -6,17 +6,31 @@
 
 gen := arch/$(ARCH)/include/generated
 kapi := $(gen)/asm
+uapi := $(gen)/uapi/asm
+syshdr := $(srctree)/$(src)/syscallhdr.sh
+sysnr := $(srctree)/$(src)/syscallnr.sh
+systbl := $(srctree)/$(src)/syscalltbl.sh
+syscall := $(srctree)/$(src)/syscall.tbl
 
-kapi-hdrs-y := $(kapi)/mach-types.h
+gen-y := $(gen)/calls-oabi.S
+gen-y += $(gen)/calls-eabi.S
+kapi-hdrs-y := $(kapi)/unistd-nr.h
+kapi-hdrs-y += $(kapi)/mach-types.h
+uapi-hdrs-y := $(uapi)/unistd-common.h
+uapi-hdrs-y += $(uapi)/unistd-oabi.h
+uapi-hdrs-y += $(uapi)/unistd-eabi.h
 
-targets += $(addprefix ../../../,$(kapi-hdrs-y))
+targets += $(addprefix ../../../,$(gen-y) $(kapi-hdrs-y) $(uapi-hdrs-y))
 
-PHONY += kapi
+PHONY += kapi uapi
 
-kapi:	$(kapi-hdrs-y)
+kapi:	$(kapi-hdrs-y) $(gen-y)
+
+uapi:	$(uapi-hdrs-y)
 
 # Create output directory if not already present
-_dummy := $(shell [ -d '$(kapi)' ] || mkdir -p '$(kapi)')
+_dummy := $(shell [ -d '$(kapi)' ] || mkdir -p '$(kapi)') \
+          $(shell [ -d '$(uapi)' ] || mkdir -p '$(uapi)')
 
 quiet_cmd_gen_mach = GEN     $@
       cmd_gen_mach = mkdir -p $(dir $@) && \
@@ -25,3 +39,41 @@ quiet_cmd_gen_mach = GEN     $@
 
 $(kapi)/mach-types.h: $(src)/gen-mach-types $(src)/mach-types FORCE
 	$(call if_changed,gen_mach)
+
+quiet_cmd_syshdr = SYSHDR  $@
+      cmd_syshdr = $(CONFIG_SHELL) '$(syshdr)' '$<' '$@' \
+		   '$(syshdr_abi_$(basetarget))' \
+		   '$(syshdr_pfx_$(basetarget))' \
+		   '__NR_SYSCALL_BASE'
+
+quiet_cmd_systbl = SYSTBL  $@
+      cmd_systbl = $(CONFIG_SHELL) '$(systbl)' '$<' '$@' \
+		   '$(systbl_abi_$(basetarget))'
+
+quiet_cmd_sysnr  = SYSNR   $@
+      cmd_sysnr  = $(CONFIG_SHELL) '$(sysnr)' '$<' '$@' \
+		   '$(syshdr_abi_$(basetarget))'
+
+syshdr_abi_unistd-common := common
+$(uapi)/unistd-common.h: $(syscall) $(syshdr) FORCE
+	$(call if_changed,syshdr)
+
+syshdr_abi_unistd-oabi := oabi
+$(uapi)/unistd-oabi.h: $(syscall) $(syshdr) FORCE
+	$(call if_changed,syshdr)
+
+syshdr_abi_unistd-eabi := eabi
+$(uapi)/unistd-eabi.h: $(syscall) $(syshdr) FORCE
+	$(call if_changed,syshdr)
+
+sysnr_abi_unistd-nr := common,oabi,eabi,compat
+$(kapi)/unistd-nr.h: $(syscall) $(sysnr) FORCE
+	$(call if_changed,sysnr)
+
+systbl_abi_calls-oabi := common,oabi
+$(gen)/calls-oabi.S: $(syscall) $(systbl) FORCE
+	$(call if_changed,systbl)
+
+systbl_abi_calls-eabi := common,eabi
+$(gen)/calls-eabi.S: $(syscall) $(systbl) FORCE
+	$(call if_changed,systbl)

arch/arm/tools/syscallhdr.sh

+#!/bin/sh
+
+in="$1"
+out="$2"
+my_abis=`echo "($3)" | tr ',' '|'`
+prefix="$4"
+offset="$5"
+
+fileguard=_ASM_ARM_`basename "$out" | sed \
+    -e 'y/abcdefghijklmnopqrstuvwxyz/ABCDEFGHIJKLMNOPQRSTUVWXYZ/' \
+    -e 's/[^A-Z0-9_]/_/g' -e 's/__/_/g'`
+if echo $out | grep -q uapi; then
+    fileguard="_UAPI$fileguard"
+fi
+grep -E "^[0-9A-Fa-fXx]+[[:space:]]+${my_abis}" "$in" | sort -n | (
+    echo "#ifndef ${fileguard}"
+    echo "#define ${fileguard} 1"
+    echo ""
+
+    while read nr abi name entry ; do
+	if [ -z "$offset" ]; then
+	    echo "#define __NR_${prefix}${name} $nr"
+	else
+	    echo "#define __NR_${prefix}${name} ($offset + $nr)"
+        fi
+    done
+
+    echo ""
+    echo "#endif /* ${fileguard} */"
+) > "$out"

arch/arm/tools/syscallnr.sh

+#!/bin/sh
+in="$1"
+out="$2"
+my_abis=`echo "($3)" | tr ',' '|'`
+align=1
+
+fileguard=_ASM_ARM_`basename "$out" | sed \
+    -e 'y/abcdefghijklmnopqrstuvwxyz/ABCDEFGHIJKLMNOPQRSTUVWXYZ/' \
+    -e 's/[^A-Z0-9_]/_/g' -e 's/__/_/g'`
+
+grep -E "^[0-9A-Fa-fXx]+[[:space:]]+${my_abis}" "$in" | sort -n | tail -n1 | (
+    echo "#ifndef ${fileguard}
+#define ${fileguard} 1
+
+/*
+ * This needs to be greater than __NR_last_syscall+1 in order to account
+ * for the padding in the syscall table.
+ */
+"
+
+    while read nr abi name entry; do
+        nr=$(($nr + 1))
+        while [ "$(($nr / (256 * $align) ))" -gt 0 ]; do
+            align=$(( $align * 4 ))
+        done
+        nr=$(( ($nr + $align - 1) & ~($align - 1) ))
+        echo "/* aligned to $align */"
+        echo "#define __NR_syscalls $nr"
+    done
+
+    echo ""
+    echo "#endif /* ${fileguard} */"
+) > "$out"

arch/arm/tools/syscalltbl.sh

+#!/bin/sh
+in="$1"
+out="$2"
+my_abis=`echo "($3)" | tr ',' '|'`
+
+grep -E "^[0-9A-Fa-fXx]+[[:space:]]+${my_abis}" "$in" | sort -n | (
+    while read nr abi name entry compat; do
+        if [ "$abi" = "eabi" -a -n "$compat" ]; then
+            echo "$in: error: a compat entry for an EABI syscall ($name) makes no sense" >&2
+            exit 1
+        fi
+
+	if [ -n "$entry" ]; then
+            if [ -z "$compat" ]; then
+                echo "NATIVE($nr, $entry)"
+            else
+                echo "COMPAT($nr, $entry, $compat)"
+            fi
+        fi
+    done
+) > "$out"