x86: Machine-readable syscall tables and scripts to process them

Create a simple set of syscall tables and scripts to turn them into
both header files (unistd_*.h) and macros for generating the system
call tables.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

arch/x86/syscalls/Makefile

@@ -0,0 +1,43 @@
+out := $(obj)/../include/generated/asm
+
+# Create output directory if not already present
+_dummy := $(shell [ -d '$(out)' ] || mkdir -p '$(out)')
+
+syscall32 := $(srctree)/$(src)/syscall_32.tbl
+syscall64 := $(srctree)/$(src)/syscall_64.tbl
+
+syshdr := $(srctree)/$(src)/syscallhdr.sh
+systbl := $(srctree)/$(src)/syscalltbl.sh
+
+quiet_cmd_syshdr = SYSHDR  $@
+      cmd_syshdr = $(CONFIG_SHELL) '$(syshdr)' $< $@ \
+		   $(syshdr_abi_$(basetarget)) $(syshdr_pfx_$(basetarget))
+quiet_cmd_systbl = SYSTBL  $@
+      cmd_systbl = $(CONFIG_SHELL) '$(systbl)' $< $@
+
+syshdr_abi_unistd_32 := i386
+$(out)/unistd_32.h: $(syscall32) $(syshdr)
+	$(call if_changed,syshdr)
+
+syshdr_abi_unistd_32_ia32 := i386
+syshdr_pfx_unistd_32_ia32 := ia32_
+$(out)/unistd_32_ia32.h: $(syscall32) $(syshdr)
+	$(call if_changed,syshdr)
+
+syshdr_abi_unistd_64 := 64
+$(out)/unistd_64.h: $(syscall64) $(syshdr)
+	$(call if_changed,syshdr)
+
+$(out)/syscalls_32.h: $(syscall32) $(systbl)
+	$(call if_changed,systbl)
+$(out)/syscalls_64.h: $(syscall64) $(systbl)
+	$(call if_changed,systbl)
+
+syshdr-y			+= unistd_32.h unistd_64.h
+syshdr-y			+= syscalls_32.h
+syshdr-$(CONFIG_X86_64)		+= unistd_32_ia32.h
+syshdr-$(CONFIG_X86_64)		+= syscalls_64.h
+
+targets	+= $(syshdr-y)
+
+all: $(addprefix $(out)/,$(targets))