1# SPDX-License-Identifier: GPL-2.0
  2# include/asm-generic contains a lot of files that are used
  3# verbatim by several architectures.
  4#
  5# This Makefile generates arch/$(SRCARCH)/include/generated/(uapi/)/asm
  6# headers from multiple sources:
  7#  - a small wrapper to include the corresponding asm-generic/*.h
  8#    is generated for each file listed as generic-y
  9#  - uapi/asm/unistd_*.h files listed as syscalls-y are generated from
 10#    syscall.tbl with the __NR_* macros
 11#  - Corresponding asm/syscall_table_*.h are generated from the same input
 12
 13PHONY := all
 14all:
 15
 16src := $(srctree)/$(subst /generated,,$(obj))
 17
 18syscall_abis_32  += common,32
 19syscall_abis_64  += common,64
 20syscalltbl := $(srctree)/scripts/syscall.tbl
 21syshdr-args := --emit-nr
 22
 23# let architectures override $(syscall_abis_%) and $(syscalltbl)
 24-include $(srctree)/arch/$(SRCARCH)/kernel/Makefile.syscalls
 25include $(srctree)/scripts/Kbuild.include
 26-include $(kbuild-file)
 27
 28syshdr := $(srctree)/scripts/syscallhdr.sh
 29systbl := $(srctree)/scripts/syscalltbl.sh
 30
 31# $(generic)/Kbuild lists mandatory-y. Exclude um since it is a special case.
 32ifneq ($(SRCARCH),um)
 33include $(srctree)/$(generic)/Kbuild
 34endif
 35
 36redundant := $(filter $(mandatory-y) $(generated-y), $(generic-y))
 37redundant += $(foreach f, $(generic-y), $(if $(wildcard $(src)/$(f)),$(f)))
 38redundant := $(sort $(redundant))
 39$(if $(redundant),\
 40	$(warning redundant generic-y found in $(src)/Kbuild: $(redundant)))
 41
 42# If arch does not implement mandatory headers, fallback to asm-generic ones.
 43mandatory-y := $(filter-out $(generated-y), $(mandatory-y))
 44generic-y   += $(foreach f, $(mandatory-y), $(if $(wildcard $(src)/$(f)),,$(f)))
 45
 46generic-y   := $(addprefix $(obj)/, $(generic-y))
 47syscall-y   := $(addprefix $(obj)/, $(syscall-y))
 48generated-y := $(addprefix $(obj)/, $(generated-y))
 49
 50# Remove stale wrappers when the corresponding files are removed from generic-y
 51old-headers := $(wildcard $(obj)/*.h)
 52unwanted    := $(filter-out $(generic-y) $(generated-y) $(syscall-y),$(old-headers))
 53
 54quiet_cmd_wrap = WRAP    $@
 55      cmd_wrap = echo "\#include <asm-generic/$*.h>" > $@
 56
 57quiet_cmd_remove = REMOVE  $(unwanted)
 58      cmd_remove = rm -f $(unwanted)
 59
 60quiet_cmd_syshdr = SYSHDR  $@
 61      cmd_syshdr = $(CONFIG_SHELL) $(syshdr) \
 62		   $(if $(syshdr-args-$*),$(syshdr-args-$*),$(syshdr-args)) \
 63		   $(if $(syscall_compat),--prefix "compat$*_") \
 64		   --abis $(subst $(space),$(comma),$(strip $(syscall_abis_$*))) \
 65		   $< $@
 66
 67quiet_cmd_systbl = SYSTBL  $@
 68      cmd_systbl = $(CONFIG_SHELL) $(systbl) \
 69		   $(if $(systbl-args-$*),$(systbl-args-$*),$(systbl-args)) \
 70		   --abis $(subst $(space),$(comma),$(strip $(syscall_abis_$*))) \
 71		   $< $@
 72
 73all: $(generic-y) $(syscall-y)
 74	$(if $(unwanted),$(call cmd,remove))
 75	@:
 76
 77$(obj)/%.h: $(srctree)/$(generic)/%.h
 78	$(call cmd,wrap)
 79
 80$(obj)/unistd_%.h: $(syscalltbl) $(syshdr) FORCE
 81	$(call if_changed,syshdr)
 82
 83$(obj)/unistd_compat_%.h: syscall_compat:=1
 84$(obj)/unistd_compat_%.h: $(syscalltbl) $(syshdr) FORCE
 85	$(call if_changed,syshdr)
 86
 87$(obj)/syscall_table_%.h: $(syscalltbl) $(systbl) FORCE
 88	$(call if_changed,systbl)
 89
 90targets := $(syscall-y)
 91
 92# Create output directory. Skip it if at least one old header exists
 93# since we know the output directory already exists.
 94ifeq ($(old-headers),)
 95$(shell mkdir -p $(obj))
 96endif
 97
 98PHONY += FORCE
 99
100FORCE:
101
102existing-targets := $(wildcard $(sort $(targets)))
103
104-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
105
106.PHONY: $(PHONY)