# SPDX-License-Identifier: GPL-2.0

  # include/asm-generic contains a lot of files that are used
  # verbatim by several architectures.
  #

  # This Makefile reads the file arch/$(SRCARCH)/include/(uapi/)/asm/Kbuild

  # and for each file listed in this file with generic-y creates

  # a small wrapper file in arch/$(SRCARCH)/include/generated/(uapi/)/asm.

  PHONY := all
  all:

  src := $(subst /generated,,$(obj))
  -include $(src)/Kbuild

  # $(generic)/Kbuild lists mandatory-y. Exclude um since it is a special case.
  ifneq ($(SRCARCH),um)
  include $(generic)/Kbuild
  endif

  include scripts/Kbuild.include

  redundant := $(filter $(mandatory-y) $(generated-y), $(generic-y))
  redundant += $(foreach f, $(generic-y), $(if $(wildcard $(srctree)/$(src)/$(f)),$(f)))
  redundant := $(sort $(redundant))
  $(if $(redundant),\
  	$(warning redundant generic-y found in $(src)/Kbuild: $(redundant)))

  # If arch does not implement mandatory headers, fallback to asm-generic ones.
  mandatory-y := $(filter-out $(generated-y), $(mandatory-y))
  generic-y   += $(foreach f, $(mandatory-y), $(if $(wildcard $(srctree)/$(src)/$(f)),,$(f)))

  generic-y   := $(addprefix $(obj)/, $(generic-y))
  generated-y := $(addprefix $(obj)/, $(generated-y))

  # Remove stale wrappers when the corresponding files are removed from generic-y
  old-headers := $(wildcard $(obj)/*.h)
  unwanted    := $(filter-out $(generic-y) $(generated-y),$(old-headers))

  quiet_cmd_wrap = WRAP    $@

        cmd_wrap = echo "\#include <asm-generic/$*.h>" > $@

  quiet_cmd_remove = REMOVE  $(unwanted)

        cmd_remove = rm -f $(unwanted)

  all: $(generic-y)
  	$(if $(unwanted),$(call cmd,remove))

  	@:

  
  $(obj)/%.h:
  	$(call cmd,wrap)

  # Create output directory. Skip it if at least one old header exists
  # since we know the output directory already exists.
  ifeq ($(old-headers),)
  $(shell mkdir -p $(obj))
  endif

  .PHONY: $(PHONY)