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)
107