1# SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
2include ../../scripts/Makefile.include
3
4OUTPUT ?= $(abspath .output)/
5
6BPFTOOL_OUTPUT := $(OUTPUT)bpftool/
7DEFAULT_BPFTOOL := $(BPFTOOL_OUTPUT)bootstrap/bpftool
8BPFTOOL ?= $(DEFAULT_BPFTOOL)
9LIBBPF_SRC := $(abspath ../../lib/bpf)
10BPFOBJ_OUTPUT := $(OUTPUT)libbpf/
11BPFOBJ := $(BPFOBJ_OUTPUT)libbpf.a
12BPF_DESTDIR := $(BPFOBJ_OUTPUT)
13BPF_INCLUDE := $(BPF_DESTDIR)/include
14INCLUDES := -I$(OUTPUT) -I$(BPF_INCLUDE) -I$(abspath ../../include/uapi)
15CFLAGS := -g -Wall $(CLANG_CROSS_FLAGS)
16CFLAGS += $(EXTRA_CFLAGS)
17LDFLAGS += $(EXTRA_LDFLAGS)
18
19# Try to detect best kernel BTF source
20KERNEL_REL := $(shell uname -r)
21VMLINUX_BTF_PATHS := $(if $(O),$(O)/vmlinux)		\
22	$(if $(KBUILD_OUTPUT),$(KBUILD_OUTPUT)/vmlinux) \
23	../../../vmlinux /sys/kernel/btf/vmlinux	\
24	/boot/vmlinux-$(KERNEL_REL)
25VMLINUX_BTF_PATH := $(or $(VMLINUX_BTF),$(firstword			       \
26					  $(wildcard $(VMLINUX_BTF_PATHS))))
27
28ifeq ($(V),1)
29Q =
30else
31Q = @
32MAKEFLAGS += --no-print-directory
33submake_extras := feature_display=0
34endif
35
36.DELETE_ON_ERROR:
37
38.PHONY: all clean runqslower libbpf_hdrs
39all: runqslower
40
41runqslower: $(OUTPUT)/runqslower
42
43clean:
44	$(call QUIET_CLEAN, runqslower)
45	$(Q)$(RM) -r $(BPFOBJ_OUTPUT) $(BPFTOOL_OUTPUT)
46	$(Q)$(RM) $(OUTPUT)*.o $(OUTPUT)*.d
47	$(Q)$(RM) $(OUTPUT)*.skel.h $(OUTPUT)vmlinux.h
48	$(Q)$(RM) $(OUTPUT)runqslower
49	$(Q)$(RM) -r .output
50
51libbpf_hdrs: $(BPFOBJ)
52
53$(OUTPUT)/runqslower: $(OUTPUT)/runqslower.o $(BPFOBJ)
54	$(QUIET_LINK)$(CC) $(CFLAGS) $^ -lelf -lz -o $@
55
56$(OUTPUT)/runqslower.o: runqslower.h $(OUTPUT)/runqslower.skel.h	      \
57			$(OUTPUT)/runqslower.bpf.o | libbpf_hdrs
58
59$(OUTPUT)/runqslower.bpf.o: $(OUTPUT)/vmlinux.h runqslower.h | libbpf_hdrs
60
61$(OUTPUT)/%.skel.h: $(OUTPUT)/%.bpf.o | $(BPFTOOL)
62	$(QUIET_GEN)$(BPFTOOL) gen skeleton $< > $@
63
64$(OUTPUT)/%.bpf.o: %.bpf.c $(BPFOBJ) | $(OUTPUT)
65	$(QUIET_GEN)$(CLANG) -g -O2 --target=bpf $(INCLUDES)		      \
66		 -c $(filter %.c,$^) -o $@ &&				      \
67	$(LLVM_STRIP) -g $@
68
69$(OUTPUT)/%.o: %.c | $(OUTPUT)
70	$(QUIET_CC)$(CC) $(CFLAGS) $(INCLUDES) -c $(filter %.c,$^) -o $@
71
72$(OUTPUT) $(BPFOBJ_OUTPUT) $(BPFTOOL_OUTPUT):
73	$(QUIET_MKDIR)mkdir -p $@
74
75$(OUTPUT)/vmlinux.h: $(VMLINUX_BTF_PATH) | $(OUTPUT) $(BPFTOOL)
76ifeq ($(VMLINUX_H),)
77	$(Q)if [ ! -e "$(VMLINUX_BTF_PATH)" ] ; then \
78		echo "Couldn't find kernel BTF; set VMLINUX_BTF to"	       \
79			"specify its location." >&2;			       \
80		exit 1;\
81	fi
82	$(QUIET_GEN)$(BPFTOOL) btf dump file $(VMLINUX_BTF_PATH) format c > $@
83else
84	$(Q)cp "$(VMLINUX_H)" $@
85endif
86
87$(BPFOBJ): $(wildcard $(LIBBPF_SRC)/*.[ch] $(LIBBPF_SRC)/Makefile) | $(BPFOBJ_OUTPUT)
88	$(Q)$(MAKE) $(submake_extras) -C $(LIBBPF_SRC) OUTPUT=$(BPFOBJ_OUTPUT) \
89		    DESTDIR=$(BPFOBJ_OUTPUT) prefix= $(abspath $@) install_headers
90
91$(DEFAULT_BPFTOOL): | $(BPFTOOL_OUTPUT)
92	$(Q)$(MAKE) $(submake_extras) -C ../bpftool OUTPUT=$(BPFTOOL_OUTPUT) bootstrap
93