1 files changed, 250 insertions, 0 deletions
diff --git a/samples/hid/Makefile b/samples/hid/Makefile
new file mode 100644
index 000000000000..026288280a03
--- /dev/null
+++ b/samples/hid/Makefile
@@ -0,0 +1,250 @@
+# SPDX-License-Identifier: GPL-2.0
+
+HID_SAMPLES_PATH ?= $(abspath $(srctree)/$(src))
+TOOLS_PATH := $(HID_SAMPLES_PATH)/../../tools
+
+pound := \#
+
+# List of programs to build
+tprogs-y += hid_mouse
+tprogs-y += hid_surface_dial
+
+# Libbpf dependencies
+LIBBPF_SRC = $(TOOLS_PATH)/lib/bpf
+LIBBPF_OUTPUT = $(abspath $(HID_SAMPLES_PATH))/libbpf
+LIBBPF_DESTDIR = $(LIBBPF_OUTPUT)
+LIBBPF_INCLUDE = $(LIBBPF_DESTDIR)/include
+LIBBPF = $(LIBBPF_OUTPUT)/libbpf.a
+
+EXTRA_HEADERS := hid_bpf_attach.h
+EXTRA_BPF_HEADERS := hid_bpf_helpers.h
+
+hid_mouse-objs := hid_mouse.o
+hid_surface_dial-objs := hid_surface_dial.o
+
+# Tell kbuild to always build the programs
+always-y := $(tprogs-y)
+
+ifeq ($(ARCH), arm)
+# Strip all except -D__LINUX_ARM_ARCH__ option needed to handle linux
+# headers when arm instruction set identification is requested.
+ARM_ARCH_SELECTOR := $(filter -D__LINUX_ARM_ARCH__%, $(KBUILD_CFLAGS))
+BPF_EXTRA_CFLAGS := $(ARM_ARCH_SELECTOR)
+TPROGS_CFLAGS += $(ARM_ARCH_SELECTOR)
+endif
+
+ifeq ($(ARCH), mips)
+TPROGS_CFLAGS += -D__SANE_USERSPACE_TYPES__
+ifdef CONFIG_MACH_LOONGSON64
+BPF_EXTRA_CFLAGS += -I$(srctree)/arch/mips/include/asm/mach-loongson64
+BPF_EXTRA_CFLAGS += -I$(srctree)/arch/mips/include/asm/mach-generic
+endif
+endif
+
+TPROGS_CFLAGS += -Wall -O2
+TPROGS_CFLAGS += -Wmissing-prototypes
+TPROGS_CFLAGS += -Wstrict-prototypes
+
+TPROGS_CFLAGS += -I$(objtree)/usr/include
+TPROGS_CFLAGS += -I$(LIBBPF_INCLUDE)
+TPROGS_CFLAGS += -I$(srctree)/tools/include
+
+ifdef SYSROOT
+TPROGS_CFLAGS += --sysroot=$(SYSROOT)
+TPROGS_LDFLAGS := -L$(SYSROOT)/usr/lib
+endif
+
+TPROGS_LDLIBS			+= $(LIBBPF) -lelf -lz
+
+# Allows pointing LLC/CLANG to a LLVM backend with bpf support, redefine on cmdline:
+# make M=samples/bpf LLC=~/git/llvm-project/llvm/build/bin/llc CLANG=~/git/llvm-project/llvm/build/bin/clang
+LLC ?= llc
+CLANG ?= clang
+OPT ?= opt
+LLVM_DIS ?= llvm-dis
+LLVM_OBJCOPY ?= llvm-objcopy
+LLVM_READELF ?= llvm-readelf
+BTF_PAHOLE ?= pahole
+
+# Detect that we're cross compiling and use the cross compiler
+ifdef CROSS_COMPILE
+CLANG_ARCH_ARGS = --target=$(notdir $(CROSS_COMPILE:%-=%))
+endif
+
+# Don't evaluate probes and warnings if we need to run make recursively
+ifneq ($(src),)
+HDR_PROBE := $(shell printf "$(pound)include <linux/types.h>\n struct list_head { int a; }; int main() { return 0; }" | \
+	$(CC) $(TPROGS_CFLAGS) $(TPROGS_LDFLAGS) -x c - \
+	-o /dev/null 2>/dev/null && echo okay)
+
+ifeq ($(HDR_PROBE),)
+$(warning WARNING: Detected possible issues with include path.)
+$(warning WARNING: Please install kernel headers locally (make headers_install).)
+endif
+
+BTF_LLC_PROBE := $(shell $(LLC) -march=bpf -mattr=help 2>&1 | grep dwarfris)
+BTF_PAHOLE_PROBE := $(shell $(BTF_PAHOLE) --help 2>&1 | grep BTF)
+BTF_OBJCOPY_PROBE := $(shell $(LLVM_OBJCOPY) --help 2>&1 | grep -i 'usage.*llvm')
+BTF_LLVM_PROBE := $(shell echo "int main() { return 0; }" | \
+			  $(CLANG) -target bpf -O2 -g -c -x c - -o ./llvm_btf_verify.o; \
+			  $(LLVM_READELF) -S ./llvm_btf_verify.o | grep BTF; \
+			  /bin/rm -f ./llvm_btf_verify.o)
+
+BPF_EXTRA_CFLAGS += -fno-stack-protector
+ifneq ($(BTF_LLVM_PROBE),)
+	BPF_EXTRA_CFLAGS += -g
+else
+ifneq ($(and $(BTF_LLC_PROBE),$(BTF_PAHOLE_PROBE),$(BTF_OBJCOPY_PROBE)),)
+	BPF_EXTRA_CFLAGS += -g
+	LLC_FLAGS += -mattr=dwarfris
+	DWARF2BTF = y
+endif
+endif
+endif
+
+# Trick to allow make to be run from this directory
+all:
+	$(MAKE) -C ../../ M=$(CURDIR) HID_SAMPLES_PATH=$(CURDIR)
+
+clean:
+	$(MAKE) -C ../../ M=$(CURDIR) clean
+	@find $(CURDIR) -type f -name '*~' -delete
+	@$(RM) -r $(CURDIR)/libbpf $(CURDIR)/bpftool
+
+$(LIBBPF): $(wildcard $(LIBBPF_SRC)/*.[ch] $(LIBBPF_SRC)/Makefile) | $(LIBBPF_OUTPUT)
+# Fix up variables inherited from Kbuild that tools/ build system won't like
+	$(MAKE) -C $(LIBBPF_SRC) RM='rm -rf' EXTRA_CFLAGS="$(TPROGS_CFLAGS)" \
+		LDFLAGS=$(TPROGS_LDFLAGS) srctree=$(HID_SAMPLES_PATH)/../../ \
+		O= OUTPUT=$(LIBBPF_OUTPUT)/ DESTDIR=$(LIBBPF_DESTDIR) prefix= \
+		$@ install_headers
+
+BPFTOOLDIR := $(TOOLS_PATH)/bpf/bpftool
+BPFTOOL_OUTPUT := $(abspath $(HID_SAMPLES_PATH))/bpftool
+BPFTOOL := $(BPFTOOL_OUTPUT)/bootstrap/bpftool
+$(BPFTOOL): $(wildcard $(BPFTOOLDIR)/*.[ch] $(BPFTOOLDIR)/Makefile) | $(BPFTOOL_OUTPUT)
+	$(MAKE) -C $(BPFTOOLDIR) srctree=$(HID_SAMPLES_PATH)/../../ 		\
+		OUTPUT=$(BPFTOOL_OUTPUT)/ bootstrap
+
+$(LIBBPF_OUTPUT) $(BPFTOOL_OUTPUT):
+	$(call msg,MKDIR,$@)
+	$(Q)mkdir -p $@
+
+FORCE:
+
+
+# Verify LLVM compiler tools are available and bpf target is supported by llc
+.PHONY: verify_cmds verify_target_bpf $(CLANG) $(LLC)
+
+verify_cmds: $(CLANG) $(LLC)
+	@for TOOL in $^ ; do \
+		if ! (which -- "$${TOOL}" > /dev/null 2>&1); then \
+			echo "*** ERROR: Cannot find LLVM tool $${TOOL}" ;\
+			exit 1; \
+		else true; fi; \
+	done
+
+verify_target_bpf: verify_cmds
+	@if ! (${LLC} -march=bpf -mattr=help > /dev/null 2>&1); then \
+		echo "*** ERROR: LLVM (${LLC}) does not support 'bpf' target" ;\
+		echo "   NOTICE: LLVM version >= 3.7.1 required" ;\
+		exit 2; \
+	else true; fi
+
+$(HID_SAMPLES_PATH)/*.c: verify_target_bpf $(LIBBPF)
+$(src)/*.c: verify_target_bpf $(LIBBPF)
+
+libbpf_hdrs: $(LIBBPF)
+
+.PHONY: libbpf_hdrs
+
+$(obj)/hid_mouse.o: $(obj)/hid_mouse.skel.h
+$(obj)/hid_surface_dial.o: $(obj)/hid_surface_dial.skel.h
+
+-include $(HID_SAMPLES_PATH)/Makefile.target
+
+VMLINUX_BTF_PATHS ?= $(abspath $(if $(O),$(O)/vmlinux))				\
+		     $(abspath $(if $(KBUILD_OUTPUT),$(KBUILD_OUTPUT)/vmlinux))	\
+		     $(abspath ./vmlinux)
+VMLINUX_BTF ?= $(abspath $(firstword $(wildcard $(VMLINUX_BTF_PATHS))))
+
+$(obj)/vmlinux.h: $(VMLINUX_BTF) $(BPFTOOL)
+ifeq ($(VMLINUX_H),)
+ifeq ($(VMLINUX_BTF),)
+	$(error Cannot find a vmlinux for VMLINUX_BTF at any of "$(VMLINUX_BTF_PATHS)",\
+		build the kernel or set VMLINUX_BTF or VMLINUX_H variable)
+endif
+	$(Q)$(BPFTOOL) btf dump file $(VMLINUX_BTF) format c > $@
+else
+	$(Q)cp "$(VMLINUX_H)" $@
+endif
+
+clean-files += vmlinux.h
+
+# Get Clang's default includes on this system, as opposed to those seen by
+# '-target bpf'. This fixes "missing" files on some architectures/distros,
+# such as asm/byteorder.h, asm/socket.h, asm/sockios.h, sys/cdefs.h etc.
+#
+# Use '-idirafter': Don't interfere with include mechanics except where the
+# build would have failed anyways.
+define get_sys_includes
+$(shell $(1) -v -E - </dev/null 2>&1 \
+        | sed -n '/<...> search starts here:/,/End of search list./{ s| \(/.*\)|-idirafter \1|p }') \
+$(shell $(1) -dM -E - </dev/null | grep '#define __riscv_xlen ' | sed 's/#define /-D/' | sed 's/ /=/')
+endef
+
+CLANG_SYS_INCLUDES = $(call get_sys_includes,$(CLANG))
+
+EXTRA_BPF_HEADERS_SRC := $(addprefix $(src)/,$(EXTRA_BPF_HEADERS))
+
+$(obj)/%.bpf.o: $(src)/%.bpf.c $(EXTRA_BPF_HEADERS_SRC) $(obj)/vmlinux.h
+	@echo "  CLANG-BPF " $@
+	$(Q)$(CLANG) -g -O2 -target bpf -D__TARGET_ARCH_$(SRCARCH) \
+		-Wno-compare-distinct-pointer-types -I$(srctree)/include \
+		-I$(srctree)/samples/bpf -I$(srctree)/tools/include \
+		-I$(LIBBPF_INCLUDE) $(CLANG_SYS_INCLUDES) \
+		-c $(filter %.bpf.c,$^) -o $@
+
+LINKED_SKELS := hid_mouse.skel.h hid_surface_dial.skel.h
+clean-files += $(LINKED_SKELS)
+
+hid_mouse.skel.h-deps := hid_mouse.bpf.o hid_bpf_attach.bpf.o
+hid_surface_dial.skel.h-deps := hid_surface_dial.bpf.o hid_bpf_attach.bpf.o
+
+LINKED_BPF_SRCS := $(patsubst %.bpf.o,%.bpf.c,$(foreach skel,$(LINKED_SKELS),$($(skel)-deps)))
+
+BPF_SRCS_LINKED := $(notdir $(wildcard $(src)/*.bpf.c))
+BPF_OBJS_LINKED := $(patsubst %.bpf.c,$(obj)/%.bpf.o, $(BPF_SRCS_LINKED))
+BPF_SKELS_LINKED := $(addprefix $(obj)/,$(LINKED_SKELS))
+
+$(BPF_SKELS_LINKED): $(BPF_OBJS_LINKED) $(BPFTOOL)
+	@echo "  BPF GEN-OBJ " $(@:.skel.h=)
+	$(Q)$(BPFTOOL) gen object $(@:.skel.h=.lbpf.o) $(addprefix $(obj)/,$($(@F)-deps))
+	@echo "  BPF GEN-SKEL" $(@:.skel.h=)
+	$(Q)$(BPFTOOL) gen skeleton $(@:.skel.h=.lbpf.o) name $(notdir $(@:.skel.h=)) > $@
+
+# asm/sysreg.h - inline assembly used by it is incompatible with llvm.
+# But, there is no easy way to fix it, so just exclude it since it is
+# useless for BPF samples.
+# below we use long chain of commands, clang | opt | llvm-dis | llc,
+# to generate final object file. 'clang' compiles the source into IR
+# with native target, e.g., x64, arm64, etc. 'opt' does bpf CORE IR builtin
+# processing (llvm12) and IR optimizations. 'llvm-dis' converts
+# 'opt' output to IR, and finally 'llc' generates bpf byte code.
+$(obj)/%.o: $(src)/%.c
+	@echo "  CLANG-bpf " $@
+	$(Q)$(CLANG) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) $(BPF_EXTRA_CFLAGS) \
+		-I$(obj) -I$(srctree)/tools/testing/selftests/bpf/ \
+		-I$(LIBBPF_INCLUDE) \
+		-D__KERNEL__ -D__BPF_TRACING__ -Wno-unused-value -Wno-pointer-sign \
+		-D__TARGET_ARCH_$(SRCARCH) -Wno-compare-distinct-pointer-types \
+		-Wno-gnu-variable-sized-type-not-at-end \
+		-Wno-address-of-packed-member -Wno-tautological-compare \
+		-Wno-unknown-warning-option $(CLANG_ARCH_ARGS) \
+		-fno-asynchronous-unwind-tables \
+		-I$(srctree)/samples/hid/ \
+		-O2 -emit-llvm -Xclang -disable-llvm-passes -c $< -o - | \
+		$(OPT) -O2 -mtriple=bpf-pc-linux | $(LLVM_DIS) | \
+		$(LLC) -march=bpf $(LLC_FLAGS) -filetype=obj -o $@
+ifeq ($(DWARF2BTF),y)
+	$(BTF_PAHOLE) -J $@
+endif