On Apr 10 2024, Benjamin Tissoires wrote:
This commit adds a fix for XPPen Artist 24 where the second button on the pen is used as an eraser.
It's a "feature" from Microsoft, but it turns out that it's actually painful for artists. So we ship here a HID-BPF program that turns this second button into an actual button.
Note that the HID-BPF program is not directly loaded by the kernel itself but by udev-hid-bpf[0]. But having the sources here allows us to also integrate tests into tools/testing/selftests/hid to ensure the HID-BPF program are actually tested.
[0] https://gitlab.freedesktop.org/libevdev/udev-hid-bpf
Signed-off-by: Benjamin Tissoires bentiss@kernel.org
drivers/hid/bpf/progs/Makefile | 91 +++++++++++ drivers/hid/bpf/progs/README | 102 +++++++++++++ drivers/hid/bpf/progs/XPPen__Artist24.bpf.c | 229 ++++++++++++++++++++++++++++ drivers/hid/bpf/progs/hid_bpf.h | 15 ++ drivers/hid/bpf/progs/hid_bpf_helpers.h | 170 +++++++++++++++++++++ 5 files changed, 607 insertions(+)
diff --git a/drivers/hid/bpf/progs/Makefile b/drivers/hid/bpf/progs/Makefile new file mode 100644 index 000000000000..63ed7e02adf1 --- /dev/null +++ b/drivers/hid/bpf/progs/Makefile @@ -0,0 +1,91 @@ +# SPDX-License-Identifier: GPL-2.0 +OUTPUT := .output +abs_out := $(abspath $(OUTPUT))
+CLANG ?= clang +LLC ?= llc +LLVM_STRIP ?= llvm-strip
+TOOLS_PATH := $(abspath ../../../../tools) +BPFTOOL_SRC := $(TOOLS_PATH)/bpf/bpftool +BPFTOOL_OUTPUT := $(abs_out)/bpftool +DEFAULT_BPFTOOL := $(BPFTOOL_OUTPUT)/bootstrap/bpftool +BPFTOOL ?= $(DEFAULT_BPFTOOL)
+LIBBPF_SRC := $(TOOLS_PATH)/lib/bpf +LIBBPF_OUTPUT := $(abs_out)/libbpf +LIBBPF_DESTDIR := $(LIBBPF_OUTPUT) +LIBBPF_INCLUDE := $(LIBBPF_DESTDIR)/include +BPFOBJ := $(LIBBPF_OUTPUT)/libbpf.a
+INCLUDES := -I$(OUTPUT) -I$(LIBBPF_INCLUDE) -I$(TOOLS_PATH)/include/uapi +CFLAGS := -g -Wall
+VMLINUX_BTF_PATHS ?= $(if $(O),$(O)/vmlinux) \
$(if $(KBUILD_OUTPUT),$(KBUILD_OUTPUT)/vmlinux) \../../../../vmlinux \/sys/kernel/btf/vmlinux \/boot/vmlinux-$(shell uname -r)+VMLINUX_BTF ?= $(abspath $(firstword $(wildcard $(VMLINUX_BTF_PATHS)))) +ifeq ($(VMLINUX_BTF),) +$(error Cannot find a vmlinux for VMLINUX_BTF at any of "$(VMLINUX_BTF_PATHS)") +endif
+ifeq ($(V),1) +Q = +msg = +else +Q = @ +msg = @printf ' %-8s %s%s\n' "$(1)" "$(notdir $(2))" "$(if $(3), $(3))"; +MAKEFLAGS += --no-print-directory +submake_extras := feature_display=0 +endif
+.DELETE_ON_ERROR:
+.PHONY: all clean
+SOURCES = $(wildcard *.bpf.c) +TARGETS = $(SOURCES:.bpf.c=.bpf.o)
+all: $(TARGETS)
+clean:
- $(call msg,CLEAN)
- $(Q)rm -rf $(OUTPUT) $(TARGETS)
+%.bpf.o: %.bpf.c vmlinux.h $(BPFOBJ) | $(OUTPUT)
- $(call msg,BPF,$@)
- $(Q)$(CLANG) -g -O2 --target=bpf $(INCLUDES) \
-c $(filter %.c,$^) -o $@ && \- $(LLVM_STRIP) -g $@
+vmlinux.h: $(VMLINUX_BTF) $(BPFTOOL) | $(INCLUDE_DIR) +ifeq ($(VMLINUX_H),)
- $(call msg,GEN,,$@)
- $(Q)$(BPFTOOL) btf dump file $(VMLINUX_BTF) format c > $@
+else
- $(call msg,CP,,$@)
- $(Q)cp "$(VMLINUX_H)" $@
+endif
+$(OUTPUT) $(LIBBPF_OUTPUT) $(BPFTOOL_OUTPUT):
- $(call msg,MKDIR,$@)
- $(Q)mkdir -p $@
+$(BPFOBJ): $(wildcard $(LIBBPF_SRC)/*.[ch] $(LIBBPF_SRC)/Makefile) | $(LIBBPF_OUTPUT)
- $(Q)$(MAKE) $(submake_extras) -C $(LIBBPF_SRC) \
OUTPUT=$(abspath $(dir $@))/ prefix= \DESTDIR=$(LIBBPF_DESTDIR) $(abspath $@) install_headers+ifeq ($(CROSS_COMPILE),) +$(DEFAULT_BPFTOOL): $(BPFOBJ) | $(BPFTOOL_OUTPUT)
- $(Q)$(MAKE) $(submake_extras) -C $(BPFTOOL_SRC) \
OUTPUT=$(BPFTOOL_OUTPUT)/ \LIBBPF_BOOTSTRAP_OUTPUT=$(LIBBPF_OUTPUT)/ \LIBBPF_BOOTSTRAP_DESTDIR=$(LIBBPF_DESTDIR)/ bootstrap+else +$(DEFAULT_BPFTOOL): | $(BPFTOOL_OUTPUT)
- $(Q)$(MAKE) $(submake_extras) -C $(BPFTOOL_SRC) \
OUTPUT=$(BPFTOOL_OUTPUT)/ bootstrap+endif diff --git a/drivers/hid/bpf/progs/README b/drivers/hid/bpf/progs/README new file mode 100644 index 000000000000..20b0928f385b --- /dev/null +++ b/drivers/hid/bpf/progs/README @@ -0,0 +1,102 @@ +# HID-BPF programs
+This directory contains various fixes for devices. They add new features or +fix some behaviors without being entirely mandatory. It is better to load them +when you have such a device, but they should not be a requirement for a device +to be working during the boot stage.
+The .bpf.c files provided here are not automatically compiled in the kernel. +They should be loaded in the kernel by `udev-hid-bpf`:
+https://gitlab.freedesktop.org/libevdev/udev-hid-bpf
+The main reasons for these fixes to be here is to have a central place to +"upstream" them, but also this way we can test them thanks to the HID +selftests.
+Once a .bpf.c file is accepted here, it is duplicated in `udev-hid-bpf` +in the `src/bpf/stable` directory, and distributions are encouraged to +only ship those bpf objects. So adding a file here should eventually +land in distributions when they update `udev-hid-bpf`
+## Compilation
+Just run `make`
+## Installation
+### Automated way
+Just run `sudo udev-hid-bpf install ./my-awesome-fix.bpf.o`
+### Manual way
+- copy the `.bpf.o` you want in `/etc/udev-hid-bpf/` +- create a new udev rule to automatically load it
+The following should do the trick (assuming udev-hid-bpf is available in +/usr/bin):
+``` +$> cp xppen-ArtistPro16Gen2.bpf.o /etc/udev-hid-bpf/ +$> udev-hid-bpf inspect xppen-ArtistPro16Gen2.bpf.o +[
- {
- "name": "xppen-ArtistPro16Gen2.bpf.o",
- "devices": [
{"bus": "0x0003","group": "0x0001","vid": "0x28BD","pid": "0x095A"},{"bus": "0x0003","group": "0x0001","vid": "0x28BD","pid": "0x095B"}- ],
+... +$> cat <EOF > /etc/udev/rules.d/99-load-hid-bpf-xppen-ArtistPro16Gen2.rules +ACTION!="add|remove", GOTO="hid_bpf_end" +SUBSYSTEM!="hid", GOTO="hid_bpf_end"
+# xppen-ArtistPro16Gen2.bpf.o +ACTION=="add",ENV{MODALIAS}=="hid:b0003g0001v000028BDp0000095A", RUN{program}+="/usr/local/bin/udev-hid-bpf add $sys$devpath /etc/udev-hid-bpf/xppen-ArtistPro16Gen2.bpf.o" +ACTION=="remove",ENV{MODALIAS}=="hid:b0003g0001v000028BDp0000095A", RUN{program}+="/usr/local/bin/udev-hid-bpf remove $sys$devpath " +# xppen-ArtistPro16Gen2.bpf.o +ACTION=="add",ENV{MODALIAS}=="hid:b0003g0001v000028BDp0000095B", RUN{program}+="/usr/local/bin/udev-hid-bpf add $sys$devpath /etc/udev-hid-bpf/xppen-ArtistPro16Gen2.bpf.o" +ACTION=="remove",ENV{MODALIAS}=="hid:b0003g0001v000028BDp0000095B", RUN{program}+="/usr/local/bin/udev-hid-bpf remove $sys$devpath "
+LABEL="hid_bpf_end" +EOF +$> udevadm control --reload +```
+Then unplug and replug the device.
+## Checks
+### udev rule
+You can check that the udev rule is correctly working by issuing
+``` +$> udevadm test /sys/bus/hid/devices/0003:28BD:095B* +... +run: '/usr/local/bin/udev-hid-bpf add /sys/devices/virtual/misc/uhid/0003:28BD:095B.0E57 /etc/udev-hid-bpf/xppen-ArtistPro16Gen2.bpf.o' +```
+### program loaded
+You can check that the program has been properly loaded with `bpftool`
+``` +$> bpftool prog +... +247: tracing name xppen_16_fix_eraser tag 18d389353ed2ef07 gpl
- loaded_at 2024-03-28T16:02:28+0100 uid 0
- xlated 120B jited 77B memlock 4096B
- btf_id 487
+``` diff --git a/drivers/hid/bpf/progs/XPPen__Artist24.bpf.c b/drivers/hid/bpf/progs/XPPen__Artist24.bpf.c new file mode 100644 index 000000000000..e1be6a12bb75 --- /dev/null +++ b/drivers/hid/bpf/progs/XPPen__Artist24.bpf.c @@ -0,0 +1,229 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright (c) 2023 Benjamin Tissoires
- */
+#include "vmlinux.h" +#include "hid_bpf.h" +#include "hid_bpf_helpers.h" +#include <bpf/bpf_tracing.h>
+#define VID_UGEE 0x28BD /* VID is shared with SinoWealth and Glorious and prob others */ +#define PID_ARTIST_24 0x093A +#define PID_ARTIST_24_PRO 0x092D
+HID_BPF_CONFIG(
- HID_DEVICE(BUS_USB, HID_GROUP_GENERIC, VID_UGEE, PID_ARTIST_24),
- HID_DEVICE(BUS_USB, HID_GROUP_GENERIC, VID_UGEE, PID_ARTIST_24_PRO)
+);
+/*
- We need to amend the report descriptor for the following:
- the device reports Eraser instead of using Secondary Barrel Switch
- the pen doesn't have a rubber tail, so basically we are removing any
- eraser/invert bits
- */
+static const __u8 fixed_rdesc[] = {
- 0x05, 0x0d, // Usage Page (Digitizers) 0
- 0x09, 0x02, // Usage (Pen) 2
- 0xa1, 0x01, // Collection (Application) 4
- 0x85, 0x07, // Report ID (7) 6
- 0x09, 0x20, // Usage (Stylus) 8
- 0xa1, 0x00, // Collection (Physical) 10
- 0x09, 0x42, // Usage (Tip Switch) 12
- 0x09, 0x44, // Usage (Barrel Switch) 14
- 0x09, 0x5a, // Usage (Secondary Barrel Switch) 16 /* changed from 0x45 (Eraser) to 0x5a (Secondary Barrel Switch) */
- 0x15, 0x00, // Logical Minimum (0) 18
- 0x25, 0x01, // Logical Maximum (1) 20
- 0x75, 0x01, // Report Size (1) 22
- 0x95, 0x03, // Report Count (3) 24
- 0x81, 0x02, // Input (Data,Var,Abs) 26
- 0x95, 0x02, // Report Count (2) 28
- 0x81, 0x03, // Input (Cnst,Var,Abs) 30
- 0x09, 0x32, // Usage (In Range) 32
- 0x95, 0x01, // Report Count (1) 34
- 0x81, 0x02, // Input (Data,Var,Abs) 36
- 0x95, 0x02, // Report Count (2) 38
- 0x81, 0x03, // Input (Cnst,Var,Abs) 40
- 0x75, 0x10, // Report Size (16) 42
- 0x95, 0x01, // Report Count (1) 44
- 0x35, 0x00, // Physical Minimum (0) 46
- 0xa4, // Push 48
- 0x05, 0x01, // Usage Page (Generic Desktop) 49
- 0x09, 0x30, // Usage (X) 51
- 0x65, 0x13, // Unit (EnglishLinear: in) 53
- 0x55, 0x0d, // Unit Exponent (-3) 55
- 0x46, 0xf0, 0x50, // Physical Maximum (20720) 57
- 0x26, 0xff, 0x7f, // Logical Maximum (32767) 60
- 0x81, 0x02, // Input (Data,Var,Abs) 63
- 0x09, 0x31, // Usage (Y) 65
- 0x46, 0x91, 0x2d, // Physical Maximum (11665) 67
- 0x26, 0xff, 0x7f, // Logical Maximum (32767) 70
- 0x81, 0x02, // Input (Data,Var,Abs) 73
- 0xb4, // Pop 75
- 0x09, 0x30, // Usage (Tip Pressure) 76
- 0x45, 0x00, // Physical Maximum (0) 78
- 0x26, 0xff, 0x1f, // Logical Maximum (8191) 80
- 0x81, 0x42, // Input (Data,Var,Abs,Null) 83
- 0x09, 0x3d, // Usage (X Tilt) 85
- 0x15, 0x81, // Logical Minimum (-127) 87
- 0x25, 0x7f, // Logical Maximum (127) 89
- 0x75, 0x08, // Report Size (8) 91
- 0x95, 0x01, // Report Count (1) 93
- 0x81, 0x02, // Input (Data,Var,Abs) 95
- 0x09, 0x3e, // Usage (Y Tilt) 97
- 0x15, 0x81, // Logical Minimum (-127) 99
- 0x25, 0x7f, // Logical Maximum (127) 101
- 0x81, 0x02, // Input (Data,Var,Abs) 103
- 0xc0, // End Collection 105
- 0xc0, // End Collection 106
+};
+#define BIT(n) (1UL << n)
+#define TIP_SWITCH BIT(0) +#define BARREL_SWITCH BIT(1) +#define ERASER BIT(2) +/* padding BIT(3) */ +/* padding BIT(4) */ +#define IN_RANGE BIT(5) +/* padding BIT(6) */ +/* padding BIT(7) */
+#define U16(index) (data[index] | (data[index + 1] << 8))
+SEC("fmod_ret/hid_bpf_rdesc_fixup") +int BPF_PROG(hid_fix_rdesc_xppen_artist24, struct hid_bpf_ctx *hctx) +{
- __u8 *data = hid_bpf_get_data(hctx, 0 /* offset */, 4096 /* size */);
- if (!data)
return 0; /* EPERM check */- __builtin_memcpy(data, fixed_rdesc, sizeof(fixed_rdesc));
- return sizeof(fixed_rdesc);
+}
+static __u8 prev_state = 0;
+/*
- There are a few cases where the device is sending wrong event
- sequences, all related to the second button (the pen doesn't
- have an eraser switch on the tail end):
- whenever the second button gets pressed or released, an
- out-of-proximity event is generated and then the firmware
- compensate for the missing state (and the firmware uses
- eraser for that button):
- if the pen is in range, an extra out-of-range is sent
when the second button is pressed/released:
// Pen is in range
E: InRange
// Second button is pressed
E:
E: Eraser InRange
// Second button is released
E:
E: InRange
This case is ignored by this filter, it's "valid"
and userspace knows how to deal with it, there are just
a few out-of-prox events generated, but the user doesn´t
see them.
- if the pen is in contact, 2 extra events are added when
the second button is pressed/released: an out of range
and an in range:
// Pen is in contact
E: TipSwitch InRange
// Second button is pressed
E: <- false release, needs to be filtered out
E: Eraser InRange <- false release, needs to be filtered out
E: TipSwitch Eraser InRange
// Second button is released
E: <- false release, needs to be filtered out
E: InRange <- false release, needs to be filtered out
E: TipSwitch InRange
- */
+SEC("fmod_ret/hid_bpf_device_event") +int BPF_PROG(xppen_24_fix_eraser, struct hid_bpf_ctx *hctx) +{
- __u8 *data = hid_bpf_get_data(hctx, 0 /* offset */, 10 /* size */);
- __u8 current_state, changed_state;
- bool prev_tip;
- __u16 tilt;
- if (!data)
return 0; /* EPERM check */- current_state = data[1];
- /* if the state is identical to previously, early return */
- if (current_state == prev_state)
return 0;- prev_tip = !!(prev_state & TIP_SWITCH);
- /*
* Illegal transition: pen is in range with the tip pressed, and* it goes into out of proximity.** Ideally we should hold the event, start a timer and deliver it* only if the timer ends, but we are not capable of that now.** And it doesn't matter because when we are in such cases, this* means we are detecting a false release.*/- if ((current_state & IN_RANGE) == 0) {
if (prev_tip)return HID_IGNORE_EVENT;return 0;- }
- /*
* XOR to only set the bits that have changed between* previous and current state*/- changed_state = prev_state ^ current_state;
- /* Store the new state for future processing */
- prev_state = current_state;
- /*
* We get both a tipswitch and eraser change in the same HID report:* this is not an authorized transition and is unlikely to happen* in real life.* This is likely to be added by the firmware to emulate the* eraser mode so we can skip the event.*/- if ((changed_state & (TIP_SWITCH | ERASER)) == (TIP_SWITCH | ERASER)) /* we get both a tipswitch and eraser change at the same time */
return HID_IGNORE_EVENT;- return 0;
+}
+SEC("syscall") +int probe(struct hid_bpf_probe_args *ctx) +{
- /*
* The device exports 3 interfaces.*/- ctx->retval = ctx->rdesc_size != 107;
- if (ctx->retval)
ctx->retval = -EINVAL;- /* ensure the kernel isn't fixed already */
- if (ctx->rdesc[17] != 0x45) /* Eraser */
ctx->retval = -EINVAL;- return 0;
+}
+char _license[] SEC("license") = "GPL"; diff --git a/drivers/hid/bpf/progs/hid_bpf.h b/drivers/hid/bpf/progs/hid_bpf.h new file mode 100644 index 000000000000..7ee371cac2e1 --- /dev/null +++ b/drivers/hid/bpf/progs/hid_bpf.h @@ -0,0 +1,15 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* Copyright (c) 2022 Benjamin Tissoires
- */
+#ifndef ____HID_BPF__H +#define ____HID_BPF__H
+struct hid_bpf_probe_args {
- unsigned int hid;
- unsigned int rdesc_size;
- unsigned char rdesc[4096];
- int retval;
+};
+#endif /* ____HID_BPF__H */ diff --git a/drivers/hid/bpf/progs/hid_bpf_helpers.h b/drivers/hid/bpf/progs/hid_bpf_helpers.h new file mode 100644 index 000000000000..1d53b10aaa2e --- /dev/null +++ b/drivers/hid/bpf/progs/hid_bpf_helpers.h @@ -0,0 +1,170 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* Copyright (c) 2022 Benjamin Tissoires
- */
+#ifndef __HID_BPF_HELPERS_H +#define __HID_BPF_HELPERS_H
+#include "vmlinux.h" +#include <bpf/bpf_helpers.h> +#include <linux/errno.h>
+extern __u8 *hid_bpf_get_data(struct hid_bpf_ctx *ctx,
unsigned int offset,const size_t __sz) __ksym;+extern struct hid_bpf_ctx *hid_bpf_allocate_context(unsigned int hid_id) __ksym; +extern void hid_bpf_release_context(struct hid_bpf_ctx *ctx) __ksym; +extern int hid_bpf_hw_request(struct hid_bpf_ctx *ctx,
__u8 *data,size_t buf__sz,enum hid_report_type type,enum hid_class_request reqtype) __ksym;+#define HID_MAX_DESCRIPTOR_SIZE 4096 +#define HID_IGNORE_EVENT -1
+/* extracted from <linux/input.h> */ +#define BUS_ANY 0x00 +#define BUS_PCI 0x01 +#define BUS_ISAPNP 0x02 +#define BUS_USB 0x03 +#define BUS_HIL 0x04 +#define BUS_BLUETOOTH 0x05 +#define BUS_VIRTUAL 0x06 +#define BUS_ISA 0x10 +#define BUS_I8042 0x11 +#define BUS_XTKBD 0x12 +#define BUS_RS232 0x13 +#define BUS_GAMEPORT 0x14 +#define BUS_PARPORT 0x15 +#define BUS_AMIGA 0x16 +#define BUS_ADB 0x17 +#define BUS_I2C 0x18 +#define BUS_HOST 0x19 +#define BUS_GSC 0x1A +#define BUS_ATARI 0x1B +#define BUS_SPI 0x1C +#define BUS_RMI 0x1D +#define BUS_CEC 0x1E +#define BUS_INTEL_ISHTP 0x1F +#define BUS_AMD_SFH 0x20
+/* extracted from <linux/hid.h> */ +#define HID_GROUP_ANY 0x0000 +#define HID_GROUP_GENERIC 0x0001 +#define HID_GROUP_MULTITOUCH 0x0002 +#define HID_GROUP_SENSOR_HUB 0x0003 +#define HID_GROUP_MULTITOUCH_WIN_8 0x0004 +#define HID_GROUP_RMI 0x0100 +#define HID_GROUP_WACOM 0x0101 +#define HID_GROUP_LOGITECH_DJ_DEVICE 0x0102 +#define HID_GROUP_STEAM 0x0103 +#define HID_GROUP_LOGITECH_27MHZ_DEVICE 0x0104 +#define HID_GROUP_VIVALDI 0x0105
+/* include/linux/mod_devicetable.h defines as (~0), but that gives us negative size arrays */ +#define HID_VID_ANY 0x0000 +#define HID_PID_ANY 0x0000
+/* duplicated from incluse/linux/array_size.h
- */
FWIW, Peter mentioned on the matching MR on udev-hid-bpf that this comment was likely superflous: https://gitlab.freedesktop.org/libevdev/udev-hid-bpf/-/merge_requests/66#not...
Cheers, Benjamin
+#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
+/* Helper macro to convert (foo, __LINE__) into foo134 so we can use __LINE__ for
- field/variable names
- */
+#define COMBINE1(X, Y) X ## Y +#define COMBINE(X, Y) COMBINE1(X, Y)
+/* Macro magic:
- __uint(foo, 123) creates a int (*foo)[1234]
- We use that macro to declare an anonymous struct with several
- fields, each is the declaration of an pointer to an array of size
- bus/group/vid/pid. (Because it's a pointer to such an array, actual storage
- would be sizeof(pointer) rather than sizeof(array). Not that we ever
- instantiate it anyway).
- This is only used for BTF introspection, we can later check "what size
- is the bus array" in the introspection data and thus extract the bus ID
- again.
- And we use the __LINE__ to give each of our structs a unique name so the
- BPF program writer doesn't have to.
- $ bpftool btf dump file target/bpf/HP_Elite_Presenter.bpf.o
- shows the inspection data, start by searching for .hid_bpf_config
- and working backwards from that (each entry references the type_id of the
- content).
- */
+#define HID_DEVICE(b, g, ven, prod) \
- struct { \
__uint(name, 0); \__uint(bus, (b)); \__uint(group, (g)); \__uint(vid, (ven)); \__uint(pid, (prod)); \- } COMBINE(_entry, __LINE__)
+/* Macro magic below is to make HID_BPF_CONFIG() look like a function call that
- we can pass multiple HID_DEVICE() invocations in.
- For up to 16 arguments, HID_BPF_CONFIG(one, two) resolves to
- union {
- HID_DEVICE(...);
- HID_DEVICE(...);
- } _device_ids SEC(".hid_bpf_config")
- */
+/* Returns the number of macro arguments, this expands
- NARGS(a, b, c) to NTH_ARG(a, b, c, 15, 14, 13, .... 4, 3, 2, 1).
- NTH_ARG always returns the 16th argument which in our case is 3.
- If we want more than 16 values _COUNTDOWN and _NTH_ARG both need to be
- updated.
- */
+#define _NARGS(...) _NARGS1(__VA_ARGS__, _COUNTDOWN) +#define _NARGS1(...) _NTH_ARG(__VA_ARGS__)
+/* Add to this if we need more than 16 args */ +#define _COUNTDOWN \
- 15, 14, 13, 12, 11, 10, 9, 8, \
7, 6, 5, 4, 3, 2, 1, 0+/* Return the 16 argument passed in. See _NARGS above for usage. Note this is
- 1-indexed.
- */
+#define _NTH_ARG( \
- _1, _2, _3, _4, _5, _6, _7, _8, \
- _9, _10, _11, _12, _13, _14, _15,\
N, ...) N+/* Turns EXPAND(_ARG, a, b, c) into _ARG3(a, b, c) */ +#define _EXPAND(func, ...) COMBINE(func, _NARGS(__VA_ARGS__)) (__VA_ARGS__)
+/* And now define all the ARG macros for each number of args we want to accept */ +#define _ARG1(_1) _1; +#define _ARG2(_1, _2) _1; _2; +#define _ARG3(_1, _2, _3) _1; _2; _3; +#define _ARG4(_1, _2, _3, _4) _1; _2; _3; _4; +#define _ARG5(_1, _2, _3, _4, _5) _1; _2; _3; _4; _5; +#define _ARG6(_1, _2, _3, _4, _5, _6) _1; _2; _3; _4; _5; _6; +#define _ARG7(_1, _2, _3, _4, _5, _6, _7) _1; _2; _3; _4; _5; _6; _7; +#define _ARG8(_1, _2, _3, _4, _5, _6, _7, _8) _1; _2; _3; _4; _5; _6; _7; _8; +#define _ARG9(_1, _2, _3, _4, _5, _6, _7, _8, _9) _1; _2; _3; _4; _5; _6; _7; _8; _9; +#define _ARG10(_1, _2, _3, _4, _5, _6, _7, _8, _9, _a) _1; _2; _3; _4; _5; _6; _7; _8; _9; _a; +#define _ARG11(_1, _2, _3, _4, _5, _6, _7, _8, _9, _a, _b) _1; _2; _3; _4; _5; _6; _7; _8; _9; _a; _b; +#define _ARG12(_1, _2, _3, _4, _5, _6, _7, _8, _9, _a, _b, _c) _1; _2; _3; _4; _5; _6; _7; _8; _9; _a; _b; _c; +#define _ARG13(_1, _2, _3, _4, _5, _6, _7, _8, _9, _a, _b, _c, _d) _1; _2; _3; _4; _5; _6; _7; _8; _9; _a; _b; _c; _d; +#define _ARG14(_1, _2, _3, _4, _5, _6, _7, _8, _9, _a, _b, _c, _d, _e) _1; _2; _3; _4; _5; _6; _7; _8; _9; _a; _b; _c; _d; _e; +#define _ARG15(_1, _2, _3, _4, _5, _6, _7, _8, _9, _a, _b, _c, _d, _e, _f) _1; _2; _3; _4; _5; _6; _7; _8; _9; _a; _b; _c; _d; _e; _f;
+#define HID_BPF_CONFIG(...) union { \
- _EXPAND(_ARG, __VA_ARGS__) \
+} _device_ids SEC(".hid_bpf_config")
+#endif /* __HID_BPF_HELPERS_H */
-- 2.44.0