From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752895AbeEOKlD (ORCPT ); Tue, 15 May 2018 06:41:03 -0400 Received: from gofer.mess.org ([88.97.38.141]:55291 "EHLO gofer.mess.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752387AbeEOKlB (ORCPT ); Tue, 15 May 2018 06:41:01 -0400 Date: Tue, 15 May 2018 11:40:58 +0100 From: Sean Young To: Y Song Cc: linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, Alexei Starovoitov , Mauro Carvalho Chehab , Daniel Borkmann , netdev , Matthias Reichl , Devin Heitmueller Subject: Re: [PATCH v1 4/4] samples/bpf: an example of a raw IR decoder Message-ID: <20180515104058.dagqdtn7pmfaxuwa@gofer.mess.org> References: <1c8efa5dca5a8b97b81946b38044f826d12b8f50.1526331777.git.sean@mess.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, May 14, 2018 at 10:34:57PM -0700, Y Song wrote: > On Mon, May 14, 2018 at 2:11 PM, Sean Young wrote: > > This implements the grundig-16 IR protocol. > > > > Signed-off-by: Sean Young > > --- > > samples/bpf/Makefile | 4 + > > samples/bpf/bpf_load.c | 9 +- > > samples/bpf/grundig_decoder_kern.c | 112 ++++++++++++++++++++++ > > samples/bpf/grundig_decoder_user.c | 54 +++++++++++ > > tools/bpf/bpftool/prog.c | 1 + > > tools/include/uapi/linux/bpf.h | 17 +++- > > tools/testing/selftests/bpf/bpf_helpers.h | 6 ++ > > 7 files changed, 200 insertions(+), 3 deletions(-) > > create mode 100644 samples/bpf/grundig_decoder_kern.c > > create mode 100644 samples/bpf/grundig_decoder_user.c > > > > diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile > > index 4d6a6edd4bf6..c6fa111f103a 100644 > > --- a/samples/bpf/Makefile > > +++ b/samples/bpf/Makefile > > @@ -44,6 +44,7 @@ hostprogs-y += xdp_monitor > > hostprogs-y += xdp_rxq_info > > hostprogs-y += syscall_tp > > hostprogs-y += cpustat > > +hostprogs-y += grundig_decoder > > > > # Libbpf dependencies > > LIBBPF := ../../tools/lib/bpf/bpf.o ../../tools/lib/bpf/nlattr.o > > @@ -95,6 +96,7 @@ xdp_monitor-objs := bpf_load.o $(LIBBPF) xdp_monitor_user.o > > xdp_rxq_info-objs := bpf_load.o $(LIBBPF) xdp_rxq_info_user.o > > syscall_tp-objs := bpf_load.o $(LIBBPF) syscall_tp_user.o > > cpustat-objs := bpf_load.o $(LIBBPF) cpustat_user.o > > +grundig_decoder-objs := bpf_load.o $(LIBBPF) grundig_decoder_user.o > > > > # Tell kbuild to always build the programs > > always := $(hostprogs-y) > > @@ -148,6 +150,7 @@ always += xdp_rxq_info_kern.o > > always += xdp2skb_meta_kern.o > > always += syscall_tp_kern.o > > always += cpustat_kern.o > > +always += grundig_decoder_kern.o > > > > HOSTCFLAGS += -I$(objtree)/usr/include > > HOSTCFLAGS += -I$(srctree)/tools/lib/ > > @@ -193,6 +196,7 @@ HOSTLOADLIBES_xdp_monitor += -lelf > > HOSTLOADLIBES_xdp_rxq_info += -lelf > > HOSTLOADLIBES_syscall_tp += -lelf > > HOSTLOADLIBES_cpustat += -lelf > > +HOSTLOADLIBES_grundig_decoder += -lelf > > > > # Allows pointing LLC/CLANG to a LLVM backend with bpf support, redefine on cmdline: > > # make samples/bpf/ LLC=~/git/llvm/build/bin/llc CLANG=~/git/llvm/build/bin/clang > > diff --git a/samples/bpf/bpf_load.c b/samples/bpf/bpf_load.c > > index bebe4188b4b3..0fd389e95bb9 100644 > > --- a/samples/bpf/bpf_load.c > > +++ b/samples/bpf/bpf_load.c > > @@ -69,6 +69,7 @@ static int load_and_attach(const char *event, struct bpf_insn *prog, int size) > > bool is_sockops = strncmp(event, "sockops", 7) == 0; > > bool is_sk_skb = strncmp(event, "sk_skb", 6) == 0; > > bool is_sk_msg = strncmp(event, "sk_msg", 6) == 0; > > + bool is_ir_decoder = strncmp(event, "ir_decoder", 10) == 0; > > size_t insns_cnt = size / sizeof(struct bpf_insn); > > enum bpf_prog_type prog_type; > > char buf[256]; > > @@ -102,6 +103,8 @@ static int load_and_attach(const char *event, struct bpf_insn *prog, int size) > > prog_type = BPF_PROG_TYPE_SK_SKB; > > } else if (is_sk_msg) { > > prog_type = BPF_PROG_TYPE_SK_MSG; > > + } else if (is_ir_decoder) { > > + prog_type = BPF_PROG_TYPE_RAWIR_DECODER; > > } else { > > printf("Unknown event '%s'\n", event); > > return -1; > > @@ -116,7 +119,8 @@ static int load_and_attach(const char *event, struct bpf_insn *prog, int size) > > > > prog_fd[prog_cnt++] = fd; > > > > - if (is_xdp || is_perf_event || is_cgroup_skb || is_cgroup_sk) > > + if (is_xdp || is_perf_event || is_cgroup_skb || is_cgroup_sk || > > + is_ir_decoder) > > return 0; > > > > if (is_socket || is_sockops || is_sk_skb || is_sk_msg) { > > @@ -607,7 +611,8 @@ static int do_load_bpf_file(const char *path, fixup_map_cb fixup_map) > > memcmp(shname, "cgroup/", 7) == 0 || > > memcmp(shname, "sockops", 7) == 0 || > > memcmp(shname, "sk_skb", 6) == 0 || > > - memcmp(shname, "sk_msg", 6) == 0) { > > + memcmp(shname, "sk_msg", 6) == 0 || > > + memcmp(shname, "ir_decoder", 10) == 0) { > > ret = load_and_attach(shname, data->d_buf, > > data->d_size); > > if (ret != 0) > > diff --git a/samples/bpf/grundig_decoder_kern.c b/samples/bpf/grundig_decoder_kern.c > > new file mode 100644 > > index 000000000000..c80f2c9cc69a > > --- /dev/null > > +++ b/samples/bpf/grundig_decoder_kern.c > > @@ -0,0 +1,112 @@ > > + > > +#include > > +#include > > +#include "bpf_helpers.h" > > +#include > > + > > +enum grundig_state { > > + STATE_INACTIVE, > > + STATE_HEADER_SPACE, > > + STATE_LEADING_PULSE, > > + STATE_BITS_SPACE, > > + STATE_BITS_PULSE, > > +}; > > + > > +struct decoder_state { > > + u32 bits; > > + enum grundig_state state; > > + u32 count; > > + u32 last_space; > > +}; > > + > > +struct bpf_map_def SEC("maps") decoder_state_map = { > > + .type = BPF_MAP_TYPE_ARRAY, > > + .key_size = sizeof(u32), > > + .value_size = sizeof(struct decoder_state), > > + .max_entries = 1, > > +}; > > + > > +#define US_TO_NS(t) 1000*(t) > > +static inline bool eq_margin(unsigned d1, unsigned d2, unsigned margin) > > +{ > > + return ((d1 > (d2 - margin)) && (d1 < (d2 + margin))); > > +} > > + > > +SEC("ir_decoder/grundig_decoder") > > +int bpf_decoder(struct ir_raw_event *raw) > > +{ > > + u32 key = 0; > > + struct decoder_state init = {}; > > + > > + struct decoder_state *s = bpf_map_lookup_elem(&decoder_state_map, &key); > > + > > + if (!s) > > + s = &init; > > + > > + if (raw->carrier_report) { > > + // ignore > > + } else if (raw->reset) { > > + s->state = STATE_INACTIVE; > > + } else if (s->state == STATE_INACTIVE) { > > + if (raw->pulse && eq_margin(US_TO_NS(900), raw->duration, US_TO_NS(100))) { > > + s->bits = 0; > > + s->state = STATE_HEADER_SPACE; > > + s->count = 0; > > + } > > + } else if (s->state == STATE_HEADER_SPACE) { > > + if (!raw->pulse && eq_margin(US_TO_NS(2900), raw->duration, US_TO_NS(200))) > > + s->state = STATE_LEADING_PULSE; > > + else > > + s->state = STATE_INACTIVE; > > + } else if (s->state == STATE_LEADING_PULSE) { > > + if (raw->pulse && eq_margin(US_TO_NS(1300), raw->duration, US_TO_NS(100))) > > + s->state = STATE_BITS_SPACE; > > + else > > + s->state = STATE_INACTIVE; > > + } else if (s->state == STATE_BITS_SPACE) { > > + s->last_space = raw->duration; > > + s->state = STATE_BITS_PULSE; > > + } else if (s->state == STATE_BITS_PULSE) { > > + int t = -1; > > + if (eq_margin(s->last_space, US_TO_NS(472), US_TO_NS(150)) && > > + eq_margin(raw->duration, US_TO_NS(583), US_TO_NS(150))) > > + t = 0; > > + if (eq_margin(s->last_space, US_TO_NS(1139), US_TO_NS(150)) && > > + eq_margin(raw->duration, US_TO_NS(583), US_TO_NS(150))) > > + t = 1; > > + if (eq_margin(s->last_space, US_TO_NS(1806), US_TO_NS(150)) && > > + eq_margin(raw->duration, US_TO_NS(583), US_TO_NS(150))) > > + t = 2; > > + if (eq_margin(s->last_space, US_TO_NS(2200), US_TO_NS(150)) && > > + eq_margin(raw->duration, US_TO_NS(1139), US_TO_NS(150))) > > + t = 3; > > + if (t < 0) { > > + s->state = STATE_INACTIVE; > > + } else { > > + s->bits <<= 2; > > + switch (t) { > > + case 3: s->bits |= 0; break; > > + case 2: s->bits |= 3; break; > > + case 1: s->bits |= 2; break; > > + case 0: s->bits |= 1; break; > > + } > > + s->count += 2; > > + if (s->count == 16) { > > + bpf_rc_keydown(raw, 0x40, s->bits, 0); > > + s->state = STATE_INACTIVE; > > + } else { > > + s->state = STATE_BITS_SPACE; > > + } > > + } > > + } > > + > > + if (s == &init) > > + bpf_map_update_elem(&decoder_state_map, &key, s, BPF_NOEXIST); > > + > > + return 0; > > +} > > + > > +char _license[] SEC("license") = "GPL"; > > + > > +u32 _version SEC("version") = LINUX_VERSION_CODE; > > + > > diff --git a/samples/bpf/grundig_decoder_user.c b/samples/bpf/grundig_decoder_user.c > > new file mode 100644 > > index 000000000000..61e8ee5f73ee > > --- /dev/null > > +++ b/samples/bpf/grundig_decoder_user.c > > @@ -0,0 +1,54 @@ > > + > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > + > > +#include "bpf_load.h" > > +#include "bpf_util.h" > > +#include "libbpf.h" > > + > > +int main(int argc, char **argv) > > +{ > > + char filename[256]; > > + int ret, lircfd; > > + > > + if (argc != 2) { > > + printf("Usage: %s /dev/lircN\n", argv[0]); > > Looks like the test requires /dev/lircN device. Is there any easy way > to test it? It can be tested using rc-loopback. > Also, looks like the program does not depend on any kernel headers, > maybe it can be > moved to tools/testing/selftests/bpf/? There are testbot to run those > tests regularly. That's a good idea. Let me see what I can do. Thanks for all review comments, I agree with all them (so I won't have to reply to every message). I'll re-roll a v2 of this series in the next couple of days. Thanks Sean > > > + return 2; > > + } > > + > > + snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]); > > + > > + if (load_bpf_file(filename)) { > > + printf("%s", bpf_log_buf); > > + return 1; > > + } > > + > > + lircfd = open(argv[1], O_RDWR); > > + if (lircfd == -1) { > > + printf("failed to open lirc device %s: %m\n", argv[1]); > > + return 1; > > + } > > + > > + ret = bpf_prog_attach(prog_fd[0], lircfd, BPF_RAWIR_DECODER, 0); > > + if (ret) { > > + printf("Failed to attach bpf to lirc device: %m\n"); > > + return 1; > > + } > > + > > + printf("Grundig IR decoder loaded and attached. Hit any key to stop\n"); > > + getchar(); > > + > > + return 0; > > +} > > diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c > > index f7a810897eac..ae1c26df212d 100644 > > --- a/tools/bpf/bpftool/prog.c > > +++ b/tools/bpf/bpftool/prog.c > > @@ -68,6 +68,7 @@ static const char * const prog_type_name[] = { > > [BPF_PROG_TYPE_SOCK_OPS] = "sock_ops", > > [BPF_PROG_TYPE_SK_SKB] = "sk_skb", > > [BPF_PROG_TYPE_CGROUP_DEVICE] = "cgroup_device", > > + [BPF_PROG_TYPE_RAWIR_DECODER] = "ir_decoder", > > }; > > > > static void print_boot_time(__u64 nsecs, char *buf, unsigned int size) > > diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h > > index c5ec89732a8d..d9740599adf6 100644 > > --- a/tools/include/uapi/linux/bpf.h > > +++ b/tools/include/uapi/linux/bpf.h > > @@ -137,6 +137,7 @@ enum bpf_prog_type { > > BPF_PROG_TYPE_SK_MSG, > > BPF_PROG_TYPE_RAW_TRACEPOINT, > > BPF_PROG_TYPE_CGROUP_SOCK_ADDR, > > + BPF_PROG_TYPE_RAWIR_DECODER, > > }; > > > > enum bpf_attach_type { > > @@ -154,6 +155,7 @@ enum bpf_attach_type { > > BPF_CGROUP_INET6_CONNECT, > > BPF_CGROUP_INET4_POST_BIND, > > BPF_CGROUP_INET6_POST_BIND, > > + BPF_RAWIR_DECODER, > > __MAX_BPF_ATTACH_TYPE > > }; > > > > @@ -755,6 +757,17 @@ union bpf_attr { > > * @addr: pointer to struct sockaddr to bind socket to > > * @addr_len: length of sockaddr structure > > * Return: 0 on success or negative error code > > + * > > + * int bpf_rc_keydown(ctx, protocol, scancode, toggle) > > + * Report decoded scancode with toggle value > > + * @ctx: pointer to ctx > > + * @protocol: decoded protocol > > + * @scancode: decoded scancode > > + * @toggle: set to 1 if button was toggled, else 0 > > + * > > + * int bpf_rc_repeat(ctx) > > + * Repeat the last decoded scancode > > + * @ctx: pointer to ctx > > */ > > #define __BPF_FUNC_MAPPER(FN) \ > > FN(unspec), \ > > @@ -821,7 +834,9 @@ union bpf_attr { > > FN(msg_apply_bytes), \ > > FN(msg_cork_bytes), \ > > FN(msg_pull_data), \ > > - FN(bind), > > + FN(bind), \ > > + FN(rc_repeat), \ > > + FN(rc_keydown), > > > > /* integer value in 'imm' field of BPF_CALL instruction selects which helper > > * function eBPF program intends to call > > diff --git a/tools/testing/selftests/bpf/bpf_helpers.h b/tools/testing/selftests/bpf/bpf_helpers.h > > index d8223d99f96d..4bf23d3dfc33 100644 > > --- a/tools/testing/selftests/bpf/bpf_helpers.h > > +++ b/tools/testing/selftests/bpf/bpf_helpers.h > > @@ -96,6 +96,12 @@ static int (*bpf_msg_pull_data)(void *ctx, int start, int end, int flags) = > > (void *) BPF_FUNC_msg_pull_data; > > static int (*bpf_bind)(void *ctx, void *addr, int addr_len) = > > (void *) BPF_FUNC_bind; > > +static int (*bpf_rc_repeat)(void *ctx) = > > + (void *) BPF_FUNC_rc_repeat; > > +static int (*bpf_rc_keydown)(void *ctx, unsigned protocol, unsigned scancode, > > + unsigned toggle) = > > + (void *) BPF_FUNC_rc_keydown; > > + > > > > /* llvm builtin functions that eBPF C program may use to > > * emit BPF_LD_ABS and BPF_LD_IND instructions > > -- > > 2.17.0 > >