From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from gofer.mess.org ([88.97.38.141]:51427 "EHLO gofer.mess.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726194AbeKZTxh (ORCPT ); Mon, 26 Nov 2018 14:53:37 -0500 Date: Mon, 26 Nov 2018 09:00:09 +0000 From: Sean Young To: Daniel Borkmann Cc: Alexei Starovoitov , Roman Gushchin , Martin KaFai Lau , linux-media@vger.kernel.org, netdev@vger.kernel.org Subject: Re: [PATCH v2] media: bpf: add bpf function to report mouse movement Message-ID: <20181126090009.rhhp5hisimuo3xvt@gofer.mess.org> References: <20181123115040.13725-1-sean@mess.org> <4d72a8da-75c5-5050-6f85-c06694ad1b64@iogearbox.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4d72a8da-75c5-5050-6f85-c06694ad1b64@iogearbox.net> Sender: linux-media-owner@vger.kernel.org List-ID: Hi Daniel, On Mon, Nov 26, 2018 at 01:55:36AM +0100, Daniel Borkmann wrote: > Hi Sean, > > On 11/23/2018 12:50 PM, Sean Young wrote: > > Some IR remotes have a directional pad or other pointer-like thing that > > can be used as a mouse. Make it possible to decode these types of IR > > protocols in BPF. > > > > Cc: netdev@vger.kernel.org > > Signed-off-by: Sean Young > > Is this patch targeted at bpf-next tree? You're right, I missed the bpf-next tag. > > --- > > drivers/media/rc/bpf-lirc.c | 24 +++++++++++++++++++++++ > > include/uapi/linux/bpf.h | 17 +++++++++++++++- > > tools/testing/selftests/bpf/bpf_helpers.h | 2 ++ > > 3 files changed, 42 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/media/rc/bpf-lirc.c b/drivers/media/rc/bpf-lirc.c > > index 8b97fd1f0cea..390a722e6211 100644 > > --- a/drivers/media/rc/bpf-lirc.c > > +++ b/drivers/media/rc/bpf-lirc.c > > @@ -59,6 +59,28 @@ static const struct bpf_func_proto rc_keydown_proto = { > > .arg4_type = ARG_ANYTHING, > > }; > > > > +BPF_CALL_3(bpf_rc_pointer_rel, u32*, sample, s32, rel_x, s32, rel_y) > > +{ > > + struct ir_raw_event_ctrl *ctrl; > > + > > + ctrl = container_of(sample, struct ir_raw_event_ctrl, bpf_sample); > > + > > + input_report_rel(ctrl->dev->input_dev, REL_X, rel_x); > > + input_report_rel(ctrl->dev->input_dev, REL_Y, rel_y); > > + input_sync(ctrl->dev->input_dev); > > + > > + return 0; > > +} > > + > > +static const struct bpf_func_proto rc_pointer_rel_proto = { > > + .func = bpf_rc_pointer_rel, > > + .gpl_only = true, > > + .ret_type = RET_INTEGER, > > + .arg1_type = ARG_PTR_TO_CTX, > > + .arg2_type = ARG_ANYTHING, > > + .arg3_type = ARG_ANYTHING, > > +}; > > + > > static const struct bpf_func_proto * > > lirc_mode2_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) > > { > > @@ -67,6 +89,8 @@ lirc_mode2_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) > > return &rc_repeat_proto; > > case BPF_FUNC_rc_keydown: > > return &rc_keydown_proto; > > + case BPF_FUNC_rc_pointer_rel: > > + return &rc_pointer_rel_proto; > > case BPF_FUNC_map_lookup_elem: > > return &bpf_map_lookup_elem_proto; > > case BPF_FUNC_map_update_elem: > > diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h > > index 23e2031a43d4..3499a1555bbf 100644 > > --- a/include/uapi/linux/bpf.h > > +++ b/include/uapi/linux/bpf.h > > @@ -2268,6 +2268,20 @@ union bpf_attr { > > * > > * Return > > * 0 on success, or a negative error in case of failure. > > + * > > + * int bpf_rc_pointer_rel(void *ctx, s32 rel_x, s32 rel_y) > > + * Description > > + * This helper is used in programs implementing IR decoding, to > > + * report a successfully decoded pointer movement. > > + * > > + * The *ctx* should point to the lirc sample as passed into > > + * the program. > > + * > > + * This helper is only available is the kernel was compiled with > > + * the **CONFIG_BPF_LIRC_MODE2** configuration option set to > > + * "**y**". > > + * Return > > + * 0 > > */ > > #define __BPF_FUNC_MAPPER(FN) \ > > FN(unspec), \ > > @@ -2360,7 +2374,8 @@ union bpf_attr { > > FN(map_push_elem), \ > > FN(map_pop_elem), \ > > FN(map_peek_elem), \ > > - FN(msg_push_data), > > + FN(msg_push_data), \ > > + FN(rc_pointer_rel), > > > > /* 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 686e57ce40f4..5c900a917fa4 100644 > > --- a/tools/testing/selftests/bpf/bpf_helpers.h > > +++ b/tools/testing/selftests/bpf/bpf_helpers.h > > @@ -168,6 +168,8 @@ static int (*bpf_skb_vlan_push)(void *ctx, __be16 vlan_proto, __u16 vlan_tci) = > > (void *) BPF_FUNC_skb_vlan_push; > > static int (*bpf_skb_vlan_pop)(void *ctx) = > > (void *) BPF_FUNC_skb_vlan_pop; > > +static int (*bpf_rc_pointer_rel)(void *ctx, int rel_x, int rel_y) = > > + (void *) BPF_FUNC_rc_pointer_rel; > > > > /* llvm builtin functions that eBPF C program may use to > > * emit BPF_LD_ABS and BPF_LD_IND instructions > > > > tools/include/uapi/linux/bpf.h would have to be synced as well here. That's true. > Probably would be good to extend the lirc2 BPF kselftest as well? Again, good point. Thank you for review! I'll post a new version when it is ready. Sean