From patchwork Fri May 19 15:52:40 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Miroslav Lichvar X-Patchwork-Id: 764751 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3wTsz03CfMz9ryr for ; Sat, 20 May 2017 01:53:16 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755910AbdESPxO (ORCPT ); Fri, 19 May 2017 11:53:14 -0400 Received: from mx1.redhat.com ([209.132.183.28]:48278 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755918AbdESPwu (ORCPT ); Fri, 19 May 2017 11:52:50 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 6C8E56598F; Fri, 19 May 2017 15:52:50 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 6C8E56598F Authentication-Results: ext-mx09.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx09.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=mlichvar@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 6C8E56598F Received: from holly.brq.redhat.com. (holly.brq.redhat.com [10.34.24.121]) by smtp.corp.redhat.com (Postfix) with ESMTP id 91ADA18C6A; Fri, 19 May 2017 15:52:49 +0000 (UTC) From: Miroslav Lichvar To: netdev@vger.kernel.org Cc: Richard Cochran , Willem de Bruijn Subject: [PATCH v6 net-next 6/7] net: allow simultaneous SW and HW transmit timestamping Date: Fri, 19 May 2017 17:52:40 +0200 Message-Id: <20170519155241.15817-7-mlichvar@redhat.com> In-Reply-To: <20170519155241.15817-1-mlichvar@redhat.com> References: <20170519155241.15817-1-mlichvar@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Fri, 19 May 2017 15:52:50 +0000 (UTC) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Add SOF_TIMESTAMPING_OPT_TX_SWHW option to allow an outgoing packet to be looped to the socket's error queue with a software timestamp even when a hardware transmit timestamp is expected to be provided by the driver. Applications using this option will receive two separate messages from the error queue, one with a software timestamp and the other with a hardware timestamp. As the hardware timestamp is saved to the shared skb info, which may happen before the first message with software timestamp is received by the application, the hardware timestamp is copied to the SCM_TIMESTAMPING control message only when the skb has no software timestamp or it is an incoming packet. While changing sw_tx_timestamp(), inline it in skb_tx_timestamp() as there are no other users. CC: Richard Cochran CC: Willem de Bruijn Signed-off-by: Miroslav Lichvar Acked-by: Willem de Bruijn --- Documentation/networking/timestamping.txt | 8 ++++++++ include/linux/skbuff.h | 10 ++-------- include/uapi/linux/net_tstamp.h | 3 ++- net/core/skbuff.c | 4 ++++ net/socket.c | 20 ++++++++++++++++++-- 5 files changed, 34 insertions(+), 11 deletions(-) diff --git a/Documentation/networking/timestamping.txt b/Documentation/networking/timestamping.txt index 50eb0e5..196ba17 100644 --- a/Documentation/networking/timestamping.txt +++ b/Documentation/networking/timestamping.txt @@ -203,6 +203,14 @@ SOF_TIMESTAMPING_OPT_PKTINFO: enabled and the driver is using NAPI. The struct contains also two other fields, but they are reserved and undefined. +SOF_TIMESTAMPING_OPT_TX_SWHW: + + Request both hardware and software timestamps for outgoing packets + when SOF_TIMESTAMPING_TX_HARDWARE and SOF_TIMESTAMPING_TX_SOFTWARE + are enabled at the same time. If both timestamps are generated, + two separate messages will be looped to the socket's error queue, + each containing just one timestamp. + New applications are encouraged to pass SOF_TIMESTAMPING_OPT_ID to disambiguate timestamps and SOF_TIMESTAMPING_OPT_TSONLY to operate regardless of the setting of sysctl net.core.tstamp_allow_data. diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 1f8028c..3b2e284 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -3254,13 +3254,6 @@ void __skb_tstamp_tx(struct sk_buff *orig_skb, void skb_tstamp_tx(struct sk_buff *orig_skb, struct skb_shared_hwtstamps *hwtstamps); -static inline void sw_tx_timestamp(struct sk_buff *skb) -{ - if (skb_shinfo(skb)->tx_flags & SKBTX_SW_TSTAMP && - !(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS)) - skb_tstamp_tx(skb, NULL); -} - /** * skb_tx_timestamp() - Driver hook for transmit timestamping * @@ -3276,7 +3269,8 @@ static inline void sw_tx_timestamp(struct sk_buff *skb) static inline void skb_tx_timestamp(struct sk_buff *skb) { skb_clone_tx_timestamp(skb); - sw_tx_timestamp(skb); + if (skb_shinfo(skb)->tx_flags & SKBTX_SW_TSTAMP) + skb_tstamp_tx(skb, NULL); } /** diff --git a/include/uapi/linux/net_tstamp.h b/include/uapi/linux/net_tstamp.h index dee74d3..3d421d9 100644 --- a/include/uapi/linux/net_tstamp.h +++ b/include/uapi/linux/net_tstamp.h @@ -28,8 +28,9 @@ enum { SOF_TIMESTAMPING_OPT_TSONLY = (1<<11), SOF_TIMESTAMPING_OPT_STATS = (1<<12), SOF_TIMESTAMPING_OPT_PKTINFO = (1<<13), + SOF_TIMESTAMPING_OPT_TX_SWHW = (1<<14), - SOF_TIMESTAMPING_LAST = SOF_TIMESTAMPING_OPT_PKTINFO, + SOF_TIMESTAMPING_LAST = SOF_TIMESTAMPING_OPT_TX_SWHW, SOF_TIMESTAMPING_MASK = (SOF_TIMESTAMPING_LAST - 1) | SOF_TIMESTAMPING_LAST }; diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 346d3e8..68c02df 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -3875,6 +3875,10 @@ void __skb_tstamp_tx(struct sk_buff *orig_skb, if (!sk) return; + if (!hwtstamps && !(sk->sk_tsflags & SOF_TIMESTAMPING_OPT_TX_SWHW) && + skb_shinfo(orig_skb)->tx_flags & SKBTX_IN_PROGRESS) + return; + tsonly = sk->sk_tsflags & SOF_TIMESTAMPING_OPT_TSONLY; if (!skb_may_tx_timestamp(sk, tsonly)) return; diff --git a/net/socket.c b/net/socket.c index 67db7d8..cb355a7 100644 --- a/net/socket.c +++ b/net/socket.c @@ -662,6 +662,19 @@ static bool skb_is_err_queue(const struct sk_buff *skb) return skb->pkt_type == PACKET_OUTGOING; } +/* On transmit, software and hardware timestamps are returned independently. + * As the two skb clones share the hardware timestamp, which may be updated + * before the software timestamp is received, a hardware TX timestamp may be + * returned only if there is no software TX timestamp. Ignore false software + * timestamps, which may be made in the __sock_recv_timestamp() call when the + * option SO_TIMESTAMP(NS) is enabled on the socket, even when the skb has a + * hardware timestamp. + */ +static bool skb_is_swtx_tstamp(const struct sk_buff *skb, int false_tstamp) +{ + return skb->tstamp && !false_tstamp && skb_is_err_queue(skb); +} + static void put_ts_pktinfo(struct msghdr *msg, struct sk_buff *skb) { struct scm_ts_pktinfo ts_pktinfo; @@ -691,14 +704,16 @@ void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk, { int need_software_tstamp = sock_flag(sk, SOCK_RCVTSTAMP); struct scm_timestamping tss; - int empty = 1; + int empty = 1, false_tstamp = 0; struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb); /* Race occurred between timestamp enabling and packet receiving. Fill in the current time for now. */ - if (need_software_tstamp && skb->tstamp == 0) + if (need_software_tstamp && skb->tstamp == 0) { __net_timestamp(skb); + false_tstamp = 1; + } if (need_software_tstamp) { if (!sock_flag(sk, SOCK_RCVTSTAMPNS)) { @@ -720,6 +735,7 @@ void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk, empty = 0; if (shhwtstamps && (sk->sk_tsflags & SOF_TIMESTAMPING_RAW_HARDWARE) && + !skb_is_swtx_tstamp(skb, false_tstamp) && ktime_to_timespec_cond(shhwtstamps->hwtstamp, tss.ts + 2)) { empty = 0; if ((sk->sk_tsflags & SOF_TIMESTAMPING_OPT_PKTINFO) &&