From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dispatch1-us1.ppe-hosted.com (dispatch1-us1.ppe-hosted.com [67.231.154.164]) by dpdk.org (Postfix) with ESMTP id 3D3BB1B01D for ; Sat, 6 Jan 2018 11:50:00 +0100 (CET) X-Virus-Scanned: Proofpoint Essentials engine Received: from webmail.solarflare.com (uk.solarflare.com [193.34.186.16]) (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1-us1.ppe-hosted.com (Proofpoint Essentials ESMTP Server) with ESMTPS id E9BEF78007B; Sat, 6 Jan 2018 10:49:58 +0000 (UTC) Received: from [192.168.38.17] (84.52.114.114) by ukex01.SolarFlarecom.com (10.17.10.4) with Microsoft SMTP Server (TLS) id 15.0.1044.25; Sat, 6 Jan 2018 10:49:54 +0000 To: Stephen Hemminger , References: <20180106010656.9167-1-stephen@networkplumber.org> <20180106010656.9167-3-stephen@networkplumber.org> From: Andrew Rybchenko Message-ID: Date: Sat, 6 Jan 2018 13:49:50 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.5.2 MIME-Version: 1.0 In-Reply-To: <20180106010656.9167-3-stephen@networkplumber.org> Content-Language: en-GB X-Originating-IP: [84.52.114.114] X-ClientProxiedBy: ocex03.SolarFlarecom.com (10.20.40.36) To ukex01.SolarFlarecom.com (10.17.10.4) X-TM-AS-Product-Ver: SMEX-11.0.0.1191-8.100.1062-23576.003 X-TM-AS-Result: No--11.660500-0.000000-31 X-TM-AS-User-Approved-Sender: Yes X-TM-AS-User-Blocked-Sender: No X-MDID: 1515235799-Q-BNInEnCKj4 Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit X-Content-Filtered-By: Mailman/MimeDel 2.1.15 Subject: Re: [dpdk-dev] [PATCH v2 02/15] ethdev: add linkstatus get/set helper functions X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 06 Jan 2018 10:50:00 -0000 On 01/06/2018 04:06 AM, Stephen Hemminger wrote: > Many drivers are all doing copy/paste of the same code to atomically > update the link status. Reduce duplication, and allow for future > changes by having common function for this. > > Signed-off-by: Stephen Hemminger > --- > lib/librte_ether/rte_ethdev.c | 35 +++++++++++++++++++++++++++++++++++ > lib/librte_ether/rte_ethdev.h | 28 ++++++++++++++++++++++++++++ > 2 files changed, 63 insertions(+) > > diff --git a/lib/librte_ether/rte_ethdev.c b/lib/librte_ether/rte_ethdev.c > index 27b52131ef01..4897e1dcda14 100644 > --- a/lib/librte_ether/rte_ethdev.c > +++ b/lib/librte_ether/rte_ethdev.c > @@ -1495,6 +1495,41 @@ rte_eth_link_get_nowait(uint16_t port_id, struct rte_eth_link *eth_link) > } > } > > +int > +_rte_eth_linkstatus_set(struct rte_eth_dev *dev, > + const struct rte_eth_link *new_link) > +{ > + volatile uint64_t *dev_link > + = (volatile uint64_t *)&(dev->data->dev_link); > + union { > + uint64_t val64; > + struct rte_eth_link link; > + } orig; > + > + RTE_BUILD_BUG_ON(sizeof(*new_link) != sizeof(uint64_t)); > + > + orig.val64 = rte_atomic64_exchange(dev_link, > + *(const uint64_t *)new_link); > + > + return (orig.link.link_status == new_link->link_status) ? -1 : 0; It looks like it contradicts to the function description saying that 0 is returned if link status is the same. > +} > + > +void > +_rte_eth_linkstatus_get(const struct rte_eth_dev *dev, > + struct rte_eth_link *link) > +{ > + const uint64_t *src = (const uint64_t *)&(dev->data->dev_link); > + volatile uint64_t *dst = (uint64_t *)link; > + > + RTE_BUILD_BUG_ON(sizeof(*link) != sizeof(uint64_t)); > + > + /* > + * Note: this should never fail since both destination and expected > + * values are the same and are a pointer from caller. > + */ > + rte_atomic64_cmpset(dst, *dst, *src); As I understand nobody says that *link (i.e. *dst) is initialized, so it could be reading uninitialized value. Not fatal, but not good as well. May be it is better to use something like rte_atomic64_read(). > +} > + > int > rte_eth_stats_get(uint16_t port_id, struct rte_eth_stats *stats) > { > diff --git a/lib/librte_ether/rte_ethdev.h b/lib/librte_ether/rte_ethdev.h > index b10e2a92da71..b47402b797c3 100644 > --- a/lib/librte_ether/rte_ethdev.h > +++ b/lib/librte_ether/rte_ethdev.h > @@ -2218,6 +2218,34 @@ int rte_eth_dev_set_link_down(uint16_t port_id); > */ > void rte_eth_dev_close(uint16_t port_id); > > + > +/** > + * @internal > + * Atomically set the link status for the specific device. > + * It is for use by DPDK device driver use only. > + * User applications should not call it > + * > + * @param dev > + * Pointer to struct rte_eth_dev. > + * @param link > + * New link status value. > + * @return > + * -1 if link state has changed, 0 if the same. > + */ > +int _rte_eth_linkstatus_set(struct rte_eth_dev *dev, > + const struct rte_eth_link *link); > + > +/** > + * @internal > + * Atomically get the link speed and status. > + * @param dev > + * Pointer to struct rte_eth_dev. > + * @param link > + * link status value. > + */ > +void _rte_eth_linkstatus_get(const struct rte_eth_dev *dev, > + struct rte_eth_link *link); > + > /** > * Reset a Ethernet device and keep its port id. > *