From mboxrd@z Thu Jan 1 00:00:00 1970
Return-Path: <gaetan.rivet@6wind.com>
Received: from mail-wr0-f176.google.com (mail-wr0-f176.google.com
[209.85.128.176]) by dpdk.org (Postfix) with ESMTP id 6F0BD2BA1
for <dev@dpdk.org>; Thu, 8 Jun 2017 13:36:37 +0200 (CEST)
Received: by mail-wr0-f176.google.com with SMTP id g76so17280405wrd.1
for <dev@dpdk.org>; Thu, 08 Jun 2017 04:36:37 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
d=6wind-com.20150623.gappssmtp.com; s=20150623;
h=date:from:to:cc:subject:message-id:references:mime-version
:content-disposition:content-transfer-encoding:in-reply-to
:user-agent; bh=Ze2Rfl3afuwEq3J6KajtdeHYo24lE2FHW+tPZe0I5GA=;
b=SBPaZoPyJmuSRCLhRktvdKbgpB1qbWBWfWpeDeMQnM7tz7lUq2+ixxfoRaXt/tQaUT
jqHuo0ySwI44y2QqPoh5DBKcqfq5TenYs0FJH79eyOg8A23kbLWVtTiEk+q5ZK3YpOzj
9XAjLTwzBR/wJZa3WikRnwfvXSnF3DhGNPaCE6CouQYVbvONlJHactvjGQNllcKFPwqu
ab7j+Ccd3tNdWfiBCM306U/zRJMEXf7YqAkagZgehCQh2qLfGA3muPmUZHepRTWIyuEh
ZZtxIUW+IUjoVal3tq6sJCPeCdNnZm8sraSbm1O4f6+FcFspwoLs6JHkl9O9CAckbDT5
QF5Q==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
d=1e100.net; s=20161025;
h=x-gm-message-state:date:from:to:cc:subject:message-id:references
:mime-version:content-disposition:content-transfer-encoding
:in-reply-to:user-agent;
bh=Ze2Rfl3afuwEq3J6KajtdeHYo24lE2FHW+tPZe0I5GA=;
b=EBtePM5SkCKazeHHKnV6ukokur0wl/Usy2HsPWhkVXJnmT6oKU9QjKlC4d6WbHAb3e
xADEWNBYBj+EhNKho4IBIOFD1/m44R8/EYQQ3cIFLCfSsQwsl3Qls62INW4lgGyv4eXY
cbWKXfOrweug9wlEBm5SAp8R0jSf0pKwFOgeZSTxc5Hm0l7J881lOy3JAmAGcgq88m+c
K1VU9Cj4fiKH0W2I3FIMdEgLKrIIslbnOfMBLDB9lv6MD+QBMsSiiHh8X5FUVocC3vDI
CEE1+Gc3YlnQMWynoeEYI7BEEhvKnVcNfivFxw6zoAK7Rs9PCrllzRGs0+/hmF8ZDQNy
UphQ==
X-Gm-Message-State: AODbwcDfO17Ibwfc4sHjaoTpKB0xhgM0becK8FjLMOPgAZu2AxVte0nZ
+2fe0HP+2Y8wyEc3
X-Received: by 10.223.142.150 with SMTP id q22mr24691103wrb.180.1496921796952;
Thu, 08 Jun 2017 04:36:36 -0700 (PDT)
Received: from bidouze.vm.6wind.com (host.78.145.23.62.rev.coltfrance.com.
[62.23.145.78])
by smtp.gmail.com with ESMTPSA id y17sm5816221wrb.39.2017.06.08.04.36.35
(version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128);
Thu, 08 Jun 2017 04:36:36 -0700 (PDT)
Date: Thu, 8 Jun 2017 13:36:30 +0200
From: =?iso-8859-1?Q?Ga=EBtan?= Rivet <gaetan.rivet@6wind.com>
To: Jan Blunck <jblunck@infradead.org>
Cc: dev <dev@dpdk.org>, Stephen Hemminger <stephen@networkplumber.org>,
Maxime Coquelin <maxime.coquelin@redhat.com>,
Jerin Jacob <jerin.jacob@caviumnetworks.com>,
David Marchand <david.marchand@6wind.com>
Message-ID: <20170608113630.GB18840@bidouze.vm.6wind.com>
References: <cover.1495629122.git.gaetan.rivet@6wind.com>
<1a54f0dd79200960921ca495aa7381817a599bc0.1495629122.git.gaetan.rivet@6wind.com>
<CALe+Z02cDRpsGLzPTfe25M8HQAKQzxpo16se5pwceCDQAYCzAQ@mail.gmail.com>
<20170607200331.GU18840@bidouze.vm.6wind.com>
<CALe+Z02JAtPqqMjT3gCJ2rfxtz3Hb3D6Y4i3ji+N=c6UopmvOw@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
In-Reply-To: <CALe+Z02JAtPqqMjT3gCJ2rfxtz3Hb3D6Y4i3ji+N=c6UopmvOw@mail.gmail.com>
User-Agent: Mutt/1.5.23 (2014-03-12)
Subject: Re: [dpdk-dev] [PATCH 7/9] bus: add helper to find a bus from a
device name
X-BeenThere: dev@dpdk.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: DPDK patches and discussions <dev.dpdk.org>
List-Unsubscribe: <http://dpdk.org/ml/options/dev>,
<mailto:dev-request@dpdk.org?subject=unsubscribe>
List-Archive: <http://dpdk.org/ml/archives/dev/>
List-Post: <mailto:dev@dpdk.org>
List-Help: <mailto:dev-request@dpdk.org?subject=help>
List-Subscribe: <http://dpdk.org/ml/listinfo/dev>,
<mailto:dev-request@dpdk.org?subject=subscribe>
X-List-Received-Date: Thu, 08 Jun 2017 11:36:37 -0000
On Thu, Jun 08, 2017 at 12:45:17PM +0200, Jan Blunck wrote:
> On Wed, Jun 7, 2017 at 10:03 PM, Gaëtan Rivet <gaetan.rivet@6wind.com> wrote:
> > On Wed, Jun 07, 2017 at 07:28:07PM +0200, Jan Blunck wrote:
> >> On Wed, May 24, 2017 at 5:12 PM, Gaetan Rivet <gaetan.rivet@6wind.com> wrote:
> >> > Find which bus should be able to parse this device name into an internal
> >> > device representation.
> >> >
> >>
> >> No, please don't add this. One should know to what bus a device
> >> belongs to before plugging it. Artificially encoding the parent bus
> >> into the device name is not the right thing to do. Please keep those
> >> things separate.
> >>
> >
>
> When plugging a device the users know about:
> - bus name
> - device name
>
> Its not the case that the users invent the device names out of thin
> air. The EAL shouldn't codify what the users of the EAL already know
> about.
>
>
Yes, but in that case the user is forced to explicitly name the bus used
for a device.
I think it might be sufficient to have this as a private function to the
EAL, as it is currently only used within the rte_devargs parsing.
Applications could use this helper to recognize a bus from a device
name, but this is contrived.
> > The EAL has no way to know this currently. As you noted, it has to know
> > onto which bus a device belongs before plugging it.
> >
> >> > Signed-off-by: Gaetan Rivet <gaetan.rivet@6wind.com>
> >> > ---
> >> > lib/librte_eal/bsdapp/eal/rte_eal_version.map | 1 +
> >> > lib/librte_eal/common/eal_common_bus.c | 15 +++++++++++++++
> >> > lib/librte_eal/common/include/rte_bus.h | 12 ++++++++++++
> >> > lib/librte_eal/linuxapp/eal/rte_eal_version.map | 1 +
> >> > 4 files changed, 29 insertions(+)
> >> >
> >> > diff --git a/lib/librte_eal/bsdapp/eal/rte_eal_version.map b/lib/librte_eal/bsdapp/eal/rte_eal_version.map
> >> > index 3517d74..04fa882 100644
> >> > --- a/lib/librte_eal/bsdapp/eal/rte_eal_version.map
> >> > +++ b/lib/librte_eal/bsdapp/eal/rte_eal_version.map
> >> > @@ -202,5 +202,6 @@ DPDK_17.08 {
> >> > global:
> >> >
> >> > rte_bus_from_name;
> >> > + rte_bus_from_dev;
> >> >
> >> > } DPDK_17.05;
> >> > diff --git a/lib/librte_eal/common/eal_common_bus.c b/lib/librte_eal/common/eal_common_bus.c
> >> > index 7977190..08fff60 100644
> >> > --- a/lib/librte_eal/common/eal_common_bus.c
> >> > +++ b/lib/librte_eal/common/eal_common_bus.c
> >> > @@ -242,3 +242,18 @@ rte_bus_from_name(const char *str)
> >> > return NULL;
> >> > return rte_bus_find(bus_cmp_name, str);
> >> > }
> >> > +
> >> > +static int
> >> > +bus_can_parse(const struct rte_bus *bus, const void *_name)
> >> > +{
> >> > + const char *name = _name;
> >> > +
> >> > + return (bus->parse && !bus->parse(name, NULL));
> >> > +}
> >> > +
> >> > +/* find a bus capable of parsing a device description */
> >> > +struct rte_bus *
> >> > +rte_bus_from_dev(const char *str)
> >> > +{
> >> > + return rte_bus_find(bus_can_parse, str);
> >> > +}
> >> > diff --git a/lib/librte_eal/common/include/rte_bus.h b/lib/librte_eal/common/include/rte_bus.h
> >> > index 5b87ac4..0b48e66 100644
> >> > --- a/lib/librte_eal/common/include/rte_bus.h
> >> > +++ b/lib/librte_eal/common/include/rte_bus.h
> >> > @@ -251,6 +251,18 @@ struct rte_bus *rte_bus_find_by_device(const struct rte_device *dev);
> >> > struct rte_bus *rte_bus_from_name(const char *str);
> >> >
> >> > /**
> >> > + * Find a bus capable of identifying a device.
> >> > + *
> >> > + * @param str
> >> > + * A device identifier (PCI address, virtual PMD name, ...).
> >> > + *
> >> > + * @return
> >> > + * A valid bus structure if found.
> >> > + * NULL if no bus is able to parse this device.
> >> > + */
> >> > +struct rte_bus *rte_bus_from_dev(const char *str);
> >> > +
> >> > +/**
> >> > * Helper for Bus registration.
> >> > * The constructor has higher priority than PMD constructors.
> >> > */
> >> > diff --git a/lib/librte_eal/linuxapp/eal/rte_eal_version.map b/lib/librte_eal/linuxapp/eal/rte_eal_version.map
> >> > index 6607acc..a5127d6 100644
> >> > --- a/lib/librte_eal/linuxapp/eal/rte_eal_version.map
> >> > +++ b/lib/librte_eal/linuxapp/eal/rte_eal_version.map
> >> > @@ -206,5 +206,6 @@ DPDK_17.08 {
> >> > global:
> >> >
> >> > rte_bus_from_name;
> >> > + rte_bus_from_dev;
> >> >
> >> > } DPDK_17.05;
> >> > --
> >> > 2.1.4
> >> >
> >
> > --
> > Gaėtan Rivet
> > 6WIND
--
Gaëtan Rivet
6WIND