Re: [PATCH v5 2/7] bus: introduce parsing functionality

From: "Gaëtan Rivet" <gaetan.rivet@6wind.com>
To: Jan Blunck <jblunck@infradead.org>
Cc: dev <dev@dpdk.org>
Subject: Re: [PATCH v5 2/7] bus: introduce parsing functionality
Date: Tue, 4 Jul 2017 03:35:17 +0200	[thread overview]
Message-ID: <20170704013517.GB11154@bidouze.vm.6wind.com> (raw)
In-Reply-To: <CALe+Z00xehZOOzDuLqOWeF37rHNcTOBwVcpR+wkAKOaie4sB4Q@mail.gmail.com>

On Tue, Jun 27, 2017 at 09:26:20PM +0200, Jan Blunck wrote:
> On Wed, Jun 21, 2017 at 1:30 AM, Gaetan Rivet <gaetan.rivet@6wind.com> wrote:
> > This operation can be used either to validate that a device
> > representation can be understood by a bus, as well as store the resulting
> > specialized device representation in any format determined by the bus.
> >
> 
> Again, I don't think this makes sense to have. Also there is no user
> for this as far as I can see. The bus specific device representation
> should come from the scan function instead of this.
> 
> 

I think it makes sense that scanning would store this representation
yes. The issue is that it requires another rte_bus_scan API evolution,
which is beyond this patchset.

Keep in mind that I was bound when writing this to follow the existing
API. I agree that some cleanup could come up in the EAL, but it cannot
all happen at once. These first steps (generic devargs / vdev & PCI move
to drivers/bus) serve to trim the EAL before these changes.

> > Signed-off-by: Gaetan Rivet <gaetan.rivet@6wind.com>
> > ---
> >  lib/librte_eal/common/include/rte_bus.h | 21 +++++++++++++++++++++
> >  1 file changed, 21 insertions(+)
> >
> > diff --git a/lib/librte_eal/common/include/rte_bus.h b/lib/librte_eal/common/include/rte_bus.h
> > index b220299..05503ea 100644
> > --- a/lib/librte_eal/common/include/rte_bus.h
> > +++ b/lib/librte_eal/common/include/rte_bus.h
> > @@ -117,6 +117,26 @@ typedef struct rte_device * (*rte_bus_plug_t)(struct rte_devargs *da);
> >  typedef int (*rte_bus_unplug_t)(struct rte_device *dev);
> >
> >  /**
> > + * Bus specific parsing function.
> > + * Validates the syntax used in the textual representation of a device,
> > + * If the syntax is valid and ``addr`` is not NULL, writes the bus-specific
> > + * device representation to ``addr``.
> > + *
> > + * @param[in] name
> > + *     device textual description
> > + *
> > + * @param[out] addr
> > + *     device information location address, into which parsed info
> > + *     should be written. If NULL, nothing should be written, which
> > + *     is not an error.
> > + *
> > + * @return
> > + *     0 if parsing was successful.
> > + *     !0 for any error.
> > + */
> > +typedef int (*rte_bus_parse_t)(const char *name, void *addr);
> > +
> > +/**
> >   * A structure describing a generic bus.
> >   */
> >  struct rte_bus {
> > @@ -127,6 +147,7 @@ struct rte_bus {
> >         rte_bus_find_device_t find_device; /**< Find device on bus */
> >         rte_bus_plug_t plug;         /**< Probe single device for drivers */
> >         rte_bus_unplug_t unplug;     /**< Remove single device from driver */
> > +       rte_bus_parse_t parse;       /**< Parse a device name */
> >  };
> >
> >  /**
> > --
> > 2.1.4
> >

-- 
Gaëtan Rivet
6WIND