Re: [dpdk-dev] [EXT] [PATCH v1 3/4] regexdev: add regexdev core functions

[Jerin Jacob <jerinjacobk@gmail.com>]

On Mon, Apr 6, 2020 at 7:00 PM Thomas Monjalon <thomas@monjalon.net> wrote:
>
> 06/04/2020 14:48, Pavan Nikhilesh Bhagavatula:
> > > From: Pavan Nikhilesh Bhagavatula
> > >> >> From: Pavan Nikhilesh Bhagavatula
> > >> >>
> > >> >> Looks like this implementation is incomplete?
> > >> >> I don't see any pmd specific helper functions for @see
> > >> >rte_cryptodev_pmd.c,
> > >> >> rte_eventdev_pmd*
> > >> >>
> > >> >I think the current implementation includes all needed functions,
> > >> >at least for the first stage.
> > >> >You can find in rte_regexdev_driver.h the functions that should be
> > >> >called
> > >> >by the PMD. We have the register / unregister which acts the same
> > >as
> > >> >create
> > >> >and destroy. For parsing argument the PMD may call
> > >rte_kvargs_parse.
> > >> >
> > >>
> > >> _driver.h should atleast include
> > >> rte_regex_dev_pci_generic_probe/rte_regex_pmd_vdev_init
> > >> else there would be a lot of code repetition and possibly udefined
> > >behavior
> > >> at the driver layer.
> > >>
> > >Why should they be included? At least in this stage, there is no code to
> > >share
> > >ethdev why should we add code for the vdev?
> >
> > Ok I think I failed to communicate my concerns across.
> > Let me retry
> >
> > 1. SW based regex devices such as PCRE/Hyperscan rely on vdev framework
> > i.e. user needs to pass an EAL argument --vdev="regex_pcre" for the driver to
> > initialize all the other EAL subsystems (ethdev, eventdev, cryptodev, etc..)support this.
>
> vdev helpers do not have to be part of the first patches which define API.
> It should be added when adding the first vdev driver.

Yes. When we add vdev, we should not rewrite again to support vdev.
So care must taken for proper implementation in the first place avoid rework.

If it abstracts it properly adding vdev and PCI is a simple change.
See

lib/librte_eventdev/rte_eventdev_pmd_vdev.h
lib/librte_eventdev/rte_eventdev_pmd_pci.h

I think, the common code should take from other matured subsystem instead if
writing from scratch,


>
> > 2. HW based independent regex devices that are exposed as PCI devices would need
> >  pci probe helpers.
>
> Same, PCI helpers can be added while adding the first PCI driver.
>
> We can synchronize about how to split the work, avoiding two developers
> doing the same thing. But let's not mandate this work to be done
> as part of this first series.
>
>
>