[EXTERNAL] Re: [PATCH v3 3/9] raw/cnxk_rvu_lf: add PMD API to get BAR addresses

[David Marchand]

On Tue, Oct 22, 2024 at 8:06 AM Akhil Goyal <gakhil at marvell.com> wrote:
> > The rational to NOT pull "Hardware abstraction library using the BAR
> > address" to DPDK are
> > -Yet another 200K of driver C++ code which does not make sense to keep
> > in dpdk.org
> > -It can not implemenent any of the current subsystems
> >
> > In this context, let me know what you think?

This hardware abstraction library will have to call some driver
specific API (like the added raw/cnxk_rvu API).
Can this library directly use the PCI driver API, and call the cnxk
common driver?
If so, there is no need to add another driver API (that breaks
layers), and the rawdev driver is only about adding the mailbox
features.


>
> Just to add one more point.
> Even if we don’t use this API, we can still get the BAR addresses as David mentioned in another mail chain
> rte_rawdev_info_get() -> get rte_device -> RTE_DEV_TO_PCI -> get bar addr
>
> This we can get for each raw PCI device, not just cnxk_rvu_lf. Right?

Any PCI driver can do this (via bus_pci_driver.h header, exported with
the enable_driver_sdk meson option).
That's not exposed to application.

Your abstraction library may cache this info if you think it will have
an impact on fast path.


-- 
David Marchand