Re: [PATCH v3 fwctl 4/5] fwctl/bnxt_fwctl: Add bnxt fwctl device

[Andy Gospodarek]

On Thu, Feb 5, 2026 at 12:33 PM Jason Gunthorpe <jgg@xxxxxxxx> wrote:
>
> On Thu, Feb 05, 2026 at 09:55:08AM +0530, Pavan Chebbi wrote:
> > >
> > > I find it a bit weird that the user needs to provide dma information and
> > > structure ! this is supposed to be completely hidden by the driver to
> > > simplify user space, the driver handles dma and access to HW, user space
> > > just provides the commands and payloads and driver carries the input/output
> > > for that user space.
> >
> > This is so because our FW commands require optional DMA-able buffers.
> > The application is only giving us the information that the driver
> > should encapsulate in additional DMA-able buffers.
> > There is a defined format for exchange of this information, because
> > every command has a different number of additional buffers. Also the
> > majority of the commands don't need any additional buffers.
> > I hope this answers your next comments also.
>
> Now I have questions, who allocates these buffers, how do they get DMA
> mapped, who does all the copying??
>

Jason, this is all done in bnxtctl_fw_rpc() and the functions it calls in this (or the v4 version) of this patch.

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