On Sat, Sep 30, 2023 at 09:06:51AM +0200, Greg Kroah-Hartman wrote:

On Fri, Sep 29, 2023 at 10:00:23AM -0700, Chris Leech wrote:

quoted

Make use of the new UIO_MEM_DMA_COHERENT type to properly handle mmap
for dma_alloc_coherent buffers.

Why are ethernet drivers messing around with UIO devices?  That's not
what UIO is for, unless you are trying to do kernel bypass for these
devices without anyone noticing?

confused,

It's confusing. The bnx2 driver stack included a cnic (converged nic?)
module that sits between the ethernet drivers (bnx2, bnx2x) and protocol
offload drivers (iscsi, fcoe, rdma).

The iscsi module (bnx2i) uses a passthrough interface from cnic to
handle some network configuration that the device firmware doesn't do.
It uses a uio device and a userspace component called iscsiuio to do
that.

Questions beyond that will probably need to be answer by one of the many
Marvell engineers copied on this thread.

- Chris