RE: [Intel-wired-lan] [PATCH iwl-next v4 09/15] idpf: refactor idpf to use libie control queues

[Salin, Samuel]

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> Subject: [Intel-wired-lan] [PATCH iwl-next v4 09/15] idpf: refactor idpf to use
> libie control queues
> 
> From: Pavan Kumar Linga <pavan.kumar.linga@xxxxxxxxx>
> 
> Support to initialize and configure controlqs, and manage their
> transactions was introduced in libie. As part of it, most of the existing
> controlq structures are renamed and modified. Use those APIs in idpf and
> make all the necessary changes.
> 
> Previously for the send and receive virtchnl messages, there used to be a
> memcpy involved in controlq code to copy the buffer info passed by the send
> function into the controlq specific buffers. There was no restriction to
> use automatic memory in that case. The new implementation in libie removed
> copying of the send buffer info and introduced DMA mapping of the send
> buffer itself. To accommodate it, use dynamic memory for the larger send
> buffers. For smaller ones (<= 128 bytes) libie still can copy them into the
> pre-allocated message memory.
> 
> In case of receive, idpf receives a page pool buffer allocated by the libie
> and care should be taken to release it after use in the idpf.
> 
> The changes are fairly trivial and localized, with a notable exception
> being the consolidation of idpf_vc_xn_shutdown and idpf_deinit_dflt_mbx
> under the latter name. This has some additional consequences that are
> addressed in the following patches.
> 
> This refactoring introduces roughly additional 40KB of module storage used
> for systems that only run idpf, so idpf + libie_cp + libie_pci takes about
> 7% more storage than just idpf before refactoring.
> 
> We now pre-allocate small TX buffers, so that does increase the memory
> usage, but reduces the need to allocate. This results in additional 256 *
> 128B of memory permanently used, increasing the worst-case memory usage
> by
> 32KB but our ctlq RX buffers need to be of size 4096B anyway (not changed
> by the patchset), so this is hardly noticeable.
> 
> As for the timings, the fact that we are mostly limited by the HW response
> time which is far from instant, is not changed by this refactor.
> 
> Reviewed-by: Michal Kubiak <michal.kubiak@xxxxxxxxx>
> Signed-off-by: Pavan Kumar Linga <pavan.kumar.linga@xxxxxxxxx>
> Co-developed-by: Larysa Zaremba <larysa.zaremba@xxxxxxxxx>
> Signed-off-by: Larysa Zaremba <larysa.zaremba@xxxxxxxxx>
> ---
> 2.47.0

Tested-by: Samuel Salin <Samuel.salin@xxxxxxxxx>