Re: [PATCH v2 07/13] mailbox: pcc: Always map the shared memory communication address

From: lihuisong (C)
Date: Tue Mar 11 2025 - 07:32:49 EST



在 2025/3/6 0:38, Sudeep Holla 写道:
Currently the shared memory communication address was mapped by the
mailbox client drivers leading to all sorts of inconsistencies.

It also has resulted in the inconsistent attributes used while mapping
the shared memory regions.

In order to remove/eliminate any issues, let us ensures the shared
memory address is always mapped and unmapped when the PCC channels are
requested and release.

We need to map them as the ACPI PCCT associates these shared memory
with each channel subspace and may need use the status or the flags in
the headers of those shared memory communication address regions to
manage the transport/channel.

Since there are no users of pcc_chan_ioremap() and also it is mapped
by default, we can stop exporting it and merge the functionality into
pcc_mbox_request_channel().
There are two ioremap for the existing mbox client driver after this patch.
The existing mbox client driver would not use this variable, and no one else uses it. So it is safe, right?
Do we need to make a statement that the two iommaps have no impact on the existing mbox client drivers?

Signed-off-by: Sudeep Holla <sudeep.holla@xxxxxxx>
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Acked-by: Huisong Li <lihuisong@xxxxxxxxxx>
Tested-by: Huisong Li <lihuisong@xxxxxxxxxx>