linux-kernel - Re: [PATCH 2/2] firmware: arm_scmi: Support 'reg-io-width' property for shared memory

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <d61451de-b6d9-405f-88e9-4a13e8972393@broadcom.com>
Date: Mon, 12 Aug 2024 14:19:44 -0700
From: Florian Fainelli <florian.fainelli@...adcom.com>
To: Cristian Marussi <cristian.marussi@....com>
Cc: linux-arm-kernel@...ts.infradead.org, Rob Herring <robh@...nel.org>,
 Krzysztof Kozlowski <krzk+dt@...nel.org>, Conor Dooley
 <conor+dt@...nel.org>, Sudeep Holla <sudeep.holla@....com>,
 "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS"
 <devicetree@...r.kernel.org>, open list <linux-kernel@...r.kernel.org>,
 arm-scmi@...r.kernel.org, james.quinlan@...adcom.com,
 justin.chen@...adcom.com, kapil.hali@...adcom.com,
 bcm-kernel-feedback-list@...adcom.com
Subject: Re: [PATCH 2/2] firmware: arm_scmi: Support 'reg-io-width' property
 for shared memory

On 8/12/24 11:01, Cristian Marussi wrote:
>> OK, I will think about more about what needs to be done here, but in
>> general, do you agree this is an acceptable approach to support "odd" SRAMs?
> 
> Yes, but one question comes up in my mind upfront (maybe similar to Rob remarks):
> is this not, in theory, something general that should be somehow addressed transparently
> by the core SRAM code when dealing with such odd SRAM, since SCMI is
> indeed only onne of the possible users ?
> (not saying to do this in this series that deals with SCMI related issues....)
> 
> Anyway, I'll have a though too about the SCMI core transport possible changes that I
> mentiond above, soon-ish... (I tried something already today, hoping to solve it quickly
> ...with poor results :D)

What do you think about keeping the status quo with the scmi_shared_mem 
singleton and instead introduce a per-shmem scmi_shared_mem_io_ops which 
would contain function pointers to read from/write to the shared memory?

This would keep the scmi_shared_mem read-only and a singleton and the 
transport would be responsible for storing and passing that set of 
function pointers around, post setup_iomap() where the determination 
would have been done.
-- 
Florian