linux-kernel - Re: [PATCH v3 15/22] firmware: arm_scmi: abstract mailbox interface

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: Windows password security audit tool. GUI, reports in PDF.

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

Date:   Fri, 6 Oct 2017 19:04:13 +0530
From:   Jassi Brar <jassisinghbrar@...il.com>
To:     Sudeep Holla <sudeep.holla@....com>
Cc:     Arnd Bergmann <arnd@...db.de>,
        ALKML <linux-arm-kernel@...ts.infradead.org>,
        LKML <linux-kernel@...r.kernel.org>,
        DTML <devicetree@...r.kernel.org>,
        Roy Franz <roy.franz@...ium.com>,
        Harb Abdulhamid <harba@...eaurora.org>,
        Nishanth Menon <nm@...com>, Loc Ho <lho@....com>,
        Alexey Klimov <alexey.klimov@....com>,
        Ryan Harkin <Ryan.Harkin@....com>
Subject: Re: [PATCH v3 15/22] firmware: arm_scmi: abstract mailbox interface

On Fri, Oct 6, 2017 at 6:57 PM, Sudeep Holla <sudeep.holla@....com> wrote:
>
>
> On 06/10/17 12:34, Jassi Brar wrote:
>> On Wed, Oct 4, 2017 at 5:02 PM, Sudeep Holla <sudeep.holla@....com> wrote:
>>
>>> Also, I have added shim only for specific controllers that need them.
>>> E.g. ARM MHU as Jassi disagreed to add doorbell mechanism to that.
>>> mbox_if provides default implementation that just calls direct mailbox
>>> APIs.
>>>
>> Yeah you could hack away the MHU driver to make your life easy at the
>> cost of duplicated code and extra DT bindings, but for a moment think
>> what if your development platform wasn't MHU but, say, Rockchip
>> mailbox controller?
>>
>
> As mentioned before I understand your concern. But the point is this
> needs to be replicated with each protocol on that controller.
>
Only generic protocols need to have a platform specific transport
layer. There's no escaping that.

> So as Arnd
> pointed out we can reduce that by generalizing common things like doorbell.
>
Rockchip, and most other controllers, has no "doorbell". And yet each
is perfectly capable of supporting SCMI.
Looking forward to your "generalised doorbell".