linux-kernel - Re: [PATCH 2/2] arm64: dts: juno: Describe the full GICv2m region

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:   Mon, 12 Feb 2018 18:22:55 +0000
From:   Robin Murphy <robin.murphy@....com>
To:     Sudeep Holla <sudeep.holla@....com>,
        Marc Zyngier <marc.zyngier@....com>,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        Liviu Dudau <liviu.dudau@....com>
Cc:     Lorenzo Pieralisi <lorenzo.pieralisi@....com>,
        Thomas Gleixner <tglx@...utronix.de>
Subject: Re: [PATCH 2/2] arm64: dts: juno: Describe the full GICv2m region

On 12/02/18 18:17, Sudeep Holla wrote:
> 
> 
> On 07/02/18 14:32, Marc Zyngier wrote:
>> From: Robin Murphy <robin.murphy@....com>
>>
>> Juno's GICv2m implementation consists of four frames providing 32
>> interrupts each. Since it is possible to plug in enough PCIe endpoints
>> to consume more than 32 MSIs, and the driver already has a bodge to
>> handle multiple frames, let's expose the other three as well.
>>
> 
> Change on it own looks good. So if you want to merge via your tree:
> 
> Acked-by: Sudeep Holla <sudeep.holla@....com>
> 
> Let me know if you decide not to take it via your tree and you want me
> to send it to arm-soc.
> 
> On the side note I just noticed the Juno TRM[1] has 64k for each of
> these MSI frames(page 3-24 section 3.3.5 Application memory map summary)
> 
> I am not sure if TRM is wrong. This patch is just copying the 4k size
> from frame 0 which got added with initial Juno DTS.

Depends what your point of view is: The address map allocates 64KB worth 
of space for the device, but the device itself only decodes the first 
4KB of that. My view is that the DT is describing the actual devices, 
not the interconnect routing between them, so there's really no need to 
tell consumers to map known-useless empty space.

Robin.