linux-kernel - Re: [RFC PATCH 0/5] Add smp booting support for Qualcomm ARMv8 SoCs

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, 10 Apr 2015 10:24:46 -0500
From:	Kumar Gala <galak@...eaurora.org>
To:	Catalin Marinas <catalin.marinas@....com>
Cc:	linux-arm-msm <linux-arm-msm@...r.kernel.org>,
	Device Tree Mailing List <devicetree@...r.kernel.org>,
	Abhimanyu Kapur <abhimany@...eaurora.org>,
	Will Deacon <will.deacon@....com>,
	linux-kernel@...r.kernel.org, arm@...nel.org,
	linux-arm-kernel@...ts.infradead.org
Subject: Re: [RFC PATCH 0/5] Add smp booting support for Qualcomm ARMv8 SoCs


On Apr 10, 2015, at 5:05 AM, Catalin Marinas <catalin.marinas@....com> wrote:

> On Thu, Apr 09, 2015 at 12:37:06PM -0500, Kumar Gala wrote:
>> This patch set adds support for SMP boot on the MSM8x16 family of Qualcomm SoCs.
>> 
>> To support SMP on the MSM8x16 SoCs we need to add ARMv8/64-bit SCM interfaces to
>> setup the boot/release addresses for the secondary CPUs.  In addition we need
>> a uniquie set of cpu ops.  I'm aware the desired methods for booting secondary
>> CPUs is either via spintable or PSCI.  However, these SoCs are shipping with a
>> firmware that does not support those methods.
> 
> And the reason is? Some guesses:
> 
> a) QC doesn't think boot interface (and cpuidle) standardisation is
>   worth the effort (to put it nicely)
> b) The hardware was available before we even mentioned PSCI
> c) PSCI is not suitable for the QC's SCM interface
> d) Any combination of the above
> 
> I strongly suspect it's point (a). Should we expect future QC hardware
> to do the same?
> 
> You could argue the reason was (b), though we've been discussing PSCI
> for at least two years and, according to QC press releases, MSM8916
> started sampling in 2014.
> 
> The only valid reason is (c) and if that's the case, I would expect a
> proposal for a new firmware interface protocol (it could be PSCI-based),
> well documented, that can be shared with others that may encounter the
> same shortcomings.
> 
> -- 
> Catalin

Does it matter?  I’ve always felt the kernel was a place of inclusion.  Qualcomm choose for whatever reason to not use PSCI or spin table.  You don’t like it, I might not like it, but it is what it is.

- k

-- 
Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/