linux-kernel - Re: [PATCH 8/9] ARM: kernel: add support for cpu cache information

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]

Message-ID: <53AC6A3A.1010001@codeaurora.org>
Date:	Thu, 26 Jun 2014 11:45:14 -0700
From:	Stephen Boyd <sboyd@...eaurora.org>
To:	Sudeep Holla <sudeep.holla@....com>
CC:	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	Heiko Carstens <heiko.carstens@...ibm.com>,
	Lorenzo Pieralisi <Lorenzo.Pieralisi@....com>,
	Russell King <linux@....linux.org.uk>,
	Will Deacon <Will.Deacon@....com>,
	Nicolas Pitre <nicolas.pitre@...aro.org>,
	"linux-arm-kernel@...ts.infradead.org" 
	<linux-arm-kernel@...ts.infradead.org>
Subject: Re: [PATCH 8/9] ARM: kernel: add support for cpu cache information

On 06/26/14 04:36, Sudeep Holla wrote:
> Hi Stephen,
>
> On 26/06/14 01:19, Stephen Boyd wrote:
>> On 06/25/14 10:30, Sudeep Holla wrote:
>>> +
>>> +/*
>>> + * Which cache CCSIDR represents depends on CSSELR value
>>> + * Make sure no one else changes CSSELR during this
>>> + * smp_call_function_single prevents preemption for us
>>> + */
>>
>> Where's the smp_call_function_single() or preemption disable happening?
>>
>
> init_cache_level is called using smp_call_function_single in
> drivers/base/cacheinfo.c(PATCH 2/9)

Oh that's unexpected. Do other architectures require the use of
smp_call_function_single() to read their cache information? It seems
like an ARM architecture specific detail that has been pushed up into
the generic layer.

-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
hosted by The Linux Foundation

--
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/