linux-kernel - Re: [RFCv3][PATCH 3/5] arm64: Implement ARCH_HAS_FORCE

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:   Tue, 13 Sep 2016 08:02:20 -0700
From:   Laura Abbott <labbott@...hat.com>
To:     Will Deacon <will.deacon@....com>
Cc:     Sumit Semwal <sumit.semwal@...aro.org>,
        John Stultz <john.stultz@...aro.org>,
        Arve Hjønnevåg <arve@...roid.com>,
        Riley Andrews <riandrews@...roid.com>,
        Daniel Vetter <daniel.vetter@...ll.ch>,
        linaro-mm-sig@...ts.linaro.org, devel@...verdev.osuosl.org,
        Russell King <linux@...linux.org.uk>,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        Catalin Marinas <catalin.marinas@....com>,
        Eun Taik Lee <eun.taik.lee@...sung.com>,
        Rohit kumar <rohit.kr@...sung.com>,
        Liviu Dudau <Liviu.Dudau@....com>,
        Jon Medhurst <tixy@...aro.org>,
        Jeremy Gebben <jgebben@...eaurora.org>,
        Bryan Huntsman <bryanh@...eaurora.org>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Android Kernel Team <kernel-team@...roid.com>,
        Arnd Bergmann <arnd@...db.de>
Subject: Re: [RFCv3][PATCH 3/5] arm64: Implement ARCH_HAS_FORCE_CACHE

On 09/13/2016 02:19 AM, Will Deacon wrote:
> Hi Laura,
>
> On Mon, Sep 12, 2016 at 02:32:56PM -0700, Laura Abbott wrote:
>>
>> arm64 may need to guarantee the caches are synced. Implement versions of
>> the kernel_force_cache API to allow this.
>>
>> Signed-off-by: Laura Abbott <labbott@...hat.com>
>> ---
>> v3: Switch to calling cache operations directly instead of relying on
>> DMA mapping.
>> ---
>>  arch/arm64/include/asm/cacheflush.h |  8 ++++++++
>>  arch/arm64/mm/cache.S               | 24 ++++++++++++++++++++----
>>  arch/arm64/mm/flush.c               | 11 +++++++++++
>>  3 files changed, 39 insertions(+), 4 deletions(-)
>
> I'm really hesitant to expose these cache routines as an API solely to
> support a driver sitting in staging/. I appreciate that there's a chicken
> and egg problem here, but we *really* don't want people using these routines
> in preference to the DMA API, and I fear that we'll simply grow a bunch
> more users of these things if we promote it as an API like you're proposing.
>
> Can the code not be contained under staging/, as part of ion?
>

I proposed that in V1 and it was suggested I make it a proper API

http://www.mail-archive.com/driverdev-devel@linuxdriverproject.org/msg47654.html
http://www.mail-archive.com/driverdev-devel@linuxdriverproject.org/msg47672.html

> Will
>

Thanks,
Laura