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From: Julien Grall <julien.grall@linaro.org>
To: Ian Campbell <Ian.Campbell@citrix.com>,
	Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: Anup Patel <apatel@apm.com>,
	Andre Przywara <andre.przywara@calxeda.com>,
	Tim Deegan <tim@xen.org>,
	Pranavkumar Sawargaonkar <psawargaonkar@apm.com>,
	"xen-devel@lists.xen.org" <xen-devel@lists.xen.org>
Subject: Re: [PATCH v2] tools: libxc: flush data cache after loading images into guest memory
Date: Mon, 16 Dec 2013 00:49:30 +0000	[thread overview]
Message-ID: <52AE4E1A.6070007@linaro.org> (raw)
In-Reply-To: <1386939215.20787.87.camel@dagon.hellion.org.uk>



On 12/13/2013 12:53 PM, Ian Campbell wrote:
>>>
>>>> Unfortunately Linux doesn't provide any syscall to call this function
>>>> for ARMv7 and it's not possible to call cache instruction from
>>>> userspace. What we could do is:
>>>>       - Use the "flags" parameters of cacheflush syscall and call a
>>>> function which DCCMVAC (for instance __cpuc_flush_dcache_area)
>>>>       - Extend privcmd to have a flush cache ioctl
>>>
>>> Personally I think the first is nicer, but ultimately we need input from
>>> l-a-k on this one and would be happy with either.
>>
>> I agree. Can you try to come up with such a patch?

There is 2 functions in kernel space to flush cache PoC:
   - flush_kern_dcache_area
   - dma_flush_range

I'm not sure if one of these are suitable to expose to user space.

> I think Julien was going to investigate, but if says not I'll take a
> stab at it.

I will try to do and send a patch tomorrow.

-- 
Julien Grall

  reply	other threads:[~2013-12-16  0:49 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-12-12 12:21 [PATCH] tools: libxc: flush data cache after loading images into guest memory Ian Campbell
2013-12-12 14:11 ` Julien Grall
2013-12-12 14:23 ` [PATCH v2] " Ian Campbell
2013-12-12 14:30   ` Stefano Stabellini
2013-12-12 14:37     ` Ian Campbell
2013-12-12 14:45       ` Stefano Stabellini
2013-12-12 14:49         ` Ian Campbell
2013-12-12 17:31   ` Ian Campbell
2013-12-12 17:52     ` Ian Jackson
2013-12-12 19:32       ` Ian Campbell
2013-12-12 19:43         ` Ian Jackson
2013-12-12 17:33   ` Ian Campbell
2013-12-13  0:49   ` Julien Grall
2013-12-13  8:26     ` Ian Campbell
2013-12-13 12:01       ` Stefano Stabellini
2013-12-13 12:53         ` Ian Campbell
2013-12-16  0:49           ` Julien Grall [this message]
2013-12-16 11:05             ` Ian Campbell

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