From: Sjur BRENDELAND <sjur.brandeland@stericsson.com>
To: Ohad Ben-Cohen <ohad@wizery.com>
Cc: Linus Walleij <linus.walleij@linaro.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        =?iso-8859-1?Q?Sjur_Br=E6ndeland?= <sjurbren@gmail.com>
Date: Tue, 14 Aug 2012 19:06:05 +0200
Subject: Remoteproc: Translating between host and device addresses.
Thread-Topic: Remoteproc: Translating between host and device addresses.
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Hi Ohad,

I have one question related to address translation between device
address and host-physical address referencing the data-buffer
transported in the virtio-rings.
The address used in the virtio-ring is the host-physical-address,
but the mapping between device-address and host-physical-address is
not necessarily known by the device. In my case.

One way for the device to figure out the translation between
host-physical and device-address is to peek into some CarveOut
resource entry and compute this translation. Because a CarveOut
resource entry contains both the host-physical-address and the
device address for the same memory location. But this feels
like a workaround, shouldn't we make a more explicit way of
communicating this mapping between host-physical and device
addresses?

Regards,
Sjur


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