Re: [PATCH 7/7] xen/arm: Blacklist some sun7i UARTs

[Julien Grall <julien.grall@linaro.org>]

On 09/22/2013 03:40 PM, Ian Campbell wrote:
> On Sat, 2013-09-21 at 21:28 +0100, Julien Grall wrote:
>> On 09/20/2013 10:41 PM, Ian Campbell wrote:
>>> On Fri, 2013-09-20 at 20:02 +0100, Julien Grall wrote:
>>>
>>>>> +    /*
>>>>> +     * These UARTs share a page with the Xen console UART, so we don't
>>>>> +     * want to map them through.
>>>>> +     */
>>>>> +    DT_MATCH_PATH("/soc@01c00000/serial@01c28000"),
>>>>> +    DT_MATCH_PATH("/soc@01c00000/serial@01c28400"),
>>>>> +    DT_MATCH_PATH("/soc@01c00000/serial@01c28800"),
>>>>> +    DT_MATCH_PATH("/soc@01c00000/serial@01c28c00"),
>>>>
>>>> Can we blacklist all the UARTs via a DT_MATCH_COMPATIBLE? It's better
>>>> than relying on the path that can be changed easily in the device tree.
>>>
>>> There are other UARTS (at 0x1c29xxx) which could safely be exposed to
>>> dom0. Perhaps it is better to just blacklist the whole lot though.
>>
>> These UARTs also share the same page, what prevents the user to use 
>> these UARTs?
> 
> Nothing, but because they don't share a page with the xen UART they
> don't cause it to get exposed to dom0.

My question wasn't clear. What does prevent the user to use another UART
for Xen?

-- 
Julien Grall