[PATCH] testsuite/spcache01: Clear allocated coherent cache memory

Chris Johns chrisj at rtems.org
Mon Oct 18 21:08:38 UTC 2021


On 18/10/21 8:37 pm, Sebastian Huber wrote:
> On 18/10/2021 09:53, Chris Johns wrote:
>> On 18/10/21 4:50 pm, Sebastian Huber wrote:
>>> On 18/10/2021 07:19,chrisj at rtems.org  wrote:
>>>> From: Chris Johns<chrisj at rtems.org>
>>>>
>>>> - Coherent cache memory is used in libbsd for things like descriptors
>>>>     and it optionally clears the memory on allocation. Test is works.
>>> There is no guarantee that memset() and memcpy() work with cache coherent
>>> memory. Such memory areas may disallow misaligned access for example.
>> That seems reasonable however this change about testing the implicit
>> requirements we have that memset works. LibBSD requires memset works ...
>>
>> https://git.rtems.org/rtems-libbsd/tree/rtemsbsd/rtems/rtems-kernel-bus-dma.c?h=6-freebsd-12#n260
>>
> 
> Using memset() here could be a bug in libbsd.

Yes, I also think so.

But what is a suitable mechanism to make sure the arch or BSP handle it
correctly? Maybe a clear routine in libbsd using the bus space API? That
interface has to work or the drivers will not work.

Chris


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