[U-Boot] Unaligned flush_dcache_range in axs101.c

[Marek Vasut]

On 04/11/2016 07:48 PM, Alexey Brodkin wrote:
> Hi Alex,
> 
> On Mon, 2016-04-04 at 09:38 +0200, Alexander Graf wrote:
>> Hi Alexey,
>>
>> Marek just pointed out to me the fact that flush_dcache_range on arm
>> expects cache line aligned arguments. However, it seems like in axs101.c
>> we have an unaligned cache flush:
>>
>>   flush_dcache_range(RESET_VECTOR_ADDR, RESET_VECTOR_ADDR + sizeof(int));
>>
>> Could you please verify whether this is correct and if not just send a
>> quick patch to fix it?
> 
> First this code is for support of Synopsys DesignWare AXS10x boards.
> And AFAIK there's no such board that may sport ARM CPU instead or ARC.
> So I'm wondering how did you bumped into that [issue?]?
> 
> Then I'm not really sure if there's a common requirement for arguments of
> flush_dcache_range(). At least in "include/common.h" there's no comment about
> that.

Such comment should then be added. Sub-cacheline flush/invalidate calls
can corrupt surrounding data.

> Personally I'd say this is up to each arch or SoC to implement flush_dcache_range()
> so it works properly on that particular hardware. I wouldn't like to
> overcomplicate high-level stuff with low-level details such as cache lines etc
> if that is not really necessary.
> 
> Please correct me if I'm missing something here.
> 
> -Alexey
> 


-- 
Best regards,
Marek Vasut