[U-Boot] [PATCH v4] nios2: convert dma_alloc_coherent to use malloc_cache_aligned

Thomas Chou
2015-10-19T08:18:06Z

Hi Albert,

On 10/19/2015 01:52 PM, Albert ARIBAUD wrote:
> Not sure I'm getting this, so for my own education: what prevents from
> invalidating the cache, or IOW, what would happen if it was invalidated
> at this point rather than flushed?

This is a hardware limitation. The nios2 cpu with 4 bytes dcache line
size does not support the initda instruction, which is needed to
invalidate dcache.

Recently we added a check, if the nios2 cpu support initda instruction,
then we use invalidate_dcache, otherwise we use flush_dcache.

Best regards,
Thomas