Re: [PATCH v3 7/7] dma-buf: system_heap: Add a system-uncached heap re-using the system heap

From: John Stultz
Date: Thu Oct 08 2020 - 01:04:09 EST


On Mon, Oct 5, 2020 at 6:45 AM Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote:
>
> How is this going to deal with VIVT caches?

Hrm. That's a good question. I'm not sure I totally have my head
around it but, I guess we could make sure to call
invalidate_kernel_vmap_range() in begin_cpu_access() and
flush_kernel_vmap_range() in end_cpu_access() rather then exiting out
early as we do now?

Unless you have better guidance?

Worse case we could check CONFIG_CPU_CACHE_VIVT and not register the
system-uncached heap.

thanks
-john