Re: [PATCH v6 19/25] iommu/arm-smmu-v3: Add support for Hardware Translation Table Update

Prabhakar Kushwaha
2020-05-04T14:24:42Z

Dear Jean,

On Thu, Apr 30, 2020 at 8:11 PM Jean-Philippe Brucker
<jean-philippe@linaro.org> wrote:
>
> If the SMMU supports it and the kernel was built with HTTU support, enable

is there any framework/config for HTTU which must be enabled to use this patch?

> We can enable HTTU even if CPUs don't support it, because the kernel
> always checks for HW dirty bit and updates the PTE flags atomically.
>
I believe, this statement is valid in context of this patch-set only.

One cannot use code snipped to test HTTU because exiting
io-pgtable-arm.c driver doesn't have framework to leverage HTTU
benfits. It by-default sets AF=1 and does not set DBM.

Thanks

--pk