Re: [PATCH 4/6] iommu/generic_pt: Add Broadcom BCM2712 page table format

[Nick Hollinghurst]

Hi Daniel,

On Sun, 12 Jul 2026 at 22:19, Daniel Drake <dan@xxxxxxxxxxxxxxx> wrote:
>
> The BCM2712 IOMMU implements a 2-level page table format. It is relatively
> simple, with one unusual aspect: leaf entries can only be installed at
> Level 0.

I should admit that a single-level huge page mapping is possible, but
I was too lazy to implement it (and haven't much tested it).

It can be done by setting bits 31, 30 and 28 of the top-level entry
(all other combinations of bits 31, 30 will point to a  next-level
table). The page number is in 4K units but must be 4MB aligned.

Regards,

 Nick