Re: [PATCH kernel v12 27/34] powerpc/powernv: Implement multilevel TCE tables

[David Gibson]

On Fri, Jun 05, 2015 at 04:35:19PM +1000, Alexey Kardashevskiy wrote:
> TCE tables might get too big in case of 4K IOMMU pages and DDW enabled
> on huge guests (hundreds of GB of RAM) so the kernel might be unable to
> allocate contiguous chunk of physical memory to store the TCE table.
> 
> To address this, POWER8 CPU (actually, IODA2) supports multi-level
> TCE tables, up to 5 levels which splits the table into a tree of
> smaller subtables.
> 
> This adds multi-level TCE tables support to
> pnv_pci_ioda2_table_alloc_pages() and pnv_pci_ioda2_table_free_pages()
> helpers.
> 
> Signed-off-by: Alexey Kardashevskiy <aik@xxxxxxxxx>

Reviewed-by: David Gibson <david@xxxxxxxxxxxxxxxxxxxxx>

-- 
David Gibson			| I'll have my music baroque, and my code
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				| _way_ _around_!
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