[PATCH v2 1/3] arm64: mm: Add p?d_large() definitions

Catalin Marinas catalin.marinas at arm.com
Mon Jul 1 19:44:17 AEST 2019


On Mon, Jul 01, 2019 at 04:40:24PM +1000, Nicholas Piggin wrote:
> walk_page_range() is going to be allowed to walk page tables other than
> those of user space. For this it needs to know when it has reached a
> 'leaf' entry in the page tables. This information will be provided by the
> p?d_large() functions/macros.
> 
> For arm64, we already have p?d_sect() macros which we can reuse for
> p?d_large().
> 
> pud_sect() is defined as a dummy function when CONFIG_PGTABLE_LEVELS < 3
> or CONFIG_ARM64_64K_PAGES is defined. However when the kernel is
> configured this way then architecturally it isn't allowed to have a
> large page that this level, and any code using these page walking macros
> is implicitly relying on the page size/number of levels being the same as
> the kernel. So it is safe to reuse this for p?d_large() as it is an
> architectural restriction.
> 
> Cc: Catalin Marinas <catalin.marinas at arm.com>
> Cc: Will Deacon <will.deacon at arm.com>
> Signed-off-by: Steven Price <steven.price at arm.com>

Acked-by: Catalin Marinas <catalin.marinas at arm.com>


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