[PATCH v4 24/39] arm64: mte: Add in-kernel MTE helpers

[Catalin Marinas]

On Fri, Oct 02, 2020 at 01:10:25AM +0200, Andrey Konovalov wrote:
> From: Vincenzo Frascino <vincenzo.frascino at arm.com>
> 
> Provide helper functions to manipulate allocation and pointer tags for
> kernel addresses.
> 
> Low-level helper functions (mte_assign_*, written in assembly) operate
> tag values from the [0x0, 0xF] range. High-level helper functions
> (mte_get/set_*) use the [0xF0, 0xFF] range to preserve compatibility
> with normal kernel pointers that have 0xFF in their top byte.
> 
> MTE_GRANULE_SIZE and related definitions are moved to mte-def.h header
> that doesn't have any dependencies and is safe to include into any
> low-level header.
> 
> Signed-off-by: Vincenzo Frascino <vincenzo.frascino at arm.com>
> Co-developed-by: Andrey Konovalov <andreyknvl at google.com>
> Signed-off-by: Andrey Konovalov <andreyknvl at google.com>

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