[PATCH 08/65] powerpc/mm: Update _PAGE_KERNEL_RO

[Balbir Singh]

On 27/03/16 19:23, Aneesh Kumar K.V wrote:
> PS3 had used PPP bit hack to implement a read only mapping in the
> kernel area. Since we are bolt mapping the ioremap area, it used
> the pte flags _PAGE_PRESENT | _PAGE_USER to get a PPP value of 0x3
> there by resulting in a read only mapping. This means the area
> can be accessed by user space, but kernel will never return such an
> address to user space.
>
> But we can do better by implementing a read only kernel mapping using
> PPP bits 0b110
Looks good!

Acked-by: Balbir Singh <bsingharora at gmail.com>