Benjamin Herrenschmidt <b...@kernel.crashing.org> writes:
> On radix, the process table entry we want to clear when
> destroying a context is entry 0, not entry 1
>
> Signed-off-by: Benjamin Herrenschmidt <b...@kernel.crashing.org>
Reviewed-by: Aneesh Kumar K.V <aneesh.ku...@linux.vnet.ibm.com>
> ---
> arch/powerpc/mm/mmu_context_book3s64.c | 12 +++++++++---
> 1 file changed, 9 insertions(+), 3 deletions(-)
>
> diff --git a/arch/powerpc/mm/mmu_context_book3s64.c
> b/arch/powerpc/mm/mmu_context_book3s64.c
> index 79d8c8a..9404b5e 100644
> --- a/arch/powerpc/mm/mmu_context_book3s64.c
> +++ b/arch/powerpc/mm/mmu_context_book3s64.c
> @@ -226,9 +226,15 @@ void destroy_context(struct mm_struct *mm)
> mm->context.cop_lockp = NULL;
> #endif /* CONFIG_PPC_ICSWX */
>
> - if (radix_enabled())
> - process_tb[mm->context.id].prtb1 = 0;
> - else
> + if (radix_enabled()) {
> + /*
> + * Radix doesn't have a valid bit in the process table
> + * entries. However we know that at least P9 implementation
> + * will avoid caching an entry with an invalid RTS field,
> + * and 0 is invalid. So this will do.
> + */
> + process_tb[mm->context.id].prtb0 = 0;
> + } else
> subpage_prot_free(mm);
> destroy_pagetable_page(mm);
> __destroy_context(mm->context.id);
