[PATCH 1/2] powerpc/mm/subpage: Init user psize correctly
From: Aneesh Kumar K.V <hidden>
Date: 2016-05-02 10:52:57
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Linus Torvalds
Check against a context.id value of zero instead of MMU_NO_CONTEXT when doing a slice psize init. Without this patch we end up with a slice psize value of zero and we always end up using 4K hpte. Signed-off-by: Aneesh Kumar K.V <redacted> --- arch/powerpc/mm/mmu_context_book3s64.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/mm/mmu_context_book3s64.c b/arch/powerpc/mm/mmu_context_book3s64.c
index b5288b460bef..a28ed6a96286 100644
--- a/arch/powerpc/mm/mmu_context_book3s64.c
+++ b/arch/powerpc/mm/mmu_context_book3s64.c@@ -85,8 +85,16 @@ int init_new_context(struct task_struct *tsk, struct mm_struct *mm) /* The old code would re-promote on fork, we don't do that * when using slices as it could cause problem promoting slices * that have been forced down to 4K + * + * For book3s we have MMU_NO_CONTEXT set to be ~0. Hence check + * explicitly against context.id == 0. This ensures that we + * properly initialize context slice details for newly allocated + * mm and don't alter context slice inherited via fork. + * + * We should not be calling init_new_context on init_mm. Hence a + * check against 0 is ok. */ - if (slice_mm_new_context(mm)) + if (mm->context.id == 0) slice_set_user_psize(mm, mmu_virtual_psize); subpage_prot_init_new_context(mm); }
--
2.7.4