powerpc: Add function to copy mm_context_t to the paca

This adds a function to copy the mm->context to the paca.  This is
only a basic conversion for now but will be used more extensively in
the next patch.

This also adds #ifdef CONFIG_PPC_BOOK3S around this code since it's
not used elsewhere.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

1 files changed, 3 insertions, 2 deletions

diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
index 4233dcccbaf7..03279eac0957 100644
--- a/arch/powerpc/mm/hash_utils_64.c
+++ b/arch/powerpc/mm/hash_utils_64.c
@@ -882,7 +882,8 @@ void demote_segment_4k(struct mm_struct *mm, unsigned long addr)
         slice_set_range_psize(mm, addr, 1, MMU_PAGE_4K);
         copro_flush_all_slbs(mm);
         if ((get_paca_psize(addr) != MMU_PAGE_4K) && (current->mm == mm)) {
-                get_paca()->context = mm->context;
+
+                copy_mm_to_paca(&mm->context);
                 slb_flush_and_rebolt();
         }
 }
@@ -949,7 +950,7 @@ static void check_paca_psize(unsigned long ea, struct mm_struct *mm,
 {
         if (user_region) {
                 if (psize != get_paca_psize(ea)) {
-                        get_paca()->context = mm->context;
+                        copy_mm_to_paca(&mm->context);
                         slb_flush_and_rebolt();
                 }
         } else if (get_paca()->vmalloc_sllp !=