powerpc/mm: Fix pgtable cache cleanup with CONFIG_PPC_SUBPAGE_PROT

Commit a0668cdc154e54bf0c85182e0535eea237d53146 cleans up the handling
of kmem_caches for allocating various levels of pagetables.
Unfortunately, it conflicts badly with CONFIG_PPC_SUBPAGE_PROT, due to
the latter's cleverly hidden technique of adding some extra allocation
space to the top level page directory to store the extra information
it needs.

Since that extra allocation really doesn't fit into the cleaned up
page directory allocating scheme, this patch alters
CONFIG_PPC_SUBPAGE_PROT to instead allocate its struct
subpage_prot_table as part of the mm_context_t.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 0 insertions, 5 deletions

diff --git a/arch/powerpc/include/asm/pgalloc-64.h b/arch/powerpc/include/asm/pgalloc-64.h
index 5c1cd73dafa8..605f5c5398d1 100644
--- a/arch/powerpc/include/asm/pgalloc-64.h
+++ b/arch/powerpc/include/asm/pgalloc-64.h
@@ -28,10 +28,6 @@
  */
 #define MAX_PGTABLE_INDEX_SIZE	0xf
 
-#ifndef CONFIG_PPC_SUBPAGE_PROT
-static inline void subpage_prot_free(pgd_t *pgd) {}
-#endif
-
 extern struct kmem_cache *pgtable_cache[];
 #define PGT_CACHE(shift) (pgtable_cache[(shift)-1])
 
@@ -42,7 +38,6 @@ static inline pgd_t *pgd_alloc(struct mm_struct *mm)
 
 static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
 {
-	subpage_prot_free(pgd);
 	kmem_cache_free(PGT_CACHE(PGD_INDEX_SIZE), pgd);
 }