powerpc/mm: Make 4K and 64K use pte_t for pgtable_t

This patch switches 4K Linux page size config to use pte_t * type
instead of struct page * for pgtable_t. This simplifies the code a lot
and helps in consolidating both 64K and 4K page allocator routines. The
changes should not have any impact, because we already store physical
address in the upper level page table tree and that implies we already
do struct page * to physical address conversion.

One change to note here is we move the pgtable_page_dtor() call for
nohash to pte_fragment_free_mm(). The nohash related change is due to
the related changes in pgtable_64.c.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

1 files changed, 9 insertions, 1 deletions

diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h
index 158574d2acf4..51db3a37bced 100644
--- a/arch/powerpc/include/asm/page.h
+++ b/arch/powerpc/include/asm/page.h
@@ -316,12 +316,20 @@ void arch_free_page(struct page *page, int order);
 #endif
 
 struct vm_area_struct;
-
+#ifdef CONFIG_PPC_BOOK3S_64
+/*
+ * For BOOK3s 64 with 4k and 64K linux page size
+ * we want to use pointers, because the page table
+ * actually store pfn
+ */
+typedef pte_t *pgtable_t;
+#else
 #if defined(CONFIG_PPC_64K_PAGES) && defined(CONFIG_PPC64)
 typedef pte_t *pgtable_t;
 #else
 typedef struct page *pgtable_t;
 #endif
+#endif
 
 #include <asm-generic/memory_model.h>
 #endif /* __ASSEMBLY__ */