POWERPC: Allow 32-bit hashed pgtable code to support 36-bit physical

This rearranges a bit of code, and adds support for
36-bit physical addressing for configs that use a
hashed page table.  The 36b physical support is not
enabled by default on any config - it must be
explicitly enabled via the config system.

This patch *only* expands the page table code to accomodate
large physical addresses on 32-bit systems and enables the
PHYS_64BIT config option for 86xx.  It does *not*
allow you to boot a board with more than about 3.5GB of
RAM - for that, SWIOTLB support is also required (and
coming soon).

Signed-off-by: Becky Bruce <becky.bruce@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

1 files changed, 7 insertions, 1 deletions

diff --git a/arch/powerpc/include/asm/page_32.h b/arch/powerpc/include/asm/page_32.h
index ebfae530a379..d77072a32cc6 100644
--- a/arch/powerpc/include/asm/page_32.h
+++ b/arch/powerpc/include/asm/page_32.h
@@ -13,10 +13,16 @@
 #define ARCH_KMALLOC_MINALIGN   L1_CACHE_BYTES
 #endif
 
+#ifdef CONFIG_PTE_64BIT
+#define PTE_FLAGS_OFFSET        4       /* offset of PTE flags, in bytes */
+#else
+#define PTE_FLAGS_OFFSET        0
+#endif
+
 #ifndef __ASSEMBLY__
 /*
  * The basic type of a PTE - 64 bits for those CPUs with > 32 bit
- * physical addressing.  For now this just the IBM PPC440.
+ * physical addressing.
  */
 #ifdef CONFIG_PTE_64BIT
 typedef unsigned long long pte_basic_t;