powerpc/44x: Support 16K/64K base page sizes on 44x

This adds support for 16k and 64k page sizes on PowerPC 44x processors.

The PGDIR table is much smaller than a page when using 16k or 64k
pages (512 and 32 bytes respectively) so we allocate the PGDIR with
kzalloc() instead of __get_free_pages().

One PTE table covers rather a large memory area when using 16k or 64k
pages (32MB or 512MB respectively), so we can easily put FIXMAP and
PKMAP in the area covered by one PTE table.

Signed-off-by: Yuri Tikhonov <yur@emcraft.com>
Signed-off-by: Vladimir Panfilov <pvr@emcraft.com>
Signed-off-by: Ilya Yanok <yanok@emcraft.com>
Acked-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 17 insertions, 0 deletions

diff --git a/arch/powerpc/include/asm/mmu-44x.h b/arch/powerpc/include/asm/mmu-44x.h
index b21af32ac6d..8a97cfb08b7 100644
--- a/arch/powerpc/include/asm/mmu-44x.h
+++ b/arch/powerpc/include/asm/mmu-44x.h
@@ -4,6 +4,8 @@
  * PPC440 support
  */
 
+#include <asm/page.h>
+
 #define PPC44x_MMUCR_TID	0x000000ff
 #define PPC44x_MMUCR_STS	0x00010000
 
@@ -74,4 +76,19 @@ typedef struct {
 /* Size of the TLBs used for pinning in lowmem */
 #define PPC_PIN_SIZE	(1 << 28)	/* 256M */
 
+#if (PAGE_SHIFT == 12)
+#define PPC44x_TLBE_SIZE	PPC44x_TLB_4K
+#elif (PAGE_SHIFT == 14)
+#define PPC44x_TLBE_SIZE	PPC44x_TLB_16K
+#elif (PAGE_SHIFT == 16)
+#define PPC44x_TLBE_SIZE	PPC44x_TLB_64K
+#else
+#error "Unsupported PAGE_SIZE"
+#endif
+
+#define PPC44x_PGD_OFF_SHIFT	(32 - PGDIR_SHIFT + PGD_T_LOG2)
+#define PPC44x_PGD_OFF_MASK_BIT	(PGDIR_SHIFT - PGD_T_LOG2)
+#define PPC44x_PTE_ADD_SHIFT	(32 - PGDIR_SHIFT + PTE_SHIFT + PTE_T_LOG2)
+#define PPC44x_PTE_ADD_MASK_BIT	(32 - PTE_T_LOG2 - PTE_SHIFT)
+
 #endif /* _ASM_POWERPC_MMU_44X_H_ */