powerpc/8xx: Implement 16k pages

This patch activates the handling of 16k pages on the MPC8xx.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <scottwood@freescale.com>

arch/powerpc/Kconfig

@@ -549,7 +549,7 @@ config PPC_4K_PAGES
 	bool "4k page size"
 
 config PPC_16K_PAGES
-	bool "16k page size" if 44x
+	bool "16k page size" if 44x || PPC_8xx
 
 config PPC_64K_PAGES
 	bool "64k page size" if 44x || PPC_STD_MMU_64 || PPC_BOOK3E_64

arch/powerpc/include/asm/mmu-8xx.h

@@ -56,6 +56,7 @@
  * additional information from the MI_EPN, and MI_TWC registers.
  */
 #define SPRN_MI_RPN	790
+#define MI_SPS16K	0x00000008	/* Small page size (0 = 4k, 1 = 16k) */
 
 /* Define an RPN value for mapping kernel memory to large virtual
  * pages for boot initialization.  This has real page number of 0,
@@ -129,6 +130,7 @@
  * additional information from the MD_EPN, and MD_TWC registers.
  */
 #define SPRN_MD_RPN	798
+#define MD_SPS16K	0x00000008	/* Small page size (0 = 4k, 1 = 16k) */
 
 /* This is a temporary storage register that could be used to save
  * a processor working register during a tablewalk.

arch/powerpc/kernel/head_8xx.S

@@ -45,7 +45,11 @@
  * Value for the bits that have fixed value in RPN entries.
  * Also used for tagging DAR for DTLBerror.
  */
+#ifdef CONFIG_PPC_16K_PAGES
+#define RPN_PATTERN	(0x00f0 | MD_SPS16K)
+#else
 #define RPN_PATTERN	0x00f0
+#endif
 
 	__HEAD
 _ENTRY(_stext);