sh: Add support for 16kB PAGE_SIZE.

16kB is a useful size on nommu, while 64kB still tends to be too big to
be useful. Newer MMUs are likely to support this as well, so plug it
in in anticipation of those, too.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

arch/sh/mm/Kconfig

@@ -155,6 +155,12 @@ config PAGE_SIZE_8KB
 	help
 	  This enables 8kB pages as supported by SH-X2 and later MMUs.
 
+config PAGE_SIZE_16KB
+	bool "16kB"
+	depends on !MMU
+	help
+	  This enables 16kB pages on MMU-less SH systems.
+
 config PAGE_SIZE_64KB
 	bool "64kB"
 	depends on !MMU || CPU_SH4 || CPU_SH5

include/asm-sh/page.h

@@ -12,6 +12,8 @@
 # define PAGE_SHIFT	12
 #elif defined(CONFIG_PAGE_SIZE_8KB)
 # define PAGE_SHIFT	13
+#elif defined(CONFIG_PAGE_SIZE_16KB)
+# define PAGE_SHIFT	14
 #elif defined(CONFIG_PAGE_SIZE_64KB)
 # define PAGE_SHIFT	16
 #else

include/asm-sh/pgtable_32.h

@@ -102,7 +102,9 @@
 #define _PAGE_FLAGS_HARDWARE_MASK	(PHYS_ADDR_MASK & ~(_PAGE_CLEAR_FLAGS))
 
 /* Hardware flags, page size encoding */
-#if defined(CONFIG_X2TLB)
+#if !defined(CONFIG_MMU)
+# define _PAGE_FLAGS_HARD	0ULL
+#elif defined(CONFIG_X2TLB)
 # if defined(CONFIG_PAGE_SIZE_4KB)
 #  define _PAGE_FLAGS_HARD	_PAGE_EXT(_PAGE_EXT_ESZ0)
 # elif defined(CONFIG_PAGE_SIZE_8KB)

include/asm-sh/thread_info.h

@@ -38,6 +38,8 @@ struct thread_info {
 #define THREAD_SIZE_ORDER	(1)
 #elif defined(CONFIG_PAGE_SIZE_8KB)
 #define THREAD_SIZE_ORDER	(1)
+#elif defined(CONFIG_PAGE_SIZE_16KB)
+#define THREAD_SIZE_ORDER	(0)
 #elif defined(CONFIG_PAGE_SIZE_64KB)
 #define THREAD_SIZE_ORDER	(0)
 #else