arm64: move {PAGE,CONT}_SHIFT into Kconfig

In some cases (e.g. the awk for CONFIG_RANDOMIZE_TEXT_OFFSET) we would
like to make use of PAGE_SHIFT outside of code that can include the
usual header files.

Add a new CONFIG_ARM64_PAGE_SHIFT for this, likewise with
ARM64_CONT_SHIFT for consistency.

Signed-off-by: Mark Rutland <[e-mail]>
Cc: Ard Biesheuvel <[e-mail]>
Cc: Catalin Marinas <[e-mail]>
Cc: Sudeep Holla <[e-mail]>
Cc: Will Deacon <[e-mail]>
Signed-off-by: Will Deacon <[e-mail]>

arch/arm64/Kconfig

···
 config MMU
 	def_bool y
 
+config ARM64_PAGE_SHIFT
+	int
+	default 16 if ARM64_64K_PAGES
+	default 14 if ARM64_16K_PAGES
+	default 12
+
+config ARM64_CONT_SHIFT
+	int
+	default 5 if ARM64_64K_PAGES
+	default 7 if ARM64_16K_PAGES
+	default 4
+
 config ARCH_MMAP_RND_BITS_MIN
        default 14 if ARM64_64K_PAGES
        default 16 if ARM64_16K_PAGES

arch/arm64/include/asm/page.h

···
 
 /* PAGE_SHIFT determines the page size */
 /* CONT_SHIFT determines the number of pages which can be tracked together  */
-#ifdef CONFIG_ARM64_64K_PAGES
-#define PAGE_SHIFT		16
-#define CONT_SHIFT		5
-#elif defined(CONFIG_ARM64_16K_PAGES)
-#define PAGE_SHIFT		14
-#define CONT_SHIFT		7
-#else
-#define PAGE_SHIFT		12
-#define CONT_SHIFT		4
-#endif
+#define PAGE_SHIFT		CONFIG_ARM64_PAGE_SHIFT
+#define CONT_SHIFT		CONFIG_ARM64_CONT_SHIFT
 #define PAGE_SIZE		(_AC(1, UL) << PAGE_SHIFT)
 #define PAGE_MASK		(~(PAGE_SIZE-1))