parisc: Add defines for Huge page support
Huge pages on parisc will have the same size as one pmd table, which
is on a 64bit kernel 2MB on a kernel with 4K kernel page sizes, and
on a 32bit kernel 4MB when used with 4K kernel pages.
Since parisc does not physically supports 2MB huge page sizes, emulate
it with two consecutive 1MB page sizes instead. Keeping the same huge
page size as one pmd will allow us to add transparent huge page support
later on.
Bit 21 in the pte flags was unused and will now be used to mark a page
as huge page (_PAGE_HPAGE_BIT).
Signed-off-by: Helge Deller <deller@gmx.de>
diff --git a/arch/parisc/include/asm/page.h b/arch/parisc/include/asm/page.h
index 60d5d17..80e742a 100644
--- a/arch/parisc/include/asm/page.h
+++ b/arch/parisc/include/asm/page.h
@@ -145,11 +145,22 @@
#endif /* CONFIG_DISCONTIGMEM */
#ifdef CONFIG_HUGETLB_PAGE
-#define HPAGE_SHIFT 22 /* 4MB (is this fixed?) */
+#define HPAGE_SHIFT PMD_SHIFT /* fixed for transparent huge pages */
#define HPAGE_SIZE ((1UL) << HPAGE_SHIFT)
#define HPAGE_MASK (~(HPAGE_SIZE - 1))
#define HUGETLB_PAGE_ORDER (HPAGE_SHIFT - PAGE_SHIFT)
+
+#if defined(CONFIG_64BIT) && defined(CONFIG_PARISC_PAGE_SIZE_4KB)
+# define REAL_HPAGE_SHIFT 20 /* 20 = 1MB */
+# define _HUGE_PAGE_SIZE_ENCODING_DEFAULT _PAGE_SIZE_ENCODING_1M
+#elif !defined(CONFIG_64BIT) && defined(CONFIG_PARISC_PAGE_SIZE_4KB)
+# define REAL_HPAGE_SHIFT 22 /* 22 = 4MB */
+# define _HUGE_PAGE_SIZE_ENCODING_DEFAULT _PAGE_SIZE_ENCODING_4M
+#else
+# define REAL_HPAGE_SHIFT 24 /* 24 = 16MB */
+# define _HUGE_PAGE_SIZE_ENCODING_DEFAULT _PAGE_SIZE_ENCODING_16M
#endif
+#endif /* CONFIG_HUGETLB_PAGE */
#define virt_addr_valid(kaddr) pfn_valid(__pa(kaddr) >> PAGE_SHIFT)