[IA64] 4-level page tables

This patch introduces 4-level page tables to ia64.  I have run
some benchmarks and found nothing interesting.  Performance has
consistently fallen within the noise range.

It also introduces a config option (setting the default to 3
levels).  The config option prevents having 4 level page
tables with 64k base page size.

Signed-off-by: Robin Holt <holt@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

1 files changed, 19 insertions, 0 deletions

diff --git a/include/asm-ia64/pgalloc.h b/include/asm-ia64/pgalloc.h
index a5f214554afd..f2f233846476 100644
--- a/include/asm-ia64/pgalloc.h
+++ b/include/asm-ia64/pgalloc.h
@@ -86,6 +86,25 @@ static inline void pgd_free(pgd_t * pgd)
         pgtable_quicklist_free(pgd);
 }
 
+#ifdef CONFIG_PGTABLE_4
+static inline void
+pgd_populate(struct mm_struct *mm, pgd_t * pgd_entry, pud_t * pud)
+{
+        pgd_val(*pgd_entry) = __pa(pud);
+}
+
+static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long addr)
+{
+        return pgtable_quicklist_alloc();
+}
+
+static inline void pud_free(pud_t * pud)
+{
+        pgtable_quicklist_free(pud);
+}
+#define __pud_free_tlb(tlb, pud)        pud_free(pud)
+#endif /* CONFIG_PGTABLE_4 */
+
 static inline void
 pud_populate(struct mm_struct *mm, pud_t * pud_entry, pmd_t * pmd)
 {