1 files changed, 101 insertions, 0 deletions

diff --git a/arch/arm/mm/hugetlbpage.c b/arch/arm/mm/hugetlbpage.c
new file mode 100644
index 000000000000..3d1e4a205b0b
--- /dev/null
+++ b/arch/arm/mm/hugetlbpage.c
@@ -0,0 +1,101 @@
+/*
+ * arch/arm/mm/hugetlbpage.c
+ *
+ * Copyright (C) 2012 ARM Ltd.
+ *
+ * Based on arch/x86/include/asm/hugetlb.h and Bill Carson's patches
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include <linux/init.h>
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/hugetlb.h>
+#include <linux/pagemap.h>
+#include <linux/err.h>
+#include <linux/sysctl.h>
+#include <asm/mman.h>
+#include <asm/tlb.h>
+#include <asm/tlbflush.h>
+#include <asm/pgalloc.h>
+
+/*
+ * On ARM, huge pages are backed by pmd's rather than pte's, so we do a lot
+ * of type casting from pmd_t * to pte_t *.
+ */
+
+pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
+{
+        pgd_t *pgd;
+        pud_t *pud;
+        pmd_t *pmd = NULL;
+
+        pgd = pgd_offset(mm, addr);
+        if (pgd_present(*pgd)) {
+                pud = pud_offset(pgd, addr);
+                if (pud_present(*pud))
+                        pmd = pmd_offset(pud, addr);
+        }
+
+        return (pte_t *)pmd;
+}
+
+struct page *follow_huge_addr(struct mm_struct *mm, unsigned long address,
+                              int write)
+{
+        return ERR_PTR(-EINVAL);
+}
+
+int pud_huge(pud_t pud)
+{
+        return 0;
+}
+
+int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep)
+{
+        return 0;
+}
+
+pte_t *huge_pte_alloc(struct mm_struct *mm,
+                        unsigned long addr, unsigned long sz)
+{
+        pgd_t *pgd;
+        pud_t *pud;
+        pte_t *pte = NULL;
+
+        pgd = pgd_offset(mm, addr);
+        pud = pud_alloc(mm, pgd, addr);
+        if (pud)
+                pte = (pte_t *)pmd_alloc(mm, pud, addr);
+
+        return pte;
+}
+
+struct page *
+follow_huge_pmd(struct mm_struct *mm, unsigned long address,
+                pmd_t *pmd, int write)
+{
+        struct page *page;
+
+        page = pte_page(*(pte_t *)pmd);
+        if (page)
+                page += ((address & ~PMD_MASK) >> PAGE_SHIFT);
+        return page;
+}
+
+int pmd_huge(pmd_t pmd)
+{
+        return pmd_val(pmd) && !(pmd_val(pmd) & PMD_TABLE_BIT);
+}