1 files changed, 115 insertions, 0 deletions
diff --git a/arch/arm/mm/pgd.c b/arch/arm/mm/pgd.c
new file mode 100644
index 00000000..b2027c15
--- /dev/null
+++ b/arch/arm/mm/pgd.c
@@ -0,0 +1,115 @@
+/*
+ *  linux/arch/arm/mm/pgd.c
+ *
+ *  Copyright (C) 1998-2005 Russell King
+ *
+ * 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.
+ */
+#include <linux/mm.h>
+#include <linux/gfp.h>
+#include <linux/highmem.h>
+
+#include <asm/pgalloc.h>
+#include <asm/page.h>
+#include <asm/tlbflush.h>
+
+#include "mm.h"
+
+/*
+ * need to get a 16k page for level 1
+ */
+pgd_t *pgd_alloc(struct mm_struct *mm)
+{
+	pgd_t *new_pgd, *init_pgd;
+	pud_t *new_pud, *init_pud;
+	pmd_t *new_pmd, *init_pmd;
+	pte_t *new_pte, *init_pte;
+
+	new_pgd = (pgd_t *)__get_free_pages(GFP_KERNEL, 2);
+	if (!new_pgd)
+		goto no_pgd;
+
+	memset(new_pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
+
+	/*
+	 * Copy over the kernel and IO PGD entries
+	 */
+	init_pgd = pgd_offset_k(0);
+	memcpy(new_pgd + USER_PTRS_PER_PGD, init_pgd + USER_PTRS_PER_PGD,
+		       (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
+
+	clean_dcache_area(new_pgd, PTRS_PER_PGD * sizeof(pgd_t));
+
+	if (!vectors_high()) {
+		/*
+		 * On ARM, first page must always be allocated since it
+		 * contains the machine vectors.
+		 */
+		new_pud = pud_alloc(mm, new_pgd, 0);
+		if (!new_pud)
+			goto no_pud;
+
+		new_pmd = pmd_alloc(mm, new_pud, 0);
+		if (!new_pmd)
+			goto no_pmd;
+
+		new_pte = pte_alloc_map(mm, NULL, new_pmd, 0);
+		if (!new_pte)
+			goto no_pte;
+
+		init_pud = pud_offset(init_pgd, 0);
+		init_pmd = pmd_offset(init_pud, 0);
+		init_pte = pte_offset_map(init_pmd, 0);
+		set_pte_ext(new_pte, *init_pte, 0);
+		pte_unmap(init_pte);
+		pte_unmap(new_pte);
+	}
+
+	return new_pgd;
+
+no_pte:
+	pmd_free(mm, new_pmd);
+no_pmd:
+	pud_free(mm, new_pud);
+no_pud:
+	free_pages((unsigned long)new_pgd, 2);
+no_pgd:
+	return NULL;
+}
+
+void pgd_free(struct mm_struct *mm, pgd_t *pgd_base)
+{
+	pgd_t *pgd;
+	pud_t *pud;
+	pmd_t *pmd;
+	pgtable_t pte;
+
+	if (!pgd_base)
+		return;
+
+	pgd = pgd_base + pgd_index(0);
+	if (pgd_none_or_clear_bad(pgd))
+		goto no_pgd;
+
+	pud = pud_offset(pgd, 0);
+	if (pud_none_or_clear_bad(pud))
+		goto no_pud;
+
+	pmd = pmd_offset(pud, 0);
+	if (pmd_none_or_clear_bad(pmd))
+		goto no_pmd;
+
+	pte = pmd_pgtable(*pmd);
+	pmd_clear(pmd);
+	pte_free(mm, pte);
+no_pmd:
+	pud_clear(pud);
+	pmd_free(mm, pmd);
+no_pud:
+	pgd_clear(pgd);
+	pud_free(mm, pud);
+no_pgd:
+	free_pages((unsigned long) pgd_base, 2);
+}