This commit was manufactured by cvs2svn to create branch 'vserver'.

[linux-2.6.git] / arch / arm / mm / pgd.c

diff --git a/arch/arm/mm/pgd.c b/arch/arm/mm/pgd.c
new file mode 100644 (file)
index 0000000..50b9aed
--- /dev/null
+++ b/arch/arm/mm/pgd.c
@@ -0,0 +1,101 @@
+/*
+ *  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/highmem.h>
+
+#include <asm/pgalloc.h>
+#include <asm/page.h>
+#include <asm/tlbflush.h>
+
+#include "mm.h"
+
+#define FIRST_KERNEL_PGD_NR    (FIRST_USER_PGD_NR + USER_PTRS_PER_PGD)
+
+/*
+ * need to get a 16k page for level 1
+ */
+pgd_t *get_pgd_slow(struct mm_struct *mm)
+{
+       pgd_t *new_pgd, *init_pgd;
+       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;
+
+       memzero(new_pgd, FIRST_KERNEL_PGD_NR * sizeof(pgd_t));
+
+       /*
+        * Copy over the kernel and IO PGD entries
+        */
+       init_pgd = pgd_offset_k(0);
+       memcpy(new_pgd + FIRST_KERNEL_PGD_NR, init_pgd + FIRST_KERNEL_PGD_NR,
+                      (PTRS_PER_PGD - FIRST_KERNEL_PGD_NR) * 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_pmd = pmd_alloc(mm, new_pgd, 0);
+               if (!new_pmd)
+                       goto no_pmd;
+
+               new_pte = pte_alloc_map(mm, new_pmd, 0);
+               if (!new_pte)
+                       goto no_pte;
+
+               init_pmd = pmd_offset(init_pgd, 0);
+               init_pte = pte_offset_map_nested(init_pmd, 0);
+               set_pte_ext(new_pte, *init_pte, 0);
+               pte_unmap_nested(init_pte);
+               pte_unmap(new_pte);
+       }
+
+       return new_pgd;
+
+no_pte:
+       pmd_free(new_pmd);
+no_pmd:
+       free_pages((unsigned long)new_pgd, 2);
+no_pgd:
+       return NULL;
+}
+
+void free_pgd_slow(pgd_t *pgd)
+{
+       pmd_t *pmd;
+       struct page *pte;
+
+       if (!pgd)
+               return;
+
+       /* pgd is always present and good */
+       pmd = pmd_off(pgd, 0);
+       if (pmd_none(*pmd))
+               goto free;
+       if (pmd_bad(*pmd)) {
+               pmd_ERROR(*pmd);
+               pmd_clear(pmd);
+               goto free;
+       }
+
+       pte = pmd_page(*pmd);
+       pmd_clear(pmd);
+       dec_zone_page_state(virt_to_page((unsigned long *)pgd), NR_PAGETABLE);
+       pte_lock_deinit(pte);
+       pte_free(pte);
+       pmd_free(pmd);
+free:
+       free_pages((unsigned long) pgd, 2);
+}