1 files changed, 36 insertions, 0 deletions

diff --git a/arch/xtensa/mm/mmu.c b/arch/xtensa/mm/mmu.c
index 861203e958da..3429b483d9f8 100644
--- a/arch/xtensa/mm/mmu.c
+++ b/arch/xtensa/mm/mmu.c
@@ -3,6 +3,7 @@
  *
  * Extracted from init.c
  */
+#include <linux/bootmem.h>
 #include <linux/percpu.h>
 #include <linux/init.h>
 #include <linux/string.h>
@@ -16,9 +17,44 @@
 #include <asm/initialize_mmu.h>
 #include <asm/io.h>
 
+#if defined(CONFIG_HIGHMEM)
+static void * __init init_pmd(unsigned long vaddr)
+{
+        pgd_t *pgd = pgd_offset_k(vaddr);
+        pmd_t *pmd = pmd_offset(pgd, vaddr);
+
+        if (pmd_none(*pmd)) {
+                unsigned i;
+                pte_t *pte = alloc_bootmem_low_pages(PAGE_SIZE);
+
+                for (i = 0; i < 1024; i++)
+                        pte_clear(NULL, 0, pte + i);
+
+                set_pmd(pmd, __pmd(((unsigned long)pte) & PAGE_MASK));
+                BUG_ON(pte != pte_offset_kernel(pmd, 0));
+                pr_debug("%s: vaddr: 0x%08lx, pmd: 0x%p, pte: 0x%p\n",
+                         __func__, vaddr, pmd, pte);
+                return pte;
+        } else {
+                return pte_offset_kernel(pmd, 0);
+        }
+}
+
+static void __init fixedrange_init(void)
+{
+        BUILD_BUG_ON(FIXADDR_SIZE > PMD_SIZE);
+        init_pmd(__fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK);
+}
+#endif
+
 void __init paging_init(void)
 {
         memset(swapper_pg_dir, 0, PAGE_SIZE);
+#ifdef CONFIG_HIGHMEM
+        fixedrange_init();
+        pkmap_page_table = init_pmd(PKMAP_BASE);
+        kmap_init();
+#endif
 }
 
 /*