summaryrefslogtreecommitdiffstats
path: root/arch/xtensa/mm/mmu.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/xtensa/mm/mmu.c')
-rw-r--r--arch/xtensa/mm/mmu.c36
1 files changed, 36 insertions, 0 deletions
diff --git a/arch/xtensa/mm/mmu.c b/arch/xtensa/mm/mmu.c
index 861203e958d..3429b483d9f 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
}
/*