parisc/mm: preallocate fixmap page tables at init

[linux-2.6-microblaze.git] / arch / parisc / mm / init.c

diff --git a/arch/parisc/mm/init.c b/arch/parisc/mm/init.c
index 406c52f..389941c 100644 (file)
--- a/arch/parisc/mm/init.c
+++ b/arch/parisc/mm/init.c
@@ -669,6 +669,39 @@ static void __init gateway_init(void)
                  PAGE_SIZE, PAGE_GATEWAY, 1);
 }
 
+static void __init fixmap_init(void)
+{
+       unsigned long addr = FIXMAP_START;
+       unsigned long end = FIXMAP_START + FIXMAP_SIZE;
+       pgd_t *pgd = pgd_offset_k(addr);
+       p4d_t *p4d = p4d_offset(pgd, addr);
+       pud_t *pud = pud_offset(p4d, addr);
+       pmd_t *pmd;
+
+       BUILD_BUG_ON(FIXMAP_SIZE > PMD_SIZE);
+
+#if CONFIG_PGTABLE_LEVELS == 3
+       if (pud_none(*pud)) {
+               pmd = memblock_alloc(PAGE_SIZE << PMD_TABLE_ORDER,
+                                    PAGE_SIZE << PMD_TABLE_ORDER);
+               if (!pmd)
+                       panic("fixmap: pmd allocation failed.\n");
+               pud_populate(NULL, pud, pmd);
+       }
+#endif
+
+       pmd = pmd_offset(pud, addr);
+       do {
+               pte_t *pte = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
+               if (!pte)
+                       panic("fixmap: pte allocation failed.\n");
+
+               pmd_populate_kernel(&init_mm, pmd, pte);
+
+               addr += PAGE_SIZE;
+       } while (addr < end);
+}
+
 static void __init parisc_bootmem_free(void)
 {
        unsigned long max_zone_pfn[MAX_NR_ZONES] = { 0, };
@@ -683,6 +716,7 @@ void __init paging_init(void)
        setup_bootmem();
        pagetable_init();
        gateway_init();
+       fixmap_init();
        flush_cache_all_local(); /* start with known state */
        flush_tlb_all_local(NULL);