sparc64: Switch to 4-level page tables.
This has become necessary with chips that support more than 43-bits
of physical addressing.
Based almost entirely upon a patch by Bob Picco.
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Bob Picco <bob.picco@oracle.com>
diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c
index bd08ed4..091f846 100644
--- a/arch/sparc/mm/init_64.c
+++ b/arch/sparc/mm/init_64.c
@@ -1390,6 +1390,13 @@
pmd_t *pmd;
pte_t *pte;
+ if (pgd_none(*pgd)) {
+ pud_t *new;
+
+ new = __alloc_bootmem(PAGE_SIZE, PAGE_SIZE, PAGE_SIZE);
+ alloc_bytes += PAGE_SIZE;
+ pgd_populate(&init_mm, pgd, new);
+ }
pud = pud_offset(pgd, vstart);
if (pud_none(*pud)) {
pmd_t *new;
@@ -1856,7 +1863,12 @@
/* paging_init() sets up the page tables */
static unsigned long last_valid_pfn;
-pgd_t swapper_pg_dir[PTRS_PER_PGD];
+
+/* These must be page aligned in order to not trigger the
+ * alignment tests of pgd_bad() and pud_bad().
+ */
+pgd_t swapper_pg_dir[PTRS_PER_PGD] __attribute__ ((aligned (PAGE_SIZE)));
+static pud_t swapper_pud_dir[PTRS_PER_PUD] __attribute__ ((aligned (PAGE_SIZE)));
static void sun4u_pgprot_init(void);
static void sun4v_pgprot_init(void);
@@ -1911,6 +1923,8 @@
{
unsigned long end_pfn, shift, phys_base;
unsigned long real_end, i;
+ pud_t *pud;
+ pmd_t *pmd;
int node;
setup_page_offset();
@@ -2008,9 +2022,18 @@
memset(swapper_low_pmd_dir, 0, sizeof(swapper_low_pmd_dir));
- /* Now can init the kernel/bad page tables. */
- pud_set(pud_offset(&swapper_pg_dir[0], 0),
- swapper_low_pmd_dir + (shift / sizeof(pgd_t)));
+ /* The kernel page tables we publish into what the rest of the
+ * world sees must be adjusted so that they see the PAGE_OFFSET
+ * address of these in-kerenel data structures. However right
+ * here we must access them from the kernel image side, because
+ * the trap tables haven't been taken over and therefore we cannot
+ * take TLB misses in the PAGE_OFFSET linear mappings yet.
+ */
+ pud = swapper_pud_dir + (shift / sizeof(pud_t));
+ pgd_set(&swapper_pg_dir[0], pud);
+
+ pmd = swapper_low_pmd_dir + (shift / sizeof(pmd_t));
+ pud_set(&swapper_pud_dir[0], pmd);
inherit_prom_mappings();