sh: page table alloc cleanups and page fault optimizations.

Cleanup of page table allocators, using generic folded PMD and PUD
helpers. TLB flushing operations are moved to a more sensible spot.

The page fault handler is also optimized slightly, we no longer waste
cycles on IRQ disabling for flushing of the page from the ITLB, since
we're already under CLI protection by the initial exception handler.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 12 insertions, 1 deletions

diff --git a/arch/sh/mm/init.c b/arch/sh/mm/init.c
index 8ea27ca4b700..d1a979eab656 100644
--- a/arch/sh/mm/init.c
+++ b/arch/sh/mm/init.c
@@ -80,6 +80,7 @@ void show_mem(void)
 static void set_pte_phys(unsigned long addr, unsigned long phys, pgprot_t prot)
 {
         pgd_t *pgd;
+        pud_t *pud;
         pmd_t *pmd;
         pte_t *pte;
 
@@ -89,7 +90,17 @@ static void set_pte_phys(unsigned long addr, unsigned long phys, pgprot_t prot)
                 return;
         }
 
-        pmd = pmd_offset(pgd, addr);
+        pud = pud_offset(pgd, addr);
+        if (pud_none(*pud)) {
+                pmd = (pmd_t *)get_zeroed_page(GFP_ATOMIC);
+                set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE | _PAGE_USER));
+                if (pmd != pmd_offset(pud, 0)) {
+                        pud_ERROR(*pud);
+                        return;
+                }
+        }
+
+        pmd = pmd_offset(pud, addr);
         if (pmd_none(*pmd)) {
                 pte = (pte_t *)get_zeroed_page(GFP_ATOMIC);
                 set_pmd(pmd, __pmd(__pa(pte) | _KERNPG_TABLE | _PAGE_USER));