mm: pgtable: add shortcuts for accessing kernel PMD and PTE

The powerpc 32-bit implementation of pgtable has nice shortcuts for
accessing kernel PMD and PTE for a given virtual address.  Make these
helpers available for all architectures.

[[email protected]: microblaze: fix page table traversal in setup_rt_frame()]
  Link: http://lkml.kernel.org/r/[email protected]
[[email protected]: s/pmd_ptr_k/pmd_off_k/ in various powerpc places]

Signed-off-by: Mike Rapoport <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Brian Cain <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Chris Zankel <[email protected]>
Cc: "David S. Miller" <[email protected]>
Cc: Geert Uytterhoeven <[email protected]>
Cc: Greentime Hu <[email protected]>
Cc: Greg Ungerer <[email protected]>
Cc: Guan Xuetao <[email protected]>
Cc: Guo Ren <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Helge Deller <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Ley Foon Tan <[email protected]>
Cc: Mark Salter <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Matt Turner <[email protected]>
Cc: Max Filippov <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Michal Simek <[email protected]>
Cc: Nick Hu <[email protected]>
Cc: Paul Walmsley <[email protected]>
Cc: Richard Weinberger <[email protected]>
Cc: Rich Felker <[email protected]>
Cc: Russell King <[email protected]>
Cc: Stafford Horne <[email protected]>
Cc: Thomas Bogendoerfer <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Tony Luck <[email protected]>
Cc: Vincent Chen <[email protected]>
Cc: Vineet Gupta <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Yoshinori Sato <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Linus Torvalds <[email protected]>

1 files changed, 1 insertions, 7 deletions

diff --git a/arch/sparc/mm/iommu.c b/arch/sparc/mm/iommu.c
index fa9e298fd985..35b002eb312e 100644
--- a/arch/sparc/mm/iommu.c
+++ b/arch/sparc/mm/iommu.c
@@ -348,9 +348,6 @@ static void *sbus_iommu_alloc(struct device *dev, size_t len,
 	while(addr < end) {
 		page = va;
 		{
-			pgd_t *pgdp;
-			p4d_t *p4dp;
-			pud_t *pudp;
 			pmd_t *pmdp;
 			pte_t *ptep;
 
@@ -361,10 +358,7 @@ static void *sbus_iommu_alloc(struct device *dev, size_t len,
 			else
 				__flush_page_to_ram(page);
 
-			pgdp = pgd_offset(&init_mm, addr);
-			p4dp = p4d_offset(pgdp, addr);
-			pudp = pud_offset(p4dp, addr);
-			pmdp = pmd_offset(pudp, addr);
+			pmdp = pmd_off_k(addr);
 			ptep = pte_offset_map(pmdp, addr);
 
 			set_pte(ptep, mk_pte(virt_to_page(page), dvma_prot));