Merge tag 'stable/for-linus-3.19-rc0b-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull additional xen update from David Vrabel:
 "Xen: additional features for 3.19-rc0

   - Linear p2m for x86 PV guests which simplifies the p2m code,
     improves performance and will allow for > 512 GB PV guests in the
     future.

  A last-minute, configuration specific issue was discovered with this
  change which is why it was not included in my previous pull request.
  This is now been fixed and tested"

* tag 'stable/for-linus-3.19-rc0b-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen: switch to post-init routines in xen mmu.c earlier
  Revert "swiotlb-xen: pass dev_addr to swiotlb_tbl_unmap_single"
  xen: annotate xen_set_identity_and_remap_chunk() with __init
  xen: introduce helper functions to do safe read and write accesses
  xen: Speed up set_phys_to_machine() by using read-only mappings
  xen: switch to linear virtual mapped sparse p2m list
  xen: Hide get_phys_to_machine() to be able to tune common path
  x86: Introduce function to get pmd entry pointer
  xen: Delay invalidating extra memory
  xen: Delay m2p_override initialization
  xen: Delay remapping memory of pv-domain
  xen: use common page allocation function in p2m.c
  xen: Make functions static
  xen: fix some style issues in p2m.c

1 files changed, 20 insertions, 0 deletions

diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index dfaf2e0f5f8f..536ea2fb6e33 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -384,6 +384,26 @@ static pte_t *_lookup_address_cpa(struct cpa_data *cpa, unsigned long address,
 }
 
 /*
+ * Lookup the PMD entry for a virtual address. Return a pointer to the entry
+ * or NULL if not present.
+ */
+pmd_t *lookup_pmd_address(unsigned long address)
+{
+	pgd_t *pgd;
+	pud_t *pud;
+
+	pgd = pgd_offset_k(address);
+	if (pgd_none(*pgd))
+		return NULL;
+
+	pud = pud_offset(pgd, address);
+	if (pud_none(*pud) || pud_large(*pud) || !pud_present(*pud))
+		return NULL;
+
+	return pmd_offset(pud, address);
+}
+
+/*
  * This is necessary because __pa() does not work on some
  * kinds of memory, like vmalloc() or the alloc_remap()
  * areas on 32-bit NUMA systems.  The percpu areas can