Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull s390 updates from Martin Schwidefsky:
 "The new features and main improvements in this merge for v4.9

   - Support for the UBSAN sanitizer

   - Set HAVE_EFFICIENT_UNALIGNED_ACCESS, it improves the code in some
     places

   - Improvements for the in-kernel fpu code, in particular the overhead
     for multiple consecutive in kernel fpu users is recuded

   - Add a SIMD implementation for the RAID6 gen and xor operations

   - Add RAID6 recovery based on the XC instruction

   - The PCI DMA flush logic has been improved to increase the speed of
     the map / unmap operations

   - The time synchronization code has seen some updates

  And bug fixes all over the place"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (48 commits)
  s390/con3270: fix insufficient space padding
  s390/con3270: fix use of uninitialised data
  MAINTAINERS: update DASD maintainer
  s390/cio: fix accidental interrupt enabling during resume
  s390/dasd: add missing \n to end of dev_err messages
  s390/config: Enable config options for Docker
  s390/dasd: make query host access interruptible
  s390/dasd: fix panic during offline processing
  s390/dasd: fix hanging offline processing
  s390/pci_dma: improve lazy flush for unmap
  s390/pci_dma: split dma_update_trans
  s390/pci_dma: improve map_sg
  s390/pci_dma: simplify dma address calculation
  s390/pci_dma: remove dma address range check
  iommu/s390: simplify registration of I/O address translation parameters
  s390: migrate exception table users off module.h and onto extable.h
  s390: export header for CLP ioctl
  s390/vmur: fix irq pointer dereference in int handler
  s390/dasd: add missing KOBJ_CHANGE event for unformatted devices
  s390: enable UBSAN
  ...

1 files changed, 15 insertions, 0 deletions

diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c
index 2ce6bb3bab32..3ba622702ce4 100644
--- a/arch/s390/mm/gmap.c
+++ b/arch/s390/mm/gmap.c
@@ -94,6 +94,7 @@ out:
 struct gmap *gmap_create(struct mm_struct *mm, unsigned long limit)
 {
 	struct gmap *gmap;
+	unsigned long gmap_asce;
 
 	gmap = gmap_alloc(limit);
 	if (!gmap)
@@ -101,6 +102,11 @@ struct gmap *gmap_create(struct mm_struct *mm, unsigned long limit)
 	gmap->mm = mm;
 	spin_lock(&mm->context.gmap_lock);
 	list_add_rcu(&gmap->list, &mm->context.gmap_list);
+	if (list_is_singular(&mm->context.gmap_list))
+		gmap_asce = gmap->asce;
+	else
+		gmap_asce = -1UL;
+	WRITE_ONCE(mm->context.gmap_asce, gmap_asce);
 	spin_unlock(&mm->context.gmap_lock);
 	return gmap;
 }
@@ -230,6 +236,7 @@ EXPORT_SYMBOL_GPL(gmap_put);
 void gmap_remove(struct gmap *gmap)
 {
 	struct gmap *sg, *next;
+	unsigned long gmap_asce;
 
 	/* Remove all shadow gmaps linked to this gmap */
 	if (!list_empty(&gmap->children)) {
@@ -243,6 +250,14 @@ void gmap_remove(struct gmap *gmap)
 	/* Remove gmap from the pre-mm list */
 	spin_lock(&gmap->mm->context.gmap_lock);
 	list_del_rcu(&gmap->list);
+	if (list_empty(&gmap->mm->context.gmap_list))
+		gmap_asce = 0;
+	else if (list_is_singular(&gmap->mm->context.gmap_list))
+		gmap_asce = list_first_entry(&gmap->mm->context.gmap_list,
+					     struct gmap, list)->asce;
+	else
+		gmap_asce = -1UL;
+	WRITE_ONCE(gmap->mm->context.gmap_asce, gmap_asce);
 	spin_unlock(&gmap->mm->context.gmap_lock);
 	synchronize_rcu();
 	/* Put reference */