Merge tag 's390-5.9-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull more s390 updates from Heiko Carstens:

 - Allow s390 debug feature to handle finally more than 256 CPU numbers,
   instead of truncating the most significant bits.

 - Improve THP splitting required by qemu processes by making use of
   walk_page_vma() instead of calling follow_page() for every single
   page within each vma.

 - Add missing ZCRYPT dependency to VFIO_AP to fix potential compile
   problems.

 - Remove not required select CLOCKSOURCE_VALIDATE_LAST_CYCLE again.

 - Set node distance to LOCAL_DISTANCE instead of 0, since e.g. libnuma
   translates a node distance of 0 to "no NUMA support available".

 - Couple of other minor fixes and improvements.

* tag 's390-5.9-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/numa: move code to arch/s390/kernel
  s390/time: remove select CLOCKSOURCE_VALIDATE_LAST_CYCLE again
  s390/debug: debug feature version 3
  s390/Kconfig: add missing ZCRYPT dependency to VFIO_AP
  s390/numa: set node distance to LOCAL_DISTANCE
  s390/pkey: remove redundant variable initialization
  s390/test_unwind: fix possible memleak in test_unwind()
  s390/gmap: improve THP splitting
  s390/atomic: circumvent gcc 10 build regression

1 files changed, 20 insertions, 7 deletions

diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c
index 8747487c50a8..373542ca1113 100644
--- a/arch/s390/mm/gmap.c
+++ b/arch/s390/mm/gmap.c
@@ -2485,23 +2485,36 @@ void gmap_sync_dirty_log_pmd(struct gmap *gmap, unsigned long bitmap[4],
 }
 EXPORT_SYMBOL_GPL(gmap_sync_dirty_log_pmd);
 
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+static int thp_split_walk_pmd_entry(pmd_t *pmd, unsigned long addr,
+				    unsigned long end, struct mm_walk *walk)
+{
+	struct vm_area_struct *vma = walk->vma;
+
+	split_huge_pmd(vma, pmd, addr);
+	return 0;
+}
+
+static const struct mm_walk_ops thp_split_walk_ops = {
+	.pmd_entry	= thp_split_walk_pmd_entry,
+};
+
 static inline void thp_split_mm(struct mm_struct *mm)
 {
-#ifdef CONFIG_TRANSPARENT_HUGEPAGE
 	struct vm_area_struct *vma;
-	unsigned long addr;
 
 	for (vma = mm->mmap; vma != NULL; vma = vma->vm_next) {
-		for (addr = vma->vm_start;
-		     addr < vma->vm_end;
-		     addr += PAGE_SIZE)
-			follow_page(vma, addr, FOLL_SPLIT);
 		vma->vm_flags &= ~VM_HUGEPAGE;
 		vma->vm_flags |= VM_NOHUGEPAGE;
+		walk_page_vma(vma, &thp_split_walk_ops, NULL);
 	}
 	mm->def_flags |= VM_NOHUGEPAGE;
-#endif
 }
+#else
+static inline void thp_split_mm(struct mm_struct *mm)
+{
+}
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 
 /*
  * Remove all empty zero pages from the mapping for lazy refaulting