[S390] pm: add kernel_page_present

Fix the following build failure caused by make allyesconfig using
CONFIG_HIBERNATION and CONFIG_DEBUG_PAGEALLOC

kernel/built-in.o: In function `saveable_page':
kernel/power/snapshot.c:897: undefined reference to `kernel_page_present'
kernel/built-in.o: In function `safe_copy_page':
kernel/power/snapshot.c:948: undefined reference to `kernel_page_present'
make: *** [.tmp_vmlinux1] Error 1

Signed-off-by: Hans-Joachim Picht <hans@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 19 insertions, 0 deletions

diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c
index 4ca8e826bf30..565667207985 100644
--- a/arch/s390/mm/pgtable.c
+++ b/arch/s390/mm/pgtable.c
@@ -313,3 +313,22 @@ int s390_enable_sie(void)
         return 0;
 }
 EXPORT_SYMBOL_GPL(s390_enable_sie);
+
+#ifdef CONFIG_DEBUG_PAGEALLOC
+#ifdef CONFIG_HIBERNATION
+bool kernel_page_present(struct page *page)
+{
+        unsigned long addr;
+        int cc;
+
+        addr = page_to_phys(page);
+        asm("lra %1,0(%1)\n"
+            "ipm %0\n"
+            "srl %0,28"
+            :"=d"(cc),"+a"(addr)::"cc");
+        return cc == 0;
+}
+
+#endif /* CONFIG_HIBERNATION */
+#endif /* CONFIG_DEBUG_PAGEALLOC */
+