[S390] add support for nonquiescing sske

Improve performance of the sske operation by using the nonquiescing
variant if the affected page has no mappings established. On machines
with no support for the new sske variant the mask bit will be ignored.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 6 insertions, 2 deletions

diff --git a/arch/s390/include/asm/page.h b/arch/s390/include/asm/page.h
index af650fb47206..a8729ea7e9ac 100644
--- a/arch/s390/include/asm/page.h
+++ b/arch/s390/include/asm/page.h
@@ -108,9 +108,13 @@ typedef pte_t *pgtable_t;
 #define __pgprot(x)     ((pgprot_t) { (x) } )
 
 static inline void
-page_set_storage_key(unsigned long addr, unsigned int skey)
+page_set_storage_key(unsigned long addr, unsigned int skey, int mapped)
 {
-        asm volatile("sske %0,%1" : : "d" (skey), "a" (addr));
+        if (!mapped)
+                asm volatile(".insn rrf,0xb22b0000,%0,%1,8,0"
+                             : : "d" (skey), "a" (addr));
+        else
+                asm volatile("sske %0,%1" : : "d" (skey), "a" (addr));
 }
 
 static inline unsigned int