s390/pgtable: introduce and use generic csp inline asm

We have already two inline assemblies which make use of the csp
instruction. Since I need a third instance let's introduce a generic
inline assmebly which can be used by everyone.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
index 18d2beb..58e9950 100644
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -424,6 +424,19 @@
 	return 0;
 }
 
+static inline void csp(unsigned int *ptr, unsigned int old, unsigned int new)
+{
+	register unsigned long reg2 asm("2") = old;
+	register unsigned long reg3 asm("3") = new;
+	unsigned long address = (unsigned long)ptr | 1;
+
+	asm volatile(
+		"	csp	%0,%3"
+		: "+d" (reg2), "+m" (*ptr)
+		: "d" (reg3), "d" (address)
+		: "cc");
+}
+
 /*
  * pgd/pmd/pte query functions
  */
@@ -1068,15 +1081,8 @@
 
 static inline void __pmdp_csp(pmd_t *pmdp)
 {
-	register unsigned long reg2 asm("2") = pmd_val(*pmdp);
-	register unsigned long reg3 asm("3") = pmd_val(*pmdp) |
-					       _SEGMENT_ENTRY_INVALID;
-	register unsigned long reg4 asm("4") = ((unsigned long) pmdp) + 5;
-
-	asm volatile(
-		"	csp %1,%3"
-		: "=m" (*pmdp)
-		: "d" (reg2), "d" (reg3), "d" (reg4), "m" (*pmdp) : "cc");
+	csp((unsigned int *)pmdp + 1, pmd_val(*pmdp),
+	    pmd_val(*pmdp) | _SEGMENT_ENTRY_INVALID);
 }
 
 static inline void __pmdp_idte(unsigned long address, pmd_t *pmdp)