[S390] cleanup facility list handling
Store the facility list once at system startup with stfl/stfle and
reuse the result for all facility tests.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/include/asm/system.h b/arch/s390/include/asm/system.h
index 3c079dd..3ad16db 100644
--- a/arch/s390/include/asm/system.h
+++ b/arch/s390/include/asm/system.h
@@ -420,30 +420,21 @@
#endif /* CONFIG_SMP */
-static inline unsigned int stfl(void)
-{
- asm volatile(
- " .insn s,0xb2b10000,0(0)\n" /* stfl */
- "0:\n"
- EX_TABLE(0b,0b));
- return S390_lowcore.stfl_fac_list;
-}
+#define MAX_FACILITY_BIT (256*8) /* stfle_fac_list has 256 bytes */
-static inline int __stfle(unsigned long long *list, int doublewords)
+/*
+ * The test_facility function uses the bit odering where the MSB is bit 0.
+ * That makes it easier to query facility bits with the bit number as
+ * documented in the Principles of Operation.
+ */
+static inline int test_facility(unsigned long nr)
{
- typedef struct { unsigned long long _[doublewords]; } addrtype;
- register unsigned long __nr asm("0") = doublewords - 1;
+ unsigned char *ptr;
- asm volatile(".insn s,0xb2b00000,%0" /* stfle */
- : "=m" (*(addrtype *) list), "+d" (__nr) : : "cc");
- return __nr + 1;
-}
-
-static inline int stfle(unsigned long long *list, int doublewords)
-{
- if (!(stfl() & (1UL << 24)))
- return -EOPNOTSUPP;
- return __stfle(list, doublewords);
+ if (nr >= MAX_FACILITY_BIT)
+ return 0;
+ ptr = (unsigned char *) &S390_lowcore.stfle_fac_list + (nr >> 3);
+ return (*ptr & (0x80 >> (nr & 7))) != 0;
}
static inline unsigned short stap(void)