1 files changed, 98 insertions, 0 deletions
diff --git a/arch/s390/include/asm/facility.h b/arch/s390/include/asm/facility.h
new file mode 100644
index 000000000..7ffbc5d7c
--- /dev/null
+++ b/arch/s390/include/asm/facility.h
@@ -0,0 +1,98 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright IBM Corp. 1999, 2009
+ *
+ * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
+ */
+
+#ifndef __ASM_FACILITY_H
+#define __ASM_FACILITY_H
+
+#include <asm/facility-defs.h>
+#include <linux/string.h>
+#include <linux/preempt.h>
+#include <asm/lowcore.h>
+
+#define MAX_FACILITY_BIT (sizeof(((struct lowcore *)0)->stfle_fac_list) * 8)
+
+static inline void __set_facility(unsigned long nr, void *facilities)
+{
+	unsigned char *ptr = (unsigned char *) facilities;
+
+	if (nr >= MAX_FACILITY_BIT)
+		return;
+	ptr[nr >> 3] |= 0x80 >> (nr & 7);
+}
+
+static inline void __clear_facility(unsigned long nr, void *facilities)
+{
+	unsigned char *ptr = (unsigned char *) facilities;
+
+	if (nr >= MAX_FACILITY_BIT)
+		return;
+	ptr[nr >> 3] &= ~(0x80 >> (nr & 7));
+}
+
+static inline int __test_facility(unsigned long nr, void *facilities)
+{
+	unsigned char *ptr;
+
+	if (nr >= MAX_FACILITY_BIT)
+		return 0;
+	ptr = (unsigned char *) facilities + (nr >> 3);
+	return (*ptr & (0x80 >> (nr & 7))) != 0;
+}
+
+/*
+ * 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)
+{
+	unsigned long facilities_als[] = { FACILITIES_ALS };
+
+	if (__builtin_constant_p(nr) && nr < sizeof(facilities_als) * 8) {
+		if (__test_facility(nr, &facilities_als))
+			return 1;
+	}
+	return __test_facility(nr, &S390_lowcore.stfle_fac_list);
+}
+
+static inline unsigned long __stfle_asm(u64 *stfle_fac_list, int size)
+{
+	register unsigned long reg0 asm("0") = size - 1;
+
+	asm volatile(
+		".insn s,0xb2b00000,0(%1)" /* stfle */
+		: "+d" (reg0)
+		: "a" (stfle_fac_list)
+		: "memory", "cc");
+	return reg0;
+}
+
+/**
+ * stfle - Store facility list extended
+ * @stfle_fac_list: array where facility list can be stored
+ * @size: size of passed in array in double words
+ */
+static inline void stfle(u64 *stfle_fac_list, int size)
+{
+	unsigned long nr;
+
+	preempt_disable();
+	asm volatile(
+		"	stfl	0(0)\n"
+		: "=m" (S390_lowcore.stfl_fac_list));
+	nr = 4; /* bytes stored by stfl */
+	memcpy(stfle_fac_list, &S390_lowcore.stfl_fac_list, 4);
+	if (S390_lowcore.stfl_fac_list & 0x01000000) {
+		/* More facility bits available with stfle */
+		nr = __stfle_asm(stfle_fac_list, size);
+		nr = min_t(unsigned long, (nr + 1) * 8, size * 8);
+	}
+	memset((char *) stfle_fac_list + nr, 0, size * 8 - nr);
+	preempt_enable();
+}
+
+#endif /* __ASM_FACILITY_H */