xref: /linux/tools/testing/selftests/kvm/include/s390x/facility.h (revision 7f71507851fc7764b36a3221839607d3a45c2025)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Copyright IBM Corp. 2024
4  *
5  * Authors:
6  *  Hariharan Mari <hari55@linux.ibm.com>
7  *
8  * Get the facility bits with the STFLE instruction
9  */
10 
11 #ifndef SELFTEST_KVM_FACILITY_H
12 #define SELFTEST_KVM_FACILITY_H
13 
14 #include <linux/bitops.h>
15 
16 /* alt_stfle_fac_list[16] + stfle_fac_list[16] */
17 #define NB_STFL_DOUBLEWORDS 32
18 
19 extern uint64_t stfl_doublewords[NB_STFL_DOUBLEWORDS];
20 extern bool stfle_flag;
21 
22 static inline bool test_bit_inv(unsigned long nr, const unsigned long *ptr)
23 {
24 	return test_bit(nr ^ (BITS_PER_LONG - 1), ptr);
25 }
26 
27 static inline void stfle(uint64_t *fac, unsigned int nb_doublewords)
28 {
29 	register unsigned long r0 asm("0") = nb_doublewords - 1;
30 
31 	asm volatile("	.insn	s,0xb2b00000,0(%1)\n"
32 			: "+d" (r0)
33 			: "a" (fac)
34 			: "memory", "cc");
35 }
36 
37 static inline void setup_facilities(void)
38 {
39 	stfle(stfl_doublewords, NB_STFL_DOUBLEWORDS);
40 	stfle_flag = true;
41 }
42 
43 static inline bool test_facility(int nr)
44 {
45 	if (!stfle_flag)
46 		setup_facilities();
47 	return test_bit_inv(nr, stfl_doublewords);
48 }
49 
50 #endif
51