1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Copyright IBM Corp. 1999, 2009
4 *
5 * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
6 */
7
8#ifndef __ASM_FACILITY_H
9#define __ASM_FACILITY_H
10
11#include <asm/facility-defs.h>
12#include <linux/string.h>
13#include <linux/preempt.h>
14#include <asm/lowcore.h>
15
16#define MAX_FACILITY_BIT (sizeof(((struct lowcore *)0)->stfle_fac_list) * 8)
17
18static inline void __set_facility(unsigned long nr, void *facilities)
19{
20	unsigned char *ptr = (unsigned char *) facilities;
21
22	if (nr >= MAX_FACILITY_BIT)
23		return;
24	ptr[nr >> 3] |= 0x80 >> (nr & 7);
25}
26
27static inline void __clear_facility(unsigned long nr, void *facilities)
28{
29	unsigned char *ptr = (unsigned char *) facilities;
30
31	if (nr >= MAX_FACILITY_BIT)
32		return;
33	ptr[nr >> 3] &= ~(0x80 >> (nr & 7));
34}
35
36static inline int __test_facility(unsigned long nr, void *facilities)
37{
38	unsigned char *ptr;
39
40	if (nr >= MAX_FACILITY_BIT)
41		return 0;
42	ptr = (unsigned char *) facilities + (nr >> 3);
43	return (*ptr & (0x80 >> (nr & 7))) != 0;
44}
45
46/*
47 * The test_facility function uses the bit odering where the MSB is bit 0.
48 * That makes it easier to query facility bits with the bit number as
49 * documented in the Principles of Operation.
50 */
51static inline int test_facility(unsigned long nr)
52{
53	unsigned long facilities_als[] = { FACILITIES_ALS };
54
55	if (__builtin_constant_p(nr) && nr < sizeof(facilities_als) * 8) {
56		if (__test_facility(nr, &facilities_als))
57			return 1;
58	}
59	return __test_facility(nr, &S390_lowcore.stfle_fac_list);
60}
61
62static inline unsigned long __stfle_asm(u64 *stfle_fac_list, int size)
63{
64	register unsigned long reg0 asm("0") = size - 1;
65
66	asm volatile(
67		".insn s,0xb2b00000,0(%1)" /* stfle */
68		: "+d" (reg0)
69		: "a" (stfle_fac_list)
70		: "memory", "cc");
71	return reg0;
72}
73
74/**
75 * stfle - Store facility list extended
76 * @stfle_fac_list: array where facility list can be stored
77 * @size: size of passed in array in double words
78 */
79static inline void __stfle(u64 *stfle_fac_list, int size)
80{
81	unsigned long nr;
82
83	asm volatile(
84		"	stfl	0(0)\n"
85		: "=m" (S390_lowcore.stfl_fac_list));
86	nr = 4; /* bytes stored by stfl */
87	memcpy(stfle_fac_list, &S390_lowcore.stfl_fac_list, 4);
88	if (S390_lowcore.stfl_fac_list & 0x01000000) {
89		/* More facility bits available with stfle */
90		nr = __stfle_asm(stfle_fac_list, size);
91		nr = min_t(unsigned long, (nr + 1) * 8, size * 8);
92	}
93	memset((char *) stfle_fac_list + nr, 0, size * 8 - nr);
94}
95
96static inline void stfle(u64 *stfle_fac_list, int size)
97{
98	preempt_disable();
99	__stfle(stfle_fac_list, size);
100	preempt_enable();
101}
102
103#endif /* __ASM_FACILITY_H */
104