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
13#include <linux/minmax.h>
14#include <linux/string.h>
15#include <linux/types.h>
16#include <linux/preempt.h>
17
18#include <asm/lowcore.h>
19
20#define MAX_FACILITY_BIT (sizeof(stfle_fac_list) * 8)
21
22extern u64 stfle_fac_list[16];
23extern u64 alt_stfle_fac_list[16];
24
25static inline void __set_facility(unsigned long nr, void *facilities)
26{
27	unsigned char *ptr = (unsigned char *) facilities;
28
29	if (nr >= MAX_FACILITY_BIT)
30		return;
31	ptr[nr >> 3] |= 0x80 >> (nr & 7);
32}
33
34static inline void __clear_facility(unsigned long nr, void *facilities)
35{
36	unsigned char *ptr = (unsigned char *) facilities;
37
38	if (nr >= MAX_FACILITY_BIT)
39		return;
40	ptr[nr >> 3] &= ~(0x80 >> (nr & 7));
41}
42
43static inline int __test_facility(unsigned long nr, void *facilities)
44{
45	unsigned char *ptr;
46
47	if (nr >= MAX_FACILITY_BIT)
48		return 0;
49	ptr = (unsigned char *) facilities + (nr >> 3);
50	return (*ptr & (0x80 >> (nr & 7))) != 0;
51}
52
53/*
54 * The test_facility function uses the bit ordering where the MSB is bit 0.
55 * That makes it easier to query facility bits with the bit number as
56 * documented in the Principles of Operation.
57 */
58static inline int test_facility(unsigned long nr)
59{
60	unsigned long facilities_als[] = { FACILITIES_ALS };
61
62	if (__builtin_constant_p(nr) && nr < sizeof(facilities_als) * 8) {
63		if (__test_facility(nr, &facilities_als))
64			return 1;
65	}
66	return __test_facility(nr, &stfle_fac_list);
67}
68
69static inline unsigned long __stfle_asm(u64 *stfle_fac_list, int size)
70{
71	unsigned long reg0 = size - 1;
72
73	asm volatile(
74		"	lgr	0,%[reg0]\n"
75		"	.insn	s,0xb2b00000,%[list]\n" /* stfle */
76		"	lgr	%[reg0],0\n"
77		: [reg0] "+&d" (reg0), [list] "+Q" (*stfle_fac_list)
78		:
79		: "memory", "cc", "0");
80	return reg0;
81}
82
83/**
84 * stfle - Store facility list extended
85 * @stfle_fac_list: array where facility list can be stored
86 * @size: size of passed in array in double words
87 */
88static inline void __stfle(u64 *stfle_fac_list, int size)
89{
90	unsigned long nr;
91	u32 stfl_fac_list;
92
93	asm volatile(
94		"	stfl	0(0)\n"
95		: "=m" (S390_lowcore.stfl_fac_list));
96	stfl_fac_list = S390_lowcore.stfl_fac_list;
97	memcpy(stfle_fac_list, &stfl_fac_list, 4);
98	nr = 4; /* bytes stored by stfl */
99	if (stfl_fac_list & 0x01000000) {
100		/* More facility bits available with stfle */
101		nr = __stfle_asm(stfle_fac_list, size);
102		nr = min_t(unsigned long, (nr + 1) * 8, size * 8);
103	}
104	memset((char *) stfle_fac_list + nr, 0, size * 8 - nr);
105}
106
107static inline void stfle(u64 *stfle_fac_list, int size)
108{
109	preempt_disable();
110	__stfle(stfle_fac_list, size);
111	preempt_enable();
112}
113
114/**
115 * stfle_size - Actual size of the facility list as specified by stfle
116 * (number of double words)
117 */
118unsigned int stfle_size(void);
119
120#endif /* __ASM_FACILITY_H */
121