xref: /linux/arch/s390/include/asm/facility.h (revision a9aaf1ff88a8cb99a1335c9eb76de637f0cf8c10)
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 
22 extern u64 stfle_fac_list[16];
23 
24 static inline void __set_facility(unsigned long nr, void *facilities)
25 {
26 	unsigned char *ptr = (unsigned char *) facilities;
27 
28 	if (nr >= MAX_FACILITY_BIT)
29 		return;
30 	ptr[nr >> 3] |= 0x80 >> (nr & 7);
31 }
32 
33 static inline void __clear_facility(unsigned long nr, void *facilities)
34 {
35 	unsigned char *ptr = (unsigned char *) facilities;
36 
37 	if (nr >= MAX_FACILITY_BIT)
38 		return;
39 	ptr[nr >> 3] &= ~(0x80 >> (nr & 7));
40 }
41 
42 static inline int __test_facility(unsigned long nr, void *facilities)
43 {
44 	unsigned char *ptr;
45 
46 	if (nr >= MAX_FACILITY_BIT)
47 		return 0;
48 	ptr = (unsigned char *) facilities + (nr >> 3);
49 	return (*ptr & (0x80 >> (nr & 7))) != 0;
50 }
51 
52 /*
53  * The test_facility function uses the bit ordering where the MSB is bit 0.
54  * That makes it easier to query facility bits with the bit number as
55  * documented in the Principles of Operation.
56  */
57 static inline int test_facility(unsigned long nr)
58 {
59 	unsigned long facilities_als[] = { FACILITIES_ALS };
60 
61 	if (__builtin_constant_p(nr) && nr < sizeof(facilities_als) * 8) {
62 		if (__test_facility(nr, &facilities_als))
63 			return 1;
64 	}
65 	return __test_facility(nr, &stfle_fac_list);
66 }
67 
68 static inline unsigned long __stfle_asm(u64 *stfle_fac_list, int size)
69 {
70 	unsigned long reg0 = size - 1;
71 
72 	asm volatile(
73 		"	lgr	0,%[reg0]\n"
74 		"	.insn	s,0xb2b00000,%[list]\n" /* stfle */
75 		"	lgr	%[reg0],0\n"
76 		: [reg0] "+&d" (reg0), [list] "+Q" (*stfle_fac_list)
77 		:
78 		: "memory", "cc", "0");
79 	return reg0;
80 }
81 
82 /**
83  * stfle - Store facility list extended
84  * @stfle_fac_list: array where facility list can be stored
85  * @size: size of passed in array in double words
86  */
87 static inline void __stfle(u64 *stfle_fac_list, int size)
88 {
89 	unsigned long nr;
90 	u32 stfl_fac_list;
91 
92 	asm volatile(
93 		"	stfl	0(0)\n"
94 		: "=m" (get_lowcore()->stfl_fac_list));
95 	stfl_fac_list = get_lowcore()->stfl_fac_list;
96 	memcpy(stfle_fac_list, &stfl_fac_list, 4);
97 	nr = 4; /* bytes stored by stfl */
98 	if (stfl_fac_list & 0x01000000) {
99 		/* More facility bits available with stfle */
100 		nr = __stfle_asm(stfle_fac_list, size);
101 		nr = min_t(unsigned long, (nr + 1) * 8, size * 8);
102 	}
103 	memset((char *) stfle_fac_list + nr, 0, size * 8 - nr);
104 }
105 
106 static inline void stfle(u64 *stfle_fac_list, int size)
107 {
108 	preempt_disable();
109 	__stfle(stfle_fac_list, size);
110 	preempt_enable();
111 }
112 
113 /**
114  * stfle_size - Actual size of the facility list as specified by stfle
115  * (number of double words)
116  */
117 unsigned int stfle_size(void);
118 
119 #endif /* __ASM_FACILITY_H */
120