xref: /openbmc/linux/arch/riscv/include/asm/hwcap.h (revision 709f34b4)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Copied from arch/arm64/include/asm/hwcap.h
4  *
5  * Copyright (C) 2012 ARM Ltd.
6  * Copyright (C) 2017 SiFive
7  */
8 #ifndef _ASM_RISCV_HWCAP_H
9 #define _ASM_RISCV_HWCAP_H
10 
11 #include <asm/alternative-macros.h>
12 #include <asm/errno.h>
13 #include <linux/bits.h>
14 #include <uapi/asm/hwcap.h>
15 
16 #define RISCV_ISA_EXT_a		('a' - 'a')
17 #define RISCV_ISA_EXT_c		('c' - 'a')
18 #define RISCV_ISA_EXT_d		('d' - 'a')
19 #define RISCV_ISA_EXT_f		('f' - 'a')
20 #define RISCV_ISA_EXT_h		('h' - 'a')
21 #define RISCV_ISA_EXT_i		('i' - 'a')
22 #define RISCV_ISA_EXT_m		('m' - 'a')
23 #define RISCV_ISA_EXT_s		('s' - 'a')
24 #define RISCV_ISA_EXT_u		('u' - 'a')
25 
26 /*
27  * These macros represent the logical IDs of each multi-letter RISC-V ISA
28  * extension and are used in the ISA bitmap. The logical IDs start from
29  * RISCV_ISA_EXT_BASE, which allows the 0-25 range to be reserved for single
30  * letter extensions. The maximum, RISCV_ISA_EXT_MAX, is defined in order
31  * to allocate the bitmap and may be increased when necessary.
32  *
33  * New extensions should just be added to the bottom, rather than added
34  * alphabetically, in order to avoid unnecessary shuffling.
35  */
36 #define RISCV_ISA_EXT_BASE		26
37 
38 #define RISCV_ISA_EXT_SSCOFPMF		26
39 #define RISCV_ISA_EXT_SSTC		27
40 #define RISCV_ISA_EXT_SVINVAL		28
41 #define RISCV_ISA_EXT_SVPBMT		29
42 #define RISCV_ISA_EXT_ZBB		30
43 #define RISCV_ISA_EXT_ZICBOM		31
44 #define RISCV_ISA_EXT_ZIHINTPAUSE	32
45 #define RISCV_ISA_EXT_SVNAPOT		33
46 #define RISCV_ISA_EXT_ZICBOZ		34
47 #define RISCV_ISA_EXT_SMAIA		35
48 #define RISCV_ISA_EXT_SSAIA		36
49 
50 #define RISCV_ISA_EXT_MAX		64
51 #define RISCV_ISA_EXT_NAME_LEN_MAX	32
52 
53 #ifdef CONFIG_RISCV_M_MODE
54 #define RISCV_ISA_EXT_SxAIA		RISCV_ISA_EXT_SMAIA
55 #else
56 #define RISCV_ISA_EXT_SxAIA		RISCV_ISA_EXT_SSAIA
57 #endif
58 
59 #ifndef __ASSEMBLY__
60 
61 #include <linux/jump_label.h>
62 
63 struct riscv_isa_ext_data {
64 	/* Name of the extension displayed to userspace via /proc/cpuinfo */
65 	char uprop[RISCV_ISA_EXT_NAME_LEN_MAX];
66 	/* The logical ISA extension ID */
67 	unsigned int isa_ext_id;
68 };
69 
70 unsigned long riscv_isa_extension_base(const unsigned long *isa_bitmap);
71 
72 #define riscv_isa_extension_mask(ext) BIT_MASK(RISCV_ISA_EXT_##ext)
73 
74 bool __riscv_isa_extension_available(const unsigned long *isa_bitmap, int bit);
75 #define riscv_isa_extension_available(isa_bitmap, ext)	\
76 	__riscv_isa_extension_available(isa_bitmap, RISCV_ISA_EXT_##ext)
77 
78 static __always_inline bool
79 riscv_has_extension_likely(const unsigned long ext)
80 {
81 	compiletime_assert(ext < RISCV_ISA_EXT_MAX,
82 			   "ext must be < RISCV_ISA_EXT_MAX");
83 
84 	if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE)) {
85 		asm_volatile_goto(
86 		ALTERNATIVE("j	%l[l_no]", "nop", 0, %[ext], 1)
87 		:
88 		: [ext] "i" (ext)
89 		:
90 		: l_no);
91 	} else {
92 		if (!__riscv_isa_extension_available(NULL, ext))
93 			goto l_no;
94 	}
95 
96 	return true;
97 l_no:
98 	return false;
99 }
100 
101 static __always_inline bool
102 riscv_has_extension_unlikely(const unsigned long ext)
103 {
104 	compiletime_assert(ext < RISCV_ISA_EXT_MAX,
105 			   "ext must be < RISCV_ISA_EXT_MAX");
106 
107 	if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE)) {
108 		asm_volatile_goto(
109 		ALTERNATIVE("nop", "j	%l[l_yes]", 0, %[ext], 1)
110 		:
111 		: [ext] "i" (ext)
112 		:
113 		: l_yes);
114 	} else {
115 		if (__riscv_isa_extension_available(NULL, ext))
116 			goto l_yes;
117 	}
118 
119 	return false;
120 l_yes:
121 	return true;
122 }
123 
124 #endif
125 
126 #endif /* _ASM_RISCV_HWCAP_H */
127