xref: /openbmc/linux/arch/riscv/include/asm/hwcap.h (revision ef97e774)
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 
46 #define RISCV_ISA_EXT_MAX		64
47 #define RISCV_ISA_EXT_NAME_LEN_MAX	32
48 
49 #ifndef __ASSEMBLY__
50 
51 #include <linux/jump_label.h>
52 
53 struct riscv_isa_ext_data {
54 	/* Name of the extension displayed to userspace via /proc/cpuinfo */
55 	char uprop[RISCV_ISA_EXT_NAME_LEN_MAX];
56 	/* The logical ISA extension ID */
57 	unsigned int isa_ext_id;
58 };
59 
60 unsigned long riscv_isa_extension_base(const unsigned long *isa_bitmap);
61 
62 #define riscv_isa_extension_mask(ext) BIT_MASK(RISCV_ISA_EXT_##ext)
63 
64 bool __riscv_isa_extension_available(const unsigned long *isa_bitmap, int bit);
65 #define riscv_isa_extension_available(isa_bitmap, ext)	\
66 	__riscv_isa_extension_available(isa_bitmap, RISCV_ISA_EXT_##ext)
67 
68 static __always_inline bool
69 riscv_has_extension_likely(const unsigned long ext)
70 {
71 	compiletime_assert(ext < RISCV_ISA_EXT_MAX,
72 			   "ext must be < RISCV_ISA_EXT_MAX");
73 
74 	if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE)) {
75 		asm_volatile_goto(
76 		ALTERNATIVE("j	%l[l_no]", "nop", 0, %[ext], 1)
77 		:
78 		: [ext] "i" (ext)
79 		:
80 		: l_no);
81 	} else {
82 		if (!__riscv_isa_extension_available(NULL, ext))
83 			goto l_no;
84 	}
85 
86 	return true;
87 l_no:
88 	return false;
89 }
90 
91 static __always_inline bool
92 riscv_has_extension_unlikely(const unsigned long ext)
93 {
94 	compiletime_assert(ext < RISCV_ISA_EXT_MAX,
95 			   "ext must be < RISCV_ISA_EXT_MAX");
96 
97 	if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE)) {
98 		asm_volatile_goto(
99 		ALTERNATIVE("nop", "j	%l[l_yes]", 0, %[ext], 1)
100 		:
101 		: [ext] "i" (ext)
102 		:
103 		: l_yes);
104 	} else {
105 		if (__riscv_isa_extension_available(NULL, ext))
106 			goto l_yes;
107 	}
108 
109 	return false;
110 l_yes:
111 	return true;
112 }
113 
114 #endif
115 
116 #endif /* _ASM_RISCV_HWCAP_H */
117