xref: /linux/arch/riscv/include/asm/cpufeature.h (revision 09b1704f5b02c18dd02b21343530463fcfc92c54)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Copyright 2022-2024 Rivos, Inc
4  */
5 
6 #ifndef _ASM_CPUFEATURE_H
7 #define _ASM_CPUFEATURE_H
8 
9 #include <linux/bitmap.h>
10 #include <linux/jump_label.h>
11 #include <linux/workqueue.h>
12 #include <linux/kconfig.h>
13 #include <linux/percpu-defs.h>
14 #include <linux/threads.h>
15 #include <asm/hwcap.h>
16 #include <asm/cpufeature-macros.h>
17 
18 /*
19  * These are probed via a device_initcall(), via either the SBI or directly
20  * from the corresponding CSRs.
21  */
22 struct riscv_cpuinfo {
23 	unsigned long mvendorid;
24 	unsigned long marchid;
25 	unsigned long mimpid;
26 };
27 
28 struct riscv_isainfo {
29 	DECLARE_BITMAP(isa, RISCV_ISA_EXT_MAX);
30 };
31 
32 DECLARE_PER_CPU(struct riscv_cpuinfo, riscv_cpuinfo);
33 
34 extern const struct seq_operations cpuinfo_op;
35 
36 /* Per-cpu ISA extensions. */
37 extern struct riscv_isainfo hart_isa[NR_CPUS];
38 
39 extern u32 thead_vlenb_of;
40 
41 void __init riscv_user_isa_enable(void);
42 
43 #define _RISCV_ISA_EXT_DATA(_name, _id, _subset_exts, _subset_exts_size, _validate) {	\
44 	.name = #_name,									\
45 	.property = #_name,								\
46 	.id = _id,									\
47 	.subset_ext_ids = _subset_exts,							\
48 	.subset_ext_size = _subset_exts_size,						\
49 	.validate = _validate								\
50 }
51 
52 #define __RISCV_ISA_EXT_DATA(_name, _id) _RISCV_ISA_EXT_DATA(_name, _id, NULL, 0, NULL)
53 
54 #define __RISCV_ISA_EXT_DATA_VALIDATE(_name, _id, _validate) \
55 			_RISCV_ISA_EXT_DATA(_name, _id, NULL, 0, _validate)
56 
57 /* Used to declare pure "lasso" extension (Zk for instance) */
58 #define __RISCV_ISA_EXT_BUNDLE(_name, _bundled_exts) \
59 	_RISCV_ISA_EXT_DATA(_name, RISCV_ISA_EXT_INVALID, _bundled_exts, \
60 			    ARRAY_SIZE(_bundled_exts), NULL)
61 #define __RISCV_ISA_EXT_BUNDLE_VALIDATE(_name, _bundled_exts, _validate) \
62 	_RISCV_ISA_EXT_DATA(_name, RISCV_ISA_EXT_INVALID, _bundled_exts, \
63 			    ARRAY_SIZE(_bundled_exts), _validate)
64 
65 /* Used to declare extensions that are a superset of other extensions (Zvbb for instance) */
66 #define __RISCV_ISA_EXT_SUPERSET(_name, _id, _sub_exts) \
67 	_RISCV_ISA_EXT_DATA(_name, _id, _sub_exts, ARRAY_SIZE(_sub_exts), NULL)
68 #define __RISCV_ISA_EXT_SUPERSET_VALIDATE(_name, _id, _sub_exts, _validate) \
69 	_RISCV_ISA_EXT_DATA(_name, _id, _sub_exts, ARRAY_SIZE(_sub_exts), _validate)
70 
71 bool __init check_unaligned_access_emulated_all_cpus(void);
72 void unaligned_access_init(void);
73 int cpu_online_unaligned_access_init(unsigned int cpu);
74 #if defined(CONFIG_RISCV_SCALAR_MISALIGNED)
75 void unaligned_emulation_finish(void);
76 bool unaligned_ctl_available(void);
77 #else
78 static inline bool unaligned_ctl_available(void)
79 {
80 	return false;
81 }
82 #endif
83 
84 #if defined(CONFIG_RISCV_MISALIGNED)
85 DECLARE_PER_CPU(long, misaligned_access_speed);
86 bool misaligned_traps_can_delegate(void);
87 #else
88 static inline bool misaligned_traps_can_delegate(void)
89 {
90 	return false;
91 }
92 #endif
93 
94 bool __init check_vector_unaligned_access_emulated_all_cpus(void);
95 #if defined(CONFIG_RISCV_VECTOR_MISALIGNED)
96 void check_vector_unaligned_access_emulated(struct work_struct *work __always_unused);
97 DECLARE_PER_CPU(long, vector_misaligned_access);
98 #endif
99 
100 #if defined(CONFIG_RISCV_PROBE_UNALIGNED_ACCESS)
101 DECLARE_STATIC_KEY_FALSE(fast_unaligned_access_speed_key);
102 
103 static __always_inline bool has_fast_unaligned_accesses(void)
104 {
105 	return static_branch_likely(&fast_unaligned_access_speed_key);
106 }
107 #else
108 static __always_inline bool has_fast_unaligned_accesses(void)
109 {
110 	if (IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS))
111 		return true;
112 	else
113 		return false;
114 }
115 #endif
116 
117 unsigned long riscv_get_elf_hwcap(void);
118 
119 struct riscv_isa_ext_data {
120 	const unsigned int id;
121 	const char *name;
122 	const char *property;
123 	const unsigned int *subset_ext_ids;
124 	const unsigned int subset_ext_size;
125 	int (*validate)(const struct riscv_isa_ext_data *data, const unsigned long *isa_bitmap);
126 };
127 
128 extern const struct riscv_isa_ext_data riscv_isa_ext[];
129 extern const size_t riscv_isa_ext_count;
130 extern bool riscv_isa_fallback;
131 
132 unsigned long riscv_isa_extension_base(const unsigned long *isa_bitmap);
133 static __always_inline bool riscv_cpu_has_extension_likely(int cpu, const unsigned long ext)
134 {
135 	compiletime_assert(ext < RISCV_ISA_EXT_MAX, "ext must be < RISCV_ISA_EXT_MAX");
136 
137 	if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE) &&
138 	    __riscv_has_extension_likely(STANDARD_EXT, ext))
139 		return true;
140 
141 	return __riscv_isa_extension_available(hart_isa[cpu].isa, ext);
142 }
143 
144 static __always_inline bool riscv_cpu_has_extension_unlikely(int cpu, const unsigned long ext)
145 {
146 	compiletime_assert(ext < RISCV_ISA_EXT_MAX, "ext must be < RISCV_ISA_EXT_MAX");
147 
148 	if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE) &&
149 	    __riscv_has_extension_unlikely(STANDARD_EXT, ext))
150 		return true;
151 
152 	return __riscv_isa_extension_available(hart_isa[cpu].isa, ext);
153 }
154 
155 #endif
156