xref: /linux/arch/riscv/include/asm/cpufeature.h (revision ba6ec09911b805778a2fed6d626bfe77b011a717)
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 /* Per-cpu ISA extensions. */
35 extern struct riscv_isainfo hart_isa[NR_CPUS];
36 
37 extern u32 thead_vlenb_of;
38 
39 void __init riscv_user_isa_enable(void);
40 
41 #define _RISCV_ISA_EXT_DATA(_name, _id, _subset_exts, _subset_exts_size, _validate) {	\
42 	.name = #_name,									\
43 	.property = #_name,								\
44 	.id = _id,									\
45 	.subset_ext_ids = _subset_exts,							\
46 	.subset_ext_size = _subset_exts_size,						\
47 	.validate = _validate								\
48 }
49 
50 #define __RISCV_ISA_EXT_DATA(_name, _id) _RISCV_ISA_EXT_DATA(_name, _id, NULL, 0, NULL)
51 
52 #define __RISCV_ISA_EXT_DATA_VALIDATE(_name, _id, _validate) \
53 			_RISCV_ISA_EXT_DATA(_name, _id, NULL, 0, _validate)
54 
55 /* Used to declare pure "lasso" extension (Zk for instance) */
56 #define __RISCV_ISA_EXT_BUNDLE(_name, _bundled_exts) \
57 	_RISCV_ISA_EXT_DATA(_name, RISCV_ISA_EXT_INVALID, _bundled_exts, \
58 			    ARRAY_SIZE(_bundled_exts), NULL)
59 
60 /* Used to declare extensions that are a superset of other extensions (Zvbb for instance) */
61 #define __RISCV_ISA_EXT_SUPERSET(_name, _id, _sub_exts) \
62 	_RISCV_ISA_EXT_DATA(_name, _id, _sub_exts, ARRAY_SIZE(_sub_exts), NULL)
63 #define __RISCV_ISA_EXT_SUPERSET_VALIDATE(_name, _id, _sub_exts, _validate) \
64 	_RISCV_ISA_EXT_DATA(_name, _id, _sub_exts, ARRAY_SIZE(_sub_exts), _validate)
65 
66 bool check_unaligned_access_emulated_all_cpus(void);
67 #if defined(CONFIG_RISCV_SCALAR_MISALIGNED)
68 void check_unaligned_access_emulated(struct work_struct *work __always_unused);
69 void unaligned_emulation_finish(void);
70 bool unaligned_ctl_available(void);
71 DECLARE_PER_CPU(long, misaligned_access_speed);
72 #else
unaligned_ctl_available(void)73 static inline bool unaligned_ctl_available(void)
74 {
75 	return false;
76 }
77 #endif
78 
79 bool check_vector_unaligned_access_emulated_all_cpus(void);
80 #if defined(CONFIG_RISCV_VECTOR_MISALIGNED)
81 void check_vector_unaligned_access_emulated(struct work_struct *work __always_unused);
82 DECLARE_PER_CPU(long, vector_misaligned_access);
83 #endif
84 
85 #if defined(CONFIG_RISCV_PROBE_UNALIGNED_ACCESS)
86 DECLARE_STATIC_KEY_FALSE(fast_unaligned_access_speed_key);
87 
has_fast_unaligned_accesses(void)88 static __always_inline bool has_fast_unaligned_accesses(void)
89 {
90 	return static_branch_likely(&fast_unaligned_access_speed_key);
91 }
92 #else
has_fast_unaligned_accesses(void)93 static __always_inline bool has_fast_unaligned_accesses(void)
94 {
95 	if (IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS))
96 		return true;
97 	else
98 		return false;
99 }
100 #endif
101 
102 unsigned long riscv_get_elf_hwcap(void);
103 
104 struct riscv_isa_ext_data {
105 	const unsigned int id;
106 	const char *name;
107 	const char *property;
108 	const unsigned int *subset_ext_ids;
109 	const unsigned int subset_ext_size;
110 	int (*validate)(const struct riscv_isa_ext_data *data, const unsigned long *isa_bitmap);
111 };
112 
113 extern const struct riscv_isa_ext_data riscv_isa_ext[];
114 extern const size_t riscv_isa_ext_count;
115 extern bool riscv_isa_fallback;
116 
117 unsigned long riscv_isa_extension_base(const unsigned long *isa_bitmap);
riscv_cpu_has_extension_likely(int cpu,const unsigned long ext)118 static __always_inline bool riscv_cpu_has_extension_likely(int cpu, const unsigned long ext)
119 {
120 	compiletime_assert(ext < RISCV_ISA_EXT_MAX, "ext must be < RISCV_ISA_EXT_MAX");
121 
122 	if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE) &&
123 	    __riscv_has_extension_likely(STANDARD_EXT, ext))
124 		return true;
125 
126 	return __riscv_isa_extension_available(hart_isa[cpu].isa, ext);
127 }
128 
riscv_cpu_has_extension_unlikely(int cpu,const unsigned long ext)129 static __always_inline bool riscv_cpu_has_extension_unlikely(int cpu, const unsigned long ext)
130 {
131 	compiletime_assert(ext < RISCV_ISA_EXT_MAX, "ext must be < RISCV_ISA_EXT_MAX");
132 
133 	if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE) &&
134 	    __riscv_has_extension_unlikely(STANDARD_EXT, ext))
135 		return true;
136 
137 	return __riscv_isa_extension_available(hart_isa[cpu].isa, ext);
138 }
139 
140 #endif
141