xref: /linux/arch/riscv/include/asm/vector.h (revision 533925cb760431cb496a8c965cfd765a1a21d37e)
1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  * Copyright (C) 2020 SiFive
4  */
5 
6 #ifndef __ASM_RISCV_VECTOR_H
7 #define __ASM_RISCV_VECTOR_H
8 
9 #include <linux/types.h>
10 #include <uapi/asm-generic/errno.h>
11 
12 #ifdef CONFIG_RISCV_ISA_V
13 
14 #include <linux/stringify.h>
15 #include <linux/sched.h>
16 #include <linux/sched/task_stack.h>
17 #include <asm/ptrace.h>
18 #include <asm/hwcap.h>
19 #include <asm/csr.h>
20 #include <asm/asm.h>
21 
22 extern unsigned long riscv_v_vsize;
23 int riscv_v_setup_vsize(void);
24 bool riscv_v_first_use_handler(struct pt_regs *regs);
25 
26 static __always_inline bool has_vector(void)
27 {
28 	return riscv_has_extension_unlikely(RISCV_ISA_EXT_v);
29 }
30 
31 static inline void __riscv_v_vstate_clean(struct pt_regs *regs)
32 {
33 	regs->status = (regs->status & ~SR_VS) | SR_VS_CLEAN;
34 }
35 
36 static inline void riscv_v_vstate_off(struct pt_regs *regs)
37 {
38 	regs->status = (regs->status & ~SR_VS) | SR_VS_OFF;
39 }
40 
41 static inline void riscv_v_vstate_on(struct pt_regs *regs)
42 {
43 	regs->status = (regs->status & ~SR_VS) | SR_VS_INITIAL;
44 }
45 
46 static inline bool riscv_v_vstate_query(struct pt_regs *regs)
47 {
48 	return (regs->status & SR_VS) != 0;
49 }
50 
51 static __always_inline void riscv_v_enable(void)
52 {
53 	csr_set(CSR_SSTATUS, SR_VS);
54 }
55 
56 static __always_inline void riscv_v_disable(void)
57 {
58 	csr_clear(CSR_SSTATUS, SR_VS);
59 }
60 
61 static __always_inline void __vstate_csr_save(struct __riscv_v_ext_state *dest)
62 {
63 	asm volatile (
64 		"csrr	%0, " __stringify(CSR_VSTART) "\n\t"
65 		"csrr	%1, " __stringify(CSR_VTYPE) "\n\t"
66 		"csrr	%2, " __stringify(CSR_VL) "\n\t"
67 		"csrr	%3, " __stringify(CSR_VCSR) "\n\t"
68 		: "=r" (dest->vstart), "=r" (dest->vtype), "=r" (dest->vl),
69 		  "=r" (dest->vcsr) : :);
70 }
71 
72 static __always_inline void __vstate_csr_restore(struct __riscv_v_ext_state *src)
73 {
74 	asm volatile (
75 		".option push\n\t"
76 		".option arch, +v\n\t"
77 		"vsetvl	 x0, %2, %1\n\t"
78 		".option pop\n\t"
79 		"csrw	" __stringify(CSR_VSTART) ", %0\n\t"
80 		"csrw	" __stringify(CSR_VCSR) ", %3\n\t"
81 		: : "r" (src->vstart), "r" (src->vtype), "r" (src->vl),
82 		    "r" (src->vcsr) :);
83 }
84 
85 static inline void __riscv_v_vstate_save(struct __riscv_v_ext_state *save_to,
86 					 void *datap)
87 {
88 	unsigned long vl;
89 
90 	riscv_v_enable();
91 	__vstate_csr_save(save_to);
92 	asm volatile (
93 		".option push\n\t"
94 		".option arch, +v\n\t"
95 		"vsetvli	%0, x0, e8, m8, ta, ma\n\t"
96 		"vse8.v		v0, (%1)\n\t"
97 		"add		%1, %1, %0\n\t"
98 		"vse8.v		v8, (%1)\n\t"
99 		"add		%1, %1, %0\n\t"
100 		"vse8.v		v16, (%1)\n\t"
101 		"add		%1, %1, %0\n\t"
102 		"vse8.v		v24, (%1)\n\t"
103 		".option pop\n\t"
104 		: "=&r" (vl) : "r" (datap) : "memory");
105 	riscv_v_disable();
106 }
107 
108 static inline void __riscv_v_vstate_restore(struct __riscv_v_ext_state *restore_from,
109 					    void *datap)
110 {
111 	unsigned long vl;
112 
113 	riscv_v_enable();
114 	asm volatile (
115 		".option push\n\t"
116 		".option arch, +v\n\t"
117 		"vsetvli	%0, x0, e8, m8, ta, ma\n\t"
118 		"vle8.v		v0, (%1)\n\t"
119 		"add		%1, %1, %0\n\t"
120 		"vle8.v		v8, (%1)\n\t"
121 		"add		%1, %1, %0\n\t"
122 		"vle8.v		v16, (%1)\n\t"
123 		"add		%1, %1, %0\n\t"
124 		"vle8.v		v24, (%1)\n\t"
125 		".option pop\n\t"
126 		: "=&r" (vl) : "r" (datap) : "memory");
127 	__vstate_csr_restore(restore_from);
128 	riscv_v_disable();
129 }
130 
131 static inline void riscv_v_vstate_save(struct task_struct *task,
132 				       struct pt_regs *regs)
133 {
134 	if ((regs->status & SR_VS) == SR_VS_DIRTY) {
135 		struct __riscv_v_ext_state *vstate = &task->thread.vstate;
136 
137 		__riscv_v_vstate_save(vstate, vstate->datap);
138 		__riscv_v_vstate_clean(regs);
139 	}
140 }
141 
142 static inline void riscv_v_vstate_restore(struct task_struct *task,
143 					  struct pt_regs *regs)
144 {
145 	if ((regs->status & SR_VS) != SR_VS_OFF) {
146 		struct __riscv_v_ext_state *vstate = &task->thread.vstate;
147 
148 		__riscv_v_vstate_restore(vstate, vstate->datap);
149 		__riscv_v_vstate_clean(regs);
150 	}
151 }
152 
153 static inline void __switch_to_vector(struct task_struct *prev,
154 				      struct task_struct *next)
155 {
156 	struct pt_regs *regs;
157 
158 	regs = task_pt_regs(prev);
159 	riscv_v_vstate_save(prev, regs);
160 	riscv_v_vstate_restore(next, task_pt_regs(next));
161 }
162 
163 void riscv_v_vstate_ctrl_init(struct task_struct *tsk);
164 bool riscv_v_vstate_ctrl_user_allowed(void);
165 
166 #else /* ! CONFIG_RISCV_ISA_V  */
167 
168 struct pt_regs;
169 
170 static inline int riscv_v_setup_vsize(void) { return -EOPNOTSUPP; }
171 static __always_inline bool has_vector(void) { return false; }
172 static inline bool riscv_v_first_use_handler(struct pt_regs *regs) { return false; }
173 static inline bool riscv_v_vstate_query(struct pt_regs *regs) { return false; }
174 static inline bool riscv_v_vstate_ctrl_user_allowed(void) { return false; }
175 #define riscv_v_vsize (0)
176 #define riscv_v_vstate_save(task, regs)		do {} while (0)
177 #define riscv_v_vstate_restore(task, regs)	do {} while (0)
178 #define __switch_to_vector(__prev, __next)	do {} while (0)
179 #define riscv_v_vstate_off(regs)		do {} while (0)
180 #define riscv_v_vstate_on(regs)			do {} while (0)
181 
182 #endif /* CONFIG_RISCV_ISA_V */
183 
184 #endif /* ! __ASM_RISCV_VECTOR_H */
185