summaryrefslogtreecommitdiff
path: root/arch/loongarch/include/asm/fpu.h
blob: 3177674228f8961408be4e2e028d5d083fb8e71c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Author: Huacai Chen <chenhuacai@loongson.cn>
 * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
 */
#ifndef _ASM_FPU_H
#define _ASM_FPU_H

#include <linux/sched.h>
#include <linux/sched/task_stack.h>
#include <linux/ptrace.h>
#include <linux/thread_info.h>
#include <linux/bitops.h>

#include <asm/cpu.h>
#include <asm/cpu-features.h>
#include <asm/current.h>
#include <asm/loongarch.h>
#include <asm/processor.h>
#include <asm/ptrace.h>

struct sigcontext;

#define kernel_fpu_available() cpu_has_fpu
extern void kernel_fpu_begin(void);
extern void kernel_fpu_end(void);

extern void _init_fpu(unsigned int);
extern void _save_fp(struct loongarch_fpu *);
extern void _restore_fp(struct loongarch_fpu *);

extern void _save_lsx(struct loongarch_fpu *fpu);
extern void _restore_lsx(struct loongarch_fpu *fpu);
extern void _init_lsx_upper(void);
extern void _restore_lsx_upper(struct loongarch_fpu *fpu);

extern void _save_lasx(struct loongarch_fpu *fpu);
extern void _restore_lasx(struct loongarch_fpu *fpu);
extern void _init_lasx_upper(void);
extern void _restore_lasx_upper(struct loongarch_fpu *fpu);

static inline void enable_lsx(void);
static inline void disable_lsx(void);
static inline void save_lsx(struct task_struct *t);
static inline void restore_lsx(struct task_struct *t);

static inline void enable_lasx(void);
static inline void disable_lasx(void);
static inline void save_lasx(struct task_struct *t);
static inline void restore_lasx(struct task_struct *t);

/*
 * Mask the FCSR Cause bits according to the Enable bits, observing
 * that Unimplemented is always enabled.
 */
static inline unsigned long mask_fcsr_x(unsigned long fcsr)
{
	return fcsr & ((fcsr & FPU_CSR_ALL_E) <<
			(ffs(FPU_CSR_ALL_X) - ffs(FPU_CSR_ALL_E)));
}

static inline int is_fp_enabled(void)
{
	return (csr_read32(LOONGARCH_CSR_EUEN) & CSR_EUEN_FPEN) ?
		1 : 0;
}

static inline int is_lsx_enabled(void)
{
	if (!cpu_has_lsx)
		return 0;

	return (csr_read32(LOONGARCH_CSR_EUEN) & CSR_EUEN_LSXEN) ?
		1 : 0;
}

static inline int is_lasx_enabled(void)
{
	if (!cpu_has_lasx)
		return 0;

	return (csr_read32(LOONGARCH_CSR_EUEN) & CSR_EUEN_LASXEN) ?
		1 : 0;
}

static inline int is_simd_enabled(void)
{
	return is_lsx_enabled() | is_lasx_enabled();
}

#define enable_fpu()		set_csr_euen(CSR_EUEN_FPEN)

#define disable_fpu()		clear_csr_euen(CSR_EUEN_FPEN)

#define clear_fpu_owner()	clear_thread_flag(TIF_USEDFPU)

static inline int is_fpu_owner(void)
{
	return test_thread_flag(TIF_USEDFPU);
}

static inline void __own_fpu(void)
{
	enable_fpu();
	set_thread_flag(TIF_USEDFPU);
	KSTK_EUEN(current) |= CSR_EUEN_FPEN;
}

static inline void own_fpu_inatomic(int restore)
{
	if (cpu_has_fpu && !is_fpu_owner()) {
		__own_fpu();
		if (restore)
			_restore_fp(&current->thread.fpu);
	}
}

static inline void own_fpu(int restore)
{
	preempt_disable();
	own_fpu_inatomic(restore);
	preempt_enable();
}

static inline void lose_fpu_inatomic(int save, struct task_struct *tsk)
{
	if (is_fpu_owner()) {
		if (!is_simd_enabled()) {
			if (save)
				_save_fp(&tsk->thread.fpu);
			disable_fpu();
		} else {
			if (save) {
				if (!is_lasx_enabled())
					save_lsx(tsk);
				else
					save_lasx(tsk);
			}
			disable_fpu();
			disable_lsx();
			disable_lasx();
			clear_tsk_thread_flag(tsk, TIF_USEDSIMD);
		}
		clear_tsk_thread_flag(tsk, TIF_USEDFPU);
	}
	KSTK_EUEN(tsk) &= ~(CSR_EUEN_FPEN | CSR_EUEN_LSXEN | CSR_EUEN_LASXEN);
}

static inline void lose_fpu(int save)
{
	preempt_disable();
	lose_fpu_inatomic(save, current);
	preempt_enable();
}

static inline void init_fpu(void)
{
	unsigned int fcsr = current->thread.fpu.fcsr;

	__own_fpu();
	_init_fpu(fcsr);
	set_used_math();
}

static inline void save_fp(struct task_struct *tsk)
{
	if (cpu_has_fpu)
		_save_fp(&tsk->thread.fpu);
}

static inline void restore_fp(struct task_struct *tsk)
{
	if (cpu_has_fpu)
		_restore_fp(&tsk->thread.fpu);
}

static inline void save_fpu_regs(struct task_struct *tsk)
{
	unsigned int euen;

	if (tsk == current) {
		preempt_disable();

		euen = csr_read32(LOONGARCH_CSR_EUEN);

#ifdef CONFIG_CPU_HAS_LASX
		if (euen & CSR_EUEN_LASXEN)
			_save_lasx(&current->thread.fpu);
		else
#endif
#ifdef CONFIG_CPU_HAS_LSX
		if (euen & CSR_EUEN_LSXEN)
			_save_lsx(&current->thread.fpu);
		else
#endif
		if (euen & CSR_EUEN_FPEN)
			_save_fp(&current->thread.fpu);

		preempt_enable();
	}
}

static inline int is_simd_owner(void)
{
	return test_thread_flag(TIF_USEDSIMD);
}

#ifdef CONFIG_CPU_HAS_LSX

static inline void enable_lsx(void)
{
	if (cpu_has_lsx)
		csr_xchg32(CSR_EUEN_LSXEN, CSR_EUEN_LSXEN, LOONGARCH_CSR_EUEN);
}

static inline void disable_lsx(void)
{
	if (cpu_has_lsx)
		csr_xchg32(0, CSR_EUEN_LSXEN, LOONGARCH_CSR_EUEN);
}

static inline void save_lsx(struct task_struct *t)
{
	if (cpu_has_lsx)
		_save_lsx(&t->thread.fpu);
}

static inline void restore_lsx(struct task_struct *t)
{
	if (cpu_has_lsx)
		_restore_lsx(&t->thread.fpu);
}

static inline void init_lsx_upper(void)
{
	if (cpu_has_lsx)
		_init_lsx_upper();
}

static inline void restore_lsx_upper(struct task_struct *t)
{
	if (cpu_has_lsx)
		_restore_lsx_upper(&t->thread.fpu);
}

#else
static inline void enable_lsx(void) {}
static inline void disable_lsx(void) {}
static inline void save_lsx(struct task_struct *t) {}
static inline void restore_lsx(struct task_struct *t) {}
static inline void init_lsx_upper(void) {}
static inline void restore_lsx_upper(struct task_struct *t) {}
#endif

#ifdef CONFIG_CPU_HAS_LASX

static inline void enable_lasx(void)
{

	if (cpu_has_lasx)
		csr_xchg32(CSR_EUEN_LASXEN, CSR_EUEN_LASXEN, LOONGARCH_CSR_EUEN);
}

static inline void disable_lasx(void)
{
	if (cpu_has_lasx)
		csr_xchg32(0, CSR_EUEN_LASXEN, LOONGARCH_CSR_EUEN);
}

static inline void save_lasx(struct task_struct *t)
{
	if (cpu_has_lasx)
		_save_lasx(&t->thread.fpu);
}

static inline void restore_lasx(struct task_struct *t)
{
	if (cpu_has_lasx)
		_restore_lasx(&t->thread.fpu);
}

static inline void init_lasx_upper(void)
{
	if (cpu_has_lasx)
		_init_lasx_upper();
}

static inline void restore_lasx_upper(struct task_struct *t)
{
	if (cpu_has_lasx)
		_restore_lasx_upper(&t->thread.fpu);
}

#else
static inline void enable_lasx(void) {}
static inline void disable_lasx(void) {}
static inline void save_lasx(struct task_struct *t) {}
static inline void restore_lasx(struct task_struct *t) {}
static inline void init_lasx_upper(void) {}
static inline void restore_lasx_upper(struct task_struct *t) {}
#endif

static inline int thread_lsx_context_live(void)
{
	if (!cpu_has_lsx)
		return 0;

	return test_thread_flag(TIF_LSX_CTX_LIVE);
}

static inline int thread_lasx_context_live(void)
{
	if (!cpu_has_lasx)
		return 0;

	return test_thread_flag(TIF_LASX_CTX_LIVE);
}

#endif /* _ASM_FPU_H */