summaryrefslogtreecommitdiff
path: root/arch/riscv/kernel/fpu.S
blob: 2c543f130f9389aa4f1d9fee05f5027d99adaa78 (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
/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Copyright (C) 2012 Regents of the University of California
 * Copyright (C) 2017 SiFive
 *
 *   This program is free software; you can redistribute it and/or
 *   modify it under the terms of the GNU General Public License
 *   as published by the Free Software Foundation, version 2.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 */

#include <linux/linkage.h>

#include <asm/asm.h>
#include <asm/csr.h>
#include <asm/asm-offsets.h>

SYM_FUNC_START(__fstate_save)
	li  a2,  TASK_THREAD_F0
	add a0, a0, a2
	li t1, SR_FS
	csrs CSR_STATUS, t1
	frcsr t0
	fsd f0,  TASK_THREAD_F0_F0(a0)
	fsd f1,  TASK_THREAD_F1_F0(a0)
	fsd f2,  TASK_THREAD_F2_F0(a0)
	fsd f3,  TASK_THREAD_F3_F0(a0)
	fsd f4,  TASK_THREAD_F4_F0(a0)
	fsd f5,  TASK_THREAD_F5_F0(a0)
	fsd f6,  TASK_THREAD_F6_F0(a0)
	fsd f7,  TASK_THREAD_F7_F0(a0)
	fsd f8,  TASK_THREAD_F8_F0(a0)
	fsd f9,  TASK_THREAD_F9_F0(a0)
	fsd f10, TASK_THREAD_F10_F0(a0)
	fsd f11, TASK_THREAD_F11_F0(a0)
	fsd f12, TASK_THREAD_F12_F0(a0)
	fsd f13, TASK_THREAD_F13_F0(a0)
	fsd f14, TASK_THREAD_F14_F0(a0)
	fsd f15, TASK_THREAD_F15_F0(a0)
	fsd f16, TASK_THREAD_F16_F0(a0)
	fsd f17, TASK_THREAD_F17_F0(a0)
	fsd f18, TASK_THREAD_F18_F0(a0)
	fsd f19, TASK_THREAD_F19_F0(a0)
	fsd f20, TASK_THREAD_F20_F0(a0)
	fsd f21, TASK_THREAD_F21_F0(a0)
	fsd f22, TASK_THREAD_F22_F0(a0)
	fsd f23, TASK_THREAD_F23_F0(a0)
	fsd f24, TASK_THREAD_F24_F0(a0)
	fsd f25, TASK_THREAD_F25_F0(a0)
	fsd f26, TASK_THREAD_F26_F0(a0)
	fsd f27, TASK_THREAD_F27_F0(a0)
	fsd f28, TASK_THREAD_F28_F0(a0)
	fsd f29, TASK_THREAD_F29_F0(a0)
	fsd f30, TASK_THREAD_F30_F0(a0)
	fsd f31, TASK_THREAD_F31_F0(a0)
	sw t0, TASK_THREAD_FCSR_F0(a0)
	csrc CSR_STATUS, t1
	ret
SYM_FUNC_END(__fstate_save)

SYM_FUNC_START(__fstate_restore)
	li  a2,  TASK_THREAD_F0
	add a0, a0, a2
	li t1, SR_FS
	lw t0, TASK_THREAD_FCSR_F0(a0)
	csrs CSR_STATUS, t1
	fld f0,  TASK_THREAD_F0_F0(a0)
	fld f1,  TASK_THREAD_F1_F0(a0)
	fld f2,  TASK_THREAD_F2_F0(a0)
	fld f3,  TASK_THREAD_F3_F0(a0)
	fld f4,  TASK_THREAD_F4_F0(a0)
	fld f5,  TASK_THREAD_F5_F0(a0)
	fld f6,  TASK_THREAD_F6_F0(a0)
	fld f7,  TASK_THREAD_F7_F0(a0)
	fld f8,  TASK_THREAD_F8_F0(a0)
	fld f9,  TASK_THREAD_F9_F0(a0)
	fld f10, TASK_THREAD_F10_F0(a0)
	fld f11, TASK_THREAD_F11_F0(a0)
	fld f12, TASK_THREAD_F12_F0(a0)
	fld f13, TASK_THREAD_F13_F0(a0)
	fld f14, TASK_THREAD_F14_F0(a0)
	fld f15, TASK_THREAD_F15_F0(a0)
	fld f16, TASK_THREAD_F16_F0(a0)
	fld f17, TASK_THREAD_F17_F0(a0)
	fld f18, TASK_THREAD_F18_F0(a0)
	fld f19, TASK_THREAD_F19_F0(a0)
	fld f20, TASK_THREAD_F20_F0(a0)
	fld f21, TASK_THREAD_F21_F0(a0)
	fld f22, TASK_THREAD_F22_F0(a0)
	fld f23, TASK_THREAD_F23_F0(a0)
	fld f24, TASK_THREAD_F24_F0(a0)
	fld f25, TASK_THREAD_F25_F0(a0)
	fld f26, TASK_THREAD_F26_F0(a0)
	fld f27, TASK_THREAD_F27_F0(a0)
	fld f28, TASK_THREAD_F28_F0(a0)
	fld f29, TASK_THREAD_F29_F0(a0)
	fld f30, TASK_THREAD_F30_F0(a0)
	fld f31, TASK_THREAD_F31_F0(a0)
	fscsr t0
	csrc CSR_STATUS, t1
	ret
SYM_FUNC_END(__fstate_restore)

#define get_f32(which) fmv.x.s a0, which; j 2f
#define put_f32(which) fmv.s.x which, a1; j 2f
#if __riscv_xlen == 64
# define get_f64(which) fmv.x.d a0, which; j 2f
# define put_f64(which) fmv.d.x which, a1; j 2f
#else
# define get_f64(which) fsd which, 0(a1); j 2f
# define put_f64(which) fld which, 0(a1); j 2f
#endif

.macro fp_access_prologue
	/*
	 * Compute jump offset to store the correct FP register since we don't
	 * have indirect FP register access
	 */
	sll t0, a0, 3
	la t2, 1f
	add t0, t0, t2
	li t1, SR_FS
	csrs CSR_STATUS, t1
	jr t0
1:
.endm

.macro fp_access_epilogue
2:
	csrc CSR_STATUS, t1
	ret
.endm

#define fp_access_body(__access_func) \
	__access_func(f0); \
	__access_func(f1); \
	__access_func(f2); \
	__access_func(f3); \
	__access_func(f4); \
	__access_func(f5); \
	__access_func(f6); \
	__access_func(f7); \
	__access_func(f8); \
	__access_func(f9); \
	__access_func(f10); \
	__access_func(f11); \
	__access_func(f12); \
	__access_func(f13); \
	__access_func(f14); \
	__access_func(f15); \
	__access_func(f16); \
	__access_func(f17); \
	__access_func(f18); \
	__access_func(f19); \
	__access_func(f20); \
	__access_func(f21); \
	__access_func(f22); \
	__access_func(f23); \
	__access_func(f24); \
	__access_func(f25); \
	__access_func(f26); \
	__access_func(f27); \
	__access_func(f28); \
	__access_func(f29); \
	__access_func(f30); \
	__access_func(f31)


#ifdef CONFIG_RISCV_MISALIGNED

/*
 * Disable compressed instructions set to keep a constant offset between FP
 * load/store/move instructions
 */
.option norvc
/*
 * put_f32_reg - Set a FP register from a register containing the value
 * a0 = FP register index to be set
 * a1 = value to be loaded in the FP register
 */
SYM_FUNC_START(put_f32_reg)
	fp_access_prologue
	fp_access_body(put_f32)
	fp_access_epilogue
SYM_FUNC_END(put_f32_reg)

/*
 * get_f32_reg - Get a FP register value and return it
 * a0 = FP register index to be retrieved
 */
SYM_FUNC_START(get_f32_reg)
	fp_access_prologue
	fp_access_body(get_f32)
	fp_access_epilogue
SYM_FUNC_END(get_f32_reg)

/*
 * put_f64_reg - Set a 64 bits FP register from a value or a pointer.
 * a0 = FP register index to be set
 * a1 = value/pointer to be loaded in the FP register (when xlen == 32 bits, we
 * load the value to a pointer).
 */
SYM_FUNC_START(put_f64_reg)
	fp_access_prologue
	fp_access_body(put_f64)
	fp_access_epilogue
SYM_FUNC_END(put_f64_reg)

/*
 * put_f64_reg - Get a 64 bits FP register value and returned it or store it to
 *	 	 a pointer.
 * a0 = FP register index to be retrieved
 * a1 = If xlen == 32, pointer which should be loaded with the FP register value
 *	or unused if xlen == 64. In which case the FP register value is returned
 *	through a0
 */
SYM_FUNC_START(get_f64_reg)
	fp_access_prologue
	fp_access_body(get_f64)
	fp_access_epilogue
SYM_FUNC_END(get_f64_reg)

#endif /* CONFIG_RISCV_MISALIGNED */