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Merge tag 'amd-drm-next-6.5-2023-06-09' of https://gitlab.freedesktop.org/agd5f/linux...
[linux.git] / arch / loongarch / include / asm / fpu.h
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Author: Huacai Chen <[email protected]>
4  * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
5  */
6 #ifndef _ASM_FPU_H
7 #define _ASM_FPU_H
8
9 #include <linux/sched.h>
10 #include <linux/sched/task_stack.h>
11 #include <linux/ptrace.h>
12 #include <linux/thread_info.h>
13 #include <linux/bitops.h>
14
15 #include <asm/cpu.h>
16 #include <asm/cpu-features.h>
17 #include <asm/current.h>
18 #include <asm/loongarch.h>
19 #include <asm/processor.h>
20 #include <asm/ptrace.h>
21
22 struct sigcontext;
23
24 extern void kernel_fpu_begin(void);
25 extern void kernel_fpu_end(void);
26
27 extern void _init_fpu(unsigned int);
28 extern void _save_fp(struct loongarch_fpu *);
29 extern void _restore_fp(struct loongarch_fpu *);
30
31 /*
32  * Mask the FCSR Cause bits according to the Enable bits, observing
33  * that Unimplemented is always enabled.
34  */
35 static inline unsigned long mask_fcsr_x(unsigned long fcsr)
36 {
37         return fcsr & ((fcsr & FPU_CSR_ALL_E) <<
38                         (ffs(FPU_CSR_ALL_X) - ffs(FPU_CSR_ALL_E)));
39 }
40
41 static inline int is_fp_enabled(void)
42 {
43         return (csr_read32(LOONGARCH_CSR_EUEN) & CSR_EUEN_FPEN) ?
44                 1 : 0;
45 }
46
47 #define enable_fpu()            set_csr_euen(CSR_EUEN_FPEN)
48
49 #define disable_fpu()           clear_csr_euen(CSR_EUEN_FPEN)
50
51 #define clear_fpu_owner()       clear_thread_flag(TIF_USEDFPU)
52
53 static inline int is_fpu_owner(void)
54 {
55         return test_thread_flag(TIF_USEDFPU);
56 }
57
58 static inline void __own_fpu(void)
59 {
60         enable_fpu();
61         set_thread_flag(TIF_USEDFPU);
62         KSTK_EUEN(current) |= CSR_EUEN_FPEN;
63 }
64
65 static inline void own_fpu_inatomic(int restore)
66 {
67         if (cpu_has_fpu && !is_fpu_owner()) {
68                 __own_fpu();
69                 if (restore)
70                         _restore_fp(&current->thread.fpu);
71         }
72 }
73
74 static inline void own_fpu(int restore)
75 {
76         preempt_disable();
77         own_fpu_inatomic(restore);
78         preempt_enable();
79 }
80
81 static inline void lose_fpu_inatomic(int save, struct task_struct *tsk)
82 {
83         if (is_fpu_owner()) {
84                 if (save)
85                         _save_fp(&tsk->thread.fpu);
86                 disable_fpu();
87                 clear_tsk_thread_flag(tsk, TIF_USEDFPU);
88         }
89         KSTK_EUEN(tsk) &= ~(CSR_EUEN_FPEN | CSR_EUEN_LSXEN | CSR_EUEN_LASXEN);
90 }
91
92 static inline void lose_fpu(int save)
93 {
94         preempt_disable();
95         lose_fpu_inatomic(save, current);
96         preempt_enable();
97 }
98
99 static inline void init_fpu(void)
100 {
101         unsigned int fcsr = current->thread.fpu.fcsr;
102
103         __own_fpu();
104         _init_fpu(fcsr);
105         set_used_math();
106 }
107
108 static inline void save_fp(struct task_struct *tsk)
109 {
110         if (cpu_has_fpu)
111                 _save_fp(&tsk->thread.fpu);
112 }
113
114 static inline void restore_fp(struct task_struct *tsk)
115 {
116         if (cpu_has_fpu)
117                 _restore_fp(&tsk->thread.fpu);
118 }
119
120 static inline union fpureg *get_fpu_regs(struct task_struct *tsk)
121 {
122         if (tsk == current) {
123                 preempt_disable();
124                 if (is_fpu_owner())
125                         _save_fp(&current->thread.fpu);
126                 preempt_enable();
127         }
128
129         return tsk->thread.fpu.fpr;
130 }
131
132 #endif /* _ASM_FPU_H */
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