1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-2.0-only */
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * Copyright (C) 2012 Regents of the University of California
4*4882a593Smuzhiyun */
5*4882a593Smuzhiyun
6*4882a593Smuzhiyun #ifndef _ASM_RISCV_SWITCH_TO_H
7*4882a593Smuzhiyun #define _ASM_RISCV_SWITCH_TO_H
8*4882a593Smuzhiyun
9*4882a593Smuzhiyun #include <linux/sched/task_stack.h>
10*4882a593Smuzhiyun #include <asm/processor.h>
11*4882a593Smuzhiyun #include <asm/ptrace.h>
12*4882a593Smuzhiyun #include <asm/csr.h>
13*4882a593Smuzhiyun
14*4882a593Smuzhiyun #ifdef CONFIG_FPU
15*4882a593Smuzhiyun extern void __fstate_save(struct task_struct *save_to);
16*4882a593Smuzhiyun extern void __fstate_restore(struct task_struct *restore_from);
17*4882a593Smuzhiyun
__fstate_clean(struct pt_regs * regs)18*4882a593Smuzhiyun static inline void __fstate_clean(struct pt_regs *regs)
19*4882a593Smuzhiyun {
20*4882a593Smuzhiyun regs->status = (regs->status & ~SR_FS) | SR_FS_CLEAN;
21*4882a593Smuzhiyun }
22*4882a593Smuzhiyun
fstate_off(struct task_struct * task,struct pt_regs * regs)23*4882a593Smuzhiyun static inline void fstate_off(struct task_struct *task,
24*4882a593Smuzhiyun struct pt_regs *regs)
25*4882a593Smuzhiyun {
26*4882a593Smuzhiyun regs->status = (regs->status & ~SR_FS) | SR_FS_OFF;
27*4882a593Smuzhiyun }
28*4882a593Smuzhiyun
fstate_save(struct task_struct * task,struct pt_regs * regs)29*4882a593Smuzhiyun static inline void fstate_save(struct task_struct *task,
30*4882a593Smuzhiyun struct pt_regs *regs)
31*4882a593Smuzhiyun {
32*4882a593Smuzhiyun if ((regs->status & SR_FS) == SR_FS_DIRTY) {
33*4882a593Smuzhiyun __fstate_save(task);
34*4882a593Smuzhiyun __fstate_clean(regs);
35*4882a593Smuzhiyun }
36*4882a593Smuzhiyun }
37*4882a593Smuzhiyun
fstate_restore(struct task_struct * task,struct pt_regs * regs)38*4882a593Smuzhiyun static inline void fstate_restore(struct task_struct *task,
39*4882a593Smuzhiyun struct pt_regs *regs)
40*4882a593Smuzhiyun {
41*4882a593Smuzhiyun if ((regs->status & SR_FS) != SR_FS_OFF) {
42*4882a593Smuzhiyun __fstate_restore(task);
43*4882a593Smuzhiyun __fstate_clean(regs);
44*4882a593Smuzhiyun }
45*4882a593Smuzhiyun }
46*4882a593Smuzhiyun
__switch_to_aux(struct task_struct * prev,struct task_struct * next)47*4882a593Smuzhiyun static inline void __switch_to_aux(struct task_struct *prev,
48*4882a593Smuzhiyun struct task_struct *next)
49*4882a593Smuzhiyun {
50*4882a593Smuzhiyun struct pt_regs *regs;
51*4882a593Smuzhiyun
52*4882a593Smuzhiyun regs = task_pt_regs(prev);
53*4882a593Smuzhiyun if (unlikely(regs->status & SR_SD))
54*4882a593Smuzhiyun fstate_save(prev, regs);
55*4882a593Smuzhiyun fstate_restore(next, task_pt_regs(next));
56*4882a593Smuzhiyun }
57*4882a593Smuzhiyun
58*4882a593Smuzhiyun extern bool has_fpu;
59*4882a593Smuzhiyun #else
60*4882a593Smuzhiyun #define has_fpu false
61*4882a593Smuzhiyun #define fstate_save(task, regs) do { } while (0)
62*4882a593Smuzhiyun #define fstate_restore(task, regs) do { } while (0)
63*4882a593Smuzhiyun #define __switch_to_aux(__prev, __next) do { } while (0)
64*4882a593Smuzhiyun #endif
65*4882a593Smuzhiyun
66*4882a593Smuzhiyun extern struct task_struct *__switch_to(struct task_struct *,
67*4882a593Smuzhiyun struct task_struct *);
68*4882a593Smuzhiyun
69*4882a593Smuzhiyun #define switch_to(prev, next, last) \
70*4882a593Smuzhiyun do { \
71*4882a593Smuzhiyun struct task_struct *__prev = (prev); \
72*4882a593Smuzhiyun struct task_struct *__next = (next); \
73*4882a593Smuzhiyun if (has_fpu) \
74*4882a593Smuzhiyun __switch_to_aux(__prev, __next); \
75*4882a593Smuzhiyun ((last) = __switch_to(__prev, __next)); \
76*4882a593Smuzhiyun } while (0)
77*4882a593Smuzhiyun
78*4882a593Smuzhiyun #endif /* _ASM_RISCV_SWITCH_TO_H */
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