| b.liu | e958203 | 2025-04-17 19:18:16 +0800 | [diff] [blame^] | 1 | /* SPDX-License-Identifier: GPL-2.0-only */ |
| 2 | /* |
| 3 | * Copyright (C) 2012 Regents of the University of California |
| 4 | */ |
| 5 | |
| 6 | #ifndef _ASM_RISCV_SWITCH_TO_H |
| 7 | #define _ASM_RISCV_SWITCH_TO_H |
| 8 | |
| 9 | #include <linux/sched/task_stack.h> |
| 10 | #include <asm/processor.h> |
| 11 | #include <asm/ptrace.h> |
| 12 | #include <asm/csr.h> |
| 13 | |
| 14 | #ifdef CONFIG_FPU |
| 15 | extern void __fstate_save(struct task_struct *save_to); |
| 16 | extern void __fstate_restore(struct task_struct *restore_from); |
| 17 | |
| 18 | static inline void __fstate_clean(struct pt_regs *regs) |
| 19 | { |
| 20 | regs->sstatus = (regs->sstatus & ~SR_FS) | SR_FS_CLEAN; |
| 21 | } |
| 22 | |
| 23 | static inline void fstate_off(struct task_struct *task, |
| 24 | struct pt_regs *regs) |
| 25 | { |
| 26 | regs->sstatus = (regs->sstatus & ~SR_FS) | SR_FS_OFF; |
| 27 | } |
| 28 | |
| 29 | static inline void fstate_save(struct task_struct *task, |
| 30 | struct pt_regs *regs) |
| 31 | { |
| 32 | if ((regs->sstatus & SR_FS) == SR_FS_DIRTY) { |
| 33 | __fstate_save(task); |
| 34 | __fstate_clean(regs); |
| 35 | } |
| 36 | } |
| 37 | |
| 38 | static inline void fstate_restore(struct task_struct *task, |
| 39 | struct pt_regs *regs) |
| 40 | { |
| 41 | if ((regs->sstatus & SR_FS) != SR_FS_OFF) { |
| 42 | __fstate_restore(task); |
| 43 | __fstate_clean(regs); |
| 44 | } |
| 45 | } |
| 46 | |
| 47 | static inline void __switch_to_aux(struct task_struct *prev, |
| 48 | struct task_struct *next) |
| 49 | { |
| 50 | struct pt_regs *regs; |
| 51 | |
| 52 | regs = task_pt_regs(prev); |
| 53 | if (unlikely(regs->sstatus & SR_SD)) |
| 54 | fstate_save(prev, regs); |
| 55 | fstate_restore(next, task_pt_regs(next)); |
| 56 | } |
| 57 | |
| 58 | extern bool has_fpu; |
| 59 | #else |
| 60 | #define has_fpu false |
| 61 | #define fstate_save(task, regs) do { } while (0) |
| 62 | #define fstate_restore(task, regs) do { } while (0) |
| 63 | #define __switch_to_aux(__prev, __next) do { } while (0) |
| 64 | #endif |
| 65 | |
| 66 | extern struct task_struct *__switch_to(struct task_struct *, |
| 67 | struct task_struct *); |
| 68 | |
| 69 | #define switch_to(prev, next, last) \ |
| 70 | do { \ |
| 71 | struct task_struct *__prev = (prev); \ |
| 72 | struct task_struct *__next = (next); \ |
| 73 | if (has_fpu) \ |
| 74 | __switch_to_aux(__prev, __next); \ |
| 75 | ((last) = __switch_to(__prev, __next)); \ |
| 76 | } while (0) |
| 77 | |
| 78 | #endif /* _ASM_RISCV_SWITCH_TO_H */ |