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83 lines
2.1 KiB
83 lines
2.1 KiB
/* SPDX-License-Identifier: GPL-2.0-only */ |
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/* |
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* Copyright (C) 2012 Regents of the University of California |
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*/ |
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#ifndef _ASM_RISCV_SWITCH_TO_H |
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#define _ASM_RISCV_SWITCH_TO_H |
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#include <linux/jump_label.h> |
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#include <linux/sched/task_stack.h> |
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#include <asm/processor.h> |
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#include <asm/ptrace.h> |
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#include <asm/csr.h> |
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#ifdef CONFIG_FPU |
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extern void __fstate_save(struct task_struct *save_to); |
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extern void __fstate_restore(struct task_struct *restore_from); |
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static inline void __fstate_clean(struct pt_regs *regs) |
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{ |
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regs->status = (regs->status & ~SR_FS) | SR_FS_CLEAN; |
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} |
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static inline void fstate_off(struct task_struct *task, |
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struct pt_regs *regs) |
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{ |
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regs->status = (regs->status & ~SR_FS) | SR_FS_OFF; |
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} |
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static inline void fstate_save(struct task_struct *task, |
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struct pt_regs *regs) |
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{ |
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if ((regs->status & SR_FS) == SR_FS_DIRTY) { |
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__fstate_save(task); |
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__fstate_clean(regs); |
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} |
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} |
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static inline void fstate_restore(struct task_struct *task, |
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struct pt_regs *regs) |
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{ |
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if ((regs->status & SR_FS) != SR_FS_OFF) { |
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__fstate_restore(task); |
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__fstate_clean(regs); |
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} |
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} |
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static inline void __switch_to_aux(struct task_struct *prev, |
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struct task_struct *next) |
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{ |
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struct pt_regs *regs; |
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regs = task_pt_regs(prev); |
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if (unlikely(regs->status & SR_SD)) |
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fstate_save(prev, regs); |
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fstate_restore(next, task_pt_regs(next)); |
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} |
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extern struct static_key_false cpu_hwcap_fpu; |
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static __always_inline bool has_fpu(void) |
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{ |
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return static_branch_likely(&cpu_hwcap_fpu); |
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} |
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#else |
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static __always_inline bool has_fpu(void) { return false; } |
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#define fstate_save(task, regs) do { } while (0) |
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#define fstate_restore(task, regs) do { } while (0) |
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#define __switch_to_aux(__prev, __next) do { } while (0) |
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#endif |
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extern struct task_struct *__switch_to(struct task_struct *, |
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struct task_struct *); |
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#define switch_to(prev, next, last) \ |
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do { \ |
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struct task_struct *__prev = (prev); \ |
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struct task_struct *__next = (next); \ |
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if (has_fpu()) \ |
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__switch_to_aux(__prev, __next); \ |
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((last) = __switch_to(__prev, __next)); \ |
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} while (0) |
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#endif /* _ASM_RISCV_SWITCH_TO_H */
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