130 lines
2.6 KiB
C
130 lines
2.6 KiB
C
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/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* Author: Huacai Chen <chenhuacai@loongson.cn>
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* Copyright (C) 2020-2022 Loongson Technology Corporation Limited
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*/
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#ifndef _ASM_FPU_H
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#define _ASM_FPU_H
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#include <linux/sched.h>
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#include <linux/sched/task_stack.h>
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#include <linux/ptrace.h>
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#include <linux/thread_info.h>
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#include <linux/bitops.h>
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#include <asm/cpu.h>
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#include <asm/cpu-features.h>
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#include <asm/current.h>
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#include <asm/loongarch.h>
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#include <asm/processor.h>
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#include <asm/ptrace.h>
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struct sigcontext;
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extern void _init_fpu(unsigned int);
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extern void _save_fp(struct loongarch_fpu *);
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extern void _restore_fp(struct loongarch_fpu *);
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/*
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* Mask the FCSR Cause bits according to the Enable bits, observing
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* that Unimplemented is always enabled.
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*/
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static inline unsigned long mask_fcsr_x(unsigned long fcsr)
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{
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return fcsr & ((fcsr & FPU_CSR_ALL_E) <<
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(ffs(FPU_CSR_ALL_X) - ffs(FPU_CSR_ALL_E)));
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}
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static inline int is_fp_enabled(void)
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{
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return (csr_read32(LOONGARCH_CSR_EUEN) & CSR_EUEN_FPEN) ?
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1 : 0;
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}
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#define enable_fpu() set_csr_euen(CSR_EUEN_FPEN)
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#define disable_fpu() clear_csr_euen(CSR_EUEN_FPEN)
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#define clear_fpu_owner() clear_thread_flag(TIF_USEDFPU)
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static inline int is_fpu_owner(void)
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{
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return test_thread_flag(TIF_USEDFPU);
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}
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static inline void __own_fpu(void)
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{
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enable_fpu();
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set_thread_flag(TIF_USEDFPU);
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KSTK_EUEN(current) |= CSR_EUEN_FPEN;
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}
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static inline void own_fpu_inatomic(int restore)
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{
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if (cpu_has_fpu && !is_fpu_owner()) {
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__own_fpu();
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if (restore)
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_restore_fp(¤t->thread.fpu);
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}
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}
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static inline void own_fpu(int restore)
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{
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preempt_disable();
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own_fpu_inatomic(restore);
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preempt_enable();
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}
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static inline void lose_fpu_inatomic(int save, struct task_struct *tsk)
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{
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if (is_fpu_owner()) {
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if (save)
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_save_fp(&tsk->thread.fpu);
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disable_fpu();
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clear_tsk_thread_flag(tsk, TIF_USEDFPU);
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}
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KSTK_EUEN(tsk) &= ~(CSR_EUEN_FPEN | CSR_EUEN_LSXEN | CSR_EUEN_LASXEN);
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}
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static inline void lose_fpu(int save)
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{
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preempt_disable();
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lose_fpu_inatomic(save, current);
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preempt_enable();
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}
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static inline void init_fpu(void)
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{
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unsigned int fcsr = current->thread.fpu.fcsr;
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__own_fpu();
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_init_fpu(fcsr);
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set_used_math();
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}
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static inline void save_fp(struct task_struct *tsk)
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{
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if (cpu_has_fpu)
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_save_fp(&tsk->thread.fpu);
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}
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static inline void restore_fp(struct task_struct *tsk)
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{
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if (cpu_has_fpu)
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_restore_fp(&tsk->thread.fpu);
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}
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static inline union fpureg *get_fpu_regs(struct task_struct *tsk)
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{
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if (tsk == current) {
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preempt_disable();
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if (is_fpu_owner())
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_save_fp(¤t->thread.fpu);
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preempt_enable();
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}
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return tsk->thread.fpu.fpr;
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}
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#endif /* _ASM_FPU_H */
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