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