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/* SPDX-License-Identifier: GPL-2.0 */
/* Copyright (C) 2005-2018 Andes Technology Corporation */
#ifndef __ASM_NDS32_FPU_H
#define __ASM_NDS32_FPU_H
#if IS_ENABLED(CONFIG_FPU)
#ifndef __ASSEMBLY__
#include <linux/sched/task_stack.h>
#include <linux/preempt.h>
#include <asm/ptrace.h>
extern bool has_fpu;
extern void save_fpu(struct task_struct *__tsk);
extern void load_fpu(const struct fpu_struct *fpregs);
extern bool do_fpu_exception(unsigned int subtype, struct pt_regs *regs);
extern int do_fpuemu(struct pt_regs *regs, struct fpu_struct *fpu);
#define test_tsk_fpu(regs) (regs->fucop_ctl & FUCOP_CTL_mskCP0EN)
/*
* Initially load the FPU with signalling NANS. This bit pattern
* has the property that no matter whether considered as single or as
* double precision, it still represents a signalling NAN.
*/
#define sNAN64 0xFFFFFFFFFFFFFFFFULL
#define sNAN32 0xFFFFFFFFUL
#if IS_ENABLED(CONFIG_SUPPORT_DENORMAL_ARITHMETIC)
/*
* Denormalized number is unsupported by nds32 FPU. Hence the operation
* is treated as underflow cases when the final result is a denormalized
* number. To enhance precision, underflow exception trap should be
* enabled by default and kerenl will re-execute it by fpu emulator
* when getting underflow exception.
*/
#define FPCSR_INIT (FPCSR_mskUDFE | FPCSR_mskIEXE)
#else
#define FPCSR_INIT 0x0UL
#endif
extern const struct fpu_struct init_fpuregs;
static inline void disable_ptreg_fpu(struct pt_regs *regs)
{
regs->fucop_ctl &= ~FUCOP_CTL_mskCP0EN;
}
static inline void enable_ptreg_fpu(struct pt_regs *regs)
{
regs->fucop_ctl |= FUCOP_CTL_mskCP0EN;
}
static inline void enable_fpu(void)
{
unsigned long fucop_ctl;
fucop_ctl = __nds32__mfsr(NDS32_SR_FUCOP_CTL) | FUCOP_CTL_mskCP0EN;
__nds32__mtsr(fucop_ctl, NDS32_SR_FUCOP_CTL);
__nds32__isb();
}
static inline void disable_fpu(void)
{
unsigned long fucop_ctl;
fucop_ctl = __nds32__mfsr(NDS32_SR_FUCOP_CTL) & ~FUCOP_CTL_mskCP0EN;
__nds32__mtsr(fucop_ctl, NDS32_SR_FUCOP_CTL);
__nds32__isb();
}
static inline void lose_fpu(void)
{
preempt_disable();
#if IS_ENABLED(CONFIG_LAZY_FPU)
if (last_task_used_math == current) {
last_task_used_math = NULL;
#else
if (test_tsk_fpu(task_pt_regs(current))) {
#endif
save_fpu(current);
}
disable_ptreg_fpu(task_pt_regs(current));
preempt_enable();
}
static inline void own_fpu(void)
{
preempt_disable();
#if IS_ENABLED(CONFIG_LAZY_FPU)
if (last_task_used_math != current) {
if (last_task_used_math != NULL)
save_fpu(last_task_used_math);
load_fpu(¤t->thread.fpu);
last_task_used_math = current;
}
#else
if (!test_tsk_fpu(task_pt_regs(current))) {
load_fpu(¤t->thread.fpu);
}
#endif
enable_ptreg_fpu(task_pt_regs(current));
preempt_enable();
}
#if !IS_ENABLED(CONFIG_LAZY_FPU)
static inline void unlazy_fpu(struct task_struct *tsk)
{
preempt_disable();
if (test_tsk_fpu(task_pt_regs(tsk)))
save_fpu(tsk);
preempt_enable();
}
#endif /* !CONFIG_LAZY_FPU */
static inline void clear_fpu(struct pt_regs *regs)
{
preempt_disable();
if (test_tsk_fpu(regs))
disable_ptreg_fpu(regs);
preempt_enable();
}
#endif /* CONFIG_FPU */
#endif /* __ASSEMBLY__ */
#endif /* __ASM_NDS32_FPU_H */
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