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