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126 lines
3.1 KiB
126 lines
3.1 KiB
/* 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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