bd3c579848
Loongson Binary Translation (LBT) is used to accelerate binary translation, which contains 4 scratch registers (scr0 to scr3), x86/ARM eflags (eflags) and x87 fpu stack pointer (ftop). This patch support kernel to save/restore these registers, handle the LBT exception and maintain sigcontext. Signed-off-by: Qi Hu <huqi@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
110 lines
2.1 KiB
C
110 lines
2.1 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* Author: Qi Hu <huqi@loongson.cn>
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* Huacai Chen <chenhuacai@loongson.cn>
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* Copyright (C) 2020-2023 Loongson Technology Corporation Limited
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*/
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#ifndef _ASM_LBT_H
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#define _ASM_LBT_H
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#include <asm/cpu.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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extern void _init_lbt(void);
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extern void _save_lbt(struct loongarch_lbt *);
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extern void _restore_lbt(struct loongarch_lbt *);
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static inline int is_lbt_enabled(void)
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{
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if (!cpu_has_lbt)
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return 0;
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return (csr_read32(LOONGARCH_CSR_EUEN) & CSR_EUEN_LBTEN) ?
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1 : 0;
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}
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static inline int is_lbt_owner(void)
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{
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return test_thread_flag(TIF_USEDLBT);
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}
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#ifdef CONFIG_CPU_HAS_LBT
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static inline void enable_lbt(void)
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{
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if (cpu_has_lbt)
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csr_xchg32(CSR_EUEN_LBTEN, CSR_EUEN_LBTEN, LOONGARCH_CSR_EUEN);
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}
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static inline void disable_lbt(void)
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{
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if (cpu_has_lbt)
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csr_xchg32(0, CSR_EUEN_LBTEN, LOONGARCH_CSR_EUEN);
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}
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static inline void __own_lbt(void)
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{
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enable_lbt();
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set_thread_flag(TIF_USEDLBT);
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KSTK_EUEN(current) |= CSR_EUEN_LBTEN;
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}
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static inline void own_lbt_inatomic(int restore)
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{
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if (cpu_has_lbt && !is_lbt_owner()) {
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__own_lbt();
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if (restore)
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_restore_lbt(¤t->thread.lbt);
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}
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}
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static inline void own_lbt(int restore)
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{
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preempt_disable();
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own_lbt_inatomic(restore);
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preempt_enable();
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}
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static inline void lose_lbt_inatomic(int save, struct task_struct *tsk)
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{
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if (cpu_has_lbt && is_lbt_owner()) {
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if (save)
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_save_lbt(&tsk->thread.lbt);
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disable_lbt();
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clear_tsk_thread_flag(tsk, TIF_USEDLBT);
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}
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KSTK_EUEN(tsk) &= ~(CSR_EUEN_LBTEN);
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}
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static inline void lose_lbt(int save)
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{
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preempt_disable();
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lose_lbt_inatomic(save, current);
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preempt_enable();
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}
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static inline void init_lbt(void)
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{
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__own_lbt();
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_init_lbt();
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}
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#else
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static inline void own_lbt_inatomic(int restore) {}
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static inline void lose_lbt_inatomic(int save, struct task_struct *tsk) {}
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static inline void init_lbt(void) {}
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static inline void lose_lbt(int save) {}
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#endif
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static inline int thread_lbt_context_live(void)
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{
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if (!cpu_has_lbt)
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return 0;
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return test_thread_flag(TIF_LBT_CTX_LIVE);
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}
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#endif /* _ASM_LBT_H */
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