1 /* SPDX-License-Identifier: GPL-2.0 */
3 * Author: Qi Hu <huqi@loongson.cn>
4 * Huacai Chen <chenhuacai@loongson.cn>
5 * Copyright (C) 2020-2023 Loongson Technology Corporation Limited
11 #include <asm/current.h>
12 #include <asm/loongarch.h>
13 #include <asm/processor.h>
15 extern void _init_lbt(void);
16 extern void _save_lbt(struct loongarch_lbt *);
17 extern void _restore_lbt(struct loongarch_lbt *);
19 static inline int is_lbt_enabled(void)
24 return (csr_read32(LOONGARCH_CSR_EUEN) & CSR_EUEN_LBTEN) ?
28 static inline int is_lbt_owner(void)
30 return test_thread_flag(TIF_USEDLBT);
33 #ifdef CONFIG_CPU_HAS_LBT
35 static inline void enable_lbt(void)
38 csr_xchg32(CSR_EUEN_LBTEN, CSR_EUEN_LBTEN, LOONGARCH_CSR_EUEN);
41 static inline void disable_lbt(void)
44 csr_xchg32(0, CSR_EUEN_LBTEN, LOONGARCH_CSR_EUEN);
47 static inline void __own_lbt(void)
50 set_thread_flag(TIF_USEDLBT);
51 KSTK_EUEN(current) |= CSR_EUEN_LBTEN;
54 static inline void own_lbt_inatomic(int restore)
56 if (cpu_has_lbt && !is_lbt_owner()) {
59 _restore_lbt(¤t->thread.lbt);
63 static inline void own_lbt(int restore)
66 own_lbt_inatomic(restore);
70 static inline void lose_lbt_inatomic(int save, struct task_struct *tsk)
72 if (cpu_has_lbt && is_lbt_owner()) {
74 _save_lbt(&tsk->thread.lbt);
77 clear_tsk_thread_flag(tsk, TIF_USEDLBT);
79 KSTK_EUEN(tsk) &= ~(CSR_EUEN_LBTEN);
82 static inline void lose_lbt(int save)
85 lose_lbt_inatomic(save, current);
89 static inline void init_lbt(void)
95 static inline void own_lbt_inatomic(int restore) {}
96 static inline void lose_lbt_inatomic(int save, struct task_struct *tsk) {}
97 static inline void init_lbt(void) {}
98 static inline void lose_lbt(int save) {}
101 static inline int thread_lbt_context_live(void)
106 return test_thread_flag(TIF_LBT_CTX_LIVE);
109 #endif /* _ASM_LBT_H */