diff options
Diffstat (limited to 'arch/loongarch/kernel/lbt.S')
| -rw-r--r-- | arch/loongarch/kernel/lbt.S | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/arch/loongarch/kernel/lbt.S b/arch/loongarch/kernel/lbt.S new file mode 100644 index 000000000000..9c75120a26d8 --- /dev/null +++ b/arch/loongarch/kernel/lbt.S @@ -0,0 +1,155 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Author: Qi Hu <huqi@loongson.cn> + * Huacai Chen <chenhuacai@loongson.cn> + * + * Copyright (C) 2020-2023 Loongson Technology Corporation Limited + */ +#include <asm/asm.h> +#include <asm/asmmacro.h> +#include <asm/asm-extable.h> +#include <asm/asm-offsets.h> +#include <asm/errno.h> +#include <asm/regdef.h> + +#define SCR_REG_WIDTH 8 + + .macro EX insn, reg, src, offs +.ex\@: \insn \reg, \src, \offs + _asm_extable .ex\@, .L_lbt_fault + .endm + +/* + * Save a thread's lbt context. + */ +SYM_FUNC_START(_save_lbt) + movscr2gr t1, $scr0 # save scr + stptr.d t1, a0, THREAD_SCR0 + movscr2gr t1, $scr1 + stptr.d t1, a0, THREAD_SCR1 + movscr2gr t1, $scr2 + stptr.d t1, a0, THREAD_SCR2 + movscr2gr t1, $scr3 + stptr.d t1, a0, THREAD_SCR3 + + x86mfflag t1, 0x3f # save eflags + stptr.d t1, a0, THREAD_EFLAGS + jr ra +SYM_FUNC_END(_save_lbt) +EXPORT_SYMBOL(_save_lbt) + +/* + * Restore a thread's lbt context. + */ +SYM_FUNC_START(_restore_lbt) + ldptr.d t1, a0, THREAD_SCR0 # restore scr + movgr2scr $scr0, t1 + ldptr.d t1, a0, THREAD_SCR1 + movgr2scr $scr1, t1 + ldptr.d t1, a0, THREAD_SCR2 + movgr2scr $scr2, t1 + ldptr.d t1, a0, THREAD_SCR3 + movgr2scr $scr3, t1 + + ldptr.d t1, a0, THREAD_EFLAGS # restore eflags + x86mtflag t1, 0x3f + jr ra +SYM_FUNC_END(_restore_lbt) +EXPORT_SYMBOL(_restore_lbt) + +/* + * Load scr/eflag with zero. + */ +SYM_FUNC_START(_init_lbt) + movgr2scr $scr0, zero + movgr2scr $scr1, zero + movgr2scr $scr2, zero + movgr2scr $scr3, zero + + x86mtflag zero, 0x3f + jr ra +SYM_FUNC_END(_init_lbt) + +/* + * a0: scr + * a1: eflag + */ +SYM_FUNC_START(_save_lbt_context) + movscr2gr t1, $scr0 # save scr + EX st.d t1, a0, (0 * SCR_REG_WIDTH) + movscr2gr t1, $scr1 + EX st.d t1, a0, (1 * SCR_REG_WIDTH) + movscr2gr t1, $scr2 + EX st.d t1, a0, (2 * SCR_REG_WIDTH) + movscr2gr t1, $scr3 + EX st.d t1, a0, (3 * SCR_REG_WIDTH) + + x86mfflag t1, 0x3f # save eflags + EX st.w t1, a1, 0 + li.w a0, 0 # success + jr ra +SYM_FUNC_END(_save_lbt_context) + +/* + * a0: scr + * a1: eflag + */ +SYM_FUNC_START(_restore_lbt_context) + EX ld.d t1, a0, (0 * SCR_REG_WIDTH) # restore scr + movgr2scr $scr0, t1 + EX ld.d t1, a0, (1 * SCR_REG_WIDTH) + movgr2scr $scr1, t1 + EX ld.d t1, a0, (2 * SCR_REG_WIDTH) + movgr2scr $scr2, t1 + EX ld.d t1, a0, (3 * SCR_REG_WIDTH) + movgr2scr $scr3, t1 + + EX ld.w t1, a1, 0 # restore eflags + x86mtflag t1, 0x3f + li.w a0, 0 # success + jr ra +SYM_FUNC_END(_restore_lbt_context) + +/* + * a0: ftop + */ +SYM_FUNC_START(_save_ftop_context) + x86mftop t1 + st.w t1, a0, 0 + li.w a0, 0 # success + jr ra +SYM_FUNC_END(_save_ftop_context) + +/* + * a0: ftop + */ +SYM_FUNC_START(_restore_ftop_context) + ld.w t1, a0, 0 + andi t1, t1, 0x7 + la.pcrel a0, 1f + alsl.d a0, t1, a0, 3 + jr a0 +1: + x86mttop 0 + b 2f + x86mttop 1 + b 2f + x86mttop 2 + b 2f + x86mttop 3 + b 2f + x86mttop 4 + b 2f + x86mttop 5 + b 2f + x86mttop 6 + b 2f + x86mttop 7 +2: + li.w a0, 0 # success + jr ra +SYM_FUNC_END(_restore_ftop_context) + +.L_lbt_fault: + li.w a0, -EFAULT # failure + jr ra |