/* 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>
#include <asm/unwind_hints.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)
EXPORT_SYMBOL_GPL(_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)
EXPORT_SYMBOL_GPL(_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)
EXPORT_SYMBOL_GPL(_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)
EXPORT_SYMBOL_GPL(_restore_ftop_context)
.L_lbt_fault:
li.w a0, -EFAULT # failure
jr ra
STACK_FRAME_NON_STANDARD _restore_ftop_context
