lbt.S

  1/* SPDX-License-Identifier: GPL-2.0 */
  2/*
  3 * Author: Qi Hu <huqi@loongson.cn>
  4 *         Huacai Chen <chenhuacai@loongson.cn>
  5 *
  6 * Copyright (C) 2020-2023 Loongson Technology Corporation Limited
  7 */
  8#include <asm/asm.h>
  9#include <asm/asmmacro.h>
 10#include <asm/asm-extable.h>
 11#include <asm/asm-offsets.h>
 12#include <asm/errno.h>
 13#include <asm/regdef.h>
 14#include <asm/unwind_hints.h>
 15
 16#define SCR_REG_WIDTH 8
 17
 18	.macro	EX insn, reg, src, offs
 19.ex\@:	\insn	\reg, \src, \offs
 20	_asm_extable .ex\@, .L_lbt_fault
 21	.endm
 22
 23/*
 24 * Save a thread's lbt context.
 25 */
 26SYM_FUNC_START(_save_lbt)
 27	movscr2gr	t1, $scr0		# save scr
 28	stptr.d		t1, a0, THREAD_SCR0
 29	movscr2gr	t1, $scr1
 30	stptr.d		t1, a0, THREAD_SCR1
 31	movscr2gr	t1, $scr2
 32	stptr.d		t1, a0, THREAD_SCR2
 33	movscr2gr	t1, $scr3
 34	stptr.d		t1, a0, THREAD_SCR3
 35
 36	x86mfflag	t1, 0x3f		# save eflags
 37	stptr.d		t1, a0, THREAD_EFLAGS
 38	jr		ra
 39SYM_FUNC_END(_save_lbt)
 40EXPORT_SYMBOL(_save_lbt)
 41
 42/*
 43 * Restore a thread's lbt context.
 44 */
 45SYM_FUNC_START(_restore_lbt)
 46	ldptr.d		t1, a0, THREAD_SCR0	# restore scr
 47	movgr2scr	$scr0, t1
 48	ldptr.d		t1, a0, THREAD_SCR1
 49	movgr2scr	$scr1, t1
 50	ldptr.d		t1, a0, THREAD_SCR2
 51	movgr2scr	$scr2, t1
 52	ldptr.d		t1, a0, THREAD_SCR3
 53	movgr2scr	$scr3, t1
 54
 55	ldptr.d		t1, a0, THREAD_EFLAGS	# restore eflags
 56	x86mtflag	t1, 0x3f
 57	jr		ra
 58SYM_FUNC_END(_restore_lbt)
 59EXPORT_SYMBOL(_restore_lbt)
 60
 61/*
 62 * Load scr/eflag with zero.
 63 */
 64SYM_FUNC_START(_init_lbt)
 65	movgr2scr	$scr0, zero
 66	movgr2scr	$scr1, zero
 67	movgr2scr	$scr2, zero
 68	movgr2scr	$scr3, zero
 69
 70	x86mtflag	zero, 0x3f
 71	jr		ra
 72SYM_FUNC_END(_init_lbt)
 73
 74/*
 75 * a0: scr
 76 * a1: eflag
 77 */
 78SYM_FUNC_START(_save_lbt_context)
 79	movscr2gr	t1, $scr0		# save scr
 80	EX	st.d	t1, a0, (0 * SCR_REG_WIDTH)
 81	movscr2gr	t1, $scr1
 82	EX	st.d	t1, a0, (1 * SCR_REG_WIDTH)
 83	movscr2gr	t1, $scr2
 84	EX	st.d	t1, a0, (2 * SCR_REG_WIDTH)
 85	movscr2gr	t1, $scr3
 86	EX	st.d	t1, a0, (3 * SCR_REG_WIDTH)
 87
 88	x86mfflag	t1, 0x3f		# save eflags
 89	EX 	st.w	t1, a1, 0
 90	li.w		a0, 0			# success
 91	jr		ra
 92SYM_FUNC_END(_save_lbt_context)
 93EXPORT_SYMBOL_GPL(_save_lbt_context)
 94
 95/*
 96 * a0: scr
 97 * a1: eflag
 98 */
 99SYM_FUNC_START(_restore_lbt_context)
100	EX	ld.d	t1, a0, (0 * SCR_REG_WIDTH)	# restore scr
101	movgr2scr	$scr0, t1
102	EX	ld.d	t1, a0, (1 * SCR_REG_WIDTH)
103	movgr2scr	$scr1, t1
104	EX	ld.d	t1, a0, (2 * SCR_REG_WIDTH)
105	movgr2scr	$scr2, t1
106	EX	ld.d	t1, a0, (3 * SCR_REG_WIDTH)
107	movgr2scr	$scr3, t1
108
109	EX 	ld.w	t1, a1, 0			# restore eflags
110	x86mtflag	t1, 0x3f
111	li.w		a0, 0			# success
112	jr		ra
113SYM_FUNC_END(_restore_lbt_context)
114EXPORT_SYMBOL_GPL(_restore_lbt_context)
115
116/*
117 * a0: ftop
118 */
119SYM_FUNC_START(_save_ftop_context)
120	x86mftop	t1
121	st.w		t1, a0, 0
122	li.w		a0, 0			# success
123	jr		ra
124SYM_FUNC_END(_save_ftop_context)
125EXPORT_SYMBOL_GPL(_save_ftop_context)
126
127/*
128 * a0: ftop
129 */
130SYM_FUNC_START(_restore_ftop_context)
131	ld.w		t1, a0, 0
132	andi		t1, t1, 0x7
133	la.pcrel	a0, 1f
134	alsl.d		a0, t1, a0, 3
135	jr		a0
1361:
137	x86mttop	0
138	b	2f
139	x86mttop	1
140	b	2f
141	x86mttop	2
142	b	2f
143	x86mttop	3
144	b	2f
145	x86mttop	4
146	b	2f
147	x86mttop	5
148	b	2f
149	x86mttop	6
150	b	2f
151	x86mttop	7
1522:
153	li.w		a0, 0			# success
154	jr		ra
155SYM_FUNC_END(_restore_ftop_context)
156EXPORT_SYMBOL_GPL(_restore_ftop_context)
157
158.L_lbt_fault:
159	li.w		a0, -EFAULT		# failure
160	jr		ra
161
162STACK_FRAME_NON_STANDARD _restore_ftop_context