[linux-2.6-block.git] / arch / loongarch / lib / copy_user.S

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
 */

#include <asm/alternative-asm.h>
#include <asm/asm.h>
#include <asm/asmmacro.h>
#include <asm/asm-extable.h>
#include <asm/cpu.h>
#include <asm/export.h>
#include <asm/regdef.h>

.irp to, 0, 1, 2, 3, 4, 5, 6, 7
.L_fixup_handle_\to\():
	addi.d	a0, a2, (\to) * (-8)
	jr	ra
.endr

SYM_FUNC_START(__copy_user)
	/*
	 * Some CPUs support hardware unaligned access
	 */
	ALTERNATIVE	"b __copy_user_generic",	\
			"b __copy_user_fast", CPU_FEATURE_UAL
SYM_FUNC_END(__copy_user)

EXPORT_SYMBOL(__copy_user)

/*
 * unsigned long __copy_user_generic(void *to, const void *from, size_t n)
 *
 * a0: to
 * a1: from
 * a2: n
 */
SYM_FUNC_START(__copy_user_generic)
	beqz	a2, 3f

1:	ld.b	t0, a1, 0
2:	st.b	t0, a0, 0
	addi.d	a0, a0, 1
	addi.d	a1, a1, 1
	addi.d	a2, a2, -1
	bgtz	a2, 1b

3:	move	a0, a2
	jr	ra

	_asm_extable 1b, .L_fixup_handle_0
	_asm_extable 2b, .L_fixup_handle_0
SYM_FUNC_END(__copy_user_generic)

/*
 * unsigned long __copy_user_fast(void *to, const void *from, unsigned long n)
 *
 * a0: to
 * a1: from
 * a2: n
 */
SYM_FUNC_START(__copy_user_fast)
	beqz	a2, 19f

	ori	a3, zero, 64
	blt	a2, a3, 17f

	/* copy 64 bytes at a time */
1:	ld.d	t0, a1, 0
2:	ld.d	t1, a1, 8
3:	ld.d	t2, a1, 16
4:	ld.d	t3, a1, 24
5:	ld.d	t4, a1, 32
6:	ld.d	t5, a1, 40
7:	ld.d	t6, a1, 48
8:	ld.d	t7, a1, 56
9:	st.d	t0, a0, 0
10:	st.d	t1, a0, 8
11:	st.d	t2, a0, 16
12:	st.d	t3, a0, 24
13:	st.d	t4, a0, 32
14:	st.d	t5, a0, 40
15:	st.d	t6, a0, 48
16:	st.d	t7, a0, 56

	addi.d	a0, a0, 64
	addi.d	a1, a1, 64
	addi.d	a2, a2, -64
	bge	a2, a3, 1b

	beqz	a2, 19f

	/* copy the remaining bytes */
17:	ld.b	t0, a1, 0
18:	st.b	t0, a0, 0
	addi.d	a0, a0, 1
	addi.d	a1, a1, 1
	addi.d	a2, a2, -1
	bgt	a2, zero, 17b

	/* return */
19:	move	a0, a2
	jr	ra

	/* fixup and ex_table */
	_asm_extable 1b, .L_fixup_handle_0
	_asm_extable 2b, .L_fixup_handle_1
	_asm_extable 3b, .L_fixup_handle_2
	_asm_extable 4b, .L_fixup_handle_3
	_asm_extable 5b, .L_fixup_handle_4
	_asm_extable 6b, .L_fixup_handle_5
	_asm_extable 7b, .L_fixup_handle_6
	_asm_extable 8b, .L_fixup_handle_7
	_asm_extable 9b, .L_fixup_handle_0
	_asm_extable 10b, .L_fixup_handle_1
	_asm_extable 11b, .L_fixup_handle_2
	_asm_extable 12b, .L_fixup_handle_3
	_asm_extable 13b, .L_fixup_handle_4
	_asm_extable 14b, .L_fixup_handle_5
	_asm_extable 15b, .L_fixup_handle_6
	_asm_extable 16b, .L_fixup_handle_7
	_asm_extable 17b, .L_fixup_handle_0
	_asm_extable 18b, .L_fixup_handle_0
SYM_FUNC_END(__copy_user_fast)
Commit	Line	Data
559671e0 HC	1	/* SPDX-License-Identifier: GPL-2.0 */
	2	/*
	3	* Copyright (C) 2020-2022 Loongson Technology Corporation Limited
	4	*/
	5
a275a82d	6	#include <asm/alternative-asm.h>
559671e0 HC	7	#include <asm/asm.h>
559671e0 HC	8	#include <asm/asmmacro.h>
508f28c6	9	#include <asm/asm-extable.h>
a275a82d	10	#include <asm/cpu.h>
559671e0 HC	11	#include <asm/export.h>
	12	#include <asm/regdef.h>
	13
a275a82d	14	.irp to, 0, 1, 2, 3, 4, 5, 6, 7
912bcfaf YT	15	.L_fixup_handle_\to\():
912bcfaf YT	16	addi.d a0, a2, (\to) * (-8)
559671e0	17	jr ra
912bcfaf	18	.endr
559671e0	19
a275a82d HC	20	SYM_FUNC_START(__copy_user)
	21	/*
	22	* Some CPUs support hardware unaligned access
	23	*/
	24	ALTERNATIVE "b __copy_user_generic", \
	25	"b __copy_user_fast", CPU_FEATURE_UAL
	26	SYM_FUNC_END(__copy_user)
	27
	28	EXPORT_SYMBOL(__copy_user)
	29
559671e0	30	/*
a275a82d	31	* unsigned long __copy_user_generic(void to, const void from, size_t n)
559671e0 HC	32	*
	33	* a0: to
	34	* a1: from
	35	* a2: n
	36	*/
a275a82d	37	SYM_FUNC_START(__copy_user_generic)
559671e0 HC	38	beqz a2, 3f
	39
	40	1: ld.b t0, a1, 0
	41	2: st.b t0, a0, 0
	42	addi.d a0, a0, 1
	43	addi.d a1, a1, 1
	44	addi.d a2, a2, -1
1fdb9a92	45	bgtz a2, 1b
559671e0 HC	46
	47	3: move a0, a2
	48	jr ra
	49
912bcfaf YT	50	_asm_extable 1b, .L_fixup_handle_0
912bcfaf YT	51	_asm_extable 2b, .L_fixup_handle_0
a275a82d	52	SYM_FUNC_END(__copy_user_generic)
559671e0	53
a275a82d HC	54	/*
	55	* unsigned long __copy_user_fast(void to, const void from, unsigned long n)
	56	*
	57	* a0: to
	58	* a1: from
	59	* a2: n
	60	*/
	61	SYM_FUNC_START(__copy_user_fast)
	62	beqz a2, 19f
	63
	64	ori a3, zero, 64
	65	blt a2, a3, 17f
	66
	67	/* copy 64 bytes at a time */
	68	1: ld.d t0, a1, 0
	69	2: ld.d t1, a1, 8
	70	3: ld.d t2, a1, 16
	71	4: ld.d t3, a1, 24
	72	5: ld.d t4, a1, 32
	73	6: ld.d t5, a1, 40
	74	7: ld.d t6, a1, 48
	75	8: ld.d t7, a1, 56
	76	9: st.d t0, a0, 0
	77	10: st.d t1, a0, 8
	78	11: st.d t2, a0, 16
	79	12: st.d t3, a0, 24
	80	13: st.d t4, a0, 32
	81	14: st.d t5, a0, 40
	82	15: st.d t6, a0, 48
	83	16: st.d t7, a0, 56
	84
	85	addi.d a0, a0, 64
	86	addi.d a1, a1, 64
	87	addi.d a2, a2, -64
	88	bge a2, a3, 1b
	89
	90	beqz a2, 19f
	91
	92	/* copy the remaining bytes */
	93	17: ld.b t0, a1, 0
	94	18: st.b t0, a0, 0
	95	addi.d a0, a0, 1
	96	addi.d a1, a1, 1
	97	addi.d a2, a2, -1
	98	bgt a2, zero, 17b
	99
	100	/* return */
	101	19: move a0, a2
	102	jr ra
	103
	104	/* fixup and ex_table */
	105	_asm_extable 1b, .L_fixup_handle_0
	106	_asm_extable 2b, .L_fixup_handle_1
	107	_asm_extable 3b, .L_fixup_handle_2
	108	_asm_extable 4b, .L_fixup_handle_3
	109	_asm_extable 5b, .L_fixup_handle_4
	110	_asm_extable 6b, .L_fixup_handle_5
	111	_asm_extable 7b, .L_fixup_handle_6
	112	_asm_extable 8b, .L_fixup_handle_7
	113	_asm_extable 9b, .L_fixup_handle_0
	114	_asm_extable 10b, .L_fixup_handle_1
	115	_asm_extable 11b, .L_fixup_handle_2
	116	_asm_extable 12b, .L_fixup_handle_3
	117	_asm_extable 13b, .L_fixup_handle_4
118	_asm_extable 14b, .L_fixup_handle_5
119	_asm_extable 15b, .L_fixup_handle_6
120	_asm_extable 16b, .L_fixup_handle_7
121	_asm_extable 17b, .L_fixup_handle_0
122	_asm_extable 18b, .L_fixup_handle_0
123	SYM_FUNC_END(__copy_user_fast)