[GitHub/mt8127/android_kernel_alcatel_ttab.git] / arch / arm64 / lib / copy_in_user.S

/*
 * Copy from user space to user space
 *
 * Copyright (C) 2012 ARM Ltd.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <linux/linkage.h>
#include <asm/assembler.h>

/*
 * Copy from user space to user space (alignment handled by the hardware)
 *
 * Parameters:
 *	x0 - to
 *	x1 - from
 *	x2 - n
 * Returns:
 *	x0 - bytes not copied
 */
ENTRY(__copy_in_user)
	add	x4, x0, x2			// upper user buffer boundary
	subs	x2, x2, #8
	b.mi	2f
1:
USER(9f, ldr	x3, [x1], #8	)
	subs	x2, x2, #8
USER(9f, str	x3, [x0], #8	)
	b.pl	1b
2:	adds	x2, x2, #4
	b.mi	3f
USER(9f, ldr	w3, [x1], #4	)
	sub	x2, x2, #4
USER(9f, str	w3, [x0], #4	)
3:	adds	x2, x2, #2
	b.mi	4f
USER(9f, ldrh	w3, [x1], #2	)
	sub	x2, x2, #2
USER(9f, strh	w3, [x0], #2	)
4:	adds	x2, x2, #1
	b.mi	5f
USER(9f, ldrb	w3, [x1]	)
USER(9f, strb	w3, [x0]	)
5:	mov	x0, #0
	ret
ENDPROC(__copy_in_user)

	.section .fixup,"ax"
	.align	2
9:	sub	x0, x4, x0			// bytes not copied
	ret
	.previous
Commit	Line	Data
0aea86a2 CM	1	/*
	2	* Copy from user space to user space
	3	*
	4	* Copyright (C) 2012 ARM Ltd.
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License version 2 as
	8	* published by the Free Software Foundation.
	9	*
	10	* This program is distributed in the hope that it will be useful,
	11	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	13	* GNU General Public License for more details.
	14	*
	15	* You should have received a copy of the GNU General Public License
	16	* along with this program. If not, see <http://www.gnu.org/licenses/>.
	17	*/
	18
	19	#include <linux/linkage.h>
	20	#include <asm/assembler.h>
	21
	22	/*
	23	* Copy from user space to user space (alignment handled by the hardware)
	24	*
	25	* Parameters:
	26	* x0 - to
	27	* x1 - from
	28	* x2 - n
	29	* Returns:
	30	* x0 - bytes not copied
	31	*/
	32	ENTRY(__copy_in_user)
	33	add x4, x0, x2 // upper user buffer boundary
	34	subs x2, x2, #8
	35	b.mi 2f
	36	1:
	37	USER(9f, ldr x3, [x1], #8 )
	38	subs x2, x2, #8
	39	USER(9f, str x3, [x0], #8 )
	40	b.pl 1b
	41	2: adds x2, x2, #4
	42	b.mi 3f
	43	USER(9f, ldr w3, [x1], #4 )
	44	sub x2, x2, #4
	45	USER(9f, str w3, [x0], #4 )
	46	3: adds x2, x2, #2
	47	b.mi 4f
	48	USER(9f, ldrh w3, [x1], #2 )
	49	sub x2, x2, #2
	50	USER(9f, strh w3, [x0], #2 )
	51	4: adds x2, x2, #1
	52	b.mi 5f
	53	USER(9f, ldrb w3, [x1] )
	54	USER(9f, strb w3, [x0] )
	55	5: mov x0, #0
	56	ret
	57	ENDPROC(__copy_in_user)
	58
	59	.section .fixup,"ax"
	60	.align 2
	61	9: sub x0, x4, x0 // bytes not copied
	62	ret
	63	.previous