1/*
 2 * Copyright 2011 Tilera Corporation. All Rights Reserved.
 3 *
 4 *   This program is free software; you can redistribute it and/or
 5 *   modify it under the terms of the GNU General Public License
 6 *   as published by the Free Software Foundation, version 2.
 7 *
 8 *   This program is distributed in the hope that it will be useful, but
 9 *   WITHOUT ANY WARRANTY; without even the implied warranty of
10 *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
11 *   NON INFRINGEMENT.  See the GNU General Public License for
12 *   more details.
13 *
14 * Atomically access user memory, but use MMU to avoid propagating
15 * kernel exceptions.
16 */
17
18#include <linux/linkage.h>
19#include <asm/errno.h>
20#include <asm/futex.h>
21#include <asm/page.h>
22#include <asm/processor.h>
23
24/*
25 * Provide a set of atomic memory operations supporting <asm/futex.h>.
26 *
27 * r0: user address to manipulate
28 * r1: new value to write, or for cmpxchg, old value to compare against
29 * r2: (cmpxchg only) new value to write
30 *
31 * Return __get_user struct, r0 with value, r1 with error.
32 */
33#define FUTEX_OP(name, ...) \
34STD_ENTRY(futex_##name)			\
35	__VA_ARGS__;			\
36	{				\
37	 move   r1, zero;		\
38	 jrp    lr			\
39	};				\
40	STD_ENDPROC(futex_##name);	\
41	.pushsection __ex_table,"a";	\
42	.quad 1b, get_user_fault;	\
43	.popsection
44
45	.pushsection .fixup,"ax"
46get_user_fault:
47	{ movei r1, -EFAULT; jrp lr }
48	ENDPROC(get_user_fault)
49	.popsection
50
51FUTEX_OP(cmpxchg, mtspr CMPEXCH_VALUE, r1; 1: cmpexch4 r0, r0, r2)
52FUTEX_OP(set, 1: exch4 r0, r0, r1)
53FUTEX_OP(add, 1: fetchadd4 r0, r0, r1)
54FUTEX_OP(or, 1: fetchor4 r0, r0, r1)
55FUTEX_OP(andn, nor r1, r1, zero; 1: fetchand4 r0, r0, r1)

 1/*
 2 * Copyright 2011 Tilera Corporation. All Rights Reserved.
 3 *
 4 *   This program is free software; you can redistribute it and/or
 5 *   modify it under the terms of the GNU General Public License
 6 *   as published by the Free Software Foundation, version 2.
 7 *
 8 *   This program is distributed in the hope that it will be useful, but
 9 *   WITHOUT ANY WARRANTY; without even the implied warranty of
10 *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
11 *   NON INFRINGEMENT.  See the GNU General Public License for
12 *   more details.
13 *
14 * Atomically access user memory, but use MMU to avoid propagating
15 * kernel exceptions.
16 */
17
18#include <linux/linkage.h>
19#include <asm/errno.h>
20#include <asm/futex.h>
21#include <asm/page.h>
22#include <asm/processor.h>
23
24/*
25 * Provide a set of atomic memory operations supporting <asm/futex.h>.
26 *
27 * r0: user address to manipulate
28 * r1: new value to write, or for cmpxchg, old value to compare against
29 * r2: (cmpxchg only) new value to write
30 *
31 * Return __get_user struct, r0 with value, r1 with error.
32 */
33#define FUTEX_OP(name, ...) \
34STD_ENTRY(futex_##name)			\
35	__VA_ARGS__;			\
36	{				\
37	 move   r1, zero;		\
38	 jrp    lr			\
39	};				\
40	STD_ENDPROC(futex_##name);	\
41	.pushsection __ex_table,"a";	\
42	.quad 1b, get_user_fault;	\
43	.popsection
44
45	.pushsection .fixup,"ax"
46get_user_fault:
47	{ movei r1, -EFAULT; jrp lr }
48	ENDPROC(get_user_fault)
49	.popsection
50
51FUTEX_OP(cmpxchg, mtspr CMPEXCH_VALUE, r1; 1: cmpexch4 r0, r0, r2)
52FUTEX_OP(set, 1: exch4 r0, r0, r1)
53FUTEX_OP(add, 1: fetchadd4 r0, r0, r1)
54FUTEX_OP(or, 1: fetchor4 r0, r0, r1)
55FUTEX_OP(andn, nor r1, r1, zero; 1: fetchand4 r0, r0, r1)