1/*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License.  See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * Copyright (c) 2006  Ralf Baechle (ralf@linux-mips.org)
7 */
8#ifndef _ASM_FUTEX_H
9#define _ASM_FUTEX_H
10
11#ifdef __KERNEL__
12
13#include <linux/futex.h>
14#include <linux/uaccess.h>
15#include <asm/asm-eva.h>
16#include <asm/barrier.h>
17#include <asm/compiler.h>
18#include <asm/errno.h>
19#include <asm/sync.h>
20#include <asm/war.h>
21
22#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg)		\
23{									\
24	if (cpu_has_llsc && IS_ENABLED(CONFIG_WAR_R10000_LLSC)) {	\
25		__asm__ __volatile__(					\
26		"	.set	push				\n"	\
27		"	.set	noat				\n"	\
28		"	.set	push				\n"	\
29		"	.set	arch=r4000			\n"	\
30		"1:	ll	%1, %4	# __futex_atomic_op	\n"	\
31		"	.set	pop				\n"	\
32		"	" insn	"				\n"	\
33		"	.set	arch=r4000			\n"	\
34		"2:	sc	$1, %2				\n"	\
35		"	beqzl	$1, 1b				\n"	\
36		__stringify(__WEAK_LLSC_MB) "			\n"	\
37		"3:						\n"	\
38		"	.insn					\n"	\
39		"	.set	pop				\n"	\
40		"	.section .fixup,\"ax\"			\n"	\
41		"4:	li	%0, %6				\n"	\
42		"	j	3b				\n"	\
43		"	.previous				\n"	\
44		"	.section __ex_table,\"a\"		\n"	\
45		"	"__UA_ADDR "\t1b, 4b			\n"	\
46		"	"__UA_ADDR "\t2b, 4b			\n"	\
47		"	.previous				\n"	\
48		: "=r" (ret), "=&r" (oldval),				\
49		  "=" GCC_OFF_SMALL_ASM() (*uaddr)				\
50		: "0" (0), GCC_OFF_SMALL_ASM() (*uaddr), "Jr" (oparg),	\
51		  "i" (-EFAULT)						\
52		: "memory");						\
53	} else if (cpu_has_llsc) {					\
54		__asm__ __volatile__(					\
55		"	.set	push				\n"	\
56		"	.set	noat				\n"	\
57		"	.set	push				\n"	\
58		"	.set	"MIPS_ISA_ARCH_LEVEL"		\n"	\
59		"	" __SYNC(full, loongson3_war) "		\n"	\
60		"1:	"user_ll("%1", "%4")" # __futex_atomic_op\n"	\
61		"	.set	pop				\n"	\
62		"	" insn	"				\n"	\
63		"	.set	"MIPS_ISA_ARCH_LEVEL"		\n"	\
64		"2:	"user_sc("$1", "%2")"			\n"	\
65		"	beqz	$1, 1b				\n"	\
66		__stringify(__WEAK_LLSC_MB) "			\n"	\
67		"3:						\n"	\
68		"	.insn					\n"	\
69		"	.set	pop				\n"	\
70		"	.section .fixup,\"ax\"			\n"	\
71		"4:	li	%0, %6				\n"	\
72		"	j	3b				\n"	\
73		"	.previous				\n"	\
74		"	.section __ex_table,\"a\"		\n"	\
75		"	"__UA_ADDR "\t1b, 4b			\n"	\
76		"	"__UA_ADDR "\t2b, 4b			\n"	\
77		"	.previous				\n"	\
78		: "=r" (ret), "=&r" (oldval),				\
79		  "=" GCC_OFF_SMALL_ASM() (*uaddr)				\
80		: "0" (0), GCC_OFF_SMALL_ASM() (*uaddr), "Jr" (oparg),	\
81		  "i" (-EFAULT)						\
82		: "memory");						\
83	} else								\
84		ret = -ENOSYS;						\
85}
86
87static inline int
88arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr)
89{
90	int oldval = 0, ret;
91
92	if (!access_ok(uaddr, sizeof(u32)))
93		return -EFAULT;
94
95	switch (op) {
96	case FUTEX_OP_SET:
97		__futex_atomic_op("move $1, %z5", ret, oldval, uaddr, oparg);
98		break;
99
100	case FUTEX_OP_ADD:
101		__futex_atomic_op("addu $1, %1, %z5",
102				  ret, oldval, uaddr, oparg);
103		break;
104	case FUTEX_OP_OR:
105		__futex_atomic_op("or	$1, %1, %z5",
106				  ret, oldval, uaddr, oparg);
107		break;
108	case FUTEX_OP_ANDN:
109		__futex_atomic_op("and	$1, %1, %z5",
110				  ret, oldval, uaddr, ~oparg);
111		break;
112	case FUTEX_OP_XOR:
113		__futex_atomic_op("xor	$1, %1, %z5",
114				  ret, oldval, uaddr, oparg);
115		break;
116	default:
117		ret = -ENOSYS;
118	}
119
120	if (!ret)
121		*oval = oldval;
122
123	return ret;
124}
125
126static inline int
127futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
128			      u32 oldval, u32 newval)
129{
130	int ret = 0;
131	u32 val;
132
133	if (!access_ok(uaddr, sizeof(u32)))
134		return -EFAULT;
135
136	if (cpu_has_llsc && IS_ENABLED(CONFIG_WAR_R10000_LLSC)) {
137		__asm__ __volatile__(
138		"# futex_atomic_cmpxchg_inatomic			\n"
139		"	.set	push					\n"
140		"	.set	noat					\n"
141		"	.set	push					\n"
142		"	.set	arch=r4000				\n"
143		"1:	ll	%1, %3					\n"
144		"	bne	%1, %z4, 3f				\n"
145		"	.set	pop					\n"
146		"	move	$1, %z5					\n"
147		"	.set	arch=r4000				\n"
148		"2:	sc	$1, %2					\n"
149		"	beqzl	$1, 1b					\n"
150		__stringify(__WEAK_LLSC_MB) "				\n"
151		"3:							\n"
152		"	.insn						\n"
153		"	.set	pop					\n"
154		"	.section .fixup,\"ax\"				\n"
155		"4:	li	%0, %6					\n"
156		"	j	3b					\n"
157		"	.previous					\n"
158		"	.section __ex_table,\"a\"			\n"
159		"	"__UA_ADDR "\t1b, 4b				\n"
160		"	"__UA_ADDR "\t2b, 4b				\n"
161		"	.previous					\n"
162		: "+r" (ret), "=&r" (val), "=" GCC_OFF_SMALL_ASM() (*uaddr)
163		: GCC_OFF_SMALL_ASM() (*uaddr), "Jr" (oldval), "Jr" (newval),
164		  "i" (-EFAULT)
165		: "memory");
166	} else if (cpu_has_llsc) {
167		__asm__ __volatile__(
168		"# futex_atomic_cmpxchg_inatomic			\n"
169		"	.set	push					\n"
170		"	.set	noat					\n"
171		"	.set	push					\n"
172		"	.set	"MIPS_ISA_ARCH_LEVEL"			\n"
173		"	" __SYNC(full, loongson3_war) "			\n"
174		"1:	"user_ll("%1", "%3")"				\n"
175		"	bne	%1, %z4, 3f				\n"
176		"	.set	pop					\n"
177		"	move	$1, %z5					\n"
178		"	.set	"MIPS_ISA_ARCH_LEVEL"			\n"
179		"2:	"user_sc("$1", "%2")"				\n"
180		"	beqz	$1, 1b					\n"
181		"3:	" __SYNC_ELSE(full, loongson3_war, __WEAK_LLSC_MB) "\n"
182		"	.insn						\n"
183		"	.set	pop					\n"
184		"	.section .fixup,\"ax\"				\n"
185		"4:	li	%0, %6					\n"
186		"	j	3b					\n"
187		"	.previous					\n"
188		"	.section __ex_table,\"a\"			\n"
189		"	"__UA_ADDR "\t1b, 4b				\n"
190		"	"__UA_ADDR "\t2b, 4b				\n"
191		"	.previous					\n"
192		: "+r" (ret), "=&r" (val), "=" GCC_OFF_SMALL_ASM() (*uaddr)
193		: GCC_OFF_SMALL_ASM() (*uaddr), "Jr" (oldval), "Jr" (newval),
194		  "i" (-EFAULT)
195		: "memory");
196	} else
197		return -ENOSYS;
198
199	*uval = val;
200	return ret;
201}
202
203#endif
204#endif /* _ASM_FUTEX_H */
205