xref: /openbmc/linux/arch/mips/include/asm/futex.h (revision 256ec489)
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 
87 static inline int
88 arch_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 
126 static inline int
127 futex_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