xref: /openbmc/linux/arch/mips/include/asm/futex.h (revision d87c25e8)
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 arch_futex_atomic_op_inuser arch_futex_atomic_op_inuser
23 #define futex_atomic_cmpxchg_inatomic futex_atomic_cmpxchg_inatomic
24 #include <asm-generic/futex.h>
25 
26 #define __futex_atomic_op(op, insn, ret, oldval, uaddr, oparg)		\
27 {									\
28 	if (cpu_has_llsc && IS_ENABLED(CONFIG_WAR_R10000_LLSC)) {	\
29 		__asm__ __volatile__(					\
30 		"	.set	push				\n"	\
31 		"	.set	noat				\n"	\
32 		"	.set	push				\n"	\
33 		"	.set	arch=r4000			\n"	\
34 		"1:	ll	%1, %4	# __futex_atomic_op	\n"	\
35 		"	.set	pop				\n"	\
36 		"	" insn	"				\n"	\
37 		"	.set	arch=r4000			\n"	\
38 		"2:	sc	$1, %2				\n"	\
39 		"	beqzl	$1, 1b				\n"	\
40 		__stringify(__WEAK_LLSC_MB) "			\n"	\
41 		"3:						\n"	\
42 		"	.insn					\n"	\
43 		"	.set	pop				\n"	\
44 		"	.section .fixup,\"ax\"			\n"	\
45 		"4:	li	%0, %6				\n"	\
46 		"	j	3b				\n"	\
47 		"	.previous				\n"	\
48 		"	.section __ex_table,\"a\"		\n"	\
49 		"	"__UA_ADDR "\t1b, 4b			\n"	\
50 		"	"__UA_ADDR "\t2b, 4b			\n"	\
51 		"	.previous				\n"	\
52 		: "=r" (ret), "=&r" (oldval),				\
53 		  "=" GCC_OFF_SMALL_ASM() (*uaddr)				\
54 		: "0" (0), GCC_OFF_SMALL_ASM() (*uaddr), "Jr" (oparg),	\
55 		  "i" (-EFAULT)						\
56 		: "memory");						\
57 	} else if (cpu_has_llsc) {					\
58 		__asm__ __volatile__(					\
59 		"	.set	push				\n"	\
60 		"	.set	noat				\n"	\
61 		"	.set	push				\n"	\
62 		"	.set	"MIPS_ISA_ARCH_LEVEL"		\n"	\
63 		"	" __SYNC(full, loongson3_war) "		\n"	\
64 		"1:	"user_ll("%1", "%4")" # __futex_atomic_op\n"	\
65 		"	.set	pop				\n"	\
66 		"	" insn	"				\n"	\
67 		"	.set	"MIPS_ISA_ARCH_LEVEL"		\n"	\
68 		"2:	"user_sc("$1", "%2")"			\n"	\
69 		"	beqz	$1, 1b				\n"	\
70 		__stringify(__WEAK_LLSC_MB) "			\n"	\
71 		"3:						\n"	\
72 		"	.insn					\n"	\
73 		"	.set	pop				\n"	\
74 		"	.section .fixup,\"ax\"			\n"	\
75 		"4:	li	%0, %6				\n"	\
76 		"	j	3b				\n"	\
77 		"	.previous				\n"	\
78 		"	.section __ex_table,\"a\"		\n"	\
79 		"	"__UA_ADDR "\t1b, 4b			\n"	\
80 		"	"__UA_ADDR "\t2b, 4b			\n"	\
81 		"	.previous				\n"	\
82 		: "=r" (ret), "=&r" (oldval),				\
83 		  "=" GCC_OFF_SMALL_ASM() (*uaddr)				\
84 		: "0" (0), GCC_OFF_SMALL_ASM() (*uaddr), "Jr" (oparg),	\
85 		  "i" (-EFAULT)						\
86 		: "memory");						\
87 	} else {							\
88 		/* fallback for non-SMP */				\
89 		ret = futex_atomic_op_inuser_local(op, oparg, oval, uaddr);	\
90 	}								\
91 }
92 
93 static inline int
94 arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr)
95 {
96 	int oldval = 0, ret;
97 
98 	if (!access_ok(uaddr, sizeof(u32)))
99 		return -EFAULT;
100 
101 	switch (op) {
102 	case FUTEX_OP_SET:
103 		__futex_atomic_op(op, "move $1, %z5", ret, oldval, uaddr, oparg);
104 		break;
105 
106 	case FUTEX_OP_ADD:
107 		__futex_atomic_op(op, "addu $1, %1, %z5",
108 				  ret, oldval, uaddr, oparg);
109 		break;
110 	case FUTEX_OP_OR:
111 		__futex_atomic_op(op, "or	$1, %1, %z5",
112 				  ret, oldval, uaddr, oparg);
113 		break;
114 	case FUTEX_OP_ANDN:
115 		__futex_atomic_op(op, "and	$1, %1, %z5",
116 				  ret, oldval, uaddr, ~oparg);
117 		break;
118 	case FUTEX_OP_XOR:
119 		__futex_atomic_op(op, "xor	$1, %1, %z5",
120 				  ret, oldval, uaddr, oparg);
121 		break;
122 	default:
123 		ret = -ENOSYS;
124 	}
125 
126 	if (!ret)
127 		*oval = oldval;
128 
129 	return ret;
130 }
131 
132 static inline int
133 futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
134 			      u32 oldval, u32 newval)
135 {
136 	int ret = 0;
137 	u32 val;
138 
139 	if (!access_ok(uaddr, sizeof(u32)))
140 		return -EFAULT;
141 
142 	if (cpu_has_llsc && IS_ENABLED(CONFIG_WAR_R10000_LLSC)) {
143 		__asm__ __volatile__(
144 		"# futex_atomic_cmpxchg_inatomic			\n"
145 		"	.set	push					\n"
146 		"	.set	noat					\n"
147 		"	.set	push					\n"
148 		"	.set	arch=r4000				\n"
149 		"1:	ll	%1, %3					\n"
150 		"	bne	%1, %z4, 3f				\n"
151 		"	.set	pop					\n"
152 		"	move	$1, %z5					\n"
153 		"	.set	arch=r4000				\n"
154 		"2:	sc	$1, %2					\n"
155 		"	beqzl	$1, 1b					\n"
156 		__stringify(__WEAK_LLSC_MB) "				\n"
157 		"3:							\n"
158 		"	.insn						\n"
159 		"	.set	pop					\n"
160 		"	.section .fixup,\"ax\"				\n"
161 		"4:	li	%0, %6					\n"
162 		"	j	3b					\n"
163 		"	.previous					\n"
164 		"	.section __ex_table,\"a\"			\n"
165 		"	"__UA_ADDR "\t1b, 4b				\n"
166 		"	"__UA_ADDR "\t2b, 4b				\n"
167 		"	.previous					\n"
168 		: "+r" (ret), "=&r" (val), "=" GCC_OFF_SMALL_ASM() (*uaddr)
169 		: GCC_OFF_SMALL_ASM() (*uaddr), "Jr" (oldval), "Jr" (newval),
170 		  "i" (-EFAULT)
171 		: "memory");
172 	} else if (cpu_has_llsc) {
173 		__asm__ __volatile__(
174 		"# futex_atomic_cmpxchg_inatomic			\n"
175 		"	.set	push					\n"
176 		"	.set	noat					\n"
177 		"	.set	push					\n"
178 		"	.set	"MIPS_ISA_ARCH_LEVEL"			\n"
179 		"	" __SYNC(full, loongson3_war) "			\n"
180 		"1:	"user_ll("%1", "%3")"				\n"
181 		"	bne	%1, %z4, 3f				\n"
182 		"	.set	pop					\n"
183 		"	move	$1, %z5					\n"
184 		"	.set	"MIPS_ISA_ARCH_LEVEL"			\n"
185 		"2:	"user_sc("$1", "%2")"				\n"
186 		"	beqz	$1, 1b					\n"
187 		"3:	" __SYNC_ELSE(full, loongson3_war, __WEAK_LLSC_MB) "\n"
188 		"	.insn						\n"
189 		"	.set	pop					\n"
190 		"	.section .fixup,\"ax\"				\n"
191 		"4:	li	%0, %6					\n"
192 		"	j	3b					\n"
193 		"	.previous					\n"
194 		"	.section __ex_table,\"a\"			\n"
195 		"	"__UA_ADDR "\t1b, 4b				\n"
196 		"	"__UA_ADDR "\t2b, 4b				\n"
197 		"	.previous					\n"
198 		: "+r" (ret), "=&r" (val), "=" GCC_OFF_SMALL_ASM() (*uaddr)
199 		: GCC_OFF_SMALL_ASM() (*uaddr), "Jr" (oldval), "Jr" (newval),
200 		  "i" (-EFAULT)
201 		: "memory");
202 	} else {
203 		return futex_atomic_cmpxchg_inatomic_local(uval, uaddr, oldval, newval);
204 	}
205 
206 	*uval = val;
207 	return ret;
208 }
209 
210 #endif
211 #endif /* _ASM_FUTEX_H */
212