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