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
arch_futex_atomic_op_inuser(int op,int oparg,int * oval,u32 __user * uaddr)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
futex_atomic_cmpxchg_inatomic(u32 * uval,u32 __user * uaddr,u32 oldval,u32 newval)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