1
2
3
4
5
6
7
8
9
10
11#ifndef _ASM_FUTEX_H
12#define _ASM_FUTEX_H
13
14#include <linux/futex.h>
15#include <linux/preempt.h>
16#include <linux/uaccess.h>
17#include <asm/errno.h>
18
19#ifdef CONFIG_ARC_HAS_LLSC
20
21#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg)\
22 \
23 smp_mb(); \
24 __asm__ __volatile__( \
25 "1: llock %1, [%2] \n" \
26 insn "\n" \
27 "2: scond %0, [%2] \n" \
28 " bnz 1b \n" \
29 " mov %0, 0 \n" \
30 "3: \n" \
31 " .section .fixup,\"ax\" \n" \
32 " .align 4 \n" \
33 "4: mov %0, %4 \n" \
34 " j 3b \n" \
35 " .previous \n" \
36 " .section __ex_table,\"a\" \n" \
37 " .align 4 \n" \
38 " .word 1b, 4b \n" \
39 " .word 2b, 4b \n" \
40 " .previous \n" \
41 \
42 : "=&r" (ret), "=&r" (oldval) \
43 : "r" (uaddr), "r" (oparg), "ir" (-EFAULT) \
44 : "cc", "memory"); \
45 smp_mb() \
46
47#else
48
49#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg)\
50 \
51 smp_mb(); \
52 __asm__ __volatile__( \
53 "1: ld %1, [%2] \n" \
54 insn "\n" \
55 "2: st %0, [%2] \n" \
56 " mov %0, 0 \n" \
57 "3: \n" \
58 " .section .fixup,\"ax\" \n" \
59 " .align 4 \n" \
60 "4: mov %0, %4 \n" \
61 " j 3b \n" \
62 " .previous \n" \
63 " .section __ex_table,\"a\" \n" \
64 " .align 4 \n" \
65 " .word 1b, 4b \n" \
66 " .word 2b, 4b \n" \
67 " .previous \n" \
68 \
69 : "=&r" (ret), "=&r" (oldval) \
70 : "r" (uaddr), "r" (oparg), "ir" (-EFAULT) \
71 : "cc", "memory"); \
72 smp_mb() \
73
74#endif
75
76static inline int futex_atomic_op_inuser(int encoded_op, u32 __user *uaddr)
77{
78 int op = (encoded_op >> 28) & 7;
79 int cmp = (encoded_op >> 24) & 15;
80 int oparg = (encoded_op << 8) >> 20;
81 int cmparg = (encoded_op << 20) >> 20;
82 int oldval = 0, ret;
83
84 if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
85 oparg = 1 << oparg;
86
87 if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
88 return -EFAULT;
89
90#ifndef CONFIG_ARC_HAS_LLSC
91 preempt_disable();
92#endif
93 pagefault_disable();
94
95 switch (op) {
96 case FUTEX_OP_SET:
97 __futex_atomic_op("mov %0, %3", ret, oldval, uaddr, oparg);
98 break;
99 case FUTEX_OP_ADD:
100
101 __futex_atomic_op("add %0, %1, %3", ret, oldval, uaddr, oparg);
102 break;
103 case FUTEX_OP_OR:
104 __futex_atomic_op("or %0, %1, %3", ret, oldval, uaddr, oparg);
105 break;
106 case FUTEX_OP_ANDN:
107 __futex_atomic_op("bic %0, %1, %3", ret, oldval, uaddr, oparg);
108 break;
109 case FUTEX_OP_XOR:
110 __futex_atomic_op("xor %0, %1, %3", ret, oldval, uaddr, oparg);
111 break;
112 default:
113 ret = -ENOSYS;
114 }
115
116 pagefault_enable();
117#ifndef CONFIG_ARC_HAS_LLSC
118 preempt_enable();
119#endif
120
121 if (!ret) {
122 switch (cmp) {
123 case FUTEX_OP_CMP_EQ:
124 ret = (oldval == cmparg);
125 break;
126 case FUTEX_OP_CMP_NE:
127 ret = (oldval != cmparg);
128 break;
129 case FUTEX_OP_CMP_LT:
130 ret = (oldval < cmparg);
131 break;
132 case FUTEX_OP_CMP_GE:
133 ret = (oldval >= cmparg);
134 break;
135 case FUTEX_OP_CMP_LE:
136 ret = (oldval <= cmparg);
137 break;
138 case FUTEX_OP_CMP_GT:
139 ret = (oldval > cmparg);
140 break;
141 default:
142 ret = -ENOSYS;
143 }
144 }
145 return ret;
146}
147
148
149
150
151
152static inline int
153futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, u32 expval,
154 u32 newval)
155{
156 int ret = 0;
157 u32 existval;
158
159 if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
160 return -EFAULT;
161
162#ifndef CONFIG_ARC_HAS_LLSC
163 preempt_disable();
164#endif
165 smp_mb();
166
167 __asm__ __volatile__(
168#ifdef CONFIG_ARC_HAS_LLSC
169 "1: llock %1, [%4] \n"
170 " brne %1, %2, 3f \n"
171 "2: scond %3, [%4] \n"
172 " bnz 1b \n"
173#else
174 "1: ld %1, [%4] \n"
175 " brne %1, %2, 3f \n"
176 "2: st %3, [%4] \n"
177#endif
178 "3: \n"
179 " .section .fixup,\"ax\" \n"
180 "4: mov %0, %5 \n"
181 " j 3b \n"
182 " .previous \n"
183 " .section __ex_table,\"a\" \n"
184 " .align 4 \n"
185 " .word 1b, 4b \n"
186 " .word 2b, 4b \n"
187 " .previous\n"
188 : "+&r"(ret), "=&r"(existval)
189 : "r"(expval), "r"(newval), "r"(uaddr), "ir"(-EFAULT)
190 : "cc", "memory");
191
192 smp_mb();
193
194#ifndef CONFIG_ARC_HAS_LLSC
195 preempt_enable();
196#endif
197 *uval = existval;
198 return ret;
199}
200
201#endif
202
