This source file includes following definitions.
- arch_futex_atomic_op_inuser
- futex_atomic_cmpxchg_inatomic
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7 #ifndef _ASM_FUTEX_H
8 #define _ASM_FUTEX_H
9
10 #include <linux/futex.h>
11 #include <linux/uaccess.h>
12 #include <linux/errno.h>
13 #include <asm/asm.h>
14
15 #define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
16 { \
17 uintptr_t tmp; \
18 __enable_user_access(); \
19 __asm__ __volatile__ ( \
20 "1: " insn " \n" \
21 "2: \n" \
22 " .section .fixup,\"ax\" \n" \
23 " .balign 4 \n" \
24 "3: li %[r],%[e] \n" \
25 " jump 2b,%[t] \n" \
26 " .previous \n" \
27 " .section __ex_table,\"a\" \n" \
28 " .balign " RISCV_SZPTR " \n" \
29 " " RISCV_PTR " 1b, 3b \n" \
30 " .previous \n" \
31 : [r] "+r" (ret), [ov] "=&r" (oldval), \
32 [u] "+m" (*uaddr), [t] "=&r" (tmp) \
33 : [op] "Jr" (oparg), [e] "i" (-EFAULT) \
34 : "memory"); \
35 __disable_user_access(); \
36 }
37
38 static inline int
39 arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr)
40 {
41 int oldval = 0, ret = 0;
42
43 pagefault_disable();
44
45 switch (op) {
46 case FUTEX_OP_SET:
47 __futex_atomic_op("amoswap.w.aqrl %[ov],%z[op],%[u]",
48 ret, oldval, uaddr, oparg);
49 break;
50 case FUTEX_OP_ADD:
51 __futex_atomic_op("amoadd.w.aqrl %[ov],%z[op],%[u]",
52 ret, oldval, uaddr, oparg);
53 break;
54 case FUTEX_OP_OR:
55 __futex_atomic_op("amoor.w.aqrl %[ov],%z[op],%[u]",
56 ret, oldval, uaddr, oparg);
57 break;
58 case FUTEX_OP_ANDN:
59 __futex_atomic_op("amoand.w.aqrl %[ov],%z[op],%[u]",
60 ret, oldval, uaddr, ~oparg);
61 break;
62 case FUTEX_OP_XOR:
63 __futex_atomic_op("amoxor.w.aqrl %[ov],%z[op],%[u]",
64 ret, oldval, uaddr, oparg);
65 break;
66 default:
67 ret = -ENOSYS;
68 }
69
70 pagefault_enable();
71
72 if (!ret)
73 *oval = oldval;
74
75 return ret;
76 }
77
78 static inline int
79 futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
80 u32 oldval, u32 newval)
81 {
82 int ret = 0;
83 u32 val;
84 uintptr_t tmp;
85
86 if (!access_ok(uaddr, sizeof(u32)))
87 return -EFAULT;
88
89 __enable_user_access();
90 __asm__ __volatile__ (
91 "1: lr.w.aqrl %[v],%[u] \n"
92 " bne %[v],%z[ov],3f \n"
93 "2: sc.w.aqrl %[t],%z[nv],%[u] \n"
94 " bnez %[t],1b \n"
95 "3: \n"
96 " .section .fixup,\"ax\" \n"
97 " .balign 4 \n"
98 "4: li %[r],%[e] \n"
99 " jump 3b,%[t] \n"
100 " .previous \n"
101 " .section __ex_table,\"a\" \n"
102 " .balign " RISCV_SZPTR " \n"
103 " " RISCV_PTR " 1b, 4b \n"
104 " " RISCV_PTR " 2b, 4b \n"
105 " .previous \n"
106 : [r] "+r" (ret), [v] "=&r" (val), [u] "+m" (*uaddr), [t] "=&r" (tmp)
107 : [ov] "Jr" (oldval), [nv] "Jr" (newval), [e] "i" (-EFAULT)
108 : "memory");
109 __disable_user_access();
110
111 *uval = val;
112 return ret;
113 }
114
115 #endif