1 #ifndef _ASM_PARISC_FUTEX_H
2 #define _ASM_PARISC_FUTEX_H
3
4 #ifdef __KERNEL__
5
6 #include <linux/futex.h>
7 #include <linux/uaccess.h>
8 #include <asm/atomic.h>
9 #include <asm/errno.h>
10
11 static inline int
futex_atomic_op_inuser(int encoded_op,u32 __user * uaddr)12 futex_atomic_op_inuser (int encoded_op, u32 __user *uaddr)
13 {
14 unsigned long int flags;
15 u32 val;
16 int op = (encoded_op >> 28) & 7;
17 int cmp = (encoded_op >> 24) & 15;
18 int oparg = (encoded_op << 8) >> 20;
19 int cmparg = (encoded_op << 20) >> 20;
20 int oldval = 0, ret;
21 if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
22 oparg = 1 << oparg;
23
24 if (!access_ok(VERIFY_WRITE, uaddr, sizeof(*uaddr)))
25 return -EFAULT;
26
27 pagefault_disable();
28
29 _atomic_spin_lock_irqsave(uaddr, flags);
30
31 switch (op) {
32 case FUTEX_OP_SET:
33 /* *(int *)UADDR2 = OPARG; */
34 ret = get_user(oldval, uaddr);
35 if (!ret)
36 ret = put_user(oparg, uaddr);
37 break;
38 case FUTEX_OP_ADD:
39 /* *(int *)UADDR2 += OPARG; */
40 ret = get_user(oldval, uaddr);
41 if (!ret) {
42 val = oldval + oparg;
43 ret = put_user(val, uaddr);
44 }
45 break;
46 case FUTEX_OP_OR:
47 /* *(int *)UADDR2 |= OPARG; */
48 ret = get_user(oldval, uaddr);
49 if (!ret) {
50 val = oldval | oparg;
51 ret = put_user(val, uaddr);
52 }
53 break;
54 case FUTEX_OP_ANDN:
55 /* *(int *)UADDR2 &= ~OPARG; */
56 ret = get_user(oldval, uaddr);
57 if (!ret) {
58 val = oldval & ~oparg;
59 ret = put_user(val, uaddr);
60 }
61 break;
62 case FUTEX_OP_XOR:
63 /* *(int *)UADDR2 ^= OPARG; */
64 ret = get_user(oldval, uaddr);
65 if (!ret) {
66 val = oldval ^ oparg;
67 ret = put_user(val, uaddr);
68 }
69 break;
70 default:
71 ret = -ENOSYS;
72 }
73
74 _atomic_spin_unlock_irqrestore(uaddr, flags);
75
76 pagefault_enable();
77
78 if (!ret) {
79 switch (cmp) {
80 case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break;
81 case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break;
82 case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break;
83 case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break;
84 case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break;
85 case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break;
86 default: ret = -ENOSYS;
87 }
88 }
89 return ret;
90 }
91
92 /* Non-atomic version */
93 static inline int
futex_atomic_cmpxchg_inatomic(u32 * uval,u32 __user * uaddr,u32 oldval,u32 newval)94 futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
95 u32 oldval, u32 newval)
96 {
97 int ret;
98 u32 val;
99 unsigned long flags;
100
101 /* futex.c wants to do a cmpxchg_inatomic on kernel NULL, which is
102 * our gateway page, and causes no end of trouble...
103 */
104 if (segment_eq(KERNEL_DS, get_fs()) && !uaddr)
105 return -EFAULT;
106
107 if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
108 return -EFAULT;
109
110 /* HPPA has no cmpxchg in hardware and therefore the
111 * best we can do here is use an array of locks. The
112 * lock selected is based on a hash of the userspace
113 * address. This should scale to a couple of CPUs.
114 */
115
116 _atomic_spin_lock_irqsave(uaddr, flags);
117
118 ret = get_user(val, uaddr);
119
120 if (!ret && val == oldval)
121 ret = put_user(newval, uaddr);
122
123 *uval = val;
124
125 _atomic_spin_unlock_irqrestore(uaddr, flags);
126
127 return ret;
128 }
129
130 #endif /*__KERNEL__*/
131 #endif /*_ASM_PARISC_FUTEX_H*/
132