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/* The following has to match the LWS code in syscall.S.  We have
12   sixteen four-word locks. */
13
14static inline void
15_futex_spin_lock_irqsave(u32 __user *uaddr, unsigned long int *flags)
16{
17	extern u32 lws_lock_start[];
18	long index = ((long)uaddr & 0xf0) >> 2;
19	arch_spinlock_t *s = (arch_spinlock_t *)&lws_lock_start[index];
20	local_irq_save(*flags);
21	arch_spin_lock(s);
22}
23
24static inline void
25_futex_spin_unlock_irqrestore(u32 __user *uaddr, unsigned long int *flags)
26{
27	extern u32 lws_lock_start[];
28	long index = ((long)uaddr & 0xf0) >> 2;
29	arch_spinlock_t *s = (arch_spinlock_t *)&lws_lock_start[index];
30	arch_spin_unlock(s);
31	local_irq_restore(*flags);
32}
33
34static inline int
35futex_atomic_op_inuser (int encoded_op, u32 __user *uaddr)
36{
37	unsigned long int flags;
38	u32 val;
39	int op = (encoded_op >> 28) & 7;
40	int cmp = (encoded_op >> 24) & 15;
41	int oparg = (encoded_op << 8) >> 20;
42	int cmparg = (encoded_op << 20) >> 20;
43	int oldval = 0, ret;
44	if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
45		oparg = 1 << oparg;
46
47	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(*uaddr)))
48		return -EFAULT;
49
50	pagefault_disable();
51
52	_futex_spin_lock_irqsave(uaddr, &flags);
53
54	switch (op) {
55	case FUTEX_OP_SET:
56		/* *(int *)UADDR2 = OPARG; */
57		ret = get_user(oldval, uaddr);
58		if (!ret)
59			ret = put_user(oparg, uaddr);
60		break;
61	case FUTEX_OP_ADD:
62		/* *(int *)UADDR2 += OPARG; */
63		ret = get_user(oldval, uaddr);
64		if (!ret) {
65			val = oldval + oparg;
66			ret = put_user(val, uaddr);
67		}
68		break;
69	case FUTEX_OP_OR:
70		/* *(int *)UADDR2 |= OPARG; */
71		ret = get_user(oldval, uaddr);
72		if (!ret) {
73			val = oldval | oparg;
74			ret = put_user(val, uaddr);
75		}
76		break;
77	case FUTEX_OP_ANDN:
78		/* *(int *)UADDR2 &= ~OPARG; */
79		ret = get_user(oldval, uaddr);
80		if (!ret) {
81			val = oldval & ~oparg;
82			ret = put_user(val, uaddr);
83		}
84		break;
85	case FUTEX_OP_XOR:
86		/* *(int *)UADDR2 ^= OPARG; */
87		ret = get_user(oldval, uaddr);
88		if (!ret) {
89			val = oldval ^ oparg;
90			ret = put_user(val, uaddr);
91		}
92		break;
93	default:
94		ret = -ENOSYS;
95	}
96
97	_futex_spin_unlock_irqrestore(uaddr, &flags);
98
99	pagefault_enable();
100
101	if (!ret) {
102		switch (cmp) {
103		case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break;
104		case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break;
105		case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break;
106		case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break;
107		case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break;
108		case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break;
109		default: ret = -ENOSYS;
110		}
111	}
112	return ret;
113}
114
115/* Non-atomic version */
116static inline int
117futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
118			      u32 oldval, u32 newval)
119{
120	int ret;
121	u32 val;
122	unsigned long flags;
123
124	/* futex.c wants to do a cmpxchg_inatomic on kernel NULL, which is
125	 * our gateway page, and causes no end of trouble...
126	 */
127	if (segment_eq(KERNEL_DS, get_fs()) && !uaddr)
128		return -EFAULT;
129
130	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
131		return -EFAULT;
132
133	/* HPPA has no cmpxchg in hardware and therefore the
134	 * best we can do here is use an array of locks. The
135	 * lock selected is based on a hash of the userspace
136	 * address. This should scale to a couple of CPUs.
137	 */
138
139	_futex_spin_lock_irqsave(uaddr, &flags);
140
141	ret = get_user(val, uaddr);
142
143	if (!ret && val == oldval)
144		ret = put_user(newval, uaddr);
145
146	*uval = val;
147
148	_futex_spin_unlock_irqrestore(uaddr, &flags);
149
150	return ret;
151}
152
153#endif /*__KERNEL__*/
154#endif /*_ASM_PARISC_FUTEX_H*/
155