1#ifndef _ASM_POWERPC_FUTEX_H
2#define _ASM_POWERPC_FUTEX_H
3
4#ifdef __KERNEL__
5
6#include <linux/futex.h>
7#include <linux/uaccess.h>
8#include <asm/errno.h>
9#include <asm/synch.h>
10#include <asm/asm-compat.h>
11
12#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
13  __asm__ __volatile ( \
14	PPC_ATOMIC_ENTRY_BARRIER \
15"1:	lwarx	%0,0,%2\n" \
16	insn \
17	PPC405_ERR77(0, %2) \
18"2:	stwcx.	%1,0,%2\n" \
19	"bne-	1b\n" \
20	PPC_ATOMIC_EXIT_BARRIER \
21	"li	%1,0\n" \
22"3:	.section .fixup,\"ax\"\n" \
23"4:	li	%1,%3\n" \
24	"b	3b\n" \
25	".previous\n" \
26	".section __ex_table,\"a\"\n" \
27	".align 3\n" \
28	PPC_LONG "1b,4b,2b,4b\n" \
29	".previous" \
30	: "=&r" (oldval), "=&r" (ret) \
31	: "b" (uaddr), "i" (-EFAULT), "r" (oparg) \
32	: "cr0", "memory")
33
34static inline int futex_atomic_op_inuser (int encoded_op, u32 __user *uaddr)
35{
36	int op = (encoded_op >> 28) & 7;
37	int cmp = (encoded_op >> 24) & 15;
38	int oparg = (encoded_op << 8) >> 20;
39	int cmparg = (encoded_op << 20) >> 20;
40	int oldval = 0, ret;
41	if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
42		oparg = 1 << oparg;
43
44	if (! access_ok (VERIFY_WRITE, uaddr, sizeof(u32)))
45		return -EFAULT;
46
47	pagefault_disable();
48
49	switch (op) {
50	case FUTEX_OP_SET:
51		__futex_atomic_op("mr %1,%4\n", ret, oldval, uaddr, oparg);
52		break;
53	case FUTEX_OP_ADD:
54		__futex_atomic_op("add %1,%0,%4\n", ret, oldval, uaddr, oparg);
55		break;
56	case FUTEX_OP_OR:
57		__futex_atomic_op("or %1,%0,%4\n", ret, oldval, uaddr, oparg);
58		break;
59	case FUTEX_OP_ANDN:
60		__futex_atomic_op("andc %1,%0,%4\n", ret, oldval, uaddr, oparg);
61		break;
62	case FUTEX_OP_XOR:
63		__futex_atomic_op("xor %1,%0,%4\n", ret, oldval, uaddr, oparg);
64		break;
65	default:
66		ret = -ENOSYS;
67	}
68
69	pagefault_enable();
70
71	if (!ret) {
72		switch (cmp) {
73		case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break;
74		case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break;
75		case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break;
76		case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break;
77		case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break;
78		case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break;
79		default: ret = -ENOSYS;
80		}
81	}
82	return ret;
83}
84
85static inline int
86futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
87			      u32 oldval, u32 newval)
88{
89	int ret = 0;
90	u32 prev;
91
92	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
93		return -EFAULT;
94
95        __asm__ __volatile__ (
96        PPC_ATOMIC_ENTRY_BARRIER
97"1:     lwarx   %1,0,%3         # futex_atomic_cmpxchg_inatomic\n\
98        cmpw    0,%1,%4\n\
99        bne-    3f\n"
100        PPC405_ERR77(0,%3)
101"2:     stwcx.  %5,0,%3\n\
102        bne-    1b\n"
103        PPC_ATOMIC_EXIT_BARRIER
104"3:	.section .fixup,\"ax\"\n\
1054:	li	%0,%6\n\
106	b	3b\n\
107	.previous\n\
108	.section __ex_table,\"a\"\n\
109	.align 3\n\
110	" PPC_LONG "1b,4b,2b,4b\n\
111	.previous" \
112        : "+r" (ret), "=&r" (prev), "+m" (*uaddr)
113        : "r" (uaddr), "r" (oldval), "r" (newval), "i" (-EFAULT)
114        : "cc", "memory");
115
116	*uval = prev;
117        return ret;
118}
119
120#endif /* __KERNEL__ */
121#endif /* _ASM_POWERPC_FUTEX_H */
122