[PATCH] FUTEX_WAKE_OP: pthread_cond_signal() speedup
[linux-3.10.git] / include / asm-ppc64 / futex.h
1 #ifndef _ASM_FUTEX_H
2 #define _ASM_FUTEX_H
3
4 #ifdef __KERNEL__
5
6 #include <linux/futex.h>
7 #include <asm/errno.h>
8 #include <asm/memory.h>
9 #include <asm/uaccess.h>
10
11 #define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
12   __asm__ __volatile (SYNC_ON_SMP                               \
13 "1:     lwarx   %0,0,%2\n"                                      \
14         insn                                                    \
15 "2:     stwcx.  %1,0,%2\n\
16         bne-    1b\n\
17         li      %1,0\n\
18 3:      .section .fixup,\"ax\"\n\
19 4:      li      %1,%3\n\
20         b       3b\n\
21         .previous\n\
22         .section __ex_table,\"a\"\n\
23         .align 3\n\
24         .llong  1b,4b,2b,4b\n\
25         .previous"                                              \
26         : "=&r" (oldval), "=&r" (ret)                           \
27         : "b" (uaddr), "i" (-EFAULT), "1" (oparg)               \
28         : "cr0", "memory")
29
30 static inline int
31 futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
32 {
33         int op = (encoded_op >> 28) & 7;
34         int cmp = (encoded_op >> 24) & 15;
35         int oparg = (encoded_op << 8) >> 20;
36         int cmparg = (encoded_op << 20) >> 20;
37         int oldval = 0, ret;
38         if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
39                 oparg = 1 << oparg;
40
41         if (! access_ok (VERIFY_WRITE, uaddr, sizeof(int)))
42                 return -EFAULT;
43
44         inc_preempt_count();
45
46         switch (op) {
47         case FUTEX_OP_SET:
48                 __futex_atomic_op("", ret, oldval, uaddr, oparg);
49                 break;
50         case FUTEX_OP_ADD:
51                 __futex_atomic_op("add %1,%0,%1\n", ret, oldval, uaddr, oparg);
52                 break;
53         case FUTEX_OP_OR:
54                 __futex_atomic_op("or %1,%0,%1\n", ret, oldval, uaddr, oparg);
55                 break;
56         case FUTEX_OP_ANDN:
57                 __futex_atomic_op("andc %1,%0,%1\n", ret, oldval, uaddr, oparg);
58                 break;
59         case FUTEX_OP_XOR:
60                 __futex_atomic_op("xor %1,%0,%1\n", ret, oldval, uaddr, oparg);
61                 break;
62         default:
63                 ret = -ENOSYS;
64         }
65
66         dec_preempt_count();
67
68         if (!ret) {
69                 switch (cmp) {
70                 case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break;
71                 case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break;
72                 case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break;
73                 case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break;
74                 case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break;
75                 case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break;
76                 default: ret = -ENOSYS;
77                 }
78         }
79         return ret;
80 }
81
82 #endif
83 #endif