tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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 EX_TABLE(1b, 4b) \
27 EX_TABLE(2b, 4b) \
28 : "=&r" (oldval), "=&r" (ret) \
29 : "b" (uaddr), "i" (-EFAULT), "r" (oparg) \
30 : "cr0", "memory")
31
32static inline int futex_atomic_op_inuser (int encoded_op, u32 __user *uaddr)
33{
34 int op = (encoded_op >> 28) & 7;
35 int cmp = (encoded_op >> 24) & 15;
36 int oparg = (encoded_op << 8) >> 20;
37 int cmparg = (encoded_op << 20) >> 20;
38 int oldval = 0, ret;
39 if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
40 oparg = 1 << oparg;
41
42 if (! access_ok (VERIFY_WRITE, uaddr, sizeof(u32)))
43 return -EFAULT;
44
45 pagefault_disable();
46
47 switch (op) {
48 case FUTEX_OP_SET:
49 __futex_atomic_op("mr %1,%4\n", ret, oldval, uaddr, oparg);
50 break;
51 case FUTEX_OP_ADD:
52 __futex_atomic_op("add %1,%0,%4\n", ret, oldval, uaddr, oparg);
53 break;
54 case FUTEX_OP_OR:
55 __futex_atomic_op("or %1,%0,%4\n", ret, oldval, uaddr, oparg);
56 break;
57 case FUTEX_OP_ANDN:
58 __futex_atomic_op("andc %1,%0,%4\n", ret, oldval, uaddr, oparg);
59 break;
60 case FUTEX_OP_XOR:
61 __futex_atomic_op("xor %1,%0,%4\n", ret, oldval, uaddr, oparg);
62 break;
63 default:
64 ret = -ENOSYS;
65 }
66
67 pagefault_enable();
68
69 if (!ret) {
70 switch (cmp) {
71 case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break;
72 case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break;
73 case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break;
74 case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break;
75 case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break;
76 case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break;
77 default: ret = -ENOSYS;
78 }
79 }
80 return ret;
81}
82
83static inline int
84futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
85 u32 oldval, u32 newval)
86{
87 int ret = 0;
88 u32 prev;
89
90 if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
91 return -EFAULT;
92
93 __asm__ __volatile__ (
94 PPC_ATOMIC_ENTRY_BARRIER
95"1: lwarx %1,0,%3 # futex_atomic_cmpxchg_inatomic\n\
96 cmpw 0,%1,%4\n\
97 bne- 3f\n"
98 PPC405_ERR77(0,%3)
99"2: stwcx. %5,0,%3\n\
100 bne- 1b\n"
101 PPC_ATOMIC_EXIT_BARRIER
102"3: .section .fixup,\"ax\"\n\
1034: li %0,%6\n\
104 b 3b\n\
105 .previous\n"
106 EX_TABLE(1b, 4b)
107 EX_TABLE(2b, 4b)
108 : "+r" (ret), "=&r" (prev), "+m" (*uaddr)
109 : "r" (uaddr), "r" (oldval), "r" (newval), "i" (-EFAULT)
110 : "cc", "memory");
111
112 *uval = prev;
113 return ret;
114}
115
116#endif /* __KERNEL__ */
117#endif /* _ASM_POWERPC_FUTEX_H */