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 arch_futex_atomic_op_inuser(int op, int oparg, int *oval,
33 u32 __user *uaddr)
34{
35 int oldval = 0, ret;
36
37 pagefault_disable();
38
39 switch (op) {
40 case FUTEX_OP_SET:
41 __futex_atomic_op("mr %1,%4\n", ret, oldval, uaddr, oparg);
42 break;
43 case FUTEX_OP_ADD:
44 __futex_atomic_op("add %1,%0,%4\n", ret, oldval, uaddr, oparg);
45 break;
46 case FUTEX_OP_OR:
47 __futex_atomic_op("or %1,%0,%4\n", ret, oldval, uaddr, oparg);
48 break;
49 case FUTEX_OP_ANDN:
50 __futex_atomic_op("andc %1,%0,%4\n", ret, oldval, uaddr, oparg);
51 break;
52 case FUTEX_OP_XOR:
53 __futex_atomic_op("xor %1,%0,%4\n", ret, oldval, uaddr, oparg);
54 break;
55 default:
56 ret = -ENOSYS;
57 }
58
59 pagefault_enable();
60
61 if (!ret)
62 *oval = oldval;
63
64 return ret;
65}
66
67static inline int
68futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
69 u32 oldval, u32 newval)
70{
71 int ret = 0;
72 u32 prev;
73
74 if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
75 return -EFAULT;
76
77 __asm__ __volatile__ (
78 PPC_ATOMIC_ENTRY_BARRIER
79"1: lwarx %1,0,%3 # futex_atomic_cmpxchg_inatomic\n\
80 cmpw 0,%1,%4\n\
81 bne- 3f\n"
82 PPC405_ERR77(0,%3)
83"2: stwcx. %5,0,%3\n\
84 bne- 1b\n"
85 PPC_ATOMIC_EXIT_BARRIER
86"3: .section .fixup,\"ax\"\n\
874: li %0,%6\n\
88 b 3b\n\
89 .previous\n"
90 EX_TABLE(1b, 4b)
91 EX_TABLE(2b, 4b)
92 : "+r" (ret), "=&r" (prev), "+m" (*uaddr)
93 : "r" (uaddr), "r" (oldval), "r" (newval), "i" (-EFAULT)
94 : "cc", "memory");
95
96 *uval = prev;
97 return ret;
98}
99
100#endif /* __KERNEL__ */
101#endif /* _ASM_POWERPC_FUTEX_H */