TAS
TCP Acceleration as an OS Service
utils_sync.h
1 /*-
2  * BSD LICENSE
3  *
4  * Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
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13  * * Redistributions in binary form must reproduce the above copyright
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32  */
33 
34 /* spinlock implementation from DPDK (copied to remove dependencies on dpdk
35  * includes everywhere) */
36 
37 #ifndef UTILS_SYNC_H_
38 #define UTILS_SYNC_H_
39 
40 #include <stdint.h>
41 
42 static inline void util_spin_lock(volatile uint32_t *sl)
43 {
44  uint32_t lock_val = 1;
45 
46  asm volatile (
47  "1:\n"
48  "xchg %[locked], %[lv]\n"
49  "test %[lv], %[lv]\n"
50  "jz 3f\n"
51  "2:\n"
52  "pause\n"
53  "cmpl $0, %[locked]\n"
54  "jnz 2b\n"
55  "jmp 1b\n"
56  "3:\n"
57  : [locked] "=m" (*sl), [lv] "=q" (lock_val)
58  : "[lv]" (lock_val)
59  : "memory");
60 }
61 
62 static inline void util_spin_unlock(volatile uint32_t *sl)
63 {
64  uint32_t unlock_val = 0;
65 
66  asm volatile (
67  "xchg %[locked], %[ulv]\n"
68  : [locked] "=m" (*sl), [ulv] "=q" (unlock_val)
69  : "[ulv]" (unlock_val)
70  : "memory");
71 }
72 
73 static inline int util_spin_trylock(volatile uint32_t *sl)
74 {
75  uint32_t lockval = 1;
76 
77  asm volatile (
78  "xchg %[locked], %[lockval]"
79  : [locked] "=m" (*sl), [lockval] "=q" (lockval)
80  : "[lockval]" (lockval)
81  : "memory");
82 
83  return lockval == 0;
84 }
85 #endif /* ndef UTILS_SYNC_H_ */