5f31354b |
1 | /***************************************************************************** |
2 | * kernelutils-arm.h |
3 | * |
4 | * This file holds the code needed by LTT usertrace that comes from the |
5 | * kernel headers. Since including kernel headers is not recommended in |
6 | * userspace programs/libraries, we rewrote implementations HIGHLY INSPIRED |
7 | * (i.e. copied/pasted) from the original kernel headers (2.6.18). |
8 | * |
9 | * Do not use these functions within signal handlers, as the architecture offers |
10 | * no atomic operations. (Mathieu Desnoyers) It is safe to do multithreaded |
11 | * tracing though, as the buffers are per thread. |
12 | * |
13 | * Deepak Saxena, October 2006 |
14 | */ |
15 | |
16 | #ifndef _KERNELUTILS_ARM_H |
17 | #define _KERNELUTILS_ARM_H |
18 | |
19 | #include <time.h> |
20 | |
21 | #ifdef __cplusplus |
22 | extern "C" { |
23 | #endif |
24 | |
25 | typedef struct { volatile int counter; } atomic_t; |
26 | |
27 | #define atomic_read(v) ((v)->counter) |
28 | |
29 | static inline int atomic_add_return(int i, atomic_t *v) |
30 | { |
31 | unsigned long flags; |
32 | int val; |
33 | |
34 | val = v->counter; |
35 | v->counter = val += i; |
36 | |
37 | return val; |
38 | } |
39 | |
40 | #define atomic_add(i, v) (void) atomic_add_return(i, v) |
41 | #define atomic_inc(v) (void) atomic_add_return(1, v) |
42 | |
43 | static inline unsigned long cmpxchg(volatile void *ptr, |
44 | unsigned long old, |
45 | unsigned long new) |
46 | { |
47 | unsigned long flags, prev; |
48 | volatile unsigned long *p = ptr; |
49 | |
50 | if ((prev = *p) == old) |
51 | *p = new; |
52 | return(prev); |
53 | } |
54 | |
55 | static inline unsigned long long get_cycles(void) |
56 | { |
57 | struct timespec tp; |
58 | clock_gettime(CLOCK_MONOTONIC, &tp); |
59 | return tp.tv_sec * 1000000000 + tp.tv_nsec; |
60 | } |
61 | |
62 | |
63 | #ifdef __cplusplus |
64 | } /* end of extern "C" */ |
65 | #endif |
66 | |
67 | #endif |