1 | /** |
---|
2 | * @file |
---|
3 | * |
---|
4 | * @ingroup ScoreSMPLockPowerPC |
---|
5 | * |
---|
6 | * @brief PowerPC SMP Lock Implementation |
---|
7 | */ |
---|
8 | |
---|
9 | /* |
---|
10 | * Copyright (c) 2013 embedded brains GmbH |
---|
11 | * |
---|
12 | * The license and distribution terms for this file may be |
---|
13 | * found in the file LICENSE in this distribution or at |
---|
14 | * http://www.rtems.com/license/LICENSE. |
---|
15 | */ |
---|
16 | |
---|
17 | #ifndef _RTEMS_SCORE_POWERPC_SMPLOCK_H |
---|
18 | #define _RTEMS_SCORE_POWERPC_SMPLOCK_H |
---|
19 | |
---|
20 | #include <rtems/score/cpu.h> |
---|
21 | |
---|
22 | #ifdef __cplusplus |
---|
23 | extern "C" { |
---|
24 | #endif /* __cplusplus */ |
---|
25 | |
---|
26 | /** |
---|
27 | * @defgroup ScoreSMPLockPowerPC PowerPC SMP Locks |
---|
28 | * |
---|
29 | * @ingroup ScoreSMPLock |
---|
30 | * |
---|
31 | * A ticket lock implementation is used. |
---|
32 | * |
---|
33 | * @{ |
---|
34 | */ |
---|
35 | |
---|
36 | typedef struct { |
---|
37 | uint32_t next_ticket; |
---|
38 | uint32_t now_serving; |
---|
39 | } CPU_SMP_lock_Control; |
---|
40 | |
---|
41 | #define CPU_SMP_LOCK_INITIALIZER { 0, 0 } |
---|
42 | |
---|
43 | static inline void _CPU_SMP_lock_Initialize( CPU_SMP_lock_Control *lock ) |
---|
44 | { |
---|
45 | lock->next_ticket = 0; |
---|
46 | lock->now_serving = 0; |
---|
47 | } |
---|
48 | |
---|
49 | static inline void _CPU_SMP_lock_Acquire( CPU_SMP_lock_Control *lock ) |
---|
50 | { |
---|
51 | uint32_t my_ticket; |
---|
52 | uint32_t next_ticket; |
---|
53 | |
---|
54 | __asm__ volatile ( |
---|
55 | "1: lwarx %[my_ticket], 0, %[next_ticket_addr]\n" |
---|
56 | "addi %[next_ticket], %[my_ticket], 1\n" |
---|
57 | "stwcx. %[next_ticket], 0, [%[next_ticket_addr]]\n" |
---|
58 | "bne 1b\n" |
---|
59 | "isync" |
---|
60 | : [my_ticket] "=&r" (my_ticket), |
---|
61 | [next_ticket] "=&r" (next_ticket) |
---|
62 | : [next_ticket_addr] "r" (&lock->next_ticket) |
---|
63 | : "cc", "memory" |
---|
64 | ); |
---|
65 | |
---|
66 | while ( my_ticket != lock->now_serving ) { |
---|
67 | __asm__ volatile ( "" : : : "memory" ); |
---|
68 | } |
---|
69 | } |
---|
70 | |
---|
71 | static inline void _CPU_SMP_lock_Release( CPU_SMP_lock_Control *lock ) |
---|
72 | { |
---|
73 | __asm__ volatile ( "msync" : : : "memory" ); |
---|
74 | ++lock->now_serving; |
---|
75 | } |
---|
76 | |
---|
77 | #define _CPU_SMP_lock_ISR_disable_and_acquire( lock, isr_cookie ) \ |
---|
78 | do { \ |
---|
79 | _CPU_ISR_Disable( isr_cookie ); \ |
---|
80 | _CPU_SMP_lock_Acquire( lock ); \ |
---|
81 | } while (0) |
---|
82 | |
---|
83 | #define _CPU_SMP_lock_Release_and_ISR_enable( lock, isr_cookie ) \ |
---|
84 | do { \ |
---|
85 | _CPU_SMP_lock_Release( lock ); \ |
---|
86 | _CPU_ISR_Enable( isr_cookie ); \ |
---|
87 | } while (0) |
---|
88 | |
---|
89 | /**@}*/ |
---|
90 | |
---|
91 | #ifdef __cplusplus |
---|
92 | } |
---|
93 | #endif /* __cplusplus */ |
---|
94 | |
---|
95 | #endif /* _RTEMS_SCORE_POWERPC_SMPLOCK_H */ |
---|