| yuezonghe | 824eb0c | 2024-06-27 02:32:26 -0700 | [diff] [blame^] | 1 | /* POSIX spinlock implementation. MIPS version. |
| 2 | Copyright (C) 2000, 2002, 2003, 2004 Free Software Foundation, Inc. |
| 3 | This file is part of the GNU C Library. |
| 4 | |
| 5 | The GNU C Library is free software; you can redistribute it and/or |
| 6 | modify it under the terms of the GNU Lesser General Public License as |
| 7 | published by the Free Software Foundation; either version 2.1 of the |
| 8 | License, or (at your option) any later version. |
| 9 | |
| 10 | The GNU C Library is distributed in the hope that it will be useful, |
| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 13 | Lesser General Public License for more details. |
| 14 | |
| 15 | You should have received a copy of the GNU Lesser General Public |
| 16 | License along with the GNU C Library; see the file COPYING.LIB. If not, |
| 17 | write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, |
| 18 | Boston, MA 02111-1307, USA. */ |
| 19 | |
| 20 | #include <errno.h> |
| 21 | #include <pthread.h> |
| 22 | #include <sgidefs.h> |
| 23 | #include <sys/tas.h> |
| 24 | #include "internals.h" |
| 25 | |
| 26 | /* This implementation is similar to the one used in the Linux kernel. */ |
| 27 | int |
| 28 | __pthread_spin_lock (pthread_spinlock_t *lock) |
| 29 | { |
| 30 | unsigned int tmp1, tmp2; |
| 31 | |
| 32 | __asm__ __volatile__ |
| 33 | ("\t\t\t# spin_lock\n" |
| 34 | "1:\n\t" |
| 35 | ".set push\n\t" |
| 36 | #if _MIPS_SIM == _ABIO32 |
| 37 | ".set mips2\n\t" |
| 38 | #endif |
| 39 | "ll %1,%3\n\t" |
| 40 | "li %2,1\n\t" |
| 41 | "bnez %1,1b\n\t" |
| 42 | "sc %2,%0\n\t" |
| 43 | ".set pop\n\t" |
| 44 | "beqz %2,1b" |
| 45 | : "=m" (*lock), "=&r" (tmp1), "=&r" (tmp2) |
| 46 | : "m" (*lock) |
| 47 | : "memory"); |
| 48 | |
| 49 | return 0; |
| 50 | } |
| 51 | |
| 52 | weak_alias (__pthread_spin_lock, pthread_spin_lock) |
| 53 | |
| 54 | |
| 55 | int |
| 56 | __pthread_spin_trylock (pthread_spinlock_t *lock) |
| 57 | { |
| 58 | /* To be done. */ |
| 59 | return 0; |
| 60 | } |
| 61 | weak_alias (__pthread_spin_trylock, pthread_spin_trylock) |
| 62 | |
| 63 | |
| 64 | int |
| 65 | __pthread_spin_unlock (pthread_spinlock_t *lock) |
| 66 | { |
| 67 | __asm__ __volatile__ |
| 68 | ("\t\t\t# spin_unlock\n\t" |
| 69 | "sw $0,%0" |
| 70 | : "=m" (*lock) |
| 71 | : |
| 72 | : "memory"); |
| 73 | return 0; |
| 74 | } |
| 75 | weak_alias (__pthread_spin_unlock, pthread_spin_unlock) |
| 76 | |
| 77 | |
| 78 | int |
| 79 | __pthread_spin_init (pthread_spinlock_t *lock, int pshared) |
| 80 | { |
| 81 | /* We can ignore the `pshared' parameter. Since we are busy-waiting |
| 82 | all processes which can access the memory location `lock' points |
| 83 | to can use the spinlock. */ |
| 84 | *lock = 0; |
| 85 | return 0; |
| 86 | } |
| 87 | weak_alias (__pthread_spin_init, pthread_spin_init) |
| 88 | |
| 89 | |
| 90 | int |
| 91 | __pthread_spin_destroy (pthread_spinlock_t *lock) |
| 92 | { |
| 93 | /* Nothing to do. */ |
| 94 | return 0; |
| 95 | } |
| 96 | weak_alias (__pthread_spin_destroy, pthread_spin_destroy) |