| 1 | /*
|
|---|
| 2 | * Copyright (c) 2003 Fabrice Bellard
|
|---|
| 3 | *
|
|---|
| 4 | * This library is free software; you can redistribute it and/or
|
|---|
| 5 | * modify it under the terms of the GNU Lesser General Public
|
|---|
| 6 | * License as published by the Free Software Foundation; either
|
|---|
| 7 | * version 2 of the License, or (at your option) any later version.
|
|---|
| 8 | *
|
|---|
| 9 | * This library is distributed in the hope that it will be useful,
|
|---|
| 10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|---|
| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|---|
| 12 | * Lesser General Public License for more details.
|
|---|
| 13 | *
|
|---|
| 14 | * You should have received a copy of the GNU Lesser General Public
|
|---|
| 15 | * License along with this library; if not, write to the Free Software
|
|---|
| 16 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
|---|
| 17 | */
|
|---|
| 18 | /*
|
|---|
| 19 | * Sun LGPL Disclaimer: For the avoidance of doubt, except that if any license choice
|
|---|
| 20 | * other than GPL or LGPL is available it will apply instead, Sun elects to use only
|
|---|
| 21 | * the Lesser General Public License version 2.1 (LGPLv2) at this time for any software where
|
|---|
| 22 | * a choice of LGPL license versions is made available with the language indicating
|
|---|
| 23 | * that LGPLv2 or any later version may be used, or where a choice of which version
|
|---|
| 24 | * of the LGPL is applied is otherwise unspecified.
|
|---|
| 25 | */
|
|---|
| 26 |
|
|---|
| 27 |
|
|---|
| 28 | /* Locking primitives. Most of this code should be redundant -
|
|---|
| 29 | system emulation doesn't need/use locking, NPTL userspace uses
|
|---|
| 30 | pthread mutexes, and non-NPTL userspace isn't threadsafe anyway.
|
|---|
| 31 | In either case a spinlock is probably the wrong kind of lock.
|
|---|
| 32 | Spinlocks are only good if you know annother CPU has the lock and is
|
|---|
| 33 | likely to release it soon. In environments where you have more threads
|
|---|
| 34 | than physical CPUs (the extreme case being a single CPU host) a spinlock
|
|---|
| 35 | simply wastes CPU until the OS decides to preempt it. */
|
|---|
| 36 | #if defined(USE_NPTL)
|
|---|
| 37 |
|
|---|
| 38 | #include <pthread.h>
|
|---|
| 39 | #define spin_lock pthread_mutex_lock
|
|---|
| 40 | #define spin_unlock pthread_mutex_unlock
|
|---|
| 41 | #define spinlock_t pthread_mutex_t
|
|---|
| 42 | #define SPIN_LOCK_UNLOCKED PTHREAD_MUTEX_INITIALIZER
|
|---|
| 43 |
|
|---|
| 44 | #else
|
|---|
| 45 |
|
|---|
| 46 | #if defined(__hppa__)
|
|---|
| 47 |
|
|---|
| 48 | typedef int spinlock_t[4];
|
|---|
| 49 |
|
|---|
| 50 | #define SPIN_LOCK_UNLOCKED { 1, 1, 1, 1 }
|
|---|
| 51 |
|
|---|
| 52 | static inline void resetlock (spinlock_t *p)
|
|---|
| 53 | {
|
|---|
| 54 | (*p)[0] = (*p)[1] = (*p)[2] = (*p)[3] = 1;
|
|---|
| 55 | }
|
|---|
| 56 |
|
|---|
| 57 | #else
|
|---|
| 58 |
|
|---|
| 59 | typedef int spinlock_t;
|
|---|
| 60 |
|
|---|
| 61 | #define SPIN_LOCK_UNLOCKED 0
|
|---|
| 62 |
|
|---|
| 63 | #ifndef VBOX
|
|---|
| 64 | static inline void resetlock (spinlock_t *p)
|
|---|
| 65 | #else
|
|---|
| 66 | DECLINLINE(void) resetlock (spinlock_t *p)
|
|---|
| 67 | #endif
|
|---|
| 68 | {
|
|---|
| 69 | *p = SPIN_LOCK_UNLOCKED;
|
|---|
| 70 | }
|
|---|
| 71 |
|
|---|
| 72 | #endif
|
|---|
| 73 |
|
|---|
| 74 | #ifdef VBOX
|
|---|
| 75 | DECLINLINE(int) testandset (int *p)
|
|---|
| 76 | {
|
|---|
| 77 |
|
|---|
| 78 | return ASMAtomicCmpXchgU32((volatile uint32_t *)p, 1, 0) ? 0 : 1;
|
|---|
| 79 | }
|
|---|
| 80 | #elif defined(__powerpc__)
|
|---|
| 81 | static inline int testandset (int *p)
|
|---|
| 82 | {
|
|---|
| 83 | int ret;
|
|---|
| 84 | __asm__ __volatile__ (
|
|---|
| 85 | "0: lwarx %0,0,%1\n"
|
|---|
| 86 | " xor. %0,%3,%0\n"
|
|---|
| 87 | " bne 1f\n"
|
|---|
| 88 | " stwcx. %2,0,%1\n"
|
|---|
| 89 | " bne- 0b\n"
|
|---|
| 90 | "1: "
|
|---|
| 91 | : "=&r" (ret)
|
|---|
| 92 | : "r" (p), "r" (1), "r" (0)
|
|---|
| 93 | : "cr0", "memory");
|
|---|
| 94 | return ret;
|
|---|
| 95 | }
|
|---|
| 96 | #elif defined(__i386__)
|
|---|
| 97 | static inline int testandset (int *p)
|
|---|
| 98 | {
|
|---|
| 99 | long int readval = 0;
|
|---|
| 100 |
|
|---|
| 101 | __asm__ __volatile__ ("lock; cmpxchgl %2, %0"
|
|---|
| 102 | : "+m" (*p), "+a" (readval)
|
|---|
| 103 | : "r" (1)
|
|---|
| 104 | : "cc");
|
|---|
| 105 | return readval;
|
|---|
| 106 | }
|
|---|
| 107 | #elif defined(__x86_64__)
|
|---|
| 108 | static inline int testandset (int *p)
|
|---|
| 109 | {
|
|---|
| 110 | long int readval = 0;
|
|---|
| 111 |
|
|---|
| 112 | __asm__ __volatile__ ("lock; cmpxchgl %2, %0"
|
|---|
| 113 | : "+m" (*p), "+a" (readval)
|
|---|
| 114 | : "r" (1)
|
|---|
| 115 | : "cc");
|
|---|
| 116 | return readval;
|
|---|
| 117 | }
|
|---|
| 118 | #elif defined(__s390__)
|
|---|
| 119 | static inline int testandset (int *p)
|
|---|
| 120 | {
|
|---|
| 121 | int ret;
|
|---|
| 122 |
|
|---|
| 123 | __asm__ __volatile__ ("0: cs %0,%1,0(%2)\n"
|
|---|
| 124 | " jl 0b"
|
|---|
| 125 | : "=&d" (ret)
|
|---|
| 126 | : "r" (1), "a" (p), "0" (*p)
|
|---|
| 127 | : "cc", "memory" );
|
|---|
| 128 | return ret;
|
|---|
| 129 | }
|
|---|
| 130 | #elif defined(__alpha__)
|
|---|
| 131 | static inline int testandset (int *p)
|
|---|
| 132 | {
|
|---|
| 133 | int ret;
|
|---|
| 134 | unsigned long one;
|
|---|
| 135 |
|
|---|
| 136 | __asm__ __volatile__ ("0: mov 1,%2\n"
|
|---|
| 137 | " ldl_l %0,%1\n"
|
|---|
| 138 | " stl_c %2,%1\n"
|
|---|
| 139 | " beq %2,1f\n"
|
|---|
| 140 | ".subsection 2\n"
|
|---|
| 141 | "1: br 0b\n"
|
|---|
| 142 | ".previous"
|
|---|
| 143 | : "=r" (ret), "=m" (*p), "=r" (one)
|
|---|
| 144 | : "m" (*p));
|
|---|
| 145 | return ret;
|
|---|
| 146 | }
|
|---|
| 147 | #elif defined(__sparc__)
|
|---|
| 148 | static inline int testandset (int *p)
|
|---|
| 149 | {
|
|---|
| 150 | int ret;
|
|---|
| 151 |
|
|---|
| 152 | __asm__ __volatile__("ldstub [%1], %0"
|
|---|
| 153 | : "=r" (ret)
|
|---|
| 154 | : "r" (p)
|
|---|
| 155 | : "memory");
|
|---|
| 156 |
|
|---|
| 157 | return (ret ? 1 : 0);
|
|---|
| 158 | }
|
|---|
| 159 | #elif defined(__arm__)
|
|---|
| 160 | static inline int testandset (int *spinlock)
|
|---|
| 161 | {
|
|---|
| 162 | register unsigned int ret;
|
|---|
| 163 | __asm__ __volatile__("swp %0, %1, [%2]"
|
|---|
| 164 | : "=r"(ret)
|
|---|
| 165 | : "0"(1), "r"(spinlock));
|
|---|
| 166 |
|
|---|
| 167 | return ret;
|
|---|
| 168 | }
|
|---|
| 169 | #elif defined(__mc68000)
|
|---|
| 170 | static inline int testandset (int *p)
|
|---|
| 171 | {
|
|---|
| 172 | char ret;
|
|---|
| 173 | __asm__ __volatile__("tas %1; sne %0"
|
|---|
| 174 | : "=r" (ret)
|
|---|
| 175 | : "m" (p)
|
|---|
| 176 | : "cc","memory");
|
|---|
| 177 | return ret;
|
|---|
| 178 | }
|
|---|
| 179 | #elif defined(__hppa__)
|
|---|
| 180 |
|
|---|
| 181 | /* Because malloc only guarantees 8-byte alignment for malloc'd data,
|
|---|
| 182 | and GCC only guarantees 8-byte alignment for stack locals, we can't
|
|---|
| 183 | be assured of 16-byte alignment for atomic lock data even if we
|
|---|
| 184 | specify "__attribute ((aligned(16)))" in the type declaration. So,
|
|---|
| 185 | we use a struct containing an array of four ints for the atomic lock
|
|---|
| 186 | type and dynamically select the 16-byte aligned int from the array
|
|---|
| 187 | for the semaphore. */
|
|---|
| 188 | #define __PA_LDCW_ALIGNMENT 16
|
|---|
| 189 | static inline void *ldcw_align (void *p) {
|
|---|
| 190 | unsigned long a = (unsigned long)p;
|
|---|
| 191 | a = (a + __PA_LDCW_ALIGNMENT - 1) & ~(__PA_LDCW_ALIGNMENT - 1);
|
|---|
| 192 | return (void *)a;
|
|---|
| 193 | }
|
|---|
| 194 |
|
|---|
| 195 | static inline int testandset (spinlock_t *p)
|
|---|
| 196 | {
|
|---|
| 197 | unsigned int ret;
|
|---|
| 198 | p = ldcw_align(p);
|
|---|
| 199 | __asm__ __volatile__("ldcw 0(%1),%0"
|
|---|
| 200 | : "=r" (ret)
|
|---|
| 201 | : "r" (p)
|
|---|
| 202 | : "memory" );
|
|---|
| 203 | return !ret;
|
|---|
| 204 | }
|
|---|
| 205 |
|
|---|
| 206 | #elif defined(__ia64)
|
|---|
| 207 |
|
|---|
| 208 | #include <ia64intrin.h>
|
|---|
| 209 |
|
|---|
| 210 | static inline int testandset (int *p)
|
|---|
| 211 | {
|
|---|
| 212 | return __sync_lock_test_and_set (p, 1);
|
|---|
| 213 | }
|
|---|
| 214 | #elif defined(__mips__)
|
|---|
| 215 | static inline int testandset (int *p)
|
|---|
| 216 | {
|
|---|
| 217 | int ret;
|
|---|
| 218 |
|
|---|
| 219 | __asm__ __volatile__ (
|
|---|
| 220 | " .set push \n"
|
|---|
| 221 | " .set noat \n"
|
|---|
| 222 | " .set mips2 \n"
|
|---|
| 223 | "1: li $1, 1 \n"
|
|---|
| 224 | " ll %0, %1 \n"
|
|---|
| 225 | " sc $1, %1 \n"
|
|---|
| 226 | " beqz $1, 1b \n"
|
|---|
| 227 | " .set pop "
|
|---|
| 228 | : "=r" (ret), "+R" (*p)
|
|---|
| 229 | :
|
|---|
| 230 | : "memory");
|
|---|
| 231 |
|
|---|
| 232 | return ret;
|
|---|
| 233 | }
|
|---|
| 234 | #else
|
|---|
| 235 | #error unimplemented CPU support
|
|---|
| 236 | #endif
|
|---|
| 237 |
|
|---|
| 238 | #if defined(CONFIG_USER_ONLY)
|
|---|
| 239 | static inline void spin_lock(spinlock_t *lock)
|
|---|
| 240 | {
|
|---|
| 241 | while (testandset(lock));
|
|---|
| 242 | }
|
|---|
| 243 |
|
|---|
| 244 | static inline void spin_unlock(spinlock_t *lock)
|
|---|
| 245 | {
|
|---|
| 246 | resetlock(lock);
|
|---|
| 247 | }
|
|---|
| 248 |
|
|---|
| 249 | static inline int spin_trylock(spinlock_t *lock)
|
|---|
| 250 | {
|
|---|
| 251 | return !testandset(lock);
|
|---|
| 252 | }
|
|---|
| 253 | #else
|
|---|
| 254 | #ifndef VBOX
|
|---|
| 255 | static inline void spin_lock(spinlock_t *lock)
|
|---|
| 256 | #else
|
|---|
| 257 | DECLINLINE(void) spin_lock(spinlock_t *lock)
|
|---|
| 258 | #endif
|
|---|
| 259 | {
|
|---|
| 260 | }
|
|---|
| 261 |
|
|---|
| 262 | #ifndef VBOX
|
|---|
| 263 | static inline void spin_unlock(spinlock_t *lock)
|
|---|
| 264 | #else
|
|---|
| 265 | DECLINLINE(void) spin_unlock(spinlock_t *lock)
|
|---|
| 266 | #endif
|
|---|
| 267 | {
|
|---|
| 268 | }
|
|---|
| 269 |
|
|---|
| 270 | #ifndef VBOX
|
|---|
| 271 | static inline int spin_trylock(spinlock_t *lock)
|
|---|
| 272 | #else
|
|---|
| 273 | DECLINLINE(int) spin_trylock(spinlock_t *lock)
|
|---|
| 274 | #endif
|
|---|
| 275 | {
|
|---|
| 276 | return 1;
|
|---|
| 277 | }
|
|---|
| 278 | #endif
|
|---|
| 279 |
|
|---|
| 280 | #endif
|
|---|
