reactos/ntoskrnl/ke/spinlock.c

   1 /*
   2  * PROJECT:         ReactOS Kernel
   3  * LICENSE:         GPL - See COPYING in the top level directory
   4  * FILE:            ntoskrnl/ke/spinlock.c
   5  * PURPOSE:         Spinlock and Queued Spinlock Support
   6  * PROGRAMMERS:     Alex Ionescu (alex.ionescu@reactos.org)
   7  */
   8
   9 /* INCLUDES ******************************************************************/
  10
  11 #include <ntoskrnl.h>
  12 #define NDEBUG
  13 #include <debug.h>
  14
  15 #define LQ_WAIT     1
  16 #define LQ_OWN      2
  17
  18 /* PRIVATE FUNCTIONS *********************************************************/
  19
  20 VOID
  21 FASTCALL
  22 KeAcquireQueuedSpinLockAtDpcLevel(IN PKSPIN_LOCK_QUEUE LockHandle)
  23 {
  24 #ifdef CONFIG_SMP
  25     PKSPIN_LOCK_QUEUE Prev;
  26
  27     /* Set the new lock */
  28     Prev = (PKSPIN_LOCK_QUEUE)
  29            InterlockedExchange((PLONG)LockHandle->Next,
  30                                (LONG)LockHandle);
  31     if (!Prev)
  32     {
  33         /* There was nothing there before. We now own it */
  34          *LockHandle->Lock |= LQ_OWN;
  35         return;
  36     }
  37
  38     /* Set the wait flag */
  39      *LockHandle->Lock |= LQ_WAIT;
  40
  41     /* Link us */
  42     Prev->Next = (PKSPIN_LOCK_QUEUE)LockHandle;
  43
  44     /* Loop and wait */
  45     while (*LockHandle->Lock & LQ_WAIT)
  46         YieldProcessor();
  47 #endif
  48 }
  49
  50 VOID
  51 FASTCALL
  52 KeReleaseQueuedSpinLockFromDpcLevel(IN PKSPIN_LOCK_QUEUE LockHandle)
  53 {
  54 #ifdef CONFIG_SMP
  55     KSPIN_LOCK LockVal;
  56     PKSPIN_LOCK_QUEUE Waiter;
  57
  58     /* Remove own and wait flags */
  59     *LockHandle->Lock &= ~(LQ_OWN | LQ_WAIT);
  60     LockVal = *LockHandle->Lock;
  61
  62     /* Check if we already own it */
  63     if (LockVal == (KSPIN_LOCK)LockHandle)
  64     {
  65         /* Disown it */
  66         LockVal = (KSPIN_LOCK)
  67                   InterlockedCompareExchangePointer(LockHandle->Lock,
  68                                                     NULL,
  69                                                     LockHandle);
  70     }
  71     if (LockVal == (KSPIN_LOCK)LockHandle) return;
  72
  73     /* Need to wait for it */
  74     Waiter = LockHandle->Next;
  75     while (!Waiter)
  76     {
  77         YieldProcessor();
  78         Waiter = LockHandle->Next;
  79     }
  80
  81     /* It's gone */
  82     *(ULONG_PTR*)&Waiter->Lock ^= (LQ_OWN | LQ_WAIT);
  83     LockHandle->Next = NULL;
  84 #endif
  85 }
  86
  87 /* PUBLIC FUNCTIONS **********************************************************/
  88
  89 /*
  90  * @implemented
  91  */
  92 VOID
  93 NTAPI
  94 KeInitializeSpinLock(IN PKSPIN_LOCK SpinLock)
  95 {
  96     /* Clear it */
  97     *SpinLock = 0;
  98 }
  99
 100 /*
 101  * @implemented
 102  */
 103 #undef KeAcquireSpinLockAtDpcLevel
 104 VOID
 105 NTAPI
 106 KeAcquireSpinLockAtDpcLevel(IN PKSPIN_LOCK SpinLock)
 107 {
 108     /* Do the inlined function */
 109     KxAcquireSpinLock(SpinLock);
 110 }
 111
 112 /*
 113  * @implemented
 114  */
 115 #undef KeReleaseSpinLockFromDpcLevel
 116 VOID
 117 NTAPI
 118 KeReleaseSpinLockFromDpcLevel(IN PKSPIN_LOCK SpinLock)
 119 {
 120     /* Do the lined function */
 121     KxReleaseSpinLock(SpinLock);
 122 }
 123
 124 /*
 125  * @implemented
 126  */
 127 VOID
 128 FASTCALL
 129 KefAcquireSpinLockAtDpcLevel(IN PKSPIN_LOCK SpinLock)
 130 {
 131     /* Do the inlined function */
 132     KxAcquireSpinLock(SpinLock);
 133 }
 134
 135 /*
 136  * @implemented
 137  */
 138 VOID
 139 FASTCALL
 140 KefReleaseSpinLockFromDpcLevel(IN PKSPIN_LOCK SpinLock)
 141 {
 142     /* Do the lined function */
 143     KxReleaseSpinLock(SpinLock);
 144 }
 145
 146 /*
 147  * @implemented
 148  */
 149 VOID
 150 FASTCALL
 151 KiAcquireSpinLock(IN PKSPIN_LOCK SpinLock)
 152 {
 153     /* Do the inlined function */
 154     KxAcquireSpinLock(SpinLock);
 155 }
 156
 157 /*
 158  * @implemented
 159  */
 160 VOID
 161 FASTCALL
 162 KiReleaseSpinLock(IN PKSPIN_LOCK SpinLock)
 163 {
 164     /* Do the lined function */
 165     KxReleaseSpinLock(SpinLock);
 166 }
 167
 168 /*
 169  * @implemented
 170  */
 171 BOOLEAN
 172 FASTCALL
 173 KeTryToAcquireSpinLockAtDpcLevel(IN OUT PKSPIN_LOCK SpinLock)
 174 {
 175 #ifdef CONFIG_SMP
 176     /* Check if it's already acquired */
 177     if (!(*SpinLock))
 178     {
 179         /* Try to acquire it */
 180         if (InterlockedBitTestAndSet((PLONG)SpinLock, 0))
 181         {
 182             /* Someone else acquired it */
 183             return FALSE;
 184         }
 185     }
 186     else
 187     {
 188         /* It was already acquired */
 189         return FALSE;
 190     }
 191
 192 #if DBG
 193     /* On debug builds, we OR in the KTHREAD */
 194     *SpinLock = (ULONG_PTR)KeGetCurrentThread() | 1;
 195 #endif
 196 #endif
 197
 198     /* All is well, return TRUE */
 199     return TRUE;
 200 }
 201
 202 /*
 203  * @implemented
 204  */
 205 VOID
 206 FASTCALL
 207 KeAcquireInStackQueuedSpinLockAtDpcLevel(IN PKSPIN_LOCK SpinLock,
 208                                          IN PKLOCK_QUEUE_HANDLE LockHandle)
 209 {
 210 #ifdef CONFIG_SMP
 211     /* Set it up properly */
 212     LockHandle->LockQueue.Next = NULL;
 213     LockHandle->LockQueue.Lock = SpinLock;
 214     KeAcquireQueuedSpinLockAtDpcLevel(LockHandle->LockQueue.Next);
 215 #endif
 216 }
 217
 218 /*
 219  * @implemented
 220  */
 221 VOID
 222 FASTCALL
 223 KeReleaseInStackQueuedSpinLockFromDpcLevel(IN PKLOCK_QUEUE_HANDLE LockHandle)
 224 {
 225 #ifdef CONFIG_SMP
 226     /* Call the internal function */
 227     KeReleaseQueuedSpinLockFromDpcLevel(LockHandle->LockQueue.Next);
 228 #endif
 229 }
 230
 231 /*
 232  * @implemented
 233  */
 234 KIRQL
 235 NTAPI
 236 KeAcquireInterruptSpinLock(IN PKINTERRUPT Interrupt)
 237 {
 238     KIRQL OldIrql;
 239
 240     /* Raise IRQL */
 241     KeRaiseIrql(Interrupt->SynchronizeIrql, &OldIrql);
 242
 243     /* Acquire spinlock on MP */
 244     KefAcquireSpinLockAtDpcLevel(Interrupt->ActualLock);
 245     return OldIrql;
 246 }
 247
 248 /*
 249  * @implemented
 250  */
 251 VOID
 252 NTAPI
 253 KeReleaseInterruptSpinLock(IN PKINTERRUPT Interrupt,
 254                            IN KIRQL OldIrql)
 255 {
 256     /* Release lock on MP */
 257     KefReleaseSpinLockFromDpcLevel(Interrupt->ActualLock);
 258
 259     /* Lower IRQL */
 260     KeLowerIrql(OldIrql);
 261 }
 262
 263 /*
 264  * @unimplemented
 265  */
 266 KIRQL
 267 FASTCALL
 268 KeAcquireSpinLockForDpc(IN PKSPIN_LOCK SpinLock)
 269 {
 270     UNIMPLEMENTED;
 271     return 0;
 272 }
 273
 274 /*
 275  * @unimplemented
 276  */
 277 VOID
 278 FASTCALL
 279 KeReleaseSpinLockForDpc(IN PKSPIN_LOCK SpinLock,
 280                         IN KIRQL OldIrql)
 281 {
 282     UNIMPLEMENTED;
 283 }
 284
 285 /*
 286  * @unimplemented
 287  */
 288 KIRQL
 289 FASTCALL
 290 KeAcquireInStackQueuedSpinLockForDpc(IN PKSPIN_LOCK SpinLock,
 291                                      IN PKLOCK_QUEUE_HANDLE LockHandle)
 292 {
 293     UNIMPLEMENTED;
 294     return 0;
 295 }
 296
 297 /*
 298  * @unimplemented
 299  */
 300 VOID
 301 FASTCALL
 302 KeReleaseInStackQueuedSpinLockForDpc(IN PKLOCK_QUEUE_HANDLE LockHandle)
 303 {
 304     UNIMPLEMENTED;
 305 }
 306
 307 /*
 308  * @implemented
 309  */
 310 BOOLEAN
 311 FASTCALL
 312 KeTestSpinLock(IN PKSPIN_LOCK SpinLock)
 313 {
 314     /* Test this spinlock */
 315     if (*SpinLock)
 316     {
 317         /* Spinlock is busy, yield execution */
 318         YieldProcessor();
 319
 320         /* Return busy flag */
 321         return FALSE;
 322     }
 323
 324     /* Spinlock appears to be free */
 325     return TRUE;
 326 }
 327
 328 /* EOF */