drivers/net/bcm570x_queue.h

   1
   2 /******************************************************************************/
   3 /*                                                                            */
   4 /* Broadcom BCM5700 Linux Network Driver, Copyright (c) 2000 Broadcom         */
   5 /* Corporation.                                                               */
   6 /* All rights reserved.                                                       */
   7 /*                                                                            */
   8 /* This program is free software; you can redistribute it and/or modify       */
   9 /* it under the terms of the GNU General Public License as published by       */
  10 /* the Free Software Foundation, located in the file LICENSE.                 */
  11 /*                                                                            */
  12 /* Queue functions.                                                           */
  13 /*    void          QQ_InitQueue(PQQ_CONTAINER pQueue)                        */
  14 /*    char          QQ_Full(PQQ_CONTAINER pQueue)                             */
  15 /*    char          QQ_Empty(PQQ_CONTAINER pQueue)                            */
  16 /*    unsigned int QQ_GetSize(PQQ_CONTAINER pQueue)                          */
  17 /*    unsigned int QQ_GetEntryCnt(PQQ_CONTAINER pQueue)                      */
  18 /*    char          QQ_PushHead(PQQ_CONTAINER pQueue, PQQ_ENTRY pEntry)       */
  19 /*    char          QQ_PushTail(PQQ_CONTAINER pQueue, PQQ_ENTRY pEntry)       */
  20 /*    PQQ_ENTRY     QQ_PopHead(PQQ_CONTAINER pQueue)                          */
  21 /*    PQQ_ENTRY     QQ_PopTail(PQQ_CONTAINER pQueue)                          */
  22 /*    PQQ_ENTRY     QQ_GetHead(PQQ_CONTAINER pQueue, unsigned int Idx)       */
  23 /*    PQQ_ENTRY     QQ_GetTail(PQQ_CONTAINER pQueue, unsigned int Idx)       */
  24 /*                                                                            */
  25 /*                                                                            */
  26 /* History:                                                                   */
  27 /*    02/25/00 Hav Khauv        Initial version.                              */
  28 /******************************************************************************/
  29
  30 #ifndef BCM_QUEUE_H
  31 #define BCM_QUEUE_H
  32 #ifndef EMBEDDED
  33 #define EMBEDDED 1
  34 #endif
  35
  36 /******************************************************************************/
  37 /* Queue definitions. */
  38 /******************************************************************************/
  39
  40 /* Entry for queueing. */
  41 typedef void *PQQ_ENTRY;
  42
  43 /* Linux Atomic Ops support */
  44 typedef struct { int counter; } atomic_t;
  45
  46
  47 /*
  48  * This combination of `inline' and `extern' has almost the effect of a
  49  * macro.  The way to use it is to put a function definition in a header
  50  * file with these keywords, and put another copy of the definition
  51  * (lacking `inline' and `extern') in a library file.  The definition in
  52  * the header file will cause most calls to the function to be inlined.
  53  * If any uses of the function remain, they will refer to the single copy
  54  * in the library.
  55  */
  56 extern __inline void
  57 atomic_set(atomic_t* entry, int val)
  58 {
  59     entry->counter = val;
  60 }
  61 extern __inline int
  62 atomic_read(atomic_t* entry)
  63 {
  64     return entry->counter;
  65 }
  66 extern __inline void
  67 atomic_inc(atomic_t* entry)
  68 {
  69     if(entry)
  70         entry->counter++;
  71 }
  72
  73 extern __inline void
  74 atomic_dec(atomic_t* entry)
  75 {
  76     if(entry)
  77         entry->counter--;
  78 }
  79
  80 extern __inline void
  81 atomic_sub(int a, atomic_t* entry)
  82 {
  83     if(entry)
  84         entry->counter -= a;
  85 }
  86 extern __inline void
  87 atomic_add(int a, atomic_t* entry)
  88 {
  89     if(entry)
  90         entry->counter += a;
  91 }
  92
  93
  94 /* Queue header -- base type. */
  95 typedef struct {
  96     unsigned int Head;
  97     unsigned int Tail;
  98     unsigned int Size;
  99     atomic_t EntryCnt;
 100     PQQ_ENTRY Array[1];
 101 } QQ_CONTAINER, *PQQ_CONTAINER;
 102
 103
 104 /* Declare queue type macro. */
 105 #define DECLARE_QUEUE_TYPE(_QUEUE_TYPE, _QUEUE_SIZE)            \
 106                                                                 \
 107     typedef struct {                                            \
 108         QQ_CONTAINER Container;                                 \
 109         PQQ_ENTRY EntryBuffer[_QUEUE_SIZE];                     \
 110     } _QUEUE_TYPE, *P##_QUEUE_TYPE
 111
 112
 113 /******************************************************************************/
 114 /* Compilation switches. */
 115 /******************************************************************************/
 116
 117 #if DBG
 118 #undef QQ_NO_OVERFLOW_CHECK
 119 #undef QQ_NO_UNDERFLOW_CHECK
 120 #endif /* DBG */
 121
 122 #ifdef QQ_USE_MACROS
 123 /* notdone */
 124 #else
 125
 126 #ifdef QQ_NO_INLINE
 127 #define __inline
 128 #endif /* QQ_NO_INLINE */
 129
 130 /******************************************************************************/
 131 /* Description:                                                               */
 132 /*                                                                            */
 133 /* Return:                                                                    */
 134 /******************************************************************************/
 135 extern __inline void
 136 QQ_InitQueue(
 137 PQQ_CONTAINER pQueue,
 138 unsigned int QueueSize) {
 139     pQueue->Head = 0;
 140     pQueue->Tail = 0;
 141     pQueue->Size = QueueSize+1;
 142     atomic_set(&pQueue->EntryCnt, 0);
 143 } /* QQ_InitQueue */
 144
 145
 146 /******************************************************************************/
 147 /* Description:                                                               */
 148 /*                                                                            */
 149 /* Return:                                                                    */
 150 /******************************************************************************/
 151 extern __inline char
 152 QQ_Full(
 153 PQQ_CONTAINER pQueue) {
 154     unsigned int NewHead;
 155
 156     NewHead = (pQueue->Head + 1) % pQueue->Size;
 157
 158     return(NewHead == pQueue->Tail);
 159 } /* QQ_Full */
 160
 161
 162 /******************************************************************************/
 163 /* Description:                                                               */
 164 /*                                                                            */
 165 /* Return:                                                                    */
 166 /******************************************************************************/
 167 extern __inline char
 168 QQ_Empty(
 169 PQQ_CONTAINER pQueue) {
 170     return(pQueue->Head == pQueue->Tail);
 171 } /* QQ_Empty */
 172
 173
 174 /******************************************************************************/
 175 /* Description:                                                               */
 176 /*                                                                            */
 177 /* Return:                                                                    */
 178 /******************************************************************************/
 179 extern __inline unsigned int
 180 QQ_GetSize(
 181 PQQ_CONTAINER pQueue) {
 182     return pQueue->Size;
 183 } /* QQ_GetSize */
 184
 185
 186 /******************************************************************************/
 187 /* Description:                                                               */
 188 /*                                                                            */
 189 /* Return:                                                                    */
 190 /******************************************************************************/
 191 extern __inline unsigned int
 192 QQ_GetEntryCnt(
 193 PQQ_CONTAINER pQueue) {
 194     return atomic_read(&pQueue->EntryCnt);
 195 } /* QQ_GetEntryCnt */
 196
 197
 198 /******************************************************************************/
 199 /* Description:                                                               */
 200 /*                                                                            */
 201 /* Return:                                                                    */
 202 /*    TRUE entry was added successfully.                                      */
 203 /*    FALSE queue is full.                                                    */
 204 /******************************************************************************/
 205 extern __inline char
 206 QQ_PushHead(
 207 PQQ_CONTAINER pQueue,
 208 PQQ_ENTRY pEntry) {
 209     unsigned int Head;
 210
 211     Head = (pQueue->Head + 1) % pQueue->Size;
 212
 213 #if !defined(QQ_NO_OVERFLOW_CHECK)
 214     if(Head == pQueue->Tail) {
 215         return 0;
 216     } /* if */
 217 #endif /* QQ_NO_OVERFLOW_CHECK */
 218
 219     pQueue->Array[pQueue->Head] = pEntry;
 220     wmb();
 221     pQueue->Head = Head;
 222     atomic_inc(&pQueue->EntryCnt);
 223
 224     return -1;
 225 } /* QQ_PushHead */
 226
 227
 228 /******************************************************************************/
 229 /* Description:                                                               */
 230 /*                                                                            */
 231 /* Return:                                                                    */
 232 /*    TRUE entry was added successfully.                                      */
 233 /*    FALSE queue is full.                                                    */
 234 /******************************************************************************/
 235 extern __inline char
 236 QQ_PushTail(
 237 PQQ_CONTAINER pQueue,
 238 PQQ_ENTRY pEntry) {
 239     unsigned int Tail;
 240
 241     Tail = pQueue->Tail;
 242     if(Tail == 0) {
 243         Tail = pQueue->Size;
 244     } /* if */
 245     Tail--;
 246
 247 #if !defined(QQ_NO_OVERFLOW_CHECK)
 248     if(Tail == pQueue->Head) {
 249         return 0;
 250     } /* if */
 251 #endif /* QQ_NO_OVERFLOW_CHECK */
 252
 253     pQueue->Array[Tail] = pEntry;
 254     wmb();
 255     pQueue->Tail = Tail;
 256     atomic_inc(&pQueue->EntryCnt);
 257
 258     return -1;
 259 } /* QQ_PushTail */
 260
 261
 262 /******************************************************************************/
 263 /* Description:                                                               */
 264 /*                                                                            */
 265 /* Return:                                                                    */
 266 /******************************************************************************/
 267 extern __inline PQQ_ENTRY
 268 QQ_PopHead(
 269 PQQ_CONTAINER pQueue) {
 270     unsigned int Head;
 271     PQQ_ENTRY Entry;
 272
 273     Head = pQueue->Head;
 274
 275 #if !defined(QQ_NO_UNDERFLOW_CHECK)
 276     if(Head == pQueue->Tail) {
 277         return (PQQ_ENTRY) 0;
 278     } /* if */
 279 #endif /* QQ_NO_UNDERFLOW_CHECK */
 280
 281     if(Head == 0) {
 282         Head = pQueue->Size;
 283     } /* if */
 284     Head--;
 285
 286     Entry = pQueue->Array[Head];
 287 #ifdef EMBEDDED
 288     membar();
 289 #else
 290     mb();
 291 #endif
 292     pQueue->Head = Head;
 293     atomic_dec(&pQueue->EntryCnt);
 294
 295     return Entry;
 296 } /* QQ_PopHead */
 297
 298
 299 /******************************************************************************/
 300 /* Description:                                                               */
 301 /*                                                                            */
 302 /* Return:                                                                    */
 303 /******************************************************************************/
 304 extern __inline PQQ_ENTRY
 305 QQ_PopTail(
 306 PQQ_CONTAINER pQueue) {
 307     unsigned int Tail;
 308     PQQ_ENTRY Entry;
 309
 310     Tail = pQueue->Tail;
 311
 312 #if !defined(QQ_NO_UNDERFLOW_CHECK)
 313     if(Tail == pQueue->Head) {
 314         return (PQQ_ENTRY) 0;
 315     } /* if */
 316 #endif /* QQ_NO_UNDERFLOW_CHECK */
 317
 318     Entry = pQueue->Array[Tail];
 319 #ifdef EMBEDDED
 320     membar();
 321 #else
 322     mb();
 323 #endif
 324     pQueue->Tail = (Tail + 1) % pQueue->Size;
 325     atomic_dec(&pQueue->EntryCnt);
 326
 327     return Entry;
 328 } /* QQ_PopTail */
 329
 330
 331 /******************************************************************************/
 332 /* Description:                                                               */
 333 /*                                                                            */
 334 /* Return:                                                                    */
 335 /******************************************************************************/
 336 extern __inline PQQ_ENTRY
 337 QQ_GetHead(
 338     PQQ_CONTAINER pQueue,
 339     unsigned int Idx)
 340 {
 341     if(Idx >= atomic_read(&pQueue->EntryCnt))
 342     {
 343         return (PQQ_ENTRY) 0;
 344     }
 345
 346     if(pQueue->Head > Idx)
 347     {
 348         Idx = pQueue->Head - Idx;
 349     }
 350     else
 351     {
 352         Idx = pQueue->Size - (Idx - pQueue->Head);
 353     }
 354     Idx--;
 355
 356     return pQueue->Array[Idx];
 357 }
 358
 359
 360 /******************************************************************************/
 361 /* Description:                                                               */
 362 /*                                                                            */
 363 /* Return:                                                                    */
 364 /******************************************************************************/
 365 extern __inline PQQ_ENTRY
 366 QQ_GetTail(
 367     PQQ_CONTAINER pQueue,
 368     unsigned int Idx)
 369 {
 370     if(Idx >= atomic_read(&pQueue->EntryCnt))
 371     {
 372         return (PQQ_ENTRY) 0;
 373     }
 374
 375     Idx += pQueue->Tail;
 376     if(Idx >= pQueue->Size)
 377     {
 378         Idx = Idx - pQueue->Size;
 379     }
 380
 381     return pQueue->Array[Idx];
 382 }
 383
 384 #endif /* QQ_USE_MACROS */
 385
 386
 387 #endif /* QUEUE_H */