drivers/staging/csr/csr_wifi_hip_send.c

   1 /*****************************************************************************
   2
   3             (c) Cambridge Silicon Radio Limited 2011
   4             All rights reserved and confidential information of CSR
   5
   6             Refer to LICENSE.txt included with this source for details
   7             on the license terms.
   8
   9 *****************************************************************************/
  10
  11 /*
  12  * ***************************************************************************
  13  *
  14  *  FILE:     csr_wifi_hip_send.c
  15  *
  16  *  PURPOSE:
  17  *      Code for adding a signal request to the from-host queue.
  18  *      When the driver bottom-half is run, it will take requests from the
  19  *      queue and pass them to the UniFi.
  20  *
  21  * ***************************************************************************
  22  */
  23 #include "csr_wifi_hip_unifi.h"
  24 #include "csr_wifi_hip_conversions.h"
  25 #include "csr_wifi_hip_sigs.h"
  26 #include "csr_wifi_hip_card.h"
  27
  28 unifi_TrafficQueue unifi_frame_priority_to_queue(CSR_PRIORITY priority)
  29 {
  30     switch (priority)
  31     {
  32         case CSR_QOS_UP0:
  33         case CSR_QOS_UP3:
  34             return UNIFI_TRAFFIC_Q_BE;
  35         case CSR_QOS_UP1:
  36         case CSR_QOS_UP2:
  37             return UNIFI_TRAFFIC_Q_BK;
  38         case CSR_QOS_UP4:
  39         case CSR_QOS_UP5:
  40             return UNIFI_TRAFFIC_Q_VI;
  41         case CSR_QOS_UP6:
  42         case CSR_QOS_UP7:
  43         case CSR_MANAGEMENT:
  44             return UNIFI_TRAFFIC_Q_VO;
  45         default:
  46             return UNIFI_TRAFFIC_Q_BE;
  47     }
  48 }
  49
  50
  51 CSR_PRIORITY unifi_get_default_downgrade_priority(unifi_TrafficQueue queue)
  52 {
  53     switch (queue)
  54     {
  55         case UNIFI_TRAFFIC_Q_BE:
  56             return CSR_QOS_UP0;
  57         case UNIFI_TRAFFIC_Q_BK:
  58             return CSR_QOS_UP1;
  59         case UNIFI_TRAFFIC_Q_VI:
  60             return CSR_QOS_UP5;
  61         case UNIFI_TRAFFIC_Q_VO:
  62             return CSR_QOS_UP6;
  63         default:
  64             return CSR_QOS_UP0;
  65     }
  66 }
  67
  68
  69 /*
  70  * ---------------------------------------------------------------------------
  71  *  send_signal
  72  *
  73  *      This function queues a signal for sending to UniFi.  It first checks
  74  *      that there is space on the fh_signal_queue for another entry, then
  75  *      claims any bulk data slots required and copies data into them. Then
  76  *      increments the fh_signal_queue write count.
  77  *
  78  *      The fh_signal_queue is later processed by the driver bottom half
  79  *      (in unifi_bh()).
  80  *
  81  *      This function call unifi_pause_xmit() to pause the flow of data plane
  82  *      packets when:
  83  *        - the fh_signal_queue ring buffer is full
  84  *        - there are less than UNIFI_MAX_DATA_REFERENCES (2) bulk data
  85  *          slots available.
  86  *
  87  *  Arguments:
  88  *      card            Pointer to card context structure
  89  *      sigptr          Pointer to the signal to write to UniFi.
  90  *      siglen          Number of bytes pointer to by sigptr.
  91  *      bulkdata        Array of pointers to an associated bulk data.
  92  *      sigq            To which from-host queue to add the signal.
  93  *
  94  *  Returns:
  95  *      CSR_RESULT_SUCCESS on success
  96  *      CSR_WIFI_HIP_RESULT_NO_SPACE if there were insufficient data slots or
  97  *                              no free signal queue entry
  98  *
  99  * Notes:
 100  *      Calls unifi_pause_xmit() when the last slots are used.
 101  * ---------------------------------------------------------------------------
 102  */
 103 static CsrResult send_signal(card_t *card, const u8 *sigptr, u32 siglen,
 104                              const bulk_data_param_t *bulkdata,
 105                              q_t *sigq, u32 priority_q, u32 run_bh)
 106 {
 107     u16 i, data_slot_size;
 108     card_signal_t *csptr;
 109     s16 qe;
 110     CsrResult r;
 111     s16 debug_print = 0;
 112
 113     data_slot_size = CardGetDataSlotSize(card);
 114
 115     /* Check that the fh_data_queue has a free slot */
 116     if (!CSR_WIFI_HIP_Q_SLOTS_FREE(sigq))
 117     {
 118         unifi_trace(card->ospriv, UDBG3, "send_signal: %s full\n", sigq->name);
 119
 120         return CSR_WIFI_HIP_RESULT_NO_SPACE;
 121     }
 122
 123     /*
 124      * Now add the signal to the From Host signal queue
 125      */
 126     /* Get next slot on queue */
 127     qe = CSR_WIFI_HIP_Q_NEXT_W_SLOT(sigq);
 128     csptr = CSR_WIFI_HIP_Q_SLOT_DATA(sigq, qe);
 129
 130     /* Make up the card_signal struct */
 131     csptr->signal_length = (u16)siglen;
 132     memcpy((void *)csptr->sigbuf, (void *)sigptr, siglen);
 133
 134     for (i = 0; i < UNIFI_MAX_DATA_REFERENCES; ++i)
 135     {
 136         if ((bulkdata != NULL) && (bulkdata->d[i].data_length != 0))
 137         {
 138             u32 datalen = bulkdata->d[i].data_length;
 139
 140             /* Make sure data will fit in a bulk data slot */
 141             if (bulkdata->d[i].os_data_ptr == NULL)
 142             {
 143                 unifi_error(card->ospriv, "send_signal - NULL bulkdata[%d]\n", i);
 144                 debug_print++;
 145                 csptr->bulkdata[i].data_length = 0;
 146             }
 147             else
 148             {
 149                 if (datalen > data_slot_size)
 150                 {
 151                     unifi_error(card->ospriv,
 152                                 "send_signal - Invalid data length %u (@%p), "
 153                                 "truncating\n",
 154                                 datalen, bulkdata->d[i].os_data_ptr);
 155                     datalen = data_slot_size;
 156                     debug_print++;
 157                 }
 158                 /* Store the bulk data info in the soft queue. */
 159                 csptr->bulkdata[i].os_data_ptr = (u8 *)bulkdata->d[i].os_data_ptr;
 160                 csptr->bulkdata[i].os_net_buf_ptr = (u8 *)bulkdata->d[i].os_net_buf_ptr;
 161                 csptr->bulkdata[i].net_buf_length = bulkdata->d[i].net_buf_length;
 162                 csptr->bulkdata[i].data_length = datalen;
 163             }
 164         }
 165         else
 166         {
 167             UNIFI_INIT_BULK_DATA(&csptr->bulkdata[i]);
 168         }
 169     }
 170
 171     if (debug_print)
 172     {
 173         const u8 *sig = sigptr;
 174
 175                 unifi_error(card->ospriv, "Signal(%d): %*ph\n", siglen,
 176                                           16, sig);
 177         unifi_error(card->ospriv, "Bulkdata pointer %p(%d), %p(%d)\n",
 178                     bulkdata != NULL?bulkdata->d[0].os_data_ptr : NULL,
 179                     bulkdata != NULL?bulkdata->d[0].data_length : 0,
 180                     bulkdata != NULL?bulkdata->d[1].os_data_ptr : NULL,
 181                     bulkdata != NULL?bulkdata->d[1].data_length : 0);
 182     }
 183
 184     /* Advance the written count to say there is a new entry */
 185     CSR_WIFI_HIP_Q_INC_W(sigq);
 186
 187     /*
 188      * Set the flag to say reason for waking was a host request.
 189      * Then ask the OS layer to run the unifi_bh.
 190      */
 191     if (run_bh == 1)
 192     {
 193         card->bh_reason_host = 1;
 194         r = unifi_run_bh(card->ospriv);
 195         if (r != CSR_RESULT_SUCCESS)
 196         {
 197             unifi_error(card->ospriv, "failed to run bh.\n");
 198             card->bh_reason_host = 0;
 199
 200             /*
 201              * The bulk data buffer will be freed by the caller.
 202              * We need to invalidate the description of the bulk data in our
 203              * soft queue, to prevent the core freeing the bulk data again later.
 204              */
 205             for (i = 0; i < UNIFI_MAX_DATA_REFERENCES; ++i)
 206             {
 207                 if (csptr->bulkdata[i].data_length != 0)
 208                 {
 209                     csptr->bulkdata[i].os_data_ptr = csptr->bulkdata[i].os_net_buf_ptr = NULL;
 210                     csptr->bulkdata[i].net_buf_length = csptr->bulkdata[i].data_length = 0;
 211                 }
 212             }
 213             return r;
 214         }
 215     }
 216     else
 217     {
 218         unifi_error(card->ospriv, "run_bh=%d, bh not called.\n", run_bh);
 219     }
 220
 221     /*
 222      * Have we used up all the fh signal list entries?
 223      */
 224     if (CSR_WIFI_HIP_Q_SLOTS_FREE(sigq) == 0)
 225     {
 226         /* We have filled the queue, so stop the upper layer. The command queue
 227          * is an exception, as suspending due to that being full could delay
 228          * resume/retry until new commands or data are received.
 229          */
 230         if (sigq != &card->fh_command_queue)
 231         {
 232             /*
 233              * Must call unifi_pause_xmit() *before* setting the paused flag.
 234              * (the unifi_pause_xmit call should not be after setting the flag because of the possibility of being interrupted
 235              * by the bh thread between our setting the flag and the call to unifi_pause_xmit()
 236              * If bh thread then cleared the flag, we would end up paused, but without the flag set)
 237              * Instead, setting it afterwards means that if this thread is interrupted by the bh thread
 238              * the pause flag is still guaranteed to end up set
 239              * However the potential deadlock now is that if bh thread emptied the queue and cleared the flag before this thread's
 240              * call to unifi_pause_xmit(), then bh thread may not run again because it will be waiting for
 241              * a packet to appear in the queue but nothing ever will because xmit is paused.
 242              * So we will end up with the queue paused, and the flag set to say it is paused, but bh never runs to unpause it.
 243              * (Note even this bad situation would not persist long in practice, because something else (eg rx, or tx in different queue)
 244              * is likely to wake bh thread quite soon)
 245              * But to avoid this deadlock completely, after setting the flag we check that there is something left in the queue.
 246              * If there is, we know that bh thread has not emptied the queue yet.
 247              * Since bh thread checks to unpause the queue *after* taking packets from the queue, we know that it is still going to make at
 248              * least one more check to see whether it needs to unpause the queue.  So all is well.
 249              * If there are no packets in the queue, then the deadlock described above might happen.  To make sure it does not, we
 250              * unpause the queue here. A possible side effect is that unifi_restart_xmit() may (rarely) be called for second time
 251              *  unnecessarily, which is harmless
 252              */
 253
 254 #if defined (CSR_WIFI_HIP_DEBUG_OFFLINE) && defined (CSR_WIFI_HIP_DATA_PLANE_PROFILE)
 255             unifi_debug_log_to_buf("P");
 256 #endif
 257             unifi_pause_xmit(card->ospriv, (unifi_TrafficQueue)priority_q);
 258             card_tx_q_pause(card, priority_q);
 259             if (CSR_WIFI_HIP_Q_SLOTS_USED(sigq) == 0)
 260             {
 261                 card_tx_q_unpause(card, priority_q);
 262                 unifi_restart_xmit(card->ospriv, (unifi_TrafficQueue) priority_q);
 263             }
 264         }
 265         else
 266         {
 267             unifi_warning(card->ospriv,
 268                           "send_signal: fh_cmd_q full, not pausing (run_bh=%d)\n",
 269                           run_bh);
 270         }
 271     }
 272
 273     return CSR_RESULT_SUCCESS;
 274 } /*  send_signal() */
 275
 276
 277 /*
 278  * ---------------------------------------------------------------------------
 279  *  unifi_send_signal
 280  *
 281  *    Invokes send_signal() to queue a signal in the command or traffic queue
 282  *    If sigptr pointer is NULL, it pokes the bh to check if UniFi is responsive.
 283  *
 284  *  Arguments:
 285  *      card        Pointer to card context struct
 286  *      sigptr      Pointer to signal from card.
 287  *      siglen      Size of the signal
 288  *      bulkdata    Pointer to the bulk data of the signal
 289  *
 290  *  Returns:
 291  *      CSR_RESULT_SUCCESS on success
 292  *      CSR_WIFI_HIP_RESULT_NO_SPACE if there were insufficient data slots or no free signal queue entry
 293  *
 294  *  Notes:
 295  *      unifi_send_signal() is used to queue signals, created by the driver,
 296  *      to the device. Signals are constructed using the UniFi packed structures.
 297  * ---------------------------------------------------------------------------
 298  */
 299 CsrResult unifi_send_signal(card_t *card, const u8 *sigptr, u32 siglen,
 300                             const bulk_data_param_t *bulkdata)
 301 {
 302     q_t *sig_soft_q;
 303     u16 signal_id;
 304     CsrResult r;
 305     u32 run_bh;
 306     u32 priority_q;
 307
 308     /* A NULL signal pointer is a request to check if UniFi is responsive */
 309     if (sigptr == NULL)
 310     {
 311         card->bh_reason_host = 1;
 312         return unifi_run_bh(card->ospriv);
 313     }
 314
 315     priority_q = 0;
 316     run_bh = 1;
 317     signal_id = GET_SIGNAL_ID(sigptr);
 318     /*
 319      * If the signal is a CSR_MA_PACKET_REQUEST ,
 320      * we send it using the traffic soft queue. Else we use the command soft queue.
 321      */
 322     if (signal_id == CSR_MA_PACKET_REQUEST_ID)
 323     {
 324         u16 frame_priority;
 325
 326         if (card->periodic_wake_mode == UNIFI_PERIODIC_WAKE_HOST_ENABLED)
 327         {
 328             run_bh = 0;
 329         }
 330
 331 #if defined (CSR_WIFI_HIP_DEBUG_OFFLINE) && defined (CSR_WIFI_HIP_DATA_PLANE_PROFILE)
 332         unifi_debug_log_to_buf("D");
 333 #endif
 334         /* Sanity check: MA-PACKET.req must have a valid bulk data */
 335         if ((bulkdata->d[0].data_length == 0) || (bulkdata->d[0].os_data_ptr == NULL))
 336         {
 337             unifi_error(card->ospriv, "MA-PACKET.req with empty bulk data (%d bytes in %p)\n",
 338                         bulkdata->d[0].data_length, bulkdata->d[0].os_data_ptr);
 339             dump((void *)sigptr, siglen);
 340             return CSR_RESULT_FAILURE;
 341         }
 342
 343         /* Map the frame priority to a traffic queue index. */
 344         frame_priority = GET_PACKED_MA_PACKET_REQUEST_FRAME_PRIORITY(sigptr);
 345         priority_q = unifi_frame_priority_to_queue((CSR_PRIORITY)frame_priority);
 346
 347         sig_soft_q = &card->fh_traffic_queue[priority_q];
 348     }
 349     else
 350     {
 351         sig_soft_q = &card->fh_command_queue;
 352     }
 353
 354     r = send_signal(card, sigptr, siglen, bulkdata, sig_soft_q, priority_q, run_bh);
 355     /* On error, the caller must free or requeue bulkdata buffers */
 356
 357     return r;
 358 } /* unifi_send_signal() */
 359
 360
 361 /*
 362  * ---------------------------------------------------------------------------
 363  *  unifi_send_resources_available
 364  *
 365  *      Examines whether there is available space to queue
 366  *      a signal in the command or traffic queue
 367  *
 368  *  Arguments:
 369  *      card        Pointer to card context struct
 370  *      sigptr      Pointer to signal.
 371  *
 372  *  Returns:
 373  *      CSR_RESULT_SUCCESS if resources available
 374  *      CSR_WIFI_HIP_RESULT_NO_SPACE if there was no free signal queue entry
 375  *
 376  *  Notes:
 377  * ---------------------------------------------------------------------------
 378  */
 379 CsrResult unifi_send_resources_available(card_t *card, const u8 *sigptr)
 380 {
 381     q_t *sig_soft_q;
 382     u16 signal_id = GET_SIGNAL_ID(sigptr);
 383
 384     /*
 385      * If the signal is a CSR_MA_PACKET_REQUEST ,
 386      * we send it using the traffic soft queue. Else we use the command soft queue.
 387      */
 388     if (signal_id == CSR_MA_PACKET_REQUEST_ID)
 389     {
 390         u16 frame_priority;
 391         u32 priority_q;
 392
 393         /* Map the frame priority to a traffic queue index. */
 394         frame_priority = GET_PACKED_MA_PACKET_REQUEST_FRAME_PRIORITY(sigptr);
 395         priority_q = unifi_frame_priority_to_queue((CSR_PRIORITY)frame_priority);
 396
 397         sig_soft_q = &card->fh_traffic_queue[priority_q];
 398     }
 399     else
 400     {
 401         sig_soft_q = &card->fh_command_queue;
 402     }
 403
 404     /* Check that the fh_data_queue has a free slot */
 405     if (!CSR_WIFI_HIP_Q_SLOTS_FREE(sig_soft_q))
 406     {
 407         unifi_notice(card->ospriv, "unifi_send_resources_available: %s full\n",
 408                      sig_soft_q->name);
 409         return CSR_WIFI_HIP_RESULT_NO_SPACE;
 410     }
 411
 412     return CSR_RESULT_SUCCESS;
 413 } /* unifi_send_resources_available() */
 414
 415