/***************************************************************************** (c) Cambridge Silicon Radio Limited 2011 All rights reserved and confidential information of CSR Refer to LICENSE.txt included with this source for details on the license terms. *****************************************************************************/ /* * *************************************************************************** * * FILE: csr_wifi_hip_send.c * * PURPOSE: * Code for adding a signal request to the from-host queue. * When the driver bottom-half is run, it will take requests from the * queue and pass them to the UniFi. * * *************************************************************************** */ #include "csr_wifi_hip_unifi.h" #include "csr_wifi_hip_conversions.h" #include "csr_wifi_hip_sigs.h" #include "csr_wifi_hip_card.h" unifi_TrafficQueue unifi_frame_priority_to_queue(CSR_PRIORITY priority) { switch (priority) { case CSR_QOS_UP0: case CSR_QOS_UP3: return UNIFI_TRAFFIC_Q_BE; case CSR_QOS_UP1: case CSR_QOS_UP2: return UNIFI_TRAFFIC_Q_BK; case CSR_QOS_UP4: case CSR_QOS_UP5: return UNIFI_TRAFFIC_Q_VI; case CSR_QOS_UP6: case CSR_QOS_UP7: case CSR_MANAGEMENT: return UNIFI_TRAFFIC_Q_VO; default: return UNIFI_TRAFFIC_Q_BE; } } CSR_PRIORITY unifi_get_default_downgrade_priority(unifi_TrafficQueue queue) { switch (queue) { case UNIFI_TRAFFIC_Q_BE: return CSR_QOS_UP0; case UNIFI_TRAFFIC_Q_BK: return CSR_QOS_UP1; case UNIFI_TRAFFIC_Q_VI: return CSR_QOS_UP5; case UNIFI_TRAFFIC_Q_VO: return CSR_QOS_UP6; default: return CSR_QOS_UP0; } } /* * --------------------------------------------------------------------------- * send_signal * * This function queues a signal for sending to UniFi. It first checks * that there is space on the fh_signal_queue for another entry, then * claims any bulk data slots required and copies data into them. Then * increments the fh_signal_queue write count. * * The fh_signal_queue is later processed by the driver bottom half * (in unifi_bh()). * * This function call unifi_pause_xmit() to pause the flow of data plane * packets when: * - the fh_signal_queue ring buffer is full * - there are less than UNIFI_MAX_DATA_REFERENCES (2) bulk data * slots available. * * Arguments: * card Pointer to card context structure * sigptr Pointer to the signal to write to UniFi. * siglen Number of bytes pointer to by sigptr. * bulkdata Array of pointers to an associated bulk data. * sigq To which from-host queue to add the signal. * * Returns: * CSR_RESULT_SUCCESS on success * CSR_WIFI_HIP_RESULT_NO_SPACE if there were insufficient data slots or * no free signal queue entry * * Notes: * Calls unifi_pause_xmit() when the last slots are used. * --------------------------------------------------------------------------- */ static CsrResult send_signal(card_t *card, const u8 *sigptr, u32 siglen, const bulk_data_param_t *bulkdata, q_t *sigq, u32 priority_q, u32 run_bh) { u16 i, data_slot_size; card_signal_t *csptr; s16 qe; CsrResult r; s16 debug_print = 0; data_slot_size = CardGetDataSlotSize(card); /* Check that the fh_data_queue has a free slot */ if (!CSR_WIFI_HIP_Q_SLOTS_FREE(sigq)) { unifi_trace(card->ospriv, UDBG3, "send_signal: %s full\n", sigq->name); return CSR_WIFI_HIP_RESULT_NO_SPACE; } /* * Now add the signal to the From Host signal queue */ /* Get next slot on queue */ qe = CSR_WIFI_HIP_Q_NEXT_W_SLOT(sigq); csptr = CSR_WIFI_HIP_Q_SLOT_DATA(sigq, qe); /* Make up the card_signal struct */ csptr->signal_length = (u16)siglen; memcpy((void *)csptr->sigbuf, (void *)sigptr, siglen); for (i = 0; i < UNIFI_MAX_DATA_REFERENCES; ++i) { if ((bulkdata != NULL) && (bulkdata->d[i].data_length != 0)) { u32 datalen = bulkdata->d[i].data_length; /* Make sure data will fit in a bulk data slot */ if (bulkdata->d[i].os_data_ptr == NULL) { unifi_error(card->ospriv, "send_signal - NULL bulkdata[%d]\n", i); debug_print++; csptr->bulkdata[i].data_length = 0; } else { if (datalen > data_slot_size) { unifi_error(card->ospriv, "send_signal - Invalid data length %u (@%p), " "truncating\n", datalen, bulkdata->d[i].os_data_ptr); datalen = data_slot_size; debug_print++; } /* Store the bulk data info in the soft queue. */ csptr->bulkdata[i].os_data_ptr = (u8 *)bulkdata->d[i].os_data_ptr; csptr->bulkdata[i].os_net_buf_ptr = (u8 *)bulkdata->d[i].os_net_buf_ptr; csptr->bulkdata[i].net_buf_length = bulkdata->d[i].net_buf_length; csptr->bulkdata[i].data_length = datalen; } } else { UNIFI_INIT_BULK_DATA(&csptr->bulkdata[i]); } } if (debug_print) { const u8 *sig = sigptr; unifi_error(card->ospriv, "Signal(%d): %*ph\n", siglen, 16, sig); unifi_error(card->ospriv, "Bulkdata pointer %p(%d), %p(%d)\n", bulkdata != NULL?bulkdata->d[0].os_data_ptr : NULL, bulkdata != NULL?bulkdata->d[0].data_length : 0, bulkdata != NULL?bulkdata->d[1].os_data_ptr : NULL, bulkdata != NULL?bulkdata->d[1].data_length : 0); } /* Advance the written count to say there is a new entry */ CSR_WIFI_HIP_Q_INC_W(sigq); /* * Set the flag to say reason for waking was a host request. * Then ask the OS layer to run the unifi_bh. */ if (run_bh == 1) { card->bh_reason_host = 1; r = unifi_run_bh(card->ospriv); if (r != CSR_RESULT_SUCCESS) { unifi_error(card->ospriv, "failed to run bh.\n"); card->bh_reason_host = 0; /* * The bulk data buffer will be freed by the caller. * We need to invalidate the description of the bulk data in our * soft queue, to prevent the core freeing the bulk data again later. */ for (i = 0; i < UNIFI_MAX_DATA_REFERENCES; ++i) { if (csptr->bulkdata[i].data_length != 0) { csptr->bulkdata[i].os_data_ptr = csptr->bulkdata[i].os_net_buf_ptr = NULL; csptr->bulkdata[i].net_buf_length = csptr->bulkdata[i].data_length = 0; } } return r; } } else { unifi_error(card->ospriv, "run_bh=%d, bh not called.\n", run_bh); } /* * Have we used up all the fh signal list entries? */ if (CSR_WIFI_HIP_Q_SLOTS_FREE(sigq) == 0) { /* We have filled the queue, so stop the upper layer. The command queue * is an exception, as suspending due to that being full could delay * resume/retry until new commands or data are received. */ if (sigq != &card->fh_command_queue) { /* * Must call unifi_pause_xmit() *before* setting the paused flag. * (the unifi_pause_xmit call should not be after setting the flag because of the possibility of being interrupted * by the bh thread between our setting the flag and the call to unifi_pause_xmit() * If bh thread then cleared the flag, we would end up paused, but without the flag set) * Instead, setting it afterwards means that if this thread is interrupted by the bh thread * the pause flag is still guaranteed to end up set * However the potential deadlock now is that if bh thread emptied the queue and cleared the flag before this thread's * call to unifi_pause_xmit(), then bh thread may not run again because it will be waiting for * a packet to appear in the queue but nothing ever will because xmit is paused. * 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. * (Note even this bad situation would not persist long in practice, because something else (eg rx, or tx in different queue) * is likely to wake bh thread quite soon) * But to avoid this deadlock completely, after setting the flag we check that there is something left in the queue. * If there is, we know that bh thread has not emptied the queue yet. * Since bh thread checks to unpause the queue *after* taking packets from the queue, we know that it is still going to make at * least one more check to see whether it needs to unpause the queue. So all is well. * If there are no packets in the queue, then the deadlock described above might happen. To make sure it does not, we * unpause the queue here. A possible side effect is that unifi_restart_xmit() may (rarely) be called for second time * unnecessarily, which is harmless */ #if defined (CSR_WIFI_HIP_DEBUG_OFFLINE) && defined (CSR_WIFI_HIP_DATA_PLANE_PROFILE) unifi_debug_log_to_buf("P"); #endif unifi_pause_xmit(card->ospriv, (unifi_TrafficQueue)priority_q); card_tx_q_pause(card, priority_q); if (CSR_WIFI_HIP_Q_SLOTS_USED(sigq) == 0) { card_tx_q_unpause(card, priority_q); unifi_restart_xmit(card->ospriv, (unifi_TrafficQueue) priority_q); } } else { unifi_warning(card->ospriv, "send_signal: fh_cmd_q full, not pausing (run_bh=%d)\n", run_bh); } } return CSR_RESULT_SUCCESS; } /* send_signal() */ /* * --------------------------------------------------------------------------- * unifi_send_signal * * Invokes send_signal() to queue a signal in the command or traffic queue * If sigptr pointer is NULL, it pokes the bh to check if UniFi is responsive. * * Arguments: * card Pointer to card context struct * sigptr Pointer to signal from card. * siglen Size of the signal * bulkdata Pointer to the bulk data of the signal * * Returns: * CSR_RESULT_SUCCESS on success * CSR_WIFI_HIP_RESULT_NO_SPACE if there were insufficient data slots or no free signal queue entry * * Notes: * unifi_send_signal() is used to queue signals, created by the driver, * to the device. Signals are constructed using the UniFi packed structures. * --------------------------------------------------------------------------- */ CsrResult unifi_send_signal(card_t *card, const u8 *sigptr, u32 siglen, const bulk_data_param_t *bulkdata) { q_t *sig_soft_q; u16 signal_id; CsrResult r; u32 run_bh; u32 priority_q; /* A NULL signal pointer is a request to check if UniFi is responsive */ if (sigptr == NULL) { card->bh_reason_host = 1; return unifi_run_bh(card->ospriv); } priority_q = 0; run_bh = 1; signal_id = GET_SIGNAL_ID(sigptr); /* * If the signal is a CSR_MA_PACKET_REQUEST , * we send it using the traffic soft queue. Else we use the command soft queue. */ if (signal_id == CSR_MA_PACKET_REQUEST_ID) { u16 frame_priority; if (card->periodic_wake_mode == UNIFI_PERIODIC_WAKE_HOST_ENABLED) { run_bh = 0; } #if defined (CSR_WIFI_HIP_DEBUG_OFFLINE) && defined (CSR_WIFI_HIP_DATA_PLANE_PROFILE) unifi_debug_log_to_buf("D"); #endif /* Sanity check: MA-PACKET.req must have a valid bulk data */ if ((bulkdata->d[0].data_length == 0) || (bulkdata->d[0].os_data_ptr == NULL)) { unifi_error(card->ospriv, "MA-PACKET.req with empty bulk data (%d bytes in %p)\n", bulkdata->d[0].data_length, bulkdata->d[0].os_data_ptr); dump((void *)sigptr, siglen); return CSR_RESULT_FAILURE; } /* Map the frame priority to a traffic queue index. */ frame_priority = GET_PACKED_MA_PACKET_REQUEST_FRAME_PRIORITY(sigptr); priority_q = unifi_frame_priority_to_queue((CSR_PRIORITY)frame_priority); sig_soft_q = &card->fh_traffic_queue[priority_q]; } else { sig_soft_q = &card->fh_command_queue; } r = send_signal(card, sigptr, siglen, bulkdata, sig_soft_q, priority_q, run_bh); /* On error, the caller must free or requeue bulkdata buffers */ return r; } /* unifi_send_signal() */ /* * --------------------------------------------------------------------------- * unifi_send_resources_available * * Examines whether there is available space to queue * a signal in the command or traffic queue * * Arguments: * card Pointer to card context struct * sigptr Pointer to signal. * * Returns: * CSR_RESULT_SUCCESS if resources available * CSR_WIFI_HIP_RESULT_NO_SPACE if there was no free signal queue entry * * Notes: * --------------------------------------------------------------------------- */ CsrResult unifi_send_resources_available(card_t *card, const u8 *sigptr) { q_t *sig_soft_q; u16 signal_id = GET_SIGNAL_ID(sigptr); /* * If the signal is a CSR_MA_PACKET_REQUEST , * we send it using the traffic soft queue. Else we use the command soft queue. */ if (signal_id == CSR_MA_PACKET_REQUEST_ID) { u16 frame_priority; u32 priority_q; /* Map the frame priority to a traffic queue index. */ frame_priority = GET_PACKED_MA_PACKET_REQUEST_FRAME_PRIORITY(sigptr); priority_q = unifi_frame_priority_to_queue((CSR_PRIORITY)frame_priority); sig_soft_q = &card->fh_traffic_queue[priority_q]; } else { sig_soft_q = &card->fh_command_queue; } /* Check that the fh_data_queue has a free slot */ if (!CSR_WIFI_HIP_Q_SLOTS_FREE(sig_soft_q)) { unifi_notice(card->ospriv, "unifi_send_resources_available: %s full\n", sig_soft_q->name); return CSR_WIFI_HIP_RESULT_NO_SPACE; } return CSR_RESULT_SUCCESS; } /* unifi_send_resources_available() */