drivers/net/ethernet/cavium/liquidio/response_manager.c

   1 /**********************************************************************
   2  * Author: Cavium, Inc.
   3  *
   4  * Contact: support@cavium.com
   5  *          Please include "LiquidIO" in the subject.
   6  *
   7  * Copyright (c) 2003-2015 Cavium, Inc.
   8  *
   9  * This file is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License, Version 2, as
  11  * published by the Free Software Foundation.
  12  *
  13  * This file is distributed in the hope that it will be useful, but
  14  * AS-IS and WITHOUT ANY WARRANTY; without even the implied warranty
  15  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, TITLE, or
  16  * NONINFRINGEMENT.  See the GNU General Public License for more
  17  * details.
  18  *
  19  * This file may also be available under a different license from Cavium.
  20  * Contact Cavium, Inc. for more information
  21  **********************************************************************/
  22 #include <linux/pci.h>
  23 #include <linux/netdevice.h>
  24 #include "liquidio_common.h"
  25 #include "octeon_droq.h"
  26 #include "octeon_iq.h"
  27 #include "response_manager.h"
  28 #include "octeon_device.h"
  29 #include "octeon_main.h"
  30
  31 static void oct_poll_req_completion(struct work_struct *work);
  32
  33 int octeon_setup_response_list(struct octeon_device *oct)
  34 {
  35         int i, ret = 0;
  36         struct cavium_wq *cwq;
  37
  38         for (i = 0; i < MAX_RESPONSE_LISTS; i++) {
  39                 INIT_LIST_HEAD(&oct->response_list[i].head);
  40                 spin_lock_init(&oct->response_list[i].lock);
  41                 atomic_set(&oct->response_list[i].pending_req_count, 0);
  42         }
  43         spin_lock_init(&oct->cmd_resp_wqlock);
  44
  45         oct->dma_comp_wq.wq = alloc_workqueue("dma-comp", WQ_MEM_RECLAIM, 0);
  46         if (!oct->dma_comp_wq.wq) {
  47                 dev_err(&oct->pci_dev->dev, "failed to create wq thread\n");
  48                 return -ENOMEM;
  49         }
  50
  51         cwq = &oct->dma_comp_wq;
  52         INIT_DELAYED_WORK(&cwq->wk.work, oct_poll_req_completion);
  53         cwq->wk.ctxptr = oct;
  54         oct->cmd_resp_state = OCT_DRV_ONLINE;
  55         queue_delayed_work(cwq->wq, &cwq->wk.work, msecs_to_jiffies(50));
  56
  57         return ret;
  58 }
  59
  60 void octeon_delete_response_list(struct octeon_device *oct)
  61 {
  62         cancel_delayed_work_sync(&oct->dma_comp_wq.wk.work);
  63         destroy_workqueue(oct->dma_comp_wq.wq);
  64 }
  65
  66 int lio_process_ordered_list(struct octeon_device *octeon_dev,
  67                              u32 force_quit)
  68 {
  69         struct octeon_response_list *ordered_sc_list;
  70         struct octeon_soft_command *sc;
  71         int request_complete = 0;
  72         int resp_to_process = MAX_ORD_REQS_TO_PROCESS;
  73         u32 status;
  74         u64 status64;
  75         struct octeon_instr_rdp *rdp;
  76         u64 rptr;
  77
  78         ordered_sc_list = &octeon_dev->response_list[OCTEON_ORDERED_SC_LIST];
  79
  80         do {
  81                 spin_lock_bh(&ordered_sc_list->lock);
  82
  83                 if (ordered_sc_list->head.next == &ordered_sc_list->head) {
  84                         /* ordered_sc_list is empty; there is
  85                          * nothing to process
  86                          */
  87                         spin_unlock_bh
  88                             (&ordered_sc_list->lock);
  89                         return 1;
  90                 }
  91
  92                 sc = (struct octeon_soft_command *)ordered_sc_list->
  93                     head.next;
  94                 rdp = (struct octeon_instr_rdp *)&sc->cmd.cmd2.rdp;
  95                 rptr = sc->cmd.cmd2.rptr;
  96
  97                 status = OCTEON_REQUEST_PENDING;
  98
  99                 /* check if octeon has finished DMA'ing a response
 100                  * to where rptr is pointing to
 101                  */
 102                 dma_sync_single_for_cpu(&octeon_dev->pci_dev->dev,
 103                                         rptr, rdp->rlen,
 104                                         DMA_FROM_DEVICE);
 105                 status64 = *sc->status_word;
 106
 107                 if (status64 != COMPLETION_WORD_INIT) {
 108                         if ((status64 & 0xff) != 0xff) {
 109                                 octeon_swap_8B_data(&status64, 1);
 110                                 if (((status64 & 0xff) != 0xff)) {
 111                                         status = (u32)(status64 &
 112                                                        0xffffffffULL);
 113                                 }
 114                         }
 115                 } else if (force_quit || (sc->timeout &&
 116                         time_after(jiffies, (unsigned long)sc->timeout))) {
 117                         status = OCTEON_REQUEST_TIMEOUT;
 118                 }
 119
 120                 if (status != OCTEON_REQUEST_PENDING) {
 121                         /* we have received a response or we have timed out */
 122                         /* remove node from linked list */
 123                         list_del(&sc->node);
 124                         atomic_dec(&octeon_dev->response_list
 125                                           [OCTEON_ORDERED_SC_LIST].
 126                                           pending_req_count);
 127                         spin_unlock_bh
 128                             (&ordered_sc_list->lock);
 129
 130                         if (sc->callback)
 131                                 sc->callback(octeon_dev, status,
 132                                              sc->callback_arg);
 133
 134                         request_complete++;
 135
 136                 } else {
 137                         /* no response yet */
 138                         request_complete = 0;
 139                         spin_unlock_bh
 140                             (&ordered_sc_list->lock);
 141                 }
 142
 143                 /* If we hit the Max Ordered requests to process every loop,
 144                  * we quit
 145                  * and let this function be invoked the next time the poll
 146                  * thread runs
 147                  * to process the remaining requests. This function can take up
 148                  * the entire CPU if there is no upper limit to the requests
 149                  * processed.
 150                  */
 151                 if (request_complete >= resp_to_process)
 152                         break;
 153         } while (request_complete);
 154
 155         return 0;
 156 }
 157
 158 static void oct_poll_req_completion(struct work_struct *work)
 159 {
 160         struct cavium_wk *wk = (struct cavium_wk *)work;
 161         struct octeon_device *oct = (struct octeon_device *)wk->ctxptr;
 162         struct cavium_wq *cwq = &oct->dma_comp_wq;
 163
 164         lio_process_ordered_list(oct, 0);
 165         queue_delayed_work(cwq->wq, &cwq->wk.work, msecs_to_jiffies(50));
 166 }