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) 2003-2016 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 #include <linux/pci.h>
  20 #include <linux/netdevice.h>
  21 #include "liquidio_common.h"
  22 #include "octeon_droq.h"
  23 #include "octeon_iq.h"
  24 #include "response_manager.h"
  25 #include "octeon_device.h"
  26 #include "octeon_main.h"
  27
  28 static void oct_poll_req_completion(struct work_struct *work);
  29
  30 int octeon_setup_response_list(struct octeon_device *oct)
  31 {
  32         int i, ret = 0;
  33         struct cavium_wq *cwq;
  34
  35         for (i = 0; i < MAX_RESPONSE_LISTS; i++) {
  36                 INIT_LIST_HEAD(&oct->response_list[i].head);
  37                 spin_lock_init(&oct->response_list[i].lock);
  38                 atomic_set(&oct->response_list[i].pending_req_count, 0);
  39         }
  40         spin_lock_init(&oct->cmd_resp_wqlock);
  41
  42         oct->dma_comp_wq.wq = alloc_workqueue("dma-comp", WQ_MEM_RECLAIM, 0);
  43         if (!oct->dma_comp_wq.wq) {
  44                 dev_err(&oct->pci_dev->dev, "failed to create wq thread\n");
  45                 return -ENOMEM;
  46         }
  47
  48         cwq = &oct->dma_comp_wq;
  49         INIT_DELAYED_WORK(&cwq->wk.work, oct_poll_req_completion);
  50         cwq->wk.ctxptr = oct;
  51         oct->cmd_resp_state = OCT_DRV_ONLINE;
  52         queue_delayed_work(cwq->wq, &cwq->wk.work, msecs_to_jiffies(50));
  53
  54         return ret;
  55 }
  56
  57 void octeon_delete_response_list(struct octeon_device *oct)
  58 {
  59         cancel_delayed_work_sync(&oct->dma_comp_wq.wk.work);
  60         destroy_workqueue(oct->dma_comp_wq.wq);
  61 }
  62
  63 int lio_process_ordered_list(struct octeon_device *octeon_dev,
  64                              u32 force_quit)
  65 {
  66         struct octeon_response_list *ordered_sc_list;
  67         struct octeon_soft_command *sc;
  68         int request_complete = 0;
  69         int resp_to_process = MAX_ORD_REQS_TO_PROCESS;
  70         u32 status;
  71         u64 status64;
  72         struct octeon_instr_rdp *rdp;
  73         u64 rptr;
  74
  75         ordered_sc_list = &octeon_dev->response_list[OCTEON_ORDERED_SC_LIST];
  76
  77         do {
  78                 spin_lock_bh(&ordered_sc_list->lock);
  79
  80                 if (ordered_sc_list->head.next == &ordered_sc_list->head) {
  81                         spin_unlock_bh(&ordered_sc_list->lock);
  82                         return 1;
  83                 }
  84
  85                 sc = (struct octeon_soft_command *)ordered_sc_list->
  86                     head.next;
  87                 if (OCTEON_CN23XX_PF(octeon_dev)) {
  88                         rdp = (struct octeon_instr_rdp *)&sc->cmd.cmd3.rdp;
  89                         rptr = sc->cmd.cmd3.rptr;
  90                 } else {
  91                         rdp = (struct octeon_instr_rdp *)&sc->cmd.cmd2.rdp;
  92                         rptr = sc->cmd.cmd2.rptr;
  93                 }
  94
  95                 status = OCTEON_REQUEST_PENDING;
  96
  97                 /* check if octeon has finished DMA'ing a response
  98                  * to where rptr is pointing to
  99                  */
 100                 dma_sync_single_for_cpu(&octeon_dev->pci_dev->dev,
 101                                         rptr, rdp->rlen,
 102                                         DMA_FROM_DEVICE);
 103                 status64 = *sc->status_word;
 104
 105                 if (status64 != COMPLETION_WORD_INIT) {
 106                         if ((status64 & 0xff) != 0xff) {
 107                                 octeon_swap_8B_data(&status64, 1);
 108                                 if (((status64 & 0xff) != 0xff)) {
 109                                         status = (u32)(status64 &
 110                                                        0xffffffffULL);
 111                                 }
 112                         }
 113                 } else if (force_quit || (sc->timeout &&
 114                         time_after(jiffies, (unsigned long)sc->timeout))) {
 115                         status = OCTEON_REQUEST_TIMEOUT;
 116                 }
 117
 118                 if (status != OCTEON_REQUEST_PENDING) {
 119                         /* we have received a response or we have timed out */
 120                         /* remove node from linked list */
 121                         list_del(&sc->node);
 122                         atomic_dec(&octeon_dev->response_list
 123                                           [OCTEON_ORDERED_SC_LIST].
 124                                           pending_req_count);
 125                         spin_unlock_bh
 126                             (&ordered_sc_list->lock);
 127
 128                         if (sc->callback)
 129                                 sc->callback(octeon_dev, status,
 130                                              sc->callback_arg);
 131
 132                         request_complete++;
 133
 134                 } else {
 135                         /* no response yet */
 136                         request_complete = 0;
 137                         spin_unlock_bh
 138                             (&ordered_sc_list->lock);
 139                 }
 140
 141                 /* If we hit the Max Ordered requests to process every loop,
 142                  * we quit
 143                  * and let this function be invoked the next time the poll
 144                  * thread runs
 145                  * to process the remaining requests. This function can take up
 146                  * the entire CPU if there is no upper limit to the requests
 147                  * processed.
 148                  */
 149                 if (request_complete >= resp_to_process)
 150                         break;
 151         } while (request_complete);
 152
 153         return 0;
 154 }
 155
 156 static void oct_poll_req_completion(struct work_struct *work)
 157 {
 158         struct cavium_wk *wk = (struct cavium_wk *)work;
 159         struct octeon_device *oct = (struct octeon_device *)wk->ctxptr;
 160         struct cavium_wq *cwq = &oct->dma_comp_wq;
 161
 162         lio_process_ordered_list(oct, 0);
 163         queue_delayed_work(cwq->wq, &cwq->wk.work, msecs_to_jiffies(50));
 164 }