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
  53         return ret;
  54 }
  55
  56 void octeon_delete_response_list(struct octeon_device *oct)
  57 {
  58         cancel_delayed_work_sync(&oct->dma_comp_wq.wk.work);
  59         destroy_workqueue(oct->dma_comp_wq.wq);
  60 }
  61
  62 int lio_process_ordered_list(struct octeon_device *octeon_dev,
  63                              u32 force_quit)
  64 {
  65         struct octeon_response_list *ordered_sc_list;
  66         struct octeon_soft_command *sc;
  67         int request_complete = 0;
  68         int resp_to_process = MAX_ORD_REQS_TO_PROCESS;
  69         u32 status;
  70         u64 status64;
  71
  72         ordered_sc_list = &octeon_dev->response_list[OCTEON_ORDERED_SC_LIST];
  73
  74         do {
  75                 spin_lock_bh(&ordered_sc_list->lock);
  76
  77                 if (list_empty(&ordered_sc_list->head)) {
  78                         spin_unlock_bh(&ordered_sc_list->lock);
  79                         return 1;
  80                 }
  81
  82                 sc = list_first_entry(&ordered_sc_list->head,
  83                                       struct octeon_soft_command, node);
  84
  85                 status = OCTEON_REQUEST_PENDING;
  86
  87                 /* check if octeon has finished DMA'ing a response
  88                  * to where rptr is pointing to
  89                  */
  90                 status64 = *sc->status_word;
  91
  92                 if (status64 != COMPLETION_WORD_INIT) {
  93                         /* This logic ensures that all 64b have been written.
  94                          * 1. check byte 0 for non-FF
  95                          * 2. if non-FF, then swap result from BE to host order
  96                          * 3. check byte 7 (swapped to 0) for non-FF
  97                          * 4. if non-FF, use the low 32-bit status code
  98                          * 5. if either byte 0 or byte 7 is FF, don't use status
  99                          */
 100                         if ((status64 & 0xff) != 0xff) {
 101                                 octeon_swap_8B_data(&status64, 1);
 102                                 if (((status64 & 0xff) != 0xff)) {
 103                                         /* retrieve 16-bit firmware status */
 104                                         status = (u32)(status64 & 0xffffULL);
 105                                         if (status) {
 106                                                 status =
 107                                                   FIRMWARE_STATUS_CODE(status);
 108                                         } else {
 109                                                 /* i.e. no error */
 110                                                 status = OCTEON_REQUEST_DONE;
 111                                         }
 112                                 }
 113                         }
 114                 } else if (force_quit || (sc->timeout &&
 115                         time_after(jiffies, (unsigned long)sc->timeout))) {
 116                         dev_err(&octeon_dev->pci_dev->dev, "%s: cmd failed, timeout (%ld, %ld)\n",
 117                                 __func__, (long)jiffies, (long)sc->timeout);
 118                         status = OCTEON_REQUEST_TIMEOUT;
 119                 }
 120
 121                 if (status != OCTEON_REQUEST_PENDING) {
 122                         /* we have received a response or we have timed out */
 123                         /* remove node from linked list */
 124                         list_del(&sc->node);
 125                         atomic_dec(&octeon_dev->response_list
 126                                           [OCTEON_ORDERED_SC_LIST].
 127                                           pending_req_count);
 128                         spin_unlock_bh
 129                             (&ordered_sc_list->lock);
 130
 131                         if (sc->callback)
 132                                 sc->callback(octeon_dev, status,
 133                                              sc->callback_arg);
 134
 135                         request_complete++;
 136
 137                 } else {
 138                         /* no response yet */
 139                         request_complete = 0;
 140                         spin_unlock_bh
 141                             (&ordered_sc_list->lock);
 142                 }
 143
 144                 /* If we hit the Max Ordered requests to process every loop,
 145                  * we quit
 146                  * and let this function be invoked the next time the poll
 147                  * thread runs
 148                  * to process the remaining requests. This function can take up
 149                  * the entire CPU if there is no upper limit to the requests
 150                  * processed.
 151                  */
 152                 if (request_complete >= resp_to_process)
 153                         break;
 154         } while (request_complete);
 155
 156         return 0;
 157 }
 158
 159 static void oct_poll_req_completion(struct work_struct *work)
 160 {
 161         struct cavium_wk *wk = (struct cavium_wk *)work;
 162         struct octeon_device *oct = (struct octeon_device *)wk->ctxptr;
 163         struct cavium_wq *cwq = &oct->dma_comp_wq;
 164
 165         lio_process_ordered_list(oct, 0);
 166
 167         if (atomic_read(&oct->response_list
 168                         [OCTEON_ORDERED_SC_LIST].pending_req_count))
 169                 queue_delayed_work(cwq->wq, &cwq->wk.work, msecs_to_jiffies(1));
 170 }