LXR linux/drivers/net/ethernet/cavium/liquidio/response

   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
  31static void oct_poll_req_completion(struct work_struct *work);
  32
  33int 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
  60void 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
  66int 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                if (OCTEON_CN23XX_PF(octeon_dev)) {
  95                        rdp = (struct octeon_instr_rdp *)&sc->cmd.cmd3.rdp;
  96                        rptr = sc->cmd.cmd3.rptr;
  97                } else {
  98                        rdp = (struct octeon_instr_rdp *)&sc->cmd.cmd2.rdp;
  99                        rptr = sc->cmd.cmd2.rptr;
 100                }
 101
 102                status = OCTEON_REQUEST_PENDING;
 103
 104                /* check if octeon has finished DMA'ing a response
 105                 * to where rptr is pointing to
 106                 */
 107                dma_sync_single_for_cpu(&octeon_dev->pci_dev->dev,
 108                                        rptr, rdp->rlen,
 109                                        DMA_FROM_DEVICE);
 110                status64 = *sc->status_word;
 111
 112                if (status64 != COMPLETION_WORD_INIT) {
 113                        if ((status64 & 0xff) != 0xff) {
 114                                octeon_swap_8B_data(&status64, 1);
 115                                if (((status64 & 0xff) != 0xff)) {
 116                                        status = (u32)(status64 &
 117                                                       0xffffffffULL);
 118                                }
 119                        }
 120                } else if (force_quit || (sc->timeout &&
 121                        time_after(jiffies, (unsigned long)sc->timeout))) {
 122                        status = OCTEON_REQUEST_TIMEOUT;
 123                }
 124
 125                if (status != OCTEON_REQUEST_PENDING) {
 126                        /* we have received a response or we have timed out */
 127                        /* remove node from linked list */
 128                        list_del(&sc->node);
 129                        atomic_dec(&octeon_dev->response_list
 130                                          [OCTEON_ORDERED_SC_LIST].
 131                                          pending_req_count);
 132                        spin_unlock_bh
 133                            (&ordered_sc_list->lock);
 134
 135                        if (sc->callback)
 136                                sc->callback(octeon_dev, status,
 137                                             sc->callback_arg);
 138
 139                        request_complete++;
 140
 141                } else {
 142                        /* no response yet */
 143                        request_complete = 0;
 144                        spin_unlock_bh
 145                            (&ordered_sc_list->lock);
 146                }
 147
 148                /* If we hit the Max Ordered requests to process every loop,
 149                 * we quit
 150                 * and let this function be invoked the next time the poll
 151                 * thread runs
 152                 * to process the remaining requests. This function can take up
 153                 * the entire CPU if there is no upper limit to the requests
 154                 * processed.
 155                 */
 156                if (request_complete >= resp_to_process)
 157                        break;
 158        } while (request_complete);
 159
 160        return 0;
 161}
 162
 163static void oct_poll_req_completion(struct work_struct *work)
 164{
 165        struct cavium_wk *wk = (struct cavium_wk *)work;
 166        struct octeon_device *oct = (struct octeon_device *)wk->ctxptr;
 167        struct cavium_wq *cwq = &oct->dma_comp_wq;
 168
 169        lio_process_ordered_list(oct, 0);
 170        queue_delayed_work(cwq->wq, &cwq->wk.work, msecs_to_jiffies(50));
 171}
 172