drivers/net/wimax/i2400m/sdio-tx.c

   1 /*
   2  * Intel Wireless WiMAX Connection 2400m
   3  * SDIO TX transaction backends
   4  *
   5  *
   6  * Copyright (C) 2007-2008 Intel Corporation. All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  *
  12  *   * Redistributions of source code must retain the above copyright
  13  *     notice, this list of conditions and the following disclaimer.
  14  *   * Redistributions in binary form must reproduce the above copyright
  15  *     notice, this list of conditions and the following disclaimer in
  16  *     the documentation and/or other materials provided with the
  17  *     distribution.
  18  *   * Neither the name of Intel Corporation nor the names of its
  19  *     contributors may be used to endorse or promote products derived
  20  *     from this software without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  23  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  24  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  25  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  26  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  27  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  28  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  29  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  30  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  31  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  32  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  33  *
  34  *
  35  * Intel Corporation <linux-wimax@intel.com>
  36  * Dirk Brandewie <dirk.j.brandewie@intel.com>
  37  *  - Initial implementation
  38  *
  39  *
  40  * Takes the TX messages in the i2400m's driver TX FIFO and sends them
  41  * to the device until there are no more.
  42  *
  43  * If we fail sending the message, we just drop it. There isn't much
  44  * we can do at this point. Most of the traffic is network, which has
  45  * recovery methods for dropped packets.
  46  *
  47  * The SDIO functions are not atomic, so we can't run from the context
  48  * where i2400m->bus_tx_kick() [i2400ms_bus_tx_kick()] is being called
  49  * (some times atomic). Thus, the actual TX work is deferred to a
  50  * workqueue.
  51  *
  52  * ROADMAP
  53  *
  54  * i2400ms_bus_tx_kick()
  55  *   i2400ms_tx_submit()     [through workqueue]
  56  *
  57  * i2400m_tx_setup()
  58  *
  59  * i2400m_tx_release()
  60  */
  61 #include <linux/mmc/sdio_func.h>
  62 #include "i2400m-sdio.h"
  63
  64 #define D_SUBMODULE tx
  65 #include "sdio-debug-levels.h"
  66
  67
  68 /*
  69  * Pull TX transations from the TX FIFO and send them to the device
  70  * until there are no more.
  71  */
  72 static
  73 void i2400ms_tx_submit(struct work_struct *ws)
  74 {
  75         int result;
  76         struct i2400ms *i2400ms = container_of(ws, struct i2400ms, tx_worker);
  77         struct i2400m *i2400m = &i2400ms->i2400m;
  78         struct sdio_func *func = i2400ms->func;
  79         struct device *dev = &func->dev;
  80         struct i2400m_msg_hdr *tx_msg;
  81         size_t tx_msg_size;
  82
  83         d_fnstart(4, dev, "(i2400ms %p, i2400m %p)\n", i2400ms, i2400ms);
  84
  85         while (NULL != (tx_msg = i2400m_tx_msg_get(i2400m, &tx_msg_size))) {
  86                 d_printf(2, dev, "TX: submitting %zu bytes\n", tx_msg_size);
  87                 d_dump(5, dev, tx_msg, tx_msg_size);
  88
  89                 sdio_claim_host(func);
  90                 result = sdio_memcpy_toio(func, 0, tx_msg, tx_msg_size);
  91                 sdio_release_host(func);
  92
  93                 i2400m_tx_msg_sent(i2400m);
  94
  95                 if (result < 0) {
  96                         dev_err(dev, "TX: cannot submit TX; tx_msg @%zu %zu B:"
  97                                 " %d\n", (void *) tx_msg - i2400m->tx_buf,
  98                                 tx_msg_size, result);
  99                 }
 100
 101                 if (result == -ETIMEDOUT) {
 102                         i2400m_error_recovery(i2400m);
 103                         break;
 104                 }
 105                 d_printf(2, dev, "TX: %zub submitted\n", tx_msg_size);
 106         }
 107
 108         d_fnend(4, dev, "(i2400ms %p) = void\n", i2400ms);
 109 }
 110
 111
 112 /*
 113  * The generic driver notifies us that there is data ready for TX
 114  *
 115  * Schedule a run of i2400ms_tx_submit() to handle it.
 116  */
 117 void i2400ms_bus_tx_kick(struct i2400m *i2400m)
 118 {
 119         struct i2400ms *i2400ms = container_of(i2400m, struct i2400ms, i2400m);
 120         struct device *dev = &i2400ms->func->dev;
 121         unsigned long flags;
 122
 123         d_fnstart(3, dev, "(i2400m %p) = void\n", i2400m);
 124
 125         /* schedule tx work, this is because tx may block, therefore
 126          * it has to run in a thread context.
 127          */
 128         spin_lock_irqsave(&i2400m->tx_lock, flags);
 129         if (i2400ms->tx_workqueue != NULL)
 130                 queue_work(i2400ms->tx_workqueue, &i2400ms->tx_worker);
 131         spin_unlock_irqrestore(&i2400m->tx_lock, flags);
 132
 133         d_fnend(3, dev, "(i2400m %p) = void\n", i2400m);
 134 }
 135
 136 int i2400ms_tx_setup(struct i2400ms *i2400ms)
 137 {
 138         int result;
 139         struct device *dev = &i2400ms->func->dev;
 140         struct i2400m *i2400m = &i2400ms->i2400m;
 141         struct workqueue_struct *tx_workqueue;
 142         unsigned long flags;
 143
 144         d_fnstart(5, dev, "(i2400ms %p)\n", i2400ms);
 145
 146         INIT_WORK(&i2400ms->tx_worker, i2400ms_tx_submit);
 147         snprintf(i2400ms->tx_wq_name, sizeof(i2400ms->tx_wq_name),
 148                  "%s-tx", i2400m->wimax_dev.name);
 149         tx_workqueue =
 150                 create_singlethread_workqueue(i2400ms->tx_wq_name);
 151         if (tx_workqueue == NULL) {
 152                 dev_err(dev, "TX: failed to create workqueue\n");
 153                 result = -ENOMEM;
 154         } else
 155                 result = 0;
 156         spin_lock_irqsave(&i2400m->tx_lock, flags);
 157         i2400ms->tx_workqueue = tx_workqueue;
 158         spin_unlock_irqrestore(&i2400m->tx_lock, flags);
 159         d_fnend(5, dev, "(i2400ms %p) = %d\n", i2400ms, result);
 160         return result;
 161 }
 162
 163 void i2400ms_tx_release(struct i2400ms *i2400ms)
 164 {
 165         struct i2400m *i2400m = &i2400ms->i2400m;
 166         struct workqueue_struct *tx_workqueue;
 167         unsigned long flags;
 168
 169         tx_workqueue = i2400ms->tx_workqueue;
 170
 171         spin_lock_irqsave(&i2400m->tx_lock, flags);
 172         i2400ms->tx_workqueue = NULL;
 173         spin_unlock_irqrestore(&i2400m->tx_lock, flags);
 174
 175         if (tx_workqueue)
 176                 destroy_workqueue(tx_workqueue);
 177 }