sound/soc/intel/common/sst-ipc.c

   1 /*
   2  * Intel SST generic IPC Support
   3  *
   4  * Copyright (C) 2015, Intel Corporation. All rights reserved.
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License version
   8  * 2 as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  */
  16
  17 #include <linux/types.h>
  18 #include <linux/kernel.h>
  19 #include <linux/list.h>
  20 #include <linux/wait.h>
  21 #include <linux/module.h>
  22 #include <linux/spinlock.h>
  23 #include <linux/device.h>
  24 #include <linux/slab.h>
  25 #include <linux/workqueue.h>
  26 #include <linux/sched.h>
  27 #include <linux/delay.h>
  28 #include <linux/platform_device.h>
  29 #include <linux/kthread.h>
  30 #include <sound/asound.h>
  31
  32 #include "sst-dsp.h"
  33 #include "sst-dsp-priv.h"
  34 #include "sst-ipc.h"
  35
  36 /* IPC message timeout (msecs) */
  37 #define IPC_TIMEOUT_MSECS       300
  38
  39 #define IPC_EMPTY_LIST_SIZE     8
  40
  41 /* locks held by caller */
  42 static struct ipc_message *msg_get_empty(struct sst_generic_ipc *ipc)
  43 {
  44         struct ipc_message *msg = NULL;
  45
  46         if (!list_empty(&ipc->empty_list)) {
  47                 msg = list_first_entry(&ipc->empty_list, struct ipc_message,
  48                         list);
  49                 list_del(&msg->list);
  50         }
  51
  52         return msg;
  53 }
  54
  55 static int tx_wait_done(struct sst_generic_ipc *ipc,
  56         struct ipc_message *msg, void *rx_data)
  57 {
  58         unsigned long flags;
  59         int ret;
  60
  61         /* wait for DSP completion (in all cases atm inc pending) */
  62         ret = wait_event_timeout(msg->waitq, msg->complete,
  63                 msecs_to_jiffies(IPC_TIMEOUT_MSECS));
  64
  65         spin_lock_irqsave(&ipc->dsp->spinlock, flags);
  66         if (ret == 0) {
  67                 if (ipc->ops.shim_dbg != NULL)
  68                         ipc->ops.shim_dbg(ipc, "message timeout");
  69
  70                 list_del(&msg->list);
  71                 ret = -ETIMEDOUT;
  72         } else {
  73
  74                 /* copy the data returned from DSP */
  75                 if (msg->rx_size)
  76                         memcpy(rx_data, msg->rx_data, msg->rx_size);
  77                 ret = msg->errno;
  78         }
  79
  80         list_add_tail(&msg->list, &ipc->empty_list);
  81         spin_unlock_irqrestore(&ipc->dsp->spinlock, flags);
  82         return ret;
  83 }
  84
  85 static int ipc_tx_message(struct sst_generic_ipc *ipc, u64 header,
  86         void *tx_data, size_t tx_bytes, void *rx_data,
  87         size_t rx_bytes, int wait)
  88 {
  89         struct ipc_message *msg;
  90         unsigned long flags;
  91
  92         spin_lock_irqsave(&ipc->dsp->spinlock, flags);
  93
  94         msg = msg_get_empty(ipc);
  95         if (msg == NULL) {
  96                 spin_unlock_irqrestore(&ipc->dsp->spinlock, flags);
  97                 return -EBUSY;
  98         }
  99
 100         msg->header = header;
 101         msg->tx_size = tx_bytes;
 102         msg->rx_size = rx_bytes;
 103         msg->wait = wait;
 104         msg->errno = 0;
 105         msg->pending = false;
 106         msg->complete = false;
 107
 108         if ((tx_bytes) && (ipc->ops.tx_data_copy != NULL))
 109                 ipc->ops.tx_data_copy(msg, tx_data, tx_bytes);
 110
 111         list_add_tail(&msg->list, &ipc->tx_list);
 112         spin_unlock_irqrestore(&ipc->dsp->spinlock, flags);
 113
 114         queue_kthread_work(&ipc->kworker, &ipc->kwork);
 115
 116         if (wait)
 117                 return tx_wait_done(ipc, msg, rx_data);
 118         else
 119                 return 0;
 120 }
 121
 122 static int msg_empty_list_init(struct sst_generic_ipc *ipc)
 123 {
 124         int i;
 125
 126         ipc->msg = kzalloc(sizeof(struct ipc_message) *
 127                 IPC_EMPTY_LIST_SIZE, GFP_KERNEL);
 128         if (ipc->msg == NULL)
 129                 return -ENOMEM;
 130
 131         for (i = 0; i < IPC_EMPTY_LIST_SIZE; i++) {
 132                 init_waitqueue_head(&ipc->msg[i].waitq);
 133                 list_add(&ipc->msg[i].list, &ipc->empty_list);
 134         }
 135
 136         return 0;
 137 }
 138
 139 static void ipc_tx_msgs(struct kthread_work *work)
 140 {
 141         struct sst_generic_ipc *ipc =
 142                 container_of(work, struct sst_generic_ipc, kwork);
 143         struct ipc_message *msg;
 144         unsigned long flags;
 145         u64 ipcx;
 146
 147         spin_lock_irqsave(&ipc->dsp->spinlock, flags);
 148
 149         if (list_empty(&ipc->tx_list) || ipc->pending) {
 150                 spin_unlock_irqrestore(&ipc->dsp->spinlock, flags);
 151                 return;
 152         }
 153
 154         /* if the DSP is busy, we will TX messages after IRQ.
 155          * also postpone if we are in the middle of procesing completion irq*/
 156         ipcx = sst_dsp_shim_read_unlocked(ipc->dsp, SST_IPCX);
 157         if (ipcx & (SST_IPCX_BUSY | SST_IPCX_DONE)) {
 158                 spin_unlock_irqrestore(&ipc->dsp->spinlock, flags);
 159                 return;
 160         }
 161
 162         msg = list_first_entry(&ipc->tx_list, struct ipc_message, list);
 163         list_move(&msg->list, &ipc->rx_list);
 164
 165         if (ipc->ops.tx_msg != NULL)
 166                 ipc->ops.tx_msg(ipc, msg);
 167
 168         spin_unlock_irqrestore(&ipc->dsp->spinlock, flags);
 169 }
 170
 171 int sst_ipc_tx_message_wait(struct sst_generic_ipc *ipc, u64 header,
 172         void *tx_data, size_t tx_bytes, void *rx_data, size_t rx_bytes)
 173 {
 174         return ipc_tx_message(ipc, header, tx_data, tx_bytes,
 175                 rx_data, rx_bytes, 1);
 176 }
 177 EXPORT_SYMBOL_GPL(sst_ipc_tx_message_wait);
 178
 179 int sst_ipc_tx_message_nowait(struct sst_generic_ipc *ipc, u64 header,
 180         void *tx_data, size_t tx_bytes)
 181 {
 182         return ipc_tx_message(ipc, header, tx_data, tx_bytes,
 183                 NULL, 0, 0);
 184 }
 185 EXPORT_SYMBOL_GPL(sst_ipc_tx_message_nowait);
 186
 187 struct ipc_message *sst_ipc_reply_find_msg(struct sst_generic_ipc *ipc,
 188         u64 header)
 189 {
 190         struct ipc_message *msg;
 191         u64 mask;
 192
 193         if (ipc->ops.reply_msg_match != NULL)
 194                 header = ipc->ops.reply_msg_match(header, &mask);
 195
 196         if (list_empty(&ipc->rx_list)) {
 197                 dev_err(ipc->dev, "error: rx list empty but received 0x%llx\n",
 198                         header);
 199                 return NULL;
 200         }
 201
 202         list_for_each_entry(msg, &ipc->rx_list, list) {
 203                 if ((msg->header & mask) == header)
 204                         return msg;
 205         }
 206
 207         return NULL;
 208 }
 209 EXPORT_SYMBOL_GPL(sst_ipc_reply_find_msg);
 210
 211 /* locks held by caller */
 212 void sst_ipc_tx_msg_reply_complete(struct sst_generic_ipc *ipc,
 213         struct ipc_message *msg)
 214 {
 215         msg->complete = true;
 216
 217         if (!msg->wait)
 218                 list_add_tail(&msg->list, &ipc->empty_list);
 219         else
 220                 wake_up(&msg->waitq);
 221 }
 222 EXPORT_SYMBOL_GPL(sst_ipc_tx_msg_reply_complete);
 223
 224 void sst_ipc_drop_all(struct sst_generic_ipc *ipc)
 225 {
 226         struct ipc_message *msg, *tmp;
 227         unsigned long flags;
 228         int tx_drop_cnt = 0, rx_drop_cnt = 0;
 229
 230         /* drop all TX and Rx messages before we stall + reset DSP */
 231         spin_lock_irqsave(&ipc->dsp->spinlock, flags);
 232
 233         list_for_each_entry_safe(msg, tmp, &ipc->tx_list, list) {
 234                 list_move(&msg->list, &ipc->empty_list);
 235                 tx_drop_cnt++;
 236         }
 237
 238         list_for_each_entry_safe(msg, tmp, &ipc->rx_list, list) {
 239                 list_move(&msg->list, &ipc->empty_list);
 240                 rx_drop_cnt++;
 241         }
 242
 243         spin_unlock_irqrestore(&ipc->dsp->spinlock, flags);
 244
 245         if (tx_drop_cnt || rx_drop_cnt)
 246                 dev_err(ipc->dev, "dropped IPC msg RX=%d, TX=%d\n",
 247                         tx_drop_cnt, rx_drop_cnt);
 248 }
 249 EXPORT_SYMBOL_GPL(sst_ipc_drop_all);
 250
 251 int sst_ipc_init(struct sst_generic_ipc *ipc)
 252 {
 253         int ret;
 254
 255         INIT_LIST_HEAD(&ipc->tx_list);
 256         INIT_LIST_HEAD(&ipc->rx_list);
 257         INIT_LIST_HEAD(&ipc->empty_list);
 258         init_waitqueue_head(&ipc->wait_txq);
 259
 260         ret = msg_empty_list_init(ipc);
 261         if (ret < 0)
 262                 return -ENOMEM;
 263
 264         /* start the IPC message thread */
 265         init_kthread_worker(&ipc->kworker);
 266         ipc->tx_thread = kthread_run(kthread_worker_fn,
 267                                         &ipc->kworker, "%s",
 268                                         dev_name(ipc->dev));
 269         if (IS_ERR(ipc->tx_thread)) {
 270                 dev_err(ipc->dev, "error: failed to create message TX task\n");
 271                 ret = PTR_ERR(ipc->tx_thread);
 272                 kfree(ipc->msg);
 273                 return ret;
 274         }
 275
 276         init_kthread_work(&ipc->kwork, ipc_tx_msgs);
 277         return 0;
 278 }
 279 EXPORT_SYMBOL_GPL(sst_ipc_init);
 280
 281 void sst_ipc_fini(struct sst_generic_ipc *ipc)
 282 {
 283         if (ipc->tx_thread)
 284                 kthread_stop(ipc->tx_thread);
 285
 286         if (ipc->msg)
 287                 kfree(ipc->msg);
 288 }
 289 EXPORT_SYMBOL_GPL(sst_ipc_fini);
 290
 291 /* Module information */
 292 MODULE_AUTHOR("Jin Yao");
 293 MODULE_DESCRIPTION("Intel SST IPC generic");
 294 MODULE_LICENSE("GPL v2");