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                 ipc->msg[i].tx_data = kzalloc(ipc->tx_data_max_size, GFP_KERNEL);
 133                 if (ipc->msg[i].tx_data == NULL)
 134                         goto free_mem;
 135
 136                 ipc->msg[i].rx_data = kzalloc(ipc->rx_data_max_size, GFP_KERNEL);
 137                 if (ipc->msg[i].rx_data == NULL) {
 138                         kfree(ipc->msg[i].tx_data);
 139                         goto free_mem;
 140                 }
 141
 142                 init_waitqueue_head(&ipc->msg[i].waitq);
 143                 list_add(&ipc->msg[i].list, &ipc->empty_list);
 144         }
 145
 146         return 0;
 147
 148 free_mem:
 149         while (i > 0) {
 150                 kfree(ipc->msg[i-1].tx_data);
 151                 kfree(ipc->msg[i-1].rx_data);
 152                 --i;
 153         }
 154         kfree(ipc->msg);
 155
 156         return -ENOMEM;
 157 }
 158
 159 static void ipc_tx_msgs(struct kthread_work *work)
 160 {
 161         struct sst_generic_ipc *ipc =
 162                 container_of(work, struct sst_generic_ipc, kwork);
 163         struct ipc_message *msg;
 164         unsigned long flags;
 165
 166         spin_lock_irqsave(&ipc->dsp->spinlock, flags);
 167
 168         if (list_empty(&ipc->tx_list) || ipc->pending) {
 169                 spin_unlock_irqrestore(&ipc->dsp->spinlock, flags);
 170                 return;
 171         }
 172
 173         /* if the DSP is busy, we will TX messages after IRQ.
 174          * also postpone if we are in the middle of procesing completion irq*/
 175         if (ipc->ops.is_dsp_busy && ipc->ops.is_dsp_busy(ipc->dsp)) {
 176                 dev_dbg(ipc->dev, "ipc_tx_msgs dsp busy\n");
 177                 spin_unlock_irqrestore(&ipc->dsp->spinlock, flags);
 178                 return;
 179         }
 180
 181         msg = list_first_entry(&ipc->tx_list, struct ipc_message, list);
 182         list_move(&msg->list, &ipc->rx_list);
 183
 184         if (ipc->ops.tx_msg != NULL)
 185                 ipc->ops.tx_msg(ipc, msg);
 186
 187         spin_unlock_irqrestore(&ipc->dsp->spinlock, flags);
 188 }
 189
 190 int sst_ipc_tx_message_wait(struct sst_generic_ipc *ipc, u64 header,
 191         void *tx_data, size_t tx_bytes, void *rx_data, size_t rx_bytes)
 192 {
 193         return ipc_tx_message(ipc, header, tx_data, tx_bytes,
 194                 rx_data, rx_bytes, 1);
 195 }
 196 EXPORT_SYMBOL_GPL(sst_ipc_tx_message_wait);
 197
 198 int sst_ipc_tx_message_nowait(struct sst_generic_ipc *ipc, u64 header,
 199         void *tx_data, size_t tx_bytes)
 200 {
 201         return ipc_tx_message(ipc, header, tx_data, tx_bytes,
 202                 NULL, 0, 0);
 203 }
 204 EXPORT_SYMBOL_GPL(sst_ipc_tx_message_nowait);
 205
 206 struct ipc_message *sst_ipc_reply_find_msg(struct sst_generic_ipc *ipc,
 207         u64 header)
 208 {
 209         struct ipc_message *msg;
 210         u64 mask;
 211
 212         if (ipc->ops.reply_msg_match != NULL)
 213                 header = ipc->ops.reply_msg_match(header, &mask);
 214
 215         if (list_empty(&ipc->rx_list)) {
 216                 dev_err(ipc->dev, "error: rx list empty but received 0x%llx\n",
 217                         header);
 218                 return NULL;
 219         }
 220
 221         list_for_each_entry(msg, &ipc->rx_list, list) {
 222                 if ((msg->header & mask) == header)
 223                         return msg;
 224         }
 225
 226         return NULL;
 227 }
 228 EXPORT_SYMBOL_GPL(sst_ipc_reply_find_msg);
 229
 230 /* locks held by caller */
 231 void sst_ipc_tx_msg_reply_complete(struct sst_generic_ipc *ipc,
 232         struct ipc_message *msg)
 233 {
 234         msg->complete = true;
 235
 236         if (!msg->wait)
 237                 list_add_tail(&msg->list, &ipc->empty_list);
 238         else
 239                 wake_up(&msg->waitq);
 240 }
 241 EXPORT_SYMBOL_GPL(sst_ipc_tx_msg_reply_complete);
 242
 243 void sst_ipc_drop_all(struct sst_generic_ipc *ipc)
 244 {
 245         struct ipc_message *msg, *tmp;
 246         unsigned long flags;
 247         int tx_drop_cnt = 0, rx_drop_cnt = 0;
 248
 249         /* drop all TX and Rx messages before we stall + reset DSP */
 250         spin_lock_irqsave(&ipc->dsp->spinlock, flags);
 251
 252         list_for_each_entry_safe(msg, tmp, &ipc->tx_list, list) {
 253                 list_move(&msg->list, &ipc->empty_list);
 254                 tx_drop_cnt++;
 255         }
 256
 257         list_for_each_entry_safe(msg, tmp, &ipc->rx_list, list) {
 258                 list_move(&msg->list, &ipc->empty_list);
 259                 rx_drop_cnt++;
 260         }
 261
 262         spin_unlock_irqrestore(&ipc->dsp->spinlock, flags);
 263
 264         if (tx_drop_cnt || rx_drop_cnt)
 265                 dev_err(ipc->dev, "dropped IPC msg RX=%d, TX=%d\n",
 266                         tx_drop_cnt, rx_drop_cnt);
 267 }
 268 EXPORT_SYMBOL_GPL(sst_ipc_drop_all);
 269
 270 int sst_ipc_init(struct sst_generic_ipc *ipc)
 271 {
 272         int ret;
 273
 274         INIT_LIST_HEAD(&ipc->tx_list);
 275         INIT_LIST_HEAD(&ipc->rx_list);
 276         INIT_LIST_HEAD(&ipc->empty_list);
 277         init_waitqueue_head(&ipc->wait_txq);
 278
 279         ret = msg_empty_list_init(ipc);
 280         if (ret < 0)
 281                 return -ENOMEM;
 282
 283         /* start the IPC message thread */
 284         init_kthread_worker(&ipc->kworker);
 285         ipc->tx_thread = kthread_run(kthread_worker_fn,
 286                                         &ipc->kworker, "%s",
 287                                         dev_name(ipc->dev));
 288         if (IS_ERR(ipc->tx_thread)) {
 289                 dev_err(ipc->dev, "error: failed to create message TX task\n");
 290                 ret = PTR_ERR(ipc->tx_thread);
 291                 kfree(ipc->msg);
 292                 return ret;
 293         }
 294
 295         init_kthread_work(&ipc->kwork, ipc_tx_msgs);
 296         return 0;
 297 }
 298 EXPORT_SYMBOL_GPL(sst_ipc_init);
 299
 300 void sst_ipc_fini(struct sst_generic_ipc *ipc)
 301 {
 302         int i;
 303
 304         if (ipc->tx_thread)
 305                 kthread_stop(ipc->tx_thread);
 306
 307         if (ipc->msg) {
 308                 for (i = 0; i < IPC_EMPTY_LIST_SIZE; i++) {
 309                         kfree(ipc->msg[i].tx_data);
 310                         kfree(ipc->msg[i].rx_data);
 311                 }
 312                 kfree(ipc->msg);
 313         }
 314 }
 315 EXPORT_SYMBOL_GPL(sst_ipc_fini);
 316
 317 /* Module information */
 318 MODULE_AUTHOR("Jin Yao");
 319 MODULE_DESCRIPTION("Intel SST IPC generic");
 320 MODULE_LICENSE("GPL v2");