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 <sound/asound.h> 30 31 #include "sst-dsp.h" 32 #include "sst-dsp-priv.h" 33 #include "sst-ipc.h" 34 35 /* IPC message timeout (msecs) */ 36 #define IPC_TIMEOUT_MSECS 300 37 38 #define IPC_EMPTY_LIST_SIZE 8 39 40 /* locks held by caller */ 41 static struct ipc_message *msg_get_empty(struct sst_generic_ipc *ipc) 42 { 43 struct ipc_message *msg = NULL; 44 45 if (!list_empty(&ipc->empty_list)) { 46 msg = list_first_entry(&ipc->empty_list, struct ipc_message, 47 list); 48 list_del(&msg->list); 49 } 50 51 return msg; 52 } 53 54 static int tx_wait_done(struct sst_generic_ipc *ipc, 55 struct ipc_message *msg, void *rx_data) 56 { 57 unsigned long flags; 58 int ret; 59 60 /* wait for DSP completion (in all cases atm inc pending) */ 61 ret = wait_event_timeout(msg->waitq, msg->complete, 62 msecs_to_jiffies(IPC_TIMEOUT_MSECS)); 63 64 spin_lock_irqsave(&ipc->dsp->spinlock, flags); 65 if (ret == 0) { 66 if (ipc->ops.shim_dbg != NULL) 67 ipc->ops.shim_dbg(ipc, "message timeout"); 68 69 list_del(&msg->list); 70 ret = -ETIMEDOUT; 71 } else { 72 73 /* copy the data returned from DSP */ 74 if (msg->rx_size) 75 memcpy(rx_data, msg->rx_data, msg->rx_size); 76 ret = msg->errno; 77 } 78 79 list_add_tail(&msg->list, &ipc->empty_list); 80 spin_unlock_irqrestore(&ipc->dsp->spinlock, flags); 81 return ret; 82 } 83 84 static int ipc_tx_message(struct sst_generic_ipc *ipc, u64 header, 85 void *tx_data, size_t tx_bytes, void *rx_data, 86 size_t rx_bytes, int wait) 87 { 88 struct ipc_message *msg; 89 unsigned long flags; 90 91 spin_lock_irqsave(&ipc->dsp->spinlock, flags); 92 93 msg = msg_get_empty(ipc); 94 if (msg == NULL) { 95 spin_unlock_irqrestore(&ipc->dsp->spinlock, flags); 96 return -EBUSY; 97 } 98 99 msg->header = header; 100 msg->tx_size = tx_bytes; 101 msg->rx_size = rx_bytes; 102 msg->wait = wait; 103 msg->errno = 0; 104 msg->pending = false; 105 msg->complete = false; 106 107 if ((tx_bytes) && (ipc->ops.tx_data_copy != NULL)) 108 ipc->ops.tx_data_copy(msg, tx_data, tx_bytes); 109 110 list_add_tail(&msg->list, &ipc->tx_list); 111 schedule_work(&ipc->kwork); 112 spin_unlock_irqrestore(&ipc->dsp->spinlock, flags); 113 114 if (wait) 115 return tx_wait_done(ipc, msg, rx_data); 116 else 117 return 0; 118 } 119 120 static int msg_empty_list_init(struct sst_generic_ipc *ipc) 121 { 122 int i; 123 124 ipc->msg = kcalloc(IPC_EMPTY_LIST_SIZE, sizeof(struct ipc_message), 125 GFP_KERNEL); 126 if (ipc->msg == NULL) 127 return -ENOMEM; 128 129 for (i = 0; i < IPC_EMPTY_LIST_SIZE; i++) { 130 ipc->msg[i].tx_data = kzalloc(ipc->tx_data_max_size, GFP_KERNEL); 131 if (ipc->msg[i].tx_data == NULL) 132 goto free_mem; 133 134 ipc->msg[i].rx_data = kzalloc(ipc->rx_data_max_size, GFP_KERNEL); 135 if (ipc->msg[i].rx_data == NULL) { 136 kfree(ipc->msg[i].tx_data); 137 goto free_mem; 138 } 139 140 init_waitqueue_head(&ipc->msg[i].waitq); 141 list_add(&ipc->msg[i].list, &ipc->empty_list); 142 } 143 144 return 0; 145 146 free_mem: 147 while (i > 0) { 148 kfree(ipc->msg[i-1].tx_data); 149 kfree(ipc->msg[i-1].rx_data); 150 --i; 151 } 152 kfree(ipc->msg); 153 154 return -ENOMEM; 155 } 156 157 static void ipc_tx_msgs(struct work_struct *work) 158 { 159 struct sst_generic_ipc *ipc = 160 container_of(work, struct sst_generic_ipc, kwork); 161 struct ipc_message *msg; 162 163 spin_lock_irq(&ipc->dsp->spinlock); 164 165 while (!list_empty(&ipc->tx_list) && !ipc->pending) { 166 /* if the DSP is busy, we will TX messages after IRQ. 167 * also postpone if we are in the middle of processing 168 * completion irq 169 */ 170 if (ipc->ops.is_dsp_busy && ipc->ops.is_dsp_busy(ipc->dsp)) { 171 dev_dbg(ipc->dev, "ipc_tx_msgs dsp busy\n"); 172 break; 173 } 174 175 msg = list_first_entry(&ipc->tx_list, struct ipc_message, list); 176 list_move(&msg->list, &ipc->rx_list); 177 178 if (ipc->ops.tx_msg != NULL) 179 ipc->ops.tx_msg(ipc, msg); 180 } 181 182 spin_unlock_irq(&ipc->dsp->spinlock); 183 } 184 185 int sst_ipc_tx_message_wait(struct sst_generic_ipc *ipc, u64 header, 186 void *tx_data, size_t tx_bytes, void *rx_data, size_t rx_bytes) 187 { 188 int ret; 189 190 /* 191 * DSP maybe in lower power active state, so 192 * check if the DSP supports DSP lp On method 193 * if so invoke that before sending IPC 194 */ 195 if (ipc->ops.check_dsp_lp_on) 196 if (ipc->ops.check_dsp_lp_on(ipc->dsp, true)) 197 return -EIO; 198 199 ret = ipc_tx_message(ipc, header, tx_data, tx_bytes, 200 rx_data, rx_bytes, 1); 201 202 if (ipc->ops.check_dsp_lp_on) 203 if (ipc->ops.check_dsp_lp_on(ipc->dsp, false)) 204 return -EIO; 205 206 return ret; 207 } 208 EXPORT_SYMBOL_GPL(sst_ipc_tx_message_wait); 209 210 int sst_ipc_tx_message_nowait(struct sst_generic_ipc *ipc, u64 header, 211 void *tx_data, size_t tx_bytes) 212 { 213 return ipc_tx_message(ipc, header, tx_data, tx_bytes, 214 NULL, 0, 0); 215 } 216 EXPORT_SYMBOL_GPL(sst_ipc_tx_message_nowait); 217 218 int sst_ipc_tx_message_nopm(struct sst_generic_ipc *ipc, u64 header, 219 void *tx_data, size_t tx_bytes, void *rx_data, size_t rx_bytes) 220 { 221 return ipc_tx_message(ipc, header, tx_data, tx_bytes, 222 rx_data, rx_bytes, 1); 223 } 224 EXPORT_SYMBOL_GPL(sst_ipc_tx_message_nopm); 225 226 struct ipc_message *sst_ipc_reply_find_msg(struct sst_generic_ipc *ipc, 227 u64 header) 228 { 229 struct ipc_message *msg; 230 u64 mask; 231 232 if (ipc->ops.reply_msg_match != NULL) 233 header = ipc->ops.reply_msg_match(header, &mask); 234 235 if (list_empty(&ipc->rx_list)) { 236 dev_err(ipc->dev, "error: rx list empty but received 0x%llx\n", 237 header); 238 return NULL; 239 } 240 241 list_for_each_entry(msg, &ipc->rx_list, list) { 242 if ((msg->header & mask) == header) 243 return msg; 244 } 245 246 return NULL; 247 } 248 EXPORT_SYMBOL_GPL(sst_ipc_reply_find_msg); 249 250 /* locks held by caller */ 251 void sst_ipc_tx_msg_reply_complete(struct sst_generic_ipc *ipc, 252 struct ipc_message *msg) 253 { 254 msg->complete = true; 255 256 if (!msg->wait) 257 list_add_tail(&msg->list, &ipc->empty_list); 258 else 259 wake_up(&msg->waitq); 260 } 261 EXPORT_SYMBOL_GPL(sst_ipc_tx_msg_reply_complete); 262 263 void sst_ipc_drop_all(struct sst_generic_ipc *ipc) 264 { 265 struct ipc_message *msg, *tmp; 266 unsigned long flags; 267 int tx_drop_cnt = 0, rx_drop_cnt = 0; 268 269 /* drop all TX and Rx messages before we stall + reset DSP */ 270 spin_lock_irqsave(&ipc->dsp->spinlock, flags); 271 272 list_for_each_entry_safe(msg, tmp, &ipc->tx_list, list) { 273 list_move(&msg->list, &ipc->empty_list); 274 tx_drop_cnt++; 275 } 276 277 list_for_each_entry_safe(msg, tmp, &ipc->rx_list, list) { 278 list_move(&msg->list, &ipc->empty_list); 279 rx_drop_cnt++; 280 } 281 282 spin_unlock_irqrestore(&ipc->dsp->spinlock, flags); 283 284 if (tx_drop_cnt || rx_drop_cnt) 285 dev_err(ipc->dev, "dropped IPC msg RX=%d, TX=%d\n", 286 tx_drop_cnt, rx_drop_cnt); 287 } 288 EXPORT_SYMBOL_GPL(sst_ipc_drop_all); 289 290 int sst_ipc_init(struct sst_generic_ipc *ipc) 291 { 292 int ret; 293 294 INIT_LIST_HEAD(&ipc->tx_list); 295 INIT_LIST_HEAD(&ipc->rx_list); 296 INIT_LIST_HEAD(&ipc->empty_list); 297 init_waitqueue_head(&ipc->wait_txq); 298 299 ret = msg_empty_list_init(ipc); 300 if (ret < 0) 301 return -ENOMEM; 302 303 INIT_WORK(&ipc->kwork, ipc_tx_msgs); 304 return 0; 305 } 306 EXPORT_SYMBOL_GPL(sst_ipc_init); 307 308 void sst_ipc_fini(struct sst_generic_ipc *ipc) 309 { 310 int i; 311 312 cancel_work_sync(&ipc->kwork); 313 314 if (ipc->msg) { 315 for (i = 0; i < IPC_EMPTY_LIST_SIZE; i++) { 316 kfree(ipc->msg[i].tx_data); 317 kfree(ipc->msg[i].rx_data); 318 } 319 kfree(ipc->msg); 320 } 321 } 322 EXPORT_SYMBOL_GPL(sst_ipc_fini); 323 324 /* Module information */ 325 MODULE_AUTHOR("Jin Yao"); 326 MODULE_DESCRIPTION("Intel SST IPC generic"); 327 MODULE_LICENSE("GPL v2"); 328