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 */
msg_get_empty(struct sst_generic_ipc * ipc)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
tx_wait_done(struct sst_generic_ipc * ipc,struct ipc_message * msg,void * rx_data)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
ipc_tx_message(struct sst_generic_ipc * ipc,u64 header,void * tx_data,size_t tx_bytes,void * rx_data,size_t rx_bytes,int wait)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
msg_empty_list_init(struct sst_generic_ipc * ipc)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
ipc_tx_msgs(struct kthread_work * work)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
sst_ipc_tx_message_wait(struct sst_generic_ipc * ipc,u64 header,void * tx_data,size_t tx_bytes,void * rx_data,size_t rx_bytes)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
sst_ipc_tx_message_nowait(struct sst_generic_ipc * ipc,u64 header,void * tx_data,size_t tx_bytes)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
sst_ipc_reply_find_msg(struct sst_generic_ipc * ipc,u64 header)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 else
215 mask = (u64)-1;
216
217 if (list_empty(&ipc->rx_list)) {
218 dev_err(ipc->dev, "error: rx list empty but received 0x%llx\n",
219 header);
220 return NULL;
221 }
222
223 list_for_each_entry(msg, &ipc->rx_list, list) {
224 if ((msg->header & mask) == header)
225 return msg;
226 }
227
228 return NULL;
229 }
230 EXPORT_SYMBOL_GPL(sst_ipc_reply_find_msg);
231
232 /* locks held by caller */
sst_ipc_tx_msg_reply_complete(struct sst_generic_ipc * ipc,struct ipc_message * msg)233 void sst_ipc_tx_msg_reply_complete(struct sst_generic_ipc *ipc,
234 struct ipc_message *msg)
235 {
236 msg->complete = true;
237
238 if (!msg->wait)
239 list_add_tail(&msg->list, &ipc->empty_list);
240 else
241 wake_up(&msg->waitq);
242 }
243 EXPORT_SYMBOL_GPL(sst_ipc_tx_msg_reply_complete);
244
sst_ipc_drop_all(struct sst_generic_ipc * ipc)245 void sst_ipc_drop_all(struct sst_generic_ipc *ipc)
246 {
247 struct ipc_message *msg, *tmp;
248 unsigned long flags;
249 int tx_drop_cnt = 0, rx_drop_cnt = 0;
250
251 /* drop all TX and Rx messages before we stall + reset DSP */
252 spin_lock_irqsave(&ipc->dsp->spinlock, flags);
253
254 list_for_each_entry_safe(msg, tmp, &ipc->tx_list, list) {
255 list_move(&msg->list, &ipc->empty_list);
256 tx_drop_cnt++;
257 }
258
259 list_for_each_entry_safe(msg, tmp, &ipc->rx_list, list) {
260 list_move(&msg->list, &ipc->empty_list);
261 rx_drop_cnt++;
262 }
263
264 spin_unlock_irqrestore(&ipc->dsp->spinlock, flags);
265
266 if (tx_drop_cnt || rx_drop_cnt)
267 dev_err(ipc->dev, "dropped IPC msg RX=%d, TX=%d\n",
268 tx_drop_cnt, rx_drop_cnt);
269 }
270 EXPORT_SYMBOL_GPL(sst_ipc_drop_all);
271
sst_ipc_init(struct sst_generic_ipc * ipc)272 int sst_ipc_init(struct sst_generic_ipc *ipc)
273 {
274 int ret;
275
276 INIT_LIST_HEAD(&ipc->tx_list);
277 INIT_LIST_HEAD(&ipc->rx_list);
278 INIT_LIST_HEAD(&ipc->empty_list);
279 init_waitqueue_head(&ipc->wait_txq);
280
281 ret = msg_empty_list_init(ipc);
282 if (ret < 0)
283 return -ENOMEM;
284
285 /* start the IPC message thread */
286 init_kthread_worker(&ipc->kworker);
287 ipc->tx_thread = kthread_run(kthread_worker_fn,
288 &ipc->kworker, "%s",
289 dev_name(ipc->dev));
290 if (IS_ERR(ipc->tx_thread)) {
291 dev_err(ipc->dev, "error: failed to create message TX task\n");
292 ret = PTR_ERR(ipc->tx_thread);
293 kfree(ipc->msg);
294 return ret;
295 }
296
297 init_kthread_work(&ipc->kwork, ipc_tx_msgs);
298 return 0;
299 }
300 EXPORT_SYMBOL_GPL(sst_ipc_init);
301
sst_ipc_fini(struct sst_generic_ipc * ipc)302 void sst_ipc_fini(struct sst_generic_ipc *ipc)
303 {
304 int i;
305
306 if (ipc->tx_thread)
307 kthread_stop(ipc->tx_thread);
308
309 if (ipc->msg) {
310 for (i = 0; i < IPC_EMPTY_LIST_SIZE; i++) {
311 kfree(ipc->msg[i].tx_data);
312 kfree(ipc->msg[i].rx_data);
313 }
314 kfree(ipc->msg);
315 }
316 }
317 EXPORT_SYMBOL_GPL(sst_ipc_fini);
318
319 /* Module information */
320 MODULE_AUTHOR("Jin Yao");
321 MODULE_DESCRIPTION("Intel SST IPC generic");
322 MODULE_LICENSE("GPL v2");
323