1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Intel SST generic IPC Support
4  *
5  * Copyright (C) 2015, Intel Corporation. All rights reserved.
6  */
7 
8 #include <linux/types.h>
9 #include <linux/kernel.h>
10 #include <linux/list.h>
11 #include <linux/wait.h>
12 #include <linux/module.h>
13 #include <linux/spinlock.h>
14 #include <linux/device.h>
15 #include <linux/slab.h>
16 #include <linux/workqueue.h>
17 #include <linux/sched.h>
18 #include <linux/delay.h>
19 #include <linux/platform_device.h>
20 #include <sound/asound.h>
21 
22 #include "sst-dsp.h"
23 #include "sst-dsp-priv.h"
24 #include "sst-ipc.h"
25 
26 /* IPC message timeout (msecs) */
27 #define IPC_TIMEOUT_MSECS	300
28 
29 #define IPC_EMPTY_LIST_SIZE	8
30 
31 /* locks held by caller */
msg_get_empty(struct sst_generic_ipc * ipc)32 static struct ipc_message *msg_get_empty(struct sst_generic_ipc *ipc)
33 {
34 	struct ipc_message *msg = NULL;
35 
36 	if (!list_empty(&ipc->empty_list)) {
37 		msg = list_first_entry(&ipc->empty_list, struct ipc_message,
38 			list);
39 		list_del(&msg->list);
40 	}
41 
42 	return msg;
43 }
44 
tx_wait_done(struct sst_generic_ipc * ipc,struct ipc_message * msg,struct sst_ipc_message * reply)45 static int tx_wait_done(struct sst_generic_ipc *ipc,
46 	struct ipc_message *msg, struct sst_ipc_message *reply)
47 {
48 	unsigned long flags;
49 	int ret;
50 
51 	/* wait for DSP completion (in all cases atm inc pending) */
52 	ret = wait_event_timeout(msg->waitq, msg->complete,
53 		msecs_to_jiffies(IPC_TIMEOUT_MSECS));
54 
55 	spin_lock_irqsave(&ipc->dsp->spinlock, flags);
56 	if (ret == 0) {
57 		if (ipc->ops.shim_dbg != NULL)
58 			ipc->ops.shim_dbg(ipc, "message timeout");
59 
60 		list_del(&msg->list);
61 		ret = -ETIMEDOUT;
62 	} else {
63 
64 		/* copy the data returned from DSP */
65 		if (reply) {
66 			reply->header = msg->rx.header;
67 			if (reply->data)
68 				memcpy(reply->data, msg->rx.data, msg->rx.size);
69 		}
70 		ret = msg->errno;
71 	}
72 
73 	list_add_tail(&msg->list, &ipc->empty_list);
74 	spin_unlock_irqrestore(&ipc->dsp->spinlock, flags);
75 	return ret;
76 }
77 
ipc_tx_message(struct sst_generic_ipc * ipc,struct sst_ipc_message request,struct sst_ipc_message * reply,int wait)78 static int ipc_tx_message(struct sst_generic_ipc *ipc,
79 	struct sst_ipc_message request,
80 	struct sst_ipc_message *reply, int wait)
81 {
82 	struct ipc_message *msg;
83 	unsigned long flags;
84 
85 	spin_lock_irqsave(&ipc->dsp->spinlock, flags);
86 
87 	msg = msg_get_empty(ipc);
88 	if (msg == NULL) {
89 		spin_unlock_irqrestore(&ipc->dsp->spinlock, flags);
90 		return -EBUSY;
91 	}
92 
93 	msg->tx.header = request.header;
94 	msg->tx.size = request.size;
95 	msg->rx.header = 0;
96 	msg->rx.size = reply ? reply->size : 0;
97 	msg->wait = wait;
98 	msg->errno = 0;
99 	msg->pending = false;
100 	msg->complete = false;
101 
102 	if ((request.size) && (ipc->ops.tx_data_copy != NULL))
103 		ipc->ops.tx_data_copy(msg, request.data, request.size);
104 
105 	list_add_tail(&msg->list, &ipc->tx_list);
106 	schedule_work(&ipc->kwork);
107 	spin_unlock_irqrestore(&ipc->dsp->spinlock, flags);
108 
109 	if (wait)
110 		return tx_wait_done(ipc, msg, reply);
111 	else
112 		return 0;
113 }
114 
msg_empty_list_init(struct sst_generic_ipc * ipc)115 static int msg_empty_list_init(struct sst_generic_ipc *ipc)
116 {
117 	int i;
118 
119 	ipc->msg = kcalloc(IPC_EMPTY_LIST_SIZE, sizeof(struct ipc_message),
120 			   GFP_KERNEL);
121 	if (ipc->msg == NULL)
122 		return -ENOMEM;
123 
124 	for (i = 0; i < IPC_EMPTY_LIST_SIZE; i++) {
125 		ipc->msg[i].tx.data = kzalloc(ipc->tx_data_max_size, GFP_KERNEL);
126 		if (ipc->msg[i].tx.data == NULL)
127 			goto free_mem;
128 
129 		ipc->msg[i].rx.data = kzalloc(ipc->rx_data_max_size, GFP_KERNEL);
130 		if (ipc->msg[i].rx.data == NULL) {
131 			kfree(ipc->msg[i].tx.data);
132 			goto free_mem;
133 		}
134 
135 		init_waitqueue_head(&ipc->msg[i].waitq);
136 		list_add(&ipc->msg[i].list, &ipc->empty_list);
137 	}
138 
139 	return 0;
140 
141 free_mem:
142 	while (i > 0) {
143 		kfree(ipc->msg[i-1].tx.data);
144 		kfree(ipc->msg[i-1].rx.data);
145 		--i;
146 	}
147 	kfree(ipc->msg);
148 
149 	return -ENOMEM;
150 }
151 
ipc_tx_msgs(struct work_struct * work)152 static void ipc_tx_msgs(struct work_struct *work)
153 {
154 	struct sst_generic_ipc *ipc =
155 		container_of(work, struct sst_generic_ipc, kwork);
156 	struct ipc_message *msg;
157 
158 	spin_lock_irq(&ipc->dsp->spinlock);
159 
160 	while (!list_empty(&ipc->tx_list) && !ipc->pending) {
161 		/* if the DSP is busy, we will TX messages after IRQ.
162 		 * also postpone if we are in the middle of processing
163 		 * completion irq
164 		 */
165 		if (ipc->ops.is_dsp_busy && ipc->ops.is_dsp_busy(ipc->dsp)) {
166 			dev_dbg(ipc->dev, "ipc_tx_msgs dsp busy\n");
167 			break;
168 		}
169 
170 		msg = list_first_entry(&ipc->tx_list, struct ipc_message, list);
171 		list_move(&msg->list, &ipc->rx_list);
172 
173 		if (ipc->ops.tx_msg != NULL)
174 			ipc->ops.tx_msg(ipc, msg);
175 	}
176 
177 	spin_unlock_irq(&ipc->dsp->spinlock);
178 }
179 
sst_ipc_tx_message_wait(struct sst_generic_ipc * ipc,struct sst_ipc_message request,struct sst_ipc_message * reply)180 int sst_ipc_tx_message_wait(struct sst_generic_ipc *ipc,
181 	struct sst_ipc_message request, struct sst_ipc_message *reply)
182 {
183 	int ret;
184 
185 	/*
186 	 * DSP maybe in lower power active state, so
187 	 * check if the DSP supports DSP lp On method
188 	 * if so invoke that before sending IPC
189 	 */
190 	if (ipc->ops.check_dsp_lp_on)
191 		if (ipc->ops.check_dsp_lp_on(ipc->dsp, true))
192 			return -EIO;
193 
194 	ret = ipc_tx_message(ipc, request, reply, 1);
195 
196 	if (ipc->ops.check_dsp_lp_on)
197 		if (ipc->ops.check_dsp_lp_on(ipc->dsp, false))
198 			return -EIO;
199 
200 	return ret;
201 }
202 EXPORT_SYMBOL_GPL(sst_ipc_tx_message_wait);
203 
sst_ipc_tx_message_nowait(struct sst_generic_ipc * ipc,struct sst_ipc_message request)204 int sst_ipc_tx_message_nowait(struct sst_generic_ipc *ipc,
205 	struct sst_ipc_message request)
206 {
207 	return ipc_tx_message(ipc, request, NULL, 0);
208 }
209 EXPORT_SYMBOL_GPL(sst_ipc_tx_message_nowait);
210 
sst_ipc_tx_message_nopm(struct sst_generic_ipc * ipc,struct sst_ipc_message request,struct sst_ipc_message * reply)211 int sst_ipc_tx_message_nopm(struct sst_generic_ipc *ipc,
212 	struct sst_ipc_message request, struct sst_ipc_message *reply)
213 {
214 	return ipc_tx_message(ipc, request, reply, 1);
215 }
216 EXPORT_SYMBOL_GPL(sst_ipc_tx_message_nopm);
217 
sst_ipc_reply_find_msg(struct sst_generic_ipc * ipc,u64 header)218 struct ipc_message *sst_ipc_reply_find_msg(struct sst_generic_ipc *ipc,
219 	u64 header)
220 {
221 	struct ipc_message *msg;
222 	u64 mask;
223 
224 	if (ipc->ops.reply_msg_match != NULL)
225 		header = ipc->ops.reply_msg_match(header, &mask);
226 	else
227 		mask = (u64)-1;
228 
229 	if (list_empty(&ipc->rx_list)) {
230 		dev_err(ipc->dev, "error: rx list empty but received 0x%llx\n",
231 			header);
232 		return NULL;
233 	}
234 
235 	list_for_each_entry(msg, &ipc->rx_list, list) {
236 		if ((msg->tx.header & mask) == header)
237 			return msg;
238 	}
239 
240 	return NULL;
241 }
242 EXPORT_SYMBOL_GPL(sst_ipc_reply_find_msg);
243 
244 /* locks held by caller */
sst_ipc_tx_msg_reply_complete(struct sst_generic_ipc * ipc,struct ipc_message * msg)245 void sst_ipc_tx_msg_reply_complete(struct sst_generic_ipc *ipc,
246 	struct ipc_message *msg)
247 {
248 	msg->complete = true;
249 
250 	if (!msg->wait)
251 		list_add_tail(&msg->list, &ipc->empty_list);
252 	else
253 		wake_up(&msg->waitq);
254 }
255 EXPORT_SYMBOL_GPL(sst_ipc_tx_msg_reply_complete);
256 
sst_ipc_init(struct sst_generic_ipc * ipc)257 int sst_ipc_init(struct sst_generic_ipc *ipc)
258 {
259 	int ret;
260 
261 	INIT_LIST_HEAD(&ipc->tx_list);
262 	INIT_LIST_HEAD(&ipc->rx_list);
263 	INIT_LIST_HEAD(&ipc->empty_list);
264 	init_waitqueue_head(&ipc->wait_txq);
265 
266 	ret = msg_empty_list_init(ipc);
267 	if (ret < 0)
268 		return -ENOMEM;
269 
270 	INIT_WORK(&ipc->kwork, ipc_tx_msgs);
271 	return 0;
272 }
273 EXPORT_SYMBOL_GPL(sst_ipc_init);
274 
sst_ipc_fini(struct sst_generic_ipc * ipc)275 void sst_ipc_fini(struct sst_generic_ipc *ipc)
276 {
277 	int i;
278 
279 	cancel_work_sync(&ipc->kwork);
280 
281 	if (ipc->msg) {
282 		for (i = 0; i < IPC_EMPTY_LIST_SIZE; i++) {
283 			kfree(ipc->msg[i].tx.data);
284 			kfree(ipc->msg[i].rx.data);
285 		}
286 		kfree(ipc->msg);
287 	}
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");
295