aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/rpmsg/qcom_glink_smem.c
blob: 9d73ced075e79f92ddc6e1337afdfb07bdb16a85 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
/*
 * Copyright (c) 2016, Linaro Ltd
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 and
 * only version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/mfd/syscon.h>
#include <linux/slab.h>
#include <linux/rpmsg.h>
#include <linux/idr.h>
#include <linux/circ_buf.h>
#include <linux/soc/qcom/smem.h>
#include <linux/sizes.h>
#include <linux/delay.h>
#include <linux/regmap.h>
#include <linux/workqueue.h>
#include <linux/list.h>

#include <linux/delay.h>
#include <linux/rpmsg.h>
#include <linux/rpmsg/qcom_glink.h>

#include "qcom_glink_native.h"

#define FIFO_FULL_RESERVE 8
#define FIFO_ALIGNMENT 8
#define TX_BLOCKED_CMD_RESERVE 8 /* size of struct read_notif_request */

#define SMEM_GLINK_NATIVE_XPRT_DESCRIPTOR	478
#define SMEM_GLINK_NATIVE_XPRT_FIFO_0		479
#define SMEM_GLINK_NATIVE_XPRT_FIFO_1		480

struct glink_smem_pipe {
	struct qcom_glink_pipe native;

	__le32 *tail;
	__le32 *head;

	void *fifo;

	int remote_pid;
};

#define to_smem_pipe(p) container_of(p, struct glink_smem_pipe, native)

static size_t glink_smem_rx_avail(struct qcom_glink_pipe *np)
{
	struct glink_smem_pipe *pipe = to_smem_pipe(np);
	size_t len;
	void *fifo;
	u32 head;
	u32 tail;

	if (!pipe->fifo) {
		fifo = qcom_smem_get(pipe->remote_pid,
				     SMEM_GLINK_NATIVE_XPRT_FIFO_1, &len);
		if (IS_ERR(fifo)) {
			pr_err("failed to acquire RX fifo handle: %ld\n",
			       PTR_ERR(fifo));
			return 0;
		}

		pipe->fifo = fifo;
		pipe->native.length = len;
	}

	head = le32_to_cpu(*pipe->head);
	tail = le32_to_cpu(*pipe->tail);

	if (head < tail)
		return pipe->native.length - tail + head;
	else
		return head - tail;
}

static void glink_smem_rx_peak(struct qcom_glink_pipe *np,
			       void *data, size_t count)
{
	struct glink_smem_pipe *pipe = to_smem_pipe(np);
	size_t len;
	u32 tail;

	tail = le32_to_cpu(*pipe->tail);

	len = min_t(size_t, count, pipe->native.length - tail);
	if (len) {
		__ioread32_copy(data, pipe->fifo + tail,
				len / sizeof(u32));
	}

	if (len != count) {
		__ioread32_copy(data + len, pipe->fifo,
				(count - len) / sizeof(u32));
	}
}

static void glink_smem_rx_advance(struct qcom_glink_pipe *np,
				  size_t count)
{
	struct glink_smem_pipe *pipe = to_smem_pipe(np);
	u32 tail;

	tail = le32_to_cpu(*pipe->tail);

	tail += count;
	if (tail > pipe->native.length)
		tail -= pipe->native.length;

	*pipe->tail = cpu_to_le32(tail);
}

static size_t glink_smem_tx_avail(struct qcom_glink_pipe *np)
{
	struct glink_smem_pipe *pipe = to_smem_pipe(np);
	u32 head;
	u32 tail;
	u32 avail;

	head = le32_to_cpu(*pipe->head);
	tail = le32_to_cpu(*pipe->tail);

	if (tail <= head)
		avail = pipe->native.length - head + tail;
	else
		avail = tail - head;

	if (avail < (FIFO_FULL_RESERVE + TX_BLOCKED_CMD_RESERVE))
		avail = 0;
	else
		avail -= FIFO_FULL_RESERVE + TX_BLOCKED_CMD_RESERVE;

	return avail;
}

static unsigned int glink_smem_tx_write_one(struct glink_smem_pipe *pipe,
					    unsigned int head,
					    const void *data, size_t count)
{
	size_t len;

	len = min_t(size_t, count, pipe->native.length - head);
	if (len)
		memcpy(pipe->fifo + head, data, len);

	if (len != count)
		memcpy(pipe->fifo, data + len, count - len);

	head += count;
	if (head >= pipe->native.length)
		head -= pipe->native.length;

	return head;
}

static void glink_smem_tx_write(struct qcom_glink_pipe *glink_pipe,
				const void *hdr, size_t hlen,
				const void *data, size_t dlen)
{
	struct glink_smem_pipe *pipe = to_smem_pipe(glink_pipe);
	unsigned int head;

	head = le32_to_cpu(*pipe->head);

	head = glink_smem_tx_write_one(pipe, head, hdr, hlen);
	head = glink_smem_tx_write_one(pipe, head, data, dlen);

	/* Ensure head is always aligned to 8 bytes */
	head = ALIGN(head, 8);
	if (head >= pipe->native.length)
		head -= pipe->native.length;

	*pipe->head = cpu_to_le32(head);
}

static void qcom_glink_smem_release(struct device *dev)
{
	kfree(dev);
}

struct qcom_glink *qcom_glink_smem_register(struct device *parent,
					    struct device_node *node)
{
	struct glink_smem_pipe *rx_pipe;
	struct glink_smem_pipe *tx_pipe;
	struct qcom_glink *glink;
	struct device *dev;
	u32 remote_pid;
	__le32 *descs;
	size_t size;
	int ret;

	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
	if (!dev)
		return ERR_PTR(-ENOMEM);

	dev->parent = parent;
	dev->of_node = node;
	dev->release = qcom_glink_smem_release;
	dev_set_name(dev, "%s:%s", node->parent->name, node->name);
	ret = device_register(dev);
	if (ret) {
		pr_err("failed to register glink edge\n");
		return ERR_PTR(ret);
	}

	ret = of_property_read_u32(dev->of_node, "qcom,remote-pid",
				   &remote_pid);
	if (ret) {
		dev_err(dev, "failed to parse qcom,remote-pid\n");
		goto err_put_dev;
	}

	rx_pipe = devm_kzalloc(dev, sizeof(*rx_pipe), GFP_KERNEL);
	tx_pipe = devm_kzalloc(dev, sizeof(*tx_pipe), GFP_KERNEL);
	if (!rx_pipe || !tx_pipe) {
		ret = -ENOMEM;
		goto err_put_dev;
	}

	ret = qcom_smem_alloc(remote_pid,
			      SMEM_GLINK_NATIVE_XPRT_DESCRIPTOR, 32);
	if (ret && ret != -EEXIST) {
		dev_err(dev, "failed to allocate glink descriptors\n");
		goto err_put_dev;
	}

	descs = qcom_smem_get(remote_pid,
			      SMEM_GLINK_NATIVE_XPRT_DESCRIPTOR, &size);
	if (IS_ERR(descs)) {
		dev_err(dev, "failed to acquire xprt descriptor\n");
		ret = PTR_ERR(descs);
		goto err_put_dev;
	}

	if (size != 32) {
		dev_err(dev, "glink descriptor of invalid size\n");
		ret = -EINVAL;
		goto err_put_dev;
	}

	tx_pipe->tail = &descs[0];
	tx_pipe->head = &descs[1];
	rx_pipe->tail = &descs[2];
	rx_pipe->head = &descs[3];

	ret = qcom_smem_alloc(remote_pid, SMEM_GLINK_NATIVE_XPRT_FIFO_0,
			      SZ_16K);
	if (ret && ret != -EEXIST) {
		dev_err(dev, "failed to allocate TX fifo\n");
		goto err_put_dev;
	}

	tx_pipe->fifo = qcom_smem_get(remote_pid, SMEM_GLINK_NATIVE_XPRT_FIFO_0,
				      &tx_pipe->native.length);
	if (IS_ERR(tx_pipe->fifo)) {
		dev_err(dev, "failed to acquire TX fifo\n");
		ret = PTR_ERR(tx_pipe->fifo);
		goto err_put_dev;
	}

	rx_pipe->native.avail = glink_smem_rx_avail;
	rx_pipe->native.peak = glink_smem_rx_peak;
	rx_pipe->native.advance = glink_smem_rx_advance;
	rx_pipe->remote_pid = remote_pid;

	tx_pipe->native.avail = glink_smem_tx_avail;
	tx_pipe->native.write = glink_smem_tx_write;
	tx_pipe->remote_pid = remote_pid;

	*rx_pipe->tail = 0;
	*tx_pipe->head = 0;

	glink = qcom_glink_native_probe(dev,
					GLINK_FEATURE_INTENT_REUSE,
					&rx_pipe->native, &tx_pipe->native,
					false);
	if (IS_ERR(glink)) {
		ret = PTR_ERR(glink);
		goto err_put_dev;
	}

	return glink;

err_put_dev:
	put_device(dev);

	return ERR_PTR(ret);
}
EXPORT_SYMBOL_GPL(qcom_glink_smem_register);

void qcom_glink_smem_unregister(struct qcom_glink *glink)
{
	qcom_glink_native_remove(glink);
	qcom_glink_native_unregister(glink);
}
EXPORT_SYMBOL_GPL(qcom_glink_smem_unregister);

MODULE_AUTHOR("Bjorn Andersson <bjorn.andersson@linaro.org>");
MODULE_DESCRIPTION("Qualcomm GLINK SMEM driver");
MODULE_LICENSE("GPL v2");

Privacy Policy