GNU Linux-libre 5.19-rc6-gnu
[releases.git] / drivers / rpmsg / qcom_glink_smem.c
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2016, Linaro Ltd
4  */
5
6 #include <linux/io.h>
7 #include <linux/module.h>
8 #include <linux/of.h>
9 #include <linux/of_address.h>
10 #include <linux/interrupt.h>
11 #include <linux/platform_device.h>
12 #include <linux/mfd/syscon.h>
13 #include <linux/slab.h>
14 #include <linux/rpmsg.h>
15 #include <linux/idr.h>
16 #include <linux/circ_buf.h>
17 #include <linux/soc/qcom/smem.h>
18 #include <linux/sizes.h>
19 #include <linux/delay.h>
20 #include <linux/regmap.h>
21 #include <linux/workqueue.h>
22 #include <linux/list.h>
23
24 #include <linux/rpmsg/qcom_glink.h>
25
26 #include "qcom_glink_native.h"
27
28 #define FIFO_FULL_RESERVE 8
29 #define FIFO_ALIGNMENT 8
30 #define TX_BLOCKED_CMD_RESERVE 8 /* size of struct read_notif_request */
31
32 #define SMEM_GLINK_NATIVE_XPRT_DESCRIPTOR       478
33 #define SMEM_GLINK_NATIVE_XPRT_FIFO_0           479
34 #define SMEM_GLINK_NATIVE_XPRT_FIFO_1           480
35
36 struct glink_smem_pipe {
37         struct qcom_glink_pipe native;
38
39         __le32 *tail;
40         __le32 *head;
41
42         void *fifo;
43
44         int remote_pid;
45 };
46
47 #define to_smem_pipe(p) container_of(p, struct glink_smem_pipe, native)
48
49 static size_t glink_smem_rx_avail(struct qcom_glink_pipe *np)
50 {
51         struct glink_smem_pipe *pipe = to_smem_pipe(np);
52         size_t len;
53         void *fifo;
54         u32 head;
55         u32 tail;
56
57         if (!pipe->fifo) {
58                 fifo = qcom_smem_get(pipe->remote_pid,
59                                      SMEM_GLINK_NATIVE_XPRT_FIFO_1, &len);
60                 if (IS_ERR(fifo)) {
61                         pr_err("failed to acquire RX fifo handle: %ld\n",
62                                PTR_ERR(fifo));
63                         return 0;
64                 }
65
66                 pipe->fifo = fifo;
67                 pipe->native.length = len;
68         }
69
70         head = le32_to_cpu(*pipe->head);
71         tail = le32_to_cpu(*pipe->tail);
72
73         if (head < tail)
74                 return pipe->native.length - tail + head;
75         else
76                 return head - tail;
77 }
78
79 static void glink_smem_rx_peak(struct qcom_glink_pipe *np,
80                                void *data, unsigned int offset, size_t count)
81 {
82         struct glink_smem_pipe *pipe = to_smem_pipe(np);
83         size_t len;
84         u32 tail;
85
86         tail = le32_to_cpu(*pipe->tail);
87         tail += offset;
88         if (tail >= pipe->native.length)
89                 tail -= pipe->native.length;
90
91         len = min_t(size_t, count, pipe->native.length - tail);
92         if (len)
93                 memcpy_fromio(data, pipe->fifo + tail, len);
94
95         if (len != count)
96                 memcpy_fromio(data + len, pipe->fifo, (count - len));
97 }
98
99 static void glink_smem_rx_advance(struct qcom_glink_pipe *np,
100                                   size_t count)
101 {
102         struct glink_smem_pipe *pipe = to_smem_pipe(np);
103         u32 tail;
104
105         tail = le32_to_cpu(*pipe->tail);
106
107         tail += count;
108         if (tail >= pipe->native.length)
109                 tail -= pipe->native.length;
110
111         *pipe->tail = cpu_to_le32(tail);
112 }
113
114 static size_t glink_smem_tx_avail(struct qcom_glink_pipe *np)
115 {
116         struct glink_smem_pipe *pipe = to_smem_pipe(np);
117         u32 head;
118         u32 tail;
119         u32 avail;
120
121         head = le32_to_cpu(*pipe->head);
122         tail = le32_to_cpu(*pipe->tail);
123
124         if (tail <= head)
125                 avail = pipe->native.length - head + tail;
126         else
127                 avail = tail - head;
128
129         if (avail < (FIFO_FULL_RESERVE + TX_BLOCKED_CMD_RESERVE))
130                 avail = 0;
131         else
132                 avail -= FIFO_FULL_RESERVE + TX_BLOCKED_CMD_RESERVE;
133
134         return avail;
135 }
136
137 static unsigned int glink_smem_tx_write_one(struct glink_smem_pipe *pipe,
138                                             unsigned int head,
139                                             const void *data, size_t count)
140 {
141         size_t len;
142
143         len = min_t(size_t, count, pipe->native.length - head);
144         if (len)
145                 memcpy(pipe->fifo + head, data, len);
146
147         if (len != count)
148                 memcpy(pipe->fifo, data + len, count - len);
149
150         head += count;
151         if (head >= pipe->native.length)
152                 head -= pipe->native.length;
153
154         return head;
155 }
156
157 static void glink_smem_tx_write(struct qcom_glink_pipe *glink_pipe,
158                                 const void *hdr, size_t hlen,
159                                 const void *data, size_t dlen)
160 {
161         struct glink_smem_pipe *pipe = to_smem_pipe(glink_pipe);
162         unsigned int head;
163
164         head = le32_to_cpu(*pipe->head);
165
166         head = glink_smem_tx_write_one(pipe, head, hdr, hlen);
167         head = glink_smem_tx_write_one(pipe, head, data, dlen);
168
169         /* Ensure head is always aligned to 8 bytes */
170         head = ALIGN(head, 8);
171         if (head >= pipe->native.length)
172                 head -= pipe->native.length;
173
174         /* Ensure ordering of fifo and head update */
175         wmb();
176
177         *pipe->head = cpu_to_le32(head);
178 }
179
180 static void qcom_glink_smem_release(struct device *dev)
181 {
182         kfree(dev);
183 }
184
185 struct qcom_glink *qcom_glink_smem_register(struct device *parent,
186                                             struct device_node *node)
187 {
188         struct glink_smem_pipe *rx_pipe;
189         struct glink_smem_pipe *tx_pipe;
190         struct qcom_glink *glink;
191         struct device *dev;
192         u32 remote_pid;
193         __le32 *descs;
194         size_t size;
195         int ret;
196
197         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
198         if (!dev)
199                 return ERR_PTR(-ENOMEM);
200
201         dev->parent = parent;
202         dev->of_node = node;
203         dev->release = qcom_glink_smem_release;
204         dev_set_name(dev, "%s:%pOFn", dev_name(parent->parent), node);
205         ret = device_register(dev);
206         if (ret) {
207                 pr_err("failed to register glink edge\n");
208                 put_device(dev);
209                 return ERR_PTR(ret);
210         }
211
212         ret = of_property_read_u32(dev->of_node, "qcom,remote-pid",
213                                    &remote_pid);
214         if (ret) {
215                 dev_err(dev, "failed to parse qcom,remote-pid\n");
216                 goto err_put_dev;
217         }
218
219         rx_pipe = devm_kzalloc(dev, sizeof(*rx_pipe), GFP_KERNEL);
220         tx_pipe = devm_kzalloc(dev, sizeof(*tx_pipe), GFP_KERNEL);
221         if (!rx_pipe || !tx_pipe) {
222                 ret = -ENOMEM;
223                 goto err_put_dev;
224         }
225
226         ret = qcom_smem_alloc(remote_pid,
227                               SMEM_GLINK_NATIVE_XPRT_DESCRIPTOR, 32);
228         if (ret && ret != -EEXIST) {
229                 dev_err(dev, "failed to allocate glink descriptors\n");
230                 goto err_put_dev;
231         }
232
233         descs = qcom_smem_get(remote_pid,
234                               SMEM_GLINK_NATIVE_XPRT_DESCRIPTOR, &size);
235         if (IS_ERR(descs)) {
236                 dev_err(dev, "failed to acquire xprt descriptor\n");
237                 ret = PTR_ERR(descs);
238                 goto err_put_dev;
239         }
240
241         if (size != 32) {
242                 dev_err(dev, "glink descriptor of invalid size\n");
243                 ret = -EINVAL;
244                 goto err_put_dev;
245         }
246
247         tx_pipe->tail = &descs[0];
248         tx_pipe->head = &descs[1];
249         rx_pipe->tail = &descs[2];
250         rx_pipe->head = &descs[3];
251
252         ret = qcom_smem_alloc(remote_pid, SMEM_GLINK_NATIVE_XPRT_FIFO_0,
253                               SZ_16K);
254         if (ret && ret != -EEXIST) {
255                 dev_err(dev, "failed to allocate TX fifo\n");
256                 goto err_put_dev;
257         }
258
259         tx_pipe->fifo = qcom_smem_get(remote_pid, SMEM_GLINK_NATIVE_XPRT_FIFO_0,
260                                       &tx_pipe->native.length);
261         if (IS_ERR(tx_pipe->fifo)) {
262                 dev_err(dev, "failed to acquire TX fifo\n");
263                 ret = PTR_ERR(tx_pipe->fifo);
264                 goto err_put_dev;
265         }
266
267         rx_pipe->native.avail = glink_smem_rx_avail;
268         rx_pipe->native.peak = glink_smem_rx_peak;
269         rx_pipe->native.advance = glink_smem_rx_advance;
270         rx_pipe->remote_pid = remote_pid;
271
272         tx_pipe->native.avail = glink_smem_tx_avail;
273         tx_pipe->native.write = glink_smem_tx_write;
274         tx_pipe->remote_pid = remote_pid;
275
276         *rx_pipe->tail = 0;
277         *tx_pipe->head = 0;
278
279         glink = qcom_glink_native_probe(dev,
280                                         GLINK_FEATURE_INTENT_REUSE,
281                                         &rx_pipe->native, &tx_pipe->native,
282                                         false);
283         if (IS_ERR(glink)) {
284                 ret = PTR_ERR(glink);
285                 goto err_put_dev;
286         }
287
288         return glink;
289
290 err_put_dev:
291         device_unregister(dev);
292
293         return ERR_PTR(ret);
294 }
295 EXPORT_SYMBOL_GPL(qcom_glink_smem_register);
296
297 void qcom_glink_smem_unregister(struct qcom_glink *glink)
298 {
299         qcom_glink_native_remove(glink);
300         qcom_glink_native_unregister(glink);
301 }
302 EXPORT_SYMBOL_GPL(qcom_glink_smem_unregister);
303
304 MODULE_AUTHOR("Bjorn Andersson <bjorn.andersson@linaro.org>");
305 MODULE_DESCRIPTION("Qualcomm GLINK SMEM driver");
306 MODULE_LICENSE("GPL v2");