Loading...
1/* SPDX-License-Identifier: BSD-3-Clause */
2/*
3 * Remote processor messaging
4 *
5 * Copyright (C) 2011 Texas Instruments, Inc.
6 * Copyright (C) 2011 Google, Inc.
7 * All rights reserved.
8 */
9
10#ifndef _LINUX_RPMSG_H
11#define _LINUX_RPMSG_H
12
13#include <linux/types.h>
14#include <linux/device.h>
15#include <linux/err.h>
16#include <linux/mod_devicetable.h>
17#include <linux/kref.h>
18#include <linux/mutex.h>
19#include <linux/poll.h>
20#include <linux/rpmsg/byteorder.h>
21#include <uapi/linux/rpmsg.h>
22
23struct rpmsg_device;
24struct rpmsg_endpoint;
25struct rpmsg_device_ops;
26struct rpmsg_endpoint_ops;
27
28/**
29 * struct rpmsg_channel_info - channel info representation
30 * @name: name of service
31 * @src: local address
32 * @dst: destination address
33 */
34struct rpmsg_channel_info {
35 char name[RPMSG_NAME_SIZE];
36 u32 src;
37 u32 dst;
38};
39
40/**
41 * rpmsg_device - device that belong to the rpmsg bus
42 * @dev: the device struct
43 * @id: device id (used to match between rpmsg drivers and devices)
44 * @driver_override: driver name to force a match
45 * @src: local address
46 * @dst: destination address
47 * @ept: the rpmsg endpoint of this channel
48 * @announce: if set, rpmsg will announce the creation/removal of this channel
49 * @little_endian: True if transport is using little endian byte representation
50 */
51struct rpmsg_device {
52 struct device dev;
53 struct rpmsg_device_id id;
54 char *driver_override;
55 u32 src;
56 u32 dst;
57 struct rpmsg_endpoint *ept;
58 bool announce;
59 bool little_endian;
60
61 const struct rpmsg_device_ops *ops;
62};
63
64typedef int (*rpmsg_rx_cb_t)(struct rpmsg_device *, void *, int, void *, u32);
65
66/**
67 * struct rpmsg_endpoint - binds a local rpmsg address to its user
68 * @rpdev: rpmsg channel device
69 * @refcount: when this drops to zero, the ept is deallocated
70 * @cb: rx callback handler
71 * @cb_lock: must be taken before accessing/changing @cb
72 * @addr: local rpmsg address
73 * @priv: private data for the driver's use
74 *
75 * In essence, an rpmsg endpoint represents a listener on the rpmsg bus, as
76 * it binds an rpmsg address with an rx callback handler.
77 *
78 * Simple rpmsg drivers shouldn't use this struct directly, because
79 * things just work: every rpmsg driver provides an rx callback upon
80 * registering to the bus, and that callback is then bound to its rpmsg
81 * address when the driver is probed. When relevant inbound messages arrive
82 * (i.e. messages which their dst address equals to the src address of
83 * the rpmsg channel), the driver's handler is invoked to process it.
84 *
85 * More complicated drivers though, that do need to allocate additional rpmsg
86 * addresses, and bind them to different rx callbacks, must explicitly
87 * create additional endpoints by themselves (see rpmsg_create_ept()).
88 */
89struct rpmsg_endpoint {
90 struct rpmsg_device *rpdev;
91 struct kref refcount;
92 rpmsg_rx_cb_t cb;
93 struct mutex cb_lock;
94 u32 addr;
95 void *priv;
96
97 const struct rpmsg_endpoint_ops *ops;
98};
99
100/**
101 * struct rpmsg_driver - rpmsg driver struct
102 * @drv: underlying device driver
103 * @id_table: rpmsg ids serviced by this driver
104 * @probe: invoked when a matching rpmsg channel (i.e. device) is found
105 * @remove: invoked when the rpmsg channel is removed
106 * @callback: invoked when an inbound message is received on the channel
107 */
108struct rpmsg_driver {
109 struct device_driver drv;
110 const struct rpmsg_device_id *id_table;
111 int (*probe)(struct rpmsg_device *dev);
112 void (*remove)(struct rpmsg_device *dev);
113 int (*callback)(struct rpmsg_device *, void *, int, void *, u32);
114};
115
116static inline u16 rpmsg16_to_cpu(struct rpmsg_device *rpdev, __rpmsg16 val)
117{
118 if (!rpdev)
119 return __rpmsg16_to_cpu(rpmsg_is_little_endian(), val);
120 else
121 return __rpmsg16_to_cpu(rpdev->little_endian, val);
122}
123
124static inline __rpmsg16 cpu_to_rpmsg16(struct rpmsg_device *rpdev, u16 val)
125{
126 if (!rpdev)
127 return __cpu_to_rpmsg16(rpmsg_is_little_endian(), val);
128 else
129 return __cpu_to_rpmsg16(rpdev->little_endian, val);
130}
131
132static inline u32 rpmsg32_to_cpu(struct rpmsg_device *rpdev, __rpmsg32 val)
133{
134 if (!rpdev)
135 return __rpmsg32_to_cpu(rpmsg_is_little_endian(), val);
136 else
137 return __rpmsg32_to_cpu(rpdev->little_endian, val);
138}
139
140static inline __rpmsg32 cpu_to_rpmsg32(struct rpmsg_device *rpdev, u32 val)
141{
142 if (!rpdev)
143 return __cpu_to_rpmsg32(rpmsg_is_little_endian(), val);
144 else
145 return __cpu_to_rpmsg32(rpdev->little_endian, val);
146}
147
148static inline u64 rpmsg64_to_cpu(struct rpmsg_device *rpdev, __rpmsg64 val)
149{
150 if (!rpdev)
151 return __rpmsg64_to_cpu(rpmsg_is_little_endian(), val);
152 else
153 return __rpmsg64_to_cpu(rpdev->little_endian, val);
154}
155
156static inline __rpmsg64 cpu_to_rpmsg64(struct rpmsg_device *rpdev, u64 val)
157{
158 if (!rpdev)
159 return __cpu_to_rpmsg64(rpmsg_is_little_endian(), val);
160 else
161 return __cpu_to_rpmsg64(rpdev->little_endian, val);
162}
163
164#if IS_ENABLED(CONFIG_RPMSG)
165
166int rpmsg_register_device(struct rpmsg_device *rpdev);
167int rpmsg_unregister_device(struct device *parent,
168 struct rpmsg_channel_info *chinfo);
169int __register_rpmsg_driver(struct rpmsg_driver *drv, struct module *owner);
170void unregister_rpmsg_driver(struct rpmsg_driver *drv);
171void rpmsg_destroy_ept(struct rpmsg_endpoint *);
172struct rpmsg_endpoint *rpmsg_create_ept(struct rpmsg_device *,
173 rpmsg_rx_cb_t cb, void *priv,
174 struct rpmsg_channel_info chinfo);
175
176int rpmsg_send(struct rpmsg_endpoint *ept, void *data, int len);
177int rpmsg_sendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst);
178int rpmsg_send_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst,
179 void *data, int len);
180
181int rpmsg_trysend(struct rpmsg_endpoint *ept, void *data, int len);
182int rpmsg_trysendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst);
183int rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst,
184 void *data, int len);
185
186__poll_t rpmsg_poll(struct rpmsg_endpoint *ept, struct file *filp,
187 poll_table *wait);
188
189#else
190
191static inline int rpmsg_register_device(struct rpmsg_device *rpdev)
192{
193 return -ENXIO;
194}
195
196static inline int rpmsg_unregister_device(struct device *parent,
197 struct rpmsg_channel_info *chinfo)
198{
199 /* This shouldn't be possible */
200 WARN_ON(1);
201
202 return -ENXIO;
203}
204
205static inline int __register_rpmsg_driver(struct rpmsg_driver *drv,
206 struct module *owner)
207{
208 /* This shouldn't be possible */
209 WARN_ON(1);
210
211 return -ENXIO;
212}
213
214static inline void unregister_rpmsg_driver(struct rpmsg_driver *drv)
215{
216 /* This shouldn't be possible */
217 WARN_ON(1);
218}
219
220static inline void rpmsg_destroy_ept(struct rpmsg_endpoint *ept)
221{
222 /* This shouldn't be possible */
223 WARN_ON(1);
224}
225
226static inline struct rpmsg_endpoint *rpmsg_create_ept(struct rpmsg_device *rpdev,
227 rpmsg_rx_cb_t cb,
228 void *priv,
229 struct rpmsg_channel_info chinfo)
230{
231 /* This shouldn't be possible */
232 WARN_ON(1);
233
234 return ERR_PTR(-ENXIO);
235}
236
237static inline int rpmsg_send(struct rpmsg_endpoint *ept, void *data, int len)
238{
239 /* This shouldn't be possible */
240 WARN_ON(1);
241
242 return -ENXIO;
243}
244
245static inline int rpmsg_sendto(struct rpmsg_endpoint *ept, void *data, int len,
246 u32 dst)
247{
248 /* This shouldn't be possible */
249 WARN_ON(1);
250
251 return -ENXIO;
252
253}
254
255static inline int rpmsg_send_offchannel(struct rpmsg_endpoint *ept, u32 src,
256 u32 dst, void *data, int len)
257{
258 /* This shouldn't be possible */
259 WARN_ON(1);
260
261 return -ENXIO;
262}
263
264static inline int rpmsg_trysend(struct rpmsg_endpoint *ept, void *data, int len)
265{
266 /* This shouldn't be possible */
267 WARN_ON(1);
268
269 return -ENXIO;
270}
271
272static inline int rpmsg_trysendto(struct rpmsg_endpoint *ept, void *data,
273 int len, u32 dst)
274{
275 /* This shouldn't be possible */
276 WARN_ON(1);
277
278 return -ENXIO;
279}
280
281static inline int rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src,
282 u32 dst, void *data, int len)
283{
284 /* This shouldn't be possible */
285 WARN_ON(1);
286
287 return -ENXIO;
288}
289
290static inline __poll_t rpmsg_poll(struct rpmsg_endpoint *ept,
291 struct file *filp, poll_table *wait)
292{
293 /* This shouldn't be possible */
294 WARN_ON(1);
295
296 return 0;
297}
298
299#endif /* IS_ENABLED(CONFIG_RPMSG) */
300
301/* use a macro to avoid include chaining to get THIS_MODULE */
302#define register_rpmsg_driver(drv) \
303 __register_rpmsg_driver(drv, THIS_MODULE)
304
305/**
306 * module_rpmsg_driver() - Helper macro for registering an rpmsg driver
307 * @__rpmsg_driver: rpmsg_driver struct
308 *
309 * Helper macro for rpmsg drivers which do not do anything special in module
310 * init/exit. This eliminates a lot of boilerplate. Each module may only
311 * use this macro once, and calling it replaces module_init() and module_exit()
312 */
313#define module_rpmsg_driver(__rpmsg_driver) \
314 module_driver(__rpmsg_driver, register_rpmsg_driver, \
315 unregister_rpmsg_driver)
316
317#endif /* _LINUX_RPMSG_H */
1/*
2 * Remote processor messaging
3 *
4 * Copyright (C) 2011 Texas Instruments, Inc.
5 * Copyright (C) 2011 Google, Inc.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * * Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * * Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in
16 * the documentation and/or other materials provided with the
17 * distribution.
18 * * Neither the name Texas Instruments nor the names of its
19 * contributors may be used to endorse or promote products derived
20 * from this software without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
23 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
24 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
25 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
26 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
27 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
28 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
29 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
30 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
31 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
32 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33 */
34
35#ifndef _LINUX_RPMSG_H
36#define _LINUX_RPMSG_H
37
38#include <linux/types.h>
39#include <linux/device.h>
40#include <linux/mod_devicetable.h>
41#include <linux/kref.h>
42#include <linux/mutex.h>
43
44/* The feature bitmap for virtio rpmsg */
45#define VIRTIO_RPMSG_F_NS 0 /* RP supports name service notifications */
46
47/**
48 * struct rpmsg_hdr - common header for all rpmsg messages
49 * @src: source address
50 * @dst: destination address
51 * @reserved: reserved for future use
52 * @len: length of payload (in bytes)
53 * @flags: message flags
54 * @data: @len bytes of message payload data
55 *
56 * Every message sent(/received) on the rpmsg bus begins with this header.
57 */
58struct rpmsg_hdr {
59 u32 src;
60 u32 dst;
61 u32 reserved;
62 u16 len;
63 u16 flags;
64 u8 data[0];
65} __packed;
66
67/**
68 * struct rpmsg_ns_msg - dynamic name service announcement message
69 * @name: name of remote service that is published
70 * @addr: address of remote service that is published
71 * @flags: indicates whether service is created or destroyed
72 *
73 * This message is sent across to publish a new service, or announce
74 * about its removal. When we receive these messages, an appropriate
75 * rpmsg channel (i.e device) is created/destroyed. In turn, the ->probe()
76 * or ->remove() handler of the appropriate rpmsg driver will be invoked
77 * (if/as-soon-as one is registered).
78 */
79struct rpmsg_ns_msg {
80 char name[RPMSG_NAME_SIZE];
81 u32 addr;
82 u32 flags;
83} __packed;
84
85/**
86 * enum rpmsg_ns_flags - dynamic name service announcement flags
87 *
88 * @RPMSG_NS_CREATE: a new remote service was just created
89 * @RPMSG_NS_DESTROY: a known remote service was just destroyed
90 */
91enum rpmsg_ns_flags {
92 RPMSG_NS_CREATE = 0,
93 RPMSG_NS_DESTROY = 1,
94};
95
96#define RPMSG_ADDR_ANY 0xFFFFFFFF
97
98struct virtproc_info;
99
100/**
101 * rpmsg_channel - devices that belong to the rpmsg bus are called channels
102 * @vrp: the remote processor this channel belongs to
103 * @dev: the device struct
104 * @id: device id (used to match between rpmsg drivers and devices)
105 * @src: local address
106 * @dst: destination address
107 * @ept: the rpmsg endpoint of this channel
108 * @announce: if set, rpmsg will announce the creation/removal of this channel
109 */
110struct rpmsg_channel {
111 struct virtproc_info *vrp;
112 struct device dev;
113 struct rpmsg_device_id id;
114 u32 src;
115 u32 dst;
116 struct rpmsg_endpoint *ept;
117 bool announce;
118};
119
120typedef void (*rpmsg_rx_cb_t)(struct rpmsg_channel *, void *, int, void *, u32);
121
122/**
123 * struct rpmsg_endpoint - binds a local rpmsg address to its user
124 * @rpdev: rpmsg channel device
125 * @refcount: when this drops to zero, the ept is deallocated
126 * @cb: rx callback handler
127 * @cb_lock: must be taken before accessing/changing @cb
128 * @addr: local rpmsg address
129 * @priv: private data for the driver's use
130 *
131 * In essence, an rpmsg endpoint represents a listener on the rpmsg bus, as
132 * it binds an rpmsg address with an rx callback handler.
133 *
134 * Simple rpmsg drivers shouldn't use this struct directly, because
135 * things just work: every rpmsg driver provides an rx callback upon
136 * registering to the bus, and that callback is then bound to its rpmsg
137 * address when the driver is probed. When relevant inbound messages arrive
138 * (i.e. messages which their dst address equals to the src address of
139 * the rpmsg channel), the driver's handler is invoked to process it.
140 *
141 * More complicated drivers though, that do need to allocate additional rpmsg
142 * addresses, and bind them to different rx callbacks, must explicitly
143 * create additional endpoints by themselves (see rpmsg_create_ept()).
144 */
145struct rpmsg_endpoint {
146 struct rpmsg_channel *rpdev;
147 struct kref refcount;
148 rpmsg_rx_cb_t cb;
149 struct mutex cb_lock;
150 u32 addr;
151 void *priv;
152};
153
154/**
155 * struct rpmsg_driver - rpmsg driver struct
156 * @drv: underlying device driver
157 * @id_table: rpmsg ids serviced by this driver
158 * @probe: invoked when a matching rpmsg channel (i.e. device) is found
159 * @remove: invoked when the rpmsg channel is removed
160 * @callback: invoked when an inbound message is received on the channel
161 */
162struct rpmsg_driver {
163 struct device_driver drv;
164 const struct rpmsg_device_id *id_table;
165 int (*probe)(struct rpmsg_channel *dev);
166 void (*remove)(struct rpmsg_channel *dev);
167 void (*callback)(struct rpmsg_channel *, void *, int, void *, u32);
168};
169
170int register_rpmsg_device(struct rpmsg_channel *dev);
171void unregister_rpmsg_device(struct rpmsg_channel *dev);
172int register_rpmsg_driver(struct rpmsg_driver *drv);
173void unregister_rpmsg_driver(struct rpmsg_driver *drv);
174void rpmsg_destroy_ept(struct rpmsg_endpoint *);
175struct rpmsg_endpoint *rpmsg_create_ept(struct rpmsg_channel *,
176 rpmsg_rx_cb_t cb, void *priv, u32 addr);
177int
178rpmsg_send_offchannel_raw(struct rpmsg_channel *, u32, u32, void *, int, bool);
179
180/**
181 * rpmsg_send() - send a message across to the remote processor
182 * @rpdev: the rpmsg channel
183 * @data: payload of message
184 * @len: length of payload
185 *
186 * This function sends @data of length @len on the @rpdev channel.
187 * The message will be sent to the remote processor which the @rpdev
188 * channel belongs to, using @rpdev's source and destination addresses.
189 * In case there are no TX buffers available, the function will block until
190 * one becomes available, or a timeout of 15 seconds elapses. When the latter
191 * happens, -ERESTARTSYS is returned.
192 *
193 * Can only be called from process context (for now).
194 *
195 * Returns 0 on success and an appropriate error value on failure.
196 */
197static inline int rpmsg_send(struct rpmsg_channel *rpdev, void *data, int len)
198{
199 u32 src = rpdev->src, dst = rpdev->dst;
200
201 return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, true);
202}
203
204/**
205 * rpmsg_sendto() - send a message across to the remote processor, specify dst
206 * @rpdev: the rpmsg channel
207 * @data: payload of message
208 * @len: length of payload
209 * @dst: destination address
210 *
211 * This function sends @data of length @len to the remote @dst address.
212 * The message will be sent to the remote processor which the @rpdev
213 * channel belongs to, using @rpdev's source address.
214 * In case there are no TX buffers available, the function will block until
215 * one becomes available, or a timeout of 15 seconds elapses. When the latter
216 * happens, -ERESTARTSYS is returned.
217 *
218 * Can only be called from process context (for now).
219 *
220 * Returns 0 on success and an appropriate error value on failure.
221 */
222static inline
223int rpmsg_sendto(struct rpmsg_channel *rpdev, void *data, int len, u32 dst)
224{
225 u32 src = rpdev->src;
226
227 return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, true);
228}
229
230/**
231 * rpmsg_send_offchannel() - send a message using explicit src/dst addresses
232 * @rpdev: the rpmsg channel
233 * @src: source address
234 * @dst: destination address
235 * @data: payload of message
236 * @len: length of payload
237 *
238 * This function sends @data of length @len to the remote @dst address,
239 * and uses @src as the source address.
240 * The message will be sent to the remote processor which the @rpdev
241 * channel belongs to.
242 * In case there are no TX buffers available, the function will block until
243 * one becomes available, or a timeout of 15 seconds elapses. When the latter
244 * happens, -ERESTARTSYS is returned.
245 *
246 * Can only be called from process context (for now).
247 *
248 * Returns 0 on success and an appropriate error value on failure.
249 */
250static inline
251int rpmsg_send_offchannel(struct rpmsg_channel *rpdev, u32 src, u32 dst,
252 void *data, int len)
253{
254 return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, true);
255}
256
257/**
258 * rpmsg_send() - send a message across to the remote processor
259 * @rpdev: the rpmsg channel
260 * @data: payload of message
261 * @len: length of payload
262 *
263 * This function sends @data of length @len on the @rpdev channel.
264 * The message will be sent to the remote processor which the @rpdev
265 * channel belongs to, using @rpdev's source and destination addresses.
266 * In case there are no TX buffers available, the function will immediately
267 * return -ENOMEM without waiting until one becomes available.
268 *
269 * Can only be called from process context (for now).
270 *
271 * Returns 0 on success and an appropriate error value on failure.
272 */
273static inline
274int rpmsg_trysend(struct rpmsg_channel *rpdev, void *data, int len)
275{
276 u32 src = rpdev->src, dst = rpdev->dst;
277
278 return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, false);
279}
280
281/**
282 * rpmsg_sendto() - send a message across to the remote processor, specify dst
283 * @rpdev: the rpmsg channel
284 * @data: payload of message
285 * @len: length of payload
286 * @dst: destination address
287 *
288 * This function sends @data of length @len to the remote @dst address.
289 * The message will be sent to the remote processor which the @rpdev
290 * channel belongs to, using @rpdev's source address.
291 * In case there are no TX buffers available, the function will immediately
292 * return -ENOMEM without waiting until one becomes available.
293 *
294 * Can only be called from process context (for now).
295 *
296 * Returns 0 on success and an appropriate error value on failure.
297 */
298static inline
299int rpmsg_trysendto(struct rpmsg_channel *rpdev, void *data, int len, u32 dst)
300{
301 u32 src = rpdev->src;
302
303 return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, false);
304}
305
306/**
307 * rpmsg_send_offchannel() - send a message using explicit src/dst addresses
308 * @rpdev: the rpmsg channel
309 * @src: source address
310 * @dst: destination address
311 * @data: payload of message
312 * @len: length of payload
313 *
314 * This function sends @data of length @len to the remote @dst address,
315 * and uses @src as the source address.
316 * The message will be sent to the remote processor which the @rpdev
317 * channel belongs to.
318 * In case there are no TX buffers available, the function will immediately
319 * return -ENOMEM without waiting until one becomes available.
320 *
321 * Can only be called from process context (for now).
322 *
323 * Returns 0 on success and an appropriate error value on failure.
324 */
325static inline
326int rpmsg_trysend_offchannel(struct rpmsg_channel *rpdev, u32 src, u32 dst,
327 void *data, int len)
328{
329 return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, false);
330}
331
332#endif /* _LINUX_RPMSG_H */