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 */ 58 struct 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 */ 79 struct 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 */ 91 enum rpmsg_ns_flags { 92 RPMSG_NS_CREATE = 0, 93 RPMSG_NS_DESTROY = 1, 94 }; 95 96 #define RPMSG_ADDR_ANY 0xFFFFFFFF 97 98 struct 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 */ 110 struct 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 }; 119 120 typedef 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 */ 145 struct 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 */ 162 struct 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 }; 169 170 int register_rpmsg_device(struct rpmsg_channel *dev); 171 void unregister_rpmsg_device(struct rpmsg_channel *dev); 172 int __register_rpmsg_driver(struct rpmsg_driver *drv, struct module *owner); 173 void unregister_rpmsg_driver(struct rpmsg_driver *drv); 174 void rpmsg_destroy_ept(struct rpmsg_endpoint *); 175 struct rpmsg_endpoint *rpmsg_create_ept(struct rpmsg_channel *, 176 rpmsg_rx_cb_t cb, void *priv, u32 addr); 177 int 178 rpmsg_send_offchannel_raw(struct rpmsg_channel *, u32, u32, void *, int, bool); 179 180 /* use a macro to avoid include chaining to get THIS_MODULE */ 181 #define register_rpmsg_driver(drv) \ 182 __register_rpmsg_driver(drv, THIS_MODULE) 183 184 /** 185 * rpmsg_send() - send a message across to the remote processor 186 * @rpdev: the rpmsg channel 187 * @data: payload of message 188 * @len: length of payload 189 * 190 * This function sends @data of length @len on the @rpdev channel. 191 * The message will be sent to the remote processor which the @rpdev 192 * channel belongs to, using @rpdev's source and destination addresses. 193 * In case there are no TX buffers available, the function will block until 194 * one becomes available, or a timeout of 15 seconds elapses. When the latter 195 * happens, -ERESTARTSYS is returned. 196 * 197 * Can only be called from process context (for now). 198 * 199 * Returns 0 on success and an appropriate error value on failure. 200 */ 201 static inline int rpmsg_send(struct rpmsg_channel *rpdev, void *data, int len) 202 { 203 u32 src = rpdev->src, dst = rpdev->dst; 204 205 return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, true); 206 } 207 208 /** 209 * rpmsg_sendto() - send a message across to the remote processor, specify dst 210 * @rpdev: the rpmsg channel 211 * @data: payload of message 212 * @len: length of payload 213 * @dst: destination address 214 * 215 * This function sends @data of length @len to the remote @dst address. 216 * The message will be sent to the remote processor which the @rpdev 217 * channel belongs to, using @rpdev's source address. 218 * In case there are no TX buffers available, the function will block until 219 * one becomes available, or a timeout of 15 seconds elapses. When the latter 220 * happens, -ERESTARTSYS is returned. 221 * 222 * Can only be called from process context (for now). 223 * 224 * Returns 0 on success and an appropriate error value on failure. 225 */ 226 static inline 227 int rpmsg_sendto(struct rpmsg_channel *rpdev, void *data, int len, u32 dst) 228 { 229 u32 src = rpdev->src; 230 231 return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, true); 232 } 233 234 /** 235 * rpmsg_send_offchannel() - send a message using explicit src/dst addresses 236 * @rpdev: the rpmsg channel 237 * @src: source address 238 * @dst: destination address 239 * @data: payload of message 240 * @len: length of payload 241 * 242 * This function sends @data of length @len to the remote @dst address, 243 * and uses @src as the source address. 244 * The message will be sent to the remote processor which the @rpdev 245 * channel belongs to. 246 * In case there are no TX buffers available, the function will block until 247 * one becomes available, or a timeout of 15 seconds elapses. When the latter 248 * happens, -ERESTARTSYS is returned. 249 * 250 * Can only be called from process context (for now). 251 * 252 * Returns 0 on success and an appropriate error value on failure. 253 */ 254 static inline 255 int rpmsg_send_offchannel(struct rpmsg_channel *rpdev, u32 src, u32 dst, 256 void *data, int len) 257 { 258 return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, true); 259 } 260 261 /** 262 * rpmsg_send() - send a message across to the remote processor 263 * @rpdev: the rpmsg channel 264 * @data: payload of message 265 * @len: length of payload 266 * 267 * This function sends @data of length @len on the @rpdev channel. 268 * The message will be sent to the remote processor which the @rpdev 269 * channel belongs to, using @rpdev's source and destination addresses. 270 * In case there are no TX buffers available, the function will immediately 271 * return -ENOMEM without waiting until one becomes available. 272 * 273 * Can only be called from process context (for now). 274 * 275 * Returns 0 on success and an appropriate error value on failure. 276 */ 277 static inline 278 int rpmsg_trysend(struct rpmsg_channel *rpdev, void *data, int len) 279 { 280 u32 src = rpdev->src, dst = rpdev->dst; 281 282 return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, false); 283 } 284 285 /** 286 * rpmsg_sendto() - send a message across to the remote processor, specify dst 287 * @rpdev: the rpmsg channel 288 * @data: payload of message 289 * @len: length of payload 290 * @dst: destination address 291 * 292 * This function sends @data of length @len to the remote @dst address. 293 * The message will be sent to the remote processor which the @rpdev 294 * channel belongs to, using @rpdev's source address. 295 * In case there are no TX buffers available, the function will immediately 296 * return -ENOMEM without waiting until one becomes available. 297 * 298 * Can only be called from process context (for now). 299 * 300 * Returns 0 on success and an appropriate error value on failure. 301 */ 302 static inline 303 int rpmsg_trysendto(struct rpmsg_channel *rpdev, void *data, int len, u32 dst) 304 { 305 u32 src = rpdev->src; 306 307 return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, false); 308 } 309 310 /** 311 * rpmsg_send_offchannel() - send a message using explicit src/dst addresses 312 * @rpdev: the rpmsg channel 313 * @src: source address 314 * @dst: destination address 315 * @data: payload of message 316 * @len: length of payload 317 * 318 * This function sends @data of length @len to the remote @dst address, 319 * and uses @src as the source address. 320 * The message will be sent to the remote processor which the @rpdev 321 * channel belongs to. 322 * In case there are no TX buffers available, the function will immediately 323 * return -ENOMEM without waiting until one becomes available. 324 * 325 * Can only be called from process context (for now). 326 * 327 * Returns 0 on success and an appropriate error value on failure. 328 */ 329 static inline 330 int rpmsg_trysend_offchannel(struct rpmsg_channel *rpdev, u32 src, u32 dst, 331 void *data, int len) 332 { 333 return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, false); 334 } 335 336 #endif /* _LINUX_RPMSG_H */ 337