/* * Remote processor messaging * * Copyright (C) 2011 Texas Instruments, Inc. * Copyright (C) 2011 Google, Inc. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * * Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * * Neither the name Texas Instruments nor the names of its * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #ifndef _LINUX_RPMSG_H #define _LINUX_RPMSG_H #include #include #include #include #include /* The feature bitmap for virtio rpmsg */ #define VIRTIO_RPMSG_F_NS 0 /* RP supports name service notifications */ /** * struct rpmsg_hdr - common header for all rpmsg messages * @src: source address * @dst: destination address * @reserved: reserved for future use * @len: length of payload (in bytes) * @flags: message flags * @data: @len bytes of message payload data * * Every message sent(/received) on the rpmsg bus begins with this header. */ struct rpmsg_hdr { u32 src; u32 dst; u32 reserved; u16 len; u16 flags; u8 data[0]; } __packed; /** * struct rpmsg_ns_msg - dynamic name service announcement message * @name: name of remote service that is published * @addr: address of remote service that is published * @flags: indicates whether service is created or destroyed * * This message is sent across to publish a new service, or announce * about its removal. When we receive these messages, an appropriate * rpmsg channel (i.e device) is created/destroyed. In turn, the ->probe() * or ->remove() handler of the appropriate rpmsg driver will be invoked * (if/as-soon-as one is registered). */ struct rpmsg_ns_msg { char name[RPMSG_NAME_SIZE]; u32 addr; u32 flags; } __packed; /** * enum rpmsg_ns_flags - dynamic name service announcement flags * * @RPMSG_NS_CREATE: a new remote service was just created * @RPMSG_NS_DESTROY: a known remote service was just destroyed */ enum rpmsg_ns_flags { RPMSG_NS_CREATE = 0, RPMSG_NS_DESTROY = 1, }; #define RPMSG_ADDR_ANY 0xFFFFFFFF struct virtproc_info; /** * rpmsg_channel - devices that belong to the rpmsg bus are called channels * @vrp: the remote processor this channel belongs to * @dev: the device struct * @id: device id (used to match between rpmsg drivers and devices) * @src: local address * @dst: destination address * @ept: the rpmsg endpoint of this channel * @announce: if set, rpmsg will announce the creation/removal of this channel */ struct rpmsg_channel { struct virtproc_info *vrp; struct device dev; struct rpmsg_device_id id; u32 src; u32 dst; struct rpmsg_endpoint *ept; bool announce; }; typedef void (*rpmsg_rx_cb_t)(struct rpmsg_channel *, void *, int, void *, u32); /** * struct rpmsg_endpoint - binds a local rpmsg address to its user * @rpdev: rpmsg channel device * @refcount: when this drops to zero, the ept is deallocated * @cb: rx callback handler * @cb_lock: must be taken before accessing/changing @cb * @addr: local rpmsg address * @priv: private data for the driver's use * * In essence, an rpmsg endpoint represents a listener on the rpmsg bus, as * it binds an rpmsg address with an rx callback handler. * * Simple rpmsg drivers shouldn't use this struct directly, because * things just work: every rpmsg driver provides an rx callback upon * registering to the bus, and that callback is then bound to its rpmsg * address when the driver is probed. When relevant inbound messages arrive * (i.e. messages which their dst address equals to the src address of * the rpmsg channel), the driver's handler is invoked to process it. * * More complicated drivers though, that do need to allocate additional rpmsg * addresses, and bind them to different rx callbacks, must explicitly * create additional endpoints by themselves (see rpmsg_create_ept()). */ struct rpmsg_endpoint { struct rpmsg_channel *rpdev; struct kref refcount; rpmsg_rx_cb_t cb; struct mutex cb_lock; u32 addr; void *priv; }; /** * struct rpmsg_driver - rpmsg driver struct * @drv: underlying device driver * @id_table: rpmsg ids serviced by this driver * @probe: invoked when a matching rpmsg channel (i.e. device) is found * @remove: invoked when the rpmsg channel is removed * @callback: invoked when an inbound message is received on the channel */ struct rpmsg_driver { struct device_driver drv; const struct rpmsg_device_id *id_table; int (*probe)(struct rpmsg_channel *dev); void (*remove)(struct rpmsg_channel *dev); void (*callback)(struct rpmsg_channel *, void *, int, void *, u32); }; int register_rpmsg_device(struct rpmsg_channel *dev); void unregister_rpmsg_device(struct rpmsg_channel *dev); int register_rpmsg_driver(struct rpmsg_driver *drv); void unregister_rpmsg_driver(struct rpmsg_driver *drv); void rpmsg_destroy_ept(struct rpmsg_endpoint *); struct rpmsg_endpoint *rpmsg_create_ept(struct rpmsg_channel *, rpmsg_rx_cb_t cb, void *priv, u32 addr); int rpmsg_send_offchannel_raw(struct rpmsg_channel *, u32, u32, void *, int, bool); /** * rpmsg_send() - send a message across to the remote processor * @rpdev: the rpmsg channel * @data: payload of message * @len: length of payload * * This function sends @data of length @len on the @rpdev channel. * The message will be sent to the remote processor which the @rpdev * channel belongs to, using @rpdev's source and destination addresses. * In case there are no TX buffers available, the function will block until * one becomes available, or a timeout of 15 seconds elapses. When the latter * happens, -ERESTARTSYS is returned. * * Can only be called from process context (for now). * * Returns 0 on success and an appropriate error value on failure. */ static inline int rpmsg_send(struct rpmsg_channel *rpdev, void *data, int len) { u32 src = rpdev->src, dst = rpdev->dst; return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, true); } /** * rpmsg_sendto() - send a message across to the remote processor, specify dst * @rpdev: the rpmsg channel * @data: payload of message * @len: length of payload * @dst: destination address * * This function sends @data of length @len to the remote @dst address. * The message will be sent to the remote processor which the @rpdev * channel belongs to, using @rpdev's source address. * In case there are no TX buffers available, the function will block until * one becomes available, or a timeout of 15 seconds elapses. When the latter * happens, -ERESTARTSYS is returned. * * Can only be called from process context (for now). * * Returns 0 on success and an appropriate error value on failure. */ static inline int rpmsg_sendto(struct rpmsg_channel *rpdev, void *data, int len, u32 dst) { u32 src = rpdev->src; return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, true); } /** * rpmsg_send_offchannel() - send a message using explicit src/dst addresses * @rpdev: the rpmsg channel * @src: source address * @dst: destination address * @data: payload of message * @len: length of payload * * This function sends @data of length @len to the remote @dst address, * and uses @src as the source address. * The message will be sent to the remote processor which the @rpdev * channel belongs to. * In case there are no TX buffers available, the function will block until * one becomes available, or a timeout of 15 seconds elapses. When the latter * happens, -ERESTARTSYS is returned. * * Can only be called from process context (for now). * * Returns 0 on success and an appropriate error value on failure. */ static inline int rpmsg_send_offchannel(struct rpmsg_channel *rpdev, u32 src, u32 dst, void *data, int len) { return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, true); } /** * rpmsg_send() - send a message across to the remote processor * @rpdev: the rpmsg channel * @data: payload of message * @len: length of payload * * This function sends @data of length @len on the @rpdev channel. * The message will be sent to the remote processor which the @rpdev * channel belongs to, using @rpdev's source and destination addresses. * In case there are no TX buffers available, the function will immediately * return -ENOMEM without waiting until one becomes available. * * Can only be called from process context (for now). * * Returns 0 on success and an appropriate error value on failure. */ static inline int rpmsg_trysend(struct rpmsg_channel *rpdev, void *data, int len) { u32 src = rpdev->src, dst = rpdev->dst; return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, false); } /** * rpmsg_sendto() - send a message across to the remote processor, specify dst * @rpdev: the rpmsg channel * @data: payload of message * @len: length of payload * @dst: destination address * * This function sends @data of length @len to the remote @dst address. * The message will be sent to the remote processor which the @rpdev * channel belongs to, using @rpdev's source address. * In case there are no TX buffers available, the function will immediately * return -ENOMEM without waiting until one becomes available. * * Can only be called from process context (for now). * * Returns 0 on success and an appropriate error value on failure. */ static inline int rpmsg_trysendto(struct rpmsg_channel *rpdev, void *data, int len, u32 dst) { u32 src = rpdev->src; return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, false); } /** * rpmsg_send_offchannel() - send a message using explicit src/dst addresses * @rpdev: the rpmsg channel * @src: source address * @dst: destination address * @data: payload of message * @len: length of payload * * This function sends @data of length @len to the remote @dst address, * and uses @src as the source address. * The message will be sent to the remote processor which the @rpdev * channel belongs to. * In case there are no TX buffers available, the function will immediately * return -ENOMEM without waiting until one becomes available. * * Can only be called from process context (for now). * * Returns 0 on success and an appropriate error value on failure. */ static inline int rpmsg_trysend_offchannel(struct rpmsg_channel *rpdev, u32 src, u32 dst, void *data, int len) { return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, false); } #endif /* _LINUX_RPMSG_H */