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