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Diffstat (limited to 'kernel/include/linux/rpmsg.h')
| -rw-r--r-- | kernel/include/linux/rpmsg.h | 332 |
1 files changed, 332 insertions, 0 deletions
diff --git a/kernel/include/linux/rpmsg.h b/kernel/include/linux/rpmsg.h new file mode 100644 index 000000000..82a673905 --- /dev/null +++ b/kernel/include/linux/rpmsg.h @@ -0,0 +1,332 @@ +/* + * 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 <linux/types.h> +#include <linux/device.h> +#include <linux/mod_devicetable.h> +#include <linux/kref.h> +#include <linux/mutex.h> + +/* 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 */ |