freebsd-skq/sys/xen/xenbus/xenbusb.h
Conrad Meyer db4fcadf52 "Buses" is the preferred plural of "bus"
Replace archaic "busses" with modern form "buses."

Intentionally excluded:
* Old/random drivers I didn't recognize
  * Old hardware in general
* Use of "busses" in code as identifiers

No functional change.

http://grammarist.com/spelling/buses-busses/

PR:		216099
Reported by:	bltsrc at mail.ru
Sponsored by:	Dell EMC Isilon
2017-01-15 17:54:01 +00:00

299 lines
9.6 KiB
C

/*-
* Core definitions and data structures shareable across OS platforms.
*
* Copyright (c) 2010 Spectra Logic Corporation
* Copyright (C) 2008 Doug Rabson
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions, and the following disclaimer,
* without modification.
* 2. Redistributions in binary form must reproduce at minimum a disclaimer
* substantially similar to the "NO WARRANTY" disclaimer below
* ("Disclaimer") and any redistribution must be conditioned upon
* including a substantially similar Disclaimer requirement for further
* binary redistribution.
*
* NO WARRANTY
* 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 MERCHANTIBILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDERS OR CONTRIBUTORS BE LIABLE FOR 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 DAMAGES.
*
* $FreeBSD$
*/
#ifndef _XEN_XENBUS_XENBUSB_H
#define _XEN_XENBUS_XENBUSB_H
/**
* \file xenbusb.h
*
* Datastructures and function declarations for use in implementing
* bus attachements (e.g. frontend and backend device buses) for XenBus.
*/
/**
* Enumeration of state flag values for the xbs_flags field of
* the xenbusb_softc structure.
*/
typedef enum {
/** */
XBS_ATTACH_CH_ACTIVE = 0x01
} xenbusb_softc_flag;
/**
* \brief Container for all state needed to manage a Xenbus Bus
* attachment.
*/
struct xenbusb_softc {
/**
* XenStore watch used to monitor the subtree of the
* XenStore where devices for this bus attachment arrive
* and depart.
*/
struct xs_watch xbs_device_watch;
/** Mutex used to protect fields of the xenbusb_softc. */
struct mtx xbs_lock;
/** State flags. */
xenbusb_softc_flag xbs_flags;
/**
* A dedicated task for processing child arrival and
* departure events.
*/
struct task xbs_probe_children;
/**
* Config Hook used to block boot processing until
* XenBus devices complete their connection processing
* with other VMs.
*/
struct intr_config_hook xbs_attach_ch;
/**
* The number of children for this bus that are still
* in the connecting (to other VMs) state. This variable
* is used to determine when to release xbs_attach_ch.
*/
u_int xbs_connecting_children;
/** The NewBus device_t for this bus attachment. */
device_t xbs_dev;
/**
* The VM relative path to the XenStore subtree this
* bus attachment manages.
*/
const char *xbs_node;
/**
* The number of path components (strings separated by the '/'
* character) that make up the device ID on this bus.
*/
u_int xbs_id_components;
};
/**
* Enumeration of state flag values for the xbs_flags field of
* the xenbusb_softc structure.
*/
typedef enum {
/**
* This device is contributing to the xbs_connecting_children
* count of its parent bus.
*/
XDF_CONNECTING = 0x01
} xenbus_dev_flag;
/** Instance variables for devices on a XenBus bus. */
struct xenbus_device_ivars {
/**
* XenStore watch used to monitor the subtree of the
* XenStore where information about the otherend of
* the split Xen device this device instance represents.
*/
struct xs_watch xd_otherend_watch;
/**
* XenStore watch used to monitor the XenStore sub-tree
* associated with this device. This watch will fire
* for modifications that we make from our domain as
* well as for those made by the control domain.
*/
struct xs_watch xd_local_watch;
/** Sleepable lock used to protect instance data. */
struct sx xd_lock;
/** State flags. */
xenbus_dev_flag xd_flags;
/** The NewBus device_t for this XenBus device instance. */
device_t xd_dev;
/**
* The VM relative path to the XenStore subtree representing
* this VMs half of this device.
*/
char *xd_node;
/** The length of xd_node. */
int xd_node_len;
/** XenBus device type ("vbd", "vif", etc.). */
char *xd_type;
/**
* Cached version of <xd_node>/state node in the XenStore.
*/
enum xenbus_state xd_state;
/** The VM identifier of the other end of this split device. */
int xd_otherend_id;
/**
* The path to the subtree of the XenStore where information
* about the otherend of this split device instance.
*/
char *xd_otherend_path;
/** The length of xd_otherend_path. */
int xd_otherend_path_len;
};
/**
* \brief Identify instances of this device type in the system.
*
* \param driver The driver performing this identify action.
* \param parent The NewBus parent device for any devices this method adds.
*/
void xenbusb_identify(driver_t *driver __unused, device_t parent);
/**
* \brief Perform common XenBus bus attach processing.
*
* \param dev The NewBus device representing this XenBus bus.
* \param bus_node The XenStore path to the XenStore subtree for
* this XenBus bus.
* \param id_components The number of '/' separated path components that
* make up a unique device ID on this XenBus bus.
*
* \return On success, 0. Otherwise an errno value indicating the
* type of failure.
*
* Intiailizes the softc for this bus, installs an interrupt driven
* configuration hook to block boot processing until XenBus devices fully
* configure, performs an initial probe/attach of the bus, and registers
* a XenStore watch so we are notified when the bus topology changes.
*/
int xenbusb_attach(device_t dev, char *bus_node, u_int id_components);
/**
* \brief Perform common XenBus bus resume handling.
*
* \param dev The NewBus device representing this XenBus bus.
*
* \return On success, 0. Otherwise an errno value indicating the
* type of failure.
*/
int xenbusb_resume(device_t dev);
/**
* \brief Pretty-prints information about a child of a XenBus bus.
*
* \param dev The NewBus device representing this XenBus bus.
* \param child The NewBus device representing a child of dev%'s XenBus bus.
*
* \return On success, 0. Otherwise an errno value indicating the
* type of failure.
*/
int xenbusb_print_child(device_t dev, device_t child);
/**
* \brief Common XenBus child instance variable read access method.
*
* \param dev The NewBus device representing this XenBus bus.
* \param child The NewBus device representing a child of dev%'s XenBus bus.
* \param index The index of the instance variable to access.
* \param result The value of the instance variable accessed.
*
* \return On success, 0. Otherwise an errno value indicating the
* type of failure.
*/
int xenbusb_read_ivar(device_t dev, device_t child, int index,
uintptr_t *result);
/**
* \brief Common XenBus child instance variable write access method.
*
* \param dev The NewBus device representing this XenBus bus.
* \param child The NewBus device representing a child of dev%'s XenBus bus.
* \param index The index of the instance variable to access.
* \param value The new value to set in the instance variable accessed.
*
* \return On success, 0. Otherwise an errno value indicating the
* type of failure.
*/
int xenbusb_write_ivar(device_t dev, device_t child, int index,
uintptr_t value);
/**
* \brief Common XenBus method implementing responses to peer state changes.
*
* \param bus The XenBus bus parent of child.
* \param child The XenBus child whose peer stat has changed.
* \param state The current state of the peer.
*/
void xenbusb_otherend_changed(device_t bus, device_t child,
enum xenbus_state state);
/**
* \brief Common XenBus method implementing responses to local XenStore changes.
*
* \param bus The XenBus bus parent of child.
* \param child The XenBus child whose peer stat has changed.
* \param path The tree relative sub-path to the modified node. The empty
* string indicates the root of the tree was destroyed.
*/
void xenbusb_localend_changed(device_t bus, device_t child, const char *path);
/**
* \brief Attempt to add a XenBus device instance to this XenBus bus.
*
* \param dev The NewBus device representing this XenBus bus.
* \param type The device type being added (e.g. "vbd", "vif").
* \param id The device ID for this device.
*
* \return On success, 0. Otherwise an errno value indicating the
* type of failure. Failure indicates that either the
* path to this device no longer exists or insufficient
* information exists in the XenStore to create a new
* device.
*
* If successful, this routine will add a device_t with instance
* variable storage to the NewBus device topology. Probe/Attach
* processing is not performed by this routine, but must be scheduled
* via the xbs_probe_children task. This separation of responsibilities
* is required to avoid hanging up the XenStore event delivery thread
* with our probe/attach work in the event a device is added via
* a callback from the XenStore.
*/
int xenbusb_add_device(device_t dev, const char *type, const char *id);
#include "xenbusb_if.h"
#endif /* _XEN_XENBUS_XENBUSB_H */