1/*- 2 * Core definitions and data structures shareable across OS platforms. 3 * 4 * SPDX-License-Identifier: BSD-2-Clause 5 * 6 * Copyright (c) 2010 Spectra Logic Corporation 7 * Copyright (C) 2008 Doug Rabson 8 * All rights reserved. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions, and the following disclaimer, 15 * without modification. 16 * 2. Redistributions in binary form must reproduce at minimum a disclaimer 17 * substantially similar to the "NO WARRANTY" disclaimer below 18 * ("Disclaimer") and any redistribution must be conditioned upon 19 * including a substantially similar Disclaimer requirement for further 20 * binary redistribution. 21 * 22 * NO WARRANTY 23 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 24 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 25 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR 26 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 27 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 31 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 32 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 33 * POSSIBILITY OF SUCH DAMAGES. 34 */ 35#ifndef _XEN_XENBUS_XENBUSB_H 36#define _XEN_XENBUS_XENBUSB_H 37 38/** 39 * \file xenbusb.h 40 * 41 * Datastructures and function declarations for use in implementing 42 * bus attachements (e.g. frontend and backend device buses) for XenBus. 43 */ 44 45/** 46 * Enumeration of state flag values for the xbs_flags field of 47 * the xenbusb_softc structure. 48 */ 49typedef enum { 50 /** */ 51 XBS_ATTACH_CH_ACTIVE = 0x01 52} xenbusb_softc_flag; 53 54/** 55 * \brief Container for all state needed to manage a Xenbus Bus 56 * attachment. 57 */ 58struct xenbusb_softc { 59 /** 60 * XenStore watch used to monitor the subtree of the 61 * XenStore where devices for this bus attachment arrive 62 * and depart. 63 */ 64 struct xs_watch xbs_device_watch; 65 66 /** Mutex used to protect fields of the xenbusb_softc. */ 67 struct mtx xbs_lock; 68 69 /** State flags. */ 70 xenbusb_softc_flag xbs_flags; 71 72 /** 73 * A dedicated task for processing child arrival and 74 * departure events. 75 */ 76 struct task xbs_probe_children; 77 78 /** 79 * Config Hook used to block boot processing until 80 * XenBus devices complete their connection processing 81 * with other VMs. 82 */ 83 struct intr_config_hook xbs_attach_ch; 84 85 /** 86 * The number of children for this bus that are still 87 * in the connecting (to other VMs) state. This variable 88 * is used to determine when to release xbs_attach_ch. 89 */ 90 u_int xbs_connecting_children; 91 92 /** The NewBus device_t for this bus attachment. */ 93 device_t xbs_dev; 94 95 /** 96 * The VM relative path to the XenStore subtree this 97 * bus attachment manages. 98 */ 99 const char *xbs_node; 100 101 /** 102 * The number of path components (strings separated by the '/' 103 * character) that make up the device ID on this bus. 104 */ 105 u_int xbs_id_components; 106}; 107 108/** 109 * Enumeration of state flag values for the xbs_flags field of 110 * the xenbusb_softc structure. 111 */ 112typedef enum { 113 /** 114 * This device is contributing to the xbs_connecting_children 115 * count of its parent bus. 116 */ 117 XDF_CONNECTING = 0x01 118} xenbus_dev_flag; 119 120/** Instance variables for devices on a XenBus bus. */ 121struct xenbus_device_ivars { 122 /** 123 * XenStore watch used to monitor the subtree of the 124 * XenStore where information about the otherend of 125 * the split Xen device this device instance represents. 126 */ 127 struct xs_watch xd_otherend_watch; 128 129 /** 130 * XenStore watch used to monitor the XenStore sub-tree 131 * associated with this device. This watch will fire 132 * for modifications that we make from our domain as 133 * well as for those made by the control domain. 134 */ 135 struct xs_watch xd_local_watch; 136 137 /** Sleepable lock used to protect instance data. */ 138 struct sx xd_lock; 139 140 /** State flags. */ 141 xenbus_dev_flag xd_flags; 142 143 /** The NewBus device_t for this XenBus device instance. */ 144 device_t xd_dev; 145 146 /** 147 * The VM relative path to the XenStore subtree representing 148 * this VMs half of this device. 149 */ 150 char *xd_node; 151 152 /** The length of xd_node. */ 153 int xd_node_len; 154 155 /** XenBus device type ("vbd", "vif", etc.). */ 156 char *xd_type; 157 158 /** 159 * Cached version of <xd_node>/state node in the XenStore. 160 */ 161 enum xenbus_state xd_state; 162 163 /** The VM identifier of the other end of this split device. */ 164 int xd_otherend_id; 165 166 /** 167 * The path to the subtree of the XenStore where information 168 * about the otherend of this split device instance. 169 */ 170 char *xd_otherend_path; 171 172 /** The length of xd_otherend_path. */ 173 int xd_otherend_path_len; 174}; 175 176/** 177 * \brief Identify instances of this device type in the system. 178 * 179 * \param driver The driver performing this identify action. 180 * \param parent The NewBus parent device for any devices this method adds. 181 */ 182void xenbusb_identify(driver_t *driver __unused, device_t parent); 183 184/** 185 * \brief Perform common XenBus bus attach processing. 186 * 187 * \param dev The NewBus device representing this XenBus bus. 188 * \param bus_node The XenStore path to the XenStore subtree for 189 * this XenBus bus. 190 * \param id_components The number of '/' separated path components that 191 * make up a unique device ID on this XenBus bus. 192 * 193 * \return On success, 0. Otherwise an errno value indicating the 194 * type of failure. 195 * 196 * Intiailizes the softc for this bus, installs an interrupt driven 197 * configuration hook to block boot processing until XenBus devices fully 198 * configure, performs an initial probe/attach of the bus, and registers 199 * a XenStore watch so we are notified when the bus topology changes. 200 */ 201int xenbusb_attach(device_t dev, char *bus_node, u_int id_components); 202 203/** 204 * \brief Perform common XenBus bus resume handling. 205 * 206 * \param dev The NewBus device representing this XenBus bus. 207 * 208 * \return On success, 0. Otherwise an errno value indicating the 209 * type of failure. 210 */ 211int xenbusb_resume(device_t dev); 212 213/** 214 * \brief Pretty-prints information about a child of a XenBus bus. 215 * 216 * \param dev The NewBus device representing this XenBus bus. 217 * \param child The NewBus device representing a child of dev%'s XenBus bus. 218 * 219 * \return On success, 0. Otherwise an errno value indicating the 220 * type of failure. 221 */ 222int xenbusb_print_child(device_t dev, device_t child); 223 224/** 225 * \brief Common XenBus child instance variable read access method. 226 * 227 * \param dev The NewBus device representing this XenBus bus. 228 * \param child The NewBus device representing a child of dev%'s XenBus bus. 229 * \param index The index of the instance variable to access. 230 * \param result The value of the instance variable accessed. 231 * 232 * \return On success, 0. Otherwise an errno value indicating the 233 * type of failure. 234 */ 235int xenbusb_read_ivar(device_t dev, device_t child, int index, 236 uintptr_t *result); 237 238/** 239 * \brief Common XenBus child instance variable write access method. 240 * 241 * \param dev The NewBus device representing this XenBus bus. 242 * \param child The NewBus device representing a child of dev%'s XenBus bus. 243 * \param index The index of the instance variable to access. 244 * \param value The new value to set in the instance variable accessed. 245 * 246 * \return On success, 0. Otherwise an errno value indicating the 247 * type of failure. 248 */ 249int xenbusb_write_ivar(device_t dev, device_t child, int index, 250 uintptr_t value); 251 252/** 253 * \brief Common XenBus method implementing responses to peer state changes. 254 * 255 * \param bus The XenBus bus parent of child. 256 * \param child The XenBus child whose peer stat has changed. 257 * \param state The current state of the peer. 258 */ 259void xenbusb_otherend_changed(device_t bus, device_t child, 260 enum xenbus_state state); 261 262/** 263 * \brief Common XenBus method implementing responses to local XenStore changes. 264 * 265 * \param bus The XenBus bus parent of child. 266 * \param child The XenBus child whose peer stat has changed. 267 * \param path The tree relative sub-path to the modified node. The empty 268 * string indicates the root of the tree was destroyed. 269 */ 270void xenbusb_localend_changed(device_t bus, device_t child, const char *path); 271 272/** 273 * \brief Attempt to add a XenBus device instance to this XenBus bus. 274 * 275 * \param dev The NewBus device representing this XenBus bus. 276 * \param type The device type being added (e.g. "vbd", "vif"). 277 * \param id The device ID for this device. 278 * 279 * \return On success, 0. Otherwise an errno value indicating the 280 * type of failure. Failure indicates that either the 281 * path to this device no longer exists or insufficient 282 * information exists in the XenStore to create a new 283 * device. 284 * 285 * If successful, this routine will add a device_t with instance 286 * variable storage to the NewBus device topology. Probe/Attach 287 * processing is not performed by this routine, but must be scheduled 288 * via the xbs_probe_children task. This separation of responsibilities 289 * is required to avoid hanging up the XenStore event delivery thread 290 * with our probe/attach work in the event a device is added via 291 * a callback from the XenStore. 292 */ 293int xenbusb_add_device(device_t dev, const char *type, const char *id); 294 295#include "xenbusb_if.h" 296 297#endif /* _XEN_XENBUS_XENBUSB_H */ 298