1 /****************************************************************************** 2 * Talks to Xen Store to figure out what devices we have. 3 * 4 * Copyright (C) 2009, 2010 Spectra Logic Corporation 5 * Copyright (C) 2008 Doug Rabson 6 * Copyright (C) 2005 Rusty Russell, IBM Corporation 7 * Copyright (C) 2005 Mike Wray, Hewlett-Packard 8 * Copyright (C) 2005 XenSource Ltd 9 * 10 * This file may be distributed separately from the Linux kernel, or 11 * incorporated into other software packages, subject to the following license: 12 * 13 * Permission is hereby granted, free of charge, to any person obtaining a copy 14 * of this source file (the "Software"), to deal in the Software without 15 * restriction, including without limitation the rights to use, copy, modify, 16 * merge, publish, distribute, sublicense, and/or sell copies of the Software, 17 * and to permit persons to whom the Software is furnished to do so, subject to 18 * the following conditions: 19 * 20 * The above copyright notice and this permission notice shall be included in 21 * all copies or substantial portions of the Software. 22 * 23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 24 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 25 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 26 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 27 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 28 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS 29 * IN THE SOFTWARE. 30 */ 31 32 /** 33 * \file xenbusb_front.c 34 * 35 * XenBus management of the NewBus bus containing the frontend instances of 36 * Xen split devices. 37 */ 38 #include <sys/cdefs.h> 39 __FBSDID("$FreeBSD$"); 40 41 #include <sys/param.h> 42 #include <sys/bus.h> 43 #include <sys/kernel.h> 44 #include <sys/lock.h> 45 #include <sys/malloc.h> 46 #include <sys/module.h> 47 #include <sys/sbuf.h> 48 #include <sys/sysctl.h> 49 #include <sys/syslog.h> 50 #include <sys/systm.h> 51 #include <sys/sx.h> 52 #include <sys/taskqueue.h> 53 54 #include <machine/stdarg.h> 55 56 #include <xen/xen-os.h> 57 #include <xen/gnttab.h> 58 #include <xen/xenbus/xenbusvar.h> 59 #include <xen/xenbus/xenbusb.h> 60 61 /*------------------ Private Device Attachment Functions --------------------*/ 62 /** 63 * \brief Probe for the existance of the XenBus front bus. 64 * 65 * \param dev NewBus device_t for this XenBus front bus instance. 66 * 67 * \return Always returns 0 indicating success. 68 */ 69 static int 70 xenbusb_front_probe(device_t dev) 71 { 72 device_set_desc(dev, "Xen Frontend Devices"); 73 74 return (0); 75 } 76 77 /** 78 * \brief Attach the XenBus front bus. 79 * 80 * \param dev NewBus device_t for this XenBus front bus instance. 81 * 82 * \return On success, 0. Otherwise an errno value indicating the 83 * type of failure. 84 */ 85 static int 86 xenbusb_front_attach(device_t dev) 87 { 88 return (xenbusb_attach(dev, "device", /*id_components*/1)); 89 } 90 91 /** 92 * \brief Enumerate all devices of the given type on this bus. 93 * 94 * \param dev NewBus device_t for this XenBus front bus instance. 95 * \param type String indicating the device sub-tree (e.g. "vfb", "vif") 96 * to enumerate. 97 * 98 * \return On success, 0. Otherwise an errno value indicating the 99 * type of failure. 100 * 101 * Devices that are found are entered into the NewBus hierarchy via 102 * xenbusb_add_device(). xenbusb_add_device() ignores duplicate detects 103 * and ignores duplicate devices, so it can be called unconditionally 104 * for any device found in the XenStore. 105 */ 106 static int 107 xenbusb_front_enumerate_type(device_t dev, const char *type) 108 { 109 struct xenbusb_softc *xbs; 110 const char **dir; 111 unsigned int i, count; 112 int error; 113 114 xbs = device_get_softc(dev); 115 error = xs_directory(XST_NIL, xbs->xbs_node, type, &count, &dir); 116 if (error) 117 return (error); 118 for (i = 0; i < count; i++) 119 xenbusb_add_device(dev, type, dir[i]); 120 121 free(dir, M_XENSTORE); 122 123 return (0); 124 } 125 126 /** 127 * \brief Determine and store the XenStore path for the other end of 128 * a split device whose local end is represented by ivars. 129 * 130 * If successful, the xd_otherend_path field of the child's instance 131 * variables will be updated. 132 * 133 * \param dev NewBus device_t for this XenBus front bus instance. 134 * \param ivars Instance variables from the XenBus child device for 135 * which to perform this function. 136 * 137 * \return On success, 0. Otherwise an errno value indicating the 138 * type of failure. 139 */ 140 static int 141 xenbusb_front_get_otherend_node(device_t dev, struct xenbus_device_ivars *ivars) 142 { 143 char *otherend_path; 144 int error; 145 146 if (ivars->xd_otherend_path != NULL) { 147 free(ivars->xd_otherend_path, M_XENBUS); 148 ivars->xd_otherend_path = NULL; 149 } 150 151 error = xs_gather(XST_NIL, ivars->xd_node, 152 "backend-id", "%i", &ivars->xd_otherend_id, 153 "backend", NULL, &otherend_path, 154 NULL); 155 156 if (error == 0) { 157 ivars->xd_otherend_path = strdup(otherend_path, M_XENBUS); 158 ivars->xd_otherend_path_len = strlen(otherend_path); 159 free(otherend_path, M_XENSTORE); 160 } 161 return (error); 162 } 163 164 /*-------------------- Private Device Attachment Data -----------------------*/ 165 static device_method_t xenbusb_front_methods[] = { 166 /* Device interface */ 167 DEVMETHOD(device_identify, xenbusb_identify), 168 DEVMETHOD(device_probe, xenbusb_front_probe), 169 DEVMETHOD(device_attach, xenbusb_front_attach), 170 DEVMETHOD(device_detach, bus_generic_detach), 171 DEVMETHOD(device_shutdown, bus_generic_shutdown), 172 DEVMETHOD(device_suspend, bus_generic_suspend), 173 DEVMETHOD(device_resume, xenbusb_resume), 174 175 /* Bus Interface */ 176 DEVMETHOD(bus_print_child, xenbusb_print_child), 177 DEVMETHOD(bus_read_ivar, xenbusb_read_ivar), 178 DEVMETHOD(bus_write_ivar, xenbusb_write_ivar), 179 DEVMETHOD(bus_alloc_resource, bus_generic_alloc_resource), 180 DEVMETHOD(bus_release_resource, bus_generic_release_resource), 181 DEVMETHOD(bus_activate_resource, bus_generic_activate_resource), 182 DEVMETHOD(bus_deactivate_resource, bus_generic_deactivate_resource), 183 184 /* XenBus Bus Interface */ 185 DEVMETHOD(xenbusb_enumerate_type, xenbusb_front_enumerate_type), 186 DEVMETHOD(xenbusb_get_otherend_node, xenbusb_front_get_otherend_node), 187 { 0, 0 } 188 }; 189 190 DEFINE_CLASS_0(xenbusb_front, xenbusb_front_driver, xenbusb_front_methods, 191 sizeof(struct xenbusb_softc)); 192 devclass_t xenbusb_front_devclass; 193 194 DRIVER_MODULE(xenbusb_front, xenstore, xenbusb_front_driver, 195 xenbusb_front_devclass, 0, 0); 196