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 39 #include <sys/param.h> 40 #include <sys/bus.h> 41 #include <sys/kernel.h> 42 #include <sys/lock.h> 43 #include <sys/malloc.h> 44 #include <sys/module.h> 45 #include <sys/sbuf.h> 46 #include <sys/sysctl.h> 47 #include <sys/syslog.h> 48 #include <sys/systm.h> 49 #include <sys/sx.h> 50 #include <sys/taskqueue.h> 51 52 #include <machine/stdarg.h> 53 54 #include <xen/xen-os.h> 55 #include <xen/gnttab.h> 56 #include <xen/xenbus/xenbusvar.h> 57 #include <xen/xenbus/xenbusb.h> 58 59 /*------------------ Private Device Attachment Functions --------------------*/ 60 /** 61 * \brief Probe for the existence of the XenBus front bus. 62 * 63 * \param dev NewBus device_t for this XenBus front bus instance. 64 * 65 * \return Always returns 0 indicating success. 66 */ 67 static int 68 xenbusb_front_probe(device_t dev) 69 { 70 device_set_desc(dev, "Xen Frontend Devices"); 71 72 return (0); 73 } 74 75 /** 76 * \brief Attach the XenBus front bus. 77 * 78 * \param dev NewBus device_t for this XenBus front bus instance. 79 * 80 * \return On success, 0. Otherwise an errno value indicating the 81 * type of failure. 82 */ 83 static int 84 xenbusb_front_attach(device_t dev) 85 { 86 return (xenbusb_attach(dev, "device", /*id_components*/1)); 87 } 88 89 /** 90 * \brief Enumerate all devices of the given type on this bus. 91 * 92 * \param dev NewBus device_t for this XenBus front bus instance. 93 * \param type String indicating the device sub-tree (e.g. "vfb", "vif") 94 * to enumerate. 95 * 96 * \return On success, 0. Otherwise an errno value indicating the 97 * type of failure. 98 * 99 * Devices that are found are entered into the NewBus hierarchy via 100 * xenbusb_add_device(). xenbusb_add_device() ignores duplicate detects 101 * and ignores duplicate devices, so it can be called unconditionally 102 * for any device found in the XenStore. 103 */ 104 static int 105 xenbusb_front_enumerate_type(device_t dev, const char *type) 106 { 107 struct xenbusb_softc *xbs; 108 const char **dir; 109 unsigned int i, count; 110 int error; 111 112 xbs = device_get_softc(dev); 113 error = xs_directory(XST_NIL, xbs->xbs_node, type, &count, &dir); 114 if (error) 115 return (error); 116 for (i = 0; i < count; i++) 117 xenbusb_add_device(dev, type, dir[i]); 118 119 free(dir, M_XENSTORE); 120 121 return (0); 122 } 123 124 /** 125 * \brief Determine and store the XenStore path for the other end of 126 * a split device whose local end is represented by ivars. 127 * 128 * If successful, the xd_otherend_path field of the child's instance 129 * variables will be updated. 130 * 131 * \param dev NewBus device_t for this XenBus front bus instance. 132 * \param ivars Instance variables from the XenBus child device for 133 * which to perform this function. 134 * 135 * \return On success, 0. Otherwise an errno value indicating the 136 * type of failure. 137 */ 138 static int 139 xenbusb_front_get_otherend_node(device_t dev, struct xenbus_device_ivars *ivars) 140 { 141 char *otherend_path; 142 int error; 143 144 if (ivars->xd_otherend_path != NULL) { 145 free(ivars->xd_otherend_path, M_XENBUS); 146 ivars->xd_otherend_path = NULL; 147 } 148 149 error = xs_gather(XST_NIL, ivars->xd_node, 150 "backend-id", "%i", &ivars->xd_otherend_id, 151 "backend", NULL, &otherend_path, 152 NULL); 153 154 if (error == 0) { 155 ivars->xd_otherend_path = strdup(otherend_path, M_XENBUS); 156 ivars->xd_otherend_path_len = strlen(otherend_path); 157 free(otherend_path, M_XENSTORE); 158 } 159 return (error); 160 } 161 162 /*-------------------- Private Device Attachment Data -----------------------*/ 163 static device_method_t xenbusb_front_methods[] = { 164 /* Device interface */ 165 DEVMETHOD(device_identify, xenbusb_identify), 166 DEVMETHOD(device_probe, xenbusb_front_probe), 167 DEVMETHOD(device_attach, xenbusb_front_attach), 168 DEVMETHOD(device_detach, bus_generic_detach), 169 DEVMETHOD(device_shutdown, bus_generic_shutdown), 170 DEVMETHOD(device_suspend, bus_generic_suspend), 171 DEVMETHOD(device_resume, xenbusb_resume), 172 173 /* Bus Interface */ 174 DEVMETHOD(bus_print_child, xenbusb_print_child), 175 DEVMETHOD(bus_read_ivar, xenbusb_read_ivar), 176 DEVMETHOD(bus_write_ivar, xenbusb_write_ivar), 177 DEVMETHOD(bus_alloc_resource, bus_generic_alloc_resource), 178 DEVMETHOD(bus_release_resource, bus_generic_release_resource), 179 DEVMETHOD(bus_activate_resource, bus_generic_activate_resource), 180 DEVMETHOD(bus_deactivate_resource, bus_generic_deactivate_resource), 181 182 /* XenBus Bus Interface */ 183 DEVMETHOD(xenbusb_enumerate_type, xenbusb_front_enumerate_type), 184 DEVMETHOD(xenbusb_get_otherend_node, xenbusb_front_get_otherend_node), 185 186 DEVMETHOD_END 187 }; 188 189 DEFINE_CLASS_0(xenbusb_front, xenbusb_front_driver, xenbusb_front_methods, 190 sizeof(struct xenbusb_softc)); 191 192 DRIVER_MODULE(xenbusb_front, xenstore, xenbusb_front_driver, 0, 0); 193