xenbusb_front.c revision 214077
1214077Sgibbs/****************************************************************************** 2214077Sgibbs * Talks to Xen Store to figure out what devices we have. 3214077Sgibbs * 4214077Sgibbs * Copyright (C) 2009, 2010 Spectra Logic Corporation 5214077Sgibbs * Copyright (C) 2008 Doug Rabson 6214077Sgibbs * Copyright (C) 2005 Rusty Russell, IBM Corporation 7214077Sgibbs * Copyright (C) 2005 Mike Wray, Hewlett-Packard 8214077Sgibbs * Copyright (C) 2005 XenSource Ltd 9214077Sgibbs * 10214077Sgibbs * This file may be distributed separately from the Linux kernel, or 11214077Sgibbs * incorporated into other software packages, subject to the following license: 12214077Sgibbs * 13214077Sgibbs * Permission is hereby granted, free of charge, to any person obtaining a copy 14214077Sgibbs * of this source file (the "Software"), to deal in the Software without 15214077Sgibbs * restriction, including without limitation the rights to use, copy, modify, 16214077Sgibbs * merge, publish, distribute, sublicense, and/or sell copies of the Software, 17214077Sgibbs * and to permit persons to whom the Software is furnished to do so, subject to 18214077Sgibbs * the following conditions: 19214077Sgibbs * 20214077Sgibbs * The above copyright notice and this permission notice shall be included in 21214077Sgibbs * all copies or substantial portions of the Software. 22214077Sgibbs * 23214077Sgibbs * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 24214077Sgibbs * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 25214077Sgibbs * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 26214077Sgibbs * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 27214077Sgibbs * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 28214077Sgibbs * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS 29214077Sgibbs * IN THE SOFTWARE. 30214077Sgibbs */ 31214077Sgibbs 32214077Sgibbs/** 33214077Sgibbs * \file xenbusb_front.c 34214077Sgibbs * 35214077Sgibbs * XenBus management of the NewBus bus containing the frontend instances of 36214077Sgibbs * Xen split devices. 37214077Sgibbs */ 38214077Sgibbs#include <sys/cdefs.h> 39214077Sgibbs__FBSDID("$FreeBSD: head/sys/xen/xenbus/xenbusb_front.c 214077 2010-10-19 20:53:30Z gibbs $"); 40214077Sgibbs 41214077Sgibbs#include <sys/param.h> 42214077Sgibbs#include <sys/bus.h> 43214077Sgibbs#include <sys/kernel.h> 44214077Sgibbs#include <sys/lock.h> 45214077Sgibbs#include <sys/malloc.h> 46214077Sgibbs#include <sys/module.h> 47214077Sgibbs#include <sys/sbuf.h> 48214077Sgibbs#include <sys/sysctl.h> 49214077Sgibbs#include <sys/syslog.h> 50214077Sgibbs#include <sys/systm.h> 51214077Sgibbs#include <sys/sx.h> 52214077Sgibbs#include <sys/taskqueue.h> 53214077Sgibbs 54214077Sgibbs#include <machine/xen/xen-os.h> 55214077Sgibbs#include <machine/stdarg.h> 56214077Sgibbs 57214077Sgibbs#include <xen/gnttab.h> 58214077Sgibbs#include <xen/xenbus/xenbusvar.h> 59214077Sgibbs#include <xen/xenbus/xenbusb.h> 60214077Sgibbs 61214077Sgibbs 62214077Sgibbs/*------------------ Private Device Attachment Functions --------------------*/ 63214077Sgibbs/** 64214077Sgibbs * \brief Probe for the existance of the XenBus front bus. 65214077Sgibbs * 66214077Sgibbs * \param dev NewBus device_t for this XenBus front bus instance. 67214077Sgibbs * 68214077Sgibbs * \return Always returns 0 indicating success. 69214077Sgibbs */ 70214077Sgibbsstatic int 71214077Sgibbsxenbusb_front_probe(device_t dev) 72214077Sgibbs{ 73214077Sgibbs device_set_desc(dev, "Xen Frontend Devices"); 74214077Sgibbs 75214077Sgibbs return (0); 76214077Sgibbs} 77214077Sgibbs 78214077Sgibbs/** 79214077Sgibbs * \brief Attach the XenBus front bus. 80214077Sgibbs * 81214077Sgibbs * \param dev NewBus device_t for this XenBus front bus instance. 82214077Sgibbs * 83214077Sgibbs * \return On success, 0. Otherwise an errno value indicating the 84214077Sgibbs * type of failure. 85214077Sgibbs */ 86214077Sgibbsstatic int 87214077Sgibbsxenbusb_front_attach(device_t dev) 88214077Sgibbs{ 89214077Sgibbs return (xenbusb_attach(dev, "device", /*id_components*/1)); 90214077Sgibbs} 91214077Sgibbs 92214077Sgibbs/** 93214077Sgibbs * \brief Enumerate all devices of the given type on this bus. 94214077Sgibbs * 95214077Sgibbs * \param dev NewBus device_t for this XenBus front bus instance. 96214077Sgibbs * \param type String indicating the device sub-tree (e.g. "vfb", "vif") 97214077Sgibbs * to enumerate. 98214077Sgibbs * 99214077Sgibbs * \return On success, 0. Otherwise an errno value indicating the 100214077Sgibbs * type of failure. 101214077Sgibbs * 102214077Sgibbs * Devices that are found are entered into the NewBus hierarchy via 103214077Sgibbs * xenbusb_add_device(). xenbusb_add_device() ignores duplicate detects 104214077Sgibbs * and ignores duplicate devices, so it can be called unconditionally 105214077Sgibbs * for any device found in the XenStore. 106214077Sgibbs */ 107214077Sgibbsstatic int 108214077Sgibbsxenbusb_front_enumerate_type(device_t dev, const char *type) 109214077Sgibbs{ 110214077Sgibbs struct xenbusb_softc *xbs; 111214077Sgibbs const char **dir; 112214077Sgibbs unsigned int i, count; 113214077Sgibbs int error; 114214077Sgibbs 115214077Sgibbs xbs = device_get_softc(dev); 116214077Sgibbs error = xs_directory(XST_NIL, xbs->xbs_node, type, &count, &dir); 117214077Sgibbs if (error) 118214077Sgibbs return (error); 119214077Sgibbs for (i = 0; i < count; i++) 120214077Sgibbs xenbusb_add_device(dev, type, dir[i]); 121214077Sgibbs 122214077Sgibbs free(dir, M_XENSTORE); 123214077Sgibbs 124214077Sgibbs return (0); 125214077Sgibbs} 126214077Sgibbs 127214077Sgibbs/** 128214077Sgibbs * \brief Determine and store the XenStore path for the other end of 129214077Sgibbs * a split device whose local end is represented by ivars. 130214077Sgibbs * 131214077Sgibbs * If successful, the xd_otherend_path field of the child's instance 132214077Sgibbs * variables will be updated. 133214077Sgibbs * 134214077Sgibbs * \param dev NewBus device_t for this XenBus front bus instance. 135214077Sgibbs * \param ivars Instance variables from the XenBus child device for 136214077Sgibbs * which to perform this function. 137214077Sgibbs * 138214077Sgibbs * \return On success, 0. Otherwise an errno value indicating the 139214077Sgibbs * type of failure. 140214077Sgibbs */ 141214077Sgibbsstatic int 142214077Sgibbsxenbusb_front_get_otherend_node(device_t dev, struct xenbus_device_ivars *ivars) 143214077Sgibbs{ 144214077Sgibbs char *otherend_path; 145214077Sgibbs int error; 146214077Sgibbs 147214077Sgibbs if (ivars->xd_otherend_path != NULL) { 148214077Sgibbs free(ivars->xd_otherend_path, M_XENBUS); 149214077Sgibbs ivars->xd_otherend_path = NULL; 150214077Sgibbs } 151214077Sgibbs 152214077Sgibbs error = xs_gather(XST_NIL, ivars->xd_node, 153214077Sgibbs "backend-id", "%i", &ivars->xd_otherend_id, 154214077Sgibbs "backend", NULL, &otherend_path, 155214077Sgibbs NULL); 156214077Sgibbs 157214077Sgibbs if (error == 0) { 158214077Sgibbs ivars->xd_otherend_path = strdup(otherend_path, M_XENBUS); 159214077Sgibbs free(otherend_path, M_XENSTORE); 160214077Sgibbs } 161214077Sgibbs return (error); 162214077Sgibbs} 163214077Sgibbs 164214077Sgibbs/*-------------------- Private Device Attachment Data -----------------------*/ 165214077Sgibbsstatic device_method_t xenbusb_front_methods[] = { 166214077Sgibbs /* Device interface */ 167214077Sgibbs DEVMETHOD(device_identify, xenbusb_identify), 168214077Sgibbs DEVMETHOD(device_probe, xenbusb_front_probe), 169214077Sgibbs DEVMETHOD(device_attach, xenbusb_front_attach), 170214077Sgibbs DEVMETHOD(device_detach, bus_generic_detach), 171214077Sgibbs DEVMETHOD(device_shutdown, bus_generic_shutdown), 172214077Sgibbs DEVMETHOD(device_suspend, bus_generic_suspend), 173214077Sgibbs DEVMETHOD(device_resume, bus_generic_resume), 174214077Sgibbs 175214077Sgibbs /* Bus Interface */ 176214077Sgibbs DEVMETHOD(bus_print_child, xenbusb_print_child), 177214077Sgibbs DEVMETHOD(bus_read_ivar, xenbusb_read_ivar), 178214077Sgibbs DEVMETHOD(bus_write_ivar, xenbusb_write_ivar), 179214077Sgibbs DEVMETHOD(bus_alloc_resource, bus_generic_alloc_resource), 180214077Sgibbs DEVMETHOD(bus_release_resource, bus_generic_release_resource), 181214077Sgibbs DEVMETHOD(bus_activate_resource, bus_generic_activate_resource), 182214077Sgibbs DEVMETHOD(bus_deactivate_resource, bus_generic_deactivate_resource), 183214077Sgibbs 184214077Sgibbs /* XenBus Bus Interface */ 185214077Sgibbs DEVMETHOD(xenbusb_enumerate_type, xenbusb_front_enumerate_type), 186214077Sgibbs DEVMETHOD(xenbusb_get_otherend_node, xenbusb_front_get_otherend_node), 187214077Sgibbs { 0, 0 } 188214077Sgibbs}; 189214077Sgibbs 190214077SgibbsDEFINE_CLASS_0(xenbusb_front, xenbusb_front_driver, xenbusb_front_methods, 191214077Sgibbs sizeof(struct xenbusb_softc)); 192214077Sgibbsdevclass_t xenbusb_front_devclass; 193214077Sgibbs 194214077SgibbsDRIVER_MODULE(xenbusb_front, xenstore, xenbusb_front_driver, 195214077Sgibbs xenbusb_front_devclass, 0, 0); 196