/****************************************************************************** * Talks to Xen Store to figure out what devices we have. * * Copyright (C) 2009, 2010 Spectra Logic Corporation * Copyright (C) 2008 Doug Rabson * Copyright (C) 2005 Rusty Russell, IBM Corporation * Copyright (C) 2005 Mike Wray, Hewlett-Packard * Copyright (C) 2005 XenSource Ltd * * This file may be distributed separately from the Linux kernel, or * incorporated into other software packages, subject to the following license: * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this source file (the "Software"), to deal in the Software without * restriction, including without limitation the rights to use, copy, modify, * merge, publish, distribute, sublicense, and/or sell copies of the Software, * and to permit persons to whom the Software is furnished to do so, subject to * the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS * IN THE SOFTWARE. */ /** * \file xenbusb_front.c * * XenBus management of the NewBus bus containing the frontend instances of * Xen split devices. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /*------------------ Private Device Attachment Functions --------------------*/ /** * \brief Probe for the existence of the XenBus front bus. * * \param dev NewBus device_t for this XenBus front bus instance. * * \return Always returns 0 indicating success. */ static int xenbusb_front_probe(device_t dev) { device_set_desc(dev, "Xen Frontend Devices"); return (0); } /** * \brief Attach the XenBus front bus. * * \param dev NewBus device_t for this XenBus front bus instance. * * \return On success, 0. Otherwise an errno value indicating the * type of failure. */ static int xenbusb_front_attach(device_t dev) { return (xenbusb_attach(dev, "device", /*id_components*/1)); } /** * \brief Enumerate all devices of the given type on this bus. * * \param dev NewBus device_t for this XenBus front bus instance. * \param type String indicating the device sub-tree (e.g. "vfb", "vif") * to enumerate. * * \return On success, 0. Otherwise an errno value indicating the * type of failure. * * Devices that are found are entered into the NewBus hierarchy via * xenbusb_add_device(). xenbusb_add_device() ignores duplicate detects * and ignores duplicate devices, so it can be called unconditionally * for any device found in the XenStore. */ static int xenbusb_front_enumerate_type(device_t dev, const char *type) { struct xenbusb_softc *xbs; const char **dir; unsigned int i, count; int error; xbs = device_get_softc(dev); error = xs_directory(XST_NIL, xbs->xbs_node, type, &count, &dir); if (error) return (error); for (i = 0; i < count; i++) xenbusb_add_device(dev, type, dir[i]); free(dir, M_XENSTORE); return (0); } /** * \brief Determine and store the XenStore path for the other end of * a split device whose local end is represented by ivars. * * If successful, the xd_otherend_path field of the child's instance * variables will be updated. * * \param dev NewBus device_t for this XenBus front bus instance. * \param ivars Instance variables from the XenBus child device for * which to perform this function. * * \return On success, 0. Otherwise an errno value indicating the * type of failure. */ static int xenbusb_front_get_otherend_node(device_t dev, struct xenbus_device_ivars *ivars) { char *otherend_path; int error; if (ivars->xd_otherend_path != NULL) { free(ivars->xd_otherend_path, M_XENBUS); ivars->xd_otherend_path = NULL; } error = xs_gather(XST_NIL, ivars->xd_node, "backend-id", "%i", &ivars->xd_otherend_id, "backend", NULL, &otherend_path, NULL); if (error == 0) { ivars->xd_otherend_path = strdup(otherend_path, M_XENBUS); ivars->xd_otherend_path_len = strlen(otherend_path); free(otherend_path, M_XENSTORE); } return (error); } /*-------------------- Private Device Attachment Data -----------------------*/ static device_method_t xenbusb_front_methods[] = { /* Device interface */ DEVMETHOD(device_identify, xenbusb_identify), DEVMETHOD(device_probe, xenbusb_front_probe), DEVMETHOD(device_attach, xenbusb_front_attach), DEVMETHOD(device_detach, bus_generic_detach), DEVMETHOD(device_shutdown, bus_generic_shutdown), DEVMETHOD(device_suspend, bus_generic_suspend), DEVMETHOD(device_resume, xenbusb_resume), /* Bus Interface */ DEVMETHOD(bus_print_child, xenbusb_print_child), DEVMETHOD(bus_read_ivar, xenbusb_read_ivar), DEVMETHOD(bus_write_ivar, xenbusb_write_ivar), DEVMETHOD(bus_alloc_resource, bus_generic_alloc_resource), DEVMETHOD(bus_release_resource, bus_generic_release_resource), DEVMETHOD(bus_activate_resource, bus_generic_activate_resource), DEVMETHOD(bus_deactivate_resource, bus_generic_deactivate_resource), /* XenBus Bus Interface */ DEVMETHOD(xenbusb_enumerate_type, xenbusb_front_enumerate_type), DEVMETHOD(xenbusb_get_otherend_node, xenbusb_front_get_otherend_node), { 0, 0 } }; DEFINE_CLASS_0(xenbusb_front, xenbusb_front_driver, xenbusb_front_methods, sizeof(struct xenbusb_softc)); DRIVER_MODULE(xenbusb_front, xenstore, xenbusb_front_driver, 0, 0);