/****************************************************************************** * Copyright (C) 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.c * * \brief Shared support functions for managing the NewBus buses that contain * Xen front and back end device instances. * * The NewBus implementation of XenBus attaches a xenbusb_front and xenbusb_back * child bus to the xenstore device. This strategy allows the small differences * in the handling of XenBus operations for front and back devices to be handled * as overrides in xenbusb_front/back.c. Front and back specific device * classes are also provided so device drivers can register for the devices they * can handle without the need to filter within their probe routines. The * net result is a device hierarchy that might look like this: * * xenstore0/ * xenbusb_front0/ * xn0 * xbd0 * xbd1 * xenbusb_back0/ * xbbd0 * xnb0 * xnb1 */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /*------------------------- Private Functions --------------------------------*/ /** * \brief Deallocate XenBus device instance variables. * * \param ivars The instance variable block to free. */ static void xenbusb_free_child_ivars(struct xenbus_device_ivars *ivars) { if (ivars->xd_otherend_watch.node != NULL) { xs_unregister_watch(&ivars->xd_otherend_watch); free(ivars->xd_otherend_watch.node, M_XENBUS); ivars->xd_otherend_watch.node = NULL; } if (ivars->xd_local_watch.node != NULL) { xs_unregister_watch(&ivars->xd_local_watch); ivars->xd_local_watch.node = NULL; } if (ivars->xd_node != NULL) { free(ivars->xd_node, M_XENBUS); ivars->xd_node = NULL; } ivars->xd_node_len = 0; if (ivars->xd_type != NULL) { free(ivars->xd_type, M_XENBUS); ivars->xd_type = NULL; } if (ivars->xd_otherend_path != NULL) { free(ivars->xd_otherend_path, M_XENBUS); ivars->xd_otherend_path = NULL; } ivars->xd_otherend_path_len = 0; free(ivars, M_XENBUS); } /** * XenBus watch callback registered against the "state" XenStore * node of the other-end of a split device connection. * * This callback is invoked whenever the state of a device instance's * peer changes. * * \param watch The xs_watch object used to register this callback * function. * \param vec An array of pointers to NUL terminated strings containing * watch event data. The vector should be indexed via the * xs_watch_type enum in xs_wire.h. * \param vec_size The number of elements in vec. */ static void xenbusb_otherend_watch_cb(struct xs_watch *watch, const char **vec, unsigned int vec_size __unused) { struct xenbus_device_ivars *ivars; device_t child; device_t bus; const char *path; enum xenbus_state newstate; ivars = (struct xenbus_device_ivars *)watch->callback_data; child = ivars->xd_dev; bus = device_get_parent(child); path = vec[XS_WATCH_PATH]; if (ivars->xd_otherend_path == NULL || strncmp(ivars->xd_otherend_path, path, ivars->xd_otherend_path_len)) return; newstate = xenbus_read_driver_state(ivars->xd_otherend_path); XENBUSB_OTHEREND_CHANGED(bus, child, newstate); } /** * XenBus watch callback registered against the XenStore sub-tree * represnting the local half of a split device connection. * * This callback is invoked whenever any XenStore data in the subtree * is modified, either by us or another privledged domain. * * \param watch The xs_watch object used to register this callback * function. * \param vec An array of pointers to NUL terminated strings containing * watch event data. The vector should be indexed via the * xs_watch_type enum in xs_wire.h. * \param vec_size The number of elements in vec. * */ static void xenbusb_local_watch_cb(struct xs_watch *watch, const char **vec, unsigned int vec_size __unused) { struct xenbus_device_ivars *ivars; device_t child; device_t bus; const char *path; ivars = (struct xenbus_device_ivars *)watch->callback_data; child = ivars->xd_dev; bus = device_get_parent(child); path = vec[XS_WATCH_PATH]; if (ivars->xd_node == NULL || strncmp(ivars->xd_node, path, ivars->xd_node_len)) return; XENBUSB_LOCALEND_CHANGED(bus, child, &path[ivars->xd_node_len]); } /** * Search our internal record of configured devices (not the XenStore) * to determine if the XenBus device indicated by \a node is known to * the system. * * \param dev The XenBus bus instance to search for device children. * \param node The XenStore node path for the device to find. * * \return The device_t of the found device if any, or NULL. * * \note device_t is a pointer type, so it can be compared against * NULL for validity. */ static device_t xenbusb_device_exists(device_t dev, const char *node) { device_t *kids; device_t result; struct xenbus_device_ivars *ivars; int i, count; if (device_get_children(dev, &kids, &count)) return (FALSE); result = NULL; for (i = 0; i < count; i++) { ivars = device_get_ivars(kids[i]); if (!strcmp(ivars->xd_node, node)) { result = kids[i]; break; } } free(kids, M_TEMP); return (result); } static void xenbusb_delete_child(device_t dev, device_t child) { struct xenbus_device_ivars *ivars; ivars = device_get_ivars(child); /* * We no longer care about the otherend of the * connection. Cancel the watches now so that we * don't try to handle an event for a partially * detached child. */ if (ivars->xd_otherend_watch.node != NULL) xs_unregister_watch(&ivars->xd_otherend_watch); if (ivars->xd_local_watch.node != NULL) xs_unregister_watch(&ivars->xd_local_watch); device_delete_child(dev, child); xenbusb_free_child_ivars(ivars); } /** * \param dev The NewBus device representing this XenBus bus. * \param child The NewBus device representing a child of dev%'s XenBus bus. */ static void xenbusb_verify_device(device_t dev, device_t child) { if (xs_exists(XST_NIL, xenbus_get_node(child), "state") == 0) { /* * Device tree has been removed from Xenbus. * Tear down the device. */ xenbusb_delete_child(dev, child); } } /** * \brief Enumerate the devices on a XenBus bus and register them with * the NewBus device tree. * * xenbusb_enumerate_bus() will create entries (in state DS_NOTPRESENT) * for nodes that appear in the XenStore, but will not invoke probe/attach * operations on drivers. Probe/Attach processing must be separately * performed via an invocation of xenbusb_probe_children(). This is usually * done via the xbs_probe_children task. * * \param xbs XenBus Bus device softc of the owner of the bus to enumerate. * * \return On success, 0. Otherwise an errno value indicating the * type of failure. */ static int xenbusb_enumerate_bus(struct xenbusb_softc *xbs) { const char **types; u_int type_idx; u_int type_count; int error; error = xs_directory(XST_NIL, xbs->xbs_node, "", &type_count, &types); if (error) return (error); for (type_idx = 0; type_idx < type_count; type_idx++) XENBUSB_ENUMERATE_TYPE(xbs->xbs_dev, types[type_idx]); free(types, M_XENSTORE); return (0); } /** * Handler for all generic XenBus device systcl nodes. */ static int xenbusb_device_sysctl_handler(SYSCTL_HANDLER_ARGS) { device_t dev; const char *value; dev = (device_t)arg1; switch (arg2) { case XENBUS_IVAR_NODE: value = xenbus_get_node(dev); break; case XENBUS_IVAR_TYPE: value = xenbus_get_type(dev); break; case XENBUS_IVAR_STATE: value = xenbus_strstate(xenbus_get_state(dev)); break; case XENBUS_IVAR_OTHEREND_ID: return (sysctl_handle_int(oidp, NULL, xenbus_get_otherend_id(dev), req)); /* NOTREACHED */ case XENBUS_IVAR_OTHEREND_PATH: value = xenbus_get_otherend_path(dev); break; default: return (EINVAL); } return (SYSCTL_OUT_STR(req, value)); } /** * Create read-only systcl nodes for xenbusb device ivar data. * * \param dev The XenBus device instance to register with sysctl. */ static void xenbusb_device_sysctl_init(device_t dev) { struct sysctl_ctx_list *ctx; struct sysctl_oid *tree; ctx = device_get_sysctl_ctx(dev); tree = device_get_sysctl_tree(dev); SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, "xenstore_path", CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, dev, XENBUS_IVAR_NODE, xenbusb_device_sysctl_handler, "A", "XenStore path to device"); SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, "xenbus_dev_type", CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, dev, XENBUS_IVAR_TYPE, xenbusb_device_sysctl_handler, "A", "XenBus device type"); SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, "xenbus_connection_state", CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, dev, XENBUS_IVAR_STATE, xenbusb_device_sysctl_handler, "A", "XenBus state of peer connection"); SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, "xenbus_peer_domid", CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_MPSAFE, dev, XENBUS_IVAR_OTHEREND_ID, xenbusb_device_sysctl_handler, "I", "Xen domain ID of peer"); SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, "xenstore_peer_path", CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, dev, XENBUS_IVAR_OTHEREND_PATH, xenbusb_device_sysctl_handler, "A", "XenStore path to peer device"); } /** * \brief Decrement the number of XenBus child devices in the * connecting state by one and release the xbs_attch_ch * interrupt configuration hook if the connecting count * drops to zero. * * \param xbs XenBus Bus device softc of the owner of the bus to enumerate. */ static void xenbusb_release_confighook(struct xenbusb_softc *xbs) { mtx_lock(&xbs->xbs_lock); KASSERT(xbs->xbs_connecting_children > 0, ("Connecting device count error\n")); xbs->xbs_connecting_children--; if (xbs->xbs_connecting_children == 0 && (xbs->xbs_flags & XBS_ATTACH_CH_ACTIVE) != 0) { xbs->xbs_flags &= ~XBS_ATTACH_CH_ACTIVE; mtx_unlock(&xbs->xbs_lock); config_intrhook_disestablish(&xbs->xbs_attach_ch); } else { mtx_unlock(&xbs->xbs_lock); } } /** * \brief Verify the existence of attached device instances and perform * probe/attach processing for newly arrived devices. * * \param dev The NewBus device representing this XenBus bus. * * \return On success, 0. Otherwise an errno value indicating the * type of failure. */ static int xenbusb_probe_children(device_t dev) { device_t *kids; struct xenbus_device_ivars *ivars; int i, count, error; if (device_get_children(dev, &kids, &count) == 0) { for (i = 0; i < count; i++) { if (device_get_state(kids[i]) != DS_NOTPRESENT) { /* * We already know about this one. * Make sure it's still here. */ xenbusb_verify_device(dev, kids[i]); continue; } error = device_probe_and_attach(kids[i]); if (error == ENXIO) { struct xenbusb_softc *xbs; /* * We don't have a PV driver for this device. * However, an emulated device we do support * may share this backend. Hide the node from * XenBus until the next rescan, but leave it's * state unchanged so we don't inadvertently * prevent attachment of any emulated device. */ xenbusb_delete_child(dev, kids[i]); /* * Since the XenStore state of this device * still indicates a pending attach, manually * release it's hold on the boot process. */ xbs = device_get_softc(dev); xenbusb_release_confighook(xbs); continue; } else if (error) { /* * Transition device to the closed state * so the world knows that attachment will * not occur. */ xenbus_set_state(kids[i], XenbusStateClosed); /* * Remove our record of this device. * So long as it remains in the closed * state in the XenStore, we will not find * it again. The state will only change * if the control domain actively reconfigures * this device. */ xenbusb_delete_child(dev, kids[i]); continue; } /* * Augment default newbus provided dynamic sysctl * variables with the standard ivar contents of * XenBus devices. */ xenbusb_device_sysctl_init(kids[i]); /* * Now that we have a driver managing this device * that can receive otherend state change events, * hook up a watch for them. */ ivars = device_get_ivars(kids[i]); xs_register_watch(&ivars->xd_otherend_watch); xs_register_watch(&ivars->xd_local_watch); } free(kids, M_TEMP); } return (0); } /** * \brief Task callback function to perform XenBus probe operations * from a known safe context. * * \param arg The NewBus device_t representing the bus instance to * on which to perform probe processing. * \param pending The number of times this task was queued before it could * be run. */ static void xenbusb_probe_children_cb(void *arg, int pending __unused) { device_t dev = (device_t)arg; bus_topo_lock(); xenbusb_probe_children(dev); bus_topo_unlock(); } /** * \brief XenStore watch callback for the root node of the XenStore * subtree representing a XenBus. * * This callback performs, or delegates to the xbs_probe_children task, * all processing necessary to handle dynmaic device arrival and departure * events from a XenBus. * * \param watch The XenStore watch object associated with this callback. * \param vec The XenStore watch event data. * \param len The number of fields in the event data stream. */ static void xenbusb_devices_changed(struct xs_watch *watch, const char **vec, unsigned int len) { struct xenbusb_softc *xbs; device_t dev; char *node; char *type; char *id; char *p; u_int component; xbs = (struct xenbusb_softc *)watch->callback_data; dev = xbs->xbs_dev; if (len <= XS_WATCH_PATH) { device_printf(dev, "xenbusb_devices_changed: " "Short Event Data.\n"); return; } node = strdup(vec[XS_WATCH_PATH], M_XENBUS); p = strchr(node, '/'); if (p == NULL) goto out; *p = 0; type = p + 1; p = strchr(type, '/'); if (p == NULL) goto out; *p++ = 0; /* * Extract the device ID. A device ID has one or more path * components separated by the '/' character. * * e.g. "/" for backend devices. */ id = p; for (component = 0; component < xbs->xbs_id_components; component++) { p = strchr(p, '/'); if (p == NULL) break; p++; } if (p != NULL) *p = 0; if (*id != 0 && component >= xbs->xbs_id_components - 1) { xenbusb_add_device(xbs->xbs_dev, type, id); taskqueue_enqueue(taskqueue_thread, &xbs->xbs_probe_children); } out: free(node, M_XENBUS); } /** * \brief Interrupt configuration hook callback associated with xbs_attch_ch. * * Since interrupts are always functional at the time of XenBus configuration, * there is nothing to be done when the callback occurs. This hook is only * registered to hold up boot processing while XenBus devices come online. * * \param arg Unused configuration hook callback argument. */ static void xenbusb_nop_confighook_cb(void *arg __unused) { } /*--------------------------- Public Functions -------------------------------*/ /*--------- API comments for these methods can be found in xenbusb.h ---------*/ void xenbusb_identify(driver_t *driver __unused, device_t parent) { /* * A single instance of each bus type for which we have a driver * is always present in a system operating under Xen. */ BUS_ADD_CHILD(parent, 0, driver->name, 0); } int xenbusb_add_device(device_t dev, const char *type, const char *id) { struct xenbusb_softc *xbs; struct sbuf *devpath_sbuf; char *devpath; struct xenbus_device_ivars *ivars; int error; xbs = device_get_softc(dev); devpath_sbuf = sbuf_new_auto(); sbuf_printf(devpath_sbuf, "%s/%s/%s", xbs->xbs_node, type, id); sbuf_finish(devpath_sbuf); devpath = sbuf_data(devpath_sbuf); ivars = malloc(sizeof(*ivars), M_XENBUS, M_ZERO|M_WAITOK); error = ENXIO; if (xs_exists(XST_NIL, devpath, "") != 0) { device_t child; enum xenbus_state state; char *statepath; child = xenbusb_device_exists(dev, devpath); if (child != NULL) { /* * We are already tracking this node */ error = 0; goto out; } state = xenbus_read_driver_state(devpath); if (state != XenbusStateInitialising) { /* * Device is not new, so ignore it. This can * happen if a device is going away after * switching to Closed. */ printf("xenbusb_add_device: Device %s ignored. " "State %d\n", devpath, state); error = 0; goto out; } sx_init(&ivars->xd_lock, "xdlock"); ivars->xd_flags = XDF_CONNECTING; ivars->xd_node = strdup(devpath, M_XENBUS); ivars->xd_node_len = strlen(devpath); ivars->xd_type = strdup(type, M_XENBUS); ivars->xd_state = XenbusStateInitialising; error = XENBUSB_GET_OTHEREND_NODE(dev, ivars); if (error) { printf("xenbus_update_device: %s no otherend id\n", devpath); goto out; } statepath = malloc(ivars->xd_otherend_path_len + strlen("/state") + 1, M_XENBUS, M_WAITOK); sprintf(statepath, "%s/state", ivars->xd_otherend_path); ivars->xd_otherend_watch.node = statepath; ivars->xd_otherend_watch.callback = xenbusb_otherend_watch_cb; ivars->xd_otherend_watch.callback_data = (uintptr_t)ivars; /* * Other end state node watch, limit to one pending event * to prevent frontends from queuing too many events that * could cause resource starvation. */ ivars->xd_otherend_watch.max_pending = 1; ivars->xd_local_watch.node = ivars->xd_node; ivars->xd_local_watch.callback = xenbusb_local_watch_cb; ivars->xd_local_watch.callback_data = (uintptr_t)ivars; /* * Watch our local path, only writable by us or a privileged * domain, no need to limit. */ ivars->xd_local_watch.max_pending = 0; mtx_lock(&xbs->xbs_lock); xbs->xbs_connecting_children++; mtx_unlock(&xbs->xbs_lock); child = device_add_child(dev, NULL, -1); ivars->xd_dev = child; device_set_ivars(child, ivars); } out: sbuf_delete(devpath_sbuf); if (error != 0) xenbusb_free_child_ivars(ivars); return (error); } int xenbusb_attach(device_t dev, char *bus_node, u_int id_components) { struct xenbusb_softc *xbs; xbs = device_get_softc(dev); mtx_init(&xbs->xbs_lock, "xenbusb softc lock", NULL, MTX_DEF); xbs->xbs_node = bus_node; xbs->xbs_id_components = id_components; xbs->xbs_dev = dev; /* * Since XenBus buses are attached to the XenStore, and * the XenStore does not probe children until after interrupt * services are available, this config hook is used solely * to ensure that the remainder of the boot process (e.g. * mount root) is deferred until child devices are adequately * probed. We unblock the boot process as soon as the * connecting child count in our softc goes to 0. */ xbs->xbs_attach_ch.ich_func = xenbusb_nop_confighook_cb; xbs->xbs_attach_ch.ich_arg = dev; config_intrhook_establish(&xbs->xbs_attach_ch); xbs->xbs_flags |= XBS_ATTACH_CH_ACTIVE; xbs->xbs_connecting_children = 1; /* * The subtree for this bus type may not yet exist * causing initial enumeration to fail. We still * want to return success from our attach though * so that we are ready to handle devices for this * bus when they are dynamically attached to us * by a Xen management action. */ (void)xenbusb_enumerate_bus(xbs); xenbusb_probe_children(dev); xbs->xbs_device_watch.node = bus_node; xbs->xbs_device_watch.callback = xenbusb_devices_changed; xbs->xbs_device_watch.callback_data = (uintptr_t)xbs; /* * Allow for unlimited pending watches, as those are local paths * either controlled by the guest or only writable by privileged * domains. */ xbs->xbs_device_watch.max_pending = 0; TASK_INIT(&xbs->xbs_probe_children, 0, xenbusb_probe_children_cb, dev); xs_register_watch(&xbs->xbs_device_watch); xenbusb_release_confighook(xbs); return (0); } int xenbusb_resume(device_t dev) { device_t *kids; struct xenbus_device_ivars *ivars; int i, count, error; char *statepath; /* * We must re-examine each device and find the new path for * its backend. */ if (device_get_children(dev, &kids, &count) == 0) { for (i = 0; i < count; i++) { if (device_get_state(kids[i]) == DS_NOTPRESENT) continue; if (xen_suspend_cancelled) { DEVICE_RESUME(kids[i]); continue; } ivars = device_get_ivars(kids[i]); xs_unregister_watch(&ivars->xd_otherend_watch); xenbus_set_state(kids[i], XenbusStateInitialising); /* * Find the new backend details and * re-register our watch. */ error = XENBUSB_GET_OTHEREND_NODE(dev, ivars); if (error) return (error); statepath = malloc(ivars->xd_otherend_path_len + strlen("/state") + 1, M_XENBUS, M_WAITOK); sprintf(statepath, "%s/state", ivars->xd_otherend_path); free(ivars->xd_otherend_watch.node, M_XENBUS); ivars->xd_otherend_watch.node = statepath; DEVICE_RESUME(kids[i]); xs_register_watch(&ivars->xd_otherend_watch); #if 0 /* * Can't do this yet since we are running in * the xenwatch thread and if we sleep here, * we will stop delivering watch notifications * and the device will never come back online. */ sx_xlock(&ivars->xd_lock); while (ivars->xd_state != XenbusStateClosed && ivars->xd_state != XenbusStateConnected) sx_sleep(&ivars->xd_state, &ivars->xd_lock, 0, "xdresume", 0); sx_xunlock(&ivars->xd_lock); #endif } free(kids, M_TEMP); } return (0); } int xenbusb_print_child(device_t dev, device_t child) { struct xenbus_device_ivars *ivars = device_get_ivars(child); int retval = 0; retval += bus_print_child_header(dev, child); retval += printf(" at %s", ivars->xd_node); retval += bus_print_child_footer(dev, child); return (retval); } int xenbusb_read_ivar(device_t dev, device_t child, int index, uintptr_t *result) { struct xenbus_device_ivars *ivars = device_get_ivars(child); switch (index) { case XENBUS_IVAR_NODE: *result = (uintptr_t) ivars->xd_node; return (0); case XENBUS_IVAR_TYPE: *result = (uintptr_t) ivars->xd_type; return (0); case XENBUS_IVAR_STATE: *result = (uintptr_t) ivars->xd_state; return (0); case XENBUS_IVAR_OTHEREND_ID: *result = (uintptr_t) ivars->xd_otherend_id; return (0); case XENBUS_IVAR_OTHEREND_PATH: *result = (uintptr_t) ivars->xd_otherend_path; return (0); } return (ENOENT); } int xenbusb_write_ivar(device_t dev, device_t child, int index, uintptr_t value) { struct xenbus_device_ivars *ivars = device_get_ivars(child); enum xenbus_state newstate; int currstate; switch (index) { case XENBUS_IVAR_STATE: { int error; struct xs_transaction xst; newstate = (enum xenbus_state)value; sx_xlock(&ivars->xd_lock); if (ivars->xd_state == newstate) { error = 0; goto out; } do { error = xs_transaction_start(&xst); if (error != 0) goto out; do { error = xs_scanf(xst, ivars->xd_node, "state", NULL, "%d", &currstate); } while (error == EAGAIN); if (error) goto out; do { error = xs_printf(xst, ivars->xd_node, "state", "%d", newstate); } while (error == EAGAIN); if (error) { /* * Avoid looping through xenbus_dev_fatal() * which calls xenbus_write_ivar to set the * state to closing. */ if (newstate != XenbusStateClosing) xenbus_dev_fatal(dev, error, "writing new state"); goto out; } } while (xs_transaction_end(xst, 0)); ivars->xd_state = newstate; if ((ivars->xd_flags & XDF_CONNECTING) != 0 && (newstate == XenbusStateClosed || newstate == XenbusStateConnected)) { struct xenbusb_softc *xbs; ivars->xd_flags &= ~XDF_CONNECTING; xbs = device_get_softc(dev); xenbusb_release_confighook(xbs); } wakeup(&ivars->xd_state); out: if (error != 0) xs_transaction_end(xst, 1); sx_xunlock(&ivars->xd_lock); /* * Shallow ENOENT errors, as returning an error here will * trigger a panic. ENOENT is fine to ignore, because it means * the toolstack has removed the state node as part of * destroying the device, and so we have to shut down the * device without recreating it or else the node would be * leaked. */ return (error == ENOENT ? 0 : error); } case XENBUS_IVAR_NODE: case XENBUS_IVAR_TYPE: case XENBUS_IVAR_OTHEREND_ID: case XENBUS_IVAR_OTHEREND_PATH: /* * These variables are read-only. */ return (EINVAL); } return (ENOENT); } void xenbusb_otherend_changed(device_t bus, device_t child, enum xenbus_state state) { XENBUS_OTHEREND_CHANGED(child, state); } void xenbusb_localend_changed(device_t bus, device_t child, const char *path) { if (strcmp(path, "/state") != 0) { struct xenbus_device_ivars *ivars; ivars = device_get_ivars(child); sx_xlock(&ivars->xd_lock); ivars->xd_state = xenbus_read_driver_state(ivars->xd_node); sx_xunlock(&ivars->xd_lock); } XENBUS_LOCALEND_CHANGED(child, path); }