/****************************************************************************** * xenbus.h * * Talks to Xen Store to figure out what devices we have. * * Copyright (C) 2005 Rusty Russell, IBM Corporation * Copyright (C) 2005 XenSource Ltd. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License version 2 * as published by the Free Software Foundation; or, when 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. */ #ifndef _XEN_XENBUS_H #define _XEN_XENBUS_H #include #include #include #include #include #include #include /* Register callback to watch this node. */ struct xenbus_watch { struct list_head list; /* Path being watched. */ const char *node; /* Callback (executed in a process context with no locks held). */ void (*callback)(struct xenbus_watch *, const char **vec, unsigned int len); /* See XBWF_ definitions below. */ unsigned long flags; }; /* * Execute callback in its own kthread. Useful if the callback is long * running or heavily serialised, to avoid taking out the main xenwatch thread * for a long period of time (or even unwittingly causing a deadlock). */ #define XBWF_new_thread 1 /* A xenbus device. */ struct xenbus_device { const char *devicetype; const char *nodename; const char *otherend; int otherend_id; struct xenbus_watch otherend_watch; struct device dev; enum xenbus_state state; }; static inline struct xenbus_device *to_xenbus_device(struct device *dev) { return container_of(dev, struct xenbus_device, dev); } struct xenbus_device_id { /* .../device// */ char devicetype[32]; /* General class of device. */ }; /* A xenbus driver. */ struct xenbus_driver { char *name; struct module *owner; const struct xenbus_device_id *ids; int (*probe)(struct xenbus_device *dev, const struct xenbus_device_id *id); void (*otherend_changed)(struct xenbus_device *dev, enum xenbus_state backend_state); int (*remove)(struct xenbus_device *dev); int (*suspend)(struct xenbus_device *dev); int (*resume)(struct xenbus_device *dev); int (*uevent)(struct xenbus_device *, char **, int, char *, int); struct device_driver driver; int (*read_otherend_details)(struct xenbus_device *dev); }; static inline struct xenbus_driver *to_xenbus_driver(struct device_driver *drv) { return container_of(drv, struct xenbus_driver, driver); } int xenbus_register_frontend(struct xenbus_driver *drv); int xenbus_register_backend(struct xenbus_driver *drv); void xenbus_unregister_driver(struct xenbus_driver *drv); struct xenbus_transaction { u32 id; }; /* Nil transaction ID. */ #define XBT_NIL ((struct xenbus_transaction) { 0 }) char **xenbus_directory(struct xenbus_transaction t, const char *dir, const char *node, unsigned int *num); void *xenbus_read(struct xenbus_transaction t, const char *dir, const char *node, unsigned int *len); int xenbus_write(struct xenbus_transaction t, const char *dir, const char *node, const char *string); int xenbus_mkdir(struct xenbus_transaction t, const char *dir, const char *node); int xenbus_exists(struct xenbus_transaction t, const char *dir, const char *node); int xenbus_rm(struct xenbus_transaction t, const char *dir, const char *node); int xenbus_transaction_start(struct xenbus_transaction *t); int xenbus_transaction_end(struct xenbus_transaction t, int abort); /* Single read and scanf: returns -errno or num scanned if > 0. */ int xenbus_scanf(struct xenbus_transaction t, const char *dir, const char *node, const char *fmt, ...) __attribute__((format(scanf, 4, 5))); /* Single printf and write: returns -errno or 0. */ int xenbus_printf(struct xenbus_transaction t, const char *dir, const char *node, const char *fmt, ...) __attribute__((format(printf, 4, 5))); /* Generic read function: NULL-terminated triples of name, * sprintf-style type string, and pointer. Returns 0 or errno.*/ int xenbus_gather(struct xenbus_transaction t, const char *dir, ...); /* notifer routines for when the xenstore comes up */ int register_xenstore_notifier(struct notifier_block *nb); void unregister_xenstore_notifier(struct notifier_block *nb); int register_xenbus_watch(struct xenbus_watch *watch); void unregister_xenbus_watch(struct xenbus_watch *watch); void xs_suspend(void); void xs_resume(void); /* Used by xenbus_dev to borrow kernel's store connection. */ void *xenbus_dev_request_and_reply(struct xsd_sockmsg *msg); /* Called from xen core code. */ void xenbus_suspend(void); void xenbus_resume(void); #define XENBUS_IS_ERR_READ(str) ({ \ if (!IS_ERR(str) && strlen(str) == 0) { \ kfree(str); \ str = ERR_PTR(-ERANGE); \ } \ IS_ERR(str); \ }) #define XENBUS_EXIST_ERR(err) ((err) == -ENOENT || (err) == -ERANGE) /** * Register a watch on the given path, using the given xenbus_watch structure * for storage, and the given callback function as the callback. Return 0 on * success, or -errno on error. On success, the given path will be saved as * watch->node, and remains the caller's to free. On error, watch->node will * be NULL, the device will switch to XenbusStateClosing, and the error will * be saved in the store. */ int xenbus_watch_path(struct xenbus_device *dev, const char *path, struct xenbus_watch *watch, void (*callback)(struct xenbus_watch *, const char **, unsigned int)); /** * Register a watch on the given path/path2, using the given xenbus_watch * structure for storage, and the given callback function as the callback. * Return 0 on success, or -errno on error. On success, the watched path * (path/path2) will be saved as watch->node, and becomes the caller's to * kfree(). On error, watch->node will be NULL, so the caller has nothing to * free, the device will switch to XenbusStateClosing, and the error will be * saved in the store. */ int xenbus_watch_path2(struct xenbus_device *dev, const char *path, const char *path2, struct xenbus_watch *watch, void (*callback)(struct xenbus_watch *, const char **, unsigned int)); /** * Advertise in the store a change of the given driver to the given new_state. * Return 0 on success, or -errno on error. On error, the device will switch * to XenbusStateClosing, and the error will be saved in the store. */ int xenbus_switch_state(struct xenbus_device *dev, enum xenbus_state new_state); /** * Grant access to the given ring_mfn to the peer of the given device. Return * 0 on success, or -errno on error. On error, the device will switch to * XenbusStateClosing, and the error will be saved in the store. */ int xenbus_grant_ring(struct xenbus_device *dev, unsigned long ring_mfn); /** * Map a page of memory into this domain from another domain's grant table. * xenbus_map_ring_valloc allocates a page of virtual address space, maps the * page to that address, and sets *vaddr to that address. * xenbus_map_ring does not allocate the virtual address space (you must do * this yourself!). It only maps in the page to the specified address. * Returns 0 on success, and GNTST_* (see xen/include/interface/grant_table.h) * or -ENOMEM on error. If an error is returned, device will switch to * XenbusStateClosing and the error message will be saved in XenStore. */ struct vm_struct *xenbus_map_ring_valloc(struct xenbus_device *dev, int gnt_ref); int xenbus_map_ring(struct xenbus_device *dev, int gnt_ref, grant_handle_t *handle, void *vaddr); /** * Unmap a page of memory in this domain that was imported from another domain. * Use xenbus_unmap_ring_vfree if you mapped in your memory with * xenbus_map_ring_valloc (it will free the virtual address space). * Returns 0 on success and returns GNTST_* on error * (see xen/include/interface/grant_table.h). */ int xenbus_unmap_ring_vfree(struct xenbus_device *dev, struct vm_struct *); int xenbus_unmap_ring(struct xenbus_device *dev, grant_handle_t handle, void *vaddr); /** * Allocate an event channel for the given xenbus_device, assigning the newly * created local port to *port. Return 0 on success, or -errno on error. On * error, the device will switch to XenbusStateClosing, and the error will be * saved in the store. */ int xenbus_alloc_evtchn(struct xenbus_device *dev, int *port); /** * Bind to an existing interdomain event channel in another domain. Returns 0 * on success and stores the local port in *port. On error, returns -errno, * switches the device to XenbusStateClosing, and saves the error in XenStore. */ int xenbus_bind_evtchn(struct xenbus_device *dev, int remote_port, int *port); /** * Free an existing event channel. Returns 0 on success or -errno on error. */ int xenbus_free_evtchn(struct xenbus_device *dev, int port); /** * Return the state of the driver rooted at the given store path, or * XenbusStateClosed if no state can be read. */ enum xenbus_state xenbus_read_driver_state(const char *path); /*** * Report the given negative errno into the store, along with the given * formatted message. */ void xenbus_dev_error(struct xenbus_device *dev, int err, const char *fmt, ...); /*** * Equivalent to xenbus_dev_error(dev, err, fmt, args), followed by * xenbus_switch_state(dev, NULL, XenbusStateClosing) to schedule an orderly * closedown of this driver and its peer. */ void xenbus_dev_fatal(struct xenbus_device *dev, int err, const char *fmt, ...); #endif /* _XEN_XENBUS_H */