X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=include%2Fxen%2Fxenbus.h;fp=include%2Fxen%2Fxenbus.h;h=f65dc9b972cb162d71490a4761c763027ea8aa93;hb=1db395853d4f30d6120458bd279ede1f882a8525;hp=0000000000000000000000000000000000000000;hpb=34a75f0025b9cf803b6a88db032e6ad6950c9313;p=linux-2.6.git diff --git a/include/xen/xenbus.h b/include/xen/xenbus.h new file mode 100644 index 000000000..f65dc9b97 --- /dev/null +++ b/include/xen/xenbus.h @@ -0,0 +1,299 @@ +/****************************************************************************** + * 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 */