--- /dev/null
+/******************************************************************************
+ * 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 <linux/device.h>
+#include <linux/notifier.h>
+#include <linux/mutex.h>
+#include <xen/interface/xen.h>
+#include <xen/interface/grant_table.h>
+#include <xen/interface/io/xenbus.h>
+#include <xen/interface/io/xs_wire.h>
+
+/* 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/<device_type>/<identifier> */
+ 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 */
git://git.onelab.eu / linux-2.6.git / blobdiff