xref: /openbmc/linux/include/xen/xenbus.h (revision c819e2cf)
1  /******************************************************************************
2   * xenbus.h
3   *
4   * Talks to Xen Store to figure out what devices we have.
5   *
6   * Copyright (C) 2005 Rusty Russell, IBM Corporation
7   * Copyright (C) 2005 XenSource Ltd.
8   *
9   * This program is free software; you can redistribute it and/or
10   * modify it under the terms of the GNU General Public License version 2
11   * as published by the Free Software Foundation; or, when distributed
12   * separately from the Linux kernel or incorporated into other
13   * software packages, subject to the following license:
14   *
15   * Permission is hereby granted, free of charge, to any person obtaining a copy
16   * of this source file (the "Software"), to deal in the Software without
17   * restriction, including without limitation the rights to use, copy, modify,
18   * merge, publish, distribute, sublicense, and/or sell copies of the Software,
19   * and to permit persons to whom the Software is furnished to do so, subject to
20   * the following conditions:
21   *
22   * The above copyright notice and this permission notice shall be included in
23   * all copies or substantial portions of the Software.
24   *
25   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
26   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
27   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
28   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
29   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
30   * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
31   * IN THE SOFTWARE.
32   */
33  
34  #ifndef _XEN_XENBUS_H
35  #define _XEN_XENBUS_H
36  
37  #include <linux/device.h>
38  #include <linux/notifier.h>
39  #include <linux/mutex.h>
40  #include <linux/export.h>
41  #include <linux/completion.h>
42  #include <linux/init.h>
43  #include <linux/slab.h>
44  #include <xen/interface/xen.h>
45  #include <xen/interface/grant_table.h>
46  #include <xen/interface/io/xenbus.h>
47  #include <xen/interface/io/xs_wire.h>
48  
49  /* Register callback to watch this node. */
50  struct xenbus_watch
51  {
52  	struct list_head list;
53  
54  	/* Path being watched. */
55  	const char *node;
56  
57  	/* Callback (executed in a process context with no locks held). */
58  	void (*callback)(struct xenbus_watch *,
59  			 const char **vec, unsigned int len);
60  };
61  
62  
63  /* A xenbus device. */
64  struct xenbus_device {
65  	const char *devicetype;
66  	const char *nodename;
67  	const char *otherend;
68  	int otherend_id;
69  	struct xenbus_watch otherend_watch;
70  	struct device dev;
71  	enum xenbus_state state;
72  	struct completion down;
73  	struct work_struct work;
74  };
75  
76  static inline struct xenbus_device *to_xenbus_device(struct device *dev)
77  {
78  	return container_of(dev, struct xenbus_device, dev);
79  }
80  
81  struct xenbus_device_id
82  {
83  	/* .../device/<device_type>/<identifier> */
84  	char devicetype[32]; 	/* General class of device. */
85  };
86  
87  /* A xenbus driver. */
88  struct xenbus_driver {
89  	const char *name;       /* defaults to ids[0].devicetype */
90  	const struct xenbus_device_id *ids;
91  	int (*probe)(struct xenbus_device *dev,
92  		     const struct xenbus_device_id *id);
93  	void (*otherend_changed)(struct xenbus_device *dev,
94  				 enum xenbus_state backend_state);
95  	int (*remove)(struct xenbus_device *dev);
96  	int (*suspend)(struct xenbus_device *dev);
97  	int (*resume)(struct xenbus_device *dev);
98  	int (*uevent)(struct xenbus_device *, struct kobj_uevent_env *);
99  	struct device_driver driver;
100  	int (*read_otherend_details)(struct xenbus_device *dev);
101  	int (*is_ready)(struct xenbus_device *dev);
102  };
103  
104  static inline struct xenbus_driver *to_xenbus_driver(struct device_driver *drv)
105  {
106  	return container_of(drv, struct xenbus_driver, driver);
107  }
108  
109  int __must_check __xenbus_register_frontend(struct xenbus_driver *drv,
110  					    struct module *owner,
111  					    const char *mod_name);
112  int __must_check __xenbus_register_backend(struct xenbus_driver *drv,
113  					   struct module *owner,
114  					   const char *mod_name);
115  
116  #define xenbus_register_frontend(drv) \
117  	__xenbus_register_frontend(drv, THIS_MODULE, KBUILD_MODNAME);
118  #define xenbus_register_backend(drv) \
119  	__xenbus_register_backend(drv, THIS_MODULE, KBUILD_MODNAME);
120  
121  void xenbus_unregister_driver(struct xenbus_driver *drv);
122  
123  struct xenbus_transaction
124  {
125  	u32 id;
126  };
127  
128  /* Nil transaction ID. */
129  #define XBT_NIL ((struct xenbus_transaction) { 0 })
130  
131  char **xenbus_directory(struct xenbus_transaction t,
132  			const char *dir, const char *node, unsigned int *num);
133  void *xenbus_read(struct xenbus_transaction t,
134  		  const char *dir, const char *node, unsigned int *len);
135  int xenbus_write(struct xenbus_transaction t,
136  		 const char *dir, const char *node, const char *string);
137  int xenbus_mkdir(struct xenbus_transaction t,
138  		 const char *dir, const char *node);
139  int xenbus_exists(struct xenbus_transaction t,
140  		  const char *dir, const char *node);
141  int xenbus_rm(struct xenbus_transaction t, const char *dir, const char *node);
142  int xenbus_transaction_start(struct xenbus_transaction *t);
143  int xenbus_transaction_end(struct xenbus_transaction t, int abort);
144  
145  /* Single read and scanf: returns -errno or num scanned if > 0. */
146  __scanf(4, 5)
147  int xenbus_scanf(struct xenbus_transaction t,
148  		 const char *dir, const char *node, const char *fmt, ...);
149  
150  /* Single printf and write: returns -errno or 0. */
151  __printf(4, 5)
152  int xenbus_printf(struct xenbus_transaction t,
153  		  const char *dir, const char *node, const char *fmt, ...);
154  
155  /* Generic read function: NULL-terminated triples of name,
156   * sprintf-style type string, and pointer. Returns 0 or errno.*/
157  int xenbus_gather(struct xenbus_transaction t, const char *dir, ...);
158  
159  /* notifer routines for when the xenstore comes up */
160  extern int xenstored_ready;
161  int register_xenstore_notifier(struct notifier_block *nb);
162  void unregister_xenstore_notifier(struct notifier_block *nb);
163  
164  int register_xenbus_watch(struct xenbus_watch *watch);
165  void unregister_xenbus_watch(struct xenbus_watch *watch);
166  void xs_suspend(void);
167  void xs_resume(void);
168  void xs_suspend_cancel(void);
169  
170  /* Used by xenbus_dev to borrow kernel's store connection. */
171  void *xenbus_dev_request_and_reply(struct xsd_sockmsg *msg);
172  
173  struct work_struct;
174  
175  /* Prepare for domain suspend: then resume or cancel the suspend. */
176  void xenbus_suspend(void);
177  void xenbus_resume(void);
178  void xenbus_probe(struct work_struct *);
179  void xenbus_suspend_cancel(void);
180  
181  #define XENBUS_IS_ERR_READ(str) ({			\
182  	if (!IS_ERR(str) && strlen(str) == 0) {		\
183  		kfree(str);				\
184  		str = ERR_PTR(-ERANGE);			\
185  	}						\
186  	IS_ERR(str);					\
187  })
188  
189  #define XENBUS_EXIST_ERR(err) ((err) == -ENOENT || (err) == -ERANGE)
190  
191  int xenbus_watch_path(struct xenbus_device *dev, const char *path,
192  		      struct xenbus_watch *watch,
193  		      void (*callback)(struct xenbus_watch *,
194  				       const char **, unsigned int));
195  __printf(4, 5)
196  int xenbus_watch_pathfmt(struct xenbus_device *dev, struct xenbus_watch *watch,
197  			 void (*callback)(struct xenbus_watch *,
198  					  const char **, unsigned int),
199  			 const char *pathfmt, ...);
200  
201  int xenbus_switch_state(struct xenbus_device *dev, enum xenbus_state new_state);
202  int xenbus_grant_ring(struct xenbus_device *dev, unsigned long ring_mfn);
203  int xenbus_map_ring_valloc(struct xenbus_device *dev,
204  			   int gnt_ref, void **vaddr);
205  int xenbus_map_ring(struct xenbus_device *dev, int gnt_ref,
206  			   grant_handle_t *handle, void *vaddr);
207  
208  int xenbus_unmap_ring_vfree(struct xenbus_device *dev, void *vaddr);
209  int xenbus_unmap_ring(struct xenbus_device *dev,
210  		      grant_handle_t handle, void *vaddr);
211  
212  int xenbus_alloc_evtchn(struct xenbus_device *dev, int *port);
213  int xenbus_free_evtchn(struct xenbus_device *dev, int port);
214  
215  enum xenbus_state xenbus_read_driver_state(const char *path);
216  
217  __printf(3, 4)
218  void xenbus_dev_error(struct xenbus_device *dev, int err, const char *fmt, ...);
219  __printf(3, 4)
220  void xenbus_dev_fatal(struct xenbus_device *dev, int err, const char *fmt, ...);
221  
222  const char *xenbus_strstate(enum xenbus_state state);
223  int xenbus_dev_is_online(struct xenbus_device *dev);
224  int xenbus_frontend_closed(struct xenbus_device *dev);
225  
226  #endif /* _XEN_XENBUS_H */
227