/* $NetBSD: xenbus.h,v 1.25 2020/04/25 15:26:17 bouyer Exp $ */
/******************************************************************************
* 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 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.
*/
/* xenbus to hypervisor attach */
struct xenbus_attach_args {
const char *xa_device;
int xa_handle;
bus_dma_tag_t xa_dmat;
};
/* devices to xenbus attach */
struct xenbusdev_attach_args {
const char *xa_type;
int xa_id;
struct xenbus_device *xa_xbusd;
};
/* Register callback to watch this node. */
struct xenbus_watch {
SLIST_ENTRY(xenbus_watch) watch_next;
/* Path being watched. */
char *node;
size_t node_sz;
/* Callback (executed in a process context with no locks held). */
void (*xbw_callback)(struct xenbus_watch *,
const char **vec, unsigned int len);
struct xenbus_device *xbw_dev;
};
/*
* A xenbus device. Note that the malloced memory will be larger than
* sizeof(xenbus_device) to have the storage for xbusd_path, so xbusd_path
* has to be the last entry.
*/
typedef enum {
XENBUS_FRONTEND_DEVICE,
XENBUS_BACKEND_DEVICE
} xenbusdev_type_t;
struct xenbus_device {
SLIST_ENTRY(xenbus_device) xbusd_entries;
char xbusd_otherend[64]; /* the otherend path (size arbitrary) */
int xbusd_otherend_id; /* the otherend's id */
/* callback for otherend change */
void (*xbusd_otherend_changed)(void *, XenbusState);
xenbusdev_type_t xbusd_type;
union {
struct {
device_t f_dev;
} f;
struct {
void *b_cookie; /* private to backend driver */
int (*b_detach)(void *);
} b;
} xbusd_u;
int xbusd_has_error;
/* for xenbus internal use */
struct xenbus_watch xbusd_otherend_watch;
size_t xbusd_sz; /* size of allocated structure */
bus_dma_tag_t xbusd_dmat;
const char xbusd_path[1]; /* our path */
};
/*
* frontend devices use the normal autoconf(9) framework to attach.
* backend drivers need something more clever because we want the
* domain's name or uid in the device's name. Each backend driver registers
* to xenbus.
*/
struct xenbus_backend_driver {
SLIST_ENTRY(xenbus_backend_driver) xbakd_entries;
int (*xbakd_create) (struct xenbus_device *); /* called for new devs */
const char *xbakd_type; /* device type we register for */
};
int xenbus_directory(struct xenbus_transaction *t,
const char *dir, const char *node, unsigned int *num,
char ***);
void xenbus_directory_free(unsigned int, char **);
int xenbus_read(struct xenbus_transaction *,
const char *, const char *, char *, size_t);
int xenbus_read_ul(struct xenbus_transaction *,
const char *, const char *, unsigned long *, int);
int xenbus_read_ull(struct xenbus_transaction *,
const char *, const char *, unsigned long long *, int);
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);
struct xenbus_transaction *xenbus_transaction_start(void);
int xenbus_transaction_end(struct xenbus_transaction *t, int abort);
/* 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)));
/* notifer routines for when the xenstore comes up */
// XXX int register_xenstore_notifier(struct notifier_block *nb);
// XXX void unregister_xenstore_notifier(struct notifier_block *nb);
/* Used by xenbus_dev to borrow kernel's store connection. */
int xenbus_dev_request_and_reply(struct xsd_sockmsg *msg, void **);
void xenbus_dev_reply_free(struct xsd_sockmsg *msg, void *);
/**
* 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));
/* Unregister the watch, and free associated internal structures. */
void xenbus_unwatch_path(struct xenbus_watch *);
/**
* Advertise in the store a change of the given driver to the given new_state.
* Perform the change inside the given transaction xbt. xbt may be NULL, in
* which case this is performed inside its own transaction. 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,
struct xenbus_transaction *xbt,
XenbusState 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 *, paddr_t, grant_ref_t *);
/**
* 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);
/**
* Return the state of the driver rooted at the given store path, or
* XenbusStateClosed if no state can be read.
*/
XenbusState 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,
...);
