4 * Driver giving user-space access to the kernel's connection to the
7 * Copyright (c) 2005, Christian Limpach
8 * Copyright (c) 2005, Rusty Russell, IBM Corporation
10 * This file may be distributed separately from the Linux kernel, or
11 * incorporated into other software packages, subject to the following license:
13 * Permission is hereby granted, free of charge, to any person obtaining a copy
14 * of this source file (the "Software"), to deal in the Software without
15 * restriction, including without limitation the rights to use, copy, modify,
16 * merge, publish, distribute, sublicense, and/or sell copies of the Software,
17 * and to permit persons to whom the Software is furnished to do so, subject to
18 * the following conditions:
20 * The above copyright notice and this permission notice shall be included in
21 * all copies or substantial portions of the Software.
23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
24 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
25 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
26 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
27 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
28 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
33 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD$");
36 #include <sys/types.h>
37 #include <sys/cdefs.h>
38 #include <sys/errno.h>
40 #include <sys/param.h>
41 #include <sys/systm.h>
43 #include <sys/kernel.h>
44 #include <sys/malloc.h>
47 #include <machine/xen/xen-os.h>
49 #include <xen/hypervisor.h>
50 #include <xen/xenstore/xenstorevar.h>
51 #include <xen/xenstore/xenstore_internal.h>
53 struct xs_dev_transaction {
54 LIST_ENTRY(xs_dev_transaction) list;
55 struct xs_transaction handle;
59 /* In-progress transaction. */
60 LIST_HEAD(xdd_list_head, xs_dev_transaction) transactions;
62 /* Partial request. */
65 struct xsd_sockmsg msg;
66 char buffer[PAGE_SIZE];
70 #define MASK_READ_IDX(idx) ((idx)&(PAGE_SIZE-1))
71 char read_buffer[PAGE_SIZE];
72 unsigned int read_cons, read_prod;
76 xs_dev_read(struct cdev *dev, struct uio *uio, int ioflag)
79 struct xs_dev_data *u = dev->si_drv1;
81 while (u->read_prod == u->read_cons) {
82 error = tsleep(u, PCATCH, "xsdread", hz/10);
83 if (error && error != EWOULDBLOCK)
87 while (uio->uio_resid > 0) {
88 if (u->read_cons == u->read_prod)
90 error = uiomove(&u->read_buffer[MASK_READ_IDX(u->read_cons)],
100 xs_queue_reply(struct xs_dev_data *u, char *data, unsigned int len)
104 for (i = 0; i < len; i++, u->read_prod++)
105 u->read_buffer[MASK_READ_IDX(u->read_prod)] = data[i];
107 KASSERT((u->read_prod - u->read_cons) <= sizeof(u->read_buffer),
108 ("xenstore reply too big"));
114 xs_dev_write(struct cdev *dev, struct uio *uio, int ioflag)
117 struct xs_dev_data *u = dev->si_drv1;
118 struct xs_dev_transaction *trans;
120 int len = uio->uio_resid;
122 if ((len + u->len) > sizeof(u->u.buffer))
125 error = uiomove(u->u.buffer + u->len, len, uio);
130 if (u->len < (sizeof(u->u.msg) + u->u.msg.len))
133 switch (u->u.msg.type) {
134 case XS_TRANSACTION_START:
135 case XS_TRANSACTION_END:
140 case XS_GET_DOMAIN_PATH:
145 error = xs_dev_request_and_reply(&u->u.msg, &reply);
147 if (u->u.msg.type == XS_TRANSACTION_START) {
148 trans = malloc(sizeof(*trans), M_XENSTORE,
150 trans->handle.id = strtoul(reply, NULL, 0);
151 LIST_INSERT_HEAD(&u->transactions, trans, list);
152 } else if (u->u.msg.type == XS_TRANSACTION_END) {
153 LIST_FOREACH(trans, &u->transactions, list)
154 if (trans->handle.id == u->u.msg.tx_id)
156 #if 0 /* XXX does this mean the list is empty? */
157 BUG_ON(&trans->list == &u->transactions);
159 LIST_REMOVE(trans, list);
160 free(trans, M_XENSTORE);
162 xs_queue_reply(u, (char *)&u->u.msg, sizeof(u->u.msg));
163 xs_queue_reply(u, (char *)reply, u->u.msg.len);
164 free(reply, M_XENSTORE);
180 xs_dev_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
182 struct xs_dev_data *u;
184 #if 0 /* XXX figure out if equiv needed */
185 nonseekable_open(inode, filp);
187 u = malloc(sizeof(*u), M_XENSTORE, M_WAITOK|M_ZERO);
188 LIST_INIT(&u->transactions);
195 xs_dev_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
197 struct xs_dev_data *u = dev->si_drv1;
198 struct xs_dev_transaction *trans, *tmp;
200 LIST_FOREACH_SAFE(trans, &u->transactions, list, tmp) {
201 xs_transaction_end(trans->handle, 1);
202 LIST_REMOVE(trans, list);
203 free(trans, M_XENSTORE);
210 static struct cdevsw xs_dev_cdevsw = {
211 .d_version = D_VERSION,
212 .d_read = xs_dev_read,
213 .d_write = xs_dev_write,
214 .d_open = xs_dev_open,
215 .d_close = xs_dev_close,
222 make_dev(&xs_dev_cdevsw, 0, UID_ROOT, GID_WHEEL, 0400,