freebsd-dev/sys/xen/xenbus/xenbus_dev.c
Kip Macy 30d1eefe39 Import OS interfaces to Xen services.
MFC after:	2 weeks
2008-08-12 07:36:56 +00:00

261 lines
6.4 KiB
C

/*
* xenbus_dev.c
*
* Driver giving user-space access to the kernel's xenbus connection
* to xenstore.
*
* Copyright (c) 2005, Christian Limpach
* Copyright (c) 2005, Rusty Russell, IBM Corporation
*
* 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <sys/cdefs.h>
#include <sys/errno.h>
#include <sys/uio.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/conf.h>
#include <machine/xen/hypervisor.h>
#include <machine/xen/xenbus.h>
#include <machine/xen/hypervisor.h>
#include <xen/xenbus/xenbus_comms.h>
#define kmalloc(size, unused) malloc(size, M_DEVBUF, M_WAITOK)
#define BUG_ON PANIC_IF
#define semaphore sema
#define rw_semaphore sema
#define spin_lock mtx_lock
#define spin_unlock mtx_unlock
#define DEFINE_SPINLOCK(lock) struct mtx lock
#define DECLARE_MUTEX(lock) struct sema lock
#define u32 uint32_t
#define simple_strtoul strtoul
struct xenbus_dev_transaction {
LIST_ENTRY(xenbus_dev_transaction) list;
struct xenbus_transaction handle;
};
struct xenbus_dev_data {
/* In-progress transaction. */
LIST_HEAD(xdd_list_head, xenbus_dev_transaction) transactions;
/* Partial request. */
unsigned int len;
union {
struct xsd_sockmsg msg;
char buffer[PAGE_SIZE];
} u;
/* Response queue. */
#define MASK_READ_IDX(idx) ((idx)&(PAGE_SIZE-1))
char read_buffer[PAGE_SIZE];
unsigned int read_cons, read_prod;
int read_waitq;
};
#if 0
static struct proc_dir_entry *xenbus_dev_intf;
#endif
static int
xenbus_dev_read(struct cdev *dev, struct uio *uio, int ioflag)
{
int i = 0;
struct xenbus_dev_data *u = dev->si_drv1;
if (wait_event_interruptible(&u->read_waitq,
u->read_prod != u->read_cons))
return EINTR;
for (i = 0; i < uio->uio_iov[0].iov_len; i++) {
if (u->read_cons == u->read_prod)
break;
copyout(&u->read_buffer[MASK_READ_IDX(u->read_cons)], (char *)uio->uio_iov[0].iov_base+i, 1);
u->read_cons++;
uio->uio_resid--;
}
return 0;
}
static void queue_reply(struct xenbus_dev_data *u,
char *data, unsigned int len)
{
int i;
for (i = 0; i < len; i++, u->read_prod++)
u->read_buffer[MASK_READ_IDX(u->read_prod)] = data[i];
BUG_ON((u->read_prod - u->read_cons) > sizeof(u->read_buffer));
wakeup(&u->read_waitq);
}
static int
xenbus_dev_write(struct cdev *dev, struct uio *uio, int ioflag)
{
int err = 0;
struct xenbus_dev_data *u = dev->si_drv1;
struct xenbus_dev_transaction *trans;
void *reply;
int len = uio->uio_iov[0].iov_len;
if ((len + u->len) > sizeof(u->u.buffer))
return EINVAL;
if (copyin(u->u.buffer + u->len, uio->uio_iov[0].iov_base, len) != 0)
return EFAULT;
u->len += len;
if (u->len < (sizeof(u->u.msg) + u->u.msg.len))
return len;
switch (u->u.msg.type) {
case XS_TRANSACTION_START:
case XS_TRANSACTION_END:
case XS_DIRECTORY:
case XS_READ:
case XS_GET_PERMS:
case XS_RELEASE:
case XS_GET_DOMAIN_PATH:
case XS_WRITE:
case XS_MKDIR:
case XS_RM:
case XS_SET_PERMS:
reply = xenbus_dev_request_and_reply(&u->u.msg);
if (IS_ERR(reply)) {
err = PTR_ERR(reply);
} else {
if (u->u.msg.type == XS_TRANSACTION_START) {
trans = kmalloc(sizeof(*trans), GFP_KERNEL);
trans->handle.id = simple_strtoul(reply, NULL, 0);
LIST_INSERT_HEAD(&u->transactions, trans, list);
} else if (u->u.msg.type == XS_TRANSACTION_END) {
LIST_FOREACH(trans, &u->transactions,
list)
if (trans->handle.id ==
u->u.msg.tx_id)
break;
#if 0 /* XXX does this mean the list is empty? */
BUG_ON(&trans->list == &u->transactions);
#endif
LIST_REMOVE(trans, list);
kfree(trans);
}
queue_reply(u, (char *)&u->u.msg, sizeof(u->u.msg));
queue_reply(u, (char *)reply, u->u.msg.len);
kfree(reply);
}
break;
default:
err = EINVAL;
break;
}
if (err == 0) {
u->len = 0;
err = len;
}
return err;
}
static int xenbus_dev_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
{
struct xenbus_dev_data *u;
if (xen_start_info->store_evtchn == 0)
return ENOENT;
#if 0 /* XXX figure out if equiv needed */
nonseekable_open(inode, filp);
#endif
u = kmalloc(sizeof(*u), GFP_KERNEL);
if (u == NULL)
return ENOMEM;
memset(u, 0, sizeof(*u));
LIST_INIT(&u->transactions);
dev->si_drv1 = u;
return 0;
}
static int xenbus_dev_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
{
struct xenbus_dev_data *u = dev->si_drv1;
struct xenbus_dev_transaction *trans, *tmp;
LIST_FOREACH_SAFE(trans, &u->transactions, list, tmp) {
xenbus_transaction_end(trans->handle, 1);
LIST_REMOVE(trans, list);
kfree(trans);
}
kfree(u);
return 0;
}
static struct cdevsw xenbus_dev_cdevsw = {
.d_version = D_VERSION,
.d_read = xenbus_dev_read,
.d_write = xenbus_dev_write,
.d_open = xenbus_dev_open,
.d_close = xenbus_dev_close,
.d_name = "xenbus_dev",
};
static int
xenbus_dev_sysinit(void)
{
make_dev(&xenbus_dev_cdevsw, 0, UID_ROOT, GID_WHEEL, 0400, "xenbus");
return 0;
}
SYSINIT(xenbus_dev_sysinit, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, xenbus_dev_sysinit, NULL);
/* SYSINIT NEEDED XXX */
/*
* Local variables:
* c-file-style: "linux"
* indent-tabs-mode: t
* c-indent-level: 8
* c-basic-offset: 8
* tab-width: 8
* End:
*/