1/*
 2 * This program is free software; you can redistribute it and/or modify
 3 * it under the terms of the GNU General Public License as published by
 4 * the Free Software Foundation; either version 2 of the License.
 5 *
 6 * This program is distributed in the hope that it will be useful,
 7 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 8 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 9 * GNU General Public License for more details.
10 *
11 * You should have received a copy of the GNU General Public License
12 * along with this program; if not, write to the Free Software
13 * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
14 */
15
16#ifndef __KVM_IODEV_H__
17#define __KVM_IODEV_H__
18
19#include <linux/kvm_types.h>
20#include <asm/errno.h>
21
22struct kvm_io_device;
23
24/**
25 * kvm_io_device_ops are called under kvm slots_lock.
26 * read and write handlers return 0 if the transaction has been handled,
27 * or non-zero to have it passed to the next device.
28 **/
29struct kvm_io_device_ops {
30	int (*read)(struct kvm_io_device *this,
31		    gpa_t addr,
32		    int len,
33		    void *val);
34	int (*write)(struct kvm_io_device *this,
35		     gpa_t addr,
36		     int len,
37		     const void *val);
38	void (*destructor)(struct kvm_io_device *this);
39};
40
41
42struct kvm_io_device {
43	const struct kvm_io_device_ops *ops;
44};
45
46static inline void kvm_iodevice_init(struct kvm_io_device *dev,
47				     const struct kvm_io_device_ops *ops)
48{
49	dev->ops = ops;
50}
51
52static inline int kvm_iodevice_read(struct kvm_io_device *dev,
53				    gpa_t addr, int l, void *v)
54{
55	return dev->ops->read ? dev->ops->read(dev, addr, l, v) : -EOPNOTSUPP;
56}
57
58static inline int kvm_iodevice_write(struct kvm_io_device *dev,
59				     gpa_t addr, int l, const void *v)
60{
61	return dev->ops->write ? dev->ops->write(dev, addr, l, v) : -EOPNOTSUPP;
62}
63
64static inline void kvm_iodevice_destructor(struct kvm_io_device *dev)
65{
66	if (dev->ops->destructor)
67		dev->ops->destructor(dev);
68}
69
70#endif /* __KVM_IODEV_H__ */