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 
22 struct 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  **/
29 struct 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 
42 struct kvm_io_device {
43 	const struct kvm_io_device_ops *ops;
44 };
45 
kvm_iodevice_init(struct kvm_io_device * dev,const struct kvm_io_device_ops * ops)46 static 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 
kvm_iodevice_read(struct kvm_io_device * dev,gpa_t addr,int l,void * v)52 static 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 
kvm_iodevice_write(struct kvm_io_device * dev,gpa_t addr,int l,const void * v)58 static 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 
kvm_iodevice_destructor(struct kvm_io_device * dev)64 static 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__ */
71