1 #ifndef _LINUX_VIRTIO_CONFIG_H
2 #define _LINUX_VIRTIO_CONFIG_H
6 #include <linux/virtio.h>
7 #include <uapi/linux/virtio_config.h>
10 * virtio_config_ops - operations for configuring a virtio device
11 * @get: read the value of a configuration field
12 * vdev: the virtio_device
13 * offset: the offset of the configuration field
14 * buf: the buffer to write the field value into.
15 * len: the length of the buffer
16 * @set: write the value of a configuration field
17 * vdev: the virtio_device
18 * offset: the offset of the configuration field
19 * buf: the buffer to read the field value from.
20 * len: the length of the buffer
21 * @get_status: read the status byte
22 * vdev: the virtio_device
23 * Returns the status byte
24 * @set_status: write the status byte
25 * vdev: the virtio_device
26 * status: the new status byte
27 * @reset: reset the device
28 * vdev: the virtio device
29 * After this, status and feature negotiation must be done again
30 * Device must not be reset from its vq/config callbacks, or in
31 * parallel with being added/removed.
32 * @find_vqs: find virtqueues and instantiate them.
33 * vdev: the virtio_device
34 * nvqs: the number of virtqueues to find
35 * vqs: on success, includes new virtqueues
36 * callbacks: array of callbacks, for each virtqueue
37 * include a NULL entry for vqs that do not need a callback
38 * names: array of virtqueue names (mainly for debugging)
39 * include a NULL entry for vqs unused by driver
40 * Returns 0 on success or error status
41 * @del_vqs: free virtqueues found by find_vqs().
42 * @get_features: get the array of feature bits for this device.
43 * vdev: the virtio_device
44 * Returns the first 32 feature bits (all we currently need).
45 * @finalize_features: confirm what device features we'll be using.
46 * vdev: the virtio_device
47 * This gives the final feature bits for the device: it can change
48 * the dev->feature bits if it wants.
49 * @bus_name: return the bus name associated with the device
50 * vdev: the virtio_device
51 * This returns a pointer to the bus name a la pci_name from which
52 * the caller can then copy.
53 * @set_vq_affinity: set the affinity for a virtqueue.
55 typedef void vq_callback_t(struct virtqueue
*);
56 struct virtio_config_ops
{
57 void (*get
)(struct virtio_device
*vdev
, unsigned offset
,
58 void *buf
, unsigned len
);
59 void (*set
)(struct virtio_device
*vdev
, unsigned offset
,
60 const void *buf
, unsigned len
);
61 u8 (*get_status
)(struct virtio_device
*vdev
);
62 void (*set_status
)(struct virtio_device
*vdev
, u8 status
);
63 void (*reset
)(struct virtio_device
*vdev
);
64 int (*find_vqs
)(struct virtio_device
*, unsigned nvqs
,
65 struct virtqueue
*vqs
[],
66 vq_callback_t
*callbacks
[],
68 void (*del_vqs
)(struct virtio_device
*);
69 u32 (*get_features
)(struct virtio_device
*vdev
);
70 void (*finalize_features
)(struct virtio_device
*vdev
);
71 const char *(*bus_name
)(struct virtio_device
*vdev
);
72 int (*set_vq_affinity
)(struct virtqueue
*vq
, int cpu
);
75 /* If driver didn't advertise the feature, it will never appear. */
76 void virtio_check_driver_offered_feature(const struct virtio_device
*vdev
,
80 * virtio_has_feature - helper to determine if this device has this feature.
82 * @fbit: the feature bit
84 static inline bool virtio_has_feature(const struct virtio_device
*vdev
,
87 /* Did you forget to fix assumptions on max features? */
88 if (__builtin_constant_p(fbit
))
89 BUILD_BUG_ON(fbit
>= 32);
93 if (fbit
< VIRTIO_TRANSPORT_F_START
)
94 virtio_check_driver_offered_feature(vdev
, fbit
);
96 return test_bit(fbit
, vdev
->features
);
100 struct virtqueue
*virtio_find_single_vq(struct virtio_device
*vdev
,
101 vq_callback_t
*c
, const char *n
)
103 vq_callback_t
*callbacks
[] = { c
};
104 const char *names
[] = { n
};
105 struct virtqueue
*vq
;
106 int err
= vdev
->config
->find_vqs(vdev
, 1, &vq
, callbacks
, names
);
113 * virtio_device_ready - enable vq use in probe function
116 * Driver must call this to use vqs in the probe function.
118 * Note: vqs are enabled automatically after probe returns.
121 void virtio_device_ready(struct virtio_device
*dev
)
123 unsigned status
= dev
->config
->get_status(dev
);
125 BUG_ON(status
& VIRTIO_CONFIG_S_DRIVER_OK
);
126 dev
->config
->set_status(dev
, status
| VIRTIO_CONFIG_S_DRIVER_OK
);
130 const char *virtio_bus_name(struct virtio_device
*vdev
)
132 if (!vdev
->config
->bus_name
)
134 return vdev
->config
->bus_name(vdev
);
138 * virtqueue_set_affinity - setting affinity for a virtqueue
142 * Pay attention the function are best-effort: the affinity hint may not be set
143 * due to config support, irq type and sharing.
147 int virtqueue_set_affinity(struct virtqueue
*vq
, int cpu
)
149 struct virtio_device
*vdev
= vq
->vdev
;
150 if (vdev
->config
->set_vq_affinity
)
151 return vdev
->config
->set_vq_affinity(vq
, cpu
);
155 /* Config space accessors. */
156 #define virtio_cread(vdev, structname, member, ptr) \
158 /* Must match the member's type, and be integer */ \
159 if (!typecheck(typeof((((structname*)0)->member)), *(ptr))) \
162 switch (sizeof(*ptr)) { \
164 *(ptr) = virtio_cread8(vdev, \
165 offsetof(structname, member)); \
168 *(ptr) = virtio_cread16(vdev, \
169 offsetof(structname, member)); \
172 *(ptr) = virtio_cread32(vdev, \
173 offsetof(structname, member)); \
176 *(ptr) = virtio_cread64(vdev, \
177 offsetof(structname, member)); \
184 /* Config space accessors. */
185 #define virtio_cwrite(vdev, structname, member, ptr) \
187 /* Must match the member's type, and be integer */ \
188 if (!typecheck(typeof((((structname*)0)->member)), *(ptr))) \
189 BUG_ON((*ptr) == 1); \
191 switch (sizeof(*ptr)) { \
193 virtio_cwrite8(vdev, \
194 offsetof(structname, member), \
198 virtio_cwrite16(vdev, \
199 offsetof(structname, member), \
203 virtio_cwrite32(vdev, \
204 offsetof(structname, member), \
208 virtio_cwrite64(vdev, \
209 offsetof(structname, member), \
217 static inline u8
virtio_cread8(struct virtio_device
*vdev
, unsigned int offset
)
220 vdev
->config
->get(vdev
, offset
, &ret
, sizeof(ret
));
224 static inline void virtio_cread_bytes(struct virtio_device
*vdev
,
226 void *buf
, size_t len
)
228 vdev
->config
->get(vdev
, offset
, buf
, len
);
231 static inline void virtio_cwrite8(struct virtio_device
*vdev
,
232 unsigned int offset
, u8 val
)
234 vdev
->config
->set(vdev
, offset
, &val
, sizeof(val
));
237 static inline u16
virtio_cread16(struct virtio_device
*vdev
,
241 vdev
->config
->get(vdev
, offset
, &ret
, sizeof(ret
));
245 static inline void virtio_cwrite16(struct virtio_device
*vdev
,
246 unsigned int offset
, u16 val
)
248 vdev
->config
->set(vdev
, offset
, &val
, sizeof(val
));
251 static inline u32
virtio_cread32(struct virtio_device
*vdev
,
255 vdev
->config
->get(vdev
, offset
, &ret
, sizeof(ret
));
259 static inline void virtio_cwrite32(struct virtio_device
*vdev
,
260 unsigned int offset
, u32 val
)
262 vdev
->config
->set(vdev
, offset
, &val
, sizeof(val
));
265 static inline u64
virtio_cread64(struct virtio_device
*vdev
,
269 vdev
->config
->get(vdev
, offset
, &ret
, sizeof(ret
));
273 static inline void virtio_cwrite64(struct virtio_device
*vdev
,
274 unsigned int offset
, u64 val
)
276 vdev
->config
->set(vdev
, offset
, &val
, sizeof(val
));
279 /* Conditional config space accessors. */
280 #define virtio_cread_feature(vdev, fbit, structname, member, ptr) \
283 if (!virtio_has_feature(vdev, fbit)) \
286 virtio_cread((vdev), structname, member, ptr); \
290 #endif /* _LINUX_VIRTIO_CONFIG_H */