Commit | Line | Data |
---|---|---|
ec3d41c4 RR |
1 | #ifndef _LINUX_VIRTIO_CONFIG_H |
2 | #define _LINUX_VIRTIO_CONFIG_H | |
3 | /* Virtio devices use a standardized configuration space to define their | |
4 | * features and pass configuration information, but each implementation can | |
5 | * store and access that space differently. */ | |
6 | #include <linux/types.h> | |
7 | ||
a586d4f6 | 8 | /* Status byte for guest to report progress, and synchronize features. */ |
ec3d41c4 RR |
9 | /* We have seen device and processed generic fields (VIRTIO_CONFIG_F_VIRTIO) */ |
10 | #define VIRTIO_CONFIG_S_ACKNOWLEDGE 1 | |
11 | /* We have found a driver for the device. */ | |
12 | #define VIRTIO_CONFIG_S_DRIVER 2 | |
13 | /* Driver has used its parts of the config, and is happy */ | |
14 | #define VIRTIO_CONFIG_S_DRIVER_OK 4 | |
15 | /* We've given up on this device. */ | |
16 | #define VIRTIO_CONFIG_S_FAILED 0x80 | |
17 | ||
ec3d41c4 RR |
18 | #ifdef __KERNEL__ |
19 | struct virtio_device; | |
20 | ||
21 | /** | |
22 | * virtio_config_ops - operations for configuring a virtio device | |
a586d4f6 | 23 | * @feature: search for a feature in this config |
ec3d41c4 | 24 | * vdev: the virtio_device |
a586d4f6 RR |
25 | * bit: the feature bit |
26 | * Returns true if the feature is supported. Acknowledges the feature | |
27 | * so the host can see it. | |
28 | * @get: read the value of a configuration field | |
ec3d41c4 | 29 | * vdev: the virtio_device |
a586d4f6 | 30 | * offset: the offset of the configuration field |
ec3d41c4 | 31 | * buf: the buffer to write the field value into. |
a586d4f6 | 32 | * len: the length of the buffer |
ec3d41c4 | 33 | * Note that contents are conventionally little-endian. |
a586d4f6 | 34 | * @set: write the value of a configuration field |
ec3d41c4 | 35 | * vdev: the virtio_device |
a586d4f6 | 36 | * offset: the offset of the configuration field |
ec3d41c4 | 37 | * buf: the buffer to read the field value from. |
a586d4f6 | 38 | * len: the length of the buffer |
ec3d41c4 RR |
39 | * Note that contents are conventionally little-endian. |
40 | * @get_status: read the status byte | |
41 | * vdev: the virtio_device | |
42 | * Returns the status byte | |
43 | * @set_status: write the status byte | |
44 | * vdev: the virtio_device | |
45 | * status: the new status byte | |
a586d4f6 | 46 | * @find_vq: find a virtqueue and instantiate it. |
ec3d41c4 | 47 | * vdev: the virtio_device |
a586d4f6 | 48 | * index: the 0-based virtqueue number in case there's more than one. |
ec3d41c4 | 49 | * callback: the virqtueue callback |
a586d4f6 | 50 | * Returns the new virtqueue or ERR_PTR() (eg. -ENOENT). |
ec3d41c4 RR |
51 | * @del_vq: free a virtqueue found by find_vq(). |
52 | */ | |
53 | struct virtio_config_ops | |
54 | { | |
a586d4f6 RR |
55 | bool (*feature)(struct virtio_device *vdev, unsigned bit); |
56 | void (*get)(struct virtio_device *vdev, unsigned offset, | |
ec3d41c4 | 57 | void *buf, unsigned len); |
a586d4f6 | 58 | void (*set)(struct virtio_device *vdev, unsigned offset, |
ec3d41c4 RR |
59 | const void *buf, unsigned len); |
60 | u8 (*get_status)(struct virtio_device *vdev); | |
61 | void (*set_status)(struct virtio_device *vdev, u8 status); | |
62 | struct virtqueue *(*find_vq)(struct virtio_device *vdev, | |
a586d4f6 | 63 | unsigned index, |
18445c4d | 64 | void (*callback)(struct virtqueue *)); |
ec3d41c4 RR |
65 | void (*del_vq)(struct virtqueue *vq); |
66 | }; | |
67 | ||
68 | /** | |
a586d4f6 RR |
69 | * virtio_config_val - look for a feature and get a single virtio config. |
70 | * @vdev: the virtio device | |
71 | * @fbit: the feature bit | |
72 | * @offset: the type to search for. | |
ec3d41c4 RR |
73 | * @val: a pointer to the value to fill in. |
74 | * | |
a586d4f6 RR |
75 | * The return value is -ENOENT if the feature doesn't exist. Otherwise |
76 | * the value is endian-corrected and returned in v. */ | |
77 | #define virtio_config_val(vdev, fbit, offset, v) ({ \ | |
78 | int _err; \ | |
79 | if ((vdev)->config->feature((vdev), (fbit))) { \ | |
80 | __virtio_config_val((vdev), (offset), (v)); \ | |
81 | _err = 0; \ | |
82 | } else \ | |
83 | _err = -ENOENT; \ | |
ec3d41c4 RR |
84 | _err; \ |
85 | }) | |
86 | ||
ec3d41c4 | 87 | /** |
a586d4f6 RR |
88 | * __virtio_config_val - get a single virtio config without feature check. |
89 | * @vdev: the virtio device | |
90 | * @offset: the type to search for. | |
91 | * @val: a pointer to the value to fill in. | |
ec3d41c4 | 92 | * |
a586d4f6 RR |
93 | * The value is endian-corrected and returned in v. */ |
94 | #define __virtio_config_val(vdev, offset, v) do { \ | |
95 | BUILD_BUG_ON(sizeof(*(v)) != 1 && sizeof(*(v)) != 2 \ | |
96 | && sizeof(*(v)) != 4 && sizeof(*(v)) != 8); \ | |
97 | (vdev)->config->get((vdev), (offset), (v), sizeof(*(v))); \ | |
98 | switch (sizeof(*(v))) { \ | |
99 | case 2: le16_to_cpus((__u16 *) v); break; \ | |
100 | case 4: le32_to_cpus((__u32 *) v); break; \ | |
101 | case 8: le64_to_cpus((__u64 *) v); break; \ | |
102 | } \ | |
103 | } while(0) | |
ec3d41c4 RR |
104 | #endif /* __KERNEL__ */ |
105 | #endif /* _LINUX_VIRTIO_CONFIG_H */ |