Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 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 | |
Rusty Russell | a586d4f | 2008-02-04 23:49:56 -0500 | [diff] [blame] | 8 | /* Status byte for guest to report progress, and synchronize features. */ |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 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 | |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 18 | #ifdef __KERNEL__ |
Rusty Russell | 72e61eb | 2008-05-02 21:50:49 -0500 | [diff] [blame] | 19 | #include <linux/virtio.h> |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 20 | |
| 21 | /** |
| 22 | * virtio_config_ops - operations for configuring a virtio device |
Rusty Russell | a586d4f | 2008-02-04 23:49:56 -0500 | [diff] [blame] | 23 | * @get: read the value of a configuration field |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 24 | * vdev: the virtio_device |
Rusty Russell | a586d4f | 2008-02-04 23:49:56 -0500 | [diff] [blame] | 25 | * offset: the offset of the configuration field |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 26 | * buf: the buffer to write the field value into. |
Rusty Russell | a586d4f | 2008-02-04 23:49:56 -0500 | [diff] [blame] | 27 | * len: the length of the buffer |
Rusty Russell | a586d4f | 2008-02-04 23:49:56 -0500 | [diff] [blame] | 28 | * @set: write the value of a configuration field |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 29 | * vdev: the virtio_device |
Rusty Russell | a586d4f | 2008-02-04 23:49:56 -0500 | [diff] [blame] | 30 | * offset: the offset of the configuration field |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 31 | * buf: the buffer to read the field value from. |
Rusty Russell | a586d4f | 2008-02-04 23:49:56 -0500 | [diff] [blame] | 32 | * len: the length of the buffer |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 33 | * @get_status: read the status byte |
| 34 | * vdev: the virtio_device |
| 35 | * Returns the status byte |
| 36 | * @set_status: write the status byte |
| 37 | * vdev: the virtio_device |
| 38 | * status: the new status byte |
Rusty Russell | 6e5aa7e | 2008-02-04 23:50:03 -0500 | [diff] [blame] | 39 | * @reset: reset the device |
| 40 | * vdev: the virtio device |
| 41 | * After this, status and feature negotiation must be done again |
Rusty Russell | a586d4f | 2008-02-04 23:49:56 -0500 | [diff] [blame] | 42 | * @find_vq: find a virtqueue and instantiate it. |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 43 | * vdev: the virtio_device |
Rusty Russell | a586d4f | 2008-02-04 23:49:56 -0500 | [diff] [blame] | 44 | * index: the 0-based virtqueue number in case there's more than one. |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 45 | * callback: the virqtueue callback |
Rusty Russell | a586d4f | 2008-02-04 23:49:56 -0500 | [diff] [blame] | 46 | * Returns the new virtqueue or ERR_PTR() (eg. -ENOENT). |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 47 | * @del_vq: free a virtqueue found by find_vq(). |
Rusty Russell | c45a681 | 2008-05-02 21:50:50 -0500 | [diff] [blame^] | 48 | * @get_features: get the array of feature bits for this device. |
| 49 | * vdev: the virtio_device |
| 50 | * Returns the first 32 feature bits (all we currently need). |
| 51 | * @set_features: confirm what device features we'll be using. |
| 52 | * vdev: the virtio_device |
| 53 | * feature: the first 32 feature bits |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 54 | */ |
| 55 | struct virtio_config_ops |
| 56 | { |
Rusty Russell | a586d4f | 2008-02-04 23:49:56 -0500 | [diff] [blame] | 57 | void (*get)(struct virtio_device *vdev, unsigned offset, |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 58 | void *buf, unsigned len); |
Rusty Russell | a586d4f | 2008-02-04 23:49:56 -0500 | [diff] [blame] | 59 | void (*set)(struct virtio_device *vdev, unsigned offset, |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 60 | const void *buf, unsigned len); |
| 61 | u8 (*get_status)(struct virtio_device *vdev); |
| 62 | void (*set_status)(struct virtio_device *vdev, u8 status); |
Rusty Russell | 6e5aa7e | 2008-02-04 23:50:03 -0500 | [diff] [blame] | 63 | void (*reset)(struct virtio_device *vdev); |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 64 | struct virtqueue *(*find_vq)(struct virtio_device *vdev, |
Rusty Russell | a586d4f | 2008-02-04 23:49:56 -0500 | [diff] [blame] | 65 | unsigned index, |
Rusty Russell | 18445c4 | 2008-02-04 23:49:57 -0500 | [diff] [blame] | 66 | void (*callback)(struct virtqueue *)); |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 67 | void (*del_vq)(struct virtqueue *vq); |
Rusty Russell | c45a681 | 2008-05-02 21:50:50 -0500 | [diff] [blame^] | 68 | u32 (*get_features)(struct virtio_device *vdev); |
| 69 | void (*set_features)(struct virtio_device *vdev, u32 features); |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 70 | }; |
| 71 | |
Rusty Russell | c45a681 | 2008-05-02 21:50:50 -0500 | [diff] [blame^] | 72 | /* If driver didn't advertise the feature, it will never appear. */ |
| 73 | void virtio_check_driver_offered_feature(const struct virtio_device *vdev, |
| 74 | unsigned int fbit); |
| 75 | |
| 76 | /** |
| 77 | * virtio_has_feature - helper to determine if this device has this feature. |
| 78 | * @vdev: the device |
| 79 | * @fbit: the feature bit |
| 80 | */ |
| 81 | static inline bool virtio_has_feature(const struct virtio_device *vdev, |
| 82 | unsigned int fbit) |
| 83 | { |
| 84 | /* Did you forget to fix assumptions on max features? */ |
| 85 | if (__builtin_constant_p(fbit)) |
| 86 | BUILD_BUG_ON(fbit >= 32); |
| 87 | |
| 88 | virtio_check_driver_offered_feature(vdev, fbit); |
| 89 | return test_bit(fbit, vdev->features); |
| 90 | } |
| 91 | |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 92 | /** |
Rusty Russell | 72e61eb | 2008-05-02 21:50:49 -0500 | [diff] [blame] | 93 | * virtio_config_val - look for a feature and get a virtio config entry. |
Rusty Russell | a586d4f | 2008-02-04 23:49:56 -0500 | [diff] [blame] | 94 | * @vdev: the virtio device |
| 95 | * @fbit: the feature bit |
| 96 | * @offset: the type to search for. |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 97 | * @val: a pointer to the value to fill in. |
| 98 | * |
Rusty Russell | a586d4f | 2008-02-04 23:49:56 -0500 | [diff] [blame] | 99 | * The return value is -ENOENT if the feature doesn't exist. Otherwise |
Rusty Russell | 72e61eb | 2008-05-02 21:50:49 -0500 | [diff] [blame] | 100 | * the config value is copied into whatever is pointed to by v. */ |
| 101 | #define virtio_config_val(vdev, fbit, offset, v) \ |
| 102 | virtio_config_buf((vdev), (fbit), (offset), (v), sizeof(v)) |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 103 | |
Rusty Russell | 72e61eb | 2008-05-02 21:50:49 -0500 | [diff] [blame] | 104 | static inline int virtio_config_buf(struct virtio_device *vdev, |
| 105 | unsigned int fbit, |
| 106 | unsigned int offset, |
| 107 | void *buf, unsigned len) |
| 108 | { |
Rusty Russell | c45a681 | 2008-05-02 21:50:50 -0500 | [diff] [blame^] | 109 | if (!virtio_has_feature(vdev, fbit)) |
Rusty Russell | 72e61eb | 2008-05-02 21:50:49 -0500 | [diff] [blame] | 110 | return -ENOENT; |
| 111 | |
| 112 | vdev->config->get(vdev, offset, buf, len); |
| 113 | return 0; |
| 114 | } |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 115 | #endif /* __KERNEL__ */ |
| 116 | #endif /* _LINUX_VIRTIO_CONFIG_H */ |