Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 1 | #ifndef _LINUX_VIRTIO_CONFIG_H |
| 2 | #define _LINUX_VIRTIO_CONFIG_H |
Rusty Russell | 674bfc2 | 2008-07-25 12:06:03 -0500 | [diff] [blame] | 3 | /* This header, excluding the #ifdef __KERNEL__ part, is BSD licensed so |
| 4 | * anyone can use the definitions to implement compatible drivers/servers. */ |
| 5 | |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 6 | /* Virtio devices use a standardized configuration space to define their |
| 7 | * features and pass configuration information, but each implementation can |
| 8 | * store and access that space differently. */ |
| 9 | #include <linux/types.h> |
| 10 | |
Rusty Russell | a586d4f | 2008-02-04 23:49:56 -0500 | [diff] [blame] | 11 | /* Status byte for guest to report progress, and synchronize features. */ |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 12 | /* We have seen device and processed generic fields (VIRTIO_CONFIG_F_VIRTIO) */ |
| 13 | #define VIRTIO_CONFIG_S_ACKNOWLEDGE 1 |
| 14 | /* We have found a driver for the device. */ |
| 15 | #define VIRTIO_CONFIG_S_DRIVER 2 |
| 16 | /* Driver has used its parts of the config, and is happy */ |
| 17 | #define VIRTIO_CONFIG_S_DRIVER_OK 4 |
| 18 | /* We've given up on this device. */ |
| 19 | #define VIRTIO_CONFIG_S_FAILED 0x80 |
| 20 | |
Rusty Russell | dd7c7bc | 2008-07-25 12:06:07 -0500 | [diff] [blame] | 21 | /* Some virtio feature bits (currently bits 28 through 31) are reserved for the |
| 22 | * transport being used (eg. virtio_ring), the rest are per-device feature |
| 23 | * bits. */ |
| 24 | #define VIRTIO_TRANSPORT_F_START 28 |
| 25 | #define VIRTIO_TRANSPORT_F_END 32 |
| 26 | |
Rusty Russell | b4f68be | 2008-05-30 15:09:45 -0500 | [diff] [blame] | 27 | /* Do we get callbacks when the ring is completely used, even if we've |
| 28 | * suppressed them? */ |
| 29 | #define VIRTIO_F_NOTIFY_ON_EMPTY 24 |
| 30 | |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 31 | #ifdef __KERNEL__ |
Rusty Russell | 72e61eb | 2008-05-02 21:50:49 -0500 | [diff] [blame] | 32 | #include <linux/virtio.h> |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 33 | |
| 34 | /** |
| 35 | * virtio_config_ops - operations for configuring a virtio device |
Rusty Russell | a586d4f | 2008-02-04 23:49:56 -0500 | [diff] [blame] | 36 | * @get: read the value of a configuration field |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 37 | * vdev: the virtio_device |
Rusty Russell | a586d4f | 2008-02-04 23:49:56 -0500 | [diff] [blame] | 38 | * offset: the offset of the configuration field |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 39 | * buf: the buffer to write the field value into. |
Rusty Russell | a586d4f | 2008-02-04 23:49:56 -0500 | [diff] [blame] | 40 | * len: the length of the buffer |
Rusty Russell | a586d4f | 2008-02-04 23:49:56 -0500 | [diff] [blame] | 41 | * @set: write the value of a configuration field |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 42 | * vdev: the virtio_device |
Rusty Russell | a586d4f | 2008-02-04 23:49:56 -0500 | [diff] [blame] | 43 | * offset: the offset of the configuration field |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 44 | * buf: the buffer to read the field value from. |
Rusty Russell | a586d4f | 2008-02-04 23:49:56 -0500 | [diff] [blame] | 45 | * len: the length of the buffer |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 46 | * @get_status: read the status byte |
| 47 | * vdev: the virtio_device |
| 48 | * Returns the status byte |
| 49 | * @set_status: write the status byte |
| 50 | * vdev: the virtio_device |
| 51 | * status: the new status byte |
Rusty Russell | 6e5aa7e | 2008-02-04 23:50:03 -0500 | [diff] [blame] | 52 | * @reset: reset the device |
| 53 | * vdev: the virtio device |
| 54 | * After this, status and feature negotiation must be done again |
Rusty Russell | a586d4f | 2008-02-04 23:49:56 -0500 | [diff] [blame] | 55 | * @find_vq: find a virtqueue and instantiate it. |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 56 | * vdev: the virtio_device |
Rusty Russell | a586d4f | 2008-02-04 23:49:56 -0500 | [diff] [blame] | 57 | * 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] | 58 | * callback: the virqtueue callback |
Rusty Russell | a586d4f | 2008-02-04 23:49:56 -0500 | [diff] [blame] | 59 | * Returns the new virtqueue or ERR_PTR() (eg. -ENOENT). |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 60 | * @del_vq: free a virtqueue found by find_vq(). |
Rusty Russell | c45a681 | 2008-05-02 21:50:50 -0500 | [diff] [blame] | 61 | * @get_features: get the array of feature bits for this device. |
| 62 | * vdev: the virtio_device |
| 63 | * Returns the first 32 feature bits (all we currently need). |
Rusty Russell | c624896 | 2008-07-25 12:06:07 -0500 | [diff] [blame^] | 64 | * @finalize_features: confirm what device features we'll be using. |
Rusty Russell | c45a681 | 2008-05-02 21:50:50 -0500 | [diff] [blame] | 65 | * vdev: the virtio_device |
Rusty Russell | c624896 | 2008-07-25 12:06:07 -0500 | [diff] [blame^] | 66 | * This gives the final feature bits for the device: it can change |
| 67 | * the dev->feature bits if it wants. |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 68 | */ |
| 69 | struct virtio_config_ops |
| 70 | { |
Rusty Russell | a586d4f | 2008-02-04 23:49:56 -0500 | [diff] [blame] | 71 | void (*get)(struct virtio_device *vdev, unsigned offset, |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 72 | void *buf, unsigned len); |
Rusty Russell | a586d4f | 2008-02-04 23:49:56 -0500 | [diff] [blame] | 73 | void (*set)(struct virtio_device *vdev, unsigned offset, |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 74 | const void *buf, unsigned len); |
| 75 | u8 (*get_status)(struct virtio_device *vdev); |
| 76 | void (*set_status)(struct virtio_device *vdev, u8 status); |
Rusty Russell | 6e5aa7e | 2008-02-04 23:50:03 -0500 | [diff] [blame] | 77 | void (*reset)(struct virtio_device *vdev); |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 78 | struct virtqueue *(*find_vq)(struct virtio_device *vdev, |
Rusty Russell | a586d4f | 2008-02-04 23:49:56 -0500 | [diff] [blame] | 79 | unsigned index, |
Rusty Russell | 18445c4 | 2008-02-04 23:49:57 -0500 | [diff] [blame] | 80 | void (*callback)(struct virtqueue *)); |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 81 | void (*del_vq)(struct virtqueue *vq); |
Rusty Russell | c45a681 | 2008-05-02 21:50:50 -0500 | [diff] [blame] | 82 | u32 (*get_features)(struct virtio_device *vdev); |
Rusty Russell | c624896 | 2008-07-25 12:06:07 -0500 | [diff] [blame^] | 83 | void (*finalize_features)(struct virtio_device *vdev); |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 84 | }; |
| 85 | |
Rusty Russell | c45a681 | 2008-05-02 21:50:50 -0500 | [diff] [blame] | 86 | /* If driver didn't advertise the feature, it will never appear. */ |
| 87 | void virtio_check_driver_offered_feature(const struct virtio_device *vdev, |
| 88 | unsigned int fbit); |
| 89 | |
| 90 | /** |
| 91 | * virtio_has_feature - helper to determine if this device has this feature. |
| 92 | * @vdev: the device |
| 93 | * @fbit: the feature bit |
| 94 | */ |
| 95 | static inline bool virtio_has_feature(const struct virtio_device *vdev, |
| 96 | unsigned int fbit) |
| 97 | { |
| 98 | /* Did you forget to fix assumptions on max features? */ |
| 99 | if (__builtin_constant_p(fbit)) |
| 100 | BUILD_BUG_ON(fbit >= 32); |
| 101 | |
| 102 | virtio_check_driver_offered_feature(vdev, fbit); |
| 103 | return test_bit(fbit, vdev->features); |
| 104 | } |
| 105 | |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 106 | /** |
Rusty Russell | 72e61eb | 2008-05-02 21:50:49 -0500 | [diff] [blame] | 107 | * 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] | 108 | * @vdev: the virtio device |
| 109 | * @fbit: the feature bit |
| 110 | * @offset: the type to search for. |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 111 | * @val: a pointer to the value to fill in. |
| 112 | * |
Rusty Russell | a586d4f | 2008-02-04 23:49:56 -0500 | [diff] [blame] | 113 | * The return value is -ENOENT if the feature doesn't exist. Otherwise |
Rusty Russell | 72e61eb | 2008-05-02 21:50:49 -0500 | [diff] [blame] | 114 | * the config value is copied into whatever is pointed to by v. */ |
| 115 | #define virtio_config_val(vdev, fbit, offset, v) \ |
Christian Borntraeger | 7f31fe0 | 2008-05-29 11:08:01 +0200 | [diff] [blame] | 116 | virtio_config_buf((vdev), (fbit), (offset), (v), sizeof(*v)) |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 117 | |
Rusty Russell | 72e61eb | 2008-05-02 21:50:49 -0500 | [diff] [blame] | 118 | static inline int virtio_config_buf(struct virtio_device *vdev, |
| 119 | unsigned int fbit, |
| 120 | unsigned int offset, |
| 121 | void *buf, unsigned len) |
| 122 | { |
Rusty Russell | c45a681 | 2008-05-02 21:50:50 -0500 | [diff] [blame] | 123 | if (!virtio_has_feature(vdev, fbit)) |
Rusty Russell | 72e61eb | 2008-05-02 21:50:49 -0500 | [diff] [blame] | 124 | return -ENOENT; |
| 125 | |
| 126 | vdev->config->get(vdev, offset, buf, len); |
| 127 | return 0; |
| 128 | } |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 129 | #endif /* __KERNEL__ */ |
| 130 | #endif /* _LINUX_VIRTIO_CONFIG_H */ |