| 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 | |
| 8 | /* Status byte for guest to report progress, and synchronize config. */ |
| 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 | |
| 18 | /* Feature byte (actually 7 bits availabe): */ |
| 19 | /* Requirements/features of the virtio implementation. */ |
| 20 | #define VIRTIO_CONFIG_F_VIRTIO 1 |
| 21 | /* Requirements/features of the virtqueue (may have more than one). */ |
| 22 | #define VIRTIO_CONFIG_F_VIRTQUEUE 2 |
| 23 | |
| 24 | #ifdef __KERNEL__ |
| 25 | struct virtio_device; |
| 26 | |
| 27 | /** |
| 28 | * virtio_config_ops - operations for configuring a virtio device |
| 29 | * @find: search for the next configuration field of the given type. |
| 30 | * vdev: the virtio_device |
| 31 | * type: the feature type |
| 32 | * len: the (returned) length of the field if found. |
| 33 | * Returns a token if found, or NULL. Never returnes the same field twice |
| 34 | * (ie. it's used up). |
| 35 | * @get: read the value of a configuration field after find(). |
| 36 | * vdev: the virtio_device |
| 37 | * token: the token returned from find(). |
| 38 | * buf: the buffer to write the field value into. |
| 39 | * len: the length of the buffer (given by find()). |
| 40 | * Note that contents are conventionally little-endian. |
| 41 | * @set: write the value of a configuration field after find(). |
| 42 | * vdev: the virtio_device |
| 43 | * token: the token returned from find(). |
| 44 | * buf: the buffer to read the field value from. |
| 45 | * len: the length of the buffer (given by find()). |
| 46 | * Note that contents are conventionally little-endian. |
| 47 | * @get_status: read the status byte |
| 48 | * vdev: the virtio_device |
| 49 | * Returns the status byte |
| 50 | * @set_status: write the status byte |
| 51 | * vdev: the virtio_device |
| 52 | * status: the new status byte |
| 53 | * @find_vq: find the first VIRTIO_CONFIG_F_VIRTQUEUE and create a virtqueue. |
| 54 | * vdev: the virtio_device |
| 55 | * callback: the virqtueue callback |
| 56 | * Returns the new virtqueue or ERR_PTR(). |
| 57 | * @del_vq: free a virtqueue found by find_vq(). |
| 58 | */ |
| 59 | struct virtio_config_ops |
| 60 | { |
| 61 | void *(*find)(struct virtio_device *vdev, u8 type, unsigned *len); |
| 62 | void (*get)(struct virtio_device *vdev, void *token, |
| 63 | void *buf, unsigned len); |
| 64 | void (*set)(struct virtio_device *vdev, void *token, |
| 65 | const void *buf, unsigned len); |
| 66 | u8 (*get_status)(struct virtio_device *vdev); |
| 67 | void (*set_status)(struct virtio_device *vdev, u8 status); |
| 68 | struct virtqueue *(*find_vq)(struct virtio_device *vdev, |
| 69 | bool (*callback)(struct virtqueue *)); |
| 70 | void (*del_vq)(struct virtqueue *vq); |
| 71 | }; |
| 72 | |
| 73 | /** |
| 74 | * virtio_config_val - get a single virtio config and mark it used. |
| 75 | * @config: the virtio config space |
| 76 | * @type: the type to search for. |
| 77 | * @val: a pointer to the value to fill in. |
| 78 | * |
| 79 | * Once used, the config type is marked with VIRTIO_CONFIG_F_USED so it can't |
| 80 | * be found again. This version does endian conversion. */ |
| 81 | #define virtio_config_val(vdev, type, v) ({ \ |
| 82 | int _err = __virtio_config_val((vdev),(type),(v),sizeof(*(v))); \ |
| 83 | \ |
| 84 | BUILD_BUG_ON(sizeof(*(v)) != 1 && sizeof(*(v)) != 2 \ |
| 85 | && sizeof(*(v)) != 4 && sizeof(*(v)) != 8); \ |
| 86 | if (!_err) { \ |
| 87 | switch (sizeof(*(v))) { \ |
| 88 | case 2: le16_to_cpus((__u16 *) v); break; \ |
| 89 | case 4: le32_to_cpus((__u32 *) v); break; \ |
| 90 | case 8: le64_to_cpus((__u64 *) v); break; \ |
| 91 | } \ |
| 92 | } \ |
| 93 | _err; \ |
| 94 | }) |
| 95 | |
| 96 | int __virtio_config_val(struct virtio_device *dev, |
| 97 | u8 type, void *val, size_t size); |
| 98 | |
| 99 | /** |
| 100 | * virtio_use_bit - helper to use a feature bit in a bitfield value. |
| 101 | * @dev: the virtio device |
| 102 | * @token: the token as returned from vdev->config->find(). |
| 103 | * @len: the length of the field. |
| 104 | * @bitnum: the bit to test. |
| 105 | * |
| 106 | * If handed a NULL token, it returns false, otherwise returns bit status. |
| 107 | * If it's one, it sets the mirroring acknowledgement bit. */ |
| 108 | int virtio_use_bit(struct virtio_device *vdev, |
| 109 | void *token, unsigned int len, unsigned int bitnum); |
| 110 | #endif /* __KERNEL__ */ |
| 111 | #endif /* _LINUX_VIRTIO_CONFIG_H */ |