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 |
Rusty Russell | a1b3838 | 2011-05-30 11:14:13 -0600 | [diff] [blame] | 4 | * anyone can use the definitions to implement compatible drivers/servers. |
| 5 | * |
| 6 | * Redistribution and use in source and binary forms, with or without |
| 7 | * modification, are permitted provided that the following conditions |
| 8 | * are met: |
| 9 | * 1. Redistributions of source code must retain the above copyright |
| 10 | * notice, this list of conditions and the following disclaimer. |
| 11 | * 2. Redistributions in binary form must reproduce the above copyright |
| 12 | * notice, this list of conditions and the following disclaimer in the |
| 13 | * documentation and/or other materials provided with the distribution. |
| 14 | * 3. Neither the name of IBM nor the names of its contributors |
| 15 | * may be used to endorse or promote products derived from this software |
| 16 | * without specific prior written permission. |
| 17 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS'' AND |
| 18 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 19 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 20 | * ARE DISCLAIMED. IN NO EVENT SHALL IBM OR CONTRIBUTORS BE LIABLE |
| 21 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 22 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 23 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 24 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 25 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 26 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 27 | * SUCH DAMAGE. */ |
Rusty Russell | 674bfc2 | 2008-07-25 12:06:03 -0500 | [diff] [blame] | 28 | |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 29 | /* Virtio devices use a standardized configuration space to define their |
| 30 | * features and pass configuration information, but each implementation can |
| 31 | * store and access that space differently. */ |
| 32 | #include <linux/types.h> |
| 33 | |
Rusty Russell | a586d4f | 2008-02-04 23:49:56 -0500 | [diff] [blame] | 34 | /* Status byte for guest to report progress, and synchronize features. */ |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 35 | /* We have seen device and processed generic fields (VIRTIO_CONFIG_F_VIRTIO) */ |
| 36 | #define VIRTIO_CONFIG_S_ACKNOWLEDGE 1 |
| 37 | /* We have found a driver for the device. */ |
| 38 | #define VIRTIO_CONFIG_S_DRIVER 2 |
| 39 | /* Driver has used its parts of the config, and is happy */ |
| 40 | #define VIRTIO_CONFIG_S_DRIVER_OK 4 |
| 41 | /* We've given up on this device. */ |
| 42 | #define VIRTIO_CONFIG_S_FAILED 0x80 |
| 43 | |
Rusty Russell | dd7c7bc | 2008-07-25 12:06:07 -0500 | [diff] [blame] | 44 | /* Some virtio feature bits (currently bits 28 through 31) are reserved for the |
| 45 | * transport being used (eg. virtio_ring), the rest are per-device feature |
| 46 | * bits. */ |
| 47 | #define VIRTIO_TRANSPORT_F_START 28 |
| 48 | #define VIRTIO_TRANSPORT_F_END 32 |
| 49 | |
Rusty Russell | b4f68be | 2008-05-30 15:09:45 -0500 | [diff] [blame] | 50 | /* Do we get callbacks when the ring is completely used, even if we've |
| 51 | * suppressed them? */ |
| 52 | #define VIRTIO_F_NOTIFY_ON_EMPTY 24 |
| 53 | |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 54 | #ifdef __KERNEL__ |
Michael S. Tsirkin | d2a7ddd | 2009-06-12 22:16:36 -0600 | [diff] [blame] | 55 | #include <linux/err.h> |
Rusty Russell | 72e61eb | 2008-05-02 21:50:49 -0500 | [diff] [blame] | 56 | #include <linux/virtio.h> |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 57 | |
| 58 | /** |
| 59 | * virtio_config_ops - operations for configuring a virtio device |
Rusty Russell | a586d4f | 2008-02-04 23:49:56 -0500 | [diff] [blame] | 60 | * @get: read the value of a configuration field |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 61 | * vdev: the virtio_device |
Rusty Russell | a586d4f | 2008-02-04 23:49:56 -0500 | [diff] [blame] | 62 | * offset: the offset of the configuration field |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 63 | * buf: the buffer to write the field value into. |
Rusty Russell | a586d4f | 2008-02-04 23:49:56 -0500 | [diff] [blame] | 64 | * len: the length of the buffer |
Rusty Russell | a586d4f | 2008-02-04 23:49:56 -0500 | [diff] [blame] | 65 | * @set: write the value of a configuration field |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 66 | * vdev: the virtio_device |
Rusty Russell | a586d4f | 2008-02-04 23:49:56 -0500 | [diff] [blame] | 67 | * offset: the offset of the configuration field |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 68 | * buf: the buffer to read the field value from. |
Rusty Russell | a586d4f | 2008-02-04 23:49:56 -0500 | [diff] [blame] | 69 | * len: the length of the buffer |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 70 | * @get_status: read the status byte |
| 71 | * vdev: the virtio_device |
| 72 | * Returns the status byte |
| 73 | * @set_status: write the status byte |
| 74 | * vdev: the virtio_device |
| 75 | * status: the new status byte |
Michael S. Tsirkin | d2a7ddd | 2009-06-12 22:16:36 -0600 | [diff] [blame] | 76 | * @request_vqs: request the specified number of virtqueues |
| 77 | * vdev: the virtio_device |
| 78 | * max_vqs: the max number of virtqueues we want |
| 79 | * If supplied, must call before any virtqueues are instantiated. |
| 80 | * To modify the max number of virtqueues after request_vqs has been |
| 81 | * called, call free_vqs and then request_vqs with a new value. |
| 82 | * @free_vqs: cleanup resources allocated by request_vqs |
| 83 | * vdev: the virtio_device |
| 84 | * If supplied, must call after all virtqueues have been deleted. |
Rusty Russell | 6e5aa7e | 2008-02-04 23:50:03 -0500 | [diff] [blame] | 85 | * @reset: reset the device |
| 86 | * vdev: the virtio device |
| 87 | * After this, status and feature negotiation must be done again |
Michael S. Tsirkin | d2a7ddd | 2009-06-12 22:16:36 -0600 | [diff] [blame] | 88 | * @find_vqs: find virtqueues and instantiate them. |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 89 | * vdev: the virtio_device |
Michael S. Tsirkin | d2a7ddd | 2009-06-12 22:16:36 -0600 | [diff] [blame] | 90 | * nvqs: the number of virtqueues to find |
| 91 | * vqs: on success, includes new virtqueues |
| 92 | * callbacks: array of callbacks, for each virtqueue |
| 93 | * names: array of virtqueue names (mainly for debugging) |
| 94 | * Returns 0 on success or error status |
| 95 | * @del_vqs: free virtqueues found by find_vqs(). |
Rusty Russell | c45a681 | 2008-05-02 21:50:50 -0500 | [diff] [blame] | 96 | * @get_features: get the array of feature bits for this device. |
| 97 | * vdev: the virtio_device |
| 98 | * Returns the first 32 feature bits (all we currently need). |
Rusty Russell | c624896 | 2008-07-25 12:06:07 -0500 | [diff] [blame] | 99 | * @finalize_features: confirm what device features we'll be using. |
Rusty Russell | c45a681 | 2008-05-02 21:50:50 -0500 | [diff] [blame] | 100 | * vdev: the virtio_device |
Rusty Russell | c624896 | 2008-07-25 12:06:07 -0500 | [diff] [blame] | 101 | * This gives the final feature bits for the device: it can change |
| 102 | * the dev->feature bits if it wants. |
Rick Jones | 6684604 | 2011-11-14 14:17:08 +0000 | [diff] [blame^] | 103 | * @bus_name: return the bus name associated with the device |
| 104 | * vdev: the virtio_device |
| 105 | * This returns a pointer to the bus name a la pci_name from which |
| 106 | * the caller can then copy. |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 107 | */ |
Michael S. Tsirkin | d2a7ddd | 2009-06-12 22:16:36 -0600 | [diff] [blame] | 108 | typedef void vq_callback_t(struct virtqueue *); |
Rusty Russell | 1842f23 | 2009-07-30 16:03:46 -0600 | [diff] [blame] | 109 | struct virtio_config_ops { |
Rusty Russell | a586d4f | 2008-02-04 23:49:56 -0500 | [diff] [blame] | 110 | void (*get)(struct virtio_device *vdev, unsigned offset, |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 111 | void *buf, unsigned len); |
Rusty Russell | a586d4f | 2008-02-04 23:49:56 -0500 | [diff] [blame] | 112 | void (*set)(struct virtio_device *vdev, unsigned offset, |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 113 | const void *buf, unsigned len); |
| 114 | u8 (*get_status)(struct virtio_device *vdev); |
| 115 | void (*set_status)(struct virtio_device *vdev, u8 status); |
Rusty Russell | 6e5aa7e | 2008-02-04 23:50:03 -0500 | [diff] [blame] | 116 | void (*reset)(struct virtio_device *vdev); |
Michael S. Tsirkin | d2a7ddd | 2009-06-12 22:16:36 -0600 | [diff] [blame] | 117 | int (*find_vqs)(struct virtio_device *, unsigned nvqs, |
| 118 | struct virtqueue *vqs[], |
| 119 | vq_callback_t *callbacks[], |
| 120 | const char *names[]); |
| 121 | void (*del_vqs)(struct virtio_device *); |
Rusty Russell | c45a681 | 2008-05-02 21:50:50 -0500 | [diff] [blame] | 122 | u32 (*get_features)(struct virtio_device *vdev); |
Rusty Russell | c624896 | 2008-07-25 12:06:07 -0500 | [diff] [blame] | 123 | void (*finalize_features)(struct virtio_device *vdev); |
Rick Jones | 6684604 | 2011-11-14 14:17:08 +0000 | [diff] [blame^] | 124 | const char *(*bus_name)(struct virtio_device *vdev); |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 125 | }; |
| 126 | |
Rusty Russell | c45a681 | 2008-05-02 21:50:50 -0500 | [diff] [blame] | 127 | /* If driver didn't advertise the feature, it will never appear. */ |
| 128 | void virtio_check_driver_offered_feature(const struct virtio_device *vdev, |
| 129 | unsigned int fbit); |
| 130 | |
| 131 | /** |
| 132 | * virtio_has_feature - helper to determine if this device has this feature. |
| 133 | * @vdev: the device |
| 134 | * @fbit: the feature bit |
| 135 | */ |
| 136 | static inline bool virtio_has_feature(const struct virtio_device *vdev, |
| 137 | unsigned int fbit) |
| 138 | { |
| 139 | /* Did you forget to fix assumptions on max features? */ |
Rusty Russell | 1765e3a | 2011-01-24 14:45:10 -0600 | [diff] [blame] | 140 | if (__builtin_constant_p(fbit)) |
| 141 | BUILD_BUG_ON(fbit >= 32); |
| 142 | else |
| 143 | BUG_ON(fbit >= 32); |
Rusty Russell | c45a681 | 2008-05-02 21:50:50 -0500 | [diff] [blame] | 144 | |
Mark McLoughlin | ee006b3 | 2009-05-11 18:11:44 +0100 | [diff] [blame] | 145 | if (fbit < VIRTIO_TRANSPORT_F_START) |
| 146 | virtio_check_driver_offered_feature(vdev, fbit); |
| 147 | |
Rusty Russell | c45a681 | 2008-05-02 21:50:50 -0500 | [diff] [blame] | 148 | return test_bit(fbit, vdev->features); |
| 149 | } |
| 150 | |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 151 | /** |
Rusty Russell | 72e61eb | 2008-05-02 21:50:49 -0500 | [diff] [blame] | 152 | * 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] | 153 | * @vdev: the virtio device |
| 154 | * @fbit: the feature bit |
| 155 | * @offset: the type to search for. |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 156 | * @val: a pointer to the value to fill in. |
| 157 | * |
Rusty Russell | a586d4f | 2008-02-04 23:49:56 -0500 | [diff] [blame] | 158 | * The return value is -ENOENT if the feature doesn't exist. Otherwise |
Rusty Russell | 72e61eb | 2008-05-02 21:50:49 -0500 | [diff] [blame] | 159 | * the config value is copied into whatever is pointed to by v. */ |
| 160 | #define virtio_config_val(vdev, fbit, offset, v) \ |
Christian Borntraeger | 7f31fe0 | 2008-05-29 11:08:01 +0200 | [diff] [blame] | 161 | virtio_config_buf((vdev), (fbit), (offset), (v), sizeof(*v)) |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 162 | |
Sasha Levin | 3ead6f4 | 2011-08-14 17:52:32 +0300 | [diff] [blame] | 163 | #define virtio_config_val_len(vdev, fbit, offset, v, len) \ |
| 164 | virtio_config_buf((vdev), (fbit), (offset), (v), (len)) |
| 165 | |
Rusty Russell | 72e61eb | 2008-05-02 21:50:49 -0500 | [diff] [blame] | 166 | static inline int virtio_config_buf(struct virtio_device *vdev, |
| 167 | unsigned int fbit, |
| 168 | unsigned int offset, |
| 169 | void *buf, unsigned len) |
| 170 | { |
Rusty Russell | c45a681 | 2008-05-02 21:50:50 -0500 | [diff] [blame] | 171 | if (!virtio_has_feature(vdev, fbit)) |
Rusty Russell | 72e61eb | 2008-05-02 21:50:49 -0500 | [diff] [blame] | 172 | return -ENOENT; |
| 173 | |
| 174 | vdev->config->get(vdev, offset, buf, len); |
| 175 | return 0; |
| 176 | } |
Michael S. Tsirkin | d2a7ddd | 2009-06-12 22:16:36 -0600 | [diff] [blame] | 177 | |
| 178 | static inline |
| 179 | struct virtqueue *virtio_find_single_vq(struct virtio_device *vdev, |
| 180 | vq_callback_t *c, const char *n) |
| 181 | { |
| 182 | vq_callback_t *callbacks[] = { c }; |
| 183 | const char *names[] = { n }; |
| 184 | struct virtqueue *vq; |
| 185 | int err = vdev->config->find_vqs(vdev, 1, &vq, callbacks, names); |
| 186 | if (err < 0) |
| 187 | return ERR_PTR(err); |
| 188 | return vq; |
| 189 | } |
Rick Jones | 6684604 | 2011-11-14 14:17:08 +0000 | [diff] [blame^] | 190 | |
| 191 | static inline |
| 192 | const char *virtio_bus_name(struct virtio_device *vdev) |
| 193 | { |
| 194 | if (!vdev->config->bus_name) |
| 195 | return "virtio"; |
| 196 | return vdev->config->bus_name(vdev); |
| 197 | } |
| 198 | |
Rusty Russell | ec3d41c | 2007-10-22 11:03:36 +1000 | [diff] [blame] | 199 | #endif /* __KERNEL__ */ |
| 200 | #endif /* _LINUX_VIRTIO_CONFIG_H */ |