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ec3d41c4 RR |
1 | #ifndef _LINUX_VIRTIO_CONFIG_H |
2 | #define _LINUX_VIRTIO_CONFIG_H | |
b4f68be6 | 3 | |
d2a7ddda | 4 | #include <linux/err.h> |
187f1882 | 5 | #include <linux/bug.h> |
72e61eb4 | 6 | #include <linux/virtio.h> |
607ca46e | 7 | #include <uapi/linux/virtio_config.h> |
ec3d41c4 RR |
8 | |
9 | /** | |
10 | * virtio_config_ops - operations for configuring a virtio device | |
a586d4f6 | 11 | * @get: read the value of a configuration field |
ec3d41c4 | 12 | * vdev: the virtio_device |
a586d4f6 | 13 | * offset: the offset of the configuration field |
ec3d41c4 | 14 | * buf: the buffer to write the field value into. |
a586d4f6 | 15 | * len: the length of the buffer |
a586d4f6 | 16 | * @set: write the value of a configuration field |
ec3d41c4 | 17 | * vdev: the virtio_device |
a586d4f6 | 18 | * offset: the offset of the configuration field |
ec3d41c4 | 19 | * buf: the buffer to read the field value from. |
a586d4f6 | 20 | * len: the length of the buffer |
ec3d41c4 RR |
21 | * @get_status: read the status byte |
22 | * vdev: the virtio_device | |
23 | * Returns the status byte | |
24 | * @set_status: write the status byte | |
25 | * vdev: the virtio_device | |
26 | * status: the new status byte | |
6e5aa7ef RR |
27 | * @reset: reset the device |
28 | * vdev: the virtio device | |
29 | * After this, status and feature negotiation must be done again | |
e6af578c MT |
30 | * Device must not be reset from its vq/config callbacks, or in |
31 | * parallel with being added/removed. | |
d2a7ddda | 32 | * @find_vqs: find virtqueues and instantiate them. |
ec3d41c4 | 33 | * vdev: the virtio_device |
d2a7ddda MT |
34 | * nvqs: the number of virtqueues to find |
35 | * vqs: on success, includes new virtqueues | |
36 | * callbacks: array of callbacks, for each virtqueue | |
6457f126 | 37 | * include a NULL entry for vqs that do not need a callback |
d2a7ddda | 38 | * names: array of virtqueue names (mainly for debugging) |
6457f126 | 39 | * include a NULL entry for vqs unused by driver |
d2a7ddda MT |
40 | * Returns 0 on success or error status |
41 | * @del_vqs: free virtqueues found by find_vqs(). | |
c45a6816 RR |
42 | * @get_features: get the array of feature bits for this device. |
43 | * vdev: the virtio_device | |
44 | * Returns the first 32 feature bits (all we currently need). | |
c624896e | 45 | * @finalize_features: confirm what device features we'll be using. |
c45a6816 | 46 | * vdev: the virtio_device |
c624896e RR |
47 | * This gives the final feature bits for the device: it can change |
48 | * the dev->feature bits if it wants. | |
66846048 RJ |
49 | * @bus_name: return the bus name associated with the device |
50 | * vdev: the virtio_device | |
51 | * This returns a pointer to the bus name a la pci_name from which | |
52 | * the caller can then copy. | |
75a0a52b | 53 | * @set_vq_affinity: set the affinity for a virtqueue. |
ec3d41c4 | 54 | */ |
d2a7ddda | 55 | typedef void vq_callback_t(struct virtqueue *); |
1842f23c | 56 | struct virtio_config_ops { |
a586d4f6 | 57 | void (*get)(struct virtio_device *vdev, unsigned offset, |
ec3d41c4 | 58 | void *buf, unsigned len); |
a586d4f6 | 59 | void (*set)(struct virtio_device *vdev, unsigned offset, |
ec3d41c4 RR |
60 | const void *buf, unsigned len); |
61 | u8 (*get_status)(struct virtio_device *vdev); | |
62 | void (*set_status)(struct virtio_device *vdev, u8 status); | |
6e5aa7ef | 63 | void (*reset)(struct virtio_device *vdev); |
d2a7ddda MT |
64 | int (*find_vqs)(struct virtio_device *, unsigned nvqs, |
65 | struct virtqueue *vqs[], | |
66 | vq_callback_t *callbacks[], | |
67 | const char *names[]); | |
68 | void (*del_vqs)(struct virtio_device *); | |
c45a6816 | 69 | u32 (*get_features)(struct virtio_device *vdev); |
c624896e | 70 | void (*finalize_features)(struct virtio_device *vdev); |
66846048 | 71 | const char *(*bus_name)(struct virtio_device *vdev); |
75a0a52b | 72 | int (*set_vq_affinity)(struct virtqueue *vq, int cpu); |
ec3d41c4 RR |
73 | }; |
74 | ||
c45a6816 RR |
75 | /* If driver didn't advertise the feature, it will never appear. */ |
76 | void virtio_check_driver_offered_feature(const struct virtio_device *vdev, | |
77 | unsigned int fbit); | |
78 | ||
79 | /** | |
80 | * virtio_has_feature - helper to determine if this device has this feature. | |
81 | * @vdev: the device | |
82 | * @fbit: the feature bit | |
83 | */ | |
84 | static inline bool virtio_has_feature(const struct virtio_device *vdev, | |
85 | unsigned int fbit) | |
86 | { | |
87 | /* Did you forget to fix assumptions on max features? */ | |
1765e3a4 RR |
88 | if (__builtin_constant_p(fbit)) |
89 | BUILD_BUG_ON(fbit >= 32); | |
90 | else | |
91 | BUG_ON(fbit >= 32); | |
c45a6816 | 92 | |
ee006b35 MM |
93 | if (fbit < VIRTIO_TRANSPORT_F_START) |
94 | virtio_check_driver_offered_feature(vdev, fbit); | |
95 | ||
c45a6816 RR |
96 | return test_bit(fbit, vdev->features); |
97 | } | |
98 | ||
ec3d41c4 | 99 | /** |
72e61eb4 | 100 | * virtio_config_val - look for a feature and get a virtio config entry. |
a586d4f6 RR |
101 | * @vdev: the virtio device |
102 | * @fbit: the feature bit | |
103 | * @offset: the type to search for. | |
c6190804 | 104 | * @v: a pointer to the value to fill in. |
ec3d41c4 | 105 | * |
a586d4f6 | 106 | * The return value is -ENOENT if the feature doesn't exist. Otherwise |
72e61eb4 RR |
107 | * the config value is copied into whatever is pointed to by v. */ |
108 | #define virtio_config_val(vdev, fbit, offset, v) \ | |
7f31fe05 | 109 | virtio_config_buf((vdev), (fbit), (offset), (v), sizeof(*v)) |
ec3d41c4 | 110 | |
3ead6f4d SL |
111 | #define virtio_config_val_len(vdev, fbit, offset, v, len) \ |
112 | virtio_config_buf((vdev), (fbit), (offset), (v), (len)) | |
113 | ||
72e61eb4 RR |
114 | static inline int virtio_config_buf(struct virtio_device *vdev, |
115 | unsigned int fbit, | |
116 | unsigned int offset, | |
117 | void *buf, unsigned len) | |
118 | { | |
c45a6816 | 119 | if (!virtio_has_feature(vdev, fbit)) |
72e61eb4 RR |
120 | return -ENOENT; |
121 | ||
122 | vdev->config->get(vdev, offset, buf, len); | |
123 | return 0; | |
124 | } | |
d2a7ddda MT |
125 | |
126 | static inline | |
127 | struct virtqueue *virtio_find_single_vq(struct virtio_device *vdev, | |
128 | vq_callback_t *c, const char *n) | |
129 | { | |
130 | vq_callback_t *callbacks[] = { c }; | |
131 | const char *names[] = { n }; | |
132 | struct virtqueue *vq; | |
133 | int err = vdev->config->find_vqs(vdev, 1, &vq, callbacks, names); | |
134 | if (err < 0) | |
135 | return ERR_PTR(err); | |
136 | return vq; | |
137 | } | |
66846048 RJ |
138 | |
139 | static inline | |
140 | const char *virtio_bus_name(struct virtio_device *vdev) | |
141 | { | |
142 | if (!vdev->config->bus_name) | |
143 | return "virtio"; | |
144 | return vdev->config->bus_name(vdev); | |
145 | } | |
146 | ||
75a0a52b JW |
147 | /** |
148 | * virtqueue_set_affinity - setting affinity for a virtqueue | |
149 | * @vq: the virtqueue | |
150 | * @cpu: the cpu no. | |
151 | * | |
152 | * Pay attention the function are best-effort: the affinity hint may not be set | |
153 | * due to config support, irq type and sharing. | |
154 | * | |
155 | */ | |
156 | static inline | |
157 | int virtqueue_set_affinity(struct virtqueue *vq, int cpu) | |
158 | { | |
159 | struct virtio_device *vdev = vq->vdev; | |
160 | if (vdev->config->set_vq_affinity) | |
161 | return vdev->config->set_vq_affinity(vq, cpu); | |
162 | return 0; | |
163 | } | |
164 | ||
165 | ||
ec3d41c4 | 166 | #endif /* _LINUX_VIRTIO_CONFIG_H */ |