1 #ifndef _LINUX_VIRTIO_CONFIG_H
2 #define _LINUX_VIRTIO_CONFIG_H
6 #include <linux/virtio.h>
7 #include <linux/virtio_byteorder.h>
8 #include <uapi/linux/virtio_config.h>
13 * virtio_config_ops - operations for configuring a virtio device
14 * @get: read the value of a configuration field
15 * vdev: the virtio_device
16 * offset: the offset of the configuration field
17 * buf: the buffer to write the field value into.
18 * len: the length of the buffer
19 * @set: write the value of a configuration field
20 * vdev: the virtio_device
21 * offset: the offset of the configuration field
22 * buf: the buffer to read the field value from.
23 * len: the length of the buffer
24 * @generation: config generation counter
25 * vdev: the virtio_device
26 * Returns the config generation counter
27 * @get_status: read the status byte
28 * vdev: the virtio_device
29 * Returns the status byte
30 * @set_status: write the status byte
31 * vdev: the virtio_device
32 * status: the new status byte
33 * @reset: reset the device
34 * vdev: the virtio device
35 * After this, status and feature negotiation must be done again
36 * Device must not be reset from its vq/config callbacks, or in
37 * parallel with being added/removed.
38 * @find_vqs: find virtqueues and instantiate them.
39 * vdev: the virtio_device
40 * nvqs: the number of virtqueues to find
41 * vqs: on success, includes new virtqueues
42 * callbacks: array of callbacks, for each virtqueue
43 * include a NULL entry for vqs that do not need a callback
44 * names: array of virtqueue names (mainly for debugging)
45 * include a NULL entry for vqs unused by driver
46 * Returns 0 on success or error status
47 * @del_vqs: free virtqueues found by find_vqs().
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 * @finalize_features: confirm what device features we'll be using.
52 * vdev: the virtio_device
53 * This gives the final feature bits for the device: it can change
54 * the dev->feature bits if it wants.
55 * Returns 0 on success or error status
56 * @bus_name: return the bus name associated with the device
57 * vdev: the virtio_device
58 * This returns a pointer to the bus name a la pci_name from which
59 * the caller can then copy.
60 * @set_vq_affinity: set the affinity for a virtqueue.
61 * @get_vq_affinity: get the affinity for a virtqueue (optional).
63 typedef void vq_callback_t(struct virtqueue *);
64 struct virtio_config_ops {
65 void (*get)(struct virtio_device *vdev, unsigned offset,
66 void *buf, unsigned len);
67 void (*set)(struct virtio_device *vdev, unsigned offset,
68 const void *buf, unsigned len);
69 u32 (*generation)(struct virtio_device *vdev);
70 u8 (*get_status)(struct virtio_device *vdev);
71 void (*set_status)(struct virtio_device *vdev, u8 status);
72 void (*reset)(struct virtio_device *vdev);
73 int (*find_vqs)(struct virtio_device *, unsigned nvqs,
74 struct virtqueue *vqs[], vq_callback_t *callbacks[],
75 const char * const names[], struct irq_affinity *desc);
76 void (*del_vqs)(struct virtio_device *);
77 u64 (*get_features)(struct virtio_device *vdev);
78 int (*finalize_features)(struct virtio_device *vdev);
79 const char *(*bus_name)(struct virtio_device *vdev);
80 int (*set_vq_affinity)(struct virtqueue *vq, int cpu);
81 const struct cpumask *(*get_vq_affinity)(struct virtio_device *vdev,
85 /* If driver didn't advertise the feature, it will never appear. */
86 void virtio_check_driver_offered_feature(const struct virtio_device *vdev,
90 * __virtio_test_bit - helper to test feature bits. For use by transports.
91 * Devices should normally use virtio_has_feature,
92 * which includes more checks.
94 * @fbit: the feature bit
96 static inline bool __virtio_test_bit(const struct virtio_device *vdev,
99 /* Did you forget to fix assumptions on max features? */
100 if (__builtin_constant_p(fbit))
101 BUILD_BUG_ON(fbit >= 64);
105 return vdev->features & BIT_ULL(fbit);
109 * __virtio_set_bit - helper to set feature bits. For use by transports.
111 * @fbit: the feature bit
113 static inline void __virtio_set_bit(struct virtio_device *vdev,
116 /* Did you forget to fix assumptions on max features? */
117 if (__builtin_constant_p(fbit))
118 BUILD_BUG_ON(fbit >= 64);
122 vdev->features |= BIT_ULL(fbit);
126 * __virtio_clear_bit - helper to clear feature bits. For use by transports.
128 * @fbit: the feature bit
130 static inline void __virtio_clear_bit(struct virtio_device *vdev,
133 /* Did you forget to fix assumptions on max features? */
134 if (__builtin_constant_p(fbit))
135 BUILD_BUG_ON(fbit >= 64);
139 vdev->features &= ~BIT_ULL(fbit);
143 * virtio_has_feature - helper to determine if this device has this feature.
145 * @fbit: the feature bit
147 static inline bool virtio_has_feature(const struct virtio_device *vdev,
150 if (fbit < VIRTIO_TRANSPORT_F_START)
151 virtio_check_driver_offered_feature(vdev, fbit);
153 return __virtio_test_bit(vdev, fbit);
157 * virtio_has_iommu_quirk - determine whether this device has the iommu quirk
160 static inline bool virtio_has_iommu_quirk(const struct virtio_device *vdev)
163 * Note the reverse polarity of the quirk feature (compared to most
164 * other features), this is for compatibility with legacy systems.
166 return !virtio_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM);
170 struct virtqueue *virtio_find_single_vq(struct virtio_device *vdev,
171 vq_callback_t *c, const char *n)
173 vq_callback_t *callbacks[] = { c };
174 const char *names[] = { n };
175 struct virtqueue *vq;
176 int err = vdev->config->find_vqs(vdev, 1, &vq, callbacks, names, NULL);
183 * virtio_device_ready - enable vq use in probe function
186 * Driver must call this to use vqs in the probe function.
188 * Note: vqs are enabled automatically after probe returns.
191 void virtio_device_ready(struct virtio_device *dev)
193 unsigned status = dev->config->get_status(dev);
195 BUG_ON(status & VIRTIO_CONFIG_S_DRIVER_OK);
196 dev->config->set_status(dev, status | VIRTIO_CONFIG_S_DRIVER_OK);
200 const char *virtio_bus_name(struct virtio_device *vdev)
202 if (!vdev->config->bus_name)
204 return vdev->config->bus_name(vdev);
208 * virtqueue_set_affinity - setting affinity for a virtqueue
212 * Pay attention the function are best-effort: the affinity hint may not be set
213 * due to config support, irq type and sharing.
217 int virtqueue_set_affinity(struct virtqueue *vq, int cpu)
219 struct virtio_device *vdev = vq->vdev;
220 if (vdev->config->set_vq_affinity)
221 return vdev->config->set_vq_affinity(vq, cpu);
225 static inline bool virtio_is_little_endian(struct virtio_device *vdev)
227 return virtio_has_feature(vdev, VIRTIO_F_VERSION_1) ||
228 virtio_legacy_is_little_endian();
231 /* Memory accessors */
232 static inline u16 virtio16_to_cpu(struct virtio_device *vdev, __virtio16 val)
234 return __virtio16_to_cpu(virtio_is_little_endian(vdev), val);
237 static inline __virtio16 cpu_to_virtio16(struct virtio_device *vdev, u16 val)
239 return __cpu_to_virtio16(virtio_is_little_endian(vdev), val);
242 static inline u32 virtio32_to_cpu(struct virtio_device *vdev, __virtio32 val)
244 return __virtio32_to_cpu(virtio_is_little_endian(vdev), val);
247 static inline __virtio32 cpu_to_virtio32(struct virtio_device *vdev, u32 val)
249 return __cpu_to_virtio32(virtio_is_little_endian(vdev), val);
252 static inline u64 virtio64_to_cpu(struct virtio_device *vdev, __virtio64 val)
254 return __virtio64_to_cpu(virtio_is_little_endian(vdev), val);
257 static inline __virtio64 cpu_to_virtio64(struct virtio_device *vdev, u64 val)
259 return __cpu_to_virtio64(virtio_is_little_endian(vdev), val);
262 /* Config space accessors. */
263 #define virtio_cread(vdev, structname, member, ptr) \
265 /* Must match the member's type, and be integer */ \
266 if (!typecheck(typeof((((structname*)0)->member)), *(ptr))) \
269 switch (sizeof(*ptr)) { \
271 *(ptr) = virtio_cread8(vdev, \
272 offsetof(structname, member)); \
275 *(ptr) = virtio_cread16(vdev, \
276 offsetof(structname, member)); \
279 *(ptr) = virtio_cread32(vdev, \
280 offsetof(structname, member)); \
283 *(ptr) = virtio_cread64(vdev, \
284 offsetof(structname, member)); \
291 /* Config space accessors. */
292 #define virtio_cwrite(vdev, structname, member, ptr) \
294 /* Must match the member's type, and be integer */ \
295 if (!typecheck(typeof((((structname*)0)->member)), *(ptr))) \
296 BUG_ON((*ptr) == 1); \
298 switch (sizeof(*ptr)) { \
300 virtio_cwrite8(vdev, \
301 offsetof(structname, member), \
305 virtio_cwrite16(vdev, \
306 offsetof(structname, member), \
310 virtio_cwrite32(vdev, \
311 offsetof(structname, member), \
315 virtio_cwrite64(vdev, \
316 offsetof(structname, member), \
324 /* Read @count fields, @bytes each. */
325 static inline void __virtio_cread_many(struct virtio_device *vdev,
327 void *buf, size_t count, size_t bytes)
329 u32 old, gen = vdev->config->generation ?
330 vdev->config->generation(vdev) : 0;
336 for (i = 0; i < count; i++)
337 vdev->config->get(vdev, offset + bytes * i,
338 buf + i * bytes, bytes);
340 gen = vdev->config->generation ?
341 vdev->config->generation(vdev) : 0;
342 } while (gen != old);
345 static inline void virtio_cread_bytes(struct virtio_device *vdev,
347 void *buf, size_t len)
349 __virtio_cread_many(vdev, offset, buf, len, 1);
352 static inline u8 virtio_cread8(struct virtio_device *vdev, unsigned int offset)
355 vdev->config->get(vdev, offset, &ret, sizeof(ret));
359 static inline void virtio_cwrite8(struct virtio_device *vdev,
360 unsigned int offset, u8 val)
362 vdev->config->set(vdev, offset, &val, sizeof(val));
365 static inline u16 virtio_cread16(struct virtio_device *vdev,
369 vdev->config->get(vdev, offset, &ret, sizeof(ret));
370 return virtio16_to_cpu(vdev, (__force __virtio16)ret);
373 static inline void virtio_cwrite16(struct virtio_device *vdev,
374 unsigned int offset, u16 val)
376 val = (__force u16)cpu_to_virtio16(vdev, val);
377 vdev->config->set(vdev, offset, &val, sizeof(val));
380 static inline u32 virtio_cread32(struct virtio_device *vdev,
384 vdev->config->get(vdev, offset, &ret, sizeof(ret));
385 return virtio32_to_cpu(vdev, (__force __virtio32)ret);
388 static inline void virtio_cwrite32(struct virtio_device *vdev,
389 unsigned int offset, u32 val)
391 val = (__force u32)cpu_to_virtio32(vdev, val);
392 vdev->config->set(vdev, offset, &val, sizeof(val));
395 static inline u64 virtio_cread64(struct virtio_device *vdev,
399 __virtio_cread_many(vdev, offset, &ret, 1, sizeof(ret));
400 return virtio64_to_cpu(vdev, (__force __virtio64)ret);
403 static inline void virtio_cwrite64(struct virtio_device *vdev,
404 unsigned int offset, u64 val)
406 val = (__force u64)cpu_to_virtio64(vdev, val);
407 vdev->config->set(vdev, offset, &val, sizeof(val));
410 /* Conditional config space accessors. */
411 #define virtio_cread_feature(vdev, fbit, structname, member, ptr) \
414 if (!virtio_has_feature(vdev, fbit)) \
417 virtio_cread((vdev), structname, member, ptr); \
421 #endif /* _LINUX_VIRTIO_CONFIG_H */