1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_VIRTIO_CONFIG_H
3 #define _LINUX_VIRTIO_CONFIG_H
7 #include <linux/virtio.h>
8 #include <linux/virtio_byteorder.h>
9 #include <linux/compiler_types.h>
10 #include <uapi/linux/virtio_config.h>
15 * virtio_config_ops - operations for configuring a virtio device
16 * Note: Do not assume that a transport implements all of the operations
17 * getting/setting a value as a simple read/write! Generally speaking,
18 * any of @get/@set, @get_status/@set_status, or @get_features/
19 * @finalize_features are NOT safe to be called from an atomic
21 * @get: read the value of a configuration field
22 * vdev: the virtio_device
23 * offset: the offset of the configuration field
24 * buf: the buffer to write the field value into.
25 * len: the length of the buffer
26 * @set: write the value of a configuration field
27 * vdev: the virtio_device
28 * offset: the offset of the configuration field
29 * buf: the buffer to read the field value from.
30 * len: the length of the buffer
31 * @generation: config generation counter (optional)
32 * vdev: the virtio_device
33 * Returns the config generation counter
34 * @get_status: read the status byte
35 * vdev: the virtio_device
36 * Returns the status byte
37 * @set_status: write the status byte
38 * vdev: the virtio_device
39 * status: the new status byte
40 * @reset: reset the device
41 * vdev: the virtio device
42 * After this, status and feature negotiation must be done again
43 * Device must not be reset from its vq/config callbacks, or in
44 * parallel with being added/removed.
45 * @find_vqs: find virtqueues and instantiate them.
46 * vdev: the virtio_device
47 * nvqs: the number of virtqueues to find
48 * vqs: on success, includes new virtqueues
49 * callbacks: array of callbacks, for each virtqueue
50 * include a NULL entry for vqs that do not need a callback
51 * names: array of virtqueue names (mainly for debugging)
52 * include a NULL entry for vqs unused by driver
53 * Returns 0 on success or error status
54 * @del_vqs: free virtqueues found by find_vqs().
55 * @get_features: get the array of feature bits for this device.
56 * vdev: the virtio_device
57 * Returns the first 64 feature bits (all we currently need).
58 * @finalize_features: confirm what device features we'll be using.
59 * vdev: the virtio_device
60 * This gives the final feature bits for the device: it can change
61 * the dev->feature bits if it wants.
62 * Returns 0 on success or error status
63 * @bus_name: return the bus name associated with the device (optional)
64 * vdev: the virtio_device
65 * This returns a pointer to the bus name a la pci_name from which
66 * the caller can then copy.
67 * @set_vq_affinity: set the affinity for a virtqueue (optional).
68 * @get_vq_affinity: get the affinity for a virtqueue (optional).
70 typedef void vq_callback_t(struct virtqueue
*);
71 struct virtio_config_ops
{
72 void (*get
)(struct virtio_device
*vdev
, unsigned offset
,
73 void *buf
, unsigned len
);
74 void (*set
)(struct virtio_device
*vdev
, unsigned offset
,
75 const void *buf
, unsigned len
);
76 u32 (*generation
)(struct virtio_device
*vdev
);
77 u8 (*get_status
)(struct virtio_device
*vdev
);
78 void (*set_status
)(struct virtio_device
*vdev
, u8 status
);
79 void (*reset
)(struct virtio_device
*vdev
);
80 int (*find_vqs
)(struct virtio_device
*, unsigned nvqs
,
81 struct virtqueue
*vqs
[], vq_callback_t
*callbacks
[],
82 const char * const names
[], const bool *ctx
,
83 struct irq_affinity
*desc
);
84 void (*del_vqs
)(struct virtio_device
*);
85 u64 (*get_features
)(struct virtio_device
*vdev
);
86 int (*finalize_features
)(struct virtio_device
*vdev
);
87 const char *(*bus_name
)(struct virtio_device
*vdev
);
88 int (*set_vq_affinity
)(struct virtqueue
*vq
,
89 const struct cpumask
*cpu_mask
);
90 const struct cpumask
*(*get_vq_affinity
)(struct virtio_device
*vdev
,
94 /* If driver didn't advertise the feature, it will never appear. */
95 void virtio_check_driver_offered_feature(const struct virtio_device
*vdev
,
99 * __virtio_test_bit - helper to test feature bits. For use by transports.
100 * Devices should normally use virtio_has_feature,
101 * which includes more checks.
103 * @fbit: the feature bit
105 static inline bool __virtio_test_bit(const struct virtio_device
*vdev
,
108 /* Did you forget to fix assumptions on max features? */
109 if (__builtin_constant_p(fbit
))
110 BUILD_BUG_ON(fbit
>= 64);
114 return vdev
->features
& BIT_ULL(fbit
);
118 * __virtio_set_bit - helper to set feature bits. For use by transports.
120 * @fbit: the feature bit
122 static inline void __virtio_set_bit(struct virtio_device
*vdev
,
125 /* Did you forget to fix assumptions on max features? */
126 if (__builtin_constant_p(fbit
))
127 BUILD_BUG_ON(fbit
>= 64);
131 vdev
->features
|= BIT_ULL(fbit
);
135 * __virtio_clear_bit - helper to clear feature bits. For use by transports.
137 * @fbit: the feature bit
139 static inline void __virtio_clear_bit(struct virtio_device
*vdev
,
142 /* Did you forget to fix assumptions on max features? */
143 if (__builtin_constant_p(fbit
))
144 BUILD_BUG_ON(fbit
>= 64);
148 vdev
->features
&= ~BIT_ULL(fbit
);
152 * virtio_has_feature - helper to determine if this device has this feature.
154 * @fbit: the feature bit
156 static inline bool virtio_has_feature(const struct virtio_device
*vdev
,
159 if (fbit
< VIRTIO_TRANSPORT_F_START
)
160 virtio_check_driver_offered_feature(vdev
, fbit
);
162 return __virtio_test_bit(vdev
, fbit
);
166 * virtio_has_dma_quirk - determine whether this device has the DMA quirk
169 static inline bool virtio_has_dma_quirk(const struct virtio_device
*vdev
)
172 * Note the reverse polarity of the quirk feature (compared to most
173 * other features), this is for compatibility with legacy systems.
175 return !virtio_has_feature(vdev
, VIRTIO_F_ACCESS_PLATFORM
);
179 struct virtqueue
*virtio_find_single_vq(struct virtio_device
*vdev
,
180 vq_callback_t
*c
, const char *n
)
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
, NULL
,
193 int virtio_find_vqs(struct virtio_device
*vdev
, unsigned nvqs
,
194 struct virtqueue
*vqs
[], vq_callback_t
*callbacks
[],
195 const char * const names
[],
196 struct irq_affinity
*desc
)
198 return vdev
->config
->find_vqs(vdev
, nvqs
, vqs
, callbacks
, names
, NULL
, desc
);
202 int virtio_find_vqs_ctx(struct virtio_device
*vdev
, unsigned nvqs
,
203 struct virtqueue
*vqs
[], vq_callback_t
*callbacks
[],
204 const char * const names
[], const bool *ctx
,
205 struct irq_affinity
*desc
)
207 return vdev
->config
->find_vqs(vdev
, nvqs
, vqs
, callbacks
, names
, ctx
,
212 * virtio_device_ready - enable vq use in probe function
215 * Driver must call this to use vqs in the probe function.
217 * Note: vqs are enabled automatically after probe returns.
220 void virtio_device_ready(struct virtio_device
*dev
)
222 unsigned status
= dev
->config
->get_status(dev
);
224 BUG_ON(status
& VIRTIO_CONFIG_S_DRIVER_OK
);
225 dev
->config
->set_status(dev
, status
| VIRTIO_CONFIG_S_DRIVER_OK
);
229 const char *virtio_bus_name(struct virtio_device
*vdev
)
231 if (!vdev
->config
->bus_name
)
233 return vdev
->config
->bus_name(vdev
);
237 * virtqueue_set_affinity - setting affinity for a virtqueue
241 * Pay attention the function are best-effort: the affinity hint may not be set
242 * due to config support, irq type and sharing.
246 int virtqueue_set_affinity(struct virtqueue
*vq
, const struct cpumask
*cpu_mask
)
248 struct virtio_device
*vdev
= vq
->vdev
;
249 if (vdev
->config
->set_vq_affinity
)
250 return vdev
->config
->set_vq_affinity(vq
, cpu_mask
);
254 static inline bool virtio_is_little_endian(struct virtio_device
*vdev
)
256 return virtio_has_feature(vdev
, VIRTIO_F_VERSION_1
) ||
257 virtio_legacy_is_little_endian();
260 /* Memory accessors */
261 static inline u16
virtio16_to_cpu(struct virtio_device
*vdev
, __virtio16 val
)
263 return __virtio16_to_cpu(virtio_is_little_endian(vdev
), val
);
266 static inline __virtio16
cpu_to_virtio16(struct virtio_device
*vdev
, u16 val
)
268 return __cpu_to_virtio16(virtio_is_little_endian(vdev
), val
);
271 static inline u32
virtio32_to_cpu(struct virtio_device
*vdev
, __virtio32 val
)
273 return __virtio32_to_cpu(virtio_is_little_endian(vdev
), val
);
276 static inline __virtio32
cpu_to_virtio32(struct virtio_device
*vdev
, u32 val
)
278 return __cpu_to_virtio32(virtio_is_little_endian(vdev
), val
);
281 static inline u64
virtio64_to_cpu(struct virtio_device
*vdev
, __virtio64 val
)
283 return __virtio64_to_cpu(virtio_is_little_endian(vdev
), val
);
286 static inline __virtio64
cpu_to_virtio64(struct virtio_device
*vdev
, u64 val
)
288 return __cpu_to_virtio64(virtio_is_little_endian(vdev
), val
);
291 #define virtio_to_cpu(vdev, x) \
294 __virtio16: virtio16_to_cpu((vdev), (x)), \
295 __virtio32: virtio32_to_cpu((vdev), (x)), \
296 __virtio64: virtio64_to_cpu((vdev), (x)) \
299 #define cpu_to_virtio(vdev, x, m) \
302 __virtio16: cpu_to_virtio16((vdev), (x)), \
303 __virtio32: cpu_to_virtio32((vdev), (x)), \
304 __virtio64: cpu_to_virtio64((vdev), (x)) \
307 #define __virtio_native_type(structname, member) \
308 typeof(virtio_to_cpu(NULL, ((structname*)0)->member))
310 /* Config space accessors. */
311 #define virtio_cread(vdev, structname, member, ptr) \
313 typeof(((structname*)0)->member) virtio_cread_v; \
316 /* Sanity check: must match the member's type */ \
317 typecheck(typeof(virtio_to_cpu((vdev), virtio_cread_v)), *(ptr)); \
319 switch (sizeof(virtio_cread_v)) { \
323 vdev->config->get((vdev), \
324 offsetof(structname, member), \
326 sizeof(virtio_cread_v)); \
329 __virtio_cread_many((vdev), \
330 offsetof(structname, member), \
333 sizeof(virtio_cread_v)); \
336 *(ptr) = virtio_to_cpu(vdev, virtio_cread_v); \
339 /* Config space accessors. */
340 #define virtio_cwrite(vdev, structname, member, ptr) \
342 typeof(((structname*)0)->member) virtio_cwrite_v = \
343 cpu_to_virtio(vdev, *(ptr), ((structname*)0)->member); \
346 /* Sanity check: must match the member's type */ \
347 typecheck(typeof(virtio_to_cpu((vdev), virtio_cwrite_v)), *(ptr)); \
349 vdev->config->set((vdev), offsetof(structname, member), \
351 sizeof(virtio_cwrite_v)); \
355 * Nothing virtio-specific about these, but let's worry about generalizing
358 #define virtio_le_to_cpu(x) \
361 __le16: (u16)le16_to_cpu(x), \
362 __le32: (u32)le32_to_cpu(x), \
363 __le64: (u64)le64_to_cpu(x) \
366 #define virtio_cpu_to_le(x, m) \
369 __le16: cpu_to_le16(x), \
370 __le32: cpu_to_le32(x), \
371 __le64: cpu_to_le64(x) \
374 /* LE (e.g. modern) Config space accessors. */
375 #define virtio_cread_le(vdev, structname, member, ptr) \
377 typeof(((structname*)0)->member) virtio_cread_v; \
380 /* Sanity check: must match the member's type */ \
381 typecheck(typeof(virtio_le_to_cpu(virtio_cread_v)), *(ptr)); \
383 switch (sizeof(virtio_cread_v)) { \
387 vdev->config->get((vdev), \
388 offsetof(structname, member), \
390 sizeof(virtio_cread_v)); \
393 __virtio_cread_many((vdev), \
394 offsetof(structname, member), \
397 sizeof(virtio_cread_v)); \
400 *(ptr) = virtio_le_to_cpu(virtio_cread_v); \
403 #define virtio_cwrite_le(vdev, structname, member, ptr) \
405 typeof(((structname*)0)->member) virtio_cwrite_v = \
406 virtio_cpu_to_le(*(ptr), ((structname*)0)->member); \
409 /* Sanity check: must match the member's type */ \
410 typecheck(typeof(virtio_le_to_cpu(virtio_cwrite_v)), *(ptr)); \
412 vdev->config->set((vdev), offsetof(structname, member), \
414 sizeof(virtio_cwrite_v)); \
418 /* Read @count fields, @bytes each. */
419 static inline void __virtio_cread_many(struct virtio_device
*vdev
,
421 void *buf
, size_t count
, size_t bytes
)
423 u32 old
, gen
= vdev
->config
->generation
?
424 vdev
->config
->generation(vdev
) : 0;
431 for (i
= 0; i
< count
; i
++)
432 vdev
->config
->get(vdev
, offset
+ bytes
* i
,
433 buf
+ i
* bytes
, bytes
);
435 gen
= vdev
->config
->generation
?
436 vdev
->config
->generation(vdev
) : 0;
437 } while (gen
!= old
);
440 static inline void virtio_cread_bytes(struct virtio_device
*vdev
,
442 void *buf
, size_t len
)
444 __virtio_cread_many(vdev
, offset
, buf
, len
, 1);
447 static inline u8
virtio_cread8(struct virtio_device
*vdev
, unsigned int offset
)
452 vdev
->config
->get(vdev
, offset
, &ret
, sizeof(ret
));
456 static inline void virtio_cwrite8(struct virtio_device
*vdev
,
457 unsigned int offset
, u8 val
)
460 vdev
->config
->set(vdev
, offset
, &val
, sizeof(val
));
463 static inline u16
virtio_cread16(struct virtio_device
*vdev
,
469 vdev
->config
->get(vdev
, offset
, &ret
, sizeof(ret
));
470 return virtio16_to_cpu(vdev
, ret
);
473 static inline void virtio_cwrite16(struct virtio_device
*vdev
,
474 unsigned int offset
, u16 val
)
479 v
= cpu_to_virtio16(vdev
, val
);
480 vdev
->config
->set(vdev
, offset
, &v
, sizeof(v
));
483 static inline u32
virtio_cread32(struct virtio_device
*vdev
,
489 vdev
->config
->get(vdev
, offset
, &ret
, sizeof(ret
));
490 return virtio32_to_cpu(vdev
, ret
);
493 static inline void virtio_cwrite32(struct virtio_device
*vdev
,
494 unsigned int offset
, u32 val
)
499 v
= cpu_to_virtio32(vdev
, val
);
500 vdev
->config
->set(vdev
, offset
, &v
, sizeof(v
));
503 static inline u64
virtio_cread64(struct virtio_device
*vdev
,
508 __virtio_cread_many(vdev
, offset
, &ret
, 1, sizeof(ret
));
509 return virtio64_to_cpu(vdev
, ret
);
512 static inline void virtio_cwrite64(struct virtio_device
*vdev
,
513 unsigned int offset
, u64 val
)
518 v
= cpu_to_virtio64(vdev
, val
);
519 vdev
->config
->set(vdev
, offset
, &v
, sizeof(v
));
522 /* Conditional config space accessors. */
523 #define virtio_cread_feature(vdev, fbit, structname, member, ptr) \
526 if (!virtio_has_feature(vdev, fbit)) \
529 virtio_cread((vdev), structname, member, ptr); \
533 /* Conditional config space accessors. */
534 #define virtio_cread_le_feature(vdev, fbit, structname, member, ptr) \
537 if (!virtio_has_feature(vdev, fbit)) \
540 virtio_cread_le((vdev), structname, member, ptr); \
543 #endif /* _LINUX_VIRTIO_CONFIG_H */