Line data Source code
1 : /* SPDX-License-Identifier: GPL-2.0 */
2 : #ifndef _LINUX_VIRTIO_CONFIG_H
3 : #define _LINUX_VIRTIO_CONFIG_H
4 :
5 : #include <linux/err.h>
6 : #include <linux/bug.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>
11 :
12 : struct irq_affinity;
13 :
14 : struct virtio_shm_region {
15 : u64 addr;
16 : u64 len;
17 : };
18 :
19 : /**
20 : * virtio_config_ops - operations for configuring a virtio device
21 : * Note: Do not assume that a transport implements all of the operations
22 : * getting/setting a value as a simple read/write! Generally speaking,
23 : * any of @get/@set, @get_status/@set_status, or @get_features/
24 : * @finalize_features are NOT safe to be called from an atomic
25 : * context.
26 : * @get: read the value of a configuration field
27 : * vdev: the virtio_device
28 : * offset: the offset of the configuration field
29 : * buf: the buffer to write the field value into.
30 : * len: the length of the buffer
31 : * @set: write the value of a configuration field
32 : * vdev: the virtio_device
33 : * offset: the offset of the configuration field
34 : * buf: the buffer to read the field value from.
35 : * len: the length of the buffer
36 : * @generation: config generation counter (optional)
37 : * vdev: the virtio_device
38 : * Returns the config generation counter
39 : * @get_status: read the status byte
40 : * vdev: the virtio_device
41 : * Returns the status byte
42 : * @set_status: write the status byte
43 : * vdev: the virtio_device
44 : * status: the new status byte
45 : * @reset: reset the device
46 : * vdev: the virtio device
47 : * After this, status and feature negotiation must be done again
48 : * Device must not be reset from its vq/config callbacks, or in
49 : * parallel with being added/removed.
50 : * @find_vqs: find virtqueues and instantiate them.
51 : * vdev: the virtio_device
52 : * nvqs: the number of virtqueues to find
53 : * vqs: on success, includes new virtqueues
54 : * callbacks: array of callbacks, for each virtqueue
55 : * include a NULL entry for vqs that do not need a callback
56 : * names: array of virtqueue names (mainly for debugging)
57 : * include a NULL entry for vqs unused by driver
58 : * Returns 0 on success or error status
59 : * @del_vqs: free virtqueues found by find_vqs().
60 : * @get_features: get the array of feature bits for this device.
61 : * vdev: the virtio_device
62 : * Returns the first 64 feature bits (all we currently need).
63 : * @finalize_features: confirm what device features we'll be using.
64 : * vdev: the virtio_device
65 : * This sends the driver feature bits to the device: it can change
66 : * the dev->feature bits if it wants.
67 : * Note: despite the name this can be called any number of times.
68 : * Returns 0 on success or error status
69 : * @bus_name: return the bus name associated with the device (optional)
70 : * vdev: the virtio_device
71 : * This returns a pointer to the bus name a la pci_name from which
72 : * the caller can then copy.
73 : * @set_vq_affinity: set the affinity for a virtqueue (optional).
74 : * @get_vq_affinity: get the affinity for a virtqueue (optional).
75 : * @get_shm_region: get a shared memory region based on the index.
76 : */
77 : typedef void vq_callback_t(struct virtqueue *);
78 : struct virtio_config_ops {
79 : void (*get)(struct virtio_device *vdev, unsigned offset,
80 : void *buf, unsigned len);
81 : void (*set)(struct virtio_device *vdev, unsigned offset,
82 : const void *buf, unsigned len);
83 : u32 (*generation)(struct virtio_device *vdev);
84 : u8 (*get_status)(struct virtio_device *vdev);
85 : void (*set_status)(struct virtio_device *vdev, u8 status);
86 : void (*reset)(struct virtio_device *vdev);
87 : int (*find_vqs)(struct virtio_device *, unsigned nvqs,
88 : struct virtqueue *vqs[], vq_callback_t *callbacks[],
89 : const char * const names[], const bool *ctx,
90 : struct irq_affinity *desc);
91 : void (*del_vqs)(struct virtio_device *);
92 : u64 (*get_features)(struct virtio_device *vdev);
93 : int (*finalize_features)(struct virtio_device *vdev);
94 : const char *(*bus_name)(struct virtio_device *vdev);
95 : int (*set_vq_affinity)(struct virtqueue *vq,
96 : const struct cpumask *cpu_mask);
97 : const struct cpumask *(*get_vq_affinity)(struct virtio_device *vdev,
98 : int index);
99 : bool (*get_shm_region)(struct virtio_device *vdev,
100 : struct virtio_shm_region *region, u8 id);
101 : };
102 :
103 : /* If driver didn't advertise the feature, it will never appear. */
104 : void virtio_check_driver_offered_feature(const struct virtio_device *vdev,
105 : unsigned int fbit);
106 :
107 : /**
108 : * __virtio_test_bit - helper to test feature bits. For use by transports.
109 : * Devices should normally use virtio_has_feature,
110 : * which includes more checks.
111 : * @vdev: the device
112 : * @fbit: the feature bit
113 : */
114 0 : static inline bool __virtio_test_bit(const struct virtio_device *vdev,
115 : unsigned int fbit)
116 : {
117 : /* Did you forget to fix assumptions on max features? */
118 0 : if (__builtin_constant_p(fbit))
119 0 : BUILD_BUG_ON(fbit >= 64);
120 : else
121 0 : BUG_ON(fbit >= 64);
122 :
123 0 : return vdev->features & BIT_ULL(fbit);
124 : }
125 :
126 : /**
127 : * __virtio_set_bit - helper to set feature bits. For use by transports.
128 : * @vdev: the device
129 : * @fbit: the feature bit
130 : */
131 0 : static inline void __virtio_set_bit(struct virtio_device *vdev,
132 : unsigned int fbit)
133 : {
134 : /* Did you forget to fix assumptions on max features? */
135 0 : if (__builtin_constant_p(fbit))
136 0 : BUILD_BUG_ON(fbit >= 64);
137 : else
138 0 : BUG_ON(fbit >= 64);
139 :
140 0 : vdev->features |= BIT_ULL(fbit);
141 0 : }
142 :
143 : /**
144 : * __virtio_clear_bit - helper to clear feature bits. For use by transports.
145 : * @vdev: the device
146 : * @fbit: the feature bit
147 : */
148 0 : static inline void __virtio_clear_bit(struct virtio_device *vdev,
149 : unsigned int fbit)
150 : {
151 : /* Did you forget to fix assumptions on max features? */
152 0 : if (__builtin_constant_p(fbit))
153 0 : BUILD_BUG_ON(fbit >= 64);
154 : else
155 0 : BUG_ON(fbit >= 64);
156 :
157 0 : vdev->features &= ~BIT_ULL(fbit);
158 0 : }
159 :
160 : /**
161 : * virtio_has_feature - helper to determine if this device has this feature.
162 : * @vdev: the device
163 : * @fbit: the feature bit
164 : */
165 : static inline bool virtio_has_feature(const struct virtio_device *vdev,
166 : unsigned int fbit)
167 : {
168 : if (fbit < VIRTIO_TRANSPORT_F_START)
169 : virtio_check_driver_offered_feature(vdev, fbit);
170 :
171 0 : return __virtio_test_bit(vdev, fbit);
172 : }
173 :
174 : /**
175 : * virtio_has_dma_quirk - determine whether this device has the DMA quirk
176 : * @vdev: the device
177 : */
178 : static inline bool virtio_has_dma_quirk(const struct virtio_device *vdev)
179 : {
180 : /*
181 : * Note the reverse polarity of the quirk feature (compared to most
182 : * other features), this is for compatibility with legacy systems.
183 : */
184 0 : return !virtio_has_feature(vdev, VIRTIO_F_ACCESS_PLATFORM);
185 : }
186 :
187 : static inline
188 : struct virtqueue *virtio_find_single_vq(struct virtio_device *vdev,
189 : vq_callback_t *c, const char *n)
190 : {
191 : vq_callback_t *callbacks[] = { c };
192 : const char *names[] = { n };
193 : struct virtqueue *vq;
194 : int err = vdev->config->find_vqs(vdev, 1, &vq, callbacks, names, NULL,
195 : NULL);
196 : if (err < 0)
197 : return ERR_PTR(err);
198 : return vq;
199 : }
200 :
201 : static inline
202 : int virtio_find_vqs(struct virtio_device *vdev, unsigned nvqs,
203 : struct virtqueue *vqs[], vq_callback_t *callbacks[],
204 : const char * const names[],
205 : struct irq_affinity *desc)
206 : {
207 0 : return vdev->config->find_vqs(vdev, nvqs, vqs, callbacks, names, NULL, desc);
208 : }
209 :
210 : static inline
211 : int virtio_find_vqs_ctx(struct virtio_device *vdev, unsigned nvqs,
212 : struct virtqueue *vqs[], vq_callback_t *callbacks[],
213 : const char * const names[], const bool *ctx,
214 : struct irq_affinity *desc)
215 : {
216 : return vdev->config->find_vqs(vdev, nvqs, vqs, callbacks, names, ctx,
217 : desc);
218 : }
219 :
220 : /**
221 : * virtio_device_ready - enable vq use in probe function
222 : * @vdev: the device
223 : *
224 : * Driver must call this to use vqs in the probe function.
225 : *
226 : * Note: vqs are enabled automatically after probe returns.
227 : */
228 : static inline
229 0 : void virtio_device_ready(struct virtio_device *dev)
230 : {
231 0 : unsigned status = dev->config->get_status(dev);
232 :
233 0 : BUG_ON(status & VIRTIO_CONFIG_S_DRIVER_OK);
234 0 : dev->config->set_status(dev, status | VIRTIO_CONFIG_S_DRIVER_OK);
235 0 : }
236 :
237 : static inline
238 : const char *virtio_bus_name(struct virtio_device *vdev)
239 : {
240 : if (!vdev->config->bus_name)
241 : return "virtio";
242 : return vdev->config->bus_name(vdev);
243 : }
244 :
245 : /**
246 : * virtqueue_set_affinity - setting affinity for a virtqueue
247 : * @vq: the virtqueue
248 : * @cpu: the cpu no.
249 : *
250 : * Pay attention the function are best-effort: the affinity hint may not be set
251 : * due to config support, irq type and sharing.
252 : *
253 : */
254 : static inline
255 : int virtqueue_set_affinity(struct virtqueue *vq, const struct cpumask *cpu_mask)
256 : {
257 : struct virtio_device *vdev = vq->vdev;
258 : if (vdev->config->set_vq_affinity)
259 : return vdev->config->set_vq_affinity(vq, cpu_mask);
260 : return 0;
261 : }
262 :
263 : static inline
264 : bool virtio_get_shm_region(struct virtio_device *vdev,
265 : struct virtio_shm_region *region, u8 id)
266 : {
267 : if (!vdev->config->get_shm_region)
268 : return false;
269 : return vdev->config->get_shm_region(vdev, region, id);
270 : }
271 :
272 : static inline bool virtio_is_little_endian(struct virtio_device *vdev)
273 : {
274 0 : return virtio_has_feature(vdev, VIRTIO_F_VERSION_1) ||
275 : virtio_legacy_is_little_endian();
276 : }
277 :
278 : /* Memory accessors */
279 : static inline u16 virtio16_to_cpu(struct virtio_device *vdev, __virtio16 val)
280 : {
281 0 : return __virtio16_to_cpu(virtio_is_little_endian(vdev), val);
282 : }
283 :
284 : static inline __virtio16 cpu_to_virtio16(struct virtio_device *vdev, u16 val)
285 : {
286 0 : return __cpu_to_virtio16(virtio_is_little_endian(vdev), val);
287 : }
288 :
289 : static inline u32 virtio32_to_cpu(struct virtio_device *vdev, __virtio32 val)
290 : {
291 0 : return __virtio32_to_cpu(virtio_is_little_endian(vdev), val);
292 : }
293 :
294 : static inline __virtio32 cpu_to_virtio32(struct virtio_device *vdev, u32 val)
295 : {
296 0 : return __cpu_to_virtio32(virtio_is_little_endian(vdev), val);
297 : }
298 :
299 : static inline u64 virtio64_to_cpu(struct virtio_device *vdev, __virtio64 val)
300 : {
301 0 : return __virtio64_to_cpu(virtio_is_little_endian(vdev), val);
302 : }
303 :
304 : static inline __virtio64 cpu_to_virtio64(struct virtio_device *vdev, u64 val)
305 : {
306 0 : return __cpu_to_virtio64(virtio_is_little_endian(vdev), val);
307 : }
308 :
309 : #define virtio_to_cpu(vdev, x) \
310 : _Generic((x), \
311 : __u8: (x), \
312 : __virtio16: virtio16_to_cpu((vdev), (x)), \
313 : __virtio32: virtio32_to_cpu((vdev), (x)), \
314 : __virtio64: virtio64_to_cpu((vdev), (x)) \
315 : )
316 :
317 : #define cpu_to_virtio(vdev, x, m) \
318 : _Generic((m), \
319 : __u8: (x), \
320 : __virtio16: cpu_to_virtio16((vdev), (x)), \
321 : __virtio32: cpu_to_virtio32((vdev), (x)), \
322 : __virtio64: cpu_to_virtio64((vdev), (x)) \
323 : )
324 :
325 : #define __virtio_native_type(structname, member) \
326 : typeof(virtio_to_cpu(NULL, ((structname*)0)->member))
327 :
328 : /* Config space accessors. */
329 : #define virtio_cread(vdev, structname, member, ptr) \
330 : do { \
331 : typeof(((structname*)0)->member) virtio_cread_v; \
332 : \
333 : might_sleep(); \
334 : /* Sanity check: must match the member's type */ \
335 : typecheck(typeof(virtio_to_cpu((vdev), virtio_cread_v)), *(ptr)); \
336 : \
337 : switch (sizeof(virtio_cread_v)) { \
338 : case 1: \
339 : case 2: \
340 : case 4: \
341 : vdev->config->get((vdev), \
342 : offsetof(structname, member), \
343 : &virtio_cread_v, \
344 : sizeof(virtio_cread_v)); \
345 : break; \
346 : default: \
347 : __virtio_cread_many((vdev), \
348 : offsetof(structname, member), \
349 : &virtio_cread_v, \
350 : 1, \
351 : sizeof(virtio_cread_v)); \
352 : break; \
353 : } \
354 : *(ptr) = virtio_to_cpu(vdev, virtio_cread_v); \
355 : } while(0)
356 :
357 : /* Config space accessors. */
358 : #define virtio_cwrite(vdev, structname, member, ptr) \
359 : do { \
360 : typeof(((structname*)0)->member) virtio_cwrite_v = \
361 : cpu_to_virtio(vdev, *(ptr), ((structname*)0)->member); \
362 : \
363 : might_sleep(); \
364 : /* Sanity check: must match the member's type */ \
365 : typecheck(typeof(virtio_to_cpu((vdev), virtio_cwrite_v)), *(ptr)); \
366 : \
367 : vdev->config->set((vdev), offsetof(structname, member), \
368 : &virtio_cwrite_v, \
369 : sizeof(virtio_cwrite_v)); \
370 : } while(0)
371 :
372 : /*
373 : * Nothing virtio-specific about these, but let's worry about generalizing
374 : * these later.
375 : */
376 : #define virtio_le_to_cpu(x) \
377 : _Generic((x), \
378 : __u8: (u8)(x), \
379 : __le16: (u16)le16_to_cpu(x), \
380 : __le32: (u32)le32_to_cpu(x), \
381 : __le64: (u64)le64_to_cpu(x) \
382 : )
383 :
384 : #define virtio_cpu_to_le(x, m) \
385 : _Generic((m), \
386 : __u8: (x), \
387 : __le16: cpu_to_le16(x), \
388 : __le32: cpu_to_le32(x), \
389 : __le64: cpu_to_le64(x) \
390 : )
391 :
392 : /* LE (e.g. modern) Config space accessors. */
393 : #define virtio_cread_le(vdev, structname, member, ptr) \
394 : do { \
395 : typeof(((structname*)0)->member) virtio_cread_v; \
396 : \
397 : might_sleep(); \
398 : /* Sanity check: must match the member's type */ \
399 : typecheck(typeof(virtio_le_to_cpu(virtio_cread_v)), *(ptr)); \
400 : \
401 : switch (sizeof(virtio_cread_v)) { \
402 : case 1: \
403 : case 2: \
404 : case 4: \
405 : vdev->config->get((vdev), \
406 : offsetof(structname, member), \
407 : &virtio_cread_v, \
408 : sizeof(virtio_cread_v)); \
409 : break; \
410 : default: \
411 : __virtio_cread_many((vdev), \
412 : offsetof(structname, member), \
413 : &virtio_cread_v, \
414 : 1, \
415 : sizeof(virtio_cread_v)); \
416 : break; \
417 : } \
418 : *(ptr) = virtio_le_to_cpu(virtio_cread_v); \
419 : } while(0)
420 :
421 : #define virtio_cwrite_le(vdev, structname, member, ptr) \
422 : do { \
423 : typeof(((structname*)0)->member) virtio_cwrite_v = \
424 : virtio_cpu_to_le(*(ptr), ((structname*)0)->member); \
425 : \
426 : might_sleep(); \
427 : /* Sanity check: must match the member's type */ \
428 : typecheck(typeof(virtio_le_to_cpu(virtio_cwrite_v)), *(ptr)); \
429 : \
430 : vdev->config->set((vdev), offsetof(structname, member), \
431 : &virtio_cwrite_v, \
432 : sizeof(virtio_cwrite_v)); \
433 : } while(0)
434 :
435 :
436 : /* Read @count fields, @bytes each. */
437 : static inline void __virtio_cread_many(struct virtio_device *vdev,
438 : unsigned int offset,
439 : void *buf, size_t count, size_t bytes)
440 : {
441 : u32 old, gen = vdev->config->generation ?
442 : vdev->config->generation(vdev) : 0;
443 : int i;
444 :
445 : might_sleep();
446 : do {
447 : old = gen;
448 :
449 : for (i = 0; i < count; i++)
450 : vdev->config->get(vdev, offset + bytes * i,
451 : buf + i * bytes, bytes);
452 :
453 : gen = vdev->config->generation ?
454 : vdev->config->generation(vdev) : 0;
455 : } while (gen != old);
456 : }
457 :
458 : static inline void virtio_cread_bytes(struct virtio_device *vdev,
459 : unsigned int offset,
460 : void *buf, size_t len)
461 : {
462 : __virtio_cread_many(vdev, offset, buf, len, 1);
463 : }
464 :
465 : static inline u8 virtio_cread8(struct virtio_device *vdev, unsigned int offset)
466 : {
467 : u8 ret;
468 :
469 : might_sleep();
470 : vdev->config->get(vdev, offset, &ret, sizeof(ret));
471 : return ret;
472 : }
473 :
474 : static inline void virtio_cwrite8(struct virtio_device *vdev,
475 : unsigned int offset, u8 val)
476 : {
477 : might_sleep();
478 : vdev->config->set(vdev, offset, &val, sizeof(val));
479 : }
480 :
481 : static inline u16 virtio_cread16(struct virtio_device *vdev,
482 : unsigned int offset)
483 : {
484 : __virtio16 ret;
485 :
486 : might_sleep();
487 : vdev->config->get(vdev, offset, &ret, sizeof(ret));
488 : return virtio16_to_cpu(vdev, ret);
489 : }
490 :
491 : static inline void virtio_cwrite16(struct virtio_device *vdev,
492 : unsigned int offset, u16 val)
493 : {
494 : __virtio16 v;
495 :
496 : might_sleep();
497 : v = cpu_to_virtio16(vdev, val);
498 : vdev->config->set(vdev, offset, &v, sizeof(v));
499 : }
500 :
501 : static inline u32 virtio_cread32(struct virtio_device *vdev,
502 : unsigned int offset)
503 : {
504 : __virtio32 ret;
505 :
506 : might_sleep();
507 : vdev->config->get(vdev, offset, &ret, sizeof(ret));
508 : return virtio32_to_cpu(vdev, ret);
509 : }
510 :
511 : static inline void virtio_cwrite32(struct virtio_device *vdev,
512 : unsigned int offset, u32 val)
513 : {
514 : __virtio32 v;
515 :
516 : might_sleep();
517 : v = cpu_to_virtio32(vdev, val);
518 : vdev->config->set(vdev, offset, &v, sizeof(v));
519 : }
520 :
521 : static inline u64 virtio_cread64(struct virtio_device *vdev,
522 : unsigned int offset)
523 : {
524 : __virtio64 ret;
525 :
526 : __virtio_cread_many(vdev, offset, &ret, 1, sizeof(ret));
527 : return virtio64_to_cpu(vdev, ret);
528 : }
529 :
530 : static inline void virtio_cwrite64(struct virtio_device *vdev,
531 : unsigned int offset, u64 val)
532 : {
533 : __virtio64 v;
534 :
535 : might_sleep();
536 : v = cpu_to_virtio64(vdev, val);
537 : vdev->config->set(vdev, offset, &v, sizeof(v));
538 : }
539 :
540 : /* Conditional config space accessors. */
541 : #define virtio_cread_feature(vdev, fbit, structname, member, ptr) \
542 : ({ \
543 : int _r = 0; \
544 : if (!virtio_has_feature(vdev, fbit)) \
545 : _r = -ENOENT; \
546 : else \
547 : virtio_cread((vdev), structname, member, ptr); \
548 : _r; \
549 : })
550 :
551 : /* Conditional config space accessors. */
552 : #define virtio_cread_le_feature(vdev, fbit, structname, member, ptr) \
553 : ({ \
554 : int _r = 0; \
555 : if (!virtio_has_feature(vdev, fbit)) \
556 : _r = -ENOENT; \
557 : else \
558 : virtio_cread_le((vdev), structname, member, ptr); \
559 : _r; \
560 : })
561 :
562 : #ifdef CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS
563 : int arch_has_restricted_virtio_memory_access(void);
564 : #else
565 : static inline int arch_has_restricted_virtio_memory_access(void)
566 : {
567 : return 0;
568 : }
569 : #endif /* CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS */
570 :
571 : #endif /* _LINUX_VIRTIO_CONFIG_H */
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