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 | typedef void vq_callback_t(struct virtqueue *); |
20 | |
21 | /** |
22 | * struct virtio_config_ops - operations for configuring a virtio device |
23 | * Note: Do not assume that a transport implements all of the operations |
24 | * getting/setting a value as a simple read/write! Generally speaking, |
25 | * any of @get/@set, @get_status/@set_status, or @get_features/ |
26 | * @finalize_features are NOT safe to be called from an atomic |
27 | * context. |
28 | * @get: read the value of a configuration field |
29 | * vdev: the virtio_device |
30 | * offset: the offset of the configuration field |
31 | * buf: the buffer to write the field value into. |
32 | * len: the length of the buffer |
33 | * @set: write the value of a configuration field |
34 | * vdev: the virtio_device |
35 | * offset: the offset of the configuration field |
36 | * buf: the buffer to read the field value from. |
37 | * len: the length of the buffer |
38 | * @generation: config generation counter (optional) |
39 | * vdev: the virtio_device |
40 | * Returns the config generation counter |
41 | * @get_status: read the status byte |
42 | * vdev: the virtio_device |
43 | * Returns the status byte |
44 | * @set_status: write the status byte |
45 | * vdev: the virtio_device |
46 | * status: the new status byte |
47 | * @reset: reset the device |
48 | * vdev: the virtio device |
49 | * After this, status and feature negotiation must be done again |
50 | * Device must not be reset from its vq/config callbacks, or in |
51 | * parallel with being added/removed. |
52 | * @find_vqs: find virtqueues and instantiate them. |
53 | * vdev: the virtio_device |
54 | * nvqs: the number of virtqueues to find |
55 | * vqs: on success, includes new virtqueues |
56 | * callbacks: array of callbacks, for each virtqueue |
57 | * include a NULL entry for vqs that do not need a callback |
58 | * names: array of virtqueue names (mainly for debugging) |
59 | * include a NULL entry for vqs unused by driver |
60 | * Returns 0 on success or error status |
61 | * @del_vqs: free virtqueues found by find_vqs(). |
62 | * @synchronize_cbs: synchronize with the virtqueue callbacks (optional) |
63 | * The function guarantees that all memory operations on the |
64 | * queue before it are visible to the vring_interrupt() that is |
65 | * called after it. |
66 | * vdev: the virtio_device |
67 | * @get_features: get the array of feature bits for this device. |
68 | * vdev: the virtio_device |
69 | * Returns the first 64 feature bits (all we currently need). |
70 | * @finalize_features: confirm what device features we'll be using. |
71 | * vdev: the virtio_device |
72 | * This sends the driver feature bits to the device: it can change |
73 | * the dev->feature bits if it wants. |
74 | * Note that despite the name this can be called any number of |
75 | * times. |
76 | * Returns 0 on success or error status |
77 | * @bus_name: return the bus name associated with the device (optional) |
78 | * vdev: the virtio_device |
79 | * This returns a pointer to the bus name a la pci_name from which |
80 | * the caller can then copy. |
81 | * @set_vq_affinity: set the affinity for a virtqueue (optional). |
82 | * @get_vq_affinity: get the affinity for a virtqueue (optional). |
83 | * @get_shm_region: get a shared memory region based on the index. |
84 | * @disable_vq_and_reset: reset a queue individually (optional). |
85 | * vq: the virtqueue |
86 | * Returns 0 on success or error status |
87 | * disable_vq_and_reset will guarantee that the callbacks are disabled and |
88 | * synchronized. |
89 | * Except for the callback, the caller should guarantee that the vring is |
90 | * not accessed by any functions of virtqueue. |
91 | * @enable_vq_after_reset: enable a reset queue |
92 | * vq: the virtqueue |
93 | * Returns 0 on success or error status |
94 | * If disable_vq_and_reset is set, then enable_vq_after_reset must also be |
95 | * set. |
96 | */ |
97 | struct virtio_config_ops { |
98 | void (*get)(struct virtio_device *vdev, unsigned offset, |
99 | void *buf, unsigned len); |
100 | void (*set)(struct virtio_device *vdev, unsigned offset, |
101 | const void *buf, unsigned len); |
102 | u32 (*generation)(struct virtio_device *vdev); |
103 | u8 (*get_status)(struct virtio_device *vdev); |
104 | void (*set_status)(struct virtio_device *vdev, u8 status); |
105 | void (*reset)(struct virtio_device *vdev); |
106 | int (*find_vqs)(struct virtio_device *, unsigned nvqs, |
107 | struct virtqueue *vqs[], vq_callback_t *callbacks[], |
108 | const char * const names[], const bool *ctx, |
109 | struct irq_affinity *desc); |
110 | void (*del_vqs)(struct virtio_device *); |
111 | void (*synchronize_cbs)(struct virtio_device *); |
112 | u64 (*get_features)(struct virtio_device *vdev); |
113 | int (*finalize_features)(struct virtio_device *vdev); |
114 | const char *(*bus_name)(struct virtio_device *vdev); |
115 | int (*set_vq_affinity)(struct virtqueue *vq, |
116 | const struct cpumask *cpu_mask); |
117 | const struct cpumask *(*get_vq_affinity)(struct virtio_device *vdev, |
118 | int index); |
119 | bool (*get_shm_region)(struct virtio_device *vdev, |
120 | struct virtio_shm_region *region, u8 id); |
121 | int (*disable_vq_and_reset)(struct virtqueue *vq); |
122 | int (*enable_vq_after_reset)(struct virtqueue *vq); |
123 | }; |
124 | |
125 | /* If driver didn't advertise the feature, it will never appear. */ |
126 | void virtio_check_driver_offered_feature(const struct virtio_device *vdev, |
127 | unsigned int fbit); |
128 | |
129 | /** |
130 | * __virtio_test_bit - helper to test feature bits. For use by transports. |
131 | * Devices should normally use virtio_has_feature, |
132 | * which includes more checks. |
133 | * @vdev: the device |
134 | * @fbit: the feature bit |
135 | */ |
136 | static inline bool __virtio_test_bit(const struct virtio_device *vdev, |
137 | unsigned int fbit) |
138 | { |
139 | /* Did you forget to fix assumptions on max features? */ |
140 | if (__builtin_constant_p(fbit)) |
141 | BUILD_BUG_ON(fbit >= 64); |
142 | else |
143 | BUG_ON(fbit >= 64); |
144 | |
145 | return vdev->features & BIT_ULL(fbit); |
146 | } |
147 | |
148 | /** |
149 | * __virtio_set_bit - helper to set feature bits. For use by transports. |
150 | * @vdev: the device |
151 | * @fbit: the feature bit |
152 | */ |
153 | static inline void __virtio_set_bit(struct virtio_device *vdev, |
154 | unsigned int fbit) |
155 | { |
156 | /* Did you forget to fix assumptions on max features? */ |
157 | if (__builtin_constant_p(fbit)) |
158 | BUILD_BUG_ON(fbit >= 64); |
159 | else |
160 | BUG_ON(fbit >= 64); |
161 | |
162 | vdev->features |= BIT_ULL(fbit); |
163 | } |
164 | |
165 | /** |
166 | * __virtio_clear_bit - helper to clear feature bits. For use by transports. |
167 | * @vdev: the device |
168 | * @fbit: the feature bit |
169 | */ |
170 | static inline void __virtio_clear_bit(struct virtio_device *vdev, |
171 | unsigned int fbit) |
172 | { |
173 | /* Did you forget to fix assumptions on max features? */ |
174 | if (__builtin_constant_p(fbit)) |
175 | BUILD_BUG_ON(fbit >= 64); |
176 | else |
177 | BUG_ON(fbit >= 64); |
178 | |
179 | vdev->features &= ~BIT_ULL(fbit); |
180 | } |
181 | |
182 | /** |
183 | * virtio_has_feature - helper to determine if this device has this feature. |
184 | * @vdev: the device |
185 | * @fbit: the feature bit |
186 | */ |
187 | static inline bool virtio_has_feature(const struct virtio_device *vdev, |
188 | unsigned int fbit) |
189 | { |
190 | if (fbit < VIRTIO_TRANSPORT_F_START) |
191 | virtio_check_driver_offered_feature(vdev, fbit); |
192 | |
193 | return __virtio_test_bit(vdev, fbit); |
194 | } |
195 | |
196 | /** |
197 | * virtio_has_dma_quirk - determine whether this device has the DMA quirk |
198 | * @vdev: the device |
199 | */ |
200 | static inline bool virtio_has_dma_quirk(const struct virtio_device *vdev) |
201 | { |
202 | /* |
203 | * Note the reverse polarity of the quirk feature (compared to most |
204 | * other features), this is for compatibility with legacy systems. |
205 | */ |
206 | return !virtio_has_feature(vdev, VIRTIO_F_ACCESS_PLATFORM); |
207 | } |
208 | |
209 | static inline |
210 | struct virtqueue *virtio_find_single_vq(struct virtio_device *vdev, |
211 | vq_callback_t *c, const char *n) |
212 | { |
213 | vq_callback_t *callbacks[] = { c }; |
214 | const char *names[] = { n }; |
215 | struct virtqueue *vq; |
216 | int err = vdev->config->find_vqs(vdev, 1, &vq, callbacks, names, NULL, |
217 | NULL); |
218 | if (err < 0) |
219 | return ERR_PTR(error: err); |
220 | return vq; |
221 | } |
222 | |
223 | static inline |
224 | int virtio_find_vqs(struct virtio_device *vdev, unsigned nvqs, |
225 | struct virtqueue *vqs[], vq_callback_t *callbacks[], |
226 | const char * const names[], |
227 | struct irq_affinity *desc) |
228 | { |
229 | return vdev->config->find_vqs(vdev, nvqs, vqs, callbacks, names, NULL, desc); |
230 | } |
231 | |
232 | static inline |
233 | int virtio_find_vqs_ctx(struct virtio_device *vdev, unsigned nvqs, |
234 | struct virtqueue *vqs[], vq_callback_t *callbacks[], |
235 | const char * const names[], const bool *ctx, |
236 | struct irq_affinity *desc) |
237 | { |
238 | return vdev->config->find_vqs(vdev, nvqs, vqs, callbacks, names, ctx, |
239 | desc); |
240 | } |
241 | |
242 | /** |
243 | * virtio_synchronize_cbs - synchronize with virtqueue callbacks |
244 | * @dev: the virtio device |
245 | */ |
246 | static inline |
247 | void virtio_synchronize_cbs(struct virtio_device *dev) |
248 | { |
249 | if (dev->config->synchronize_cbs) { |
250 | dev->config->synchronize_cbs(dev); |
251 | } else { |
252 | /* |
253 | * A best effort fallback to synchronize with |
254 | * interrupts, preemption and softirq disabled |
255 | * regions. See comment above synchronize_rcu(). |
256 | */ |
257 | synchronize_rcu(); |
258 | } |
259 | } |
260 | |
261 | /** |
262 | * virtio_device_ready - enable vq use in probe function |
263 | * @dev: the virtio device |
264 | * |
265 | * Driver must call this to use vqs in the probe function. |
266 | * |
267 | * Note: vqs are enabled automatically after probe returns. |
268 | */ |
269 | static inline |
270 | void virtio_device_ready(struct virtio_device *dev) |
271 | { |
272 | unsigned status = dev->config->get_status(dev); |
273 | |
274 | WARN_ON(status & VIRTIO_CONFIG_S_DRIVER_OK); |
275 | |
276 | #ifdef CONFIG_VIRTIO_HARDEN_NOTIFICATION |
277 | /* |
278 | * The virtio_synchronize_cbs() makes sure vring_interrupt() |
279 | * will see the driver specific setup if it sees vq->broken |
280 | * as false (even if the notifications come before DRIVER_OK). |
281 | */ |
282 | virtio_synchronize_cbs(dev); |
283 | __virtio_unbreak_device(dev); |
284 | #endif |
285 | /* |
286 | * The transport should ensure the visibility of vq->broken |
287 | * before setting DRIVER_OK. See the comments for the transport |
288 | * specific set_status() method. |
289 | * |
290 | * A well behaved device will only notify a virtqueue after |
291 | * DRIVER_OK, this means the device should "see" the coherenct |
292 | * memory write that set vq->broken as false which is done by |
293 | * the driver when it sees DRIVER_OK, then the following |
294 | * driver's vring_interrupt() will see vq->broken as false so |
295 | * we won't lose any notification. |
296 | */ |
297 | dev->config->set_status(dev, status | VIRTIO_CONFIG_S_DRIVER_OK); |
298 | } |
299 | |
300 | static inline |
301 | const char *virtio_bus_name(struct virtio_device *vdev) |
302 | { |
303 | if (!vdev->config->bus_name) |
304 | return "virtio" ; |
305 | return vdev->config->bus_name(vdev); |
306 | } |
307 | |
308 | /** |
309 | * virtqueue_set_affinity - setting affinity for a virtqueue |
310 | * @vq: the virtqueue |
311 | * @cpu_mask: the cpu mask |
312 | * |
313 | * Pay attention the function are best-effort: the affinity hint may not be set |
314 | * due to config support, irq type and sharing. |
315 | * |
316 | */ |
317 | static inline |
318 | int virtqueue_set_affinity(struct virtqueue *vq, const struct cpumask *cpu_mask) |
319 | { |
320 | struct virtio_device *vdev = vq->vdev; |
321 | if (vdev->config->set_vq_affinity) |
322 | return vdev->config->set_vq_affinity(vq, cpu_mask); |
323 | return 0; |
324 | } |
325 | |
326 | static inline |
327 | bool virtio_get_shm_region(struct virtio_device *vdev, |
328 | struct virtio_shm_region *region, u8 id) |
329 | { |
330 | if (!vdev->config->get_shm_region) |
331 | return false; |
332 | return vdev->config->get_shm_region(vdev, region, id); |
333 | } |
334 | |
335 | static inline bool virtio_is_little_endian(struct virtio_device *vdev) |
336 | { |
337 | return virtio_has_feature(vdev, VIRTIO_F_VERSION_1) || |
338 | virtio_legacy_is_little_endian(); |
339 | } |
340 | |
341 | /* Memory accessors */ |
342 | static inline u16 virtio16_to_cpu(struct virtio_device *vdev, __virtio16 val) |
343 | { |
344 | return __virtio16_to_cpu(little_endian: virtio_is_little_endian(vdev), val); |
345 | } |
346 | |
347 | static inline __virtio16 cpu_to_virtio16(struct virtio_device *vdev, u16 val) |
348 | { |
349 | return __cpu_to_virtio16(little_endian: virtio_is_little_endian(vdev), val); |
350 | } |
351 | |
352 | static inline u32 virtio32_to_cpu(struct virtio_device *vdev, __virtio32 val) |
353 | { |
354 | return __virtio32_to_cpu(little_endian: virtio_is_little_endian(vdev), val); |
355 | } |
356 | |
357 | static inline __virtio32 cpu_to_virtio32(struct virtio_device *vdev, u32 val) |
358 | { |
359 | return __cpu_to_virtio32(little_endian: virtio_is_little_endian(vdev), val); |
360 | } |
361 | |
362 | static inline u64 virtio64_to_cpu(struct virtio_device *vdev, __virtio64 val) |
363 | { |
364 | return __virtio64_to_cpu(little_endian: virtio_is_little_endian(vdev), val); |
365 | } |
366 | |
367 | static inline __virtio64 cpu_to_virtio64(struct virtio_device *vdev, u64 val) |
368 | { |
369 | return __cpu_to_virtio64(little_endian: virtio_is_little_endian(vdev), val); |
370 | } |
371 | |
372 | #define virtio_to_cpu(vdev, x) \ |
373 | _Generic((x), \ |
374 | __u8: (x), \ |
375 | __virtio16: virtio16_to_cpu((vdev), (x)), \ |
376 | __virtio32: virtio32_to_cpu((vdev), (x)), \ |
377 | __virtio64: virtio64_to_cpu((vdev), (x)) \ |
378 | ) |
379 | |
380 | #define cpu_to_virtio(vdev, x, m) \ |
381 | _Generic((m), \ |
382 | __u8: (x), \ |
383 | __virtio16: cpu_to_virtio16((vdev), (x)), \ |
384 | __virtio32: cpu_to_virtio32((vdev), (x)), \ |
385 | __virtio64: cpu_to_virtio64((vdev), (x)) \ |
386 | ) |
387 | |
388 | #define __virtio_native_type(structname, member) \ |
389 | typeof(virtio_to_cpu(NULL, ((structname*)0)->member)) |
390 | |
391 | /* Config space accessors. */ |
392 | #define virtio_cread(vdev, structname, member, ptr) \ |
393 | do { \ |
394 | typeof(((structname*)0)->member) virtio_cread_v; \ |
395 | \ |
396 | might_sleep(); \ |
397 | /* Sanity check: must match the member's type */ \ |
398 | typecheck(typeof(virtio_to_cpu((vdev), virtio_cread_v)), *(ptr)); \ |
399 | \ |
400 | switch (sizeof(virtio_cread_v)) { \ |
401 | case 1: \ |
402 | case 2: \ |
403 | case 4: \ |
404 | vdev->config->get((vdev), \ |
405 | offsetof(structname, member), \ |
406 | &virtio_cread_v, \ |
407 | sizeof(virtio_cread_v)); \ |
408 | break; \ |
409 | default: \ |
410 | __virtio_cread_many((vdev), \ |
411 | offsetof(structname, member), \ |
412 | &virtio_cread_v, \ |
413 | 1, \ |
414 | sizeof(virtio_cread_v)); \ |
415 | break; \ |
416 | } \ |
417 | *(ptr) = virtio_to_cpu(vdev, virtio_cread_v); \ |
418 | } while(0) |
419 | |
420 | /* Config space accessors. */ |
421 | #define virtio_cwrite(vdev, structname, member, ptr) \ |
422 | do { \ |
423 | typeof(((structname*)0)->member) virtio_cwrite_v = \ |
424 | cpu_to_virtio(vdev, *(ptr), ((structname*)0)->member); \ |
425 | \ |
426 | might_sleep(); \ |
427 | /* Sanity check: must match the member's type */ \ |
428 | typecheck(typeof(virtio_to_cpu((vdev), 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 | * Nothing virtio-specific about these, but let's worry about generalizing |
437 | * these later. |
438 | */ |
439 | #define virtio_le_to_cpu(x) \ |
440 | _Generic((x), \ |
441 | __u8: (u8)(x), \ |
442 | __le16: (u16)le16_to_cpu(x), \ |
443 | __le32: (u32)le32_to_cpu(x), \ |
444 | __le64: (u64)le64_to_cpu(x) \ |
445 | ) |
446 | |
447 | #define virtio_cpu_to_le(x, m) \ |
448 | _Generic((m), \ |
449 | __u8: (x), \ |
450 | __le16: cpu_to_le16(x), \ |
451 | __le32: cpu_to_le32(x), \ |
452 | __le64: cpu_to_le64(x) \ |
453 | ) |
454 | |
455 | /* LE (e.g. modern) Config space accessors. */ |
456 | #define virtio_cread_le(vdev, structname, member, ptr) \ |
457 | do { \ |
458 | typeof(((structname*)0)->member) virtio_cread_v; \ |
459 | \ |
460 | might_sleep(); \ |
461 | /* Sanity check: must match the member's type */ \ |
462 | typecheck(typeof(virtio_le_to_cpu(virtio_cread_v)), *(ptr)); \ |
463 | \ |
464 | switch (sizeof(virtio_cread_v)) { \ |
465 | case 1: \ |
466 | case 2: \ |
467 | case 4: \ |
468 | vdev->config->get((vdev), \ |
469 | offsetof(structname, member), \ |
470 | &virtio_cread_v, \ |
471 | sizeof(virtio_cread_v)); \ |
472 | break; \ |
473 | default: \ |
474 | __virtio_cread_many((vdev), \ |
475 | offsetof(structname, member), \ |
476 | &virtio_cread_v, \ |
477 | 1, \ |
478 | sizeof(virtio_cread_v)); \ |
479 | break; \ |
480 | } \ |
481 | *(ptr) = virtio_le_to_cpu(virtio_cread_v); \ |
482 | } while(0) |
483 | |
484 | #define virtio_cwrite_le(vdev, structname, member, ptr) \ |
485 | do { \ |
486 | typeof(((structname*)0)->member) virtio_cwrite_v = \ |
487 | virtio_cpu_to_le(*(ptr), ((structname*)0)->member); \ |
488 | \ |
489 | might_sleep(); \ |
490 | /* Sanity check: must match the member's type */ \ |
491 | typecheck(typeof(virtio_le_to_cpu(virtio_cwrite_v)), *(ptr)); \ |
492 | \ |
493 | vdev->config->set((vdev), offsetof(structname, member), \ |
494 | &virtio_cwrite_v, \ |
495 | sizeof(virtio_cwrite_v)); \ |
496 | } while(0) |
497 | |
498 | |
499 | /* Read @count fields, @bytes each. */ |
500 | static inline void __virtio_cread_many(struct virtio_device *vdev, |
501 | unsigned int offset, |
502 | void *buf, size_t count, size_t bytes) |
503 | { |
504 | u32 old, gen = vdev->config->generation ? |
505 | vdev->config->generation(vdev) : 0; |
506 | int i; |
507 | |
508 | might_sleep(); |
509 | do { |
510 | old = gen; |
511 | |
512 | for (i = 0; i < count; i++) |
513 | vdev->config->get(vdev, offset + bytes * i, |
514 | buf + i * bytes, bytes); |
515 | |
516 | gen = vdev->config->generation ? |
517 | vdev->config->generation(vdev) : 0; |
518 | } while (gen != old); |
519 | } |
520 | |
521 | static inline void virtio_cread_bytes(struct virtio_device *vdev, |
522 | unsigned int offset, |
523 | void *buf, size_t len) |
524 | { |
525 | __virtio_cread_many(vdev, offset, buf, count: len, bytes: 1); |
526 | } |
527 | |
528 | static inline u8 virtio_cread8(struct virtio_device *vdev, unsigned int offset) |
529 | { |
530 | u8 ret; |
531 | |
532 | might_sleep(); |
533 | vdev->config->get(vdev, offset, &ret, sizeof(ret)); |
534 | return ret; |
535 | } |
536 | |
537 | static inline void virtio_cwrite8(struct virtio_device *vdev, |
538 | unsigned int offset, u8 val) |
539 | { |
540 | might_sleep(); |
541 | vdev->config->set(vdev, offset, &val, sizeof(val)); |
542 | } |
543 | |
544 | static inline u16 virtio_cread16(struct virtio_device *vdev, |
545 | unsigned int offset) |
546 | { |
547 | __virtio16 ret; |
548 | |
549 | might_sleep(); |
550 | vdev->config->get(vdev, offset, &ret, sizeof(ret)); |
551 | return virtio16_to_cpu(vdev, val: ret); |
552 | } |
553 | |
554 | static inline void virtio_cwrite16(struct virtio_device *vdev, |
555 | unsigned int offset, u16 val) |
556 | { |
557 | __virtio16 v; |
558 | |
559 | might_sleep(); |
560 | v = cpu_to_virtio16(vdev, val); |
561 | vdev->config->set(vdev, offset, &v, sizeof(v)); |
562 | } |
563 | |
564 | static inline u32 virtio_cread32(struct virtio_device *vdev, |
565 | unsigned int offset) |
566 | { |
567 | __virtio32 ret; |
568 | |
569 | might_sleep(); |
570 | vdev->config->get(vdev, offset, &ret, sizeof(ret)); |
571 | return virtio32_to_cpu(vdev, val: ret); |
572 | } |
573 | |
574 | static inline void virtio_cwrite32(struct virtio_device *vdev, |
575 | unsigned int offset, u32 val) |
576 | { |
577 | __virtio32 v; |
578 | |
579 | might_sleep(); |
580 | v = cpu_to_virtio32(vdev, val); |
581 | vdev->config->set(vdev, offset, &v, sizeof(v)); |
582 | } |
583 | |
584 | static inline u64 virtio_cread64(struct virtio_device *vdev, |
585 | unsigned int offset) |
586 | { |
587 | __virtio64 ret; |
588 | |
589 | __virtio_cread_many(vdev, offset, buf: &ret, count: 1, bytes: sizeof(ret)); |
590 | return virtio64_to_cpu(vdev, val: ret); |
591 | } |
592 | |
593 | static inline void virtio_cwrite64(struct virtio_device *vdev, |
594 | unsigned int offset, u64 val) |
595 | { |
596 | __virtio64 v; |
597 | |
598 | might_sleep(); |
599 | v = cpu_to_virtio64(vdev, val); |
600 | vdev->config->set(vdev, offset, &v, sizeof(v)); |
601 | } |
602 | |
603 | /* Conditional config space accessors. */ |
604 | #define virtio_cread_feature(vdev, fbit, structname, member, ptr) \ |
605 | ({ \ |
606 | int _r = 0; \ |
607 | if (!virtio_has_feature(vdev, fbit)) \ |
608 | _r = -ENOENT; \ |
609 | else \ |
610 | virtio_cread((vdev), structname, member, ptr); \ |
611 | _r; \ |
612 | }) |
613 | |
614 | /* Conditional config space accessors. */ |
615 | #define virtio_cread_le_feature(vdev, fbit, structname, member, ptr) \ |
616 | ({ \ |
617 | int _r = 0; \ |
618 | if (!virtio_has_feature(vdev, fbit)) \ |
619 | _r = -ENOENT; \ |
620 | else \ |
621 | virtio_cread_le((vdev), structname, member, ptr); \ |
622 | _r; \ |
623 | }) |
624 | |
625 | #endif /* _LINUX_VIRTIO_CONFIG_H */ |
626 | |