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Bin Meng8fb49b42018-10-15 02:21:00 -07001/* SPDX-License-Identifier: GPL-2.0+ */
2/*
3 * Copyright (C) 2018, Tuomas Tynkkynen <tuomas.tynkkynen@iki.fi>
4 * Copyright (C) 2018, Bin Meng <bmeng.cn@gmail.com>
5 *
6 * VirtIO is a virtualization standard for network and disk device drivers
7 * where just the guest's device driver "knows" it is running in a virtual
8 * environment, and cooperates with the hypervisor. This enables guests to
9 * get high performance network and disk operations, and gives most of the
10 * performance benefits of paravirtualization. In the U-Boot case, the guest
11 * is U-Boot itself, while the virtual environment are normally QEMU targets
12 * like ARM, RISC-V and x86.
13 *
14 * See http://docs.oasis-open.org/virtio/virtio/v1.0/virtio-v1.0.pdf for
15 * the VirtIO specification v1.0.
16 *
17 * This file is largely based on Linux kernel virtio_*.h files
18 */
19
20#ifndef __VIRTIO_H__
21#define __VIRTIO_H__
22
Simon Glasscd93d622020-05-10 11:40:13 -060023#include <linux/bitops.h>
Simon Glasseb41d8a2020-05-10 11:40:08 -060024#include <linux/bug.h>
Bin Meng8fb49b42018-10-15 02:21:00 -070025#define VIRTIO_ID_NET 1 /* virtio net */
26#define VIRTIO_ID_BLOCK 2 /* virtio block */
Sughosh Ganu03018ea2019-12-29 15:30:14 +053027#define VIRTIO_ID_RNG 4 /* virtio rng */
28#define VIRTIO_ID_MAX_NUM 5
Bin Meng8fb49b42018-10-15 02:21:00 -070029
30#define VIRTIO_NET_DRV_NAME "virtio-net"
31#define VIRTIO_BLK_DRV_NAME "virtio-blk"
Sughosh Ganu03018ea2019-12-29 15:30:14 +053032#define VIRTIO_RNG_DRV_NAME "virtio-rng"
Bin Meng8fb49b42018-10-15 02:21:00 -070033
34/* Status byte for guest to report progress, and synchronize features */
35
36/* We have seen device and processed generic fields (VIRTIO_CONFIG_F_VIRTIO) */
37#define VIRTIO_CONFIG_S_ACKNOWLEDGE 1
38/* We have found a driver for the device */
39#define VIRTIO_CONFIG_S_DRIVER 2
40/* Driver has used its parts of the config, and is happy */
41#define VIRTIO_CONFIG_S_DRIVER_OK 4
42/* Driver has finished configuring features */
43#define VIRTIO_CONFIG_S_FEATURES_OK 8
44/* Device entered invalid state, driver must reset it */
45#define VIRTIO_CONFIG_S_NEEDS_RESET 0x40
46/* We've given up on this device */
47#define VIRTIO_CONFIG_S_FAILED 0x80
48
49/*
50 * Virtio feature bits VIRTIO_TRANSPORT_F_START through VIRTIO_TRANSPORT_F_END
51 * are reserved for the transport being used (eg: virtio_ring, virtio_pci etc.),
52 * the rest are per-device feature bits.
53 */
54#define VIRTIO_TRANSPORT_F_START 28
55#define VIRTIO_TRANSPORT_F_END 38
56
57#ifndef VIRTIO_CONFIG_NO_LEGACY
58/*
59 * Do we get callbacks when the ring is completely used,
60 * even if we've suppressed them?
61 */
62#define VIRTIO_F_NOTIFY_ON_EMPTY 24
63
64/* Can the device handle any descriptor layout? */
65#define VIRTIO_F_ANY_LAYOUT 27
66#endif /* VIRTIO_CONFIG_NO_LEGACY */
67
68/* v1.0 compliant */
69#define VIRTIO_F_VERSION_1 32
70
71/*
72 * If clear - device has the IOMMU bypass quirk feature.
73 * If set - use platform tools to detect the IOMMU.
74 *
75 * Note the reverse polarity (compared to most other features),
76 * this is for compatibility with legacy systems.
77 */
78#define VIRTIO_F_IOMMU_PLATFORM 33
79
80/* Does the device support Single Root I/O Virtualization? */
81#define VIRTIO_F_SR_IOV 37
82
83/**
84 * virtio scatter-gather struct
85 *
86 * @addr: sg buffer address
87 * @lengh: sg buffer length
88 */
89struct virtio_sg {
90 void *addr;
91 size_t length;
92};
93
94struct virtqueue;
95
96/* virtio bus operations */
97struct dm_virtio_ops {
98 /**
99 * get_config() - read the value of a configuration field
100 *
101 * @vdev: the real virtio device
102 * @offset: the offset of the configuration field
103 * @buf: the buffer to write the field value into
104 * @len: the length of the buffer
105 * @return 0 if OK, -ve on error
106 */
107 int (*get_config)(struct udevice *vdev, unsigned int offset,
108 void *buf, unsigned int len);
109 /**
110 * set_config() - write the value of a configuration field
111 *
112 * @vdev: the real virtio device
113 * @offset: the offset of the configuration field
114 * @buf: the buffer to read the field value from
115 * @len: the length of the buffer
116 * @return 0 if OK, -ve on error
117 */
118 int (*set_config)(struct udevice *vdev, unsigned int offset,
119 const void *buf, unsigned int len);
120 /**
121 * generation() - config generation counter
122 *
123 * @vdev: the real virtio device
124 * @counter: the returned config generation counter
125 * @return 0 if OK, -ve on error
126 */
127 int (*generation)(struct udevice *vdev, u32 *counter);
128 /**
129 * get_status() - read the status byte
130 *
131 * @vdev: the real virtio device
132 * @status: the returned status byte
133 * @return 0 if OK, -ve on error
134 */
135 int (*get_status)(struct udevice *vdev, u8 *status);
136 /**
137 * set_status() - write the status byte
138 *
139 * @vdev: the real virtio device
140 * @status: the new status byte
141 * @return 0 if OK, -ve on error
142 */
143 int (*set_status)(struct udevice *vdev, u8 status);
144 /**
145 * reset() - reset the device
146 *
147 * @vdev: the real virtio device
148 * @return 0 if OK, -ve on error
149 */
150 int (*reset)(struct udevice *vdev);
151 /**
152 * get_features() - get the array of feature bits for this device
153 *
154 * @vdev: the real virtio device
155 * @features: the first 32 feature bits (all we currently need)
156 * @return 0 if OK, -ve on error
157 */
158 int (*get_features)(struct udevice *vdev, u64 *features);
159 /**
160 * set_features() - confirm what device features we'll be using
161 *
162 * @vdev: the real virtio device
163 * @return 0 if OK, -ve on error
164 */
165 int (*set_features)(struct udevice *vdev);
166 /**
167 * find_vqs() - find virtqueues and instantiate them
168 *
169 * @vdev: the real virtio device
170 * @nvqs: the number of virtqueues to find
171 * @vqs: on success, includes new virtqueues
172 * @return 0 if OK, -ve on error
173 */
174 int (*find_vqs)(struct udevice *vdev, unsigned int nvqs,
175 struct virtqueue *vqs[]);
176 /**
177 * del_vqs() - free virtqueues found by find_vqs()
178 *
179 * @vdev: the real virtio device
180 * @return 0 if OK, -ve on error
181 */
182 int (*del_vqs)(struct udevice *vdev);
183 /**
184 * notify() - notify the device to process the queue
185 *
186 * @vdev: the real virtio device
187 * @vq: virtqueue to process
188 * @return 0 if OK, -ve on error
189 */
190 int (*notify)(struct udevice *vdev, struct virtqueue *vq);
191};
192
193/* Get access to a virtio bus' operations */
194#define virtio_get_ops(dev) ((struct dm_virtio_ops *)(dev)->driver->ops)
195
196/**
197 * virtio uclass per device private data
198 *
199 * @vqs: virtualqueue for the virtio device
200 * @vdev: the real virtio device underneath
201 * @legacy: is it a legacy device?
202 * @device: virtio device ID
203 * @vendor: virtio vendor ID
204 * @features: negotiated supported features
205 * @feature_table: an array of feature supported by the driver
206 * @feature_table_size: number of entries in the feature table array
207 * @feature_table_legacy: same as feature_table but working in legacy mode
208 * @feature_table_size_legacy: number of entries in feature table legacy array
209 */
210struct virtio_dev_priv {
211 struct list_head vqs;
212 struct udevice *vdev;
213 bool legacy;
214 u32 device;
215 u32 vendor;
216 u64 features;
217 const u32 *feature_table;
218 u32 feature_table_size;
219 const u32 *feature_table_legacy;
220 u32 feature_table_size_legacy;
221};
222
223/**
224 * virtio_get_config() - read the value of a configuration field
225 *
226 * @vdev: the real virtio device
227 * @offset: the offset of the configuration field
228 * @buf: the buffer to write the field value into
229 * @len: the length of the buffer
230 * @return 0 if OK, -ve on error
231 */
232int virtio_get_config(struct udevice *vdev, unsigned int offset,
233 void *buf, unsigned int len);
234
235/**
236 * virtio_set_config() - write the value of a configuration field
237 *
238 * @vdev: the real virtio device
239 * @offset: the offset of the configuration field
240 * @buf: the buffer to read the field value from
241 * @len: the length of the buffer
242 * @return 0 if OK, -ve on error
243 */
244int virtio_set_config(struct udevice *vdev, unsigned int offset,
245 void *buf, unsigned int len);
246
247/**
248 * virtio_generation() - config generation counter
249 *
250 * @vdev: the real virtio device
251 * @counter: the returned config generation counter
252 * @return 0 if OK, -ve on error
253 */
254int virtio_generation(struct udevice *vdev, u32 *counter);
255
256/**
257 * virtio_get_status() - read the status byte
258 *
259 * @vdev: the real virtio device
260 * @status: the returned status byte
261 * @return 0 if OK, -ve on error
262 */
263int virtio_get_status(struct udevice *vdev, u8 *status);
264
265/**
266 * virtio_set_status() - write the status byte
267 *
268 * @vdev: the real virtio device
269 * @status: the new status byte
270 * @return 0 if OK, -ve on error
271 */
272int virtio_set_status(struct udevice *vdev, u8 status);
273
274/**
275 * virtio_reset() - reset the device
276 *
277 * @vdev: the real virtio device
278 * @return 0 if OK, -ve on error
279 */
280int virtio_reset(struct udevice *vdev);
281
282/**
283 * virtio_get_features() - get the array of feature bits for this device
284 *
285 * @vdev: the real virtio device
286 * @features: the first 32 feature bits (all we currently need)
287 * @return 0 if OK, -ve on error
288 */
289int virtio_get_features(struct udevice *vdev, u64 *features);
290
291/**
292 * virtio_set_features() - confirm what device features we'll be using
293 *
294 * @vdev: the real virtio device
295 * @return 0 if OK, -ve on error
296 */
297int virtio_set_features(struct udevice *vdev);
298
299/**
300 * virtio_find_vqs() - find virtqueues and instantiate them
301 *
302 * @vdev: the real virtio device
303 * @nvqs: the number of virtqueues to find
304 * @vqs: on success, includes new virtqueues
305 * @return 0 if OK, -ve on error
306 */
307int virtio_find_vqs(struct udevice *vdev, unsigned int nvqs,
308 struct virtqueue *vqs[]);
309
310/**
311 * virtio_del_vqs() - free virtqueues found by find_vqs()
312 *
313 * @vdev: the real virtio device
314 * @return 0 if OK, -ve on error
315 */
316int virtio_del_vqs(struct udevice *vdev);
317
318/**
319 * virtio_notify() - notify the device to process the queue
320 *
321 * @vdev: the real virtio device
322 * @vq: virtqueue to process
323 * @return 0 if OK, -ve on error
324 */
325int virtio_notify(struct udevice *vdev, struct virtqueue *vq);
326
327/**
328 * virtio_add_status() - helper to set a new status code to the device
329 *
330 * @vdev: the real virtio device
331 * @status: new status code to be added
332 */
333void virtio_add_status(struct udevice *vdev, u8 status);
334
335/**
336 * virtio_finalize_features() - helper to finalize features
337 *
338 * @vdev: the real virtio device
339 * @return 0 if OK, -ve on error
340 */
341int virtio_finalize_features(struct udevice *vdev);
342
343/**
344 * virtio_driver_features_init() - initialize driver supported features
345 *
346 * This fills in the virtio device parent per child private data with the given
347 * information, which contains driver supported features and legacy features.
348 *
349 * This API should be called in the virtio device driver's bind method, so that
350 * later virtio transport uclass driver can utilize the driver supplied features
351 * to negotiate with the device on the final supported features.
352 *
353 * @priv: virtio uclass per device private data
354 * @feature: an array of feature supported by the driver
355 * @feature_size: number of entries in the feature table array
356 * @feature_legacy: same as feature_table but working in legacy mode
357 * @feature_legacy_size:number of entries in feature table legacy array
358 */
359void virtio_driver_features_init(struct virtio_dev_priv *priv,
360 const u32 *feature,
361 u32 feature_size,
362 const u32 *feature_legacy,
363 u32 feature_legacy_size);
364
365/**
366 * virtio_init() - helper to enumerate all known virtio devices
367 *
368 * @return 0 if OK, -ve on error
369 */
370int virtio_init(void);
371
372static inline u16 __virtio16_to_cpu(bool little_endian, __virtio16 val)
373{
374 if (little_endian)
375 return le16_to_cpu((__force __le16)val);
376 else
377 return be16_to_cpu((__force __be16)val);
378}
379
380static inline __virtio16 __cpu_to_virtio16(bool little_endian, u16 val)
381{
382 if (little_endian)
383 return (__force __virtio16)cpu_to_le16(val);
384 else
385 return (__force __virtio16)cpu_to_be16(val);
386}
387
388static inline u32 __virtio32_to_cpu(bool little_endian, __virtio32 val)
389{
390 if (little_endian)
391 return le32_to_cpu((__force __le32)val);
392 else
393 return be32_to_cpu((__force __be32)val);
394}
395
396static inline __virtio32 __cpu_to_virtio32(bool little_endian, u32 val)
397{
398 if (little_endian)
399 return (__force __virtio32)cpu_to_le32(val);
400 else
401 return (__force __virtio32)cpu_to_be32(val);
402}
403
404static inline u64 __virtio64_to_cpu(bool little_endian, __virtio64 val)
405{
406 if (little_endian)
407 return le64_to_cpu((__force __le64)val);
408 else
409 return be64_to_cpu((__force __be64)val);
410}
411
412static inline __virtio64 __cpu_to_virtio64(bool little_endian, u64 val)
413{
414 if (little_endian)
415 return (__force __virtio64)cpu_to_le64(val);
416 else
417 return (__force __virtio64)cpu_to_be64(val);
418}
419
420/**
421 * __virtio_test_bit - helper to test feature bits
422 *
423 * For use by transports. Devices should normally use virtio_has_feature,
424 * which includes more checks.
425 *
426 * @udev: the transport device
427 * @fbit: the feature bit
428 */
429static inline bool __virtio_test_bit(struct udevice *udev, unsigned int fbit)
430{
431 struct virtio_dev_priv *uc_priv = dev_get_uclass_priv(udev);
432
433 /* Did you forget to fix assumptions on max features? */
434 if (__builtin_constant_p(fbit))
435 BUILD_BUG_ON(fbit >= 64);
436 else
437 WARN_ON(fbit >= 64);
438
439 return uc_priv->features & BIT_ULL(fbit);
440}
441
442/**
443 * __virtio_set_bit - helper to set feature bits
444 *
445 * For use by transports.
446 *
447 * @udev: the transport device
448 * @fbit: the feature bit
449 */
450static inline void __virtio_set_bit(struct udevice *udev, unsigned int fbit)
451{
452 struct virtio_dev_priv *uc_priv = dev_get_uclass_priv(udev);
453
454 /* Did you forget to fix assumptions on max features? */
455 if (__builtin_constant_p(fbit))
456 BUILD_BUG_ON(fbit >= 64);
457 else
458 WARN_ON(fbit >= 64);
459
460 uc_priv->features |= BIT_ULL(fbit);
461}
462
463/**
464 * __virtio_clear_bit - helper to clear feature bits
465 *
466 * For use by transports.
467 *
468 * @vdev: the transport device
469 * @fbit: the feature bit
470 */
471static inline void __virtio_clear_bit(struct udevice *udev, unsigned int fbit)
472{
473 struct virtio_dev_priv *uc_priv = dev_get_uclass_priv(udev);
474
475 /* Did you forget to fix assumptions on max features? */
476 if (__builtin_constant_p(fbit))
477 BUILD_BUG_ON(fbit >= 64);
478 else
479 WARN_ON(fbit >= 64);
480
481 uc_priv->features &= ~BIT_ULL(fbit);
482}
483
484/**
485 * virtio_has_feature - helper to determine if this device has this feature
486 *
487 * Note this API is only usable after the virtio device driver's bind phase,
488 * as the feature has been negotiated between the device and the driver.
489 *
490 * @vdev: the virtio device
491 * @fbit: the feature bit
492 */
493static inline bool virtio_has_feature(struct udevice *vdev, unsigned int fbit)
494{
Simon Glass73466df2020-12-19 10:40:10 -0700495 if (!(dev_get_flags(vdev) & DM_FLAG_BOUND))
Bin Meng8fb49b42018-10-15 02:21:00 -0700496 WARN_ON(true);
497
498 return __virtio_test_bit(vdev->parent, fbit);
499}
500
501static inline bool virtio_legacy_is_little_endian(void)
502{
503#ifdef __LITTLE_ENDIAN
504 return true;
505#else
506 return false;
507#endif
508}
509
510static inline bool virtio_is_little_endian(struct udevice *vdev)
511{
512 struct virtio_dev_priv *uc_priv = dev_get_uclass_priv(vdev->parent);
513
514 return !uc_priv->legacy || virtio_legacy_is_little_endian();
515}
516
517/* Memory accessors */
518static inline u16 virtio16_to_cpu(struct udevice *vdev, __virtio16 val)
519{
520 return __virtio16_to_cpu(virtio_is_little_endian(vdev), val);
521}
522
523static inline __virtio16 cpu_to_virtio16(struct udevice *vdev, u16 val)
524{
525 return __cpu_to_virtio16(virtio_is_little_endian(vdev), val);
526}
527
528static inline u32 virtio32_to_cpu(struct udevice *vdev, __virtio32 val)
529{
530 return __virtio32_to_cpu(virtio_is_little_endian(vdev), val);
531}
532
533static inline __virtio32 cpu_to_virtio32(struct udevice *vdev, u32 val)
534{
535 return __cpu_to_virtio32(virtio_is_little_endian(vdev), val);
536}
537
538static inline u64 virtio64_to_cpu(struct udevice *vdev, __virtio64 val)
539{
540 return __virtio64_to_cpu(virtio_is_little_endian(vdev), val);
541}
542
543static inline __virtio64 cpu_to_virtio64(struct udevice *vdev, u64 val)
544{
545 return __cpu_to_virtio64(virtio_is_little_endian(vdev), val);
546}
547
548/* Read @count fields, @bytes each */
549static inline void __virtio_cread_many(struct udevice *vdev,
550 unsigned int offset,
551 void *buf, size_t count, size_t bytes)
552{
553 u32 old, gen;
554 int i;
555
556 /* no need to check return value as generation can be optional */
557 virtio_generation(vdev, &gen);
558 do {
559 old = gen;
560
561 for (i = 0; i < count; i++)
562 virtio_get_config(vdev, offset + bytes * i,
563 buf + i * bytes, bytes);
564
565 virtio_generation(vdev, &gen);
566 } while (gen != old);
567}
568
569static inline void virtio_cread_bytes(struct udevice *vdev,
570 unsigned int offset,
571 void *buf, size_t len)
572{
573 __virtio_cread_many(vdev, offset, buf, len, 1);
574}
575
576static inline u8 virtio_cread8(struct udevice *vdev, unsigned int offset)
577{
578 u8 ret;
579
580 virtio_get_config(vdev, offset, &ret, sizeof(ret));
581 return ret;
582}
583
584static inline void virtio_cwrite8(struct udevice *vdev,
585 unsigned int offset, u8 val)
586{
587 virtio_set_config(vdev, offset, &val, sizeof(val));
588}
589
590static inline u16 virtio_cread16(struct udevice *vdev,
591 unsigned int offset)
592{
593 u16 ret;
594
595 virtio_get_config(vdev, offset, &ret, sizeof(ret));
596 return virtio16_to_cpu(vdev, (__force __virtio16)ret);
597}
598
599static inline void virtio_cwrite16(struct udevice *vdev,
600 unsigned int offset, u16 val)
601{
602 val = (__force u16)cpu_to_virtio16(vdev, val);
603 virtio_set_config(vdev, offset, &val, sizeof(val));
604}
605
606static inline u32 virtio_cread32(struct udevice *vdev,
607 unsigned int offset)
608{
609 u32 ret;
610
611 virtio_get_config(vdev, offset, &ret, sizeof(ret));
612 return virtio32_to_cpu(vdev, (__force __virtio32)ret);
613}
614
615static inline void virtio_cwrite32(struct udevice *vdev,
616 unsigned int offset, u32 val)
617{
618 val = (__force u32)cpu_to_virtio32(vdev, val);
619 virtio_set_config(vdev, offset, &val, sizeof(val));
620}
621
622static inline u64 virtio_cread64(struct udevice *vdev,
623 unsigned int offset)
624{
625 u64 ret;
626
627 __virtio_cread_many(vdev, offset, &ret, 1, sizeof(ret));
628 return virtio64_to_cpu(vdev, (__force __virtio64)ret);
629}
630
631static inline void virtio_cwrite64(struct udevice *vdev,
632 unsigned int offset, u64 val)
633{
634 val = (__force u64)cpu_to_virtio64(vdev, val);
635 virtio_set_config(vdev, offset, &val, sizeof(val));
636}
637
638/* Config space read accessor */
639#define virtio_cread(vdev, structname, member, ptr) \
640 do { \
641 /* Must match the member's type, and be integer */ \
642 if (!typecheck(typeof((((structname *)0)->member)), *(ptr))) \
643 (*ptr) = 1; \
644 \
645 switch (sizeof(*ptr)) { \
646 case 1: \
647 *(ptr) = virtio_cread8(vdev, \
648 offsetof(structname, member)); \
649 break; \
650 case 2: \
651 *(ptr) = virtio_cread16(vdev, \
652 offsetof(structname, member)); \
653 break; \
654 case 4: \
655 *(ptr) = virtio_cread32(vdev, \
656 offsetof(structname, member)); \
657 break; \
658 case 8: \
659 *(ptr) = virtio_cread64(vdev, \
660 offsetof(structname, member)); \
661 break; \
662 default: \
663 WARN_ON(true); \
664 } \
665 } while (0)
666
667/* Config space write accessor */
668#define virtio_cwrite(vdev, structname, member, ptr) \
669 do { \
670 /* Must match the member's type, and be integer */ \
671 if (!typecheck(typeof((((structname *)0)->member)), *(ptr))) \
672 WARN_ON((*ptr) == 1); \
673 \
674 switch (sizeof(*ptr)) { \
675 case 1: \
676 virtio_cwrite8(vdev, \
677 offsetof(structname, member), \
678 *(ptr)); \
679 break; \
680 case 2: \
681 virtio_cwrite16(vdev, \
682 offsetof(structname, member), \
683 *(ptr)); \
684 break; \
685 case 4: \
686 virtio_cwrite32(vdev, \
687 offsetof(structname, member), \
688 *(ptr)); \
689 break; \
690 case 8: \
691 virtio_cwrite64(vdev, \
692 offsetof(structname, member), \
693 *(ptr)); \
694 break; \
695 default: \
696 WARN_ON(true); \
697 } \
698 } while (0)
699
700/* Conditional config space accessors */
701#define virtio_cread_feature(vdev, fbit, structname, member, ptr) \
702 ({ \
703 int _r = 0; \
704 if (!virtio_has_feature(vdev, fbit)) \
705 _r = -ENOENT; \
706 else \
707 virtio_cread(vdev, structname, member, ptr); \
708 _r; \
709 })
710
711#endif /* __VIRTIO_H__ */