Commit | Line | Data |
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fd534e9b | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
0a8a69dd RR |
2 | /* Virtio ring implementation. |
3 | * | |
4 | * Copyright 2007 Rusty Russell IBM Corporation | |
0a8a69dd RR |
5 | */ |
6 | #include <linux/virtio.h> | |
7 | #include <linux/virtio_ring.h> | |
e34f8725 | 8 | #include <linux/virtio_config.h> |
0a8a69dd | 9 | #include <linux/device.h> |
5a0e3ad6 | 10 | #include <linux/slab.h> |
b5a2c4f1 | 11 | #include <linux/module.h> |
e93300b1 | 12 | #include <linux/hrtimer.h> |
780bc790 | 13 | #include <linux/dma-mapping.h> |
f8ce7263 | 14 | #include <linux/spinlock.h> |
78fe3987 | 15 | #include <xen/xen.h> |
0a8a69dd RR |
16 | |
17 | #ifdef DEBUG | |
18 | /* For development, we want to crash whenever the ring is screwed. */ | |
9499f5e7 RR |
19 | #define BAD_RING(_vq, fmt, args...) \ |
20 | do { \ | |
21 | dev_err(&(_vq)->vq.vdev->dev, \ | |
22 | "%s:"fmt, (_vq)->vq.name, ##args); \ | |
23 | BUG(); \ | |
24 | } while (0) | |
c5f841f1 RR |
25 | /* Caller is supposed to guarantee no reentry. */ |
26 | #define START_USE(_vq) \ | |
27 | do { \ | |
28 | if ((_vq)->in_use) \ | |
9499f5e7 RR |
29 | panic("%s:in_use = %i\n", \ |
30 | (_vq)->vq.name, (_vq)->in_use); \ | |
c5f841f1 | 31 | (_vq)->in_use = __LINE__; \ |
9499f5e7 | 32 | } while (0) |
3a35ce7d | 33 | #define END_USE(_vq) \ |
97a545ab | 34 | do { BUG_ON(!(_vq)->in_use); (_vq)->in_use = 0; } while(0) |
4d6a105e TB |
35 | #define LAST_ADD_TIME_UPDATE(_vq) \ |
36 | do { \ | |
37 | ktime_t now = ktime_get(); \ | |
38 | \ | |
39 | /* No kick or get, with .1 second between? Warn. */ \ | |
40 | if ((_vq)->last_add_time_valid) \ | |
41 | WARN_ON(ktime_to_ms(ktime_sub(now, \ | |
42 | (_vq)->last_add_time)) > 100); \ | |
43 | (_vq)->last_add_time = now; \ | |
44 | (_vq)->last_add_time_valid = true; \ | |
45 | } while (0) | |
46 | #define LAST_ADD_TIME_CHECK(_vq) \ | |
47 | do { \ | |
48 | if ((_vq)->last_add_time_valid) { \ | |
49 | WARN_ON(ktime_to_ms(ktime_sub(ktime_get(), \ | |
50 | (_vq)->last_add_time)) > 100); \ | |
51 | } \ | |
52 | } while (0) | |
53 | #define LAST_ADD_TIME_INVALID(_vq) \ | |
54 | ((_vq)->last_add_time_valid = false) | |
0a8a69dd | 55 | #else |
9499f5e7 RR |
56 | #define BAD_RING(_vq, fmt, args...) \ |
57 | do { \ | |
58 | dev_err(&_vq->vq.vdev->dev, \ | |
59 | "%s:"fmt, (_vq)->vq.name, ##args); \ | |
60 | (_vq)->broken = true; \ | |
61 | } while (0) | |
0a8a69dd RR |
62 | #define START_USE(vq) |
63 | #define END_USE(vq) | |
4d6a105e TB |
64 | #define LAST_ADD_TIME_UPDATE(vq) |
65 | #define LAST_ADD_TIME_CHECK(vq) | |
66 | #define LAST_ADD_TIME_INVALID(vq) | |
0a8a69dd RR |
67 | #endif |
68 | ||
cbeedb72 | 69 | struct vring_desc_state_split { |
780bc790 AL |
70 | void *data; /* Data for callback. */ |
71 | struct vring_desc *indir_desc; /* Indirect descriptor, if any. */ | |
72 | }; | |
73 | ||
1ce9e605 TB |
74 | struct vring_desc_state_packed { |
75 | void *data; /* Data for callback. */ | |
76 | struct vring_packed_desc *indir_desc; /* Indirect descriptor, if any. */ | |
77 | u16 num; /* Descriptor list length. */ | |
1ce9e605 TB |
78 | u16 last; /* The last desc state in a list. */ |
79 | }; | |
80 | ||
1f28750f | 81 | struct vring_desc_extra { |
ef5c366f JW |
82 | dma_addr_t addr; /* Descriptor DMA addr. */ |
83 | u32 len; /* Descriptor length. */ | |
1ce9e605 | 84 | u16 flags; /* Descriptor flags. */ |
aeef9b47 | 85 | u16 next; /* The next desc state in a list. */ |
1ce9e605 TB |
86 | }; |
87 | ||
d76136e4 XZ |
88 | struct vring_virtqueue_split { |
89 | /* Actual memory layout for this queue. */ | |
90 | struct vring vring; | |
91 | ||
92 | /* Last written value to avail->flags */ | |
93 | u16 avail_flags_shadow; | |
94 | ||
95 | /* | |
96 | * Last written value to avail->idx in | |
97 | * guest byte order. | |
98 | */ | |
99 | u16 avail_idx_shadow; | |
100 | ||
101 | /* Per-descriptor state. */ | |
102 | struct vring_desc_state_split *desc_state; | |
103 | struct vring_desc_extra *desc_extra; | |
104 | ||
105 | /* DMA address and size information */ | |
106 | dma_addr_t queue_dma_addr; | |
107 | size_t queue_size_in_bytes; | |
af36b16f XZ |
108 | |
109 | /* | |
110 | * The parameters for creating vrings are reserved for creating new | |
111 | * vring. | |
112 | */ | |
113 | u32 vring_align; | |
114 | bool may_reduce_num; | |
d76136e4 XZ |
115 | }; |
116 | ||
117 | struct vring_virtqueue_packed { | |
118 | /* Actual memory layout for this queue. */ | |
119 | struct { | |
120 | unsigned int num; | |
121 | struct vring_packed_desc *desc; | |
122 | struct vring_packed_desc_event *driver; | |
123 | struct vring_packed_desc_event *device; | |
124 | } vring; | |
125 | ||
126 | /* Driver ring wrap counter. */ | |
127 | bool avail_wrap_counter; | |
128 | ||
129 | /* Avail used flags. */ | |
130 | u16 avail_used_flags; | |
131 | ||
132 | /* Index of the next avail descriptor. */ | |
133 | u16 next_avail_idx; | |
134 | ||
135 | /* | |
136 | * Last written value to driver->flags in | |
137 | * guest byte order. | |
138 | */ | |
139 | u16 event_flags_shadow; | |
140 | ||
141 | /* Per-descriptor state. */ | |
142 | struct vring_desc_state_packed *desc_state; | |
143 | struct vring_desc_extra *desc_extra; | |
144 | ||
145 | /* DMA address and size information */ | |
146 | dma_addr_t ring_dma_addr; | |
147 | dma_addr_t driver_event_dma_addr; | |
148 | dma_addr_t device_event_dma_addr; | |
149 | size_t ring_size_in_bytes; | |
150 | size_t event_size_in_bytes; | |
151 | }; | |
152 | ||
43b4f721 | 153 | struct vring_virtqueue { |
0a8a69dd RR |
154 | struct virtqueue vq; |
155 | ||
1ce9e605 TB |
156 | /* Is this a packed ring? */ |
157 | bool packed_ring; | |
158 | ||
fb3fba6b TB |
159 | /* Is DMA API used? */ |
160 | bool use_dma_api; | |
161 | ||
7b21e34f RR |
162 | /* Can we use weak barriers? */ |
163 | bool weak_barriers; | |
164 | ||
0a8a69dd RR |
165 | /* Other side has made a mess, don't try any more. */ |
166 | bool broken; | |
167 | ||
9fa29b9d MM |
168 | /* Host supports indirect buffers */ |
169 | bool indirect; | |
170 | ||
a5c262c5 MT |
171 | /* Host publishes avail event idx */ |
172 | bool event; | |
173 | ||
0a8a69dd RR |
174 | /* Head of free buffer list. */ |
175 | unsigned int free_head; | |
176 | /* Number we've added since last sync. */ | |
177 | unsigned int num_added; | |
178 | ||
a7722890 | 179 | /* Last used index we've seen. |
180 | * for split ring, it just contains last used index | |
181 | * for packed ring: | |
182 | * bits up to VRING_PACKED_EVENT_F_WRAP_CTR include the last used index. | |
183 | * bits from VRING_PACKED_EVENT_F_WRAP_CTR include the used wrap counter. | |
184 | */ | |
1bc4953e | 185 | u16 last_used_idx; |
0a8a69dd | 186 | |
8d622d21 MT |
187 | /* Hint for event idx: already triggered no need to disable. */ |
188 | bool event_triggered; | |
189 | ||
1ce9e605 TB |
190 | union { |
191 | /* Available for split ring */ | |
d76136e4 | 192 | struct vring_virtqueue_split split; |
e593bf97 | 193 | |
1ce9e605 | 194 | /* Available for packed ring */ |
d76136e4 | 195 | struct vring_virtqueue_packed packed; |
1ce9e605 | 196 | }; |
f277ec42 | 197 | |
0a8a69dd | 198 | /* How to notify other side. FIXME: commonalize hcalls! */ |
46f9c2b9 | 199 | bool (*notify)(struct virtqueue *vq); |
0a8a69dd | 200 | |
2a2d1382 AL |
201 | /* DMA, allocation, and size information */ |
202 | bool we_own_ring; | |
2a2d1382 | 203 | |
0a8a69dd RR |
204 | #ifdef DEBUG |
205 | /* They're supposed to lock for us. */ | |
206 | unsigned int in_use; | |
e93300b1 RR |
207 | |
208 | /* Figure out if their kicks are too delayed. */ | |
209 | bool last_add_time_valid; | |
210 | ktime_t last_add_time; | |
0a8a69dd | 211 | #endif |
0a8a69dd RR |
212 | }; |
213 | ||
07d9629d | 214 | static struct virtqueue *__vring_new_virtqueue(unsigned int index, |
cd4c812a | 215 | struct vring_virtqueue_split *vring_split, |
07d9629d XZ |
216 | struct virtio_device *vdev, |
217 | bool weak_barriers, | |
218 | bool context, | |
219 | bool (*notify)(struct virtqueue *), | |
220 | void (*callback)(struct virtqueue *), | |
221 | const char *name); | |
a2b36c8d | 222 | static struct vring_desc_extra *vring_alloc_desc_extra(unsigned int num); |
6fea20e5 | 223 | static void vring_free(struct virtqueue *_vq); |
e6f633e5 TB |
224 | |
225 | /* | |
226 | * Helpers. | |
227 | */ | |
228 | ||
0a8a69dd RR |
229 | #define to_vvq(_vq) container_of(_vq, struct vring_virtqueue, vq) |
230 | ||
35c51e09 | 231 | static inline bool virtqueue_use_indirect(struct vring_virtqueue *vq, |
2f18c2d1 TB |
232 | unsigned int total_sg) |
233 | { | |
2f18c2d1 TB |
234 | /* |
235 | * If the host supports indirect descriptor tables, and we have multiple | |
236 | * buffers, then go indirect. FIXME: tune this threshold | |
237 | */ | |
238 | return (vq->indirect && total_sg > 1 && vq->vq.num_free); | |
239 | } | |
240 | ||
d26c96c8 | 241 | /* |
1a937693 MT |
242 | * Modern virtio devices have feature bits to specify whether they need a |
243 | * quirk and bypass the IOMMU. If not there, just use the DMA API. | |
244 | * | |
245 | * If there, the interaction between virtio and DMA API is messy. | |
d26c96c8 AL |
246 | * |
247 | * On most systems with virtio, physical addresses match bus addresses, | |
248 | * and it doesn't particularly matter whether we use the DMA API. | |
249 | * | |
250 | * On some systems, including Xen and any system with a physical device | |
251 | * that speaks virtio behind a physical IOMMU, we must use the DMA API | |
252 | * for virtio DMA to work at all. | |
253 | * | |
254 | * On other systems, including SPARC and PPC64, virtio-pci devices are | |
255 | * enumerated as though they are behind an IOMMU, but the virtio host | |
256 | * ignores the IOMMU, so we must either pretend that the IOMMU isn't | |
257 | * there or somehow map everything as the identity. | |
258 | * | |
259 | * For the time being, we preserve historic behavior and bypass the DMA | |
260 | * API. | |
1a937693 MT |
261 | * |
262 | * TODO: install a per-device DMA ops structure that does the right thing | |
263 | * taking into account all the above quirks, and use the DMA API | |
264 | * unconditionally on data path. | |
d26c96c8 AL |
265 | */ |
266 | ||
267 | static bool vring_use_dma_api(struct virtio_device *vdev) | |
268 | { | |
24b6842a | 269 | if (!virtio_has_dma_quirk(vdev)) |
1a937693 MT |
270 | return true; |
271 | ||
272 | /* Otherwise, we are left to guess. */ | |
78fe3987 AL |
273 | /* |
274 | * In theory, it's possible to have a buggy QEMU-supposed | |
275 | * emulated Q35 IOMMU and Xen enabled at the same time. On | |
276 | * such a configuration, virtio has never worked and will | |
277 | * not work without an even larger kludge. Instead, enable | |
278 | * the DMA API if we're a Xen guest, which at least allows | |
279 | * all of the sensible Xen configurations to work correctly. | |
280 | */ | |
281 | if (xen_domain()) | |
282 | return true; | |
283 | ||
d26c96c8 AL |
284 | return false; |
285 | } | |
286 | ||
e6d6dd6c JR |
287 | size_t virtio_max_dma_size(struct virtio_device *vdev) |
288 | { | |
289 | size_t max_segment_size = SIZE_MAX; | |
290 | ||
291 | if (vring_use_dma_api(vdev)) | |
817fc978 | 292 | max_segment_size = dma_max_mapping_size(vdev->dev.parent); |
e6d6dd6c JR |
293 | |
294 | return max_segment_size; | |
295 | } | |
296 | EXPORT_SYMBOL_GPL(virtio_max_dma_size); | |
297 | ||
d79dca75 TB |
298 | static void *vring_alloc_queue(struct virtio_device *vdev, size_t size, |
299 | dma_addr_t *dma_handle, gfp_t flag) | |
300 | { | |
301 | if (vring_use_dma_api(vdev)) { | |
302 | return dma_alloc_coherent(vdev->dev.parent, size, | |
303 | dma_handle, flag); | |
304 | } else { | |
305 | void *queue = alloc_pages_exact(PAGE_ALIGN(size), flag); | |
306 | ||
307 | if (queue) { | |
308 | phys_addr_t phys_addr = virt_to_phys(queue); | |
309 | *dma_handle = (dma_addr_t)phys_addr; | |
310 | ||
311 | /* | |
312 | * Sanity check: make sure we dind't truncate | |
313 | * the address. The only arches I can find that | |
314 | * have 64-bit phys_addr_t but 32-bit dma_addr_t | |
315 | * are certain non-highmem MIPS and x86 | |
316 | * configurations, but these configurations | |
317 | * should never allocate physical pages above 32 | |
318 | * bits, so this is fine. Just in case, throw a | |
319 | * warning and abort if we end up with an | |
320 | * unrepresentable address. | |
321 | */ | |
322 | if (WARN_ON_ONCE(*dma_handle != phys_addr)) { | |
323 | free_pages_exact(queue, PAGE_ALIGN(size)); | |
324 | return NULL; | |
325 | } | |
326 | } | |
327 | return queue; | |
328 | } | |
329 | } | |
330 | ||
331 | static void vring_free_queue(struct virtio_device *vdev, size_t size, | |
332 | void *queue, dma_addr_t dma_handle) | |
333 | { | |
334 | if (vring_use_dma_api(vdev)) | |
335 | dma_free_coherent(vdev->dev.parent, size, queue, dma_handle); | |
336 | else | |
337 | free_pages_exact(queue, PAGE_ALIGN(size)); | |
338 | } | |
339 | ||
780bc790 AL |
340 | /* |
341 | * The DMA ops on various arches are rather gnarly right now, and | |
342 | * making all of the arch DMA ops work on the vring device itself | |
343 | * is a mess. For now, we use the parent device for DMA ops. | |
344 | */ | |
75bfa81b | 345 | static inline struct device *vring_dma_dev(const struct vring_virtqueue *vq) |
780bc790 AL |
346 | { |
347 | return vq->vq.vdev->dev.parent; | |
348 | } | |
349 | ||
350 | /* Map one sg entry. */ | |
351 | static dma_addr_t vring_map_one_sg(const struct vring_virtqueue *vq, | |
352 | struct scatterlist *sg, | |
353 | enum dma_data_direction direction) | |
354 | { | |
fb3fba6b | 355 | if (!vq->use_dma_api) |
780bc790 AL |
356 | return (dma_addr_t)sg_phys(sg); |
357 | ||
358 | /* | |
359 | * We can't use dma_map_sg, because we don't use scatterlists in | |
360 | * the way it expects (we don't guarantee that the scatterlist | |
361 | * will exist for the lifetime of the mapping). | |
362 | */ | |
363 | return dma_map_page(vring_dma_dev(vq), | |
364 | sg_page(sg), sg->offset, sg->length, | |
365 | direction); | |
366 | } | |
367 | ||
368 | static dma_addr_t vring_map_single(const struct vring_virtqueue *vq, | |
369 | void *cpu_addr, size_t size, | |
370 | enum dma_data_direction direction) | |
371 | { | |
fb3fba6b | 372 | if (!vq->use_dma_api) |
780bc790 AL |
373 | return (dma_addr_t)virt_to_phys(cpu_addr); |
374 | ||
375 | return dma_map_single(vring_dma_dev(vq), | |
376 | cpu_addr, size, direction); | |
377 | } | |
378 | ||
e6f633e5 TB |
379 | static int vring_mapping_error(const struct vring_virtqueue *vq, |
380 | dma_addr_t addr) | |
381 | { | |
fb3fba6b | 382 | if (!vq->use_dma_api) |
e6f633e5 TB |
383 | return 0; |
384 | ||
385 | return dma_mapping_error(vring_dma_dev(vq), addr); | |
386 | } | |
387 | ||
3a897128 XZ |
388 | static void virtqueue_init(struct vring_virtqueue *vq, u32 num) |
389 | { | |
390 | vq->vq.num_free = num; | |
391 | ||
392 | if (vq->packed_ring) | |
393 | vq->last_used_idx = 0 | (1 << VRING_PACKED_EVENT_F_WRAP_CTR); | |
394 | else | |
395 | vq->last_used_idx = 0; | |
396 | ||
397 | vq->event_triggered = false; | |
398 | vq->num_added = 0; | |
399 | ||
400 | #ifdef DEBUG | |
401 | vq->in_use = false; | |
402 | vq->last_add_time_valid = false; | |
403 | #endif | |
404 | } | |
405 | ||
e6f633e5 TB |
406 | |
407 | /* | |
408 | * Split ring specific functions - *_split(). | |
409 | */ | |
410 | ||
72b5e895 JW |
411 | static void vring_unmap_one_split_indirect(const struct vring_virtqueue *vq, |
412 | struct vring_desc *desc) | |
780bc790 AL |
413 | { |
414 | u16 flags; | |
415 | ||
fb3fba6b | 416 | if (!vq->use_dma_api) |
780bc790 AL |
417 | return; |
418 | ||
419 | flags = virtio16_to_cpu(vq->vq.vdev, desc->flags); | |
420 | ||
b4282ebc XZ |
421 | dma_unmap_page(vring_dma_dev(vq), |
422 | virtio64_to_cpu(vq->vq.vdev, desc->addr), | |
423 | virtio32_to_cpu(vq->vq.vdev, desc->len), | |
424 | (flags & VRING_DESC_F_WRITE) ? | |
425 | DMA_FROM_DEVICE : DMA_TO_DEVICE); | |
780bc790 AL |
426 | } |
427 | ||
72b5e895 JW |
428 | static unsigned int vring_unmap_one_split(const struct vring_virtqueue *vq, |
429 | unsigned int i) | |
430 | { | |
431 | struct vring_desc_extra *extra = vq->split.desc_extra; | |
432 | u16 flags; | |
433 | ||
434 | if (!vq->use_dma_api) | |
435 | goto out; | |
436 | ||
437 | flags = extra[i].flags; | |
438 | ||
439 | if (flags & VRING_DESC_F_INDIRECT) { | |
440 | dma_unmap_single(vring_dma_dev(vq), | |
441 | extra[i].addr, | |
442 | extra[i].len, | |
443 | (flags & VRING_DESC_F_WRITE) ? | |
444 | DMA_FROM_DEVICE : DMA_TO_DEVICE); | |
445 | } else { | |
446 | dma_unmap_page(vring_dma_dev(vq), | |
447 | extra[i].addr, | |
448 | extra[i].len, | |
449 | (flags & VRING_DESC_F_WRITE) ? | |
450 | DMA_FROM_DEVICE : DMA_TO_DEVICE); | |
451 | } | |
452 | ||
453 | out: | |
454 | return extra[i].next; | |
455 | } | |
456 | ||
138fd251 TB |
457 | static struct vring_desc *alloc_indirect_split(struct virtqueue *_vq, |
458 | unsigned int total_sg, | |
459 | gfp_t gfp) | |
9fa29b9d MM |
460 | { |
461 | struct vring_desc *desc; | |
b25bd251 | 462 | unsigned int i; |
9fa29b9d | 463 | |
b92b1b89 WD |
464 | /* |
465 | * We require lowmem mappings for the descriptors because | |
466 | * otherwise virt_to_phys will give us bogus addresses in the | |
467 | * virtqueue. | |
468 | */ | |
82107539 | 469 | gfp &= ~__GFP_HIGHMEM; |
b92b1b89 | 470 | |
6da2ec56 | 471 | desc = kmalloc_array(total_sg, sizeof(struct vring_desc), gfp); |
9fa29b9d | 472 | if (!desc) |
b25bd251 | 473 | return NULL; |
9fa29b9d | 474 | |
b25bd251 | 475 | for (i = 0; i < total_sg; i++) |
00e6f3d9 | 476 | desc[i].next = cpu_to_virtio16(_vq->vdev, i + 1); |
b25bd251 | 477 | return desc; |
9fa29b9d MM |
478 | } |
479 | ||
fe4c3862 JW |
480 | static inline unsigned int virtqueue_add_desc_split(struct virtqueue *vq, |
481 | struct vring_desc *desc, | |
482 | unsigned int i, | |
483 | dma_addr_t addr, | |
484 | unsigned int len, | |
72b5e895 JW |
485 | u16 flags, |
486 | bool indirect) | |
fe4c3862 | 487 | { |
72b5e895 JW |
488 | struct vring_virtqueue *vring = to_vvq(vq); |
489 | struct vring_desc_extra *extra = vring->split.desc_extra; | |
490 | u16 next; | |
491 | ||
fe4c3862 JW |
492 | desc[i].flags = cpu_to_virtio16(vq->vdev, flags); |
493 | desc[i].addr = cpu_to_virtio64(vq->vdev, addr); | |
494 | desc[i].len = cpu_to_virtio32(vq->vdev, len); | |
495 | ||
72b5e895 JW |
496 | if (!indirect) { |
497 | next = extra[i].next; | |
498 | desc[i].next = cpu_to_virtio16(vq->vdev, next); | |
499 | ||
500 | extra[i].addr = addr; | |
501 | extra[i].len = len; | |
502 | extra[i].flags = flags; | |
503 | } else | |
504 | next = virtio16_to_cpu(vq->vdev, desc[i].next); | |
505 | ||
506 | return next; | |
fe4c3862 JW |
507 | } |
508 | ||
138fd251 TB |
509 | static inline int virtqueue_add_split(struct virtqueue *_vq, |
510 | struct scatterlist *sgs[], | |
511 | unsigned int total_sg, | |
512 | unsigned int out_sgs, | |
513 | unsigned int in_sgs, | |
514 | void *data, | |
515 | void *ctx, | |
516 | gfp_t gfp) | |
0a8a69dd RR |
517 | { |
518 | struct vring_virtqueue *vq = to_vvq(_vq); | |
13816c76 | 519 | struct scatterlist *sg; |
b25bd251 | 520 | struct vring_desc *desc; |
3f649ab7 | 521 | unsigned int i, n, avail, descs_used, prev, err_idx; |
1fe9b6fe | 522 | int head; |
b25bd251 | 523 | bool indirect; |
0a8a69dd | 524 | |
9fa29b9d MM |
525 | START_USE(vq); |
526 | ||
0a8a69dd | 527 | BUG_ON(data == NULL); |
5a08b04f | 528 | BUG_ON(ctx && vq->indirect); |
9fa29b9d | 529 | |
70670444 RR |
530 | if (unlikely(vq->broken)) { |
531 | END_USE(vq); | |
532 | return -EIO; | |
533 | } | |
534 | ||
4d6a105e | 535 | LAST_ADD_TIME_UPDATE(vq); |
e93300b1 | 536 | |
b25bd251 RR |
537 | BUG_ON(total_sg == 0); |
538 | ||
539 | head = vq->free_head; | |
540 | ||
35c51e09 | 541 | if (virtqueue_use_indirect(vq, total_sg)) |
138fd251 | 542 | desc = alloc_indirect_split(_vq, total_sg, gfp); |
44ed8089 | 543 | else { |
b25bd251 | 544 | desc = NULL; |
e593bf97 | 545 | WARN_ON_ONCE(total_sg > vq->split.vring.num && !vq->indirect); |
44ed8089 | 546 | } |
b25bd251 RR |
547 | |
548 | if (desc) { | |
549 | /* Use a single buffer which doesn't continue */ | |
780bc790 | 550 | indirect = true; |
b25bd251 RR |
551 | /* Set up rest to use this indirect table. */ |
552 | i = 0; | |
553 | descs_used = 1; | |
b25bd251 | 554 | } else { |
780bc790 | 555 | indirect = false; |
e593bf97 | 556 | desc = vq->split.vring.desc; |
b25bd251 RR |
557 | i = head; |
558 | descs_used = total_sg; | |
9fa29b9d MM |
559 | } |
560 | ||
b4b4ff73 | 561 | if (unlikely(vq->vq.num_free < descs_used)) { |
0a8a69dd | 562 | pr_debug("Can't add buf len %i - avail = %i\n", |
b25bd251 | 563 | descs_used, vq->vq.num_free); |
44653eae RR |
564 | /* FIXME: for historical reasons, we force a notify here if |
565 | * there are outgoing parts to the buffer. Presumably the | |
566 | * host should service the ring ASAP. */ | |
13816c76 | 567 | if (out_sgs) |
44653eae | 568 | vq->notify(&vq->vq); |
58625edf WY |
569 | if (indirect) |
570 | kfree(desc); | |
0a8a69dd RR |
571 | END_USE(vq); |
572 | return -ENOSPC; | |
573 | } | |
574 | ||
13816c76 | 575 | for (n = 0; n < out_sgs; n++) { |
eeebf9b1 | 576 | for (sg = sgs[n]; sg; sg = sg_next(sg)) { |
780bc790 AL |
577 | dma_addr_t addr = vring_map_one_sg(vq, sg, DMA_TO_DEVICE); |
578 | if (vring_mapping_error(vq, addr)) | |
579 | goto unmap_release; | |
580 | ||
13816c76 | 581 | prev = i; |
72b5e895 JW |
582 | /* Note that we trust indirect descriptor |
583 | * table since it use stream DMA mapping. | |
584 | */ | |
fe4c3862 | 585 | i = virtqueue_add_desc_split(_vq, desc, i, addr, sg->length, |
72b5e895 JW |
586 | VRING_DESC_F_NEXT, |
587 | indirect); | |
13816c76 | 588 | } |
0a8a69dd | 589 | } |
13816c76 | 590 | for (; n < (out_sgs + in_sgs); n++) { |
eeebf9b1 | 591 | for (sg = sgs[n]; sg; sg = sg_next(sg)) { |
780bc790 AL |
592 | dma_addr_t addr = vring_map_one_sg(vq, sg, DMA_FROM_DEVICE); |
593 | if (vring_mapping_error(vq, addr)) | |
594 | goto unmap_release; | |
595 | ||
13816c76 | 596 | prev = i; |
72b5e895 JW |
597 | /* Note that we trust indirect descriptor |
598 | * table since it use stream DMA mapping. | |
599 | */ | |
fe4c3862 JW |
600 | i = virtqueue_add_desc_split(_vq, desc, i, addr, |
601 | sg->length, | |
602 | VRING_DESC_F_NEXT | | |
72b5e895 JW |
603 | VRING_DESC_F_WRITE, |
604 | indirect); | |
13816c76 | 605 | } |
0a8a69dd RR |
606 | } |
607 | /* Last one doesn't continue. */ | |
00e6f3d9 | 608 | desc[prev].flags &= cpu_to_virtio16(_vq->vdev, ~VRING_DESC_F_NEXT); |
72b5e895 | 609 | if (!indirect && vq->use_dma_api) |
890d3356 | 610 | vq->split.desc_extra[prev & (vq->split.vring.num - 1)].flags &= |
72b5e895 | 611 | ~VRING_DESC_F_NEXT; |
0a8a69dd | 612 | |
780bc790 AL |
613 | if (indirect) { |
614 | /* Now that the indirect table is filled in, map it. */ | |
615 | dma_addr_t addr = vring_map_single( | |
616 | vq, desc, total_sg * sizeof(struct vring_desc), | |
617 | DMA_TO_DEVICE); | |
618 | if (vring_mapping_error(vq, addr)) | |
619 | goto unmap_release; | |
620 | ||
fe4c3862 JW |
621 | virtqueue_add_desc_split(_vq, vq->split.vring.desc, |
622 | head, addr, | |
623 | total_sg * sizeof(struct vring_desc), | |
72b5e895 JW |
624 | VRING_DESC_F_INDIRECT, |
625 | false); | |
780bc790 AL |
626 | } |
627 | ||
628 | /* We're using some buffers from the free list. */ | |
629 | vq->vq.num_free -= descs_used; | |
630 | ||
0a8a69dd | 631 | /* Update free pointer */ |
b25bd251 | 632 | if (indirect) |
72b5e895 | 633 | vq->free_head = vq->split.desc_extra[head].next; |
b25bd251 RR |
634 | else |
635 | vq->free_head = i; | |
0a8a69dd | 636 | |
780bc790 | 637 | /* Store token and indirect buffer state. */ |
cbeedb72 | 638 | vq->split.desc_state[head].data = data; |
780bc790 | 639 | if (indirect) |
cbeedb72 | 640 | vq->split.desc_state[head].indir_desc = desc; |
87646a34 | 641 | else |
cbeedb72 | 642 | vq->split.desc_state[head].indir_desc = ctx; |
0a8a69dd RR |
643 | |
644 | /* Put entry in available array (but don't update avail->idx until they | |
3b720b8c | 645 | * do sync). */ |
e593bf97 TB |
646 | avail = vq->split.avail_idx_shadow & (vq->split.vring.num - 1); |
647 | vq->split.vring.avail->ring[avail] = cpu_to_virtio16(_vq->vdev, head); | |
0a8a69dd | 648 | |
ee7cd898 RR |
649 | /* Descriptors and available array need to be set before we expose the |
650 | * new available array entries. */ | |
a9a0fef7 | 651 | virtio_wmb(vq->weak_barriers); |
e593bf97 TB |
652 | vq->split.avail_idx_shadow++; |
653 | vq->split.vring.avail->idx = cpu_to_virtio16(_vq->vdev, | |
654 | vq->split.avail_idx_shadow); | |
ee7cd898 RR |
655 | vq->num_added++; |
656 | ||
5e05bf58 TH |
657 | pr_debug("Added buffer head %i to %p\n", head, vq); |
658 | END_USE(vq); | |
659 | ||
ee7cd898 RR |
660 | /* This is very unlikely, but theoretically possible. Kick |
661 | * just in case. */ | |
662 | if (unlikely(vq->num_added == (1 << 16) - 1)) | |
663 | virtqueue_kick(_vq); | |
664 | ||
98e8c6bc | 665 | return 0; |
780bc790 AL |
666 | |
667 | unmap_release: | |
668 | err_idx = i; | |
cf8f1696 ML |
669 | |
670 | if (indirect) | |
671 | i = 0; | |
672 | else | |
673 | i = head; | |
780bc790 AL |
674 | |
675 | for (n = 0; n < total_sg; n++) { | |
676 | if (i == err_idx) | |
677 | break; | |
72b5e895 JW |
678 | if (indirect) { |
679 | vring_unmap_one_split_indirect(vq, &desc[i]); | |
680 | i = virtio16_to_cpu(_vq->vdev, desc[i].next); | |
681 | } else | |
682 | i = vring_unmap_one_split(vq, i); | |
780bc790 AL |
683 | } |
684 | ||
780bc790 AL |
685 | if (indirect) |
686 | kfree(desc); | |
687 | ||
3cc36f6e | 688 | END_USE(vq); |
f7728002 | 689 | return -ENOMEM; |
0a8a69dd | 690 | } |
13816c76 | 691 | |
138fd251 | 692 | static bool virtqueue_kick_prepare_split(struct virtqueue *_vq) |
0a8a69dd RR |
693 | { |
694 | struct vring_virtqueue *vq = to_vvq(_vq); | |
a5c262c5 | 695 | u16 new, old; |
41f0377f RR |
696 | bool needs_kick; |
697 | ||
0a8a69dd | 698 | START_USE(vq); |
a72caae2 JW |
699 | /* We need to expose available array entries before checking avail |
700 | * event. */ | |
a9a0fef7 | 701 | virtio_mb(vq->weak_barriers); |
0a8a69dd | 702 | |
e593bf97 TB |
703 | old = vq->split.avail_idx_shadow - vq->num_added; |
704 | new = vq->split.avail_idx_shadow; | |
0a8a69dd RR |
705 | vq->num_added = 0; |
706 | ||
4d6a105e TB |
707 | LAST_ADD_TIME_CHECK(vq); |
708 | LAST_ADD_TIME_INVALID(vq); | |
e93300b1 | 709 | |
41f0377f | 710 | if (vq->event) { |
e593bf97 TB |
711 | needs_kick = vring_need_event(virtio16_to_cpu(_vq->vdev, |
712 | vring_avail_event(&vq->split.vring)), | |
41f0377f RR |
713 | new, old); |
714 | } else { | |
e593bf97 TB |
715 | needs_kick = !(vq->split.vring.used->flags & |
716 | cpu_to_virtio16(_vq->vdev, | |
717 | VRING_USED_F_NO_NOTIFY)); | |
41f0377f | 718 | } |
0a8a69dd | 719 | END_USE(vq); |
41f0377f RR |
720 | return needs_kick; |
721 | } | |
138fd251 | 722 | |
138fd251 TB |
723 | static void detach_buf_split(struct vring_virtqueue *vq, unsigned int head, |
724 | void **ctx) | |
0a8a69dd | 725 | { |
780bc790 | 726 | unsigned int i, j; |
c60923cb | 727 | __virtio16 nextflag = cpu_to_virtio16(vq->vq.vdev, VRING_DESC_F_NEXT); |
0a8a69dd RR |
728 | |
729 | /* Clear data ptr. */ | |
cbeedb72 | 730 | vq->split.desc_state[head].data = NULL; |
0a8a69dd | 731 | |
780bc790 | 732 | /* Put back on free list: unmap first-level descriptors and find end */ |
0a8a69dd | 733 | i = head; |
9fa29b9d | 734 | |
e593bf97 | 735 | while (vq->split.vring.desc[i].flags & nextflag) { |
72b5e895 JW |
736 | vring_unmap_one_split(vq, i); |
737 | i = vq->split.desc_extra[i].next; | |
06ca287d | 738 | vq->vq.num_free++; |
0a8a69dd RR |
739 | } |
740 | ||
72b5e895 JW |
741 | vring_unmap_one_split(vq, i); |
742 | vq->split.desc_extra[i].next = vq->free_head; | |
0a8a69dd | 743 | vq->free_head = head; |
780bc790 | 744 | |
0a8a69dd | 745 | /* Plus final descriptor */ |
06ca287d | 746 | vq->vq.num_free++; |
780bc790 | 747 | |
5a08b04f | 748 | if (vq->indirect) { |
cbeedb72 TB |
749 | struct vring_desc *indir_desc = |
750 | vq->split.desc_state[head].indir_desc; | |
5a08b04f MT |
751 | u32 len; |
752 | ||
753 | /* Free the indirect table, if any, now that it's unmapped. */ | |
754 | if (!indir_desc) | |
755 | return; | |
756 | ||
72b5e895 | 757 | len = vq->split.desc_extra[head].len; |
780bc790 | 758 | |
72b5e895 JW |
759 | BUG_ON(!(vq->split.desc_extra[head].flags & |
760 | VRING_DESC_F_INDIRECT)); | |
780bc790 AL |
761 | BUG_ON(len == 0 || len % sizeof(struct vring_desc)); |
762 | ||
763 | for (j = 0; j < len / sizeof(struct vring_desc); j++) | |
72b5e895 | 764 | vring_unmap_one_split_indirect(vq, &indir_desc[j]); |
780bc790 | 765 | |
5a08b04f | 766 | kfree(indir_desc); |
cbeedb72 | 767 | vq->split.desc_state[head].indir_desc = NULL; |
5a08b04f | 768 | } else if (ctx) { |
cbeedb72 | 769 | *ctx = vq->split.desc_state[head].indir_desc; |
780bc790 | 770 | } |
0a8a69dd RR |
771 | } |
772 | ||
138fd251 | 773 | static inline bool more_used_split(const struct vring_virtqueue *vq) |
0a8a69dd | 774 | { |
e593bf97 TB |
775 | return vq->last_used_idx != virtio16_to_cpu(vq->vq.vdev, |
776 | vq->split.vring.used->idx); | |
0a8a69dd RR |
777 | } |
778 | ||
138fd251 TB |
779 | static void *virtqueue_get_buf_ctx_split(struct virtqueue *_vq, |
780 | unsigned int *len, | |
781 | void **ctx) | |
0a8a69dd RR |
782 | { |
783 | struct vring_virtqueue *vq = to_vvq(_vq); | |
784 | void *ret; | |
785 | unsigned int i; | |
3b720b8c | 786 | u16 last_used; |
0a8a69dd RR |
787 | |
788 | START_USE(vq); | |
789 | ||
5ef82752 RR |
790 | if (unlikely(vq->broken)) { |
791 | END_USE(vq); | |
792 | return NULL; | |
793 | } | |
794 | ||
138fd251 | 795 | if (!more_used_split(vq)) { |
0a8a69dd RR |
796 | pr_debug("No more buffers in queue\n"); |
797 | END_USE(vq); | |
798 | return NULL; | |
799 | } | |
800 | ||
2d61ba95 | 801 | /* Only get used array entries after they have been exposed by host. */ |
a9a0fef7 | 802 | virtio_rmb(vq->weak_barriers); |
2d61ba95 | 803 | |
e593bf97 TB |
804 | last_used = (vq->last_used_idx & (vq->split.vring.num - 1)); |
805 | i = virtio32_to_cpu(_vq->vdev, | |
806 | vq->split.vring.used->ring[last_used].id); | |
807 | *len = virtio32_to_cpu(_vq->vdev, | |
808 | vq->split.vring.used->ring[last_used].len); | |
0a8a69dd | 809 | |
e593bf97 | 810 | if (unlikely(i >= vq->split.vring.num)) { |
0a8a69dd RR |
811 | BAD_RING(vq, "id %u out of range\n", i); |
812 | return NULL; | |
813 | } | |
cbeedb72 | 814 | if (unlikely(!vq->split.desc_state[i].data)) { |
0a8a69dd RR |
815 | BAD_RING(vq, "id %u is not a head!\n", i); |
816 | return NULL; | |
817 | } | |
818 | ||
138fd251 | 819 | /* detach_buf_split clears data, so grab it now. */ |
cbeedb72 | 820 | ret = vq->split.desc_state[i].data; |
138fd251 | 821 | detach_buf_split(vq, i, ctx); |
0a8a69dd | 822 | vq->last_used_idx++; |
a5c262c5 MT |
823 | /* If we expect an interrupt for the next entry, tell host |
824 | * by writing event index and flush out the write before | |
825 | * the read in the next get_buf call. */ | |
e593bf97 | 826 | if (!(vq->split.avail_flags_shadow & VRING_AVAIL_F_NO_INTERRUPT)) |
788e5b3a | 827 | virtio_store_mb(vq->weak_barriers, |
e593bf97 | 828 | &vring_used_event(&vq->split.vring), |
788e5b3a | 829 | cpu_to_virtio16(_vq->vdev, vq->last_used_idx)); |
a5c262c5 | 830 | |
4d6a105e | 831 | LAST_ADD_TIME_INVALID(vq); |
e93300b1 | 832 | |
0a8a69dd RR |
833 | END_USE(vq); |
834 | return ret; | |
835 | } | |
138fd251 | 836 | |
138fd251 | 837 | static void virtqueue_disable_cb_split(struct virtqueue *_vq) |
18445c4d RR |
838 | { |
839 | struct vring_virtqueue *vq = to_vvq(_vq); | |
840 | ||
e593bf97 TB |
841 | if (!(vq->split.avail_flags_shadow & VRING_AVAIL_F_NO_INTERRUPT)) { |
842 | vq->split.avail_flags_shadow |= VRING_AVAIL_F_NO_INTERRUPT; | |
8d622d21 MT |
843 | if (vq->event) |
844 | /* TODO: this is a hack. Figure out a cleaner value to write. */ | |
845 | vring_used_event(&vq->split.vring) = 0x0; | |
846 | else | |
e593bf97 TB |
847 | vq->split.vring.avail->flags = |
848 | cpu_to_virtio16(_vq->vdev, | |
849 | vq->split.avail_flags_shadow); | |
f277ec42 | 850 | } |
18445c4d RR |
851 | } |
852 | ||
31532340 | 853 | static unsigned int virtqueue_enable_cb_prepare_split(struct virtqueue *_vq) |
0a8a69dd RR |
854 | { |
855 | struct vring_virtqueue *vq = to_vvq(_vq); | |
cc229884 | 856 | u16 last_used_idx; |
0a8a69dd RR |
857 | |
858 | START_USE(vq); | |
0a8a69dd RR |
859 | |
860 | /* We optimistically turn back on interrupts, then check if there was | |
861 | * more to do. */ | |
a5c262c5 MT |
862 | /* Depending on the VIRTIO_RING_F_EVENT_IDX feature, we need to |
863 | * either clear the flags bit or point the event index at the next | |
864 | * entry. Always do both to keep code simple. */ | |
e593bf97 TB |
865 | if (vq->split.avail_flags_shadow & VRING_AVAIL_F_NO_INTERRUPT) { |
866 | vq->split.avail_flags_shadow &= ~VRING_AVAIL_F_NO_INTERRUPT; | |
0ea1e4a6 | 867 | if (!vq->event) |
e593bf97 TB |
868 | vq->split.vring.avail->flags = |
869 | cpu_to_virtio16(_vq->vdev, | |
870 | vq->split.avail_flags_shadow); | |
f277ec42 | 871 | } |
e593bf97 TB |
872 | vring_used_event(&vq->split.vring) = cpu_to_virtio16(_vq->vdev, |
873 | last_used_idx = vq->last_used_idx); | |
cc229884 MT |
874 | END_USE(vq); |
875 | return last_used_idx; | |
876 | } | |
138fd251 | 877 | |
31532340 | 878 | static bool virtqueue_poll_split(struct virtqueue *_vq, unsigned int last_used_idx) |
138fd251 TB |
879 | { |
880 | struct vring_virtqueue *vq = to_vvq(_vq); | |
881 | ||
882 | return (u16)last_used_idx != virtio16_to_cpu(_vq->vdev, | |
e593bf97 | 883 | vq->split.vring.used->idx); |
138fd251 TB |
884 | } |
885 | ||
138fd251 | 886 | static bool virtqueue_enable_cb_delayed_split(struct virtqueue *_vq) |
7ab358c2 MT |
887 | { |
888 | struct vring_virtqueue *vq = to_vvq(_vq); | |
889 | u16 bufs; | |
890 | ||
891 | START_USE(vq); | |
892 | ||
893 | /* We optimistically turn back on interrupts, then check if there was | |
894 | * more to do. */ | |
895 | /* Depending on the VIRTIO_RING_F_USED_EVENT_IDX feature, we need to | |
896 | * either clear the flags bit or point the event index at the next | |
0ea1e4a6 | 897 | * entry. Always update the event index to keep code simple. */ |
e593bf97 TB |
898 | if (vq->split.avail_flags_shadow & VRING_AVAIL_F_NO_INTERRUPT) { |
899 | vq->split.avail_flags_shadow &= ~VRING_AVAIL_F_NO_INTERRUPT; | |
0ea1e4a6 | 900 | if (!vq->event) |
e593bf97 TB |
901 | vq->split.vring.avail->flags = |
902 | cpu_to_virtio16(_vq->vdev, | |
903 | vq->split.avail_flags_shadow); | |
f277ec42 | 904 | } |
7ab358c2 | 905 | /* TODO: tune this threshold */ |
e593bf97 | 906 | bufs = (u16)(vq->split.avail_idx_shadow - vq->last_used_idx) * 3 / 4; |
788e5b3a MT |
907 | |
908 | virtio_store_mb(vq->weak_barriers, | |
e593bf97 | 909 | &vring_used_event(&vq->split.vring), |
788e5b3a MT |
910 | cpu_to_virtio16(_vq->vdev, vq->last_used_idx + bufs)); |
911 | ||
e593bf97 TB |
912 | if (unlikely((u16)(virtio16_to_cpu(_vq->vdev, vq->split.vring.used->idx) |
913 | - vq->last_used_idx) > bufs)) { | |
7ab358c2 MT |
914 | END_USE(vq); |
915 | return false; | |
916 | } | |
917 | ||
918 | END_USE(vq); | |
919 | return true; | |
920 | } | |
7ab358c2 | 921 | |
138fd251 | 922 | static void *virtqueue_detach_unused_buf_split(struct virtqueue *_vq) |
c021eac4 SM |
923 | { |
924 | struct vring_virtqueue *vq = to_vvq(_vq); | |
925 | unsigned int i; | |
926 | void *buf; | |
927 | ||
928 | START_USE(vq); | |
929 | ||
e593bf97 | 930 | for (i = 0; i < vq->split.vring.num; i++) { |
cbeedb72 | 931 | if (!vq->split.desc_state[i].data) |
c021eac4 | 932 | continue; |
138fd251 | 933 | /* detach_buf_split clears data, so grab it now. */ |
cbeedb72 | 934 | buf = vq->split.desc_state[i].data; |
138fd251 | 935 | detach_buf_split(vq, i, NULL); |
e593bf97 TB |
936 | vq->split.avail_idx_shadow--; |
937 | vq->split.vring.avail->idx = cpu_to_virtio16(_vq->vdev, | |
938 | vq->split.avail_idx_shadow); | |
c021eac4 SM |
939 | END_USE(vq); |
940 | return buf; | |
941 | } | |
942 | /* That should have freed everything. */ | |
e593bf97 | 943 | BUG_ON(vq->vq.num_free != vq->split.vring.num); |
c021eac4 SM |
944 | |
945 | END_USE(vq); | |
946 | return NULL; | |
947 | } | |
138fd251 | 948 | |
198fa7be XZ |
949 | static void virtqueue_vring_init_split(struct vring_virtqueue_split *vring_split, |
950 | struct vring_virtqueue *vq) | |
951 | { | |
952 | struct virtio_device *vdev; | |
953 | ||
954 | vdev = vq->vq.vdev; | |
955 | ||
956 | vring_split->avail_flags_shadow = 0; | |
957 | vring_split->avail_idx_shadow = 0; | |
958 | ||
959 | /* No callback? Tell other side not to bother us. */ | |
960 | if (!vq->vq.callback) { | |
961 | vring_split->avail_flags_shadow |= VRING_AVAIL_F_NO_INTERRUPT; | |
962 | if (!vq->event) | |
963 | vring_split->vring.avail->flags = cpu_to_virtio16(vdev, | |
964 | vring_split->avail_flags_shadow); | |
965 | } | |
966 | } | |
967 | ||
e5175b41 XZ |
968 | static void virtqueue_reinit_split(struct vring_virtqueue *vq) |
969 | { | |
970 | int num; | |
971 | ||
972 | num = vq->split.vring.num; | |
973 | ||
974 | vq->split.vring.avail->flags = 0; | |
975 | vq->split.vring.avail->idx = 0; | |
976 | ||
977 | /* reset avail event */ | |
978 | vq->split.vring.avail->ring[num] = 0; | |
979 | ||
980 | vq->split.vring.used->flags = 0; | |
981 | vq->split.vring.used->idx = 0; | |
982 | ||
983 | /* reset used event */ | |
984 | *(__virtio16 *)&(vq->split.vring.used->ring[num]) = 0; | |
985 | ||
986 | virtqueue_init(vq, num); | |
987 | ||
988 | virtqueue_vring_init_split(&vq->split, vq); | |
989 | } | |
990 | ||
e1d6a423 XZ |
991 | static void virtqueue_vring_attach_split(struct vring_virtqueue *vq, |
992 | struct vring_virtqueue_split *vring_split) | |
993 | { | |
994 | vq->split = *vring_split; | |
995 | ||
996 | /* Put everything in free lists. */ | |
997 | vq->free_head = 0; | |
998 | } | |
999 | ||
a2b36c8d XZ |
1000 | static int vring_alloc_state_extra_split(struct vring_virtqueue_split *vring_split) |
1001 | { | |
1002 | struct vring_desc_state_split *state; | |
1003 | struct vring_desc_extra *extra; | |
1004 | u32 num = vring_split->vring.num; | |
1005 | ||
1006 | state = kmalloc_array(num, sizeof(struct vring_desc_state_split), GFP_KERNEL); | |
1007 | if (!state) | |
1008 | goto err_state; | |
1009 | ||
1010 | extra = vring_alloc_desc_extra(num); | |
1011 | if (!extra) | |
1012 | goto err_extra; | |
1013 | ||
1014 | memset(state, 0, num * sizeof(struct vring_desc_state_split)); | |
1015 | ||
1016 | vring_split->desc_state = state; | |
1017 | vring_split->desc_extra = extra; | |
1018 | return 0; | |
1019 | ||
1020 | err_extra: | |
1021 | kfree(state); | |
1022 | err_state: | |
1023 | return -ENOMEM; | |
1024 | } | |
1025 | ||
89f05d94 XZ |
1026 | static void vring_free_split(struct vring_virtqueue_split *vring_split, |
1027 | struct virtio_device *vdev) | |
1028 | { | |
1029 | vring_free_queue(vdev, vring_split->queue_size_in_bytes, | |
1030 | vring_split->vring.desc, | |
1031 | vring_split->queue_dma_addr); | |
1032 | ||
1033 | kfree(vring_split->desc_state); | |
1034 | kfree(vring_split->desc_extra); | |
1035 | } | |
1036 | ||
c2d87fe6 XZ |
1037 | static int vring_alloc_queue_split(struct vring_virtqueue_split *vring_split, |
1038 | struct virtio_device *vdev, | |
1039 | u32 num, | |
1040 | unsigned int vring_align, | |
1041 | bool may_reduce_num) | |
d79dca75 | 1042 | { |
d79dca75 TB |
1043 | void *queue = NULL; |
1044 | dma_addr_t dma_addr; | |
d79dca75 TB |
1045 | |
1046 | /* We assume num is a power of 2. */ | |
1047 | if (num & (num - 1)) { | |
1048 | dev_warn(&vdev->dev, "Bad virtqueue length %u\n", num); | |
c2d87fe6 | 1049 | return -EINVAL; |
d79dca75 TB |
1050 | } |
1051 | ||
1052 | /* TODO: allocate each queue chunk individually */ | |
1053 | for (; num && vring_size(num, vring_align) > PAGE_SIZE; num /= 2) { | |
1054 | queue = vring_alloc_queue(vdev, vring_size(num, vring_align), | |
1055 | &dma_addr, | |
c7cc29aa | 1056 | GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO); |
d79dca75 TB |
1057 | if (queue) |
1058 | break; | |
cf94db21 | 1059 | if (!may_reduce_num) |
c2d87fe6 | 1060 | return -ENOMEM; |
d79dca75 TB |
1061 | } |
1062 | ||
1063 | if (!num) | |
c2d87fe6 | 1064 | return -ENOMEM; |
d79dca75 TB |
1065 | |
1066 | if (!queue) { | |
1067 | /* Try to get a single page. You are my only hope! */ | |
1068 | queue = vring_alloc_queue(vdev, vring_size(num, vring_align), | |
1069 | &dma_addr, GFP_KERNEL|__GFP_ZERO); | |
1070 | } | |
1071 | if (!queue) | |
c2d87fe6 XZ |
1072 | return -ENOMEM; |
1073 | ||
1074 | vring_init(&vring_split->vring, num, queue, vring_align); | |
1075 | ||
1076 | vring_split->queue_dma_addr = dma_addr; | |
1077 | vring_split->queue_size_in_bytes = vring_size(num, vring_align); | |
d79dca75 | 1078 | |
af36b16f XZ |
1079 | vring_split->vring_align = vring_align; |
1080 | vring_split->may_reduce_num = may_reduce_num; | |
1081 | ||
c2d87fe6 XZ |
1082 | return 0; |
1083 | } | |
1084 | ||
1085 | static struct virtqueue *vring_create_virtqueue_split( | |
1086 | unsigned int index, | |
1087 | unsigned int num, | |
1088 | unsigned int vring_align, | |
1089 | struct virtio_device *vdev, | |
1090 | bool weak_barriers, | |
1091 | bool may_reduce_num, | |
1092 | bool context, | |
1093 | bool (*notify)(struct virtqueue *), | |
1094 | void (*callback)(struct virtqueue *), | |
1095 | const char *name) | |
1096 | { | |
1097 | struct vring_virtqueue_split vring_split = {}; | |
1098 | struct virtqueue *vq; | |
1099 | int err; | |
1100 | ||
1101 | err = vring_alloc_queue_split(&vring_split, vdev, num, vring_align, | |
1102 | may_reduce_num); | |
1103 | if (err) | |
1104 | return NULL; | |
d79dca75 | 1105 | |
cd4c812a XZ |
1106 | vq = __vring_new_virtqueue(index, &vring_split, vdev, weak_barriers, |
1107 | context, notify, callback, name); | |
d79dca75 | 1108 | if (!vq) { |
c2d87fe6 | 1109 | vring_free_split(&vring_split, vdev); |
d79dca75 TB |
1110 | return NULL; |
1111 | } | |
1112 | ||
d79dca75 TB |
1113 | to_vvq(vq)->we_own_ring = true; |
1114 | ||
1115 | return vq; | |
1116 | } | |
1117 | ||
6fea20e5 XZ |
1118 | static int virtqueue_resize_split(struct virtqueue *_vq, u32 num) |
1119 | { | |
1120 | struct vring_virtqueue_split vring_split = {}; | |
1121 | struct vring_virtqueue *vq = to_vvq(_vq); | |
1122 | struct virtio_device *vdev = _vq->vdev; | |
1123 | int err; | |
1124 | ||
1125 | err = vring_alloc_queue_split(&vring_split, vdev, num, | |
1126 | vq->split.vring_align, | |
1127 | vq->split.may_reduce_num); | |
1128 | if (err) | |
1129 | goto err; | |
1130 | ||
1131 | err = vring_alloc_state_extra_split(&vring_split); | |
1132 | if (err) | |
1133 | goto err_state_extra; | |
1134 | ||
1135 | vring_free(&vq->vq); | |
1136 | ||
1137 | virtqueue_vring_init_split(&vring_split, vq); | |
1138 | ||
1139 | virtqueue_init(vq, vring_split.vring.num); | |
1140 | virtqueue_vring_attach_split(vq, &vring_split); | |
1141 | ||
1142 | return 0; | |
1143 | ||
1144 | err_state_extra: | |
1145 | vring_free_split(&vring_split, vdev); | |
1146 | err: | |
1147 | virtqueue_reinit_split(vq); | |
1148 | return -ENOMEM; | |
1149 | } | |
1150 | ||
e6f633e5 | 1151 | |
1ce9e605 TB |
1152 | /* |
1153 | * Packed ring specific functions - *_packed(). | |
1154 | */ | |
a7722890 | 1155 | static inline bool packed_used_wrap_counter(u16 last_used_idx) |
1156 | { | |
1157 | return !!(last_used_idx & (1 << VRING_PACKED_EVENT_F_WRAP_CTR)); | |
1158 | } | |
1159 | ||
1160 | static inline u16 packed_last_used(u16 last_used_idx) | |
1161 | { | |
1162 | return last_used_idx & ~(-(1 << VRING_PACKED_EVENT_F_WRAP_CTR)); | |
1163 | } | |
1ce9e605 | 1164 | |
d80dc15b XZ |
1165 | static void vring_unmap_extra_packed(const struct vring_virtqueue *vq, |
1166 | struct vring_desc_extra *extra) | |
1ce9e605 TB |
1167 | { |
1168 | u16 flags; | |
1169 | ||
1170 | if (!vq->use_dma_api) | |
1171 | return; | |
1172 | ||
d80dc15b | 1173 | flags = extra->flags; |
1ce9e605 TB |
1174 | |
1175 | if (flags & VRING_DESC_F_INDIRECT) { | |
1176 | dma_unmap_single(vring_dma_dev(vq), | |
d80dc15b | 1177 | extra->addr, extra->len, |
1ce9e605 TB |
1178 | (flags & VRING_DESC_F_WRITE) ? |
1179 | DMA_FROM_DEVICE : DMA_TO_DEVICE); | |
1180 | } else { | |
1181 | dma_unmap_page(vring_dma_dev(vq), | |
d80dc15b | 1182 | extra->addr, extra->len, |
1ce9e605 TB |
1183 | (flags & VRING_DESC_F_WRITE) ? |
1184 | DMA_FROM_DEVICE : DMA_TO_DEVICE); | |
1185 | } | |
1186 | } | |
1187 | ||
1188 | static void vring_unmap_desc_packed(const struct vring_virtqueue *vq, | |
1189 | struct vring_packed_desc *desc) | |
1190 | { | |
1191 | u16 flags; | |
1192 | ||
1193 | if (!vq->use_dma_api) | |
1194 | return; | |
1195 | ||
1196 | flags = le16_to_cpu(desc->flags); | |
1197 | ||
920379a4 XZ |
1198 | dma_unmap_page(vring_dma_dev(vq), |
1199 | le64_to_cpu(desc->addr), | |
1200 | le32_to_cpu(desc->len), | |
1201 | (flags & VRING_DESC_F_WRITE) ? | |
1202 | DMA_FROM_DEVICE : DMA_TO_DEVICE); | |
1ce9e605 TB |
1203 | } |
1204 | ||
1205 | static struct vring_packed_desc *alloc_indirect_packed(unsigned int total_sg, | |
1206 | gfp_t gfp) | |
1207 | { | |
1208 | struct vring_packed_desc *desc; | |
1209 | ||
1210 | /* | |
1211 | * We require lowmem mappings for the descriptors because | |
1212 | * otherwise virt_to_phys will give us bogus addresses in the | |
1213 | * virtqueue. | |
1214 | */ | |
1215 | gfp &= ~__GFP_HIGHMEM; | |
1216 | ||
1217 | desc = kmalloc_array(total_sg, sizeof(struct vring_packed_desc), gfp); | |
1218 | ||
1219 | return desc; | |
1220 | } | |
1221 | ||
1222 | static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, | |
8d7670f3 XZ |
1223 | struct scatterlist *sgs[], |
1224 | unsigned int total_sg, | |
1225 | unsigned int out_sgs, | |
1226 | unsigned int in_sgs, | |
1227 | void *data, | |
1228 | gfp_t gfp) | |
1ce9e605 TB |
1229 | { |
1230 | struct vring_packed_desc *desc; | |
1231 | struct scatterlist *sg; | |
1232 | unsigned int i, n, err_idx; | |
1233 | u16 head, id; | |
1234 | dma_addr_t addr; | |
1235 | ||
1236 | head = vq->packed.next_avail_idx; | |
1237 | desc = alloc_indirect_packed(total_sg, gfp); | |
fc6d70f4 XZ |
1238 | if (!desc) |
1239 | return -ENOMEM; | |
1ce9e605 TB |
1240 | |
1241 | if (unlikely(vq->vq.num_free < 1)) { | |
1242 | pr_debug("Can't add buf len 1 - avail = 0\n"); | |
df0bfe75 | 1243 | kfree(desc); |
1ce9e605 TB |
1244 | END_USE(vq); |
1245 | return -ENOSPC; | |
1246 | } | |
1247 | ||
1248 | i = 0; | |
1249 | id = vq->free_head; | |
1250 | BUG_ON(id == vq->packed.vring.num); | |
1251 | ||
1252 | for (n = 0; n < out_sgs + in_sgs; n++) { | |
1253 | for (sg = sgs[n]; sg; sg = sg_next(sg)) { | |
1254 | addr = vring_map_one_sg(vq, sg, n < out_sgs ? | |
1255 | DMA_TO_DEVICE : DMA_FROM_DEVICE); | |
1256 | if (vring_mapping_error(vq, addr)) | |
1257 | goto unmap_release; | |
1258 | ||
1259 | desc[i].flags = cpu_to_le16(n < out_sgs ? | |
1260 | 0 : VRING_DESC_F_WRITE); | |
1261 | desc[i].addr = cpu_to_le64(addr); | |
1262 | desc[i].len = cpu_to_le32(sg->length); | |
1263 | i++; | |
1264 | } | |
1265 | } | |
1266 | ||
1267 | /* Now that the indirect table is filled in, map it. */ | |
1268 | addr = vring_map_single(vq, desc, | |
1269 | total_sg * sizeof(struct vring_packed_desc), | |
1270 | DMA_TO_DEVICE); | |
1271 | if (vring_mapping_error(vq, addr)) | |
1272 | goto unmap_release; | |
1273 | ||
1274 | vq->packed.vring.desc[head].addr = cpu_to_le64(addr); | |
1275 | vq->packed.vring.desc[head].len = cpu_to_le32(total_sg * | |
1276 | sizeof(struct vring_packed_desc)); | |
1277 | vq->packed.vring.desc[head].id = cpu_to_le16(id); | |
1278 | ||
1279 | if (vq->use_dma_api) { | |
1280 | vq->packed.desc_extra[id].addr = addr; | |
1281 | vq->packed.desc_extra[id].len = total_sg * | |
1282 | sizeof(struct vring_packed_desc); | |
1283 | vq->packed.desc_extra[id].flags = VRING_DESC_F_INDIRECT | | |
1284 | vq->packed.avail_used_flags; | |
1285 | } | |
1286 | ||
1287 | /* | |
1288 | * A driver MUST NOT make the first descriptor in the list | |
1289 | * available before all subsequent descriptors comprising | |
1290 | * the list are made available. | |
1291 | */ | |
1292 | virtio_wmb(vq->weak_barriers); | |
1293 | vq->packed.vring.desc[head].flags = cpu_to_le16(VRING_DESC_F_INDIRECT | | |
1294 | vq->packed.avail_used_flags); | |
1295 | ||
1296 | /* We're using some buffers from the free list. */ | |
1297 | vq->vq.num_free -= 1; | |
1298 | ||
1299 | /* Update free pointer */ | |
1300 | n = head + 1; | |
1301 | if (n >= vq->packed.vring.num) { | |
1302 | n = 0; | |
1303 | vq->packed.avail_wrap_counter ^= 1; | |
1304 | vq->packed.avail_used_flags ^= | |
1305 | 1 << VRING_PACKED_DESC_F_AVAIL | | |
1306 | 1 << VRING_PACKED_DESC_F_USED; | |
1307 | } | |
1308 | vq->packed.next_avail_idx = n; | |
aeef9b47 | 1309 | vq->free_head = vq->packed.desc_extra[id].next; |
1ce9e605 TB |
1310 | |
1311 | /* Store token and indirect buffer state. */ | |
1312 | vq->packed.desc_state[id].num = 1; | |
1313 | vq->packed.desc_state[id].data = data; | |
1314 | vq->packed.desc_state[id].indir_desc = desc; | |
1315 | vq->packed.desc_state[id].last = id; | |
1316 | ||
1317 | vq->num_added += 1; | |
1318 | ||
1319 | pr_debug("Added buffer head %i to %p\n", head, vq); | |
1320 | END_USE(vq); | |
1321 | ||
1322 | return 0; | |
1323 | ||
1324 | unmap_release: | |
1325 | err_idx = i; | |
1326 | ||
1327 | for (i = 0; i < err_idx; i++) | |
1328 | vring_unmap_desc_packed(vq, &desc[i]); | |
1329 | ||
1330 | kfree(desc); | |
1331 | ||
1332 | END_USE(vq); | |
f7728002 | 1333 | return -ENOMEM; |
1ce9e605 TB |
1334 | } |
1335 | ||
1336 | static inline int virtqueue_add_packed(struct virtqueue *_vq, | |
1337 | struct scatterlist *sgs[], | |
1338 | unsigned int total_sg, | |
1339 | unsigned int out_sgs, | |
1340 | unsigned int in_sgs, | |
1341 | void *data, | |
1342 | void *ctx, | |
1343 | gfp_t gfp) | |
1344 | { | |
1345 | struct vring_virtqueue *vq = to_vvq(_vq); | |
1346 | struct vring_packed_desc *desc; | |
1347 | struct scatterlist *sg; | |
1348 | unsigned int i, n, c, descs_used, err_idx; | |
3f649ab7 KC |
1349 | __le16 head_flags, flags; |
1350 | u16 head, id, prev, curr, avail_used_flags; | |
fc6d70f4 | 1351 | int err; |
1ce9e605 TB |
1352 | |
1353 | START_USE(vq); | |
1354 | ||
1355 | BUG_ON(data == NULL); | |
1356 | BUG_ON(ctx && vq->indirect); | |
1357 | ||
1358 | if (unlikely(vq->broken)) { | |
1359 | END_USE(vq); | |
1360 | return -EIO; | |
1361 | } | |
1362 | ||
1363 | LAST_ADD_TIME_UPDATE(vq); | |
1364 | ||
1365 | BUG_ON(total_sg == 0); | |
1366 | ||
35c51e09 | 1367 | if (virtqueue_use_indirect(vq, total_sg)) { |
fc6d70f4 XZ |
1368 | err = virtqueue_add_indirect_packed(vq, sgs, total_sg, out_sgs, |
1369 | in_sgs, data, gfp); | |
1861ba62 MT |
1370 | if (err != -ENOMEM) { |
1371 | END_USE(vq); | |
fc6d70f4 | 1372 | return err; |
1861ba62 | 1373 | } |
fc6d70f4 XZ |
1374 | |
1375 | /* fall back on direct */ | |
1376 | } | |
1ce9e605 TB |
1377 | |
1378 | head = vq->packed.next_avail_idx; | |
1379 | avail_used_flags = vq->packed.avail_used_flags; | |
1380 | ||
1381 | WARN_ON_ONCE(total_sg > vq->packed.vring.num && !vq->indirect); | |
1382 | ||
1383 | desc = vq->packed.vring.desc; | |
1384 | i = head; | |
1385 | descs_used = total_sg; | |
1386 | ||
1387 | if (unlikely(vq->vq.num_free < descs_used)) { | |
1388 | pr_debug("Can't add buf len %i - avail = %i\n", | |
1389 | descs_used, vq->vq.num_free); | |
1390 | END_USE(vq); | |
1391 | return -ENOSPC; | |
1392 | } | |
1393 | ||
1394 | id = vq->free_head; | |
1395 | BUG_ON(id == vq->packed.vring.num); | |
1396 | ||
1397 | curr = id; | |
1398 | c = 0; | |
1399 | for (n = 0; n < out_sgs + in_sgs; n++) { | |
1400 | for (sg = sgs[n]; sg; sg = sg_next(sg)) { | |
1401 | dma_addr_t addr = vring_map_one_sg(vq, sg, n < out_sgs ? | |
1402 | DMA_TO_DEVICE : DMA_FROM_DEVICE); | |
1403 | if (vring_mapping_error(vq, addr)) | |
1404 | goto unmap_release; | |
1405 | ||
1406 | flags = cpu_to_le16(vq->packed.avail_used_flags | | |
1407 | (++c == total_sg ? 0 : VRING_DESC_F_NEXT) | | |
1408 | (n < out_sgs ? 0 : VRING_DESC_F_WRITE)); | |
1409 | if (i == head) | |
1410 | head_flags = flags; | |
1411 | else | |
1412 | desc[i].flags = flags; | |
1413 | ||
1414 | desc[i].addr = cpu_to_le64(addr); | |
1415 | desc[i].len = cpu_to_le32(sg->length); | |
1416 | desc[i].id = cpu_to_le16(id); | |
1417 | ||
1418 | if (unlikely(vq->use_dma_api)) { | |
1419 | vq->packed.desc_extra[curr].addr = addr; | |
1420 | vq->packed.desc_extra[curr].len = sg->length; | |
1421 | vq->packed.desc_extra[curr].flags = | |
1422 | le16_to_cpu(flags); | |
1423 | } | |
1424 | prev = curr; | |
aeef9b47 | 1425 | curr = vq->packed.desc_extra[curr].next; |
1ce9e605 TB |
1426 | |
1427 | if ((unlikely(++i >= vq->packed.vring.num))) { | |
1428 | i = 0; | |
1429 | vq->packed.avail_used_flags ^= | |
1430 | 1 << VRING_PACKED_DESC_F_AVAIL | | |
1431 | 1 << VRING_PACKED_DESC_F_USED; | |
1432 | } | |
1433 | } | |
1434 | } | |
1435 | ||
1436 | if (i < head) | |
1437 | vq->packed.avail_wrap_counter ^= 1; | |
1438 | ||
1439 | /* We're using some buffers from the free list. */ | |
1440 | vq->vq.num_free -= descs_used; | |
1441 | ||
1442 | /* Update free pointer */ | |
1443 | vq->packed.next_avail_idx = i; | |
1444 | vq->free_head = curr; | |
1445 | ||
1446 | /* Store token. */ | |
1447 | vq->packed.desc_state[id].num = descs_used; | |
1448 | vq->packed.desc_state[id].data = data; | |
1449 | vq->packed.desc_state[id].indir_desc = ctx; | |
1450 | vq->packed.desc_state[id].last = prev; | |
1451 | ||
1452 | /* | |
1453 | * A driver MUST NOT make the first descriptor in the list | |
1454 | * available before all subsequent descriptors comprising | |
1455 | * the list are made available. | |
1456 | */ | |
1457 | virtio_wmb(vq->weak_barriers); | |
1458 | vq->packed.vring.desc[head].flags = head_flags; | |
1459 | vq->num_added += descs_used; | |
1460 | ||
1461 | pr_debug("Added buffer head %i to %p\n", head, vq); | |
1462 | END_USE(vq); | |
1463 | ||
1464 | return 0; | |
1465 | ||
1466 | unmap_release: | |
1467 | err_idx = i; | |
1468 | i = head; | |
44593865 | 1469 | curr = vq->free_head; |
1ce9e605 TB |
1470 | |
1471 | vq->packed.avail_used_flags = avail_used_flags; | |
1472 | ||
1473 | for (n = 0; n < total_sg; n++) { | |
1474 | if (i == err_idx) | |
1475 | break; | |
d80dc15b | 1476 | vring_unmap_extra_packed(vq, &vq->packed.desc_extra[curr]); |
44593865 | 1477 | curr = vq->packed.desc_extra[curr].next; |
1ce9e605 TB |
1478 | i++; |
1479 | if (i >= vq->packed.vring.num) | |
1480 | i = 0; | |
1481 | } | |
1482 | ||
1483 | END_USE(vq); | |
1484 | return -EIO; | |
1485 | } | |
1486 | ||
1487 | static bool virtqueue_kick_prepare_packed(struct virtqueue *_vq) | |
1488 | { | |
1489 | struct vring_virtqueue *vq = to_vvq(_vq); | |
f51f9826 | 1490 | u16 new, old, off_wrap, flags, wrap_counter, event_idx; |
1ce9e605 TB |
1491 | bool needs_kick; |
1492 | union { | |
1493 | struct { | |
1494 | __le16 off_wrap; | |
1495 | __le16 flags; | |
1496 | }; | |
1497 | u32 u32; | |
1498 | } snapshot; | |
1499 | ||
1500 | START_USE(vq); | |
1501 | ||
1502 | /* | |
1503 | * We need to expose the new flags value before checking notification | |
1504 | * suppressions. | |
1505 | */ | |
1506 | virtio_mb(vq->weak_barriers); | |
1507 | ||
f51f9826 TB |
1508 | old = vq->packed.next_avail_idx - vq->num_added; |
1509 | new = vq->packed.next_avail_idx; | |
1ce9e605 TB |
1510 | vq->num_added = 0; |
1511 | ||
1512 | snapshot.u32 = *(u32 *)vq->packed.vring.device; | |
1513 | flags = le16_to_cpu(snapshot.flags); | |
1514 | ||
1515 | LAST_ADD_TIME_CHECK(vq); | |
1516 | LAST_ADD_TIME_INVALID(vq); | |
1517 | ||
f51f9826 TB |
1518 | if (flags != VRING_PACKED_EVENT_FLAG_DESC) { |
1519 | needs_kick = (flags != VRING_PACKED_EVENT_FLAG_DISABLE); | |
1520 | goto out; | |
1521 | } | |
1522 | ||
1523 | off_wrap = le16_to_cpu(snapshot.off_wrap); | |
1524 | ||
1525 | wrap_counter = off_wrap >> VRING_PACKED_EVENT_F_WRAP_CTR; | |
1526 | event_idx = off_wrap & ~(1 << VRING_PACKED_EVENT_F_WRAP_CTR); | |
1527 | if (wrap_counter != vq->packed.avail_wrap_counter) | |
1528 | event_idx -= vq->packed.vring.num; | |
1529 | ||
1530 | needs_kick = vring_need_event(event_idx, new, old); | |
1531 | out: | |
1ce9e605 TB |
1532 | END_USE(vq); |
1533 | return needs_kick; | |
1534 | } | |
1535 | ||
1536 | static void detach_buf_packed(struct vring_virtqueue *vq, | |
1537 | unsigned int id, void **ctx) | |
1538 | { | |
1539 | struct vring_desc_state_packed *state = NULL; | |
1540 | struct vring_packed_desc *desc; | |
1541 | unsigned int i, curr; | |
1542 | ||
1543 | state = &vq->packed.desc_state[id]; | |
1544 | ||
1545 | /* Clear data ptr. */ | |
1546 | state->data = NULL; | |
1547 | ||
aeef9b47 | 1548 | vq->packed.desc_extra[state->last].next = vq->free_head; |
1ce9e605 TB |
1549 | vq->free_head = id; |
1550 | vq->vq.num_free += state->num; | |
1551 | ||
1552 | if (unlikely(vq->use_dma_api)) { | |
1553 | curr = id; | |
1554 | for (i = 0; i < state->num; i++) { | |
d80dc15b XZ |
1555 | vring_unmap_extra_packed(vq, |
1556 | &vq->packed.desc_extra[curr]); | |
aeef9b47 | 1557 | curr = vq->packed.desc_extra[curr].next; |
1ce9e605 TB |
1558 | } |
1559 | } | |
1560 | ||
1561 | if (vq->indirect) { | |
1562 | u32 len; | |
1563 | ||
1564 | /* Free the indirect table, if any, now that it's unmapped. */ | |
1565 | desc = state->indir_desc; | |
1566 | if (!desc) | |
1567 | return; | |
1568 | ||
1569 | if (vq->use_dma_api) { | |
1570 | len = vq->packed.desc_extra[id].len; | |
1571 | for (i = 0; i < len / sizeof(struct vring_packed_desc); | |
1572 | i++) | |
1573 | vring_unmap_desc_packed(vq, &desc[i]); | |
1574 | } | |
1575 | kfree(desc); | |
1576 | state->indir_desc = NULL; | |
1577 | } else if (ctx) { | |
1578 | *ctx = state->indir_desc; | |
1579 | } | |
1580 | } | |
1581 | ||
1582 | static inline bool is_used_desc_packed(const struct vring_virtqueue *vq, | |
1583 | u16 idx, bool used_wrap_counter) | |
1584 | { | |
1585 | bool avail, used; | |
1586 | u16 flags; | |
1587 | ||
1588 | flags = le16_to_cpu(vq->packed.vring.desc[idx].flags); | |
1589 | avail = !!(flags & (1 << VRING_PACKED_DESC_F_AVAIL)); | |
1590 | used = !!(flags & (1 << VRING_PACKED_DESC_F_USED)); | |
1591 | ||
1592 | return avail == used && used == used_wrap_counter; | |
1593 | } | |
1594 | ||
1595 | static inline bool more_used_packed(const struct vring_virtqueue *vq) | |
1596 | { | |
a7722890 | 1597 | u16 last_used; |
1598 | u16 last_used_idx; | |
1599 | bool used_wrap_counter; | |
1600 | ||
1601 | last_used_idx = READ_ONCE(vq->last_used_idx); | |
1602 | last_used = packed_last_used(last_used_idx); | |
1603 | used_wrap_counter = packed_used_wrap_counter(last_used_idx); | |
1604 | return is_used_desc_packed(vq, last_used, used_wrap_counter); | |
1ce9e605 TB |
1605 | } |
1606 | ||
1607 | static void *virtqueue_get_buf_ctx_packed(struct virtqueue *_vq, | |
1608 | unsigned int *len, | |
1609 | void **ctx) | |
1610 | { | |
1611 | struct vring_virtqueue *vq = to_vvq(_vq); | |
a7722890 | 1612 | u16 last_used, id, last_used_idx; |
1613 | bool used_wrap_counter; | |
1ce9e605 TB |
1614 | void *ret; |
1615 | ||
1616 | START_USE(vq); | |
1617 | ||
1618 | if (unlikely(vq->broken)) { | |
1619 | END_USE(vq); | |
1620 | return NULL; | |
1621 | } | |
1622 | ||
1623 | if (!more_used_packed(vq)) { | |
1624 | pr_debug("No more buffers in queue\n"); | |
1625 | END_USE(vq); | |
1626 | return NULL; | |
1627 | } | |
1628 | ||
1629 | /* Only get used elements after they have been exposed by host. */ | |
1630 | virtio_rmb(vq->weak_barriers); | |
1631 | ||
a7722890 | 1632 | last_used_idx = READ_ONCE(vq->last_used_idx); |
1633 | used_wrap_counter = packed_used_wrap_counter(last_used_idx); | |
1634 | last_used = packed_last_used(last_used_idx); | |
1ce9e605 TB |
1635 | id = le16_to_cpu(vq->packed.vring.desc[last_used].id); |
1636 | *len = le32_to_cpu(vq->packed.vring.desc[last_used].len); | |
1637 | ||
1638 | if (unlikely(id >= vq->packed.vring.num)) { | |
1639 | BAD_RING(vq, "id %u out of range\n", id); | |
1640 | return NULL; | |
1641 | } | |
1642 | if (unlikely(!vq->packed.desc_state[id].data)) { | |
1643 | BAD_RING(vq, "id %u is not a head!\n", id); | |
1644 | return NULL; | |
1645 | } | |
1646 | ||
1647 | /* detach_buf_packed clears data, so grab it now. */ | |
1648 | ret = vq->packed.desc_state[id].data; | |
1649 | detach_buf_packed(vq, id, ctx); | |
1650 | ||
a7722890 | 1651 | last_used += vq->packed.desc_state[id].num; |
1652 | if (unlikely(last_used >= vq->packed.vring.num)) { | |
1653 | last_used -= vq->packed.vring.num; | |
1654 | used_wrap_counter ^= 1; | |
1ce9e605 TB |
1655 | } |
1656 | ||
a7722890 | 1657 | last_used = (last_used | (used_wrap_counter << VRING_PACKED_EVENT_F_WRAP_CTR)); |
1658 | WRITE_ONCE(vq->last_used_idx, last_used); | |
1659 | ||
f51f9826 TB |
1660 | /* |
1661 | * If we expect an interrupt for the next entry, tell host | |
1662 | * by writing event index and flush out the write before | |
1663 | * the read in the next get_buf call. | |
1664 | */ | |
1665 | if (vq->packed.event_flags_shadow == VRING_PACKED_EVENT_FLAG_DESC) | |
1666 | virtio_store_mb(vq->weak_barriers, | |
1667 | &vq->packed.vring.driver->off_wrap, | |
a7722890 | 1668 | cpu_to_le16(vq->last_used_idx)); |
f51f9826 | 1669 | |
1ce9e605 TB |
1670 | LAST_ADD_TIME_INVALID(vq); |
1671 | ||
1672 | END_USE(vq); | |
1673 | return ret; | |
1674 | } | |
1675 | ||
1676 | static void virtqueue_disable_cb_packed(struct virtqueue *_vq) | |
1677 | { | |
1678 | struct vring_virtqueue *vq = to_vvq(_vq); | |
1679 | ||
1680 | if (vq->packed.event_flags_shadow != VRING_PACKED_EVENT_FLAG_DISABLE) { | |
1681 | vq->packed.event_flags_shadow = VRING_PACKED_EVENT_FLAG_DISABLE; | |
1682 | vq->packed.vring.driver->flags = | |
1683 | cpu_to_le16(vq->packed.event_flags_shadow); | |
1684 | } | |
1685 | } | |
1686 | ||
31532340 | 1687 | static unsigned int virtqueue_enable_cb_prepare_packed(struct virtqueue *_vq) |
1ce9e605 TB |
1688 | { |
1689 | struct vring_virtqueue *vq = to_vvq(_vq); | |
1690 | ||
1691 | START_USE(vq); | |
1692 | ||
1693 | /* | |
1694 | * We optimistically turn back on interrupts, then check if there was | |
1695 | * more to do. | |
1696 | */ | |
1697 | ||
f51f9826 TB |
1698 | if (vq->event) { |
1699 | vq->packed.vring.driver->off_wrap = | |
a7722890 | 1700 | cpu_to_le16(vq->last_used_idx); |
f51f9826 TB |
1701 | /* |
1702 | * We need to update event offset and event wrap | |
1703 | * counter first before updating event flags. | |
1704 | */ | |
1705 | virtio_wmb(vq->weak_barriers); | |
1706 | } | |
1707 | ||
1ce9e605 | 1708 | if (vq->packed.event_flags_shadow == VRING_PACKED_EVENT_FLAG_DISABLE) { |
f51f9826 TB |
1709 | vq->packed.event_flags_shadow = vq->event ? |
1710 | VRING_PACKED_EVENT_FLAG_DESC : | |
1711 | VRING_PACKED_EVENT_FLAG_ENABLE; | |
1ce9e605 TB |
1712 | vq->packed.vring.driver->flags = |
1713 | cpu_to_le16(vq->packed.event_flags_shadow); | |
1714 | } | |
1715 | ||
1716 | END_USE(vq); | |
a7722890 | 1717 | return vq->last_used_idx; |
1ce9e605 TB |
1718 | } |
1719 | ||
1720 | static bool virtqueue_poll_packed(struct virtqueue *_vq, u16 off_wrap) | |
1721 | { | |
1722 | struct vring_virtqueue *vq = to_vvq(_vq); | |
1723 | bool wrap_counter; | |
1724 | u16 used_idx; | |
1725 | ||
1726 | wrap_counter = off_wrap >> VRING_PACKED_EVENT_F_WRAP_CTR; | |
1727 | used_idx = off_wrap & ~(1 << VRING_PACKED_EVENT_F_WRAP_CTR); | |
1728 | ||
1729 | return is_used_desc_packed(vq, used_idx, wrap_counter); | |
1730 | } | |
1731 | ||
1732 | static bool virtqueue_enable_cb_delayed_packed(struct virtqueue *_vq) | |
1733 | { | |
1734 | struct vring_virtqueue *vq = to_vvq(_vq); | |
a7722890 | 1735 | u16 used_idx, wrap_counter, last_used_idx; |
f51f9826 | 1736 | u16 bufs; |
1ce9e605 TB |
1737 | |
1738 | START_USE(vq); | |
1739 | ||
1740 | /* | |
1741 | * We optimistically turn back on interrupts, then check if there was | |
1742 | * more to do. | |
1743 | */ | |
1744 | ||
f51f9826 TB |
1745 | if (vq->event) { |
1746 | /* TODO: tune this threshold */ | |
1747 | bufs = (vq->packed.vring.num - vq->vq.num_free) * 3 / 4; | |
a7722890 | 1748 | last_used_idx = READ_ONCE(vq->last_used_idx); |
1749 | wrap_counter = packed_used_wrap_counter(last_used_idx); | |
f51f9826 | 1750 | |
a7722890 | 1751 | used_idx = packed_last_used(last_used_idx) + bufs; |
f51f9826 TB |
1752 | if (used_idx >= vq->packed.vring.num) { |
1753 | used_idx -= vq->packed.vring.num; | |
1754 | wrap_counter ^= 1; | |
1755 | } | |
1756 | ||
1757 | vq->packed.vring.driver->off_wrap = cpu_to_le16(used_idx | | |
1758 | (wrap_counter << VRING_PACKED_EVENT_F_WRAP_CTR)); | |
1759 | ||
1760 | /* | |
1761 | * We need to update event offset and event wrap | |
1762 | * counter first before updating event flags. | |
1763 | */ | |
1764 | virtio_wmb(vq->weak_barriers); | |
f51f9826 | 1765 | } |
1ce9e605 TB |
1766 | |
1767 | if (vq->packed.event_flags_shadow == VRING_PACKED_EVENT_FLAG_DISABLE) { | |
f51f9826 TB |
1768 | vq->packed.event_flags_shadow = vq->event ? |
1769 | VRING_PACKED_EVENT_FLAG_DESC : | |
1770 | VRING_PACKED_EVENT_FLAG_ENABLE; | |
1ce9e605 TB |
1771 | vq->packed.vring.driver->flags = |
1772 | cpu_to_le16(vq->packed.event_flags_shadow); | |
1773 | } | |
1774 | ||
1775 | /* | |
1776 | * We need to update event suppression structure first | |
1777 | * before re-checking for more used buffers. | |
1778 | */ | |
1779 | virtio_mb(vq->weak_barriers); | |
1780 | ||
a7722890 | 1781 | last_used_idx = READ_ONCE(vq->last_used_idx); |
1782 | wrap_counter = packed_used_wrap_counter(last_used_idx); | |
1783 | used_idx = packed_last_used(last_used_idx); | |
1784 | if (is_used_desc_packed(vq, used_idx, wrap_counter)) { | |
1ce9e605 TB |
1785 | END_USE(vq); |
1786 | return false; | |
1787 | } | |
1788 | ||
1789 | END_USE(vq); | |
1790 | return true; | |
1791 | } | |
1792 | ||
1793 | static void *virtqueue_detach_unused_buf_packed(struct virtqueue *_vq) | |
1794 | { | |
1795 | struct vring_virtqueue *vq = to_vvq(_vq); | |
1796 | unsigned int i; | |
1797 | void *buf; | |
1798 | ||
1799 | START_USE(vq); | |
1800 | ||
1801 | for (i = 0; i < vq->packed.vring.num; i++) { | |
1802 | if (!vq->packed.desc_state[i].data) | |
1803 | continue; | |
1804 | /* detach_buf clears data, so grab it now. */ | |
1805 | buf = vq->packed.desc_state[i].data; | |
1806 | detach_buf_packed(vq, i, NULL); | |
1807 | END_USE(vq); | |
1808 | return buf; | |
1809 | } | |
1810 | /* That should have freed everything. */ | |
1811 | BUG_ON(vq->vq.num_free != vq->packed.vring.num); | |
1812 | ||
1813 | END_USE(vq); | |
1814 | return NULL; | |
1815 | } | |
1816 | ||
96ef18a2 | 1817 | static struct vring_desc_extra *vring_alloc_desc_extra(unsigned int num) |
5a222421 JW |
1818 | { |
1819 | struct vring_desc_extra *desc_extra; | |
1820 | unsigned int i; | |
1821 | ||
1822 | desc_extra = kmalloc_array(num, sizeof(struct vring_desc_extra), | |
1823 | GFP_KERNEL); | |
1824 | if (!desc_extra) | |
1825 | return NULL; | |
1826 | ||
1827 | memset(desc_extra, 0, num * sizeof(struct vring_desc_extra)); | |
1828 | ||
1829 | for (i = 0; i < num - 1; i++) | |
1830 | desc_extra[i].next = i + 1; | |
1831 | ||
1832 | return desc_extra; | |
1833 | } | |
1834 | ||
6356f8bb XZ |
1835 | static void vring_free_packed(struct vring_virtqueue_packed *vring_packed, |
1836 | struct virtio_device *vdev) | |
1837 | { | |
1838 | if (vring_packed->vring.desc) | |
1839 | vring_free_queue(vdev, vring_packed->ring_size_in_bytes, | |
1840 | vring_packed->vring.desc, | |
1841 | vring_packed->ring_dma_addr); | |
1842 | ||
1843 | if (vring_packed->vring.driver) | |
1844 | vring_free_queue(vdev, vring_packed->event_size_in_bytes, | |
1845 | vring_packed->vring.driver, | |
1846 | vring_packed->driver_event_dma_addr); | |
1847 | ||
1848 | if (vring_packed->vring.device) | |
1849 | vring_free_queue(vdev, vring_packed->event_size_in_bytes, | |
1850 | vring_packed->vring.device, | |
1851 | vring_packed->device_event_dma_addr); | |
1852 | ||
1853 | kfree(vring_packed->desc_state); | |
1854 | kfree(vring_packed->desc_extra); | |
1855 | } | |
1856 | ||
6b60b9c0 XZ |
1857 | static int vring_alloc_queue_packed(struct vring_virtqueue_packed *vring_packed, |
1858 | struct virtio_device *vdev, | |
1859 | u32 num) | |
1ce9e605 | 1860 | { |
1ce9e605 TB |
1861 | struct vring_packed_desc *ring; |
1862 | struct vring_packed_desc_event *driver, *device; | |
1863 | dma_addr_t ring_dma_addr, driver_event_dma_addr, device_event_dma_addr; | |
1864 | size_t ring_size_in_bytes, event_size_in_bytes; | |
1ce9e605 TB |
1865 | |
1866 | ring_size_in_bytes = num * sizeof(struct vring_packed_desc); | |
1867 | ||
1868 | ring = vring_alloc_queue(vdev, ring_size_in_bytes, | |
1869 | &ring_dma_addr, | |
1870 | GFP_KERNEL|__GFP_NOWARN|__GFP_ZERO); | |
1871 | if (!ring) | |
6b60b9c0 XZ |
1872 | goto err; |
1873 | ||
1874 | vring_packed->vring.desc = ring; | |
1875 | vring_packed->ring_dma_addr = ring_dma_addr; | |
1876 | vring_packed->ring_size_in_bytes = ring_size_in_bytes; | |
1ce9e605 TB |
1877 | |
1878 | event_size_in_bytes = sizeof(struct vring_packed_desc_event); | |
1879 | ||
1880 | driver = vring_alloc_queue(vdev, event_size_in_bytes, | |
1881 | &driver_event_dma_addr, | |
1882 | GFP_KERNEL|__GFP_NOWARN|__GFP_ZERO); | |
1883 | if (!driver) | |
6b60b9c0 XZ |
1884 | goto err; |
1885 | ||
1886 | vring_packed->vring.driver = driver; | |
1887 | vring_packed->event_size_in_bytes = event_size_in_bytes; | |
1888 | vring_packed->driver_event_dma_addr = driver_event_dma_addr; | |
1ce9e605 TB |
1889 | |
1890 | device = vring_alloc_queue(vdev, event_size_in_bytes, | |
1891 | &device_event_dma_addr, | |
1892 | GFP_KERNEL|__GFP_NOWARN|__GFP_ZERO); | |
1893 | if (!device) | |
6b60b9c0 XZ |
1894 | goto err; |
1895 | ||
1896 | vring_packed->vring.device = device; | |
1897 | vring_packed->device_event_dma_addr = device_event_dma_addr; | |
1898 | ||
1899 | vring_packed->vring.num = num; | |
1900 | ||
1901 | return 0; | |
1902 | ||
1903 | err: | |
1904 | vring_free_packed(vring_packed, vdev); | |
1905 | return -ENOMEM; | |
1906 | } | |
1907 | ||
ef3167cf XZ |
1908 | static int vring_alloc_state_extra_packed(struct vring_virtqueue_packed *vring_packed) |
1909 | { | |
1910 | struct vring_desc_state_packed *state; | |
1911 | struct vring_desc_extra *extra; | |
1912 | u32 num = vring_packed->vring.num; | |
1913 | ||
1914 | state = kmalloc_array(num, sizeof(struct vring_desc_state_packed), GFP_KERNEL); | |
1915 | if (!state) | |
1916 | goto err_desc_state; | |
1917 | ||
1918 | memset(state, 0, num * sizeof(struct vring_desc_state_packed)); | |
1919 | ||
1920 | extra = vring_alloc_desc_extra(num); | |
1921 | if (!extra) | |
1922 | goto err_desc_extra; | |
1923 | ||
1924 | vring_packed->desc_state = state; | |
1925 | vring_packed->desc_extra = extra; | |
1926 | ||
1927 | return 0; | |
1928 | ||
1929 | err_desc_extra: | |
1930 | kfree(state); | |
1931 | err_desc_state: | |
1932 | return -ENOMEM; | |
1933 | } | |
1934 | ||
1a107c87 XZ |
1935 | static void virtqueue_vring_init_packed(struct vring_virtqueue_packed *vring_packed, |
1936 | bool callback) | |
1937 | { | |
1938 | vring_packed->next_avail_idx = 0; | |
1939 | vring_packed->avail_wrap_counter = 1; | |
1940 | vring_packed->event_flags_shadow = 0; | |
1941 | vring_packed->avail_used_flags = 1 << VRING_PACKED_DESC_F_AVAIL; | |
1942 | ||
1943 | /* No callback? Tell other side not to bother us. */ | |
1944 | if (!callback) { | |
1945 | vring_packed->event_flags_shadow = VRING_PACKED_EVENT_FLAG_DISABLE; | |
1946 | vring_packed->vring.driver->flags = | |
1947 | cpu_to_le16(vring_packed->event_flags_shadow); | |
1948 | } | |
1949 | } | |
1950 | ||
51d649f1 XZ |
1951 | static void virtqueue_vring_attach_packed(struct vring_virtqueue *vq, |
1952 | struct vring_virtqueue_packed *vring_packed) | |
1953 | { | |
1954 | vq->packed = *vring_packed; | |
1955 | ||
1956 | /* Put everything in free lists. */ | |
1957 | vq->free_head = 0; | |
1958 | } | |
1959 | ||
56775e14 XZ |
1960 | static void virtqueue_reinit_packed(struct vring_virtqueue *vq) |
1961 | { | |
1962 | memset(vq->packed.vring.device, 0, vq->packed.event_size_in_bytes); | |
1963 | memset(vq->packed.vring.driver, 0, vq->packed.event_size_in_bytes); | |
1964 | ||
1965 | /* we need to reset the desc.flags. For more, see is_used_desc_packed() */ | |
1966 | memset(vq->packed.vring.desc, 0, vq->packed.ring_size_in_bytes); | |
1967 | ||
1968 | virtqueue_init(vq, vq->packed.vring.num); | |
1969 | virtqueue_vring_init_packed(&vq->packed, !!vq->vq.callback); | |
1970 | } | |
1971 | ||
6b60b9c0 XZ |
1972 | static struct virtqueue *vring_create_virtqueue_packed( |
1973 | unsigned int index, | |
1974 | unsigned int num, | |
1975 | unsigned int vring_align, | |
1976 | struct virtio_device *vdev, | |
1977 | bool weak_barriers, | |
1978 | bool may_reduce_num, | |
1979 | bool context, | |
1980 | bool (*notify)(struct virtqueue *), | |
1981 | void (*callback)(struct virtqueue *), | |
1982 | const char *name) | |
1983 | { | |
1984 | struct vring_virtqueue_packed vring_packed = {}; | |
1985 | struct vring_virtqueue *vq; | |
ef3167cf | 1986 | int err; |
6b60b9c0 XZ |
1987 | |
1988 | if (vring_alloc_queue_packed(&vring_packed, vdev, num)) | |
1989 | goto err_ring; | |
1ce9e605 TB |
1990 | |
1991 | vq = kmalloc(sizeof(*vq), GFP_KERNEL); | |
1992 | if (!vq) | |
1993 | goto err_vq; | |
1994 | ||
1995 | vq->vq.callback = callback; | |
1996 | vq->vq.vdev = vdev; | |
1997 | vq->vq.name = name; | |
1ce9e605 | 1998 | vq->vq.index = index; |
4913e854 | 1999 | vq->vq.reset = false; |
1ce9e605 TB |
2000 | vq->we_own_ring = true; |
2001 | vq->notify = notify; | |
2002 | vq->weak_barriers = weak_barriers; | |
c346dae4 | 2003 | #ifdef CONFIG_VIRTIO_HARDEN_NOTIFICATION |
8b4ec69d | 2004 | vq->broken = true; |
c346dae4 JW |
2005 | #else |
2006 | vq->broken = false; | |
2007 | #endif | |
1ce9e605 TB |
2008 | vq->packed_ring = true; |
2009 | vq->use_dma_api = vring_use_dma_api(vdev); | |
1ce9e605 TB |
2010 | |
2011 | vq->indirect = virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC) && | |
2012 | !context; | |
2013 | vq->event = virtio_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX); | |
2014 | ||
45383fb0 TB |
2015 | if (virtio_has_feature(vdev, VIRTIO_F_ORDER_PLATFORM)) |
2016 | vq->weak_barriers = false; | |
2017 | ||
ef3167cf XZ |
2018 | err = vring_alloc_state_extra_packed(&vring_packed); |
2019 | if (err) | |
2020 | goto err_state_extra; | |
1ce9e605 | 2021 | |
1a107c87 | 2022 | virtqueue_vring_init_packed(&vring_packed, !!callback); |
1ce9e605 | 2023 | |
3a897128 | 2024 | virtqueue_init(vq, num); |
51d649f1 | 2025 | virtqueue_vring_attach_packed(vq, &vring_packed); |
3a897128 | 2026 | |
0e566c8f | 2027 | spin_lock(&vdev->vqs_list_lock); |
e152d8af | 2028 | list_add_tail(&vq->vq.list, &vdev->vqs); |
0e566c8f | 2029 | spin_unlock(&vdev->vqs_list_lock); |
1ce9e605 TB |
2030 | return &vq->vq; |
2031 | ||
ef3167cf | 2032 | err_state_extra: |
1ce9e605 TB |
2033 | kfree(vq); |
2034 | err_vq: | |
6b60b9c0 | 2035 | vring_free_packed(&vring_packed, vdev); |
1ce9e605 TB |
2036 | err_ring: |
2037 | return NULL; | |
2038 | } | |
2039 | ||
947f9fcf XZ |
2040 | static int virtqueue_resize_packed(struct virtqueue *_vq, u32 num) |
2041 | { | |
2042 | struct vring_virtqueue_packed vring_packed = {}; | |
2043 | struct vring_virtqueue *vq = to_vvq(_vq); | |
2044 | struct virtio_device *vdev = _vq->vdev; | |
2045 | int err; | |
2046 | ||
2047 | if (vring_alloc_queue_packed(&vring_packed, vdev, num)) | |
2048 | goto err_ring; | |
2049 | ||
2050 | err = vring_alloc_state_extra_packed(&vring_packed); | |
2051 | if (err) | |
2052 | goto err_state_extra; | |
2053 | ||
2054 | vring_free(&vq->vq); | |
2055 | ||
2056 | virtqueue_vring_init_packed(&vring_packed, !!vq->vq.callback); | |
2057 | ||
2058 | virtqueue_init(vq, vring_packed.vring.num); | |
2059 | virtqueue_vring_attach_packed(vq, &vring_packed); | |
2060 | ||
2061 | return 0; | |
2062 | ||
2063 | err_state_extra: | |
2064 | vring_free_packed(&vring_packed, vdev); | |
2065 | err_ring: | |
2066 | virtqueue_reinit_packed(vq); | |
2067 | return -ENOMEM; | |
2068 | } | |
2069 | ||
1ce9e605 | 2070 | |
e6f633e5 TB |
2071 | /* |
2072 | * Generic functions and exported symbols. | |
2073 | */ | |
2074 | ||
2075 | static inline int virtqueue_add(struct virtqueue *_vq, | |
2076 | struct scatterlist *sgs[], | |
2077 | unsigned int total_sg, | |
2078 | unsigned int out_sgs, | |
2079 | unsigned int in_sgs, | |
2080 | void *data, | |
2081 | void *ctx, | |
2082 | gfp_t gfp) | |
2083 | { | |
1ce9e605 TB |
2084 | struct vring_virtqueue *vq = to_vvq(_vq); |
2085 | ||
2086 | return vq->packed_ring ? virtqueue_add_packed(_vq, sgs, total_sg, | |
2087 | out_sgs, in_sgs, data, ctx, gfp) : | |
2088 | virtqueue_add_split(_vq, sgs, total_sg, | |
2089 | out_sgs, in_sgs, data, ctx, gfp); | |
e6f633e5 TB |
2090 | } |
2091 | ||
2092 | /** | |
2093 | * virtqueue_add_sgs - expose buffers to other end | |
a5581206 | 2094 | * @_vq: the struct virtqueue we're talking about. |
e6f633e5 | 2095 | * @sgs: array of terminated scatterlists. |
a5581206 JB |
2096 | * @out_sgs: the number of scatterlists readable by other side |
2097 | * @in_sgs: the number of scatterlists which are writable (after readable ones) | |
e6f633e5 TB |
2098 | * @data: the token identifying the buffer. |
2099 | * @gfp: how to do memory allocations (if necessary). | |
2100 | * | |
2101 | * Caller must ensure we don't call this with other virtqueue operations | |
2102 | * at the same time (except where noted). | |
2103 | * | |
2104 | * Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO). | |
2105 | */ | |
2106 | int virtqueue_add_sgs(struct virtqueue *_vq, | |
2107 | struct scatterlist *sgs[], | |
2108 | unsigned int out_sgs, | |
2109 | unsigned int in_sgs, | |
2110 | void *data, | |
2111 | gfp_t gfp) | |
2112 | { | |
2113 | unsigned int i, total_sg = 0; | |
2114 | ||
2115 | /* Count them first. */ | |
2116 | for (i = 0; i < out_sgs + in_sgs; i++) { | |
2117 | struct scatterlist *sg; | |
2118 | ||
2119 | for (sg = sgs[i]; sg; sg = sg_next(sg)) | |
2120 | total_sg++; | |
2121 | } | |
2122 | return virtqueue_add(_vq, sgs, total_sg, out_sgs, in_sgs, | |
2123 | data, NULL, gfp); | |
2124 | } | |
2125 | EXPORT_SYMBOL_GPL(virtqueue_add_sgs); | |
2126 | ||
2127 | /** | |
2128 | * virtqueue_add_outbuf - expose output buffers to other end | |
2129 | * @vq: the struct virtqueue we're talking about. | |
2130 | * @sg: scatterlist (must be well-formed and terminated!) | |
2131 | * @num: the number of entries in @sg readable by other side | |
2132 | * @data: the token identifying the buffer. | |
2133 | * @gfp: how to do memory allocations (if necessary). | |
2134 | * | |
2135 | * Caller must ensure we don't call this with other virtqueue operations | |
2136 | * at the same time (except where noted). | |
2137 | * | |
2138 | * Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO). | |
2139 | */ | |
2140 | int virtqueue_add_outbuf(struct virtqueue *vq, | |
2141 | struct scatterlist *sg, unsigned int num, | |
2142 | void *data, | |
2143 | gfp_t gfp) | |
2144 | { | |
2145 | return virtqueue_add(vq, &sg, num, 1, 0, data, NULL, gfp); | |
2146 | } | |
2147 | EXPORT_SYMBOL_GPL(virtqueue_add_outbuf); | |
2148 | ||
2149 | /** | |
2150 | * virtqueue_add_inbuf - expose input buffers to other end | |
2151 | * @vq: the struct virtqueue we're talking about. | |
2152 | * @sg: scatterlist (must be well-formed and terminated!) | |
2153 | * @num: the number of entries in @sg writable by other side | |
2154 | * @data: the token identifying the buffer. | |
2155 | * @gfp: how to do memory allocations (if necessary). | |
2156 | * | |
2157 | * Caller must ensure we don't call this with other virtqueue operations | |
2158 | * at the same time (except where noted). | |
2159 | * | |
2160 | * Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO). | |
2161 | */ | |
2162 | int virtqueue_add_inbuf(struct virtqueue *vq, | |
2163 | struct scatterlist *sg, unsigned int num, | |
2164 | void *data, | |
2165 | gfp_t gfp) | |
2166 | { | |
2167 | return virtqueue_add(vq, &sg, num, 0, 1, data, NULL, gfp); | |
2168 | } | |
2169 | EXPORT_SYMBOL_GPL(virtqueue_add_inbuf); | |
2170 | ||
2171 | /** | |
2172 | * virtqueue_add_inbuf_ctx - expose input buffers to other end | |
2173 | * @vq: the struct virtqueue we're talking about. | |
2174 | * @sg: scatterlist (must be well-formed and terminated!) | |
2175 | * @num: the number of entries in @sg writable by other side | |
2176 | * @data: the token identifying the buffer. | |
2177 | * @ctx: extra context for the token | |
2178 | * @gfp: how to do memory allocations (if necessary). | |
2179 | * | |
2180 | * Caller must ensure we don't call this with other virtqueue operations | |
2181 | * at the same time (except where noted). | |
2182 | * | |
2183 | * Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO). | |
2184 | */ | |
2185 | int virtqueue_add_inbuf_ctx(struct virtqueue *vq, | |
2186 | struct scatterlist *sg, unsigned int num, | |
2187 | void *data, | |
2188 | void *ctx, | |
2189 | gfp_t gfp) | |
2190 | { | |
2191 | return virtqueue_add(vq, &sg, num, 0, 1, data, ctx, gfp); | |
2192 | } | |
2193 | EXPORT_SYMBOL_GPL(virtqueue_add_inbuf_ctx); | |
2194 | ||
2195 | /** | |
2196 | * virtqueue_kick_prepare - first half of split virtqueue_kick call. | |
a5581206 | 2197 | * @_vq: the struct virtqueue |
e6f633e5 TB |
2198 | * |
2199 | * Instead of virtqueue_kick(), you can do: | |
2200 | * if (virtqueue_kick_prepare(vq)) | |
2201 | * virtqueue_notify(vq); | |
2202 | * | |
2203 | * This is sometimes useful because the virtqueue_kick_prepare() needs | |
2204 | * to be serialized, but the actual virtqueue_notify() call does not. | |
2205 | */ | |
2206 | bool virtqueue_kick_prepare(struct virtqueue *_vq) | |
2207 | { | |
1ce9e605 TB |
2208 | struct vring_virtqueue *vq = to_vvq(_vq); |
2209 | ||
2210 | return vq->packed_ring ? virtqueue_kick_prepare_packed(_vq) : | |
2211 | virtqueue_kick_prepare_split(_vq); | |
e6f633e5 TB |
2212 | } |
2213 | EXPORT_SYMBOL_GPL(virtqueue_kick_prepare); | |
2214 | ||
2215 | /** | |
2216 | * virtqueue_notify - second half of split virtqueue_kick call. | |
a5581206 | 2217 | * @_vq: the struct virtqueue |
e6f633e5 TB |
2218 | * |
2219 | * This does not need to be serialized. | |
2220 | * | |
2221 | * Returns false if host notify failed or queue is broken, otherwise true. | |
2222 | */ | |
2223 | bool virtqueue_notify(struct virtqueue *_vq) | |
2224 | { | |
2225 | struct vring_virtqueue *vq = to_vvq(_vq); | |
2226 | ||
2227 | if (unlikely(vq->broken)) | |
2228 | return false; | |
2229 | ||
2230 | /* Prod other side to tell it about changes. */ | |
2231 | if (!vq->notify(_vq)) { | |
2232 | vq->broken = true; | |
2233 | return false; | |
2234 | } | |
2235 | return true; | |
2236 | } | |
2237 | EXPORT_SYMBOL_GPL(virtqueue_notify); | |
2238 | ||
2239 | /** | |
2240 | * virtqueue_kick - update after add_buf | |
2241 | * @vq: the struct virtqueue | |
2242 | * | |
2243 | * After one or more virtqueue_add_* calls, invoke this to kick | |
2244 | * the other side. | |
2245 | * | |
2246 | * Caller must ensure we don't call this with other virtqueue | |
2247 | * operations at the same time (except where noted). | |
2248 | * | |
2249 | * Returns false if kick failed, otherwise true. | |
2250 | */ | |
2251 | bool virtqueue_kick(struct virtqueue *vq) | |
2252 | { | |
2253 | if (virtqueue_kick_prepare(vq)) | |
2254 | return virtqueue_notify(vq); | |
2255 | return true; | |
2256 | } | |
2257 | EXPORT_SYMBOL_GPL(virtqueue_kick); | |
2258 | ||
2259 | /** | |
31c11db6 | 2260 | * virtqueue_get_buf_ctx - get the next used buffer |
a5581206 | 2261 | * @_vq: the struct virtqueue we're talking about. |
e6f633e5 | 2262 | * @len: the length written into the buffer |
a5581206 | 2263 | * @ctx: extra context for the token |
e6f633e5 TB |
2264 | * |
2265 | * If the device wrote data into the buffer, @len will be set to the | |
2266 | * amount written. This means you don't need to clear the buffer | |
2267 | * beforehand to ensure there's no data leakage in the case of short | |
2268 | * writes. | |
2269 | * | |
2270 | * Caller must ensure we don't call this with other virtqueue | |
2271 | * operations at the same time (except where noted). | |
2272 | * | |
2273 | * Returns NULL if there are no used buffers, or the "data" token | |
2274 | * handed to virtqueue_add_*(). | |
2275 | */ | |
2276 | void *virtqueue_get_buf_ctx(struct virtqueue *_vq, unsigned int *len, | |
2277 | void **ctx) | |
2278 | { | |
1ce9e605 TB |
2279 | struct vring_virtqueue *vq = to_vvq(_vq); |
2280 | ||
2281 | return vq->packed_ring ? virtqueue_get_buf_ctx_packed(_vq, len, ctx) : | |
2282 | virtqueue_get_buf_ctx_split(_vq, len, ctx); | |
e6f633e5 TB |
2283 | } |
2284 | EXPORT_SYMBOL_GPL(virtqueue_get_buf_ctx); | |
2285 | ||
2286 | void *virtqueue_get_buf(struct virtqueue *_vq, unsigned int *len) | |
2287 | { | |
2288 | return virtqueue_get_buf_ctx(_vq, len, NULL); | |
2289 | } | |
2290 | EXPORT_SYMBOL_GPL(virtqueue_get_buf); | |
e6f633e5 TB |
2291 | /** |
2292 | * virtqueue_disable_cb - disable callbacks | |
a5581206 | 2293 | * @_vq: the struct virtqueue we're talking about. |
e6f633e5 TB |
2294 | * |
2295 | * Note that this is not necessarily synchronous, hence unreliable and only | |
2296 | * useful as an optimization. | |
2297 | * | |
2298 | * Unlike other operations, this need not be serialized. | |
2299 | */ | |
2300 | void virtqueue_disable_cb(struct virtqueue *_vq) | |
2301 | { | |
1ce9e605 TB |
2302 | struct vring_virtqueue *vq = to_vvq(_vq); |
2303 | ||
8d622d21 MT |
2304 | /* If device triggered an event already it won't trigger one again: |
2305 | * no need to disable. | |
2306 | */ | |
2307 | if (vq->event_triggered) | |
2308 | return; | |
2309 | ||
1ce9e605 TB |
2310 | if (vq->packed_ring) |
2311 | virtqueue_disable_cb_packed(_vq); | |
2312 | else | |
2313 | virtqueue_disable_cb_split(_vq); | |
e6f633e5 TB |
2314 | } |
2315 | EXPORT_SYMBOL_GPL(virtqueue_disable_cb); | |
2316 | ||
2317 | /** | |
2318 | * virtqueue_enable_cb_prepare - restart callbacks after disable_cb | |
a5581206 | 2319 | * @_vq: the struct virtqueue we're talking about. |
e6f633e5 TB |
2320 | * |
2321 | * This re-enables callbacks; it returns current queue state | |
2322 | * in an opaque unsigned value. This value should be later tested by | |
2323 | * virtqueue_poll, to detect a possible race between the driver checking for | |
2324 | * more work, and enabling callbacks. | |
2325 | * | |
2326 | * Caller must ensure we don't call this with other virtqueue | |
2327 | * operations at the same time (except where noted). | |
2328 | */ | |
31532340 | 2329 | unsigned int virtqueue_enable_cb_prepare(struct virtqueue *_vq) |
e6f633e5 | 2330 | { |
1ce9e605 TB |
2331 | struct vring_virtqueue *vq = to_vvq(_vq); |
2332 | ||
8d622d21 MT |
2333 | if (vq->event_triggered) |
2334 | vq->event_triggered = false; | |
2335 | ||
1ce9e605 TB |
2336 | return vq->packed_ring ? virtqueue_enable_cb_prepare_packed(_vq) : |
2337 | virtqueue_enable_cb_prepare_split(_vq); | |
e6f633e5 TB |
2338 | } |
2339 | EXPORT_SYMBOL_GPL(virtqueue_enable_cb_prepare); | |
2340 | ||
2341 | /** | |
2342 | * virtqueue_poll - query pending used buffers | |
a5581206 | 2343 | * @_vq: the struct virtqueue we're talking about. |
e6f633e5 TB |
2344 | * @last_used_idx: virtqueue state (from call to virtqueue_enable_cb_prepare). |
2345 | * | |
2346 | * Returns "true" if there are pending used buffers in the queue. | |
2347 | * | |
2348 | * This does not need to be serialized. | |
2349 | */ | |
31532340 | 2350 | bool virtqueue_poll(struct virtqueue *_vq, unsigned int last_used_idx) |
e6f633e5 TB |
2351 | { |
2352 | struct vring_virtqueue *vq = to_vvq(_vq); | |
2353 | ||
481a0d74 MW |
2354 | if (unlikely(vq->broken)) |
2355 | return false; | |
2356 | ||
e6f633e5 | 2357 | virtio_mb(vq->weak_barriers); |
1ce9e605 TB |
2358 | return vq->packed_ring ? virtqueue_poll_packed(_vq, last_used_idx) : |
2359 | virtqueue_poll_split(_vq, last_used_idx); | |
e6f633e5 TB |
2360 | } |
2361 | EXPORT_SYMBOL_GPL(virtqueue_poll); | |
2362 | ||
2363 | /** | |
2364 | * virtqueue_enable_cb - restart callbacks after disable_cb. | |
a5581206 | 2365 | * @_vq: the struct virtqueue we're talking about. |
e6f633e5 TB |
2366 | * |
2367 | * This re-enables callbacks; it returns "false" if there are pending | |
2368 | * buffers in the queue, to detect a possible race between the driver | |
2369 | * checking for more work, and enabling callbacks. | |
2370 | * | |
2371 | * Caller must ensure we don't call this with other virtqueue | |
2372 | * operations at the same time (except where noted). | |
2373 | */ | |
2374 | bool virtqueue_enable_cb(struct virtqueue *_vq) | |
2375 | { | |
31532340 | 2376 | unsigned int last_used_idx = virtqueue_enable_cb_prepare(_vq); |
e6f633e5 TB |
2377 | |
2378 | return !virtqueue_poll(_vq, last_used_idx); | |
2379 | } | |
2380 | EXPORT_SYMBOL_GPL(virtqueue_enable_cb); | |
2381 | ||
2382 | /** | |
2383 | * virtqueue_enable_cb_delayed - restart callbacks after disable_cb. | |
a5581206 | 2384 | * @_vq: the struct virtqueue we're talking about. |
e6f633e5 TB |
2385 | * |
2386 | * This re-enables callbacks but hints to the other side to delay | |
2387 | * interrupts until most of the available buffers have been processed; | |
2388 | * it returns "false" if there are many pending buffers in the queue, | |
2389 | * to detect a possible race between the driver checking for more work, | |
2390 | * and enabling callbacks. | |
2391 | * | |
2392 | * Caller must ensure we don't call this with other virtqueue | |
2393 | * operations at the same time (except where noted). | |
2394 | */ | |
2395 | bool virtqueue_enable_cb_delayed(struct virtqueue *_vq) | |
2396 | { | |
1ce9e605 TB |
2397 | struct vring_virtqueue *vq = to_vvq(_vq); |
2398 | ||
8d622d21 MT |
2399 | if (vq->event_triggered) |
2400 | vq->event_triggered = false; | |
2401 | ||
1ce9e605 TB |
2402 | return vq->packed_ring ? virtqueue_enable_cb_delayed_packed(_vq) : |
2403 | virtqueue_enable_cb_delayed_split(_vq); | |
e6f633e5 TB |
2404 | } |
2405 | EXPORT_SYMBOL_GPL(virtqueue_enable_cb_delayed); | |
2406 | ||
138fd251 TB |
2407 | /** |
2408 | * virtqueue_detach_unused_buf - detach first unused buffer | |
a5581206 | 2409 | * @_vq: the struct virtqueue we're talking about. |
138fd251 TB |
2410 | * |
2411 | * Returns NULL or the "data" token handed to virtqueue_add_*(). | |
a62eecb3 XZ |
2412 | * This is not valid on an active queue; it is useful for device |
2413 | * shutdown or the reset queue. | |
138fd251 TB |
2414 | */ |
2415 | void *virtqueue_detach_unused_buf(struct virtqueue *_vq) | |
2416 | { | |
1ce9e605 TB |
2417 | struct vring_virtqueue *vq = to_vvq(_vq); |
2418 | ||
2419 | return vq->packed_ring ? virtqueue_detach_unused_buf_packed(_vq) : | |
2420 | virtqueue_detach_unused_buf_split(_vq); | |
138fd251 | 2421 | } |
7c5e9ed0 | 2422 | EXPORT_SYMBOL_GPL(virtqueue_detach_unused_buf); |
c021eac4 | 2423 | |
138fd251 TB |
2424 | static inline bool more_used(const struct vring_virtqueue *vq) |
2425 | { | |
1ce9e605 | 2426 | return vq->packed_ring ? more_used_packed(vq) : more_used_split(vq); |
138fd251 TB |
2427 | } |
2428 | ||
0a8a69dd RR |
2429 | irqreturn_t vring_interrupt(int irq, void *_vq) |
2430 | { | |
2431 | struct vring_virtqueue *vq = to_vvq(_vq); | |
2432 | ||
2433 | if (!more_used(vq)) { | |
2434 | pr_debug("virtqueue interrupt with no work for %p\n", vq); | |
2435 | return IRQ_NONE; | |
2436 | } | |
2437 | ||
8b4ec69d | 2438 | if (unlikely(vq->broken)) { |
c346dae4 | 2439 | #ifdef CONFIG_VIRTIO_HARDEN_NOTIFICATION |
8b4ec69d JW |
2440 | dev_warn_once(&vq->vq.vdev->dev, |
2441 | "virtio vring IRQ raised before DRIVER_OK"); | |
2442 | return IRQ_NONE; | |
c346dae4 JW |
2443 | #else |
2444 | return IRQ_HANDLED; | |
2445 | #endif | |
8b4ec69d | 2446 | } |
0a8a69dd | 2447 | |
8d622d21 MT |
2448 | /* Just a hint for performance: so it's ok that this can be racy! */ |
2449 | if (vq->event) | |
2450 | vq->event_triggered = true; | |
2451 | ||
0a8a69dd | 2452 | pr_debug("virtqueue callback for %p (%p)\n", vq, vq->vq.callback); |
18445c4d RR |
2453 | if (vq->vq.callback) |
2454 | vq->vq.callback(&vq->vq); | |
0a8a69dd RR |
2455 | |
2456 | return IRQ_HANDLED; | |
2457 | } | |
c6fd4701 | 2458 | EXPORT_SYMBOL_GPL(vring_interrupt); |
0a8a69dd | 2459 | |
1ce9e605 | 2460 | /* Only available for split ring */ |
07d9629d | 2461 | static struct virtqueue *__vring_new_virtqueue(unsigned int index, |
cd4c812a | 2462 | struct vring_virtqueue_split *vring_split, |
07d9629d XZ |
2463 | struct virtio_device *vdev, |
2464 | bool weak_barriers, | |
2465 | bool context, | |
2466 | bool (*notify)(struct virtqueue *), | |
2467 | void (*callback)(struct virtqueue *), | |
2468 | const char *name) | |
0a8a69dd | 2469 | { |
2a2d1382 | 2470 | struct vring_virtqueue *vq; |
a2b36c8d | 2471 | int err; |
0a8a69dd | 2472 | |
1ce9e605 TB |
2473 | if (virtio_has_feature(vdev, VIRTIO_F_RING_PACKED)) |
2474 | return NULL; | |
2475 | ||
cbeedb72 | 2476 | vq = kmalloc(sizeof(*vq), GFP_KERNEL); |
0a8a69dd RR |
2477 | if (!vq) |
2478 | return NULL; | |
2479 | ||
1ce9e605 | 2480 | vq->packed_ring = false; |
0a8a69dd RR |
2481 | vq->vq.callback = callback; |
2482 | vq->vq.vdev = vdev; | |
9499f5e7 | 2483 | vq->vq.name = name; |
06ca287d | 2484 | vq->vq.index = index; |
4913e854 | 2485 | vq->vq.reset = false; |
2a2d1382 | 2486 | vq->we_own_ring = false; |
0a8a69dd | 2487 | vq->notify = notify; |
7b21e34f | 2488 | vq->weak_barriers = weak_barriers; |
c346dae4 | 2489 | #ifdef CONFIG_VIRTIO_HARDEN_NOTIFICATION |
8b4ec69d | 2490 | vq->broken = true; |
c346dae4 JW |
2491 | #else |
2492 | vq->broken = false; | |
2493 | #endif | |
fb3fba6b | 2494 | vq->use_dma_api = vring_use_dma_api(vdev); |
0a8a69dd | 2495 | |
5a08b04f MT |
2496 | vq->indirect = virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC) && |
2497 | !context; | |
a5c262c5 | 2498 | vq->event = virtio_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX); |
9fa29b9d | 2499 | |
45383fb0 TB |
2500 | if (virtio_has_feature(vdev, VIRTIO_F_ORDER_PLATFORM)) |
2501 | vq->weak_barriers = false; | |
2502 | ||
a2b36c8d XZ |
2503 | err = vring_alloc_state_extra_split(vring_split); |
2504 | if (err) { | |
2505 | kfree(vq); | |
2506 | return NULL; | |
2507 | } | |
72b5e895 | 2508 | |
198fa7be XZ |
2509 | virtqueue_vring_init_split(vring_split, vq); |
2510 | ||
cd4c812a | 2511 | virtqueue_init(vq, vring_split->vring.num); |
e1d6a423 | 2512 | virtqueue_vring_attach_split(vq, vring_split); |
3a897128 | 2513 | |
0e566c8f | 2514 | spin_lock(&vdev->vqs_list_lock); |
e152d8af | 2515 | list_add_tail(&vq->vq.list, &vdev->vqs); |
0e566c8f | 2516 | spin_unlock(&vdev->vqs_list_lock); |
0a8a69dd RR |
2517 | return &vq->vq; |
2518 | } | |
2a2d1382 | 2519 | |
2a2d1382 AL |
2520 | struct virtqueue *vring_create_virtqueue( |
2521 | unsigned int index, | |
2522 | unsigned int num, | |
2523 | unsigned int vring_align, | |
2524 | struct virtio_device *vdev, | |
2525 | bool weak_barriers, | |
2526 | bool may_reduce_num, | |
f94682dd | 2527 | bool context, |
2a2d1382 AL |
2528 | bool (*notify)(struct virtqueue *), |
2529 | void (*callback)(struct virtqueue *), | |
2530 | const char *name) | |
2531 | { | |
1ce9e605 TB |
2532 | |
2533 | if (virtio_has_feature(vdev, VIRTIO_F_RING_PACKED)) | |
2534 | return vring_create_virtqueue_packed(index, num, vring_align, | |
2535 | vdev, weak_barriers, may_reduce_num, | |
2536 | context, notify, callback, name); | |
2537 | ||
d79dca75 TB |
2538 | return vring_create_virtqueue_split(index, num, vring_align, |
2539 | vdev, weak_barriers, may_reduce_num, | |
2540 | context, notify, callback, name); | |
2a2d1382 AL |
2541 | } |
2542 | EXPORT_SYMBOL_GPL(vring_create_virtqueue); | |
2543 | ||
c790e8e1 XZ |
2544 | /** |
2545 | * virtqueue_resize - resize the vring of vq | |
2546 | * @_vq: the struct virtqueue we're talking about. | |
2547 | * @num: new ring num | |
2548 | * @recycle: callback for recycle the useless buffer | |
2549 | * | |
2550 | * When it is really necessary to create a new vring, it will set the current vq | |
2551 | * into the reset state. Then call the passed callback to recycle the buffer | |
2552 | * that is no longer used. Only after the new vring is successfully created, the | |
2553 | * old vring will be released. | |
2554 | * | |
2555 | * Caller must ensure we don't call this with other virtqueue operations | |
2556 | * at the same time (except where noted). | |
2557 | * | |
2558 | * Returns zero or a negative error. | |
2559 | * 0: success. | |
2560 | * -ENOMEM: Failed to allocate a new ring, fall back to the original ring size. | |
2561 | * vq can still work normally | |
2562 | * -EBUSY: Failed to sync with device, vq may not work properly | |
2563 | * -ENOENT: Transport or device not supported | |
2564 | * -E2BIG/-EINVAL: num error | |
2565 | * -EPERM: Operation not permitted | |
2566 | * | |
2567 | */ | |
2568 | int virtqueue_resize(struct virtqueue *_vq, u32 num, | |
2569 | void (*recycle)(struct virtqueue *vq, void *buf)) | |
2570 | { | |
2571 | struct vring_virtqueue *vq = to_vvq(_vq); | |
2572 | struct virtio_device *vdev = vq->vq.vdev; | |
2573 | void *buf; | |
2574 | int err; | |
2575 | ||
2576 | if (!vq->we_own_ring) | |
2577 | return -EPERM; | |
2578 | ||
2579 | if (num > vq->vq.num_max) | |
2580 | return -E2BIG; | |
2581 | ||
2582 | if (!num) | |
2583 | return -EINVAL; | |
2584 | ||
2585 | if ((vq->packed_ring ? vq->packed.vring.num : vq->split.vring.num) == num) | |
2586 | return 0; | |
2587 | ||
2588 | if (!vdev->config->disable_vq_and_reset) | |
2589 | return -ENOENT; | |
2590 | ||
2591 | if (!vdev->config->enable_vq_after_reset) | |
2592 | return -ENOENT; | |
2593 | ||
2594 | err = vdev->config->disable_vq_and_reset(_vq); | |
2595 | if (err) | |
2596 | return err; | |
2597 | ||
2598 | while ((buf = virtqueue_detach_unused_buf(_vq)) != NULL) | |
2599 | recycle(_vq, buf); | |
2600 | ||
2601 | if (vq->packed_ring) | |
2602 | err = virtqueue_resize_packed(_vq, num); | |
2603 | else | |
2604 | err = virtqueue_resize_split(_vq, num); | |
2605 | ||
2606 | if (vdev->config->enable_vq_after_reset(_vq)) | |
2607 | return -EBUSY; | |
2608 | ||
2609 | return err; | |
2610 | } | |
2611 | EXPORT_SYMBOL_GPL(virtqueue_resize); | |
2612 | ||
1ce9e605 | 2613 | /* Only available for split ring */ |
2a2d1382 AL |
2614 | struct virtqueue *vring_new_virtqueue(unsigned int index, |
2615 | unsigned int num, | |
2616 | unsigned int vring_align, | |
2617 | struct virtio_device *vdev, | |
2618 | bool weak_barriers, | |
f94682dd | 2619 | bool context, |
2a2d1382 AL |
2620 | void *pages, |
2621 | bool (*notify)(struct virtqueue *vq), | |
2622 | void (*callback)(struct virtqueue *vq), | |
2623 | const char *name) | |
2624 | { | |
cd4c812a | 2625 | struct vring_virtqueue_split vring_split = {}; |
1ce9e605 TB |
2626 | |
2627 | if (virtio_has_feature(vdev, VIRTIO_F_RING_PACKED)) | |
2628 | return NULL; | |
2629 | ||
cd4c812a XZ |
2630 | vring_init(&vring_split.vring, num, pages, vring_align); |
2631 | return __vring_new_virtqueue(index, &vring_split, vdev, weak_barriers, | |
2632 | context, notify, callback, name); | |
2a2d1382 | 2633 | } |
c6fd4701 | 2634 | EXPORT_SYMBOL_GPL(vring_new_virtqueue); |
0a8a69dd | 2635 | |
3ea19e32 | 2636 | static void vring_free(struct virtqueue *_vq) |
0a8a69dd | 2637 | { |
2a2d1382 AL |
2638 | struct vring_virtqueue *vq = to_vvq(_vq); |
2639 | ||
2640 | if (vq->we_own_ring) { | |
1ce9e605 TB |
2641 | if (vq->packed_ring) { |
2642 | vring_free_queue(vq->vq.vdev, | |
2643 | vq->packed.ring_size_in_bytes, | |
2644 | vq->packed.vring.desc, | |
2645 | vq->packed.ring_dma_addr); | |
2646 | ||
2647 | vring_free_queue(vq->vq.vdev, | |
2648 | vq->packed.event_size_in_bytes, | |
2649 | vq->packed.vring.driver, | |
2650 | vq->packed.driver_event_dma_addr); | |
2651 | ||
2652 | vring_free_queue(vq->vq.vdev, | |
2653 | vq->packed.event_size_in_bytes, | |
2654 | vq->packed.vring.device, | |
2655 | vq->packed.device_event_dma_addr); | |
2656 | ||
2657 | kfree(vq->packed.desc_state); | |
2658 | kfree(vq->packed.desc_extra); | |
2659 | } else { | |
2660 | vring_free_queue(vq->vq.vdev, | |
2661 | vq->split.queue_size_in_bytes, | |
2662 | vq->split.vring.desc, | |
2663 | vq->split.queue_dma_addr); | |
1ce9e605 | 2664 | } |
2a2d1382 | 2665 | } |
72b5e895 | 2666 | if (!vq->packed_ring) { |
f13f09a1 | 2667 | kfree(vq->split.desc_state); |
72b5e895 JW |
2668 | kfree(vq->split.desc_extra); |
2669 | } | |
3ea19e32 XZ |
2670 | } |
2671 | ||
2672 | void vring_del_virtqueue(struct virtqueue *_vq) | |
2673 | { | |
2674 | struct vring_virtqueue *vq = to_vvq(_vq); | |
2675 | ||
2676 | spin_lock(&vq->vq.vdev->vqs_list_lock); | |
2677 | list_del(&_vq->list); | |
2678 | spin_unlock(&vq->vq.vdev->vqs_list_lock); | |
2679 | ||
2680 | vring_free(_vq); | |
2681 | ||
2a2d1382 | 2682 | kfree(vq); |
0a8a69dd | 2683 | } |
c6fd4701 | 2684 | EXPORT_SYMBOL_GPL(vring_del_virtqueue); |
0a8a69dd | 2685 | |
e34f8725 RR |
2686 | /* Manipulates transport-specific feature bits. */ |
2687 | void vring_transport_features(struct virtio_device *vdev) | |
2688 | { | |
2689 | unsigned int i; | |
2690 | ||
2691 | for (i = VIRTIO_TRANSPORT_F_START; i < VIRTIO_TRANSPORT_F_END; i++) { | |
2692 | switch (i) { | |
9fa29b9d MM |
2693 | case VIRTIO_RING_F_INDIRECT_DESC: |
2694 | break; | |
a5c262c5 MT |
2695 | case VIRTIO_RING_F_EVENT_IDX: |
2696 | break; | |
747ae34a MT |
2697 | case VIRTIO_F_VERSION_1: |
2698 | break; | |
321bd212 | 2699 | case VIRTIO_F_ACCESS_PLATFORM: |
1a937693 | 2700 | break; |
f959a128 TB |
2701 | case VIRTIO_F_RING_PACKED: |
2702 | break; | |
45383fb0 TB |
2703 | case VIRTIO_F_ORDER_PLATFORM: |
2704 | break; | |
e34f8725 RR |
2705 | default: |
2706 | /* We don't understand this bit. */ | |
e16e12be | 2707 | __virtio_clear_bit(vdev, i); |
e34f8725 RR |
2708 | } |
2709 | } | |
2710 | } | |
2711 | EXPORT_SYMBOL_GPL(vring_transport_features); | |
2712 | ||
5dfc1762 RR |
2713 | /** |
2714 | * virtqueue_get_vring_size - return the size of the virtqueue's vring | |
a5581206 | 2715 | * @_vq: the struct virtqueue containing the vring of interest. |
5dfc1762 RR |
2716 | * |
2717 | * Returns the size of the vring. This is mainly used for boasting to | |
2718 | * userspace. Unlike other operations, this need not be serialized. | |
2719 | */ | |
8f9f4668 RJ |
2720 | unsigned int virtqueue_get_vring_size(struct virtqueue *_vq) |
2721 | { | |
2722 | ||
2723 | struct vring_virtqueue *vq = to_vvq(_vq); | |
2724 | ||
1ce9e605 | 2725 | return vq->packed_ring ? vq->packed.vring.num : vq->split.vring.num; |
8f9f4668 RJ |
2726 | } |
2727 | EXPORT_SYMBOL_GPL(virtqueue_get_vring_size); | |
2728 | ||
32510631 XZ |
2729 | /* |
2730 | * This function should only be called by the core, not directly by the driver. | |
2731 | */ | |
2732 | void __virtqueue_break(struct virtqueue *_vq) | |
2733 | { | |
2734 | struct vring_virtqueue *vq = to_vvq(_vq); | |
2735 | ||
2736 | /* Pairs with READ_ONCE() in virtqueue_is_broken(). */ | |
2737 | WRITE_ONCE(vq->broken, true); | |
2738 | } | |
2739 | EXPORT_SYMBOL_GPL(__virtqueue_break); | |
2740 | ||
2741 | /* | |
2742 | * This function should only be called by the core, not directly by the driver. | |
2743 | */ | |
2744 | void __virtqueue_unbreak(struct virtqueue *_vq) | |
2745 | { | |
2746 | struct vring_virtqueue *vq = to_vvq(_vq); | |
2747 | ||
2748 | /* Pairs with READ_ONCE() in virtqueue_is_broken(). */ | |
2749 | WRITE_ONCE(vq->broken, false); | |
2750 | } | |
2751 | EXPORT_SYMBOL_GPL(__virtqueue_unbreak); | |
2752 | ||
b3b32c94 HG |
2753 | bool virtqueue_is_broken(struct virtqueue *_vq) |
2754 | { | |
2755 | struct vring_virtqueue *vq = to_vvq(_vq); | |
2756 | ||
60f07798 | 2757 | return READ_ONCE(vq->broken); |
b3b32c94 HG |
2758 | } |
2759 | EXPORT_SYMBOL_GPL(virtqueue_is_broken); | |
2760 | ||
e2dcdfe9 RR |
2761 | /* |
2762 | * This should prevent the device from being used, allowing drivers to | |
2763 | * recover. You may need to grab appropriate locks to flush. | |
2764 | */ | |
2765 | void virtio_break_device(struct virtio_device *dev) | |
2766 | { | |
2767 | struct virtqueue *_vq; | |
2768 | ||
0e566c8f | 2769 | spin_lock(&dev->vqs_list_lock); |
e2dcdfe9 RR |
2770 | list_for_each_entry(_vq, &dev->vqs, list) { |
2771 | struct vring_virtqueue *vq = to_vvq(_vq); | |
60f07798 PP |
2772 | |
2773 | /* Pairs with READ_ONCE() in virtqueue_is_broken(). */ | |
2774 | WRITE_ONCE(vq->broken, true); | |
e2dcdfe9 | 2775 | } |
0e566c8f | 2776 | spin_unlock(&dev->vqs_list_lock); |
e2dcdfe9 RR |
2777 | } |
2778 | EXPORT_SYMBOL_GPL(virtio_break_device); | |
2779 | ||
be83f04d JW |
2780 | /* |
2781 | * This should allow the device to be used by the driver. You may | |
2782 | * need to grab appropriate locks to flush the write to | |
2783 | * vq->broken. This should only be used in some specific case e.g | |
2784 | * (probing and restoring). This function should only be called by the | |
2785 | * core, not directly by the driver. | |
2786 | */ | |
2787 | void __virtio_unbreak_device(struct virtio_device *dev) | |
2788 | { | |
2789 | struct virtqueue *_vq; | |
2790 | ||
2791 | spin_lock(&dev->vqs_list_lock); | |
2792 | list_for_each_entry(_vq, &dev->vqs, list) { | |
2793 | struct vring_virtqueue *vq = to_vvq(_vq); | |
2794 | ||
2795 | /* Pairs with READ_ONCE() in virtqueue_is_broken(). */ | |
2796 | WRITE_ONCE(vq->broken, false); | |
2797 | } | |
2798 | spin_unlock(&dev->vqs_list_lock); | |
2799 | } | |
2800 | EXPORT_SYMBOL_GPL(__virtio_unbreak_device); | |
2801 | ||
2a2d1382 | 2802 | dma_addr_t virtqueue_get_desc_addr(struct virtqueue *_vq) |
89062652 CH |
2803 | { |
2804 | struct vring_virtqueue *vq = to_vvq(_vq); | |
2805 | ||
2a2d1382 AL |
2806 | BUG_ON(!vq->we_own_ring); |
2807 | ||
1ce9e605 TB |
2808 | if (vq->packed_ring) |
2809 | return vq->packed.ring_dma_addr; | |
2810 | ||
d79dca75 | 2811 | return vq->split.queue_dma_addr; |
89062652 | 2812 | } |
2a2d1382 | 2813 | EXPORT_SYMBOL_GPL(virtqueue_get_desc_addr); |
89062652 | 2814 | |
2a2d1382 | 2815 | dma_addr_t virtqueue_get_avail_addr(struct virtqueue *_vq) |
89062652 CH |
2816 | { |
2817 | struct vring_virtqueue *vq = to_vvq(_vq); | |
2818 | ||
2a2d1382 AL |
2819 | BUG_ON(!vq->we_own_ring); |
2820 | ||
1ce9e605 TB |
2821 | if (vq->packed_ring) |
2822 | return vq->packed.driver_event_dma_addr; | |
2823 | ||
d79dca75 | 2824 | return vq->split.queue_dma_addr + |
e593bf97 | 2825 | ((char *)vq->split.vring.avail - (char *)vq->split.vring.desc); |
2a2d1382 AL |
2826 | } |
2827 | EXPORT_SYMBOL_GPL(virtqueue_get_avail_addr); | |
2828 | ||
2829 | dma_addr_t virtqueue_get_used_addr(struct virtqueue *_vq) | |
2830 | { | |
2831 | struct vring_virtqueue *vq = to_vvq(_vq); | |
2832 | ||
2833 | BUG_ON(!vq->we_own_ring); | |
2834 | ||
1ce9e605 TB |
2835 | if (vq->packed_ring) |
2836 | return vq->packed.device_event_dma_addr; | |
2837 | ||
d79dca75 | 2838 | return vq->split.queue_dma_addr + |
e593bf97 | 2839 | ((char *)vq->split.vring.used - (char *)vq->split.vring.desc); |
2a2d1382 AL |
2840 | } |
2841 | EXPORT_SYMBOL_GPL(virtqueue_get_used_addr); | |
2842 | ||
1ce9e605 | 2843 | /* Only available for split ring */ |
2a2d1382 AL |
2844 | const struct vring *virtqueue_get_vring(struct virtqueue *vq) |
2845 | { | |
e593bf97 | 2846 | return &to_vvq(vq)->split.vring; |
89062652 | 2847 | } |
2a2d1382 | 2848 | EXPORT_SYMBOL_GPL(virtqueue_get_vring); |
89062652 | 2849 | |
c6fd4701 | 2850 | MODULE_LICENSE("GPL"); |