Commit | Line | Data |
---|---|---|
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> |
78fe3987 | 14 | #include <xen/xen.h> |
0a8a69dd RR |
15 | |
16 | #ifdef DEBUG | |
17 | /* For development, we want to crash whenever the ring is screwed. */ | |
9499f5e7 RR |
18 | #define BAD_RING(_vq, fmt, args...) \ |
19 | do { \ | |
20 | dev_err(&(_vq)->vq.vdev->dev, \ | |
21 | "%s:"fmt, (_vq)->vq.name, ##args); \ | |
22 | BUG(); \ | |
23 | } while (0) | |
c5f841f1 RR |
24 | /* Caller is supposed to guarantee no reentry. */ |
25 | #define START_USE(_vq) \ | |
26 | do { \ | |
27 | if ((_vq)->in_use) \ | |
9499f5e7 RR |
28 | panic("%s:in_use = %i\n", \ |
29 | (_vq)->vq.name, (_vq)->in_use); \ | |
c5f841f1 | 30 | (_vq)->in_use = __LINE__; \ |
9499f5e7 | 31 | } while (0) |
3a35ce7d | 32 | #define END_USE(_vq) \ |
97a545ab | 33 | do { BUG_ON(!(_vq)->in_use); (_vq)->in_use = 0; } while(0) |
4d6a105e TB |
34 | #define LAST_ADD_TIME_UPDATE(_vq) \ |
35 | do { \ | |
36 | ktime_t now = ktime_get(); \ | |
37 | \ | |
38 | /* No kick or get, with .1 second between? Warn. */ \ | |
39 | if ((_vq)->last_add_time_valid) \ | |
40 | WARN_ON(ktime_to_ms(ktime_sub(now, \ | |
41 | (_vq)->last_add_time)) > 100); \ | |
42 | (_vq)->last_add_time = now; \ | |
43 | (_vq)->last_add_time_valid = true; \ | |
44 | } while (0) | |
45 | #define LAST_ADD_TIME_CHECK(_vq) \ | |
46 | do { \ | |
47 | if ((_vq)->last_add_time_valid) { \ | |
48 | WARN_ON(ktime_to_ms(ktime_sub(ktime_get(), \ | |
49 | (_vq)->last_add_time)) > 100); \ | |
50 | } \ | |
51 | } while (0) | |
52 | #define LAST_ADD_TIME_INVALID(_vq) \ | |
53 | ((_vq)->last_add_time_valid = false) | |
0a8a69dd | 54 | #else |
9499f5e7 RR |
55 | #define BAD_RING(_vq, fmt, args...) \ |
56 | do { \ | |
57 | dev_err(&_vq->vq.vdev->dev, \ | |
58 | "%s:"fmt, (_vq)->vq.name, ##args); \ | |
59 | (_vq)->broken = true; \ | |
60 | } while (0) | |
0a8a69dd RR |
61 | #define START_USE(vq) |
62 | #define END_USE(vq) | |
4d6a105e TB |
63 | #define LAST_ADD_TIME_UPDATE(vq) |
64 | #define LAST_ADD_TIME_CHECK(vq) | |
65 | #define LAST_ADD_TIME_INVALID(vq) | |
0a8a69dd RR |
66 | #endif |
67 | ||
cbeedb72 | 68 | struct vring_desc_state_split { |
780bc790 AL |
69 | void *data; /* Data for callback. */ |
70 | struct vring_desc *indir_desc; /* Indirect descriptor, if any. */ | |
71 | }; | |
72 | ||
1ce9e605 TB |
73 | struct vring_desc_state_packed { |
74 | void *data; /* Data for callback. */ | |
75 | struct vring_packed_desc *indir_desc; /* Indirect descriptor, if any. */ | |
76 | u16 num; /* Descriptor list length. */ | |
1ce9e605 TB |
77 | u16 last; /* The last desc state in a list. */ |
78 | }; | |
79 | ||
1f28750f | 80 | struct vring_desc_extra { |
1ce9e605 TB |
81 | dma_addr_t addr; /* Buffer DMA addr. */ |
82 | u32 len; /* Buffer length. */ | |
83 | u16 flags; /* Descriptor flags. */ | |
aeef9b47 | 84 | u16 next; /* The next desc state in a list. */ |
1ce9e605 TB |
85 | }; |
86 | ||
43b4f721 | 87 | struct vring_virtqueue { |
0a8a69dd RR |
88 | struct virtqueue vq; |
89 | ||
1ce9e605 TB |
90 | /* Is this a packed ring? */ |
91 | bool packed_ring; | |
92 | ||
fb3fba6b TB |
93 | /* Is DMA API used? */ |
94 | bool use_dma_api; | |
95 | ||
7b21e34f RR |
96 | /* Can we use weak barriers? */ |
97 | bool weak_barriers; | |
98 | ||
0a8a69dd RR |
99 | /* Other side has made a mess, don't try any more. */ |
100 | bool broken; | |
101 | ||
9fa29b9d MM |
102 | /* Host supports indirect buffers */ |
103 | bool indirect; | |
104 | ||
a5c262c5 MT |
105 | /* Host publishes avail event idx */ |
106 | bool event; | |
107 | ||
0a8a69dd RR |
108 | /* Head of free buffer list. */ |
109 | unsigned int free_head; | |
110 | /* Number we've added since last sync. */ | |
111 | unsigned int num_added; | |
112 | ||
113 | /* Last used index we've seen. */ | |
1bc4953e | 114 | u16 last_used_idx; |
0a8a69dd | 115 | |
8d622d21 MT |
116 | /* Hint for event idx: already triggered no need to disable. */ |
117 | bool event_triggered; | |
118 | ||
1ce9e605 TB |
119 | union { |
120 | /* Available for split ring */ | |
121 | struct { | |
122 | /* Actual memory layout for this queue. */ | |
123 | struct vring vring; | |
124 | ||
125 | /* Last written value to avail->flags */ | |
126 | u16 avail_flags_shadow; | |
f277ec42 | 127 | |
1ce9e605 TB |
128 | /* |
129 | * Last written value to avail->idx in | |
130 | * guest byte order. | |
131 | */ | |
132 | u16 avail_idx_shadow; | |
133 | ||
134 | /* Per-descriptor state. */ | |
135 | struct vring_desc_state_split *desc_state; | |
136 | ||
137 | /* DMA address and size information */ | |
138 | dma_addr_t queue_dma_addr; | |
139 | size_t queue_size_in_bytes; | |
140 | } split; | |
e593bf97 | 141 | |
1ce9e605 TB |
142 | /* Available for packed ring */ |
143 | struct { | |
144 | /* Actual memory layout for this queue. */ | |
9c0644ee MT |
145 | struct { |
146 | unsigned int num; | |
147 | struct vring_packed_desc *desc; | |
148 | struct vring_packed_desc_event *driver; | |
149 | struct vring_packed_desc_event *device; | |
150 | } vring; | |
cbeedb72 | 151 | |
1ce9e605 TB |
152 | /* Driver ring wrap counter. */ |
153 | bool avail_wrap_counter; | |
d79dca75 | 154 | |
1ce9e605 TB |
155 | /* Device ring wrap counter. */ |
156 | bool used_wrap_counter; | |
157 | ||
158 | /* Avail used flags. */ | |
159 | u16 avail_used_flags; | |
160 | ||
161 | /* Index of the next avail descriptor. */ | |
162 | u16 next_avail_idx; | |
163 | ||
164 | /* | |
165 | * Last written value to driver->flags in | |
166 | * guest byte order. | |
167 | */ | |
168 | u16 event_flags_shadow; | |
169 | ||
170 | /* Per-descriptor state. */ | |
171 | struct vring_desc_state_packed *desc_state; | |
1f28750f | 172 | struct vring_desc_extra *desc_extra; |
1ce9e605 TB |
173 | |
174 | /* DMA address and size information */ | |
175 | dma_addr_t ring_dma_addr; | |
176 | dma_addr_t driver_event_dma_addr; | |
177 | dma_addr_t device_event_dma_addr; | |
178 | size_t ring_size_in_bytes; | |
179 | size_t event_size_in_bytes; | |
180 | } packed; | |
181 | }; | |
f277ec42 | 182 | |
0a8a69dd | 183 | /* How to notify other side. FIXME: commonalize hcalls! */ |
46f9c2b9 | 184 | bool (*notify)(struct virtqueue *vq); |
0a8a69dd | 185 | |
2a2d1382 AL |
186 | /* DMA, allocation, and size information */ |
187 | bool we_own_ring; | |
2a2d1382 | 188 | |
0a8a69dd RR |
189 | #ifdef DEBUG |
190 | /* They're supposed to lock for us. */ | |
191 | unsigned int in_use; | |
e93300b1 RR |
192 | |
193 | /* Figure out if their kicks are too delayed. */ | |
194 | bool last_add_time_valid; | |
195 | ktime_t last_add_time; | |
0a8a69dd | 196 | #endif |
0a8a69dd RR |
197 | }; |
198 | ||
e6f633e5 TB |
199 | |
200 | /* | |
201 | * Helpers. | |
202 | */ | |
203 | ||
0a8a69dd RR |
204 | #define to_vvq(_vq) container_of(_vq, struct vring_virtqueue, vq) |
205 | ||
2f18c2d1 TB |
206 | static inline bool virtqueue_use_indirect(struct virtqueue *_vq, |
207 | unsigned int total_sg) | |
208 | { | |
209 | struct vring_virtqueue *vq = to_vvq(_vq); | |
210 | ||
211 | /* | |
212 | * If the host supports indirect descriptor tables, and we have multiple | |
213 | * buffers, then go indirect. FIXME: tune this threshold | |
214 | */ | |
215 | return (vq->indirect && total_sg > 1 && vq->vq.num_free); | |
216 | } | |
217 | ||
d26c96c8 | 218 | /* |
1a937693 MT |
219 | * Modern virtio devices have feature bits to specify whether they need a |
220 | * quirk and bypass the IOMMU. If not there, just use the DMA API. | |
221 | * | |
222 | * If there, the interaction between virtio and DMA API is messy. | |
d26c96c8 AL |
223 | * |
224 | * On most systems with virtio, physical addresses match bus addresses, | |
225 | * and it doesn't particularly matter whether we use the DMA API. | |
226 | * | |
227 | * On some systems, including Xen and any system with a physical device | |
228 | * that speaks virtio behind a physical IOMMU, we must use the DMA API | |
229 | * for virtio DMA to work at all. | |
230 | * | |
231 | * On other systems, including SPARC and PPC64, virtio-pci devices are | |
232 | * enumerated as though they are behind an IOMMU, but the virtio host | |
233 | * ignores the IOMMU, so we must either pretend that the IOMMU isn't | |
234 | * there or somehow map everything as the identity. | |
235 | * | |
236 | * For the time being, we preserve historic behavior and bypass the DMA | |
237 | * API. | |
1a937693 MT |
238 | * |
239 | * TODO: install a per-device DMA ops structure that does the right thing | |
240 | * taking into account all the above quirks, and use the DMA API | |
241 | * unconditionally on data path. | |
d26c96c8 AL |
242 | */ |
243 | ||
244 | static bool vring_use_dma_api(struct virtio_device *vdev) | |
245 | { | |
24b6842a | 246 | if (!virtio_has_dma_quirk(vdev)) |
1a937693 MT |
247 | return true; |
248 | ||
249 | /* Otherwise, we are left to guess. */ | |
78fe3987 AL |
250 | /* |
251 | * In theory, it's possible to have a buggy QEMU-supposed | |
252 | * emulated Q35 IOMMU and Xen enabled at the same time. On | |
253 | * such a configuration, virtio has never worked and will | |
254 | * not work without an even larger kludge. Instead, enable | |
255 | * the DMA API if we're a Xen guest, which at least allows | |
256 | * all of the sensible Xen configurations to work correctly. | |
257 | */ | |
258 | if (xen_domain()) | |
259 | return true; | |
260 | ||
d26c96c8 AL |
261 | return false; |
262 | } | |
263 | ||
e6d6dd6c JR |
264 | size_t virtio_max_dma_size(struct virtio_device *vdev) |
265 | { | |
266 | size_t max_segment_size = SIZE_MAX; | |
267 | ||
268 | if (vring_use_dma_api(vdev)) | |
269 | max_segment_size = dma_max_mapping_size(&vdev->dev); | |
270 | ||
271 | return max_segment_size; | |
272 | } | |
273 | EXPORT_SYMBOL_GPL(virtio_max_dma_size); | |
274 | ||
d79dca75 TB |
275 | static void *vring_alloc_queue(struct virtio_device *vdev, size_t size, |
276 | dma_addr_t *dma_handle, gfp_t flag) | |
277 | { | |
278 | if (vring_use_dma_api(vdev)) { | |
279 | return dma_alloc_coherent(vdev->dev.parent, size, | |
280 | dma_handle, flag); | |
281 | } else { | |
282 | void *queue = alloc_pages_exact(PAGE_ALIGN(size), flag); | |
283 | ||
284 | if (queue) { | |
285 | phys_addr_t phys_addr = virt_to_phys(queue); | |
286 | *dma_handle = (dma_addr_t)phys_addr; | |
287 | ||
288 | /* | |
289 | * Sanity check: make sure we dind't truncate | |
290 | * the address. The only arches I can find that | |
291 | * have 64-bit phys_addr_t but 32-bit dma_addr_t | |
292 | * are certain non-highmem MIPS and x86 | |
293 | * configurations, but these configurations | |
294 | * should never allocate physical pages above 32 | |
295 | * bits, so this is fine. Just in case, throw a | |
296 | * warning and abort if we end up with an | |
297 | * unrepresentable address. | |
298 | */ | |
299 | if (WARN_ON_ONCE(*dma_handle != phys_addr)) { | |
300 | free_pages_exact(queue, PAGE_ALIGN(size)); | |
301 | return NULL; | |
302 | } | |
303 | } | |
304 | return queue; | |
305 | } | |
306 | } | |
307 | ||
308 | static void vring_free_queue(struct virtio_device *vdev, size_t size, | |
309 | void *queue, dma_addr_t dma_handle) | |
310 | { | |
311 | if (vring_use_dma_api(vdev)) | |
312 | dma_free_coherent(vdev->dev.parent, size, queue, dma_handle); | |
313 | else | |
314 | free_pages_exact(queue, PAGE_ALIGN(size)); | |
315 | } | |
316 | ||
780bc790 AL |
317 | /* |
318 | * The DMA ops on various arches are rather gnarly right now, and | |
319 | * making all of the arch DMA ops work on the vring device itself | |
320 | * is a mess. For now, we use the parent device for DMA ops. | |
321 | */ | |
75bfa81b | 322 | static inline struct device *vring_dma_dev(const struct vring_virtqueue *vq) |
780bc790 AL |
323 | { |
324 | return vq->vq.vdev->dev.parent; | |
325 | } | |
326 | ||
327 | /* Map one sg entry. */ | |
328 | static dma_addr_t vring_map_one_sg(const struct vring_virtqueue *vq, | |
329 | struct scatterlist *sg, | |
330 | enum dma_data_direction direction) | |
331 | { | |
fb3fba6b | 332 | if (!vq->use_dma_api) |
780bc790 AL |
333 | return (dma_addr_t)sg_phys(sg); |
334 | ||
335 | /* | |
336 | * We can't use dma_map_sg, because we don't use scatterlists in | |
337 | * the way it expects (we don't guarantee that the scatterlist | |
338 | * will exist for the lifetime of the mapping). | |
339 | */ | |
340 | return dma_map_page(vring_dma_dev(vq), | |
341 | sg_page(sg), sg->offset, sg->length, | |
342 | direction); | |
343 | } | |
344 | ||
345 | static dma_addr_t vring_map_single(const struct vring_virtqueue *vq, | |
346 | void *cpu_addr, size_t size, | |
347 | enum dma_data_direction direction) | |
348 | { | |
fb3fba6b | 349 | if (!vq->use_dma_api) |
780bc790 AL |
350 | return (dma_addr_t)virt_to_phys(cpu_addr); |
351 | ||
352 | return dma_map_single(vring_dma_dev(vq), | |
353 | cpu_addr, size, direction); | |
354 | } | |
355 | ||
e6f633e5 TB |
356 | static int vring_mapping_error(const struct vring_virtqueue *vq, |
357 | dma_addr_t addr) | |
358 | { | |
fb3fba6b | 359 | if (!vq->use_dma_api) |
e6f633e5 TB |
360 | return 0; |
361 | ||
362 | return dma_mapping_error(vring_dma_dev(vq), addr); | |
363 | } | |
364 | ||
365 | ||
366 | /* | |
367 | * Split ring specific functions - *_split(). | |
368 | */ | |
369 | ||
138fd251 TB |
370 | static void vring_unmap_one_split(const struct vring_virtqueue *vq, |
371 | struct vring_desc *desc) | |
780bc790 AL |
372 | { |
373 | u16 flags; | |
374 | ||
fb3fba6b | 375 | if (!vq->use_dma_api) |
780bc790 AL |
376 | return; |
377 | ||
378 | flags = virtio16_to_cpu(vq->vq.vdev, desc->flags); | |
379 | ||
380 | if (flags & VRING_DESC_F_INDIRECT) { | |
381 | dma_unmap_single(vring_dma_dev(vq), | |
382 | virtio64_to_cpu(vq->vq.vdev, desc->addr), | |
383 | virtio32_to_cpu(vq->vq.vdev, desc->len), | |
384 | (flags & VRING_DESC_F_WRITE) ? | |
385 | DMA_FROM_DEVICE : DMA_TO_DEVICE); | |
386 | } else { | |
387 | dma_unmap_page(vring_dma_dev(vq), | |
388 | virtio64_to_cpu(vq->vq.vdev, desc->addr), | |
389 | virtio32_to_cpu(vq->vq.vdev, desc->len), | |
390 | (flags & VRING_DESC_F_WRITE) ? | |
391 | DMA_FROM_DEVICE : DMA_TO_DEVICE); | |
392 | } | |
393 | } | |
394 | ||
138fd251 TB |
395 | static struct vring_desc *alloc_indirect_split(struct virtqueue *_vq, |
396 | unsigned int total_sg, | |
397 | gfp_t gfp) | |
9fa29b9d MM |
398 | { |
399 | struct vring_desc *desc; | |
b25bd251 | 400 | unsigned int i; |
9fa29b9d | 401 | |
b92b1b89 WD |
402 | /* |
403 | * We require lowmem mappings for the descriptors because | |
404 | * otherwise virt_to_phys will give us bogus addresses in the | |
405 | * virtqueue. | |
406 | */ | |
82107539 | 407 | gfp &= ~__GFP_HIGHMEM; |
b92b1b89 | 408 | |
6da2ec56 | 409 | desc = kmalloc_array(total_sg, sizeof(struct vring_desc), gfp); |
9fa29b9d | 410 | if (!desc) |
b25bd251 | 411 | return NULL; |
9fa29b9d | 412 | |
b25bd251 | 413 | for (i = 0; i < total_sg; i++) |
00e6f3d9 | 414 | desc[i].next = cpu_to_virtio16(_vq->vdev, i + 1); |
b25bd251 | 415 | return desc; |
9fa29b9d MM |
416 | } |
417 | ||
fe4c3862 JW |
418 | static inline unsigned int virtqueue_add_desc_split(struct virtqueue *vq, |
419 | struct vring_desc *desc, | |
420 | unsigned int i, | |
421 | dma_addr_t addr, | |
422 | unsigned int len, | |
423 | u16 flags) | |
424 | { | |
425 | desc[i].flags = cpu_to_virtio16(vq->vdev, flags); | |
426 | desc[i].addr = cpu_to_virtio64(vq->vdev, addr); | |
427 | desc[i].len = cpu_to_virtio32(vq->vdev, len); | |
428 | ||
429 | return virtio16_to_cpu(vq->vdev, desc[i].next); | |
430 | } | |
431 | ||
138fd251 TB |
432 | static inline int virtqueue_add_split(struct virtqueue *_vq, |
433 | struct scatterlist *sgs[], | |
434 | unsigned int total_sg, | |
435 | unsigned int out_sgs, | |
436 | unsigned int in_sgs, | |
437 | void *data, | |
438 | void *ctx, | |
439 | gfp_t gfp) | |
0a8a69dd RR |
440 | { |
441 | struct vring_virtqueue *vq = to_vvq(_vq); | |
13816c76 | 442 | struct scatterlist *sg; |
b25bd251 | 443 | struct vring_desc *desc; |
3f649ab7 | 444 | unsigned int i, n, avail, descs_used, prev, err_idx; |
1fe9b6fe | 445 | int head; |
b25bd251 | 446 | bool indirect; |
0a8a69dd | 447 | |
9fa29b9d MM |
448 | START_USE(vq); |
449 | ||
0a8a69dd | 450 | BUG_ON(data == NULL); |
5a08b04f | 451 | BUG_ON(ctx && vq->indirect); |
9fa29b9d | 452 | |
70670444 RR |
453 | if (unlikely(vq->broken)) { |
454 | END_USE(vq); | |
455 | return -EIO; | |
456 | } | |
457 | ||
4d6a105e | 458 | LAST_ADD_TIME_UPDATE(vq); |
e93300b1 | 459 | |
b25bd251 RR |
460 | BUG_ON(total_sg == 0); |
461 | ||
462 | head = vq->free_head; | |
463 | ||
2f18c2d1 | 464 | if (virtqueue_use_indirect(_vq, total_sg)) |
138fd251 | 465 | desc = alloc_indirect_split(_vq, total_sg, gfp); |
44ed8089 | 466 | else { |
b25bd251 | 467 | desc = NULL; |
e593bf97 | 468 | WARN_ON_ONCE(total_sg > vq->split.vring.num && !vq->indirect); |
44ed8089 | 469 | } |
b25bd251 RR |
470 | |
471 | if (desc) { | |
472 | /* Use a single buffer which doesn't continue */ | |
780bc790 | 473 | indirect = true; |
b25bd251 RR |
474 | /* Set up rest to use this indirect table. */ |
475 | i = 0; | |
476 | descs_used = 1; | |
b25bd251 | 477 | } else { |
780bc790 | 478 | indirect = false; |
e593bf97 | 479 | desc = vq->split.vring.desc; |
b25bd251 RR |
480 | i = head; |
481 | descs_used = total_sg; | |
9fa29b9d MM |
482 | } |
483 | ||
b25bd251 | 484 | if (vq->vq.num_free < descs_used) { |
0a8a69dd | 485 | pr_debug("Can't add buf len %i - avail = %i\n", |
b25bd251 | 486 | descs_used, vq->vq.num_free); |
44653eae RR |
487 | /* FIXME: for historical reasons, we force a notify here if |
488 | * there are outgoing parts to the buffer. Presumably the | |
489 | * host should service the ring ASAP. */ | |
13816c76 | 490 | if (out_sgs) |
44653eae | 491 | vq->notify(&vq->vq); |
58625edf WY |
492 | if (indirect) |
493 | kfree(desc); | |
0a8a69dd RR |
494 | END_USE(vq); |
495 | return -ENOSPC; | |
496 | } | |
497 | ||
13816c76 | 498 | for (n = 0; n < out_sgs; n++) { |
eeebf9b1 | 499 | for (sg = sgs[n]; sg; sg = sg_next(sg)) { |
780bc790 AL |
500 | dma_addr_t addr = vring_map_one_sg(vq, sg, DMA_TO_DEVICE); |
501 | if (vring_mapping_error(vq, addr)) | |
502 | goto unmap_release; | |
503 | ||
13816c76 | 504 | prev = i; |
fe4c3862 JW |
505 | i = virtqueue_add_desc_split(_vq, desc, i, addr, sg->length, |
506 | VRING_DESC_F_NEXT); | |
13816c76 | 507 | } |
0a8a69dd | 508 | } |
13816c76 | 509 | for (; n < (out_sgs + in_sgs); n++) { |
eeebf9b1 | 510 | for (sg = sgs[n]; sg; sg = sg_next(sg)) { |
780bc790 AL |
511 | dma_addr_t addr = vring_map_one_sg(vq, sg, DMA_FROM_DEVICE); |
512 | if (vring_mapping_error(vq, addr)) | |
513 | goto unmap_release; | |
514 | ||
13816c76 | 515 | prev = i; |
fe4c3862 JW |
516 | i = virtqueue_add_desc_split(_vq, desc, i, addr, |
517 | sg->length, | |
518 | VRING_DESC_F_NEXT | | |
519 | VRING_DESC_F_WRITE); | |
13816c76 | 520 | } |
0a8a69dd RR |
521 | } |
522 | /* Last one doesn't continue. */ | |
00e6f3d9 | 523 | desc[prev].flags &= cpu_to_virtio16(_vq->vdev, ~VRING_DESC_F_NEXT); |
0a8a69dd | 524 | |
780bc790 AL |
525 | if (indirect) { |
526 | /* Now that the indirect table is filled in, map it. */ | |
527 | dma_addr_t addr = vring_map_single( | |
528 | vq, desc, total_sg * sizeof(struct vring_desc), | |
529 | DMA_TO_DEVICE); | |
530 | if (vring_mapping_error(vq, addr)) | |
531 | goto unmap_release; | |
532 | ||
fe4c3862 JW |
533 | virtqueue_add_desc_split(_vq, vq->split.vring.desc, |
534 | head, addr, | |
535 | total_sg * sizeof(struct vring_desc), | |
536 | VRING_DESC_F_INDIRECT); | |
780bc790 AL |
537 | } |
538 | ||
539 | /* We're using some buffers from the free list. */ | |
540 | vq->vq.num_free -= descs_used; | |
541 | ||
0a8a69dd | 542 | /* Update free pointer */ |
b25bd251 | 543 | if (indirect) |
e593bf97 TB |
544 | vq->free_head = virtio16_to_cpu(_vq->vdev, |
545 | vq->split.vring.desc[head].next); | |
b25bd251 RR |
546 | else |
547 | vq->free_head = i; | |
0a8a69dd | 548 | |
780bc790 | 549 | /* Store token and indirect buffer state. */ |
cbeedb72 | 550 | vq->split.desc_state[head].data = data; |
780bc790 | 551 | if (indirect) |
cbeedb72 | 552 | vq->split.desc_state[head].indir_desc = desc; |
87646a34 | 553 | else |
cbeedb72 | 554 | vq->split.desc_state[head].indir_desc = ctx; |
0a8a69dd RR |
555 | |
556 | /* Put entry in available array (but don't update avail->idx until they | |
3b720b8c | 557 | * do sync). */ |
e593bf97 TB |
558 | avail = vq->split.avail_idx_shadow & (vq->split.vring.num - 1); |
559 | vq->split.vring.avail->ring[avail] = cpu_to_virtio16(_vq->vdev, head); | |
0a8a69dd | 560 | |
ee7cd898 RR |
561 | /* Descriptors and available array need to be set before we expose the |
562 | * new available array entries. */ | |
a9a0fef7 | 563 | virtio_wmb(vq->weak_barriers); |
e593bf97 TB |
564 | vq->split.avail_idx_shadow++; |
565 | vq->split.vring.avail->idx = cpu_to_virtio16(_vq->vdev, | |
566 | vq->split.avail_idx_shadow); | |
ee7cd898 RR |
567 | vq->num_added++; |
568 | ||
5e05bf58 TH |
569 | pr_debug("Added buffer head %i to %p\n", head, vq); |
570 | END_USE(vq); | |
571 | ||
ee7cd898 RR |
572 | /* This is very unlikely, but theoretically possible. Kick |
573 | * just in case. */ | |
574 | if (unlikely(vq->num_added == (1 << 16) - 1)) | |
575 | virtqueue_kick(_vq); | |
576 | ||
98e8c6bc | 577 | return 0; |
780bc790 AL |
578 | |
579 | unmap_release: | |
580 | err_idx = i; | |
cf8f1696 ML |
581 | |
582 | if (indirect) | |
583 | i = 0; | |
584 | else | |
585 | i = head; | |
780bc790 AL |
586 | |
587 | for (n = 0; n < total_sg; n++) { | |
588 | if (i == err_idx) | |
589 | break; | |
138fd251 | 590 | vring_unmap_one_split(vq, &desc[i]); |
cf8f1696 | 591 | i = virtio16_to_cpu(_vq->vdev, desc[i].next); |
780bc790 AL |
592 | } |
593 | ||
780bc790 AL |
594 | if (indirect) |
595 | kfree(desc); | |
596 | ||
3cc36f6e | 597 | END_USE(vq); |
f7728002 | 598 | return -ENOMEM; |
0a8a69dd | 599 | } |
13816c76 | 600 | |
138fd251 | 601 | static bool virtqueue_kick_prepare_split(struct virtqueue *_vq) |
0a8a69dd RR |
602 | { |
603 | struct vring_virtqueue *vq = to_vvq(_vq); | |
a5c262c5 | 604 | u16 new, old; |
41f0377f RR |
605 | bool needs_kick; |
606 | ||
0a8a69dd | 607 | START_USE(vq); |
a72caae2 JW |
608 | /* We need to expose available array entries before checking avail |
609 | * event. */ | |
a9a0fef7 | 610 | virtio_mb(vq->weak_barriers); |
0a8a69dd | 611 | |
e593bf97 TB |
612 | old = vq->split.avail_idx_shadow - vq->num_added; |
613 | new = vq->split.avail_idx_shadow; | |
0a8a69dd RR |
614 | vq->num_added = 0; |
615 | ||
4d6a105e TB |
616 | LAST_ADD_TIME_CHECK(vq); |
617 | LAST_ADD_TIME_INVALID(vq); | |
e93300b1 | 618 | |
41f0377f | 619 | if (vq->event) { |
e593bf97 TB |
620 | needs_kick = vring_need_event(virtio16_to_cpu(_vq->vdev, |
621 | vring_avail_event(&vq->split.vring)), | |
41f0377f RR |
622 | new, old); |
623 | } else { | |
e593bf97 TB |
624 | needs_kick = !(vq->split.vring.used->flags & |
625 | cpu_to_virtio16(_vq->vdev, | |
626 | VRING_USED_F_NO_NOTIFY)); | |
41f0377f | 627 | } |
0a8a69dd | 628 | END_USE(vq); |
41f0377f RR |
629 | return needs_kick; |
630 | } | |
138fd251 | 631 | |
138fd251 TB |
632 | static void detach_buf_split(struct vring_virtqueue *vq, unsigned int head, |
633 | void **ctx) | |
0a8a69dd | 634 | { |
780bc790 | 635 | unsigned int i, j; |
c60923cb | 636 | __virtio16 nextflag = cpu_to_virtio16(vq->vq.vdev, VRING_DESC_F_NEXT); |
0a8a69dd RR |
637 | |
638 | /* Clear data ptr. */ | |
cbeedb72 | 639 | vq->split.desc_state[head].data = NULL; |
0a8a69dd | 640 | |
780bc790 | 641 | /* Put back on free list: unmap first-level descriptors and find end */ |
0a8a69dd | 642 | i = head; |
9fa29b9d | 643 | |
e593bf97 TB |
644 | while (vq->split.vring.desc[i].flags & nextflag) { |
645 | vring_unmap_one_split(vq, &vq->split.vring.desc[i]); | |
646 | i = virtio16_to_cpu(vq->vq.vdev, vq->split.vring.desc[i].next); | |
06ca287d | 647 | vq->vq.num_free++; |
0a8a69dd RR |
648 | } |
649 | ||
e593bf97 TB |
650 | vring_unmap_one_split(vq, &vq->split.vring.desc[i]); |
651 | vq->split.vring.desc[i].next = cpu_to_virtio16(vq->vq.vdev, | |
652 | vq->free_head); | |
0a8a69dd | 653 | vq->free_head = head; |
780bc790 | 654 | |
0a8a69dd | 655 | /* Plus final descriptor */ |
06ca287d | 656 | vq->vq.num_free++; |
780bc790 | 657 | |
5a08b04f | 658 | if (vq->indirect) { |
cbeedb72 TB |
659 | struct vring_desc *indir_desc = |
660 | vq->split.desc_state[head].indir_desc; | |
5a08b04f MT |
661 | u32 len; |
662 | ||
663 | /* Free the indirect table, if any, now that it's unmapped. */ | |
664 | if (!indir_desc) | |
665 | return; | |
666 | ||
e593bf97 TB |
667 | len = virtio32_to_cpu(vq->vq.vdev, |
668 | vq->split.vring.desc[head].len); | |
780bc790 | 669 | |
e593bf97 | 670 | BUG_ON(!(vq->split.vring.desc[head].flags & |
780bc790 AL |
671 | cpu_to_virtio16(vq->vq.vdev, VRING_DESC_F_INDIRECT))); |
672 | BUG_ON(len == 0 || len % sizeof(struct vring_desc)); | |
673 | ||
674 | for (j = 0; j < len / sizeof(struct vring_desc); j++) | |
138fd251 | 675 | vring_unmap_one_split(vq, &indir_desc[j]); |
780bc790 | 676 | |
5a08b04f | 677 | kfree(indir_desc); |
cbeedb72 | 678 | vq->split.desc_state[head].indir_desc = NULL; |
5a08b04f | 679 | } else if (ctx) { |
cbeedb72 | 680 | *ctx = vq->split.desc_state[head].indir_desc; |
780bc790 | 681 | } |
0a8a69dd RR |
682 | } |
683 | ||
138fd251 | 684 | static inline bool more_used_split(const struct vring_virtqueue *vq) |
0a8a69dd | 685 | { |
e593bf97 TB |
686 | return vq->last_used_idx != virtio16_to_cpu(vq->vq.vdev, |
687 | vq->split.vring.used->idx); | |
0a8a69dd RR |
688 | } |
689 | ||
138fd251 TB |
690 | static void *virtqueue_get_buf_ctx_split(struct virtqueue *_vq, |
691 | unsigned int *len, | |
692 | void **ctx) | |
0a8a69dd RR |
693 | { |
694 | struct vring_virtqueue *vq = to_vvq(_vq); | |
695 | void *ret; | |
696 | unsigned int i; | |
3b720b8c | 697 | u16 last_used; |
0a8a69dd RR |
698 | |
699 | START_USE(vq); | |
700 | ||
5ef82752 RR |
701 | if (unlikely(vq->broken)) { |
702 | END_USE(vq); | |
703 | return NULL; | |
704 | } | |
705 | ||
138fd251 | 706 | if (!more_used_split(vq)) { |
0a8a69dd RR |
707 | pr_debug("No more buffers in queue\n"); |
708 | END_USE(vq); | |
709 | return NULL; | |
710 | } | |
711 | ||
2d61ba95 | 712 | /* Only get used array entries after they have been exposed by host. */ |
a9a0fef7 | 713 | virtio_rmb(vq->weak_barriers); |
2d61ba95 | 714 | |
e593bf97 TB |
715 | last_used = (vq->last_used_idx & (vq->split.vring.num - 1)); |
716 | i = virtio32_to_cpu(_vq->vdev, | |
717 | vq->split.vring.used->ring[last_used].id); | |
718 | *len = virtio32_to_cpu(_vq->vdev, | |
719 | vq->split.vring.used->ring[last_used].len); | |
0a8a69dd | 720 | |
e593bf97 | 721 | if (unlikely(i >= vq->split.vring.num)) { |
0a8a69dd RR |
722 | BAD_RING(vq, "id %u out of range\n", i); |
723 | return NULL; | |
724 | } | |
cbeedb72 | 725 | if (unlikely(!vq->split.desc_state[i].data)) { |
0a8a69dd RR |
726 | BAD_RING(vq, "id %u is not a head!\n", i); |
727 | return NULL; | |
728 | } | |
729 | ||
138fd251 | 730 | /* detach_buf_split clears data, so grab it now. */ |
cbeedb72 | 731 | ret = vq->split.desc_state[i].data; |
138fd251 | 732 | detach_buf_split(vq, i, ctx); |
0a8a69dd | 733 | vq->last_used_idx++; |
a5c262c5 MT |
734 | /* If we expect an interrupt for the next entry, tell host |
735 | * by writing event index and flush out the write before | |
736 | * the read in the next get_buf call. */ | |
e593bf97 | 737 | if (!(vq->split.avail_flags_shadow & VRING_AVAIL_F_NO_INTERRUPT)) |
788e5b3a | 738 | virtio_store_mb(vq->weak_barriers, |
e593bf97 | 739 | &vring_used_event(&vq->split.vring), |
788e5b3a | 740 | cpu_to_virtio16(_vq->vdev, vq->last_used_idx)); |
a5c262c5 | 741 | |
4d6a105e | 742 | LAST_ADD_TIME_INVALID(vq); |
e93300b1 | 743 | |
0a8a69dd RR |
744 | END_USE(vq); |
745 | return ret; | |
746 | } | |
138fd251 | 747 | |
138fd251 | 748 | static void virtqueue_disable_cb_split(struct virtqueue *_vq) |
18445c4d RR |
749 | { |
750 | struct vring_virtqueue *vq = to_vvq(_vq); | |
751 | ||
e593bf97 TB |
752 | if (!(vq->split.avail_flags_shadow & VRING_AVAIL_F_NO_INTERRUPT)) { |
753 | vq->split.avail_flags_shadow |= VRING_AVAIL_F_NO_INTERRUPT; | |
8d622d21 MT |
754 | if (vq->event) |
755 | /* TODO: this is a hack. Figure out a cleaner value to write. */ | |
756 | vring_used_event(&vq->split.vring) = 0x0; | |
757 | else | |
e593bf97 TB |
758 | vq->split.vring.avail->flags = |
759 | cpu_to_virtio16(_vq->vdev, | |
760 | vq->split.avail_flags_shadow); | |
f277ec42 | 761 | } |
18445c4d RR |
762 | } |
763 | ||
138fd251 | 764 | static unsigned virtqueue_enable_cb_prepare_split(struct virtqueue *_vq) |
0a8a69dd RR |
765 | { |
766 | struct vring_virtqueue *vq = to_vvq(_vq); | |
cc229884 | 767 | u16 last_used_idx; |
0a8a69dd RR |
768 | |
769 | START_USE(vq); | |
0a8a69dd RR |
770 | |
771 | /* We optimistically turn back on interrupts, then check if there was | |
772 | * more to do. */ | |
a5c262c5 MT |
773 | /* Depending on the VIRTIO_RING_F_EVENT_IDX feature, we need to |
774 | * either clear the flags bit or point the event index at the next | |
775 | * entry. Always do both to keep code simple. */ | |
e593bf97 TB |
776 | if (vq->split.avail_flags_shadow & VRING_AVAIL_F_NO_INTERRUPT) { |
777 | vq->split.avail_flags_shadow &= ~VRING_AVAIL_F_NO_INTERRUPT; | |
0ea1e4a6 | 778 | if (!vq->event) |
e593bf97 TB |
779 | vq->split.vring.avail->flags = |
780 | cpu_to_virtio16(_vq->vdev, | |
781 | vq->split.avail_flags_shadow); | |
f277ec42 | 782 | } |
e593bf97 TB |
783 | vring_used_event(&vq->split.vring) = cpu_to_virtio16(_vq->vdev, |
784 | last_used_idx = vq->last_used_idx); | |
cc229884 MT |
785 | END_USE(vq); |
786 | return last_used_idx; | |
787 | } | |
138fd251 | 788 | |
138fd251 TB |
789 | static bool virtqueue_poll_split(struct virtqueue *_vq, unsigned last_used_idx) |
790 | { | |
791 | struct vring_virtqueue *vq = to_vvq(_vq); | |
792 | ||
793 | return (u16)last_used_idx != virtio16_to_cpu(_vq->vdev, | |
e593bf97 | 794 | vq->split.vring.used->idx); |
138fd251 TB |
795 | } |
796 | ||
138fd251 | 797 | static bool virtqueue_enable_cb_delayed_split(struct virtqueue *_vq) |
7ab358c2 MT |
798 | { |
799 | struct vring_virtqueue *vq = to_vvq(_vq); | |
800 | u16 bufs; | |
801 | ||
802 | START_USE(vq); | |
803 | ||
804 | /* We optimistically turn back on interrupts, then check if there was | |
805 | * more to do. */ | |
806 | /* Depending on the VIRTIO_RING_F_USED_EVENT_IDX feature, we need to | |
807 | * either clear the flags bit or point the event index at the next | |
0ea1e4a6 | 808 | * entry. Always update the event index to keep code simple. */ |
e593bf97 TB |
809 | if (vq->split.avail_flags_shadow & VRING_AVAIL_F_NO_INTERRUPT) { |
810 | vq->split.avail_flags_shadow &= ~VRING_AVAIL_F_NO_INTERRUPT; | |
0ea1e4a6 | 811 | if (!vq->event) |
e593bf97 TB |
812 | vq->split.vring.avail->flags = |
813 | cpu_to_virtio16(_vq->vdev, | |
814 | vq->split.avail_flags_shadow); | |
f277ec42 | 815 | } |
7ab358c2 | 816 | /* TODO: tune this threshold */ |
e593bf97 | 817 | bufs = (u16)(vq->split.avail_idx_shadow - vq->last_used_idx) * 3 / 4; |
788e5b3a MT |
818 | |
819 | virtio_store_mb(vq->weak_barriers, | |
e593bf97 | 820 | &vring_used_event(&vq->split.vring), |
788e5b3a MT |
821 | cpu_to_virtio16(_vq->vdev, vq->last_used_idx + bufs)); |
822 | ||
e593bf97 TB |
823 | if (unlikely((u16)(virtio16_to_cpu(_vq->vdev, vq->split.vring.used->idx) |
824 | - vq->last_used_idx) > bufs)) { | |
7ab358c2 MT |
825 | END_USE(vq); |
826 | return false; | |
827 | } | |
828 | ||
829 | END_USE(vq); | |
830 | return true; | |
831 | } | |
7ab358c2 | 832 | |
138fd251 | 833 | static void *virtqueue_detach_unused_buf_split(struct virtqueue *_vq) |
c021eac4 SM |
834 | { |
835 | struct vring_virtqueue *vq = to_vvq(_vq); | |
836 | unsigned int i; | |
837 | void *buf; | |
838 | ||
839 | START_USE(vq); | |
840 | ||
e593bf97 | 841 | for (i = 0; i < vq->split.vring.num; i++) { |
cbeedb72 | 842 | if (!vq->split.desc_state[i].data) |
c021eac4 | 843 | continue; |
138fd251 | 844 | /* detach_buf_split clears data, so grab it now. */ |
cbeedb72 | 845 | buf = vq->split.desc_state[i].data; |
138fd251 | 846 | detach_buf_split(vq, i, NULL); |
e593bf97 TB |
847 | vq->split.avail_idx_shadow--; |
848 | vq->split.vring.avail->idx = cpu_to_virtio16(_vq->vdev, | |
849 | vq->split.avail_idx_shadow); | |
c021eac4 SM |
850 | END_USE(vq); |
851 | return buf; | |
852 | } | |
853 | /* That should have freed everything. */ | |
e593bf97 | 854 | BUG_ON(vq->vq.num_free != vq->split.vring.num); |
c021eac4 SM |
855 | |
856 | END_USE(vq); | |
857 | return NULL; | |
858 | } | |
138fd251 | 859 | |
d79dca75 TB |
860 | static struct virtqueue *vring_create_virtqueue_split( |
861 | unsigned int index, | |
862 | unsigned int num, | |
863 | unsigned int vring_align, | |
864 | struct virtio_device *vdev, | |
865 | bool weak_barriers, | |
866 | bool may_reduce_num, | |
867 | bool context, | |
868 | bool (*notify)(struct virtqueue *), | |
869 | void (*callback)(struct virtqueue *), | |
870 | const char *name) | |
871 | { | |
872 | struct virtqueue *vq; | |
873 | void *queue = NULL; | |
874 | dma_addr_t dma_addr; | |
875 | size_t queue_size_in_bytes; | |
876 | struct vring vring; | |
877 | ||
878 | /* We assume num is a power of 2. */ | |
879 | if (num & (num - 1)) { | |
880 | dev_warn(&vdev->dev, "Bad virtqueue length %u\n", num); | |
881 | return NULL; | |
882 | } | |
883 | ||
884 | /* TODO: allocate each queue chunk individually */ | |
885 | for (; num && vring_size(num, vring_align) > PAGE_SIZE; num /= 2) { | |
886 | queue = vring_alloc_queue(vdev, vring_size(num, vring_align), | |
887 | &dma_addr, | |
888 | GFP_KERNEL|__GFP_NOWARN|__GFP_ZERO); | |
889 | if (queue) | |
890 | break; | |
cf94db21 CH |
891 | if (!may_reduce_num) |
892 | return NULL; | |
d79dca75 TB |
893 | } |
894 | ||
895 | if (!num) | |
896 | return NULL; | |
897 | ||
898 | if (!queue) { | |
899 | /* Try to get a single page. You are my only hope! */ | |
900 | queue = vring_alloc_queue(vdev, vring_size(num, vring_align), | |
901 | &dma_addr, GFP_KERNEL|__GFP_ZERO); | |
902 | } | |
903 | if (!queue) | |
904 | return NULL; | |
905 | ||
906 | queue_size_in_bytes = vring_size(num, vring_align); | |
907 | vring_init(&vring, num, queue, vring_align); | |
908 | ||
909 | vq = __vring_new_virtqueue(index, vring, vdev, weak_barriers, context, | |
910 | notify, callback, name); | |
911 | if (!vq) { | |
912 | vring_free_queue(vdev, queue_size_in_bytes, queue, | |
913 | dma_addr); | |
914 | return NULL; | |
915 | } | |
916 | ||
917 | to_vvq(vq)->split.queue_dma_addr = dma_addr; | |
918 | to_vvq(vq)->split.queue_size_in_bytes = queue_size_in_bytes; | |
919 | to_vvq(vq)->we_own_ring = true; | |
920 | ||
921 | return vq; | |
922 | } | |
923 | ||
e6f633e5 | 924 | |
1ce9e605 TB |
925 | /* |
926 | * Packed ring specific functions - *_packed(). | |
927 | */ | |
928 | ||
929 | static void vring_unmap_state_packed(const struct vring_virtqueue *vq, | |
1f28750f | 930 | struct vring_desc_extra *state) |
1ce9e605 TB |
931 | { |
932 | u16 flags; | |
933 | ||
934 | if (!vq->use_dma_api) | |
935 | return; | |
936 | ||
937 | flags = state->flags; | |
938 | ||
939 | if (flags & VRING_DESC_F_INDIRECT) { | |
940 | dma_unmap_single(vring_dma_dev(vq), | |
941 | state->addr, state->len, | |
942 | (flags & VRING_DESC_F_WRITE) ? | |
943 | DMA_FROM_DEVICE : DMA_TO_DEVICE); | |
944 | } else { | |
945 | dma_unmap_page(vring_dma_dev(vq), | |
946 | state->addr, state->len, | |
947 | (flags & VRING_DESC_F_WRITE) ? | |
948 | DMA_FROM_DEVICE : DMA_TO_DEVICE); | |
949 | } | |
950 | } | |
951 | ||
952 | static void vring_unmap_desc_packed(const struct vring_virtqueue *vq, | |
953 | struct vring_packed_desc *desc) | |
954 | { | |
955 | u16 flags; | |
956 | ||
957 | if (!vq->use_dma_api) | |
958 | return; | |
959 | ||
960 | flags = le16_to_cpu(desc->flags); | |
961 | ||
962 | if (flags & VRING_DESC_F_INDIRECT) { | |
963 | dma_unmap_single(vring_dma_dev(vq), | |
964 | le64_to_cpu(desc->addr), | |
965 | le32_to_cpu(desc->len), | |
966 | (flags & VRING_DESC_F_WRITE) ? | |
967 | DMA_FROM_DEVICE : DMA_TO_DEVICE); | |
968 | } else { | |
969 | dma_unmap_page(vring_dma_dev(vq), | |
970 | le64_to_cpu(desc->addr), | |
971 | le32_to_cpu(desc->len), | |
972 | (flags & VRING_DESC_F_WRITE) ? | |
973 | DMA_FROM_DEVICE : DMA_TO_DEVICE); | |
974 | } | |
975 | } | |
976 | ||
977 | static struct vring_packed_desc *alloc_indirect_packed(unsigned int total_sg, | |
978 | gfp_t gfp) | |
979 | { | |
980 | struct vring_packed_desc *desc; | |
981 | ||
982 | /* | |
983 | * We require lowmem mappings for the descriptors because | |
984 | * otherwise virt_to_phys will give us bogus addresses in the | |
985 | * virtqueue. | |
986 | */ | |
987 | gfp &= ~__GFP_HIGHMEM; | |
988 | ||
989 | desc = kmalloc_array(total_sg, sizeof(struct vring_packed_desc), gfp); | |
990 | ||
991 | return desc; | |
992 | } | |
993 | ||
994 | static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, | |
995 | struct scatterlist *sgs[], | |
996 | unsigned int total_sg, | |
997 | unsigned int out_sgs, | |
998 | unsigned int in_sgs, | |
999 | void *data, | |
1000 | gfp_t gfp) | |
1001 | { | |
1002 | struct vring_packed_desc *desc; | |
1003 | struct scatterlist *sg; | |
1004 | unsigned int i, n, err_idx; | |
1005 | u16 head, id; | |
1006 | dma_addr_t addr; | |
1007 | ||
1008 | head = vq->packed.next_avail_idx; | |
1009 | desc = alloc_indirect_packed(total_sg, gfp); | |
1010 | ||
1011 | if (unlikely(vq->vq.num_free < 1)) { | |
1012 | pr_debug("Can't add buf len 1 - avail = 0\n"); | |
df0bfe75 | 1013 | kfree(desc); |
1ce9e605 TB |
1014 | END_USE(vq); |
1015 | return -ENOSPC; | |
1016 | } | |
1017 | ||
1018 | i = 0; | |
1019 | id = vq->free_head; | |
1020 | BUG_ON(id == vq->packed.vring.num); | |
1021 | ||
1022 | for (n = 0; n < out_sgs + in_sgs; n++) { | |
1023 | for (sg = sgs[n]; sg; sg = sg_next(sg)) { | |
1024 | addr = vring_map_one_sg(vq, sg, n < out_sgs ? | |
1025 | DMA_TO_DEVICE : DMA_FROM_DEVICE); | |
1026 | if (vring_mapping_error(vq, addr)) | |
1027 | goto unmap_release; | |
1028 | ||
1029 | desc[i].flags = cpu_to_le16(n < out_sgs ? | |
1030 | 0 : VRING_DESC_F_WRITE); | |
1031 | desc[i].addr = cpu_to_le64(addr); | |
1032 | desc[i].len = cpu_to_le32(sg->length); | |
1033 | i++; | |
1034 | } | |
1035 | } | |
1036 | ||
1037 | /* Now that the indirect table is filled in, map it. */ | |
1038 | addr = vring_map_single(vq, desc, | |
1039 | total_sg * sizeof(struct vring_packed_desc), | |
1040 | DMA_TO_DEVICE); | |
1041 | if (vring_mapping_error(vq, addr)) | |
1042 | goto unmap_release; | |
1043 | ||
1044 | vq->packed.vring.desc[head].addr = cpu_to_le64(addr); | |
1045 | vq->packed.vring.desc[head].len = cpu_to_le32(total_sg * | |
1046 | sizeof(struct vring_packed_desc)); | |
1047 | vq->packed.vring.desc[head].id = cpu_to_le16(id); | |
1048 | ||
1049 | if (vq->use_dma_api) { | |
1050 | vq->packed.desc_extra[id].addr = addr; | |
1051 | vq->packed.desc_extra[id].len = total_sg * | |
1052 | sizeof(struct vring_packed_desc); | |
1053 | vq->packed.desc_extra[id].flags = VRING_DESC_F_INDIRECT | | |
1054 | vq->packed.avail_used_flags; | |
1055 | } | |
1056 | ||
1057 | /* | |
1058 | * A driver MUST NOT make the first descriptor in the list | |
1059 | * available before all subsequent descriptors comprising | |
1060 | * the list are made available. | |
1061 | */ | |
1062 | virtio_wmb(vq->weak_barriers); | |
1063 | vq->packed.vring.desc[head].flags = cpu_to_le16(VRING_DESC_F_INDIRECT | | |
1064 | vq->packed.avail_used_flags); | |
1065 | ||
1066 | /* We're using some buffers from the free list. */ | |
1067 | vq->vq.num_free -= 1; | |
1068 | ||
1069 | /* Update free pointer */ | |
1070 | n = head + 1; | |
1071 | if (n >= vq->packed.vring.num) { | |
1072 | n = 0; | |
1073 | vq->packed.avail_wrap_counter ^= 1; | |
1074 | vq->packed.avail_used_flags ^= | |
1075 | 1 << VRING_PACKED_DESC_F_AVAIL | | |
1076 | 1 << VRING_PACKED_DESC_F_USED; | |
1077 | } | |
1078 | vq->packed.next_avail_idx = n; | |
aeef9b47 | 1079 | vq->free_head = vq->packed.desc_extra[id].next; |
1ce9e605 TB |
1080 | |
1081 | /* Store token and indirect buffer state. */ | |
1082 | vq->packed.desc_state[id].num = 1; | |
1083 | vq->packed.desc_state[id].data = data; | |
1084 | vq->packed.desc_state[id].indir_desc = desc; | |
1085 | vq->packed.desc_state[id].last = id; | |
1086 | ||
1087 | vq->num_added += 1; | |
1088 | ||
1089 | pr_debug("Added buffer head %i to %p\n", head, vq); | |
1090 | END_USE(vq); | |
1091 | ||
1092 | return 0; | |
1093 | ||
1094 | unmap_release: | |
1095 | err_idx = i; | |
1096 | ||
1097 | for (i = 0; i < err_idx; i++) | |
1098 | vring_unmap_desc_packed(vq, &desc[i]); | |
1099 | ||
1100 | kfree(desc); | |
1101 | ||
1102 | END_USE(vq); | |
f7728002 | 1103 | return -ENOMEM; |
1ce9e605 TB |
1104 | } |
1105 | ||
1106 | static inline int virtqueue_add_packed(struct virtqueue *_vq, | |
1107 | struct scatterlist *sgs[], | |
1108 | unsigned int total_sg, | |
1109 | unsigned int out_sgs, | |
1110 | unsigned int in_sgs, | |
1111 | void *data, | |
1112 | void *ctx, | |
1113 | gfp_t gfp) | |
1114 | { | |
1115 | struct vring_virtqueue *vq = to_vvq(_vq); | |
1116 | struct vring_packed_desc *desc; | |
1117 | struct scatterlist *sg; | |
1118 | unsigned int i, n, c, descs_used, err_idx; | |
3f649ab7 KC |
1119 | __le16 head_flags, flags; |
1120 | u16 head, id, prev, curr, avail_used_flags; | |
1ce9e605 TB |
1121 | |
1122 | START_USE(vq); | |
1123 | ||
1124 | BUG_ON(data == NULL); | |
1125 | BUG_ON(ctx && vq->indirect); | |
1126 | ||
1127 | if (unlikely(vq->broken)) { | |
1128 | END_USE(vq); | |
1129 | return -EIO; | |
1130 | } | |
1131 | ||
1132 | LAST_ADD_TIME_UPDATE(vq); | |
1133 | ||
1134 | BUG_ON(total_sg == 0); | |
1135 | ||
1136 | if (virtqueue_use_indirect(_vq, total_sg)) | |
1137 | return virtqueue_add_indirect_packed(vq, sgs, total_sg, | |
1138 | out_sgs, in_sgs, data, gfp); | |
1139 | ||
1140 | head = vq->packed.next_avail_idx; | |
1141 | avail_used_flags = vq->packed.avail_used_flags; | |
1142 | ||
1143 | WARN_ON_ONCE(total_sg > vq->packed.vring.num && !vq->indirect); | |
1144 | ||
1145 | desc = vq->packed.vring.desc; | |
1146 | i = head; | |
1147 | descs_used = total_sg; | |
1148 | ||
1149 | if (unlikely(vq->vq.num_free < descs_used)) { | |
1150 | pr_debug("Can't add buf len %i - avail = %i\n", | |
1151 | descs_used, vq->vq.num_free); | |
1152 | END_USE(vq); | |
1153 | return -ENOSPC; | |
1154 | } | |
1155 | ||
1156 | id = vq->free_head; | |
1157 | BUG_ON(id == vq->packed.vring.num); | |
1158 | ||
1159 | curr = id; | |
1160 | c = 0; | |
1161 | for (n = 0; n < out_sgs + in_sgs; n++) { | |
1162 | for (sg = sgs[n]; sg; sg = sg_next(sg)) { | |
1163 | dma_addr_t addr = vring_map_one_sg(vq, sg, n < out_sgs ? | |
1164 | DMA_TO_DEVICE : DMA_FROM_DEVICE); | |
1165 | if (vring_mapping_error(vq, addr)) | |
1166 | goto unmap_release; | |
1167 | ||
1168 | flags = cpu_to_le16(vq->packed.avail_used_flags | | |
1169 | (++c == total_sg ? 0 : VRING_DESC_F_NEXT) | | |
1170 | (n < out_sgs ? 0 : VRING_DESC_F_WRITE)); | |
1171 | if (i == head) | |
1172 | head_flags = flags; | |
1173 | else | |
1174 | desc[i].flags = flags; | |
1175 | ||
1176 | desc[i].addr = cpu_to_le64(addr); | |
1177 | desc[i].len = cpu_to_le32(sg->length); | |
1178 | desc[i].id = cpu_to_le16(id); | |
1179 | ||
1180 | if (unlikely(vq->use_dma_api)) { | |
1181 | vq->packed.desc_extra[curr].addr = addr; | |
1182 | vq->packed.desc_extra[curr].len = sg->length; | |
1183 | vq->packed.desc_extra[curr].flags = | |
1184 | le16_to_cpu(flags); | |
1185 | } | |
1186 | prev = curr; | |
aeef9b47 | 1187 | curr = vq->packed.desc_extra[curr].next; |
1ce9e605 TB |
1188 | |
1189 | if ((unlikely(++i >= vq->packed.vring.num))) { | |
1190 | i = 0; | |
1191 | vq->packed.avail_used_flags ^= | |
1192 | 1 << VRING_PACKED_DESC_F_AVAIL | | |
1193 | 1 << VRING_PACKED_DESC_F_USED; | |
1194 | } | |
1195 | } | |
1196 | } | |
1197 | ||
1198 | if (i < head) | |
1199 | vq->packed.avail_wrap_counter ^= 1; | |
1200 | ||
1201 | /* We're using some buffers from the free list. */ | |
1202 | vq->vq.num_free -= descs_used; | |
1203 | ||
1204 | /* Update free pointer */ | |
1205 | vq->packed.next_avail_idx = i; | |
1206 | vq->free_head = curr; | |
1207 | ||
1208 | /* Store token. */ | |
1209 | vq->packed.desc_state[id].num = descs_used; | |
1210 | vq->packed.desc_state[id].data = data; | |
1211 | vq->packed.desc_state[id].indir_desc = ctx; | |
1212 | vq->packed.desc_state[id].last = prev; | |
1213 | ||
1214 | /* | |
1215 | * A driver MUST NOT make the first descriptor in the list | |
1216 | * available before all subsequent descriptors comprising | |
1217 | * the list are made available. | |
1218 | */ | |
1219 | virtio_wmb(vq->weak_barriers); | |
1220 | vq->packed.vring.desc[head].flags = head_flags; | |
1221 | vq->num_added += descs_used; | |
1222 | ||
1223 | pr_debug("Added buffer head %i to %p\n", head, vq); | |
1224 | END_USE(vq); | |
1225 | ||
1226 | return 0; | |
1227 | ||
1228 | unmap_release: | |
1229 | err_idx = i; | |
1230 | i = head; | |
44593865 | 1231 | curr = vq->free_head; |
1ce9e605 TB |
1232 | |
1233 | vq->packed.avail_used_flags = avail_used_flags; | |
1234 | ||
1235 | for (n = 0; n < total_sg; n++) { | |
1236 | if (i == err_idx) | |
1237 | break; | |
44593865 JW |
1238 | vring_unmap_state_packed(vq, |
1239 | &vq->packed.desc_extra[curr]); | |
1240 | curr = vq->packed.desc_extra[curr].next; | |
1ce9e605 TB |
1241 | i++; |
1242 | if (i >= vq->packed.vring.num) | |
1243 | i = 0; | |
1244 | } | |
1245 | ||
1246 | END_USE(vq); | |
1247 | return -EIO; | |
1248 | } | |
1249 | ||
1250 | static bool virtqueue_kick_prepare_packed(struct virtqueue *_vq) | |
1251 | { | |
1252 | struct vring_virtqueue *vq = to_vvq(_vq); | |
f51f9826 | 1253 | u16 new, old, off_wrap, flags, wrap_counter, event_idx; |
1ce9e605 TB |
1254 | bool needs_kick; |
1255 | union { | |
1256 | struct { | |
1257 | __le16 off_wrap; | |
1258 | __le16 flags; | |
1259 | }; | |
1260 | u32 u32; | |
1261 | } snapshot; | |
1262 | ||
1263 | START_USE(vq); | |
1264 | ||
1265 | /* | |
1266 | * We need to expose the new flags value before checking notification | |
1267 | * suppressions. | |
1268 | */ | |
1269 | virtio_mb(vq->weak_barriers); | |
1270 | ||
f51f9826 TB |
1271 | old = vq->packed.next_avail_idx - vq->num_added; |
1272 | new = vq->packed.next_avail_idx; | |
1ce9e605 TB |
1273 | vq->num_added = 0; |
1274 | ||
1275 | snapshot.u32 = *(u32 *)vq->packed.vring.device; | |
1276 | flags = le16_to_cpu(snapshot.flags); | |
1277 | ||
1278 | LAST_ADD_TIME_CHECK(vq); | |
1279 | LAST_ADD_TIME_INVALID(vq); | |
1280 | ||
f51f9826 TB |
1281 | if (flags != VRING_PACKED_EVENT_FLAG_DESC) { |
1282 | needs_kick = (flags != VRING_PACKED_EVENT_FLAG_DISABLE); | |
1283 | goto out; | |
1284 | } | |
1285 | ||
1286 | off_wrap = le16_to_cpu(snapshot.off_wrap); | |
1287 | ||
1288 | wrap_counter = off_wrap >> VRING_PACKED_EVENT_F_WRAP_CTR; | |
1289 | event_idx = off_wrap & ~(1 << VRING_PACKED_EVENT_F_WRAP_CTR); | |
1290 | if (wrap_counter != vq->packed.avail_wrap_counter) | |
1291 | event_idx -= vq->packed.vring.num; | |
1292 | ||
1293 | needs_kick = vring_need_event(event_idx, new, old); | |
1294 | out: | |
1ce9e605 TB |
1295 | END_USE(vq); |
1296 | return needs_kick; | |
1297 | } | |
1298 | ||
1299 | static void detach_buf_packed(struct vring_virtqueue *vq, | |
1300 | unsigned int id, void **ctx) | |
1301 | { | |
1302 | struct vring_desc_state_packed *state = NULL; | |
1303 | struct vring_packed_desc *desc; | |
1304 | unsigned int i, curr; | |
1305 | ||
1306 | state = &vq->packed.desc_state[id]; | |
1307 | ||
1308 | /* Clear data ptr. */ | |
1309 | state->data = NULL; | |
1310 | ||
aeef9b47 | 1311 | vq->packed.desc_extra[state->last].next = vq->free_head; |
1ce9e605 TB |
1312 | vq->free_head = id; |
1313 | vq->vq.num_free += state->num; | |
1314 | ||
1315 | if (unlikely(vq->use_dma_api)) { | |
1316 | curr = id; | |
1317 | for (i = 0; i < state->num; i++) { | |
1318 | vring_unmap_state_packed(vq, | |
1319 | &vq->packed.desc_extra[curr]); | |
aeef9b47 | 1320 | curr = vq->packed.desc_extra[curr].next; |
1ce9e605 TB |
1321 | } |
1322 | } | |
1323 | ||
1324 | if (vq->indirect) { | |
1325 | u32 len; | |
1326 | ||
1327 | /* Free the indirect table, if any, now that it's unmapped. */ | |
1328 | desc = state->indir_desc; | |
1329 | if (!desc) | |
1330 | return; | |
1331 | ||
1332 | if (vq->use_dma_api) { | |
1333 | len = vq->packed.desc_extra[id].len; | |
1334 | for (i = 0; i < len / sizeof(struct vring_packed_desc); | |
1335 | i++) | |
1336 | vring_unmap_desc_packed(vq, &desc[i]); | |
1337 | } | |
1338 | kfree(desc); | |
1339 | state->indir_desc = NULL; | |
1340 | } else if (ctx) { | |
1341 | *ctx = state->indir_desc; | |
1342 | } | |
1343 | } | |
1344 | ||
1345 | static inline bool is_used_desc_packed(const struct vring_virtqueue *vq, | |
1346 | u16 idx, bool used_wrap_counter) | |
1347 | { | |
1348 | bool avail, used; | |
1349 | u16 flags; | |
1350 | ||
1351 | flags = le16_to_cpu(vq->packed.vring.desc[idx].flags); | |
1352 | avail = !!(flags & (1 << VRING_PACKED_DESC_F_AVAIL)); | |
1353 | used = !!(flags & (1 << VRING_PACKED_DESC_F_USED)); | |
1354 | ||
1355 | return avail == used && used == used_wrap_counter; | |
1356 | } | |
1357 | ||
1358 | static inline bool more_used_packed(const struct vring_virtqueue *vq) | |
1359 | { | |
1360 | return is_used_desc_packed(vq, vq->last_used_idx, | |
1361 | vq->packed.used_wrap_counter); | |
1362 | } | |
1363 | ||
1364 | static void *virtqueue_get_buf_ctx_packed(struct virtqueue *_vq, | |
1365 | unsigned int *len, | |
1366 | void **ctx) | |
1367 | { | |
1368 | struct vring_virtqueue *vq = to_vvq(_vq); | |
1369 | u16 last_used, id; | |
1370 | void *ret; | |
1371 | ||
1372 | START_USE(vq); | |
1373 | ||
1374 | if (unlikely(vq->broken)) { | |
1375 | END_USE(vq); | |
1376 | return NULL; | |
1377 | } | |
1378 | ||
1379 | if (!more_used_packed(vq)) { | |
1380 | pr_debug("No more buffers in queue\n"); | |
1381 | END_USE(vq); | |
1382 | return NULL; | |
1383 | } | |
1384 | ||
1385 | /* Only get used elements after they have been exposed by host. */ | |
1386 | virtio_rmb(vq->weak_barriers); | |
1387 | ||
1388 | last_used = vq->last_used_idx; | |
1389 | id = le16_to_cpu(vq->packed.vring.desc[last_used].id); | |
1390 | *len = le32_to_cpu(vq->packed.vring.desc[last_used].len); | |
1391 | ||
1392 | if (unlikely(id >= vq->packed.vring.num)) { | |
1393 | BAD_RING(vq, "id %u out of range\n", id); | |
1394 | return NULL; | |
1395 | } | |
1396 | if (unlikely(!vq->packed.desc_state[id].data)) { | |
1397 | BAD_RING(vq, "id %u is not a head!\n", id); | |
1398 | return NULL; | |
1399 | } | |
1400 | ||
1401 | /* detach_buf_packed clears data, so grab it now. */ | |
1402 | ret = vq->packed.desc_state[id].data; | |
1403 | detach_buf_packed(vq, id, ctx); | |
1404 | ||
1405 | vq->last_used_idx += vq->packed.desc_state[id].num; | |
1406 | if (unlikely(vq->last_used_idx >= vq->packed.vring.num)) { | |
1407 | vq->last_used_idx -= vq->packed.vring.num; | |
1408 | vq->packed.used_wrap_counter ^= 1; | |
1409 | } | |
1410 | ||
f51f9826 TB |
1411 | /* |
1412 | * If we expect an interrupt for the next entry, tell host | |
1413 | * by writing event index and flush out the write before | |
1414 | * the read in the next get_buf call. | |
1415 | */ | |
1416 | if (vq->packed.event_flags_shadow == VRING_PACKED_EVENT_FLAG_DESC) | |
1417 | virtio_store_mb(vq->weak_barriers, | |
1418 | &vq->packed.vring.driver->off_wrap, | |
1419 | cpu_to_le16(vq->last_used_idx | | |
1420 | (vq->packed.used_wrap_counter << | |
1421 | VRING_PACKED_EVENT_F_WRAP_CTR))); | |
1422 | ||
1ce9e605 TB |
1423 | LAST_ADD_TIME_INVALID(vq); |
1424 | ||
1425 | END_USE(vq); | |
1426 | return ret; | |
1427 | } | |
1428 | ||
1429 | static void virtqueue_disable_cb_packed(struct virtqueue *_vq) | |
1430 | { | |
1431 | struct vring_virtqueue *vq = to_vvq(_vq); | |
1432 | ||
1433 | if (vq->packed.event_flags_shadow != VRING_PACKED_EVENT_FLAG_DISABLE) { | |
1434 | vq->packed.event_flags_shadow = VRING_PACKED_EVENT_FLAG_DISABLE; | |
1435 | vq->packed.vring.driver->flags = | |
1436 | cpu_to_le16(vq->packed.event_flags_shadow); | |
1437 | } | |
1438 | } | |
1439 | ||
1440 | static unsigned virtqueue_enable_cb_prepare_packed(struct virtqueue *_vq) | |
1441 | { | |
1442 | struct vring_virtqueue *vq = to_vvq(_vq); | |
1443 | ||
1444 | START_USE(vq); | |
1445 | ||
1446 | /* | |
1447 | * We optimistically turn back on interrupts, then check if there was | |
1448 | * more to do. | |
1449 | */ | |
1450 | ||
f51f9826 TB |
1451 | if (vq->event) { |
1452 | vq->packed.vring.driver->off_wrap = | |
1453 | cpu_to_le16(vq->last_used_idx | | |
1454 | (vq->packed.used_wrap_counter << | |
1455 | VRING_PACKED_EVENT_F_WRAP_CTR)); | |
1456 | /* | |
1457 | * We need to update event offset and event wrap | |
1458 | * counter first before updating event flags. | |
1459 | */ | |
1460 | virtio_wmb(vq->weak_barriers); | |
1461 | } | |
1462 | ||
1ce9e605 | 1463 | if (vq->packed.event_flags_shadow == VRING_PACKED_EVENT_FLAG_DISABLE) { |
f51f9826 TB |
1464 | vq->packed.event_flags_shadow = vq->event ? |
1465 | VRING_PACKED_EVENT_FLAG_DESC : | |
1466 | VRING_PACKED_EVENT_FLAG_ENABLE; | |
1ce9e605 TB |
1467 | vq->packed.vring.driver->flags = |
1468 | cpu_to_le16(vq->packed.event_flags_shadow); | |
1469 | } | |
1470 | ||
1471 | END_USE(vq); | |
1472 | return vq->last_used_idx | ((u16)vq->packed.used_wrap_counter << | |
1473 | VRING_PACKED_EVENT_F_WRAP_CTR); | |
1474 | } | |
1475 | ||
1476 | static bool virtqueue_poll_packed(struct virtqueue *_vq, u16 off_wrap) | |
1477 | { | |
1478 | struct vring_virtqueue *vq = to_vvq(_vq); | |
1479 | bool wrap_counter; | |
1480 | u16 used_idx; | |
1481 | ||
1482 | wrap_counter = off_wrap >> VRING_PACKED_EVENT_F_WRAP_CTR; | |
1483 | used_idx = off_wrap & ~(1 << VRING_PACKED_EVENT_F_WRAP_CTR); | |
1484 | ||
1485 | return is_used_desc_packed(vq, used_idx, wrap_counter); | |
1486 | } | |
1487 | ||
1488 | static bool virtqueue_enable_cb_delayed_packed(struct virtqueue *_vq) | |
1489 | { | |
1490 | struct vring_virtqueue *vq = to_vvq(_vq); | |
1491 | u16 used_idx, wrap_counter; | |
f51f9826 | 1492 | u16 bufs; |
1ce9e605 TB |
1493 | |
1494 | START_USE(vq); | |
1495 | ||
1496 | /* | |
1497 | * We optimistically turn back on interrupts, then check if there was | |
1498 | * more to do. | |
1499 | */ | |
1500 | ||
f51f9826 TB |
1501 | if (vq->event) { |
1502 | /* TODO: tune this threshold */ | |
1503 | bufs = (vq->packed.vring.num - vq->vq.num_free) * 3 / 4; | |
1504 | wrap_counter = vq->packed.used_wrap_counter; | |
1505 | ||
1506 | used_idx = vq->last_used_idx + bufs; | |
1507 | if (used_idx >= vq->packed.vring.num) { | |
1508 | used_idx -= vq->packed.vring.num; | |
1509 | wrap_counter ^= 1; | |
1510 | } | |
1511 | ||
1512 | vq->packed.vring.driver->off_wrap = cpu_to_le16(used_idx | | |
1513 | (wrap_counter << VRING_PACKED_EVENT_F_WRAP_CTR)); | |
1514 | ||
1515 | /* | |
1516 | * We need to update event offset and event wrap | |
1517 | * counter first before updating event flags. | |
1518 | */ | |
1519 | virtio_wmb(vq->weak_barriers); | |
f51f9826 | 1520 | } |
1ce9e605 TB |
1521 | |
1522 | if (vq->packed.event_flags_shadow == VRING_PACKED_EVENT_FLAG_DISABLE) { | |
f51f9826 TB |
1523 | vq->packed.event_flags_shadow = vq->event ? |
1524 | VRING_PACKED_EVENT_FLAG_DESC : | |
1525 | VRING_PACKED_EVENT_FLAG_ENABLE; | |
1ce9e605 TB |
1526 | vq->packed.vring.driver->flags = |
1527 | cpu_to_le16(vq->packed.event_flags_shadow); | |
1528 | } | |
1529 | ||
1530 | /* | |
1531 | * We need to update event suppression structure first | |
1532 | * before re-checking for more used buffers. | |
1533 | */ | |
1534 | virtio_mb(vq->weak_barriers); | |
1535 | ||
40ce7919 ML |
1536 | if (is_used_desc_packed(vq, |
1537 | vq->last_used_idx, | |
1538 | vq->packed.used_wrap_counter)) { | |
1ce9e605 TB |
1539 | END_USE(vq); |
1540 | return false; | |
1541 | } | |
1542 | ||
1543 | END_USE(vq); | |
1544 | return true; | |
1545 | } | |
1546 | ||
1547 | static void *virtqueue_detach_unused_buf_packed(struct virtqueue *_vq) | |
1548 | { | |
1549 | struct vring_virtqueue *vq = to_vvq(_vq); | |
1550 | unsigned int i; | |
1551 | void *buf; | |
1552 | ||
1553 | START_USE(vq); | |
1554 | ||
1555 | for (i = 0; i < vq->packed.vring.num; i++) { | |
1556 | if (!vq->packed.desc_state[i].data) | |
1557 | continue; | |
1558 | /* detach_buf clears data, so grab it now. */ | |
1559 | buf = vq->packed.desc_state[i].data; | |
1560 | detach_buf_packed(vq, i, NULL); | |
1561 | END_USE(vq); | |
1562 | return buf; | |
1563 | } | |
1564 | /* That should have freed everything. */ | |
1565 | BUG_ON(vq->vq.num_free != vq->packed.vring.num); | |
1566 | ||
1567 | END_USE(vq); | |
1568 | return NULL; | |
1569 | } | |
1570 | ||
5a222421 JW |
1571 | static struct vring_desc_extra *vring_alloc_desc_extra(struct vring_virtqueue *vq, |
1572 | unsigned int num) | |
1573 | { | |
1574 | struct vring_desc_extra *desc_extra; | |
1575 | unsigned int i; | |
1576 | ||
1577 | desc_extra = kmalloc_array(num, sizeof(struct vring_desc_extra), | |
1578 | GFP_KERNEL); | |
1579 | if (!desc_extra) | |
1580 | return NULL; | |
1581 | ||
1582 | memset(desc_extra, 0, num * sizeof(struct vring_desc_extra)); | |
1583 | ||
1584 | for (i = 0; i < num - 1; i++) | |
1585 | desc_extra[i].next = i + 1; | |
1586 | ||
1587 | return desc_extra; | |
1588 | } | |
1589 | ||
1ce9e605 TB |
1590 | static struct virtqueue *vring_create_virtqueue_packed( |
1591 | unsigned int index, | |
1592 | unsigned int num, | |
1593 | unsigned int vring_align, | |
1594 | struct virtio_device *vdev, | |
1595 | bool weak_barriers, | |
1596 | bool may_reduce_num, | |
1597 | bool context, | |
1598 | bool (*notify)(struct virtqueue *), | |
1599 | void (*callback)(struct virtqueue *), | |
1600 | const char *name) | |
1601 | { | |
1602 | struct vring_virtqueue *vq; | |
1603 | struct vring_packed_desc *ring; | |
1604 | struct vring_packed_desc_event *driver, *device; | |
1605 | dma_addr_t ring_dma_addr, driver_event_dma_addr, device_event_dma_addr; | |
1606 | size_t ring_size_in_bytes, event_size_in_bytes; | |
1ce9e605 TB |
1607 | |
1608 | ring_size_in_bytes = num * sizeof(struct vring_packed_desc); | |
1609 | ||
1610 | ring = vring_alloc_queue(vdev, ring_size_in_bytes, | |
1611 | &ring_dma_addr, | |
1612 | GFP_KERNEL|__GFP_NOWARN|__GFP_ZERO); | |
1613 | if (!ring) | |
1614 | goto err_ring; | |
1615 | ||
1616 | event_size_in_bytes = sizeof(struct vring_packed_desc_event); | |
1617 | ||
1618 | driver = vring_alloc_queue(vdev, event_size_in_bytes, | |
1619 | &driver_event_dma_addr, | |
1620 | GFP_KERNEL|__GFP_NOWARN|__GFP_ZERO); | |
1621 | if (!driver) | |
1622 | goto err_driver; | |
1623 | ||
1624 | device = vring_alloc_queue(vdev, event_size_in_bytes, | |
1625 | &device_event_dma_addr, | |
1626 | GFP_KERNEL|__GFP_NOWARN|__GFP_ZERO); | |
1627 | if (!device) | |
1628 | goto err_device; | |
1629 | ||
1630 | vq = kmalloc(sizeof(*vq), GFP_KERNEL); | |
1631 | if (!vq) | |
1632 | goto err_vq; | |
1633 | ||
1634 | vq->vq.callback = callback; | |
1635 | vq->vq.vdev = vdev; | |
1636 | vq->vq.name = name; | |
1637 | vq->vq.num_free = num; | |
1638 | vq->vq.index = index; | |
1639 | vq->we_own_ring = true; | |
1640 | vq->notify = notify; | |
1641 | vq->weak_barriers = weak_barriers; | |
1642 | vq->broken = false; | |
1643 | vq->last_used_idx = 0; | |
8d622d21 | 1644 | vq->event_triggered = false; |
1ce9e605 TB |
1645 | vq->num_added = 0; |
1646 | vq->packed_ring = true; | |
1647 | vq->use_dma_api = vring_use_dma_api(vdev); | |
1ce9e605 TB |
1648 | #ifdef DEBUG |
1649 | vq->in_use = false; | |
1650 | vq->last_add_time_valid = false; | |
1651 | #endif | |
1652 | ||
1653 | vq->indirect = virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC) && | |
1654 | !context; | |
1655 | vq->event = virtio_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX); | |
1656 | ||
45383fb0 TB |
1657 | if (virtio_has_feature(vdev, VIRTIO_F_ORDER_PLATFORM)) |
1658 | vq->weak_barriers = false; | |
1659 | ||
1ce9e605 TB |
1660 | vq->packed.ring_dma_addr = ring_dma_addr; |
1661 | vq->packed.driver_event_dma_addr = driver_event_dma_addr; | |
1662 | vq->packed.device_event_dma_addr = device_event_dma_addr; | |
1663 | ||
1664 | vq->packed.ring_size_in_bytes = ring_size_in_bytes; | |
1665 | vq->packed.event_size_in_bytes = event_size_in_bytes; | |
1666 | ||
1667 | vq->packed.vring.num = num; | |
1668 | vq->packed.vring.desc = ring; | |
1669 | vq->packed.vring.driver = driver; | |
1670 | vq->packed.vring.device = device; | |
1671 | ||
1672 | vq->packed.next_avail_idx = 0; | |
1673 | vq->packed.avail_wrap_counter = 1; | |
1674 | vq->packed.used_wrap_counter = 1; | |
1675 | vq->packed.event_flags_shadow = 0; | |
1676 | vq->packed.avail_used_flags = 1 << VRING_PACKED_DESC_F_AVAIL; | |
1677 | ||
1678 | vq->packed.desc_state = kmalloc_array(num, | |
1679 | sizeof(struct vring_desc_state_packed), | |
1680 | GFP_KERNEL); | |
1681 | if (!vq->packed.desc_state) | |
1682 | goto err_desc_state; | |
1683 | ||
1684 | memset(vq->packed.desc_state, 0, | |
1685 | num * sizeof(struct vring_desc_state_packed)); | |
1686 | ||
1687 | /* Put everything in free lists. */ | |
1688 | vq->free_head = 0; | |
1ce9e605 | 1689 | |
5a222421 | 1690 | vq->packed.desc_extra = vring_alloc_desc_extra(vq, num); |
1ce9e605 TB |
1691 | if (!vq->packed.desc_extra) |
1692 | goto err_desc_extra; | |
1693 | ||
1ce9e605 TB |
1694 | /* No callback? Tell other side not to bother us. */ |
1695 | if (!callback) { | |
1696 | vq->packed.event_flags_shadow = VRING_PACKED_EVENT_FLAG_DISABLE; | |
1697 | vq->packed.vring.driver->flags = | |
1698 | cpu_to_le16(vq->packed.event_flags_shadow); | |
1699 | } | |
1700 | ||
e152d8af | 1701 | list_add_tail(&vq->vq.list, &vdev->vqs); |
1ce9e605 TB |
1702 | return &vq->vq; |
1703 | ||
1704 | err_desc_extra: | |
1705 | kfree(vq->packed.desc_state); | |
1706 | err_desc_state: | |
1707 | kfree(vq); | |
1708 | err_vq: | |
ae93d8ea | 1709 | vring_free_queue(vdev, event_size_in_bytes, device, device_event_dma_addr); |
1ce9e605 | 1710 | err_device: |
ae93d8ea | 1711 | vring_free_queue(vdev, event_size_in_bytes, driver, driver_event_dma_addr); |
1ce9e605 TB |
1712 | err_driver: |
1713 | vring_free_queue(vdev, ring_size_in_bytes, ring, ring_dma_addr); | |
1714 | err_ring: | |
1715 | return NULL; | |
1716 | } | |
1717 | ||
1718 | ||
e6f633e5 TB |
1719 | /* |
1720 | * Generic functions and exported symbols. | |
1721 | */ | |
1722 | ||
1723 | static inline int virtqueue_add(struct virtqueue *_vq, | |
1724 | struct scatterlist *sgs[], | |
1725 | unsigned int total_sg, | |
1726 | unsigned int out_sgs, | |
1727 | unsigned int in_sgs, | |
1728 | void *data, | |
1729 | void *ctx, | |
1730 | gfp_t gfp) | |
1731 | { | |
1ce9e605 TB |
1732 | struct vring_virtqueue *vq = to_vvq(_vq); |
1733 | ||
1734 | return vq->packed_ring ? virtqueue_add_packed(_vq, sgs, total_sg, | |
1735 | out_sgs, in_sgs, data, ctx, gfp) : | |
1736 | virtqueue_add_split(_vq, sgs, total_sg, | |
1737 | out_sgs, in_sgs, data, ctx, gfp); | |
e6f633e5 TB |
1738 | } |
1739 | ||
1740 | /** | |
1741 | * virtqueue_add_sgs - expose buffers to other end | |
a5581206 | 1742 | * @_vq: the struct virtqueue we're talking about. |
e6f633e5 | 1743 | * @sgs: array of terminated scatterlists. |
a5581206 JB |
1744 | * @out_sgs: the number of scatterlists readable by other side |
1745 | * @in_sgs: the number of scatterlists which are writable (after readable ones) | |
e6f633e5 TB |
1746 | * @data: the token identifying the buffer. |
1747 | * @gfp: how to do memory allocations (if necessary). | |
1748 | * | |
1749 | * Caller must ensure we don't call this with other virtqueue operations | |
1750 | * at the same time (except where noted). | |
1751 | * | |
1752 | * Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO). | |
1753 | */ | |
1754 | int virtqueue_add_sgs(struct virtqueue *_vq, | |
1755 | struct scatterlist *sgs[], | |
1756 | unsigned int out_sgs, | |
1757 | unsigned int in_sgs, | |
1758 | void *data, | |
1759 | gfp_t gfp) | |
1760 | { | |
1761 | unsigned int i, total_sg = 0; | |
1762 | ||
1763 | /* Count them first. */ | |
1764 | for (i = 0; i < out_sgs + in_sgs; i++) { | |
1765 | struct scatterlist *sg; | |
1766 | ||
1767 | for (sg = sgs[i]; sg; sg = sg_next(sg)) | |
1768 | total_sg++; | |
1769 | } | |
1770 | return virtqueue_add(_vq, sgs, total_sg, out_sgs, in_sgs, | |
1771 | data, NULL, gfp); | |
1772 | } | |
1773 | EXPORT_SYMBOL_GPL(virtqueue_add_sgs); | |
1774 | ||
1775 | /** | |
1776 | * virtqueue_add_outbuf - expose output buffers to other end | |
1777 | * @vq: the struct virtqueue we're talking about. | |
1778 | * @sg: scatterlist (must be well-formed and terminated!) | |
1779 | * @num: the number of entries in @sg readable by other side | |
1780 | * @data: the token identifying the buffer. | |
1781 | * @gfp: how to do memory allocations (if necessary). | |
1782 | * | |
1783 | * Caller must ensure we don't call this with other virtqueue operations | |
1784 | * at the same time (except where noted). | |
1785 | * | |
1786 | * Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO). | |
1787 | */ | |
1788 | int virtqueue_add_outbuf(struct virtqueue *vq, | |
1789 | struct scatterlist *sg, unsigned int num, | |
1790 | void *data, | |
1791 | gfp_t gfp) | |
1792 | { | |
1793 | return virtqueue_add(vq, &sg, num, 1, 0, data, NULL, gfp); | |
1794 | } | |
1795 | EXPORT_SYMBOL_GPL(virtqueue_add_outbuf); | |
1796 | ||
1797 | /** | |
1798 | * virtqueue_add_inbuf - expose input buffers to other end | |
1799 | * @vq: the struct virtqueue we're talking about. | |
1800 | * @sg: scatterlist (must be well-formed and terminated!) | |
1801 | * @num: the number of entries in @sg writable by other side | |
1802 | * @data: the token identifying the buffer. | |
1803 | * @gfp: how to do memory allocations (if necessary). | |
1804 | * | |
1805 | * Caller must ensure we don't call this with other virtqueue operations | |
1806 | * at the same time (except where noted). | |
1807 | * | |
1808 | * Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO). | |
1809 | */ | |
1810 | int virtqueue_add_inbuf(struct virtqueue *vq, | |
1811 | struct scatterlist *sg, unsigned int num, | |
1812 | void *data, | |
1813 | gfp_t gfp) | |
1814 | { | |
1815 | return virtqueue_add(vq, &sg, num, 0, 1, data, NULL, gfp); | |
1816 | } | |
1817 | EXPORT_SYMBOL_GPL(virtqueue_add_inbuf); | |
1818 | ||
1819 | /** | |
1820 | * virtqueue_add_inbuf_ctx - expose input buffers to other end | |
1821 | * @vq: the struct virtqueue we're talking about. | |
1822 | * @sg: scatterlist (must be well-formed and terminated!) | |
1823 | * @num: the number of entries in @sg writable by other side | |
1824 | * @data: the token identifying the buffer. | |
1825 | * @ctx: extra context for the token | |
1826 | * @gfp: how to do memory allocations (if necessary). | |
1827 | * | |
1828 | * Caller must ensure we don't call this with other virtqueue operations | |
1829 | * at the same time (except where noted). | |
1830 | * | |
1831 | * Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO). | |
1832 | */ | |
1833 | int virtqueue_add_inbuf_ctx(struct virtqueue *vq, | |
1834 | struct scatterlist *sg, unsigned int num, | |
1835 | void *data, | |
1836 | void *ctx, | |
1837 | gfp_t gfp) | |
1838 | { | |
1839 | return virtqueue_add(vq, &sg, num, 0, 1, data, ctx, gfp); | |
1840 | } | |
1841 | EXPORT_SYMBOL_GPL(virtqueue_add_inbuf_ctx); | |
1842 | ||
1843 | /** | |
1844 | * virtqueue_kick_prepare - first half of split virtqueue_kick call. | |
a5581206 | 1845 | * @_vq: the struct virtqueue |
e6f633e5 TB |
1846 | * |
1847 | * Instead of virtqueue_kick(), you can do: | |
1848 | * if (virtqueue_kick_prepare(vq)) | |
1849 | * virtqueue_notify(vq); | |
1850 | * | |
1851 | * This is sometimes useful because the virtqueue_kick_prepare() needs | |
1852 | * to be serialized, but the actual virtqueue_notify() call does not. | |
1853 | */ | |
1854 | bool virtqueue_kick_prepare(struct virtqueue *_vq) | |
1855 | { | |
1ce9e605 TB |
1856 | struct vring_virtqueue *vq = to_vvq(_vq); |
1857 | ||
1858 | return vq->packed_ring ? virtqueue_kick_prepare_packed(_vq) : | |
1859 | virtqueue_kick_prepare_split(_vq); | |
e6f633e5 TB |
1860 | } |
1861 | EXPORT_SYMBOL_GPL(virtqueue_kick_prepare); | |
1862 | ||
1863 | /** | |
1864 | * virtqueue_notify - second half of split virtqueue_kick call. | |
a5581206 | 1865 | * @_vq: the struct virtqueue |
e6f633e5 TB |
1866 | * |
1867 | * This does not need to be serialized. | |
1868 | * | |
1869 | * Returns false if host notify failed or queue is broken, otherwise true. | |
1870 | */ | |
1871 | bool virtqueue_notify(struct virtqueue *_vq) | |
1872 | { | |
1873 | struct vring_virtqueue *vq = to_vvq(_vq); | |
1874 | ||
1875 | if (unlikely(vq->broken)) | |
1876 | return false; | |
1877 | ||
1878 | /* Prod other side to tell it about changes. */ | |
1879 | if (!vq->notify(_vq)) { | |
1880 | vq->broken = true; | |
1881 | return false; | |
1882 | } | |
1883 | return true; | |
1884 | } | |
1885 | EXPORT_SYMBOL_GPL(virtqueue_notify); | |
1886 | ||
1887 | /** | |
1888 | * virtqueue_kick - update after add_buf | |
1889 | * @vq: the struct virtqueue | |
1890 | * | |
1891 | * After one or more virtqueue_add_* calls, invoke this to kick | |
1892 | * the other side. | |
1893 | * | |
1894 | * Caller must ensure we don't call this with other virtqueue | |
1895 | * operations at the same time (except where noted). | |
1896 | * | |
1897 | * Returns false if kick failed, otherwise true. | |
1898 | */ | |
1899 | bool virtqueue_kick(struct virtqueue *vq) | |
1900 | { | |
1901 | if (virtqueue_kick_prepare(vq)) | |
1902 | return virtqueue_notify(vq); | |
1903 | return true; | |
1904 | } | |
1905 | EXPORT_SYMBOL_GPL(virtqueue_kick); | |
1906 | ||
1907 | /** | |
31c11db6 | 1908 | * virtqueue_get_buf_ctx - get the next used buffer |
a5581206 | 1909 | * @_vq: the struct virtqueue we're talking about. |
e6f633e5 | 1910 | * @len: the length written into the buffer |
a5581206 | 1911 | * @ctx: extra context for the token |
e6f633e5 TB |
1912 | * |
1913 | * If the device wrote data into the buffer, @len will be set to the | |
1914 | * amount written. This means you don't need to clear the buffer | |
1915 | * beforehand to ensure there's no data leakage in the case of short | |
1916 | * writes. | |
1917 | * | |
1918 | * Caller must ensure we don't call this with other virtqueue | |
1919 | * operations at the same time (except where noted). | |
1920 | * | |
1921 | * Returns NULL if there are no used buffers, or the "data" token | |
1922 | * handed to virtqueue_add_*(). | |
1923 | */ | |
1924 | void *virtqueue_get_buf_ctx(struct virtqueue *_vq, unsigned int *len, | |
1925 | void **ctx) | |
1926 | { | |
1ce9e605 TB |
1927 | struct vring_virtqueue *vq = to_vvq(_vq); |
1928 | ||
1929 | return vq->packed_ring ? virtqueue_get_buf_ctx_packed(_vq, len, ctx) : | |
1930 | virtqueue_get_buf_ctx_split(_vq, len, ctx); | |
e6f633e5 TB |
1931 | } |
1932 | EXPORT_SYMBOL_GPL(virtqueue_get_buf_ctx); | |
1933 | ||
1934 | void *virtqueue_get_buf(struct virtqueue *_vq, unsigned int *len) | |
1935 | { | |
1936 | return virtqueue_get_buf_ctx(_vq, len, NULL); | |
1937 | } | |
1938 | EXPORT_SYMBOL_GPL(virtqueue_get_buf); | |
e6f633e5 TB |
1939 | /** |
1940 | * virtqueue_disable_cb - disable callbacks | |
a5581206 | 1941 | * @_vq: the struct virtqueue we're talking about. |
e6f633e5 TB |
1942 | * |
1943 | * Note that this is not necessarily synchronous, hence unreliable and only | |
1944 | * useful as an optimization. | |
1945 | * | |
1946 | * Unlike other operations, this need not be serialized. | |
1947 | */ | |
1948 | void virtqueue_disable_cb(struct virtqueue *_vq) | |
1949 | { | |
1ce9e605 TB |
1950 | struct vring_virtqueue *vq = to_vvq(_vq); |
1951 | ||
8d622d21 MT |
1952 | /* If device triggered an event already it won't trigger one again: |
1953 | * no need to disable. | |
1954 | */ | |
1955 | if (vq->event_triggered) | |
1956 | return; | |
1957 | ||
1ce9e605 TB |
1958 | if (vq->packed_ring) |
1959 | virtqueue_disable_cb_packed(_vq); | |
1960 | else | |
1961 | virtqueue_disable_cb_split(_vq); | |
e6f633e5 TB |
1962 | } |
1963 | EXPORT_SYMBOL_GPL(virtqueue_disable_cb); | |
1964 | ||
1965 | /** | |
1966 | * virtqueue_enable_cb_prepare - restart callbacks after disable_cb | |
a5581206 | 1967 | * @_vq: the struct virtqueue we're talking about. |
e6f633e5 TB |
1968 | * |
1969 | * This re-enables callbacks; it returns current queue state | |
1970 | * in an opaque unsigned value. This value should be later tested by | |
1971 | * virtqueue_poll, to detect a possible race between the driver checking for | |
1972 | * more work, and enabling callbacks. | |
1973 | * | |
1974 | * Caller must ensure we don't call this with other virtqueue | |
1975 | * operations at the same time (except where noted). | |
1976 | */ | |
1977 | unsigned virtqueue_enable_cb_prepare(struct virtqueue *_vq) | |
1978 | { | |
1ce9e605 TB |
1979 | struct vring_virtqueue *vq = to_vvq(_vq); |
1980 | ||
8d622d21 MT |
1981 | if (vq->event_triggered) |
1982 | vq->event_triggered = false; | |
1983 | ||
1ce9e605 TB |
1984 | return vq->packed_ring ? virtqueue_enable_cb_prepare_packed(_vq) : |
1985 | virtqueue_enable_cb_prepare_split(_vq); | |
e6f633e5 TB |
1986 | } |
1987 | EXPORT_SYMBOL_GPL(virtqueue_enable_cb_prepare); | |
1988 | ||
1989 | /** | |
1990 | * virtqueue_poll - query pending used buffers | |
a5581206 | 1991 | * @_vq: the struct virtqueue we're talking about. |
e6f633e5 TB |
1992 | * @last_used_idx: virtqueue state (from call to virtqueue_enable_cb_prepare). |
1993 | * | |
1994 | * Returns "true" if there are pending used buffers in the queue. | |
1995 | * | |
1996 | * This does not need to be serialized. | |
1997 | */ | |
1998 | bool virtqueue_poll(struct virtqueue *_vq, unsigned last_used_idx) | |
1999 | { | |
2000 | struct vring_virtqueue *vq = to_vvq(_vq); | |
2001 | ||
481a0d74 MW |
2002 | if (unlikely(vq->broken)) |
2003 | return false; | |
2004 | ||
e6f633e5 | 2005 | virtio_mb(vq->weak_barriers); |
1ce9e605 TB |
2006 | return vq->packed_ring ? virtqueue_poll_packed(_vq, last_used_idx) : |
2007 | virtqueue_poll_split(_vq, last_used_idx); | |
e6f633e5 TB |
2008 | } |
2009 | EXPORT_SYMBOL_GPL(virtqueue_poll); | |
2010 | ||
2011 | /** | |
2012 | * virtqueue_enable_cb - restart callbacks after disable_cb. | |
a5581206 | 2013 | * @_vq: the struct virtqueue we're talking about. |
e6f633e5 TB |
2014 | * |
2015 | * This re-enables callbacks; it returns "false" if there are pending | |
2016 | * buffers in the queue, to detect a possible race between the driver | |
2017 | * checking for more work, and enabling callbacks. | |
2018 | * | |
2019 | * Caller must ensure we don't call this with other virtqueue | |
2020 | * operations at the same time (except where noted). | |
2021 | */ | |
2022 | bool virtqueue_enable_cb(struct virtqueue *_vq) | |
2023 | { | |
2024 | unsigned last_used_idx = virtqueue_enable_cb_prepare(_vq); | |
2025 | ||
2026 | return !virtqueue_poll(_vq, last_used_idx); | |
2027 | } | |
2028 | EXPORT_SYMBOL_GPL(virtqueue_enable_cb); | |
2029 | ||
2030 | /** | |
2031 | * virtqueue_enable_cb_delayed - restart callbacks after disable_cb. | |
a5581206 | 2032 | * @_vq: the struct virtqueue we're talking about. |
e6f633e5 TB |
2033 | * |
2034 | * This re-enables callbacks but hints to the other side to delay | |
2035 | * interrupts until most of the available buffers have been processed; | |
2036 | * it returns "false" if there are many pending buffers in the queue, | |
2037 | * to detect a possible race between the driver checking for more work, | |
2038 | * and enabling callbacks. | |
2039 | * | |
2040 | * Caller must ensure we don't call this with other virtqueue | |
2041 | * operations at the same time (except where noted). | |
2042 | */ | |
2043 | bool virtqueue_enable_cb_delayed(struct virtqueue *_vq) | |
2044 | { | |
1ce9e605 TB |
2045 | struct vring_virtqueue *vq = to_vvq(_vq); |
2046 | ||
8d622d21 MT |
2047 | if (vq->event_triggered) |
2048 | vq->event_triggered = false; | |
2049 | ||
1ce9e605 TB |
2050 | return vq->packed_ring ? virtqueue_enable_cb_delayed_packed(_vq) : |
2051 | virtqueue_enable_cb_delayed_split(_vq); | |
e6f633e5 TB |
2052 | } |
2053 | EXPORT_SYMBOL_GPL(virtqueue_enable_cb_delayed); | |
2054 | ||
138fd251 TB |
2055 | /** |
2056 | * virtqueue_detach_unused_buf - detach first unused buffer | |
a5581206 | 2057 | * @_vq: the struct virtqueue we're talking about. |
138fd251 TB |
2058 | * |
2059 | * Returns NULL or the "data" token handed to virtqueue_add_*(). | |
2060 | * This is not valid on an active queue; it is useful only for device | |
2061 | * shutdown. | |
2062 | */ | |
2063 | void *virtqueue_detach_unused_buf(struct virtqueue *_vq) | |
2064 | { | |
1ce9e605 TB |
2065 | struct vring_virtqueue *vq = to_vvq(_vq); |
2066 | ||
2067 | return vq->packed_ring ? virtqueue_detach_unused_buf_packed(_vq) : | |
2068 | virtqueue_detach_unused_buf_split(_vq); | |
138fd251 | 2069 | } |
7c5e9ed0 | 2070 | EXPORT_SYMBOL_GPL(virtqueue_detach_unused_buf); |
c021eac4 | 2071 | |
138fd251 TB |
2072 | static inline bool more_used(const struct vring_virtqueue *vq) |
2073 | { | |
1ce9e605 | 2074 | return vq->packed_ring ? more_used_packed(vq) : more_used_split(vq); |
138fd251 TB |
2075 | } |
2076 | ||
0a8a69dd RR |
2077 | irqreturn_t vring_interrupt(int irq, void *_vq) |
2078 | { | |
2079 | struct vring_virtqueue *vq = to_vvq(_vq); | |
2080 | ||
2081 | if (!more_used(vq)) { | |
2082 | pr_debug("virtqueue interrupt with no work for %p\n", vq); | |
2083 | return IRQ_NONE; | |
2084 | } | |
2085 | ||
2086 | if (unlikely(vq->broken)) | |
2087 | return IRQ_HANDLED; | |
2088 | ||
8d622d21 MT |
2089 | /* Just a hint for performance: so it's ok that this can be racy! */ |
2090 | if (vq->event) | |
2091 | vq->event_triggered = true; | |
2092 | ||
0a8a69dd | 2093 | pr_debug("virtqueue callback for %p (%p)\n", vq, vq->vq.callback); |
18445c4d RR |
2094 | if (vq->vq.callback) |
2095 | vq->vq.callback(&vq->vq); | |
0a8a69dd RR |
2096 | |
2097 | return IRQ_HANDLED; | |
2098 | } | |
c6fd4701 | 2099 | EXPORT_SYMBOL_GPL(vring_interrupt); |
0a8a69dd | 2100 | |
1ce9e605 | 2101 | /* Only available for split ring */ |
2a2d1382 AL |
2102 | struct virtqueue *__vring_new_virtqueue(unsigned int index, |
2103 | struct vring vring, | |
2104 | struct virtio_device *vdev, | |
2105 | bool weak_barriers, | |
f94682dd | 2106 | bool context, |
2a2d1382 AL |
2107 | bool (*notify)(struct virtqueue *), |
2108 | void (*callback)(struct virtqueue *), | |
2109 | const char *name) | |
0a8a69dd | 2110 | { |
0a8a69dd | 2111 | unsigned int i; |
2a2d1382 | 2112 | struct vring_virtqueue *vq; |
0a8a69dd | 2113 | |
1ce9e605 TB |
2114 | if (virtio_has_feature(vdev, VIRTIO_F_RING_PACKED)) |
2115 | return NULL; | |
2116 | ||
cbeedb72 | 2117 | vq = kmalloc(sizeof(*vq), GFP_KERNEL); |
0a8a69dd RR |
2118 | if (!vq) |
2119 | return NULL; | |
2120 | ||
1ce9e605 | 2121 | vq->packed_ring = false; |
0a8a69dd RR |
2122 | vq->vq.callback = callback; |
2123 | vq->vq.vdev = vdev; | |
9499f5e7 | 2124 | vq->vq.name = name; |
2a2d1382 | 2125 | vq->vq.num_free = vring.num; |
06ca287d | 2126 | vq->vq.index = index; |
2a2d1382 | 2127 | vq->we_own_ring = false; |
0a8a69dd | 2128 | vq->notify = notify; |
7b21e34f | 2129 | vq->weak_barriers = weak_barriers; |
0a8a69dd RR |
2130 | vq->broken = false; |
2131 | vq->last_used_idx = 0; | |
8d622d21 | 2132 | vq->event_triggered = false; |
0a8a69dd | 2133 | vq->num_added = 0; |
fb3fba6b | 2134 | vq->use_dma_api = vring_use_dma_api(vdev); |
0a8a69dd RR |
2135 | #ifdef DEBUG |
2136 | vq->in_use = false; | |
e93300b1 | 2137 | vq->last_add_time_valid = false; |
0a8a69dd RR |
2138 | #endif |
2139 | ||
5a08b04f MT |
2140 | vq->indirect = virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC) && |
2141 | !context; | |
a5c262c5 | 2142 | vq->event = virtio_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX); |
9fa29b9d | 2143 | |
45383fb0 TB |
2144 | if (virtio_has_feature(vdev, VIRTIO_F_ORDER_PLATFORM)) |
2145 | vq->weak_barriers = false; | |
2146 | ||
d79dca75 TB |
2147 | vq->split.queue_dma_addr = 0; |
2148 | vq->split.queue_size_in_bytes = 0; | |
2149 | ||
e593bf97 TB |
2150 | vq->split.vring = vring; |
2151 | vq->split.avail_flags_shadow = 0; | |
2152 | vq->split.avail_idx_shadow = 0; | |
2153 | ||
0a8a69dd | 2154 | /* No callback? Tell other side not to bother us. */ |
f277ec42 | 2155 | if (!callback) { |
e593bf97 | 2156 | vq->split.avail_flags_shadow |= VRING_AVAIL_F_NO_INTERRUPT; |
0ea1e4a6 | 2157 | if (!vq->event) |
e593bf97 TB |
2158 | vq->split.vring.avail->flags = cpu_to_virtio16(vdev, |
2159 | vq->split.avail_flags_shadow); | |
f277ec42 | 2160 | } |
0a8a69dd | 2161 | |
cbeedb72 TB |
2162 | vq->split.desc_state = kmalloc_array(vring.num, |
2163 | sizeof(struct vring_desc_state_split), GFP_KERNEL); | |
5bc72234 JW |
2164 | if (!vq->split.desc_state) |
2165 | goto err_state; | |
cbeedb72 | 2166 | |
0a8a69dd | 2167 | /* Put everything in free lists. */ |
0a8a69dd | 2168 | vq->free_head = 0; |
2a2d1382 | 2169 | for (i = 0; i < vring.num-1; i++) |
e593bf97 | 2170 | vq->split.vring.desc[i].next = cpu_to_virtio16(vdev, i + 1); |
cbeedb72 TB |
2171 | memset(vq->split.desc_state, 0, vring.num * |
2172 | sizeof(struct vring_desc_state_split)); | |
0a8a69dd | 2173 | |
e152d8af | 2174 | list_add_tail(&vq->vq.list, &vdev->vqs); |
0a8a69dd | 2175 | return &vq->vq; |
5bc72234 JW |
2176 | |
2177 | err_state: | |
2178 | kfree(vq); | |
2179 | return NULL; | |
0a8a69dd | 2180 | } |
2a2d1382 AL |
2181 | EXPORT_SYMBOL_GPL(__vring_new_virtqueue); |
2182 | ||
2a2d1382 AL |
2183 | struct virtqueue *vring_create_virtqueue( |
2184 | unsigned int index, | |
2185 | unsigned int num, | |
2186 | unsigned int vring_align, | |
2187 | struct virtio_device *vdev, | |
2188 | bool weak_barriers, | |
2189 | bool may_reduce_num, | |
f94682dd | 2190 | bool context, |
2a2d1382 AL |
2191 | bool (*notify)(struct virtqueue *), |
2192 | void (*callback)(struct virtqueue *), | |
2193 | const char *name) | |
2194 | { | |
1ce9e605 TB |
2195 | |
2196 | if (virtio_has_feature(vdev, VIRTIO_F_RING_PACKED)) | |
2197 | return vring_create_virtqueue_packed(index, num, vring_align, | |
2198 | vdev, weak_barriers, may_reduce_num, | |
2199 | context, notify, callback, name); | |
2200 | ||
d79dca75 TB |
2201 | return vring_create_virtqueue_split(index, num, vring_align, |
2202 | vdev, weak_barriers, may_reduce_num, | |
2203 | context, notify, callback, name); | |
2a2d1382 AL |
2204 | } |
2205 | EXPORT_SYMBOL_GPL(vring_create_virtqueue); | |
2206 | ||
1ce9e605 | 2207 | /* Only available for split ring */ |
2a2d1382 AL |
2208 | struct virtqueue *vring_new_virtqueue(unsigned int index, |
2209 | unsigned int num, | |
2210 | unsigned int vring_align, | |
2211 | struct virtio_device *vdev, | |
2212 | bool weak_barriers, | |
f94682dd | 2213 | bool context, |
2a2d1382 AL |
2214 | void *pages, |
2215 | bool (*notify)(struct virtqueue *vq), | |
2216 | void (*callback)(struct virtqueue *vq), | |
2217 | const char *name) | |
2218 | { | |
2219 | struct vring vring; | |
1ce9e605 TB |
2220 | |
2221 | if (virtio_has_feature(vdev, VIRTIO_F_RING_PACKED)) | |
2222 | return NULL; | |
2223 | ||
2a2d1382 | 2224 | vring_init(&vring, num, pages, vring_align); |
f94682dd | 2225 | return __vring_new_virtqueue(index, vring, vdev, weak_barriers, context, |
2a2d1382 AL |
2226 | notify, callback, name); |
2227 | } | |
c6fd4701 | 2228 | EXPORT_SYMBOL_GPL(vring_new_virtqueue); |
0a8a69dd | 2229 | |
2a2d1382 | 2230 | void vring_del_virtqueue(struct virtqueue *_vq) |
0a8a69dd | 2231 | { |
2a2d1382 AL |
2232 | struct vring_virtqueue *vq = to_vvq(_vq); |
2233 | ||
2234 | if (vq->we_own_ring) { | |
1ce9e605 TB |
2235 | if (vq->packed_ring) { |
2236 | vring_free_queue(vq->vq.vdev, | |
2237 | vq->packed.ring_size_in_bytes, | |
2238 | vq->packed.vring.desc, | |
2239 | vq->packed.ring_dma_addr); | |
2240 | ||
2241 | vring_free_queue(vq->vq.vdev, | |
2242 | vq->packed.event_size_in_bytes, | |
2243 | vq->packed.vring.driver, | |
2244 | vq->packed.driver_event_dma_addr); | |
2245 | ||
2246 | vring_free_queue(vq->vq.vdev, | |
2247 | vq->packed.event_size_in_bytes, | |
2248 | vq->packed.vring.device, | |
2249 | vq->packed.device_event_dma_addr); | |
2250 | ||
2251 | kfree(vq->packed.desc_state); | |
2252 | kfree(vq->packed.desc_extra); | |
2253 | } else { | |
2254 | vring_free_queue(vq->vq.vdev, | |
2255 | vq->split.queue_size_in_bytes, | |
2256 | vq->split.vring.desc, | |
2257 | vq->split.queue_dma_addr); | |
1ce9e605 | 2258 | } |
2a2d1382 | 2259 | } |
f13f09a1 SA |
2260 | if (!vq->packed_ring) |
2261 | kfree(vq->split.desc_state); | |
2a2d1382 AL |
2262 | list_del(&_vq->list); |
2263 | kfree(vq); | |
0a8a69dd | 2264 | } |
c6fd4701 | 2265 | EXPORT_SYMBOL_GPL(vring_del_virtqueue); |
0a8a69dd | 2266 | |
e34f8725 RR |
2267 | /* Manipulates transport-specific feature bits. */ |
2268 | void vring_transport_features(struct virtio_device *vdev) | |
2269 | { | |
2270 | unsigned int i; | |
2271 | ||
2272 | for (i = VIRTIO_TRANSPORT_F_START; i < VIRTIO_TRANSPORT_F_END; i++) { | |
2273 | switch (i) { | |
9fa29b9d MM |
2274 | case VIRTIO_RING_F_INDIRECT_DESC: |
2275 | break; | |
a5c262c5 MT |
2276 | case VIRTIO_RING_F_EVENT_IDX: |
2277 | break; | |
747ae34a MT |
2278 | case VIRTIO_F_VERSION_1: |
2279 | break; | |
321bd212 | 2280 | case VIRTIO_F_ACCESS_PLATFORM: |
1a937693 | 2281 | break; |
f959a128 TB |
2282 | case VIRTIO_F_RING_PACKED: |
2283 | break; | |
45383fb0 TB |
2284 | case VIRTIO_F_ORDER_PLATFORM: |
2285 | break; | |
e34f8725 RR |
2286 | default: |
2287 | /* We don't understand this bit. */ | |
e16e12be | 2288 | __virtio_clear_bit(vdev, i); |
e34f8725 RR |
2289 | } |
2290 | } | |
2291 | } | |
2292 | EXPORT_SYMBOL_GPL(vring_transport_features); | |
2293 | ||
5dfc1762 RR |
2294 | /** |
2295 | * virtqueue_get_vring_size - return the size of the virtqueue's vring | |
a5581206 | 2296 | * @_vq: the struct virtqueue containing the vring of interest. |
5dfc1762 RR |
2297 | * |
2298 | * Returns the size of the vring. This is mainly used for boasting to | |
2299 | * userspace. Unlike other operations, this need not be serialized. | |
2300 | */ | |
8f9f4668 RJ |
2301 | unsigned int virtqueue_get_vring_size(struct virtqueue *_vq) |
2302 | { | |
2303 | ||
2304 | struct vring_virtqueue *vq = to_vvq(_vq); | |
2305 | ||
1ce9e605 | 2306 | return vq->packed_ring ? vq->packed.vring.num : vq->split.vring.num; |
8f9f4668 RJ |
2307 | } |
2308 | EXPORT_SYMBOL_GPL(virtqueue_get_vring_size); | |
2309 | ||
b3b32c94 HG |
2310 | bool virtqueue_is_broken(struct virtqueue *_vq) |
2311 | { | |
2312 | struct vring_virtqueue *vq = to_vvq(_vq); | |
2313 | ||
2314 | return vq->broken; | |
2315 | } | |
2316 | EXPORT_SYMBOL_GPL(virtqueue_is_broken); | |
2317 | ||
e2dcdfe9 RR |
2318 | /* |
2319 | * This should prevent the device from being used, allowing drivers to | |
2320 | * recover. You may need to grab appropriate locks to flush. | |
2321 | */ | |
2322 | void virtio_break_device(struct virtio_device *dev) | |
2323 | { | |
2324 | struct virtqueue *_vq; | |
2325 | ||
2326 | list_for_each_entry(_vq, &dev->vqs, list) { | |
2327 | struct vring_virtqueue *vq = to_vvq(_vq); | |
2328 | vq->broken = true; | |
2329 | } | |
2330 | } | |
2331 | EXPORT_SYMBOL_GPL(virtio_break_device); | |
2332 | ||
2a2d1382 | 2333 | dma_addr_t virtqueue_get_desc_addr(struct virtqueue *_vq) |
89062652 CH |
2334 | { |
2335 | struct vring_virtqueue *vq = to_vvq(_vq); | |
2336 | ||
2a2d1382 AL |
2337 | BUG_ON(!vq->we_own_ring); |
2338 | ||
1ce9e605 TB |
2339 | if (vq->packed_ring) |
2340 | return vq->packed.ring_dma_addr; | |
2341 | ||
d79dca75 | 2342 | return vq->split.queue_dma_addr; |
89062652 | 2343 | } |
2a2d1382 | 2344 | EXPORT_SYMBOL_GPL(virtqueue_get_desc_addr); |
89062652 | 2345 | |
2a2d1382 | 2346 | dma_addr_t virtqueue_get_avail_addr(struct virtqueue *_vq) |
89062652 CH |
2347 | { |
2348 | struct vring_virtqueue *vq = to_vvq(_vq); | |
2349 | ||
2a2d1382 AL |
2350 | BUG_ON(!vq->we_own_ring); |
2351 | ||
1ce9e605 TB |
2352 | if (vq->packed_ring) |
2353 | return vq->packed.driver_event_dma_addr; | |
2354 | ||
d79dca75 | 2355 | return vq->split.queue_dma_addr + |
e593bf97 | 2356 | ((char *)vq->split.vring.avail - (char *)vq->split.vring.desc); |
2a2d1382 AL |
2357 | } |
2358 | EXPORT_SYMBOL_GPL(virtqueue_get_avail_addr); | |
2359 | ||
2360 | dma_addr_t virtqueue_get_used_addr(struct virtqueue *_vq) | |
2361 | { | |
2362 | struct vring_virtqueue *vq = to_vvq(_vq); | |
2363 | ||
2364 | BUG_ON(!vq->we_own_ring); | |
2365 | ||
1ce9e605 TB |
2366 | if (vq->packed_ring) |
2367 | return vq->packed.device_event_dma_addr; | |
2368 | ||
d79dca75 | 2369 | return vq->split.queue_dma_addr + |
e593bf97 | 2370 | ((char *)vq->split.vring.used - (char *)vq->split.vring.desc); |
2a2d1382 AL |
2371 | } |
2372 | EXPORT_SYMBOL_GPL(virtqueue_get_used_addr); | |
2373 | ||
1ce9e605 | 2374 | /* Only available for split ring */ |
2a2d1382 AL |
2375 | const struct vring *virtqueue_get_vring(struct virtqueue *vq) |
2376 | { | |
e593bf97 | 2377 | return &to_vvq(vq)->split.vring; |
89062652 | 2378 | } |
2a2d1382 | 2379 | EXPORT_SYMBOL_GPL(virtqueue_get_vring); |
89062652 | 2380 | |
c6fd4701 | 2381 | MODULE_LICENSE("GPL"); |