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