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> |
f8ce7263 | 14 | #include <linux/spinlock.h> |
78fe3987 | 15 | #include <xen/xen.h> |
0a8a69dd RR |
16 | |
17 | #ifdef DEBUG | |
18 | /* For development, we want to crash whenever the ring is screwed. */ | |
9499f5e7 RR |
19 | #define BAD_RING(_vq, fmt, args...) \ |
20 | do { \ | |
21 | dev_err(&(_vq)->vq.vdev->dev, \ | |
22 | "%s:"fmt, (_vq)->vq.name, ##args); \ | |
23 | BUG(); \ | |
24 | } while (0) | |
c5f841f1 RR |
25 | /* Caller is supposed to guarantee no reentry. */ |
26 | #define START_USE(_vq) \ | |
27 | do { \ | |
28 | if ((_vq)->in_use) \ | |
9499f5e7 RR |
29 | panic("%s:in_use = %i\n", \ |
30 | (_vq)->vq.name, (_vq)->in_use); \ | |
c5f841f1 | 31 | (_vq)->in_use = __LINE__; \ |
9499f5e7 | 32 | } while (0) |
3a35ce7d | 33 | #define END_USE(_vq) \ |
97a545ab | 34 | do { BUG_ON(!(_vq)->in_use); (_vq)->in_use = 0; } while(0) |
4d6a105e TB |
35 | #define LAST_ADD_TIME_UPDATE(_vq) \ |
36 | do { \ | |
37 | ktime_t now = ktime_get(); \ | |
38 | \ | |
39 | /* No kick or get, with .1 second between? Warn. */ \ | |
40 | if ((_vq)->last_add_time_valid) \ | |
41 | WARN_ON(ktime_to_ms(ktime_sub(now, \ | |
42 | (_vq)->last_add_time)) > 100); \ | |
43 | (_vq)->last_add_time = now; \ | |
44 | (_vq)->last_add_time_valid = true; \ | |
45 | } while (0) | |
46 | #define LAST_ADD_TIME_CHECK(_vq) \ | |
47 | do { \ | |
48 | if ((_vq)->last_add_time_valid) { \ | |
49 | WARN_ON(ktime_to_ms(ktime_sub(ktime_get(), \ | |
50 | (_vq)->last_add_time)) > 100); \ | |
51 | } \ | |
52 | } while (0) | |
53 | #define LAST_ADD_TIME_INVALID(_vq) \ | |
54 | ((_vq)->last_add_time_valid = false) | |
0a8a69dd | 55 | #else |
9499f5e7 RR |
56 | #define BAD_RING(_vq, fmt, args...) \ |
57 | do { \ | |
58 | dev_err(&_vq->vq.vdev->dev, \ | |
59 | "%s:"fmt, (_vq)->vq.name, ##args); \ | |
60 | (_vq)->broken = true; \ | |
61 | } while (0) | |
0a8a69dd RR |
62 | #define START_USE(vq) |
63 | #define END_USE(vq) | |
4d6a105e TB |
64 | #define LAST_ADD_TIME_UPDATE(vq) |
65 | #define LAST_ADD_TIME_CHECK(vq) | |
66 | #define LAST_ADD_TIME_INVALID(vq) | |
0a8a69dd RR |
67 | #endif |
68 | ||
cbeedb72 | 69 | struct vring_desc_state_split { |
780bc790 AL |
70 | void *data; /* Data for callback. */ |
71 | struct vring_desc *indir_desc; /* Indirect descriptor, if any. */ | |
72 | }; | |
73 | ||
1ce9e605 TB |
74 | struct vring_desc_state_packed { |
75 | void *data; /* Data for callback. */ | |
76 | struct vring_packed_desc *indir_desc; /* Indirect descriptor, if any. */ | |
77 | u16 num; /* Descriptor list length. */ | |
1ce9e605 TB |
78 | u16 last; /* The last desc state in a list. */ |
79 | }; | |
80 | ||
1f28750f | 81 | struct vring_desc_extra { |
1ce9e605 TB |
82 | dma_addr_t addr; /* Buffer DMA addr. */ |
83 | u32 len; /* Buffer length. */ | |
84 | u16 flags; /* Descriptor flags. */ | |
aeef9b47 | 85 | u16 next; /* The next desc state in a list. */ |
1ce9e605 TB |
86 | }; |
87 | ||
43b4f721 | 88 | struct vring_virtqueue { |
0a8a69dd RR |
89 | struct virtqueue vq; |
90 | ||
1ce9e605 TB |
91 | /* Is this a packed ring? */ |
92 | bool packed_ring; | |
93 | ||
fb3fba6b TB |
94 | /* Is DMA API used? */ |
95 | bool use_dma_api; | |
96 | ||
7b21e34f RR |
97 | /* Can we use weak barriers? */ |
98 | bool weak_barriers; | |
99 | ||
0a8a69dd RR |
100 | /* Other side has made a mess, don't try any more. */ |
101 | bool broken; | |
102 | ||
9fa29b9d MM |
103 | /* Host supports indirect buffers */ |
104 | bool indirect; | |
105 | ||
a5c262c5 MT |
106 | /* Host publishes avail event idx */ |
107 | bool event; | |
108 | ||
0a8a69dd RR |
109 | /* Head of free buffer list. */ |
110 | unsigned int free_head; | |
111 | /* Number we've added since last sync. */ | |
112 | unsigned int num_added; | |
113 | ||
114 | /* Last used index we've seen. */ | |
1bc4953e | 115 | u16 last_used_idx; |
0a8a69dd | 116 | |
8d622d21 MT |
117 | /* Hint for event idx: already triggered no need to disable. */ |
118 | bool event_triggered; | |
119 | ||
1ce9e605 TB |
120 | union { |
121 | /* Available for split ring */ | |
122 | struct { | |
123 | /* Actual memory layout for this queue. */ | |
124 | struct vring vring; | |
125 | ||
126 | /* Last written value to avail->flags */ | |
127 | u16 avail_flags_shadow; | |
f277ec42 | 128 | |
1ce9e605 TB |
129 | /* |
130 | * Last written value to avail->idx in | |
131 | * guest byte order. | |
132 | */ | |
133 | u16 avail_idx_shadow; | |
134 | ||
135 | /* Per-descriptor state. */ | |
136 | struct vring_desc_state_split *desc_state; | |
72b5e895 | 137 | struct vring_desc_extra *desc_extra; |
1ce9e605 TB |
138 | |
139 | /* DMA address and size information */ | |
140 | dma_addr_t queue_dma_addr; | |
141 | size_t queue_size_in_bytes; | |
142 | } split; | |
e593bf97 | 143 | |
1ce9e605 TB |
144 | /* Available for packed ring */ |
145 | struct { | |
146 | /* Actual memory layout for this queue. */ | |
9c0644ee MT |
147 | struct { |
148 | unsigned int num; | |
149 | struct vring_packed_desc *desc; | |
150 | struct vring_packed_desc_event *driver; | |
151 | struct vring_packed_desc_event *device; | |
152 | } vring; | |
cbeedb72 | 153 | |
1ce9e605 TB |
154 | /* Driver ring wrap counter. */ |
155 | bool avail_wrap_counter; | |
d79dca75 | 156 | |
1ce9e605 TB |
157 | /* Device ring wrap counter. */ |
158 | bool used_wrap_counter; | |
159 | ||
160 | /* Avail used flags. */ | |
161 | u16 avail_used_flags; | |
162 | ||
163 | /* Index of the next avail descriptor. */ | |
164 | u16 next_avail_idx; | |
165 | ||
166 | /* | |
167 | * Last written value to driver->flags in | |
168 | * guest byte order. | |
169 | */ | |
170 | u16 event_flags_shadow; | |
171 | ||
172 | /* Per-descriptor state. */ | |
173 | struct vring_desc_state_packed *desc_state; | |
1f28750f | 174 | struct vring_desc_extra *desc_extra; |
1ce9e605 TB |
175 | |
176 | /* DMA address and size information */ | |
177 | dma_addr_t ring_dma_addr; | |
178 | dma_addr_t driver_event_dma_addr; | |
179 | dma_addr_t device_event_dma_addr; | |
180 | size_t ring_size_in_bytes; | |
181 | size_t event_size_in_bytes; | |
182 | } packed; | |
183 | }; | |
f277ec42 | 184 | |
0a8a69dd | 185 | /* How to notify other side. FIXME: commonalize hcalls! */ |
46f9c2b9 | 186 | bool (*notify)(struct virtqueue *vq); |
0a8a69dd | 187 | |
2a2d1382 AL |
188 | /* DMA, allocation, and size information */ |
189 | bool we_own_ring; | |
2a2d1382 | 190 | |
0a8a69dd RR |
191 | #ifdef DEBUG |
192 | /* They're supposed to lock for us. */ | |
193 | unsigned int in_use; | |
e93300b1 RR |
194 | |
195 | /* Figure out if their kicks are too delayed. */ | |
196 | bool last_add_time_valid; | |
197 | ktime_t last_add_time; | |
0a8a69dd | 198 | #endif |
0a8a69dd RR |
199 | }; |
200 | ||
e6f633e5 TB |
201 | |
202 | /* | |
203 | * Helpers. | |
204 | */ | |
205 | ||
0a8a69dd RR |
206 | #define to_vvq(_vq) container_of(_vq, struct vring_virtqueue, vq) |
207 | ||
2f18c2d1 TB |
208 | static inline bool virtqueue_use_indirect(struct virtqueue *_vq, |
209 | unsigned int total_sg) | |
210 | { | |
211 | struct vring_virtqueue *vq = to_vvq(_vq); | |
212 | ||
213 | /* | |
214 | * If the host supports indirect descriptor tables, and we have multiple | |
215 | * buffers, then go indirect. FIXME: tune this threshold | |
216 | */ | |
217 | return (vq->indirect && total_sg > 1 && vq->vq.num_free); | |
218 | } | |
219 | ||
d26c96c8 | 220 | /* |
1a937693 MT |
221 | * Modern virtio devices have feature bits to specify whether they need a |
222 | * quirk and bypass the IOMMU. If not there, just use the DMA API. | |
223 | * | |
224 | * If there, the interaction between virtio and DMA API is messy. | |
d26c96c8 AL |
225 | * |
226 | * On most systems with virtio, physical addresses match bus addresses, | |
227 | * and it doesn't particularly matter whether we use the DMA API. | |
228 | * | |
229 | * On some systems, including Xen and any system with a physical device | |
230 | * that speaks virtio behind a physical IOMMU, we must use the DMA API | |
231 | * for virtio DMA to work at all. | |
232 | * | |
233 | * On other systems, including SPARC and PPC64, virtio-pci devices are | |
234 | * enumerated as though they are behind an IOMMU, but the virtio host | |
235 | * ignores the IOMMU, so we must either pretend that the IOMMU isn't | |
236 | * there or somehow map everything as the identity. | |
237 | * | |
238 | * For the time being, we preserve historic behavior and bypass the DMA | |
239 | * API. | |
1a937693 MT |
240 | * |
241 | * TODO: install a per-device DMA ops structure that does the right thing | |
242 | * taking into account all the above quirks, and use the DMA API | |
243 | * unconditionally on data path. | |
d26c96c8 AL |
244 | */ |
245 | ||
246 | static bool vring_use_dma_api(struct virtio_device *vdev) | |
247 | { | |
24b6842a | 248 | if (!virtio_has_dma_quirk(vdev)) |
1a937693 MT |
249 | return true; |
250 | ||
251 | /* Otherwise, we are left to guess. */ | |
78fe3987 AL |
252 | /* |
253 | * In theory, it's possible to have a buggy QEMU-supposed | |
254 | * emulated Q35 IOMMU and Xen enabled at the same time. On | |
255 | * such a configuration, virtio has never worked and will | |
256 | * not work without an even larger kludge. Instead, enable | |
257 | * the DMA API if we're a Xen guest, which at least allows | |
258 | * all of the sensible Xen configurations to work correctly. | |
259 | */ | |
260 | if (xen_domain()) | |
261 | return true; | |
262 | ||
d26c96c8 AL |
263 | return false; |
264 | } | |
265 | ||
e6d6dd6c JR |
266 | size_t virtio_max_dma_size(struct virtio_device *vdev) |
267 | { | |
268 | size_t max_segment_size = SIZE_MAX; | |
269 | ||
270 | if (vring_use_dma_api(vdev)) | |
271 | max_segment_size = dma_max_mapping_size(&vdev->dev); | |
272 | ||
273 | return max_segment_size; | |
274 | } | |
275 | EXPORT_SYMBOL_GPL(virtio_max_dma_size); | |
276 | ||
d79dca75 TB |
277 | static void *vring_alloc_queue(struct virtio_device *vdev, size_t size, |
278 | dma_addr_t *dma_handle, gfp_t flag) | |
279 | { | |
280 | if (vring_use_dma_api(vdev)) { | |
281 | return dma_alloc_coherent(vdev->dev.parent, size, | |
282 | dma_handle, flag); | |
283 | } else { | |
284 | void *queue = alloc_pages_exact(PAGE_ALIGN(size), flag); | |
285 | ||
286 | if (queue) { | |
287 | phys_addr_t phys_addr = virt_to_phys(queue); | |
288 | *dma_handle = (dma_addr_t)phys_addr; | |
289 | ||
290 | /* | |
291 | * Sanity check: make sure we dind't truncate | |
292 | * the address. The only arches I can find that | |
293 | * have 64-bit phys_addr_t but 32-bit dma_addr_t | |
294 | * are certain non-highmem MIPS and x86 | |
295 | * configurations, but these configurations | |
296 | * should never allocate physical pages above 32 | |
297 | * bits, so this is fine. Just in case, throw a | |
298 | * warning and abort if we end up with an | |
299 | * unrepresentable address. | |
300 | */ | |
301 | if (WARN_ON_ONCE(*dma_handle != phys_addr)) { | |
302 | free_pages_exact(queue, PAGE_ALIGN(size)); | |
303 | return NULL; | |
304 | } | |
305 | } | |
306 | return queue; | |
307 | } | |
308 | } | |
309 | ||
310 | static void vring_free_queue(struct virtio_device *vdev, size_t size, | |
311 | void *queue, dma_addr_t dma_handle) | |
312 | { | |
313 | if (vring_use_dma_api(vdev)) | |
314 | dma_free_coherent(vdev->dev.parent, size, queue, dma_handle); | |
315 | else | |
316 | free_pages_exact(queue, PAGE_ALIGN(size)); | |
317 | } | |
318 | ||
780bc790 AL |
319 | /* |
320 | * The DMA ops on various arches are rather gnarly right now, and | |
321 | * making all of the arch DMA ops work on the vring device itself | |
322 | * is a mess. For now, we use the parent device for DMA ops. | |
323 | */ | |
75bfa81b | 324 | static inline struct device *vring_dma_dev(const struct vring_virtqueue *vq) |
780bc790 AL |
325 | { |
326 | return vq->vq.vdev->dev.parent; | |
327 | } | |
328 | ||
329 | /* Map one sg entry. */ | |
330 | static dma_addr_t vring_map_one_sg(const struct vring_virtqueue *vq, | |
331 | struct scatterlist *sg, | |
332 | enum dma_data_direction direction) | |
333 | { | |
fb3fba6b | 334 | if (!vq->use_dma_api) |
780bc790 AL |
335 | return (dma_addr_t)sg_phys(sg); |
336 | ||
337 | /* | |
338 | * We can't use dma_map_sg, because we don't use scatterlists in | |
339 | * the way it expects (we don't guarantee that the scatterlist | |
340 | * will exist for the lifetime of the mapping). | |
341 | */ | |
342 | return dma_map_page(vring_dma_dev(vq), | |
343 | sg_page(sg), sg->offset, sg->length, | |
344 | direction); | |
345 | } | |
346 | ||
347 | static dma_addr_t vring_map_single(const struct vring_virtqueue *vq, | |
348 | void *cpu_addr, size_t size, | |
349 | enum dma_data_direction direction) | |
350 | { | |
fb3fba6b | 351 | if (!vq->use_dma_api) |
780bc790 AL |
352 | return (dma_addr_t)virt_to_phys(cpu_addr); |
353 | ||
354 | return dma_map_single(vring_dma_dev(vq), | |
355 | cpu_addr, size, direction); | |
356 | } | |
357 | ||
e6f633e5 TB |
358 | static int vring_mapping_error(const struct vring_virtqueue *vq, |
359 | dma_addr_t addr) | |
360 | { | |
fb3fba6b | 361 | if (!vq->use_dma_api) |
e6f633e5 TB |
362 | return 0; |
363 | ||
364 | return dma_mapping_error(vring_dma_dev(vq), addr); | |
365 | } | |
366 | ||
367 | ||
368 | /* | |
369 | * Split ring specific functions - *_split(). | |
370 | */ | |
371 | ||
72b5e895 JW |
372 | static void vring_unmap_one_split_indirect(const struct vring_virtqueue *vq, |
373 | struct vring_desc *desc) | |
780bc790 AL |
374 | { |
375 | u16 flags; | |
376 | ||
fb3fba6b | 377 | if (!vq->use_dma_api) |
780bc790 AL |
378 | return; |
379 | ||
380 | flags = virtio16_to_cpu(vq->vq.vdev, desc->flags); | |
381 | ||
382 | if (flags & VRING_DESC_F_INDIRECT) { | |
383 | dma_unmap_single(vring_dma_dev(vq), | |
384 | virtio64_to_cpu(vq->vq.vdev, desc->addr), | |
385 | virtio32_to_cpu(vq->vq.vdev, desc->len), | |
386 | (flags & VRING_DESC_F_WRITE) ? | |
387 | DMA_FROM_DEVICE : DMA_TO_DEVICE); | |
388 | } else { | |
389 | dma_unmap_page(vring_dma_dev(vq), | |
390 | virtio64_to_cpu(vq->vq.vdev, desc->addr), | |
391 | virtio32_to_cpu(vq->vq.vdev, desc->len), | |
392 | (flags & VRING_DESC_F_WRITE) ? | |
393 | DMA_FROM_DEVICE : DMA_TO_DEVICE); | |
394 | } | |
395 | } | |
396 | ||
72b5e895 JW |
397 | static unsigned int vring_unmap_one_split(const struct vring_virtqueue *vq, |
398 | unsigned int i) | |
399 | { | |
400 | struct vring_desc_extra *extra = vq->split.desc_extra; | |
401 | u16 flags; | |
402 | ||
403 | if (!vq->use_dma_api) | |
404 | goto out; | |
405 | ||
406 | flags = extra[i].flags; | |
407 | ||
408 | if (flags & VRING_DESC_F_INDIRECT) { | |
409 | dma_unmap_single(vring_dma_dev(vq), | |
410 | extra[i].addr, | |
411 | extra[i].len, | |
412 | (flags & VRING_DESC_F_WRITE) ? | |
413 | DMA_FROM_DEVICE : DMA_TO_DEVICE); | |
414 | } else { | |
415 | dma_unmap_page(vring_dma_dev(vq), | |
416 | extra[i].addr, | |
417 | extra[i].len, | |
418 | (flags & VRING_DESC_F_WRITE) ? | |
419 | DMA_FROM_DEVICE : DMA_TO_DEVICE); | |
420 | } | |
421 | ||
422 | out: | |
423 | return extra[i].next; | |
424 | } | |
425 | ||
138fd251 TB |
426 | static struct vring_desc *alloc_indirect_split(struct virtqueue *_vq, |
427 | unsigned int total_sg, | |
428 | gfp_t gfp) | |
9fa29b9d MM |
429 | { |
430 | struct vring_desc *desc; | |
b25bd251 | 431 | unsigned int i; |
9fa29b9d | 432 | |
b92b1b89 WD |
433 | /* |
434 | * We require lowmem mappings for the descriptors because | |
435 | * otherwise virt_to_phys will give us bogus addresses in the | |
436 | * virtqueue. | |
437 | */ | |
82107539 | 438 | gfp &= ~__GFP_HIGHMEM; |
b92b1b89 | 439 | |
6da2ec56 | 440 | desc = kmalloc_array(total_sg, sizeof(struct vring_desc), gfp); |
9fa29b9d | 441 | if (!desc) |
b25bd251 | 442 | return NULL; |
9fa29b9d | 443 | |
b25bd251 | 444 | for (i = 0; i < total_sg; i++) |
00e6f3d9 | 445 | desc[i].next = cpu_to_virtio16(_vq->vdev, i + 1); |
b25bd251 | 446 | return desc; |
9fa29b9d MM |
447 | } |
448 | ||
fe4c3862 JW |
449 | static inline unsigned int virtqueue_add_desc_split(struct virtqueue *vq, |
450 | struct vring_desc *desc, | |
451 | unsigned int i, | |
452 | dma_addr_t addr, | |
453 | unsigned int len, | |
72b5e895 JW |
454 | u16 flags, |
455 | bool indirect) | |
fe4c3862 | 456 | { |
72b5e895 JW |
457 | struct vring_virtqueue *vring = to_vvq(vq); |
458 | struct vring_desc_extra *extra = vring->split.desc_extra; | |
459 | u16 next; | |
460 | ||
fe4c3862 JW |
461 | desc[i].flags = cpu_to_virtio16(vq->vdev, flags); |
462 | desc[i].addr = cpu_to_virtio64(vq->vdev, addr); | |
463 | desc[i].len = cpu_to_virtio32(vq->vdev, len); | |
464 | ||
72b5e895 JW |
465 | if (!indirect) { |
466 | next = extra[i].next; | |
467 | desc[i].next = cpu_to_virtio16(vq->vdev, next); | |
468 | ||
469 | extra[i].addr = addr; | |
470 | extra[i].len = len; | |
471 | extra[i].flags = flags; | |
472 | } else | |
473 | next = virtio16_to_cpu(vq->vdev, desc[i].next); | |
474 | ||
475 | return next; | |
fe4c3862 JW |
476 | } |
477 | ||
138fd251 TB |
478 | static inline int virtqueue_add_split(struct virtqueue *_vq, |
479 | struct scatterlist *sgs[], | |
480 | unsigned int total_sg, | |
481 | unsigned int out_sgs, | |
482 | unsigned int in_sgs, | |
483 | void *data, | |
484 | void *ctx, | |
485 | gfp_t gfp) | |
0a8a69dd RR |
486 | { |
487 | struct vring_virtqueue *vq = to_vvq(_vq); | |
13816c76 | 488 | struct scatterlist *sg; |
b25bd251 | 489 | struct vring_desc *desc; |
3f649ab7 | 490 | unsigned int i, n, avail, descs_used, prev, err_idx; |
1fe9b6fe | 491 | int head; |
b25bd251 | 492 | bool indirect; |
0a8a69dd | 493 | |
9fa29b9d MM |
494 | START_USE(vq); |
495 | ||
0a8a69dd | 496 | BUG_ON(data == NULL); |
5a08b04f | 497 | BUG_ON(ctx && vq->indirect); |
9fa29b9d | 498 | |
70670444 RR |
499 | if (unlikely(vq->broken)) { |
500 | END_USE(vq); | |
501 | return -EIO; | |
502 | } | |
503 | ||
4d6a105e | 504 | LAST_ADD_TIME_UPDATE(vq); |
e93300b1 | 505 | |
b25bd251 RR |
506 | BUG_ON(total_sg == 0); |
507 | ||
508 | head = vq->free_head; | |
509 | ||
2f18c2d1 | 510 | if (virtqueue_use_indirect(_vq, total_sg)) |
138fd251 | 511 | desc = alloc_indirect_split(_vq, total_sg, gfp); |
44ed8089 | 512 | else { |
b25bd251 | 513 | desc = NULL; |
e593bf97 | 514 | WARN_ON_ONCE(total_sg > vq->split.vring.num && !vq->indirect); |
44ed8089 | 515 | } |
b25bd251 RR |
516 | |
517 | if (desc) { | |
518 | /* Use a single buffer which doesn't continue */ | |
780bc790 | 519 | indirect = true; |
b25bd251 RR |
520 | /* Set up rest to use this indirect table. */ |
521 | i = 0; | |
522 | descs_used = 1; | |
b25bd251 | 523 | } else { |
780bc790 | 524 | indirect = false; |
e593bf97 | 525 | desc = vq->split.vring.desc; |
b25bd251 RR |
526 | i = head; |
527 | descs_used = total_sg; | |
9fa29b9d MM |
528 | } |
529 | ||
b25bd251 | 530 | if (vq->vq.num_free < descs_used) { |
0a8a69dd | 531 | pr_debug("Can't add buf len %i - avail = %i\n", |
b25bd251 | 532 | descs_used, vq->vq.num_free); |
44653eae RR |
533 | /* FIXME: for historical reasons, we force a notify here if |
534 | * there are outgoing parts to the buffer. Presumably the | |
535 | * host should service the ring ASAP. */ | |
13816c76 | 536 | if (out_sgs) |
44653eae | 537 | vq->notify(&vq->vq); |
58625edf WY |
538 | if (indirect) |
539 | kfree(desc); | |
0a8a69dd RR |
540 | END_USE(vq); |
541 | return -ENOSPC; | |
542 | } | |
543 | ||
13816c76 | 544 | for (n = 0; n < out_sgs; n++) { |
eeebf9b1 | 545 | for (sg = sgs[n]; sg; sg = sg_next(sg)) { |
780bc790 AL |
546 | dma_addr_t addr = vring_map_one_sg(vq, sg, DMA_TO_DEVICE); |
547 | if (vring_mapping_error(vq, addr)) | |
548 | goto unmap_release; | |
549 | ||
13816c76 | 550 | prev = i; |
72b5e895 JW |
551 | /* Note that we trust indirect descriptor |
552 | * table since it use stream DMA mapping. | |
553 | */ | |
fe4c3862 | 554 | i = virtqueue_add_desc_split(_vq, desc, i, addr, sg->length, |
72b5e895 JW |
555 | VRING_DESC_F_NEXT, |
556 | indirect); | |
13816c76 | 557 | } |
0a8a69dd | 558 | } |
13816c76 | 559 | for (; n < (out_sgs + in_sgs); n++) { |
eeebf9b1 | 560 | for (sg = sgs[n]; sg; sg = sg_next(sg)) { |
780bc790 AL |
561 | dma_addr_t addr = vring_map_one_sg(vq, sg, DMA_FROM_DEVICE); |
562 | if (vring_mapping_error(vq, addr)) | |
563 | goto unmap_release; | |
564 | ||
13816c76 | 565 | prev = i; |
72b5e895 JW |
566 | /* Note that we trust indirect descriptor |
567 | * table since it use stream DMA mapping. | |
568 | */ | |
fe4c3862 JW |
569 | i = virtqueue_add_desc_split(_vq, desc, i, addr, |
570 | sg->length, | |
571 | VRING_DESC_F_NEXT | | |
72b5e895 JW |
572 | VRING_DESC_F_WRITE, |
573 | indirect); | |
13816c76 | 574 | } |
0a8a69dd RR |
575 | } |
576 | /* Last one doesn't continue. */ | |
00e6f3d9 | 577 | desc[prev].flags &= cpu_to_virtio16(_vq->vdev, ~VRING_DESC_F_NEXT); |
72b5e895 | 578 | if (!indirect && vq->use_dma_api) |
890d3356 | 579 | vq->split.desc_extra[prev & (vq->split.vring.num - 1)].flags &= |
72b5e895 | 580 | ~VRING_DESC_F_NEXT; |
0a8a69dd | 581 | |
780bc790 AL |
582 | if (indirect) { |
583 | /* Now that the indirect table is filled in, map it. */ | |
584 | dma_addr_t addr = vring_map_single( | |
585 | vq, desc, total_sg * sizeof(struct vring_desc), | |
586 | DMA_TO_DEVICE); | |
587 | if (vring_mapping_error(vq, addr)) | |
588 | goto unmap_release; | |
589 | ||
fe4c3862 JW |
590 | virtqueue_add_desc_split(_vq, vq->split.vring.desc, |
591 | head, addr, | |
592 | total_sg * sizeof(struct vring_desc), | |
72b5e895 JW |
593 | VRING_DESC_F_INDIRECT, |
594 | false); | |
780bc790 AL |
595 | } |
596 | ||
597 | /* We're using some buffers from the free list. */ | |
598 | vq->vq.num_free -= descs_used; | |
599 | ||
0a8a69dd | 600 | /* Update free pointer */ |
b25bd251 | 601 | if (indirect) |
72b5e895 | 602 | vq->free_head = vq->split.desc_extra[head].next; |
b25bd251 RR |
603 | else |
604 | vq->free_head = i; | |
0a8a69dd | 605 | |
780bc790 | 606 | /* Store token and indirect buffer state. */ |
cbeedb72 | 607 | vq->split.desc_state[head].data = data; |
780bc790 | 608 | if (indirect) |
cbeedb72 | 609 | vq->split.desc_state[head].indir_desc = desc; |
87646a34 | 610 | else |
cbeedb72 | 611 | vq->split.desc_state[head].indir_desc = ctx; |
0a8a69dd RR |
612 | |
613 | /* Put entry in available array (but don't update avail->idx until they | |
3b720b8c | 614 | * do sync). */ |
e593bf97 TB |
615 | avail = vq->split.avail_idx_shadow & (vq->split.vring.num - 1); |
616 | vq->split.vring.avail->ring[avail] = cpu_to_virtio16(_vq->vdev, head); | |
0a8a69dd | 617 | |
ee7cd898 RR |
618 | /* Descriptors and available array need to be set before we expose the |
619 | * new available array entries. */ | |
a9a0fef7 | 620 | virtio_wmb(vq->weak_barriers); |
e593bf97 TB |
621 | vq->split.avail_idx_shadow++; |
622 | vq->split.vring.avail->idx = cpu_to_virtio16(_vq->vdev, | |
623 | vq->split.avail_idx_shadow); | |
ee7cd898 RR |
624 | vq->num_added++; |
625 | ||
5e05bf58 TH |
626 | pr_debug("Added buffer head %i to %p\n", head, vq); |
627 | END_USE(vq); | |
628 | ||
ee7cd898 RR |
629 | /* This is very unlikely, but theoretically possible. Kick |
630 | * just in case. */ | |
631 | if (unlikely(vq->num_added == (1 << 16) - 1)) | |
632 | virtqueue_kick(_vq); | |
633 | ||
98e8c6bc | 634 | return 0; |
780bc790 AL |
635 | |
636 | unmap_release: | |
637 | err_idx = i; | |
cf8f1696 ML |
638 | |
639 | if (indirect) | |
640 | i = 0; | |
641 | else | |
642 | i = head; | |
780bc790 AL |
643 | |
644 | for (n = 0; n < total_sg; n++) { | |
645 | if (i == err_idx) | |
646 | break; | |
72b5e895 JW |
647 | if (indirect) { |
648 | vring_unmap_one_split_indirect(vq, &desc[i]); | |
649 | i = virtio16_to_cpu(_vq->vdev, desc[i].next); | |
650 | } else | |
651 | i = vring_unmap_one_split(vq, i); | |
780bc790 AL |
652 | } |
653 | ||
780bc790 AL |
654 | if (indirect) |
655 | kfree(desc); | |
656 | ||
3cc36f6e | 657 | END_USE(vq); |
f7728002 | 658 | return -ENOMEM; |
0a8a69dd | 659 | } |
13816c76 | 660 | |
138fd251 | 661 | static bool virtqueue_kick_prepare_split(struct virtqueue *_vq) |
0a8a69dd RR |
662 | { |
663 | struct vring_virtqueue *vq = to_vvq(_vq); | |
a5c262c5 | 664 | u16 new, old; |
41f0377f RR |
665 | bool needs_kick; |
666 | ||
0a8a69dd | 667 | START_USE(vq); |
a72caae2 JW |
668 | /* We need to expose available array entries before checking avail |
669 | * event. */ | |
a9a0fef7 | 670 | virtio_mb(vq->weak_barriers); |
0a8a69dd | 671 | |
e593bf97 TB |
672 | old = vq->split.avail_idx_shadow - vq->num_added; |
673 | new = vq->split.avail_idx_shadow; | |
0a8a69dd RR |
674 | vq->num_added = 0; |
675 | ||
4d6a105e TB |
676 | LAST_ADD_TIME_CHECK(vq); |
677 | LAST_ADD_TIME_INVALID(vq); | |
e93300b1 | 678 | |
41f0377f | 679 | if (vq->event) { |
e593bf97 TB |
680 | needs_kick = vring_need_event(virtio16_to_cpu(_vq->vdev, |
681 | vring_avail_event(&vq->split.vring)), | |
41f0377f RR |
682 | new, old); |
683 | } else { | |
e593bf97 TB |
684 | needs_kick = !(vq->split.vring.used->flags & |
685 | cpu_to_virtio16(_vq->vdev, | |
686 | VRING_USED_F_NO_NOTIFY)); | |
41f0377f | 687 | } |
0a8a69dd | 688 | END_USE(vq); |
41f0377f RR |
689 | return needs_kick; |
690 | } | |
138fd251 | 691 | |
138fd251 TB |
692 | static void detach_buf_split(struct vring_virtqueue *vq, unsigned int head, |
693 | void **ctx) | |
0a8a69dd | 694 | { |
780bc790 | 695 | unsigned int i, j; |
c60923cb | 696 | __virtio16 nextflag = cpu_to_virtio16(vq->vq.vdev, VRING_DESC_F_NEXT); |
0a8a69dd RR |
697 | |
698 | /* Clear data ptr. */ | |
cbeedb72 | 699 | vq->split.desc_state[head].data = NULL; |
0a8a69dd | 700 | |
780bc790 | 701 | /* Put back on free list: unmap first-level descriptors and find end */ |
0a8a69dd | 702 | i = head; |
9fa29b9d | 703 | |
e593bf97 | 704 | while (vq->split.vring.desc[i].flags & nextflag) { |
72b5e895 JW |
705 | vring_unmap_one_split(vq, i); |
706 | i = vq->split.desc_extra[i].next; | |
06ca287d | 707 | vq->vq.num_free++; |
0a8a69dd RR |
708 | } |
709 | ||
72b5e895 JW |
710 | vring_unmap_one_split(vq, i); |
711 | vq->split.desc_extra[i].next = vq->free_head; | |
0a8a69dd | 712 | vq->free_head = head; |
780bc790 | 713 | |
0a8a69dd | 714 | /* Plus final descriptor */ |
06ca287d | 715 | vq->vq.num_free++; |
780bc790 | 716 | |
5a08b04f | 717 | if (vq->indirect) { |
cbeedb72 TB |
718 | struct vring_desc *indir_desc = |
719 | vq->split.desc_state[head].indir_desc; | |
5a08b04f MT |
720 | u32 len; |
721 | ||
722 | /* Free the indirect table, if any, now that it's unmapped. */ | |
723 | if (!indir_desc) | |
724 | return; | |
725 | ||
72b5e895 | 726 | len = vq->split.desc_extra[head].len; |
780bc790 | 727 | |
72b5e895 JW |
728 | BUG_ON(!(vq->split.desc_extra[head].flags & |
729 | VRING_DESC_F_INDIRECT)); | |
780bc790 AL |
730 | BUG_ON(len == 0 || len % sizeof(struct vring_desc)); |
731 | ||
732 | for (j = 0; j < len / sizeof(struct vring_desc); j++) | |
72b5e895 | 733 | vring_unmap_one_split_indirect(vq, &indir_desc[j]); |
780bc790 | 734 | |
5a08b04f | 735 | kfree(indir_desc); |
cbeedb72 | 736 | vq->split.desc_state[head].indir_desc = NULL; |
5a08b04f | 737 | } else if (ctx) { |
cbeedb72 | 738 | *ctx = vq->split.desc_state[head].indir_desc; |
780bc790 | 739 | } |
0a8a69dd RR |
740 | } |
741 | ||
138fd251 | 742 | static inline bool more_used_split(const struct vring_virtqueue *vq) |
0a8a69dd | 743 | { |
e593bf97 TB |
744 | return vq->last_used_idx != virtio16_to_cpu(vq->vq.vdev, |
745 | vq->split.vring.used->idx); | |
0a8a69dd RR |
746 | } |
747 | ||
138fd251 TB |
748 | static void *virtqueue_get_buf_ctx_split(struct virtqueue *_vq, |
749 | unsigned int *len, | |
750 | void **ctx) | |
0a8a69dd RR |
751 | { |
752 | struct vring_virtqueue *vq = to_vvq(_vq); | |
753 | void *ret; | |
754 | unsigned int i; | |
3b720b8c | 755 | u16 last_used; |
0a8a69dd RR |
756 | |
757 | START_USE(vq); | |
758 | ||
5ef82752 RR |
759 | if (unlikely(vq->broken)) { |
760 | END_USE(vq); | |
761 | return NULL; | |
762 | } | |
763 | ||
138fd251 | 764 | if (!more_used_split(vq)) { |
0a8a69dd RR |
765 | pr_debug("No more buffers in queue\n"); |
766 | END_USE(vq); | |
767 | return NULL; | |
768 | } | |
769 | ||
2d61ba95 | 770 | /* Only get used array entries after they have been exposed by host. */ |
a9a0fef7 | 771 | virtio_rmb(vq->weak_barriers); |
2d61ba95 | 772 | |
e593bf97 TB |
773 | last_used = (vq->last_used_idx & (vq->split.vring.num - 1)); |
774 | i = virtio32_to_cpu(_vq->vdev, | |
775 | vq->split.vring.used->ring[last_used].id); | |
776 | *len = virtio32_to_cpu(_vq->vdev, | |
777 | vq->split.vring.used->ring[last_used].len); | |
0a8a69dd | 778 | |
e593bf97 | 779 | if (unlikely(i >= vq->split.vring.num)) { |
0a8a69dd RR |
780 | BAD_RING(vq, "id %u out of range\n", i); |
781 | return NULL; | |
782 | } | |
cbeedb72 | 783 | if (unlikely(!vq->split.desc_state[i].data)) { |
0a8a69dd RR |
784 | BAD_RING(vq, "id %u is not a head!\n", i); |
785 | return NULL; | |
786 | } | |
787 | ||
138fd251 | 788 | /* detach_buf_split clears data, so grab it now. */ |
cbeedb72 | 789 | ret = vq->split.desc_state[i].data; |
138fd251 | 790 | detach_buf_split(vq, i, ctx); |
0a8a69dd | 791 | vq->last_used_idx++; |
a5c262c5 MT |
792 | /* If we expect an interrupt for the next entry, tell host |
793 | * by writing event index and flush out the write before | |
794 | * the read in the next get_buf call. */ | |
e593bf97 | 795 | if (!(vq->split.avail_flags_shadow & VRING_AVAIL_F_NO_INTERRUPT)) |
788e5b3a | 796 | virtio_store_mb(vq->weak_barriers, |
e593bf97 | 797 | &vring_used_event(&vq->split.vring), |
788e5b3a | 798 | cpu_to_virtio16(_vq->vdev, vq->last_used_idx)); |
a5c262c5 | 799 | |
4d6a105e | 800 | LAST_ADD_TIME_INVALID(vq); |
e93300b1 | 801 | |
0a8a69dd RR |
802 | END_USE(vq); |
803 | return ret; | |
804 | } | |
138fd251 | 805 | |
138fd251 | 806 | static void virtqueue_disable_cb_split(struct virtqueue *_vq) |
18445c4d RR |
807 | { |
808 | struct vring_virtqueue *vq = to_vvq(_vq); | |
809 | ||
e593bf97 TB |
810 | if (!(vq->split.avail_flags_shadow & VRING_AVAIL_F_NO_INTERRUPT)) { |
811 | vq->split.avail_flags_shadow |= VRING_AVAIL_F_NO_INTERRUPT; | |
8d622d21 MT |
812 | if (vq->event) |
813 | /* TODO: this is a hack. Figure out a cleaner value to write. */ | |
814 | vring_used_event(&vq->split.vring) = 0x0; | |
815 | else | |
e593bf97 TB |
816 | vq->split.vring.avail->flags = |
817 | cpu_to_virtio16(_vq->vdev, | |
818 | vq->split.avail_flags_shadow); | |
f277ec42 | 819 | } |
18445c4d RR |
820 | } |
821 | ||
138fd251 | 822 | static unsigned virtqueue_enable_cb_prepare_split(struct virtqueue *_vq) |
0a8a69dd RR |
823 | { |
824 | struct vring_virtqueue *vq = to_vvq(_vq); | |
cc229884 | 825 | u16 last_used_idx; |
0a8a69dd RR |
826 | |
827 | START_USE(vq); | |
0a8a69dd RR |
828 | |
829 | /* We optimistically turn back on interrupts, then check if there was | |
830 | * more to do. */ | |
a5c262c5 MT |
831 | /* Depending on the VIRTIO_RING_F_EVENT_IDX feature, we need to |
832 | * either clear the flags bit or point the event index at the next | |
833 | * entry. Always do both to keep code simple. */ | |
e593bf97 TB |
834 | if (vq->split.avail_flags_shadow & VRING_AVAIL_F_NO_INTERRUPT) { |
835 | vq->split.avail_flags_shadow &= ~VRING_AVAIL_F_NO_INTERRUPT; | |
0ea1e4a6 | 836 | if (!vq->event) |
e593bf97 TB |
837 | vq->split.vring.avail->flags = |
838 | cpu_to_virtio16(_vq->vdev, | |
839 | vq->split.avail_flags_shadow); | |
f277ec42 | 840 | } |
e593bf97 TB |
841 | vring_used_event(&vq->split.vring) = cpu_to_virtio16(_vq->vdev, |
842 | last_used_idx = vq->last_used_idx); | |
cc229884 MT |
843 | END_USE(vq); |
844 | return last_used_idx; | |
845 | } | |
138fd251 | 846 | |
138fd251 TB |
847 | static bool virtqueue_poll_split(struct virtqueue *_vq, unsigned last_used_idx) |
848 | { | |
849 | struct vring_virtqueue *vq = to_vvq(_vq); | |
850 | ||
851 | return (u16)last_used_idx != virtio16_to_cpu(_vq->vdev, | |
e593bf97 | 852 | vq->split.vring.used->idx); |
138fd251 TB |
853 | } |
854 | ||
138fd251 | 855 | static bool virtqueue_enable_cb_delayed_split(struct virtqueue *_vq) |
7ab358c2 MT |
856 | { |
857 | struct vring_virtqueue *vq = to_vvq(_vq); | |
858 | u16 bufs; | |
859 | ||
860 | START_USE(vq); | |
861 | ||
862 | /* We optimistically turn back on interrupts, then check if there was | |
863 | * more to do. */ | |
864 | /* Depending on the VIRTIO_RING_F_USED_EVENT_IDX feature, we need to | |
865 | * either clear the flags bit or point the event index at the next | |
0ea1e4a6 | 866 | * entry. Always update the event index to keep code simple. */ |
e593bf97 TB |
867 | if (vq->split.avail_flags_shadow & VRING_AVAIL_F_NO_INTERRUPT) { |
868 | vq->split.avail_flags_shadow &= ~VRING_AVAIL_F_NO_INTERRUPT; | |
0ea1e4a6 | 869 | if (!vq->event) |
e593bf97 TB |
870 | vq->split.vring.avail->flags = |
871 | cpu_to_virtio16(_vq->vdev, | |
872 | vq->split.avail_flags_shadow); | |
f277ec42 | 873 | } |
7ab358c2 | 874 | /* TODO: tune this threshold */ |
e593bf97 | 875 | bufs = (u16)(vq->split.avail_idx_shadow - vq->last_used_idx) * 3 / 4; |
788e5b3a MT |
876 | |
877 | virtio_store_mb(vq->weak_barriers, | |
e593bf97 | 878 | &vring_used_event(&vq->split.vring), |
788e5b3a MT |
879 | cpu_to_virtio16(_vq->vdev, vq->last_used_idx + bufs)); |
880 | ||
e593bf97 TB |
881 | if (unlikely((u16)(virtio16_to_cpu(_vq->vdev, vq->split.vring.used->idx) |
882 | - vq->last_used_idx) > bufs)) { | |
7ab358c2 MT |
883 | END_USE(vq); |
884 | return false; | |
885 | } | |
886 | ||
887 | END_USE(vq); | |
888 | return true; | |
889 | } | |
7ab358c2 | 890 | |
138fd251 | 891 | static void *virtqueue_detach_unused_buf_split(struct virtqueue *_vq) |
c021eac4 SM |
892 | { |
893 | struct vring_virtqueue *vq = to_vvq(_vq); | |
894 | unsigned int i; | |
895 | void *buf; | |
896 | ||
897 | START_USE(vq); | |
898 | ||
e593bf97 | 899 | for (i = 0; i < vq->split.vring.num; i++) { |
cbeedb72 | 900 | if (!vq->split.desc_state[i].data) |
c021eac4 | 901 | continue; |
138fd251 | 902 | /* detach_buf_split clears data, so grab it now. */ |
cbeedb72 | 903 | buf = vq->split.desc_state[i].data; |
138fd251 | 904 | detach_buf_split(vq, i, NULL); |
e593bf97 TB |
905 | vq->split.avail_idx_shadow--; |
906 | vq->split.vring.avail->idx = cpu_to_virtio16(_vq->vdev, | |
907 | vq->split.avail_idx_shadow); | |
c021eac4 SM |
908 | END_USE(vq); |
909 | return buf; | |
910 | } | |
911 | /* That should have freed everything. */ | |
e593bf97 | 912 | BUG_ON(vq->vq.num_free != vq->split.vring.num); |
c021eac4 SM |
913 | |
914 | END_USE(vq); | |
915 | return NULL; | |
916 | } | |
138fd251 | 917 | |
d79dca75 TB |
918 | static struct virtqueue *vring_create_virtqueue_split( |
919 | unsigned int index, | |
920 | unsigned int num, | |
921 | unsigned int vring_align, | |
922 | struct virtio_device *vdev, | |
923 | bool weak_barriers, | |
924 | bool may_reduce_num, | |
925 | bool context, | |
926 | bool (*notify)(struct virtqueue *), | |
927 | void (*callback)(struct virtqueue *), | |
928 | const char *name) | |
929 | { | |
930 | struct virtqueue *vq; | |
931 | void *queue = NULL; | |
932 | dma_addr_t dma_addr; | |
933 | size_t queue_size_in_bytes; | |
934 | struct vring vring; | |
935 | ||
936 | /* We assume num is a power of 2. */ | |
937 | if (num & (num - 1)) { | |
938 | dev_warn(&vdev->dev, "Bad virtqueue length %u\n", num); | |
939 | return NULL; | |
940 | } | |
941 | ||
942 | /* TODO: allocate each queue chunk individually */ | |
943 | for (; num && vring_size(num, vring_align) > PAGE_SIZE; num /= 2) { | |
944 | queue = vring_alloc_queue(vdev, vring_size(num, vring_align), | |
945 | &dma_addr, | |
946 | GFP_KERNEL|__GFP_NOWARN|__GFP_ZERO); | |
947 | if (queue) | |
948 | break; | |
cf94db21 CH |
949 | if (!may_reduce_num) |
950 | return NULL; | |
d79dca75 TB |
951 | } |
952 | ||
953 | if (!num) | |
954 | return NULL; | |
955 | ||
956 | if (!queue) { | |
957 | /* Try to get a single page. You are my only hope! */ | |
958 | queue = vring_alloc_queue(vdev, vring_size(num, vring_align), | |
959 | &dma_addr, GFP_KERNEL|__GFP_ZERO); | |
960 | } | |
961 | if (!queue) | |
962 | return NULL; | |
963 | ||
964 | queue_size_in_bytes = vring_size(num, vring_align); | |
965 | vring_init(&vring, num, queue, vring_align); | |
966 | ||
967 | vq = __vring_new_virtqueue(index, vring, vdev, weak_barriers, context, | |
968 | notify, callback, name); | |
969 | if (!vq) { | |
970 | vring_free_queue(vdev, queue_size_in_bytes, queue, | |
971 | dma_addr); | |
972 | return NULL; | |
973 | } | |
974 | ||
975 | to_vvq(vq)->split.queue_dma_addr = dma_addr; | |
976 | to_vvq(vq)->split.queue_size_in_bytes = queue_size_in_bytes; | |
977 | to_vvq(vq)->we_own_ring = true; | |
978 | ||
979 | return vq; | |
980 | } | |
981 | ||
e6f633e5 | 982 | |
1ce9e605 TB |
983 | /* |
984 | * Packed ring specific functions - *_packed(). | |
985 | */ | |
986 | ||
987 | static void vring_unmap_state_packed(const struct vring_virtqueue *vq, | |
1f28750f | 988 | struct vring_desc_extra *state) |
1ce9e605 TB |
989 | { |
990 | u16 flags; | |
991 | ||
992 | if (!vq->use_dma_api) | |
993 | return; | |
994 | ||
995 | flags = state->flags; | |
996 | ||
997 | if (flags & VRING_DESC_F_INDIRECT) { | |
998 | dma_unmap_single(vring_dma_dev(vq), | |
999 | state->addr, state->len, | |
1000 | (flags & VRING_DESC_F_WRITE) ? | |
1001 | DMA_FROM_DEVICE : DMA_TO_DEVICE); | |
1002 | } else { | |
1003 | dma_unmap_page(vring_dma_dev(vq), | |
1004 | state->addr, state->len, | |
1005 | (flags & VRING_DESC_F_WRITE) ? | |
1006 | DMA_FROM_DEVICE : DMA_TO_DEVICE); | |
1007 | } | |
1008 | } | |
1009 | ||
1010 | static void vring_unmap_desc_packed(const struct vring_virtqueue *vq, | |
1011 | struct vring_packed_desc *desc) | |
1012 | { | |
1013 | u16 flags; | |
1014 | ||
1015 | if (!vq->use_dma_api) | |
1016 | return; | |
1017 | ||
1018 | flags = le16_to_cpu(desc->flags); | |
1019 | ||
1020 | if (flags & VRING_DESC_F_INDIRECT) { | |
1021 | dma_unmap_single(vring_dma_dev(vq), | |
1022 | le64_to_cpu(desc->addr), | |
1023 | le32_to_cpu(desc->len), | |
1024 | (flags & VRING_DESC_F_WRITE) ? | |
1025 | DMA_FROM_DEVICE : DMA_TO_DEVICE); | |
1026 | } else { | |
1027 | dma_unmap_page(vring_dma_dev(vq), | |
1028 | le64_to_cpu(desc->addr), | |
1029 | le32_to_cpu(desc->len), | |
1030 | (flags & VRING_DESC_F_WRITE) ? | |
1031 | DMA_FROM_DEVICE : DMA_TO_DEVICE); | |
1032 | } | |
1033 | } | |
1034 | ||
1035 | static struct vring_packed_desc *alloc_indirect_packed(unsigned int total_sg, | |
1036 | gfp_t gfp) | |
1037 | { | |
1038 | struct vring_packed_desc *desc; | |
1039 | ||
1040 | /* | |
1041 | * We require lowmem mappings for the descriptors because | |
1042 | * otherwise virt_to_phys will give us bogus addresses in the | |
1043 | * virtqueue. | |
1044 | */ | |
1045 | gfp &= ~__GFP_HIGHMEM; | |
1046 | ||
1047 | desc = kmalloc_array(total_sg, sizeof(struct vring_packed_desc), gfp); | |
1048 | ||
1049 | return desc; | |
1050 | } | |
1051 | ||
1052 | static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, | |
1053 | struct scatterlist *sgs[], | |
1054 | unsigned int total_sg, | |
1055 | unsigned int out_sgs, | |
1056 | unsigned int in_sgs, | |
1057 | void *data, | |
1058 | gfp_t gfp) | |
1059 | { | |
1060 | struct vring_packed_desc *desc; | |
1061 | struct scatterlist *sg; | |
1062 | unsigned int i, n, err_idx; | |
1063 | u16 head, id; | |
1064 | dma_addr_t addr; | |
1065 | ||
1066 | head = vq->packed.next_avail_idx; | |
1067 | desc = alloc_indirect_packed(total_sg, gfp); | |
1068 | ||
1069 | if (unlikely(vq->vq.num_free < 1)) { | |
1070 | pr_debug("Can't add buf len 1 - avail = 0\n"); | |
df0bfe75 | 1071 | kfree(desc); |
1ce9e605 TB |
1072 | END_USE(vq); |
1073 | return -ENOSPC; | |
1074 | } | |
1075 | ||
1076 | i = 0; | |
1077 | id = vq->free_head; | |
1078 | BUG_ON(id == vq->packed.vring.num); | |
1079 | ||
1080 | for (n = 0; n < out_sgs + in_sgs; n++) { | |
1081 | for (sg = sgs[n]; sg; sg = sg_next(sg)) { | |
1082 | addr = vring_map_one_sg(vq, sg, n < out_sgs ? | |
1083 | DMA_TO_DEVICE : DMA_FROM_DEVICE); | |
1084 | if (vring_mapping_error(vq, addr)) | |
1085 | goto unmap_release; | |
1086 | ||
1087 | desc[i].flags = cpu_to_le16(n < out_sgs ? | |
1088 | 0 : VRING_DESC_F_WRITE); | |
1089 | desc[i].addr = cpu_to_le64(addr); | |
1090 | desc[i].len = cpu_to_le32(sg->length); | |
1091 | i++; | |
1092 | } | |
1093 | } | |
1094 | ||
1095 | /* Now that the indirect table is filled in, map it. */ | |
1096 | addr = vring_map_single(vq, desc, | |
1097 | total_sg * sizeof(struct vring_packed_desc), | |
1098 | DMA_TO_DEVICE); | |
1099 | if (vring_mapping_error(vq, addr)) | |
1100 | goto unmap_release; | |
1101 | ||
1102 | vq->packed.vring.desc[head].addr = cpu_to_le64(addr); | |
1103 | vq->packed.vring.desc[head].len = cpu_to_le32(total_sg * | |
1104 | sizeof(struct vring_packed_desc)); | |
1105 | vq->packed.vring.desc[head].id = cpu_to_le16(id); | |
1106 | ||
1107 | if (vq->use_dma_api) { | |
1108 | vq->packed.desc_extra[id].addr = addr; | |
1109 | vq->packed.desc_extra[id].len = total_sg * | |
1110 | sizeof(struct vring_packed_desc); | |
1111 | vq->packed.desc_extra[id].flags = VRING_DESC_F_INDIRECT | | |
1112 | vq->packed.avail_used_flags; | |
1113 | } | |
1114 | ||
1115 | /* | |
1116 | * A driver MUST NOT make the first descriptor in the list | |
1117 | * available before all subsequent descriptors comprising | |
1118 | * the list are made available. | |
1119 | */ | |
1120 | virtio_wmb(vq->weak_barriers); | |
1121 | vq->packed.vring.desc[head].flags = cpu_to_le16(VRING_DESC_F_INDIRECT | | |
1122 | vq->packed.avail_used_flags); | |
1123 | ||
1124 | /* We're using some buffers from the free list. */ | |
1125 | vq->vq.num_free -= 1; | |
1126 | ||
1127 | /* Update free pointer */ | |
1128 | n = head + 1; | |
1129 | if (n >= vq->packed.vring.num) { | |
1130 | n = 0; | |
1131 | vq->packed.avail_wrap_counter ^= 1; | |
1132 | vq->packed.avail_used_flags ^= | |
1133 | 1 << VRING_PACKED_DESC_F_AVAIL | | |
1134 | 1 << VRING_PACKED_DESC_F_USED; | |
1135 | } | |
1136 | vq->packed.next_avail_idx = n; | |
aeef9b47 | 1137 | vq->free_head = vq->packed.desc_extra[id].next; |
1ce9e605 TB |
1138 | |
1139 | /* Store token and indirect buffer state. */ | |
1140 | vq->packed.desc_state[id].num = 1; | |
1141 | vq->packed.desc_state[id].data = data; | |
1142 | vq->packed.desc_state[id].indir_desc = desc; | |
1143 | vq->packed.desc_state[id].last = id; | |
1144 | ||
1145 | vq->num_added += 1; | |
1146 | ||
1147 | pr_debug("Added buffer head %i to %p\n", head, vq); | |
1148 | END_USE(vq); | |
1149 | ||
1150 | return 0; | |
1151 | ||
1152 | unmap_release: | |
1153 | err_idx = i; | |
1154 | ||
1155 | for (i = 0; i < err_idx; i++) | |
1156 | vring_unmap_desc_packed(vq, &desc[i]); | |
1157 | ||
1158 | kfree(desc); | |
1159 | ||
1160 | END_USE(vq); | |
f7728002 | 1161 | return -ENOMEM; |
1ce9e605 TB |
1162 | } |
1163 | ||
1164 | static inline int virtqueue_add_packed(struct virtqueue *_vq, | |
1165 | struct scatterlist *sgs[], | |
1166 | unsigned int total_sg, | |
1167 | unsigned int out_sgs, | |
1168 | unsigned int in_sgs, | |
1169 | void *data, | |
1170 | void *ctx, | |
1171 | gfp_t gfp) | |
1172 | { | |
1173 | struct vring_virtqueue *vq = to_vvq(_vq); | |
1174 | struct vring_packed_desc *desc; | |
1175 | struct scatterlist *sg; | |
1176 | unsigned int i, n, c, descs_used, err_idx; | |
3f649ab7 KC |
1177 | __le16 head_flags, flags; |
1178 | u16 head, id, prev, curr, avail_used_flags; | |
1ce9e605 TB |
1179 | |
1180 | START_USE(vq); | |
1181 | ||
1182 | BUG_ON(data == NULL); | |
1183 | BUG_ON(ctx && vq->indirect); | |
1184 | ||
1185 | if (unlikely(vq->broken)) { | |
1186 | END_USE(vq); | |
1187 | return -EIO; | |
1188 | } | |
1189 | ||
1190 | LAST_ADD_TIME_UPDATE(vq); | |
1191 | ||
1192 | BUG_ON(total_sg == 0); | |
1193 | ||
1194 | if (virtqueue_use_indirect(_vq, total_sg)) | |
1195 | return virtqueue_add_indirect_packed(vq, sgs, total_sg, | |
1196 | out_sgs, in_sgs, data, gfp); | |
1197 | ||
1198 | head = vq->packed.next_avail_idx; | |
1199 | avail_used_flags = vq->packed.avail_used_flags; | |
1200 | ||
1201 | WARN_ON_ONCE(total_sg > vq->packed.vring.num && !vq->indirect); | |
1202 | ||
1203 | desc = vq->packed.vring.desc; | |
1204 | i = head; | |
1205 | descs_used = total_sg; | |
1206 | ||
1207 | if (unlikely(vq->vq.num_free < descs_used)) { | |
1208 | pr_debug("Can't add buf len %i - avail = %i\n", | |
1209 | descs_used, vq->vq.num_free); | |
1210 | END_USE(vq); | |
1211 | return -ENOSPC; | |
1212 | } | |
1213 | ||
1214 | id = vq->free_head; | |
1215 | BUG_ON(id == vq->packed.vring.num); | |
1216 | ||
1217 | curr = id; | |
1218 | c = 0; | |
1219 | for (n = 0; n < out_sgs + in_sgs; n++) { | |
1220 | for (sg = sgs[n]; sg; sg = sg_next(sg)) { | |
1221 | dma_addr_t addr = vring_map_one_sg(vq, sg, n < out_sgs ? | |
1222 | DMA_TO_DEVICE : DMA_FROM_DEVICE); | |
1223 | if (vring_mapping_error(vq, addr)) | |
1224 | goto unmap_release; | |
1225 | ||
1226 | flags = cpu_to_le16(vq->packed.avail_used_flags | | |
1227 | (++c == total_sg ? 0 : VRING_DESC_F_NEXT) | | |
1228 | (n < out_sgs ? 0 : VRING_DESC_F_WRITE)); | |
1229 | if (i == head) | |
1230 | head_flags = flags; | |
1231 | else | |
1232 | desc[i].flags = flags; | |
1233 | ||
1234 | desc[i].addr = cpu_to_le64(addr); | |
1235 | desc[i].len = cpu_to_le32(sg->length); | |
1236 | desc[i].id = cpu_to_le16(id); | |
1237 | ||
1238 | if (unlikely(vq->use_dma_api)) { | |
1239 | vq->packed.desc_extra[curr].addr = addr; | |
1240 | vq->packed.desc_extra[curr].len = sg->length; | |
1241 | vq->packed.desc_extra[curr].flags = | |
1242 | le16_to_cpu(flags); | |
1243 | } | |
1244 | prev = curr; | |
aeef9b47 | 1245 | curr = vq->packed.desc_extra[curr].next; |
1ce9e605 TB |
1246 | |
1247 | if ((unlikely(++i >= vq->packed.vring.num))) { | |
1248 | i = 0; | |
1249 | vq->packed.avail_used_flags ^= | |
1250 | 1 << VRING_PACKED_DESC_F_AVAIL | | |
1251 | 1 << VRING_PACKED_DESC_F_USED; | |
1252 | } | |
1253 | } | |
1254 | } | |
1255 | ||
1256 | if (i < head) | |
1257 | vq->packed.avail_wrap_counter ^= 1; | |
1258 | ||
1259 | /* We're using some buffers from the free list. */ | |
1260 | vq->vq.num_free -= descs_used; | |
1261 | ||
1262 | /* Update free pointer */ | |
1263 | vq->packed.next_avail_idx = i; | |
1264 | vq->free_head = curr; | |
1265 | ||
1266 | /* Store token. */ | |
1267 | vq->packed.desc_state[id].num = descs_used; | |
1268 | vq->packed.desc_state[id].data = data; | |
1269 | vq->packed.desc_state[id].indir_desc = ctx; | |
1270 | vq->packed.desc_state[id].last = prev; | |
1271 | ||
1272 | /* | |
1273 | * A driver MUST NOT make the first descriptor in the list | |
1274 | * available before all subsequent descriptors comprising | |
1275 | * the list are made available. | |
1276 | */ | |
1277 | virtio_wmb(vq->weak_barriers); | |
1278 | vq->packed.vring.desc[head].flags = head_flags; | |
1279 | vq->num_added += descs_used; | |
1280 | ||
1281 | pr_debug("Added buffer head %i to %p\n", head, vq); | |
1282 | END_USE(vq); | |
1283 | ||
1284 | return 0; | |
1285 | ||
1286 | unmap_release: | |
1287 | err_idx = i; | |
1288 | i = head; | |
44593865 | 1289 | curr = vq->free_head; |
1ce9e605 TB |
1290 | |
1291 | vq->packed.avail_used_flags = avail_used_flags; | |
1292 | ||
1293 | for (n = 0; n < total_sg; n++) { | |
1294 | if (i == err_idx) | |
1295 | break; | |
44593865 JW |
1296 | vring_unmap_state_packed(vq, |
1297 | &vq->packed.desc_extra[curr]); | |
1298 | curr = vq->packed.desc_extra[curr].next; | |
1ce9e605 TB |
1299 | i++; |
1300 | if (i >= vq->packed.vring.num) | |
1301 | i = 0; | |
1302 | } | |
1303 | ||
1304 | END_USE(vq); | |
1305 | return -EIO; | |
1306 | } | |
1307 | ||
1308 | static bool virtqueue_kick_prepare_packed(struct virtqueue *_vq) | |
1309 | { | |
1310 | struct vring_virtqueue *vq = to_vvq(_vq); | |
f51f9826 | 1311 | u16 new, old, off_wrap, flags, wrap_counter, event_idx; |
1ce9e605 TB |
1312 | bool needs_kick; |
1313 | union { | |
1314 | struct { | |
1315 | __le16 off_wrap; | |
1316 | __le16 flags; | |
1317 | }; | |
1318 | u32 u32; | |
1319 | } snapshot; | |
1320 | ||
1321 | START_USE(vq); | |
1322 | ||
1323 | /* | |
1324 | * We need to expose the new flags value before checking notification | |
1325 | * suppressions. | |
1326 | */ | |
1327 | virtio_mb(vq->weak_barriers); | |
1328 | ||
f51f9826 TB |
1329 | old = vq->packed.next_avail_idx - vq->num_added; |
1330 | new = vq->packed.next_avail_idx; | |
1ce9e605 TB |
1331 | vq->num_added = 0; |
1332 | ||
1333 | snapshot.u32 = *(u32 *)vq->packed.vring.device; | |
1334 | flags = le16_to_cpu(snapshot.flags); | |
1335 | ||
1336 | LAST_ADD_TIME_CHECK(vq); | |
1337 | LAST_ADD_TIME_INVALID(vq); | |
1338 | ||
f51f9826 TB |
1339 | if (flags != VRING_PACKED_EVENT_FLAG_DESC) { |
1340 | needs_kick = (flags != VRING_PACKED_EVENT_FLAG_DISABLE); | |
1341 | goto out; | |
1342 | } | |
1343 | ||
1344 | off_wrap = le16_to_cpu(snapshot.off_wrap); | |
1345 | ||
1346 | wrap_counter = off_wrap >> VRING_PACKED_EVENT_F_WRAP_CTR; | |
1347 | event_idx = off_wrap & ~(1 << VRING_PACKED_EVENT_F_WRAP_CTR); | |
1348 | if (wrap_counter != vq->packed.avail_wrap_counter) | |
1349 | event_idx -= vq->packed.vring.num; | |
1350 | ||
1351 | needs_kick = vring_need_event(event_idx, new, old); | |
1352 | out: | |
1ce9e605 TB |
1353 | END_USE(vq); |
1354 | return needs_kick; | |
1355 | } | |
1356 | ||
1357 | static void detach_buf_packed(struct vring_virtqueue *vq, | |
1358 | unsigned int id, void **ctx) | |
1359 | { | |
1360 | struct vring_desc_state_packed *state = NULL; | |
1361 | struct vring_packed_desc *desc; | |
1362 | unsigned int i, curr; | |
1363 | ||
1364 | state = &vq->packed.desc_state[id]; | |
1365 | ||
1366 | /* Clear data ptr. */ | |
1367 | state->data = NULL; | |
1368 | ||
aeef9b47 | 1369 | vq->packed.desc_extra[state->last].next = vq->free_head; |
1ce9e605 TB |
1370 | vq->free_head = id; |
1371 | vq->vq.num_free += state->num; | |
1372 | ||
1373 | if (unlikely(vq->use_dma_api)) { | |
1374 | curr = id; | |
1375 | for (i = 0; i < state->num; i++) { | |
1376 | vring_unmap_state_packed(vq, | |
1377 | &vq->packed.desc_extra[curr]); | |
aeef9b47 | 1378 | curr = vq->packed.desc_extra[curr].next; |
1ce9e605 TB |
1379 | } |
1380 | } | |
1381 | ||
1382 | if (vq->indirect) { | |
1383 | u32 len; | |
1384 | ||
1385 | /* Free the indirect table, if any, now that it's unmapped. */ | |
1386 | desc = state->indir_desc; | |
1387 | if (!desc) | |
1388 | return; | |
1389 | ||
1390 | if (vq->use_dma_api) { | |
1391 | len = vq->packed.desc_extra[id].len; | |
1392 | for (i = 0; i < len / sizeof(struct vring_packed_desc); | |
1393 | i++) | |
1394 | vring_unmap_desc_packed(vq, &desc[i]); | |
1395 | } | |
1396 | kfree(desc); | |
1397 | state->indir_desc = NULL; | |
1398 | } else if (ctx) { | |
1399 | *ctx = state->indir_desc; | |
1400 | } | |
1401 | } | |
1402 | ||
1403 | static inline bool is_used_desc_packed(const struct vring_virtqueue *vq, | |
1404 | u16 idx, bool used_wrap_counter) | |
1405 | { | |
1406 | bool avail, used; | |
1407 | u16 flags; | |
1408 | ||
1409 | flags = le16_to_cpu(vq->packed.vring.desc[idx].flags); | |
1410 | avail = !!(flags & (1 << VRING_PACKED_DESC_F_AVAIL)); | |
1411 | used = !!(flags & (1 << VRING_PACKED_DESC_F_USED)); | |
1412 | ||
1413 | return avail == used && used == used_wrap_counter; | |
1414 | } | |
1415 | ||
1416 | static inline bool more_used_packed(const struct vring_virtqueue *vq) | |
1417 | { | |
1418 | return is_used_desc_packed(vq, vq->last_used_idx, | |
1419 | vq->packed.used_wrap_counter); | |
1420 | } | |
1421 | ||
1422 | static void *virtqueue_get_buf_ctx_packed(struct virtqueue *_vq, | |
1423 | unsigned int *len, | |
1424 | void **ctx) | |
1425 | { | |
1426 | struct vring_virtqueue *vq = to_vvq(_vq); | |
1427 | u16 last_used, id; | |
1428 | void *ret; | |
1429 | ||
1430 | START_USE(vq); | |
1431 | ||
1432 | if (unlikely(vq->broken)) { | |
1433 | END_USE(vq); | |
1434 | return NULL; | |
1435 | } | |
1436 | ||
1437 | if (!more_used_packed(vq)) { | |
1438 | pr_debug("No more buffers in queue\n"); | |
1439 | END_USE(vq); | |
1440 | return NULL; | |
1441 | } | |
1442 | ||
1443 | /* Only get used elements after they have been exposed by host. */ | |
1444 | virtio_rmb(vq->weak_barriers); | |
1445 | ||
1446 | last_used = vq->last_used_idx; | |
1447 | id = le16_to_cpu(vq->packed.vring.desc[last_used].id); | |
1448 | *len = le32_to_cpu(vq->packed.vring.desc[last_used].len); | |
1449 | ||
1450 | if (unlikely(id >= vq->packed.vring.num)) { | |
1451 | BAD_RING(vq, "id %u out of range\n", id); | |
1452 | return NULL; | |
1453 | } | |
1454 | if (unlikely(!vq->packed.desc_state[id].data)) { | |
1455 | BAD_RING(vq, "id %u is not a head!\n", id); | |
1456 | return NULL; | |
1457 | } | |
1458 | ||
1459 | /* detach_buf_packed clears data, so grab it now. */ | |
1460 | ret = vq->packed.desc_state[id].data; | |
1461 | detach_buf_packed(vq, id, ctx); | |
1462 | ||
1463 | vq->last_used_idx += vq->packed.desc_state[id].num; | |
1464 | if (unlikely(vq->last_used_idx >= vq->packed.vring.num)) { | |
1465 | vq->last_used_idx -= vq->packed.vring.num; | |
1466 | vq->packed.used_wrap_counter ^= 1; | |
1467 | } | |
1468 | ||
f51f9826 TB |
1469 | /* |
1470 | * If we expect an interrupt for the next entry, tell host | |
1471 | * by writing event index and flush out the write before | |
1472 | * the read in the next get_buf call. | |
1473 | */ | |
1474 | if (vq->packed.event_flags_shadow == VRING_PACKED_EVENT_FLAG_DESC) | |
1475 | virtio_store_mb(vq->weak_barriers, | |
1476 | &vq->packed.vring.driver->off_wrap, | |
1477 | cpu_to_le16(vq->last_used_idx | | |
1478 | (vq->packed.used_wrap_counter << | |
1479 | VRING_PACKED_EVENT_F_WRAP_CTR))); | |
1480 | ||
1ce9e605 TB |
1481 | LAST_ADD_TIME_INVALID(vq); |
1482 | ||
1483 | END_USE(vq); | |
1484 | return ret; | |
1485 | } | |
1486 | ||
1487 | static void virtqueue_disable_cb_packed(struct virtqueue *_vq) | |
1488 | { | |
1489 | struct vring_virtqueue *vq = to_vvq(_vq); | |
1490 | ||
1491 | if (vq->packed.event_flags_shadow != VRING_PACKED_EVENT_FLAG_DISABLE) { | |
1492 | vq->packed.event_flags_shadow = VRING_PACKED_EVENT_FLAG_DISABLE; | |
1493 | vq->packed.vring.driver->flags = | |
1494 | cpu_to_le16(vq->packed.event_flags_shadow); | |
1495 | } | |
1496 | } | |
1497 | ||
1498 | static unsigned virtqueue_enable_cb_prepare_packed(struct virtqueue *_vq) | |
1499 | { | |
1500 | struct vring_virtqueue *vq = to_vvq(_vq); | |
1501 | ||
1502 | START_USE(vq); | |
1503 | ||
1504 | /* | |
1505 | * We optimistically turn back on interrupts, then check if there was | |
1506 | * more to do. | |
1507 | */ | |
1508 | ||
f51f9826 TB |
1509 | if (vq->event) { |
1510 | vq->packed.vring.driver->off_wrap = | |
1511 | cpu_to_le16(vq->last_used_idx | | |
1512 | (vq->packed.used_wrap_counter << | |
1513 | VRING_PACKED_EVENT_F_WRAP_CTR)); | |
1514 | /* | |
1515 | * We need to update event offset and event wrap | |
1516 | * counter first before updating event flags. | |
1517 | */ | |
1518 | virtio_wmb(vq->weak_barriers); | |
1519 | } | |
1520 | ||
1ce9e605 | 1521 | if (vq->packed.event_flags_shadow == VRING_PACKED_EVENT_FLAG_DISABLE) { |
f51f9826 TB |
1522 | vq->packed.event_flags_shadow = vq->event ? |
1523 | VRING_PACKED_EVENT_FLAG_DESC : | |
1524 | VRING_PACKED_EVENT_FLAG_ENABLE; | |
1ce9e605 TB |
1525 | vq->packed.vring.driver->flags = |
1526 | cpu_to_le16(vq->packed.event_flags_shadow); | |
1527 | } | |
1528 | ||
1529 | END_USE(vq); | |
1530 | return vq->last_used_idx | ((u16)vq->packed.used_wrap_counter << | |
1531 | VRING_PACKED_EVENT_F_WRAP_CTR); | |
1532 | } | |
1533 | ||
1534 | static bool virtqueue_poll_packed(struct virtqueue *_vq, u16 off_wrap) | |
1535 | { | |
1536 | struct vring_virtqueue *vq = to_vvq(_vq); | |
1537 | bool wrap_counter; | |
1538 | u16 used_idx; | |
1539 | ||
1540 | wrap_counter = off_wrap >> VRING_PACKED_EVENT_F_WRAP_CTR; | |
1541 | used_idx = off_wrap & ~(1 << VRING_PACKED_EVENT_F_WRAP_CTR); | |
1542 | ||
1543 | return is_used_desc_packed(vq, used_idx, wrap_counter); | |
1544 | } | |
1545 | ||
1546 | static bool virtqueue_enable_cb_delayed_packed(struct virtqueue *_vq) | |
1547 | { | |
1548 | struct vring_virtqueue *vq = to_vvq(_vq); | |
1549 | u16 used_idx, wrap_counter; | |
f51f9826 | 1550 | u16 bufs; |
1ce9e605 TB |
1551 | |
1552 | START_USE(vq); | |
1553 | ||
1554 | /* | |
1555 | * We optimistically turn back on interrupts, then check if there was | |
1556 | * more to do. | |
1557 | */ | |
1558 | ||
f51f9826 TB |
1559 | if (vq->event) { |
1560 | /* TODO: tune this threshold */ | |
1561 | bufs = (vq->packed.vring.num - vq->vq.num_free) * 3 / 4; | |
1562 | wrap_counter = vq->packed.used_wrap_counter; | |
1563 | ||
1564 | used_idx = vq->last_used_idx + bufs; | |
1565 | if (used_idx >= vq->packed.vring.num) { | |
1566 | used_idx -= vq->packed.vring.num; | |
1567 | wrap_counter ^= 1; | |
1568 | } | |
1569 | ||
1570 | vq->packed.vring.driver->off_wrap = cpu_to_le16(used_idx | | |
1571 | (wrap_counter << VRING_PACKED_EVENT_F_WRAP_CTR)); | |
1572 | ||
1573 | /* | |
1574 | * We need to update event offset and event wrap | |
1575 | * counter first before updating event flags. | |
1576 | */ | |
1577 | virtio_wmb(vq->weak_barriers); | |
f51f9826 | 1578 | } |
1ce9e605 TB |
1579 | |
1580 | if (vq->packed.event_flags_shadow == VRING_PACKED_EVENT_FLAG_DISABLE) { | |
f51f9826 TB |
1581 | vq->packed.event_flags_shadow = vq->event ? |
1582 | VRING_PACKED_EVENT_FLAG_DESC : | |
1583 | VRING_PACKED_EVENT_FLAG_ENABLE; | |
1ce9e605 TB |
1584 | vq->packed.vring.driver->flags = |
1585 | cpu_to_le16(vq->packed.event_flags_shadow); | |
1586 | } | |
1587 | ||
1588 | /* | |
1589 | * We need to update event suppression structure first | |
1590 | * before re-checking for more used buffers. | |
1591 | */ | |
1592 | virtio_mb(vq->weak_barriers); | |
1593 | ||
40ce7919 ML |
1594 | if (is_used_desc_packed(vq, |
1595 | vq->last_used_idx, | |
1596 | vq->packed.used_wrap_counter)) { | |
1ce9e605 TB |
1597 | END_USE(vq); |
1598 | return false; | |
1599 | } | |
1600 | ||
1601 | END_USE(vq); | |
1602 | return true; | |
1603 | } | |
1604 | ||
1605 | static void *virtqueue_detach_unused_buf_packed(struct virtqueue *_vq) | |
1606 | { | |
1607 | struct vring_virtqueue *vq = to_vvq(_vq); | |
1608 | unsigned int i; | |
1609 | void *buf; | |
1610 | ||
1611 | START_USE(vq); | |
1612 | ||
1613 | for (i = 0; i < vq->packed.vring.num; i++) { | |
1614 | if (!vq->packed.desc_state[i].data) | |
1615 | continue; | |
1616 | /* detach_buf clears data, so grab it now. */ | |
1617 | buf = vq->packed.desc_state[i].data; | |
1618 | detach_buf_packed(vq, i, NULL); | |
1619 | END_USE(vq); | |
1620 | return buf; | |
1621 | } | |
1622 | /* That should have freed everything. */ | |
1623 | BUG_ON(vq->vq.num_free != vq->packed.vring.num); | |
1624 | ||
1625 | END_USE(vq); | |
1626 | return NULL; | |
1627 | } | |
1628 | ||
5a222421 JW |
1629 | static struct vring_desc_extra *vring_alloc_desc_extra(struct vring_virtqueue *vq, |
1630 | unsigned int num) | |
1631 | { | |
1632 | struct vring_desc_extra *desc_extra; | |
1633 | unsigned int i; | |
1634 | ||
1635 | desc_extra = kmalloc_array(num, sizeof(struct vring_desc_extra), | |
1636 | GFP_KERNEL); | |
1637 | if (!desc_extra) | |
1638 | return NULL; | |
1639 | ||
1640 | memset(desc_extra, 0, num * sizeof(struct vring_desc_extra)); | |
1641 | ||
1642 | for (i = 0; i < num - 1; i++) | |
1643 | desc_extra[i].next = i + 1; | |
1644 | ||
1645 | return desc_extra; | |
1646 | } | |
1647 | ||
1ce9e605 TB |
1648 | static struct virtqueue *vring_create_virtqueue_packed( |
1649 | unsigned int index, | |
1650 | unsigned int num, | |
1651 | unsigned int vring_align, | |
1652 | struct virtio_device *vdev, | |
1653 | bool weak_barriers, | |
1654 | bool may_reduce_num, | |
1655 | bool context, | |
1656 | bool (*notify)(struct virtqueue *), | |
1657 | void (*callback)(struct virtqueue *), | |
1658 | const char *name) | |
1659 | { | |
1660 | struct vring_virtqueue *vq; | |
1661 | struct vring_packed_desc *ring; | |
1662 | struct vring_packed_desc_event *driver, *device; | |
1663 | dma_addr_t ring_dma_addr, driver_event_dma_addr, device_event_dma_addr; | |
1664 | size_t ring_size_in_bytes, event_size_in_bytes; | |
1ce9e605 TB |
1665 | |
1666 | ring_size_in_bytes = num * sizeof(struct vring_packed_desc); | |
1667 | ||
1668 | ring = vring_alloc_queue(vdev, ring_size_in_bytes, | |
1669 | &ring_dma_addr, | |
1670 | GFP_KERNEL|__GFP_NOWARN|__GFP_ZERO); | |
1671 | if (!ring) | |
1672 | goto err_ring; | |
1673 | ||
1674 | event_size_in_bytes = sizeof(struct vring_packed_desc_event); | |
1675 | ||
1676 | driver = vring_alloc_queue(vdev, event_size_in_bytes, | |
1677 | &driver_event_dma_addr, | |
1678 | GFP_KERNEL|__GFP_NOWARN|__GFP_ZERO); | |
1679 | if (!driver) | |
1680 | goto err_driver; | |
1681 | ||
1682 | device = vring_alloc_queue(vdev, event_size_in_bytes, | |
1683 | &device_event_dma_addr, | |
1684 | GFP_KERNEL|__GFP_NOWARN|__GFP_ZERO); | |
1685 | if (!device) | |
1686 | goto err_device; | |
1687 | ||
1688 | vq = kmalloc(sizeof(*vq), GFP_KERNEL); | |
1689 | if (!vq) | |
1690 | goto err_vq; | |
1691 | ||
1692 | vq->vq.callback = callback; | |
1693 | vq->vq.vdev = vdev; | |
1694 | vq->vq.name = name; | |
1695 | vq->vq.num_free = num; | |
1696 | vq->vq.index = index; | |
1697 | vq->we_own_ring = true; | |
1698 | vq->notify = notify; | |
1699 | vq->weak_barriers = weak_barriers; | |
1700 | vq->broken = false; | |
1701 | vq->last_used_idx = 0; | |
8d622d21 | 1702 | vq->event_triggered = false; |
1ce9e605 TB |
1703 | vq->num_added = 0; |
1704 | vq->packed_ring = true; | |
1705 | vq->use_dma_api = vring_use_dma_api(vdev); | |
1ce9e605 TB |
1706 | #ifdef DEBUG |
1707 | vq->in_use = false; | |
1708 | vq->last_add_time_valid = false; | |
1709 | #endif | |
1710 | ||
1711 | vq->indirect = virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC) && | |
1712 | !context; | |
1713 | vq->event = virtio_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX); | |
1714 | ||
45383fb0 TB |
1715 | if (virtio_has_feature(vdev, VIRTIO_F_ORDER_PLATFORM)) |
1716 | vq->weak_barriers = false; | |
1717 | ||
1ce9e605 TB |
1718 | vq->packed.ring_dma_addr = ring_dma_addr; |
1719 | vq->packed.driver_event_dma_addr = driver_event_dma_addr; | |
1720 | vq->packed.device_event_dma_addr = device_event_dma_addr; | |
1721 | ||
1722 | vq->packed.ring_size_in_bytes = ring_size_in_bytes; | |
1723 | vq->packed.event_size_in_bytes = event_size_in_bytes; | |
1724 | ||
1725 | vq->packed.vring.num = num; | |
1726 | vq->packed.vring.desc = ring; | |
1727 | vq->packed.vring.driver = driver; | |
1728 | vq->packed.vring.device = device; | |
1729 | ||
1730 | vq->packed.next_avail_idx = 0; | |
1731 | vq->packed.avail_wrap_counter = 1; | |
1732 | vq->packed.used_wrap_counter = 1; | |
1733 | vq->packed.event_flags_shadow = 0; | |
1734 | vq->packed.avail_used_flags = 1 << VRING_PACKED_DESC_F_AVAIL; | |
1735 | ||
1736 | vq->packed.desc_state = kmalloc_array(num, | |
1737 | sizeof(struct vring_desc_state_packed), | |
1738 | GFP_KERNEL); | |
1739 | if (!vq->packed.desc_state) | |
1740 | goto err_desc_state; | |
1741 | ||
1742 | memset(vq->packed.desc_state, 0, | |
1743 | num * sizeof(struct vring_desc_state_packed)); | |
1744 | ||
1745 | /* Put everything in free lists. */ | |
1746 | vq->free_head = 0; | |
1ce9e605 | 1747 | |
5a222421 | 1748 | vq->packed.desc_extra = vring_alloc_desc_extra(vq, num); |
1ce9e605 TB |
1749 | if (!vq->packed.desc_extra) |
1750 | goto err_desc_extra; | |
1751 | ||
1ce9e605 TB |
1752 | /* No callback? Tell other side not to bother us. */ |
1753 | if (!callback) { | |
1754 | vq->packed.event_flags_shadow = VRING_PACKED_EVENT_FLAG_DISABLE; | |
1755 | vq->packed.vring.driver->flags = | |
1756 | cpu_to_le16(vq->packed.event_flags_shadow); | |
1757 | } | |
1758 | ||
0e566c8f | 1759 | spin_lock(&vdev->vqs_list_lock); |
e152d8af | 1760 | list_add_tail(&vq->vq.list, &vdev->vqs); |
0e566c8f | 1761 | spin_unlock(&vdev->vqs_list_lock); |
1ce9e605 TB |
1762 | return &vq->vq; |
1763 | ||
1764 | err_desc_extra: | |
1765 | kfree(vq->packed.desc_state); | |
1766 | err_desc_state: | |
1767 | kfree(vq); | |
1768 | err_vq: | |
ae93d8ea | 1769 | vring_free_queue(vdev, event_size_in_bytes, device, device_event_dma_addr); |
1ce9e605 | 1770 | err_device: |
ae93d8ea | 1771 | vring_free_queue(vdev, event_size_in_bytes, driver, driver_event_dma_addr); |
1ce9e605 TB |
1772 | err_driver: |
1773 | vring_free_queue(vdev, ring_size_in_bytes, ring, ring_dma_addr); | |
1774 | err_ring: | |
1775 | return NULL; | |
1776 | } | |
1777 | ||
1778 | ||
e6f633e5 TB |
1779 | /* |
1780 | * Generic functions and exported symbols. | |
1781 | */ | |
1782 | ||
1783 | static inline int virtqueue_add(struct virtqueue *_vq, | |
1784 | struct scatterlist *sgs[], | |
1785 | unsigned int total_sg, | |
1786 | unsigned int out_sgs, | |
1787 | unsigned int in_sgs, | |
1788 | void *data, | |
1789 | void *ctx, | |
1790 | gfp_t gfp) | |
1791 | { | |
1ce9e605 TB |
1792 | struct vring_virtqueue *vq = to_vvq(_vq); |
1793 | ||
1794 | return vq->packed_ring ? virtqueue_add_packed(_vq, sgs, total_sg, | |
1795 | out_sgs, in_sgs, data, ctx, gfp) : | |
1796 | virtqueue_add_split(_vq, sgs, total_sg, | |
1797 | out_sgs, in_sgs, data, ctx, gfp); | |
e6f633e5 TB |
1798 | } |
1799 | ||
1800 | /** | |
1801 | * virtqueue_add_sgs - expose buffers to other end | |
a5581206 | 1802 | * @_vq: the struct virtqueue we're talking about. |
e6f633e5 | 1803 | * @sgs: array of terminated scatterlists. |
a5581206 JB |
1804 | * @out_sgs: the number of scatterlists readable by other side |
1805 | * @in_sgs: the number of scatterlists which are writable (after readable ones) | |
e6f633e5 TB |
1806 | * @data: the token identifying the buffer. |
1807 | * @gfp: how to do memory allocations (if necessary). | |
1808 | * | |
1809 | * Caller must ensure we don't call this with other virtqueue operations | |
1810 | * at the same time (except where noted). | |
1811 | * | |
1812 | * Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO). | |
1813 | */ | |
1814 | int virtqueue_add_sgs(struct virtqueue *_vq, | |
1815 | struct scatterlist *sgs[], | |
1816 | unsigned int out_sgs, | |
1817 | unsigned int in_sgs, | |
1818 | void *data, | |
1819 | gfp_t gfp) | |
1820 | { | |
1821 | unsigned int i, total_sg = 0; | |
1822 | ||
1823 | /* Count them first. */ | |
1824 | for (i = 0; i < out_sgs + in_sgs; i++) { | |
1825 | struct scatterlist *sg; | |
1826 | ||
1827 | for (sg = sgs[i]; sg; sg = sg_next(sg)) | |
1828 | total_sg++; | |
1829 | } | |
1830 | return virtqueue_add(_vq, sgs, total_sg, out_sgs, in_sgs, | |
1831 | data, NULL, gfp); | |
1832 | } | |
1833 | EXPORT_SYMBOL_GPL(virtqueue_add_sgs); | |
1834 | ||
1835 | /** | |
1836 | * virtqueue_add_outbuf - expose output buffers to other end | |
1837 | * @vq: the struct virtqueue we're talking about. | |
1838 | * @sg: scatterlist (must be well-formed and terminated!) | |
1839 | * @num: the number of entries in @sg readable by other side | |
1840 | * @data: the token identifying the buffer. | |
1841 | * @gfp: how to do memory allocations (if necessary). | |
1842 | * | |
1843 | * Caller must ensure we don't call this with other virtqueue operations | |
1844 | * at the same time (except where noted). | |
1845 | * | |
1846 | * Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO). | |
1847 | */ | |
1848 | int virtqueue_add_outbuf(struct virtqueue *vq, | |
1849 | struct scatterlist *sg, unsigned int num, | |
1850 | void *data, | |
1851 | gfp_t gfp) | |
1852 | { | |
1853 | return virtqueue_add(vq, &sg, num, 1, 0, data, NULL, gfp); | |
1854 | } | |
1855 | EXPORT_SYMBOL_GPL(virtqueue_add_outbuf); | |
1856 | ||
1857 | /** | |
1858 | * virtqueue_add_inbuf - expose input buffers to other end | |
1859 | * @vq: the struct virtqueue we're talking about. | |
1860 | * @sg: scatterlist (must be well-formed and terminated!) | |
1861 | * @num: the number of entries in @sg writable by other side | |
1862 | * @data: the token identifying the buffer. | |
1863 | * @gfp: how to do memory allocations (if necessary). | |
1864 | * | |
1865 | * Caller must ensure we don't call this with other virtqueue operations | |
1866 | * at the same time (except where noted). | |
1867 | * | |
1868 | * Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO). | |
1869 | */ | |
1870 | int virtqueue_add_inbuf(struct virtqueue *vq, | |
1871 | struct scatterlist *sg, unsigned int num, | |
1872 | void *data, | |
1873 | gfp_t gfp) | |
1874 | { | |
1875 | return virtqueue_add(vq, &sg, num, 0, 1, data, NULL, gfp); | |
1876 | } | |
1877 | EXPORT_SYMBOL_GPL(virtqueue_add_inbuf); | |
1878 | ||
1879 | /** | |
1880 | * virtqueue_add_inbuf_ctx - expose input buffers to other end | |
1881 | * @vq: the struct virtqueue we're talking about. | |
1882 | * @sg: scatterlist (must be well-formed and terminated!) | |
1883 | * @num: the number of entries in @sg writable by other side | |
1884 | * @data: the token identifying the buffer. | |
1885 | * @ctx: extra context for the token | |
1886 | * @gfp: how to do memory allocations (if necessary). | |
1887 | * | |
1888 | * Caller must ensure we don't call this with other virtqueue operations | |
1889 | * at the same time (except where noted). | |
1890 | * | |
1891 | * Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO). | |
1892 | */ | |
1893 | int virtqueue_add_inbuf_ctx(struct virtqueue *vq, | |
1894 | struct scatterlist *sg, unsigned int num, | |
1895 | void *data, | |
1896 | void *ctx, | |
1897 | gfp_t gfp) | |
1898 | { | |
1899 | return virtqueue_add(vq, &sg, num, 0, 1, data, ctx, gfp); | |
1900 | } | |
1901 | EXPORT_SYMBOL_GPL(virtqueue_add_inbuf_ctx); | |
1902 | ||
1903 | /** | |
1904 | * virtqueue_kick_prepare - first half of split virtqueue_kick call. | |
a5581206 | 1905 | * @_vq: the struct virtqueue |
e6f633e5 TB |
1906 | * |
1907 | * Instead of virtqueue_kick(), you can do: | |
1908 | * if (virtqueue_kick_prepare(vq)) | |
1909 | * virtqueue_notify(vq); | |
1910 | * | |
1911 | * This is sometimes useful because the virtqueue_kick_prepare() needs | |
1912 | * to be serialized, but the actual virtqueue_notify() call does not. | |
1913 | */ | |
1914 | bool virtqueue_kick_prepare(struct virtqueue *_vq) | |
1915 | { | |
1ce9e605 TB |
1916 | struct vring_virtqueue *vq = to_vvq(_vq); |
1917 | ||
1918 | return vq->packed_ring ? virtqueue_kick_prepare_packed(_vq) : | |
1919 | virtqueue_kick_prepare_split(_vq); | |
e6f633e5 TB |
1920 | } |
1921 | EXPORT_SYMBOL_GPL(virtqueue_kick_prepare); | |
1922 | ||
1923 | /** | |
1924 | * virtqueue_notify - second half of split virtqueue_kick call. | |
a5581206 | 1925 | * @_vq: the struct virtqueue |
e6f633e5 TB |
1926 | * |
1927 | * This does not need to be serialized. | |
1928 | * | |
1929 | * Returns false if host notify failed or queue is broken, otherwise true. | |
1930 | */ | |
1931 | bool virtqueue_notify(struct virtqueue *_vq) | |
1932 | { | |
1933 | struct vring_virtqueue *vq = to_vvq(_vq); | |
1934 | ||
1935 | if (unlikely(vq->broken)) | |
1936 | return false; | |
1937 | ||
1938 | /* Prod other side to tell it about changes. */ | |
1939 | if (!vq->notify(_vq)) { | |
1940 | vq->broken = true; | |
1941 | return false; | |
1942 | } | |
1943 | return true; | |
1944 | } | |
1945 | EXPORT_SYMBOL_GPL(virtqueue_notify); | |
1946 | ||
1947 | /** | |
1948 | * virtqueue_kick - update after add_buf | |
1949 | * @vq: the struct virtqueue | |
1950 | * | |
1951 | * After one or more virtqueue_add_* calls, invoke this to kick | |
1952 | * the other side. | |
1953 | * | |
1954 | * Caller must ensure we don't call this with other virtqueue | |
1955 | * operations at the same time (except where noted). | |
1956 | * | |
1957 | * Returns false if kick failed, otherwise true. | |
1958 | */ | |
1959 | bool virtqueue_kick(struct virtqueue *vq) | |
1960 | { | |
1961 | if (virtqueue_kick_prepare(vq)) | |
1962 | return virtqueue_notify(vq); | |
1963 | return true; | |
1964 | } | |
1965 | EXPORT_SYMBOL_GPL(virtqueue_kick); | |
1966 | ||
1967 | /** | |
31c11db6 | 1968 | * virtqueue_get_buf_ctx - get the next used buffer |
a5581206 | 1969 | * @_vq: the struct virtqueue we're talking about. |
e6f633e5 | 1970 | * @len: the length written into the buffer |
a5581206 | 1971 | * @ctx: extra context for the token |
e6f633e5 TB |
1972 | * |
1973 | * If the device wrote data into the buffer, @len will be set to the | |
1974 | * amount written. This means you don't need to clear the buffer | |
1975 | * beforehand to ensure there's no data leakage in the case of short | |
1976 | * writes. | |
1977 | * | |
1978 | * Caller must ensure we don't call this with other virtqueue | |
1979 | * operations at the same time (except where noted). | |
1980 | * | |
1981 | * Returns NULL if there are no used buffers, or the "data" token | |
1982 | * handed to virtqueue_add_*(). | |
1983 | */ | |
1984 | void *virtqueue_get_buf_ctx(struct virtqueue *_vq, unsigned int *len, | |
1985 | void **ctx) | |
1986 | { | |
1ce9e605 TB |
1987 | struct vring_virtqueue *vq = to_vvq(_vq); |
1988 | ||
1989 | return vq->packed_ring ? virtqueue_get_buf_ctx_packed(_vq, len, ctx) : | |
1990 | virtqueue_get_buf_ctx_split(_vq, len, ctx); | |
e6f633e5 TB |
1991 | } |
1992 | EXPORT_SYMBOL_GPL(virtqueue_get_buf_ctx); | |
1993 | ||
1994 | void *virtqueue_get_buf(struct virtqueue *_vq, unsigned int *len) | |
1995 | { | |
1996 | return virtqueue_get_buf_ctx(_vq, len, NULL); | |
1997 | } | |
1998 | EXPORT_SYMBOL_GPL(virtqueue_get_buf); | |
e6f633e5 TB |
1999 | /** |
2000 | * virtqueue_disable_cb - disable callbacks | |
a5581206 | 2001 | * @_vq: the struct virtqueue we're talking about. |
e6f633e5 TB |
2002 | * |
2003 | * Note that this is not necessarily synchronous, hence unreliable and only | |
2004 | * useful as an optimization. | |
2005 | * | |
2006 | * Unlike other operations, this need not be serialized. | |
2007 | */ | |
2008 | void virtqueue_disable_cb(struct virtqueue *_vq) | |
2009 | { | |
1ce9e605 TB |
2010 | struct vring_virtqueue *vq = to_vvq(_vq); |
2011 | ||
8d622d21 MT |
2012 | /* If device triggered an event already it won't trigger one again: |
2013 | * no need to disable. | |
2014 | */ | |
2015 | if (vq->event_triggered) | |
2016 | return; | |
2017 | ||
1ce9e605 TB |
2018 | if (vq->packed_ring) |
2019 | virtqueue_disable_cb_packed(_vq); | |
2020 | else | |
2021 | virtqueue_disable_cb_split(_vq); | |
e6f633e5 TB |
2022 | } |
2023 | EXPORT_SYMBOL_GPL(virtqueue_disable_cb); | |
2024 | ||
2025 | /** | |
2026 | * virtqueue_enable_cb_prepare - restart callbacks after disable_cb | |
a5581206 | 2027 | * @_vq: the struct virtqueue we're talking about. |
e6f633e5 TB |
2028 | * |
2029 | * This re-enables callbacks; it returns current queue state | |
2030 | * in an opaque unsigned value. This value should be later tested by | |
2031 | * virtqueue_poll, to detect a possible race between the driver checking for | |
2032 | * more work, and enabling callbacks. | |
2033 | * | |
2034 | * Caller must ensure we don't call this with other virtqueue | |
2035 | * operations at the same time (except where noted). | |
2036 | */ | |
2037 | unsigned virtqueue_enable_cb_prepare(struct virtqueue *_vq) | |
2038 | { | |
1ce9e605 TB |
2039 | struct vring_virtqueue *vq = to_vvq(_vq); |
2040 | ||
8d622d21 MT |
2041 | if (vq->event_triggered) |
2042 | vq->event_triggered = false; | |
2043 | ||
1ce9e605 TB |
2044 | return vq->packed_ring ? virtqueue_enable_cb_prepare_packed(_vq) : |
2045 | virtqueue_enable_cb_prepare_split(_vq); | |
e6f633e5 TB |
2046 | } |
2047 | EXPORT_SYMBOL_GPL(virtqueue_enable_cb_prepare); | |
2048 | ||
2049 | /** | |
2050 | * virtqueue_poll - query pending used buffers | |
a5581206 | 2051 | * @_vq: the struct virtqueue we're talking about. |
e6f633e5 TB |
2052 | * @last_used_idx: virtqueue state (from call to virtqueue_enable_cb_prepare). |
2053 | * | |
2054 | * Returns "true" if there are pending used buffers in the queue. | |
2055 | * | |
2056 | * This does not need to be serialized. | |
2057 | */ | |
2058 | bool virtqueue_poll(struct virtqueue *_vq, unsigned last_used_idx) | |
2059 | { | |
2060 | struct vring_virtqueue *vq = to_vvq(_vq); | |
2061 | ||
481a0d74 MW |
2062 | if (unlikely(vq->broken)) |
2063 | return false; | |
2064 | ||
e6f633e5 | 2065 | virtio_mb(vq->weak_barriers); |
1ce9e605 TB |
2066 | return vq->packed_ring ? virtqueue_poll_packed(_vq, last_used_idx) : |
2067 | virtqueue_poll_split(_vq, last_used_idx); | |
e6f633e5 TB |
2068 | } |
2069 | EXPORT_SYMBOL_GPL(virtqueue_poll); | |
2070 | ||
2071 | /** | |
2072 | * virtqueue_enable_cb - restart callbacks after disable_cb. | |
a5581206 | 2073 | * @_vq: the struct virtqueue we're talking about. |
e6f633e5 TB |
2074 | * |
2075 | * This re-enables callbacks; it returns "false" if there are pending | |
2076 | * buffers in the queue, to detect a possible race between the driver | |
2077 | * checking for more work, and enabling callbacks. | |
2078 | * | |
2079 | * Caller must ensure we don't call this with other virtqueue | |
2080 | * operations at the same time (except where noted). | |
2081 | */ | |
2082 | bool virtqueue_enable_cb(struct virtqueue *_vq) | |
2083 | { | |
2084 | unsigned last_used_idx = virtqueue_enable_cb_prepare(_vq); | |
2085 | ||
2086 | return !virtqueue_poll(_vq, last_used_idx); | |
2087 | } | |
2088 | EXPORT_SYMBOL_GPL(virtqueue_enable_cb); | |
2089 | ||
2090 | /** | |
2091 | * virtqueue_enable_cb_delayed - restart callbacks after disable_cb. | |
a5581206 | 2092 | * @_vq: the struct virtqueue we're talking about. |
e6f633e5 TB |
2093 | * |
2094 | * This re-enables callbacks but hints to the other side to delay | |
2095 | * interrupts until most of the available buffers have been processed; | |
2096 | * it returns "false" if there are many pending buffers in the queue, | |
2097 | * to detect a possible race between the driver checking for more work, | |
2098 | * and enabling callbacks. | |
2099 | * | |
2100 | * Caller must ensure we don't call this with other virtqueue | |
2101 | * operations at the same time (except where noted). | |
2102 | */ | |
2103 | bool virtqueue_enable_cb_delayed(struct virtqueue *_vq) | |
2104 | { | |
1ce9e605 TB |
2105 | struct vring_virtqueue *vq = to_vvq(_vq); |
2106 | ||
8d622d21 MT |
2107 | if (vq->event_triggered) |
2108 | vq->event_triggered = false; | |
2109 | ||
1ce9e605 TB |
2110 | return vq->packed_ring ? virtqueue_enable_cb_delayed_packed(_vq) : |
2111 | virtqueue_enable_cb_delayed_split(_vq); | |
e6f633e5 TB |
2112 | } |
2113 | EXPORT_SYMBOL_GPL(virtqueue_enable_cb_delayed); | |
2114 | ||
138fd251 TB |
2115 | /** |
2116 | * virtqueue_detach_unused_buf - detach first unused buffer | |
a5581206 | 2117 | * @_vq: the struct virtqueue we're talking about. |
138fd251 TB |
2118 | * |
2119 | * Returns NULL or the "data" token handed to virtqueue_add_*(). | |
2120 | * This is not valid on an active queue; it is useful only for device | |
2121 | * shutdown. | |
2122 | */ | |
2123 | void *virtqueue_detach_unused_buf(struct virtqueue *_vq) | |
2124 | { | |
1ce9e605 TB |
2125 | struct vring_virtqueue *vq = to_vvq(_vq); |
2126 | ||
2127 | return vq->packed_ring ? virtqueue_detach_unused_buf_packed(_vq) : | |
2128 | virtqueue_detach_unused_buf_split(_vq); | |
138fd251 | 2129 | } |
7c5e9ed0 | 2130 | EXPORT_SYMBOL_GPL(virtqueue_detach_unused_buf); |
c021eac4 | 2131 | |
138fd251 TB |
2132 | static inline bool more_used(const struct vring_virtqueue *vq) |
2133 | { | |
1ce9e605 | 2134 | return vq->packed_ring ? more_used_packed(vq) : more_used_split(vq); |
138fd251 TB |
2135 | } |
2136 | ||
0a8a69dd RR |
2137 | irqreturn_t vring_interrupt(int irq, void *_vq) |
2138 | { | |
2139 | struct vring_virtqueue *vq = to_vvq(_vq); | |
2140 | ||
2141 | if (!more_used(vq)) { | |
2142 | pr_debug("virtqueue interrupt with no work for %p\n", vq); | |
2143 | return IRQ_NONE; | |
2144 | } | |
2145 | ||
2146 | if (unlikely(vq->broken)) | |
2147 | return IRQ_HANDLED; | |
2148 | ||
8d622d21 MT |
2149 | /* Just a hint for performance: so it's ok that this can be racy! */ |
2150 | if (vq->event) | |
2151 | vq->event_triggered = true; | |
2152 | ||
0a8a69dd | 2153 | pr_debug("virtqueue callback for %p (%p)\n", vq, vq->vq.callback); |
18445c4d RR |
2154 | if (vq->vq.callback) |
2155 | vq->vq.callback(&vq->vq); | |
0a8a69dd RR |
2156 | |
2157 | return IRQ_HANDLED; | |
2158 | } | |
c6fd4701 | 2159 | EXPORT_SYMBOL_GPL(vring_interrupt); |
0a8a69dd | 2160 | |
1ce9e605 | 2161 | /* Only available for split ring */ |
2a2d1382 AL |
2162 | struct virtqueue *__vring_new_virtqueue(unsigned int index, |
2163 | struct vring vring, | |
2164 | struct virtio_device *vdev, | |
2165 | bool weak_barriers, | |
f94682dd | 2166 | bool context, |
2a2d1382 AL |
2167 | bool (*notify)(struct virtqueue *), |
2168 | void (*callback)(struct virtqueue *), | |
2169 | const char *name) | |
0a8a69dd | 2170 | { |
2a2d1382 | 2171 | struct vring_virtqueue *vq; |
0a8a69dd | 2172 | |
1ce9e605 TB |
2173 | if (virtio_has_feature(vdev, VIRTIO_F_RING_PACKED)) |
2174 | return NULL; | |
2175 | ||
cbeedb72 | 2176 | vq = kmalloc(sizeof(*vq), GFP_KERNEL); |
0a8a69dd RR |
2177 | if (!vq) |
2178 | return NULL; | |
2179 | ||
1ce9e605 | 2180 | vq->packed_ring = false; |
0a8a69dd RR |
2181 | vq->vq.callback = callback; |
2182 | vq->vq.vdev = vdev; | |
9499f5e7 | 2183 | vq->vq.name = name; |
2a2d1382 | 2184 | vq->vq.num_free = vring.num; |
06ca287d | 2185 | vq->vq.index = index; |
2a2d1382 | 2186 | vq->we_own_ring = false; |
0a8a69dd | 2187 | vq->notify = notify; |
7b21e34f | 2188 | vq->weak_barriers = weak_barriers; |
0a8a69dd RR |
2189 | vq->broken = false; |
2190 | vq->last_used_idx = 0; | |
8d622d21 | 2191 | vq->event_triggered = false; |
0a8a69dd | 2192 | vq->num_added = 0; |
fb3fba6b | 2193 | vq->use_dma_api = vring_use_dma_api(vdev); |
0a8a69dd RR |
2194 | #ifdef DEBUG |
2195 | vq->in_use = false; | |
e93300b1 | 2196 | vq->last_add_time_valid = false; |
0a8a69dd RR |
2197 | #endif |
2198 | ||
5a08b04f MT |
2199 | vq->indirect = virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC) && |
2200 | !context; | |
a5c262c5 | 2201 | vq->event = virtio_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX); |
9fa29b9d | 2202 | |
45383fb0 TB |
2203 | if (virtio_has_feature(vdev, VIRTIO_F_ORDER_PLATFORM)) |
2204 | vq->weak_barriers = false; | |
2205 | ||
d79dca75 TB |
2206 | vq->split.queue_dma_addr = 0; |
2207 | vq->split.queue_size_in_bytes = 0; | |
2208 | ||
e593bf97 TB |
2209 | vq->split.vring = vring; |
2210 | vq->split.avail_flags_shadow = 0; | |
2211 | vq->split.avail_idx_shadow = 0; | |
2212 | ||
0a8a69dd | 2213 | /* No callback? Tell other side not to bother us. */ |
f277ec42 | 2214 | if (!callback) { |
e593bf97 | 2215 | vq->split.avail_flags_shadow |= VRING_AVAIL_F_NO_INTERRUPT; |
0ea1e4a6 | 2216 | if (!vq->event) |
e593bf97 TB |
2217 | vq->split.vring.avail->flags = cpu_to_virtio16(vdev, |
2218 | vq->split.avail_flags_shadow); | |
f277ec42 | 2219 | } |
0a8a69dd | 2220 | |
cbeedb72 TB |
2221 | vq->split.desc_state = kmalloc_array(vring.num, |
2222 | sizeof(struct vring_desc_state_split), GFP_KERNEL); | |
5bc72234 JW |
2223 | if (!vq->split.desc_state) |
2224 | goto err_state; | |
cbeedb72 | 2225 | |
72b5e895 JW |
2226 | vq->split.desc_extra = vring_alloc_desc_extra(vq, vring.num); |
2227 | if (!vq->split.desc_extra) | |
2228 | goto err_extra; | |
2229 | ||
0a8a69dd | 2230 | /* Put everything in free lists. */ |
0a8a69dd | 2231 | vq->free_head = 0; |
cbeedb72 TB |
2232 | memset(vq->split.desc_state, 0, vring.num * |
2233 | sizeof(struct vring_desc_state_split)); | |
0a8a69dd | 2234 | |
0e566c8f | 2235 | spin_lock(&vdev->vqs_list_lock); |
e152d8af | 2236 | list_add_tail(&vq->vq.list, &vdev->vqs); |
0e566c8f | 2237 | spin_unlock(&vdev->vqs_list_lock); |
0a8a69dd | 2238 | return &vq->vq; |
5bc72234 | 2239 | |
72b5e895 JW |
2240 | err_extra: |
2241 | kfree(vq->split.desc_state); | |
5bc72234 JW |
2242 | err_state: |
2243 | kfree(vq); | |
2244 | return NULL; | |
0a8a69dd | 2245 | } |
2a2d1382 AL |
2246 | EXPORT_SYMBOL_GPL(__vring_new_virtqueue); |
2247 | ||
2a2d1382 AL |
2248 | struct virtqueue *vring_create_virtqueue( |
2249 | unsigned int index, | |
2250 | unsigned int num, | |
2251 | unsigned int vring_align, | |
2252 | struct virtio_device *vdev, | |
2253 | bool weak_barriers, | |
2254 | bool may_reduce_num, | |
f94682dd | 2255 | bool context, |
2a2d1382 AL |
2256 | bool (*notify)(struct virtqueue *), |
2257 | void (*callback)(struct virtqueue *), | |
2258 | const char *name) | |
2259 | { | |
1ce9e605 TB |
2260 | |
2261 | if (virtio_has_feature(vdev, VIRTIO_F_RING_PACKED)) | |
2262 | return vring_create_virtqueue_packed(index, num, vring_align, | |
2263 | vdev, weak_barriers, may_reduce_num, | |
2264 | context, notify, callback, name); | |
2265 | ||
d79dca75 TB |
2266 | return vring_create_virtqueue_split(index, num, vring_align, |
2267 | vdev, weak_barriers, may_reduce_num, | |
2268 | context, notify, callback, name); | |
2a2d1382 AL |
2269 | } |
2270 | EXPORT_SYMBOL_GPL(vring_create_virtqueue); | |
2271 | ||
1ce9e605 | 2272 | /* Only available for split ring */ |
2a2d1382 AL |
2273 | struct virtqueue *vring_new_virtqueue(unsigned int index, |
2274 | unsigned int num, | |
2275 | unsigned int vring_align, | |
2276 | struct virtio_device *vdev, | |
2277 | bool weak_barriers, | |
f94682dd | 2278 | bool context, |
2a2d1382 AL |
2279 | void *pages, |
2280 | bool (*notify)(struct virtqueue *vq), | |
2281 | void (*callback)(struct virtqueue *vq), | |
2282 | const char *name) | |
2283 | { | |
2284 | struct vring vring; | |
1ce9e605 TB |
2285 | |
2286 | if (virtio_has_feature(vdev, VIRTIO_F_RING_PACKED)) | |
2287 | return NULL; | |
2288 | ||
2a2d1382 | 2289 | vring_init(&vring, num, pages, vring_align); |
f94682dd | 2290 | return __vring_new_virtqueue(index, vring, vdev, weak_barriers, context, |
2a2d1382 AL |
2291 | notify, callback, name); |
2292 | } | |
c6fd4701 | 2293 | EXPORT_SYMBOL_GPL(vring_new_virtqueue); |
0a8a69dd | 2294 | |
2a2d1382 | 2295 | void vring_del_virtqueue(struct virtqueue *_vq) |
0a8a69dd | 2296 | { |
2a2d1382 AL |
2297 | struct vring_virtqueue *vq = to_vvq(_vq); |
2298 | ||
0e566c8f | 2299 | spin_lock(&vq->vq.vdev->vqs_list_lock); |
249f2554 | 2300 | list_del(&_vq->list); |
0e566c8f | 2301 | spin_unlock(&vq->vq.vdev->vqs_list_lock); |
249f2554 | 2302 | |
2a2d1382 | 2303 | if (vq->we_own_ring) { |
1ce9e605 TB |
2304 | if (vq->packed_ring) { |
2305 | vring_free_queue(vq->vq.vdev, | |
2306 | vq->packed.ring_size_in_bytes, | |
2307 | vq->packed.vring.desc, | |
2308 | vq->packed.ring_dma_addr); | |
2309 | ||
2310 | vring_free_queue(vq->vq.vdev, | |
2311 | vq->packed.event_size_in_bytes, | |
2312 | vq->packed.vring.driver, | |
2313 | vq->packed.driver_event_dma_addr); | |
2314 | ||
2315 | vring_free_queue(vq->vq.vdev, | |
2316 | vq->packed.event_size_in_bytes, | |
2317 | vq->packed.vring.device, | |
2318 | vq->packed.device_event_dma_addr); | |
2319 | ||
2320 | kfree(vq->packed.desc_state); | |
2321 | kfree(vq->packed.desc_extra); | |
2322 | } else { | |
2323 | vring_free_queue(vq->vq.vdev, | |
2324 | vq->split.queue_size_in_bytes, | |
2325 | vq->split.vring.desc, | |
2326 | vq->split.queue_dma_addr); | |
1ce9e605 | 2327 | } |
2a2d1382 | 2328 | } |
72b5e895 | 2329 | if (!vq->packed_ring) { |
f13f09a1 | 2330 | kfree(vq->split.desc_state); |
72b5e895 JW |
2331 | kfree(vq->split.desc_extra); |
2332 | } | |
2a2d1382 | 2333 | kfree(vq); |
0a8a69dd | 2334 | } |
c6fd4701 | 2335 | EXPORT_SYMBOL_GPL(vring_del_virtqueue); |
0a8a69dd | 2336 | |
e34f8725 RR |
2337 | /* Manipulates transport-specific feature bits. */ |
2338 | void vring_transport_features(struct virtio_device *vdev) | |
2339 | { | |
2340 | unsigned int i; | |
2341 | ||
2342 | for (i = VIRTIO_TRANSPORT_F_START; i < VIRTIO_TRANSPORT_F_END; i++) { | |
2343 | switch (i) { | |
9fa29b9d MM |
2344 | case VIRTIO_RING_F_INDIRECT_DESC: |
2345 | break; | |
a5c262c5 MT |
2346 | case VIRTIO_RING_F_EVENT_IDX: |
2347 | break; | |
747ae34a MT |
2348 | case VIRTIO_F_VERSION_1: |
2349 | break; | |
321bd212 | 2350 | case VIRTIO_F_ACCESS_PLATFORM: |
1a937693 | 2351 | break; |
f959a128 TB |
2352 | case VIRTIO_F_RING_PACKED: |
2353 | break; | |
45383fb0 TB |
2354 | case VIRTIO_F_ORDER_PLATFORM: |
2355 | break; | |
e34f8725 RR |
2356 | default: |
2357 | /* We don't understand this bit. */ | |
e16e12be | 2358 | __virtio_clear_bit(vdev, i); |
e34f8725 RR |
2359 | } |
2360 | } | |
2361 | } | |
2362 | EXPORT_SYMBOL_GPL(vring_transport_features); | |
2363 | ||
5dfc1762 RR |
2364 | /** |
2365 | * virtqueue_get_vring_size - return the size of the virtqueue's vring | |
a5581206 | 2366 | * @_vq: the struct virtqueue containing the vring of interest. |
5dfc1762 RR |
2367 | * |
2368 | * Returns the size of the vring. This is mainly used for boasting to | |
2369 | * userspace. Unlike other operations, this need not be serialized. | |
2370 | */ | |
8f9f4668 RJ |
2371 | unsigned int virtqueue_get_vring_size(struct virtqueue *_vq) |
2372 | { | |
2373 | ||
2374 | struct vring_virtqueue *vq = to_vvq(_vq); | |
2375 | ||
1ce9e605 | 2376 | return vq->packed_ring ? vq->packed.vring.num : vq->split.vring.num; |
8f9f4668 RJ |
2377 | } |
2378 | EXPORT_SYMBOL_GPL(virtqueue_get_vring_size); | |
2379 | ||
b3b32c94 HG |
2380 | bool virtqueue_is_broken(struct virtqueue *_vq) |
2381 | { | |
2382 | struct vring_virtqueue *vq = to_vvq(_vq); | |
2383 | ||
60f07798 | 2384 | return READ_ONCE(vq->broken); |
b3b32c94 HG |
2385 | } |
2386 | EXPORT_SYMBOL_GPL(virtqueue_is_broken); | |
2387 | ||
e2dcdfe9 RR |
2388 | /* |
2389 | * This should prevent the device from being used, allowing drivers to | |
2390 | * recover. You may need to grab appropriate locks to flush. | |
2391 | */ | |
2392 | void virtio_break_device(struct virtio_device *dev) | |
2393 | { | |
2394 | struct virtqueue *_vq; | |
2395 | ||
0e566c8f | 2396 | spin_lock(&dev->vqs_list_lock); |
e2dcdfe9 RR |
2397 | list_for_each_entry(_vq, &dev->vqs, list) { |
2398 | struct vring_virtqueue *vq = to_vvq(_vq); | |
60f07798 PP |
2399 | |
2400 | /* Pairs with READ_ONCE() in virtqueue_is_broken(). */ | |
2401 | WRITE_ONCE(vq->broken, true); | |
e2dcdfe9 | 2402 | } |
0e566c8f | 2403 | spin_unlock(&dev->vqs_list_lock); |
e2dcdfe9 RR |
2404 | } |
2405 | EXPORT_SYMBOL_GPL(virtio_break_device); | |
2406 | ||
2a2d1382 | 2407 | dma_addr_t virtqueue_get_desc_addr(struct virtqueue *_vq) |
89062652 CH |
2408 | { |
2409 | struct vring_virtqueue *vq = to_vvq(_vq); | |
2410 | ||
2a2d1382 AL |
2411 | BUG_ON(!vq->we_own_ring); |
2412 | ||
1ce9e605 TB |
2413 | if (vq->packed_ring) |
2414 | return vq->packed.ring_dma_addr; | |
2415 | ||
d79dca75 | 2416 | return vq->split.queue_dma_addr; |
89062652 | 2417 | } |
2a2d1382 | 2418 | EXPORT_SYMBOL_GPL(virtqueue_get_desc_addr); |
89062652 | 2419 | |
2a2d1382 | 2420 | dma_addr_t virtqueue_get_avail_addr(struct virtqueue *_vq) |
89062652 CH |
2421 | { |
2422 | struct vring_virtqueue *vq = to_vvq(_vq); | |
2423 | ||
2a2d1382 AL |
2424 | BUG_ON(!vq->we_own_ring); |
2425 | ||
1ce9e605 TB |
2426 | if (vq->packed_ring) |
2427 | return vq->packed.driver_event_dma_addr; | |
2428 | ||
d79dca75 | 2429 | return vq->split.queue_dma_addr + |
e593bf97 | 2430 | ((char *)vq->split.vring.avail - (char *)vq->split.vring.desc); |
2a2d1382 AL |
2431 | } |
2432 | EXPORT_SYMBOL_GPL(virtqueue_get_avail_addr); | |
2433 | ||
2434 | dma_addr_t virtqueue_get_used_addr(struct virtqueue *_vq) | |
2435 | { | |
2436 | struct vring_virtqueue *vq = to_vvq(_vq); | |
2437 | ||
2438 | BUG_ON(!vq->we_own_ring); | |
2439 | ||
1ce9e605 TB |
2440 | if (vq->packed_ring) |
2441 | return vq->packed.device_event_dma_addr; | |
2442 | ||
d79dca75 | 2443 | return vq->split.queue_dma_addr + |
e593bf97 | 2444 | ((char *)vq->split.vring.used - (char *)vq->split.vring.desc); |
2a2d1382 AL |
2445 | } |
2446 | EXPORT_SYMBOL_GPL(virtqueue_get_used_addr); | |
2447 | ||
1ce9e605 | 2448 | /* Only available for split ring */ |
2a2d1382 AL |
2449 | const struct vring *virtqueue_get_vring(struct virtqueue *vq) |
2450 | { | |
e593bf97 | 2451 | return &to_vvq(vq)->split.vring; |
89062652 | 2452 | } |
2a2d1382 | 2453 | EXPORT_SYMBOL_GPL(virtqueue_get_vring); |
89062652 | 2454 | |
c6fd4701 | 2455 | MODULE_LICENSE("GPL"); |