Commit | Line | Data |
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3e7ee490 HJ |
1 | /* |
2 | * | |
3 | * Copyright (c) 2009, Microsoft Corporation. | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or modify it | |
6 | * under the terms and conditions of the GNU General Public License, | |
7 | * version 2, as published by the Free Software Foundation. | |
8 | * | |
9 | * This program is distributed in the hope it will be useful, but WITHOUT | |
10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
12 | * more details. | |
13 | * | |
14 | * You should have received a copy of the GNU General Public License along with | |
15 | * this program; if not, write to the Free Software Foundation, Inc., 59 Temple | |
16 | * Place - Suite 330, Boston, MA 02111-1307 USA. | |
17 | * | |
18 | * Authors: | |
19 | * Haiyang Zhang <haiyangz@microsoft.com> | |
20 | * Hank Janssen <hjanssen@microsoft.com> | |
b2a5a585 | 21 | * K. Y. Srinivasan <kys@microsoft.com> |
3e7ee490 HJ |
22 | * |
23 | */ | |
0a46618d | 24 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
3e7ee490 | 25 | |
a0086dc5 GKH |
26 | #include <linux/kernel.h> |
27 | #include <linux/mm.h> | |
46a97191 | 28 | #include <linux/hyperv.h> |
3f335ea2 | 29 | |
0f2a6619 | 30 | #include "hyperv_vmbus.h" |
3e7ee490 | 31 | |
6fdf3b21 S |
32 | void hv_begin_read(struct hv_ring_buffer_info *rbi) |
33 | { | |
34 | rbi->ring_buffer->interrupt_mask = 1; | |
35 | smp_mb(); | |
36 | } | |
37 | ||
38 | u32 hv_end_read(struct hv_ring_buffer_info *rbi) | |
39 | { | |
40 | u32 read; | |
41 | u32 write; | |
42 | ||
43 | rbi->ring_buffer->interrupt_mask = 0; | |
44 | smp_mb(); | |
45 | ||
46 | /* | |
47 | * Now check to see if the ring buffer is still empty. | |
48 | * If it is not, we raced and we need to process new | |
49 | * incoming messages. | |
50 | */ | |
51 | hv_get_ringbuffer_availbytes(rbi, &read, &write); | |
52 | ||
53 | return read; | |
54 | } | |
55 | ||
3e7ee490 | 56 | |
b2a5a585 S |
57 | /* |
58 | * hv_get_next_write_location() | |
59 | * | |
60 | * Get the next write location for the specified ring buffer | |
61 | * | |
62 | */ | |
4d643114 | 63 | static inline u32 |
2b8a912e | 64 | hv_get_next_write_location(struct hv_ring_buffer_info *ring_info) |
3e7ee490 | 65 | { |
fc8c72eb | 66 | u32 next = ring_info->ring_buffer->write_index; |
3e7ee490 | 67 | |
3e7ee490 HJ |
68 | return next; |
69 | } | |
70 | ||
b2a5a585 S |
71 | /* |
72 | * hv_set_next_write_location() | |
73 | * | |
74 | * Set the next write location for the specified ring buffer | |
75 | * | |
76 | */ | |
3e7ee490 | 77 | static inline void |
2b8a912e | 78 | hv_set_next_write_location(struct hv_ring_buffer_info *ring_info, |
fc8c72eb | 79 | u32 next_write_location) |
3e7ee490 | 80 | { |
fc8c72eb | 81 | ring_info->ring_buffer->write_index = next_write_location; |
3e7ee490 HJ |
82 | } |
83 | ||
b2a5a585 S |
84 | /* |
85 | * hv_get_next_read_location() | |
86 | * | |
87 | * Get the next read location for the specified ring buffer | |
88 | */ | |
4d643114 | 89 | static inline u32 |
2b8a912e | 90 | hv_get_next_read_location(struct hv_ring_buffer_info *ring_info) |
3e7ee490 | 91 | { |
fc8c72eb | 92 | u32 next = ring_info->ring_buffer->read_index; |
3e7ee490 | 93 | |
3e7ee490 HJ |
94 | return next; |
95 | } | |
96 | ||
b2a5a585 S |
97 | /* |
98 | * hv_get_next_readlocation_withoffset() | |
99 | * | |
100 | * Get the next read location + offset for the specified ring buffer. | |
101 | * This allows the caller to skip | |
102 | */ | |
4d643114 | 103 | static inline u32 |
2b8a912e | 104 | hv_get_next_readlocation_withoffset(struct hv_ring_buffer_info *ring_info, |
1ac58644 | 105 | u32 offset) |
3e7ee490 | 106 | { |
fc8c72eb | 107 | u32 next = ring_info->ring_buffer->read_index; |
3e7ee490 | 108 | |
fc8c72eb HZ |
109 | next += offset; |
110 | next %= ring_info->ring_datasize; | |
3e7ee490 HJ |
111 | |
112 | return next; | |
113 | } | |
114 | ||
b2a5a585 S |
115 | /* |
116 | * | |
117 | * hv_set_next_read_location() | |
118 | * | |
119 | * Set the next read location for the specified ring buffer | |
120 | * | |
121 | */ | |
3e7ee490 | 122 | static inline void |
2b8a912e | 123 | hv_set_next_read_location(struct hv_ring_buffer_info *ring_info, |
fc8c72eb | 124 | u32 next_read_location) |
3e7ee490 | 125 | { |
fc8c72eb | 126 | ring_info->ring_buffer->read_index = next_read_location; |
3e7ee490 HJ |
127 | } |
128 | ||
129 | ||
b2a5a585 S |
130 | /* |
131 | * | |
132 | * hv_get_ring_buffer() | |
133 | * | |
134 | * Get the start of the ring buffer | |
135 | */ | |
8282c400 | 136 | static inline void * |
2b8a912e | 137 | hv_get_ring_buffer(struct hv_ring_buffer_info *ring_info) |
3e7ee490 | 138 | { |
fc8c72eb | 139 | return (void *)ring_info->ring_buffer->buffer; |
3e7ee490 HJ |
140 | } |
141 | ||
142 | ||
b2a5a585 S |
143 | /* |
144 | * | |
145 | * hv_get_ring_buffersize() | |
146 | * | |
147 | * Get the size of the ring buffer | |
148 | */ | |
4d643114 | 149 | static inline u32 |
2b8a912e | 150 | hv_get_ring_buffersize(struct hv_ring_buffer_info *ring_info) |
3e7ee490 | 151 | { |
fc8c72eb | 152 | return ring_info->ring_datasize; |
3e7ee490 HJ |
153 | } |
154 | ||
b2a5a585 S |
155 | /* |
156 | * | |
157 | * hv_get_ring_bufferindices() | |
158 | * | |
159 | * Get the read and write indices as u64 of the specified ring buffer | |
160 | * | |
161 | */ | |
59471438 | 162 | static inline u64 |
2b8a912e | 163 | hv_get_ring_bufferindices(struct hv_ring_buffer_info *ring_info) |
3e7ee490 | 164 | { |
fc8c72eb | 165 | return (u64)ring_info->ring_buffer->write_index << 32; |
3e7ee490 HJ |
166 | } |
167 | ||
8f1136ae S |
168 | /* |
169 | * | |
170 | * hv_copyfrom_ringbuffer() | |
171 | * | |
172 | * Helper routine to copy to source from ring buffer. | |
173 | * Assume there is enough room. Handles wrap-around in src case only!! | |
174 | * | |
175 | */ | |
176 | static u32 hv_copyfrom_ringbuffer( | |
177 | struct hv_ring_buffer_info *ring_info, | |
178 | void *dest, | |
179 | u32 destlen, | |
180 | u32 start_read_offset) | |
181 | { | |
182 | void *ring_buffer = hv_get_ring_buffer(ring_info); | |
183 | u32 ring_buffer_size = hv_get_ring_buffersize(ring_info); | |
184 | ||
185 | u32 frag_len; | |
186 | ||
187 | /* wrap-around detected at the src */ | |
188 | if (destlen > ring_buffer_size - start_read_offset) { | |
189 | frag_len = ring_buffer_size - start_read_offset; | |
190 | ||
191 | memcpy(dest, ring_buffer + start_read_offset, frag_len); | |
192 | memcpy(dest + frag_len, ring_buffer, destlen - frag_len); | |
193 | } else | |
194 | ||
195 | memcpy(dest, ring_buffer + start_read_offset, destlen); | |
196 | ||
197 | ||
198 | start_read_offset += destlen; | |
199 | start_read_offset %= ring_buffer_size; | |
200 | ||
201 | return start_read_offset; | |
202 | } | |
203 | ||
204 | ||
7581578d S |
205 | /* |
206 | * | |
207 | * hv_copyto_ringbuffer() | |
208 | * | |
209 | * Helper routine to copy from source to ring buffer. | |
210 | * Assume there is enough room. Handles wrap-around in dest case only!! | |
211 | * | |
212 | */ | |
213 | static u32 hv_copyto_ringbuffer( | |
fc8c72eb HZ |
214 | struct hv_ring_buffer_info *ring_info, |
215 | u32 start_write_offset, | |
216 | void *src, | |
7581578d S |
217 | u32 srclen) |
218 | { | |
219 | void *ring_buffer = hv_get_ring_buffer(ring_info); | |
220 | u32 ring_buffer_size = hv_get_ring_buffersize(ring_info); | |
221 | u32 frag_len; | |
222 | ||
223 | /* wrap-around detected! */ | |
224 | if (srclen > ring_buffer_size - start_write_offset) { | |
225 | frag_len = ring_buffer_size - start_write_offset; | |
226 | memcpy(ring_buffer + start_write_offset, src, frag_len); | |
227 | memcpy(ring_buffer, src + frag_len, srclen - frag_len); | |
228 | } else | |
229 | memcpy(ring_buffer + start_write_offset, src, srclen); | |
3e7ee490 | 230 | |
7581578d S |
231 | start_write_offset += srclen; |
232 | start_write_offset %= ring_buffer_size; | |
233 | ||
234 | return start_write_offset; | |
235 | } | |
3e7ee490 | 236 | |
b2a5a585 S |
237 | /* |
238 | * | |
239 | * hv_ringbuffer_get_debuginfo() | |
240 | * | |
241 | * Get various debug metrics for the specified ring buffer | |
242 | * | |
243 | */ | |
a75b61d5 | 244 | void hv_ringbuffer_get_debuginfo(struct hv_ring_buffer_info *ring_info, |
80682b7a | 245 | struct hv_ring_buffer_debug_info *debug_info) |
3e7ee490 | 246 | { |
fc8c72eb HZ |
247 | u32 bytes_avail_towrite; |
248 | u32 bytes_avail_toread; | |
3e7ee490 | 249 | |
fc8c72eb | 250 | if (ring_info->ring_buffer) { |
2b8a912e | 251 | hv_get_ringbuffer_availbytes(ring_info, |
fc8c72eb HZ |
252 | &bytes_avail_toread, |
253 | &bytes_avail_towrite); | |
3e7ee490 | 254 | |
fc8c72eb HZ |
255 | debug_info->bytes_avail_toread = bytes_avail_toread; |
256 | debug_info->bytes_avail_towrite = bytes_avail_towrite; | |
82f8bd40 | 257 | debug_info->current_read_index = |
fc8c72eb | 258 | ring_info->ring_buffer->read_index; |
82f8bd40 | 259 | debug_info->current_write_index = |
fc8c72eb | 260 | ring_info->ring_buffer->write_index; |
82f8bd40 | 261 | debug_info->current_interrupt_mask = |
fc8c72eb | 262 | ring_info->ring_buffer->interrupt_mask; |
3e7ee490 HJ |
263 | } |
264 | } | |
265 | ||
266 | ||
b2a5a585 S |
267 | /* |
268 | * | |
269 | * hv_get_ringbuffer_interrupt_mask() | |
270 | * | |
271 | * Get the interrupt mask for the specified ring buffer | |
272 | * | |
273 | */ | |
decc49da | 274 | u32 hv_get_ringbuffer_interrupt_mask(struct hv_ring_buffer_info *rbi) |
3e7ee490 | 275 | { |
82f8bd40 | 276 | return rbi->ring_buffer->interrupt_mask; |
3e7ee490 HJ |
277 | } |
278 | ||
b2a5a585 S |
279 | /* |
280 | * | |
281 | * hv_ringbuffer_init() | |
282 | * | |
283 | *Initialize the ring buffer | |
284 | * | |
285 | */ | |
72a95cbc | 286 | int hv_ringbuffer_init(struct hv_ring_buffer_info *ring_info, |
fc8c72eb | 287 | void *buffer, u32 buflen) |
3e7ee490 | 288 | { |
4a1b3acc | 289 | if (sizeof(struct hv_ring_buffer) != PAGE_SIZE) |
3324fb40 | 290 | return -EINVAL; |
3e7ee490 | 291 | |
fc8c72eb | 292 | memset(ring_info, 0, sizeof(struct hv_ring_buffer_info)); |
3e7ee490 | 293 | |
fc8c72eb HZ |
294 | ring_info->ring_buffer = (struct hv_ring_buffer *)buffer; |
295 | ring_info->ring_buffer->read_index = | |
296 | ring_info->ring_buffer->write_index = 0; | |
3e7ee490 | 297 | |
fc8c72eb HZ |
298 | ring_info->ring_size = buflen; |
299 | ring_info->ring_datasize = buflen - sizeof(struct hv_ring_buffer); | |
3e7ee490 | 300 | |
fc8c72eb | 301 | spin_lock_init(&ring_info->ring_lock); |
3e7ee490 HJ |
302 | |
303 | return 0; | |
304 | } | |
305 | ||
b2a5a585 S |
306 | /* |
307 | * | |
308 | * hv_ringbuffer_cleanup() | |
309 | * | |
310 | * Cleanup the ring buffer | |
311 | * | |
312 | */ | |
2dba688b | 313 | void hv_ringbuffer_cleanup(struct hv_ring_buffer_info *ring_info) |
3e7ee490 | 314 | { |
3e7ee490 HJ |
315 | } |
316 | ||
b2a5a585 S |
317 | /* |
318 | * | |
319 | * hv_ringbuffer_write() | |
320 | * | |
321 | * Write to the ring buffer | |
322 | * | |
323 | */ | |
633c4dce | 324 | int hv_ringbuffer_write(struct hv_ring_buffer_info *outring_info, |
3523a805 | 325 | struct scatterlist *sglist, u32 sgcount) |
3e7ee490 | 326 | { |
4408f531 | 327 | int i = 0; |
fc8c72eb HZ |
328 | u32 bytes_avail_towrite; |
329 | u32 bytes_avail_toread; | |
330 | u32 totalbytes_towrite = 0; | |
3e7ee490 | 331 | |
b219b3f7 | 332 | struct scatterlist *sg; |
66a60543 | 333 | u32 next_write_location; |
fc8c72eb | 334 | u64 prev_indices = 0; |
a98f96ee | 335 | unsigned long flags; |
3e7ee490 | 336 | |
b219b3f7 | 337 | for_each_sg(sglist, sg, sgcount, i) |
3e7ee490 | 338 | { |
fc8c72eb | 339 | totalbytes_towrite += sg->length; |
3e7ee490 HJ |
340 | } |
341 | ||
fc8c72eb | 342 | totalbytes_towrite += sizeof(u64); |
3e7ee490 | 343 | |
fc8c72eb | 344 | spin_lock_irqsave(&outring_info->ring_lock, flags); |
3e7ee490 | 345 | |
2b8a912e | 346 | hv_get_ringbuffer_availbytes(outring_info, |
fc8c72eb HZ |
347 | &bytes_avail_toread, |
348 | &bytes_avail_towrite); | |
3e7ee490 | 349 | |
3e7ee490 | 350 | |
4408f531 B |
351 | /* If there is only room for the packet, assume it is full. */ |
352 | /* Otherwise, the next time around, we think the ring buffer */ | |
454f18a9 | 353 | /* is empty since the read index == write index */ |
fc8c72eb | 354 | if (bytes_avail_towrite <= totalbytes_towrite) { |
fc8c72eb | 355 | spin_unlock_irqrestore(&outring_info->ring_lock, flags); |
d2598f01 | 356 | return -EAGAIN; |
3e7ee490 HJ |
357 | } |
358 | ||
454f18a9 | 359 | /* Write to the ring buffer */ |
2b8a912e | 360 | next_write_location = hv_get_next_write_location(outring_info); |
3e7ee490 | 361 | |
b219b3f7 | 362 | for_each_sg(sglist, sg, sgcount, i) |
3e7ee490 | 363 | { |
2b8a912e | 364 | next_write_location = hv_copyto_ringbuffer(outring_info, |
fc8c72eb | 365 | next_write_location, |
b219b3f7 NP |
366 | sg_virt(sg), |
367 | sg->length); | |
3e7ee490 HJ |
368 | } |
369 | ||
454f18a9 | 370 | /* Set previous packet start */ |
2b8a912e | 371 | prev_indices = hv_get_ring_bufferindices(outring_info); |
3e7ee490 | 372 | |
2b8a912e | 373 | next_write_location = hv_copyto_ringbuffer(outring_info, |
fc8c72eb HZ |
374 | next_write_location, |
375 | &prev_indices, | |
b219b3f7 | 376 | sizeof(u64)); |
3e7ee490 | 377 | |
454f18a9 | 378 | /* Make sure we flush all writes before updating the writeIndex */ |
e690b5a9 | 379 | smp_wmb(); |
3e7ee490 | 380 | |
454f18a9 | 381 | /* Now, update the write location */ |
2b8a912e | 382 | hv_set_next_write_location(outring_info, next_write_location); |
3e7ee490 | 383 | |
3e7ee490 | 384 | |
fc8c72eb | 385 | spin_unlock_irqrestore(&outring_info->ring_lock, flags); |
3e7ee490 HJ |
386 | return 0; |
387 | } | |
388 | ||
389 | ||
b2a5a585 S |
390 | /* |
391 | * | |
392 | * hv_ringbuffer_peek() | |
393 | * | |
394 | * Read without advancing the read index | |
395 | * | |
396 | */ | |
a89186c2 | 397 | int hv_ringbuffer_peek(struct hv_ring_buffer_info *Inring_info, |
fc8c72eb | 398 | void *Buffer, u32 buflen) |
3e7ee490 | 399 | { |
fc8c72eb HZ |
400 | u32 bytes_avail_towrite; |
401 | u32 bytes_avail_toread; | |
402 | u32 next_read_location = 0; | |
a98f96ee | 403 | unsigned long flags; |
3e7ee490 | 404 | |
fc8c72eb | 405 | spin_lock_irqsave(&Inring_info->ring_lock, flags); |
3e7ee490 | 406 | |
2b8a912e | 407 | hv_get_ringbuffer_availbytes(Inring_info, |
fc8c72eb HZ |
408 | &bytes_avail_toread, |
409 | &bytes_avail_towrite); | |
3e7ee490 | 410 | |
454f18a9 | 411 | /* Make sure there is something to read */ |
fc8c72eb | 412 | if (bytes_avail_toread < buflen) { |
3e7ee490 | 413 | |
fc8c72eb | 414 | spin_unlock_irqrestore(&Inring_info->ring_lock, flags); |
3e7ee490 | 415 | |
d2598f01 | 416 | return -EAGAIN; |
3e7ee490 HJ |
417 | } |
418 | ||
454f18a9 | 419 | /* Convert to byte offset */ |
2b8a912e | 420 | next_read_location = hv_get_next_read_location(Inring_info); |
3e7ee490 | 421 | |
2b8a912e | 422 | next_read_location = hv_copyfrom_ringbuffer(Inring_info, |
4408f531 | 423 | Buffer, |
fc8c72eb HZ |
424 | buflen, |
425 | next_read_location); | |
3e7ee490 | 426 | |
fc8c72eb | 427 | spin_unlock_irqrestore(&Inring_info->ring_lock, flags); |
3e7ee490 HJ |
428 | |
429 | return 0; | |
430 | } | |
431 | ||
432 | ||
b2a5a585 S |
433 | /* |
434 | * | |
435 | * hv_ringbuffer_read() | |
436 | * | |
437 | * Read and advance the read index | |
438 | * | |
439 | */ | |
38397c8a | 440 | int hv_ringbuffer_read(struct hv_ring_buffer_info *inring_info, void *buffer, |
fc8c72eb | 441 | u32 buflen, u32 offset) |
3e7ee490 | 442 | { |
fc8c72eb HZ |
443 | u32 bytes_avail_towrite; |
444 | u32 bytes_avail_toread; | |
445 | u32 next_read_location = 0; | |
446 | u64 prev_indices = 0; | |
a98f96ee | 447 | unsigned long flags; |
3e7ee490 | 448 | |
fc8c72eb | 449 | if (buflen <= 0) |
a16e1485 | 450 | return -EINVAL; |
3e7ee490 | 451 | |
fc8c72eb | 452 | spin_lock_irqsave(&inring_info->ring_lock, flags); |
3e7ee490 | 453 | |
2b8a912e | 454 | hv_get_ringbuffer_availbytes(inring_info, |
fc8c72eb HZ |
455 | &bytes_avail_toread, |
456 | &bytes_avail_towrite); | |
3e7ee490 | 457 | |
454f18a9 | 458 | /* Make sure there is something to read */ |
fc8c72eb | 459 | if (bytes_avail_toread < buflen) { |
fc8c72eb | 460 | spin_unlock_irqrestore(&inring_info->ring_lock, flags); |
3e7ee490 | 461 | |
d2598f01 | 462 | return -EAGAIN; |
3e7ee490 HJ |
463 | } |
464 | ||
1ac58644 | 465 | next_read_location = |
2b8a912e | 466 | hv_get_next_readlocation_withoffset(inring_info, offset); |
3e7ee490 | 467 | |
2b8a912e | 468 | next_read_location = hv_copyfrom_ringbuffer(inring_info, |
fc8c72eb HZ |
469 | buffer, |
470 | buflen, | |
471 | next_read_location); | |
3e7ee490 | 472 | |
2b8a912e | 473 | next_read_location = hv_copyfrom_ringbuffer(inring_info, |
fc8c72eb | 474 | &prev_indices, |
4408f531 | 475 | sizeof(u64), |
fc8c72eb | 476 | next_read_location); |
3e7ee490 | 477 | |
454f18a9 | 478 | /* Make sure all reads are done before we update the read index since */ |
4408f531 B |
479 | /* the writer may start writing to the read area once the read index */ |
480 | /*is updated */ | |
ef0d5b23 | 481 | smp_mb(); |
3e7ee490 | 482 | |
454f18a9 | 483 | /* Update the read index */ |
2b8a912e | 484 | hv_set_next_read_location(inring_info, next_read_location); |
3e7ee490 | 485 | |
fc8c72eb | 486 | spin_unlock_irqrestore(&inring_info->ring_lock, flags); |
3e7ee490 HJ |
487 | |
488 | return 0; | |
489 | } |