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> | |
3f335ea2 S |
28 | |
29 | #include "hyperv.h" | |
0f2a6619 | 30 | #include "hyperv_vmbus.h" |
3e7ee490 | 31 | |
3e7ee490 | 32 | |
454f18a9 BP |
33 | /* #defines */ |
34 | ||
35 | ||
36 | /* Amount of space to write to */ | |
b737b2e0 S |
37 | #define BYTES_AVAIL_TO_WRITE(r, w, z) \ |
38 | ((w) >= (r)) ? ((z) - ((w) - (r))) : ((r) - (w)) | |
3e7ee490 HJ |
39 | |
40 | ||
b2a5a585 S |
41 | /* |
42 | * | |
43 | * hv_get_ringbuffer_availbytes() | |
44 | * | |
45 | * Get number of bytes available to read and to write to | |
46 | * for the specified ring buffer | |
47 | */ | |
3e7ee490 | 48 | static inline void |
2b8a912e | 49 | hv_get_ringbuffer_availbytes(struct hv_ring_buffer_info *rbi, |
1ac58644 | 50 | u32 *read, u32 *write) |
3e7ee490 | 51 | { |
4408f531 | 52 | u32 read_loc, write_loc; |
3e7ee490 | 53 | |
df2a4a71 S |
54 | smp_read_barrier_depends(); |
55 | ||
454f18a9 | 56 | /* Capture the read/write indices before they changed */ |
82f8bd40 HZ |
57 | read_loc = rbi->ring_buffer->read_index; |
58 | write_loc = rbi->ring_buffer->write_index; | |
3e7ee490 | 59 | |
82f8bd40 HZ |
60 | *write = BYTES_AVAIL_TO_WRITE(read_loc, write_loc, rbi->ring_datasize); |
61 | *read = rbi->ring_datasize - *write; | |
3e7ee490 HJ |
62 | } |
63 | ||
b2a5a585 S |
64 | /* |
65 | * hv_get_next_write_location() | |
66 | * | |
67 | * Get the next write location for the specified ring buffer | |
68 | * | |
69 | */ | |
4d643114 | 70 | static inline u32 |
2b8a912e | 71 | hv_get_next_write_location(struct hv_ring_buffer_info *ring_info) |
3e7ee490 | 72 | { |
fc8c72eb | 73 | u32 next = ring_info->ring_buffer->write_index; |
3e7ee490 | 74 | |
3e7ee490 HJ |
75 | return next; |
76 | } | |
77 | ||
b2a5a585 S |
78 | /* |
79 | * hv_set_next_write_location() | |
80 | * | |
81 | * Set the next write location for the specified ring buffer | |
82 | * | |
83 | */ | |
3e7ee490 | 84 | static inline void |
2b8a912e | 85 | hv_set_next_write_location(struct hv_ring_buffer_info *ring_info, |
fc8c72eb | 86 | u32 next_write_location) |
3e7ee490 | 87 | { |
fc8c72eb | 88 | ring_info->ring_buffer->write_index = next_write_location; |
3e7ee490 HJ |
89 | } |
90 | ||
b2a5a585 S |
91 | /* |
92 | * hv_get_next_read_location() | |
93 | * | |
94 | * Get the next read location for the specified ring buffer | |
95 | */ | |
4d643114 | 96 | static inline u32 |
2b8a912e | 97 | hv_get_next_read_location(struct hv_ring_buffer_info *ring_info) |
3e7ee490 | 98 | { |
fc8c72eb | 99 | u32 next = ring_info->ring_buffer->read_index; |
3e7ee490 | 100 | |
3e7ee490 HJ |
101 | return next; |
102 | } | |
103 | ||
b2a5a585 S |
104 | /* |
105 | * hv_get_next_readlocation_withoffset() | |
106 | * | |
107 | * Get the next read location + offset for the specified ring buffer. | |
108 | * This allows the caller to skip | |
109 | */ | |
4d643114 | 110 | static inline u32 |
2b8a912e | 111 | hv_get_next_readlocation_withoffset(struct hv_ring_buffer_info *ring_info, |
1ac58644 | 112 | u32 offset) |
3e7ee490 | 113 | { |
fc8c72eb | 114 | u32 next = ring_info->ring_buffer->read_index; |
3e7ee490 | 115 | |
fc8c72eb HZ |
116 | next += offset; |
117 | next %= ring_info->ring_datasize; | |
3e7ee490 HJ |
118 | |
119 | return next; | |
120 | } | |
121 | ||
b2a5a585 S |
122 | /* |
123 | * | |
124 | * hv_set_next_read_location() | |
125 | * | |
126 | * Set the next read location for the specified ring buffer | |
127 | * | |
128 | */ | |
3e7ee490 | 129 | static inline void |
2b8a912e | 130 | hv_set_next_read_location(struct hv_ring_buffer_info *ring_info, |
fc8c72eb | 131 | u32 next_read_location) |
3e7ee490 | 132 | { |
fc8c72eb | 133 | ring_info->ring_buffer->read_index = next_read_location; |
3e7ee490 HJ |
134 | } |
135 | ||
136 | ||
b2a5a585 S |
137 | /* |
138 | * | |
139 | * hv_get_ring_buffer() | |
140 | * | |
141 | * Get the start of the ring buffer | |
142 | */ | |
8282c400 | 143 | static inline void * |
2b8a912e | 144 | hv_get_ring_buffer(struct hv_ring_buffer_info *ring_info) |
3e7ee490 | 145 | { |
fc8c72eb | 146 | return (void *)ring_info->ring_buffer->buffer; |
3e7ee490 HJ |
147 | } |
148 | ||
149 | ||
b2a5a585 S |
150 | /* |
151 | * | |
152 | * hv_get_ring_buffersize() | |
153 | * | |
154 | * Get the size of the ring buffer | |
155 | */ | |
4d643114 | 156 | static inline u32 |
2b8a912e | 157 | hv_get_ring_buffersize(struct hv_ring_buffer_info *ring_info) |
3e7ee490 | 158 | { |
fc8c72eb | 159 | return ring_info->ring_datasize; |
3e7ee490 HJ |
160 | } |
161 | ||
b2a5a585 S |
162 | /* |
163 | * | |
164 | * hv_get_ring_bufferindices() | |
165 | * | |
166 | * Get the read and write indices as u64 of the specified ring buffer | |
167 | * | |
168 | */ | |
59471438 | 169 | static inline u64 |
2b8a912e | 170 | hv_get_ring_bufferindices(struct hv_ring_buffer_info *ring_info) |
3e7ee490 | 171 | { |
fc8c72eb | 172 | return (u64)ring_info->ring_buffer->write_index << 32; |
3e7ee490 HJ |
173 | } |
174 | ||
175 | ||
b2a5a585 S |
176 | /* |
177 | * | |
178 | * hv_dump_ring_info() | |
179 | * | |
180 | * Dump out to console the ring buffer info | |
181 | * | |
182 | */ | |
549bf93f | 183 | void hv_dump_ring_info(struct hv_ring_buffer_info *ring_info, char *prefix) |
3e7ee490 | 184 | { |
fc8c72eb HZ |
185 | u32 bytes_avail_towrite; |
186 | u32 bytes_avail_toread; | |
3e7ee490 | 187 | |
2b8a912e | 188 | hv_get_ringbuffer_availbytes(ring_info, |
fc8c72eb HZ |
189 | &bytes_avail_toread, |
190 | &bytes_avail_towrite); | |
3e7ee490 | 191 | |
4408f531 B |
192 | DPRINT(VMBUS, |
193 | DEBUG_RING_LVL, | |
194 | "%s <<ringinfo %p buffer %p avail write %u " | |
195 | "avail read %u read idx %u write idx %u>>", | |
fc8c72eb HZ |
196 | prefix, |
197 | ring_info, | |
198 | ring_info->ring_buffer->buffer, | |
199 | bytes_avail_towrite, | |
200 | bytes_avail_toread, | |
201 | ring_info->ring_buffer->read_index, | |
202 | ring_info->ring_buffer->write_index); | |
3e7ee490 HJ |
203 | } |
204 | ||
454f18a9 | 205 | |
8f1136ae S |
206 | /* |
207 | * | |
208 | * hv_copyfrom_ringbuffer() | |
209 | * | |
210 | * Helper routine to copy to source from ring buffer. | |
211 | * Assume there is enough room. Handles wrap-around in src case only!! | |
212 | * | |
213 | */ | |
214 | static u32 hv_copyfrom_ringbuffer( | |
215 | struct hv_ring_buffer_info *ring_info, | |
216 | void *dest, | |
217 | u32 destlen, | |
218 | u32 start_read_offset) | |
219 | { | |
220 | void *ring_buffer = hv_get_ring_buffer(ring_info); | |
221 | u32 ring_buffer_size = hv_get_ring_buffersize(ring_info); | |
222 | ||
223 | u32 frag_len; | |
224 | ||
225 | /* wrap-around detected at the src */ | |
226 | if (destlen > ring_buffer_size - start_read_offset) { | |
227 | frag_len = ring_buffer_size - start_read_offset; | |
228 | ||
229 | memcpy(dest, ring_buffer + start_read_offset, frag_len); | |
230 | memcpy(dest + frag_len, ring_buffer, destlen - frag_len); | |
231 | } else | |
232 | ||
233 | memcpy(dest, ring_buffer + start_read_offset, destlen); | |
234 | ||
235 | ||
236 | start_read_offset += destlen; | |
237 | start_read_offset %= ring_buffer_size; | |
238 | ||
239 | return start_read_offset; | |
240 | } | |
241 | ||
242 | ||
7581578d S |
243 | /* |
244 | * | |
245 | * hv_copyto_ringbuffer() | |
246 | * | |
247 | * Helper routine to copy from source to ring buffer. | |
248 | * Assume there is enough room. Handles wrap-around in dest case only!! | |
249 | * | |
250 | */ | |
251 | static u32 hv_copyto_ringbuffer( | |
fc8c72eb HZ |
252 | struct hv_ring_buffer_info *ring_info, |
253 | u32 start_write_offset, | |
254 | void *src, | |
7581578d S |
255 | u32 srclen) |
256 | { | |
257 | void *ring_buffer = hv_get_ring_buffer(ring_info); | |
258 | u32 ring_buffer_size = hv_get_ring_buffersize(ring_info); | |
259 | u32 frag_len; | |
260 | ||
261 | /* wrap-around detected! */ | |
262 | if (srclen > ring_buffer_size - start_write_offset) { | |
263 | frag_len = ring_buffer_size - start_write_offset; | |
264 | memcpy(ring_buffer + start_write_offset, src, frag_len); | |
265 | memcpy(ring_buffer, src + frag_len, srclen - frag_len); | |
266 | } else | |
267 | memcpy(ring_buffer + start_write_offset, src, srclen); | |
3e7ee490 | 268 | |
7581578d S |
269 | start_write_offset += srclen; |
270 | start_write_offset %= ring_buffer_size; | |
271 | ||
272 | return start_write_offset; | |
273 | } | |
3e7ee490 | 274 | |
b2a5a585 S |
275 | /* |
276 | * | |
277 | * hv_ringbuffer_get_debuginfo() | |
278 | * | |
279 | * Get various debug metrics for the specified ring buffer | |
280 | * | |
281 | */ | |
a75b61d5 | 282 | void hv_ringbuffer_get_debuginfo(struct hv_ring_buffer_info *ring_info, |
80682b7a | 283 | struct hv_ring_buffer_debug_info *debug_info) |
3e7ee490 | 284 | { |
fc8c72eb HZ |
285 | u32 bytes_avail_towrite; |
286 | u32 bytes_avail_toread; | |
3e7ee490 | 287 | |
fc8c72eb | 288 | if (ring_info->ring_buffer) { |
2b8a912e | 289 | hv_get_ringbuffer_availbytes(ring_info, |
fc8c72eb HZ |
290 | &bytes_avail_toread, |
291 | &bytes_avail_towrite); | |
3e7ee490 | 292 | |
fc8c72eb HZ |
293 | debug_info->bytes_avail_toread = bytes_avail_toread; |
294 | debug_info->bytes_avail_towrite = bytes_avail_towrite; | |
82f8bd40 | 295 | debug_info->current_read_index = |
fc8c72eb | 296 | ring_info->ring_buffer->read_index; |
82f8bd40 | 297 | debug_info->current_write_index = |
fc8c72eb | 298 | ring_info->ring_buffer->write_index; |
82f8bd40 | 299 | debug_info->current_interrupt_mask = |
fc8c72eb | 300 | ring_info->ring_buffer->interrupt_mask; |
3e7ee490 HJ |
301 | } |
302 | } | |
303 | ||
304 | ||
b2a5a585 S |
305 | /* |
306 | * | |
307 | * hv_get_ringbuffer_interrupt_mask() | |
308 | * | |
309 | * Get the interrupt mask for the specified ring buffer | |
310 | * | |
311 | */ | |
decc49da | 312 | u32 hv_get_ringbuffer_interrupt_mask(struct hv_ring_buffer_info *rbi) |
3e7ee490 | 313 | { |
82f8bd40 | 314 | return rbi->ring_buffer->interrupt_mask; |
3e7ee490 HJ |
315 | } |
316 | ||
b2a5a585 S |
317 | /* |
318 | * | |
319 | * hv_ringbuffer_init() | |
320 | * | |
321 | *Initialize the ring buffer | |
322 | * | |
323 | */ | |
72a95cbc | 324 | int hv_ringbuffer_init(struct hv_ring_buffer_info *ring_info, |
fc8c72eb | 325 | void *buffer, u32 buflen) |
3e7ee490 | 326 | { |
4a1b3acc | 327 | if (sizeof(struct hv_ring_buffer) != PAGE_SIZE) |
3324fb40 | 328 | return -EINVAL; |
3e7ee490 | 329 | |
fc8c72eb | 330 | memset(ring_info, 0, sizeof(struct hv_ring_buffer_info)); |
3e7ee490 | 331 | |
fc8c72eb HZ |
332 | ring_info->ring_buffer = (struct hv_ring_buffer *)buffer; |
333 | ring_info->ring_buffer->read_index = | |
334 | ring_info->ring_buffer->write_index = 0; | |
3e7ee490 | 335 | |
fc8c72eb HZ |
336 | ring_info->ring_size = buflen; |
337 | ring_info->ring_datasize = buflen - sizeof(struct hv_ring_buffer); | |
3e7ee490 | 338 | |
fc8c72eb | 339 | spin_lock_init(&ring_info->ring_lock); |
3e7ee490 HJ |
340 | |
341 | return 0; | |
342 | } | |
343 | ||
b2a5a585 S |
344 | /* |
345 | * | |
346 | * hv_ringbuffer_cleanup() | |
347 | * | |
348 | * Cleanup the ring buffer | |
349 | * | |
350 | */ | |
2dba688b | 351 | void hv_ringbuffer_cleanup(struct hv_ring_buffer_info *ring_info) |
3e7ee490 | 352 | { |
3e7ee490 HJ |
353 | } |
354 | ||
b2a5a585 S |
355 | /* |
356 | * | |
357 | * hv_ringbuffer_write() | |
358 | * | |
359 | * Write to the ring buffer | |
360 | * | |
361 | */ | |
633c4dce | 362 | int hv_ringbuffer_write(struct hv_ring_buffer_info *outring_info, |
3523a805 | 363 | struct scatterlist *sglist, u32 sgcount) |
3e7ee490 | 364 | { |
4408f531 | 365 | int i = 0; |
fc8c72eb HZ |
366 | u32 bytes_avail_towrite; |
367 | u32 bytes_avail_toread; | |
368 | u32 totalbytes_towrite = 0; | |
3e7ee490 | 369 | |
b219b3f7 | 370 | struct scatterlist *sg; |
66a60543 | 371 | u32 next_write_location; |
fc8c72eb | 372 | u64 prev_indices = 0; |
a98f96ee | 373 | unsigned long flags; |
3e7ee490 | 374 | |
b219b3f7 | 375 | for_each_sg(sglist, sg, sgcount, i) |
3e7ee490 | 376 | { |
fc8c72eb | 377 | totalbytes_towrite += sg->length; |
3e7ee490 HJ |
378 | } |
379 | ||
fc8c72eb | 380 | totalbytes_towrite += sizeof(u64); |
3e7ee490 | 381 | |
fc8c72eb | 382 | spin_lock_irqsave(&outring_info->ring_lock, flags); |
3e7ee490 | 383 | |
2b8a912e | 384 | hv_get_ringbuffer_availbytes(outring_info, |
fc8c72eb HZ |
385 | &bytes_avail_toread, |
386 | &bytes_avail_towrite); | |
3e7ee490 | 387 | |
3e7ee490 | 388 | |
4408f531 B |
389 | /* If there is only room for the packet, assume it is full. */ |
390 | /* Otherwise, the next time around, we think the ring buffer */ | |
454f18a9 | 391 | /* is empty since the read index == write index */ |
fc8c72eb | 392 | if (bytes_avail_towrite <= totalbytes_towrite) { |
fc8c72eb | 393 | spin_unlock_irqrestore(&outring_info->ring_lock, flags); |
d2598f01 | 394 | return -EAGAIN; |
3e7ee490 HJ |
395 | } |
396 | ||
454f18a9 | 397 | /* Write to the ring buffer */ |
2b8a912e | 398 | next_write_location = hv_get_next_write_location(outring_info); |
3e7ee490 | 399 | |
b219b3f7 | 400 | for_each_sg(sglist, sg, sgcount, i) |
3e7ee490 | 401 | { |
2b8a912e | 402 | next_write_location = hv_copyto_ringbuffer(outring_info, |
fc8c72eb | 403 | next_write_location, |
b219b3f7 NP |
404 | sg_virt(sg), |
405 | sg->length); | |
3e7ee490 HJ |
406 | } |
407 | ||
454f18a9 | 408 | /* Set previous packet start */ |
2b8a912e | 409 | prev_indices = hv_get_ring_bufferindices(outring_info); |
3e7ee490 | 410 | |
2b8a912e | 411 | next_write_location = hv_copyto_ringbuffer(outring_info, |
fc8c72eb HZ |
412 | next_write_location, |
413 | &prev_indices, | |
b219b3f7 | 414 | sizeof(u64)); |
3e7ee490 | 415 | |
454f18a9 | 416 | /* Make sure we flush all writes before updating the writeIndex */ |
e690b5a9 | 417 | smp_wmb(); |
3e7ee490 | 418 | |
454f18a9 | 419 | /* Now, update the write location */ |
2b8a912e | 420 | hv_set_next_write_location(outring_info, next_write_location); |
3e7ee490 | 421 | |
3e7ee490 | 422 | |
fc8c72eb | 423 | spin_unlock_irqrestore(&outring_info->ring_lock, flags); |
3e7ee490 HJ |
424 | return 0; |
425 | } | |
426 | ||
427 | ||
b2a5a585 S |
428 | /* |
429 | * | |
430 | * hv_ringbuffer_peek() | |
431 | * | |
432 | * Read without advancing the read index | |
433 | * | |
434 | */ | |
a89186c2 | 435 | int hv_ringbuffer_peek(struct hv_ring_buffer_info *Inring_info, |
fc8c72eb | 436 | void *Buffer, u32 buflen) |
3e7ee490 | 437 | { |
fc8c72eb HZ |
438 | u32 bytes_avail_towrite; |
439 | u32 bytes_avail_toread; | |
440 | u32 next_read_location = 0; | |
a98f96ee | 441 | unsigned long flags; |
3e7ee490 | 442 | |
fc8c72eb | 443 | spin_lock_irqsave(&Inring_info->ring_lock, flags); |
3e7ee490 | 444 | |
2b8a912e | 445 | hv_get_ringbuffer_availbytes(Inring_info, |
fc8c72eb HZ |
446 | &bytes_avail_toread, |
447 | &bytes_avail_towrite); | |
3e7ee490 | 448 | |
454f18a9 | 449 | /* Make sure there is something to read */ |
fc8c72eb | 450 | if (bytes_avail_toread < buflen) { |
3e7ee490 | 451 | |
fc8c72eb | 452 | spin_unlock_irqrestore(&Inring_info->ring_lock, flags); |
3e7ee490 | 453 | |
d2598f01 | 454 | return -EAGAIN; |
3e7ee490 HJ |
455 | } |
456 | ||
454f18a9 | 457 | /* Convert to byte offset */ |
2b8a912e | 458 | next_read_location = hv_get_next_read_location(Inring_info); |
3e7ee490 | 459 | |
2b8a912e | 460 | next_read_location = hv_copyfrom_ringbuffer(Inring_info, |
4408f531 | 461 | Buffer, |
fc8c72eb HZ |
462 | buflen, |
463 | next_read_location); | |
3e7ee490 | 464 | |
fc8c72eb | 465 | spin_unlock_irqrestore(&Inring_info->ring_lock, flags); |
3e7ee490 HJ |
466 | |
467 | return 0; | |
468 | } | |
469 | ||
470 | ||
b2a5a585 S |
471 | /* |
472 | * | |
473 | * hv_ringbuffer_read() | |
474 | * | |
475 | * Read and advance the read index | |
476 | * | |
477 | */ | |
38397c8a | 478 | int hv_ringbuffer_read(struct hv_ring_buffer_info *inring_info, void *buffer, |
fc8c72eb | 479 | u32 buflen, u32 offset) |
3e7ee490 | 480 | { |
fc8c72eb HZ |
481 | u32 bytes_avail_towrite; |
482 | u32 bytes_avail_toread; | |
483 | u32 next_read_location = 0; | |
484 | u64 prev_indices = 0; | |
a98f96ee | 485 | unsigned long flags; |
3e7ee490 | 486 | |
fc8c72eb | 487 | if (buflen <= 0) |
a16e1485 | 488 | return -EINVAL; |
3e7ee490 | 489 | |
fc8c72eb | 490 | spin_lock_irqsave(&inring_info->ring_lock, flags); |
3e7ee490 | 491 | |
2b8a912e | 492 | hv_get_ringbuffer_availbytes(inring_info, |
fc8c72eb HZ |
493 | &bytes_avail_toread, |
494 | &bytes_avail_towrite); | |
3e7ee490 | 495 | |
454f18a9 | 496 | /* Make sure there is something to read */ |
fc8c72eb | 497 | if (bytes_avail_toread < buflen) { |
fc8c72eb | 498 | spin_unlock_irqrestore(&inring_info->ring_lock, flags); |
3e7ee490 | 499 | |
d2598f01 | 500 | return -EAGAIN; |
3e7ee490 HJ |
501 | } |
502 | ||
1ac58644 | 503 | next_read_location = |
2b8a912e | 504 | hv_get_next_readlocation_withoffset(inring_info, offset); |
3e7ee490 | 505 | |
2b8a912e | 506 | next_read_location = hv_copyfrom_ringbuffer(inring_info, |
fc8c72eb HZ |
507 | buffer, |
508 | buflen, | |
509 | next_read_location); | |
3e7ee490 | 510 | |
2b8a912e | 511 | next_read_location = hv_copyfrom_ringbuffer(inring_info, |
fc8c72eb | 512 | &prev_indices, |
4408f531 | 513 | sizeof(u64), |
fc8c72eb | 514 | next_read_location); |
3e7ee490 | 515 | |
454f18a9 | 516 | /* Make sure all reads are done before we update the read index since */ |
4408f531 B |
517 | /* the writer may start writing to the read area once the read index */ |
518 | /*is updated */ | |
ef0d5b23 | 519 | smp_mb(); |
3e7ee490 | 520 | |
454f18a9 | 521 | /* Update the read index */ |
2b8a912e | 522 | hv_set_next_read_location(inring_info, next_read_location); |
3e7ee490 | 523 | |
fc8c72eb | 524 | spin_unlock_irqrestore(&inring_info->ring_lock, flags); |
3e7ee490 HJ |
525 | |
526 | return 0; | |
527 | } |