Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * |
| 3 | * dvb_ringbuffer.c: ring buffer implementation for the dvb driver |
| 4 | * |
| 5 | * Copyright (C) 2003 Oliver Endriss |
| 6 | * Copyright (C) 2004 Andrew de Quincey |
| 7 | * |
| 8 | * based on code originally found in av7110.c & dvb_ci.c: |
| 9 | * Copyright (C) 1999-2003 Ralph Metzler |
| 10 | * & Marcus Metzler for convergence integrated media GmbH |
| 11 | * |
| 12 | * This program is free software; you can redistribute it and/or |
| 13 | * modify it under the terms of the GNU Lesser General Public License |
| 14 | * as published by the Free Software Foundation; either version 2.1 |
| 15 | * of the License, or (at your option) any later version. |
| 16 | * |
| 17 | * This program is distributed in the hope that it will be useful, |
| 18 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 19 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 20 | * GNU Lesser General Public License for more details. |
| 21 | * |
| 22 | * You should have received a copy of the GNU Lesser General Public License |
| 23 | * along with this program; if not, write to the Free Software |
| 24 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| 25 | */ |
| 26 | |
| 27 | |
| 28 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 29 | #include <linux/errno.h> |
| 30 | #include <linux/kernel.h> |
| 31 | #include <linux/module.h> |
| 32 | #include <linux/sched.h> |
| 33 | #include <linux/string.h> |
| 34 | #include <asm/uaccess.h> |
| 35 | |
| 36 | #include "dvb_ringbuffer.h" |
| 37 | |
| 38 | #define PKT_READY 0 |
| 39 | #define PKT_DISPOSED 1 |
| 40 | |
| 41 | |
| 42 | void dvb_ringbuffer_init(struct dvb_ringbuffer *rbuf, void *data, size_t len) |
| 43 | { |
Mauro Carvalho Chehab | afd1a0c | 2005-12-12 00:37:27 -0800 | [diff] [blame] | 44 | rbuf->pread=rbuf->pwrite=0; |
| 45 | rbuf->data=data; |
| 46 | rbuf->size=len; |
Andreas Oberritter | 9d9d6ba | 2006-03-13 13:14:34 -0300 | [diff] [blame] | 47 | rbuf->error=0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 48 | |
Mauro Carvalho Chehab | afd1a0c | 2005-12-12 00:37:27 -0800 | [diff] [blame] | 49 | init_waitqueue_head(&rbuf->queue); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 50 | |
Mauro Carvalho Chehab | afd1a0c | 2005-12-12 00:37:27 -0800 | [diff] [blame] | 51 | spin_lock_init(&(rbuf->lock)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 52 | } |
| 53 | |
| 54 | |
| 55 | |
| 56 | int dvb_ringbuffer_empty(struct dvb_ringbuffer *rbuf) |
| 57 | { |
Soeren Moch | ca6e612 | 2016-05-11 13:49:11 -0300 | [diff] [blame] | 58 | /* smp_load_acquire() to load write pointer on reader side |
| 59 | * this pairs with smp_store_release() in dvb_ringbuffer_write(), |
| 60 | * dvb_ringbuffer_write_user(), or dvb_ringbuffer_reset() |
| 61 | * |
| 62 | * for memory barriers also see Documentation/circular-buffers.txt |
| 63 | */ |
| 64 | return (rbuf->pread == smp_load_acquire(&rbuf->pwrite)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 65 | } |
| 66 | |
| 67 | |
| 68 | |
| 69 | ssize_t dvb_ringbuffer_free(struct dvb_ringbuffer *rbuf) |
| 70 | { |
Mauro Carvalho Chehab | afd1a0c | 2005-12-12 00:37:27 -0800 | [diff] [blame] | 71 | ssize_t free; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 72 | |
Soeren Moch | ca6e612 | 2016-05-11 13:49:11 -0300 | [diff] [blame] | 73 | /* ACCESS_ONCE() to load read pointer on writer side |
| 74 | * this pairs with smp_store_release() in dvb_ringbuffer_read(), |
| 75 | * dvb_ringbuffer_read_user(), dvb_ringbuffer_flush(), |
| 76 | * or dvb_ringbuffer_reset() |
| 77 | */ |
| 78 | free = ACCESS_ONCE(rbuf->pread) - rbuf->pwrite; |
Mauro Carvalho Chehab | afd1a0c | 2005-12-12 00:37:27 -0800 | [diff] [blame] | 79 | if (free <= 0) |
| 80 | free += rbuf->size; |
| 81 | return free-1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 82 | } |
| 83 | |
| 84 | |
| 85 | |
| 86 | ssize_t dvb_ringbuffer_avail(struct dvb_ringbuffer *rbuf) |
| 87 | { |
Mauro Carvalho Chehab | afd1a0c | 2005-12-12 00:37:27 -0800 | [diff] [blame] | 88 | ssize_t avail; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 89 | |
Soeren Moch | ca6e612 | 2016-05-11 13:49:11 -0300 | [diff] [blame] | 90 | /* smp_load_acquire() to load write pointer on reader side |
| 91 | * this pairs with smp_store_release() in dvb_ringbuffer_write(), |
| 92 | * dvb_ringbuffer_write_user(), or dvb_ringbuffer_reset() |
| 93 | */ |
| 94 | avail = smp_load_acquire(&rbuf->pwrite) - rbuf->pread; |
Mauro Carvalho Chehab | afd1a0c | 2005-12-12 00:37:27 -0800 | [diff] [blame] | 95 | if (avail < 0) |
| 96 | avail += rbuf->size; |
| 97 | return avail; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 98 | } |
| 99 | |
| 100 | |
| 101 | |
| 102 | void dvb_ringbuffer_flush(struct dvb_ringbuffer *rbuf) |
| 103 | { |
Soeren Moch | ca6e612 | 2016-05-11 13:49:11 -0300 | [diff] [blame] | 104 | /* dvb_ringbuffer_flush() counts as read operation |
| 105 | * smp_load_acquire() to load write pointer |
| 106 | * smp_store_release() to update read pointer, this ensures that the |
| 107 | * correct pointer is visible for subsequent dvb_ringbuffer_free() |
| 108 | * calls on other cpu cores |
| 109 | */ |
| 110 | smp_store_release(&rbuf->pread, smp_load_acquire(&rbuf->pwrite)); |
Andreas Oberritter | 9d9d6ba | 2006-03-13 13:14:34 -0300 | [diff] [blame] | 111 | rbuf->error = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 112 | } |
Oliver Endriss | 126cd4b | 2009-12-22 04:37:53 -0300 | [diff] [blame] | 113 | EXPORT_SYMBOL(dvb_ringbuffer_flush); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 114 | |
Andrea Odetti | 48c01a9 | 2008-04-20 18:37:45 -0300 | [diff] [blame] | 115 | void dvb_ringbuffer_reset(struct dvb_ringbuffer *rbuf) |
| 116 | { |
Soeren Moch | ca6e612 | 2016-05-11 13:49:11 -0300 | [diff] [blame] | 117 | /* dvb_ringbuffer_reset() counts as read and write operation |
| 118 | * smp_store_release() to update read pointer |
| 119 | */ |
| 120 | smp_store_release(&rbuf->pread, 0); |
| 121 | /* smp_store_release() to update write pointer */ |
| 122 | smp_store_release(&rbuf->pwrite, 0); |
Andrea Odetti | 48c01a9 | 2008-04-20 18:37:45 -0300 | [diff] [blame] | 123 | rbuf->error = 0; |
| 124 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 125 | |
| 126 | void dvb_ringbuffer_flush_spinlock_wakeup(struct dvb_ringbuffer *rbuf) |
| 127 | { |
Mauro Carvalho Chehab | afd1a0c | 2005-12-12 00:37:27 -0800 | [diff] [blame] | 128 | unsigned long flags; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 129 | |
Mauro Carvalho Chehab | afd1a0c | 2005-12-12 00:37:27 -0800 | [diff] [blame] | 130 | spin_lock_irqsave(&rbuf->lock, flags); |
| 131 | dvb_ringbuffer_flush(rbuf); |
| 132 | spin_unlock_irqrestore(&rbuf->lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 133 | |
Mauro Carvalho Chehab | afd1a0c | 2005-12-12 00:37:27 -0800 | [diff] [blame] | 134 | wake_up(&rbuf->queue); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 135 | } |
| 136 | |
Al Viro | b0ba0e3 | 2008-06-22 14:20:29 -0300 | [diff] [blame] | 137 | ssize_t dvb_ringbuffer_read_user(struct dvb_ringbuffer *rbuf, u8 __user *buf, size_t len) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 138 | { |
Mauro Carvalho Chehab | afd1a0c | 2005-12-12 00:37:27 -0800 | [diff] [blame] | 139 | size_t todo = len; |
| 140 | size_t split; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 141 | |
Mauro Carvalho Chehab | afd1a0c | 2005-12-12 00:37:27 -0800 | [diff] [blame] | 142 | split = (rbuf->pread + len > rbuf->size) ? rbuf->size - rbuf->pread : 0; |
| 143 | if (split > 0) { |
Al Viro | b0ba0e3 | 2008-06-22 14:20:29 -0300 | [diff] [blame] | 144 | if (copy_to_user(buf, rbuf->data+rbuf->pread, split)) |
| 145 | return -EFAULT; |
Mauro Carvalho Chehab | afd1a0c | 2005-12-12 00:37:27 -0800 | [diff] [blame] | 146 | buf += split; |
| 147 | todo -= split; |
Soeren Moch | ca6e612 | 2016-05-11 13:49:11 -0300 | [diff] [blame] | 148 | /* smp_store_release() for read pointer update to ensure |
| 149 | * that buf is not overwritten until read is complete, |
| 150 | * this pairs with ACCESS_ONCE() in dvb_ringbuffer_free() |
| 151 | */ |
| 152 | smp_store_release(&rbuf->pread, 0); |
Mauro Carvalho Chehab | afd1a0c | 2005-12-12 00:37:27 -0800 | [diff] [blame] | 153 | } |
Al Viro | b0ba0e3 | 2008-06-22 14:20:29 -0300 | [diff] [blame] | 154 | if (copy_to_user(buf, rbuf->data+rbuf->pread, todo)) |
| 155 | return -EFAULT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 156 | |
Soeren Moch | ca6e612 | 2016-05-11 13:49:11 -0300 | [diff] [blame] | 157 | /* smp_store_release() to update read pointer, see above */ |
| 158 | smp_store_release(&rbuf->pread, (rbuf->pread + todo) % rbuf->size); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 159 | |
Mauro Carvalho Chehab | afd1a0c | 2005-12-12 00:37:27 -0800 | [diff] [blame] | 160 | return len; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 161 | } |
| 162 | |
Al Viro | b0ba0e3 | 2008-06-22 14:20:29 -0300 | [diff] [blame] | 163 | void dvb_ringbuffer_read(struct dvb_ringbuffer *rbuf, u8 *buf, size_t len) |
| 164 | { |
| 165 | size_t todo = len; |
| 166 | size_t split; |
| 167 | |
| 168 | split = (rbuf->pread + len > rbuf->size) ? rbuf->size - rbuf->pread : 0; |
| 169 | if (split > 0) { |
| 170 | memcpy(buf, rbuf->data+rbuf->pread, split); |
| 171 | buf += split; |
| 172 | todo -= split; |
Soeren Moch | ca6e612 | 2016-05-11 13:49:11 -0300 | [diff] [blame] | 173 | /* smp_store_release() for read pointer update to ensure |
| 174 | * that buf is not overwritten until read is complete, |
| 175 | * this pairs with ACCESS_ONCE() in dvb_ringbuffer_free() |
| 176 | */ |
| 177 | smp_store_release(&rbuf->pread, 0); |
Al Viro | b0ba0e3 | 2008-06-22 14:20:29 -0300 | [diff] [blame] | 178 | } |
| 179 | memcpy(buf, rbuf->data+rbuf->pread, todo); |
| 180 | |
Soeren Moch | ca6e612 | 2016-05-11 13:49:11 -0300 | [diff] [blame] | 181 | /* smp_store_release() to update read pointer, see above */ |
| 182 | smp_store_release(&rbuf->pread, (rbuf->pread + todo) % rbuf->size); |
Al Viro | b0ba0e3 | 2008-06-22 14:20:29 -0300 | [diff] [blame] | 183 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 184 | |
| 185 | |
| 186 | ssize_t dvb_ringbuffer_write(struct dvb_ringbuffer *rbuf, const u8 *buf, size_t len) |
| 187 | { |
Mauro Carvalho Chehab | afd1a0c | 2005-12-12 00:37:27 -0800 | [diff] [blame] | 188 | size_t todo = len; |
| 189 | size_t split; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 190 | |
Mauro Carvalho Chehab | afd1a0c | 2005-12-12 00:37:27 -0800 | [diff] [blame] | 191 | split = (rbuf->pwrite + len > rbuf->size) ? rbuf->size - rbuf->pwrite : 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 192 | |
Mauro Carvalho Chehab | afd1a0c | 2005-12-12 00:37:27 -0800 | [diff] [blame] | 193 | if (split > 0) { |
| 194 | memcpy(rbuf->data+rbuf->pwrite, buf, split); |
| 195 | buf += split; |
| 196 | todo -= split; |
Soeren Moch | ca6e612 | 2016-05-11 13:49:11 -0300 | [diff] [blame] | 197 | /* smp_store_release() for write pointer update to ensure that |
| 198 | * written data is visible on other cpu cores before the pointer |
| 199 | * update, this pairs with smp_load_acquire() in |
| 200 | * dvb_ringbuffer_empty() or dvb_ringbuffer_avail() |
| 201 | */ |
| 202 | smp_store_release(&rbuf->pwrite, 0); |
Mauro Carvalho Chehab | afd1a0c | 2005-12-12 00:37:27 -0800 | [diff] [blame] | 203 | } |
| 204 | memcpy(rbuf->data+rbuf->pwrite, buf, todo); |
Soeren Moch | ca6e612 | 2016-05-11 13:49:11 -0300 | [diff] [blame] | 205 | /* smp_store_release() for write pointer update, see above */ |
| 206 | smp_store_release(&rbuf->pwrite, (rbuf->pwrite + todo) % rbuf->size); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 207 | |
Mauro Carvalho Chehab | afd1a0c | 2005-12-12 00:37:27 -0800 | [diff] [blame] | 208 | return len; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 209 | } |
| 210 | |
Mauro Carvalho Chehab | 04da2da | 2014-09-03 20:44:04 -0300 | [diff] [blame] | 211 | ssize_t dvb_ringbuffer_write_user(struct dvb_ringbuffer *rbuf, |
| 212 | const u8 __user *buf, size_t len) |
| 213 | { |
| 214 | int status; |
| 215 | size_t todo = len; |
| 216 | size_t split; |
| 217 | |
| 218 | split = (rbuf->pwrite + len > rbuf->size) ? rbuf->size - rbuf->pwrite : 0; |
| 219 | |
| 220 | if (split > 0) { |
| 221 | status = copy_from_user(rbuf->data+rbuf->pwrite, buf, split); |
| 222 | if (status) |
| 223 | return len - todo; |
| 224 | buf += split; |
| 225 | todo -= split; |
Soeren Moch | ca6e612 | 2016-05-11 13:49:11 -0300 | [diff] [blame] | 226 | /* smp_store_release() for write pointer update to ensure that |
| 227 | * written data is visible on other cpu cores before the pointer |
| 228 | * update, this pairs with smp_load_acquire() in |
| 229 | * dvb_ringbuffer_empty() or dvb_ringbuffer_avail() |
| 230 | */ |
| 231 | smp_store_release(&rbuf->pwrite, 0); |
Mauro Carvalho Chehab | 04da2da | 2014-09-03 20:44:04 -0300 | [diff] [blame] | 232 | } |
| 233 | status = copy_from_user(rbuf->data+rbuf->pwrite, buf, todo); |
| 234 | if (status) |
| 235 | return len - todo; |
Soeren Moch | ca6e612 | 2016-05-11 13:49:11 -0300 | [diff] [blame] | 236 | /* smp_store_release() for write pointer update, see above */ |
| 237 | smp_store_release(&rbuf->pwrite, (rbuf->pwrite + todo) % rbuf->size); |
Mauro Carvalho Chehab | 04da2da | 2014-09-03 20:44:04 -0300 | [diff] [blame] | 238 | |
| 239 | return len; |
| 240 | } |
| 241 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 242 | ssize_t dvb_ringbuffer_pkt_write(struct dvb_ringbuffer *rbuf, u8* buf, size_t len) |
| 243 | { |
Mauro Carvalho Chehab | afd1a0c | 2005-12-12 00:37:27 -0800 | [diff] [blame] | 244 | int status; |
| 245 | ssize_t oldpwrite = rbuf->pwrite; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 246 | |
Mauro Carvalho Chehab | afd1a0c | 2005-12-12 00:37:27 -0800 | [diff] [blame] | 247 | DVB_RINGBUFFER_WRITE_BYTE(rbuf, len >> 8); |
| 248 | DVB_RINGBUFFER_WRITE_BYTE(rbuf, len & 0xff); |
| 249 | DVB_RINGBUFFER_WRITE_BYTE(rbuf, PKT_READY); |
| 250 | status = dvb_ringbuffer_write(rbuf, buf, len); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 251 | |
Mauro Carvalho Chehab | afd1a0c | 2005-12-12 00:37:27 -0800 | [diff] [blame] | 252 | if (status < 0) rbuf->pwrite = oldpwrite; |
| 253 | return status; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 254 | } |
| 255 | |
Al Viro | b0ba0e3 | 2008-06-22 14:20:29 -0300 | [diff] [blame] | 256 | ssize_t dvb_ringbuffer_pkt_read_user(struct dvb_ringbuffer *rbuf, size_t idx, |
| 257 | int offset, u8 __user *buf, size_t len) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 258 | { |
Mauro Carvalho Chehab | afd1a0c | 2005-12-12 00:37:27 -0800 | [diff] [blame] | 259 | size_t todo; |
| 260 | size_t split; |
| 261 | size_t pktlen; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 262 | |
Mauro Carvalho Chehab | afd1a0c | 2005-12-12 00:37:27 -0800 | [diff] [blame] | 263 | pktlen = rbuf->data[idx] << 8; |
| 264 | pktlen |= rbuf->data[(idx + 1) % rbuf->size]; |
| 265 | if (offset > pktlen) return -EINVAL; |
| 266 | if ((offset + len) > pktlen) len = pktlen - offset; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 267 | |
Mauro Carvalho Chehab | afd1a0c | 2005-12-12 00:37:27 -0800 | [diff] [blame] | 268 | idx = (idx + DVB_RINGBUFFER_PKTHDRSIZE + offset) % rbuf->size; |
| 269 | todo = len; |
| 270 | split = ((idx + len) > rbuf->size) ? rbuf->size - idx : 0; |
| 271 | if (split > 0) { |
Al Viro | b0ba0e3 | 2008-06-22 14:20:29 -0300 | [diff] [blame] | 272 | if (copy_to_user(buf, rbuf->data+idx, split)) |
| 273 | return -EFAULT; |
Mauro Carvalho Chehab | afd1a0c | 2005-12-12 00:37:27 -0800 | [diff] [blame] | 274 | buf += split; |
| 275 | todo -= split; |
| 276 | idx = 0; |
| 277 | } |
Al Viro | b0ba0e3 | 2008-06-22 14:20:29 -0300 | [diff] [blame] | 278 | if (copy_to_user(buf, rbuf->data+idx, todo)) |
| 279 | return -EFAULT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 280 | |
Mauro Carvalho Chehab | afd1a0c | 2005-12-12 00:37:27 -0800 | [diff] [blame] | 281 | return len; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 282 | } |
| 283 | |
Al Viro | b0ba0e3 | 2008-06-22 14:20:29 -0300 | [diff] [blame] | 284 | ssize_t dvb_ringbuffer_pkt_read(struct dvb_ringbuffer *rbuf, size_t idx, |
| 285 | int offset, u8* buf, size_t len) |
| 286 | { |
| 287 | size_t todo; |
| 288 | size_t split; |
| 289 | size_t pktlen; |
| 290 | |
| 291 | pktlen = rbuf->data[idx] << 8; |
| 292 | pktlen |= rbuf->data[(idx + 1) % rbuf->size]; |
| 293 | if (offset > pktlen) return -EINVAL; |
| 294 | if ((offset + len) > pktlen) len = pktlen - offset; |
| 295 | |
| 296 | idx = (idx + DVB_RINGBUFFER_PKTHDRSIZE + offset) % rbuf->size; |
| 297 | todo = len; |
| 298 | split = ((idx + len) > rbuf->size) ? rbuf->size - idx : 0; |
| 299 | if (split > 0) { |
| 300 | memcpy(buf, rbuf->data+idx, split); |
| 301 | buf += split; |
| 302 | todo -= split; |
| 303 | idx = 0; |
| 304 | } |
| 305 | memcpy(buf, rbuf->data+idx, todo); |
| 306 | return len; |
| 307 | } |
| 308 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 309 | void dvb_ringbuffer_pkt_dispose(struct dvb_ringbuffer *rbuf, size_t idx) |
| 310 | { |
Mauro Carvalho Chehab | afd1a0c | 2005-12-12 00:37:27 -0800 | [diff] [blame] | 311 | size_t pktlen; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 312 | |
Mauro Carvalho Chehab | afd1a0c | 2005-12-12 00:37:27 -0800 | [diff] [blame] | 313 | rbuf->data[(idx + 2) % rbuf->size] = PKT_DISPOSED; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 314 | |
Mauro Carvalho Chehab | afd1a0c | 2005-12-12 00:37:27 -0800 | [diff] [blame] | 315 | // clean up disposed packets |
| 316 | while(dvb_ringbuffer_avail(rbuf) > DVB_RINGBUFFER_PKTHDRSIZE) { |
| 317 | if (DVB_RINGBUFFER_PEEK(rbuf, 2) == PKT_DISPOSED) { |
Michael Krufky | 50c25ff | 2006-01-09 15:25:34 -0200 | [diff] [blame] | 318 | pktlen = DVB_RINGBUFFER_PEEK(rbuf, 0) << 8; |
| 319 | pktlen |= DVB_RINGBUFFER_PEEK(rbuf, 1); |
| 320 | DVB_RINGBUFFER_SKIP(rbuf, pktlen + DVB_RINGBUFFER_PKTHDRSIZE); |
Mauro Carvalho Chehab | afd1a0c | 2005-12-12 00:37:27 -0800 | [diff] [blame] | 321 | } else { |
Michael Krufky | 50c25ff | 2006-01-09 15:25:34 -0200 | [diff] [blame] | 322 | // first packet is not disposed, so we stop cleaning now |
| 323 | break; |
Mauro Carvalho Chehab | afd1a0c | 2005-12-12 00:37:27 -0800 | [diff] [blame] | 324 | } |
| 325 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 326 | } |
| 327 | |
| 328 | ssize_t dvb_ringbuffer_pkt_next(struct dvb_ringbuffer *rbuf, size_t idx, size_t* pktlen) |
| 329 | { |
Mauro Carvalho Chehab | afd1a0c | 2005-12-12 00:37:27 -0800 | [diff] [blame] | 330 | int consumed; |
| 331 | int curpktlen; |
| 332 | int curpktstatus; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 333 | |
Mauro Carvalho Chehab | afd1a0c | 2005-12-12 00:37:27 -0800 | [diff] [blame] | 334 | if (idx == -1) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 335 | idx = rbuf->pread; |
| 336 | } else { |
Mauro Carvalho Chehab | afd1a0c | 2005-12-12 00:37:27 -0800 | [diff] [blame] | 337 | curpktlen = rbuf->data[idx] << 8; |
| 338 | curpktlen |= rbuf->data[(idx + 1) % rbuf->size]; |
| 339 | idx = (idx + curpktlen + DVB_RINGBUFFER_PKTHDRSIZE) % rbuf->size; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 340 | } |
| 341 | |
Mauro Carvalho Chehab | afd1a0c | 2005-12-12 00:37:27 -0800 | [diff] [blame] | 342 | consumed = (idx - rbuf->pread) % rbuf->size; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 343 | |
Mauro Carvalho Chehab | afd1a0c | 2005-12-12 00:37:27 -0800 | [diff] [blame] | 344 | while((dvb_ringbuffer_avail(rbuf) - consumed) > DVB_RINGBUFFER_PKTHDRSIZE) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 345 | |
Mauro Carvalho Chehab | afd1a0c | 2005-12-12 00:37:27 -0800 | [diff] [blame] | 346 | curpktlen = rbuf->data[idx] << 8; |
| 347 | curpktlen |= rbuf->data[(idx + 1) % rbuf->size]; |
| 348 | curpktstatus = rbuf->data[(idx + 2) % rbuf->size]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 349 | |
Mauro Carvalho Chehab | afd1a0c | 2005-12-12 00:37:27 -0800 | [diff] [blame] | 350 | if (curpktstatus == PKT_READY) { |
Michael Krufky | 50c25ff | 2006-01-09 15:25:34 -0200 | [diff] [blame] | 351 | *pktlen = curpktlen; |
| 352 | return idx; |
Mauro Carvalho Chehab | afd1a0c | 2005-12-12 00:37:27 -0800 | [diff] [blame] | 353 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 354 | |
Mauro Carvalho Chehab | afd1a0c | 2005-12-12 00:37:27 -0800 | [diff] [blame] | 355 | consumed += curpktlen + DVB_RINGBUFFER_PKTHDRSIZE; |
| 356 | idx = (idx + curpktlen + DVB_RINGBUFFER_PKTHDRSIZE) % rbuf->size; |
| 357 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 358 | |
Mauro Carvalho Chehab | afd1a0c | 2005-12-12 00:37:27 -0800 | [diff] [blame] | 359 | // no packets available |
| 360 | return -1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 361 | } |
| 362 | |
| 363 | |
| 364 | |
| 365 | EXPORT_SYMBOL(dvb_ringbuffer_init); |
| 366 | EXPORT_SYMBOL(dvb_ringbuffer_empty); |
| 367 | EXPORT_SYMBOL(dvb_ringbuffer_free); |
| 368 | EXPORT_SYMBOL(dvb_ringbuffer_avail); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 369 | EXPORT_SYMBOL(dvb_ringbuffer_flush_spinlock_wakeup); |
Al Viro | b0ba0e3 | 2008-06-22 14:20:29 -0300 | [diff] [blame] | 370 | EXPORT_SYMBOL(dvb_ringbuffer_read_user); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 371 | EXPORT_SYMBOL(dvb_ringbuffer_read); |
| 372 | EXPORT_SYMBOL(dvb_ringbuffer_write); |
Mauro Carvalho Chehab | 04da2da | 2014-09-03 20:44:04 -0300 | [diff] [blame] | 373 | EXPORT_SYMBOL(dvb_ringbuffer_write_user); |