Inaky Perez-Gonzalez | aa5a7ac | 2008-12-20 16:57:47 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Intel Wireless WiMAX Connection 2400m |
| 3 | * Generic (non-bus specific) TX handling |
| 4 | * |
| 5 | * |
| 6 | * Copyright (C) 2007-2008 Intel Corporation. All rights reserved. |
| 7 | * |
| 8 | * Redistribution and use in source and binary forms, with or without |
| 9 | * modification, are permitted provided that the following conditions |
| 10 | * are met: |
| 11 | * |
| 12 | * * Redistributions of source code must retain the above copyright |
| 13 | * notice, this list of conditions and the following disclaimer. |
| 14 | * * Redistributions in binary form must reproduce the above copyright |
| 15 | * notice, this list of conditions and the following disclaimer in |
| 16 | * the documentation and/or other materials provided with the |
| 17 | * distribution. |
| 18 | * * Neither the name of Intel Corporation nor the names of its |
| 19 | * contributors may be used to endorse or promote products derived |
| 20 | * from this software without specific prior written permission. |
| 21 | * |
| 22 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 23 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 24 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| 25 | * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| 26 | * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| 27 | * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| 28 | * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 29 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 30 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 31 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| 32 | * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 33 | * |
| 34 | * |
| 35 | * Intel Corporation <linux-wimax@intel.com> |
| 36 | * Yanir Lubetkin <yanirx.lubetkin@intel.com> |
| 37 | * - Initial implementation |
| 38 | * |
| 39 | * Intel Corporation <linux-wimax@intel.com> |
| 40 | * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com> |
| 41 | * - Rewritten to use a single FIFO to lower the memory allocation |
| 42 | * pressure and optimize cache hits when copying to the queue, as |
| 43 | * well as splitting out bus-specific code. |
| 44 | * |
| 45 | * |
| 46 | * Implements data transmission to the device; this is done through a |
| 47 | * software FIFO, as data/control frames can be coalesced (while the |
| 48 | * device is reading the previous tx transaction, others accumulate). |
| 49 | * |
| 50 | * A FIFO is used because at the end it is resource-cheaper that trying |
| 51 | * to implement scatter/gather over USB. As well, most traffic is going |
| 52 | * to be download (vs upload). |
| 53 | * |
| 54 | * The format for sending/receiving data to/from the i2400m is |
| 55 | * described in detail in rx.c:PROTOCOL FORMAT. In here we implement |
| 56 | * the transmission of that. This is split between a bus-independent |
| 57 | * part that just prepares everything and a bus-specific part that |
| 58 | * does the actual transmission over the bus to the device (in the |
| 59 | * bus-specific driver). |
| 60 | * |
| 61 | * |
| 62 | * The general format of a device-host transaction is MSG-HDR, PLD1, |
| 63 | * PLD2...PLDN, PL1, PL2,...PLN, PADDING. |
| 64 | * |
| 65 | * Because we need the send payload descriptors and then payloads and |
| 66 | * because it is kind of expensive to do scatterlists in USB (one URB |
| 67 | * per node), it becomes cheaper to append all the data to a FIFO |
| 68 | * (copying to a FIFO potentially in cache is cheaper). |
| 69 | * |
| 70 | * Then the bus-specific code takes the parts of that FIFO that are |
| 71 | * written and passes them to the device. |
| 72 | * |
| 73 | * So the concepts to keep in mind there are: |
| 74 | * |
| 75 | * We use a FIFO to queue the data in a linear buffer. We first append |
| 76 | * a MSG-HDR, space for I2400M_TX_PLD_MAX payload descriptors and then |
| 77 | * go appending payloads until we run out of space or of payload |
| 78 | * descriptors. Then we append padding to make the whole transaction a |
| 79 | * multiple of i2400m->bus_tx_block_size (as defined by the bus layer). |
| 80 | * |
| 81 | * - A TX message: a combination of a message header, payload |
| 82 | * descriptors and payloads. |
| 83 | * |
| 84 | * Open: it is marked as active (i2400m->tx_msg is valid) and we |
| 85 | * can keep adding payloads to it. |
| 86 | * |
| 87 | * Closed: we are not appending more payloads to this TX message |
| 88 | * (exahusted space in the queue, too many payloads or |
| 89 | * whichever). We have appended padding so the whole message |
| 90 | * length is aligned to i2400m->bus_tx_block_size (as set by the |
| 91 | * bus/transport layer). |
| 92 | * |
| 93 | * - Most of the time we keep a TX message open to which we append |
| 94 | * payloads. |
| 95 | * |
| 96 | * - If we are going to append and there is no more space (we are at |
| 97 | * the end of the FIFO), we close the message, mark the rest of the |
| 98 | * FIFO space unusable (skip_tail), create a new message at the |
| 99 | * beginning of the FIFO (if there is space) and append the message |
| 100 | * there. |
| 101 | * |
| 102 | * This is because we need to give linear TX messages to the bus |
| 103 | * engine. So we don't write a message to the remaining FIFO space |
| 104 | * until the tail and continue at the head of it. |
| 105 | * |
| 106 | * - We overload one of the fields in the message header to use it as |
| 107 | * 'size' of the TX message, so we can iterate over them. It also |
| 108 | * contains a flag that indicates if we have to skip it or not. |
| 109 | * When we send the buffer, we update that to its real on-the-wire |
| 110 | * value. |
| 111 | * |
| 112 | * - The MSG-HDR PLD1...PLD2 stuff has to be a size multiple of 16. |
| 113 | * |
| 114 | * It follows that if MSG-HDR says we have N messages, the whole |
| 115 | * header + descriptors is 16 + 4*N; for those to be a multiple of |
| 116 | * 16, it follows that N can be 4, 8, 12, ... (32, 48, 64, 80... |
| 117 | * bytes). |
| 118 | * |
| 119 | * So if we have only 1 payload, we have to submit a header that in |
| 120 | * all truth has space for 4. |
| 121 | * |
| 122 | * The implication is that we reserve space for 12 (64 bytes); but |
| 123 | * if we fill up only (eg) 2, our header becomes 32 bytes only. So |
| 124 | * the TX engine has to shift those 32 bytes of msg header and 2 |
| 125 | * payloads and padding so that right after it the payloads start |
| 126 | * and the TX engine has to know about that. |
| 127 | * |
| 128 | * It is cheaper to move the header up than the whole payloads down. |
| 129 | * |
| 130 | * We do this in i2400m_tx_close(). See 'i2400m_msg_hdr->offset'. |
| 131 | * |
| 132 | * - Each payload has to be size-padded to 16 bytes; before appending |
| 133 | * it, we just do it. |
| 134 | * |
| 135 | * - The whole message has to be padded to i2400m->bus_tx_block_size; |
| 136 | * we do this at close time. Thus, when reserving space for the |
| 137 | * payload, we always make sure there is also free space for this |
| 138 | * padding that sooner or later will happen. |
| 139 | * |
| 140 | * When we append a message, we tell the bus specific code to kick in |
| 141 | * TXs. It will TX (in parallel) until the buffer is exhausted--hence |
| 142 | * the lockin we do. The TX code will only send a TX message at the |
| 143 | * time (which remember, might contain more than one payload). Of |
| 144 | * course, when the bus-specific driver attempts to TX a message that |
| 145 | * is still open, it gets closed first. |
| 146 | * |
| 147 | * Gee, this is messy; well a picture. In the example below we have a |
| 148 | * partially full FIFO, with a closed message ready to be delivered |
| 149 | * (with a moved message header to make sure it is size-aligned to |
| 150 | * 16), TAIL room that was unusable (and thus is marked with a message |
| 151 | * header that says 'skip this') and at the head of the buffer, an |
| 152 | * imcomplete message with a couple of payloads. |
| 153 | * |
| 154 | * N ___________________________________________________ |
| 155 | * | | |
| 156 | * | TAIL room | |
| 157 | * | | |
| 158 | * | msg_hdr to skip (size |= 0x80000) | |
| 159 | * |---------------------------------------------------|------- |
| 160 | * | | /|\ |
| 161 | * | | | |
| 162 | * | TX message padding | | |
| 163 | * | | | |
| 164 | * | | | |
| 165 | * |- - - - - - - - - - - - - - - - - - - - - - - - - -| | |
| 166 | * | | | |
| 167 | * | payload 1 | | |
| 168 | * | | N * tx_block_size |
| 169 | * | | | |
| 170 | * |- - - - - - - - - - - - - - - - - - - - - - - - - -| | |
| 171 | * | | | |
| 172 | * | payload 1 | | |
| 173 | * | | | |
| 174 | * | | | |
| 175 | * |- - - - - - - - - - - - - - - - - - - - - - - - - -|- -|- - - - |
| 176 | * | padding 3 /|\ | | /|\ |
| 177 | * | padding 2 | | | | |
| 178 | * | pld 1 32 bytes (2 * 16) | | | |
| 179 | * | pld 0 | | | | |
| 180 | * | moved msg_hdr \|/ | \|/ | |
| 181 | * |- - - - - - - - - - - - - - - - - - - - - - - - - -|- - - | |
| 182 | * | | _PLD_SIZE |
| 183 | * | unused | | |
| 184 | * | | | |
| 185 | * |- - - - - - - - - - - - - - - - - - - - - - - - - -| | |
| 186 | * | msg_hdr (size X) [this message is closed] | \|/ |
| 187 | * |===================================================|========== <=== OUT |
| 188 | * | | |
| 189 | * | | |
| 190 | * | | |
| 191 | * | Free rooom | |
| 192 | * | | |
| 193 | * | | |
| 194 | * | | |
| 195 | * | | |
| 196 | * | | |
| 197 | * | | |
| 198 | * | | |
| 199 | * | | |
| 200 | * | | |
| 201 | * |===================================================|========== <=== IN |
| 202 | * | | |
| 203 | * | | |
| 204 | * | | |
| 205 | * | | |
| 206 | * | payload 1 | |
| 207 | * | | |
| 208 | * | | |
| 209 | * |- - - - - - - - - - - - - - - - - - - - - - - - - -| |
| 210 | * | | |
| 211 | * | payload 0 | |
| 212 | * | | |
| 213 | * | | |
| 214 | * |- - - - - - - - - - - - - - - - - - - - - - - - - -| |
| 215 | * | pld 11 /|\ | |
| 216 | * | ... | | |
| 217 | * | pld 1 64 bytes (2 * 16) | |
| 218 | * | pld 0 | | |
| 219 | * | msg_hdr (size X) \|/ [message is open] | |
| 220 | * 0 --------------------------------------------------- |
| 221 | * |
| 222 | * |
| 223 | * ROADMAP |
| 224 | * |
| 225 | * i2400m_tx_setup() Called by i2400m_setup |
| 226 | * i2400m_tx_release() Called by i2400m_release() |
| 227 | * |
| 228 | * i2400m_tx() Called to send data or control frames |
| 229 | * i2400m_tx_fifo_push() Allocates append-space in the FIFO |
| 230 | * i2400m_tx_new() Opens a new message in the FIFO |
| 231 | * i2400m_tx_fits() Checks if a new payload fits in the message |
| 232 | * i2400m_tx_close() Closes an open message in the FIFO |
| 233 | * i2400m_tx_skip_tail() Marks unusable FIFO tail space |
| 234 | * i2400m->bus_tx_kick() |
| 235 | * |
| 236 | * Now i2400m->bus_tx_kick() is the the bus-specific driver backend |
| 237 | * implementation; that would do: |
| 238 | * |
| 239 | * i2400m->bus_tx_kick() |
| 240 | * i2400m_tx_msg_get() Gets first message ready to go |
| 241 | * ...sends it... |
| 242 | * i2400m_tx_msg_sent() Ack the message is sent; repeat from |
| 243 | * _tx_msg_get() until it returns NULL |
| 244 | * (FIFO empty). |
| 245 | */ |
| 246 | #include <linux/netdevice.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 247 | #include <linux/slab.h> |
Inaky Perez-Gonzalez | aa5a7ac | 2008-12-20 16:57:47 -0800 | [diff] [blame] | 248 | #include "i2400m.h" |
| 249 | |
| 250 | |
| 251 | #define D_SUBMODULE tx |
| 252 | #include "debug-levels.h" |
| 253 | |
| 254 | enum { |
| 255 | /** |
| 256 | * TX Buffer size |
| 257 | * |
| 258 | * Doc says maximum transaction is 16KiB. If we had 16KiB en |
| 259 | * route and 16KiB being queued, it boils down to needing |
| 260 | * 32KiB. |
| 261 | */ |
| 262 | I2400M_TX_BUF_SIZE = 32768, |
| 263 | /** |
| 264 | * Message header and payload descriptors have to be 16 |
| 265 | * aligned (16 + 4 * N = 16 * M). If we take that average sent |
| 266 | * packets are MTU size (~1400-~1500) it follows that we could |
| 267 | * fit at most 10-11 payloads in one transaction. To meet the |
| 268 | * alignment requirement, that means we need to leave space |
| 269 | * for 12 (64 bytes). To simplify, we leave space for that. If |
| 270 | * at the end there are less, we pad up to the nearest |
| 271 | * multiple of 16. |
| 272 | */ |
| 273 | I2400M_TX_PLD_MAX = 12, |
| 274 | I2400M_TX_PLD_SIZE = sizeof(struct i2400m_msg_hdr) |
| 275 | + I2400M_TX_PLD_MAX * sizeof(struct i2400m_pld), |
| 276 | I2400M_TX_SKIP = 0x80000000, |
| 277 | }; |
| 278 | |
| 279 | #define TAIL_FULL ((void *)~(unsigned long)NULL) |
| 280 | |
| 281 | /* |
Inaky Perez-Gonzalez | 2971a5b | 2009-05-20 17:40:35 -0700 | [diff] [blame] | 282 | * Calculate how much tail room is available |
| 283 | * |
| 284 | * Note the trick here. This path is ONLY caleed for Case A (see |
| 285 | * i2400m_tx_fifo_push() below), where we have: |
| 286 | * |
| 287 | * Case A |
| 288 | * N ___________ |
| 289 | * | tail room | |
| 290 | * | | |
| 291 | * |<- IN ->| |
| 292 | * | | |
| 293 | * | data | |
| 294 | * | | |
| 295 | * |<- OUT ->| |
| 296 | * | | |
| 297 | * | head room | |
| 298 | * 0 ----------- |
| 299 | * |
| 300 | * When calculating the tail_room, tx_in might get to be zero if |
| 301 | * i2400m->tx_in is right at the end of the buffer (really full |
| 302 | * buffer) if there is no head room. In this case, tail_room would be |
| 303 | * I2400M_TX_BUF_SIZE, although it is actually zero. Hence the final |
| 304 | * mod (%) operation. However, when doing this kind of optimization, |
| 305 | * i2400m->tx_in being zero would fail, so we treat is an a special |
| 306 | * case. |
| 307 | */ |
| 308 | static inline |
| 309 | size_t __i2400m_tx_tail_room(struct i2400m *i2400m) |
| 310 | { |
| 311 | size_t tail_room; |
| 312 | size_t tx_in; |
| 313 | |
Roel Kluin | 2d44f20 | 2009-07-13 00:59:53 +0200 | [diff] [blame] | 314 | if (unlikely(i2400m->tx_in == 0)) |
Inaky Perez-Gonzalez | 2971a5b | 2009-05-20 17:40:35 -0700 | [diff] [blame] | 315 | return I2400M_TX_BUF_SIZE; |
| 316 | tx_in = i2400m->tx_in % I2400M_TX_BUF_SIZE; |
| 317 | tail_room = I2400M_TX_BUF_SIZE - tx_in; |
| 318 | tail_room %= I2400M_TX_BUF_SIZE; |
| 319 | return tail_room; |
| 320 | } |
| 321 | |
| 322 | |
| 323 | /* |
Inaky Perez-Gonzalez | aa5a7ac | 2008-12-20 16:57:47 -0800 | [diff] [blame] | 324 | * Allocate @size bytes in the TX fifo, return a pointer to it |
| 325 | * |
| 326 | * @i2400m: device descriptor |
| 327 | * @size: size of the buffer we need to allocate |
| 328 | * @padding: ensure that there is at least this many bytes of free |
| 329 | * contiguous space in the fifo. This is needed because later on |
| 330 | * we might need to add padding. |
| 331 | * |
| 332 | * Returns: |
| 333 | * |
| 334 | * Pointer to the allocated space. NULL if there is no |
| 335 | * space. TAIL_FULL if there is no space at the tail but there is at |
| 336 | * the head (Case B below). |
| 337 | * |
| 338 | * These are the two basic cases we need to keep an eye for -- it is |
| 339 | * much better explained in linux/kernel/kfifo.c, but this code |
| 340 | * basically does the same. No rocket science here. |
| 341 | * |
| 342 | * Case A Case B |
| 343 | * N ___________ ___________ |
| 344 | * | tail room | | data | |
| 345 | * | | | | |
| 346 | * |<- IN ->| |<- OUT ->| |
| 347 | * | | | | |
| 348 | * | data | | room | |
| 349 | * | | | | |
| 350 | * |<- OUT ->| |<- IN ->| |
| 351 | * | | | | |
| 352 | * | head room | | data | |
| 353 | * 0 ----------- ----------- |
| 354 | * |
| 355 | * We allocate only *contiguous* space. |
| 356 | * |
| 357 | * We can allocate only from 'room'. In Case B, it is simple; in case |
| 358 | * A, we only try from the tail room; if it is not enough, we just |
| 359 | * fail and return TAIL_FULL and let the caller figure out if we wants to |
| 360 | * skip the tail room and try to allocate from the head. |
| 361 | * |
| 362 | * Note: |
| 363 | * |
| 364 | * Assumes i2400m->tx_lock is taken, and we use that as a barrier |
| 365 | * |
| 366 | * The indexes keep increasing and we reset them to zero when we |
| 367 | * pop data off the queue |
| 368 | */ |
| 369 | static |
| 370 | void *i2400m_tx_fifo_push(struct i2400m *i2400m, size_t size, size_t padding) |
| 371 | { |
| 372 | struct device *dev = i2400m_dev(i2400m); |
| 373 | size_t room, tail_room, needed_size; |
| 374 | void *ptr; |
| 375 | |
| 376 | needed_size = size + padding; |
| 377 | room = I2400M_TX_BUF_SIZE - (i2400m->tx_in - i2400m->tx_out); |
| 378 | if (room < needed_size) { /* this takes care of Case B */ |
| 379 | d_printf(2, dev, "fifo push %zu/%zu: no space\n", |
| 380 | size, padding); |
| 381 | return NULL; |
| 382 | } |
| 383 | /* Is there space at the tail? */ |
Inaky Perez-Gonzalez | 2971a5b | 2009-05-20 17:40:35 -0700 | [diff] [blame] | 384 | tail_room = __i2400m_tx_tail_room(i2400m); |
Inaky Perez-Gonzalez | aa5a7ac | 2008-12-20 16:57:47 -0800 | [diff] [blame] | 385 | if (tail_room < needed_size) { |
| 386 | if (i2400m->tx_out % I2400M_TX_BUF_SIZE |
| 387 | < i2400m->tx_in % I2400M_TX_BUF_SIZE) { |
| 388 | d_printf(2, dev, "fifo push %zu/%zu: tail full\n", |
| 389 | size, padding); |
| 390 | return TAIL_FULL; /* There might be head space */ |
| 391 | } else { |
| 392 | d_printf(2, dev, "fifo push %zu/%zu: no head space\n", |
| 393 | size, padding); |
| 394 | return NULL; /* There is no space */ |
| 395 | } |
| 396 | } |
| 397 | ptr = i2400m->tx_buf + i2400m->tx_in % I2400M_TX_BUF_SIZE; |
| 398 | d_printf(2, dev, "fifo push %zu/%zu: at @%zu\n", size, padding, |
| 399 | i2400m->tx_in % I2400M_TX_BUF_SIZE); |
| 400 | i2400m->tx_in += size; |
| 401 | return ptr; |
| 402 | } |
| 403 | |
| 404 | |
| 405 | /* |
| 406 | * Mark the tail of the FIFO buffer as 'to-skip' |
| 407 | * |
| 408 | * We should never hit the BUG_ON() because all the sizes we push to |
| 409 | * the FIFO are padded to be a multiple of 16 -- the size of *msg |
| 410 | * (I2400M_PL_PAD for the payloads, I2400M_TX_PLD_SIZE for the |
| 411 | * header). |
| 412 | * |
Inaky Perez-Gonzalez | 2971a5b | 2009-05-20 17:40:35 -0700 | [diff] [blame] | 413 | * Tail room can get to be zero if a message was opened when there was |
| 414 | * space only for a header. _tx_close() will mark it as to-skip (as it |
| 415 | * will have no payloads) and there will be no more space to flush, so |
| 416 | * nothing has to be done here. This is probably cheaper than ensuring |
| 417 | * in _tx_new() that there is some space for payloads...as we could |
| 418 | * always possibly hit the same problem if the payload wouldn't fit. |
| 419 | * |
Inaky Perez-Gonzalez | aa5a7ac | 2008-12-20 16:57:47 -0800 | [diff] [blame] | 420 | * Note: |
| 421 | * |
| 422 | * Assumes i2400m->tx_lock is taken, and we use that as a barrier |
Inaky Perez-Gonzalez | 2971a5b | 2009-05-20 17:40:35 -0700 | [diff] [blame] | 423 | * |
| 424 | * This path is only taken for Case A FIFO situations [see |
| 425 | * i2400m_tx_fifo_push()] |
Inaky Perez-Gonzalez | aa5a7ac | 2008-12-20 16:57:47 -0800 | [diff] [blame] | 426 | */ |
| 427 | static |
| 428 | void i2400m_tx_skip_tail(struct i2400m *i2400m) |
| 429 | { |
| 430 | struct device *dev = i2400m_dev(i2400m); |
| 431 | size_t tx_in = i2400m->tx_in % I2400M_TX_BUF_SIZE; |
Inaky Perez-Gonzalez | 2971a5b | 2009-05-20 17:40:35 -0700 | [diff] [blame] | 432 | size_t tail_room = __i2400m_tx_tail_room(i2400m); |
Inaky Perez-Gonzalez | aa5a7ac | 2008-12-20 16:57:47 -0800 | [diff] [blame] | 433 | struct i2400m_msg_hdr *msg = i2400m->tx_buf + tx_in; |
Inaky Perez-Gonzalez | 2971a5b | 2009-05-20 17:40:35 -0700 | [diff] [blame] | 434 | if (unlikely(tail_room == 0)) |
| 435 | return; |
Inaky Perez-Gonzalez | aa5a7ac | 2008-12-20 16:57:47 -0800 | [diff] [blame] | 436 | BUG_ON(tail_room < sizeof(*msg)); |
| 437 | msg->size = tail_room | I2400M_TX_SKIP; |
| 438 | d_printf(2, dev, "skip tail: skipping %zu bytes @%zu\n", |
| 439 | tail_room, tx_in); |
| 440 | i2400m->tx_in += tail_room; |
| 441 | } |
| 442 | |
| 443 | |
| 444 | /* |
| 445 | * Check if a skb will fit in the TX queue's current active TX |
| 446 | * message (if there are still descriptors left unused). |
| 447 | * |
| 448 | * Returns: |
| 449 | * 0 if the message won't fit, 1 if it will. |
| 450 | * |
| 451 | * Note: |
| 452 | * |
| 453 | * Assumes a TX message is active (i2400m->tx_msg). |
| 454 | * |
| 455 | * Assumes i2400m->tx_lock is taken, and we use that as a barrier |
| 456 | */ |
| 457 | static |
| 458 | unsigned i2400m_tx_fits(struct i2400m *i2400m) |
| 459 | { |
| 460 | struct i2400m_msg_hdr *msg_hdr = i2400m->tx_msg; |
| 461 | return le16_to_cpu(msg_hdr->num_pls) < I2400M_TX_PLD_MAX; |
| 462 | |
| 463 | } |
| 464 | |
| 465 | |
| 466 | /* |
| 467 | * Start a new TX message header in the queue. |
| 468 | * |
| 469 | * Reserve memory from the base FIFO engine and then just initialize |
| 470 | * the message header. |
| 471 | * |
| 472 | * We allocate the biggest TX message header we might need (one that'd |
| 473 | * fit I2400M_TX_PLD_MAX payloads) -- when it is closed it will be |
| 474 | * 'ironed it out' and the unneeded parts removed. |
| 475 | * |
| 476 | * NOTE: |
| 477 | * |
| 478 | * Assumes that the previous message is CLOSED (eg: either |
| 479 | * there was none or 'i2400m_tx_close()' was called on it). |
| 480 | * |
| 481 | * Assumes i2400m->tx_lock is taken, and we use that as a barrier |
| 482 | */ |
| 483 | static |
| 484 | void i2400m_tx_new(struct i2400m *i2400m) |
| 485 | { |
| 486 | struct device *dev = i2400m_dev(i2400m); |
| 487 | struct i2400m_msg_hdr *tx_msg; |
| 488 | BUG_ON(i2400m->tx_msg != NULL); |
| 489 | try_head: |
| 490 | tx_msg = i2400m_tx_fifo_push(i2400m, I2400M_TX_PLD_SIZE, 0); |
| 491 | if (tx_msg == NULL) |
| 492 | goto out; |
| 493 | else if (tx_msg == TAIL_FULL) { |
| 494 | i2400m_tx_skip_tail(i2400m); |
| 495 | d_printf(2, dev, "new TX message: tail full, trying head\n"); |
| 496 | goto try_head; |
| 497 | } |
| 498 | memset(tx_msg, 0, I2400M_TX_PLD_SIZE); |
| 499 | tx_msg->size = I2400M_TX_PLD_SIZE; |
| 500 | out: |
| 501 | i2400m->tx_msg = tx_msg; |
| 502 | d_printf(2, dev, "new TX message: %p @%zu\n", |
| 503 | tx_msg, (void *) tx_msg - i2400m->tx_buf); |
| 504 | } |
| 505 | |
| 506 | |
| 507 | /* |
| 508 | * Finalize the current TX message header |
| 509 | * |
| 510 | * Sets the message header to be at the proper location depending on |
| 511 | * how many descriptors we have (check documentation at the file's |
| 512 | * header for more info on that). |
| 513 | * |
| 514 | * Appends padding bytes to make sure the whole TX message (counting |
| 515 | * from the 'relocated' message header) is aligned to |
| 516 | * tx_block_size. We assume the _append() code has left enough space |
| 517 | * in the FIFO for that. If there are no payloads, just pass, as it |
| 518 | * won't be transferred. |
| 519 | * |
| 520 | * The amount of padding bytes depends on how many payloads are in the |
| 521 | * TX message, as the "msg header and payload descriptors" will be |
| 522 | * shifted up in the buffer. |
| 523 | */ |
| 524 | static |
| 525 | void i2400m_tx_close(struct i2400m *i2400m) |
| 526 | { |
| 527 | struct device *dev = i2400m_dev(i2400m); |
| 528 | struct i2400m_msg_hdr *tx_msg = i2400m->tx_msg; |
| 529 | struct i2400m_msg_hdr *tx_msg_moved; |
| 530 | size_t aligned_size, padding, hdr_size; |
| 531 | void *pad_buf; |
Inaky Perez-Gonzalez | c56affa | 2009-05-20 17:16:05 -0700 | [diff] [blame] | 532 | unsigned num_pls; |
Inaky Perez-Gonzalez | aa5a7ac | 2008-12-20 16:57:47 -0800 | [diff] [blame] | 533 | |
| 534 | if (tx_msg->size & I2400M_TX_SKIP) /* a skipper? nothing to do */ |
| 535 | goto out; |
Inaky Perez-Gonzalez | c56affa | 2009-05-20 17:16:05 -0700 | [diff] [blame] | 536 | num_pls = le16_to_cpu(tx_msg->num_pls); |
| 537 | /* We can get this situation when a new message was started |
| 538 | * and there was no space to add payloads before hitting the |
| 539 | tail (and taking padding into consideration). */ |
| 540 | if (num_pls == 0) { |
| 541 | tx_msg->size |= I2400M_TX_SKIP; |
| 542 | goto out; |
| 543 | } |
Inaky Perez-Gonzalez | aa5a7ac | 2008-12-20 16:57:47 -0800 | [diff] [blame] | 544 | /* Relocate the message header |
| 545 | * |
| 546 | * Find the current header size, align it to 16 and if we need |
| 547 | * to move it so the tail is next to the payloads, move it and |
| 548 | * set the offset. |
| 549 | * |
| 550 | * If it moved, this header is good only for transmission; the |
| 551 | * original one (it is kept if we moved) is still used to |
| 552 | * figure out where the next TX message starts (and where the |
| 553 | * offset to the moved header is). |
| 554 | */ |
| 555 | hdr_size = sizeof(*tx_msg) |
| 556 | + le16_to_cpu(tx_msg->num_pls) * sizeof(tx_msg->pld[0]); |
Inaky Perez-Gonzalez | 8593a19 | 2009-05-20 16:53:30 -0700 | [diff] [blame] | 557 | hdr_size = ALIGN(hdr_size, I2400M_PL_ALIGN); |
Inaky Perez-Gonzalez | aa5a7ac | 2008-12-20 16:57:47 -0800 | [diff] [blame] | 558 | tx_msg->offset = I2400M_TX_PLD_SIZE - hdr_size; |
| 559 | tx_msg_moved = (void *) tx_msg + tx_msg->offset; |
| 560 | memmove(tx_msg_moved, tx_msg, hdr_size); |
| 561 | tx_msg_moved->size -= tx_msg->offset; |
| 562 | /* |
| 563 | * Now figure out how much we have to add to the (moved!) |
| 564 | * message so the size is a multiple of i2400m->bus_tx_block_size. |
| 565 | */ |
| 566 | aligned_size = ALIGN(tx_msg_moved->size, i2400m->bus_tx_block_size); |
| 567 | padding = aligned_size - tx_msg_moved->size; |
| 568 | if (padding > 0) { |
| 569 | pad_buf = i2400m_tx_fifo_push(i2400m, padding, 0); |
| 570 | if (unlikely(WARN_ON(pad_buf == NULL |
| 571 | || pad_buf == TAIL_FULL))) { |
| 572 | /* This should not happen -- append should verify |
| 573 | * there is always space left at least to append |
| 574 | * tx_block_size */ |
| 575 | dev_err(dev, |
| 576 | "SW BUG! Possible data leakage from memory the " |
| 577 | "device should not read for padding - " |
| 578 | "size %lu aligned_size %zu tx_buf %p in " |
| 579 | "%zu out %zu\n", |
| 580 | (unsigned long) tx_msg_moved->size, |
| 581 | aligned_size, i2400m->tx_buf, i2400m->tx_in, |
| 582 | i2400m->tx_out); |
| 583 | } else |
| 584 | memset(pad_buf, 0xad, padding); |
| 585 | } |
| 586 | tx_msg_moved->padding = cpu_to_le16(padding); |
| 587 | tx_msg_moved->size += padding; |
| 588 | if (tx_msg != tx_msg_moved) |
| 589 | tx_msg->size += padding; |
| 590 | out: |
| 591 | i2400m->tx_msg = NULL; |
| 592 | } |
| 593 | |
| 594 | |
| 595 | /** |
| 596 | * i2400m_tx - send the data in a buffer to the device |
| 597 | * |
| 598 | * @buf: pointer to the buffer to transmit |
| 599 | * |
| 600 | * @buf_len: buffer size |
| 601 | * |
| 602 | * @pl_type: type of the payload we are sending. |
| 603 | * |
| 604 | * Returns: |
| 605 | * 0 if ok, < 0 errno code on error (-ENOSPC, if there is no more |
| 606 | * room for the message in the queue). |
| 607 | * |
| 608 | * Appends the buffer to the TX FIFO and notifies the bus-specific |
| 609 | * part of the driver that there is new data ready to transmit. |
| 610 | * Once this function returns, the buffer has been copied, so it can |
| 611 | * be reused. |
| 612 | * |
| 613 | * The steps followed to append are explained in detail in the file |
| 614 | * header. |
| 615 | * |
| 616 | * Whenever we write to a message, we increase msg->size, so it |
| 617 | * reflects exactly how big the message is. This is needed so that if |
| 618 | * we concatenate two messages before they can be sent, the code that |
| 619 | * sends the messages can find the boundaries (and it will replace the |
| 620 | * size with the real barker before sending). |
| 621 | * |
| 622 | * Note: |
| 623 | * |
| 624 | * Cold and warm reset payloads need to be sent as a single |
| 625 | * payload, so we handle that. |
| 626 | */ |
| 627 | int i2400m_tx(struct i2400m *i2400m, const void *buf, size_t buf_len, |
| 628 | enum i2400m_pt pl_type) |
| 629 | { |
| 630 | int result = -ENOSPC; |
| 631 | struct device *dev = i2400m_dev(i2400m); |
| 632 | unsigned long flags; |
| 633 | size_t padded_len; |
| 634 | void *ptr; |
| 635 | unsigned is_singleton = pl_type == I2400M_PT_RESET_WARM |
| 636 | || pl_type == I2400M_PT_RESET_COLD; |
| 637 | |
| 638 | d_fnstart(3, dev, "(i2400m %p skb %p [%zu bytes] pt %u)\n", |
| 639 | i2400m, buf, buf_len, pl_type); |
Inaky Perez-Gonzalez | 8593a19 | 2009-05-20 16:53:30 -0700 | [diff] [blame] | 640 | padded_len = ALIGN(buf_len, I2400M_PL_ALIGN); |
Inaky Perez-Gonzalez | aa5a7ac | 2008-12-20 16:57:47 -0800 | [diff] [blame] | 641 | d_printf(5, dev, "padded_len %zd buf_len %zd\n", padded_len, buf_len); |
| 642 | /* If there is no current TX message, create one; if the |
| 643 | * current one is out of payload slots or we have a singleton, |
| 644 | * close it and start a new one */ |
| 645 | spin_lock_irqsave(&i2400m->tx_lock, flags); |
Prasanna S.Panchamukhi | 4818d14 | 2010-01-18 14:28:23 -0800 | [diff] [blame^] | 646 | /* If tx_buf is NULL, device is shutdown */ |
| 647 | if (i2400m->tx_buf == NULL) { |
| 648 | result = -ESHUTDOWN; |
Inaky Perez-Gonzalez | 46c50147 | 2009-10-07 22:46:29 +0900 | [diff] [blame] | 649 | goto error_tx_new; |
Prasanna S.Panchamukhi | 4818d14 | 2010-01-18 14:28:23 -0800 | [diff] [blame^] | 650 | } |
Inaky Perez-Gonzalez | aa5a7ac | 2008-12-20 16:57:47 -0800 | [diff] [blame] | 651 | try_new: |
| 652 | if (unlikely(i2400m->tx_msg == NULL)) |
| 653 | i2400m_tx_new(i2400m); |
| 654 | else if (unlikely(!i2400m_tx_fits(i2400m) |
| 655 | || (is_singleton && i2400m->tx_msg->num_pls != 0))) { |
| 656 | d_printf(2, dev, "closing TX message (fits %u singleton " |
| 657 | "%u num_pls %u)\n", i2400m_tx_fits(i2400m), |
| 658 | is_singleton, i2400m->tx_msg->num_pls); |
| 659 | i2400m_tx_close(i2400m); |
| 660 | i2400m_tx_new(i2400m); |
| 661 | } |
Inaky Perez-Gonzalez | 59063af | 2009-05-27 01:04:40 -0700 | [diff] [blame] | 662 | if (i2400m->tx_msg == NULL) |
| 663 | goto error_tx_new; |
Inaky Perez-Gonzalez | aa5a7ac | 2008-12-20 16:57:47 -0800 | [diff] [blame] | 664 | if (i2400m->tx_msg->size + padded_len > I2400M_TX_BUF_SIZE / 2) { |
| 665 | d_printf(2, dev, "TX: message too big, going new\n"); |
| 666 | i2400m_tx_close(i2400m); |
| 667 | i2400m_tx_new(i2400m); |
| 668 | } |
| 669 | if (i2400m->tx_msg == NULL) |
| 670 | goto error_tx_new; |
| 671 | /* So we have a current message header; now append space for |
| 672 | * the message -- if there is not enough, try the head */ |
| 673 | ptr = i2400m_tx_fifo_push(i2400m, padded_len, |
| 674 | i2400m->bus_tx_block_size); |
| 675 | if (ptr == TAIL_FULL) { /* Tail is full, try head */ |
| 676 | d_printf(2, dev, "pl append: tail full\n"); |
| 677 | i2400m_tx_close(i2400m); |
| 678 | i2400m_tx_skip_tail(i2400m); |
| 679 | goto try_new; |
| 680 | } else if (ptr == NULL) { /* All full */ |
| 681 | result = -ENOSPC; |
| 682 | d_printf(2, dev, "pl append: all full\n"); |
| 683 | } else { /* Got space, copy it, set padding */ |
| 684 | struct i2400m_msg_hdr *tx_msg = i2400m->tx_msg; |
| 685 | unsigned num_pls = le16_to_cpu(tx_msg->num_pls); |
| 686 | memcpy(ptr, buf, buf_len); |
| 687 | memset(ptr + buf_len, 0xad, padded_len - buf_len); |
| 688 | i2400m_pld_set(&tx_msg->pld[num_pls], buf_len, pl_type); |
| 689 | d_printf(3, dev, "pld 0x%08x (type 0x%1x len 0x%04zx\n", |
| 690 | le32_to_cpu(tx_msg->pld[num_pls].val), |
| 691 | pl_type, buf_len); |
| 692 | tx_msg->num_pls = le16_to_cpu(num_pls+1); |
| 693 | tx_msg->size += padded_len; |
Frans Pop | 2381a55 | 2010-03-24 07:57:36 +0000 | [diff] [blame] | 694 | d_printf(2, dev, "TX: appended %zu b (up to %u b) pl #%u\n", |
Inaky Perez-Gonzalez | aa5a7ac | 2008-12-20 16:57:47 -0800 | [diff] [blame] | 695 | padded_len, tx_msg->size, num_pls+1); |
| 696 | d_printf(2, dev, |
| 697 | "TX: appended hdr @%zu %zu b pl #%u @%zu %zu/%zu b\n", |
| 698 | (void *)tx_msg - i2400m->tx_buf, (size_t)tx_msg->size, |
| 699 | num_pls+1, ptr - i2400m->tx_buf, buf_len, padded_len); |
| 700 | result = 0; |
| 701 | if (is_singleton) |
| 702 | i2400m_tx_close(i2400m); |
| 703 | } |
| 704 | error_tx_new: |
| 705 | spin_unlock_irqrestore(&i2400m->tx_lock, flags); |
Inaky Perez-Gonzalez | 46c50147 | 2009-10-07 22:46:29 +0900 | [diff] [blame] | 706 | /* kick in most cases, except when the TX subsys is down, as |
| 707 | * it might free space */ |
| 708 | if (likely(result != -ESHUTDOWN)) |
| 709 | i2400m->bus_tx_kick(i2400m); |
Inaky Perez-Gonzalez | aa5a7ac | 2008-12-20 16:57:47 -0800 | [diff] [blame] | 710 | d_fnend(3, dev, "(i2400m %p skb %p [%zu bytes] pt %u) = %d\n", |
| 711 | i2400m, buf, buf_len, pl_type, result); |
| 712 | return result; |
| 713 | } |
| 714 | EXPORT_SYMBOL_GPL(i2400m_tx); |
| 715 | |
| 716 | |
| 717 | /** |
| 718 | * i2400m_tx_msg_get - Get the first TX message in the FIFO to start sending it |
| 719 | * |
| 720 | * @i2400m: device descriptors |
| 721 | * @bus_size: where to place the size of the TX message |
| 722 | * |
| 723 | * Called by the bus-specific driver to get the first TX message at |
| 724 | * the FIF that is ready for transmission. |
| 725 | * |
| 726 | * It sets the state in @i2400m to indicate the bus-specific driver is |
| 727 | * transfering that message (i2400m->tx_msg_size). |
| 728 | * |
| 729 | * Once the transfer is completed, call i2400m_tx_msg_sent(). |
| 730 | * |
| 731 | * Notes: |
| 732 | * |
| 733 | * The size of the TX message to be transmitted might be smaller than |
| 734 | * that of the TX message in the FIFO (in case the header was |
| 735 | * shorter). Hence, we copy it in @bus_size, for the bus layer to |
| 736 | * use. We keep the message's size in i2400m->tx_msg_size so that |
| 737 | * when the bus later is done transferring we know how much to |
| 738 | * advance the fifo. |
| 739 | * |
| 740 | * We collect statistics here as all the data is available and we |
| 741 | * assume it is going to work [see i2400m_tx_msg_sent()]. |
| 742 | */ |
| 743 | struct i2400m_msg_hdr *i2400m_tx_msg_get(struct i2400m *i2400m, |
| 744 | size_t *bus_size) |
| 745 | { |
| 746 | struct device *dev = i2400m_dev(i2400m); |
| 747 | struct i2400m_msg_hdr *tx_msg, *tx_msg_moved; |
| 748 | unsigned long flags, pls; |
| 749 | |
| 750 | d_fnstart(3, dev, "(i2400m %p bus_size %p)\n", i2400m, bus_size); |
| 751 | spin_lock_irqsave(&i2400m->tx_lock, flags); |
Inaky Perez-Gonzalez | 46c50147 | 2009-10-07 22:46:29 +0900 | [diff] [blame] | 752 | tx_msg_moved = NULL; |
| 753 | if (i2400m->tx_buf == NULL) |
| 754 | goto out_unlock; |
Inaky Perez-Gonzalez | aa5a7ac | 2008-12-20 16:57:47 -0800 | [diff] [blame] | 755 | skip: |
| 756 | tx_msg_moved = NULL; |
| 757 | if (i2400m->tx_in == i2400m->tx_out) { /* Empty FIFO? */ |
| 758 | i2400m->tx_in = 0; |
| 759 | i2400m->tx_out = 0; |
| 760 | d_printf(2, dev, "TX: FIFO empty: resetting\n"); |
| 761 | goto out_unlock; |
| 762 | } |
| 763 | tx_msg = i2400m->tx_buf + i2400m->tx_out % I2400M_TX_BUF_SIZE; |
| 764 | if (tx_msg->size & I2400M_TX_SKIP) { /* skip? */ |
| 765 | d_printf(2, dev, "TX: skip: msg @%zu (%zu b)\n", |
| 766 | i2400m->tx_out % I2400M_TX_BUF_SIZE, |
| 767 | (size_t) tx_msg->size & ~I2400M_TX_SKIP); |
| 768 | i2400m->tx_out += tx_msg->size & ~I2400M_TX_SKIP; |
| 769 | goto skip; |
| 770 | } |
| 771 | |
| 772 | if (tx_msg->num_pls == 0) { /* No payloads? */ |
| 773 | if (tx_msg == i2400m->tx_msg) { /* open, we are done */ |
| 774 | d_printf(2, dev, |
| 775 | "TX: FIFO empty: open msg w/o payloads @%zu\n", |
| 776 | (void *) tx_msg - i2400m->tx_buf); |
| 777 | tx_msg = NULL; |
| 778 | goto out_unlock; |
| 779 | } else { /* closed, skip it */ |
| 780 | d_printf(2, dev, |
| 781 | "TX: skip msg w/o payloads @%zu (%zu b)\n", |
| 782 | (void *) tx_msg - i2400m->tx_buf, |
| 783 | (size_t) tx_msg->size); |
| 784 | i2400m->tx_out += tx_msg->size & ~I2400M_TX_SKIP; |
| 785 | goto skip; |
| 786 | } |
| 787 | } |
| 788 | if (tx_msg == i2400m->tx_msg) /* open msg? */ |
| 789 | i2400m_tx_close(i2400m); |
| 790 | |
| 791 | /* Now we have a valid TX message (with payloads) to TX */ |
| 792 | tx_msg_moved = (void *) tx_msg + tx_msg->offset; |
| 793 | i2400m->tx_msg_size = tx_msg->size; |
| 794 | *bus_size = tx_msg_moved->size; |
| 795 | d_printf(2, dev, "TX: pid %d msg hdr at @%zu offset +@%zu " |
| 796 | "size %zu bus_size %zu\n", |
| 797 | current->pid, (void *) tx_msg - i2400m->tx_buf, |
| 798 | (size_t) tx_msg->offset, (size_t) tx_msg->size, |
| 799 | (size_t) tx_msg_moved->size); |
| 800 | tx_msg_moved->barker = le32_to_cpu(I2400M_H2D_PREVIEW_BARKER); |
| 801 | tx_msg_moved->sequence = le32_to_cpu(i2400m->tx_sequence++); |
| 802 | |
| 803 | pls = le32_to_cpu(tx_msg_moved->num_pls); |
| 804 | i2400m->tx_pl_num += pls; /* Update stats */ |
| 805 | if (pls > i2400m->tx_pl_max) |
| 806 | i2400m->tx_pl_max = pls; |
| 807 | if (pls < i2400m->tx_pl_min) |
| 808 | i2400m->tx_pl_min = pls; |
| 809 | i2400m->tx_num++; |
| 810 | i2400m->tx_size_acc += *bus_size; |
| 811 | if (*bus_size < i2400m->tx_size_min) |
| 812 | i2400m->tx_size_min = *bus_size; |
| 813 | if (*bus_size > i2400m->tx_size_max) |
| 814 | i2400m->tx_size_max = *bus_size; |
| 815 | out_unlock: |
| 816 | spin_unlock_irqrestore(&i2400m->tx_lock, flags); |
| 817 | d_fnstart(3, dev, "(i2400m %p bus_size %p [%zu]) = %p\n", |
| 818 | i2400m, bus_size, *bus_size, tx_msg_moved); |
| 819 | return tx_msg_moved; |
| 820 | } |
| 821 | EXPORT_SYMBOL_GPL(i2400m_tx_msg_get); |
| 822 | |
| 823 | |
| 824 | /** |
| 825 | * i2400m_tx_msg_sent - indicate the transmission of a TX message |
| 826 | * |
| 827 | * @i2400m: device descriptor |
| 828 | * |
| 829 | * Called by the bus-specific driver when a message has been sent; |
| 830 | * this pops it from the FIFO; and as there is space, start the queue |
| 831 | * in case it was stopped. |
| 832 | * |
| 833 | * Should be called even if the message send failed and we are |
| 834 | * dropping this TX message. |
| 835 | */ |
| 836 | void i2400m_tx_msg_sent(struct i2400m *i2400m) |
| 837 | { |
| 838 | unsigned n; |
| 839 | unsigned long flags; |
| 840 | struct device *dev = i2400m_dev(i2400m); |
| 841 | |
| 842 | d_fnstart(3, dev, "(i2400m %p)\n", i2400m); |
| 843 | spin_lock_irqsave(&i2400m->tx_lock, flags); |
Inaky Perez-Gonzalez | 46c50147 | 2009-10-07 22:46:29 +0900 | [diff] [blame] | 844 | if (i2400m->tx_buf == NULL) |
| 845 | goto out_unlock; |
Inaky Perez-Gonzalez | aa5a7ac | 2008-12-20 16:57:47 -0800 | [diff] [blame] | 846 | i2400m->tx_out += i2400m->tx_msg_size; |
| 847 | d_printf(2, dev, "TX: sent %zu b\n", (size_t) i2400m->tx_msg_size); |
| 848 | i2400m->tx_msg_size = 0; |
| 849 | BUG_ON(i2400m->tx_out > i2400m->tx_in); |
| 850 | /* level them FIFO markers off */ |
| 851 | n = i2400m->tx_out / I2400M_TX_BUF_SIZE; |
| 852 | i2400m->tx_out %= I2400M_TX_BUF_SIZE; |
| 853 | i2400m->tx_in -= n * I2400M_TX_BUF_SIZE; |
Inaky Perez-Gonzalez | 46c50147 | 2009-10-07 22:46:29 +0900 | [diff] [blame] | 854 | out_unlock: |
Inaky Perez-Gonzalez | aa5a7ac | 2008-12-20 16:57:47 -0800 | [diff] [blame] | 855 | spin_unlock_irqrestore(&i2400m->tx_lock, flags); |
| 856 | d_fnend(3, dev, "(i2400m %p) = void\n", i2400m); |
| 857 | } |
| 858 | EXPORT_SYMBOL_GPL(i2400m_tx_msg_sent); |
| 859 | |
| 860 | |
| 861 | /** |
| 862 | * i2400m_tx_setup - Initialize the TX queue and infrastructure |
| 863 | * |
| 864 | * Make sure we reset the TX sequence to zero, as when this function |
| 865 | * is called, the firmware has been just restarted. |
| 866 | */ |
| 867 | int i2400m_tx_setup(struct i2400m *i2400m) |
| 868 | { |
| 869 | int result; |
| 870 | |
| 871 | /* Do this here only once -- can't do on |
| 872 | * i2400m_hard_start_xmit() as we'll cause race conditions if |
| 873 | * the WS was scheduled on another CPU */ |
| 874 | INIT_WORK(&i2400m->wake_tx_ws, i2400m_wake_tx_work); |
| 875 | |
| 876 | i2400m->tx_sequence = 0; |
| 877 | i2400m->tx_buf = kmalloc(I2400M_TX_BUF_SIZE, GFP_KERNEL); |
| 878 | if (i2400m->tx_buf == NULL) |
| 879 | result = -ENOMEM; |
| 880 | else |
| 881 | result = 0; |
| 882 | /* Huh? the bus layer has to define this... */ |
| 883 | BUG_ON(i2400m->bus_tx_block_size == 0); |
| 884 | return result; |
| 885 | |
| 886 | } |
| 887 | |
| 888 | |
| 889 | /** |
| 890 | * i2400m_tx_release - Tear down the TX queue and infrastructure |
| 891 | */ |
| 892 | void i2400m_tx_release(struct i2400m *i2400m) |
| 893 | { |
Inaky Perez-Gonzalez | 46c50147 | 2009-10-07 22:46:29 +0900 | [diff] [blame] | 894 | unsigned long flags; |
| 895 | spin_lock_irqsave(&i2400m->tx_lock, flags); |
Inaky Perez-Gonzalez | aa5a7ac | 2008-12-20 16:57:47 -0800 | [diff] [blame] | 896 | kfree(i2400m->tx_buf); |
Inaky Perez-Gonzalez | 46c50147 | 2009-10-07 22:46:29 +0900 | [diff] [blame] | 897 | i2400m->tx_buf = NULL; |
| 898 | spin_unlock_irqrestore(&i2400m->tx_lock, flags); |
Inaky Perez-Gonzalez | aa5a7ac | 2008-12-20 16:57:47 -0800 | [diff] [blame] | 899 | } |