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-rw-r--r--drivers/net/wimax/i2400m/rx.c534
-rw-r--r--drivers/net/wimax/i2400m/tx.c817
2 files changed, 1351 insertions, 0 deletions
diff --git a/drivers/net/wimax/i2400m/rx.c b/drivers/net/wimax/i2400m/rx.c
new file mode 100644
index 000000000000..6922022710ac
--- /dev/null
+++ b/drivers/net/wimax/i2400m/rx.c
@@ -0,0 +1,534 @@
1/*
2 * Intel Wireless WiMAX Connection 2400m
3 * Handle incoming traffic and deliver it to the control or data planes
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 * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
39 * - Use skb_clone(), break up processing in chunks
40 * - Split transport/device specific
41 * - Make buffer size dynamic to exert less memory pressure
42 *
43 *
44 * This handles the RX path.
45 *
46 * We receive an RX message from the bus-specific driver, which
47 * contains one or more payloads that have potentially different
48 * destinataries (data or control paths).
49 *
50 * So we just take that payload from the transport specific code in
51 * the form of an skb, break it up in chunks (a cloned skb each in the
52 * case of network packets) and pass it to netdev or to the
53 * command/ack handler (and from there to the WiMAX stack).
54 *
55 * PROTOCOL FORMAT
56 *
57 * The format of the buffer is:
58 *
59 * HEADER (struct i2400m_msg_hdr)
60 * PAYLOAD DESCRIPTOR 0 (struct i2400m_pld)
61 * PAYLOAD DESCRIPTOR 1
62 * ...
63 * PAYLOAD DESCRIPTOR N
64 * PAYLOAD 0 (raw bytes)
65 * PAYLOAD 1
66 * ...
67 * PAYLOAD N
68 *
69 * See tx.c for a deeper description on alignment requirements and
70 * other fun facts of it.
71 *
72 * ROADMAP
73 *
74 * i2400m_rx
75 * i2400m_rx_msg_hdr_check
76 * i2400m_rx_pl_descr_check
77 * i2400m_rx_payload
78 * i2400m_net_rx
79 * i2400m_rx_ctl
80 * i2400m_msg_size_check
81 * i2400m_report_hook_work [in a workqueue]
82 * i2400m_report_hook
83 * wimax_msg_to_user
84 * i2400m_rx_ctl_ack
85 * wimax_msg_to_user_alloc
86 * i2400m_rx_trace
87 * i2400m_msg_size_check
88 * wimax_msg
89 */
90#include <linux/kernel.h>
91#include <linux/if_arp.h>
92#include <linux/netdevice.h>
93#include <linux/workqueue.h>
94#include "i2400m.h"
95
96
97#define D_SUBMODULE rx
98#include "debug-levels.h"
99
100struct i2400m_report_hook_args {
101 struct sk_buff *skb_rx;
102 const struct i2400m_l3l4_hdr *l3l4_hdr;
103 size_t size;
104};
105
106
107/*
108 * Execute i2400m_report_hook in a workqueue
109 *
110 * Unpacks arguments from the deferred call, executes it and then
111 * drops the references.
112 *
113 * Obvious NOTE: References are needed because we are a separate
114 * thread; otherwise the buffer changes under us because it is
115 * released by the original caller.
116 */
117static
118void i2400m_report_hook_work(struct work_struct *ws)
119{
120 struct i2400m_work *iw =
121 container_of(ws, struct i2400m_work, ws);
122 struct i2400m_report_hook_args *args = (void *) iw->pl;
123 i2400m_report_hook(iw->i2400m, args->l3l4_hdr, args->size);
124 kfree_skb(args->skb_rx);
125 i2400m_put(iw->i2400m);
126 kfree(iw);
127}
128
129
130/*
131 * Process an ack to a command
132 *
133 * @i2400m: device descriptor
134 * @payload: pointer to message
135 * @size: size of the message
136 *
137 * Pass the acknodledgment (in an skb) to the thread that is waiting
138 * for it in i2400m->msg_completion.
139 *
140 * We need to coordinate properly with the thread waiting for the
141 * ack. Check if it is waiting or if it is gone. We loose the spinlock
142 * to avoid allocating on atomic contexts (yeah, could use GFP_ATOMIC,
143 * but this is not so speed critical).
144 */
145static
146void i2400m_rx_ctl_ack(struct i2400m *i2400m,
147 const void *payload, size_t size)
148{
149 struct device *dev = i2400m_dev(i2400m);
150 struct wimax_dev *wimax_dev = &i2400m->wimax_dev;
151 unsigned long flags;
152 struct sk_buff *ack_skb;
153
154 /* Anyone waiting for an answer? */
155 spin_lock_irqsave(&i2400m->rx_lock, flags);
156 if (i2400m->ack_skb != ERR_PTR(-EINPROGRESS)) {
157 dev_err(dev, "Huh? reply to command with no waiters\n");
158 goto error_no_waiter;
159 }
160 spin_unlock_irqrestore(&i2400m->rx_lock, flags);
161
162 ack_skb = wimax_msg_alloc(wimax_dev, NULL, payload, size, GFP_KERNEL);
163
164 /* Check waiter didn't time out waiting for the answer... */
165 spin_lock_irqsave(&i2400m->rx_lock, flags);
166 if (i2400m->ack_skb != ERR_PTR(-EINPROGRESS)) {
167 d_printf(1, dev, "Huh? waiter for command reply cancelled\n");
168 goto error_waiter_cancelled;
169 }
170 if (ack_skb == NULL) {
171 dev_err(dev, "CMD/GET/SET ack: cannot allocate SKB\n");
172 i2400m->ack_skb = ERR_PTR(-ENOMEM);
173 } else
174 i2400m->ack_skb = ack_skb;
175 spin_unlock_irqrestore(&i2400m->rx_lock, flags);
176 complete(&i2400m->msg_completion);
177 return;
178
179error_waiter_cancelled:
180 if (ack_skb)
181 kfree_skb(ack_skb);
182error_no_waiter:
183 spin_unlock_irqrestore(&i2400m->rx_lock, flags);
184 return;
185}
186
187
188/*
189 * Receive and process a control payload
190 *
191 * @i2400m: device descriptor
192 * @skb_rx: skb that contains the payload (for reference counting)
193 * @payload: pointer to message
194 * @size: size of the message
195 *
196 * There are two types of control RX messages: reports (asynchronous,
197 * like your every day interrupts) and 'acks' (reponses to a command,
198 * get or set request).
199 *
200 * If it is a report, we run hooks on it (to extract information for
201 * things we need to do in the driver) and then pass it over to the
202 * WiMAX stack to send it to user space.
203 *
204 * NOTE: report processing is done in a workqueue specific to the
205 * generic driver, to avoid deadlocks in the system.
206 *
207 * If it is not a report, it is an ack to a previously executed
208 * command, set or get, so wake up whoever is waiting for it from
209 * i2400m_msg_to_dev(). i2400m_rx_ctl_ack() takes care of that.
210 *
211 * Note that the sizes we pass to other functions from here are the
212 * sizes of the _l3l4_hdr + payload, not full buffer sizes, as we have
213 * verified in _msg_size_check() that they are congruent.
214 *
215 * For reports: We can't clone the original skb where the data is
216 * because we need to send this up via netlink; netlink has to add
217 * headers and we can't overwrite what's preceeding the payload...as
218 * it is another message. So we just dup them.
219 */
220static
221void i2400m_rx_ctl(struct i2400m *i2400m, struct sk_buff *skb_rx,
222 const void *payload, size_t size)
223{
224 int result;
225 struct device *dev = i2400m_dev(i2400m);
226 const struct i2400m_l3l4_hdr *l3l4_hdr = payload;
227 unsigned msg_type;
228
229 result = i2400m_msg_size_check(i2400m, l3l4_hdr, size);
230 if (result < 0) {
231 dev_err(dev, "HW BUG? device sent a bad message: %d\n",
232 result);
233 goto error_check;
234 }
235 msg_type = le16_to_cpu(l3l4_hdr->type);
236 d_printf(1, dev, "%s 0x%04x: %zu bytes\n",
237 msg_type & I2400M_MT_REPORT_MASK ? "REPORT" : "CMD/SET/GET",
238 msg_type, size);
239 d_dump(2, dev, l3l4_hdr, size);
240 if (msg_type & I2400M_MT_REPORT_MASK) {
241 /* These hooks have to be ran serialized; as well, the
242 * handling might force the execution of commands, and
243 * that might cause reentrancy issues with
244 * bus-specific subdrivers and workqueues. So we run
245 * it in a separate workqueue. */
246 struct i2400m_report_hook_args args = {
247 .skb_rx = skb_rx,
248 .l3l4_hdr = l3l4_hdr,
249 .size = size
250 };
251 if (unlikely(i2400m->ready == 0)) /* only send if up */
252 return;
253 skb_get(skb_rx);
254 i2400m_queue_work(i2400m, i2400m_report_hook_work,
255 GFP_KERNEL, &args, sizeof(args));
256 result = wimax_msg(&i2400m->wimax_dev, NULL, l3l4_hdr, size,
257 GFP_KERNEL);
258 if (result < 0)
259 dev_err(dev, "error sending report to userspace: %d\n",
260 result);
261 } else /* an ack to a CMD, GET or SET */
262 i2400m_rx_ctl_ack(i2400m, payload, size);
263error_check:
264 return;
265}
266
267
268
269
270/*
271 * Receive and send up a trace
272 *
273 * @i2400m: device descriptor
274 * @skb_rx: skb that contains the trace (for reference counting)
275 * @payload: pointer to trace message inside the skb
276 * @size: size of the message
277 *
278 * THe i2400m might produce trace information (diagnostics) and we
279 * send them through a different kernel-to-user pipe (to avoid
280 * clogging it).
281 *
282 * As in i2400m_rx_ctl(), we can't clone the original skb where the
283 * data is because we need to send this up via netlink; netlink has to
284 * add headers and we can't overwrite what's preceeding the
285 * payload...as it is another message. So we just dup them.
286 */
287static
288void i2400m_rx_trace(struct i2400m *i2400m,
289 const void *payload, size_t size)
290{
291 int result;
292 struct device *dev = i2400m_dev(i2400m);
293 struct wimax_dev *wimax_dev = &i2400m->wimax_dev;
294 const struct i2400m_l3l4_hdr *l3l4_hdr = payload;
295 unsigned msg_type;
296
297 result = i2400m_msg_size_check(i2400m, l3l4_hdr, size);
298 if (result < 0) {
299 dev_err(dev, "HW BUG? device sent a bad trace message: %d\n",
300 result);
301 goto error_check;
302 }
303 msg_type = le16_to_cpu(l3l4_hdr->type);
304 d_printf(1, dev, "Trace %s 0x%04x: %zu bytes\n",
305 msg_type & I2400M_MT_REPORT_MASK ? "REPORT" : "CMD/SET/GET",
306 msg_type, size);
307 d_dump(2, dev, l3l4_hdr, size);
308 if (unlikely(i2400m->ready == 0)) /* only send if up */
309 return;
310 result = wimax_msg(wimax_dev, "trace", l3l4_hdr, size, GFP_KERNEL);
311 if (result < 0)
312 dev_err(dev, "error sending trace to userspace: %d\n",
313 result);
314error_check:
315 return;
316}
317
318
319/*
320 * Act on a received payload
321 *
322 * @i2400m: device instance
323 * @skb_rx: skb where the transaction was received
324 * @single: 1 if there is only one payload, 0 otherwise
325 * @pld: payload descriptor
326 * @payload: payload data
327 *
328 * Upon reception of a payload, look at its guts in the payload
329 * descriptor and decide what to do with it.
330 */
331static
332void i2400m_rx_payload(struct i2400m *i2400m, struct sk_buff *skb_rx,
333 unsigned single, const struct i2400m_pld *pld,
334 const void *payload)
335{
336 struct device *dev = i2400m_dev(i2400m);
337 size_t pl_size = i2400m_pld_size(pld);
338 enum i2400m_pt pl_type = i2400m_pld_type(pld);
339
340 switch (pl_type) {
341 case I2400M_PT_DATA:
342 d_printf(3, dev, "RX: data payload %zu bytes\n", pl_size);
343 i2400m_net_rx(i2400m, skb_rx, single, payload, pl_size);
344 break;
345 case I2400M_PT_CTRL:
346 i2400m_rx_ctl(i2400m, skb_rx, payload, pl_size);
347 break;
348 case I2400M_PT_TRACE:
349 i2400m_rx_trace(i2400m, payload, pl_size);
350 break;
351 default: /* Anything else shouldn't come to the host */
352 if (printk_ratelimit())
353 dev_err(dev, "RX: HW BUG? unexpected payload type %u\n",
354 pl_type);
355 }
356}
357
358
359/*
360 * Check a received transaction's message header
361 *
362 * @i2400m: device descriptor
363 * @msg_hdr: message header
364 * @buf_size: size of the received buffer
365 *
366 * Check that the declarations done by a RX buffer message header are
367 * sane and consistent with the amount of data that was received.
368 */
369static
370int i2400m_rx_msg_hdr_check(struct i2400m *i2400m,
371 const struct i2400m_msg_hdr *msg_hdr,
372 size_t buf_size)
373{
374 int result = -EIO;
375 struct device *dev = i2400m_dev(i2400m);
376 if (buf_size < sizeof(*msg_hdr)) {
377 dev_err(dev, "RX: HW BUG? message with short header (%zu "
378 "vs %zu bytes expected)\n", buf_size, sizeof(*msg_hdr));
379 goto error;
380 }
381 if (msg_hdr->barker != cpu_to_le32(I2400M_D2H_MSG_BARKER)) {
382 dev_err(dev, "RX: HW BUG? message received with unknown "
383 "barker 0x%08x (buf_size %zu bytes)\n",
384 le32_to_cpu(msg_hdr->barker), buf_size);
385 goto error;
386 }
387 if (msg_hdr->num_pls == 0) {
388 dev_err(dev, "RX: HW BUG? zero payload packets in message\n");
389 goto error;
390 }
391 if (le16_to_cpu(msg_hdr->num_pls) > I2400M_MAX_PLS_IN_MSG) {
392 dev_err(dev, "RX: HW BUG? message contains more payload "
393 "than maximum; ignoring.\n");
394 goto error;
395 }
396 result = 0;
397error:
398 return result;
399}
400
401
402/*
403 * Check a payload descriptor against the received data
404 *
405 * @i2400m: device descriptor
406 * @pld: payload descriptor
407 * @pl_itr: offset (in bytes) in the received buffer the payload is
408 * located
409 * @buf_size: size of the received buffer
410 *
411 * Given a payload descriptor (part of a RX buffer), check it is sane
412 * and that the data it declares fits in the buffer.
413 */
414static
415int i2400m_rx_pl_descr_check(struct i2400m *i2400m,
416 const struct i2400m_pld *pld,
417 size_t pl_itr, size_t buf_size)
418{
419 int result = -EIO;
420 struct device *dev = i2400m_dev(i2400m);
421 size_t pl_size = i2400m_pld_size(pld);
422 enum i2400m_pt pl_type = i2400m_pld_type(pld);
423
424 if (pl_size > i2400m->bus_pl_size_max) {
425 dev_err(dev, "RX: HW BUG? payload @%zu: size %zu is "
426 "bigger than maximum %zu; ignoring message\n",
427 pl_itr, pl_size, i2400m->bus_pl_size_max);
428 goto error;
429 }
430 if (pl_itr + pl_size > buf_size) { /* enough? */
431 dev_err(dev, "RX: HW BUG? payload @%zu: size %zu "
432 "goes beyond the received buffer "
433 "size (%zu bytes); ignoring message\n",
434 pl_itr, pl_size, buf_size);
435 goto error;
436 }
437 if (pl_type >= I2400M_PT_ILLEGAL) {
438 dev_err(dev, "RX: HW BUG? illegal payload type %u; "
439 "ignoring message\n", pl_type);
440 goto error;
441 }
442 result = 0;
443error:
444 return result;
445}
446
447
448/**
449 * i2400m_rx - Receive a buffer of data from the device
450 *
451 * @i2400m: device descriptor
452 * @skb: skbuff where the data has been received
453 *
454 * Parse in a buffer of data that contains an RX message sent from the
455 * device. See the file header for the format. Run all checks on the
456 * buffer header, then run over each payload's descriptors, verify
457 * their consistency and act on each payload's contents. If
458 * everything is succesful, update the device's statistics.
459 *
460 * Note: You need to set the skb to contain only the length of the
461 * received buffer; for that, use skb_trim(skb, RECEIVED_SIZE).
462 *
463 * Returns:
464 *
465 * 0 if ok, < 0 errno on error
466 *
467 * If ok, this function owns now the skb and the caller DOESN'T have
468 * to run kfree_skb() on it. However, on error, the caller still owns
469 * the skb and it is responsible for releasing it.
470 */
471int i2400m_rx(struct i2400m *i2400m, struct sk_buff *skb)
472{
473 int i, result;
474 struct device *dev = i2400m_dev(i2400m);
475 const struct i2400m_msg_hdr *msg_hdr;
476 size_t pl_itr, pl_size, skb_len;
477 unsigned long flags;
478 unsigned num_pls;
479
480 skb_len = skb->len;
481 d_fnstart(4, dev, "(i2400m %p skb %p [size %zu])\n",
482 i2400m, skb, skb_len);
483 result = -EIO;
484 msg_hdr = (void *) skb->data;
485 result = i2400m_rx_msg_hdr_check(i2400m, msg_hdr, skb->len);
486 if (result < 0)
487 goto error_msg_hdr_check;
488 result = -EIO;
489 num_pls = le16_to_cpu(msg_hdr->num_pls);
490 pl_itr = sizeof(*msg_hdr) + /* Check payload descriptor(s) */
491 num_pls * sizeof(msg_hdr->pld[0]);
492 pl_itr = ALIGN(pl_itr, I2400M_PL_PAD);
493 if (pl_itr > skb->len) { /* got all the payload descriptors? */
494 dev_err(dev, "RX: HW BUG? message too short (%u bytes) for "
495 "%u payload descriptors (%zu each, total %zu)\n",
496 skb->len, num_pls, sizeof(msg_hdr->pld[0]), pl_itr);
497 goto error_pl_descr_short;
498 }
499 /* Walk each payload payload--check we really got it */
500 for (i = 0; i < num_pls; i++) {
501 /* work around old gcc warnings */
502 pl_size = i2400m_pld_size(&msg_hdr->pld[i]);
503 result = i2400m_rx_pl_descr_check(i2400m, &msg_hdr->pld[i],
504 pl_itr, skb->len);
505 if (result < 0)
506 goto error_pl_descr_check;
507 i2400m_rx_payload(i2400m, skb, num_pls == 1, &msg_hdr->pld[i],
508 skb->data + pl_itr);
509 pl_itr += ALIGN(pl_size, I2400M_PL_PAD);
510 cond_resched(); /* Don't monopolize */
511 }
512 kfree_skb(skb);
513 /* Update device statistics */
514 spin_lock_irqsave(&i2400m->rx_lock, flags);
515 i2400m->rx_pl_num += i;
516 if (i > i2400m->rx_pl_max)
517 i2400m->rx_pl_max = i;
518 if (i < i2400m->rx_pl_min)
519 i2400m->rx_pl_min = i;
520 i2400m->rx_num++;
521 i2400m->rx_size_acc += skb->len;
522 if (skb->len < i2400m->rx_size_min)
523 i2400m->rx_size_min = skb->len;
524 if (skb->len > i2400m->rx_size_max)
525 i2400m->rx_size_max = skb->len;
526 spin_unlock_irqrestore(&i2400m->rx_lock, flags);
527error_pl_descr_check:
528error_pl_descr_short:
529error_msg_hdr_check:
530 d_fnend(4, dev, "(i2400m %p skb %p [size %zu]) = %d\n",
531 i2400m, skb, skb_len, result);
532 return result;
533}
534EXPORT_SYMBOL_GPL(i2400m_rx);
diff --git a/drivers/net/wimax/i2400m/tx.c b/drivers/net/wimax/i2400m/tx.c
new file mode 100644
index 000000000000..613a88ffd651
--- /dev/null
+++ b/drivers/net/wimax/i2400m/tx.c
@@ -0,0 +1,817 @@
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>
247#include "i2400m.h"
248
249
250#define D_SUBMODULE tx
251#include "debug-levels.h"
252
253enum {
254 /**
255 * TX Buffer size
256 *
257 * Doc says maximum transaction is 16KiB. If we had 16KiB en
258 * route and 16KiB being queued, it boils down to needing
259 * 32KiB.
260 */
261 I2400M_TX_BUF_SIZE = 32768,
262 /**
263 * Message header and payload descriptors have to be 16
264 * aligned (16 + 4 * N = 16 * M). If we take that average sent
265 * packets are MTU size (~1400-~1500) it follows that we could
266 * fit at most 10-11 payloads in one transaction. To meet the
267 * alignment requirement, that means we need to leave space
268 * for 12 (64 bytes). To simplify, we leave space for that. If
269 * at the end there are less, we pad up to the nearest
270 * multiple of 16.
271 */
272 I2400M_TX_PLD_MAX = 12,
273 I2400M_TX_PLD_SIZE = sizeof(struct i2400m_msg_hdr)
274 + I2400M_TX_PLD_MAX * sizeof(struct i2400m_pld),
275 I2400M_TX_SKIP = 0x80000000,
276};
277
278#define TAIL_FULL ((void *)~(unsigned long)NULL)
279
280/*
281 * Allocate @size bytes in the TX fifo, return a pointer to it
282 *
283 * @i2400m: device descriptor
284 * @size: size of the buffer we need to allocate
285 * @padding: ensure that there is at least this many bytes of free
286 * contiguous space in the fifo. This is needed because later on
287 * we might need to add padding.
288 *
289 * Returns:
290 *
291 * Pointer to the allocated space. NULL if there is no
292 * space. TAIL_FULL if there is no space at the tail but there is at
293 * the head (Case B below).
294 *
295 * These are the two basic cases we need to keep an eye for -- it is
296 * much better explained in linux/kernel/kfifo.c, but this code
297 * basically does the same. No rocket science here.
298 *
299 * Case A Case B
300 * N ___________ ___________
301 * | tail room | | data |
302 * | | | |
303 * |<- IN ->| |<- OUT ->|
304 * | | | |
305 * | data | | room |
306 * | | | |
307 * |<- OUT ->| |<- IN ->|
308 * | | | |
309 * | head room | | data |
310 * 0 ----------- -----------
311 *
312 * We allocate only *contiguous* space.
313 *
314 * We can allocate only from 'room'. In Case B, it is simple; in case
315 * A, we only try from the tail room; if it is not enough, we just
316 * fail and return TAIL_FULL and let the caller figure out if we wants to
317 * skip the tail room and try to allocate from the head.
318 *
319 * Note:
320 *
321 * Assumes i2400m->tx_lock is taken, and we use that as a barrier
322 *
323 * The indexes keep increasing and we reset them to zero when we
324 * pop data off the queue
325 */
326static
327void *i2400m_tx_fifo_push(struct i2400m *i2400m, size_t size, size_t padding)
328{
329 struct device *dev = i2400m_dev(i2400m);
330 size_t room, tail_room, needed_size;
331 void *ptr;
332
333 needed_size = size + padding;
334 room = I2400M_TX_BUF_SIZE - (i2400m->tx_in - i2400m->tx_out);
335 if (room < needed_size) { /* this takes care of Case B */
336 d_printf(2, dev, "fifo push %zu/%zu: no space\n",
337 size, padding);
338 return NULL;
339 }
340 /* Is there space at the tail? */
341 tail_room = I2400M_TX_BUF_SIZE - i2400m->tx_in % I2400M_TX_BUF_SIZE;
342 if (tail_room < needed_size) {
343 if (i2400m->tx_out % I2400M_TX_BUF_SIZE
344 < i2400m->tx_in % I2400M_TX_BUF_SIZE) {
345 d_printf(2, dev, "fifo push %zu/%zu: tail full\n",
346 size, padding);
347 return TAIL_FULL; /* There might be head space */
348 } else {
349 d_printf(2, dev, "fifo push %zu/%zu: no head space\n",
350 size, padding);
351 return NULL; /* There is no space */
352 }
353 }
354 ptr = i2400m->tx_buf + i2400m->tx_in % I2400M_TX_BUF_SIZE;
355 d_printf(2, dev, "fifo push %zu/%zu: at @%zu\n", size, padding,
356 i2400m->tx_in % I2400M_TX_BUF_SIZE);
357 i2400m->tx_in += size;
358 return ptr;
359}
360
361
362/*
363 * Mark the tail of the FIFO buffer as 'to-skip'
364 *
365 * We should never hit the BUG_ON() because all the sizes we push to
366 * the FIFO are padded to be a multiple of 16 -- the size of *msg
367 * (I2400M_PL_PAD for the payloads, I2400M_TX_PLD_SIZE for the
368 * header).
369 *
370 * Note:
371 *
372 * Assumes i2400m->tx_lock is taken, and we use that as a barrier
373 */
374static
375void i2400m_tx_skip_tail(struct i2400m *i2400m)
376{
377 struct device *dev = i2400m_dev(i2400m);
378 size_t tx_in = i2400m->tx_in % I2400M_TX_BUF_SIZE;
379 size_t tail_room = I2400M_TX_BUF_SIZE - tx_in;
380 struct i2400m_msg_hdr *msg = i2400m->tx_buf + tx_in;
381 BUG_ON(tail_room < sizeof(*msg));
382 msg->size = tail_room | I2400M_TX_SKIP;
383 d_printf(2, dev, "skip tail: skipping %zu bytes @%zu\n",
384 tail_room, tx_in);
385 i2400m->tx_in += tail_room;
386}
387
388
389/*
390 * Check if a skb will fit in the TX queue's current active TX
391 * message (if there are still descriptors left unused).
392 *
393 * Returns:
394 * 0 if the message won't fit, 1 if it will.
395 *
396 * Note:
397 *
398 * Assumes a TX message is active (i2400m->tx_msg).
399 *
400 * Assumes i2400m->tx_lock is taken, and we use that as a barrier
401 */
402static
403unsigned i2400m_tx_fits(struct i2400m *i2400m)
404{
405 struct i2400m_msg_hdr *msg_hdr = i2400m->tx_msg;
406 return le16_to_cpu(msg_hdr->num_pls) < I2400M_TX_PLD_MAX;
407
408}
409
410
411/*
412 * Start a new TX message header in the queue.
413 *
414 * Reserve memory from the base FIFO engine and then just initialize
415 * the message header.
416 *
417 * We allocate the biggest TX message header we might need (one that'd
418 * fit I2400M_TX_PLD_MAX payloads) -- when it is closed it will be
419 * 'ironed it out' and the unneeded parts removed.
420 *
421 * NOTE:
422 *
423 * Assumes that the previous message is CLOSED (eg: either
424 * there was none or 'i2400m_tx_close()' was called on it).
425 *
426 * Assumes i2400m->tx_lock is taken, and we use that as a barrier
427 */
428static
429void i2400m_tx_new(struct i2400m *i2400m)
430{
431 struct device *dev = i2400m_dev(i2400m);
432 struct i2400m_msg_hdr *tx_msg;
433 BUG_ON(i2400m->tx_msg != NULL);
434try_head:
435 tx_msg = i2400m_tx_fifo_push(i2400m, I2400M_TX_PLD_SIZE, 0);
436 if (tx_msg == NULL)
437 goto out;
438 else if (tx_msg == TAIL_FULL) {
439 i2400m_tx_skip_tail(i2400m);
440 d_printf(2, dev, "new TX message: tail full, trying head\n");
441 goto try_head;
442 }
443 memset(tx_msg, 0, I2400M_TX_PLD_SIZE);
444 tx_msg->size = I2400M_TX_PLD_SIZE;
445out:
446 i2400m->tx_msg = tx_msg;
447 d_printf(2, dev, "new TX message: %p @%zu\n",
448 tx_msg, (void *) tx_msg - i2400m->tx_buf);
449}
450
451
452/*
453 * Finalize the current TX message header
454 *
455 * Sets the message header to be at the proper location depending on
456 * how many descriptors we have (check documentation at the file's
457 * header for more info on that).
458 *
459 * Appends padding bytes to make sure the whole TX message (counting
460 * from the 'relocated' message header) is aligned to
461 * tx_block_size. We assume the _append() code has left enough space
462 * in the FIFO for that. If there are no payloads, just pass, as it
463 * won't be transferred.
464 *
465 * The amount of padding bytes depends on how many payloads are in the
466 * TX message, as the "msg header and payload descriptors" will be
467 * shifted up in the buffer.
468 */
469static
470void i2400m_tx_close(struct i2400m *i2400m)
471{
472 struct device *dev = i2400m_dev(i2400m);
473 struct i2400m_msg_hdr *tx_msg = i2400m->tx_msg;
474 struct i2400m_msg_hdr *tx_msg_moved;
475 size_t aligned_size, padding, hdr_size;
476 void *pad_buf;
477
478 if (tx_msg->size & I2400M_TX_SKIP) /* a skipper? nothing to do */
479 goto out;
480
481 /* Relocate the message header
482 *
483 * Find the current header size, align it to 16 and if we need
484 * to move it so the tail is next to the payloads, move it and
485 * set the offset.
486 *
487 * If it moved, this header is good only for transmission; the
488 * original one (it is kept if we moved) is still used to
489 * figure out where the next TX message starts (and where the
490 * offset to the moved header is).
491 */
492 hdr_size = sizeof(*tx_msg)
493 + le16_to_cpu(tx_msg->num_pls) * sizeof(tx_msg->pld[0]);
494 hdr_size = ALIGN(hdr_size, I2400M_PL_PAD);
495 tx_msg->offset = I2400M_TX_PLD_SIZE - hdr_size;
496 tx_msg_moved = (void *) tx_msg + tx_msg->offset;
497 memmove(tx_msg_moved, tx_msg, hdr_size);
498 tx_msg_moved->size -= tx_msg->offset;
499 /*
500 * Now figure out how much we have to add to the (moved!)
501 * message so the size is a multiple of i2400m->bus_tx_block_size.
502 */
503 aligned_size = ALIGN(tx_msg_moved->size, i2400m->bus_tx_block_size);
504 padding = aligned_size - tx_msg_moved->size;
505 if (padding > 0) {
506 pad_buf = i2400m_tx_fifo_push(i2400m, padding, 0);
507 if (unlikely(WARN_ON(pad_buf == NULL
508 || pad_buf == TAIL_FULL))) {
509 /* This should not happen -- append should verify
510 * there is always space left at least to append
511 * tx_block_size */
512 dev_err(dev,
513 "SW BUG! Possible data leakage from memory the "
514 "device should not read for padding - "
515 "size %lu aligned_size %zu tx_buf %p in "
516 "%zu out %zu\n",
517 (unsigned long) tx_msg_moved->size,
518 aligned_size, i2400m->tx_buf, i2400m->tx_in,
519 i2400m->tx_out);
520 } else
521 memset(pad_buf, 0xad, padding);
522 }
523 tx_msg_moved->padding = cpu_to_le16(padding);
524 tx_msg_moved->size += padding;
525 if (tx_msg != tx_msg_moved)
526 tx_msg->size += padding;
527out:
528 i2400m->tx_msg = NULL;
529}
530
531
532/**
533 * i2400m_tx - send the data in a buffer to the device
534 *
535 * @buf: pointer to the buffer to transmit
536 *
537 * @buf_len: buffer size
538 *
539 * @pl_type: type of the payload we are sending.
540 *
541 * Returns:
542 * 0 if ok, < 0 errno code on error (-ENOSPC, if there is no more
543 * room for the message in the queue).
544 *
545 * Appends the buffer to the TX FIFO and notifies the bus-specific
546 * part of the driver that there is new data ready to transmit.
547 * Once this function returns, the buffer has been copied, so it can
548 * be reused.
549 *
550 * The steps followed to append are explained in detail in the file
551 * header.
552 *
553 * Whenever we write to a message, we increase msg->size, so it
554 * reflects exactly how big the message is. This is needed so that if
555 * we concatenate two messages before they can be sent, the code that
556 * sends the messages can find the boundaries (and it will replace the
557 * size with the real barker before sending).
558 *
559 * Note:
560 *
561 * Cold and warm reset payloads need to be sent as a single
562 * payload, so we handle that.
563 */
564int i2400m_tx(struct i2400m *i2400m, const void *buf, size_t buf_len,
565 enum i2400m_pt pl_type)
566{
567 int result = -ENOSPC;
568 struct device *dev = i2400m_dev(i2400m);
569 unsigned long flags;
570 size_t padded_len;
571 void *ptr;
572 unsigned is_singleton = pl_type == I2400M_PT_RESET_WARM
573 || pl_type == I2400M_PT_RESET_COLD;
574
575 d_fnstart(3, dev, "(i2400m %p skb %p [%zu bytes] pt %u)\n",
576 i2400m, buf, buf_len, pl_type);
577 padded_len = ALIGN(buf_len, I2400M_PL_PAD);
578 d_printf(5, dev, "padded_len %zd buf_len %zd\n", padded_len, buf_len);
579 /* If there is no current TX message, create one; if the
580 * current one is out of payload slots or we have a singleton,
581 * close it and start a new one */
582 spin_lock_irqsave(&i2400m->tx_lock, flags);
583try_new:
584 if (unlikely(i2400m->tx_msg == NULL))
585 i2400m_tx_new(i2400m);
586 else if (unlikely(!i2400m_tx_fits(i2400m)
587 || (is_singleton && i2400m->tx_msg->num_pls != 0))) {
588 d_printf(2, dev, "closing TX message (fits %u singleton "
589 "%u num_pls %u)\n", i2400m_tx_fits(i2400m),
590 is_singleton, i2400m->tx_msg->num_pls);
591 i2400m_tx_close(i2400m);
592 i2400m_tx_new(i2400m);
593 }
594 if (i2400m->tx_msg->size + padded_len > I2400M_TX_BUF_SIZE / 2) {
595 d_printf(2, dev, "TX: message too big, going new\n");
596 i2400m_tx_close(i2400m);
597 i2400m_tx_new(i2400m);
598 }
599 if (i2400m->tx_msg == NULL)
600 goto error_tx_new;
601 /* So we have a current message header; now append space for
602 * the message -- if there is not enough, try the head */
603 ptr = i2400m_tx_fifo_push(i2400m, padded_len,
604 i2400m->bus_tx_block_size);
605 if (ptr == TAIL_FULL) { /* Tail is full, try head */
606 d_printf(2, dev, "pl append: tail full\n");
607 i2400m_tx_close(i2400m);
608 i2400m_tx_skip_tail(i2400m);
609 goto try_new;
610 } else if (ptr == NULL) { /* All full */
611 result = -ENOSPC;
612 d_printf(2, dev, "pl append: all full\n");
613 } else { /* Got space, copy it, set padding */
614 struct i2400m_msg_hdr *tx_msg = i2400m->tx_msg;
615 unsigned num_pls = le16_to_cpu(tx_msg->num_pls);
616 memcpy(ptr, buf, buf_len);
617 memset(ptr + buf_len, 0xad, padded_len - buf_len);
618 i2400m_pld_set(&tx_msg->pld[num_pls], buf_len, pl_type);
619 d_printf(3, dev, "pld 0x%08x (type 0x%1x len 0x%04zx\n",
620 le32_to_cpu(tx_msg->pld[num_pls].val),
621 pl_type, buf_len);
622 tx_msg->num_pls = le16_to_cpu(num_pls+1);
623 tx_msg->size += padded_len;
624 d_printf(2, dev, "TX: appended %zu b (up to %u b) pl #%u \n",
625 padded_len, tx_msg->size, num_pls+1);
626 d_printf(2, dev,
627 "TX: appended hdr @%zu %zu b pl #%u @%zu %zu/%zu b\n",
628 (void *)tx_msg - i2400m->tx_buf, (size_t)tx_msg->size,
629 num_pls+1, ptr - i2400m->tx_buf, buf_len, padded_len);
630 result = 0;
631 if (is_singleton)
632 i2400m_tx_close(i2400m);
633 }
634error_tx_new:
635 spin_unlock_irqrestore(&i2400m->tx_lock, flags);
636 i2400m->bus_tx_kick(i2400m); /* always kick, might free up space */
637 d_fnend(3, dev, "(i2400m %p skb %p [%zu bytes] pt %u) = %d\n",
638 i2400m, buf, buf_len, pl_type, result);
639 return result;
640}
641EXPORT_SYMBOL_GPL(i2400m_tx);
642
643
644/**
645 * i2400m_tx_msg_get - Get the first TX message in the FIFO to start sending it
646 *
647 * @i2400m: device descriptors
648 * @bus_size: where to place the size of the TX message
649 *
650 * Called by the bus-specific driver to get the first TX message at
651 * the FIF that is ready for transmission.
652 *
653 * It sets the state in @i2400m to indicate the bus-specific driver is
654 * transfering that message (i2400m->tx_msg_size).
655 *
656 * Once the transfer is completed, call i2400m_tx_msg_sent().
657 *
658 * Notes:
659 *
660 * The size of the TX message to be transmitted might be smaller than
661 * that of the TX message in the FIFO (in case the header was
662 * shorter). Hence, we copy it in @bus_size, for the bus layer to
663 * use. We keep the message's size in i2400m->tx_msg_size so that
664 * when the bus later is done transferring we know how much to
665 * advance the fifo.
666 *
667 * We collect statistics here as all the data is available and we
668 * assume it is going to work [see i2400m_tx_msg_sent()].
669 */
670struct i2400m_msg_hdr *i2400m_tx_msg_get(struct i2400m *i2400m,
671 size_t *bus_size)
672{
673 struct device *dev = i2400m_dev(i2400m);
674 struct i2400m_msg_hdr *tx_msg, *tx_msg_moved;
675 unsigned long flags, pls;
676
677 d_fnstart(3, dev, "(i2400m %p bus_size %p)\n", i2400m, bus_size);
678 spin_lock_irqsave(&i2400m->tx_lock, flags);
679skip:
680 tx_msg_moved = NULL;
681 if (i2400m->tx_in == i2400m->tx_out) { /* Empty FIFO? */
682 i2400m->tx_in = 0;
683 i2400m->tx_out = 0;
684 d_printf(2, dev, "TX: FIFO empty: resetting\n");
685 goto out_unlock;
686 }
687 tx_msg = i2400m->tx_buf + i2400m->tx_out % I2400M_TX_BUF_SIZE;
688 if (tx_msg->size & I2400M_TX_SKIP) { /* skip? */
689 d_printf(2, dev, "TX: skip: msg @%zu (%zu b)\n",
690 i2400m->tx_out % I2400M_TX_BUF_SIZE,
691 (size_t) tx_msg->size & ~I2400M_TX_SKIP);
692 i2400m->tx_out += tx_msg->size & ~I2400M_TX_SKIP;
693 goto skip;
694 }
695
696 if (tx_msg->num_pls == 0) { /* No payloads? */
697 if (tx_msg == i2400m->tx_msg) { /* open, we are done */
698 d_printf(2, dev,
699 "TX: FIFO empty: open msg w/o payloads @%zu\n",
700 (void *) tx_msg - i2400m->tx_buf);
701 tx_msg = NULL;
702 goto out_unlock;
703 } else { /* closed, skip it */
704 d_printf(2, dev,
705 "TX: skip msg w/o payloads @%zu (%zu b)\n",
706 (void *) tx_msg - i2400m->tx_buf,
707 (size_t) tx_msg->size);
708 i2400m->tx_out += tx_msg->size & ~I2400M_TX_SKIP;
709 goto skip;
710 }
711 }
712 if (tx_msg == i2400m->tx_msg) /* open msg? */
713 i2400m_tx_close(i2400m);
714
715 /* Now we have a valid TX message (with payloads) to TX */
716 tx_msg_moved = (void *) tx_msg + tx_msg->offset;
717 i2400m->tx_msg_size = tx_msg->size;
718 *bus_size = tx_msg_moved->size;
719 d_printf(2, dev, "TX: pid %d msg hdr at @%zu offset +@%zu "
720 "size %zu bus_size %zu\n",
721 current->pid, (void *) tx_msg - i2400m->tx_buf,
722 (size_t) tx_msg->offset, (size_t) tx_msg->size,
723 (size_t) tx_msg_moved->size);
724 tx_msg_moved->barker = le32_to_cpu(I2400M_H2D_PREVIEW_BARKER);
725 tx_msg_moved->sequence = le32_to_cpu(i2400m->tx_sequence++);
726
727 pls = le32_to_cpu(tx_msg_moved->num_pls);
728 i2400m->tx_pl_num += pls; /* Update stats */
729 if (pls > i2400m->tx_pl_max)
730 i2400m->tx_pl_max = pls;
731 if (pls < i2400m->tx_pl_min)
732 i2400m->tx_pl_min = pls;
733 i2400m->tx_num++;
734 i2400m->tx_size_acc += *bus_size;
735 if (*bus_size < i2400m->tx_size_min)
736 i2400m->tx_size_min = *bus_size;
737 if (*bus_size > i2400m->tx_size_max)
738 i2400m->tx_size_max = *bus_size;
739out_unlock:
740 spin_unlock_irqrestore(&i2400m->tx_lock, flags);
741 d_fnstart(3, dev, "(i2400m %p bus_size %p [%zu]) = %p\n",
742 i2400m, bus_size, *bus_size, tx_msg_moved);
743 return tx_msg_moved;
744}
745EXPORT_SYMBOL_GPL(i2400m_tx_msg_get);
746
747
748/**
749 * i2400m_tx_msg_sent - indicate the transmission of a TX message
750 *
751 * @i2400m: device descriptor
752 *
753 * Called by the bus-specific driver when a message has been sent;
754 * this pops it from the FIFO; and as there is space, start the queue
755 * in case it was stopped.
756 *
757 * Should be called even if the message send failed and we are
758 * dropping this TX message.
759 */
760void i2400m_tx_msg_sent(struct i2400m *i2400m)
761{
762 unsigned n;
763 unsigned long flags;
764 struct device *dev = i2400m_dev(i2400m);
765
766 d_fnstart(3, dev, "(i2400m %p)\n", i2400m);
767 spin_lock_irqsave(&i2400m->tx_lock, flags);
768 i2400m->tx_out += i2400m->tx_msg_size;
769 d_printf(2, dev, "TX: sent %zu b\n", (size_t) i2400m->tx_msg_size);
770 i2400m->tx_msg_size = 0;
771 BUG_ON(i2400m->tx_out > i2400m->tx_in);
772 /* level them FIFO markers off */
773 n = i2400m->tx_out / I2400M_TX_BUF_SIZE;
774 i2400m->tx_out %= I2400M_TX_BUF_SIZE;
775 i2400m->tx_in -= n * I2400M_TX_BUF_SIZE;
776 netif_start_queue(i2400m->wimax_dev.net_dev);
777 spin_unlock_irqrestore(&i2400m->tx_lock, flags);
778 d_fnend(3, dev, "(i2400m %p) = void\n", i2400m);
779}
780EXPORT_SYMBOL_GPL(i2400m_tx_msg_sent);
781
782
783/**
784 * i2400m_tx_setup - Initialize the TX queue and infrastructure
785 *
786 * Make sure we reset the TX sequence to zero, as when this function
787 * is called, the firmware has been just restarted.
788 */
789int i2400m_tx_setup(struct i2400m *i2400m)
790{
791 int result;
792
793 /* Do this here only once -- can't do on
794 * i2400m_hard_start_xmit() as we'll cause race conditions if
795 * the WS was scheduled on another CPU */
796 INIT_WORK(&i2400m->wake_tx_ws, i2400m_wake_tx_work);
797
798 i2400m->tx_sequence = 0;
799 i2400m->tx_buf = kmalloc(I2400M_TX_BUF_SIZE, GFP_KERNEL);
800 if (i2400m->tx_buf == NULL)
801 result = -ENOMEM;
802 else
803 result = 0;
804 /* Huh? the bus layer has to define this... */
805 BUG_ON(i2400m->bus_tx_block_size == 0);
806 return result;
807
808}
809
810
811/**
812 * i2400m_tx_release - Tear down the TX queue and infrastructure
813 */
814void i2400m_tx_release(struct i2400m *i2400m)
815{
816 kfree(i2400m->tx_buf);
817}
generated by cgit v1.2.2 (git 2.25.0) at 2025-01-04 03:54:38 -0500