1 /*
2 * Copyright (c) 2008, 2009, 2010 QLogic Corporation. All rights reserved.
3 *
4 * This software is available to you under a choice of one of two
5 * licenses. You may choose to be licensed under the terms of the GNU
6 * General Public License (GPL) Version 2, available from the file
7 * COPYING in the main directory of this source tree, or the
8 * OpenIB.org BSD license below:
9 *
10 * Redistribution and use in source and binary forms, with or
11 * without modification, are permitted provided that the following
12 * conditions are met:
13 *
14 * - Redistributions of source code must retain the above
15 * copyright notice, this list of conditions and the following
16 * disclaimer.
17 *
18 * - Redistributions in binary form must reproduce the above
19 * copyright notice, this list of conditions and the following
20 * disclaimer in the documentation and/or other materials
21 * provided with the distribution.
22 *
23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30 * SOFTWARE.
31 */
32
33 #include <linux/spinlock.h>
34 #include <linux/pci.h>
35 #include <linux/io.h>
36 #include <linux/delay.h>
37 #include <linux/netdevice.h>
38 #include <linux/vmalloc.h>
39 #include <linux/moduleparam.h>
40
41 #include "qib.h"
42
43 static unsigned qib_hol_timeout_ms = 3000;
44 module_param_named(hol_timeout_ms, qib_hol_timeout_ms, uint, S_IRUGO);
45 MODULE_PARM_DESC(hol_timeout_ms,
46 "duration of user app suspension after link failure");
47
48 unsigned qib_sdma_fetch_arb = 1;
49 module_param_named(fetch_arb, qib_sdma_fetch_arb, uint, S_IRUGO);
50 MODULE_PARM_DESC(fetch_arb, "IBA7220: change SDMA descriptor arbitration");
51
52 /**
53 * qib_disarm_piobufs - cancel a range of PIO buffers
54 * @dd: the qlogic_ib device
55 * @first: the first PIO buffer to cancel
56 * @cnt: the number of PIO buffers to cancel
57 *
58 * Cancel a range of PIO buffers. Used at user process close,
59 * in case it died while writing to a PIO buffer.
60 */
61 void qib_disarm_piobufs(struct qib_devdata *dd, unsigned first, unsigned cnt)
62 {
63 unsigned long flags;
64 unsigned i;
65 unsigned last;
66
67 last = first + cnt;
68 spin_lock_irqsave(&dd->pioavail_lock, flags);
69 for (i = first; i < last; i++) {
70 __clear_bit(i, dd->pio_need_disarm);
71 dd->f_sendctrl(dd->pport, QIB_SENDCTRL_DISARM_BUF(i));
72 }
73 spin_unlock_irqrestore(&dd->pioavail_lock, flags);
74 }
75
76 /*
77 * This is called by a user process when it sees the DISARM_BUFS event
78 * bit is set.
79 */
80 int qib_disarm_piobufs_ifneeded(struct qib_ctxtdata *rcd)
81 {
82 struct qib_devdata *dd = rcd->dd;
83 unsigned i;
84 unsigned last;
85 unsigned n = 0;
86
87 last = rcd->pio_base + rcd->piocnt;
88 /*
89 * Don't need uctxt_lock here, since user has called in to us.
90 * Clear at start in case more interrupts set bits while we
91 * are disarming
92 */
93 if (rcd->user_event_mask) {
94 /*
95 * subctxt_cnt is 0 if not shared, so do base
96 * separately, first, then remaining subctxt, if any
97 */
98 clear_bit(_QIB_EVENT_DISARM_BUFS_BIT, &rcd->user_event_mask[0]);
99 for (i = 1; i < rcd->subctxt_cnt; i++)
100 clear_bit(_QIB_EVENT_DISARM_BUFS_BIT,
101 &rcd->user_event_mask[i]);
102 }
103 spin_lock_irq(&dd->pioavail_lock);
104 for (i = rcd->pio_base; i < last; i++) {
105 if (__test_and_clear_bit(i, dd->pio_need_disarm)) {
106 n++;
107 dd->f_sendctrl(rcd->ppd, QIB_SENDCTRL_DISARM_BUF(i));
108 }
109 }
110 spin_unlock_irq(&dd->pioavail_lock);
111 return 0;
112 }
113
114 static struct qib_pportdata *is_sdma_buf(struct qib_devdata *dd, unsigned i)
115 {
116 struct qib_pportdata *ppd;
117 unsigned pidx;
118
119 for (pidx = 0; pidx < dd->num_pports; pidx++) {
120 ppd = dd->pport + pidx;
121 if (i >= ppd->sdma_state.first_sendbuf &&
122 i < ppd->sdma_state.last_sendbuf)
123 return ppd;
124 }
125 return NULL;
126 }
127
128 /*
129 * Return true if send buffer is being used by a user context.
130 * Sets _QIB_EVENT_DISARM_BUFS_BIT in user_event_mask as a side effect
131 */
132 static int find_ctxt(struct qib_devdata *dd, unsigned bufn)
133 {
134 struct qib_ctxtdata *rcd;
135 unsigned ctxt;
136 int ret = 0;
137
138 spin_lock(&dd->uctxt_lock);
139 for (ctxt = dd->first_user_ctxt; ctxt < dd->cfgctxts; ctxt++) {
140 rcd = dd->rcd[ctxt];
141 if (!rcd || bufn < rcd->pio_base ||
142 bufn >= rcd->pio_base + rcd->piocnt)
143 continue;
144 if (rcd->user_event_mask) {
145 int i;
146 /*
147 * subctxt_cnt is 0 if not shared, so do base
148 * separately, first, then remaining subctxt, if any
149 */
150 set_bit(_QIB_EVENT_DISARM_BUFS_BIT,
151 &rcd->user_event_mask[0]);
152 for (i = 1; i < rcd->subctxt_cnt; i++)
153 set_bit(_QIB_EVENT_DISARM_BUFS_BIT,
154 &rcd->user_event_mask[i]);
155 }
156 ret = 1;
157 break;
158 }
159 spin_unlock(&dd->uctxt_lock);
160
161 return ret;
162 }
163
164 /*
165 * Disarm a set of send buffers. If the buffer might be actively being
166 * written to, mark the buffer to be disarmed later when it is not being
167 * written to.
168 *
169 * This should only be called from the IRQ error handler.
170 */
171 void qib_disarm_piobufs_set(struct qib_devdata *dd, unsigned long *mask,
172 unsigned cnt)
173 {
174 struct qib_pportdata *ppd, *pppd[QIB_MAX_IB_PORTS];
175 unsigned i;
176 unsigned long flags;
177
178 for (i = 0; i < dd->num_pports; i++)
179 pppd[i] = NULL;
180
181 for (i = 0; i < cnt; i++) {
182 if (!test_bit(i, mask))
183 continue;
184 /*
185 * If the buffer is owned by the DMA hardware,
186 * reset the DMA engine.
187 */
188 ppd = is_sdma_buf(dd, i);
189 if (ppd) {
190 pppd[ppd->port] = ppd;
191 continue;
192 }
193 /*
194 * If the kernel is writing the buffer or the buffer is
195 * owned by a user process, we can't clear it yet.
196 */
197 spin_lock_irqsave(&dd->pioavail_lock, flags);
198 if (test_bit(i, dd->pio_writing) ||
199 (!test_bit(i << 1, dd->pioavailkernel) &&
200 find_ctxt(dd, i))) {
201 __set_bit(i, dd->pio_need_disarm);
202 } else {
203 dd->f_sendctrl(dd->pport, QIB_SENDCTRL_DISARM_BUF(i));
204 }
205 spin_unlock_irqrestore(&dd->pioavail_lock, flags);
206 }
207
208 /* do cancel_sends once per port that had sdma piobufs in error */
209 for (i = 0; i < dd->num_pports; i++)
210 if (pppd[i])
211 qib_cancel_sends(pppd[i]);
212 }
213
214 /**
215 * update_send_bufs - update shadow copy of the PIO availability map
216 * @dd: the qlogic_ib device
217 *
218 * called whenever our local copy indicates we have run out of send buffers
219 */
220 static void update_send_bufs(struct qib_devdata *dd)
221 {
222 unsigned long flags;
223 unsigned i;
224 const unsigned piobregs = dd->pioavregs;
225
226 /*
227 * If the generation (check) bits have changed, then we update the
228 * busy bit for the corresponding PIO buffer. This algorithm will
229 * modify positions to the value they already have in some cases
230 * (i.e., no change), but it's faster than changing only the bits
231 * that have changed.
232 *
233 * We would like to do this atomicly, to avoid spinlocks in the
234 * critical send path, but that's not really possible, given the
235 * type of changes, and that this routine could be called on
236 * multiple cpu's simultaneously, so we lock in this routine only,
237 * to avoid conflicting updates; all we change is the shadow, and
238 * it's a single 64 bit memory location, so by definition the update
239 * is atomic in terms of what other cpu's can see in testing the
240 * bits. The spin_lock overhead isn't too bad, since it only
241 * happens when all buffers are in use, so only cpu overhead, not
242 * latency or bandwidth is affected.
243 */
244 if (!dd->pioavailregs_dma)
245 return;
246 spin_lock_irqsave(&dd->pioavail_lock, flags);
247 for (i = 0; i < piobregs; i++) {
248 u64 pchbusy, pchg, piov, pnew;
249
250 piov = le64_to_cpu(dd->pioavailregs_dma[i]);
251 pchg = dd->pioavailkernel[i] &
252 ~(dd->pioavailshadow[i] ^ piov);
253 pchbusy = pchg << QLOGIC_IB_SENDPIOAVAIL_BUSY_SHIFT;
254 if (pchg && (pchbusy & dd->pioavailshadow[i])) {
255 pnew = dd->pioavailshadow[i] & ~pchbusy;
256 pnew |= piov & pchbusy;
257 dd->pioavailshadow[i] = pnew;
258 }
259 }
260 spin_unlock_irqrestore(&dd->pioavail_lock, flags);
261 }
262
263 /*
264 * Debugging code and stats updates if no pio buffers available.
265 */
266 static noinline void no_send_bufs(struct qib_devdata *dd)
267 {
268 dd->upd_pio_shadow = 1;
269
270 /* not atomic, but if we lose a stat count in a while, that's OK */
271 qib_stats.sps_nopiobufs++;
272 }
273
274 /*
275 * Common code for normal driver send buffer allocation, and reserved
276 * allocation.
277 *
278 * Do appropriate marking as busy, etc.
279 * Returns buffer pointer if one is found, otherwise NULL.
280 */
281 u32 __iomem *qib_getsendbuf_range(struct qib_devdata *dd, u32 *pbufnum,
282 u32 first, u32 last)
283 {
284 unsigned i, j, updated = 0;
285 unsigned nbufs;
286 unsigned long flags;
287 unsigned long *shadow = dd->pioavailshadow;
288 u32 __iomem *buf;
289
290 if (!(dd->flags & QIB_PRESENT))
291 return NULL;
292
293 nbufs = last - first + 1; /* number in range to check */
294 if (dd->upd_pio_shadow) {
295 update_shadow:
296 /*
297 * Minor optimization. If we had no buffers on last call,
298 * start out by doing the update; continue and do scan even
299 * if no buffers were updated, to be paranoid.
300 */
301 update_send_bufs(dd);
302 updated++;
303 }
304 i = first;
305 /*
306 * While test_and_set_bit() is atomic, we do that and then the
307 * change_bit(), and the pair is not. See if this is the cause
308 * of the remaining armlaunch errors.
309 */
310 spin_lock_irqsave(&dd->pioavail_lock, flags);
311 if (dd->last_pio >= first && dd->last_pio <= last)
312 i = dd->last_pio + 1;
313 if (!first)
314 /* adjust to min possible */
315 nbufs = last - dd->min_kernel_pio + 1;
316 for (j = 0; j < nbufs; j++, i++) {
317 if (i > last)
318 i = !first ? dd->min_kernel_pio : first;
319 if (__test_and_set_bit((2 * i) + 1, shadow))
320 continue;
321 /* flip generation bit */
322 __change_bit(2 * i, shadow);
323 /* remember that the buffer can be written to now */
324 __set_bit(i, dd->pio_writing);
325 if (!first && first != last) /* first == last on VL15, avoid */
326 dd->last_pio = i;
327 break;
328 }
329 spin_unlock_irqrestore(&dd->pioavail_lock, flags);
330
331 if (j == nbufs) {
332 if (!updated)
333 /*
334 * First time through; shadow exhausted, but may be
335 * buffers available, try an update and then rescan.
336 */
337 goto update_shadow;
338 no_send_bufs(dd);
339 buf = NULL;
340 } else {
341 if (i < dd->piobcnt2k)
342 buf = (u32 __iomem *)(dd->pio2kbase +
343 i * dd->palign);
344 else if (i < dd->piobcnt2k + dd->piobcnt4k || !dd->piovl15base)
345 buf = (u32 __iomem *)(dd->pio4kbase +
346 (i - dd->piobcnt2k) * dd->align4k);
347 else
348 buf = (u32 __iomem *)(dd->piovl15base +
349 (i - (dd->piobcnt2k + dd->piobcnt4k)) *
350 dd->align4k);
351 if (pbufnum)
352 *pbufnum = i;
353 dd->upd_pio_shadow = 0;
354 }
355
356 return buf;
357 }
358
359 /*
360 * Record that the caller is finished writing to the buffer so we don't
361 * disarm it while it is being written and disarm it now if needed.
362 */
363 void qib_sendbuf_done(struct qib_devdata *dd, unsigned n)
364 {
365 unsigned long flags;
366
367 spin_lock_irqsave(&dd->pioavail_lock, flags);
368 __clear_bit(n, dd->pio_writing);
369 if (__test_and_clear_bit(n, dd->pio_need_disarm))
370 dd->f_sendctrl(dd->pport, QIB_SENDCTRL_DISARM_BUF(n));
371 spin_unlock_irqrestore(&dd->pioavail_lock, flags);
372 }
373
374 /**
375 * qib_chg_pioavailkernel - change which send buffers are available for kernel
376 * @dd: the qlogic_ib device
377 * @start: the starting send buffer number
378 * @len: the number of send buffers
379 * @avail: true if the buffers are available for kernel use, false otherwise
380 */
381 void qib_chg_pioavailkernel(struct qib_devdata *dd, unsigned start,
382 unsigned len, u32 avail, struct qib_ctxtdata *rcd)
383 {
384 unsigned long flags;
385 unsigned end;
386 unsigned ostart = start;
387
388 /* There are two bits per send buffer (busy and generation) */
389 start *= 2;
390 end = start + len * 2;
391
392 spin_lock_irqsave(&dd->pioavail_lock, flags);
393 /* Set or clear the busy bit in the shadow. */
394 while (start < end) {
395 if (avail) {
396 unsigned long dma;
397 int i;
398
399 /*
400 * The BUSY bit will never be set, because we disarm
401 * the user buffers before we hand them back to the
402 * kernel. We do have to make sure the generation
403 * bit is set correctly in shadow, since it could
404 * have changed many times while allocated to user.
405 * We can't use the bitmap functions on the full
406 * dma array because it is always little-endian, so
407 * we have to flip to host-order first.
408 * BITS_PER_LONG is slightly wrong, since it's
409 * always 64 bits per register in chip...
410 * We only work on 64 bit kernels, so that's OK.
411 */
412 i = start / BITS_PER_LONG;
413 __clear_bit(QLOGIC_IB_SENDPIOAVAIL_BUSY_SHIFT + start,
414 dd->pioavailshadow);
415 dma = (unsigned long)
416 le64_to_cpu(dd->pioavailregs_dma[i]);
417 if (test_bit((QLOGIC_IB_SENDPIOAVAIL_CHECK_SHIFT +
418 start) % BITS_PER_LONG, &dma))
419 __set_bit(QLOGIC_IB_SENDPIOAVAIL_CHECK_SHIFT +
420 start, dd->pioavailshadow);
421 else
422 __clear_bit(QLOGIC_IB_SENDPIOAVAIL_CHECK_SHIFT
423 + start, dd->pioavailshadow);
424 __set_bit(start, dd->pioavailkernel);
425 if ((start >> 1) < dd->min_kernel_pio)
426 dd->min_kernel_pio = start >> 1;
427 } else {
428 __set_bit(start + QLOGIC_IB_SENDPIOAVAIL_BUSY_SHIFT,
429 dd->pioavailshadow);
430 __clear_bit(start, dd->pioavailkernel);
431 if ((start >> 1) > dd->min_kernel_pio)
432 dd->min_kernel_pio = start >> 1;
433 }
434 start += 2;
435 }
436
437 if (dd->min_kernel_pio > 0 && dd->last_pio < dd->min_kernel_pio - 1)
438 dd->last_pio = dd->min_kernel_pio - 1;
439 spin_unlock_irqrestore(&dd->pioavail_lock, flags);
440
441 dd->f_txchk_change(dd, ostart, len, avail, rcd);
442 }
443
444 /*
445 * Flush all sends that might be in the ready to send state, as well as any
446 * that are in the process of being sent. Used whenever we need to be
447 * sure the send side is idle. Cleans up all buffer state by canceling
448 * all pio buffers, and issuing an abort, which cleans up anything in the
449 * launch fifo. The cancel is superfluous on some chip versions, but
450 * it's safer to always do it.
451 * PIOAvail bits are updated by the chip as if a normal send had happened.
452 */
453 void qib_cancel_sends(struct qib_pportdata *ppd)
454 {
455 struct qib_devdata *dd = ppd->dd;
456 struct qib_ctxtdata *rcd;
457 unsigned long flags;
458 unsigned ctxt;
459 unsigned i;
460 unsigned last;
461
462 /*
463 * Tell PSM to disarm buffers again before trying to reuse them.
464 * We need to be sure the rcd doesn't change out from under us
465 * while we do so. We hold the two locks sequentially. We might
466 * needlessly set some need_disarm bits as a result, if the
467 * context is closed after we release the uctxt_lock, but that's
468 * fairly benign, and safer than nesting the locks.
469 */
470 for (ctxt = dd->first_user_ctxt; ctxt < dd->cfgctxts; ctxt++) {
471 spin_lock_irqsave(&dd->uctxt_lock, flags);
472 rcd = dd->rcd[ctxt];
473 if (rcd && rcd->ppd == ppd) {
474 last = rcd->pio_base + rcd->piocnt;
475 if (rcd->user_event_mask) {
476 /*
477 * subctxt_cnt is 0 if not shared, so do base
478 * separately, first, then remaining subctxt,
479 * if any
480 */
481 set_bit(_QIB_EVENT_DISARM_BUFS_BIT,
482 &rcd->user_event_mask[0]);
483 for (i = 1; i < rcd->subctxt_cnt; i++)
484 set_bit(_QIB_EVENT_DISARM_BUFS_BIT,
485 &rcd->user_event_mask[i]);
486 }
487 i = rcd->pio_base;
488 spin_unlock_irqrestore(&dd->uctxt_lock, flags);
489 spin_lock_irqsave(&dd->pioavail_lock, flags);
490 for (; i < last; i++)
491 __set_bit(i, dd->pio_need_disarm);
492 spin_unlock_irqrestore(&dd->pioavail_lock, flags);
493 } else
494 spin_unlock_irqrestore(&dd->uctxt_lock, flags);
495 }
496
497 if (!(dd->flags & QIB_HAS_SEND_DMA))
498 dd->f_sendctrl(ppd, QIB_SENDCTRL_DISARM_ALL |
499 QIB_SENDCTRL_FLUSH);
500 }
501
502 /*
503 * Force an update of in-memory copy of the pioavail registers, when
504 * needed for any of a variety of reasons.
505 * If already off, this routine is a nop, on the assumption that the
506 * caller (or set of callers) will "do the right thing".
507 * This is a per-device operation, so just the first port.
508 */
509 void qib_force_pio_avail_update(struct qib_devdata *dd)
510 {
511 dd->f_sendctrl(dd->pport, QIB_SENDCTRL_AVAIL_BLIP);
512 }
513
514 void qib_hol_down(struct qib_pportdata *ppd)
515 {
516 /*
517 * Cancel sends when the link goes DOWN so that we aren't doing it
518 * at INIT when we might be trying to send SMI packets.
519 */
520 if (!(ppd->lflags & QIBL_IB_AUTONEG_INPROG))
521 qib_cancel_sends(ppd);
522 }
523
524 /*
525 * Link is at INIT.
526 * We start the HoL timer so we can detect stuck packets blocking SMP replies.
527 * Timer may already be running, so use mod_timer, not add_timer.
528 */
529 void qib_hol_init(struct qib_pportdata *ppd)
530 {
531 if (ppd->hol_state != QIB_HOL_INIT) {
532 ppd->hol_state = QIB_HOL_INIT;
533 mod_timer(&ppd->hol_timer,
534 jiffies + msecs_to_jiffies(qib_hol_timeout_ms));
535 }
536 }
537
538 /*
539 * Link is up, continue any user processes, and ensure timer
540 * is a nop, if running. Let timer keep running, if set; it
541 * will nop when it sees the link is up.
542 */
543 void qib_hol_up(struct qib_pportdata *ppd)
544 {
545 ppd->hol_state = QIB_HOL_UP;
546 }
547
548 /*
549 * This is only called via the timer.
550 */
551 void qib_hol_event(struct timer_list *t)
552 {
553 struct qib_pportdata *ppd = from_timer(ppd, t, hol_timer);
554
555 /* If hardware error, etc, skip. */
556 if (!(ppd->dd->flags & QIB_INITTED))
557 return;
558
559 if (ppd->hol_state != QIB_HOL_UP) {
560 /*
561 * Try to flush sends in case a stuck packet is blocking
562 * SMP replies.
563 */
564 qib_hol_down(ppd);
565 mod_timer(&ppd->hol_timer,
566 jiffies + msecs_to_jiffies(qib_hol_timeout_ms));
567 }
568 }