Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma
[linux-2.6-microblaze.git] / drivers / infiniband / hw / qib / qib_sdma.c
1 /*
2  * Copyright (c) 2012 Intel Corporation. All rights reserved.
3  * Copyright (c) 2007 - 2012 QLogic Corporation. All rights reserved.
4  *
5  * This software is available to you under a choice of one of two
6  * licenses.  You may choose to be licensed under the terms of the GNU
7  * General Public License (GPL) Version 2, available from the file
8  * COPYING in the main directory of this source tree, or the
9  * OpenIB.org BSD license below:
10  *
11  *     Redistribution and use in source and binary forms, with or
12  *     without modification, are permitted provided that the following
13  *     conditions are met:
14  *
15  *      - Redistributions of source code must retain the above
16  *        copyright notice, this list of conditions and the following
17  *        disclaimer.
18  *
19  *      - Redistributions in binary form must reproduce the above
20  *        copyright notice, this list of conditions and the following
21  *        disclaimer in the documentation and/or other materials
22  *        provided with the distribution.
23  *
24  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
25  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
26  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
27  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
28  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
29  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
30  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
31  * SOFTWARE.
32  */
33
34 #include <linux/spinlock.h>
35 #include <linux/netdevice.h>
36 #include <linux/moduleparam.h>
37
38 #include "qib.h"
39 #include "qib_common.h"
40
41 /* default pio off, sdma on */
42 static ushort sdma_descq_cnt = 256;
43 module_param_named(sdma_descq_cnt, sdma_descq_cnt, ushort, S_IRUGO);
44 MODULE_PARM_DESC(sdma_descq_cnt, "Number of SDMA descq entries");
45
46 /*
47  * Bits defined in the send DMA descriptor.
48  */
49 #define SDMA_DESC_LAST          (1ULL << 11)
50 #define SDMA_DESC_FIRST         (1ULL << 12)
51 #define SDMA_DESC_DMA_HEAD      (1ULL << 13)
52 #define SDMA_DESC_USE_LARGE_BUF (1ULL << 14)
53 #define SDMA_DESC_INTR          (1ULL << 15)
54 #define SDMA_DESC_COUNT_LSB     16
55 #define SDMA_DESC_GEN_LSB       30
56
57 /* declare all statics here rather than keep sorting */
58 static int alloc_sdma(struct qib_pportdata *);
59 static void sdma_complete(struct kref *);
60 static void sdma_finalput(struct qib_sdma_state *);
61 static void sdma_get(struct qib_sdma_state *);
62 static void sdma_put(struct qib_sdma_state *);
63 static void sdma_set_state(struct qib_pportdata *, enum qib_sdma_states);
64 static void sdma_start_sw_clean_up(struct qib_pportdata *);
65 static void sdma_sw_clean_up_task(struct tasklet_struct *);
66 static void unmap_desc(struct qib_pportdata *, unsigned);
67
68 static void sdma_get(struct qib_sdma_state *ss)
69 {
70         kref_get(&ss->kref);
71 }
72
73 static void sdma_complete(struct kref *kref)
74 {
75         struct qib_sdma_state *ss =
76                 container_of(kref, struct qib_sdma_state, kref);
77
78         complete(&ss->comp);
79 }
80
81 static void sdma_put(struct qib_sdma_state *ss)
82 {
83         kref_put(&ss->kref, sdma_complete);
84 }
85
86 static void sdma_finalput(struct qib_sdma_state *ss)
87 {
88         sdma_put(ss);
89         wait_for_completion(&ss->comp);
90 }
91
92 /*
93  * Complete all the sdma requests on the active list, in the correct
94  * order, and with appropriate processing.   Called when cleaning up
95  * after sdma shutdown, and when new sdma requests are submitted for
96  * a link that is down.   This matches what is done for requests
97  * that complete normally, it's just the full list.
98  *
99  * Must be called with sdma_lock held
100  */
101 static void clear_sdma_activelist(struct qib_pportdata *ppd)
102 {
103         struct qib_sdma_txreq *txp, *txp_next;
104
105         list_for_each_entry_safe(txp, txp_next, &ppd->sdma_activelist, list) {
106                 list_del_init(&txp->list);
107                 if (txp->flags & QIB_SDMA_TXREQ_F_FREEDESC) {
108                         unsigned idx;
109
110                         idx = txp->start_idx;
111                         while (idx != txp->next_descq_idx) {
112                                 unmap_desc(ppd, idx);
113                                 if (++idx == ppd->sdma_descq_cnt)
114                                         idx = 0;
115                         }
116                 }
117                 if (txp->callback)
118                         (*txp->callback)(txp, QIB_SDMA_TXREQ_S_ABORTED);
119         }
120 }
121
122 static void sdma_sw_clean_up_task(struct tasklet_struct *t)
123 {
124         struct qib_pportdata *ppd = from_tasklet(ppd, t,
125                                                  sdma_sw_clean_up_task);
126         unsigned long flags;
127
128         spin_lock_irqsave(&ppd->sdma_lock, flags);
129
130         /*
131          * At this point, the following should always be true:
132          * - We are halted, so no more descriptors are getting retired.
133          * - We are not running, so no one is submitting new work.
134          * - Only we can send the e40_sw_cleaned, so we can't start
135          *   running again until we say so.  So, the active list and
136          *   descq are ours to play with.
137          */
138
139         /* Process all retired requests. */
140         qib_sdma_make_progress(ppd);
141
142         clear_sdma_activelist(ppd);
143
144         /*
145          * Resync count of added and removed.  It is VERY important that
146          * sdma_descq_removed NEVER decrement - user_sdma depends on it.
147          */
148         ppd->sdma_descq_removed = ppd->sdma_descq_added;
149
150         /*
151          * Reset our notion of head and tail.
152          * Note that the HW registers will be reset when switching states
153          * due to calling __qib_sdma_process_event() below.
154          */
155         ppd->sdma_descq_tail = 0;
156         ppd->sdma_descq_head = 0;
157         ppd->sdma_head_dma[0] = 0;
158         ppd->sdma_generation = 0;
159
160         __qib_sdma_process_event(ppd, qib_sdma_event_e40_sw_cleaned);
161
162         spin_unlock_irqrestore(&ppd->sdma_lock, flags);
163 }
164
165 /*
166  * This is called when changing to state qib_sdma_state_s10_hw_start_up_wait
167  * as a result of send buffer errors or send DMA descriptor errors.
168  * We want to disarm the buffers in these cases.
169  */
170 static void sdma_hw_start_up(struct qib_pportdata *ppd)
171 {
172         struct qib_sdma_state *ss = &ppd->sdma_state;
173         unsigned bufno;
174
175         for (bufno = ss->first_sendbuf; bufno < ss->last_sendbuf; ++bufno)
176                 ppd->dd->f_sendctrl(ppd, QIB_SENDCTRL_DISARM_BUF(bufno));
177
178         ppd->dd->f_sdma_hw_start_up(ppd);
179 }
180
181 static void sdma_sw_tear_down(struct qib_pportdata *ppd)
182 {
183         struct qib_sdma_state *ss = &ppd->sdma_state;
184
185         /* Releasing this reference means the state machine has stopped. */
186         sdma_put(ss);
187 }
188
189 static void sdma_start_sw_clean_up(struct qib_pportdata *ppd)
190 {
191         tasklet_hi_schedule(&ppd->sdma_sw_clean_up_task);
192 }
193
194 static void sdma_set_state(struct qib_pportdata *ppd,
195         enum qib_sdma_states next_state)
196 {
197         struct qib_sdma_state *ss = &ppd->sdma_state;
198         struct sdma_set_state_action *action = ss->set_state_action;
199         unsigned op = 0;
200
201         /* debugging bookkeeping */
202         ss->previous_state = ss->current_state;
203         ss->previous_op = ss->current_op;
204
205         ss->current_state = next_state;
206
207         if (action[next_state].op_enable)
208                 op |= QIB_SDMA_SENDCTRL_OP_ENABLE;
209
210         if (action[next_state].op_intenable)
211                 op |= QIB_SDMA_SENDCTRL_OP_INTENABLE;
212
213         if (action[next_state].op_halt)
214                 op |= QIB_SDMA_SENDCTRL_OP_HALT;
215
216         if (action[next_state].op_drain)
217                 op |= QIB_SDMA_SENDCTRL_OP_DRAIN;
218
219         if (action[next_state].go_s99_running_tofalse)
220                 ss->go_s99_running = 0;
221
222         if (action[next_state].go_s99_running_totrue)
223                 ss->go_s99_running = 1;
224
225         ss->current_op = op;
226
227         ppd->dd->f_sdma_sendctrl(ppd, ss->current_op);
228 }
229
230 static void unmap_desc(struct qib_pportdata *ppd, unsigned head)
231 {
232         __le64 *descqp = &ppd->sdma_descq[head].qw[0];
233         u64 desc[2];
234         dma_addr_t addr;
235         size_t len;
236
237         desc[0] = le64_to_cpu(descqp[0]);
238         desc[1] = le64_to_cpu(descqp[1]);
239
240         addr = (desc[1] << 32) | (desc[0] >> 32);
241         len = (desc[0] >> 14) & (0x7ffULL << 2);
242         dma_unmap_single(&ppd->dd->pcidev->dev, addr, len, DMA_TO_DEVICE);
243 }
244
245 static int alloc_sdma(struct qib_pportdata *ppd)
246 {
247         ppd->sdma_descq_cnt = sdma_descq_cnt;
248         if (!ppd->sdma_descq_cnt)
249                 ppd->sdma_descq_cnt = 256;
250
251         /* Allocate memory for SendDMA descriptor FIFO */
252         ppd->sdma_descq = dma_alloc_coherent(&ppd->dd->pcidev->dev,
253                 ppd->sdma_descq_cnt * sizeof(u64[2]), &ppd->sdma_descq_phys,
254                 GFP_KERNEL);
255
256         if (!ppd->sdma_descq) {
257                 qib_dev_err(ppd->dd,
258                         "failed to allocate SendDMA descriptor FIFO memory\n");
259                 goto bail;
260         }
261
262         /* Allocate memory for DMA of head register to memory */
263         ppd->sdma_head_dma = dma_alloc_coherent(&ppd->dd->pcidev->dev,
264                 PAGE_SIZE, &ppd->sdma_head_phys, GFP_KERNEL);
265         if (!ppd->sdma_head_dma) {
266                 qib_dev_err(ppd->dd,
267                         "failed to allocate SendDMA head memory\n");
268                 goto cleanup_descq;
269         }
270         ppd->sdma_head_dma[0] = 0;
271         return 0;
272
273 cleanup_descq:
274         dma_free_coherent(&ppd->dd->pcidev->dev,
275                 ppd->sdma_descq_cnt * sizeof(u64[2]), (void *)ppd->sdma_descq,
276                 ppd->sdma_descq_phys);
277         ppd->sdma_descq = NULL;
278         ppd->sdma_descq_phys = 0;
279 bail:
280         ppd->sdma_descq_cnt = 0;
281         return -ENOMEM;
282 }
283
284 static void free_sdma(struct qib_pportdata *ppd)
285 {
286         struct qib_devdata *dd = ppd->dd;
287
288         if (ppd->sdma_head_dma) {
289                 dma_free_coherent(&dd->pcidev->dev, PAGE_SIZE,
290                                   (void *)ppd->sdma_head_dma,
291                                   ppd->sdma_head_phys);
292                 ppd->sdma_head_dma = NULL;
293                 ppd->sdma_head_phys = 0;
294         }
295
296         if (ppd->sdma_descq) {
297                 dma_free_coherent(&dd->pcidev->dev,
298                                   ppd->sdma_descq_cnt * sizeof(u64[2]),
299                                   ppd->sdma_descq, ppd->sdma_descq_phys);
300                 ppd->sdma_descq = NULL;
301                 ppd->sdma_descq_phys = 0;
302         }
303 }
304
305 static inline void make_sdma_desc(struct qib_pportdata *ppd,
306                                   u64 *sdmadesc, u64 addr, u64 dwlen,
307                                   u64 dwoffset)
308 {
309
310         WARN_ON(addr & 3);
311         /* SDmaPhyAddr[47:32] */
312         sdmadesc[1] = addr >> 32;
313         /* SDmaPhyAddr[31:0] */
314         sdmadesc[0] = (addr & 0xfffffffcULL) << 32;
315         /* SDmaGeneration[1:0] */
316         sdmadesc[0] |= (ppd->sdma_generation & 3ULL) <<
317                 SDMA_DESC_GEN_LSB;
318         /* SDmaDwordCount[10:0] */
319         sdmadesc[0] |= (dwlen & 0x7ffULL) << SDMA_DESC_COUNT_LSB;
320         /* SDmaBufOffset[12:2] */
321         sdmadesc[0] |= dwoffset & 0x7ffULL;
322 }
323
324 /* sdma_lock must be held */
325 int qib_sdma_make_progress(struct qib_pportdata *ppd)
326 {
327         struct list_head *lp = NULL;
328         struct qib_sdma_txreq *txp = NULL;
329         struct qib_devdata *dd = ppd->dd;
330         int progress = 0;
331         u16 hwhead;
332         u16 idx = 0;
333
334         hwhead = dd->f_sdma_gethead(ppd);
335
336         /* The reason for some of the complexity of this code is that
337          * not all descriptors have corresponding txps.  So, we have to
338          * be able to skip over descs until we wander into the range of
339          * the next txp on the list.
340          */
341
342         if (!list_empty(&ppd->sdma_activelist)) {
343                 lp = ppd->sdma_activelist.next;
344                 txp = list_entry(lp, struct qib_sdma_txreq, list);
345                 idx = txp->start_idx;
346         }
347
348         while (ppd->sdma_descq_head != hwhead) {
349                 /* if desc is part of this txp, unmap if needed */
350                 if (txp && (txp->flags & QIB_SDMA_TXREQ_F_FREEDESC) &&
351                     (idx == ppd->sdma_descq_head)) {
352                         unmap_desc(ppd, ppd->sdma_descq_head);
353                         if (++idx == ppd->sdma_descq_cnt)
354                                 idx = 0;
355                 }
356
357                 /* increment dequed desc count */
358                 ppd->sdma_descq_removed++;
359
360                 /* advance head, wrap if needed */
361                 if (++ppd->sdma_descq_head == ppd->sdma_descq_cnt)
362                         ppd->sdma_descq_head = 0;
363
364                 /* if now past this txp's descs, do the callback */
365                 if (txp && txp->next_descq_idx == ppd->sdma_descq_head) {
366                         /* remove from active list */
367                         list_del_init(&txp->list);
368                         if (txp->callback)
369                                 (*txp->callback)(txp, QIB_SDMA_TXREQ_S_OK);
370                         /* see if there is another txp */
371                         if (list_empty(&ppd->sdma_activelist))
372                                 txp = NULL;
373                         else {
374                                 lp = ppd->sdma_activelist.next;
375                                 txp = list_entry(lp, struct qib_sdma_txreq,
376                                         list);
377                                 idx = txp->start_idx;
378                         }
379                 }
380                 progress = 1;
381         }
382         if (progress)
383                 qib_verbs_sdma_desc_avail(ppd, qib_sdma_descq_freecnt(ppd));
384         return progress;
385 }
386
387 /*
388  * This is called from interrupt context.
389  */
390 void qib_sdma_intr(struct qib_pportdata *ppd)
391 {
392         unsigned long flags;
393
394         spin_lock_irqsave(&ppd->sdma_lock, flags);
395
396         __qib_sdma_intr(ppd);
397
398         spin_unlock_irqrestore(&ppd->sdma_lock, flags);
399 }
400
401 void __qib_sdma_intr(struct qib_pportdata *ppd)
402 {
403         if (__qib_sdma_running(ppd)) {
404                 qib_sdma_make_progress(ppd);
405                 if (!list_empty(&ppd->sdma_userpending))
406                         qib_user_sdma_send_desc(ppd, &ppd->sdma_userpending);
407         }
408 }
409
410 int qib_setup_sdma(struct qib_pportdata *ppd)
411 {
412         struct qib_devdata *dd = ppd->dd;
413         unsigned long flags;
414         int ret = 0;
415
416         ret = alloc_sdma(ppd);
417         if (ret)
418                 goto bail;
419
420         /* set consistent sdma state */
421         ppd->dd->f_sdma_init_early(ppd);
422         spin_lock_irqsave(&ppd->sdma_lock, flags);
423         sdma_set_state(ppd, qib_sdma_state_s00_hw_down);
424         spin_unlock_irqrestore(&ppd->sdma_lock, flags);
425
426         /* set up reference counting */
427         kref_init(&ppd->sdma_state.kref);
428         init_completion(&ppd->sdma_state.comp);
429
430         ppd->sdma_generation = 0;
431         ppd->sdma_descq_head = 0;
432         ppd->sdma_descq_removed = 0;
433         ppd->sdma_descq_added = 0;
434
435         ppd->sdma_intrequest = 0;
436         INIT_LIST_HEAD(&ppd->sdma_userpending);
437
438         INIT_LIST_HEAD(&ppd->sdma_activelist);
439
440         tasklet_setup(&ppd->sdma_sw_clean_up_task, sdma_sw_clean_up_task);
441
442         ret = dd->f_init_sdma_regs(ppd);
443         if (ret)
444                 goto bail_alloc;
445
446         qib_sdma_process_event(ppd, qib_sdma_event_e10_go_hw_start);
447
448         return 0;
449
450 bail_alloc:
451         qib_teardown_sdma(ppd);
452 bail:
453         return ret;
454 }
455
456 void qib_teardown_sdma(struct qib_pportdata *ppd)
457 {
458         qib_sdma_process_event(ppd, qib_sdma_event_e00_go_hw_down);
459
460         /*
461          * This waits for the state machine to exit so it is not
462          * necessary to kill the sdma_sw_clean_up_task to make sure
463          * it is not running.
464          */
465         sdma_finalput(&ppd->sdma_state);
466
467         free_sdma(ppd);
468 }
469
470 int qib_sdma_running(struct qib_pportdata *ppd)
471 {
472         unsigned long flags;
473         int ret;
474
475         spin_lock_irqsave(&ppd->sdma_lock, flags);
476         ret = __qib_sdma_running(ppd);
477         spin_unlock_irqrestore(&ppd->sdma_lock, flags);
478
479         return ret;
480 }
481
482 /*
483  * Complete a request when sdma not running; likely only request
484  * but to simplify the code, always queue it, then process the full
485  * activelist.  We process the entire list to ensure that this particular
486  * request does get it's callback, but in the correct order.
487  * Must be called with sdma_lock held
488  */
489 static void complete_sdma_err_req(struct qib_pportdata *ppd,
490                                   struct qib_verbs_txreq *tx)
491 {
492         struct qib_qp_priv *priv = tx->qp->priv;
493
494         atomic_inc(&priv->s_dma_busy);
495         /* no sdma descriptors, so no unmap_desc */
496         tx->txreq.start_idx = 0;
497         tx->txreq.next_descq_idx = 0;
498         list_add_tail(&tx->txreq.list, &ppd->sdma_activelist);
499         clear_sdma_activelist(ppd);
500 }
501
502 /*
503  * This function queues one IB packet onto the send DMA queue per call.
504  * The caller is responsible for checking:
505  * 1) The number of send DMA descriptor entries is less than the size of
506  *    the descriptor queue.
507  * 2) The IB SGE addresses and lengths are 32-bit aligned
508  *    (except possibly the last SGE's length)
509  * 3) The SGE addresses are suitable for passing to dma_map_single().
510  */
511 int qib_sdma_verbs_send(struct qib_pportdata *ppd,
512                         struct rvt_sge_state *ss, u32 dwords,
513                         struct qib_verbs_txreq *tx)
514 {
515         unsigned long flags;
516         struct rvt_sge *sge;
517         struct rvt_qp *qp;
518         int ret = 0;
519         u16 tail;
520         __le64 *descqp;
521         u64 sdmadesc[2];
522         u32 dwoffset;
523         dma_addr_t addr;
524         struct qib_qp_priv *priv;
525
526         spin_lock_irqsave(&ppd->sdma_lock, flags);
527
528 retry:
529         if (unlikely(!__qib_sdma_running(ppd))) {
530                 complete_sdma_err_req(ppd, tx);
531                 goto unlock;
532         }
533
534         if (tx->txreq.sg_count > qib_sdma_descq_freecnt(ppd)) {
535                 if (qib_sdma_make_progress(ppd))
536                         goto retry;
537                 if (ppd->dd->flags & QIB_HAS_SDMA_TIMEOUT)
538                         ppd->dd->f_sdma_set_desc_cnt(ppd,
539                                         ppd->sdma_descq_cnt / 2);
540                 goto busy;
541         }
542
543         dwoffset = tx->hdr_dwords;
544         make_sdma_desc(ppd, sdmadesc, (u64) tx->txreq.addr, dwoffset, 0);
545
546         sdmadesc[0] |= SDMA_DESC_FIRST;
547         if (tx->txreq.flags & QIB_SDMA_TXREQ_F_USELARGEBUF)
548                 sdmadesc[0] |= SDMA_DESC_USE_LARGE_BUF;
549
550         /* write to the descq */
551         tail = ppd->sdma_descq_tail;
552         descqp = &ppd->sdma_descq[tail].qw[0];
553         *descqp++ = cpu_to_le64(sdmadesc[0]);
554         *descqp++ = cpu_to_le64(sdmadesc[1]);
555
556         /* increment the tail */
557         if (++tail == ppd->sdma_descq_cnt) {
558                 tail = 0;
559                 descqp = &ppd->sdma_descq[0].qw[0];
560                 ++ppd->sdma_generation;
561         }
562
563         tx->txreq.start_idx = tail;
564
565         sge = &ss->sge;
566         while (dwords) {
567                 u32 dw;
568                 u32 len = rvt_get_sge_length(sge, dwords << 2);
569
570                 dw = (len + 3) >> 2;
571                 addr = dma_map_single(&ppd->dd->pcidev->dev, sge->vaddr,
572                                       dw << 2, DMA_TO_DEVICE);
573                 if (dma_mapping_error(&ppd->dd->pcidev->dev, addr)) {
574                         ret = -ENOMEM;
575                         goto unmap;
576                 }
577                 sdmadesc[0] = 0;
578                 make_sdma_desc(ppd, sdmadesc, (u64) addr, dw, dwoffset);
579                 /* SDmaUseLargeBuf has to be set in every descriptor */
580                 if (tx->txreq.flags & QIB_SDMA_TXREQ_F_USELARGEBUF)
581                         sdmadesc[0] |= SDMA_DESC_USE_LARGE_BUF;
582                 /* write to the descq */
583                 *descqp++ = cpu_to_le64(sdmadesc[0]);
584                 *descqp++ = cpu_to_le64(sdmadesc[1]);
585
586                 /* increment the tail */
587                 if (++tail == ppd->sdma_descq_cnt) {
588                         tail = 0;
589                         descqp = &ppd->sdma_descq[0].qw[0];
590                         ++ppd->sdma_generation;
591                 }
592                 rvt_update_sge(ss, len, false);
593                 dwoffset += dw;
594                 dwords -= dw;
595         }
596
597         if (!tail)
598                 descqp = &ppd->sdma_descq[ppd->sdma_descq_cnt].qw[0];
599         descqp -= 2;
600         descqp[0] |= cpu_to_le64(SDMA_DESC_LAST);
601         if (tx->txreq.flags & QIB_SDMA_TXREQ_F_HEADTOHOST)
602                 descqp[0] |= cpu_to_le64(SDMA_DESC_DMA_HEAD);
603         if (tx->txreq.flags & QIB_SDMA_TXREQ_F_INTREQ)
604                 descqp[0] |= cpu_to_le64(SDMA_DESC_INTR);
605         priv = tx->qp->priv;
606         atomic_inc(&priv->s_dma_busy);
607         tx->txreq.next_descq_idx = tail;
608         ppd->dd->f_sdma_update_tail(ppd, tail);
609         ppd->sdma_descq_added += tx->txreq.sg_count;
610         list_add_tail(&tx->txreq.list, &ppd->sdma_activelist);
611         goto unlock;
612
613 unmap:
614         for (;;) {
615                 if (!tail)
616                         tail = ppd->sdma_descq_cnt - 1;
617                 else
618                         tail--;
619                 if (tail == ppd->sdma_descq_tail)
620                         break;
621                 unmap_desc(ppd, tail);
622         }
623         qp = tx->qp;
624         priv = qp->priv;
625         qib_put_txreq(tx);
626         spin_lock(&qp->r_lock);
627         spin_lock(&qp->s_lock);
628         if (qp->ibqp.qp_type == IB_QPT_RC) {
629                 /* XXX what about error sending RDMA read responses? */
630                 if (ib_rvt_state_ops[qp->state] & RVT_PROCESS_RECV_OK)
631                         rvt_error_qp(qp, IB_WC_GENERAL_ERR);
632         } else if (qp->s_wqe)
633                 rvt_send_complete(qp, qp->s_wqe, IB_WC_GENERAL_ERR);
634         spin_unlock(&qp->s_lock);
635         spin_unlock(&qp->r_lock);
636         /* return zero to process the next send work request */
637         goto unlock;
638
639 busy:
640         qp = tx->qp;
641         priv = qp->priv;
642         spin_lock(&qp->s_lock);
643         if (ib_rvt_state_ops[qp->state] & RVT_PROCESS_RECV_OK) {
644                 struct qib_ibdev *dev;
645
646                 /*
647                  * If we couldn't queue the DMA request, save the info
648                  * and try again later rather than destroying the
649                  * buffer and undoing the side effects of the copy.
650                  */
651                 tx->ss = ss;
652                 tx->dwords = dwords;
653                 priv->s_tx = tx;
654                 dev = &ppd->dd->verbs_dev;
655                 spin_lock(&dev->rdi.pending_lock);
656                 if (list_empty(&priv->iowait)) {
657                         struct qib_ibport *ibp;
658
659                         ibp = &ppd->ibport_data;
660                         ibp->rvp.n_dmawait++;
661                         qp->s_flags |= RVT_S_WAIT_DMA_DESC;
662                         list_add_tail(&priv->iowait, &dev->dmawait);
663                 }
664                 spin_unlock(&dev->rdi.pending_lock);
665                 qp->s_flags &= ~RVT_S_BUSY;
666                 spin_unlock(&qp->s_lock);
667                 ret = -EBUSY;
668         } else {
669                 spin_unlock(&qp->s_lock);
670                 qib_put_txreq(tx);
671         }
672 unlock:
673         spin_unlock_irqrestore(&ppd->sdma_lock, flags);
674         return ret;
675 }
676
677 /*
678  * sdma_lock should be acquired before calling this routine
679  */
680 void dump_sdma_state(struct qib_pportdata *ppd)
681 {
682         struct qib_sdma_desc *descq;
683         struct qib_sdma_txreq *txp, *txpnext;
684         __le64 *descqp;
685         u64 desc[2];
686         u64 addr;
687         u16 gen, dwlen, dwoffset;
688         u16 head, tail, cnt;
689
690         head = ppd->sdma_descq_head;
691         tail = ppd->sdma_descq_tail;
692         cnt = qib_sdma_descq_freecnt(ppd);
693         descq = ppd->sdma_descq;
694
695         qib_dev_porterr(ppd->dd, ppd->port,
696                 "SDMA ppd->sdma_descq_head: %u\n", head);
697         qib_dev_porterr(ppd->dd, ppd->port,
698                 "SDMA ppd->sdma_descq_tail: %u\n", tail);
699         qib_dev_porterr(ppd->dd, ppd->port,
700                 "SDMA sdma_descq_freecnt: %u\n", cnt);
701
702         /* print info for each entry in the descriptor queue */
703         while (head != tail) {
704                 char flags[6] = { 'x', 'x', 'x', 'x', 'x', 0 };
705
706                 descqp = &descq[head].qw[0];
707                 desc[0] = le64_to_cpu(descqp[0]);
708                 desc[1] = le64_to_cpu(descqp[1]);
709                 flags[0] = (desc[0] & 1<<15) ? 'I' : '-';
710                 flags[1] = (desc[0] & 1<<14) ? 'L' : 'S';
711                 flags[2] = (desc[0] & 1<<13) ? 'H' : '-';
712                 flags[3] = (desc[0] & 1<<12) ? 'F' : '-';
713                 flags[4] = (desc[0] & 1<<11) ? 'L' : '-';
714                 addr = (desc[1] << 32) | ((desc[0] >> 32) & 0xfffffffcULL);
715                 gen = (desc[0] >> 30) & 3ULL;
716                 dwlen = (desc[0] >> 14) & (0x7ffULL << 2);
717                 dwoffset = (desc[0] & 0x7ffULL) << 2;
718                 qib_dev_porterr(ppd->dd, ppd->port,
719                         "SDMA sdmadesc[%u]: flags:%s addr:0x%016llx gen:%u len:%u bytes offset:%u bytes\n",
720                          head, flags, addr, gen, dwlen, dwoffset);
721                 if (++head == ppd->sdma_descq_cnt)
722                         head = 0;
723         }
724
725         /* print dma descriptor indices from the TX requests */
726         list_for_each_entry_safe(txp, txpnext, &ppd->sdma_activelist,
727                                  list)
728                 qib_dev_porterr(ppd->dd, ppd->port,
729                         "SDMA txp->start_idx: %u txp->next_descq_idx: %u\n",
730                         txp->start_idx, txp->next_descq_idx);
731 }
732
733 void qib_sdma_process_event(struct qib_pportdata *ppd,
734         enum qib_sdma_events event)
735 {
736         unsigned long flags;
737
738         spin_lock_irqsave(&ppd->sdma_lock, flags);
739
740         __qib_sdma_process_event(ppd, event);
741
742         if (ppd->sdma_state.current_state == qib_sdma_state_s99_running)
743                 qib_verbs_sdma_desc_avail(ppd, qib_sdma_descq_freecnt(ppd));
744
745         spin_unlock_irqrestore(&ppd->sdma_lock, flags);
746 }
747
748 void __qib_sdma_process_event(struct qib_pportdata *ppd,
749         enum qib_sdma_events event)
750 {
751         struct qib_sdma_state *ss = &ppd->sdma_state;
752
753         switch (ss->current_state) {
754         case qib_sdma_state_s00_hw_down:
755                 switch (event) {
756                 case qib_sdma_event_e00_go_hw_down:
757                         break;
758                 case qib_sdma_event_e30_go_running:
759                         /*
760                          * If down, but running requested (usually result
761                          * of link up, then we need to start up.
762                          * This can happen when hw down is requested while
763                          * bringing the link up with traffic active on
764                          * 7220, e.g. */
765                         ss->go_s99_running = 1;
766                         fallthrough;    /* and start dma engine */
767                 case qib_sdma_event_e10_go_hw_start:
768                         /* This reference means the state machine is started */
769                         sdma_get(&ppd->sdma_state);
770                         sdma_set_state(ppd,
771                                        qib_sdma_state_s10_hw_start_up_wait);
772                         break;
773                 case qib_sdma_event_e20_hw_started:
774                         break;
775                 case qib_sdma_event_e40_sw_cleaned:
776                         sdma_sw_tear_down(ppd);
777                         break;
778                 case qib_sdma_event_e50_hw_cleaned:
779                         break;
780                 case qib_sdma_event_e60_hw_halted:
781                         break;
782                 case qib_sdma_event_e70_go_idle:
783                         break;
784                 case qib_sdma_event_e7220_err_halted:
785                         break;
786                 case qib_sdma_event_e7322_err_halted:
787                         break;
788                 case qib_sdma_event_e90_timer_tick:
789                         break;
790                 }
791                 break;
792
793         case qib_sdma_state_s10_hw_start_up_wait:
794                 switch (event) {
795                 case qib_sdma_event_e00_go_hw_down:
796                         sdma_set_state(ppd, qib_sdma_state_s00_hw_down);
797                         sdma_sw_tear_down(ppd);
798                         break;
799                 case qib_sdma_event_e10_go_hw_start:
800                         break;
801                 case qib_sdma_event_e20_hw_started:
802                         sdma_set_state(ppd, ss->go_s99_running ?
803                                        qib_sdma_state_s99_running :
804                                        qib_sdma_state_s20_idle);
805                         break;
806                 case qib_sdma_event_e30_go_running:
807                         ss->go_s99_running = 1;
808                         break;
809                 case qib_sdma_event_e40_sw_cleaned:
810                         break;
811                 case qib_sdma_event_e50_hw_cleaned:
812                         break;
813                 case qib_sdma_event_e60_hw_halted:
814                         break;
815                 case qib_sdma_event_e70_go_idle:
816                         ss->go_s99_running = 0;
817                         break;
818                 case qib_sdma_event_e7220_err_halted:
819                         break;
820                 case qib_sdma_event_e7322_err_halted:
821                         break;
822                 case qib_sdma_event_e90_timer_tick:
823                         break;
824                 }
825                 break;
826
827         case qib_sdma_state_s20_idle:
828                 switch (event) {
829                 case qib_sdma_event_e00_go_hw_down:
830                         sdma_set_state(ppd, qib_sdma_state_s00_hw_down);
831                         sdma_sw_tear_down(ppd);
832                         break;
833                 case qib_sdma_event_e10_go_hw_start:
834                         break;
835                 case qib_sdma_event_e20_hw_started:
836                         break;
837                 case qib_sdma_event_e30_go_running:
838                         sdma_set_state(ppd, qib_sdma_state_s99_running);
839                         ss->go_s99_running = 1;
840                         break;
841                 case qib_sdma_event_e40_sw_cleaned:
842                         break;
843                 case qib_sdma_event_e50_hw_cleaned:
844                         break;
845                 case qib_sdma_event_e60_hw_halted:
846                         break;
847                 case qib_sdma_event_e70_go_idle:
848                         break;
849                 case qib_sdma_event_e7220_err_halted:
850                         break;
851                 case qib_sdma_event_e7322_err_halted:
852                         break;
853                 case qib_sdma_event_e90_timer_tick:
854                         break;
855                 }
856                 break;
857
858         case qib_sdma_state_s30_sw_clean_up_wait:
859                 switch (event) {
860                 case qib_sdma_event_e00_go_hw_down:
861                         sdma_set_state(ppd, qib_sdma_state_s00_hw_down);
862                         break;
863                 case qib_sdma_event_e10_go_hw_start:
864                         break;
865                 case qib_sdma_event_e20_hw_started:
866                         break;
867                 case qib_sdma_event_e30_go_running:
868                         ss->go_s99_running = 1;
869                         break;
870                 case qib_sdma_event_e40_sw_cleaned:
871                         sdma_set_state(ppd,
872                                        qib_sdma_state_s10_hw_start_up_wait);
873                         sdma_hw_start_up(ppd);
874                         break;
875                 case qib_sdma_event_e50_hw_cleaned:
876                         break;
877                 case qib_sdma_event_e60_hw_halted:
878                         break;
879                 case qib_sdma_event_e70_go_idle:
880                         ss->go_s99_running = 0;
881                         break;
882                 case qib_sdma_event_e7220_err_halted:
883                         break;
884                 case qib_sdma_event_e7322_err_halted:
885                         break;
886                 case qib_sdma_event_e90_timer_tick:
887                         break;
888                 }
889                 break;
890
891         case qib_sdma_state_s40_hw_clean_up_wait:
892                 switch (event) {
893                 case qib_sdma_event_e00_go_hw_down:
894                         sdma_set_state(ppd, qib_sdma_state_s00_hw_down);
895                         sdma_start_sw_clean_up(ppd);
896                         break;
897                 case qib_sdma_event_e10_go_hw_start:
898                         break;
899                 case qib_sdma_event_e20_hw_started:
900                         break;
901                 case qib_sdma_event_e30_go_running:
902                         ss->go_s99_running = 1;
903                         break;
904                 case qib_sdma_event_e40_sw_cleaned:
905                         break;
906                 case qib_sdma_event_e50_hw_cleaned:
907                         sdma_set_state(ppd,
908                                        qib_sdma_state_s30_sw_clean_up_wait);
909                         sdma_start_sw_clean_up(ppd);
910                         break;
911                 case qib_sdma_event_e60_hw_halted:
912                         break;
913                 case qib_sdma_event_e70_go_idle:
914                         ss->go_s99_running = 0;
915                         break;
916                 case qib_sdma_event_e7220_err_halted:
917                         break;
918                 case qib_sdma_event_e7322_err_halted:
919                         break;
920                 case qib_sdma_event_e90_timer_tick:
921                         break;
922                 }
923                 break;
924
925         case qib_sdma_state_s50_hw_halt_wait:
926                 switch (event) {
927                 case qib_sdma_event_e00_go_hw_down:
928                         sdma_set_state(ppd, qib_sdma_state_s00_hw_down);
929                         sdma_start_sw_clean_up(ppd);
930                         break;
931                 case qib_sdma_event_e10_go_hw_start:
932                         break;
933                 case qib_sdma_event_e20_hw_started:
934                         break;
935                 case qib_sdma_event_e30_go_running:
936                         ss->go_s99_running = 1;
937                         break;
938                 case qib_sdma_event_e40_sw_cleaned:
939                         break;
940                 case qib_sdma_event_e50_hw_cleaned:
941                         break;
942                 case qib_sdma_event_e60_hw_halted:
943                         sdma_set_state(ppd,
944                                        qib_sdma_state_s40_hw_clean_up_wait);
945                         ppd->dd->f_sdma_hw_clean_up(ppd);
946                         break;
947                 case qib_sdma_event_e70_go_idle:
948                         ss->go_s99_running = 0;
949                         break;
950                 case qib_sdma_event_e7220_err_halted:
951                         break;
952                 case qib_sdma_event_e7322_err_halted:
953                         break;
954                 case qib_sdma_event_e90_timer_tick:
955                         break;
956                 }
957                 break;
958
959         case qib_sdma_state_s99_running:
960                 switch (event) {
961                 case qib_sdma_event_e00_go_hw_down:
962                         sdma_set_state(ppd, qib_sdma_state_s00_hw_down);
963                         sdma_start_sw_clean_up(ppd);
964                         break;
965                 case qib_sdma_event_e10_go_hw_start:
966                         break;
967                 case qib_sdma_event_e20_hw_started:
968                         break;
969                 case qib_sdma_event_e30_go_running:
970                         break;
971                 case qib_sdma_event_e40_sw_cleaned:
972                         break;
973                 case qib_sdma_event_e50_hw_cleaned:
974                         break;
975                 case qib_sdma_event_e60_hw_halted:
976                         sdma_set_state(ppd,
977                                        qib_sdma_state_s30_sw_clean_up_wait);
978                         sdma_start_sw_clean_up(ppd);
979                         break;
980                 case qib_sdma_event_e70_go_idle:
981                         sdma_set_state(ppd, qib_sdma_state_s50_hw_halt_wait);
982                         ss->go_s99_running = 0;
983                         break;
984                 case qib_sdma_event_e7220_err_halted:
985                         sdma_set_state(ppd,
986                                        qib_sdma_state_s30_sw_clean_up_wait);
987                         sdma_start_sw_clean_up(ppd);
988                         break;
989                 case qib_sdma_event_e7322_err_halted:
990                         sdma_set_state(ppd, qib_sdma_state_s50_hw_halt_wait);
991                         break;
992                 case qib_sdma_event_e90_timer_tick:
993                         break;
994                 }
995                 break;
996         }
997
998         ss->last_event = event;
999 }