xref: /openbmc/linux/drivers/infiniband/hw/hfi1/sdma.c (revision 4b4f3acc)
1 /*
2  * Copyright(c) 2015 - 2018 Intel Corporation.
3  *
4  * This file is provided under a dual BSD/GPLv2 license.  When using or
5  * redistributing this file, you may do so under either license.
6  *
7  * GPL LICENSE SUMMARY
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of version 2 of the GNU General Public License as
11  * published by the Free Software Foundation.
12  *
13  * This program is distributed in the hope that it will be useful, but
14  * WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16  * General Public License for more details.
17  *
18  * BSD LICENSE
19  *
20  * Redistribution and use in source and binary forms, with or without
21  * modification, are permitted provided that the following conditions
22  * are met:
23  *
24  *  - Redistributions of source code must retain the above copyright
25  *    notice, this list of conditions and the following disclaimer.
26  *  - Redistributions in binary form must reproduce the above copyright
27  *    notice, this list of conditions and the following disclaimer in
28  *    the documentation and/or other materials provided with the
29  *    distribution.
30  *  - Neither the name of Intel Corporation nor the names of its
31  *    contributors may be used to endorse or promote products derived
32  *    from this software without specific prior written permission.
33  *
34  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
35  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
36  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
37  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
38  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
39  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
40  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
41  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
42  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
43  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
44  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
45  *
46  */
47 
48 #include <linux/spinlock.h>
49 #include <linux/seqlock.h>
50 #include <linux/netdevice.h>
51 #include <linux/moduleparam.h>
52 #include <linux/bitops.h>
53 #include <linux/timer.h>
54 #include <linux/vmalloc.h>
55 #include <linux/highmem.h>
56 
57 #include "hfi.h"
58 #include "common.h"
59 #include "qp.h"
60 #include "sdma.h"
61 #include "iowait.h"
62 #include "trace.h"
63 
64 /* must be a power of 2 >= 64 <= 32768 */
65 #define SDMA_DESCQ_CNT 2048
66 #define SDMA_DESC_INTR 64
67 #define INVALID_TAIL 0xffff
68 
69 static uint sdma_descq_cnt = SDMA_DESCQ_CNT;
70 module_param(sdma_descq_cnt, uint, S_IRUGO);
71 MODULE_PARM_DESC(sdma_descq_cnt, "Number of SDMA descq entries");
72 
73 static uint sdma_idle_cnt = 250;
74 module_param(sdma_idle_cnt, uint, S_IRUGO);
75 MODULE_PARM_DESC(sdma_idle_cnt, "sdma interrupt idle delay (ns,default 250)");
76 
77 uint mod_num_sdma;
78 module_param_named(num_sdma, mod_num_sdma, uint, S_IRUGO);
79 MODULE_PARM_DESC(num_sdma, "Set max number SDMA engines to use");
80 
81 static uint sdma_desct_intr = SDMA_DESC_INTR;
82 module_param_named(desct_intr, sdma_desct_intr, uint, S_IRUGO | S_IWUSR);
83 MODULE_PARM_DESC(desct_intr, "Number of SDMA descriptor before interrupt");
84 
85 #define SDMA_WAIT_BATCH_SIZE 20
86 /* max wait time for a SDMA engine to indicate it has halted */
87 #define SDMA_ERR_HALT_TIMEOUT 10 /* ms */
88 /* all SDMA engine errors that cause a halt */
89 
90 #define SD(name) SEND_DMA_##name
91 #define ALL_SDMA_ENG_HALT_ERRS \
92 	(SD(ENG_ERR_STATUS_SDMA_WRONG_DW_ERR_SMASK) \
93 	| SD(ENG_ERR_STATUS_SDMA_GEN_MISMATCH_ERR_SMASK) \
94 	| SD(ENG_ERR_STATUS_SDMA_TOO_LONG_ERR_SMASK) \
95 	| SD(ENG_ERR_STATUS_SDMA_TAIL_OUT_OF_BOUNDS_ERR_SMASK) \
96 	| SD(ENG_ERR_STATUS_SDMA_FIRST_DESC_ERR_SMASK) \
97 	| SD(ENG_ERR_STATUS_SDMA_MEM_READ_ERR_SMASK) \
98 	| SD(ENG_ERR_STATUS_SDMA_HALT_ERR_SMASK) \
99 	| SD(ENG_ERR_STATUS_SDMA_LENGTH_MISMATCH_ERR_SMASK) \
100 	| SD(ENG_ERR_STATUS_SDMA_PACKET_DESC_OVERFLOW_ERR_SMASK) \
101 	| SD(ENG_ERR_STATUS_SDMA_HEADER_SELECT_ERR_SMASK) \
102 	| SD(ENG_ERR_STATUS_SDMA_HEADER_ADDRESS_ERR_SMASK) \
103 	| SD(ENG_ERR_STATUS_SDMA_HEADER_LENGTH_ERR_SMASK) \
104 	| SD(ENG_ERR_STATUS_SDMA_TIMEOUT_ERR_SMASK) \
105 	| SD(ENG_ERR_STATUS_SDMA_DESC_TABLE_UNC_ERR_SMASK) \
106 	| SD(ENG_ERR_STATUS_SDMA_ASSEMBLY_UNC_ERR_SMASK) \
107 	| SD(ENG_ERR_STATUS_SDMA_PACKET_TRACKING_UNC_ERR_SMASK) \
108 	| SD(ENG_ERR_STATUS_SDMA_HEADER_STORAGE_UNC_ERR_SMASK) \
109 	| SD(ENG_ERR_STATUS_SDMA_HEADER_REQUEST_FIFO_UNC_ERR_SMASK))
110 
111 /* sdma_sendctrl operations */
112 #define SDMA_SENDCTRL_OP_ENABLE    BIT(0)
113 #define SDMA_SENDCTRL_OP_INTENABLE BIT(1)
114 #define SDMA_SENDCTRL_OP_HALT      BIT(2)
115 #define SDMA_SENDCTRL_OP_CLEANUP   BIT(3)
116 
117 /* handle long defines */
118 #define SDMA_EGRESS_PACKET_OCCUPANCY_SMASK \
119 SEND_EGRESS_SEND_DMA_STATUS_SDMA_EGRESS_PACKET_OCCUPANCY_SMASK
120 #define SDMA_EGRESS_PACKET_OCCUPANCY_SHIFT \
121 SEND_EGRESS_SEND_DMA_STATUS_SDMA_EGRESS_PACKET_OCCUPANCY_SHIFT
122 
123 static const char * const sdma_state_names[] = {
124 	[sdma_state_s00_hw_down]                = "s00_HwDown",
125 	[sdma_state_s10_hw_start_up_halt_wait]  = "s10_HwStartUpHaltWait",
126 	[sdma_state_s15_hw_start_up_clean_wait] = "s15_HwStartUpCleanWait",
127 	[sdma_state_s20_idle]                   = "s20_Idle",
128 	[sdma_state_s30_sw_clean_up_wait]       = "s30_SwCleanUpWait",
129 	[sdma_state_s40_hw_clean_up_wait]       = "s40_HwCleanUpWait",
130 	[sdma_state_s50_hw_halt_wait]           = "s50_HwHaltWait",
131 	[sdma_state_s60_idle_halt_wait]         = "s60_IdleHaltWait",
132 	[sdma_state_s80_hw_freeze]		= "s80_HwFreeze",
133 	[sdma_state_s82_freeze_sw_clean]	= "s82_FreezeSwClean",
134 	[sdma_state_s99_running]                = "s99_Running",
135 };
136 
137 #ifdef CONFIG_SDMA_VERBOSITY
138 static const char * const sdma_event_names[] = {
139 	[sdma_event_e00_go_hw_down]   = "e00_GoHwDown",
140 	[sdma_event_e10_go_hw_start]  = "e10_GoHwStart",
141 	[sdma_event_e15_hw_halt_done] = "e15_HwHaltDone",
142 	[sdma_event_e25_hw_clean_up_done] = "e25_HwCleanUpDone",
143 	[sdma_event_e30_go_running]   = "e30_GoRunning",
144 	[sdma_event_e40_sw_cleaned]   = "e40_SwCleaned",
145 	[sdma_event_e50_hw_cleaned]   = "e50_HwCleaned",
146 	[sdma_event_e60_hw_halted]    = "e60_HwHalted",
147 	[sdma_event_e70_go_idle]      = "e70_GoIdle",
148 	[sdma_event_e80_hw_freeze]    = "e80_HwFreeze",
149 	[sdma_event_e81_hw_frozen]    = "e81_HwFrozen",
150 	[sdma_event_e82_hw_unfreeze]  = "e82_HwUnfreeze",
151 	[sdma_event_e85_link_down]    = "e85_LinkDown",
152 	[sdma_event_e90_sw_halted]    = "e90_SwHalted",
153 };
154 #endif
155 
156 static const struct sdma_set_state_action sdma_action_table[] = {
157 	[sdma_state_s00_hw_down] = {
158 		.go_s99_running_tofalse = 1,
159 		.op_enable = 0,
160 		.op_intenable = 0,
161 		.op_halt = 0,
162 		.op_cleanup = 0,
163 	},
164 	[sdma_state_s10_hw_start_up_halt_wait] = {
165 		.op_enable = 0,
166 		.op_intenable = 0,
167 		.op_halt = 1,
168 		.op_cleanup = 0,
169 	},
170 	[sdma_state_s15_hw_start_up_clean_wait] = {
171 		.op_enable = 0,
172 		.op_intenable = 1,
173 		.op_halt = 0,
174 		.op_cleanup = 1,
175 	},
176 	[sdma_state_s20_idle] = {
177 		.op_enable = 0,
178 		.op_intenable = 1,
179 		.op_halt = 0,
180 		.op_cleanup = 0,
181 	},
182 	[sdma_state_s30_sw_clean_up_wait] = {
183 		.op_enable = 0,
184 		.op_intenable = 0,
185 		.op_halt = 0,
186 		.op_cleanup = 0,
187 	},
188 	[sdma_state_s40_hw_clean_up_wait] = {
189 		.op_enable = 0,
190 		.op_intenable = 0,
191 		.op_halt = 0,
192 		.op_cleanup = 1,
193 	},
194 	[sdma_state_s50_hw_halt_wait] = {
195 		.op_enable = 0,
196 		.op_intenable = 0,
197 		.op_halt = 0,
198 		.op_cleanup = 0,
199 	},
200 	[sdma_state_s60_idle_halt_wait] = {
201 		.go_s99_running_tofalse = 1,
202 		.op_enable = 0,
203 		.op_intenable = 0,
204 		.op_halt = 1,
205 		.op_cleanup = 0,
206 	},
207 	[sdma_state_s80_hw_freeze] = {
208 		.op_enable = 0,
209 		.op_intenable = 0,
210 		.op_halt = 0,
211 		.op_cleanup = 0,
212 	},
213 	[sdma_state_s82_freeze_sw_clean] = {
214 		.op_enable = 0,
215 		.op_intenable = 0,
216 		.op_halt = 0,
217 		.op_cleanup = 0,
218 	},
219 	[sdma_state_s99_running] = {
220 		.op_enable = 1,
221 		.op_intenable = 1,
222 		.op_halt = 0,
223 		.op_cleanup = 0,
224 		.go_s99_running_totrue = 1,
225 	},
226 };
227 
228 #define SDMA_TAIL_UPDATE_THRESH 0x1F
229 
230 /* declare all statics here rather than keep sorting */
231 static void sdma_complete(struct kref *);
232 static void sdma_finalput(struct sdma_state *);
233 static void sdma_get(struct sdma_state *);
234 static void sdma_hw_clean_up_task(unsigned long);
235 static void sdma_put(struct sdma_state *);
236 static void sdma_set_state(struct sdma_engine *, enum sdma_states);
237 static void sdma_start_hw_clean_up(struct sdma_engine *);
238 static void sdma_sw_clean_up_task(unsigned long);
239 static void sdma_sendctrl(struct sdma_engine *, unsigned);
240 static void init_sdma_regs(struct sdma_engine *, u32, uint);
241 static void sdma_process_event(
242 	struct sdma_engine *sde,
243 	enum sdma_events event);
244 static void __sdma_process_event(
245 	struct sdma_engine *sde,
246 	enum sdma_events event);
247 static void dump_sdma_state(struct sdma_engine *sde);
248 static void sdma_make_progress(struct sdma_engine *sde, u64 status);
249 static void sdma_desc_avail(struct sdma_engine *sde, uint avail);
250 static void sdma_flush_descq(struct sdma_engine *sde);
251 
252 /**
253  * sdma_state_name() - return state string from enum
254  * @state: state
255  */
256 static const char *sdma_state_name(enum sdma_states state)
257 {
258 	return sdma_state_names[state];
259 }
260 
261 static void sdma_get(struct sdma_state *ss)
262 {
263 	kref_get(&ss->kref);
264 }
265 
266 static void sdma_complete(struct kref *kref)
267 {
268 	struct sdma_state *ss =
269 		container_of(kref, struct sdma_state, kref);
270 
271 	complete(&ss->comp);
272 }
273 
274 static void sdma_put(struct sdma_state *ss)
275 {
276 	kref_put(&ss->kref, sdma_complete);
277 }
278 
279 static void sdma_finalput(struct sdma_state *ss)
280 {
281 	sdma_put(ss);
282 	wait_for_completion(&ss->comp);
283 }
284 
285 static inline void write_sde_csr(
286 	struct sdma_engine *sde,
287 	u32 offset0,
288 	u64 value)
289 {
290 	write_kctxt_csr(sde->dd, sde->this_idx, offset0, value);
291 }
292 
293 static inline u64 read_sde_csr(
294 	struct sdma_engine *sde,
295 	u32 offset0)
296 {
297 	return read_kctxt_csr(sde->dd, sde->this_idx, offset0);
298 }
299 
300 /*
301  * sdma_wait_for_packet_egress() - wait for the VL FIFO occupancy for
302  * sdma engine 'sde' to drop to 0.
303  */
304 static void sdma_wait_for_packet_egress(struct sdma_engine *sde,
305 					int pause)
306 {
307 	u64 off = 8 * sde->this_idx;
308 	struct hfi1_devdata *dd = sde->dd;
309 	int lcnt = 0;
310 	u64 reg_prev;
311 	u64 reg = 0;
312 
313 	while (1) {
314 		reg_prev = reg;
315 		reg = read_csr(dd, off + SEND_EGRESS_SEND_DMA_STATUS);
316 
317 		reg &= SDMA_EGRESS_PACKET_OCCUPANCY_SMASK;
318 		reg >>= SDMA_EGRESS_PACKET_OCCUPANCY_SHIFT;
319 		if (reg == 0)
320 			break;
321 		/* counter is reest if accupancy count changes */
322 		if (reg != reg_prev)
323 			lcnt = 0;
324 		if (lcnt++ > 500) {
325 			/* timed out - bounce the link */
326 			dd_dev_err(dd, "%s: engine %u timeout waiting for packets to egress, remaining count %u, bouncing link\n",
327 				   __func__, sde->this_idx, (u32)reg);
328 			queue_work(dd->pport->link_wq,
329 				   &dd->pport->link_bounce_work);
330 			break;
331 		}
332 		udelay(1);
333 	}
334 }
335 
336 /*
337  * sdma_wait() - wait for packet egress to complete for all SDMA engines,
338  * and pause for credit return.
339  */
340 void sdma_wait(struct hfi1_devdata *dd)
341 {
342 	int i;
343 
344 	for (i = 0; i < dd->num_sdma; i++) {
345 		struct sdma_engine *sde = &dd->per_sdma[i];
346 
347 		sdma_wait_for_packet_egress(sde, 0);
348 	}
349 }
350 
351 static inline void sdma_set_desc_cnt(struct sdma_engine *sde, unsigned cnt)
352 {
353 	u64 reg;
354 
355 	if (!(sde->dd->flags & HFI1_HAS_SDMA_TIMEOUT))
356 		return;
357 	reg = cnt;
358 	reg &= SD(DESC_CNT_CNT_MASK);
359 	reg <<= SD(DESC_CNT_CNT_SHIFT);
360 	write_sde_csr(sde, SD(DESC_CNT), reg);
361 }
362 
363 static inline void complete_tx(struct sdma_engine *sde,
364 			       struct sdma_txreq *tx,
365 			       int res)
366 {
367 	/* protect against complete modifying */
368 	struct iowait *wait = tx->wait;
369 	callback_t complete = tx->complete;
370 
371 #ifdef CONFIG_HFI1_DEBUG_SDMA_ORDER
372 	trace_hfi1_sdma_out_sn(sde, tx->sn);
373 	if (WARN_ON_ONCE(sde->head_sn != tx->sn))
374 		dd_dev_err(sde->dd, "expected %llu got %llu\n",
375 			   sde->head_sn, tx->sn);
376 	sde->head_sn++;
377 #endif
378 	__sdma_txclean(sde->dd, tx);
379 	if (complete)
380 		(*complete)(tx, res);
381 	if (iowait_sdma_dec(wait))
382 		iowait_drain_wakeup(wait);
383 }
384 
385 /*
386  * Complete all the sdma requests with a SDMA_TXREQ_S_ABORTED status
387  *
388  * Depending on timing there can be txreqs in two places:
389  * - in the descq ring
390  * - in the flush list
391  *
392  * To avoid ordering issues the descq ring needs to be flushed
393  * first followed by the flush list.
394  *
395  * This routine is called from two places
396  * - From a work queue item
397  * - Directly from the state machine just before setting the
398  *   state to running
399  *
400  * Must be called with head_lock held
401  *
402  */
403 static void sdma_flush(struct sdma_engine *sde)
404 {
405 	struct sdma_txreq *txp, *txp_next;
406 	LIST_HEAD(flushlist);
407 	unsigned long flags;
408 	uint seq;
409 
410 	/* flush from head to tail */
411 	sdma_flush_descq(sde);
412 	spin_lock_irqsave(&sde->flushlist_lock, flags);
413 	/* copy flush list */
414 	list_splice_init(&sde->flushlist, &flushlist);
415 	spin_unlock_irqrestore(&sde->flushlist_lock, flags);
416 	/* flush from flush list */
417 	list_for_each_entry_safe(txp, txp_next, &flushlist, list)
418 		complete_tx(sde, txp, SDMA_TXREQ_S_ABORTED);
419 	/* wakeup QPs orphaned on the dmawait list */
420 	do {
421 		struct iowait *w, *nw;
422 
423 		seq = read_seqbegin(&sde->waitlock);
424 		if (!list_empty(&sde->dmawait)) {
425 			write_seqlock(&sde->waitlock);
426 			list_for_each_entry_safe(w, nw, &sde->dmawait, list) {
427 				if (w->wakeup) {
428 					w->wakeup(w, SDMA_AVAIL_REASON);
429 					list_del_init(&w->list);
430 				}
431 			}
432 			write_sequnlock(&sde->waitlock);
433 		}
434 	} while (read_seqretry(&sde->waitlock, seq));
435 }
436 
437 /*
438  * Fields a work request for flushing the descq ring
439  * and the flush list
440  *
441  * If the engine has been brought to running during
442  * the scheduling delay, the flush is ignored, assuming
443  * that the process of bringing the engine to running
444  * would have done this flush prior to going to running.
445  *
446  */
447 static void sdma_field_flush(struct work_struct *work)
448 {
449 	unsigned long flags;
450 	struct sdma_engine *sde =
451 		container_of(work, struct sdma_engine, flush_worker);
452 
453 	write_seqlock_irqsave(&sde->head_lock, flags);
454 	if (!__sdma_running(sde))
455 		sdma_flush(sde);
456 	write_sequnlock_irqrestore(&sde->head_lock, flags);
457 }
458 
459 static void sdma_err_halt_wait(struct work_struct *work)
460 {
461 	struct sdma_engine *sde = container_of(work, struct sdma_engine,
462 						err_halt_worker);
463 	u64 statuscsr;
464 	unsigned long timeout;
465 
466 	timeout = jiffies + msecs_to_jiffies(SDMA_ERR_HALT_TIMEOUT);
467 	while (1) {
468 		statuscsr = read_sde_csr(sde, SD(STATUS));
469 		statuscsr &= SD(STATUS_ENG_HALTED_SMASK);
470 		if (statuscsr)
471 			break;
472 		if (time_after(jiffies, timeout)) {
473 			dd_dev_err(sde->dd,
474 				   "SDMA engine %d - timeout waiting for engine to halt\n",
475 				   sde->this_idx);
476 			/*
477 			 * Continue anyway.  This could happen if there was
478 			 * an uncorrectable error in the wrong spot.
479 			 */
480 			break;
481 		}
482 		usleep_range(80, 120);
483 	}
484 
485 	sdma_process_event(sde, sdma_event_e15_hw_halt_done);
486 }
487 
488 static void sdma_err_progress_check_schedule(struct sdma_engine *sde)
489 {
490 	if (!is_bx(sde->dd) && HFI1_CAP_IS_KSET(SDMA_AHG)) {
491 		unsigned index;
492 		struct hfi1_devdata *dd = sde->dd;
493 
494 		for (index = 0; index < dd->num_sdma; index++) {
495 			struct sdma_engine *curr_sdma = &dd->per_sdma[index];
496 
497 			if (curr_sdma != sde)
498 				curr_sdma->progress_check_head =
499 							curr_sdma->descq_head;
500 		}
501 		dd_dev_err(sde->dd,
502 			   "SDMA engine %d - check scheduled\n",
503 				sde->this_idx);
504 		mod_timer(&sde->err_progress_check_timer, jiffies + 10);
505 	}
506 }
507 
508 static void sdma_err_progress_check(struct timer_list *t)
509 {
510 	unsigned index;
511 	struct sdma_engine *sde = from_timer(sde, t, err_progress_check_timer);
512 
513 	dd_dev_err(sde->dd, "SDE progress check event\n");
514 	for (index = 0; index < sde->dd->num_sdma; index++) {
515 		struct sdma_engine *curr_sde = &sde->dd->per_sdma[index];
516 		unsigned long flags;
517 
518 		/* check progress on each engine except the current one */
519 		if (curr_sde == sde)
520 			continue;
521 		/*
522 		 * We must lock interrupts when acquiring sde->lock,
523 		 * to avoid a deadlock if interrupt triggers and spins on
524 		 * the same lock on same CPU
525 		 */
526 		spin_lock_irqsave(&curr_sde->tail_lock, flags);
527 		write_seqlock(&curr_sde->head_lock);
528 
529 		/* skip non-running queues */
530 		if (curr_sde->state.current_state != sdma_state_s99_running) {
531 			write_sequnlock(&curr_sde->head_lock);
532 			spin_unlock_irqrestore(&curr_sde->tail_lock, flags);
533 			continue;
534 		}
535 
536 		if ((curr_sde->descq_head != curr_sde->descq_tail) &&
537 		    (curr_sde->descq_head ==
538 				curr_sde->progress_check_head))
539 			__sdma_process_event(curr_sde,
540 					     sdma_event_e90_sw_halted);
541 		write_sequnlock(&curr_sde->head_lock);
542 		spin_unlock_irqrestore(&curr_sde->tail_lock, flags);
543 	}
544 	schedule_work(&sde->err_halt_worker);
545 }
546 
547 static void sdma_hw_clean_up_task(unsigned long opaque)
548 {
549 	struct sdma_engine *sde = (struct sdma_engine *)opaque;
550 	u64 statuscsr;
551 
552 	while (1) {
553 #ifdef CONFIG_SDMA_VERBOSITY
554 		dd_dev_err(sde->dd, "CONFIG SDMA(%u) %s:%d %s()\n",
555 			   sde->this_idx, slashstrip(__FILE__), __LINE__,
556 			__func__);
557 #endif
558 		statuscsr = read_sde_csr(sde, SD(STATUS));
559 		statuscsr &= SD(STATUS_ENG_CLEANED_UP_SMASK);
560 		if (statuscsr)
561 			break;
562 		udelay(10);
563 	}
564 
565 	sdma_process_event(sde, sdma_event_e25_hw_clean_up_done);
566 }
567 
568 static inline struct sdma_txreq *get_txhead(struct sdma_engine *sde)
569 {
570 	return sde->tx_ring[sde->tx_head & sde->sdma_mask];
571 }
572 
573 /*
574  * flush ring for recovery
575  */
576 static void sdma_flush_descq(struct sdma_engine *sde)
577 {
578 	u16 head, tail;
579 	int progress = 0;
580 	struct sdma_txreq *txp = get_txhead(sde);
581 
582 	/* The reason for some of the complexity of this code is that
583 	 * not all descriptors have corresponding txps.  So, we have to
584 	 * be able to skip over descs until we wander into the range of
585 	 * the next txp on the list.
586 	 */
587 	head = sde->descq_head & sde->sdma_mask;
588 	tail = sde->descq_tail & sde->sdma_mask;
589 	while (head != tail) {
590 		/* advance head, wrap if needed */
591 		head = ++sde->descq_head & sde->sdma_mask;
592 		/* if now past this txp's descs, do the callback */
593 		if (txp && txp->next_descq_idx == head) {
594 			/* remove from list */
595 			sde->tx_ring[sde->tx_head++ & sde->sdma_mask] = NULL;
596 			complete_tx(sde, txp, SDMA_TXREQ_S_ABORTED);
597 			trace_hfi1_sdma_progress(sde, head, tail, txp);
598 			txp = get_txhead(sde);
599 		}
600 		progress++;
601 	}
602 	if (progress)
603 		sdma_desc_avail(sde, sdma_descq_freecnt(sde));
604 }
605 
606 static void sdma_sw_clean_up_task(unsigned long opaque)
607 {
608 	struct sdma_engine *sde = (struct sdma_engine *)opaque;
609 	unsigned long flags;
610 
611 	spin_lock_irqsave(&sde->tail_lock, flags);
612 	write_seqlock(&sde->head_lock);
613 
614 	/*
615 	 * At this point, the following should always be true:
616 	 * - We are halted, so no more descriptors are getting retired.
617 	 * - We are not running, so no one is submitting new work.
618 	 * - Only we can send the e40_sw_cleaned, so we can't start
619 	 *   running again until we say so.  So, the active list and
620 	 *   descq are ours to play with.
621 	 */
622 
623 	/*
624 	 * In the error clean up sequence, software clean must be called
625 	 * before the hardware clean so we can use the hardware head in
626 	 * the progress routine.  A hardware clean or SPC unfreeze will
627 	 * reset the hardware head.
628 	 *
629 	 * Process all retired requests. The progress routine will use the
630 	 * latest physical hardware head - we are not running so speed does
631 	 * not matter.
632 	 */
633 	sdma_make_progress(sde, 0);
634 
635 	sdma_flush(sde);
636 
637 	/*
638 	 * Reset our notion of head and tail.
639 	 * Note that the HW registers have been reset via an earlier
640 	 * clean up.
641 	 */
642 	sde->descq_tail = 0;
643 	sde->descq_head = 0;
644 	sde->desc_avail = sdma_descq_freecnt(sde);
645 	*sde->head_dma = 0;
646 
647 	__sdma_process_event(sde, sdma_event_e40_sw_cleaned);
648 
649 	write_sequnlock(&sde->head_lock);
650 	spin_unlock_irqrestore(&sde->tail_lock, flags);
651 }
652 
653 static void sdma_sw_tear_down(struct sdma_engine *sde)
654 {
655 	struct sdma_state *ss = &sde->state;
656 
657 	/* Releasing this reference means the state machine has stopped. */
658 	sdma_put(ss);
659 
660 	/* stop waiting for all unfreeze events to complete */
661 	atomic_set(&sde->dd->sdma_unfreeze_count, -1);
662 	wake_up_interruptible(&sde->dd->sdma_unfreeze_wq);
663 }
664 
665 static void sdma_start_hw_clean_up(struct sdma_engine *sde)
666 {
667 	tasklet_hi_schedule(&sde->sdma_hw_clean_up_task);
668 }
669 
670 static void sdma_set_state(struct sdma_engine *sde,
671 			   enum sdma_states next_state)
672 {
673 	struct sdma_state *ss = &sde->state;
674 	const struct sdma_set_state_action *action = sdma_action_table;
675 	unsigned op = 0;
676 
677 	trace_hfi1_sdma_state(
678 		sde,
679 		sdma_state_names[ss->current_state],
680 		sdma_state_names[next_state]);
681 
682 	/* debugging bookkeeping */
683 	ss->previous_state = ss->current_state;
684 	ss->previous_op = ss->current_op;
685 	ss->current_state = next_state;
686 
687 	if (ss->previous_state != sdma_state_s99_running &&
688 	    next_state == sdma_state_s99_running)
689 		sdma_flush(sde);
690 
691 	if (action[next_state].op_enable)
692 		op |= SDMA_SENDCTRL_OP_ENABLE;
693 
694 	if (action[next_state].op_intenable)
695 		op |= SDMA_SENDCTRL_OP_INTENABLE;
696 
697 	if (action[next_state].op_halt)
698 		op |= SDMA_SENDCTRL_OP_HALT;
699 
700 	if (action[next_state].op_cleanup)
701 		op |= SDMA_SENDCTRL_OP_CLEANUP;
702 
703 	if (action[next_state].go_s99_running_tofalse)
704 		ss->go_s99_running = 0;
705 
706 	if (action[next_state].go_s99_running_totrue)
707 		ss->go_s99_running = 1;
708 
709 	ss->current_op = op;
710 	sdma_sendctrl(sde, ss->current_op);
711 }
712 
713 /**
714  * sdma_get_descq_cnt() - called when device probed
715  *
716  * Return a validated descq count.
717  *
718  * This is currently only used in the verbs initialization to build the tx
719  * list.
720  *
721  * This will probably be deleted in favor of a more scalable approach to
722  * alloc tx's.
723  *
724  */
725 u16 sdma_get_descq_cnt(void)
726 {
727 	u16 count = sdma_descq_cnt;
728 
729 	if (!count)
730 		return SDMA_DESCQ_CNT;
731 	/* count must be a power of 2 greater than 64 and less than
732 	 * 32768.   Otherwise return default.
733 	 */
734 	if (!is_power_of_2(count))
735 		return SDMA_DESCQ_CNT;
736 	if (count < 64 || count > 32768)
737 		return SDMA_DESCQ_CNT;
738 	return count;
739 }
740 
741 /**
742  * sdma_engine_get_vl() - return vl for a given sdma engine
743  * @sde: sdma engine
744  *
745  * This function returns the vl mapped to a given engine, or an error if
746  * the mapping can't be found. The mapping fields are protected by RCU.
747  */
748 int sdma_engine_get_vl(struct sdma_engine *sde)
749 {
750 	struct hfi1_devdata *dd = sde->dd;
751 	struct sdma_vl_map *m;
752 	u8 vl;
753 
754 	if (sde->this_idx >= TXE_NUM_SDMA_ENGINES)
755 		return -EINVAL;
756 
757 	rcu_read_lock();
758 	m = rcu_dereference(dd->sdma_map);
759 	if (unlikely(!m)) {
760 		rcu_read_unlock();
761 		return -EINVAL;
762 	}
763 	vl = m->engine_to_vl[sde->this_idx];
764 	rcu_read_unlock();
765 
766 	return vl;
767 }
768 
769 /**
770  * sdma_select_engine_vl() - select sdma engine
771  * @dd: devdata
772  * @selector: a spreading factor
773  * @vl: this vl
774  *
775  *
776  * This function returns an engine based on the selector and a vl.  The
777  * mapping fields are protected by RCU.
778  */
779 struct sdma_engine *sdma_select_engine_vl(
780 	struct hfi1_devdata *dd,
781 	u32 selector,
782 	u8 vl)
783 {
784 	struct sdma_vl_map *m;
785 	struct sdma_map_elem *e;
786 	struct sdma_engine *rval;
787 
788 	/* NOTE This should only happen if SC->VL changed after the initial
789 	 *      checks on the QP/AH
790 	 *      Default will return engine 0 below
791 	 */
792 	if (vl >= num_vls) {
793 		rval = NULL;
794 		goto done;
795 	}
796 
797 	rcu_read_lock();
798 	m = rcu_dereference(dd->sdma_map);
799 	if (unlikely(!m)) {
800 		rcu_read_unlock();
801 		return &dd->per_sdma[0];
802 	}
803 	e = m->map[vl & m->mask];
804 	rval = e->sde[selector & e->mask];
805 	rcu_read_unlock();
806 
807 done:
808 	rval =  !rval ? &dd->per_sdma[0] : rval;
809 	trace_hfi1_sdma_engine_select(dd, selector, vl, rval->this_idx);
810 	return rval;
811 }
812 
813 /**
814  * sdma_select_engine_sc() - select sdma engine
815  * @dd: devdata
816  * @selector: a spreading factor
817  * @sc5: the 5 bit sc
818  *
819  *
820  * This function returns an engine based on the selector and an sc.
821  */
822 struct sdma_engine *sdma_select_engine_sc(
823 	struct hfi1_devdata *dd,
824 	u32 selector,
825 	u8 sc5)
826 {
827 	u8 vl = sc_to_vlt(dd, sc5);
828 
829 	return sdma_select_engine_vl(dd, selector, vl);
830 }
831 
832 struct sdma_rht_map_elem {
833 	u32 mask;
834 	u8 ctr;
835 	struct sdma_engine *sde[0];
836 };
837 
838 struct sdma_rht_node {
839 	unsigned long cpu_id;
840 	struct sdma_rht_map_elem *map[HFI1_MAX_VLS_SUPPORTED];
841 	struct rhash_head node;
842 };
843 
844 #define NR_CPUS_HINT 192
845 
846 static const struct rhashtable_params sdma_rht_params = {
847 	.nelem_hint = NR_CPUS_HINT,
848 	.head_offset = offsetof(struct sdma_rht_node, node),
849 	.key_offset = offsetof(struct sdma_rht_node, cpu_id),
850 	.key_len = FIELD_SIZEOF(struct sdma_rht_node, cpu_id),
851 	.max_size = NR_CPUS,
852 	.min_size = 8,
853 	.automatic_shrinking = true,
854 };
855 
856 /*
857  * sdma_select_user_engine() - select sdma engine based on user setup
858  * @dd: devdata
859  * @selector: a spreading factor
860  * @vl: this vl
861  *
862  * This function returns an sdma engine for a user sdma request.
863  * User defined sdma engine affinity setting is honored when applicable,
864  * otherwise system default sdma engine mapping is used. To ensure correct
865  * ordering, the mapping from <selector, vl> to sde must remain unchanged.
866  */
867 struct sdma_engine *sdma_select_user_engine(struct hfi1_devdata *dd,
868 					    u32 selector, u8 vl)
869 {
870 	struct sdma_rht_node *rht_node;
871 	struct sdma_engine *sde = NULL;
872 	const struct cpumask *current_mask = &current->cpus_allowed;
873 	unsigned long cpu_id;
874 
875 	/*
876 	 * To ensure that always the same sdma engine(s) will be
877 	 * selected make sure the process is pinned to this CPU only.
878 	 */
879 	if (cpumask_weight(current_mask) != 1)
880 		goto out;
881 
882 	cpu_id = smp_processor_id();
883 	rcu_read_lock();
884 	rht_node = rhashtable_lookup_fast(dd->sdma_rht, &cpu_id,
885 					  sdma_rht_params);
886 
887 	if (rht_node && rht_node->map[vl]) {
888 		struct sdma_rht_map_elem *map = rht_node->map[vl];
889 
890 		sde = map->sde[selector & map->mask];
891 	}
892 	rcu_read_unlock();
893 
894 	if (sde)
895 		return sde;
896 
897 out:
898 	return sdma_select_engine_vl(dd, selector, vl);
899 }
900 
901 static void sdma_populate_sde_map(struct sdma_rht_map_elem *map)
902 {
903 	int i;
904 
905 	for (i = 0; i < roundup_pow_of_two(map->ctr ? : 1) - map->ctr; i++)
906 		map->sde[map->ctr + i] = map->sde[i];
907 }
908 
909 static void sdma_cleanup_sde_map(struct sdma_rht_map_elem *map,
910 				 struct sdma_engine *sde)
911 {
912 	unsigned int i, pow;
913 
914 	/* only need to check the first ctr entries for a match */
915 	for (i = 0; i < map->ctr; i++) {
916 		if (map->sde[i] == sde) {
917 			memmove(&map->sde[i], &map->sde[i + 1],
918 				(map->ctr - i - 1) * sizeof(map->sde[0]));
919 			map->ctr--;
920 			pow = roundup_pow_of_two(map->ctr ? : 1);
921 			map->mask = pow - 1;
922 			sdma_populate_sde_map(map);
923 			break;
924 		}
925 	}
926 }
927 
928 /*
929  * Prevents concurrent reads and writes of the sdma engine cpu_mask
930  */
931 static DEFINE_MUTEX(process_to_sde_mutex);
932 
933 ssize_t sdma_set_cpu_to_sde_map(struct sdma_engine *sde, const char *buf,
934 				size_t count)
935 {
936 	struct hfi1_devdata *dd = sde->dd;
937 	cpumask_var_t mask, new_mask;
938 	unsigned long cpu;
939 	int ret, vl, sz;
940 	struct sdma_rht_node *rht_node;
941 
942 	vl = sdma_engine_get_vl(sde);
943 	if (unlikely(vl < 0 || vl >= ARRAY_SIZE(rht_node->map)))
944 		return -EINVAL;
945 
946 	ret = zalloc_cpumask_var(&mask, GFP_KERNEL);
947 	if (!ret)
948 		return -ENOMEM;
949 
950 	ret = zalloc_cpumask_var(&new_mask, GFP_KERNEL);
951 	if (!ret) {
952 		free_cpumask_var(mask);
953 		return -ENOMEM;
954 	}
955 	ret = cpulist_parse(buf, mask);
956 	if (ret)
957 		goto out_free;
958 
959 	if (!cpumask_subset(mask, cpu_online_mask)) {
960 		dd_dev_warn(sde->dd, "Invalid CPU mask\n");
961 		ret = -EINVAL;
962 		goto out_free;
963 	}
964 
965 	sz = sizeof(struct sdma_rht_map_elem) +
966 			(TXE_NUM_SDMA_ENGINES * sizeof(struct sdma_engine *));
967 
968 	mutex_lock(&process_to_sde_mutex);
969 
970 	for_each_cpu(cpu, mask) {
971 		/* Check if we have this already mapped */
972 		if (cpumask_test_cpu(cpu, &sde->cpu_mask)) {
973 			cpumask_set_cpu(cpu, new_mask);
974 			continue;
975 		}
976 
977 		rht_node = rhashtable_lookup_fast(dd->sdma_rht, &cpu,
978 						  sdma_rht_params);
979 		if (!rht_node) {
980 			rht_node = kzalloc(sizeof(*rht_node), GFP_KERNEL);
981 			if (!rht_node) {
982 				ret = -ENOMEM;
983 				goto out;
984 			}
985 
986 			rht_node->map[vl] = kzalloc(sz, GFP_KERNEL);
987 			if (!rht_node->map[vl]) {
988 				kfree(rht_node);
989 				ret = -ENOMEM;
990 				goto out;
991 			}
992 			rht_node->cpu_id = cpu;
993 			rht_node->map[vl]->mask = 0;
994 			rht_node->map[vl]->ctr = 1;
995 			rht_node->map[vl]->sde[0] = sde;
996 
997 			ret = rhashtable_insert_fast(dd->sdma_rht,
998 						     &rht_node->node,
999 						     sdma_rht_params);
1000 			if (ret) {
1001 				kfree(rht_node->map[vl]);
1002 				kfree(rht_node);
1003 				dd_dev_err(sde->dd, "Failed to set process to sde affinity for cpu %lu\n",
1004 					   cpu);
1005 				goto out;
1006 			}
1007 
1008 		} else {
1009 			int ctr, pow;
1010 
1011 			/* Add new user mappings */
1012 			if (!rht_node->map[vl])
1013 				rht_node->map[vl] = kzalloc(sz, GFP_KERNEL);
1014 
1015 			if (!rht_node->map[vl]) {
1016 				ret = -ENOMEM;
1017 				goto out;
1018 			}
1019 
1020 			rht_node->map[vl]->ctr++;
1021 			ctr = rht_node->map[vl]->ctr;
1022 			rht_node->map[vl]->sde[ctr - 1] = sde;
1023 			pow = roundup_pow_of_two(ctr);
1024 			rht_node->map[vl]->mask = pow - 1;
1025 
1026 			/* Populate the sde map table */
1027 			sdma_populate_sde_map(rht_node->map[vl]);
1028 		}
1029 		cpumask_set_cpu(cpu, new_mask);
1030 	}
1031 
1032 	/* Clean up old mappings */
1033 	for_each_cpu(cpu, cpu_online_mask) {
1034 		struct sdma_rht_node *rht_node;
1035 
1036 		/* Don't cleanup sdes that are set in the new mask */
1037 		if (cpumask_test_cpu(cpu, mask))
1038 			continue;
1039 
1040 		rht_node = rhashtable_lookup_fast(dd->sdma_rht, &cpu,
1041 						  sdma_rht_params);
1042 		if (rht_node) {
1043 			bool empty = true;
1044 			int i;
1045 
1046 			/* Remove mappings for old sde */
1047 			for (i = 0; i < HFI1_MAX_VLS_SUPPORTED; i++)
1048 				if (rht_node->map[i])
1049 					sdma_cleanup_sde_map(rht_node->map[i],
1050 							     sde);
1051 
1052 			/* Free empty hash table entries */
1053 			for (i = 0; i < HFI1_MAX_VLS_SUPPORTED; i++) {
1054 				if (!rht_node->map[i])
1055 					continue;
1056 
1057 				if (rht_node->map[i]->ctr) {
1058 					empty = false;
1059 					break;
1060 				}
1061 			}
1062 
1063 			if (empty) {
1064 				ret = rhashtable_remove_fast(dd->sdma_rht,
1065 							     &rht_node->node,
1066 							     sdma_rht_params);
1067 				WARN_ON(ret);
1068 
1069 				for (i = 0; i < HFI1_MAX_VLS_SUPPORTED; i++)
1070 					kfree(rht_node->map[i]);
1071 
1072 				kfree(rht_node);
1073 			}
1074 		}
1075 	}
1076 
1077 	cpumask_copy(&sde->cpu_mask, new_mask);
1078 out:
1079 	mutex_unlock(&process_to_sde_mutex);
1080 out_free:
1081 	free_cpumask_var(mask);
1082 	free_cpumask_var(new_mask);
1083 	return ret ? : strnlen(buf, PAGE_SIZE);
1084 }
1085 
1086 ssize_t sdma_get_cpu_to_sde_map(struct sdma_engine *sde, char *buf)
1087 {
1088 	mutex_lock(&process_to_sde_mutex);
1089 	if (cpumask_empty(&sde->cpu_mask))
1090 		snprintf(buf, PAGE_SIZE, "%s\n", "empty");
1091 	else
1092 		cpumap_print_to_pagebuf(true, buf, &sde->cpu_mask);
1093 	mutex_unlock(&process_to_sde_mutex);
1094 	return strnlen(buf, PAGE_SIZE);
1095 }
1096 
1097 static void sdma_rht_free(void *ptr, void *arg)
1098 {
1099 	struct sdma_rht_node *rht_node = ptr;
1100 	int i;
1101 
1102 	for (i = 0; i < HFI1_MAX_VLS_SUPPORTED; i++)
1103 		kfree(rht_node->map[i]);
1104 
1105 	kfree(rht_node);
1106 }
1107 
1108 /**
1109  * sdma_seqfile_dump_cpu_list() - debugfs dump the cpu to sdma mappings
1110  * @s: seq file
1111  * @dd: hfi1_devdata
1112  * @cpuid: cpu id
1113  *
1114  * This routine dumps the process to sde mappings per cpu
1115  */
1116 void sdma_seqfile_dump_cpu_list(struct seq_file *s,
1117 				struct hfi1_devdata *dd,
1118 				unsigned long cpuid)
1119 {
1120 	struct sdma_rht_node *rht_node;
1121 	int i, j;
1122 
1123 	rht_node = rhashtable_lookup_fast(dd->sdma_rht, &cpuid,
1124 					  sdma_rht_params);
1125 	if (!rht_node)
1126 		return;
1127 
1128 	seq_printf(s, "cpu%3lu: ", cpuid);
1129 	for (i = 0; i < HFI1_MAX_VLS_SUPPORTED; i++) {
1130 		if (!rht_node->map[i] || !rht_node->map[i]->ctr)
1131 			continue;
1132 
1133 		seq_printf(s, " vl%d: [", i);
1134 
1135 		for (j = 0; j < rht_node->map[i]->ctr; j++) {
1136 			if (!rht_node->map[i]->sde[j])
1137 				continue;
1138 
1139 			if (j > 0)
1140 				seq_puts(s, ",");
1141 
1142 			seq_printf(s, " sdma%2d",
1143 				   rht_node->map[i]->sde[j]->this_idx);
1144 		}
1145 		seq_puts(s, " ]");
1146 	}
1147 
1148 	seq_puts(s, "\n");
1149 }
1150 
1151 /*
1152  * Free the indicated map struct
1153  */
1154 static void sdma_map_free(struct sdma_vl_map *m)
1155 {
1156 	int i;
1157 
1158 	for (i = 0; m && i < m->actual_vls; i++)
1159 		kfree(m->map[i]);
1160 	kfree(m);
1161 }
1162 
1163 /*
1164  * Handle RCU callback
1165  */
1166 static void sdma_map_rcu_callback(struct rcu_head *list)
1167 {
1168 	struct sdma_vl_map *m = container_of(list, struct sdma_vl_map, list);
1169 
1170 	sdma_map_free(m);
1171 }
1172 
1173 /**
1174  * sdma_map_init - called when # vls change
1175  * @dd: hfi1_devdata
1176  * @port: port number
1177  * @num_vls: number of vls
1178  * @vl_engines: per vl engine mapping (optional)
1179  *
1180  * This routine changes the mapping based on the number of vls.
1181  *
1182  * vl_engines is used to specify a non-uniform vl/engine loading. NULL
1183  * implies auto computing the loading and giving each VLs a uniform
1184  * distribution of engines per VL.
1185  *
1186  * The auto algorithm computes the sde_per_vl and the number of extra
1187  * engines.  Any extra engines are added from the last VL on down.
1188  *
1189  * rcu locking is used here to control access to the mapping fields.
1190  *
1191  * If either the num_vls or num_sdma are non-power of 2, the array sizes
1192  * in the struct sdma_vl_map and the struct sdma_map_elem are rounded
1193  * up to the next highest power of 2 and the first entry is reused
1194  * in a round robin fashion.
1195  *
1196  * If an error occurs the map change is not done and the mapping is
1197  * not changed.
1198  *
1199  */
1200 int sdma_map_init(struct hfi1_devdata *dd, u8 port, u8 num_vls, u8 *vl_engines)
1201 {
1202 	int i, j;
1203 	int extra, sde_per_vl;
1204 	int engine = 0;
1205 	u8 lvl_engines[OPA_MAX_VLS];
1206 	struct sdma_vl_map *oldmap, *newmap;
1207 
1208 	if (!(dd->flags & HFI1_HAS_SEND_DMA))
1209 		return 0;
1210 
1211 	if (!vl_engines) {
1212 		/* truncate divide */
1213 		sde_per_vl = dd->num_sdma / num_vls;
1214 		/* extras */
1215 		extra = dd->num_sdma % num_vls;
1216 		vl_engines = lvl_engines;
1217 		/* add extras from last vl down */
1218 		for (i = num_vls - 1; i >= 0; i--, extra--)
1219 			vl_engines[i] = sde_per_vl + (extra > 0 ? 1 : 0);
1220 	}
1221 	/* build new map */
1222 	newmap = kzalloc(
1223 		sizeof(struct sdma_vl_map) +
1224 			roundup_pow_of_two(num_vls) *
1225 			sizeof(struct sdma_map_elem *),
1226 		GFP_KERNEL);
1227 	if (!newmap)
1228 		goto bail;
1229 	newmap->actual_vls = num_vls;
1230 	newmap->vls = roundup_pow_of_two(num_vls);
1231 	newmap->mask = (1 << ilog2(newmap->vls)) - 1;
1232 	/* initialize back-map */
1233 	for (i = 0; i < TXE_NUM_SDMA_ENGINES; i++)
1234 		newmap->engine_to_vl[i] = -1;
1235 	for (i = 0; i < newmap->vls; i++) {
1236 		/* save for wrap around */
1237 		int first_engine = engine;
1238 
1239 		if (i < newmap->actual_vls) {
1240 			int sz = roundup_pow_of_two(vl_engines[i]);
1241 
1242 			/* only allocate once */
1243 			newmap->map[i] = kzalloc(
1244 				sizeof(struct sdma_map_elem) +
1245 					sz * sizeof(struct sdma_engine *),
1246 				GFP_KERNEL);
1247 			if (!newmap->map[i])
1248 				goto bail;
1249 			newmap->map[i]->mask = (1 << ilog2(sz)) - 1;
1250 			/* assign engines */
1251 			for (j = 0; j < sz; j++) {
1252 				newmap->map[i]->sde[j] =
1253 					&dd->per_sdma[engine];
1254 				if (++engine >= first_engine + vl_engines[i])
1255 					/* wrap back to first engine */
1256 					engine = first_engine;
1257 			}
1258 			/* assign back-map */
1259 			for (j = 0; j < vl_engines[i]; j++)
1260 				newmap->engine_to_vl[first_engine + j] = i;
1261 		} else {
1262 			/* just re-use entry without allocating */
1263 			newmap->map[i] = newmap->map[i % num_vls];
1264 		}
1265 		engine = first_engine + vl_engines[i];
1266 	}
1267 	/* newmap in hand, save old map */
1268 	spin_lock_irq(&dd->sde_map_lock);
1269 	oldmap = rcu_dereference_protected(dd->sdma_map,
1270 					   lockdep_is_held(&dd->sde_map_lock));
1271 
1272 	/* publish newmap */
1273 	rcu_assign_pointer(dd->sdma_map, newmap);
1274 
1275 	spin_unlock_irq(&dd->sde_map_lock);
1276 	/* success, free any old map after grace period */
1277 	if (oldmap)
1278 		call_rcu(&oldmap->list, sdma_map_rcu_callback);
1279 	return 0;
1280 bail:
1281 	/* free any partial allocation */
1282 	sdma_map_free(newmap);
1283 	return -ENOMEM;
1284 }
1285 
1286 /**
1287  * sdma_clean()  Clean up allocated memory
1288  * @dd:          struct hfi1_devdata
1289  * @num_engines: num sdma engines
1290  *
1291  * This routine can be called regardless of the success of
1292  * sdma_init()
1293  */
1294 void sdma_clean(struct hfi1_devdata *dd, size_t num_engines)
1295 {
1296 	size_t i;
1297 	struct sdma_engine *sde;
1298 
1299 	if (dd->sdma_pad_dma) {
1300 		dma_free_coherent(&dd->pcidev->dev, 4,
1301 				  (void *)dd->sdma_pad_dma,
1302 				  dd->sdma_pad_phys);
1303 		dd->sdma_pad_dma = NULL;
1304 		dd->sdma_pad_phys = 0;
1305 	}
1306 	if (dd->sdma_heads_dma) {
1307 		dma_free_coherent(&dd->pcidev->dev, dd->sdma_heads_size,
1308 				  (void *)dd->sdma_heads_dma,
1309 				  dd->sdma_heads_phys);
1310 		dd->sdma_heads_dma = NULL;
1311 		dd->sdma_heads_phys = 0;
1312 	}
1313 	for (i = 0; dd->per_sdma && i < num_engines; ++i) {
1314 		sde = &dd->per_sdma[i];
1315 
1316 		sde->head_dma = NULL;
1317 		sde->head_phys = 0;
1318 
1319 		if (sde->descq) {
1320 			dma_free_coherent(
1321 				&dd->pcidev->dev,
1322 				sde->descq_cnt * sizeof(u64[2]),
1323 				sde->descq,
1324 				sde->descq_phys
1325 			);
1326 			sde->descq = NULL;
1327 			sde->descq_phys = 0;
1328 		}
1329 		kvfree(sde->tx_ring);
1330 		sde->tx_ring = NULL;
1331 	}
1332 	spin_lock_irq(&dd->sde_map_lock);
1333 	sdma_map_free(rcu_access_pointer(dd->sdma_map));
1334 	RCU_INIT_POINTER(dd->sdma_map, NULL);
1335 	spin_unlock_irq(&dd->sde_map_lock);
1336 	synchronize_rcu();
1337 	kfree(dd->per_sdma);
1338 	dd->per_sdma = NULL;
1339 
1340 	if (dd->sdma_rht) {
1341 		rhashtable_free_and_destroy(dd->sdma_rht, sdma_rht_free, NULL);
1342 		kfree(dd->sdma_rht);
1343 		dd->sdma_rht = NULL;
1344 	}
1345 }
1346 
1347 /**
1348  * sdma_init() - called when device probed
1349  * @dd: hfi1_devdata
1350  * @port: port number (currently only zero)
1351  *
1352  * Initializes each sde and its csrs.
1353  * Interrupts are not required to be enabled.
1354  *
1355  * Returns:
1356  * 0 - success, -errno on failure
1357  */
1358 int sdma_init(struct hfi1_devdata *dd, u8 port)
1359 {
1360 	unsigned this_idx;
1361 	struct sdma_engine *sde;
1362 	struct rhashtable *tmp_sdma_rht;
1363 	u16 descq_cnt;
1364 	void *curr_head;
1365 	struct hfi1_pportdata *ppd = dd->pport + port;
1366 	u32 per_sdma_credits;
1367 	uint idle_cnt = sdma_idle_cnt;
1368 	size_t num_engines = chip_sdma_engines(dd);
1369 	int ret = -ENOMEM;
1370 
1371 	if (!HFI1_CAP_IS_KSET(SDMA)) {
1372 		HFI1_CAP_CLEAR(SDMA_AHG);
1373 		return 0;
1374 	}
1375 	if (mod_num_sdma &&
1376 	    /* can't exceed chip support */
1377 	    mod_num_sdma <= chip_sdma_engines(dd) &&
1378 	    /* count must be >= vls */
1379 	    mod_num_sdma >= num_vls)
1380 		num_engines = mod_num_sdma;
1381 
1382 	dd_dev_info(dd, "SDMA mod_num_sdma: %u\n", mod_num_sdma);
1383 	dd_dev_info(dd, "SDMA chip_sdma_engines: %u\n", chip_sdma_engines(dd));
1384 	dd_dev_info(dd, "SDMA chip_sdma_mem_size: %u\n",
1385 		    chip_sdma_mem_size(dd));
1386 
1387 	per_sdma_credits =
1388 		chip_sdma_mem_size(dd) / (num_engines * SDMA_BLOCK_SIZE);
1389 
1390 	/* set up freeze waitqueue */
1391 	init_waitqueue_head(&dd->sdma_unfreeze_wq);
1392 	atomic_set(&dd->sdma_unfreeze_count, 0);
1393 
1394 	descq_cnt = sdma_get_descq_cnt();
1395 	dd_dev_info(dd, "SDMA engines %zu descq_cnt %u\n",
1396 		    num_engines, descq_cnt);
1397 
1398 	/* alloc memory for array of send engines */
1399 	dd->per_sdma = kcalloc_node(num_engines, sizeof(*dd->per_sdma),
1400 				    GFP_KERNEL, dd->node);
1401 	if (!dd->per_sdma)
1402 		return ret;
1403 
1404 	idle_cnt = ns_to_cclock(dd, idle_cnt);
1405 	if (idle_cnt)
1406 		dd->default_desc1 =
1407 			SDMA_DESC1_HEAD_TO_HOST_FLAG;
1408 	else
1409 		dd->default_desc1 =
1410 			SDMA_DESC1_INT_REQ_FLAG;
1411 
1412 	if (!sdma_desct_intr)
1413 		sdma_desct_intr = SDMA_DESC_INTR;
1414 
1415 	/* Allocate memory for SendDMA descriptor FIFOs */
1416 	for (this_idx = 0; this_idx < num_engines; ++this_idx) {
1417 		sde = &dd->per_sdma[this_idx];
1418 		sde->dd = dd;
1419 		sde->ppd = ppd;
1420 		sde->this_idx = this_idx;
1421 		sde->descq_cnt = descq_cnt;
1422 		sde->desc_avail = sdma_descq_freecnt(sde);
1423 		sde->sdma_shift = ilog2(descq_cnt);
1424 		sde->sdma_mask = (1 << sde->sdma_shift) - 1;
1425 
1426 		/* Create a mask specifically for each interrupt source */
1427 		sde->int_mask = (u64)1 << (0 * TXE_NUM_SDMA_ENGINES +
1428 					   this_idx);
1429 		sde->progress_mask = (u64)1 << (1 * TXE_NUM_SDMA_ENGINES +
1430 						this_idx);
1431 		sde->idle_mask = (u64)1 << (2 * TXE_NUM_SDMA_ENGINES +
1432 					    this_idx);
1433 		/* Create a combined mask to cover all 3 interrupt sources */
1434 		sde->imask = sde->int_mask | sde->progress_mask |
1435 			     sde->idle_mask;
1436 
1437 		spin_lock_init(&sde->tail_lock);
1438 		seqlock_init(&sde->head_lock);
1439 		spin_lock_init(&sde->senddmactrl_lock);
1440 		spin_lock_init(&sde->flushlist_lock);
1441 		seqlock_init(&sde->waitlock);
1442 		/* insure there is always a zero bit */
1443 		sde->ahg_bits = 0xfffffffe00000000ULL;
1444 
1445 		sdma_set_state(sde, sdma_state_s00_hw_down);
1446 
1447 		/* set up reference counting */
1448 		kref_init(&sde->state.kref);
1449 		init_completion(&sde->state.comp);
1450 
1451 		INIT_LIST_HEAD(&sde->flushlist);
1452 		INIT_LIST_HEAD(&sde->dmawait);
1453 
1454 		sde->tail_csr =
1455 			get_kctxt_csr_addr(dd, this_idx, SD(TAIL));
1456 
1457 		tasklet_init(&sde->sdma_hw_clean_up_task, sdma_hw_clean_up_task,
1458 			     (unsigned long)sde);
1459 
1460 		tasklet_init(&sde->sdma_sw_clean_up_task, sdma_sw_clean_up_task,
1461 			     (unsigned long)sde);
1462 		INIT_WORK(&sde->err_halt_worker, sdma_err_halt_wait);
1463 		INIT_WORK(&sde->flush_worker, sdma_field_flush);
1464 
1465 		sde->progress_check_head = 0;
1466 
1467 		timer_setup(&sde->err_progress_check_timer,
1468 			    sdma_err_progress_check, 0);
1469 
1470 		sde->descq = dma_alloc_coherent(&dd->pcidev->dev,
1471 						descq_cnt * sizeof(u64[2]),
1472 						&sde->descq_phys, GFP_KERNEL);
1473 		if (!sde->descq)
1474 			goto bail;
1475 		sde->tx_ring =
1476 			kvzalloc_node(array_size(descq_cnt,
1477 						 sizeof(struct sdma_txreq *)),
1478 				      GFP_KERNEL, dd->node);
1479 		if (!sde->tx_ring)
1480 			goto bail;
1481 	}
1482 
1483 	dd->sdma_heads_size = L1_CACHE_BYTES * num_engines;
1484 	/* Allocate memory for DMA of head registers to memory */
1485 	dd->sdma_heads_dma = dma_alloc_coherent(&dd->pcidev->dev,
1486 						dd->sdma_heads_size,
1487 						&dd->sdma_heads_phys,
1488 						GFP_KERNEL);
1489 	if (!dd->sdma_heads_dma) {
1490 		dd_dev_err(dd, "failed to allocate SendDMA head memory\n");
1491 		goto bail;
1492 	}
1493 
1494 	/* Allocate memory for pad */
1495 	dd->sdma_pad_dma = dma_alloc_coherent(&dd->pcidev->dev, sizeof(u32),
1496 					      &dd->sdma_pad_phys, GFP_KERNEL);
1497 	if (!dd->sdma_pad_dma) {
1498 		dd_dev_err(dd, "failed to allocate SendDMA pad memory\n");
1499 		goto bail;
1500 	}
1501 
1502 	/* assign each engine to different cacheline and init registers */
1503 	curr_head = (void *)dd->sdma_heads_dma;
1504 	for (this_idx = 0; this_idx < num_engines; ++this_idx) {
1505 		unsigned long phys_offset;
1506 
1507 		sde = &dd->per_sdma[this_idx];
1508 
1509 		sde->head_dma = curr_head;
1510 		curr_head += L1_CACHE_BYTES;
1511 		phys_offset = (unsigned long)sde->head_dma -
1512 			      (unsigned long)dd->sdma_heads_dma;
1513 		sde->head_phys = dd->sdma_heads_phys + phys_offset;
1514 		init_sdma_regs(sde, per_sdma_credits, idle_cnt);
1515 	}
1516 	dd->flags |= HFI1_HAS_SEND_DMA;
1517 	dd->flags |= idle_cnt ? HFI1_HAS_SDMA_TIMEOUT : 0;
1518 	dd->num_sdma = num_engines;
1519 	ret = sdma_map_init(dd, port, ppd->vls_operational, NULL);
1520 	if (ret < 0)
1521 		goto bail;
1522 
1523 	tmp_sdma_rht = kzalloc(sizeof(*tmp_sdma_rht), GFP_KERNEL);
1524 	if (!tmp_sdma_rht) {
1525 		ret = -ENOMEM;
1526 		goto bail;
1527 	}
1528 
1529 	ret = rhashtable_init(tmp_sdma_rht, &sdma_rht_params);
1530 	if (ret < 0)
1531 		goto bail;
1532 	dd->sdma_rht = tmp_sdma_rht;
1533 
1534 	dd_dev_info(dd, "SDMA num_sdma: %u\n", dd->num_sdma);
1535 	return 0;
1536 
1537 bail:
1538 	sdma_clean(dd, num_engines);
1539 	return ret;
1540 }
1541 
1542 /**
1543  * sdma_all_running() - called when the link goes up
1544  * @dd: hfi1_devdata
1545  *
1546  * This routine moves all engines to the running state.
1547  */
1548 void sdma_all_running(struct hfi1_devdata *dd)
1549 {
1550 	struct sdma_engine *sde;
1551 	unsigned int i;
1552 
1553 	/* move all engines to running */
1554 	for (i = 0; i < dd->num_sdma; ++i) {
1555 		sde = &dd->per_sdma[i];
1556 		sdma_process_event(sde, sdma_event_e30_go_running);
1557 	}
1558 }
1559 
1560 /**
1561  * sdma_all_idle() - called when the link goes down
1562  * @dd: hfi1_devdata
1563  *
1564  * This routine moves all engines to the idle state.
1565  */
1566 void sdma_all_idle(struct hfi1_devdata *dd)
1567 {
1568 	struct sdma_engine *sde;
1569 	unsigned int i;
1570 
1571 	/* idle all engines */
1572 	for (i = 0; i < dd->num_sdma; ++i) {
1573 		sde = &dd->per_sdma[i];
1574 		sdma_process_event(sde, sdma_event_e70_go_idle);
1575 	}
1576 }
1577 
1578 /**
1579  * sdma_start() - called to kick off state processing for all engines
1580  * @dd: hfi1_devdata
1581  *
1582  * This routine is for kicking off the state processing for all required
1583  * sdma engines.  Interrupts need to be working at this point.
1584  *
1585  */
1586 void sdma_start(struct hfi1_devdata *dd)
1587 {
1588 	unsigned i;
1589 	struct sdma_engine *sde;
1590 
1591 	/* kick off the engines state processing */
1592 	for (i = 0; i < dd->num_sdma; ++i) {
1593 		sde = &dd->per_sdma[i];
1594 		sdma_process_event(sde, sdma_event_e10_go_hw_start);
1595 	}
1596 }
1597 
1598 /**
1599  * sdma_exit() - used when module is removed
1600  * @dd: hfi1_devdata
1601  */
1602 void sdma_exit(struct hfi1_devdata *dd)
1603 {
1604 	unsigned this_idx;
1605 	struct sdma_engine *sde;
1606 
1607 	for (this_idx = 0; dd->per_sdma && this_idx < dd->num_sdma;
1608 			++this_idx) {
1609 		sde = &dd->per_sdma[this_idx];
1610 		if (!list_empty(&sde->dmawait))
1611 			dd_dev_err(dd, "sde %u: dmawait list not empty!\n",
1612 				   sde->this_idx);
1613 		sdma_process_event(sde, sdma_event_e00_go_hw_down);
1614 
1615 		del_timer_sync(&sde->err_progress_check_timer);
1616 
1617 		/*
1618 		 * This waits for the state machine to exit so it is not
1619 		 * necessary to kill the sdma_sw_clean_up_task to make sure
1620 		 * it is not running.
1621 		 */
1622 		sdma_finalput(&sde->state);
1623 	}
1624 }
1625 
1626 /*
1627  * unmap the indicated descriptor
1628  */
1629 static inline void sdma_unmap_desc(
1630 	struct hfi1_devdata *dd,
1631 	struct sdma_desc *descp)
1632 {
1633 	switch (sdma_mapping_type(descp)) {
1634 	case SDMA_MAP_SINGLE:
1635 		dma_unmap_single(
1636 			&dd->pcidev->dev,
1637 			sdma_mapping_addr(descp),
1638 			sdma_mapping_len(descp),
1639 			DMA_TO_DEVICE);
1640 		break;
1641 	case SDMA_MAP_PAGE:
1642 		dma_unmap_page(
1643 			&dd->pcidev->dev,
1644 			sdma_mapping_addr(descp),
1645 			sdma_mapping_len(descp),
1646 			DMA_TO_DEVICE);
1647 		break;
1648 	}
1649 }
1650 
1651 /*
1652  * return the mode as indicated by the first
1653  * descriptor in the tx.
1654  */
1655 static inline u8 ahg_mode(struct sdma_txreq *tx)
1656 {
1657 	return (tx->descp[0].qw[1] & SDMA_DESC1_HEADER_MODE_SMASK)
1658 		>> SDMA_DESC1_HEADER_MODE_SHIFT;
1659 }
1660 
1661 /**
1662  * __sdma_txclean() - clean tx of mappings, descp *kmalloc's
1663  * @dd: hfi1_devdata for unmapping
1664  * @tx: tx request to clean
1665  *
1666  * This is used in the progress routine to clean the tx or
1667  * by the ULP to toss an in-process tx build.
1668  *
1669  * The code can be called multiple times without issue.
1670  *
1671  */
1672 void __sdma_txclean(
1673 	struct hfi1_devdata *dd,
1674 	struct sdma_txreq *tx)
1675 {
1676 	u16 i;
1677 
1678 	if (tx->num_desc) {
1679 		u8 skip = 0, mode = ahg_mode(tx);
1680 
1681 		/* unmap first */
1682 		sdma_unmap_desc(dd, &tx->descp[0]);
1683 		/* determine number of AHG descriptors to skip */
1684 		if (mode > SDMA_AHG_APPLY_UPDATE1)
1685 			skip = mode >> 1;
1686 		for (i = 1 + skip; i < tx->num_desc; i++)
1687 			sdma_unmap_desc(dd, &tx->descp[i]);
1688 		tx->num_desc = 0;
1689 	}
1690 	kfree(tx->coalesce_buf);
1691 	tx->coalesce_buf = NULL;
1692 	/* kmalloc'ed descp */
1693 	if (unlikely(tx->desc_limit > ARRAY_SIZE(tx->descs))) {
1694 		tx->desc_limit = ARRAY_SIZE(tx->descs);
1695 		kfree(tx->descp);
1696 	}
1697 }
1698 
1699 static inline u16 sdma_gethead(struct sdma_engine *sde)
1700 {
1701 	struct hfi1_devdata *dd = sde->dd;
1702 	int use_dmahead;
1703 	u16 hwhead;
1704 
1705 #ifdef CONFIG_SDMA_VERBOSITY
1706 	dd_dev_err(sde->dd, "CONFIG SDMA(%u) %s:%d %s()\n",
1707 		   sde->this_idx, slashstrip(__FILE__), __LINE__, __func__);
1708 #endif
1709 
1710 retry:
1711 	use_dmahead = HFI1_CAP_IS_KSET(USE_SDMA_HEAD) && __sdma_running(sde) &&
1712 					(dd->flags & HFI1_HAS_SDMA_TIMEOUT);
1713 	hwhead = use_dmahead ?
1714 		(u16)le64_to_cpu(*sde->head_dma) :
1715 		(u16)read_sde_csr(sde, SD(HEAD));
1716 
1717 	if (unlikely(HFI1_CAP_IS_KSET(SDMA_HEAD_CHECK))) {
1718 		u16 cnt;
1719 		u16 swtail;
1720 		u16 swhead;
1721 		int sane;
1722 
1723 		swhead = sde->descq_head & sde->sdma_mask;
1724 		/* this code is really bad for cache line trading */
1725 		swtail = READ_ONCE(sde->descq_tail) & sde->sdma_mask;
1726 		cnt = sde->descq_cnt;
1727 
1728 		if (swhead < swtail)
1729 			/* not wrapped */
1730 			sane = (hwhead >= swhead) & (hwhead <= swtail);
1731 		else if (swhead > swtail)
1732 			/* wrapped around */
1733 			sane = ((hwhead >= swhead) && (hwhead < cnt)) ||
1734 				(hwhead <= swtail);
1735 		else
1736 			/* empty */
1737 			sane = (hwhead == swhead);
1738 
1739 		if (unlikely(!sane)) {
1740 			dd_dev_err(dd, "SDMA(%u) bad head (%s) hwhd=%hu swhd=%hu swtl=%hu cnt=%hu\n",
1741 				   sde->this_idx,
1742 				   use_dmahead ? "dma" : "kreg",
1743 				   hwhead, swhead, swtail, cnt);
1744 			if (use_dmahead) {
1745 				/* try one more time, using csr */
1746 				use_dmahead = 0;
1747 				goto retry;
1748 			}
1749 			/* proceed as if no progress */
1750 			hwhead = swhead;
1751 		}
1752 	}
1753 	return hwhead;
1754 }
1755 
1756 /*
1757  * This is called when there are send DMA descriptors that might be
1758  * available.
1759  *
1760  * This is called with head_lock held.
1761  */
1762 static void sdma_desc_avail(struct sdma_engine *sde, uint avail)
1763 {
1764 	struct iowait *wait, *nw, *twait;
1765 	struct iowait *waits[SDMA_WAIT_BATCH_SIZE];
1766 	uint i, n = 0, seq, tidx = 0;
1767 
1768 #ifdef CONFIG_SDMA_VERBOSITY
1769 	dd_dev_err(sde->dd, "CONFIG SDMA(%u) %s:%d %s()\n", sde->this_idx,
1770 		   slashstrip(__FILE__), __LINE__, __func__);
1771 	dd_dev_err(sde->dd, "avail: %u\n", avail);
1772 #endif
1773 
1774 	do {
1775 		seq = read_seqbegin(&sde->waitlock);
1776 		if (!list_empty(&sde->dmawait)) {
1777 			/* at least one item */
1778 			write_seqlock(&sde->waitlock);
1779 			/* Harvest waiters wanting DMA descriptors */
1780 			list_for_each_entry_safe(
1781 					wait,
1782 					nw,
1783 					&sde->dmawait,
1784 					list) {
1785 				u32 num_desc;
1786 
1787 				if (!wait->wakeup)
1788 					continue;
1789 				if (n == ARRAY_SIZE(waits))
1790 					break;
1791 				iowait_init_priority(wait);
1792 				num_desc = iowait_get_all_desc(wait);
1793 				if (num_desc > avail)
1794 					break;
1795 				avail -= num_desc;
1796 				/* Find the top-priority wait memeber */
1797 				if (n) {
1798 					twait = waits[tidx];
1799 					tidx =
1800 					    iowait_priority_update_top(wait,
1801 								       twait,
1802 								       n,
1803 								       tidx);
1804 				}
1805 				list_del_init(&wait->list);
1806 				waits[n++] = wait;
1807 			}
1808 			write_sequnlock(&sde->waitlock);
1809 			break;
1810 		}
1811 	} while (read_seqretry(&sde->waitlock, seq));
1812 
1813 	/* Schedule the top-priority entry first */
1814 	if (n)
1815 		waits[tidx]->wakeup(waits[tidx], SDMA_AVAIL_REASON);
1816 
1817 	for (i = 0; i < n; i++)
1818 		if (i != tidx)
1819 			waits[i]->wakeup(waits[i], SDMA_AVAIL_REASON);
1820 }
1821 
1822 /* head_lock must be held */
1823 static void sdma_make_progress(struct sdma_engine *sde, u64 status)
1824 {
1825 	struct sdma_txreq *txp = NULL;
1826 	int progress = 0;
1827 	u16 hwhead, swhead;
1828 	int idle_check_done = 0;
1829 
1830 	hwhead = sdma_gethead(sde);
1831 
1832 	/* The reason for some of the complexity of this code is that
1833 	 * not all descriptors have corresponding txps.  So, we have to
1834 	 * be able to skip over descs until we wander into the range of
1835 	 * the next txp on the list.
1836 	 */
1837 
1838 retry:
1839 	txp = get_txhead(sde);
1840 	swhead = sde->descq_head & sde->sdma_mask;
1841 	trace_hfi1_sdma_progress(sde, hwhead, swhead, txp);
1842 	while (swhead != hwhead) {
1843 		/* advance head, wrap if needed */
1844 		swhead = ++sde->descq_head & sde->sdma_mask;
1845 
1846 		/* if now past this txp's descs, do the callback */
1847 		if (txp && txp->next_descq_idx == swhead) {
1848 			/* remove from list */
1849 			sde->tx_ring[sde->tx_head++ & sde->sdma_mask] = NULL;
1850 			complete_tx(sde, txp, SDMA_TXREQ_S_OK);
1851 			/* see if there is another txp */
1852 			txp = get_txhead(sde);
1853 		}
1854 		trace_hfi1_sdma_progress(sde, hwhead, swhead, txp);
1855 		progress++;
1856 	}
1857 
1858 	/*
1859 	 * The SDMA idle interrupt is not guaranteed to be ordered with respect
1860 	 * to updates to the the dma_head location in host memory. The head
1861 	 * value read might not be fully up to date. If there are pending
1862 	 * descriptors and the SDMA idle interrupt fired then read from the
1863 	 * CSR SDMA head instead to get the latest value from the hardware.
1864 	 * The hardware SDMA head should be read at most once in this invocation
1865 	 * of sdma_make_progress(..) which is ensured by idle_check_done flag
1866 	 */
1867 	if ((status & sde->idle_mask) && !idle_check_done) {
1868 		u16 swtail;
1869 
1870 		swtail = READ_ONCE(sde->descq_tail) & sde->sdma_mask;
1871 		if (swtail != hwhead) {
1872 			hwhead = (u16)read_sde_csr(sde, SD(HEAD));
1873 			idle_check_done = 1;
1874 			goto retry;
1875 		}
1876 	}
1877 
1878 	sde->last_status = status;
1879 	if (progress)
1880 		sdma_desc_avail(sde, sdma_descq_freecnt(sde));
1881 }
1882 
1883 /*
1884  * sdma_engine_interrupt() - interrupt handler for engine
1885  * @sde: sdma engine
1886  * @status: sdma interrupt reason
1887  *
1888  * Status is a mask of the 3 possible interrupts for this engine.  It will
1889  * contain bits _only_ for this SDMA engine.  It will contain at least one
1890  * bit, it may contain more.
1891  */
1892 void sdma_engine_interrupt(struct sdma_engine *sde, u64 status)
1893 {
1894 	trace_hfi1_sdma_engine_interrupt(sde, status);
1895 	write_seqlock(&sde->head_lock);
1896 	sdma_set_desc_cnt(sde, sdma_desct_intr);
1897 	if (status & sde->idle_mask)
1898 		sde->idle_int_cnt++;
1899 	else if (status & sde->progress_mask)
1900 		sde->progress_int_cnt++;
1901 	else if (status & sde->int_mask)
1902 		sde->sdma_int_cnt++;
1903 	sdma_make_progress(sde, status);
1904 	write_sequnlock(&sde->head_lock);
1905 }
1906 
1907 /**
1908  * sdma_engine_error() - error handler for engine
1909  * @sde: sdma engine
1910  * @status: sdma interrupt reason
1911  */
1912 void sdma_engine_error(struct sdma_engine *sde, u64 status)
1913 {
1914 	unsigned long flags;
1915 
1916 #ifdef CONFIG_SDMA_VERBOSITY
1917 	dd_dev_err(sde->dd, "CONFIG SDMA(%u) error status 0x%llx state %s\n",
1918 		   sde->this_idx,
1919 		   (unsigned long long)status,
1920 		   sdma_state_names[sde->state.current_state]);
1921 #endif
1922 	spin_lock_irqsave(&sde->tail_lock, flags);
1923 	write_seqlock(&sde->head_lock);
1924 	if (status & ALL_SDMA_ENG_HALT_ERRS)
1925 		__sdma_process_event(sde, sdma_event_e60_hw_halted);
1926 	if (status & ~SD(ENG_ERR_STATUS_SDMA_HALT_ERR_SMASK)) {
1927 		dd_dev_err(sde->dd,
1928 			   "SDMA (%u) engine error: 0x%llx state %s\n",
1929 			   sde->this_idx,
1930 			   (unsigned long long)status,
1931 			   sdma_state_names[sde->state.current_state]);
1932 		dump_sdma_state(sde);
1933 	}
1934 	write_sequnlock(&sde->head_lock);
1935 	spin_unlock_irqrestore(&sde->tail_lock, flags);
1936 }
1937 
1938 static void sdma_sendctrl(struct sdma_engine *sde, unsigned op)
1939 {
1940 	u64 set_senddmactrl = 0;
1941 	u64 clr_senddmactrl = 0;
1942 	unsigned long flags;
1943 
1944 #ifdef CONFIG_SDMA_VERBOSITY
1945 	dd_dev_err(sde->dd, "CONFIG SDMA(%u) senddmactrl E=%d I=%d H=%d C=%d\n",
1946 		   sde->this_idx,
1947 		   (op & SDMA_SENDCTRL_OP_ENABLE) ? 1 : 0,
1948 		   (op & SDMA_SENDCTRL_OP_INTENABLE) ? 1 : 0,
1949 		   (op & SDMA_SENDCTRL_OP_HALT) ? 1 : 0,
1950 		   (op & SDMA_SENDCTRL_OP_CLEANUP) ? 1 : 0);
1951 #endif
1952 
1953 	if (op & SDMA_SENDCTRL_OP_ENABLE)
1954 		set_senddmactrl |= SD(CTRL_SDMA_ENABLE_SMASK);
1955 	else
1956 		clr_senddmactrl |= SD(CTRL_SDMA_ENABLE_SMASK);
1957 
1958 	if (op & SDMA_SENDCTRL_OP_INTENABLE)
1959 		set_senddmactrl |= SD(CTRL_SDMA_INT_ENABLE_SMASK);
1960 	else
1961 		clr_senddmactrl |= SD(CTRL_SDMA_INT_ENABLE_SMASK);
1962 
1963 	if (op & SDMA_SENDCTRL_OP_HALT)
1964 		set_senddmactrl |= SD(CTRL_SDMA_HALT_SMASK);
1965 	else
1966 		clr_senddmactrl |= SD(CTRL_SDMA_HALT_SMASK);
1967 
1968 	spin_lock_irqsave(&sde->senddmactrl_lock, flags);
1969 
1970 	sde->p_senddmactrl |= set_senddmactrl;
1971 	sde->p_senddmactrl &= ~clr_senddmactrl;
1972 
1973 	if (op & SDMA_SENDCTRL_OP_CLEANUP)
1974 		write_sde_csr(sde, SD(CTRL),
1975 			      sde->p_senddmactrl |
1976 			      SD(CTRL_SDMA_CLEANUP_SMASK));
1977 	else
1978 		write_sde_csr(sde, SD(CTRL), sde->p_senddmactrl);
1979 
1980 	spin_unlock_irqrestore(&sde->senddmactrl_lock, flags);
1981 
1982 #ifdef CONFIG_SDMA_VERBOSITY
1983 	sdma_dumpstate(sde);
1984 #endif
1985 }
1986 
1987 static void sdma_setlengen(struct sdma_engine *sde)
1988 {
1989 #ifdef CONFIG_SDMA_VERBOSITY
1990 	dd_dev_err(sde->dd, "CONFIG SDMA(%u) %s:%d %s()\n",
1991 		   sde->this_idx, slashstrip(__FILE__), __LINE__, __func__);
1992 #endif
1993 
1994 	/*
1995 	 * Set SendDmaLenGen and clear-then-set the MSB of the generation
1996 	 * count to enable generation checking and load the internal
1997 	 * generation counter.
1998 	 */
1999 	write_sde_csr(sde, SD(LEN_GEN),
2000 		      (sde->descq_cnt / 64) << SD(LEN_GEN_LENGTH_SHIFT));
2001 	write_sde_csr(sde, SD(LEN_GEN),
2002 		      ((sde->descq_cnt / 64) << SD(LEN_GEN_LENGTH_SHIFT)) |
2003 		      (4ULL << SD(LEN_GEN_GENERATION_SHIFT)));
2004 }
2005 
2006 static inline void sdma_update_tail(struct sdma_engine *sde, u16 tail)
2007 {
2008 	/* Commit writes to memory and advance the tail on the chip */
2009 	smp_wmb(); /* see get_txhead() */
2010 	writeq(tail, sde->tail_csr);
2011 }
2012 
2013 /*
2014  * This is called when changing to state s10_hw_start_up_halt_wait as
2015  * a result of send buffer errors or send DMA descriptor errors.
2016  */
2017 static void sdma_hw_start_up(struct sdma_engine *sde)
2018 {
2019 	u64 reg;
2020 
2021 #ifdef CONFIG_SDMA_VERBOSITY
2022 	dd_dev_err(sde->dd, "CONFIG SDMA(%u) %s:%d %s()\n",
2023 		   sde->this_idx, slashstrip(__FILE__), __LINE__, __func__);
2024 #endif
2025 
2026 	sdma_setlengen(sde);
2027 	sdma_update_tail(sde, 0); /* Set SendDmaTail */
2028 	*sde->head_dma = 0;
2029 
2030 	reg = SD(ENG_ERR_CLEAR_SDMA_HEADER_REQUEST_FIFO_UNC_ERR_MASK) <<
2031 	      SD(ENG_ERR_CLEAR_SDMA_HEADER_REQUEST_FIFO_UNC_ERR_SHIFT);
2032 	write_sde_csr(sde, SD(ENG_ERR_CLEAR), reg);
2033 }
2034 
2035 /*
2036  * set_sdma_integrity
2037  *
2038  * Set the SEND_DMA_CHECK_ENABLE register for send DMA engine 'sde'.
2039  */
2040 static void set_sdma_integrity(struct sdma_engine *sde)
2041 {
2042 	struct hfi1_devdata *dd = sde->dd;
2043 
2044 	write_sde_csr(sde, SD(CHECK_ENABLE),
2045 		      hfi1_pkt_base_sdma_integrity(dd));
2046 }
2047 
2048 static void init_sdma_regs(
2049 	struct sdma_engine *sde,
2050 	u32 credits,
2051 	uint idle_cnt)
2052 {
2053 	u8 opval, opmask;
2054 #ifdef CONFIG_SDMA_VERBOSITY
2055 	struct hfi1_devdata *dd = sde->dd;
2056 
2057 	dd_dev_err(dd, "CONFIG SDMA(%u) %s:%d %s()\n",
2058 		   sde->this_idx, slashstrip(__FILE__), __LINE__, __func__);
2059 #endif
2060 
2061 	write_sde_csr(sde, SD(BASE_ADDR), sde->descq_phys);
2062 	sdma_setlengen(sde);
2063 	sdma_update_tail(sde, 0); /* Set SendDmaTail */
2064 	write_sde_csr(sde, SD(RELOAD_CNT), idle_cnt);
2065 	write_sde_csr(sde, SD(DESC_CNT), 0);
2066 	write_sde_csr(sde, SD(HEAD_ADDR), sde->head_phys);
2067 	write_sde_csr(sde, SD(MEMORY),
2068 		      ((u64)credits << SD(MEMORY_SDMA_MEMORY_CNT_SHIFT)) |
2069 		      ((u64)(credits * sde->this_idx) <<
2070 		       SD(MEMORY_SDMA_MEMORY_INDEX_SHIFT)));
2071 	write_sde_csr(sde, SD(ENG_ERR_MASK), ~0ull);
2072 	set_sdma_integrity(sde);
2073 	opmask = OPCODE_CHECK_MASK_DISABLED;
2074 	opval = OPCODE_CHECK_VAL_DISABLED;
2075 	write_sde_csr(sde, SD(CHECK_OPCODE),
2076 		      (opmask << SEND_CTXT_CHECK_OPCODE_MASK_SHIFT) |
2077 		      (opval << SEND_CTXT_CHECK_OPCODE_VALUE_SHIFT));
2078 }
2079 
2080 #ifdef CONFIG_SDMA_VERBOSITY
2081 
2082 #define sdma_dumpstate_helper0(reg) do { \
2083 		csr = read_csr(sde->dd, reg); \
2084 		dd_dev_err(sde->dd, "%36s     0x%016llx\n", #reg, csr); \
2085 	} while (0)
2086 
2087 #define sdma_dumpstate_helper(reg) do { \
2088 		csr = read_sde_csr(sde, reg); \
2089 		dd_dev_err(sde->dd, "%36s[%02u] 0x%016llx\n", \
2090 			#reg, sde->this_idx, csr); \
2091 	} while (0)
2092 
2093 #define sdma_dumpstate_helper2(reg) do { \
2094 		csr = read_csr(sde->dd, reg + (8 * i)); \
2095 		dd_dev_err(sde->dd, "%33s_%02u     0x%016llx\n", \
2096 				#reg, i, csr); \
2097 	} while (0)
2098 
2099 void sdma_dumpstate(struct sdma_engine *sde)
2100 {
2101 	u64 csr;
2102 	unsigned i;
2103 
2104 	sdma_dumpstate_helper(SD(CTRL));
2105 	sdma_dumpstate_helper(SD(STATUS));
2106 	sdma_dumpstate_helper0(SD(ERR_STATUS));
2107 	sdma_dumpstate_helper0(SD(ERR_MASK));
2108 	sdma_dumpstate_helper(SD(ENG_ERR_STATUS));
2109 	sdma_dumpstate_helper(SD(ENG_ERR_MASK));
2110 
2111 	for (i = 0; i < CCE_NUM_INT_CSRS; ++i) {
2112 		sdma_dumpstate_helper2(CCE_INT_STATUS);
2113 		sdma_dumpstate_helper2(CCE_INT_MASK);
2114 		sdma_dumpstate_helper2(CCE_INT_BLOCKED);
2115 	}
2116 
2117 	sdma_dumpstate_helper(SD(TAIL));
2118 	sdma_dumpstate_helper(SD(HEAD));
2119 	sdma_dumpstate_helper(SD(PRIORITY_THLD));
2120 	sdma_dumpstate_helper(SD(IDLE_CNT));
2121 	sdma_dumpstate_helper(SD(RELOAD_CNT));
2122 	sdma_dumpstate_helper(SD(DESC_CNT));
2123 	sdma_dumpstate_helper(SD(DESC_FETCHED_CNT));
2124 	sdma_dumpstate_helper(SD(MEMORY));
2125 	sdma_dumpstate_helper0(SD(ENGINES));
2126 	sdma_dumpstate_helper0(SD(MEM_SIZE));
2127 	/* sdma_dumpstate_helper(SEND_EGRESS_SEND_DMA_STATUS);  */
2128 	sdma_dumpstate_helper(SD(BASE_ADDR));
2129 	sdma_dumpstate_helper(SD(LEN_GEN));
2130 	sdma_dumpstate_helper(SD(HEAD_ADDR));
2131 	sdma_dumpstate_helper(SD(CHECK_ENABLE));
2132 	sdma_dumpstate_helper(SD(CHECK_VL));
2133 	sdma_dumpstate_helper(SD(CHECK_JOB_KEY));
2134 	sdma_dumpstate_helper(SD(CHECK_PARTITION_KEY));
2135 	sdma_dumpstate_helper(SD(CHECK_SLID));
2136 	sdma_dumpstate_helper(SD(CHECK_OPCODE));
2137 }
2138 #endif
2139 
2140 static void dump_sdma_state(struct sdma_engine *sde)
2141 {
2142 	struct hw_sdma_desc *descqp;
2143 	u64 desc[2];
2144 	u64 addr;
2145 	u8 gen;
2146 	u16 len;
2147 	u16 head, tail, cnt;
2148 
2149 	head = sde->descq_head & sde->sdma_mask;
2150 	tail = sde->descq_tail & sde->sdma_mask;
2151 	cnt = sdma_descq_freecnt(sde);
2152 
2153 	dd_dev_err(sde->dd,
2154 		   "SDMA (%u) descq_head: %u descq_tail: %u freecnt: %u FLE %d\n",
2155 		   sde->this_idx, head, tail, cnt,
2156 		   !list_empty(&sde->flushlist));
2157 
2158 	/* print info for each entry in the descriptor queue */
2159 	while (head != tail) {
2160 		char flags[6] = { 'x', 'x', 'x', 'x', 0 };
2161 
2162 		descqp = &sde->descq[head];
2163 		desc[0] = le64_to_cpu(descqp->qw[0]);
2164 		desc[1] = le64_to_cpu(descqp->qw[1]);
2165 		flags[0] = (desc[1] & SDMA_DESC1_INT_REQ_FLAG) ? 'I' : '-';
2166 		flags[1] = (desc[1] & SDMA_DESC1_HEAD_TO_HOST_FLAG) ?
2167 				'H' : '-';
2168 		flags[2] = (desc[0] & SDMA_DESC0_FIRST_DESC_FLAG) ? 'F' : '-';
2169 		flags[3] = (desc[0] & SDMA_DESC0_LAST_DESC_FLAG) ? 'L' : '-';
2170 		addr = (desc[0] >> SDMA_DESC0_PHY_ADDR_SHIFT)
2171 			& SDMA_DESC0_PHY_ADDR_MASK;
2172 		gen = (desc[1] >> SDMA_DESC1_GENERATION_SHIFT)
2173 			& SDMA_DESC1_GENERATION_MASK;
2174 		len = (desc[0] >> SDMA_DESC0_BYTE_COUNT_SHIFT)
2175 			& SDMA_DESC0_BYTE_COUNT_MASK;
2176 		dd_dev_err(sde->dd,
2177 			   "SDMA sdmadesc[%u]: flags:%s addr:0x%016llx gen:%u len:%u bytes\n",
2178 			   head, flags, addr, gen, len);
2179 		dd_dev_err(sde->dd,
2180 			   "\tdesc0:0x%016llx desc1 0x%016llx\n",
2181 			   desc[0], desc[1]);
2182 		if (desc[0] & SDMA_DESC0_FIRST_DESC_FLAG)
2183 			dd_dev_err(sde->dd,
2184 				   "\taidx: %u amode: %u alen: %u\n",
2185 				   (u8)((desc[1] &
2186 					 SDMA_DESC1_HEADER_INDEX_SMASK) >>
2187 					SDMA_DESC1_HEADER_INDEX_SHIFT),
2188 				   (u8)((desc[1] &
2189 					 SDMA_DESC1_HEADER_MODE_SMASK) >>
2190 					SDMA_DESC1_HEADER_MODE_SHIFT),
2191 				   (u8)((desc[1] &
2192 					 SDMA_DESC1_HEADER_DWS_SMASK) >>
2193 					SDMA_DESC1_HEADER_DWS_SHIFT));
2194 		head++;
2195 		head &= sde->sdma_mask;
2196 	}
2197 }
2198 
2199 #define SDE_FMT \
2200 	"SDE %u CPU %d STE %s C 0x%llx S 0x%016llx E 0x%llx T(HW) 0x%llx T(SW) 0x%x H(HW) 0x%llx H(SW) 0x%x H(D) 0x%llx DM 0x%llx GL 0x%llx R 0x%llx LIS 0x%llx AHGI 0x%llx TXT %u TXH %u DT %u DH %u FLNE %d DQF %u SLC 0x%llx\n"
2201 /**
2202  * sdma_seqfile_dump_sde() - debugfs dump of sde
2203  * @s: seq file
2204  * @sde: send dma engine to dump
2205  *
2206  * This routine dumps the sde to the indicated seq file.
2207  */
2208 void sdma_seqfile_dump_sde(struct seq_file *s, struct sdma_engine *sde)
2209 {
2210 	u16 head, tail;
2211 	struct hw_sdma_desc *descqp;
2212 	u64 desc[2];
2213 	u64 addr;
2214 	u8 gen;
2215 	u16 len;
2216 
2217 	head = sde->descq_head & sde->sdma_mask;
2218 	tail = READ_ONCE(sde->descq_tail) & sde->sdma_mask;
2219 	seq_printf(s, SDE_FMT, sde->this_idx,
2220 		   sde->cpu,
2221 		   sdma_state_name(sde->state.current_state),
2222 		   (unsigned long long)read_sde_csr(sde, SD(CTRL)),
2223 		   (unsigned long long)read_sde_csr(sde, SD(STATUS)),
2224 		   (unsigned long long)read_sde_csr(sde, SD(ENG_ERR_STATUS)),
2225 		   (unsigned long long)read_sde_csr(sde, SD(TAIL)), tail,
2226 		   (unsigned long long)read_sde_csr(sde, SD(HEAD)), head,
2227 		   (unsigned long long)le64_to_cpu(*sde->head_dma),
2228 		   (unsigned long long)read_sde_csr(sde, SD(MEMORY)),
2229 		   (unsigned long long)read_sde_csr(sde, SD(LEN_GEN)),
2230 		   (unsigned long long)read_sde_csr(sde, SD(RELOAD_CNT)),
2231 		   (unsigned long long)sde->last_status,
2232 		   (unsigned long long)sde->ahg_bits,
2233 		   sde->tx_tail,
2234 		   sde->tx_head,
2235 		   sde->descq_tail,
2236 		   sde->descq_head,
2237 		   !list_empty(&sde->flushlist),
2238 		   sde->descq_full_count,
2239 		   (unsigned long long)read_sde_csr(sde, SEND_DMA_CHECK_SLID));
2240 
2241 	/* print info for each entry in the descriptor queue */
2242 	while (head != tail) {
2243 		char flags[6] = { 'x', 'x', 'x', 'x', 0 };
2244 
2245 		descqp = &sde->descq[head];
2246 		desc[0] = le64_to_cpu(descqp->qw[0]);
2247 		desc[1] = le64_to_cpu(descqp->qw[1]);
2248 		flags[0] = (desc[1] & SDMA_DESC1_INT_REQ_FLAG) ? 'I' : '-';
2249 		flags[1] = (desc[1] & SDMA_DESC1_HEAD_TO_HOST_FLAG) ?
2250 				'H' : '-';
2251 		flags[2] = (desc[0] & SDMA_DESC0_FIRST_DESC_FLAG) ? 'F' : '-';
2252 		flags[3] = (desc[0] & SDMA_DESC0_LAST_DESC_FLAG) ? 'L' : '-';
2253 		addr = (desc[0] >> SDMA_DESC0_PHY_ADDR_SHIFT)
2254 			& SDMA_DESC0_PHY_ADDR_MASK;
2255 		gen = (desc[1] >> SDMA_DESC1_GENERATION_SHIFT)
2256 			& SDMA_DESC1_GENERATION_MASK;
2257 		len = (desc[0] >> SDMA_DESC0_BYTE_COUNT_SHIFT)
2258 			& SDMA_DESC0_BYTE_COUNT_MASK;
2259 		seq_printf(s,
2260 			   "\tdesc[%u]: flags:%s addr:0x%016llx gen:%u len:%u bytes\n",
2261 			   head, flags, addr, gen, len);
2262 		if (desc[0] & SDMA_DESC0_FIRST_DESC_FLAG)
2263 			seq_printf(s, "\t\tahgidx: %u ahgmode: %u\n",
2264 				   (u8)((desc[1] &
2265 					 SDMA_DESC1_HEADER_INDEX_SMASK) >>
2266 					SDMA_DESC1_HEADER_INDEX_SHIFT),
2267 				   (u8)((desc[1] &
2268 					 SDMA_DESC1_HEADER_MODE_SMASK) >>
2269 					SDMA_DESC1_HEADER_MODE_SHIFT));
2270 		head = (head + 1) & sde->sdma_mask;
2271 	}
2272 }
2273 
2274 /*
2275  * add the generation number into
2276  * the qw1 and return
2277  */
2278 static inline u64 add_gen(struct sdma_engine *sde, u64 qw1)
2279 {
2280 	u8 generation = (sde->descq_tail >> sde->sdma_shift) & 3;
2281 
2282 	qw1 &= ~SDMA_DESC1_GENERATION_SMASK;
2283 	qw1 |= ((u64)generation & SDMA_DESC1_GENERATION_MASK)
2284 			<< SDMA_DESC1_GENERATION_SHIFT;
2285 	return qw1;
2286 }
2287 
2288 /*
2289  * This routine submits the indicated tx
2290  *
2291  * Space has already been guaranteed and
2292  * tail side of ring is locked.
2293  *
2294  * The hardware tail update is done
2295  * in the caller and that is facilitated
2296  * by returning the new tail.
2297  *
2298  * There is special case logic for ahg
2299  * to not add the generation number for
2300  * up to 2 descriptors that follow the
2301  * first descriptor.
2302  *
2303  */
2304 static inline u16 submit_tx(struct sdma_engine *sde, struct sdma_txreq *tx)
2305 {
2306 	int i;
2307 	u16 tail;
2308 	struct sdma_desc *descp = tx->descp;
2309 	u8 skip = 0, mode = ahg_mode(tx);
2310 
2311 	tail = sde->descq_tail & sde->sdma_mask;
2312 	sde->descq[tail].qw[0] = cpu_to_le64(descp->qw[0]);
2313 	sde->descq[tail].qw[1] = cpu_to_le64(add_gen(sde, descp->qw[1]));
2314 	trace_hfi1_sdma_descriptor(sde, descp->qw[0], descp->qw[1],
2315 				   tail, &sde->descq[tail]);
2316 	tail = ++sde->descq_tail & sde->sdma_mask;
2317 	descp++;
2318 	if (mode > SDMA_AHG_APPLY_UPDATE1)
2319 		skip = mode >> 1;
2320 	for (i = 1; i < tx->num_desc; i++, descp++) {
2321 		u64 qw1;
2322 
2323 		sde->descq[tail].qw[0] = cpu_to_le64(descp->qw[0]);
2324 		if (skip) {
2325 			/* edits don't have generation */
2326 			qw1 = descp->qw[1];
2327 			skip--;
2328 		} else {
2329 			/* replace generation with real one for non-edits */
2330 			qw1 = add_gen(sde, descp->qw[1]);
2331 		}
2332 		sde->descq[tail].qw[1] = cpu_to_le64(qw1);
2333 		trace_hfi1_sdma_descriptor(sde, descp->qw[0], qw1,
2334 					   tail, &sde->descq[tail]);
2335 		tail = ++sde->descq_tail & sde->sdma_mask;
2336 	}
2337 	tx->next_descq_idx = tail;
2338 #ifdef CONFIG_HFI1_DEBUG_SDMA_ORDER
2339 	tx->sn = sde->tail_sn++;
2340 	trace_hfi1_sdma_in_sn(sde, tx->sn);
2341 	WARN_ON_ONCE(sde->tx_ring[sde->tx_tail & sde->sdma_mask]);
2342 #endif
2343 	sde->tx_ring[sde->tx_tail++ & sde->sdma_mask] = tx;
2344 	sde->desc_avail -= tx->num_desc;
2345 	return tail;
2346 }
2347 
2348 /*
2349  * Check for progress
2350  */
2351 static int sdma_check_progress(
2352 	struct sdma_engine *sde,
2353 	struct iowait_work *wait,
2354 	struct sdma_txreq *tx,
2355 	bool pkts_sent)
2356 {
2357 	int ret;
2358 
2359 	sde->desc_avail = sdma_descq_freecnt(sde);
2360 	if (tx->num_desc <= sde->desc_avail)
2361 		return -EAGAIN;
2362 	/* pulse the head_lock */
2363 	if (wait && iowait_ioww_to_iow(wait)->sleep) {
2364 		unsigned seq;
2365 
2366 		seq = raw_seqcount_begin(
2367 			(const seqcount_t *)&sde->head_lock.seqcount);
2368 		ret = wait->iow->sleep(sde, wait, tx, seq, pkts_sent);
2369 		if (ret == -EAGAIN)
2370 			sde->desc_avail = sdma_descq_freecnt(sde);
2371 	} else {
2372 		ret = -EBUSY;
2373 	}
2374 	return ret;
2375 }
2376 
2377 /**
2378  * sdma_send_txreq() - submit a tx req to ring
2379  * @sde: sdma engine to use
2380  * @wait: SE wait structure to use when full (may be NULL)
2381  * @tx: sdma_txreq to submit
2382  * @pkts_sent: has any packet been sent yet?
2383  *
2384  * The call submits the tx into the ring.  If a iowait structure is non-NULL
2385  * the packet will be queued to the list in wait.
2386  *
2387  * Return:
2388  * 0 - Success, -EINVAL - sdma_txreq incomplete, -EBUSY - no space in
2389  * ring (wait == NULL)
2390  * -EIOCBQUEUED - tx queued to iowait, -ECOMM bad sdma state
2391  */
2392 int sdma_send_txreq(struct sdma_engine *sde,
2393 		    struct iowait_work *wait,
2394 		    struct sdma_txreq *tx,
2395 		    bool pkts_sent)
2396 {
2397 	int ret = 0;
2398 	u16 tail;
2399 	unsigned long flags;
2400 
2401 	/* user should have supplied entire packet */
2402 	if (unlikely(tx->tlen))
2403 		return -EINVAL;
2404 	tx->wait = iowait_ioww_to_iow(wait);
2405 	spin_lock_irqsave(&sde->tail_lock, flags);
2406 retry:
2407 	if (unlikely(!__sdma_running(sde)))
2408 		goto unlock_noconn;
2409 	if (unlikely(tx->num_desc > sde->desc_avail))
2410 		goto nodesc;
2411 	tail = submit_tx(sde, tx);
2412 	if (wait)
2413 		iowait_sdma_inc(iowait_ioww_to_iow(wait));
2414 	sdma_update_tail(sde, tail);
2415 unlock:
2416 	spin_unlock_irqrestore(&sde->tail_lock, flags);
2417 	return ret;
2418 unlock_noconn:
2419 	if (wait)
2420 		iowait_sdma_inc(iowait_ioww_to_iow(wait));
2421 	tx->next_descq_idx = 0;
2422 #ifdef CONFIG_HFI1_DEBUG_SDMA_ORDER
2423 	tx->sn = sde->tail_sn++;
2424 	trace_hfi1_sdma_in_sn(sde, tx->sn);
2425 #endif
2426 	spin_lock(&sde->flushlist_lock);
2427 	list_add_tail(&tx->list, &sde->flushlist);
2428 	spin_unlock(&sde->flushlist_lock);
2429 	iowait_inc_wait_count(wait, tx->num_desc);
2430 	queue_work_on(sde->cpu, system_highpri_wq, &sde->flush_worker);
2431 	ret = -ECOMM;
2432 	goto unlock;
2433 nodesc:
2434 	ret = sdma_check_progress(sde, wait, tx, pkts_sent);
2435 	if (ret == -EAGAIN) {
2436 		ret = 0;
2437 		goto retry;
2438 	}
2439 	sde->descq_full_count++;
2440 	goto unlock;
2441 }
2442 
2443 /**
2444  * sdma_send_txlist() - submit a list of tx req to ring
2445  * @sde: sdma engine to use
2446  * @wait: SE wait structure to use when full (may be NULL)
2447  * @tx_list: list of sdma_txreqs to submit
2448  * @count: pointer to a u16 which, after return will contain the total number of
2449  *         sdma_txreqs removed from the tx_list. This will include sdma_txreqs
2450  *         whose SDMA descriptors are submitted to the ring and the sdma_txreqs
2451  *         which are added to SDMA engine flush list if the SDMA engine state is
2452  *         not running.
2453  *
2454  * The call submits the list into the ring.
2455  *
2456  * If the iowait structure is non-NULL and not equal to the iowait list
2457  * the unprocessed part of the list  will be appended to the list in wait.
2458  *
2459  * In all cases, the tx_list will be updated so the head of the tx_list is
2460  * the list of descriptors that have yet to be transmitted.
2461  *
2462  * The intent of this call is to provide a more efficient
2463  * way of submitting multiple packets to SDMA while holding the tail
2464  * side locking.
2465  *
2466  * Return:
2467  * 0 - Success,
2468  * -EINVAL - sdma_txreq incomplete, -EBUSY - no space in ring (wait == NULL)
2469  * -EIOCBQUEUED - tx queued to iowait, -ECOMM bad sdma state
2470  */
2471 int sdma_send_txlist(struct sdma_engine *sde, struct iowait_work *wait,
2472 		     struct list_head *tx_list, u16 *count_out)
2473 {
2474 	struct sdma_txreq *tx, *tx_next;
2475 	int ret = 0;
2476 	unsigned long flags;
2477 	u16 tail = INVALID_TAIL;
2478 	u32 submit_count = 0, flush_count = 0, total_count;
2479 
2480 	spin_lock_irqsave(&sde->tail_lock, flags);
2481 retry:
2482 	list_for_each_entry_safe(tx, tx_next, tx_list, list) {
2483 		tx->wait = iowait_ioww_to_iow(wait);
2484 		if (unlikely(!__sdma_running(sde)))
2485 			goto unlock_noconn;
2486 		if (unlikely(tx->num_desc > sde->desc_avail))
2487 			goto nodesc;
2488 		if (unlikely(tx->tlen)) {
2489 			ret = -EINVAL;
2490 			goto update_tail;
2491 		}
2492 		list_del_init(&tx->list);
2493 		tail = submit_tx(sde, tx);
2494 		submit_count++;
2495 		if (tail != INVALID_TAIL &&
2496 		    (submit_count & SDMA_TAIL_UPDATE_THRESH) == 0) {
2497 			sdma_update_tail(sde, tail);
2498 			tail = INVALID_TAIL;
2499 		}
2500 	}
2501 update_tail:
2502 	total_count = submit_count + flush_count;
2503 	if (wait) {
2504 		iowait_sdma_add(iowait_ioww_to_iow(wait), total_count);
2505 		iowait_starve_clear(submit_count > 0,
2506 				    iowait_ioww_to_iow(wait));
2507 	}
2508 	if (tail != INVALID_TAIL)
2509 		sdma_update_tail(sde, tail);
2510 	spin_unlock_irqrestore(&sde->tail_lock, flags);
2511 	*count_out = total_count;
2512 	return ret;
2513 unlock_noconn:
2514 	spin_lock(&sde->flushlist_lock);
2515 	list_for_each_entry_safe(tx, tx_next, tx_list, list) {
2516 		tx->wait = iowait_ioww_to_iow(wait);
2517 		list_del_init(&tx->list);
2518 		tx->next_descq_idx = 0;
2519 #ifdef CONFIG_HFI1_DEBUG_SDMA_ORDER
2520 		tx->sn = sde->tail_sn++;
2521 		trace_hfi1_sdma_in_sn(sde, tx->sn);
2522 #endif
2523 		list_add_tail(&tx->list, &sde->flushlist);
2524 		flush_count++;
2525 		iowait_inc_wait_count(wait, tx->num_desc);
2526 	}
2527 	spin_unlock(&sde->flushlist_lock);
2528 	queue_work_on(sde->cpu, system_highpri_wq, &sde->flush_worker);
2529 	ret = -ECOMM;
2530 	goto update_tail;
2531 nodesc:
2532 	ret = sdma_check_progress(sde, wait, tx, submit_count > 0);
2533 	if (ret == -EAGAIN) {
2534 		ret = 0;
2535 		goto retry;
2536 	}
2537 	sde->descq_full_count++;
2538 	goto update_tail;
2539 }
2540 
2541 static void sdma_process_event(struct sdma_engine *sde, enum sdma_events event)
2542 {
2543 	unsigned long flags;
2544 
2545 	spin_lock_irqsave(&sde->tail_lock, flags);
2546 	write_seqlock(&sde->head_lock);
2547 
2548 	__sdma_process_event(sde, event);
2549 
2550 	if (sde->state.current_state == sdma_state_s99_running)
2551 		sdma_desc_avail(sde, sdma_descq_freecnt(sde));
2552 
2553 	write_sequnlock(&sde->head_lock);
2554 	spin_unlock_irqrestore(&sde->tail_lock, flags);
2555 }
2556 
2557 static void __sdma_process_event(struct sdma_engine *sde,
2558 				 enum sdma_events event)
2559 {
2560 	struct sdma_state *ss = &sde->state;
2561 	int need_progress = 0;
2562 
2563 	/* CONFIG SDMA temporary */
2564 #ifdef CONFIG_SDMA_VERBOSITY
2565 	dd_dev_err(sde->dd, "CONFIG SDMA(%u) [%s] %s\n", sde->this_idx,
2566 		   sdma_state_names[ss->current_state],
2567 		   sdma_event_names[event]);
2568 #endif
2569 
2570 	switch (ss->current_state) {
2571 	case sdma_state_s00_hw_down:
2572 		switch (event) {
2573 		case sdma_event_e00_go_hw_down:
2574 			break;
2575 		case sdma_event_e30_go_running:
2576 			/*
2577 			 * If down, but running requested (usually result
2578 			 * of link up, then we need to start up.
2579 			 * This can happen when hw down is requested while
2580 			 * bringing the link up with traffic active on
2581 			 * 7220, e.g.
2582 			 */
2583 			ss->go_s99_running = 1;
2584 			/* fall through -- and start dma engine */
2585 		case sdma_event_e10_go_hw_start:
2586 			/* This reference means the state machine is started */
2587 			sdma_get(&sde->state);
2588 			sdma_set_state(sde,
2589 				       sdma_state_s10_hw_start_up_halt_wait);
2590 			break;
2591 		case sdma_event_e15_hw_halt_done:
2592 			break;
2593 		case sdma_event_e25_hw_clean_up_done:
2594 			break;
2595 		case sdma_event_e40_sw_cleaned:
2596 			sdma_sw_tear_down(sde);
2597 			break;
2598 		case sdma_event_e50_hw_cleaned:
2599 			break;
2600 		case sdma_event_e60_hw_halted:
2601 			break;
2602 		case sdma_event_e70_go_idle:
2603 			break;
2604 		case sdma_event_e80_hw_freeze:
2605 			break;
2606 		case sdma_event_e81_hw_frozen:
2607 			break;
2608 		case sdma_event_e82_hw_unfreeze:
2609 			break;
2610 		case sdma_event_e85_link_down:
2611 			break;
2612 		case sdma_event_e90_sw_halted:
2613 			break;
2614 		}
2615 		break;
2616 
2617 	case sdma_state_s10_hw_start_up_halt_wait:
2618 		switch (event) {
2619 		case sdma_event_e00_go_hw_down:
2620 			sdma_set_state(sde, sdma_state_s00_hw_down);
2621 			sdma_sw_tear_down(sde);
2622 			break;
2623 		case sdma_event_e10_go_hw_start:
2624 			break;
2625 		case sdma_event_e15_hw_halt_done:
2626 			sdma_set_state(sde,
2627 				       sdma_state_s15_hw_start_up_clean_wait);
2628 			sdma_start_hw_clean_up(sde);
2629 			break;
2630 		case sdma_event_e25_hw_clean_up_done:
2631 			break;
2632 		case sdma_event_e30_go_running:
2633 			ss->go_s99_running = 1;
2634 			break;
2635 		case sdma_event_e40_sw_cleaned:
2636 			break;
2637 		case sdma_event_e50_hw_cleaned:
2638 			break;
2639 		case sdma_event_e60_hw_halted:
2640 			schedule_work(&sde->err_halt_worker);
2641 			break;
2642 		case sdma_event_e70_go_idle:
2643 			ss->go_s99_running = 0;
2644 			break;
2645 		case sdma_event_e80_hw_freeze:
2646 			break;
2647 		case sdma_event_e81_hw_frozen:
2648 			break;
2649 		case sdma_event_e82_hw_unfreeze:
2650 			break;
2651 		case sdma_event_e85_link_down:
2652 			break;
2653 		case sdma_event_e90_sw_halted:
2654 			break;
2655 		}
2656 		break;
2657 
2658 	case sdma_state_s15_hw_start_up_clean_wait:
2659 		switch (event) {
2660 		case sdma_event_e00_go_hw_down:
2661 			sdma_set_state(sde, sdma_state_s00_hw_down);
2662 			sdma_sw_tear_down(sde);
2663 			break;
2664 		case sdma_event_e10_go_hw_start:
2665 			break;
2666 		case sdma_event_e15_hw_halt_done:
2667 			break;
2668 		case sdma_event_e25_hw_clean_up_done:
2669 			sdma_hw_start_up(sde);
2670 			sdma_set_state(sde, ss->go_s99_running ?
2671 				       sdma_state_s99_running :
2672 				       sdma_state_s20_idle);
2673 			break;
2674 		case sdma_event_e30_go_running:
2675 			ss->go_s99_running = 1;
2676 			break;
2677 		case sdma_event_e40_sw_cleaned:
2678 			break;
2679 		case sdma_event_e50_hw_cleaned:
2680 			break;
2681 		case sdma_event_e60_hw_halted:
2682 			break;
2683 		case sdma_event_e70_go_idle:
2684 			ss->go_s99_running = 0;
2685 			break;
2686 		case sdma_event_e80_hw_freeze:
2687 			break;
2688 		case sdma_event_e81_hw_frozen:
2689 			break;
2690 		case sdma_event_e82_hw_unfreeze:
2691 			break;
2692 		case sdma_event_e85_link_down:
2693 			break;
2694 		case sdma_event_e90_sw_halted:
2695 			break;
2696 		}
2697 		break;
2698 
2699 	case sdma_state_s20_idle:
2700 		switch (event) {
2701 		case sdma_event_e00_go_hw_down:
2702 			sdma_set_state(sde, sdma_state_s00_hw_down);
2703 			sdma_sw_tear_down(sde);
2704 			break;
2705 		case sdma_event_e10_go_hw_start:
2706 			break;
2707 		case sdma_event_e15_hw_halt_done:
2708 			break;
2709 		case sdma_event_e25_hw_clean_up_done:
2710 			break;
2711 		case sdma_event_e30_go_running:
2712 			sdma_set_state(sde, sdma_state_s99_running);
2713 			ss->go_s99_running = 1;
2714 			break;
2715 		case sdma_event_e40_sw_cleaned:
2716 			break;
2717 		case sdma_event_e50_hw_cleaned:
2718 			break;
2719 		case sdma_event_e60_hw_halted:
2720 			sdma_set_state(sde, sdma_state_s50_hw_halt_wait);
2721 			schedule_work(&sde->err_halt_worker);
2722 			break;
2723 		case sdma_event_e70_go_idle:
2724 			break;
2725 		case sdma_event_e85_link_down:
2726 			/* fall through */
2727 		case sdma_event_e80_hw_freeze:
2728 			sdma_set_state(sde, sdma_state_s80_hw_freeze);
2729 			atomic_dec(&sde->dd->sdma_unfreeze_count);
2730 			wake_up_interruptible(&sde->dd->sdma_unfreeze_wq);
2731 			break;
2732 		case sdma_event_e81_hw_frozen:
2733 			break;
2734 		case sdma_event_e82_hw_unfreeze:
2735 			break;
2736 		case sdma_event_e90_sw_halted:
2737 			break;
2738 		}
2739 		break;
2740 
2741 	case sdma_state_s30_sw_clean_up_wait:
2742 		switch (event) {
2743 		case sdma_event_e00_go_hw_down:
2744 			sdma_set_state(sde, sdma_state_s00_hw_down);
2745 			break;
2746 		case sdma_event_e10_go_hw_start:
2747 			break;
2748 		case sdma_event_e15_hw_halt_done:
2749 			break;
2750 		case sdma_event_e25_hw_clean_up_done:
2751 			break;
2752 		case sdma_event_e30_go_running:
2753 			ss->go_s99_running = 1;
2754 			break;
2755 		case sdma_event_e40_sw_cleaned:
2756 			sdma_set_state(sde, sdma_state_s40_hw_clean_up_wait);
2757 			sdma_start_hw_clean_up(sde);
2758 			break;
2759 		case sdma_event_e50_hw_cleaned:
2760 			break;
2761 		case sdma_event_e60_hw_halted:
2762 			break;
2763 		case sdma_event_e70_go_idle:
2764 			ss->go_s99_running = 0;
2765 			break;
2766 		case sdma_event_e80_hw_freeze:
2767 			break;
2768 		case sdma_event_e81_hw_frozen:
2769 			break;
2770 		case sdma_event_e82_hw_unfreeze:
2771 			break;
2772 		case sdma_event_e85_link_down:
2773 			ss->go_s99_running = 0;
2774 			break;
2775 		case sdma_event_e90_sw_halted:
2776 			break;
2777 		}
2778 		break;
2779 
2780 	case sdma_state_s40_hw_clean_up_wait:
2781 		switch (event) {
2782 		case sdma_event_e00_go_hw_down:
2783 			sdma_set_state(sde, sdma_state_s00_hw_down);
2784 			tasklet_hi_schedule(&sde->sdma_sw_clean_up_task);
2785 			break;
2786 		case sdma_event_e10_go_hw_start:
2787 			break;
2788 		case sdma_event_e15_hw_halt_done:
2789 			break;
2790 		case sdma_event_e25_hw_clean_up_done:
2791 			sdma_hw_start_up(sde);
2792 			sdma_set_state(sde, ss->go_s99_running ?
2793 				       sdma_state_s99_running :
2794 				       sdma_state_s20_idle);
2795 			break;
2796 		case sdma_event_e30_go_running:
2797 			ss->go_s99_running = 1;
2798 			break;
2799 		case sdma_event_e40_sw_cleaned:
2800 			break;
2801 		case sdma_event_e50_hw_cleaned:
2802 			break;
2803 		case sdma_event_e60_hw_halted:
2804 			break;
2805 		case sdma_event_e70_go_idle:
2806 			ss->go_s99_running = 0;
2807 			break;
2808 		case sdma_event_e80_hw_freeze:
2809 			break;
2810 		case sdma_event_e81_hw_frozen:
2811 			break;
2812 		case sdma_event_e82_hw_unfreeze:
2813 			break;
2814 		case sdma_event_e85_link_down:
2815 			ss->go_s99_running = 0;
2816 			break;
2817 		case sdma_event_e90_sw_halted:
2818 			break;
2819 		}
2820 		break;
2821 
2822 	case sdma_state_s50_hw_halt_wait:
2823 		switch (event) {
2824 		case sdma_event_e00_go_hw_down:
2825 			sdma_set_state(sde, sdma_state_s00_hw_down);
2826 			tasklet_hi_schedule(&sde->sdma_sw_clean_up_task);
2827 			break;
2828 		case sdma_event_e10_go_hw_start:
2829 			break;
2830 		case sdma_event_e15_hw_halt_done:
2831 			sdma_set_state(sde, sdma_state_s30_sw_clean_up_wait);
2832 			tasklet_hi_schedule(&sde->sdma_sw_clean_up_task);
2833 			break;
2834 		case sdma_event_e25_hw_clean_up_done:
2835 			break;
2836 		case sdma_event_e30_go_running:
2837 			ss->go_s99_running = 1;
2838 			break;
2839 		case sdma_event_e40_sw_cleaned:
2840 			break;
2841 		case sdma_event_e50_hw_cleaned:
2842 			break;
2843 		case sdma_event_e60_hw_halted:
2844 			schedule_work(&sde->err_halt_worker);
2845 			break;
2846 		case sdma_event_e70_go_idle:
2847 			ss->go_s99_running = 0;
2848 			break;
2849 		case sdma_event_e80_hw_freeze:
2850 			break;
2851 		case sdma_event_e81_hw_frozen:
2852 			break;
2853 		case sdma_event_e82_hw_unfreeze:
2854 			break;
2855 		case sdma_event_e85_link_down:
2856 			ss->go_s99_running = 0;
2857 			break;
2858 		case sdma_event_e90_sw_halted:
2859 			break;
2860 		}
2861 		break;
2862 
2863 	case sdma_state_s60_idle_halt_wait:
2864 		switch (event) {
2865 		case sdma_event_e00_go_hw_down:
2866 			sdma_set_state(sde, sdma_state_s00_hw_down);
2867 			tasklet_hi_schedule(&sde->sdma_sw_clean_up_task);
2868 			break;
2869 		case sdma_event_e10_go_hw_start:
2870 			break;
2871 		case sdma_event_e15_hw_halt_done:
2872 			sdma_set_state(sde, sdma_state_s30_sw_clean_up_wait);
2873 			tasklet_hi_schedule(&sde->sdma_sw_clean_up_task);
2874 			break;
2875 		case sdma_event_e25_hw_clean_up_done:
2876 			break;
2877 		case sdma_event_e30_go_running:
2878 			ss->go_s99_running = 1;
2879 			break;
2880 		case sdma_event_e40_sw_cleaned:
2881 			break;
2882 		case sdma_event_e50_hw_cleaned:
2883 			break;
2884 		case sdma_event_e60_hw_halted:
2885 			schedule_work(&sde->err_halt_worker);
2886 			break;
2887 		case sdma_event_e70_go_idle:
2888 			ss->go_s99_running = 0;
2889 			break;
2890 		case sdma_event_e80_hw_freeze:
2891 			break;
2892 		case sdma_event_e81_hw_frozen:
2893 			break;
2894 		case sdma_event_e82_hw_unfreeze:
2895 			break;
2896 		case sdma_event_e85_link_down:
2897 			break;
2898 		case sdma_event_e90_sw_halted:
2899 			break;
2900 		}
2901 		break;
2902 
2903 	case sdma_state_s80_hw_freeze:
2904 		switch (event) {
2905 		case sdma_event_e00_go_hw_down:
2906 			sdma_set_state(sde, sdma_state_s00_hw_down);
2907 			tasklet_hi_schedule(&sde->sdma_sw_clean_up_task);
2908 			break;
2909 		case sdma_event_e10_go_hw_start:
2910 			break;
2911 		case sdma_event_e15_hw_halt_done:
2912 			break;
2913 		case sdma_event_e25_hw_clean_up_done:
2914 			break;
2915 		case sdma_event_e30_go_running:
2916 			ss->go_s99_running = 1;
2917 			break;
2918 		case sdma_event_e40_sw_cleaned:
2919 			break;
2920 		case sdma_event_e50_hw_cleaned:
2921 			break;
2922 		case sdma_event_e60_hw_halted:
2923 			break;
2924 		case sdma_event_e70_go_idle:
2925 			ss->go_s99_running = 0;
2926 			break;
2927 		case sdma_event_e80_hw_freeze:
2928 			break;
2929 		case sdma_event_e81_hw_frozen:
2930 			sdma_set_state(sde, sdma_state_s82_freeze_sw_clean);
2931 			tasklet_hi_schedule(&sde->sdma_sw_clean_up_task);
2932 			break;
2933 		case sdma_event_e82_hw_unfreeze:
2934 			break;
2935 		case sdma_event_e85_link_down:
2936 			break;
2937 		case sdma_event_e90_sw_halted:
2938 			break;
2939 		}
2940 		break;
2941 
2942 	case sdma_state_s82_freeze_sw_clean:
2943 		switch (event) {
2944 		case sdma_event_e00_go_hw_down:
2945 			sdma_set_state(sde, sdma_state_s00_hw_down);
2946 			tasklet_hi_schedule(&sde->sdma_sw_clean_up_task);
2947 			break;
2948 		case sdma_event_e10_go_hw_start:
2949 			break;
2950 		case sdma_event_e15_hw_halt_done:
2951 			break;
2952 		case sdma_event_e25_hw_clean_up_done:
2953 			break;
2954 		case sdma_event_e30_go_running:
2955 			ss->go_s99_running = 1;
2956 			break;
2957 		case sdma_event_e40_sw_cleaned:
2958 			/* notify caller this engine is done cleaning */
2959 			atomic_dec(&sde->dd->sdma_unfreeze_count);
2960 			wake_up_interruptible(&sde->dd->sdma_unfreeze_wq);
2961 			break;
2962 		case sdma_event_e50_hw_cleaned:
2963 			break;
2964 		case sdma_event_e60_hw_halted:
2965 			break;
2966 		case sdma_event_e70_go_idle:
2967 			ss->go_s99_running = 0;
2968 			break;
2969 		case sdma_event_e80_hw_freeze:
2970 			break;
2971 		case sdma_event_e81_hw_frozen:
2972 			break;
2973 		case sdma_event_e82_hw_unfreeze:
2974 			sdma_hw_start_up(sde);
2975 			sdma_set_state(sde, ss->go_s99_running ?
2976 				       sdma_state_s99_running :
2977 				       sdma_state_s20_idle);
2978 			break;
2979 		case sdma_event_e85_link_down:
2980 			break;
2981 		case sdma_event_e90_sw_halted:
2982 			break;
2983 		}
2984 		break;
2985 
2986 	case sdma_state_s99_running:
2987 		switch (event) {
2988 		case sdma_event_e00_go_hw_down:
2989 			sdma_set_state(sde, sdma_state_s00_hw_down);
2990 			tasklet_hi_schedule(&sde->sdma_sw_clean_up_task);
2991 			break;
2992 		case sdma_event_e10_go_hw_start:
2993 			break;
2994 		case sdma_event_e15_hw_halt_done:
2995 			break;
2996 		case sdma_event_e25_hw_clean_up_done:
2997 			break;
2998 		case sdma_event_e30_go_running:
2999 			break;
3000 		case sdma_event_e40_sw_cleaned:
3001 			break;
3002 		case sdma_event_e50_hw_cleaned:
3003 			break;
3004 		case sdma_event_e60_hw_halted:
3005 			need_progress = 1;
3006 			sdma_err_progress_check_schedule(sde);
3007 			/* fall through */
3008 		case sdma_event_e90_sw_halted:
3009 			/*
3010 			* SW initiated halt does not perform engines
3011 			* progress check
3012 			*/
3013 			sdma_set_state(sde, sdma_state_s50_hw_halt_wait);
3014 			schedule_work(&sde->err_halt_worker);
3015 			break;
3016 		case sdma_event_e70_go_idle:
3017 			sdma_set_state(sde, sdma_state_s60_idle_halt_wait);
3018 			break;
3019 		case sdma_event_e85_link_down:
3020 			ss->go_s99_running = 0;
3021 			/* fall through */
3022 		case sdma_event_e80_hw_freeze:
3023 			sdma_set_state(sde, sdma_state_s80_hw_freeze);
3024 			atomic_dec(&sde->dd->sdma_unfreeze_count);
3025 			wake_up_interruptible(&sde->dd->sdma_unfreeze_wq);
3026 			break;
3027 		case sdma_event_e81_hw_frozen:
3028 			break;
3029 		case sdma_event_e82_hw_unfreeze:
3030 			break;
3031 		}
3032 		break;
3033 	}
3034 
3035 	ss->last_event = event;
3036 	if (need_progress)
3037 		sdma_make_progress(sde, 0);
3038 }
3039 
3040 /*
3041  * _extend_sdma_tx_descs() - helper to extend txreq
3042  *
3043  * This is called once the initial nominal allocation
3044  * of descriptors in the sdma_txreq is exhausted.
3045  *
3046  * The code will bump the allocation up to the max
3047  * of MAX_DESC (64) descriptors. There doesn't seem
3048  * much point in an interim step. The last descriptor
3049  * is reserved for coalesce buffer in order to support
3050  * cases where input packet has >MAX_DESC iovecs.
3051  *
3052  */
3053 static int _extend_sdma_tx_descs(struct hfi1_devdata *dd, struct sdma_txreq *tx)
3054 {
3055 	int i;
3056 
3057 	/* Handle last descriptor */
3058 	if (unlikely((tx->num_desc == (MAX_DESC - 1)))) {
3059 		/* if tlen is 0, it is for padding, release last descriptor */
3060 		if (!tx->tlen) {
3061 			tx->desc_limit = MAX_DESC;
3062 		} else if (!tx->coalesce_buf) {
3063 			/* allocate coalesce buffer with space for padding */
3064 			tx->coalesce_buf = kmalloc(tx->tlen + sizeof(u32),
3065 						   GFP_ATOMIC);
3066 			if (!tx->coalesce_buf)
3067 				goto enomem;
3068 			tx->coalesce_idx = 0;
3069 		}
3070 		return 0;
3071 	}
3072 
3073 	if (unlikely(tx->num_desc == MAX_DESC))
3074 		goto enomem;
3075 
3076 	tx->descp = kmalloc_array(
3077 			MAX_DESC,
3078 			sizeof(struct sdma_desc),
3079 			GFP_ATOMIC);
3080 	if (!tx->descp)
3081 		goto enomem;
3082 
3083 	/* reserve last descriptor for coalescing */
3084 	tx->desc_limit = MAX_DESC - 1;
3085 	/* copy ones already built */
3086 	for (i = 0; i < tx->num_desc; i++)
3087 		tx->descp[i] = tx->descs[i];
3088 	return 0;
3089 enomem:
3090 	__sdma_txclean(dd, tx);
3091 	return -ENOMEM;
3092 }
3093 
3094 /*
3095  * ext_coal_sdma_tx_descs() - extend or coalesce sdma tx descriptors
3096  *
3097  * This is called once the initial nominal allocation of descriptors
3098  * in the sdma_txreq is exhausted.
3099  *
3100  * This function calls _extend_sdma_tx_descs to extend or allocate
3101  * coalesce buffer. If there is a allocated coalesce buffer, it will
3102  * copy the input packet data into the coalesce buffer. It also adds
3103  * coalesce buffer descriptor once when whole packet is received.
3104  *
3105  * Return:
3106  * <0 - error
3107  * 0 - coalescing, don't populate descriptor
3108  * 1 - continue with populating descriptor
3109  */
3110 int ext_coal_sdma_tx_descs(struct hfi1_devdata *dd, struct sdma_txreq *tx,
3111 			   int type, void *kvaddr, struct page *page,
3112 			   unsigned long offset, u16 len)
3113 {
3114 	int pad_len, rval;
3115 	dma_addr_t addr;
3116 
3117 	rval = _extend_sdma_tx_descs(dd, tx);
3118 	if (rval) {
3119 		__sdma_txclean(dd, tx);
3120 		return rval;
3121 	}
3122 
3123 	/* If coalesce buffer is allocated, copy data into it */
3124 	if (tx->coalesce_buf) {
3125 		if (type == SDMA_MAP_NONE) {
3126 			__sdma_txclean(dd, tx);
3127 			return -EINVAL;
3128 		}
3129 
3130 		if (type == SDMA_MAP_PAGE) {
3131 			kvaddr = kmap(page);
3132 			kvaddr += offset;
3133 		} else if (WARN_ON(!kvaddr)) {
3134 			__sdma_txclean(dd, tx);
3135 			return -EINVAL;
3136 		}
3137 
3138 		memcpy(tx->coalesce_buf + tx->coalesce_idx, kvaddr, len);
3139 		tx->coalesce_idx += len;
3140 		if (type == SDMA_MAP_PAGE)
3141 			kunmap(page);
3142 
3143 		/* If there is more data, return */
3144 		if (tx->tlen - tx->coalesce_idx)
3145 			return 0;
3146 
3147 		/* Whole packet is received; add any padding */
3148 		pad_len = tx->packet_len & (sizeof(u32) - 1);
3149 		if (pad_len) {
3150 			pad_len = sizeof(u32) - pad_len;
3151 			memset(tx->coalesce_buf + tx->coalesce_idx, 0, pad_len);
3152 			/* padding is taken care of for coalescing case */
3153 			tx->packet_len += pad_len;
3154 			tx->tlen += pad_len;
3155 		}
3156 
3157 		/* dma map the coalesce buffer */
3158 		addr = dma_map_single(&dd->pcidev->dev,
3159 				      tx->coalesce_buf,
3160 				      tx->tlen,
3161 				      DMA_TO_DEVICE);
3162 
3163 		if (unlikely(dma_mapping_error(&dd->pcidev->dev, addr))) {
3164 			__sdma_txclean(dd, tx);
3165 			return -ENOSPC;
3166 		}
3167 
3168 		/* Add descriptor for coalesce buffer */
3169 		tx->desc_limit = MAX_DESC;
3170 		return _sdma_txadd_daddr(dd, SDMA_MAP_SINGLE, tx,
3171 					 addr, tx->tlen);
3172 	}
3173 
3174 	return 1;
3175 }
3176 
3177 /* Update sdes when the lmc changes */
3178 void sdma_update_lmc(struct hfi1_devdata *dd, u64 mask, u32 lid)
3179 {
3180 	struct sdma_engine *sde;
3181 	int i;
3182 	u64 sreg;
3183 
3184 	sreg = ((mask & SD(CHECK_SLID_MASK_MASK)) <<
3185 		SD(CHECK_SLID_MASK_SHIFT)) |
3186 		(((lid & mask) & SD(CHECK_SLID_VALUE_MASK)) <<
3187 		SD(CHECK_SLID_VALUE_SHIFT));
3188 
3189 	for (i = 0; i < dd->num_sdma; i++) {
3190 		hfi1_cdbg(LINKVERB, "SendDmaEngine[%d].SLID_CHECK = 0x%x",
3191 			  i, (u32)sreg);
3192 		sde = &dd->per_sdma[i];
3193 		write_sde_csr(sde, SD(CHECK_SLID), sreg);
3194 	}
3195 }
3196 
3197 /* tx not dword sized - pad */
3198 int _pad_sdma_tx_descs(struct hfi1_devdata *dd, struct sdma_txreq *tx)
3199 {
3200 	int rval = 0;
3201 
3202 	tx->num_desc++;
3203 	if ((unlikely(tx->num_desc == tx->desc_limit))) {
3204 		rval = _extend_sdma_tx_descs(dd, tx);
3205 		if (rval) {
3206 			__sdma_txclean(dd, tx);
3207 			return rval;
3208 		}
3209 	}
3210 	/* finish the one just added */
3211 	make_tx_sdma_desc(
3212 		tx,
3213 		SDMA_MAP_NONE,
3214 		dd->sdma_pad_phys,
3215 		sizeof(u32) - (tx->packet_len & (sizeof(u32) - 1)));
3216 	_sdma_close_tx(dd, tx);
3217 	return rval;
3218 }
3219 
3220 /*
3221  * Add ahg to the sdma_txreq
3222  *
3223  * The logic will consume up to 3
3224  * descriptors at the beginning of
3225  * sdma_txreq.
3226  */
3227 void _sdma_txreq_ahgadd(
3228 	struct sdma_txreq *tx,
3229 	u8 num_ahg,
3230 	u8 ahg_entry,
3231 	u32 *ahg,
3232 	u8 ahg_hlen)
3233 {
3234 	u32 i, shift = 0, desc = 0;
3235 	u8 mode;
3236 
3237 	WARN_ON_ONCE(num_ahg > 9 || (ahg_hlen & 3) || ahg_hlen == 4);
3238 	/* compute mode */
3239 	if (num_ahg == 1)
3240 		mode = SDMA_AHG_APPLY_UPDATE1;
3241 	else if (num_ahg <= 5)
3242 		mode = SDMA_AHG_APPLY_UPDATE2;
3243 	else
3244 		mode = SDMA_AHG_APPLY_UPDATE3;
3245 	tx->num_desc++;
3246 	/* initialize to consumed descriptors to zero */
3247 	switch (mode) {
3248 	case SDMA_AHG_APPLY_UPDATE3:
3249 		tx->num_desc++;
3250 		tx->descs[2].qw[0] = 0;
3251 		tx->descs[2].qw[1] = 0;
3252 		/* FALLTHROUGH */
3253 	case SDMA_AHG_APPLY_UPDATE2:
3254 		tx->num_desc++;
3255 		tx->descs[1].qw[0] = 0;
3256 		tx->descs[1].qw[1] = 0;
3257 		break;
3258 	}
3259 	ahg_hlen >>= 2;
3260 	tx->descs[0].qw[1] |=
3261 		(((u64)ahg_entry & SDMA_DESC1_HEADER_INDEX_MASK)
3262 			<< SDMA_DESC1_HEADER_INDEX_SHIFT) |
3263 		(((u64)ahg_hlen & SDMA_DESC1_HEADER_DWS_MASK)
3264 			<< SDMA_DESC1_HEADER_DWS_SHIFT) |
3265 		(((u64)mode & SDMA_DESC1_HEADER_MODE_MASK)
3266 			<< SDMA_DESC1_HEADER_MODE_SHIFT) |
3267 		(((u64)ahg[0] & SDMA_DESC1_HEADER_UPDATE1_MASK)
3268 			<< SDMA_DESC1_HEADER_UPDATE1_SHIFT);
3269 	for (i = 0; i < (num_ahg - 1); i++) {
3270 		if (!shift && !(i & 2))
3271 			desc++;
3272 		tx->descs[desc].qw[!!(i & 2)] |=
3273 			(((u64)ahg[i + 1])
3274 				<< shift);
3275 		shift = (shift + 32) & 63;
3276 	}
3277 }
3278 
3279 /**
3280  * sdma_ahg_alloc - allocate an AHG entry
3281  * @sde: engine to allocate from
3282  *
3283  * Return:
3284  * 0-31 when successful, -EOPNOTSUPP if AHG is not enabled,
3285  * -ENOSPC if an entry is not available
3286  */
3287 int sdma_ahg_alloc(struct sdma_engine *sde)
3288 {
3289 	int nr;
3290 	int oldbit;
3291 
3292 	if (!sde) {
3293 		trace_hfi1_ahg_allocate(sde, -EINVAL);
3294 		return -EINVAL;
3295 	}
3296 	while (1) {
3297 		nr = ffz(READ_ONCE(sde->ahg_bits));
3298 		if (nr > 31) {
3299 			trace_hfi1_ahg_allocate(sde, -ENOSPC);
3300 			return -ENOSPC;
3301 		}
3302 		oldbit = test_and_set_bit(nr, &sde->ahg_bits);
3303 		if (!oldbit)
3304 			break;
3305 		cpu_relax();
3306 	}
3307 	trace_hfi1_ahg_allocate(sde, nr);
3308 	return nr;
3309 }
3310 
3311 /**
3312  * sdma_ahg_free - free an AHG entry
3313  * @sde: engine to return AHG entry
3314  * @ahg_index: index to free
3315  *
3316  * This routine frees the indicate AHG entry.
3317  */
3318 void sdma_ahg_free(struct sdma_engine *sde, int ahg_index)
3319 {
3320 	if (!sde)
3321 		return;
3322 	trace_hfi1_ahg_deallocate(sde, ahg_index);
3323 	if (ahg_index < 0 || ahg_index > 31)
3324 		return;
3325 	clear_bit(ahg_index, &sde->ahg_bits);
3326 }
3327 
3328 /*
3329  * SPC freeze handling for SDMA engines.  Called when the driver knows
3330  * the SPC is going into a freeze but before the freeze is fully
3331  * settled.  Generally an error interrupt.
3332  *
3333  * This event will pull the engine out of running so no more entries can be
3334  * added to the engine's queue.
3335  */
3336 void sdma_freeze_notify(struct hfi1_devdata *dd, int link_down)
3337 {
3338 	int i;
3339 	enum sdma_events event = link_down ? sdma_event_e85_link_down :
3340 					     sdma_event_e80_hw_freeze;
3341 
3342 	/* set up the wait but do not wait here */
3343 	atomic_set(&dd->sdma_unfreeze_count, dd->num_sdma);
3344 
3345 	/* tell all engines to stop running and wait */
3346 	for (i = 0; i < dd->num_sdma; i++)
3347 		sdma_process_event(&dd->per_sdma[i], event);
3348 
3349 	/* sdma_freeze() will wait for all engines to have stopped */
3350 }
3351 
3352 /*
3353  * SPC freeze handling for SDMA engines.  Called when the driver knows
3354  * the SPC is fully frozen.
3355  */
3356 void sdma_freeze(struct hfi1_devdata *dd)
3357 {
3358 	int i;
3359 	int ret;
3360 
3361 	/*
3362 	 * Make sure all engines have moved out of the running state before
3363 	 * continuing.
3364 	 */
3365 	ret = wait_event_interruptible(dd->sdma_unfreeze_wq,
3366 				       atomic_read(&dd->sdma_unfreeze_count) <=
3367 				       0);
3368 	/* interrupted or count is negative, then unloading - just exit */
3369 	if (ret || atomic_read(&dd->sdma_unfreeze_count) < 0)
3370 		return;
3371 
3372 	/* set up the count for the next wait */
3373 	atomic_set(&dd->sdma_unfreeze_count, dd->num_sdma);
3374 
3375 	/* tell all engines that the SPC is frozen, they can start cleaning */
3376 	for (i = 0; i < dd->num_sdma; i++)
3377 		sdma_process_event(&dd->per_sdma[i], sdma_event_e81_hw_frozen);
3378 
3379 	/*
3380 	 * Wait for everyone to finish software clean before exiting.  The
3381 	 * software clean will read engine CSRs, so must be completed before
3382 	 * the next step, which will clear the engine CSRs.
3383 	 */
3384 	(void)wait_event_interruptible(dd->sdma_unfreeze_wq,
3385 				atomic_read(&dd->sdma_unfreeze_count) <= 0);
3386 	/* no need to check results - done no matter what */
3387 }
3388 
3389 /*
3390  * SPC freeze handling for the SDMA engines.  Called after the SPC is unfrozen.
3391  *
3392  * The SPC freeze acts like a SDMA halt and a hardware clean combined.  All
3393  * that is left is a software clean.  We could do it after the SPC is fully
3394  * frozen, but then we'd have to add another state to wait for the unfreeze.
3395  * Instead, just defer the software clean until the unfreeze step.
3396  */
3397 void sdma_unfreeze(struct hfi1_devdata *dd)
3398 {
3399 	int i;
3400 
3401 	/* tell all engines start freeze clean up */
3402 	for (i = 0; i < dd->num_sdma; i++)
3403 		sdma_process_event(&dd->per_sdma[i],
3404 				   sdma_event_e82_hw_unfreeze);
3405 }
3406 
3407 /**
3408  * _sdma_engine_progress_schedule() - schedule progress on engine
3409  * @sde: sdma_engine to schedule progress
3410  *
3411  */
3412 void _sdma_engine_progress_schedule(
3413 	struct sdma_engine *sde)
3414 {
3415 	trace_hfi1_sdma_engine_progress(sde, sde->progress_mask);
3416 	/* assume we have selected a good cpu */
3417 	write_csr(sde->dd,
3418 		  CCE_INT_FORCE + (8 * (IS_SDMA_START / 64)),
3419 		  sde->progress_mask);
3420 }
3421