xref: /openbmc/linux/drivers/infiniband/hw/hfi1/sdma.c (revision bc5aa3a0)
1 /*
2  * Copyright(c) 2015, 2016 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, unsigned 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->hfi1_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 (wait && 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 
409 	/* flush from head to tail */
410 	sdma_flush_descq(sde);
411 	spin_lock_irqsave(&sde->flushlist_lock, flags);
412 	/* copy flush list */
413 	list_for_each_entry_safe(txp, txp_next, &sde->flushlist, list) {
414 		list_del_init(&txp->list);
415 		list_add_tail(&txp->list, &flushlist);
416 	}
417 	spin_unlock_irqrestore(&sde->flushlist_lock, flags);
418 	/* flush from flush list */
419 	list_for_each_entry_safe(txp, txp_next, &flushlist, list)
420 		complete_tx(sde, txp, SDMA_TXREQ_S_ABORTED);
421 }
422 
423 /*
424  * Fields a work request for flushing the descq ring
425  * and the flush list
426  *
427  * If the engine has been brought to running during
428  * the scheduling delay, the flush is ignored, assuming
429  * that the process of bringing the engine to running
430  * would have done this flush prior to going to running.
431  *
432  */
433 static void sdma_field_flush(struct work_struct *work)
434 {
435 	unsigned long flags;
436 	struct sdma_engine *sde =
437 		container_of(work, struct sdma_engine, flush_worker);
438 
439 	write_seqlock_irqsave(&sde->head_lock, flags);
440 	if (!__sdma_running(sde))
441 		sdma_flush(sde);
442 	write_sequnlock_irqrestore(&sde->head_lock, flags);
443 }
444 
445 static void sdma_err_halt_wait(struct work_struct *work)
446 {
447 	struct sdma_engine *sde = container_of(work, struct sdma_engine,
448 						err_halt_worker);
449 	u64 statuscsr;
450 	unsigned long timeout;
451 
452 	timeout = jiffies + msecs_to_jiffies(SDMA_ERR_HALT_TIMEOUT);
453 	while (1) {
454 		statuscsr = read_sde_csr(sde, SD(STATUS));
455 		statuscsr &= SD(STATUS_ENG_HALTED_SMASK);
456 		if (statuscsr)
457 			break;
458 		if (time_after(jiffies, timeout)) {
459 			dd_dev_err(sde->dd,
460 				   "SDMA engine %d - timeout waiting for engine to halt\n",
461 				   sde->this_idx);
462 			/*
463 			 * Continue anyway.  This could happen if there was
464 			 * an uncorrectable error in the wrong spot.
465 			 */
466 			break;
467 		}
468 		usleep_range(80, 120);
469 	}
470 
471 	sdma_process_event(sde, sdma_event_e15_hw_halt_done);
472 }
473 
474 static void sdma_err_progress_check_schedule(struct sdma_engine *sde)
475 {
476 	if (!is_bx(sde->dd) && HFI1_CAP_IS_KSET(SDMA_AHG)) {
477 		unsigned index;
478 		struct hfi1_devdata *dd = sde->dd;
479 
480 		for (index = 0; index < dd->num_sdma; index++) {
481 			struct sdma_engine *curr_sdma = &dd->per_sdma[index];
482 
483 			if (curr_sdma != sde)
484 				curr_sdma->progress_check_head =
485 							curr_sdma->descq_head;
486 		}
487 		dd_dev_err(sde->dd,
488 			   "SDMA engine %d - check scheduled\n",
489 				sde->this_idx);
490 		mod_timer(&sde->err_progress_check_timer, jiffies + 10);
491 	}
492 }
493 
494 static void sdma_err_progress_check(unsigned long data)
495 {
496 	unsigned index;
497 	struct sdma_engine *sde = (struct sdma_engine *)data;
498 
499 	dd_dev_err(sde->dd, "SDE progress check event\n");
500 	for (index = 0; index < sde->dd->num_sdma; index++) {
501 		struct sdma_engine *curr_sde = &sde->dd->per_sdma[index];
502 		unsigned long flags;
503 
504 		/* check progress on each engine except the current one */
505 		if (curr_sde == sde)
506 			continue;
507 		/*
508 		 * We must lock interrupts when acquiring sde->lock,
509 		 * to avoid a deadlock if interrupt triggers and spins on
510 		 * the same lock on same CPU
511 		 */
512 		spin_lock_irqsave(&curr_sde->tail_lock, flags);
513 		write_seqlock(&curr_sde->head_lock);
514 
515 		/* skip non-running queues */
516 		if (curr_sde->state.current_state != sdma_state_s99_running) {
517 			write_sequnlock(&curr_sde->head_lock);
518 			spin_unlock_irqrestore(&curr_sde->tail_lock, flags);
519 			continue;
520 		}
521 
522 		if ((curr_sde->descq_head != curr_sde->descq_tail) &&
523 		    (curr_sde->descq_head ==
524 				curr_sde->progress_check_head))
525 			__sdma_process_event(curr_sde,
526 					     sdma_event_e90_sw_halted);
527 		write_sequnlock(&curr_sde->head_lock);
528 		spin_unlock_irqrestore(&curr_sde->tail_lock, flags);
529 	}
530 	schedule_work(&sde->err_halt_worker);
531 }
532 
533 static void sdma_hw_clean_up_task(unsigned long opaque)
534 {
535 	struct sdma_engine *sde = (struct sdma_engine *)opaque;
536 	u64 statuscsr;
537 
538 	while (1) {
539 #ifdef CONFIG_SDMA_VERBOSITY
540 		dd_dev_err(sde->dd, "CONFIG SDMA(%u) %s:%d %s()\n",
541 			   sde->this_idx, slashstrip(__FILE__), __LINE__,
542 			__func__);
543 #endif
544 		statuscsr = read_sde_csr(sde, SD(STATUS));
545 		statuscsr &= SD(STATUS_ENG_CLEANED_UP_SMASK);
546 		if (statuscsr)
547 			break;
548 		udelay(10);
549 	}
550 
551 	sdma_process_event(sde, sdma_event_e25_hw_clean_up_done);
552 }
553 
554 static inline struct sdma_txreq *get_txhead(struct sdma_engine *sde)
555 {
556 	smp_read_barrier_depends(); /* see sdma_update_tail() */
557 	return sde->tx_ring[sde->tx_head & sde->sdma_mask];
558 }
559 
560 /*
561  * flush ring for recovery
562  */
563 static void sdma_flush_descq(struct sdma_engine *sde)
564 {
565 	u16 head, tail;
566 	int progress = 0;
567 	struct sdma_txreq *txp = get_txhead(sde);
568 
569 	/* The reason for some of the complexity of this code is that
570 	 * not all descriptors have corresponding txps.  So, we have to
571 	 * be able to skip over descs until we wander into the range of
572 	 * the next txp on the list.
573 	 */
574 	head = sde->descq_head & sde->sdma_mask;
575 	tail = sde->descq_tail & sde->sdma_mask;
576 	while (head != tail) {
577 		/* advance head, wrap if needed */
578 		head = ++sde->descq_head & sde->sdma_mask;
579 		/* if now past this txp's descs, do the callback */
580 		if (txp && txp->next_descq_idx == head) {
581 			/* remove from list */
582 			sde->tx_ring[sde->tx_head++ & sde->sdma_mask] = NULL;
583 			complete_tx(sde, txp, SDMA_TXREQ_S_ABORTED);
584 			trace_hfi1_sdma_progress(sde, head, tail, txp);
585 			txp = get_txhead(sde);
586 		}
587 		progress++;
588 	}
589 	if (progress)
590 		sdma_desc_avail(sde, sdma_descq_freecnt(sde));
591 }
592 
593 static void sdma_sw_clean_up_task(unsigned long opaque)
594 {
595 	struct sdma_engine *sde = (struct sdma_engine *)opaque;
596 	unsigned long flags;
597 
598 	spin_lock_irqsave(&sde->tail_lock, flags);
599 	write_seqlock(&sde->head_lock);
600 
601 	/*
602 	 * At this point, the following should always be true:
603 	 * - We are halted, so no more descriptors are getting retired.
604 	 * - We are not running, so no one is submitting new work.
605 	 * - Only we can send the e40_sw_cleaned, so we can't start
606 	 *   running again until we say so.  So, the active list and
607 	 *   descq are ours to play with.
608 	 */
609 
610 	/*
611 	 * In the error clean up sequence, software clean must be called
612 	 * before the hardware clean so we can use the hardware head in
613 	 * the progress routine.  A hardware clean or SPC unfreeze will
614 	 * reset the hardware head.
615 	 *
616 	 * Process all retired requests. The progress routine will use the
617 	 * latest physical hardware head - we are not running so speed does
618 	 * not matter.
619 	 */
620 	sdma_make_progress(sde, 0);
621 
622 	sdma_flush(sde);
623 
624 	/*
625 	 * Reset our notion of head and tail.
626 	 * Note that the HW registers have been reset via an earlier
627 	 * clean up.
628 	 */
629 	sde->descq_tail = 0;
630 	sde->descq_head = 0;
631 	sde->desc_avail = sdma_descq_freecnt(sde);
632 	*sde->head_dma = 0;
633 
634 	__sdma_process_event(sde, sdma_event_e40_sw_cleaned);
635 
636 	write_sequnlock(&sde->head_lock);
637 	spin_unlock_irqrestore(&sde->tail_lock, flags);
638 }
639 
640 static void sdma_sw_tear_down(struct sdma_engine *sde)
641 {
642 	struct sdma_state *ss = &sde->state;
643 
644 	/* Releasing this reference means the state machine has stopped. */
645 	sdma_put(ss);
646 
647 	/* stop waiting for all unfreeze events to complete */
648 	atomic_set(&sde->dd->sdma_unfreeze_count, -1);
649 	wake_up_interruptible(&sde->dd->sdma_unfreeze_wq);
650 }
651 
652 static void sdma_start_hw_clean_up(struct sdma_engine *sde)
653 {
654 	tasklet_hi_schedule(&sde->sdma_hw_clean_up_task);
655 }
656 
657 static void sdma_set_state(struct sdma_engine *sde,
658 			   enum sdma_states next_state)
659 {
660 	struct sdma_state *ss = &sde->state;
661 	const struct sdma_set_state_action *action = sdma_action_table;
662 	unsigned op = 0;
663 
664 	trace_hfi1_sdma_state(
665 		sde,
666 		sdma_state_names[ss->current_state],
667 		sdma_state_names[next_state]);
668 
669 	/* debugging bookkeeping */
670 	ss->previous_state = ss->current_state;
671 	ss->previous_op = ss->current_op;
672 	ss->current_state = next_state;
673 
674 	if (ss->previous_state != sdma_state_s99_running &&
675 	    next_state == sdma_state_s99_running)
676 		sdma_flush(sde);
677 
678 	if (action[next_state].op_enable)
679 		op |= SDMA_SENDCTRL_OP_ENABLE;
680 
681 	if (action[next_state].op_intenable)
682 		op |= SDMA_SENDCTRL_OP_INTENABLE;
683 
684 	if (action[next_state].op_halt)
685 		op |= SDMA_SENDCTRL_OP_HALT;
686 
687 	if (action[next_state].op_cleanup)
688 		op |= SDMA_SENDCTRL_OP_CLEANUP;
689 
690 	if (action[next_state].go_s99_running_tofalse)
691 		ss->go_s99_running = 0;
692 
693 	if (action[next_state].go_s99_running_totrue)
694 		ss->go_s99_running = 1;
695 
696 	ss->current_op = op;
697 	sdma_sendctrl(sde, ss->current_op);
698 }
699 
700 /**
701  * sdma_get_descq_cnt() - called when device probed
702  *
703  * Return a validated descq count.
704  *
705  * This is currently only used in the verbs initialization to build the tx
706  * list.
707  *
708  * This will probably be deleted in favor of a more scalable approach to
709  * alloc tx's.
710  *
711  */
712 u16 sdma_get_descq_cnt(void)
713 {
714 	u16 count = sdma_descq_cnt;
715 
716 	if (!count)
717 		return SDMA_DESCQ_CNT;
718 	/* count must be a power of 2 greater than 64 and less than
719 	 * 32768.   Otherwise return default.
720 	 */
721 	if (!is_power_of_2(count))
722 		return SDMA_DESCQ_CNT;
723 	if (count < 64 || count > 32768)
724 		return SDMA_DESCQ_CNT;
725 	return count;
726 }
727 
728 /**
729  * sdma_select_engine_vl() - select sdma engine
730  * @dd: devdata
731  * @selector: a spreading factor
732  * @vl: this vl
733  *
734  *
735  * This function returns an engine based on the selector and a vl.  The
736  * mapping fields are protected by RCU.
737  */
738 struct sdma_engine *sdma_select_engine_vl(
739 	struct hfi1_devdata *dd,
740 	u32 selector,
741 	u8 vl)
742 {
743 	struct sdma_vl_map *m;
744 	struct sdma_map_elem *e;
745 	struct sdma_engine *rval;
746 
747 	/* NOTE This should only happen if SC->VL changed after the initial
748 	 *      checks on the QP/AH
749 	 *      Default will return engine 0 below
750 	 */
751 	if (vl >= num_vls) {
752 		rval = NULL;
753 		goto done;
754 	}
755 
756 	rcu_read_lock();
757 	m = rcu_dereference(dd->sdma_map);
758 	if (unlikely(!m)) {
759 		rcu_read_unlock();
760 		return &dd->per_sdma[0];
761 	}
762 	e = m->map[vl & m->mask];
763 	rval = e->sde[selector & e->mask];
764 	rcu_read_unlock();
765 
766 done:
767 	rval =  !rval ? &dd->per_sdma[0] : rval;
768 	trace_hfi1_sdma_engine_select(dd, selector, vl, rval->this_idx);
769 	return rval;
770 }
771 
772 /**
773  * sdma_select_engine_sc() - select sdma engine
774  * @dd: devdata
775  * @selector: a spreading factor
776  * @sc5: the 5 bit sc
777  *
778  *
779  * This function returns an engine based on the selector and an sc.
780  */
781 struct sdma_engine *sdma_select_engine_sc(
782 	struct hfi1_devdata *dd,
783 	u32 selector,
784 	u8 sc5)
785 {
786 	u8 vl = sc_to_vlt(dd, sc5);
787 
788 	return sdma_select_engine_vl(dd, selector, vl);
789 }
790 
791 /*
792  * Free the indicated map struct
793  */
794 static void sdma_map_free(struct sdma_vl_map *m)
795 {
796 	int i;
797 
798 	for (i = 0; m && i < m->actual_vls; i++)
799 		kfree(m->map[i]);
800 	kfree(m);
801 }
802 
803 /*
804  * Handle RCU callback
805  */
806 static void sdma_map_rcu_callback(struct rcu_head *list)
807 {
808 	struct sdma_vl_map *m = container_of(list, struct sdma_vl_map, list);
809 
810 	sdma_map_free(m);
811 }
812 
813 /**
814  * sdma_map_init - called when # vls change
815  * @dd: hfi1_devdata
816  * @port: port number
817  * @num_vls: number of vls
818  * @vl_engines: per vl engine mapping (optional)
819  *
820  * This routine changes the mapping based on the number of vls.
821  *
822  * vl_engines is used to specify a non-uniform vl/engine loading. NULL
823  * implies auto computing the loading and giving each VLs a uniform
824  * distribution of engines per VL.
825  *
826  * The auto algorithm computes the sde_per_vl and the number of extra
827  * engines.  Any extra engines are added from the last VL on down.
828  *
829  * rcu locking is used here to control access to the mapping fields.
830  *
831  * If either the num_vls or num_sdma are non-power of 2, the array sizes
832  * in the struct sdma_vl_map and the struct sdma_map_elem are rounded
833  * up to the next highest power of 2 and the first entry is reused
834  * in a round robin fashion.
835  *
836  * If an error occurs the map change is not done and the mapping is
837  * not changed.
838  *
839  */
840 int sdma_map_init(struct hfi1_devdata *dd, u8 port, u8 num_vls, u8 *vl_engines)
841 {
842 	int i, j;
843 	int extra, sde_per_vl;
844 	int engine = 0;
845 	u8 lvl_engines[OPA_MAX_VLS];
846 	struct sdma_vl_map *oldmap, *newmap;
847 
848 	if (!(dd->flags & HFI1_HAS_SEND_DMA))
849 		return 0;
850 
851 	if (!vl_engines) {
852 		/* truncate divide */
853 		sde_per_vl = dd->num_sdma / num_vls;
854 		/* extras */
855 		extra = dd->num_sdma % num_vls;
856 		vl_engines = lvl_engines;
857 		/* add extras from last vl down */
858 		for (i = num_vls - 1; i >= 0; i--, extra--)
859 			vl_engines[i] = sde_per_vl + (extra > 0 ? 1 : 0);
860 	}
861 	/* build new map */
862 	newmap = kzalloc(
863 		sizeof(struct sdma_vl_map) +
864 			roundup_pow_of_two(num_vls) *
865 			sizeof(struct sdma_map_elem *),
866 		GFP_KERNEL);
867 	if (!newmap)
868 		goto bail;
869 	newmap->actual_vls = num_vls;
870 	newmap->vls = roundup_pow_of_two(num_vls);
871 	newmap->mask = (1 << ilog2(newmap->vls)) - 1;
872 	/* initialize back-map */
873 	for (i = 0; i < TXE_NUM_SDMA_ENGINES; i++)
874 		newmap->engine_to_vl[i] = -1;
875 	for (i = 0; i < newmap->vls; i++) {
876 		/* save for wrap around */
877 		int first_engine = engine;
878 
879 		if (i < newmap->actual_vls) {
880 			int sz = roundup_pow_of_two(vl_engines[i]);
881 
882 			/* only allocate once */
883 			newmap->map[i] = kzalloc(
884 				sizeof(struct sdma_map_elem) +
885 					sz * sizeof(struct sdma_engine *),
886 				GFP_KERNEL);
887 			if (!newmap->map[i])
888 				goto bail;
889 			newmap->map[i]->mask = (1 << ilog2(sz)) - 1;
890 			/* assign engines */
891 			for (j = 0; j < sz; j++) {
892 				newmap->map[i]->sde[j] =
893 					&dd->per_sdma[engine];
894 				if (++engine >= first_engine + vl_engines[i])
895 					/* wrap back to first engine */
896 					engine = first_engine;
897 			}
898 			/* assign back-map */
899 			for (j = 0; j < vl_engines[i]; j++)
900 				newmap->engine_to_vl[first_engine + j] = i;
901 		} else {
902 			/* just re-use entry without allocating */
903 			newmap->map[i] = newmap->map[i % num_vls];
904 		}
905 		engine = first_engine + vl_engines[i];
906 	}
907 	/* newmap in hand, save old map */
908 	spin_lock_irq(&dd->sde_map_lock);
909 	oldmap = rcu_dereference_protected(dd->sdma_map,
910 					   lockdep_is_held(&dd->sde_map_lock));
911 
912 	/* publish newmap */
913 	rcu_assign_pointer(dd->sdma_map, newmap);
914 
915 	spin_unlock_irq(&dd->sde_map_lock);
916 	/* success, free any old map after grace period */
917 	if (oldmap)
918 		call_rcu(&oldmap->list, sdma_map_rcu_callback);
919 	return 0;
920 bail:
921 	/* free any partial allocation */
922 	sdma_map_free(newmap);
923 	return -ENOMEM;
924 }
925 
926 /*
927  * Clean up allocated memory.
928  *
929  * This routine is can be called regardless of the success of sdma_init()
930  *
931  */
932 static void sdma_clean(struct hfi1_devdata *dd, size_t num_engines)
933 {
934 	size_t i;
935 	struct sdma_engine *sde;
936 
937 	if (dd->sdma_pad_dma) {
938 		dma_free_coherent(&dd->pcidev->dev, 4,
939 				  (void *)dd->sdma_pad_dma,
940 				  dd->sdma_pad_phys);
941 		dd->sdma_pad_dma = NULL;
942 		dd->sdma_pad_phys = 0;
943 	}
944 	if (dd->sdma_heads_dma) {
945 		dma_free_coherent(&dd->pcidev->dev, dd->sdma_heads_size,
946 				  (void *)dd->sdma_heads_dma,
947 				  dd->sdma_heads_phys);
948 		dd->sdma_heads_dma = NULL;
949 		dd->sdma_heads_phys = 0;
950 	}
951 	for (i = 0; dd->per_sdma && i < num_engines; ++i) {
952 		sde = &dd->per_sdma[i];
953 
954 		sde->head_dma = NULL;
955 		sde->head_phys = 0;
956 
957 		if (sde->descq) {
958 			dma_free_coherent(
959 				&dd->pcidev->dev,
960 				sde->descq_cnt * sizeof(u64[2]),
961 				sde->descq,
962 				sde->descq_phys
963 			);
964 			sde->descq = NULL;
965 			sde->descq_phys = 0;
966 		}
967 		kvfree(sde->tx_ring);
968 		sde->tx_ring = NULL;
969 	}
970 	spin_lock_irq(&dd->sde_map_lock);
971 	sdma_map_free(rcu_access_pointer(dd->sdma_map));
972 	RCU_INIT_POINTER(dd->sdma_map, NULL);
973 	spin_unlock_irq(&dd->sde_map_lock);
974 	synchronize_rcu();
975 	kfree(dd->per_sdma);
976 	dd->per_sdma = NULL;
977 }
978 
979 /**
980  * sdma_init() - called when device probed
981  * @dd: hfi1_devdata
982  * @port: port number (currently only zero)
983  *
984  * sdma_init initializes the specified number of engines.
985  *
986  * The code initializes each sde, its csrs.  Interrupts
987  * are not required to be enabled.
988  *
989  * Returns:
990  * 0 - success, -errno on failure
991  */
992 int sdma_init(struct hfi1_devdata *dd, u8 port)
993 {
994 	unsigned this_idx;
995 	struct sdma_engine *sde;
996 	u16 descq_cnt;
997 	void *curr_head;
998 	struct hfi1_pportdata *ppd = dd->pport + port;
999 	u32 per_sdma_credits;
1000 	uint idle_cnt = sdma_idle_cnt;
1001 	size_t num_engines = dd->chip_sdma_engines;
1002 
1003 	if (!HFI1_CAP_IS_KSET(SDMA)) {
1004 		HFI1_CAP_CLEAR(SDMA_AHG);
1005 		return 0;
1006 	}
1007 	if (mod_num_sdma &&
1008 	    /* can't exceed chip support */
1009 	    mod_num_sdma <= dd->chip_sdma_engines &&
1010 	    /* count must be >= vls */
1011 	    mod_num_sdma >= num_vls)
1012 		num_engines = mod_num_sdma;
1013 
1014 	dd_dev_info(dd, "SDMA mod_num_sdma: %u\n", mod_num_sdma);
1015 	dd_dev_info(dd, "SDMA chip_sdma_engines: %u\n", dd->chip_sdma_engines);
1016 	dd_dev_info(dd, "SDMA chip_sdma_mem_size: %u\n",
1017 		    dd->chip_sdma_mem_size);
1018 
1019 	per_sdma_credits =
1020 		dd->chip_sdma_mem_size / (num_engines * SDMA_BLOCK_SIZE);
1021 
1022 	/* set up freeze waitqueue */
1023 	init_waitqueue_head(&dd->sdma_unfreeze_wq);
1024 	atomic_set(&dd->sdma_unfreeze_count, 0);
1025 
1026 	descq_cnt = sdma_get_descq_cnt();
1027 	dd_dev_info(dd, "SDMA engines %zu descq_cnt %u\n",
1028 		    num_engines, descq_cnt);
1029 
1030 	/* alloc memory for array of send engines */
1031 	dd->per_sdma = kcalloc(num_engines, sizeof(*dd->per_sdma), GFP_KERNEL);
1032 	if (!dd->per_sdma)
1033 		return -ENOMEM;
1034 
1035 	idle_cnt = ns_to_cclock(dd, idle_cnt);
1036 	if (!sdma_desct_intr)
1037 		sdma_desct_intr = SDMA_DESC_INTR;
1038 
1039 	/* Allocate memory for SendDMA descriptor FIFOs */
1040 	for (this_idx = 0; this_idx < num_engines; ++this_idx) {
1041 		sde = &dd->per_sdma[this_idx];
1042 		sde->dd = dd;
1043 		sde->ppd = ppd;
1044 		sde->this_idx = this_idx;
1045 		sde->descq_cnt = descq_cnt;
1046 		sde->desc_avail = sdma_descq_freecnt(sde);
1047 		sde->sdma_shift = ilog2(descq_cnt);
1048 		sde->sdma_mask = (1 << sde->sdma_shift) - 1;
1049 
1050 		/* Create a mask specifically for each interrupt source */
1051 		sde->int_mask = (u64)1 << (0 * TXE_NUM_SDMA_ENGINES +
1052 					   this_idx);
1053 		sde->progress_mask = (u64)1 << (1 * TXE_NUM_SDMA_ENGINES +
1054 						this_idx);
1055 		sde->idle_mask = (u64)1 << (2 * TXE_NUM_SDMA_ENGINES +
1056 					    this_idx);
1057 		/* Create a combined mask to cover all 3 interrupt sources */
1058 		sde->imask = sde->int_mask | sde->progress_mask |
1059 			     sde->idle_mask;
1060 
1061 		spin_lock_init(&sde->tail_lock);
1062 		seqlock_init(&sde->head_lock);
1063 		spin_lock_init(&sde->senddmactrl_lock);
1064 		spin_lock_init(&sde->flushlist_lock);
1065 		/* insure there is always a zero bit */
1066 		sde->ahg_bits = 0xfffffffe00000000ULL;
1067 
1068 		sdma_set_state(sde, sdma_state_s00_hw_down);
1069 
1070 		/* set up reference counting */
1071 		kref_init(&sde->state.kref);
1072 		init_completion(&sde->state.comp);
1073 
1074 		INIT_LIST_HEAD(&sde->flushlist);
1075 		INIT_LIST_HEAD(&sde->dmawait);
1076 
1077 		sde->tail_csr =
1078 			get_kctxt_csr_addr(dd, this_idx, SD(TAIL));
1079 
1080 		if (idle_cnt)
1081 			dd->default_desc1 =
1082 				SDMA_DESC1_HEAD_TO_HOST_FLAG;
1083 		else
1084 			dd->default_desc1 =
1085 				SDMA_DESC1_INT_REQ_FLAG;
1086 
1087 		tasklet_init(&sde->sdma_hw_clean_up_task, sdma_hw_clean_up_task,
1088 			     (unsigned long)sde);
1089 
1090 		tasklet_init(&sde->sdma_sw_clean_up_task, sdma_sw_clean_up_task,
1091 			     (unsigned long)sde);
1092 		INIT_WORK(&sde->err_halt_worker, sdma_err_halt_wait);
1093 		INIT_WORK(&sde->flush_worker, sdma_field_flush);
1094 
1095 		sde->progress_check_head = 0;
1096 
1097 		setup_timer(&sde->err_progress_check_timer,
1098 			    sdma_err_progress_check, (unsigned long)sde);
1099 
1100 		sde->descq = dma_zalloc_coherent(
1101 			&dd->pcidev->dev,
1102 			descq_cnt * sizeof(u64[2]),
1103 			&sde->descq_phys,
1104 			GFP_KERNEL
1105 		);
1106 		if (!sde->descq)
1107 			goto bail;
1108 		sde->tx_ring =
1109 			kcalloc(descq_cnt, sizeof(struct sdma_txreq *),
1110 				GFP_KERNEL);
1111 		if (!sde->tx_ring)
1112 			sde->tx_ring =
1113 				vzalloc(
1114 					sizeof(struct sdma_txreq *) *
1115 					descq_cnt);
1116 		if (!sde->tx_ring)
1117 			goto bail;
1118 	}
1119 
1120 	dd->sdma_heads_size = L1_CACHE_BYTES * num_engines;
1121 	/* Allocate memory for DMA of head registers to memory */
1122 	dd->sdma_heads_dma = dma_zalloc_coherent(
1123 		&dd->pcidev->dev,
1124 		dd->sdma_heads_size,
1125 		&dd->sdma_heads_phys,
1126 		GFP_KERNEL
1127 	);
1128 	if (!dd->sdma_heads_dma) {
1129 		dd_dev_err(dd, "failed to allocate SendDMA head memory\n");
1130 		goto bail;
1131 	}
1132 
1133 	/* Allocate memory for pad */
1134 	dd->sdma_pad_dma = dma_zalloc_coherent(
1135 		&dd->pcidev->dev,
1136 		sizeof(u32),
1137 		&dd->sdma_pad_phys,
1138 		GFP_KERNEL
1139 	);
1140 	if (!dd->sdma_pad_dma) {
1141 		dd_dev_err(dd, "failed to allocate SendDMA pad memory\n");
1142 		goto bail;
1143 	}
1144 
1145 	/* assign each engine to different cacheline and init registers */
1146 	curr_head = (void *)dd->sdma_heads_dma;
1147 	for (this_idx = 0; this_idx < num_engines; ++this_idx) {
1148 		unsigned long phys_offset;
1149 
1150 		sde = &dd->per_sdma[this_idx];
1151 
1152 		sde->head_dma = curr_head;
1153 		curr_head += L1_CACHE_BYTES;
1154 		phys_offset = (unsigned long)sde->head_dma -
1155 			      (unsigned long)dd->sdma_heads_dma;
1156 		sde->head_phys = dd->sdma_heads_phys + phys_offset;
1157 		init_sdma_regs(sde, per_sdma_credits, idle_cnt);
1158 	}
1159 	dd->flags |= HFI1_HAS_SEND_DMA;
1160 	dd->flags |= idle_cnt ? HFI1_HAS_SDMA_TIMEOUT : 0;
1161 	dd->num_sdma = num_engines;
1162 	if (sdma_map_init(dd, port, ppd->vls_operational, NULL))
1163 		goto bail;
1164 	dd_dev_info(dd, "SDMA num_sdma: %u\n", dd->num_sdma);
1165 	return 0;
1166 
1167 bail:
1168 	sdma_clean(dd, num_engines);
1169 	return -ENOMEM;
1170 }
1171 
1172 /**
1173  * sdma_all_running() - called when the link goes up
1174  * @dd: hfi1_devdata
1175  *
1176  * This routine moves all engines to the running state.
1177  */
1178 void sdma_all_running(struct hfi1_devdata *dd)
1179 {
1180 	struct sdma_engine *sde;
1181 	unsigned int i;
1182 
1183 	/* move all engines to running */
1184 	for (i = 0; i < dd->num_sdma; ++i) {
1185 		sde = &dd->per_sdma[i];
1186 		sdma_process_event(sde, sdma_event_e30_go_running);
1187 	}
1188 }
1189 
1190 /**
1191  * sdma_all_idle() - called when the link goes down
1192  * @dd: hfi1_devdata
1193  *
1194  * This routine moves all engines to the idle state.
1195  */
1196 void sdma_all_idle(struct hfi1_devdata *dd)
1197 {
1198 	struct sdma_engine *sde;
1199 	unsigned int i;
1200 
1201 	/* idle all engines */
1202 	for (i = 0; i < dd->num_sdma; ++i) {
1203 		sde = &dd->per_sdma[i];
1204 		sdma_process_event(sde, sdma_event_e70_go_idle);
1205 	}
1206 }
1207 
1208 /**
1209  * sdma_start() - called to kick off state processing for all engines
1210  * @dd: hfi1_devdata
1211  *
1212  * This routine is for kicking off the state processing for all required
1213  * sdma engines.  Interrupts need to be working at this point.
1214  *
1215  */
1216 void sdma_start(struct hfi1_devdata *dd)
1217 {
1218 	unsigned i;
1219 	struct sdma_engine *sde;
1220 
1221 	/* kick off the engines state processing */
1222 	for (i = 0; i < dd->num_sdma; ++i) {
1223 		sde = &dd->per_sdma[i];
1224 		sdma_process_event(sde, sdma_event_e10_go_hw_start);
1225 	}
1226 }
1227 
1228 /**
1229  * sdma_exit() - used when module is removed
1230  * @dd: hfi1_devdata
1231  */
1232 void sdma_exit(struct hfi1_devdata *dd)
1233 {
1234 	unsigned this_idx;
1235 	struct sdma_engine *sde;
1236 
1237 	for (this_idx = 0; dd->per_sdma && this_idx < dd->num_sdma;
1238 			++this_idx) {
1239 		sde = &dd->per_sdma[this_idx];
1240 		if (!list_empty(&sde->dmawait))
1241 			dd_dev_err(dd, "sde %u: dmawait list not empty!\n",
1242 				   sde->this_idx);
1243 		sdma_process_event(sde, sdma_event_e00_go_hw_down);
1244 
1245 		del_timer_sync(&sde->err_progress_check_timer);
1246 
1247 		/*
1248 		 * This waits for the state machine to exit so it is not
1249 		 * necessary to kill the sdma_sw_clean_up_task to make sure
1250 		 * it is not running.
1251 		 */
1252 		sdma_finalput(&sde->state);
1253 	}
1254 	sdma_clean(dd, dd->num_sdma);
1255 }
1256 
1257 /*
1258  * unmap the indicated descriptor
1259  */
1260 static inline void sdma_unmap_desc(
1261 	struct hfi1_devdata *dd,
1262 	struct sdma_desc *descp)
1263 {
1264 	switch (sdma_mapping_type(descp)) {
1265 	case SDMA_MAP_SINGLE:
1266 		dma_unmap_single(
1267 			&dd->pcidev->dev,
1268 			sdma_mapping_addr(descp),
1269 			sdma_mapping_len(descp),
1270 			DMA_TO_DEVICE);
1271 		break;
1272 	case SDMA_MAP_PAGE:
1273 		dma_unmap_page(
1274 			&dd->pcidev->dev,
1275 			sdma_mapping_addr(descp),
1276 			sdma_mapping_len(descp),
1277 			DMA_TO_DEVICE);
1278 		break;
1279 	}
1280 }
1281 
1282 /*
1283  * return the mode as indicated by the first
1284  * descriptor in the tx.
1285  */
1286 static inline u8 ahg_mode(struct sdma_txreq *tx)
1287 {
1288 	return (tx->descp[0].qw[1] & SDMA_DESC1_HEADER_MODE_SMASK)
1289 		>> SDMA_DESC1_HEADER_MODE_SHIFT;
1290 }
1291 
1292 /**
1293  * sdma_txclean() - clean tx of mappings, descp *kmalloc's
1294  * @dd: hfi1_devdata for unmapping
1295  * @tx: tx request to clean
1296  *
1297  * This is used in the progress routine to clean the tx or
1298  * by the ULP to toss an in-process tx build.
1299  *
1300  * The code can be called multiple times without issue.
1301  *
1302  */
1303 void sdma_txclean(
1304 	struct hfi1_devdata *dd,
1305 	struct sdma_txreq *tx)
1306 {
1307 	u16 i;
1308 
1309 	if (tx->num_desc) {
1310 		u8 skip = 0, mode = ahg_mode(tx);
1311 
1312 		/* unmap first */
1313 		sdma_unmap_desc(dd, &tx->descp[0]);
1314 		/* determine number of AHG descriptors to skip */
1315 		if (mode > SDMA_AHG_APPLY_UPDATE1)
1316 			skip = mode >> 1;
1317 		for (i = 1 + skip; i < tx->num_desc; i++)
1318 			sdma_unmap_desc(dd, &tx->descp[i]);
1319 		tx->num_desc = 0;
1320 	}
1321 	kfree(tx->coalesce_buf);
1322 	tx->coalesce_buf = NULL;
1323 	/* kmalloc'ed descp */
1324 	if (unlikely(tx->desc_limit > ARRAY_SIZE(tx->descs))) {
1325 		tx->desc_limit = ARRAY_SIZE(tx->descs);
1326 		kfree(tx->descp);
1327 	}
1328 }
1329 
1330 static inline u16 sdma_gethead(struct sdma_engine *sde)
1331 {
1332 	struct hfi1_devdata *dd = sde->dd;
1333 	int use_dmahead;
1334 	u16 hwhead;
1335 
1336 #ifdef CONFIG_SDMA_VERBOSITY
1337 	dd_dev_err(sde->dd, "CONFIG SDMA(%u) %s:%d %s()\n",
1338 		   sde->this_idx, slashstrip(__FILE__), __LINE__, __func__);
1339 #endif
1340 
1341 retry:
1342 	use_dmahead = HFI1_CAP_IS_KSET(USE_SDMA_HEAD) && __sdma_running(sde) &&
1343 					(dd->flags & HFI1_HAS_SDMA_TIMEOUT);
1344 	hwhead = use_dmahead ?
1345 		(u16)le64_to_cpu(*sde->head_dma) :
1346 		(u16)read_sde_csr(sde, SD(HEAD));
1347 
1348 	if (unlikely(HFI1_CAP_IS_KSET(SDMA_HEAD_CHECK))) {
1349 		u16 cnt;
1350 		u16 swtail;
1351 		u16 swhead;
1352 		int sane;
1353 
1354 		swhead = sde->descq_head & sde->sdma_mask;
1355 		/* this code is really bad for cache line trading */
1356 		swtail = ACCESS_ONCE(sde->descq_tail) & sde->sdma_mask;
1357 		cnt = sde->descq_cnt;
1358 
1359 		if (swhead < swtail)
1360 			/* not wrapped */
1361 			sane = (hwhead >= swhead) & (hwhead <= swtail);
1362 		else if (swhead > swtail)
1363 			/* wrapped around */
1364 			sane = ((hwhead >= swhead) && (hwhead < cnt)) ||
1365 				(hwhead <= swtail);
1366 		else
1367 			/* empty */
1368 			sane = (hwhead == swhead);
1369 
1370 		if (unlikely(!sane)) {
1371 			dd_dev_err(dd, "SDMA(%u) bad head (%s) hwhd=%hu swhd=%hu swtl=%hu cnt=%hu\n",
1372 				   sde->this_idx,
1373 				   use_dmahead ? "dma" : "kreg",
1374 				   hwhead, swhead, swtail, cnt);
1375 			if (use_dmahead) {
1376 				/* try one more time, using csr */
1377 				use_dmahead = 0;
1378 				goto retry;
1379 			}
1380 			/* proceed as if no progress */
1381 			hwhead = swhead;
1382 		}
1383 	}
1384 	return hwhead;
1385 }
1386 
1387 /*
1388  * This is called when there are send DMA descriptors that might be
1389  * available.
1390  *
1391  * This is called with head_lock held.
1392  */
1393 static void sdma_desc_avail(struct sdma_engine *sde, unsigned avail)
1394 {
1395 	struct iowait *wait, *nw;
1396 	struct iowait *waits[SDMA_WAIT_BATCH_SIZE];
1397 	unsigned i, n = 0, seq;
1398 	struct sdma_txreq *stx;
1399 	struct hfi1_ibdev *dev = &sde->dd->verbs_dev;
1400 
1401 #ifdef CONFIG_SDMA_VERBOSITY
1402 	dd_dev_err(sde->dd, "CONFIG SDMA(%u) %s:%d %s()\n", sde->this_idx,
1403 		   slashstrip(__FILE__), __LINE__, __func__);
1404 	dd_dev_err(sde->dd, "avail: %u\n", avail);
1405 #endif
1406 
1407 	do {
1408 		seq = read_seqbegin(&dev->iowait_lock);
1409 		if (!list_empty(&sde->dmawait)) {
1410 			/* at least one item */
1411 			write_seqlock(&dev->iowait_lock);
1412 			/* Harvest waiters wanting DMA descriptors */
1413 			list_for_each_entry_safe(
1414 					wait,
1415 					nw,
1416 					&sde->dmawait,
1417 					list) {
1418 				u16 num_desc = 0;
1419 
1420 				if (!wait->wakeup)
1421 					continue;
1422 				if (n == ARRAY_SIZE(waits))
1423 					break;
1424 				if (!list_empty(&wait->tx_head)) {
1425 					stx = list_first_entry(
1426 						&wait->tx_head,
1427 						struct sdma_txreq,
1428 						list);
1429 					num_desc = stx->num_desc;
1430 				}
1431 				if (num_desc > avail)
1432 					break;
1433 				avail -= num_desc;
1434 				list_del_init(&wait->list);
1435 				waits[n++] = wait;
1436 			}
1437 			write_sequnlock(&dev->iowait_lock);
1438 			break;
1439 		}
1440 	} while (read_seqretry(&dev->iowait_lock, seq));
1441 
1442 	for (i = 0; i < n; i++)
1443 		waits[i]->wakeup(waits[i], SDMA_AVAIL_REASON);
1444 }
1445 
1446 /* head_lock must be held */
1447 static void sdma_make_progress(struct sdma_engine *sde, u64 status)
1448 {
1449 	struct sdma_txreq *txp = NULL;
1450 	int progress = 0;
1451 	u16 hwhead, swhead;
1452 	int idle_check_done = 0;
1453 
1454 	hwhead = sdma_gethead(sde);
1455 
1456 	/* The reason for some of the complexity of this code is that
1457 	 * not all descriptors have corresponding txps.  So, we have to
1458 	 * be able to skip over descs until we wander into the range of
1459 	 * the next txp on the list.
1460 	 */
1461 
1462 retry:
1463 	txp = get_txhead(sde);
1464 	swhead = sde->descq_head & sde->sdma_mask;
1465 	trace_hfi1_sdma_progress(sde, hwhead, swhead, txp);
1466 	while (swhead != hwhead) {
1467 		/* advance head, wrap if needed */
1468 		swhead = ++sde->descq_head & sde->sdma_mask;
1469 
1470 		/* if now past this txp's descs, do the callback */
1471 		if (txp && txp->next_descq_idx == swhead) {
1472 			/* remove from list */
1473 			sde->tx_ring[sde->tx_head++ & sde->sdma_mask] = NULL;
1474 			complete_tx(sde, txp, SDMA_TXREQ_S_OK);
1475 			/* see if there is another txp */
1476 			txp = get_txhead(sde);
1477 		}
1478 		trace_hfi1_sdma_progress(sde, hwhead, swhead, txp);
1479 		progress++;
1480 	}
1481 
1482 	/*
1483 	 * The SDMA idle interrupt is not guaranteed to be ordered with respect
1484 	 * to updates to the the dma_head location in host memory. The head
1485 	 * value read might not be fully up to date. If there are pending
1486 	 * descriptors and the SDMA idle interrupt fired then read from the
1487 	 * CSR SDMA head instead to get the latest value from the hardware.
1488 	 * The hardware SDMA head should be read at most once in this invocation
1489 	 * of sdma_make_progress(..) which is ensured by idle_check_done flag
1490 	 */
1491 	if ((status & sde->idle_mask) && !idle_check_done) {
1492 		u16 swtail;
1493 
1494 		swtail = ACCESS_ONCE(sde->descq_tail) & sde->sdma_mask;
1495 		if (swtail != hwhead) {
1496 			hwhead = (u16)read_sde_csr(sde, SD(HEAD));
1497 			idle_check_done = 1;
1498 			goto retry;
1499 		}
1500 	}
1501 
1502 	sde->last_status = status;
1503 	if (progress)
1504 		sdma_desc_avail(sde, sdma_descq_freecnt(sde));
1505 }
1506 
1507 /*
1508  * sdma_engine_interrupt() - interrupt handler for engine
1509  * @sde: sdma engine
1510  * @status: sdma interrupt reason
1511  *
1512  * Status is a mask of the 3 possible interrupts for this engine.  It will
1513  * contain bits _only_ for this SDMA engine.  It will contain at least one
1514  * bit, it may contain more.
1515  */
1516 void sdma_engine_interrupt(struct sdma_engine *sde, u64 status)
1517 {
1518 	trace_hfi1_sdma_engine_interrupt(sde, status);
1519 	write_seqlock(&sde->head_lock);
1520 	sdma_set_desc_cnt(sde, sdma_desct_intr);
1521 	if (status & sde->idle_mask)
1522 		sde->idle_int_cnt++;
1523 	else if (status & sde->progress_mask)
1524 		sde->progress_int_cnt++;
1525 	else if (status & sde->int_mask)
1526 		sde->sdma_int_cnt++;
1527 	sdma_make_progress(sde, status);
1528 	write_sequnlock(&sde->head_lock);
1529 }
1530 
1531 /**
1532  * sdma_engine_error() - error handler for engine
1533  * @sde: sdma engine
1534  * @status: sdma interrupt reason
1535  */
1536 void sdma_engine_error(struct sdma_engine *sde, u64 status)
1537 {
1538 	unsigned long flags;
1539 
1540 #ifdef CONFIG_SDMA_VERBOSITY
1541 	dd_dev_err(sde->dd, "CONFIG SDMA(%u) error status 0x%llx state %s\n",
1542 		   sde->this_idx,
1543 		   (unsigned long long)status,
1544 		   sdma_state_names[sde->state.current_state]);
1545 #endif
1546 	spin_lock_irqsave(&sde->tail_lock, flags);
1547 	write_seqlock(&sde->head_lock);
1548 	if (status & ALL_SDMA_ENG_HALT_ERRS)
1549 		__sdma_process_event(sde, sdma_event_e60_hw_halted);
1550 	if (status & ~SD(ENG_ERR_STATUS_SDMA_HALT_ERR_SMASK)) {
1551 		dd_dev_err(sde->dd,
1552 			   "SDMA (%u) engine error: 0x%llx state %s\n",
1553 			   sde->this_idx,
1554 			   (unsigned long long)status,
1555 			   sdma_state_names[sde->state.current_state]);
1556 		dump_sdma_state(sde);
1557 	}
1558 	write_sequnlock(&sde->head_lock);
1559 	spin_unlock_irqrestore(&sde->tail_lock, flags);
1560 }
1561 
1562 static void sdma_sendctrl(struct sdma_engine *sde, unsigned op)
1563 {
1564 	u64 set_senddmactrl = 0;
1565 	u64 clr_senddmactrl = 0;
1566 	unsigned long flags;
1567 
1568 #ifdef CONFIG_SDMA_VERBOSITY
1569 	dd_dev_err(sde->dd, "CONFIG SDMA(%u) senddmactrl E=%d I=%d H=%d C=%d\n",
1570 		   sde->this_idx,
1571 		   (op & SDMA_SENDCTRL_OP_ENABLE) ? 1 : 0,
1572 		   (op & SDMA_SENDCTRL_OP_INTENABLE) ? 1 : 0,
1573 		   (op & SDMA_SENDCTRL_OP_HALT) ? 1 : 0,
1574 		   (op & SDMA_SENDCTRL_OP_CLEANUP) ? 1 : 0);
1575 #endif
1576 
1577 	if (op & SDMA_SENDCTRL_OP_ENABLE)
1578 		set_senddmactrl |= SD(CTRL_SDMA_ENABLE_SMASK);
1579 	else
1580 		clr_senddmactrl |= SD(CTRL_SDMA_ENABLE_SMASK);
1581 
1582 	if (op & SDMA_SENDCTRL_OP_INTENABLE)
1583 		set_senddmactrl |= SD(CTRL_SDMA_INT_ENABLE_SMASK);
1584 	else
1585 		clr_senddmactrl |= SD(CTRL_SDMA_INT_ENABLE_SMASK);
1586 
1587 	if (op & SDMA_SENDCTRL_OP_HALT)
1588 		set_senddmactrl |= SD(CTRL_SDMA_HALT_SMASK);
1589 	else
1590 		clr_senddmactrl |= SD(CTRL_SDMA_HALT_SMASK);
1591 
1592 	spin_lock_irqsave(&sde->senddmactrl_lock, flags);
1593 
1594 	sde->p_senddmactrl |= set_senddmactrl;
1595 	sde->p_senddmactrl &= ~clr_senddmactrl;
1596 
1597 	if (op & SDMA_SENDCTRL_OP_CLEANUP)
1598 		write_sde_csr(sde, SD(CTRL),
1599 			      sde->p_senddmactrl |
1600 			      SD(CTRL_SDMA_CLEANUP_SMASK));
1601 	else
1602 		write_sde_csr(sde, SD(CTRL), sde->p_senddmactrl);
1603 
1604 	spin_unlock_irqrestore(&sde->senddmactrl_lock, flags);
1605 
1606 #ifdef CONFIG_SDMA_VERBOSITY
1607 	sdma_dumpstate(sde);
1608 #endif
1609 }
1610 
1611 static void sdma_setlengen(struct sdma_engine *sde)
1612 {
1613 #ifdef CONFIG_SDMA_VERBOSITY
1614 	dd_dev_err(sde->dd, "CONFIG SDMA(%u) %s:%d %s()\n",
1615 		   sde->this_idx, slashstrip(__FILE__), __LINE__, __func__);
1616 #endif
1617 
1618 	/*
1619 	 * Set SendDmaLenGen and clear-then-set the MSB of the generation
1620 	 * count to enable generation checking and load the internal
1621 	 * generation counter.
1622 	 */
1623 	write_sde_csr(sde, SD(LEN_GEN),
1624 		      (sde->descq_cnt / 64) << SD(LEN_GEN_LENGTH_SHIFT));
1625 	write_sde_csr(sde, SD(LEN_GEN),
1626 		      ((sde->descq_cnt / 64) << SD(LEN_GEN_LENGTH_SHIFT)) |
1627 		      (4ULL << SD(LEN_GEN_GENERATION_SHIFT)));
1628 }
1629 
1630 static inline void sdma_update_tail(struct sdma_engine *sde, u16 tail)
1631 {
1632 	/* Commit writes to memory and advance the tail on the chip */
1633 	smp_wmb(); /* see get_txhead() */
1634 	writeq(tail, sde->tail_csr);
1635 }
1636 
1637 /*
1638  * This is called when changing to state s10_hw_start_up_halt_wait as
1639  * a result of send buffer errors or send DMA descriptor errors.
1640  */
1641 static void sdma_hw_start_up(struct sdma_engine *sde)
1642 {
1643 	u64 reg;
1644 
1645 #ifdef CONFIG_SDMA_VERBOSITY
1646 	dd_dev_err(sde->dd, "CONFIG SDMA(%u) %s:%d %s()\n",
1647 		   sde->this_idx, slashstrip(__FILE__), __LINE__, __func__);
1648 #endif
1649 
1650 	sdma_setlengen(sde);
1651 	sdma_update_tail(sde, 0); /* Set SendDmaTail */
1652 	*sde->head_dma = 0;
1653 
1654 	reg = SD(ENG_ERR_CLEAR_SDMA_HEADER_REQUEST_FIFO_UNC_ERR_MASK) <<
1655 	      SD(ENG_ERR_CLEAR_SDMA_HEADER_REQUEST_FIFO_UNC_ERR_SHIFT);
1656 	write_sde_csr(sde, SD(ENG_ERR_CLEAR), reg);
1657 }
1658 
1659 #define CLEAR_STATIC_RATE_CONTROL_SMASK(r) \
1660 (r &= ~SEND_DMA_CHECK_ENABLE_DISALLOW_PBC_STATIC_RATE_CONTROL_SMASK)
1661 
1662 #define SET_STATIC_RATE_CONTROL_SMASK(r) \
1663 (r |= SEND_DMA_CHECK_ENABLE_DISALLOW_PBC_STATIC_RATE_CONTROL_SMASK)
1664 /*
1665  * set_sdma_integrity
1666  *
1667  * Set the SEND_DMA_CHECK_ENABLE register for send DMA engine 'sde'.
1668  */
1669 static void set_sdma_integrity(struct sdma_engine *sde)
1670 {
1671 	struct hfi1_devdata *dd = sde->dd;
1672 	u64 reg;
1673 
1674 	if (unlikely(HFI1_CAP_IS_KSET(NO_INTEGRITY)))
1675 		return;
1676 
1677 	reg = hfi1_pkt_base_sdma_integrity(dd);
1678 
1679 	if (HFI1_CAP_IS_KSET(STATIC_RATE_CTRL))
1680 		CLEAR_STATIC_RATE_CONTROL_SMASK(reg);
1681 	else
1682 		SET_STATIC_RATE_CONTROL_SMASK(reg);
1683 
1684 	write_sde_csr(sde, SD(CHECK_ENABLE), reg);
1685 }
1686 
1687 static void init_sdma_regs(
1688 	struct sdma_engine *sde,
1689 	u32 credits,
1690 	uint idle_cnt)
1691 {
1692 	u8 opval, opmask;
1693 #ifdef CONFIG_SDMA_VERBOSITY
1694 	struct hfi1_devdata *dd = sde->dd;
1695 
1696 	dd_dev_err(dd, "CONFIG SDMA(%u) %s:%d %s()\n",
1697 		   sde->this_idx, slashstrip(__FILE__), __LINE__, __func__);
1698 #endif
1699 
1700 	write_sde_csr(sde, SD(BASE_ADDR), sde->descq_phys);
1701 	sdma_setlengen(sde);
1702 	sdma_update_tail(sde, 0); /* Set SendDmaTail */
1703 	write_sde_csr(sde, SD(RELOAD_CNT), idle_cnt);
1704 	write_sde_csr(sde, SD(DESC_CNT), 0);
1705 	write_sde_csr(sde, SD(HEAD_ADDR), sde->head_phys);
1706 	write_sde_csr(sde, SD(MEMORY),
1707 		      ((u64)credits << SD(MEMORY_SDMA_MEMORY_CNT_SHIFT)) |
1708 		      ((u64)(credits * sde->this_idx) <<
1709 		       SD(MEMORY_SDMA_MEMORY_INDEX_SHIFT)));
1710 	write_sde_csr(sde, SD(ENG_ERR_MASK), ~0ull);
1711 	set_sdma_integrity(sde);
1712 	opmask = OPCODE_CHECK_MASK_DISABLED;
1713 	opval = OPCODE_CHECK_VAL_DISABLED;
1714 	write_sde_csr(sde, SD(CHECK_OPCODE),
1715 		      (opmask << SEND_CTXT_CHECK_OPCODE_MASK_SHIFT) |
1716 		      (opval << SEND_CTXT_CHECK_OPCODE_VALUE_SHIFT));
1717 }
1718 
1719 #ifdef CONFIG_SDMA_VERBOSITY
1720 
1721 #define sdma_dumpstate_helper0(reg) do { \
1722 		csr = read_csr(sde->dd, reg); \
1723 		dd_dev_err(sde->dd, "%36s     0x%016llx\n", #reg, csr); \
1724 	} while (0)
1725 
1726 #define sdma_dumpstate_helper(reg) do { \
1727 		csr = read_sde_csr(sde, reg); \
1728 		dd_dev_err(sde->dd, "%36s[%02u] 0x%016llx\n", \
1729 			#reg, sde->this_idx, csr); \
1730 	} while (0)
1731 
1732 #define sdma_dumpstate_helper2(reg) do { \
1733 		csr = read_csr(sde->dd, reg + (8 * i)); \
1734 		dd_dev_err(sde->dd, "%33s_%02u     0x%016llx\n", \
1735 				#reg, i, csr); \
1736 	} while (0)
1737 
1738 void sdma_dumpstate(struct sdma_engine *sde)
1739 {
1740 	u64 csr;
1741 	unsigned i;
1742 
1743 	sdma_dumpstate_helper(SD(CTRL));
1744 	sdma_dumpstate_helper(SD(STATUS));
1745 	sdma_dumpstate_helper0(SD(ERR_STATUS));
1746 	sdma_dumpstate_helper0(SD(ERR_MASK));
1747 	sdma_dumpstate_helper(SD(ENG_ERR_STATUS));
1748 	sdma_dumpstate_helper(SD(ENG_ERR_MASK));
1749 
1750 	for (i = 0; i < CCE_NUM_INT_CSRS; ++i) {
1751 		sdma_dumpstate_helper2(CCE_INT_STATUS);
1752 		sdma_dumpstate_helper2(CCE_INT_MASK);
1753 		sdma_dumpstate_helper2(CCE_INT_BLOCKED);
1754 	}
1755 
1756 	sdma_dumpstate_helper(SD(TAIL));
1757 	sdma_dumpstate_helper(SD(HEAD));
1758 	sdma_dumpstate_helper(SD(PRIORITY_THLD));
1759 	sdma_dumpstate_helper(SD(IDLE_CNT));
1760 	sdma_dumpstate_helper(SD(RELOAD_CNT));
1761 	sdma_dumpstate_helper(SD(DESC_CNT));
1762 	sdma_dumpstate_helper(SD(DESC_FETCHED_CNT));
1763 	sdma_dumpstate_helper(SD(MEMORY));
1764 	sdma_dumpstate_helper0(SD(ENGINES));
1765 	sdma_dumpstate_helper0(SD(MEM_SIZE));
1766 	/* sdma_dumpstate_helper(SEND_EGRESS_SEND_DMA_STATUS);  */
1767 	sdma_dumpstate_helper(SD(BASE_ADDR));
1768 	sdma_dumpstate_helper(SD(LEN_GEN));
1769 	sdma_dumpstate_helper(SD(HEAD_ADDR));
1770 	sdma_dumpstate_helper(SD(CHECK_ENABLE));
1771 	sdma_dumpstate_helper(SD(CHECK_VL));
1772 	sdma_dumpstate_helper(SD(CHECK_JOB_KEY));
1773 	sdma_dumpstate_helper(SD(CHECK_PARTITION_KEY));
1774 	sdma_dumpstate_helper(SD(CHECK_SLID));
1775 	sdma_dumpstate_helper(SD(CHECK_OPCODE));
1776 }
1777 #endif
1778 
1779 static void dump_sdma_state(struct sdma_engine *sde)
1780 {
1781 	struct hw_sdma_desc *descq;
1782 	struct hw_sdma_desc *descqp;
1783 	u64 desc[2];
1784 	u64 addr;
1785 	u8 gen;
1786 	u16 len;
1787 	u16 head, tail, cnt;
1788 
1789 	head = sde->descq_head & sde->sdma_mask;
1790 	tail = sde->descq_tail & sde->sdma_mask;
1791 	cnt = sdma_descq_freecnt(sde);
1792 	descq = sde->descq;
1793 
1794 	dd_dev_err(sde->dd,
1795 		   "SDMA (%u) descq_head: %u descq_tail: %u freecnt: %u FLE %d\n",
1796 		   sde->this_idx, head, tail, cnt,
1797 		   !list_empty(&sde->flushlist));
1798 
1799 	/* print info for each entry in the descriptor queue */
1800 	while (head != tail) {
1801 		char flags[6] = { 'x', 'x', 'x', 'x', 0 };
1802 
1803 		descqp = &sde->descq[head];
1804 		desc[0] = le64_to_cpu(descqp->qw[0]);
1805 		desc[1] = le64_to_cpu(descqp->qw[1]);
1806 		flags[0] = (desc[1] & SDMA_DESC1_INT_REQ_FLAG) ? 'I' : '-';
1807 		flags[1] = (desc[1] & SDMA_DESC1_HEAD_TO_HOST_FLAG) ?
1808 				'H' : '-';
1809 		flags[2] = (desc[0] & SDMA_DESC0_FIRST_DESC_FLAG) ? 'F' : '-';
1810 		flags[3] = (desc[0] & SDMA_DESC0_LAST_DESC_FLAG) ? 'L' : '-';
1811 		addr = (desc[0] >> SDMA_DESC0_PHY_ADDR_SHIFT)
1812 			& SDMA_DESC0_PHY_ADDR_MASK;
1813 		gen = (desc[1] >> SDMA_DESC1_GENERATION_SHIFT)
1814 			& SDMA_DESC1_GENERATION_MASK;
1815 		len = (desc[0] >> SDMA_DESC0_BYTE_COUNT_SHIFT)
1816 			& SDMA_DESC0_BYTE_COUNT_MASK;
1817 		dd_dev_err(sde->dd,
1818 			   "SDMA sdmadesc[%u]: flags:%s addr:0x%016llx gen:%u len:%u bytes\n",
1819 			   head, flags, addr, gen, len);
1820 		dd_dev_err(sde->dd,
1821 			   "\tdesc0:0x%016llx desc1 0x%016llx\n",
1822 			   desc[0], desc[1]);
1823 		if (desc[0] & SDMA_DESC0_FIRST_DESC_FLAG)
1824 			dd_dev_err(sde->dd,
1825 				   "\taidx: %u amode: %u alen: %u\n",
1826 				   (u8)((desc[1] &
1827 					 SDMA_DESC1_HEADER_INDEX_SMASK) >>
1828 					SDMA_DESC1_HEADER_INDEX_SHIFT),
1829 				   (u8)((desc[1] &
1830 					 SDMA_DESC1_HEADER_MODE_SMASK) >>
1831 					SDMA_DESC1_HEADER_MODE_SHIFT),
1832 				   (u8)((desc[1] &
1833 					 SDMA_DESC1_HEADER_DWS_SMASK) >>
1834 					SDMA_DESC1_HEADER_DWS_SHIFT));
1835 		head++;
1836 		head &= sde->sdma_mask;
1837 	}
1838 }
1839 
1840 #define SDE_FMT \
1841 	"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"
1842 /**
1843  * sdma_seqfile_dump_sde() - debugfs dump of sde
1844  * @s: seq file
1845  * @sde: send dma engine to dump
1846  *
1847  * This routine dumps the sde to the indicated seq file.
1848  */
1849 void sdma_seqfile_dump_sde(struct seq_file *s, struct sdma_engine *sde)
1850 {
1851 	u16 head, tail;
1852 	struct hw_sdma_desc *descqp;
1853 	u64 desc[2];
1854 	u64 addr;
1855 	u8 gen;
1856 	u16 len;
1857 
1858 	head = sde->descq_head & sde->sdma_mask;
1859 	tail = ACCESS_ONCE(sde->descq_tail) & sde->sdma_mask;
1860 	seq_printf(s, SDE_FMT, sde->this_idx,
1861 		   sde->cpu,
1862 		   sdma_state_name(sde->state.current_state),
1863 		   (unsigned long long)read_sde_csr(sde, SD(CTRL)),
1864 		   (unsigned long long)read_sde_csr(sde, SD(STATUS)),
1865 		   (unsigned long long)read_sde_csr(sde, SD(ENG_ERR_STATUS)),
1866 		   (unsigned long long)read_sde_csr(sde, SD(TAIL)), tail,
1867 		   (unsigned long long)read_sde_csr(sde, SD(HEAD)), head,
1868 		   (unsigned long long)le64_to_cpu(*sde->head_dma),
1869 		   (unsigned long long)read_sde_csr(sde, SD(MEMORY)),
1870 		   (unsigned long long)read_sde_csr(sde, SD(LEN_GEN)),
1871 		   (unsigned long long)read_sde_csr(sde, SD(RELOAD_CNT)),
1872 		   (unsigned long long)sde->last_status,
1873 		   (unsigned long long)sde->ahg_bits,
1874 		   sde->tx_tail,
1875 		   sde->tx_head,
1876 		   sde->descq_tail,
1877 		   sde->descq_head,
1878 		   !list_empty(&sde->flushlist),
1879 		   sde->descq_full_count,
1880 		   (unsigned long long)read_sde_csr(sde, SEND_DMA_CHECK_SLID));
1881 
1882 	/* print info for each entry in the descriptor queue */
1883 	while (head != tail) {
1884 		char flags[6] = { 'x', 'x', 'x', 'x', 0 };
1885 
1886 		descqp = &sde->descq[head];
1887 		desc[0] = le64_to_cpu(descqp->qw[0]);
1888 		desc[1] = le64_to_cpu(descqp->qw[1]);
1889 		flags[0] = (desc[1] & SDMA_DESC1_INT_REQ_FLAG) ? 'I' : '-';
1890 		flags[1] = (desc[1] & SDMA_DESC1_HEAD_TO_HOST_FLAG) ?
1891 				'H' : '-';
1892 		flags[2] = (desc[0] & SDMA_DESC0_FIRST_DESC_FLAG) ? 'F' : '-';
1893 		flags[3] = (desc[0] & SDMA_DESC0_LAST_DESC_FLAG) ? 'L' : '-';
1894 		addr = (desc[0] >> SDMA_DESC0_PHY_ADDR_SHIFT)
1895 			& SDMA_DESC0_PHY_ADDR_MASK;
1896 		gen = (desc[1] >> SDMA_DESC1_GENERATION_SHIFT)
1897 			& SDMA_DESC1_GENERATION_MASK;
1898 		len = (desc[0] >> SDMA_DESC0_BYTE_COUNT_SHIFT)
1899 			& SDMA_DESC0_BYTE_COUNT_MASK;
1900 		seq_printf(s,
1901 			   "\tdesc[%u]: flags:%s addr:0x%016llx gen:%u len:%u bytes\n",
1902 			   head, flags, addr, gen, len);
1903 		if (desc[0] & SDMA_DESC0_FIRST_DESC_FLAG)
1904 			seq_printf(s, "\t\tahgidx: %u ahgmode: %u\n",
1905 				   (u8)((desc[1] &
1906 					 SDMA_DESC1_HEADER_INDEX_SMASK) >>
1907 					SDMA_DESC1_HEADER_INDEX_SHIFT),
1908 				   (u8)((desc[1] &
1909 					 SDMA_DESC1_HEADER_MODE_SMASK) >>
1910 					SDMA_DESC1_HEADER_MODE_SHIFT));
1911 		head = (head + 1) & sde->sdma_mask;
1912 	}
1913 }
1914 
1915 /*
1916  * add the generation number into
1917  * the qw1 and return
1918  */
1919 static inline u64 add_gen(struct sdma_engine *sde, u64 qw1)
1920 {
1921 	u8 generation = (sde->descq_tail >> sde->sdma_shift) & 3;
1922 
1923 	qw1 &= ~SDMA_DESC1_GENERATION_SMASK;
1924 	qw1 |= ((u64)generation & SDMA_DESC1_GENERATION_MASK)
1925 			<< SDMA_DESC1_GENERATION_SHIFT;
1926 	return qw1;
1927 }
1928 
1929 /*
1930  * This routine submits the indicated tx
1931  *
1932  * Space has already been guaranteed and
1933  * tail side of ring is locked.
1934  *
1935  * The hardware tail update is done
1936  * in the caller and that is facilitated
1937  * by returning the new tail.
1938  *
1939  * There is special case logic for ahg
1940  * to not add the generation number for
1941  * up to 2 descriptors that follow the
1942  * first descriptor.
1943  *
1944  */
1945 static inline u16 submit_tx(struct sdma_engine *sde, struct sdma_txreq *tx)
1946 {
1947 	int i;
1948 	u16 tail;
1949 	struct sdma_desc *descp = tx->descp;
1950 	u8 skip = 0, mode = ahg_mode(tx);
1951 
1952 	tail = sde->descq_tail & sde->sdma_mask;
1953 	sde->descq[tail].qw[0] = cpu_to_le64(descp->qw[0]);
1954 	sde->descq[tail].qw[1] = cpu_to_le64(add_gen(sde, descp->qw[1]));
1955 	trace_hfi1_sdma_descriptor(sde, descp->qw[0], descp->qw[1],
1956 				   tail, &sde->descq[tail]);
1957 	tail = ++sde->descq_tail & sde->sdma_mask;
1958 	descp++;
1959 	if (mode > SDMA_AHG_APPLY_UPDATE1)
1960 		skip = mode >> 1;
1961 	for (i = 1; i < tx->num_desc; i++, descp++) {
1962 		u64 qw1;
1963 
1964 		sde->descq[tail].qw[0] = cpu_to_le64(descp->qw[0]);
1965 		if (skip) {
1966 			/* edits don't have generation */
1967 			qw1 = descp->qw[1];
1968 			skip--;
1969 		} else {
1970 			/* replace generation with real one for non-edits */
1971 			qw1 = add_gen(sde, descp->qw[1]);
1972 		}
1973 		sde->descq[tail].qw[1] = cpu_to_le64(qw1);
1974 		trace_hfi1_sdma_descriptor(sde, descp->qw[0], qw1,
1975 					   tail, &sde->descq[tail]);
1976 		tail = ++sde->descq_tail & sde->sdma_mask;
1977 	}
1978 	tx->next_descq_idx = tail;
1979 #ifdef CONFIG_HFI1_DEBUG_SDMA_ORDER
1980 	tx->sn = sde->tail_sn++;
1981 	trace_hfi1_sdma_in_sn(sde, tx->sn);
1982 	WARN_ON_ONCE(sde->tx_ring[sde->tx_tail & sde->sdma_mask]);
1983 #endif
1984 	sde->tx_ring[sde->tx_tail++ & sde->sdma_mask] = tx;
1985 	sde->desc_avail -= tx->num_desc;
1986 	return tail;
1987 }
1988 
1989 /*
1990  * Check for progress
1991  */
1992 static int sdma_check_progress(
1993 	struct sdma_engine *sde,
1994 	struct iowait *wait,
1995 	struct sdma_txreq *tx)
1996 {
1997 	int ret;
1998 
1999 	sde->desc_avail = sdma_descq_freecnt(sde);
2000 	if (tx->num_desc <= sde->desc_avail)
2001 		return -EAGAIN;
2002 	/* pulse the head_lock */
2003 	if (wait && wait->sleep) {
2004 		unsigned seq;
2005 
2006 		seq = raw_seqcount_begin(
2007 			(const seqcount_t *)&sde->head_lock.seqcount);
2008 		ret = wait->sleep(sde, wait, tx, seq);
2009 		if (ret == -EAGAIN)
2010 			sde->desc_avail = sdma_descq_freecnt(sde);
2011 	} else {
2012 		ret = -EBUSY;
2013 	}
2014 	return ret;
2015 }
2016 
2017 /**
2018  * sdma_send_txreq() - submit a tx req to ring
2019  * @sde: sdma engine to use
2020  * @wait: wait structure to use when full (may be NULL)
2021  * @tx: sdma_txreq to submit
2022  *
2023  * The call submits the tx into the ring.  If a iowait structure is non-NULL
2024  * the packet will be queued to the list in wait.
2025  *
2026  * Return:
2027  * 0 - Success, -EINVAL - sdma_txreq incomplete, -EBUSY - no space in
2028  * ring (wait == NULL)
2029  * -EIOCBQUEUED - tx queued to iowait, -ECOMM bad sdma state
2030  */
2031 int sdma_send_txreq(struct sdma_engine *sde,
2032 		    struct iowait *wait,
2033 		    struct sdma_txreq *tx)
2034 {
2035 	int ret = 0;
2036 	u16 tail;
2037 	unsigned long flags;
2038 
2039 	/* user should have supplied entire packet */
2040 	if (unlikely(tx->tlen))
2041 		return -EINVAL;
2042 	tx->wait = wait;
2043 	spin_lock_irqsave(&sde->tail_lock, flags);
2044 retry:
2045 	if (unlikely(!__sdma_running(sde)))
2046 		goto unlock_noconn;
2047 	if (unlikely(tx->num_desc > sde->desc_avail))
2048 		goto nodesc;
2049 	tail = submit_tx(sde, tx);
2050 	if (wait)
2051 		iowait_sdma_inc(wait);
2052 	sdma_update_tail(sde, tail);
2053 unlock:
2054 	spin_unlock_irqrestore(&sde->tail_lock, flags);
2055 	return ret;
2056 unlock_noconn:
2057 	if (wait)
2058 		iowait_sdma_inc(wait);
2059 	tx->next_descq_idx = 0;
2060 #ifdef CONFIG_HFI1_DEBUG_SDMA_ORDER
2061 	tx->sn = sde->tail_sn++;
2062 	trace_hfi1_sdma_in_sn(sde, tx->sn);
2063 #endif
2064 	spin_lock(&sde->flushlist_lock);
2065 	list_add_tail(&tx->list, &sde->flushlist);
2066 	spin_unlock(&sde->flushlist_lock);
2067 	if (wait) {
2068 		wait->tx_count++;
2069 		wait->count += tx->num_desc;
2070 	}
2071 	schedule_work(&sde->flush_worker);
2072 	ret = -ECOMM;
2073 	goto unlock;
2074 nodesc:
2075 	ret = sdma_check_progress(sde, wait, tx);
2076 	if (ret == -EAGAIN) {
2077 		ret = 0;
2078 		goto retry;
2079 	}
2080 	sde->descq_full_count++;
2081 	goto unlock;
2082 }
2083 
2084 /**
2085  * sdma_send_txlist() - submit a list of tx req to ring
2086  * @sde: sdma engine to use
2087  * @wait: wait structure to use when full (may be NULL)
2088  * @tx_list: list of sdma_txreqs to submit
2089  *
2090  * The call submits the list into the ring.
2091  *
2092  * If the iowait structure is non-NULL and not equal to the iowait list
2093  * the unprocessed part of the list  will be appended to the list in wait.
2094  *
2095  * In all cases, the tx_list will be updated so the head of the tx_list is
2096  * the list of descriptors that have yet to be transmitted.
2097  *
2098  * The intent of this call is to provide a more efficient
2099  * way of submitting multiple packets to SDMA while holding the tail
2100  * side locking.
2101  *
2102  * Return:
2103  * > 0 - Success (value is number of sdma_txreq's submitted),
2104  * -EINVAL - sdma_txreq incomplete, -EBUSY - no space in ring (wait == NULL)
2105  * -EIOCBQUEUED - tx queued to iowait, -ECOMM bad sdma state
2106  */
2107 int sdma_send_txlist(struct sdma_engine *sde, struct iowait *wait,
2108 		     struct list_head *tx_list)
2109 {
2110 	struct sdma_txreq *tx, *tx_next;
2111 	int ret = 0;
2112 	unsigned long flags;
2113 	u16 tail = INVALID_TAIL;
2114 	int count = 0;
2115 
2116 	spin_lock_irqsave(&sde->tail_lock, flags);
2117 retry:
2118 	list_for_each_entry_safe(tx, tx_next, tx_list, list) {
2119 		tx->wait = wait;
2120 		if (unlikely(!__sdma_running(sde)))
2121 			goto unlock_noconn;
2122 		if (unlikely(tx->num_desc > sde->desc_avail))
2123 			goto nodesc;
2124 		if (unlikely(tx->tlen)) {
2125 			ret = -EINVAL;
2126 			goto update_tail;
2127 		}
2128 		list_del_init(&tx->list);
2129 		tail = submit_tx(sde, tx);
2130 		count++;
2131 		if (tail != INVALID_TAIL &&
2132 		    (count & SDMA_TAIL_UPDATE_THRESH) == 0) {
2133 			sdma_update_tail(sde, tail);
2134 			tail = INVALID_TAIL;
2135 		}
2136 	}
2137 update_tail:
2138 	if (wait)
2139 		iowait_sdma_add(wait, count);
2140 	if (tail != INVALID_TAIL)
2141 		sdma_update_tail(sde, tail);
2142 	spin_unlock_irqrestore(&sde->tail_lock, flags);
2143 	return ret == 0 ? count : ret;
2144 unlock_noconn:
2145 	spin_lock(&sde->flushlist_lock);
2146 	list_for_each_entry_safe(tx, tx_next, tx_list, list) {
2147 		tx->wait = wait;
2148 		list_del_init(&tx->list);
2149 		if (wait)
2150 			iowait_sdma_inc(wait);
2151 		tx->next_descq_idx = 0;
2152 #ifdef CONFIG_HFI1_DEBUG_SDMA_ORDER
2153 		tx->sn = sde->tail_sn++;
2154 		trace_hfi1_sdma_in_sn(sde, tx->sn);
2155 #endif
2156 		list_add_tail(&tx->list, &sde->flushlist);
2157 		if (wait) {
2158 			wait->tx_count++;
2159 			wait->count += tx->num_desc;
2160 		}
2161 	}
2162 	spin_unlock(&sde->flushlist_lock);
2163 	schedule_work(&sde->flush_worker);
2164 	ret = -ECOMM;
2165 	goto update_tail;
2166 nodesc:
2167 	ret = sdma_check_progress(sde, wait, tx);
2168 	if (ret == -EAGAIN) {
2169 		ret = 0;
2170 		goto retry;
2171 	}
2172 	sde->descq_full_count++;
2173 	goto update_tail;
2174 }
2175 
2176 static void sdma_process_event(struct sdma_engine *sde, enum sdma_events event)
2177 {
2178 	unsigned long flags;
2179 
2180 	spin_lock_irqsave(&sde->tail_lock, flags);
2181 	write_seqlock(&sde->head_lock);
2182 
2183 	__sdma_process_event(sde, event);
2184 
2185 	if (sde->state.current_state == sdma_state_s99_running)
2186 		sdma_desc_avail(sde, sdma_descq_freecnt(sde));
2187 
2188 	write_sequnlock(&sde->head_lock);
2189 	spin_unlock_irqrestore(&sde->tail_lock, flags);
2190 }
2191 
2192 static void __sdma_process_event(struct sdma_engine *sde,
2193 				 enum sdma_events event)
2194 {
2195 	struct sdma_state *ss = &sde->state;
2196 	int need_progress = 0;
2197 
2198 	/* CONFIG SDMA temporary */
2199 #ifdef CONFIG_SDMA_VERBOSITY
2200 	dd_dev_err(sde->dd, "CONFIG SDMA(%u) [%s] %s\n", sde->this_idx,
2201 		   sdma_state_names[ss->current_state],
2202 		   sdma_event_names[event]);
2203 #endif
2204 
2205 	switch (ss->current_state) {
2206 	case sdma_state_s00_hw_down:
2207 		switch (event) {
2208 		case sdma_event_e00_go_hw_down:
2209 			break;
2210 		case sdma_event_e30_go_running:
2211 			/*
2212 			 * If down, but running requested (usually result
2213 			 * of link up, then we need to start up.
2214 			 * This can happen when hw down is requested while
2215 			 * bringing the link up with traffic active on
2216 			 * 7220, e.g.
2217 			 */
2218 			ss->go_s99_running = 1;
2219 			/* fall through and start dma engine */
2220 		case sdma_event_e10_go_hw_start:
2221 			/* This reference means the state machine is started */
2222 			sdma_get(&sde->state);
2223 			sdma_set_state(sde,
2224 				       sdma_state_s10_hw_start_up_halt_wait);
2225 			break;
2226 		case sdma_event_e15_hw_halt_done:
2227 			break;
2228 		case sdma_event_e25_hw_clean_up_done:
2229 			break;
2230 		case sdma_event_e40_sw_cleaned:
2231 			sdma_sw_tear_down(sde);
2232 			break;
2233 		case sdma_event_e50_hw_cleaned:
2234 			break;
2235 		case sdma_event_e60_hw_halted:
2236 			break;
2237 		case sdma_event_e70_go_idle:
2238 			break;
2239 		case sdma_event_e80_hw_freeze:
2240 			break;
2241 		case sdma_event_e81_hw_frozen:
2242 			break;
2243 		case sdma_event_e82_hw_unfreeze:
2244 			break;
2245 		case sdma_event_e85_link_down:
2246 			break;
2247 		case sdma_event_e90_sw_halted:
2248 			break;
2249 		}
2250 		break;
2251 
2252 	case sdma_state_s10_hw_start_up_halt_wait:
2253 		switch (event) {
2254 		case sdma_event_e00_go_hw_down:
2255 			sdma_set_state(sde, sdma_state_s00_hw_down);
2256 			sdma_sw_tear_down(sde);
2257 			break;
2258 		case sdma_event_e10_go_hw_start:
2259 			break;
2260 		case sdma_event_e15_hw_halt_done:
2261 			sdma_set_state(sde,
2262 				       sdma_state_s15_hw_start_up_clean_wait);
2263 			sdma_start_hw_clean_up(sde);
2264 			break;
2265 		case sdma_event_e25_hw_clean_up_done:
2266 			break;
2267 		case sdma_event_e30_go_running:
2268 			ss->go_s99_running = 1;
2269 			break;
2270 		case sdma_event_e40_sw_cleaned:
2271 			break;
2272 		case sdma_event_e50_hw_cleaned:
2273 			break;
2274 		case sdma_event_e60_hw_halted:
2275 			schedule_work(&sde->err_halt_worker);
2276 			break;
2277 		case sdma_event_e70_go_idle:
2278 			ss->go_s99_running = 0;
2279 			break;
2280 		case sdma_event_e80_hw_freeze:
2281 			break;
2282 		case sdma_event_e81_hw_frozen:
2283 			break;
2284 		case sdma_event_e82_hw_unfreeze:
2285 			break;
2286 		case sdma_event_e85_link_down:
2287 			break;
2288 		case sdma_event_e90_sw_halted:
2289 			break;
2290 		}
2291 		break;
2292 
2293 	case sdma_state_s15_hw_start_up_clean_wait:
2294 		switch (event) {
2295 		case sdma_event_e00_go_hw_down:
2296 			sdma_set_state(sde, sdma_state_s00_hw_down);
2297 			sdma_sw_tear_down(sde);
2298 			break;
2299 		case sdma_event_e10_go_hw_start:
2300 			break;
2301 		case sdma_event_e15_hw_halt_done:
2302 			break;
2303 		case sdma_event_e25_hw_clean_up_done:
2304 			sdma_hw_start_up(sde);
2305 			sdma_set_state(sde, ss->go_s99_running ?
2306 				       sdma_state_s99_running :
2307 				       sdma_state_s20_idle);
2308 			break;
2309 		case sdma_event_e30_go_running:
2310 			ss->go_s99_running = 1;
2311 			break;
2312 		case sdma_event_e40_sw_cleaned:
2313 			break;
2314 		case sdma_event_e50_hw_cleaned:
2315 			break;
2316 		case sdma_event_e60_hw_halted:
2317 			break;
2318 		case sdma_event_e70_go_idle:
2319 			ss->go_s99_running = 0;
2320 			break;
2321 		case sdma_event_e80_hw_freeze:
2322 			break;
2323 		case sdma_event_e81_hw_frozen:
2324 			break;
2325 		case sdma_event_e82_hw_unfreeze:
2326 			break;
2327 		case sdma_event_e85_link_down:
2328 			break;
2329 		case sdma_event_e90_sw_halted:
2330 			break;
2331 		}
2332 		break;
2333 
2334 	case sdma_state_s20_idle:
2335 		switch (event) {
2336 		case sdma_event_e00_go_hw_down:
2337 			sdma_set_state(sde, sdma_state_s00_hw_down);
2338 			sdma_sw_tear_down(sde);
2339 			break;
2340 		case sdma_event_e10_go_hw_start:
2341 			break;
2342 		case sdma_event_e15_hw_halt_done:
2343 			break;
2344 		case sdma_event_e25_hw_clean_up_done:
2345 			break;
2346 		case sdma_event_e30_go_running:
2347 			sdma_set_state(sde, sdma_state_s99_running);
2348 			ss->go_s99_running = 1;
2349 			break;
2350 		case sdma_event_e40_sw_cleaned:
2351 			break;
2352 		case sdma_event_e50_hw_cleaned:
2353 			break;
2354 		case sdma_event_e60_hw_halted:
2355 			sdma_set_state(sde, sdma_state_s50_hw_halt_wait);
2356 			schedule_work(&sde->err_halt_worker);
2357 			break;
2358 		case sdma_event_e70_go_idle:
2359 			break;
2360 		case sdma_event_e85_link_down:
2361 			/* fall through */
2362 		case sdma_event_e80_hw_freeze:
2363 			sdma_set_state(sde, sdma_state_s80_hw_freeze);
2364 			atomic_dec(&sde->dd->sdma_unfreeze_count);
2365 			wake_up_interruptible(&sde->dd->sdma_unfreeze_wq);
2366 			break;
2367 		case sdma_event_e81_hw_frozen:
2368 			break;
2369 		case sdma_event_e82_hw_unfreeze:
2370 			break;
2371 		case sdma_event_e90_sw_halted:
2372 			break;
2373 		}
2374 		break;
2375 
2376 	case sdma_state_s30_sw_clean_up_wait:
2377 		switch (event) {
2378 		case sdma_event_e00_go_hw_down:
2379 			sdma_set_state(sde, sdma_state_s00_hw_down);
2380 			break;
2381 		case sdma_event_e10_go_hw_start:
2382 			break;
2383 		case sdma_event_e15_hw_halt_done:
2384 			break;
2385 		case sdma_event_e25_hw_clean_up_done:
2386 			break;
2387 		case sdma_event_e30_go_running:
2388 			ss->go_s99_running = 1;
2389 			break;
2390 		case sdma_event_e40_sw_cleaned:
2391 			sdma_set_state(sde, sdma_state_s40_hw_clean_up_wait);
2392 			sdma_start_hw_clean_up(sde);
2393 			break;
2394 		case sdma_event_e50_hw_cleaned:
2395 			break;
2396 		case sdma_event_e60_hw_halted:
2397 			break;
2398 		case sdma_event_e70_go_idle:
2399 			ss->go_s99_running = 0;
2400 			break;
2401 		case sdma_event_e80_hw_freeze:
2402 			break;
2403 		case sdma_event_e81_hw_frozen:
2404 			break;
2405 		case sdma_event_e82_hw_unfreeze:
2406 			break;
2407 		case sdma_event_e85_link_down:
2408 			ss->go_s99_running = 0;
2409 			break;
2410 		case sdma_event_e90_sw_halted:
2411 			break;
2412 		}
2413 		break;
2414 
2415 	case sdma_state_s40_hw_clean_up_wait:
2416 		switch (event) {
2417 		case sdma_event_e00_go_hw_down:
2418 			sdma_set_state(sde, sdma_state_s00_hw_down);
2419 			tasklet_hi_schedule(&sde->sdma_sw_clean_up_task);
2420 			break;
2421 		case sdma_event_e10_go_hw_start:
2422 			break;
2423 		case sdma_event_e15_hw_halt_done:
2424 			break;
2425 		case sdma_event_e25_hw_clean_up_done:
2426 			sdma_hw_start_up(sde);
2427 			sdma_set_state(sde, ss->go_s99_running ?
2428 				       sdma_state_s99_running :
2429 				       sdma_state_s20_idle);
2430 			break;
2431 		case sdma_event_e30_go_running:
2432 			ss->go_s99_running = 1;
2433 			break;
2434 		case sdma_event_e40_sw_cleaned:
2435 			break;
2436 		case sdma_event_e50_hw_cleaned:
2437 			break;
2438 		case sdma_event_e60_hw_halted:
2439 			break;
2440 		case sdma_event_e70_go_idle:
2441 			ss->go_s99_running = 0;
2442 			break;
2443 		case sdma_event_e80_hw_freeze:
2444 			break;
2445 		case sdma_event_e81_hw_frozen:
2446 			break;
2447 		case sdma_event_e82_hw_unfreeze:
2448 			break;
2449 		case sdma_event_e85_link_down:
2450 			ss->go_s99_running = 0;
2451 			break;
2452 		case sdma_event_e90_sw_halted:
2453 			break;
2454 		}
2455 		break;
2456 
2457 	case sdma_state_s50_hw_halt_wait:
2458 		switch (event) {
2459 		case sdma_event_e00_go_hw_down:
2460 			sdma_set_state(sde, sdma_state_s00_hw_down);
2461 			tasklet_hi_schedule(&sde->sdma_sw_clean_up_task);
2462 			break;
2463 		case sdma_event_e10_go_hw_start:
2464 			break;
2465 		case sdma_event_e15_hw_halt_done:
2466 			sdma_set_state(sde, sdma_state_s30_sw_clean_up_wait);
2467 			tasklet_hi_schedule(&sde->sdma_sw_clean_up_task);
2468 			break;
2469 		case sdma_event_e25_hw_clean_up_done:
2470 			break;
2471 		case sdma_event_e30_go_running:
2472 			ss->go_s99_running = 1;
2473 			break;
2474 		case sdma_event_e40_sw_cleaned:
2475 			break;
2476 		case sdma_event_e50_hw_cleaned:
2477 			break;
2478 		case sdma_event_e60_hw_halted:
2479 			schedule_work(&sde->err_halt_worker);
2480 			break;
2481 		case sdma_event_e70_go_idle:
2482 			ss->go_s99_running = 0;
2483 			break;
2484 		case sdma_event_e80_hw_freeze:
2485 			break;
2486 		case sdma_event_e81_hw_frozen:
2487 			break;
2488 		case sdma_event_e82_hw_unfreeze:
2489 			break;
2490 		case sdma_event_e85_link_down:
2491 			ss->go_s99_running = 0;
2492 			break;
2493 		case sdma_event_e90_sw_halted:
2494 			break;
2495 		}
2496 		break;
2497 
2498 	case sdma_state_s60_idle_halt_wait:
2499 		switch (event) {
2500 		case sdma_event_e00_go_hw_down:
2501 			sdma_set_state(sde, sdma_state_s00_hw_down);
2502 			tasklet_hi_schedule(&sde->sdma_sw_clean_up_task);
2503 			break;
2504 		case sdma_event_e10_go_hw_start:
2505 			break;
2506 		case sdma_event_e15_hw_halt_done:
2507 			sdma_set_state(sde, sdma_state_s30_sw_clean_up_wait);
2508 			tasklet_hi_schedule(&sde->sdma_sw_clean_up_task);
2509 			break;
2510 		case sdma_event_e25_hw_clean_up_done:
2511 			break;
2512 		case sdma_event_e30_go_running:
2513 			ss->go_s99_running = 1;
2514 			break;
2515 		case sdma_event_e40_sw_cleaned:
2516 			break;
2517 		case sdma_event_e50_hw_cleaned:
2518 			break;
2519 		case sdma_event_e60_hw_halted:
2520 			schedule_work(&sde->err_halt_worker);
2521 			break;
2522 		case sdma_event_e70_go_idle:
2523 			ss->go_s99_running = 0;
2524 			break;
2525 		case sdma_event_e80_hw_freeze:
2526 			break;
2527 		case sdma_event_e81_hw_frozen:
2528 			break;
2529 		case sdma_event_e82_hw_unfreeze:
2530 			break;
2531 		case sdma_event_e85_link_down:
2532 			break;
2533 		case sdma_event_e90_sw_halted:
2534 			break;
2535 		}
2536 		break;
2537 
2538 	case sdma_state_s80_hw_freeze:
2539 		switch (event) {
2540 		case sdma_event_e00_go_hw_down:
2541 			sdma_set_state(sde, sdma_state_s00_hw_down);
2542 			tasklet_hi_schedule(&sde->sdma_sw_clean_up_task);
2543 			break;
2544 		case sdma_event_e10_go_hw_start:
2545 			break;
2546 		case sdma_event_e15_hw_halt_done:
2547 			break;
2548 		case sdma_event_e25_hw_clean_up_done:
2549 			break;
2550 		case sdma_event_e30_go_running:
2551 			ss->go_s99_running = 1;
2552 			break;
2553 		case sdma_event_e40_sw_cleaned:
2554 			break;
2555 		case sdma_event_e50_hw_cleaned:
2556 			break;
2557 		case sdma_event_e60_hw_halted:
2558 			break;
2559 		case sdma_event_e70_go_idle:
2560 			ss->go_s99_running = 0;
2561 			break;
2562 		case sdma_event_e80_hw_freeze:
2563 			break;
2564 		case sdma_event_e81_hw_frozen:
2565 			sdma_set_state(sde, sdma_state_s82_freeze_sw_clean);
2566 			tasklet_hi_schedule(&sde->sdma_sw_clean_up_task);
2567 			break;
2568 		case sdma_event_e82_hw_unfreeze:
2569 			break;
2570 		case sdma_event_e85_link_down:
2571 			break;
2572 		case sdma_event_e90_sw_halted:
2573 			break;
2574 		}
2575 		break;
2576 
2577 	case sdma_state_s82_freeze_sw_clean:
2578 		switch (event) {
2579 		case sdma_event_e00_go_hw_down:
2580 			sdma_set_state(sde, sdma_state_s00_hw_down);
2581 			tasklet_hi_schedule(&sde->sdma_sw_clean_up_task);
2582 			break;
2583 		case sdma_event_e10_go_hw_start:
2584 			break;
2585 		case sdma_event_e15_hw_halt_done:
2586 			break;
2587 		case sdma_event_e25_hw_clean_up_done:
2588 			break;
2589 		case sdma_event_e30_go_running:
2590 			ss->go_s99_running = 1;
2591 			break;
2592 		case sdma_event_e40_sw_cleaned:
2593 			/* notify caller this engine is done cleaning */
2594 			atomic_dec(&sde->dd->sdma_unfreeze_count);
2595 			wake_up_interruptible(&sde->dd->sdma_unfreeze_wq);
2596 			break;
2597 		case sdma_event_e50_hw_cleaned:
2598 			break;
2599 		case sdma_event_e60_hw_halted:
2600 			break;
2601 		case sdma_event_e70_go_idle:
2602 			ss->go_s99_running = 0;
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 			sdma_hw_start_up(sde);
2610 			sdma_set_state(sde, ss->go_s99_running ?
2611 				       sdma_state_s99_running :
2612 				       sdma_state_s20_idle);
2613 			break;
2614 		case sdma_event_e85_link_down:
2615 			break;
2616 		case sdma_event_e90_sw_halted:
2617 			break;
2618 		}
2619 		break;
2620 
2621 	case sdma_state_s99_running:
2622 		switch (event) {
2623 		case sdma_event_e00_go_hw_down:
2624 			sdma_set_state(sde, sdma_state_s00_hw_down);
2625 			tasklet_hi_schedule(&sde->sdma_sw_clean_up_task);
2626 			break;
2627 		case sdma_event_e10_go_hw_start:
2628 			break;
2629 		case sdma_event_e15_hw_halt_done:
2630 			break;
2631 		case sdma_event_e25_hw_clean_up_done:
2632 			break;
2633 		case sdma_event_e30_go_running:
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 			need_progress = 1;
2641 			sdma_err_progress_check_schedule(sde);
2642 		case sdma_event_e90_sw_halted:
2643 			/*
2644 			* SW initiated halt does not perform engines
2645 			* progress check
2646 			*/
2647 			sdma_set_state(sde, sdma_state_s50_hw_halt_wait);
2648 			schedule_work(&sde->err_halt_worker);
2649 			break;
2650 		case sdma_event_e70_go_idle:
2651 			sdma_set_state(sde, sdma_state_s60_idle_halt_wait);
2652 			break;
2653 		case sdma_event_e85_link_down:
2654 			ss->go_s99_running = 0;
2655 			/* fall through */
2656 		case sdma_event_e80_hw_freeze:
2657 			sdma_set_state(sde, sdma_state_s80_hw_freeze);
2658 			atomic_dec(&sde->dd->sdma_unfreeze_count);
2659 			wake_up_interruptible(&sde->dd->sdma_unfreeze_wq);
2660 			break;
2661 		case sdma_event_e81_hw_frozen:
2662 			break;
2663 		case sdma_event_e82_hw_unfreeze:
2664 			break;
2665 		}
2666 		break;
2667 	}
2668 
2669 	ss->last_event = event;
2670 	if (need_progress)
2671 		sdma_make_progress(sde, 0);
2672 }
2673 
2674 /*
2675  * _extend_sdma_tx_descs() - helper to extend txreq
2676  *
2677  * This is called once the initial nominal allocation
2678  * of descriptors in the sdma_txreq is exhausted.
2679  *
2680  * The code will bump the allocation up to the max
2681  * of MAX_DESC (64) descriptors. There doesn't seem
2682  * much point in an interim step. The last descriptor
2683  * is reserved for coalesce buffer in order to support
2684  * cases where input packet has >MAX_DESC iovecs.
2685  *
2686  */
2687 static int _extend_sdma_tx_descs(struct hfi1_devdata *dd, struct sdma_txreq *tx)
2688 {
2689 	int i;
2690 
2691 	/* Handle last descriptor */
2692 	if (unlikely((tx->num_desc == (MAX_DESC - 1)))) {
2693 		/* if tlen is 0, it is for padding, release last descriptor */
2694 		if (!tx->tlen) {
2695 			tx->desc_limit = MAX_DESC;
2696 		} else if (!tx->coalesce_buf) {
2697 			/* allocate coalesce buffer with space for padding */
2698 			tx->coalesce_buf = kmalloc(tx->tlen + sizeof(u32),
2699 						   GFP_ATOMIC);
2700 			if (!tx->coalesce_buf)
2701 				goto enomem;
2702 			tx->coalesce_idx = 0;
2703 		}
2704 		return 0;
2705 	}
2706 
2707 	if (unlikely(tx->num_desc == MAX_DESC))
2708 		goto enomem;
2709 
2710 	tx->descp = kmalloc_array(
2711 			MAX_DESC,
2712 			sizeof(struct sdma_desc),
2713 			GFP_ATOMIC);
2714 	if (!tx->descp)
2715 		goto enomem;
2716 
2717 	/* reserve last descriptor for coalescing */
2718 	tx->desc_limit = MAX_DESC - 1;
2719 	/* copy ones already built */
2720 	for (i = 0; i < tx->num_desc; i++)
2721 		tx->descp[i] = tx->descs[i];
2722 	return 0;
2723 enomem:
2724 	sdma_txclean(dd, tx);
2725 	return -ENOMEM;
2726 }
2727 
2728 /*
2729  * ext_coal_sdma_tx_descs() - extend or coalesce sdma tx descriptors
2730  *
2731  * This is called once the initial nominal allocation of descriptors
2732  * in the sdma_txreq is exhausted.
2733  *
2734  * This function calls _extend_sdma_tx_descs to extend or allocate
2735  * coalesce buffer. If there is a allocated coalesce buffer, it will
2736  * copy the input packet data into the coalesce buffer. It also adds
2737  * coalesce buffer descriptor once when whole packet is received.
2738  *
2739  * Return:
2740  * <0 - error
2741  * 0 - coalescing, don't populate descriptor
2742  * 1 - continue with populating descriptor
2743  */
2744 int ext_coal_sdma_tx_descs(struct hfi1_devdata *dd, struct sdma_txreq *tx,
2745 			   int type, void *kvaddr, struct page *page,
2746 			   unsigned long offset, u16 len)
2747 {
2748 	int pad_len, rval;
2749 	dma_addr_t addr;
2750 
2751 	rval = _extend_sdma_tx_descs(dd, tx);
2752 	if (rval) {
2753 		sdma_txclean(dd, tx);
2754 		return rval;
2755 	}
2756 
2757 	/* If coalesce buffer is allocated, copy data into it */
2758 	if (tx->coalesce_buf) {
2759 		if (type == SDMA_MAP_NONE) {
2760 			sdma_txclean(dd, tx);
2761 			return -EINVAL;
2762 		}
2763 
2764 		if (type == SDMA_MAP_PAGE) {
2765 			kvaddr = kmap(page);
2766 			kvaddr += offset;
2767 		} else if (WARN_ON(!kvaddr)) {
2768 			sdma_txclean(dd, tx);
2769 			return -EINVAL;
2770 		}
2771 
2772 		memcpy(tx->coalesce_buf + tx->coalesce_idx, kvaddr, len);
2773 		tx->coalesce_idx += len;
2774 		if (type == SDMA_MAP_PAGE)
2775 			kunmap(page);
2776 
2777 		/* If there is more data, return */
2778 		if (tx->tlen - tx->coalesce_idx)
2779 			return 0;
2780 
2781 		/* Whole packet is received; add any padding */
2782 		pad_len = tx->packet_len & (sizeof(u32) - 1);
2783 		if (pad_len) {
2784 			pad_len = sizeof(u32) - pad_len;
2785 			memset(tx->coalesce_buf + tx->coalesce_idx, 0, pad_len);
2786 			/* padding is taken care of for coalescing case */
2787 			tx->packet_len += pad_len;
2788 			tx->tlen += pad_len;
2789 		}
2790 
2791 		/* dma map the coalesce buffer */
2792 		addr = dma_map_single(&dd->pcidev->dev,
2793 				      tx->coalesce_buf,
2794 				      tx->tlen,
2795 				      DMA_TO_DEVICE);
2796 
2797 		if (unlikely(dma_mapping_error(&dd->pcidev->dev, addr))) {
2798 			sdma_txclean(dd, tx);
2799 			return -ENOSPC;
2800 		}
2801 
2802 		/* Add descriptor for coalesce buffer */
2803 		tx->desc_limit = MAX_DESC;
2804 		return _sdma_txadd_daddr(dd, SDMA_MAP_SINGLE, tx,
2805 					 addr, tx->tlen);
2806 	}
2807 
2808 	return 1;
2809 }
2810 
2811 /* Update sdes when the lmc changes */
2812 void sdma_update_lmc(struct hfi1_devdata *dd, u64 mask, u32 lid)
2813 {
2814 	struct sdma_engine *sde;
2815 	int i;
2816 	u64 sreg;
2817 
2818 	sreg = ((mask & SD(CHECK_SLID_MASK_MASK)) <<
2819 		SD(CHECK_SLID_MASK_SHIFT)) |
2820 		(((lid & mask) & SD(CHECK_SLID_VALUE_MASK)) <<
2821 		SD(CHECK_SLID_VALUE_SHIFT));
2822 
2823 	for (i = 0; i < dd->num_sdma; i++) {
2824 		hfi1_cdbg(LINKVERB, "SendDmaEngine[%d].SLID_CHECK = 0x%x",
2825 			  i, (u32)sreg);
2826 		sde = &dd->per_sdma[i];
2827 		write_sde_csr(sde, SD(CHECK_SLID), sreg);
2828 	}
2829 }
2830 
2831 /* tx not dword sized - pad */
2832 int _pad_sdma_tx_descs(struct hfi1_devdata *dd, struct sdma_txreq *tx)
2833 {
2834 	int rval = 0;
2835 
2836 	tx->num_desc++;
2837 	if ((unlikely(tx->num_desc == tx->desc_limit))) {
2838 		rval = _extend_sdma_tx_descs(dd, tx);
2839 		if (rval) {
2840 			sdma_txclean(dd, tx);
2841 			return rval;
2842 		}
2843 	}
2844 	/* finish the one just added */
2845 	make_tx_sdma_desc(
2846 		tx,
2847 		SDMA_MAP_NONE,
2848 		dd->sdma_pad_phys,
2849 		sizeof(u32) - (tx->packet_len & (sizeof(u32) - 1)));
2850 	_sdma_close_tx(dd, tx);
2851 	return rval;
2852 }
2853 
2854 /*
2855  * Add ahg to the sdma_txreq
2856  *
2857  * The logic will consume up to 3
2858  * descriptors at the beginning of
2859  * sdma_txreq.
2860  */
2861 void _sdma_txreq_ahgadd(
2862 	struct sdma_txreq *tx,
2863 	u8 num_ahg,
2864 	u8 ahg_entry,
2865 	u32 *ahg,
2866 	u8 ahg_hlen)
2867 {
2868 	u32 i, shift = 0, desc = 0;
2869 	u8 mode;
2870 
2871 	WARN_ON_ONCE(num_ahg > 9 || (ahg_hlen & 3) || ahg_hlen == 4);
2872 	/* compute mode */
2873 	if (num_ahg == 1)
2874 		mode = SDMA_AHG_APPLY_UPDATE1;
2875 	else if (num_ahg <= 5)
2876 		mode = SDMA_AHG_APPLY_UPDATE2;
2877 	else
2878 		mode = SDMA_AHG_APPLY_UPDATE3;
2879 	tx->num_desc++;
2880 	/* initialize to consumed descriptors to zero */
2881 	switch (mode) {
2882 	case SDMA_AHG_APPLY_UPDATE3:
2883 		tx->num_desc++;
2884 		tx->descs[2].qw[0] = 0;
2885 		tx->descs[2].qw[1] = 0;
2886 		/* FALLTHROUGH */
2887 	case SDMA_AHG_APPLY_UPDATE2:
2888 		tx->num_desc++;
2889 		tx->descs[1].qw[0] = 0;
2890 		tx->descs[1].qw[1] = 0;
2891 		break;
2892 	}
2893 	ahg_hlen >>= 2;
2894 	tx->descs[0].qw[1] |=
2895 		(((u64)ahg_entry & SDMA_DESC1_HEADER_INDEX_MASK)
2896 			<< SDMA_DESC1_HEADER_INDEX_SHIFT) |
2897 		(((u64)ahg_hlen & SDMA_DESC1_HEADER_DWS_MASK)
2898 			<< SDMA_DESC1_HEADER_DWS_SHIFT) |
2899 		(((u64)mode & SDMA_DESC1_HEADER_MODE_MASK)
2900 			<< SDMA_DESC1_HEADER_MODE_SHIFT) |
2901 		(((u64)ahg[0] & SDMA_DESC1_HEADER_UPDATE1_MASK)
2902 			<< SDMA_DESC1_HEADER_UPDATE1_SHIFT);
2903 	for (i = 0; i < (num_ahg - 1); i++) {
2904 		if (!shift && !(i & 2))
2905 			desc++;
2906 		tx->descs[desc].qw[!!(i & 2)] |=
2907 			(((u64)ahg[i + 1])
2908 				<< shift);
2909 		shift = (shift + 32) & 63;
2910 	}
2911 }
2912 
2913 /**
2914  * sdma_ahg_alloc - allocate an AHG entry
2915  * @sde: engine to allocate from
2916  *
2917  * Return:
2918  * 0-31 when successful, -EOPNOTSUPP if AHG is not enabled,
2919  * -ENOSPC if an entry is not available
2920  */
2921 int sdma_ahg_alloc(struct sdma_engine *sde)
2922 {
2923 	int nr;
2924 	int oldbit;
2925 
2926 	if (!sde) {
2927 		trace_hfi1_ahg_allocate(sde, -EINVAL);
2928 		return -EINVAL;
2929 	}
2930 	while (1) {
2931 		nr = ffz(ACCESS_ONCE(sde->ahg_bits));
2932 		if (nr > 31) {
2933 			trace_hfi1_ahg_allocate(sde, -ENOSPC);
2934 			return -ENOSPC;
2935 		}
2936 		oldbit = test_and_set_bit(nr, &sde->ahg_bits);
2937 		if (!oldbit)
2938 			break;
2939 		cpu_relax();
2940 	}
2941 	trace_hfi1_ahg_allocate(sde, nr);
2942 	return nr;
2943 }
2944 
2945 /**
2946  * sdma_ahg_free - free an AHG entry
2947  * @sde: engine to return AHG entry
2948  * @ahg_index: index to free
2949  *
2950  * This routine frees the indicate AHG entry.
2951  */
2952 void sdma_ahg_free(struct sdma_engine *sde, int ahg_index)
2953 {
2954 	if (!sde)
2955 		return;
2956 	trace_hfi1_ahg_deallocate(sde, ahg_index);
2957 	if (ahg_index < 0 || ahg_index > 31)
2958 		return;
2959 	clear_bit(ahg_index, &sde->ahg_bits);
2960 }
2961 
2962 /*
2963  * SPC freeze handling for SDMA engines.  Called when the driver knows
2964  * the SPC is going into a freeze but before the freeze is fully
2965  * settled.  Generally an error interrupt.
2966  *
2967  * This event will pull the engine out of running so no more entries can be
2968  * added to the engine's queue.
2969  */
2970 void sdma_freeze_notify(struct hfi1_devdata *dd, int link_down)
2971 {
2972 	int i;
2973 	enum sdma_events event = link_down ? sdma_event_e85_link_down :
2974 					     sdma_event_e80_hw_freeze;
2975 
2976 	/* set up the wait but do not wait here */
2977 	atomic_set(&dd->sdma_unfreeze_count, dd->num_sdma);
2978 
2979 	/* tell all engines to stop running and wait */
2980 	for (i = 0; i < dd->num_sdma; i++)
2981 		sdma_process_event(&dd->per_sdma[i], event);
2982 
2983 	/* sdma_freeze() will wait for all engines to have stopped */
2984 }
2985 
2986 /*
2987  * SPC freeze handling for SDMA engines.  Called when the driver knows
2988  * the SPC is fully frozen.
2989  */
2990 void sdma_freeze(struct hfi1_devdata *dd)
2991 {
2992 	int i;
2993 	int ret;
2994 
2995 	/*
2996 	 * Make sure all engines have moved out of the running state before
2997 	 * continuing.
2998 	 */
2999 	ret = wait_event_interruptible(dd->sdma_unfreeze_wq,
3000 				       atomic_read(&dd->sdma_unfreeze_count) <=
3001 				       0);
3002 	/* interrupted or count is negative, then unloading - just exit */
3003 	if (ret || atomic_read(&dd->sdma_unfreeze_count) < 0)
3004 		return;
3005 
3006 	/* set up the count for the next wait */
3007 	atomic_set(&dd->sdma_unfreeze_count, dd->num_sdma);
3008 
3009 	/* tell all engines that the SPC is frozen, they can start cleaning */
3010 	for (i = 0; i < dd->num_sdma; i++)
3011 		sdma_process_event(&dd->per_sdma[i], sdma_event_e81_hw_frozen);
3012 
3013 	/*
3014 	 * Wait for everyone to finish software clean before exiting.  The
3015 	 * software clean will read engine CSRs, so must be completed before
3016 	 * the next step, which will clear the engine CSRs.
3017 	 */
3018 	(void)wait_event_interruptible(dd->sdma_unfreeze_wq,
3019 				atomic_read(&dd->sdma_unfreeze_count) <= 0);
3020 	/* no need to check results - done no matter what */
3021 }
3022 
3023 /*
3024  * SPC freeze handling for the SDMA engines.  Called after the SPC is unfrozen.
3025  *
3026  * The SPC freeze acts like a SDMA halt and a hardware clean combined.  All
3027  * that is left is a software clean.  We could do it after the SPC is fully
3028  * frozen, but then we'd have to add another state to wait for the unfreeze.
3029  * Instead, just defer the software clean until the unfreeze step.
3030  */
3031 void sdma_unfreeze(struct hfi1_devdata *dd)
3032 {
3033 	int i;
3034 
3035 	/* tell all engines start freeze clean up */
3036 	for (i = 0; i < dd->num_sdma; i++)
3037 		sdma_process_event(&dd->per_sdma[i],
3038 				   sdma_event_e82_hw_unfreeze);
3039 }
3040 
3041 /**
3042  * _sdma_engine_progress_schedule() - schedule progress on engine
3043  * @sde: sdma_engine to schedule progress
3044  *
3045  */
3046 void _sdma_engine_progress_schedule(
3047 	struct sdma_engine *sde)
3048 {
3049 	trace_hfi1_sdma_engine_progress(sde, sde->progress_mask);
3050 	/* assume we have selected a good cpu */
3051 	write_csr(sde->dd,
3052 		  CCE_INT_FORCE + (8 * (IS_SDMA_START / 64)),
3053 		  sde->progress_mask);
3054 }
3055