xref: /linux/drivers/infiniband/hw/hfi1/sdma.c (revision e95d076bc1fca7cc36fc8f2f0e9687f79fd314bd)
1 // SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
2 /*
3  * Copyright(c) 2015 - 2018 Intel Corporation.
4  */
5 
6 #include <linux/spinlock.h>
7 #include <linux/seqlock.h>
8 #include <linux/netdevice.h>
9 #include <linux/moduleparam.h>
10 #include <linux/bitops.h>
11 #include <linux/timer.h>
12 #include <linux/vmalloc.h>
13 #include <linux/highmem.h>
14 #include <linux/sysfs.h>
15 
16 #include "hfi.h"
17 #include "common.h"
18 #include "qp.h"
19 #include "sdma.h"
20 #include "iowait.h"
21 #include "trace.h"
22 
23 /* must be a power of 2 >= 64 <= 32768 */
24 #define SDMA_DESCQ_CNT 2048
25 #define SDMA_DESC_INTR 64
26 #define INVALID_TAIL 0xffff
27 #define SDMA_PAD max_t(size_t, MAX_16B_PADDING, sizeof(u32))
28 
29 static uint sdma_descq_cnt = SDMA_DESCQ_CNT;
30 module_param(sdma_descq_cnt, uint, S_IRUGO);
31 MODULE_PARM_DESC(sdma_descq_cnt, "Number of SDMA descq entries");
32 
33 static uint sdma_idle_cnt = 250;
34 module_param(sdma_idle_cnt, uint, S_IRUGO);
35 MODULE_PARM_DESC(sdma_idle_cnt, "sdma interrupt idle delay (ns,default 250)");
36 
37 uint mod_num_sdma;
38 module_param_named(num_sdma, mod_num_sdma, uint, S_IRUGO);
39 MODULE_PARM_DESC(num_sdma, "Set max number SDMA engines to use");
40 
41 static uint sdma_desct_intr = SDMA_DESC_INTR;
42 module_param_named(desct_intr, sdma_desct_intr, uint, S_IRUGO | S_IWUSR);
43 MODULE_PARM_DESC(desct_intr, "Number of SDMA descriptor before interrupt");
44 
45 #define SDMA_WAIT_BATCH_SIZE 20
46 /* max wait time for a SDMA engine to indicate it has halted */
47 #define SDMA_ERR_HALT_TIMEOUT 10 /* ms */
48 /* all SDMA engine errors that cause a halt */
49 
50 #define SD(name) SEND_DMA_##name
51 #define ALL_SDMA_ENG_HALT_ERRS \
52 	(SD(ENG_ERR_STATUS_SDMA_WRONG_DW_ERR_SMASK) \
53 	| SD(ENG_ERR_STATUS_SDMA_GEN_MISMATCH_ERR_SMASK) \
54 	| SD(ENG_ERR_STATUS_SDMA_TOO_LONG_ERR_SMASK) \
55 	| SD(ENG_ERR_STATUS_SDMA_TAIL_OUT_OF_BOUNDS_ERR_SMASK) \
56 	| SD(ENG_ERR_STATUS_SDMA_FIRST_DESC_ERR_SMASK) \
57 	| SD(ENG_ERR_STATUS_SDMA_MEM_READ_ERR_SMASK) \
58 	| SD(ENG_ERR_STATUS_SDMA_HALT_ERR_SMASK) \
59 	| SD(ENG_ERR_STATUS_SDMA_LENGTH_MISMATCH_ERR_SMASK) \
60 	| SD(ENG_ERR_STATUS_SDMA_PACKET_DESC_OVERFLOW_ERR_SMASK) \
61 	| SD(ENG_ERR_STATUS_SDMA_HEADER_SELECT_ERR_SMASK) \
62 	| SD(ENG_ERR_STATUS_SDMA_HEADER_ADDRESS_ERR_SMASK) \
63 	| SD(ENG_ERR_STATUS_SDMA_HEADER_LENGTH_ERR_SMASK) \
64 	| SD(ENG_ERR_STATUS_SDMA_TIMEOUT_ERR_SMASK) \
65 	| SD(ENG_ERR_STATUS_SDMA_DESC_TABLE_UNC_ERR_SMASK) \
66 	| SD(ENG_ERR_STATUS_SDMA_ASSEMBLY_UNC_ERR_SMASK) \
67 	| SD(ENG_ERR_STATUS_SDMA_PACKET_TRACKING_UNC_ERR_SMASK) \
68 	| SD(ENG_ERR_STATUS_SDMA_HEADER_STORAGE_UNC_ERR_SMASK) \
69 	| SD(ENG_ERR_STATUS_SDMA_HEADER_REQUEST_FIFO_UNC_ERR_SMASK))
70 
71 /* sdma_sendctrl operations */
72 #define SDMA_SENDCTRL_OP_ENABLE    BIT(0)
73 #define SDMA_SENDCTRL_OP_INTENABLE BIT(1)
74 #define SDMA_SENDCTRL_OP_HALT      BIT(2)
75 #define SDMA_SENDCTRL_OP_CLEANUP   BIT(3)
76 
77 /* handle long defines */
78 #define SDMA_EGRESS_PACKET_OCCUPANCY_SMASK \
79 SEND_EGRESS_SEND_DMA_STATUS_SDMA_EGRESS_PACKET_OCCUPANCY_SMASK
80 #define SDMA_EGRESS_PACKET_OCCUPANCY_SHIFT \
81 SEND_EGRESS_SEND_DMA_STATUS_SDMA_EGRESS_PACKET_OCCUPANCY_SHIFT
82 
83 static const char * const sdma_state_names[] = {
84 	[sdma_state_s00_hw_down]                = "s00_HwDown",
85 	[sdma_state_s10_hw_start_up_halt_wait]  = "s10_HwStartUpHaltWait",
86 	[sdma_state_s15_hw_start_up_clean_wait] = "s15_HwStartUpCleanWait",
87 	[sdma_state_s20_idle]                   = "s20_Idle",
88 	[sdma_state_s30_sw_clean_up_wait]       = "s30_SwCleanUpWait",
89 	[sdma_state_s40_hw_clean_up_wait]       = "s40_HwCleanUpWait",
90 	[sdma_state_s50_hw_halt_wait]           = "s50_HwHaltWait",
91 	[sdma_state_s60_idle_halt_wait]         = "s60_IdleHaltWait",
92 	[sdma_state_s80_hw_freeze]		= "s80_HwFreeze",
93 	[sdma_state_s82_freeze_sw_clean]	= "s82_FreezeSwClean",
94 	[sdma_state_s99_running]                = "s99_Running",
95 };
96 
97 #ifdef CONFIG_SDMA_VERBOSITY
98 static const char * const sdma_event_names[] = {
99 	[sdma_event_e00_go_hw_down]   = "e00_GoHwDown",
100 	[sdma_event_e10_go_hw_start]  = "e10_GoHwStart",
101 	[sdma_event_e15_hw_halt_done] = "e15_HwHaltDone",
102 	[sdma_event_e25_hw_clean_up_done] = "e25_HwCleanUpDone",
103 	[sdma_event_e30_go_running]   = "e30_GoRunning",
104 	[sdma_event_e40_sw_cleaned]   = "e40_SwCleaned",
105 	[sdma_event_e50_hw_cleaned]   = "e50_HwCleaned",
106 	[sdma_event_e60_hw_halted]    = "e60_HwHalted",
107 	[sdma_event_e70_go_idle]      = "e70_GoIdle",
108 	[sdma_event_e80_hw_freeze]    = "e80_HwFreeze",
109 	[sdma_event_e81_hw_frozen]    = "e81_HwFrozen",
110 	[sdma_event_e82_hw_unfreeze]  = "e82_HwUnfreeze",
111 	[sdma_event_e85_link_down]    = "e85_LinkDown",
112 	[sdma_event_e90_sw_halted]    = "e90_SwHalted",
113 };
114 #endif
115 
116 static const struct sdma_set_state_action sdma_action_table[] = {
117 	[sdma_state_s00_hw_down] = {
118 		.go_s99_running_tofalse = 1,
119 		.op_enable = 0,
120 		.op_intenable = 0,
121 		.op_halt = 0,
122 		.op_cleanup = 0,
123 	},
124 	[sdma_state_s10_hw_start_up_halt_wait] = {
125 		.op_enable = 0,
126 		.op_intenable = 0,
127 		.op_halt = 1,
128 		.op_cleanup = 0,
129 	},
130 	[sdma_state_s15_hw_start_up_clean_wait] = {
131 		.op_enable = 0,
132 		.op_intenable = 1,
133 		.op_halt = 0,
134 		.op_cleanup = 1,
135 	},
136 	[sdma_state_s20_idle] = {
137 		.op_enable = 0,
138 		.op_intenable = 1,
139 		.op_halt = 0,
140 		.op_cleanup = 0,
141 	},
142 	[sdma_state_s30_sw_clean_up_wait] = {
143 		.op_enable = 0,
144 		.op_intenable = 0,
145 		.op_halt = 0,
146 		.op_cleanup = 0,
147 	},
148 	[sdma_state_s40_hw_clean_up_wait] = {
149 		.op_enable = 0,
150 		.op_intenable = 0,
151 		.op_halt = 0,
152 		.op_cleanup = 1,
153 	},
154 	[sdma_state_s50_hw_halt_wait] = {
155 		.op_enable = 0,
156 		.op_intenable = 0,
157 		.op_halt = 0,
158 		.op_cleanup = 0,
159 	},
160 	[sdma_state_s60_idle_halt_wait] = {
161 		.go_s99_running_tofalse = 1,
162 		.op_enable = 0,
163 		.op_intenable = 0,
164 		.op_halt = 1,
165 		.op_cleanup = 0,
166 	},
167 	[sdma_state_s80_hw_freeze] = {
168 		.op_enable = 0,
169 		.op_intenable = 0,
170 		.op_halt = 0,
171 		.op_cleanup = 0,
172 	},
173 	[sdma_state_s82_freeze_sw_clean] = {
174 		.op_enable = 0,
175 		.op_intenable = 0,
176 		.op_halt = 0,
177 		.op_cleanup = 0,
178 	},
179 	[sdma_state_s99_running] = {
180 		.op_enable = 1,
181 		.op_intenable = 1,
182 		.op_halt = 0,
183 		.op_cleanup = 0,
184 		.go_s99_running_totrue = 1,
185 	},
186 };
187 
188 #define SDMA_TAIL_UPDATE_THRESH 0x1F
189 
190 /* declare all statics here rather than keep sorting */
191 static void sdma_complete(struct kref *);
192 static void sdma_finalput(struct sdma_state *);
193 static void sdma_get(struct sdma_state *);
194 static void sdma_hw_clean_up_task(struct tasklet_struct *);
195 static void sdma_put(struct sdma_state *);
196 static void sdma_set_state(struct sdma_engine *, enum sdma_states);
197 static void sdma_start_hw_clean_up(struct sdma_engine *);
198 static void sdma_sw_clean_up_task(struct tasklet_struct *);
199 static void sdma_sendctrl(struct sdma_engine *, unsigned);
200 static void init_sdma_regs(struct sdma_engine *, u32, uint);
201 static void sdma_process_event(
202 	struct sdma_engine *sde,
203 	enum sdma_events event);
204 static void __sdma_process_event(
205 	struct sdma_engine *sde,
206 	enum sdma_events event);
207 static void dump_sdma_state(struct sdma_engine *sde);
208 static void sdma_make_progress(struct sdma_engine *sde, u64 status);
209 static void sdma_desc_avail(struct sdma_engine *sde, uint avail);
210 static void sdma_flush_descq(struct sdma_engine *sde);
211 
212 /**
213  * sdma_state_name() - return state string from enum
214  * @state: state
215  */
216 static const char *sdma_state_name(enum sdma_states state)
217 {
218 	return sdma_state_names[state];
219 }
220 
221 static void sdma_get(struct sdma_state *ss)
222 {
223 	kref_get(&ss->kref);
224 }
225 
226 static void sdma_complete(struct kref *kref)
227 {
228 	struct sdma_state *ss =
229 		container_of(kref, struct sdma_state, kref);
230 
231 	complete(&ss->comp);
232 }
233 
234 static void sdma_put(struct sdma_state *ss)
235 {
236 	kref_put(&ss->kref, sdma_complete);
237 }
238 
239 static void sdma_finalput(struct sdma_state *ss)
240 {
241 	sdma_put(ss);
242 	wait_for_completion(&ss->comp);
243 }
244 
245 static inline void write_sde_csr(
246 	struct sdma_engine *sde,
247 	u32 offset0,
248 	u64 value)
249 {
250 	write_kctxt_csr(sde->dd, sde->this_idx, offset0, value);
251 }
252 
253 static inline u64 read_sde_csr(
254 	struct sdma_engine *sde,
255 	u32 offset0)
256 {
257 	return read_kctxt_csr(sde->dd, sde->this_idx, offset0);
258 }
259 
260 /*
261  * sdma_wait_for_packet_egress() - wait for the VL FIFO occupancy for
262  * sdma engine 'sde' to drop to 0.
263  */
264 static void sdma_wait_for_packet_egress(struct sdma_engine *sde,
265 					int pause)
266 {
267 	u64 off = 8 * sde->this_idx;
268 	struct hfi1_devdata *dd = sde->dd;
269 	int lcnt = 0;
270 	u64 reg_prev;
271 	u64 reg = 0;
272 
273 	while (1) {
274 		reg_prev = reg;
275 		reg = read_csr(dd, off + SEND_EGRESS_SEND_DMA_STATUS);
276 
277 		reg &= SDMA_EGRESS_PACKET_OCCUPANCY_SMASK;
278 		reg >>= SDMA_EGRESS_PACKET_OCCUPANCY_SHIFT;
279 		if (reg == 0)
280 			break;
281 		/* counter is reest if accupancy count changes */
282 		if (reg != reg_prev)
283 			lcnt = 0;
284 		if (lcnt++ > 500) {
285 			/* timed out - bounce the link */
286 			dd_dev_err(dd, "%s: engine %u timeout waiting for packets to egress, remaining count %u, bouncing link\n",
287 				   __func__, sde->this_idx, (u32)reg);
288 			queue_work(dd->pport->link_wq,
289 				   &dd->pport->link_bounce_work);
290 			break;
291 		}
292 		udelay(1);
293 	}
294 }
295 
296 /*
297  * sdma_wait() - wait for packet egress to complete for all SDMA engines,
298  * and pause for credit return.
299  */
300 void sdma_wait(struct hfi1_devdata *dd)
301 {
302 	int i;
303 
304 	for (i = 0; i < dd->num_sdma; i++) {
305 		struct sdma_engine *sde = &dd->per_sdma[i];
306 
307 		sdma_wait_for_packet_egress(sde, 0);
308 	}
309 }
310 
311 static inline void sdma_set_desc_cnt(struct sdma_engine *sde, unsigned cnt)
312 {
313 	u64 reg;
314 
315 	if (!(sde->dd->flags & HFI1_HAS_SDMA_TIMEOUT))
316 		return;
317 	reg = cnt;
318 	reg &= SD(DESC_CNT_CNT_MASK);
319 	reg <<= SD(DESC_CNT_CNT_SHIFT);
320 	write_sde_csr(sde, SD(DESC_CNT), reg);
321 }
322 
323 static inline void complete_tx(struct sdma_engine *sde,
324 			       struct sdma_txreq *tx,
325 			       int res)
326 {
327 	/* protect against complete modifying */
328 	struct iowait *wait = tx->wait;
329 	callback_t complete = tx->complete;
330 
331 #ifdef CONFIG_HFI1_DEBUG_SDMA_ORDER
332 	trace_hfi1_sdma_out_sn(sde, tx->sn);
333 	if (WARN_ON_ONCE(sde->head_sn != tx->sn))
334 		dd_dev_err(sde->dd, "expected %llu got %llu\n",
335 			   sde->head_sn, tx->sn);
336 	sde->head_sn++;
337 #endif
338 	__sdma_txclean(sde->dd, tx);
339 	if (complete)
340 		(*complete)(tx, res);
341 	if (iowait_sdma_dec(wait))
342 		iowait_drain_wakeup(wait);
343 }
344 
345 /*
346  * Complete all the sdma requests with a SDMA_TXREQ_S_ABORTED status
347  *
348  * Depending on timing there can be txreqs in two places:
349  * - in the descq ring
350  * - in the flush list
351  *
352  * To avoid ordering issues the descq ring needs to be flushed
353  * first followed by the flush list.
354  *
355  * This routine is called from two places
356  * - From a work queue item
357  * - Directly from the state machine just before setting the
358  *   state to running
359  *
360  * Must be called with head_lock held
361  *
362  */
363 static void sdma_flush(struct sdma_engine *sde)
364 {
365 	struct sdma_txreq *txp, *txp_next;
366 	LIST_HEAD(flushlist);
367 	unsigned long flags;
368 	uint seq;
369 
370 	/* flush from head to tail */
371 	sdma_flush_descq(sde);
372 	spin_lock_irqsave(&sde->flushlist_lock, flags);
373 	/* copy flush list */
374 	list_splice_init(&sde->flushlist, &flushlist);
375 	spin_unlock_irqrestore(&sde->flushlist_lock, flags);
376 	/* flush from flush list */
377 	list_for_each_entry_safe(txp, txp_next, &flushlist, list)
378 		complete_tx(sde, txp, SDMA_TXREQ_S_ABORTED);
379 	/* wakeup QPs orphaned on the dmawait list */
380 	do {
381 		struct iowait *w, *nw;
382 
383 		seq = read_seqbegin(&sde->waitlock);
384 		if (!list_empty(&sde->dmawait)) {
385 			write_seqlock(&sde->waitlock);
386 			list_for_each_entry_safe(w, nw, &sde->dmawait, list) {
387 				if (w->wakeup) {
388 					w->wakeup(w, SDMA_AVAIL_REASON);
389 					list_del_init(&w->list);
390 				}
391 			}
392 			write_sequnlock(&sde->waitlock);
393 		}
394 	} while (read_seqretry(&sde->waitlock, seq));
395 }
396 
397 /*
398  * Fields a work request for flushing the descq ring
399  * and the flush list
400  *
401  * If the engine has been brought to running during
402  * the scheduling delay, the flush is ignored, assuming
403  * that the process of bringing the engine to running
404  * would have done this flush prior to going to running.
405  *
406  */
407 static void sdma_field_flush(struct work_struct *work)
408 {
409 	unsigned long flags;
410 	struct sdma_engine *sde =
411 		container_of(work, struct sdma_engine, flush_worker);
412 
413 	write_seqlock_irqsave(&sde->head_lock, flags);
414 	if (!__sdma_running(sde))
415 		sdma_flush(sde);
416 	write_sequnlock_irqrestore(&sde->head_lock, flags);
417 }
418 
419 static void sdma_err_halt_wait(struct work_struct *work)
420 {
421 	struct sdma_engine *sde = container_of(work, struct sdma_engine,
422 						err_halt_worker);
423 	u64 statuscsr;
424 	unsigned long timeout;
425 
426 	timeout = jiffies + msecs_to_jiffies(SDMA_ERR_HALT_TIMEOUT);
427 	while (1) {
428 		statuscsr = read_sde_csr(sde, SD(STATUS));
429 		statuscsr &= SD(STATUS_ENG_HALTED_SMASK);
430 		if (statuscsr)
431 			break;
432 		if (time_after(jiffies, timeout)) {
433 			dd_dev_err(sde->dd,
434 				   "SDMA engine %d - timeout waiting for engine to halt\n",
435 				   sde->this_idx);
436 			/*
437 			 * Continue anyway.  This could happen if there was
438 			 * an uncorrectable error in the wrong spot.
439 			 */
440 			break;
441 		}
442 		usleep_range(80, 120);
443 	}
444 
445 	sdma_process_event(sde, sdma_event_e15_hw_halt_done);
446 }
447 
448 static void sdma_err_progress_check_schedule(struct sdma_engine *sde)
449 {
450 	if (!is_bx(sde->dd) && HFI1_CAP_IS_KSET(SDMA_AHG)) {
451 		unsigned index;
452 		struct hfi1_devdata *dd = sde->dd;
453 
454 		for (index = 0; index < dd->num_sdma; index++) {
455 			struct sdma_engine *curr_sdma = &dd->per_sdma[index];
456 
457 			if (curr_sdma != sde)
458 				curr_sdma->progress_check_head =
459 							curr_sdma->descq_head;
460 		}
461 		dd_dev_err(sde->dd,
462 			   "SDMA engine %d - check scheduled\n",
463 				sde->this_idx);
464 		mod_timer(&sde->err_progress_check_timer, jiffies + 10);
465 	}
466 }
467 
468 static void sdma_err_progress_check(struct timer_list *t)
469 {
470 	unsigned index;
471 	struct sdma_engine *sde = timer_container_of(sde, t,
472 						     err_progress_check_timer);
473 
474 	dd_dev_err(sde->dd, "SDE progress check event\n");
475 	for (index = 0; index < sde->dd->num_sdma; index++) {
476 		struct sdma_engine *curr_sde = &sde->dd->per_sdma[index];
477 		unsigned long flags;
478 
479 		/* check progress on each engine except the current one */
480 		if (curr_sde == sde)
481 			continue;
482 		/*
483 		 * We must lock interrupts when acquiring sde->lock,
484 		 * to avoid a deadlock if interrupt triggers and spins on
485 		 * the same lock on same CPU
486 		 */
487 		spin_lock_irqsave(&curr_sde->tail_lock, flags);
488 		write_seqlock(&curr_sde->head_lock);
489 
490 		/* skip non-running queues */
491 		if (curr_sde->state.current_state != sdma_state_s99_running) {
492 			write_sequnlock(&curr_sde->head_lock);
493 			spin_unlock_irqrestore(&curr_sde->tail_lock, flags);
494 			continue;
495 		}
496 
497 		if ((curr_sde->descq_head != curr_sde->descq_tail) &&
498 		    (curr_sde->descq_head ==
499 				curr_sde->progress_check_head))
500 			__sdma_process_event(curr_sde,
501 					     sdma_event_e90_sw_halted);
502 		write_sequnlock(&curr_sde->head_lock);
503 		spin_unlock_irqrestore(&curr_sde->tail_lock, flags);
504 	}
505 	schedule_work(&sde->err_halt_worker);
506 }
507 
508 static void sdma_hw_clean_up_task(struct tasklet_struct *t)
509 {
510 	struct sdma_engine *sde = from_tasklet(sde, t,
511 					       sdma_hw_clean_up_task);
512 	u64 statuscsr;
513 
514 	while (1) {
515 #ifdef CONFIG_SDMA_VERBOSITY
516 		dd_dev_err(sde->dd, "CONFIG SDMA(%u) %s:%d %s()\n",
517 			   sde->this_idx, slashstrip(__FILE__), __LINE__,
518 			__func__);
519 #endif
520 		statuscsr = read_sde_csr(sde, SD(STATUS));
521 		statuscsr &= SD(STATUS_ENG_CLEANED_UP_SMASK);
522 		if (statuscsr)
523 			break;
524 		udelay(10);
525 	}
526 
527 	sdma_process_event(sde, sdma_event_e25_hw_clean_up_done);
528 }
529 
530 static inline struct sdma_txreq *get_txhead(struct sdma_engine *sde)
531 {
532 	return sde->tx_ring[sde->tx_head & sde->sdma_mask];
533 }
534 
535 /*
536  * flush ring for recovery
537  */
538 static void sdma_flush_descq(struct sdma_engine *sde)
539 {
540 	u16 head, tail;
541 	int progress = 0;
542 	struct sdma_txreq *txp = get_txhead(sde);
543 
544 	/* The reason for some of the complexity of this code is that
545 	 * not all descriptors have corresponding txps.  So, we have to
546 	 * be able to skip over descs until we wander into the range of
547 	 * the next txp on the list.
548 	 */
549 	head = sde->descq_head & sde->sdma_mask;
550 	tail = sde->descq_tail & sde->sdma_mask;
551 	while (head != tail) {
552 		/* advance head, wrap if needed */
553 		head = ++sde->descq_head & sde->sdma_mask;
554 		/* if now past this txp's descs, do the callback */
555 		if (txp && txp->next_descq_idx == head) {
556 			/* remove from list */
557 			sde->tx_ring[sde->tx_head++ & sde->sdma_mask] = NULL;
558 			complete_tx(sde, txp, SDMA_TXREQ_S_ABORTED);
559 			trace_hfi1_sdma_progress(sde, head, tail, txp);
560 			txp = get_txhead(sde);
561 		}
562 		progress++;
563 	}
564 	if (progress)
565 		sdma_desc_avail(sde, sdma_descq_freecnt(sde));
566 }
567 
568 static void sdma_sw_clean_up_task(struct tasklet_struct *t)
569 {
570 	struct sdma_engine *sde = from_tasklet(sde, t, sdma_sw_clean_up_task);
571 	unsigned long flags;
572 
573 	spin_lock_irqsave(&sde->tail_lock, flags);
574 	write_seqlock(&sde->head_lock);
575 
576 	/*
577 	 * At this point, the following should always be true:
578 	 * - We are halted, so no more descriptors are getting retired.
579 	 * - We are not running, so no one is submitting new work.
580 	 * - Only we can send the e40_sw_cleaned, so we can't start
581 	 *   running again until we say so.  So, the active list and
582 	 *   descq are ours to play with.
583 	 */
584 
585 	/*
586 	 * In the error clean up sequence, software clean must be called
587 	 * before the hardware clean so we can use the hardware head in
588 	 * the progress routine.  A hardware clean or SPC unfreeze will
589 	 * reset the hardware head.
590 	 *
591 	 * Process all retired requests. The progress routine will use the
592 	 * latest physical hardware head - we are not running so speed does
593 	 * not matter.
594 	 */
595 	sdma_make_progress(sde, 0);
596 
597 	sdma_flush(sde);
598 
599 	/*
600 	 * Reset our notion of head and tail.
601 	 * Note that the HW registers have been reset via an earlier
602 	 * clean up.
603 	 */
604 	sde->descq_tail = 0;
605 	sde->descq_head = 0;
606 	sde->desc_avail = sdma_descq_freecnt(sde);
607 	*sde->head_dma = 0;
608 
609 	__sdma_process_event(sde, sdma_event_e40_sw_cleaned);
610 
611 	write_sequnlock(&sde->head_lock);
612 	spin_unlock_irqrestore(&sde->tail_lock, flags);
613 }
614 
615 static void sdma_sw_tear_down(struct sdma_engine *sde)
616 {
617 	struct sdma_state *ss = &sde->state;
618 
619 	/* Releasing this reference means the state machine has stopped. */
620 	sdma_put(ss);
621 
622 	/* stop waiting for all unfreeze events to complete */
623 	atomic_set(&sde->dd->sdma_unfreeze_count, -1);
624 	wake_up_interruptible(&sde->dd->sdma_unfreeze_wq);
625 }
626 
627 static void sdma_start_hw_clean_up(struct sdma_engine *sde)
628 {
629 	tasklet_hi_schedule(&sde->sdma_hw_clean_up_task);
630 }
631 
632 static void sdma_set_state(struct sdma_engine *sde,
633 			   enum sdma_states next_state)
634 {
635 	struct sdma_state *ss = &sde->state;
636 	const struct sdma_set_state_action *action = sdma_action_table;
637 	unsigned op = 0;
638 
639 	trace_hfi1_sdma_state(
640 		sde,
641 		sdma_state_names[ss->current_state],
642 		sdma_state_names[next_state]);
643 
644 	/* debugging bookkeeping */
645 	ss->previous_state = ss->current_state;
646 	ss->previous_op = ss->current_op;
647 	ss->current_state = next_state;
648 
649 	if (ss->previous_state != sdma_state_s99_running &&
650 	    next_state == sdma_state_s99_running)
651 		sdma_flush(sde);
652 
653 	if (action[next_state].op_enable)
654 		op |= SDMA_SENDCTRL_OP_ENABLE;
655 
656 	if (action[next_state].op_intenable)
657 		op |= SDMA_SENDCTRL_OP_INTENABLE;
658 
659 	if (action[next_state].op_halt)
660 		op |= SDMA_SENDCTRL_OP_HALT;
661 
662 	if (action[next_state].op_cleanup)
663 		op |= SDMA_SENDCTRL_OP_CLEANUP;
664 
665 	if (action[next_state].go_s99_running_tofalse)
666 		ss->go_s99_running = 0;
667 
668 	if (action[next_state].go_s99_running_totrue)
669 		ss->go_s99_running = 1;
670 
671 	ss->current_op = op;
672 	sdma_sendctrl(sde, ss->current_op);
673 }
674 
675 /**
676  * sdma_get_descq_cnt() - called when device probed
677  *
678  * Return a validated descq count.
679  *
680  * This is currently only used in the verbs initialization to build the tx
681  * list.
682  *
683  * This will probably be deleted in favor of a more scalable approach to
684  * alloc tx's.
685  *
686  */
687 u16 sdma_get_descq_cnt(void)
688 {
689 	u16 count = sdma_descq_cnt;
690 
691 	if (!count)
692 		return SDMA_DESCQ_CNT;
693 	/* count must be a power of 2 greater than 64 and less than
694 	 * 32768.   Otherwise return default.
695 	 */
696 	if (!is_power_of_2(count))
697 		return SDMA_DESCQ_CNT;
698 	if (count < 64 || count > 32768)
699 		return SDMA_DESCQ_CNT;
700 	return count;
701 }
702 
703 /**
704  * sdma_engine_get_vl() - return vl for a given sdma engine
705  * @sde: sdma engine
706  *
707  * This function returns the vl mapped to a given engine, or an error if
708  * the mapping can't be found. The mapping fields are protected by RCU.
709  */
710 int sdma_engine_get_vl(struct sdma_engine *sde)
711 {
712 	struct hfi1_devdata *dd = sde->dd;
713 	struct sdma_vl_map *m;
714 	u8 vl;
715 
716 	if (sde->this_idx >= TXE_NUM_SDMA_ENGINES)
717 		return -EINVAL;
718 
719 	rcu_read_lock();
720 	m = rcu_dereference(dd->sdma_map);
721 	if (unlikely(!m)) {
722 		rcu_read_unlock();
723 		return -EINVAL;
724 	}
725 	vl = m->engine_to_vl[sde->this_idx];
726 	rcu_read_unlock();
727 
728 	return vl;
729 }
730 
731 /**
732  * sdma_select_engine_vl() - select sdma engine
733  * @dd: devdata
734  * @selector: a spreading factor
735  * @vl: this vl
736  *
737  *
738  * This function returns an engine based on the selector and a vl.  The
739  * mapping fields are protected by RCU.
740  */
741 struct sdma_engine *sdma_select_engine_vl(
742 	struct hfi1_devdata *dd,
743 	u32 selector,
744 	u8 vl)
745 {
746 	struct sdma_vl_map *m;
747 	struct sdma_map_elem *e;
748 	struct sdma_engine *rval;
749 
750 	/* NOTE This should only happen if SC->VL changed after the initial
751 	 *      checks on the QP/AH
752 	 *      Default will return engine 0 below
753 	 */
754 	if (vl >= num_vls) {
755 		rval = NULL;
756 		goto done;
757 	}
758 
759 	rcu_read_lock();
760 	m = rcu_dereference(dd->sdma_map);
761 	if (unlikely(!m)) {
762 		rcu_read_unlock();
763 		return &dd->per_sdma[0];
764 	}
765 	e = m->map[vl & m->mask];
766 	rval = e->sde[selector & e->mask];
767 	rcu_read_unlock();
768 
769 done:
770 	rval =  !rval ? &dd->per_sdma[0] : rval;
771 	trace_hfi1_sdma_engine_select(dd, selector, vl, rval->this_idx);
772 	return rval;
773 }
774 
775 /**
776  * sdma_select_engine_sc() - select sdma engine
777  * @dd: devdata
778  * @selector: a spreading factor
779  * @sc5: the 5 bit sc
780  *
781  *
782  * This function returns an engine based on the selector and an sc.
783  */
784 struct sdma_engine *sdma_select_engine_sc(
785 	struct hfi1_devdata *dd,
786 	u32 selector,
787 	u8 sc5)
788 {
789 	u8 vl = sc_to_vlt(dd, sc5);
790 
791 	return sdma_select_engine_vl(dd, selector, vl);
792 }
793 
794 struct sdma_rht_map_elem {
795 	u32 mask;
796 	u8 ctr;
797 	struct sdma_engine *sde[];
798 };
799 
800 struct sdma_rht_node {
801 	unsigned long cpu_id;
802 	struct sdma_rht_map_elem *map[HFI1_MAX_VLS_SUPPORTED];
803 	struct rhash_head node;
804 };
805 
806 #define NR_CPUS_HINT 192
807 
808 static const struct rhashtable_params sdma_rht_params = {
809 	.nelem_hint = NR_CPUS_HINT,
810 	.head_offset = offsetof(struct sdma_rht_node, node),
811 	.key_offset = offsetof(struct sdma_rht_node, cpu_id),
812 	.key_len = sizeof_field(struct sdma_rht_node, cpu_id),
813 	.max_size = NR_CPUS,
814 	.min_size = 8,
815 	.automatic_shrinking = true,
816 };
817 
818 /*
819  * sdma_select_user_engine() - select sdma engine based on user setup
820  * @dd: devdata
821  * @selector: a spreading factor
822  * @vl: this vl
823  *
824  * This function returns an sdma engine for a user sdma request.
825  * User defined sdma engine affinity setting is honored when applicable,
826  * otherwise system default sdma engine mapping is used. To ensure correct
827  * ordering, the mapping from <selector, vl> to sde must remain unchanged.
828  */
829 struct sdma_engine *sdma_select_user_engine(struct hfi1_devdata *dd,
830 					    u32 selector, u8 vl)
831 {
832 	struct sdma_rht_node *rht_node;
833 	struct sdma_engine *sde = NULL;
834 	unsigned long cpu_id;
835 
836 	/*
837 	 * To ensure that always the same sdma engine(s) will be
838 	 * selected make sure the process is pinned to this CPU only.
839 	 */
840 	if (current->nr_cpus_allowed != 1)
841 		goto out;
842 
843 	rcu_read_lock();
844 	cpu_id = smp_processor_id();
845 	rht_node = rhashtable_lookup(dd->sdma_rht, &cpu_id,
846 				     sdma_rht_params);
847 
848 	if (rht_node && rht_node->map[vl]) {
849 		struct sdma_rht_map_elem *map = rht_node->map[vl];
850 
851 		sde = map->sde[selector & map->mask];
852 	}
853 	rcu_read_unlock();
854 
855 	if (sde)
856 		return sde;
857 
858 out:
859 	return sdma_select_engine_vl(dd, selector, vl);
860 }
861 
862 static void sdma_populate_sde_map(struct sdma_rht_map_elem *map)
863 {
864 	int i;
865 
866 	for (i = 0; i < roundup_pow_of_two(map->ctr ? : 1) - map->ctr; i++)
867 		map->sde[map->ctr + i] = map->sde[i];
868 }
869 
870 static void sdma_cleanup_sde_map(struct sdma_rht_map_elem *map,
871 				 struct sdma_engine *sde)
872 {
873 	unsigned int i, pow;
874 
875 	/* only need to check the first ctr entries for a match */
876 	for (i = 0; i < map->ctr; i++) {
877 		if (map->sde[i] == sde) {
878 			memmove(&map->sde[i], &map->sde[i + 1],
879 				(map->ctr - i - 1) * sizeof(map->sde[0]));
880 			map->ctr--;
881 			pow = roundup_pow_of_two(map->ctr ? : 1);
882 			map->mask = pow - 1;
883 			sdma_populate_sde_map(map);
884 			break;
885 		}
886 	}
887 }
888 
889 /*
890  * Prevents concurrent reads and writes of the sdma engine cpu_mask
891  */
892 static DEFINE_MUTEX(process_to_sde_mutex);
893 
894 ssize_t sdma_set_cpu_to_sde_map(struct sdma_engine *sde, const char *buf,
895 				size_t count)
896 {
897 	struct hfi1_devdata *dd = sde->dd;
898 	cpumask_var_t mask, new_mask;
899 	unsigned long cpu;
900 	int ret, vl, sz;
901 	struct sdma_rht_node *rht_node;
902 
903 	vl = sdma_engine_get_vl(sde);
904 	if (unlikely(vl < 0 || vl >= ARRAY_SIZE(rht_node->map)))
905 		return -EINVAL;
906 
907 	ret = zalloc_cpumask_var(&mask, GFP_KERNEL);
908 	if (!ret)
909 		return -ENOMEM;
910 
911 	ret = zalloc_cpumask_var(&new_mask, GFP_KERNEL);
912 	if (!ret) {
913 		free_cpumask_var(mask);
914 		return -ENOMEM;
915 	}
916 	ret = cpulist_parse(buf, mask);
917 	if (ret)
918 		goto out_free;
919 
920 	if (!cpumask_subset(mask, cpu_online_mask)) {
921 		dd_dev_warn(sde->dd, "Invalid CPU mask\n");
922 		ret = -EINVAL;
923 		goto out_free;
924 	}
925 
926 	sz = sizeof(struct sdma_rht_map_elem) +
927 			(TXE_NUM_SDMA_ENGINES * sizeof(struct sdma_engine *));
928 
929 	mutex_lock(&process_to_sde_mutex);
930 
931 	for_each_cpu(cpu, mask) {
932 		/* Check if we have this already mapped */
933 		if (cpumask_test_cpu(cpu, &sde->cpu_mask)) {
934 			cpumask_set_cpu(cpu, new_mask);
935 			continue;
936 		}
937 
938 		rht_node = rhashtable_lookup_fast(dd->sdma_rht, &cpu,
939 						  sdma_rht_params);
940 		if (!rht_node) {
941 			rht_node = kzalloc_obj(*rht_node);
942 			if (!rht_node) {
943 				ret = -ENOMEM;
944 				goto out;
945 			}
946 
947 			rht_node->map[vl] = kzalloc(sz, GFP_KERNEL);
948 			if (!rht_node->map[vl]) {
949 				kfree(rht_node);
950 				ret = -ENOMEM;
951 				goto out;
952 			}
953 			rht_node->cpu_id = cpu;
954 			rht_node->map[vl]->mask = 0;
955 			rht_node->map[vl]->ctr = 1;
956 			rht_node->map[vl]->sde[0] = sde;
957 
958 			ret = rhashtable_insert_fast(dd->sdma_rht,
959 						     &rht_node->node,
960 						     sdma_rht_params);
961 			if (ret) {
962 				kfree(rht_node->map[vl]);
963 				kfree(rht_node);
964 				dd_dev_err(sde->dd, "Failed to set process to sde affinity for cpu %lu\n",
965 					   cpu);
966 				goto out;
967 			}
968 
969 		} else {
970 			int ctr, pow;
971 
972 			/* Add new user mappings */
973 			if (!rht_node->map[vl])
974 				rht_node->map[vl] = kzalloc(sz, GFP_KERNEL);
975 
976 			if (!rht_node->map[vl]) {
977 				ret = -ENOMEM;
978 				goto out;
979 			}
980 
981 			rht_node->map[vl]->ctr++;
982 			ctr = rht_node->map[vl]->ctr;
983 			rht_node->map[vl]->sde[ctr - 1] = sde;
984 			pow = roundup_pow_of_two(ctr);
985 			rht_node->map[vl]->mask = pow - 1;
986 
987 			/* Populate the sde map table */
988 			sdma_populate_sde_map(rht_node->map[vl]);
989 		}
990 		cpumask_set_cpu(cpu, new_mask);
991 	}
992 
993 	/* Clean up old mappings */
994 	for_each_online_cpu(cpu) {
995 		struct sdma_rht_node *rht_node;
996 
997 		/* Don't cleanup sdes that are set in the new mask */
998 		if (cpumask_test_cpu(cpu, mask))
999 			continue;
1000 
1001 		rht_node = rhashtable_lookup_fast(dd->sdma_rht, &cpu,
1002 						  sdma_rht_params);
1003 		if (rht_node) {
1004 			bool empty = true;
1005 			int i;
1006 
1007 			/* Remove mappings for old sde */
1008 			for (i = 0; i < HFI1_MAX_VLS_SUPPORTED; i++)
1009 				if (rht_node->map[i])
1010 					sdma_cleanup_sde_map(rht_node->map[i],
1011 							     sde);
1012 
1013 			/* Free empty hash table entries */
1014 			for (i = 0; i < HFI1_MAX_VLS_SUPPORTED; i++) {
1015 				if (!rht_node->map[i])
1016 					continue;
1017 
1018 				if (rht_node->map[i]->ctr) {
1019 					empty = false;
1020 					break;
1021 				}
1022 			}
1023 
1024 			if (empty) {
1025 				ret = rhashtable_remove_fast(dd->sdma_rht,
1026 							     &rht_node->node,
1027 							     sdma_rht_params);
1028 				WARN_ON(ret);
1029 
1030 				for (i = 0; i < HFI1_MAX_VLS_SUPPORTED; i++)
1031 					kfree(rht_node->map[i]);
1032 
1033 				kfree(rht_node);
1034 			}
1035 		}
1036 	}
1037 
1038 	cpumask_copy(&sde->cpu_mask, new_mask);
1039 out:
1040 	mutex_unlock(&process_to_sde_mutex);
1041 out_free:
1042 	free_cpumask_var(mask);
1043 	free_cpumask_var(new_mask);
1044 	return ret ? : strnlen(buf, PAGE_SIZE);
1045 }
1046 
1047 ssize_t sdma_get_cpu_to_sde_map(struct sdma_engine *sde, char *buf)
1048 {
1049 	mutex_lock(&process_to_sde_mutex);
1050 	if (cpumask_empty(&sde->cpu_mask))
1051 		snprintf(buf, PAGE_SIZE, "%s\n", "empty");
1052 	else
1053 		sysfs_emit(buf, "%*pbl\n", cpumask_pr_args(&sde->cpu_mask));
1054 	mutex_unlock(&process_to_sde_mutex);
1055 	return strnlen(buf, PAGE_SIZE);
1056 }
1057 
1058 static void sdma_rht_free(void *ptr, void *arg)
1059 {
1060 	struct sdma_rht_node *rht_node = ptr;
1061 	int i;
1062 
1063 	for (i = 0; i < HFI1_MAX_VLS_SUPPORTED; i++)
1064 		kfree(rht_node->map[i]);
1065 
1066 	kfree(rht_node);
1067 }
1068 
1069 /**
1070  * sdma_seqfile_dump_cpu_list() - debugfs dump the cpu to sdma mappings
1071  * @s: seq file
1072  * @dd: hfi1_devdata
1073  * @cpuid: cpu id
1074  *
1075  * This routine dumps the process to sde mappings per cpu
1076  */
1077 void sdma_seqfile_dump_cpu_list(struct seq_file *s,
1078 				struct hfi1_devdata *dd,
1079 				unsigned long cpuid)
1080 {
1081 	struct sdma_rht_node *rht_node;
1082 	int i, j;
1083 
1084 	rht_node = rhashtable_lookup_fast(dd->sdma_rht, &cpuid,
1085 					  sdma_rht_params);
1086 	if (!rht_node)
1087 		return;
1088 
1089 	seq_printf(s, "cpu%3lu: ", cpuid);
1090 	for (i = 0; i < HFI1_MAX_VLS_SUPPORTED; i++) {
1091 		if (!rht_node->map[i] || !rht_node->map[i]->ctr)
1092 			continue;
1093 
1094 		seq_printf(s, " vl%d: [", i);
1095 
1096 		for (j = 0; j < rht_node->map[i]->ctr; j++) {
1097 			if (!rht_node->map[i]->sde[j])
1098 				continue;
1099 
1100 			if (j > 0)
1101 				seq_puts(s, ",");
1102 
1103 			seq_printf(s, " sdma%2d",
1104 				   rht_node->map[i]->sde[j]->this_idx);
1105 		}
1106 		seq_puts(s, " ]");
1107 	}
1108 
1109 	seq_puts(s, "\n");
1110 }
1111 
1112 /*
1113  * Free the indicated map struct
1114  */
1115 static void sdma_map_free(struct sdma_vl_map *m)
1116 {
1117 	int i;
1118 
1119 	for (i = 0; m && i < m->actual_vls; i++)
1120 		kfree(m->map[i]);
1121 	kfree(m);
1122 }
1123 
1124 /*
1125  * Handle RCU callback
1126  */
1127 static void sdma_map_rcu_callback(struct rcu_head *list)
1128 {
1129 	struct sdma_vl_map *m = container_of(list, struct sdma_vl_map, list);
1130 
1131 	sdma_map_free(m);
1132 }
1133 
1134 /**
1135  * sdma_map_init - called when # vls change
1136  * @dd: hfi1_devdata
1137  * @port: port number
1138  * @num_vls: number of vls
1139  * @vl_engines: per vl engine mapping (optional)
1140  *
1141  * This routine changes the mapping based on the number of vls.
1142  *
1143  * vl_engines is used to specify a non-uniform vl/engine loading. NULL
1144  * implies auto computing the loading and giving each VLs a uniform
1145  * distribution of engines per VL.
1146  *
1147  * The auto algorithm computes the sde_per_vl and the number of extra
1148  * engines.  Any extra engines are added from the last VL on down.
1149  *
1150  * rcu locking is used here to control access to the mapping fields.
1151  *
1152  * If either the num_vls or num_sdma are non-power of 2, the array sizes
1153  * in the struct sdma_vl_map and the struct sdma_map_elem are rounded
1154  * up to the next highest power of 2 and the first entry is reused
1155  * in a round robin fashion.
1156  *
1157  * If an error occurs the map change is not done and the mapping is
1158  * not changed.
1159  *
1160  */
1161 int sdma_map_init(struct hfi1_devdata *dd, u8 port, u8 num_vls, u8 *vl_engines)
1162 {
1163 	int i, j;
1164 	int extra, sde_per_vl;
1165 	int engine = 0;
1166 	u8 lvl_engines[OPA_MAX_VLS];
1167 	struct sdma_vl_map *oldmap, *newmap;
1168 
1169 	if (!(dd->flags & HFI1_HAS_SEND_DMA))
1170 		return 0;
1171 
1172 	if (!vl_engines) {
1173 		/* truncate divide */
1174 		sde_per_vl = dd->num_sdma / num_vls;
1175 		/* extras */
1176 		extra = dd->num_sdma % num_vls;
1177 		vl_engines = lvl_engines;
1178 		/* add extras from last vl down */
1179 		for (i = num_vls - 1; i >= 0; i--, extra--)
1180 			vl_engines[i] = sde_per_vl + (extra > 0 ? 1 : 0);
1181 	}
1182 	/* build new map */
1183 	newmap = kzalloc(
1184 		sizeof(struct sdma_vl_map) +
1185 			roundup_pow_of_two(num_vls) *
1186 			sizeof(struct sdma_map_elem *),
1187 		GFP_KERNEL);
1188 	if (!newmap)
1189 		goto bail;
1190 	newmap->actual_vls = num_vls;
1191 	newmap->vls = roundup_pow_of_two(num_vls);
1192 	newmap->mask = (1 << ilog2(newmap->vls)) - 1;
1193 	/* initialize back-map */
1194 	for (i = 0; i < TXE_NUM_SDMA_ENGINES; i++)
1195 		newmap->engine_to_vl[i] = -1;
1196 	for (i = 0; i < newmap->vls; i++) {
1197 		/* save for wrap around */
1198 		int first_engine = engine;
1199 
1200 		if (i < newmap->actual_vls) {
1201 			int sz = roundup_pow_of_two(vl_engines[i]);
1202 
1203 			/* only allocate once */
1204 			newmap->map[i] = kzalloc(
1205 				sizeof(struct sdma_map_elem) +
1206 					sz * sizeof(struct sdma_engine *),
1207 				GFP_KERNEL);
1208 			if (!newmap->map[i])
1209 				goto bail;
1210 			newmap->map[i]->mask = (1 << ilog2(sz)) - 1;
1211 			/* assign engines */
1212 			for (j = 0; j < sz; j++) {
1213 				newmap->map[i]->sde[j] =
1214 					&dd->per_sdma[engine];
1215 				if (++engine >= first_engine + vl_engines[i])
1216 					/* wrap back to first engine */
1217 					engine = first_engine;
1218 			}
1219 			/* assign back-map */
1220 			for (j = 0; j < vl_engines[i]; j++)
1221 				newmap->engine_to_vl[first_engine + j] = i;
1222 		} else {
1223 			/* just re-use entry without allocating */
1224 			newmap->map[i] = newmap->map[i % num_vls];
1225 		}
1226 		engine = first_engine + vl_engines[i];
1227 	}
1228 	/* newmap in hand, save old map */
1229 	spin_lock_irq(&dd->sde_map_lock);
1230 	oldmap = rcu_dereference_protected(dd->sdma_map,
1231 					   lockdep_is_held(&dd->sde_map_lock));
1232 
1233 	/* publish newmap */
1234 	rcu_assign_pointer(dd->sdma_map, newmap);
1235 
1236 	spin_unlock_irq(&dd->sde_map_lock);
1237 	/* success, free any old map after grace period */
1238 	if (oldmap)
1239 		call_rcu(&oldmap->list, sdma_map_rcu_callback);
1240 	return 0;
1241 bail:
1242 	/* free any partial allocation */
1243 	sdma_map_free(newmap);
1244 	return -ENOMEM;
1245 }
1246 
1247 /**
1248  * sdma_clean - Clean up allocated memory
1249  * @dd:          struct hfi1_devdata
1250  * @num_engines: num sdma engines
1251  *
1252  * This routine can be called regardless of the success of
1253  * sdma_init()
1254  */
1255 void sdma_clean(struct hfi1_devdata *dd, size_t num_engines)
1256 {
1257 	size_t i;
1258 	struct sdma_engine *sde;
1259 	struct sdma_vl_map *map;
1260 
1261 	if (dd->sdma_pad_dma) {
1262 		dma_free_coherent(&dd->pcidev->dev, SDMA_PAD,
1263 				  (void *)dd->sdma_pad_dma,
1264 				  dd->sdma_pad_phys);
1265 		dd->sdma_pad_dma = NULL;
1266 		dd->sdma_pad_phys = 0;
1267 	}
1268 	if (dd->sdma_heads_dma) {
1269 		dma_free_coherent(&dd->pcidev->dev, dd->sdma_heads_size,
1270 				  (void *)dd->sdma_heads_dma,
1271 				  dd->sdma_heads_phys);
1272 		dd->sdma_heads_dma = NULL;
1273 		dd->sdma_heads_phys = 0;
1274 	}
1275 	for (i = 0; dd->per_sdma && i < num_engines; ++i) {
1276 		sde = &dd->per_sdma[i];
1277 
1278 		sde->head_dma = NULL;
1279 		sde->head_phys = 0;
1280 
1281 		if (sde->descq) {
1282 			dma_free_coherent(
1283 				&dd->pcidev->dev,
1284 				sde->descq_cnt * sizeof(u64[2]),
1285 				sde->descq,
1286 				sde->descq_phys
1287 			);
1288 			sde->descq = NULL;
1289 			sde->descq_phys = 0;
1290 		}
1291 		kvfree(sde->tx_ring);
1292 		sde->tx_ring = NULL;
1293 	}
1294 	if (rcu_access_pointer(dd->sdma_map)) {
1295 		spin_lock_irq(&dd->sde_map_lock);
1296 		map = rcu_access_pointer(dd->sdma_map);
1297 		RCU_INIT_POINTER(dd->sdma_map, NULL);
1298 		spin_unlock_irq(&dd->sde_map_lock);
1299 		synchronize_rcu();
1300 		sdma_map_free(map);
1301 	}
1302 	kfree(dd->per_sdma);
1303 	dd->per_sdma = NULL;
1304 
1305 	if (dd->sdma_rht) {
1306 		rhashtable_free_and_destroy(dd->sdma_rht, sdma_rht_free, NULL);
1307 		kfree(dd->sdma_rht);
1308 		dd->sdma_rht = NULL;
1309 	}
1310 }
1311 
1312 /**
1313  * sdma_init() - called when device probed
1314  * @dd: hfi1_devdata
1315  * @port: port number (currently only zero)
1316  *
1317  * Initializes each sde and its csrs.
1318  * Interrupts are not required to be enabled.
1319  *
1320  * Returns:
1321  * 0 - success, -errno on failure
1322  */
1323 int sdma_init(struct hfi1_devdata *dd, u8 port)
1324 {
1325 	unsigned this_idx;
1326 	struct sdma_engine *sde;
1327 	struct rhashtable *tmp_sdma_rht;
1328 	u16 descq_cnt;
1329 	void *curr_head;
1330 	struct hfi1_pportdata *ppd = dd->pport + port;
1331 	u32 per_sdma_credits;
1332 	uint idle_cnt = sdma_idle_cnt;
1333 	size_t num_engines = chip_sdma_engines(dd);
1334 	int ret = -ENOMEM;
1335 
1336 	if (!HFI1_CAP_IS_KSET(SDMA)) {
1337 		HFI1_CAP_CLEAR(SDMA_AHG);
1338 		return 0;
1339 	}
1340 	if (mod_num_sdma &&
1341 	    /* can't exceed chip support */
1342 	    mod_num_sdma <= chip_sdma_engines(dd) &&
1343 	    /* count must be >= vls */
1344 	    mod_num_sdma >= num_vls)
1345 		num_engines = mod_num_sdma;
1346 
1347 	dd_dev_info(dd, "SDMA mod_num_sdma: %u\n", mod_num_sdma);
1348 	dd_dev_info(dd, "SDMA chip_sdma_engines: %u\n", chip_sdma_engines(dd));
1349 	dd_dev_info(dd, "SDMA chip_sdma_mem_size: %u\n",
1350 		    chip_sdma_mem_size(dd));
1351 
1352 	per_sdma_credits =
1353 		chip_sdma_mem_size(dd) / (num_engines * SDMA_BLOCK_SIZE);
1354 
1355 	/* set up freeze waitqueue */
1356 	init_waitqueue_head(&dd->sdma_unfreeze_wq);
1357 	atomic_set(&dd->sdma_unfreeze_count, 0);
1358 
1359 	descq_cnt = sdma_get_descq_cnt();
1360 	dd_dev_info(dd, "SDMA engines %zu descq_cnt %u\n",
1361 		    num_engines, descq_cnt);
1362 
1363 	/* alloc memory for array of send engines */
1364 	dd->per_sdma = kcalloc_node(num_engines, sizeof(*dd->per_sdma),
1365 				    GFP_KERNEL, dd->node);
1366 	if (!dd->per_sdma)
1367 		return ret;
1368 
1369 	idle_cnt = ns_to_cclock(dd, idle_cnt);
1370 	if (idle_cnt)
1371 		dd->default_desc1 =
1372 			SDMA_DESC1_HEAD_TO_HOST_FLAG;
1373 	else
1374 		dd->default_desc1 =
1375 			SDMA_DESC1_INT_REQ_FLAG;
1376 
1377 	if (!sdma_desct_intr)
1378 		sdma_desct_intr = SDMA_DESC_INTR;
1379 
1380 	/* Allocate memory for SendDMA descriptor FIFOs */
1381 	for (this_idx = 0; this_idx < num_engines; ++this_idx) {
1382 		sde = &dd->per_sdma[this_idx];
1383 		sde->dd = dd;
1384 		sde->ppd = ppd;
1385 		sde->this_idx = this_idx;
1386 		sde->descq_cnt = descq_cnt;
1387 		sde->desc_avail = sdma_descq_freecnt(sde);
1388 		sde->sdma_shift = ilog2(descq_cnt);
1389 		sde->sdma_mask = (1 << sde->sdma_shift) - 1;
1390 
1391 		/* Create a mask specifically for each interrupt source */
1392 		sde->int_mask = (u64)1 << (0 * TXE_NUM_SDMA_ENGINES +
1393 					   this_idx);
1394 		sde->progress_mask = (u64)1 << (1 * TXE_NUM_SDMA_ENGINES +
1395 						this_idx);
1396 		sde->idle_mask = (u64)1 << (2 * TXE_NUM_SDMA_ENGINES +
1397 					    this_idx);
1398 		/* Create a combined mask to cover all 3 interrupt sources */
1399 		sde->imask = sde->int_mask | sde->progress_mask |
1400 			     sde->idle_mask;
1401 
1402 		spin_lock_init(&sde->tail_lock);
1403 		seqlock_init(&sde->head_lock);
1404 		spin_lock_init(&sde->senddmactrl_lock);
1405 		spin_lock_init(&sde->flushlist_lock);
1406 		seqlock_init(&sde->waitlock);
1407 		/* insure there is always a zero bit */
1408 		sde->ahg_bits = 0xfffffffe00000000ULL;
1409 
1410 		sdma_set_state(sde, sdma_state_s00_hw_down);
1411 
1412 		/* set up reference counting */
1413 		kref_init(&sde->state.kref);
1414 		init_completion(&sde->state.comp);
1415 
1416 		INIT_LIST_HEAD(&sde->flushlist);
1417 		INIT_LIST_HEAD(&sde->dmawait);
1418 
1419 		sde->tail_csr =
1420 			get_kctxt_csr_addr(dd, this_idx, SD(TAIL));
1421 
1422 		tasklet_setup(&sde->sdma_hw_clean_up_task,
1423 			      sdma_hw_clean_up_task);
1424 		tasklet_setup(&sde->sdma_sw_clean_up_task,
1425 			      sdma_sw_clean_up_task);
1426 		INIT_WORK(&sde->err_halt_worker, sdma_err_halt_wait);
1427 		INIT_WORK(&sde->flush_worker, sdma_field_flush);
1428 
1429 		sde->progress_check_head = 0;
1430 
1431 		timer_setup(&sde->err_progress_check_timer,
1432 			    sdma_err_progress_check, 0);
1433 
1434 		sde->descq = dma_alloc_coherent(&dd->pcidev->dev,
1435 						descq_cnt * sizeof(u64[2]),
1436 						&sde->descq_phys, GFP_KERNEL);
1437 		if (!sde->descq)
1438 			goto bail;
1439 		sde->tx_ring =
1440 			kvzalloc_node(array_size(descq_cnt,
1441 						 sizeof(struct sdma_txreq *)),
1442 				      GFP_KERNEL, dd->node);
1443 		if (!sde->tx_ring)
1444 			goto bail;
1445 	}
1446 
1447 	dd->sdma_heads_size = L1_CACHE_BYTES * num_engines;
1448 	/* Allocate memory for DMA of head registers to memory */
1449 	dd->sdma_heads_dma = dma_alloc_coherent(&dd->pcidev->dev,
1450 						dd->sdma_heads_size,
1451 						&dd->sdma_heads_phys,
1452 						GFP_KERNEL);
1453 	if (!dd->sdma_heads_dma) {
1454 		dd_dev_err(dd, "failed to allocate SendDMA head memory\n");
1455 		goto bail;
1456 	}
1457 
1458 	/* Allocate memory for pad */
1459 	dd->sdma_pad_dma = dma_alloc_coherent(&dd->pcidev->dev, SDMA_PAD,
1460 					      &dd->sdma_pad_phys, GFP_KERNEL);
1461 	if (!dd->sdma_pad_dma) {
1462 		dd_dev_err(dd, "failed to allocate SendDMA pad memory\n");
1463 		goto bail;
1464 	}
1465 
1466 	/* assign each engine to different cacheline and init registers */
1467 	curr_head = (void *)dd->sdma_heads_dma;
1468 	for (this_idx = 0; this_idx < num_engines; ++this_idx) {
1469 		unsigned long phys_offset;
1470 
1471 		sde = &dd->per_sdma[this_idx];
1472 
1473 		sde->head_dma = curr_head;
1474 		curr_head += L1_CACHE_BYTES;
1475 		phys_offset = (unsigned long)sde->head_dma -
1476 			      (unsigned long)dd->sdma_heads_dma;
1477 		sde->head_phys = dd->sdma_heads_phys + phys_offset;
1478 		init_sdma_regs(sde, per_sdma_credits, idle_cnt);
1479 	}
1480 	dd->flags |= HFI1_HAS_SEND_DMA;
1481 	dd->flags |= idle_cnt ? HFI1_HAS_SDMA_TIMEOUT : 0;
1482 	dd->num_sdma = num_engines;
1483 	ret = sdma_map_init(dd, port, ppd->vls_operational, NULL);
1484 	if (ret < 0)
1485 		goto bail;
1486 
1487 	tmp_sdma_rht = kzalloc_obj(*tmp_sdma_rht);
1488 	if (!tmp_sdma_rht) {
1489 		ret = -ENOMEM;
1490 		goto bail;
1491 	}
1492 
1493 	ret = rhashtable_init(tmp_sdma_rht, &sdma_rht_params);
1494 	if (ret < 0) {
1495 		kfree(tmp_sdma_rht);
1496 		goto bail;
1497 	}
1498 
1499 	dd->sdma_rht = tmp_sdma_rht;
1500 
1501 	dd_dev_info(dd, "SDMA num_sdma: %u\n", dd->num_sdma);
1502 	return 0;
1503 
1504 bail:
1505 	sdma_clean(dd, num_engines);
1506 	return ret;
1507 }
1508 
1509 /**
1510  * sdma_all_running() - called when the link goes up
1511  * @dd: hfi1_devdata
1512  *
1513  * This routine moves all engines to the running state.
1514  */
1515 void sdma_all_running(struct hfi1_devdata *dd)
1516 {
1517 	struct sdma_engine *sde;
1518 	unsigned int i;
1519 
1520 	/* move all engines to running */
1521 	for (i = 0; i < dd->num_sdma; ++i) {
1522 		sde = &dd->per_sdma[i];
1523 		sdma_process_event(sde, sdma_event_e30_go_running);
1524 	}
1525 }
1526 
1527 /**
1528  * sdma_start() - called to kick off state processing for all engines
1529  * @dd: hfi1_devdata
1530  *
1531  * This routine is for kicking off the state processing for all required
1532  * sdma engines.  Interrupts need to be working at this point.
1533  *
1534  */
1535 void sdma_start(struct hfi1_devdata *dd)
1536 {
1537 	unsigned i;
1538 	struct sdma_engine *sde;
1539 
1540 	/* kick off the engines state processing */
1541 	for (i = 0; i < dd->num_sdma; ++i) {
1542 		sde = &dd->per_sdma[i];
1543 		sdma_process_event(sde, sdma_event_e10_go_hw_start);
1544 	}
1545 }
1546 
1547 /**
1548  * sdma_exit() - used when module is removed
1549  * @dd: hfi1_devdata
1550  */
1551 void sdma_exit(struct hfi1_devdata *dd)
1552 {
1553 	unsigned this_idx;
1554 	struct sdma_engine *sde;
1555 
1556 	for (this_idx = 0; dd->per_sdma && this_idx < dd->num_sdma;
1557 			++this_idx) {
1558 		sde = &dd->per_sdma[this_idx];
1559 		if (!list_empty(&sde->dmawait))
1560 			dd_dev_err(dd, "sde %u: dmawait list not empty!\n",
1561 				   sde->this_idx);
1562 		sdma_process_event(sde, sdma_event_e00_go_hw_down);
1563 
1564 		timer_delete_sync(&sde->err_progress_check_timer);
1565 
1566 		/*
1567 		 * This waits for the state machine to exit so it is not
1568 		 * necessary to kill the sdma_sw_clean_up_task to make sure
1569 		 * it is not running.
1570 		 */
1571 		sdma_finalput(&sde->state);
1572 		cancel_work_sync(&sde->err_halt_worker);
1573 		tasklet_kill(&sde->sdma_hw_clean_up_task);
1574 		cancel_work_sync(&sde->flush_worker);
1575 	}
1576 }
1577 
1578 /*
1579  * unmap the indicated descriptor
1580  */
1581 static inline void sdma_unmap_desc(
1582 	struct hfi1_devdata *dd,
1583 	struct sdma_desc *descp)
1584 {
1585 	switch (sdma_mapping_type(descp)) {
1586 	case SDMA_MAP_SINGLE:
1587 		dma_unmap_single(&dd->pcidev->dev, sdma_mapping_addr(descp),
1588 				 sdma_mapping_len(descp), DMA_TO_DEVICE);
1589 		break;
1590 	case SDMA_MAP_PAGE:
1591 		dma_unmap_page(&dd->pcidev->dev, sdma_mapping_addr(descp),
1592 			       sdma_mapping_len(descp), DMA_TO_DEVICE);
1593 		break;
1594 	}
1595 
1596 	if (descp->pinning_ctx && descp->ctx_put)
1597 		descp->ctx_put(descp->pinning_ctx);
1598 	descp->pinning_ctx = NULL;
1599 }
1600 
1601 /*
1602  * return the mode as indicated by the first
1603  * descriptor in the tx.
1604  */
1605 static inline u8 ahg_mode(struct sdma_txreq *tx)
1606 {
1607 	return (tx->descp[0].qw[1] & SDMA_DESC1_HEADER_MODE_SMASK)
1608 		>> SDMA_DESC1_HEADER_MODE_SHIFT;
1609 }
1610 
1611 /**
1612  * __sdma_txclean() - clean tx of mappings, descp *kmalloc's
1613  * @dd: hfi1_devdata for unmapping
1614  * @tx: tx request to clean
1615  *
1616  * This is used in the progress routine to clean the tx or
1617  * by the ULP to toss an in-process tx build.
1618  *
1619  * The code can be called multiple times without issue.
1620  *
1621  */
1622 void __sdma_txclean(
1623 	struct hfi1_devdata *dd,
1624 	struct sdma_txreq *tx)
1625 {
1626 	u16 i;
1627 
1628 	if (tx->num_desc) {
1629 		u8 skip = 0, mode = ahg_mode(tx);
1630 
1631 		/* unmap first */
1632 		sdma_unmap_desc(dd, &tx->descp[0]);
1633 		/* determine number of AHG descriptors to skip */
1634 		if (mode > SDMA_AHG_APPLY_UPDATE1)
1635 			skip = mode >> 1;
1636 		for (i = 1 + skip; i < tx->num_desc; i++)
1637 			sdma_unmap_desc(dd, &tx->descp[i]);
1638 		tx->num_desc = 0;
1639 	}
1640 	kfree(tx->coalesce_buf);
1641 	tx->coalesce_buf = NULL;
1642 	/* kmalloc'ed descp */
1643 	if (unlikely(tx->desc_limit > ARRAY_SIZE(tx->descs))) {
1644 		tx->desc_limit = ARRAY_SIZE(tx->descs);
1645 		kfree(tx->descp);
1646 	}
1647 }
1648 
1649 static inline u16 sdma_gethead(struct sdma_engine *sde)
1650 {
1651 	struct hfi1_devdata *dd = sde->dd;
1652 	int use_dmahead;
1653 	u16 hwhead;
1654 
1655 #ifdef CONFIG_SDMA_VERBOSITY
1656 	dd_dev_err(sde->dd, "CONFIG SDMA(%u) %s:%d %s()\n",
1657 		   sde->this_idx, slashstrip(__FILE__), __LINE__, __func__);
1658 #endif
1659 
1660 retry:
1661 	use_dmahead = HFI1_CAP_IS_KSET(USE_SDMA_HEAD) && __sdma_running(sde) &&
1662 					(dd->flags & HFI1_HAS_SDMA_TIMEOUT);
1663 	hwhead = use_dmahead ?
1664 		(u16)le64_to_cpu(*sde->head_dma) :
1665 		(u16)read_sde_csr(sde, SD(HEAD));
1666 
1667 	if (unlikely(HFI1_CAP_IS_KSET(SDMA_HEAD_CHECK))) {
1668 		u16 cnt;
1669 		u16 swtail;
1670 		u16 swhead;
1671 		int sane;
1672 
1673 		swhead = sde->descq_head & sde->sdma_mask;
1674 		/* this code is really bad for cache line trading */
1675 		swtail = READ_ONCE(sde->descq_tail) & sde->sdma_mask;
1676 		cnt = sde->descq_cnt;
1677 
1678 		if (swhead < swtail)
1679 			/* not wrapped */
1680 			sane = (hwhead >= swhead) & (hwhead <= swtail);
1681 		else if (swhead > swtail)
1682 			/* wrapped around */
1683 			sane = ((hwhead >= swhead) && (hwhead < cnt)) ||
1684 				(hwhead <= swtail);
1685 		else
1686 			/* empty */
1687 			sane = (hwhead == swhead);
1688 
1689 		if (unlikely(!sane)) {
1690 			dd_dev_err(dd, "SDMA(%u) bad head (%s) hwhd=%u swhd=%u swtl=%u cnt=%u\n",
1691 				   sde->this_idx,
1692 				   use_dmahead ? "dma" : "kreg",
1693 				   hwhead, swhead, swtail, cnt);
1694 			if (use_dmahead) {
1695 				/* try one more time, using csr */
1696 				use_dmahead = 0;
1697 				goto retry;
1698 			}
1699 			/* proceed as if no progress */
1700 			hwhead = swhead;
1701 		}
1702 	}
1703 	return hwhead;
1704 }
1705 
1706 /*
1707  * This is called when there are send DMA descriptors that might be
1708  * available.
1709  *
1710  * This is called with head_lock held.
1711  */
1712 static void sdma_desc_avail(struct sdma_engine *sde, uint avail)
1713 {
1714 	struct iowait *wait, *nw, *twait;
1715 	struct iowait *waits[SDMA_WAIT_BATCH_SIZE];
1716 	uint i, n = 0, seq, tidx = 0;
1717 
1718 #ifdef CONFIG_SDMA_VERBOSITY
1719 	dd_dev_err(sde->dd, "CONFIG SDMA(%u) %s:%d %s()\n", sde->this_idx,
1720 		   slashstrip(__FILE__), __LINE__, __func__);
1721 	dd_dev_err(sde->dd, "avail: %u\n", avail);
1722 #endif
1723 
1724 	do {
1725 		seq = read_seqbegin(&sde->waitlock);
1726 		if (!list_empty(&sde->dmawait)) {
1727 			/* at least one item */
1728 			write_seqlock(&sde->waitlock);
1729 			/* Harvest waiters wanting DMA descriptors */
1730 			list_for_each_entry_safe(
1731 					wait,
1732 					nw,
1733 					&sde->dmawait,
1734 					list) {
1735 				u32 num_desc;
1736 
1737 				if (!wait->wakeup)
1738 					continue;
1739 				if (n == ARRAY_SIZE(waits))
1740 					break;
1741 				iowait_init_priority(wait);
1742 				num_desc = iowait_get_all_desc(wait);
1743 				if (num_desc > avail)
1744 					break;
1745 				avail -= num_desc;
1746 				/* Find the top-priority wait memeber */
1747 				if (n) {
1748 					twait = waits[tidx];
1749 					tidx =
1750 					    iowait_priority_update_top(wait,
1751 								       twait,
1752 								       n,
1753 								       tidx);
1754 				}
1755 				list_del_init(&wait->list);
1756 				waits[n++] = wait;
1757 			}
1758 			write_sequnlock(&sde->waitlock);
1759 			break;
1760 		}
1761 	} while (read_seqretry(&sde->waitlock, seq));
1762 
1763 	/* Schedule the top-priority entry first */
1764 	if (n)
1765 		waits[tidx]->wakeup(waits[tidx], SDMA_AVAIL_REASON);
1766 
1767 	for (i = 0; i < n; i++)
1768 		if (i != tidx)
1769 			waits[i]->wakeup(waits[i], SDMA_AVAIL_REASON);
1770 }
1771 
1772 /* head_lock must be held */
1773 static void sdma_make_progress(struct sdma_engine *sde, u64 status)
1774 {
1775 	struct sdma_txreq *txp = NULL;
1776 	int progress = 0;
1777 	u16 hwhead, swhead;
1778 	int idle_check_done = 0;
1779 
1780 	hwhead = sdma_gethead(sde);
1781 
1782 	/* The reason for some of the complexity of this code is that
1783 	 * not all descriptors have corresponding txps.  So, we have to
1784 	 * be able to skip over descs until we wander into the range of
1785 	 * the next txp on the list.
1786 	 */
1787 
1788 retry:
1789 	txp = get_txhead(sde);
1790 	swhead = sde->descq_head & sde->sdma_mask;
1791 	trace_hfi1_sdma_progress(sde, hwhead, swhead, txp);
1792 	while (swhead != hwhead) {
1793 		/* advance head, wrap if needed */
1794 		swhead = ++sde->descq_head & sde->sdma_mask;
1795 
1796 		/* if now past this txp's descs, do the callback */
1797 		if (txp && txp->next_descq_idx == swhead) {
1798 			/* remove from list */
1799 			sde->tx_ring[sde->tx_head++ & sde->sdma_mask] = NULL;
1800 			complete_tx(sde, txp, SDMA_TXREQ_S_OK);
1801 			/* see if there is another txp */
1802 			txp = get_txhead(sde);
1803 		}
1804 		trace_hfi1_sdma_progress(sde, hwhead, swhead, txp);
1805 		progress++;
1806 	}
1807 
1808 	/*
1809 	 * The SDMA idle interrupt is not guaranteed to be ordered with respect
1810 	 * to updates to the dma_head location in host memory. The head
1811 	 * value read might not be fully up to date. If there are pending
1812 	 * descriptors and the SDMA idle interrupt fired then read from the
1813 	 * CSR SDMA head instead to get the latest value from the hardware.
1814 	 * The hardware SDMA head should be read at most once in this invocation
1815 	 * of sdma_make_progress(..) which is ensured by idle_check_done flag
1816 	 */
1817 	if ((status & sde->idle_mask) && !idle_check_done) {
1818 		u16 swtail;
1819 
1820 		swtail = READ_ONCE(sde->descq_tail) & sde->sdma_mask;
1821 		if (swtail != hwhead) {
1822 			hwhead = (u16)read_sde_csr(sde, SD(HEAD));
1823 			idle_check_done = 1;
1824 			goto retry;
1825 		}
1826 	}
1827 
1828 	sde->last_status = status;
1829 	if (progress)
1830 		sdma_desc_avail(sde, sdma_descq_freecnt(sde));
1831 }
1832 
1833 /*
1834  * sdma_engine_interrupt() - interrupt handler for engine
1835  * @sde: sdma engine
1836  * @status: sdma interrupt reason
1837  *
1838  * Status is a mask of the 3 possible interrupts for this engine.  It will
1839  * contain bits _only_ for this SDMA engine.  It will contain at least one
1840  * bit, it may contain more.
1841  */
1842 void sdma_engine_interrupt(struct sdma_engine *sde, u64 status)
1843 {
1844 	trace_hfi1_sdma_engine_interrupt(sde, status);
1845 	write_seqlock(&sde->head_lock);
1846 	sdma_set_desc_cnt(sde, sdma_desct_intr);
1847 	if (status & sde->idle_mask)
1848 		sde->idle_int_cnt++;
1849 	else if (status & sde->progress_mask)
1850 		sde->progress_int_cnt++;
1851 	else if (status & sde->int_mask)
1852 		sde->sdma_int_cnt++;
1853 	sdma_make_progress(sde, status);
1854 	write_sequnlock(&sde->head_lock);
1855 }
1856 
1857 /**
1858  * sdma_engine_error() - error handler for engine
1859  * @sde: sdma engine
1860  * @status: sdma interrupt reason
1861  */
1862 void sdma_engine_error(struct sdma_engine *sde, u64 status)
1863 {
1864 	unsigned long flags;
1865 
1866 #ifdef CONFIG_SDMA_VERBOSITY
1867 	dd_dev_err(sde->dd, "CONFIG SDMA(%u) error status 0x%llx state %s\n",
1868 		   sde->this_idx,
1869 		   (unsigned long long)status,
1870 		   sdma_state_names[sde->state.current_state]);
1871 #endif
1872 	spin_lock_irqsave(&sde->tail_lock, flags);
1873 	write_seqlock(&sde->head_lock);
1874 	if (status & ALL_SDMA_ENG_HALT_ERRS)
1875 		__sdma_process_event(sde, sdma_event_e60_hw_halted);
1876 	if (status & ~SD(ENG_ERR_STATUS_SDMA_HALT_ERR_SMASK)) {
1877 		dd_dev_err(sde->dd,
1878 			   "SDMA (%u) engine error: 0x%llx state %s\n",
1879 			   sde->this_idx,
1880 			   (unsigned long long)status,
1881 			   sdma_state_names[sde->state.current_state]);
1882 		dump_sdma_state(sde);
1883 	}
1884 	write_sequnlock(&sde->head_lock);
1885 	spin_unlock_irqrestore(&sde->tail_lock, flags);
1886 }
1887 
1888 static void sdma_sendctrl(struct sdma_engine *sde, unsigned op)
1889 {
1890 	u64 set_senddmactrl = 0;
1891 	u64 clr_senddmactrl = 0;
1892 	unsigned long flags;
1893 
1894 #ifdef CONFIG_SDMA_VERBOSITY
1895 	dd_dev_err(sde->dd, "CONFIG SDMA(%u) senddmactrl E=%d I=%d H=%d C=%d\n",
1896 		   sde->this_idx,
1897 		   (op & SDMA_SENDCTRL_OP_ENABLE) ? 1 : 0,
1898 		   (op & SDMA_SENDCTRL_OP_INTENABLE) ? 1 : 0,
1899 		   (op & SDMA_SENDCTRL_OP_HALT) ? 1 : 0,
1900 		   (op & SDMA_SENDCTRL_OP_CLEANUP) ? 1 : 0);
1901 #endif
1902 
1903 	if (op & SDMA_SENDCTRL_OP_ENABLE)
1904 		set_senddmactrl |= SD(CTRL_SDMA_ENABLE_SMASK);
1905 	else
1906 		clr_senddmactrl |= SD(CTRL_SDMA_ENABLE_SMASK);
1907 
1908 	if (op & SDMA_SENDCTRL_OP_INTENABLE)
1909 		set_senddmactrl |= SD(CTRL_SDMA_INT_ENABLE_SMASK);
1910 	else
1911 		clr_senddmactrl |= SD(CTRL_SDMA_INT_ENABLE_SMASK);
1912 
1913 	if (op & SDMA_SENDCTRL_OP_HALT)
1914 		set_senddmactrl |= SD(CTRL_SDMA_HALT_SMASK);
1915 	else
1916 		clr_senddmactrl |= SD(CTRL_SDMA_HALT_SMASK);
1917 
1918 	spin_lock_irqsave(&sde->senddmactrl_lock, flags);
1919 
1920 	sde->p_senddmactrl |= set_senddmactrl;
1921 	sde->p_senddmactrl &= ~clr_senddmactrl;
1922 
1923 	if (op & SDMA_SENDCTRL_OP_CLEANUP)
1924 		write_sde_csr(sde, SD(CTRL),
1925 			      sde->p_senddmactrl |
1926 			      SD(CTRL_SDMA_CLEANUP_SMASK));
1927 	else
1928 		write_sde_csr(sde, SD(CTRL), sde->p_senddmactrl);
1929 
1930 	spin_unlock_irqrestore(&sde->senddmactrl_lock, flags);
1931 
1932 #ifdef CONFIG_SDMA_VERBOSITY
1933 	sdma_dumpstate(sde);
1934 #endif
1935 }
1936 
1937 static void sdma_setlengen(struct sdma_engine *sde)
1938 {
1939 #ifdef CONFIG_SDMA_VERBOSITY
1940 	dd_dev_err(sde->dd, "CONFIG SDMA(%u) %s:%d %s()\n",
1941 		   sde->this_idx, slashstrip(__FILE__), __LINE__, __func__);
1942 #endif
1943 
1944 	/*
1945 	 * Set SendDmaLenGen and clear-then-set the MSB of the generation
1946 	 * count to enable generation checking and load the internal
1947 	 * generation counter.
1948 	 */
1949 	write_sde_csr(sde, SD(LEN_GEN),
1950 		      (sde->descq_cnt / 64) << SD(LEN_GEN_LENGTH_SHIFT));
1951 	write_sde_csr(sde, SD(LEN_GEN),
1952 		      ((sde->descq_cnt / 64) << SD(LEN_GEN_LENGTH_SHIFT)) |
1953 		      (4ULL << SD(LEN_GEN_GENERATION_SHIFT)));
1954 }
1955 
1956 static inline void sdma_update_tail(struct sdma_engine *sde, u16 tail)
1957 {
1958 	/* Commit writes to memory and advance the tail on the chip */
1959 	smp_wmb(); /* see get_txhead() */
1960 	writeq(tail, sde->tail_csr);
1961 }
1962 
1963 /*
1964  * This is called when changing to state s10_hw_start_up_halt_wait as
1965  * a result of send buffer errors or send DMA descriptor errors.
1966  */
1967 static void sdma_hw_start_up(struct sdma_engine *sde)
1968 {
1969 	u64 reg;
1970 
1971 #ifdef CONFIG_SDMA_VERBOSITY
1972 	dd_dev_err(sde->dd, "CONFIG SDMA(%u) %s:%d %s()\n",
1973 		   sde->this_idx, slashstrip(__FILE__), __LINE__, __func__);
1974 #endif
1975 
1976 	sdma_setlengen(sde);
1977 	sdma_update_tail(sde, 0); /* Set SendDmaTail */
1978 	*sde->head_dma = 0;
1979 
1980 	reg = SD(ENG_ERR_CLEAR_SDMA_HEADER_REQUEST_FIFO_UNC_ERR_MASK) <<
1981 	      SD(ENG_ERR_CLEAR_SDMA_HEADER_REQUEST_FIFO_UNC_ERR_SHIFT);
1982 	write_sde_csr(sde, SD(ENG_ERR_CLEAR), reg);
1983 }
1984 
1985 /*
1986  * set_sdma_integrity
1987  *
1988  * Set the SEND_DMA_CHECK_ENABLE register for send DMA engine 'sde'.
1989  */
1990 static void set_sdma_integrity(struct sdma_engine *sde)
1991 {
1992 	struct hfi1_devdata *dd = sde->dd;
1993 
1994 	write_sde_csr(sde, SD(CHECK_ENABLE),
1995 		      hfi1_pkt_base_sdma_integrity(dd));
1996 }
1997 
1998 static void init_sdma_regs(
1999 	struct sdma_engine *sde,
2000 	u32 credits,
2001 	uint idle_cnt)
2002 {
2003 	u8 opval, opmask;
2004 #ifdef CONFIG_SDMA_VERBOSITY
2005 	struct hfi1_devdata *dd = sde->dd;
2006 
2007 	dd_dev_err(dd, "CONFIG SDMA(%u) %s:%d %s()\n",
2008 		   sde->this_idx, slashstrip(__FILE__), __LINE__, __func__);
2009 #endif
2010 
2011 	write_sde_csr(sde, SD(BASE_ADDR), sde->descq_phys);
2012 	sdma_setlengen(sde);
2013 	sdma_update_tail(sde, 0); /* Set SendDmaTail */
2014 	write_sde_csr(sde, SD(RELOAD_CNT), idle_cnt);
2015 	write_sde_csr(sde, SD(DESC_CNT), 0);
2016 	write_sde_csr(sde, SD(HEAD_ADDR), sde->head_phys);
2017 	write_sde_csr(sde, SD(MEMORY),
2018 		      ((u64)credits << SD(MEMORY_SDMA_MEMORY_CNT_SHIFT)) |
2019 		      ((u64)(credits * sde->this_idx) <<
2020 		       SD(MEMORY_SDMA_MEMORY_INDEX_SHIFT)));
2021 	write_sde_csr(sde, SD(ENG_ERR_MASK), ~0ull);
2022 	set_sdma_integrity(sde);
2023 	opmask = OPCODE_CHECK_MASK_DISABLED;
2024 	opval = OPCODE_CHECK_VAL_DISABLED;
2025 	write_sde_csr(sde, SD(CHECK_OPCODE),
2026 		      (opmask << SEND_CTXT_CHECK_OPCODE_MASK_SHIFT) |
2027 		      (opval << SEND_CTXT_CHECK_OPCODE_VALUE_SHIFT));
2028 }
2029 
2030 #ifdef CONFIG_SDMA_VERBOSITY
2031 
2032 #define sdma_dumpstate_helper0(reg) do { \
2033 		csr = read_csr(sde->dd, reg); \
2034 		dd_dev_err(sde->dd, "%36s     0x%016llx\n", #reg, csr); \
2035 	} while (0)
2036 
2037 #define sdma_dumpstate_helper(reg) do { \
2038 		csr = read_sde_csr(sde, reg); \
2039 		dd_dev_err(sde->dd, "%36s[%02u] 0x%016llx\n", \
2040 			#reg, sde->this_idx, csr); \
2041 	} while (0)
2042 
2043 #define sdma_dumpstate_helper2(reg) do { \
2044 		csr = read_csr(sde->dd, reg + (8 * i)); \
2045 		dd_dev_err(sde->dd, "%33s_%02u     0x%016llx\n", \
2046 				#reg, i, csr); \
2047 	} while (0)
2048 
2049 void sdma_dumpstate(struct sdma_engine *sde)
2050 {
2051 	u64 csr;
2052 	unsigned i;
2053 
2054 	sdma_dumpstate_helper(SD(CTRL));
2055 	sdma_dumpstate_helper(SD(STATUS));
2056 	sdma_dumpstate_helper0(SD(ERR_STATUS));
2057 	sdma_dumpstate_helper0(SD(ERR_MASK));
2058 	sdma_dumpstate_helper(SD(ENG_ERR_STATUS));
2059 	sdma_dumpstate_helper(SD(ENG_ERR_MASK));
2060 
2061 	for (i = 0; i < CCE_NUM_INT_CSRS; ++i) {
2062 		sdma_dumpstate_helper2(CCE_INT_STATUS);
2063 		sdma_dumpstate_helper2(CCE_INT_MASK);
2064 		sdma_dumpstate_helper2(CCE_INT_BLOCKED);
2065 	}
2066 
2067 	sdma_dumpstate_helper(SD(TAIL));
2068 	sdma_dumpstate_helper(SD(HEAD));
2069 	sdma_dumpstate_helper(SD(PRIORITY_THLD));
2070 	sdma_dumpstate_helper(SD(IDLE_CNT));
2071 	sdma_dumpstate_helper(SD(RELOAD_CNT));
2072 	sdma_dumpstate_helper(SD(DESC_CNT));
2073 	sdma_dumpstate_helper(SD(DESC_FETCHED_CNT));
2074 	sdma_dumpstate_helper(SD(MEMORY));
2075 	sdma_dumpstate_helper0(SD(ENGINES));
2076 	sdma_dumpstate_helper0(SD(MEM_SIZE));
2077 	/* sdma_dumpstate_helper(SEND_EGRESS_SEND_DMA_STATUS);  */
2078 	sdma_dumpstate_helper(SD(BASE_ADDR));
2079 	sdma_dumpstate_helper(SD(LEN_GEN));
2080 	sdma_dumpstate_helper(SD(HEAD_ADDR));
2081 	sdma_dumpstate_helper(SD(CHECK_ENABLE));
2082 	sdma_dumpstate_helper(SD(CHECK_VL));
2083 	sdma_dumpstate_helper(SD(CHECK_JOB_KEY));
2084 	sdma_dumpstate_helper(SD(CHECK_PARTITION_KEY));
2085 	sdma_dumpstate_helper(SD(CHECK_SLID));
2086 	sdma_dumpstate_helper(SD(CHECK_OPCODE));
2087 }
2088 #endif
2089 
2090 static void dump_sdma_state(struct sdma_engine *sde)
2091 {
2092 	struct hw_sdma_desc *descqp;
2093 	u64 desc[2];
2094 	u64 addr;
2095 	u8 gen;
2096 	u16 len;
2097 	u16 head, tail, cnt;
2098 
2099 	head = sde->descq_head & sde->sdma_mask;
2100 	tail = sde->descq_tail & sde->sdma_mask;
2101 	cnt = sdma_descq_freecnt(sde);
2102 
2103 	dd_dev_err(sde->dd,
2104 		   "SDMA (%u) descq_head: %u descq_tail: %u freecnt: %u FLE %d\n",
2105 		   sde->this_idx, head, tail, cnt,
2106 		   !list_empty(&sde->flushlist));
2107 
2108 	/* print info for each entry in the descriptor queue */
2109 	while (head != tail) {
2110 		char flags[6] = { 'x', 'x', 'x', 'x', 0 };
2111 
2112 		descqp = &sde->descq[head];
2113 		desc[0] = le64_to_cpu(descqp->qw[0]);
2114 		desc[1] = le64_to_cpu(descqp->qw[1]);
2115 		flags[0] = (desc[1] & SDMA_DESC1_INT_REQ_FLAG) ? 'I' : '-';
2116 		flags[1] = (desc[1] & SDMA_DESC1_HEAD_TO_HOST_FLAG) ?
2117 				'H' : '-';
2118 		flags[2] = (desc[0] & SDMA_DESC0_FIRST_DESC_FLAG) ? 'F' : '-';
2119 		flags[3] = (desc[0] & SDMA_DESC0_LAST_DESC_FLAG) ? 'L' : '-';
2120 		addr = (desc[0] >> SDMA_DESC0_PHY_ADDR_SHIFT)
2121 			& SDMA_DESC0_PHY_ADDR_MASK;
2122 		gen = (desc[1] >> SDMA_DESC1_GENERATION_SHIFT)
2123 			& SDMA_DESC1_GENERATION_MASK;
2124 		len = (desc[0] >> SDMA_DESC0_BYTE_COUNT_SHIFT)
2125 			& SDMA_DESC0_BYTE_COUNT_MASK;
2126 		dd_dev_err(sde->dd,
2127 			   "SDMA sdmadesc[%u]: flags:%s addr:0x%016llx gen:%u len:%u bytes\n",
2128 			   head, flags, addr, gen, len);
2129 		dd_dev_err(sde->dd,
2130 			   "\tdesc0:0x%016llx desc1 0x%016llx\n",
2131 			   desc[0], desc[1]);
2132 		if (desc[0] & SDMA_DESC0_FIRST_DESC_FLAG)
2133 			dd_dev_err(sde->dd,
2134 				   "\taidx: %u amode: %u alen: %u\n",
2135 				   (u8)((desc[1] &
2136 					 SDMA_DESC1_HEADER_INDEX_SMASK) >>
2137 					SDMA_DESC1_HEADER_INDEX_SHIFT),
2138 				   (u8)((desc[1] &
2139 					 SDMA_DESC1_HEADER_MODE_SMASK) >>
2140 					SDMA_DESC1_HEADER_MODE_SHIFT),
2141 				   (u8)((desc[1] &
2142 					 SDMA_DESC1_HEADER_DWS_SMASK) >>
2143 					SDMA_DESC1_HEADER_DWS_SHIFT));
2144 		head++;
2145 		head &= sde->sdma_mask;
2146 	}
2147 }
2148 
2149 #define SDE_FMT \
2150 	"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"
2151 /**
2152  * sdma_seqfile_dump_sde() - debugfs dump of sde
2153  * @s: seq file
2154  * @sde: send dma engine to dump
2155  *
2156  * This routine dumps the sde to the indicated seq file.
2157  */
2158 void sdma_seqfile_dump_sde(struct seq_file *s, struct sdma_engine *sde)
2159 {
2160 	u16 head, tail;
2161 	struct hw_sdma_desc *descqp;
2162 	u64 desc[2];
2163 	u64 addr;
2164 	u8 gen;
2165 	u16 len;
2166 
2167 	head = sde->descq_head & sde->sdma_mask;
2168 	tail = READ_ONCE(sde->descq_tail) & sde->sdma_mask;
2169 	seq_printf(s, SDE_FMT, sde->this_idx,
2170 		   sde->cpu,
2171 		   sdma_state_name(sde->state.current_state),
2172 		   (unsigned long long)read_sde_csr(sde, SD(CTRL)),
2173 		   (unsigned long long)read_sde_csr(sde, SD(STATUS)),
2174 		   (unsigned long long)read_sde_csr(sde, SD(ENG_ERR_STATUS)),
2175 		   (unsigned long long)read_sde_csr(sde, SD(TAIL)), tail,
2176 		   (unsigned long long)read_sde_csr(sde, SD(HEAD)), head,
2177 		   (unsigned long long)le64_to_cpu(*sde->head_dma),
2178 		   (unsigned long long)read_sde_csr(sde, SD(MEMORY)),
2179 		   (unsigned long long)read_sde_csr(sde, SD(LEN_GEN)),
2180 		   (unsigned long long)read_sde_csr(sde, SD(RELOAD_CNT)),
2181 		   (unsigned long long)sde->last_status,
2182 		   (unsigned long long)sde->ahg_bits,
2183 		   sde->tx_tail,
2184 		   sde->tx_head,
2185 		   sde->descq_tail,
2186 		   sde->descq_head,
2187 		   !list_empty(&sde->flushlist),
2188 		   sde->descq_full_count,
2189 		   (unsigned long long)read_sde_csr(sde, SEND_DMA_CHECK_SLID));
2190 
2191 	/* print info for each entry in the descriptor queue */
2192 	while (head != tail) {
2193 		char flags[6] = { 'x', 'x', 'x', 'x', 0 };
2194 
2195 		descqp = &sde->descq[head];
2196 		desc[0] = le64_to_cpu(descqp->qw[0]);
2197 		desc[1] = le64_to_cpu(descqp->qw[1]);
2198 		flags[0] = (desc[1] & SDMA_DESC1_INT_REQ_FLAG) ? 'I' : '-';
2199 		flags[1] = (desc[1] & SDMA_DESC1_HEAD_TO_HOST_FLAG) ?
2200 				'H' : '-';
2201 		flags[2] = (desc[0] & SDMA_DESC0_FIRST_DESC_FLAG) ? 'F' : '-';
2202 		flags[3] = (desc[0] & SDMA_DESC0_LAST_DESC_FLAG) ? 'L' : '-';
2203 		addr = (desc[0] >> SDMA_DESC0_PHY_ADDR_SHIFT)
2204 			& SDMA_DESC0_PHY_ADDR_MASK;
2205 		gen = (desc[1] >> SDMA_DESC1_GENERATION_SHIFT)
2206 			& SDMA_DESC1_GENERATION_MASK;
2207 		len = (desc[0] >> SDMA_DESC0_BYTE_COUNT_SHIFT)
2208 			& SDMA_DESC0_BYTE_COUNT_MASK;
2209 		seq_printf(s,
2210 			   "\tdesc[%u]: flags:%s addr:0x%016llx gen:%u len:%u bytes\n",
2211 			   head, flags, addr, gen, len);
2212 		if (desc[0] & SDMA_DESC0_FIRST_DESC_FLAG)
2213 			seq_printf(s, "\t\tahgidx: %u ahgmode: %u\n",
2214 				   (u8)((desc[1] &
2215 					 SDMA_DESC1_HEADER_INDEX_SMASK) >>
2216 					SDMA_DESC1_HEADER_INDEX_SHIFT),
2217 				   (u8)((desc[1] &
2218 					 SDMA_DESC1_HEADER_MODE_SMASK) >>
2219 					SDMA_DESC1_HEADER_MODE_SHIFT));
2220 		head = (head + 1) & sde->sdma_mask;
2221 	}
2222 }
2223 
2224 /*
2225  * add the generation number into
2226  * the qw1 and return
2227  */
2228 static inline u64 add_gen(struct sdma_engine *sde, u64 qw1)
2229 {
2230 	u8 generation = (sde->descq_tail >> sde->sdma_shift) & 3;
2231 
2232 	qw1 &= ~SDMA_DESC1_GENERATION_SMASK;
2233 	qw1 |= ((u64)generation & SDMA_DESC1_GENERATION_MASK)
2234 			<< SDMA_DESC1_GENERATION_SHIFT;
2235 	return qw1;
2236 }
2237 
2238 /*
2239  * This routine submits the indicated tx
2240  *
2241  * Space has already been guaranteed and
2242  * tail side of ring is locked.
2243  *
2244  * The hardware tail update is done
2245  * in the caller and that is facilitated
2246  * by returning the new tail.
2247  *
2248  * There is special case logic for ahg
2249  * to not add the generation number for
2250  * up to 2 descriptors that follow the
2251  * first descriptor.
2252  *
2253  */
2254 static inline u16 submit_tx(struct sdma_engine *sde, struct sdma_txreq *tx)
2255 {
2256 	int i;
2257 	u16 tail;
2258 	struct sdma_desc *descp = tx->descp;
2259 	u8 skip = 0, mode = ahg_mode(tx);
2260 
2261 	tail = sde->descq_tail & sde->sdma_mask;
2262 	sde->descq[tail].qw[0] = cpu_to_le64(descp->qw[0]);
2263 	sde->descq[tail].qw[1] = cpu_to_le64(add_gen(sde, descp->qw[1]));
2264 	trace_hfi1_sdma_descriptor(sde, descp->qw[0], descp->qw[1],
2265 				   tail, &sde->descq[tail]);
2266 	tail = ++sde->descq_tail & sde->sdma_mask;
2267 	descp++;
2268 	if (mode > SDMA_AHG_APPLY_UPDATE1)
2269 		skip = mode >> 1;
2270 	for (i = 1; i < tx->num_desc; i++, descp++) {
2271 		u64 qw1;
2272 
2273 		sde->descq[tail].qw[0] = cpu_to_le64(descp->qw[0]);
2274 		if (skip) {
2275 			/* edits don't have generation */
2276 			qw1 = descp->qw[1];
2277 			skip--;
2278 		} else {
2279 			/* replace generation with real one for non-edits */
2280 			qw1 = add_gen(sde, descp->qw[1]);
2281 		}
2282 		sde->descq[tail].qw[1] = cpu_to_le64(qw1);
2283 		trace_hfi1_sdma_descriptor(sde, descp->qw[0], qw1,
2284 					   tail, &sde->descq[tail]);
2285 		tail = ++sde->descq_tail & sde->sdma_mask;
2286 	}
2287 	tx->next_descq_idx = tail;
2288 #ifdef CONFIG_HFI1_DEBUG_SDMA_ORDER
2289 	tx->sn = sde->tail_sn++;
2290 	trace_hfi1_sdma_in_sn(sde, tx->sn);
2291 	WARN_ON_ONCE(sde->tx_ring[sde->tx_tail & sde->sdma_mask]);
2292 #endif
2293 	sde->tx_ring[sde->tx_tail++ & sde->sdma_mask] = tx;
2294 	sde->desc_avail -= tx->num_desc;
2295 	return tail;
2296 }
2297 
2298 /*
2299  * Check for progress
2300  */
2301 static int sdma_check_progress(
2302 	struct sdma_engine *sde,
2303 	struct iowait_work *wait,
2304 	struct sdma_txreq *tx,
2305 	bool pkts_sent)
2306 {
2307 	int ret;
2308 
2309 	sde->desc_avail = sdma_descq_freecnt(sde);
2310 	if (tx->num_desc <= sde->desc_avail)
2311 		return -EAGAIN;
2312 	/* pulse the head_lock */
2313 	if (wait && iowait_ioww_to_iow(wait)->sleep) {
2314 		unsigned seq;
2315 
2316 		seq = raw_seqcount_begin(
2317 			(const seqcount_t *)&sde->head_lock.seqcount);
2318 		ret = wait->iow->sleep(sde, wait, tx, seq, pkts_sent);
2319 		if (ret == -EAGAIN)
2320 			sde->desc_avail = sdma_descq_freecnt(sde);
2321 	} else {
2322 		ret = -EBUSY;
2323 	}
2324 	return ret;
2325 }
2326 
2327 /**
2328  * sdma_send_txreq() - submit a tx req to ring
2329  * @sde: sdma engine to use
2330  * @wait: SE wait structure to use when full (may be NULL)
2331  * @tx: sdma_txreq to submit
2332  * @pkts_sent: has any packet been sent yet?
2333  *
2334  * The call submits the tx into the ring.  If a iowait structure is non-NULL
2335  * the packet will be queued to the list in wait.
2336  *
2337  * Return:
2338  * 0 - Success, -EINVAL - sdma_txreq incomplete, -EBUSY - no space in
2339  * ring (wait == NULL)
2340  * -EIOCBQUEUED - tx queued to iowait, -ECOMM bad sdma state
2341  */
2342 int sdma_send_txreq(struct sdma_engine *sde,
2343 		    struct iowait_work *wait,
2344 		    struct sdma_txreq *tx,
2345 		    bool pkts_sent)
2346 {
2347 	int ret = 0;
2348 	u16 tail;
2349 	unsigned long flags;
2350 
2351 	/* user should have supplied entire packet */
2352 	if (unlikely(tx->tlen))
2353 		return -EINVAL;
2354 	tx->wait = iowait_ioww_to_iow(wait);
2355 	spin_lock_irqsave(&sde->tail_lock, flags);
2356 retry:
2357 	if (unlikely(!__sdma_running(sde)))
2358 		goto unlock_noconn;
2359 	if (unlikely(tx->num_desc > sde->desc_avail))
2360 		goto nodesc;
2361 	tail = submit_tx(sde, tx);
2362 	if (wait)
2363 		iowait_sdma_inc(iowait_ioww_to_iow(wait));
2364 	sdma_update_tail(sde, tail);
2365 unlock:
2366 	spin_unlock_irqrestore(&sde->tail_lock, flags);
2367 	return ret;
2368 unlock_noconn:
2369 	if (wait)
2370 		iowait_sdma_inc(iowait_ioww_to_iow(wait));
2371 	tx->next_descq_idx = 0;
2372 #ifdef CONFIG_HFI1_DEBUG_SDMA_ORDER
2373 	tx->sn = sde->tail_sn++;
2374 	trace_hfi1_sdma_in_sn(sde, tx->sn);
2375 #endif
2376 	spin_lock(&sde->flushlist_lock);
2377 	list_add_tail(&tx->list, &sde->flushlist);
2378 	spin_unlock(&sde->flushlist_lock);
2379 	iowait_inc_wait_count(wait, tx->num_desc);
2380 	queue_work_on(sde->cpu, system_highpri_wq, &sde->flush_worker);
2381 	ret = -ECOMM;
2382 	goto unlock;
2383 nodesc:
2384 	ret = sdma_check_progress(sde, wait, tx, pkts_sent);
2385 	if (ret == -EAGAIN) {
2386 		ret = 0;
2387 		goto retry;
2388 	}
2389 	sde->descq_full_count++;
2390 	goto unlock;
2391 }
2392 
2393 /**
2394  * sdma_send_txlist() - submit a list of tx req to ring
2395  * @sde: sdma engine to use
2396  * @wait: SE wait structure to use when full (may be NULL)
2397  * @tx_list: list of sdma_txreqs to submit
2398  * @count_out: pointer to a u16 which, after return will contain the total number of
2399  *             sdma_txreqs removed from the tx_list. This will include sdma_txreqs
2400  *             whose SDMA descriptors are submitted to the ring and the sdma_txreqs
2401  *             which are added to SDMA engine flush list if the SDMA engine state is
2402  *             not running.
2403  *
2404  * The call submits the list into the ring.
2405  *
2406  * If the iowait structure is non-NULL and not equal to the iowait list
2407  * the unprocessed part of the list  will be appended to the list in wait.
2408  *
2409  * In all cases, the tx_list will be updated so the head of the tx_list is
2410  * the list of descriptors that have yet to be transmitted.
2411  *
2412  * The intent of this call is to provide a more efficient
2413  * way of submitting multiple packets to SDMA while holding the tail
2414  * side locking.
2415  *
2416  * Return:
2417  * 0 - Success,
2418  * -EINVAL - sdma_txreq incomplete, -EBUSY - no space in ring (wait == NULL)
2419  * -EIOCBQUEUED - tx queued to iowait, -ECOMM bad sdma state
2420  */
2421 int sdma_send_txlist(struct sdma_engine *sde, struct iowait_work *wait,
2422 		     struct list_head *tx_list, u16 *count_out)
2423 {
2424 	struct sdma_txreq *tx, *tx_next;
2425 	int ret = 0;
2426 	unsigned long flags;
2427 	u16 tail = INVALID_TAIL;
2428 	u32 submit_count = 0, flush_count = 0, total_count;
2429 
2430 	spin_lock_irqsave(&sde->tail_lock, flags);
2431 retry:
2432 	list_for_each_entry_safe(tx, tx_next, tx_list, list) {
2433 		tx->wait = iowait_ioww_to_iow(wait);
2434 		if (unlikely(!__sdma_running(sde)))
2435 			goto unlock_noconn;
2436 		if (unlikely(tx->num_desc > sde->desc_avail))
2437 			goto nodesc;
2438 		if (unlikely(tx->tlen)) {
2439 			ret = -EINVAL;
2440 			goto update_tail;
2441 		}
2442 		list_del_init(&tx->list);
2443 		tail = submit_tx(sde, tx);
2444 		submit_count++;
2445 		if (tail != INVALID_TAIL &&
2446 		    (submit_count & SDMA_TAIL_UPDATE_THRESH) == 0) {
2447 			sdma_update_tail(sde, tail);
2448 			tail = INVALID_TAIL;
2449 		}
2450 	}
2451 update_tail:
2452 	total_count = submit_count + flush_count;
2453 	if (wait) {
2454 		iowait_sdma_add(iowait_ioww_to_iow(wait), total_count);
2455 		iowait_starve_clear(submit_count > 0,
2456 				    iowait_ioww_to_iow(wait));
2457 	}
2458 	if (tail != INVALID_TAIL)
2459 		sdma_update_tail(sde, tail);
2460 	spin_unlock_irqrestore(&sde->tail_lock, flags);
2461 	*count_out = total_count;
2462 	return ret;
2463 unlock_noconn:
2464 	spin_lock(&sde->flushlist_lock);
2465 	list_for_each_entry_safe(tx, tx_next, tx_list, list) {
2466 		tx->wait = iowait_ioww_to_iow(wait);
2467 		list_del_init(&tx->list);
2468 		tx->next_descq_idx = 0;
2469 #ifdef CONFIG_HFI1_DEBUG_SDMA_ORDER
2470 		tx->sn = sde->tail_sn++;
2471 		trace_hfi1_sdma_in_sn(sde, tx->sn);
2472 #endif
2473 		list_add_tail(&tx->list, &sde->flushlist);
2474 		flush_count++;
2475 		iowait_inc_wait_count(wait, tx->num_desc);
2476 	}
2477 	spin_unlock(&sde->flushlist_lock);
2478 	queue_work_on(sde->cpu, system_highpri_wq, &sde->flush_worker);
2479 	ret = -ECOMM;
2480 	goto update_tail;
2481 nodesc:
2482 	ret = sdma_check_progress(sde, wait, tx, submit_count > 0);
2483 	if (ret == -EAGAIN) {
2484 		ret = 0;
2485 		goto retry;
2486 	}
2487 	sde->descq_full_count++;
2488 	goto update_tail;
2489 }
2490 
2491 static void sdma_process_event(struct sdma_engine *sde, enum sdma_events event)
2492 {
2493 	unsigned long flags;
2494 
2495 	spin_lock_irqsave(&sde->tail_lock, flags);
2496 	write_seqlock(&sde->head_lock);
2497 
2498 	__sdma_process_event(sde, event);
2499 
2500 	if (sde->state.current_state == sdma_state_s99_running)
2501 		sdma_desc_avail(sde, sdma_descq_freecnt(sde));
2502 
2503 	write_sequnlock(&sde->head_lock);
2504 	spin_unlock_irqrestore(&sde->tail_lock, flags);
2505 }
2506 
2507 static void __sdma_process_event(struct sdma_engine *sde,
2508 				 enum sdma_events event)
2509 {
2510 	struct sdma_state *ss = &sde->state;
2511 	int need_progress = 0;
2512 
2513 	/* CONFIG SDMA temporary */
2514 #ifdef CONFIG_SDMA_VERBOSITY
2515 	dd_dev_err(sde->dd, "CONFIG SDMA(%u) [%s] %s\n", sde->this_idx,
2516 		   sdma_state_names[ss->current_state],
2517 		   sdma_event_names[event]);
2518 #endif
2519 
2520 	switch (ss->current_state) {
2521 	case sdma_state_s00_hw_down:
2522 		switch (event) {
2523 		case sdma_event_e00_go_hw_down:
2524 			break;
2525 		case sdma_event_e30_go_running:
2526 			/*
2527 			 * If down, but running requested (usually result
2528 			 * of link up, then we need to start up.
2529 			 * This can happen when hw down is requested while
2530 			 * bringing the link up with traffic active on
2531 			 * 7220, e.g.
2532 			 */
2533 			ss->go_s99_running = 1;
2534 			fallthrough;	/* and start dma engine */
2535 		case sdma_event_e10_go_hw_start:
2536 			/* This reference means the state machine is started */
2537 			sdma_get(&sde->state);
2538 			sdma_set_state(sde,
2539 				       sdma_state_s10_hw_start_up_halt_wait);
2540 			break;
2541 		case sdma_event_e15_hw_halt_done:
2542 			break;
2543 		case sdma_event_e25_hw_clean_up_done:
2544 			break;
2545 		case sdma_event_e40_sw_cleaned:
2546 			sdma_sw_tear_down(sde);
2547 			break;
2548 		case sdma_event_e50_hw_cleaned:
2549 			break;
2550 		case sdma_event_e60_hw_halted:
2551 			break;
2552 		case sdma_event_e70_go_idle:
2553 			break;
2554 		case sdma_event_e80_hw_freeze:
2555 			break;
2556 		case sdma_event_e81_hw_frozen:
2557 			break;
2558 		case sdma_event_e82_hw_unfreeze:
2559 			break;
2560 		case sdma_event_e85_link_down:
2561 			break;
2562 		case sdma_event_e90_sw_halted:
2563 			break;
2564 		}
2565 		break;
2566 
2567 	case sdma_state_s10_hw_start_up_halt_wait:
2568 		switch (event) {
2569 		case sdma_event_e00_go_hw_down:
2570 			sdma_set_state(sde, sdma_state_s00_hw_down);
2571 			sdma_sw_tear_down(sde);
2572 			break;
2573 		case sdma_event_e10_go_hw_start:
2574 			break;
2575 		case sdma_event_e15_hw_halt_done:
2576 			sdma_set_state(sde,
2577 				       sdma_state_s15_hw_start_up_clean_wait);
2578 			sdma_start_hw_clean_up(sde);
2579 			break;
2580 		case sdma_event_e25_hw_clean_up_done:
2581 			break;
2582 		case sdma_event_e30_go_running:
2583 			ss->go_s99_running = 1;
2584 			break;
2585 		case sdma_event_e40_sw_cleaned:
2586 			break;
2587 		case sdma_event_e50_hw_cleaned:
2588 			break;
2589 		case sdma_event_e60_hw_halted:
2590 			schedule_work(&sde->err_halt_worker);
2591 			break;
2592 		case sdma_event_e70_go_idle:
2593 			ss->go_s99_running = 0;
2594 			break;
2595 		case sdma_event_e80_hw_freeze:
2596 			break;
2597 		case sdma_event_e81_hw_frozen:
2598 			break;
2599 		case sdma_event_e82_hw_unfreeze:
2600 			break;
2601 		case sdma_event_e85_link_down:
2602 			break;
2603 		case sdma_event_e90_sw_halted:
2604 			break;
2605 		}
2606 		break;
2607 
2608 	case sdma_state_s15_hw_start_up_clean_wait:
2609 		switch (event) {
2610 		case sdma_event_e00_go_hw_down:
2611 			sdma_set_state(sde, sdma_state_s00_hw_down);
2612 			sdma_sw_tear_down(sde);
2613 			break;
2614 		case sdma_event_e10_go_hw_start:
2615 			break;
2616 		case sdma_event_e15_hw_halt_done:
2617 			break;
2618 		case sdma_event_e25_hw_clean_up_done:
2619 			sdma_hw_start_up(sde);
2620 			sdma_set_state(sde, ss->go_s99_running ?
2621 				       sdma_state_s99_running :
2622 				       sdma_state_s20_idle);
2623 			break;
2624 		case sdma_event_e30_go_running:
2625 			ss->go_s99_running = 1;
2626 			break;
2627 		case sdma_event_e40_sw_cleaned:
2628 			break;
2629 		case sdma_event_e50_hw_cleaned:
2630 			break;
2631 		case sdma_event_e60_hw_halted:
2632 			break;
2633 		case sdma_event_e70_go_idle:
2634 			ss->go_s99_running = 0;
2635 			break;
2636 		case sdma_event_e80_hw_freeze:
2637 			break;
2638 		case sdma_event_e81_hw_frozen:
2639 			break;
2640 		case sdma_event_e82_hw_unfreeze:
2641 			break;
2642 		case sdma_event_e85_link_down:
2643 			break;
2644 		case sdma_event_e90_sw_halted:
2645 			break;
2646 		}
2647 		break;
2648 
2649 	case sdma_state_s20_idle:
2650 		switch (event) {
2651 		case sdma_event_e00_go_hw_down:
2652 			sdma_set_state(sde, sdma_state_s00_hw_down);
2653 			sdma_sw_tear_down(sde);
2654 			break;
2655 		case sdma_event_e10_go_hw_start:
2656 			break;
2657 		case sdma_event_e15_hw_halt_done:
2658 			break;
2659 		case sdma_event_e25_hw_clean_up_done:
2660 			break;
2661 		case sdma_event_e30_go_running:
2662 			sdma_set_state(sde, sdma_state_s99_running);
2663 			ss->go_s99_running = 1;
2664 			break;
2665 		case sdma_event_e40_sw_cleaned:
2666 			break;
2667 		case sdma_event_e50_hw_cleaned:
2668 			break;
2669 		case sdma_event_e60_hw_halted:
2670 			sdma_set_state(sde, sdma_state_s50_hw_halt_wait);
2671 			schedule_work(&sde->err_halt_worker);
2672 			break;
2673 		case sdma_event_e70_go_idle:
2674 			break;
2675 		case sdma_event_e85_link_down:
2676 		case sdma_event_e80_hw_freeze:
2677 			sdma_set_state(sde, sdma_state_s80_hw_freeze);
2678 			atomic_dec(&sde->dd->sdma_unfreeze_count);
2679 			wake_up_interruptible(&sde->dd->sdma_unfreeze_wq);
2680 			break;
2681 		case sdma_event_e81_hw_frozen:
2682 			break;
2683 		case sdma_event_e82_hw_unfreeze:
2684 			break;
2685 		case sdma_event_e90_sw_halted:
2686 			break;
2687 		}
2688 		break;
2689 
2690 	case sdma_state_s30_sw_clean_up_wait:
2691 		switch (event) {
2692 		case sdma_event_e00_go_hw_down:
2693 			sdma_set_state(sde, sdma_state_s00_hw_down);
2694 			break;
2695 		case sdma_event_e10_go_hw_start:
2696 			break;
2697 		case sdma_event_e15_hw_halt_done:
2698 			break;
2699 		case sdma_event_e25_hw_clean_up_done:
2700 			break;
2701 		case sdma_event_e30_go_running:
2702 			ss->go_s99_running = 1;
2703 			break;
2704 		case sdma_event_e40_sw_cleaned:
2705 			sdma_set_state(sde, sdma_state_s40_hw_clean_up_wait);
2706 			sdma_start_hw_clean_up(sde);
2707 			break;
2708 		case sdma_event_e50_hw_cleaned:
2709 			break;
2710 		case sdma_event_e60_hw_halted:
2711 			break;
2712 		case sdma_event_e70_go_idle:
2713 			ss->go_s99_running = 0;
2714 			break;
2715 		case sdma_event_e80_hw_freeze:
2716 			break;
2717 		case sdma_event_e81_hw_frozen:
2718 			break;
2719 		case sdma_event_e82_hw_unfreeze:
2720 			break;
2721 		case sdma_event_e85_link_down:
2722 			ss->go_s99_running = 0;
2723 			break;
2724 		case sdma_event_e90_sw_halted:
2725 			break;
2726 		}
2727 		break;
2728 
2729 	case sdma_state_s40_hw_clean_up_wait:
2730 		switch (event) {
2731 		case sdma_event_e00_go_hw_down:
2732 			sdma_set_state(sde, sdma_state_s00_hw_down);
2733 			tasklet_hi_schedule(&sde->sdma_sw_clean_up_task);
2734 			break;
2735 		case sdma_event_e10_go_hw_start:
2736 			break;
2737 		case sdma_event_e15_hw_halt_done:
2738 			break;
2739 		case sdma_event_e25_hw_clean_up_done:
2740 			sdma_hw_start_up(sde);
2741 			sdma_set_state(sde, ss->go_s99_running ?
2742 				       sdma_state_s99_running :
2743 				       sdma_state_s20_idle);
2744 			break;
2745 		case sdma_event_e30_go_running:
2746 			ss->go_s99_running = 1;
2747 			break;
2748 		case sdma_event_e40_sw_cleaned:
2749 			break;
2750 		case sdma_event_e50_hw_cleaned:
2751 			break;
2752 		case sdma_event_e60_hw_halted:
2753 			break;
2754 		case sdma_event_e70_go_idle:
2755 			ss->go_s99_running = 0;
2756 			break;
2757 		case sdma_event_e80_hw_freeze:
2758 			break;
2759 		case sdma_event_e81_hw_frozen:
2760 			break;
2761 		case sdma_event_e82_hw_unfreeze:
2762 			break;
2763 		case sdma_event_e85_link_down:
2764 			ss->go_s99_running = 0;
2765 			break;
2766 		case sdma_event_e90_sw_halted:
2767 			break;
2768 		}
2769 		break;
2770 
2771 	case sdma_state_s50_hw_halt_wait:
2772 		switch (event) {
2773 		case sdma_event_e00_go_hw_down:
2774 			sdma_set_state(sde, sdma_state_s00_hw_down);
2775 			tasklet_hi_schedule(&sde->sdma_sw_clean_up_task);
2776 			break;
2777 		case sdma_event_e10_go_hw_start:
2778 			break;
2779 		case sdma_event_e15_hw_halt_done:
2780 			sdma_set_state(sde, sdma_state_s30_sw_clean_up_wait);
2781 			tasklet_hi_schedule(&sde->sdma_sw_clean_up_task);
2782 			break;
2783 		case sdma_event_e25_hw_clean_up_done:
2784 			break;
2785 		case sdma_event_e30_go_running:
2786 			ss->go_s99_running = 1;
2787 			break;
2788 		case sdma_event_e40_sw_cleaned:
2789 			break;
2790 		case sdma_event_e50_hw_cleaned:
2791 			break;
2792 		case sdma_event_e60_hw_halted:
2793 			schedule_work(&sde->err_halt_worker);
2794 			break;
2795 		case sdma_event_e70_go_idle:
2796 			ss->go_s99_running = 0;
2797 			break;
2798 		case sdma_event_e80_hw_freeze:
2799 			break;
2800 		case sdma_event_e81_hw_frozen:
2801 			break;
2802 		case sdma_event_e82_hw_unfreeze:
2803 			break;
2804 		case sdma_event_e85_link_down:
2805 			ss->go_s99_running = 0;
2806 			break;
2807 		case sdma_event_e90_sw_halted:
2808 			break;
2809 		}
2810 		break;
2811 
2812 	case sdma_state_s60_idle_halt_wait:
2813 		switch (event) {
2814 		case sdma_event_e00_go_hw_down:
2815 			sdma_set_state(sde, sdma_state_s00_hw_down);
2816 			tasklet_hi_schedule(&sde->sdma_sw_clean_up_task);
2817 			break;
2818 		case sdma_event_e10_go_hw_start:
2819 			break;
2820 		case sdma_event_e15_hw_halt_done:
2821 			sdma_set_state(sde, sdma_state_s30_sw_clean_up_wait);
2822 			tasklet_hi_schedule(&sde->sdma_sw_clean_up_task);
2823 			break;
2824 		case sdma_event_e25_hw_clean_up_done:
2825 			break;
2826 		case sdma_event_e30_go_running:
2827 			ss->go_s99_running = 1;
2828 			break;
2829 		case sdma_event_e40_sw_cleaned:
2830 			break;
2831 		case sdma_event_e50_hw_cleaned:
2832 			break;
2833 		case sdma_event_e60_hw_halted:
2834 			schedule_work(&sde->err_halt_worker);
2835 			break;
2836 		case sdma_event_e70_go_idle:
2837 			ss->go_s99_running = 0;
2838 			break;
2839 		case sdma_event_e80_hw_freeze:
2840 			break;
2841 		case sdma_event_e81_hw_frozen:
2842 			break;
2843 		case sdma_event_e82_hw_unfreeze:
2844 			break;
2845 		case sdma_event_e85_link_down:
2846 			break;
2847 		case sdma_event_e90_sw_halted:
2848 			break;
2849 		}
2850 		break;
2851 
2852 	case sdma_state_s80_hw_freeze:
2853 		switch (event) {
2854 		case sdma_event_e00_go_hw_down:
2855 			sdma_set_state(sde, sdma_state_s00_hw_down);
2856 			tasklet_hi_schedule(&sde->sdma_sw_clean_up_task);
2857 			break;
2858 		case sdma_event_e10_go_hw_start:
2859 			break;
2860 		case sdma_event_e15_hw_halt_done:
2861 			break;
2862 		case sdma_event_e25_hw_clean_up_done:
2863 			break;
2864 		case sdma_event_e30_go_running:
2865 			ss->go_s99_running = 1;
2866 			break;
2867 		case sdma_event_e40_sw_cleaned:
2868 			break;
2869 		case sdma_event_e50_hw_cleaned:
2870 			break;
2871 		case sdma_event_e60_hw_halted:
2872 			break;
2873 		case sdma_event_e70_go_idle:
2874 			ss->go_s99_running = 0;
2875 			break;
2876 		case sdma_event_e80_hw_freeze:
2877 			break;
2878 		case sdma_event_e81_hw_frozen:
2879 			sdma_set_state(sde, sdma_state_s82_freeze_sw_clean);
2880 			tasklet_hi_schedule(&sde->sdma_sw_clean_up_task);
2881 			break;
2882 		case sdma_event_e82_hw_unfreeze:
2883 			break;
2884 		case sdma_event_e85_link_down:
2885 			break;
2886 		case sdma_event_e90_sw_halted:
2887 			break;
2888 		}
2889 		break;
2890 
2891 	case sdma_state_s82_freeze_sw_clean:
2892 		switch (event) {
2893 		case sdma_event_e00_go_hw_down:
2894 			sdma_set_state(sde, sdma_state_s00_hw_down);
2895 			tasklet_hi_schedule(&sde->sdma_sw_clean_up_task);
2896 			break;
2897 		case sdma_event_e10_go_hw_start:
2898 			break;
2899 		case sdma_event_e15_hw_halt_done:
2900 			break;
2901 		case sdma_event_e25_hw_clean_up_done:
2902 			break;
2903 		case sdma_event_e30_go_running:
2904 			ss->go_s99_running = 1;
2905 			break;
2906 		case sdma_event_e40_sw_cleaned:
2907 			/* notify caller this engine is done cleaning */
2908 			atomic_dec(&sde->dd->sdma_unfreeze_count);
2909 			wake_up_interruptible(&sde->dd->sdma_unfreeze_wq);
2910 			break;
2911 		case sdma_event_e50_hw_cleaned:
2912 			break;
2913 		case sdma_event_e60_hw_halted:
2914 			break;
2915 		case sdma_event_e70_go_idle:
2916 			ss->go_s99_running = 0;
2917 			break;
2918 		case sdma_event_e80_hw_freeze:
2919 			break;
2920 		case sdma_event_e81_hw_frozen:
2921 			break;
2922 		case sdma_event_e82_hw_unfreeze:
2923 			sdma_hw_start_up(sde);
2924 			sdma_set_state(sde, ss->go_s99_running ?
2925 				       sdma_state_s99_running :
2926 				       sdma_state_s20_idle);
2927 			break;
2928 		case sdma_event_e85_link_down:
2929 			break;
2930 		case sdma_event_e90_sw_halted:
2931 			break;
2932 		}
2933 		break;
2934 
2935 	case sdma_state_s99_running:
2936 		switch (event) {
2937 		case sdma_event_e00_go_hw_down:
2938 			sdma_set_state(sde, sdma_state_s00_hw_down);
2939 			tasklet_hi_schedule(&sde->sdma_sw_clean_up_task);
2940 			break;
2941 		case sdma_event_e10_go_hw_start:
2942 			break;
2943 		case sdma_event_e15_hw_halt_done:
2944 			break;
2945 		case sdma_event_e25_hw_clean_up_done:
2946 			break;
2947 		case sdma_event_e30_go_running:
2948 			break;
2949 		case sdma_event_e40_sw_cleaned:
2950 			break;
2951 		case sdma_event_e50_hw_cleaned:
2952 			break;
2953 		case sdma_event_e60_hw_halted:
2954 			need_progress = 1;
2955 			sdma_err_progress_check_schedule(sde);
2956 			fallthrough;
2957 		case sdma_event_e90_sw_halted:
2958 			/*
2959 			* SW initiated halt does not perform engines
2960 			* progress check
2961 			*/
2962 			sdma_set_state(sde, sdma_state_s50_hw_halt_wait);
2963 			schedule_work(&sde->err_halt_worker);
2964 			break;
2965 		case sdma_event_e70_go_idle:
2966 			sdma_set_state(sde, sdma_state_s60_idle_halt_wait);
2967 			break;
2968 		case sdma_event_e85_link_down:
2969 			ss->go_s99_running = 0;
2970 			fallthrough;
2971 		case sdma_event_e80_hw_freeze:
2972 			sdma_set_state(sde, sdma_state_s80_hw_freeze);
2973 			atomic_dec(&sde->dd->sdma_unfreeze_count);
2974 			wake_up_interruptible(&sde->dd->sdma_unfreeze_wq);
2975 			break;
2976 		case sdma_event_e81_hw_frozen:
2977 			break;
2978 		case sdma_event_e82_hw_unfreeze:
2979 			break;
2980 		}
2981 		break;
2982 	}
2983 
2984 	ss->last_event = event;
2985 	if (need_progress)
2986 		sdma_make_progress(sde, 0);
2987 }
2988 
2989 /*
2990  * _extend_sdma_tx_descs() - helper to extend txreq
2991  *
2992  * This is called once the initial nominal allocation
2993  * of descriptors in the sdma_txreq is exhausted.
2994  *
2995  * The code will bump the allocation up to the max
2996  * of MAX_DESC (64) descriptors. There doesn't seem
2997  * much point in an interim step. The last descriptor
2998  * is reserved for coalesce buffer in order to support
2999  * cases where input packet has >MAX_DESC iovecs.
3000  *
3001  */
3002 static int _extend_sdma_tx_descs(struct hfi1_devdata *dd, struct sdma_txreq *tx)
3003 {
3004 	int i;
3005 	struct sdma_desc *descp;
3006 
3007 	/* Handle last descriptor */
3008 	if (unlikely((tx->num_desc == (MAX_DESC - 1)))) {
3009 		/* if tlen is 0, it is for padding, release last descriptor */
3010 		if (!tx->tlen) {
3011 			tx->desc_limit = MAX_DESC;
3012 		} else if (!tx->coalesce_buf) {
3013 			/* allocate coalesce buffer with space for padding */
3014 			tx->coalesce_buf = kmalloc(tx->tlen + sizeof(u32),
3015 						   GFP_ATOMIC);
3016 			if (!tx->coalesce_buf)
3017 				goto enomem;
3018 			tx->coalesce_idx = 0;
3019 		}
3020 		return 0;
3021 	}
3022 
3023 	if (unlikely(tx->num_desc == MAX_DESC))
3024 		goto enomem;
3025 
3026 	descp = kmalloc_objs(struct sdma_desc, MAX_DESC, GFP_ATOMIC);
3027 	if (!descp)
3028 		goto enomem;
3029 	tx->descp = descp;
3030 
3031 	/* reserve last descriptor for coalescing */
3032 	tx->desc_limit = MAX_DESC - 1;
3033 	/* copy ones already built */
3034 	for (i = 0; i < tx->num_desc; i++)
3035 		tx->descp[i] = tx->descs[i];
3036 	return 0;
3037 enomem:
3038 	__sdma_txclean(dd, tx);
3039 	return -ENOMEM;
3040 }
3041 
3042 /*
3043  * ext_coal_sdma_tx_descs() - extend or coalesce sdma tx descriptors
3044  *
3045  * This is called once the initial nominal allocation of descriptors
3046  * in the sdma_txreq is exhausted.
3047  *
3048  * This function calls _extend_sdma_tx_descs to extend or allocate
3049  * coalesce buffer. If there is a allocated coalesce buffer, it will
3050  * copy the input packet data into the coalesce buffer. It also adds
3051  * coalesce buffer descriptor once when whole packet is received.
3052  *
3053  * Return:
3054  * <0 - error
3055  * 0 - coalescing, don't populate descriptor
3056  * 1 - continue with populating descriptor
3057  */
3058 int ext_coal_sdma_tx_descs(struct hfi1_devdata *dd, struct sdma_txreq *tx,
3059 			   int type, void *kvaddr, struct page *page,
3060 			   unsigned long offset, u16 len)
3061 {
3062 	int pad_len, rval;
3063 	dma_addr_t addr;
3064 
3065 	rval = _extend_sdma_tx_descs(dd, tx);
3066 	if (rval) {
3067 		__sdma_txclean(dd, tx);
3068 		return rval;
3069 	}
3070 
3071 	/* If coalesce buffer is allocated, copy data into it */
3072 	if (tx->coalesce_buf) {
3073 		if (type == SDMA_MAP_NONE) {
3074 			__sdma_txclean(dd, tx);
3075 			return -EINVAL;
3076 		}
3077 
3078 		if (type == SDMA_MAP_PAGE) {
3079 			kvaddr = kmap_local_page(page);
3080 			kvaddr += offset;
3081 		} else if (WARN_ON(!kvaddr)) {
3082 			__sdma_txclean(dd, tx);
3083 			return -EINVAL;
3084 		}
3085 
3086 		memcpy(tx->coalesce_buf + tx->coalesce_idx, kvaddr, len);
3087 		tx->coalesce_idx += len;
3088 		if (type == SDMA_MAP_PAGE)
3089 			kunmap_local(kvaddr);
3090 
3091 		/* If there is more data, return */
3092 		if (tx->tlen - tx->coalesce_idx)
3093 			return 0;
3094 
3095 		/* Whole packet is received; add any padding */
3096 		pad_len = tx->packet_len & (sizeof(u32) - 1);
3097 		if (pad_len) {
3098 			pad_len = sizeof(u32) - pad_len;
3099 			memset(tx->coalesce_buf + tx->coalesce_idx, 0, pad_len);
3100 			/* padding is taken care of for coalescing case */
3101 			tx->packet_len += pad_len;
3102 			tx->tlen += pad_len;
3103 		}
3104 
3105 		/* dma map the coalesce buffer */
3106 		addr = dma_map_single(&dd->pcidev->dev,
3107 				      tx->coalesce_buf,
3108 				      tx->tlen,
3109 				      DMA_TO_DEVICE);
3110 
3111 		if (unlikely(dma_mapping_error(&dd->pcidev->dev, addr))) {
3112 			__sdma_txclean(dd, tx);
3113 			return -ENOSPC;
3114 		}
3115 
3116 		/* Add descriptor for coalesce buffer */
3117 		tx->desc_limit = MAX_DESC;
3118 		return _sdma_txadd_daddr(dd, SDMA_MAP_SINGLE, tx,
3119 					 addr, tx->tlen, NULL, NULL, NULL);
3120 	}
3121 
3122 	return 1;
3123 }
3124 
3125 /* Update sdes when the lmc changes */
3126 void sdma_update_lmc(struct hfi1_devdata *dd, u64 mask, u32 lid)
3127 {
3128 	struct sdma_engine *sde;
3129 	int i;
3130 	u64 sreg;
3131 
3132 	sreg = ((mask & SD(CHECK_SLID_MASK_MASK)) <<
3133 		SD(CHECK_SLID_MASK_SHIFT)) |
3134 		(((lid & mask) & SD(CHECK_SLID_VALUE_MASK)) <<
3135 		SD(CHECK_SLID_VALUE_SHIFT));
3136 
3137 	for (i = 0; i < dd->num_sdma; i++) {
3138 		hfi1_cdbg(LINKVERB, "SendDmaEngine[%d].SLID_CHECK = 0x%x",
3139 			  i, (u32)sreg);
3140 		sde = &dd->per_sdma[i];
3141 		write_sde_csr(sde, SD(CHECK_SLID), sreg);
3142 	}
3143 }
3144 
3145 /* tx not dword sized - pad */
3146 int _pad_sdma_tx_descs(struct hfi1_devdata *dd, struct sdma_txreq *tx)
3147 {
3148 	int rval = 0;
3149 
3150 	if ((unlikely(tx->num_desc == tx->desc_limit))) {
3151 		rval = _extend_sdma_tx_descs(dd, tx);
3152 		if (rval) {
3153 			__sdma_txclean(dd, tx);
3154 			return rval;
3155 		}
3156 	}
3157 
3158 	/* finish the one just added */
3159 	make_tx_sdma_desc(
3160 		tx,
3161 		SDMA_MAP_NONE,
3162 		dd->sdma_pad_phys,
3163 		sizeof(u32) - (tx->packet_len & (sizeof(u32) - 1)),
3164 		NULL, NULL, NULL);
3165 	tx->num_desc++;
3166 	_sdma_close_tx(dd, tx);
3167 	return rval;
3168 }
3169 
3170 /*
3171  * Add ahg to the sdma_txreq
3172  *
3173  * The logic will consume up to 3
3174  * descriptors at the beginning of
3175  * sdma_txreq.
3176  */
3177 void _sdma_txreq_ahgadd(
3178 	struct sdma_txreq *tx,
3179 	u8 num_ahg,
3180 	u8 ahg_entry,
3181 	u32 *ahg,
3182 	u8 ahg_hlen)
3183 {
3184 	u32 i, shift = 0, desc = 0;
3185 	u8 mode;
3186 
3187 	WARN_ON_ONCE(num_ahg > 9 || (ahg_hlen & 3) || ahg_hlen == 4);
3188 	/* compute mode */
3189 	if (num_ahg == 1)
3190 		mode = SDMA_AHG_APPLY_UPDATE1;
3191 	else if (num_ahg <= 5)
3192 		mode = SDMA_AHG_APPLY_UPDATE2;
3193 	else
3194 		mode = SDMA_AHG_APPLY_UPDATE3;
3195 	tx->num_desc++;
3196 	/* initialize to consumed descriptors to zero */
3197 	switch (mode) {
3198 	case SDMA_AHG_APPLY_UPDATE3:
3199 		tx->num_desc++;
3200 		tx->descs[2].qw[0] = 0;
3201 		tx->descs[2].qw[1] = 0;
3202 		fallthrough;
3203 	case SDMA_AHG_APPLY_UPDATE2:
3204 		tx->num_desc++;
3205 		tx->descs[1].qw[0] = 0;
3206 		tx->descs[1].qw[1] = 0;
3207 		break;
3208 	}
3209 	ahg_hlen >>= 2;
3210 	tx->descs[0].qw[1] |=
3211 		(((u64)ahg_entry & SDMA_DESC1_HEADER_INDEX_MASK)
3212 			<< SDMA_DESC1_HEADER_INDEX_SHIFT) |
3213 		(((u64)ahg_hlen & SDMA_DESC1_HEADER_DWS_MASK)
3214 			<< SDMA_DESC1_HEADER_DWS_SHIFT) |
3215 		(((u64)mode & SDMA_DESC1_HEADER_MODE_MASK)
3216 			<< SDMA_DESC1_HEADER_MODE_SHIFT) |
3217 		(((u64)ahg[0] & SDMA_DESC1_HEADER_UPDATE1_MASK)
3218 			<< SDMA_DESC1_HEADER_UPDATE1_SHIFT);
3219 	for (i = 0; i < (num_ahg - 1); i++) {
3220 		if (!shift && !(i & 2))
3221 			desc++;
3222 		tx->descs[desc].qw[!!(i & 2)] |=
3223 			(((u64)ahg[i + 1])
3224 				<< shift);
3225 		shift = (shift + 32) & 63;
3226 	}
3227 }
3228 
3229 /**
3230  * sdma_ahg_alloc - allocate an AHG entry
3231  * @sde: engine to allocate from
3232  *
3233  * Return:
3234  * 0-31 when successful, -EOPNOTSUPP if AHG is not enabled,
3235  * -ENOSPC if an entry is not available
3236  */
3237 int sdma_ahg_alloc(struct sdma_engine *sde)
3238 {
3239 	int nr;
3240 	int oldbit;
3241 
3242 	if (!sde) {
3243 		trace_hfi1_ahg_allocate(sde, -EINVAL);
3244 		return -EINVAL;
3245 	}
3246 	while (1) {
3247 		nr = ffz(READ_ONCE(sde->ahg_bits));
3248 		if (nr > 31) {
3249 			trace_hfi1_ahg_allocate(sde, -ENOSPC);
3250 			return -ENOSPC;
3251 		}
3252 		oldbit = test_and_set_bit(nr, &sde->ahg_bits);
3253 		if (!oldbit)
3254 			break;
3255 		cpu_relax();
3256 	}
3257 	trace_hfi1_ahg_allocate(sde, nr);
3258 	return nr;
3259 }
3260 
3261 /**
3262  * sdma_ahg_free - free an AHG entry
3263  * @sde: engine to return AHG entry
3264  * @ahg_index: index to free
3265  *
3266  * This routine frees the indicate AHG entry.
3267  */
3268 void sdma_ahg_free(struct sdma_engine *sde, int ahg_index)
3269 {
3270 	if (!sde)
3271 		return;
3272 	trace_hfi1_ahg_deallocate(sde, ahg_index);
3273 	if (ahg_index < 0 || ahg_index > 31)
3274 		return;
3275 	clear_bit(ahg_index, &sde->ahg_bits);
3276 }
3277 
3278 /*
3279  * SPC freeze handling for SDMA engines.  Called when the driver knows
3280  * the SPC is going into a freeze but before the freeze is fully
3281  * settled.  Generally an error interrupt.
3282  *
3283  * This event will pull the engine out of running so no more entries can be
3284  * added to the engine's queue.
3285  */
3286 void sdma_freeze_notify(struct hfi1_devdata *dd, int link_down)
3287 {
3288 	int i;
3289 	enum sdma_events event = link_down ? sdma_event_e85_link_down :
3290 					     sdma_event_e80_hw_freeze;
3291 
3292 	/* set up the wait but do not wait here */
3293 	atomic_set(&dd->sdma_unfreeze_count, dd->num_sdma);
3294 
3295 	/* tell all engines to stop running and wait */
3296 	for (i = 0; i < dd->num_sdma; i++)
3297 		sdma_process_event(&dd->per_sdma[i], event);
3298 
3299 	/* sdma_freeze() will wait for all engines to have stopped */
3300 }
3301 
3302 /*
3303  * SPC freeze handling for SDMA engines.  Called when the driver knows
3304  * the SPC is fully frozen.
3305  */
3306 void sdma_freeze(struct hfi1_devdata *dd)
3307 {
3308 	int i;
3309 	int ret;
3310 
3311 	/*
3312 	 * Make sure all engines have moved out of the running state before
3313 	 * continuing.
3314 	 */
3315 	ret = wait_event_interruptible(dd->sdma_unfreeze_wq,
3316 				       atomic_read(&dd->sdma_unfreeze_count) <=
3317 				       0);
3318 	/* interrupted or count is negative, then unloading - just exit */
3319 	if (ret || atomic_read(&dd->sdma_unfreeze_count) < 0)
3320 		return;
3321 
3322 	/* set up the count for the next wait */
3323 	atomic_set(&dd->sdma_unfreeze_count, dd->num_sdma);
3324 
3325 	/* tell all engines that the SPC is frozen, they can start cleaning */
3326 	for (i = 0; i < dd->num_sdma; i++)
3327 		sdma_process_event(&dd->per_sdma[i], sdma_event_e81_hw_frozen);
3328 
3329 	/*
3330 	 * Wait for everyone to finish software clean before exiting.  The
3331 	 * software clean will read engine CSRs, so must be completed before
3332 	 * the next step, which will clear the engine CSRs.
3333 	 */
3334 	(void)wait_event_interruptible(dd->sdma_unfreeze_wq,
3335 				atomic_read(&dd->sdma_unfreeze_count) <= 0);
3336 	/* no need to check results - done no matter what */
3337 }
3338 
3339 /*
3340  * SPC freeze handling for the SDMA engines.  Called after the SPC is unfrozen.
3341  *
3342  * The SPC freeze acts like a SDMA halt and a hardware clean combined.  All
3343  * that is left is a software clean.  We could do it after the SPC is fully
3344  * frozen, but then we'd have to add another state to wait for the unfreeze.
3345  * Instead, just defer the software clean until the unfreeze step.
3346  */
3347 void sdma_unfreeze(struct hfi1_devdata *dd)
3348 {
3349 	int i;
3350 
3351 	/* tell all engines start freeze clean up */
3352 	for (i = 0; i < dd->num_sdma; i++)
3353 		sdma_process_event(&dd->per_sdma[i],
3354 				   sdma_event_e82_hw_unfreeze);
3355 }
3356 
3357 /**
3358  * _sdma_engine_progress_schedule() - schedule progress on engine
3359  * @sde: sdma_engine to schedule progress
3360  *
3361  */
3362 void _sdma_engine_progress_schedule(
3363 	struct sdma_engine *sde)
3364 {
3365 	trace_hfi1_sdma_engine_progress(sde, sde->progress_mask);
3366 	/* assume we have selected a good cpu */
3367 	write_csr(sde->dd,
3368 		  CCE_INT_FORCE + (8 * (IS_SDMA_START / 64)),
3369 		  sde->progress_mask);
3370 }
3371