xref: /openbmc/linux/drivers/dma/ioat/dma.c (revision b5265c81)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Intel I/OAT DMA Linux driver
4  * Copyright(c) 2004 - 2015 Intel Corporation.
5  */
6 
7 /*
8  * This driver supports an Intel I/OAT DMA engine, which does asynchronous
9  * copy operations.
10  */
11 
12 #include <linux/init.h>
13 #include <linux/module.h>
14 #include <linux/slab.h>
15 #include <linux/pci.h>
16 #include <linux/interrupt.h>
17 #include <linux/dmaengine.h>
18 #include <linux/delay.h>
19 #include <linux/dma-mapping.h>
20 #include <linux/workqueue.h>
21 #include <linux/prefetch.h>
22 #include <linux/sizes.h>
23 #include "dma.h"
24 #include "registers.h"
25 #include "hw.h"
26 
27 #include "../dmaengine.h"
28 
29 static char *chanerr_str[] = {
30 	"DMA Transfer Source Address Error",
31 	"DMA Transfer Destination Address Error",
32 	"Next Descriptor Address Error",
33 	"Descriptor Error",
34 	"Chan Address Value Error",
35 	"CHANCMD Error",
36 	"Chipset Uncorrectable Data Integrity Error",
37 	"DMA Uncorrectable Data Integrity Error",
38 	"Read Data Error",
39 	"Write Data Error",
40 	"Descriptor Control Error",
41 	"Descriptor Transfer Size Error",
42 	"Completion Address Error",
43 	"Interrupt Configuration Error",
44 	"Super extended descriptor Address Error",
45 	"Unaffiliated Error",
46 	"CRC or XOR P Error",
47 	"XOR Q Error",
48 	"Descriptor Count Error",
49 	"DIF All F detect Error",
50 	"Guard Tag verification Error",
51 	"Application Tag verification Error",
52 	"Reference Tag verification Error",
53 	"Bundle Bit Error",
54 	"Result DIF All F detect Error",
55 	"Result Guard Tag verification Error",
56 	"Result Application Tag verification Error",
57 	"Result Reference Tag verification Error",
58 };
59 
60 static void ioat_eh(struct ioatdma_chan *ioat_chan);
61 
62 static void ioat_print_chanerrs(struct ioatdma_chan *ioat_chan, u32 chanerr)
63 {
64 	int i;
65 
66 	for (i = 0; i < ARRAY_SIZE(chanerr_str); i++) {
67 		if ((chanerr >> i) & 1) {
68 			dev_err(to_dev(ioat_chan), "Err(%d): %s\n",
69 				i, chanerr_str[i]);
70 		}
71 	}
72 }
73 
74 /**
75  * ioat_dma_do_interrupt - handler used for single vector interrupt mode
76  * @irq: interrupt id
77  * @data: interrupt data
78  */
79 irqreturn_t ioat_dma_do_interrupt(int irq, void *data)
80 {
81 	struct ioatdma_device *instance = data;
82 	struct ioatdma_chan *ioat_chan;
83 	unsigned long attnstatus;
84 	int bit;
85 	u8 intrctrl;
86 
87 	intrctrl = readb(instance->reg_base + IOAT_INTRCTRL_OFFSET);
88 
89 	if (!(intrctrl & IOAT_INTRCTRL_MASTER_INT_EN))
90 		return IRQ_NONE;
91 
92 	if (!(intrctrl & IOAT_INTRCTRL_INT_STATUS)) {
93 		writeb(intrctrl, instance->reg_base + IOAT_INTRCTRL_OFFSET);
94 		return IRQ_NONE;
95 	}
96 
97 	attnstatus = readl(instance->reg_base + IOAT_ATTNSTATUS_OFFSET);
98 	for_each_set_bit(bit, &attnstatus, BITS_PER_LONG) {
99 		ioat_chan = ioat_chan_by_index(instance, bit);
100 		if (test_bit(IOAT_RUN, &ioat_chan->state))
101 			tasklet_schedule(&ioat_chan->cleanup_task);
102 	}
103 
104 	writeb(intrctrl, instance->reg_base + IOAT_INTRCTRL_OFFSET);
105 	return IRQ_HANDLED;
106 }
107 
108 /**
109  * ioat_dma_do_interrupt_msix - handler used for vector-per-channel interrupt mode
110  * @irq: interrupt id
111  * @data: interrupt data
112  */
113 irqreturn_t ioat_dma_do_interrupt_msix(int irq, void *data)
114 {
115 	struct ioatdma_chan *ioat_chan = data;
116 
117 	if (test_bit(IOAT_RUN, &ioat_chan->state))
118 		tasklet_schedule(&ioat_chan->cleanup_task);
119 
120 	return IRQ_HANDLED;
121 }
122 
123 void ioat_stop(struct ioatdma_chan *ioat_chan)
124 {
125 	struct ioatdma_device *ioat_dma = ioat_chan->ioat_dma;
126 	struct pci_dev *pdev = ioat_dma->pdev;
127 	int chan_id = chan_num(ioat_chan);
128 	struct msix_entry *msix;
129 
130 	/* 1/ stop irq from firing tasklets
131 	 * 2/ stop the tasklet from re-arming irqs
132 	 */
133 	clear_bit(IOAT_RUN, &ioat_chan->state);
134 
135 	/* flush inflight interrupts */
136 	switch (ioat_dma->irq_mode) {
137 	case IOAT_MSIX:
138 		msix = &ioat_dma->msix_entries[chan_id];
139 		synchronize_irq(msix->vector);
140 		break;
141 	case IOAT_MSI:
142 	case IOAT_INTX:
143 		synchronize_irq(pdev->irq);
144 		break;
145 	default:
146 		break;
147 	}
148 
149 	/* flush inflight timers */
150 	del_timer_sync(&ioat_chan->timer);
151 
152 	/* flush inflight tasklet runs */
153 	tasklet_kill(&ioat_chan->cleanup_task);
154 
155 	/* final cleanup now that everything is quiesced and can't re-arm */
156 	ioat_cleanup_event((unsigned long)&ioat_chan->dma_chan);
157 }
158 
159 static void __ioat_issue_pending(struct ioatdma_chan *ioat_chan)
160 {
161 	ioat_chan->dmacount += ioat_ring_pending(ioat_chan);
162 	ioat_chan->issued = ioat_chan->head;
163 	writew(ioat_chan->dmacount,
164 	       ioat_chan->reg_base + IOAT_CHAN_DMACOUNT_OFFSET);
165 	dev_dbg(to_dev(ioat_chan),
166 		"%s: head: %#x tail: %#x issued: %#x count: %#x\n",
167 		__func__, ioat_chan->head, ioat_chan->tail,
168 		ioat_chan->issued, ioat_chan->dmacount);
169 }
170 
171 void ioat_issue_pending(struct dma_chan *c)
172 {
173 	struct ioatdma_chan *ioat_chan = to_ioat_chan(c);
174 
175 	if (ioat_ring_pending(ioat_chan)) {
176 		spin_lock_bh(&ioat_chan->prep_lock);
177 		__ioat_issue_pending(ioat_chan);
178 		spin_unlock_bh(&ioat_chan->prep_lock);
179 	}
180 }
181 
182 /**
183  * ioat_update_pending - log pending descriptors
184  * @ioat: ioat+ channel
185  *
186  * Check if the number of unsubmitted descriptors has exceeded the
187  * watermark.  Called with prep_lock held
188  */
189 static void ioat_update_pending(struct ioatdma_chan *ioat_chan)
190 {
191 	if (ioat_ring_pending(ioat_chan) > ioat_pending_level)
192 		__ioat_issue_pending(ioat_chan);
193 }
194 
195 static void __ioat_start_null_desc(struct ioatdma_chan *ioat_chan)
196 {
197 	struct ioat_ring_ent *desc;
198 	struct ioat_dma_descriptor *hw;
199 
200 	if (ioat_ring_space(ioat_chan) < 1) {
201 		dev_err(to_dev(ioat_chan),
202 			"Unable to start null desc - ring full\n");
203 		return;
204 	}
205 
206 	dev_dbg(to_dev(ioat_chan),
207 		"%s: head: %#x tail: %#x issued: %#x\n",
208 		__func__, ioat_chan->head, ioat_chan->tail, ioat_chan->issued);
209 	desc = ioat_get_ring_ent(ioat_chan, ioat_chan->head);
210 
211 	hw = desc->hw;
212 	hw->ctl = 0;
213 	hw->ctl_f.null = 1;
214 	hw->ctl_f.int_en = 1;
215 	hw->ctl_f.compl_write = 1;
216 	/* set size to non-zero value (channel returns error when size is 0) */
217 	hw->size = NULL_DESC_BUFFER_SIZE;
218 	hw->src_addr = 0;
219 	hw->dst_addr = 0;
220 	async_tx_ack(&desc->txd);
221 	ioat_set_chainaddr(ioat_chan, desc->txd.phys);
222 	dump_desc_dbg(ioat_chan, desc);
223 	/* make sure descriptors are written before we submit */
224 	wmb();
225 	ioat_chan->head += 1;
226 	__ioat_issue_pending(ioat_chan);
227 }
228 
229 void ioat_start_null_desc(struct ioatdma_chan *ioat_chan)
230 {
231 	spin_lock_bh(&ioat_chan->prep_lock);
232 	if (!test_bit(IOAT_CHAN_DOWN, &ioat_chan->state))
233 		__ioat_start_null_desc(ioat_chan);
234 	spin_unlock_bh(&ioat_chan->prep_lock);
235 }
236 
237 static void __ioat_restart_chan(struct ioatdma_chan *ioat_chan)
238 {
239 	/* set the tail to be re-issued */
240 	ioat_chan->issued = ioat_chan->tail;
241 	ioat_chan->dmacount = 0;
242 	mod_timer(&ioat_chan->timer, jiffies + COMPLETION_TIMEOUT);
243 
244 	dev_dbg(to_dev(ioat_chan),
245 		"%s: head: %#x tail: %#x issued: %#x count: %#x\n",
246 		__func__, ioat_chan->head, ioat_chan->tail,
247 		ioat_chan->issued, ioat_chan->dmacount);
248 
249 	if (ioat_ring_pending(ioat_chan)) {
250 		struct ioat_ring_ent *desc;
251 
252 		desc = ioat_get_ring_ent(ioat_chan, ioat_chan->tail);
253 		ioat_set_chainaddr(ioat_chan, desc->txd.phys);
254 		__ioat_issue_pending(ioat_chan);
255 	} else
256 		__ioat_start_null_desc(ioat_chan);
257 }
258 
259 static int ioat_quiesce(struct ioatdma_chan *ioat_chan, unsigned long tmo)
260 {
261 	unsigned long end = jiffies + tmo;
262 	int err = 0;
263 	u32 status;
264 
265 	status = ioat_chansts(ioat_chan);
266 	if (is_ioat_active(status) || is_ioat_idle(status))
267 		ioat_suspend(ioat_chan);
268 	while (is_ioat_active(status) || is_ioat_idle(status)) {
269 		if (tmo && time_after(jiffies, end)) {
270 			err = -ETIMEDOUT;
271 			break;
272 		}
273 		status = ioat_chansts(ioat_chan);
274 		cpu_relax();
275 	}
276 
277 	return err;
278 }
279 
280 static int ioat_reset_sync(struct ioatdma_chan *ioat_chan, unsigned long tmo)
281 {
282 	unsigned long end = jiffies + tmo;
283 	int err = 0;
284 
285 	ioat_reset(ioat_chan);
286 	while (ioat_reset_pending(ioat_chan)) {
287 		if (end && time_after(jiffies, end)) {
288 			err = -ETIMEDOUT;
289 			break;
290 		}
291 		cpu_relax();
292 	}
293 
294 	return err;
295 }
296 
297 static dma_cookie_t ioat_tx_submit_unlock(struct dma_async_tx_descriptor *tx)
298 	__releases(&ioat_chan->prep_lock)
299 {
300 	struct dma_chan *c = tx->chan;
301 	struct ioatdma_chan *ioat_chan = to_ioat_chan(c);
302 	dma_cookie_t cookie;
303 
304 	cookie = dma_cookie_assign(tx);
305 	dev_dbg(to_dev(ioat_chan), "%s: cookie: %d\n", __func__, cookie);
306 
307 	if (!test_and_set_bit(IOAT_CHAN_ACTIVE, &ioat_chan->state))
308 		mod_timer(&ioat_chan->timer, jiffies + COMPLETION_TIMEOUT);
309 
310 	/* make descriptor updates visible before advancing ioat->head,
311 	 * this is purposefully not smp_wmb() since we are also
312 	 * publishing the descriptor updates to a dma device
313 	 */
314 	wmb();
315 
316 	ioat_chan->head += ioat_chan->produce;
317 
318 	ioat_update_pending(ioat_chan);
319 	spin_unlock_bh(&ioat_chan->prep_lock);
320 
321 	return cookie;
322 }
323 
324 static struct ioat_ring_ent *
325 ioat_alloc_ring_ent(struct dma_chan *chan, int idx, gfp_t flags)
326 {
327 	struct ioat_dma_descriptor *hw;
328 	struct ioat_ring_ent *desc;
329 	struct ioatdma_chan *ioat_chan = to_ioat_chan(chan);
330 	int chunk;
331 	dma_addr_t phys;
332 	u8 *pos;
333 	off_t offs;
334 
335 	chunk = idx / IOAT_DESCS_PER_CHUNK;
336 	idx &= (IOAT_DESCS_PER_CHUNK - 1);
337 	offs = idx * IOAT_DESC_SZ;
338 	pos = (u8 *)ioat_chan->descs[chunk].virt + offs;
339 	phys = ioat_chan->descs[chunk].hw + offs;
340 	hw = (struct ioat_dma_descriptor *)pos;
341 	memset(hw, 0, sizeof(*hw));
342 
343 	desc = kmem_cache_zalloc(ioat_cache, flags);
344 	if (!desc)
345 		return NULL;
346 
347 	dma_async_tx_descriptor_init(&desc->txd, chan);
348 	desc->txd.tx_submit = ioat_tx_submit_unlock;
349 	desc->hw = hw;
350 	desc->txd.phys = phys;
351 	return desc;
352 }
353 
354 void ioat_free_ring_ent(struct ioat_ring_ent *desc, struct dma_chan *chan)
355 {
356 	kmem_cache_free(ioat_cache, desc);
357 }
358 
359 struct ioat_ring_ent **
360 ioat_alloc_ring(struct dma_chan *c, int order, gfp_t flags)
361 {
362 	struct ioatdma_chan *ioat_chan = to_ioat_chan(c);
363 	struct ioatdma_device *ioat_dma = ioat_chan->ioat_dma;
364 	struct ioat_ring_ent **ring;
365 	int total_descs = 1 << order;
366 	int i, chunks;
367 
368 	/* allocate the array to hold the software ring */
369 	ring = kcalloc(total_descs, sizeof(*ring), flags);
370 	if (!ring)
371 		return NULL;
372 
373 	chunks = (total_descs * IOAT_DESC_SZ) / IOAT_CHUNK_SIZE;
374 	ioat_chan->desc_chunks = chunks;
375 
376 	for (i = 0; i < chunks; i++) {
377 		struct ioat_descs *descs = &ioat_chan->descs[i];
378 
379 		descs->virt = dma_alloc_coherent(to_dev(ioat_chan),
380 						 SZ_2M, &descs->hw, flags);
381 		if (!descs->virt) {
382 			int idx;
383 
384 			for (idx = 0; idx < i; idx++) {
385 				descs = &ioat_chan->descs[idx];
386 				dma_free_coherent(to_dev(ioat_chan),
387 						IOAT_CHUNK_SIZE,
388 						descs->virt, descs->hw);
389 				descs->virt = NULL;
390 				descs->hw = 0;
391 			}
392 
393 			ioat_chan->desc_chunks = 0;
394 			kfree(ring);
395 			return NULL;
396 		}
397 	}
398 
399 	for (i = 0; i < total_descs; i++) {
400 		ring[i] = ioat_alloc_ring_ent(c, i, flags);
401 		if (!ring[i]) {
402 			int idx;
403 
404 			while (i--)
405 				ioat_free_ring_ent(ring[i], c);
406 
407 			for (idx = 0; idx < ioat_chan->desc_chunks; idx++) {
408 				dma_free_coherent(to_dev(ioat_chan),
409 						  IOAT_CHUNK_SIZE,
410 						  ioat_chan->descs[idx].virt,
411 						  ioat_chan->descs[idx].hw);
412 				ioat_chan->descs[idx].virt = NULL;
413 				ioat_chan->descs[idx].hw = 0;
414 			}
415 
416 			ioat_chan->desc_chunks = 0;
417 			kfree(ring);
418 			return NULL;
419 		}
420 		set_desc_id(ring[i], i);
421 	}
422 
423 	/* link descs */
424 	for (i = 0; i < total_descs-1; i++) {
425 		struct ioat_ring_ent *next = ring[i+1];
426 		struct ioat_dma_descriptor *hw = ring[i]->hw;
427 
428 		hw->next = next->txd.phys;
429 	}
430 	ring[i]->hw->next = ring[0]->txd.phys;
431 
432 	/* setup descriptor pre-fetching for v3.4 */
433 	if (ioat_dma->cap & IOAT_CAP_DPS) {
434 		u16 drsctl = IOAT_CHAN_DRSZ_2MB | IOAT_CHAN_DRS_EN;
435 
436 		if (chunks == 1)
437 			drsctl |= IOAT_CHAN_DRS_AUTOWRAP;
438 
439 		writew(drsctl, ioat_chan->reg_base + IOAT_CHAN_DRSCTL_OFFSET);
440 
441 	}
442 
443 	return ring;
444 }
445 
446 /**
447  * ioat_check_space_lock - verify space and grab ring producer lock
448  * @ioat: ioat,3 channel (ring) to operate on
449  * @num_descs: allocation length
450  */
451 int ioat_check_space_lock(struct ioatdma_chan *ioat_chan, int num_descs)
452 	__acquires(&ioat_chan->prep_lock)
453 {
454 	spin_lock_bh(&ioat_chan->prep_lock);
455 	/* never allow the last descriptor to be consumed, we need at
456 	 * least one free at all times to allow for on-the-fly ring
457 	 * resizing.
458 	 */
459 	if (likely(ioat_ring_space(ioat_chan) > num_descs)) {
460 		dev_dbg(to_dev(ioat_chan), "%s: num_descs: %d (%x:%x:%x)\n",
461 			__func__, num_descs, ioat_chan->head,
462 			ioat_chan->tail, ioat_chan->issued);
463 		ioat_chan->produce = num_descs;
464 		return 0;  /* with ioat->prep_lock held */
465 	}
466 	spin_unlock_bh(&ioat_chan->prep_lock);
467 
468 	dev_dbg_ratelimited(to_dev(ioat_chan),
469 			    "%s: ring full! num_descs: %d (%x:%x:%x)\n",
470 			    __func__, num_descs, ioat_chan->head,
471 			    ioat_chan->tail, ioat_chan->issued);
472 
473 	/* progress reclaim in the allocation failure case we may be
474 	 * called under bh_disabled so we need to trigger the timer
475 	 * event directly
476 	 */
477 	if (time_is_before_jiffies(ioat_chan->timer.expires)
478 	    && timer_pending(&ioat_chan->timer)) {
479 		mod_timer(&ioat_chan->timer, jiffies + COMPLETION_TIMEOUT);
480 		ioat_timer_event(&ioat_chan->timer);
481 	}
482 
483 	return -ENOMEM;
484 }
485 
486 static bool desc_has_ext(struct ioat_ring_ent *desc)
487 {
488 	struct ioat_dma_descriptor *hw = desc->hw;
489 
490 	if (hw->ctl_f.op == IOAT_OP_XOR ||
491 	    hw->ctl_f.op == IOAT_OP_XOR_VAL) {
492 		struct ioat_xor_descriptor *xor = desc->xor;
493 
494 		if (src_cnt_to_sw(xor->ctl_f.src_cnt) > 5)
495 			return true;
496 	} else if (hw->ctl_f.op == IOAT_OP_PQ ||
497 		   hw->ctl_f.op == IOAT_OP_PQ_VAL) {
498 		struct ioat_pq_descriptor *pq = desc->pq;
499 
500 		if (src_cnt_to_sw(pq->ctl_f.src_cnt) > 3)
501 			return true;
502 	}
503 
504 	return false;
505 }
506 
507 static void
508 ioat_free_sed(struct ioatdma_device *ioat_dma, struct ioat_sed_ent *sed)
509 {
510 	if (!sed)
511 		return;
512 
513 	dma_pool_free(ioat_dma->sed_hw_pool[sed->hw_pool], sed->hw, sed->dma);
514 	kmem_cache_free(ioat_sed_cache, sed);
515 }
516 
517 static u64 ioat_get_current_completion(struct ioatdma_chan *ioat_chan)
518 {
519 	u64 phys_complete;
520 	u64 completion;
521 
522 	completion = *ioat_chan->completion;
523 	phys_complete = ioat_chansts_to_addr(completion);
524 
525 	dev_dbg(to_dev(ioat_chan), "%s: phys_complete: %#llx\n", __func__,
526 		(unsigned long long) phys_complete);
527 
528 	return phys_complete;
529 }
530 
531 static bool ioat_cleanup_preamble(struct ioatdma_chan *ioat_chan,
532 				   u64 *phys_complete)
533 {
534 	*phys_complete = ioat_get_current_completion(ioat_chan);
535 	if (*phys_complete == ioat_chan->last_completion)
536 		return false;
537 
538 	clear_bit(IOAT_COMPLETION_ACK, &ioat_chan->state);
539 	mod_timer(&ioat_chan->timer, jiffies + COMPLETION_TIMEOUT);
540 
541 	return true;
542 }
543 
544 static void
545 desc_get_errstat(struct ioatdma_chan *ioat_chan, struct ioat_ring_ent *desc)
546 {
547 	struct ioat_dma_descriptor *hw = desc->hw;
548 
549 	switch (hw->ctl_f.op) {
550 	case IOAT_OP_PQ_VAL:
551 	case IOAT_OP_PQ_VAL_16S:
552 	{
553 		struct ioat_pq_descriptor *pq = desc->pq;
554 
555 		/* check if there's error written */
556 		if (!pq->dwbes_f.wbes)
557 			return;
558 
559 		/* need to set a chanerr var for checking to clear later */
560 
561 		if (pq->dwbes_f.p_val_err)
562 			*desc->result |= SUM_CHECK_P_RESULT;
563 
564 		if (pq->dwbes_f.q_val_err)
565 			*desc->result |= SUM_CHECK_Q_RESULT;
566 
567 		return;
568 	}
569 	default:
570 		return;
571 	}
572 }
573 
574 /**
575  * __cleanup - reclaim used descriptors
576  * @ioat: channel (ring) to clean
577  */
578 static void __cleanup(struct ioatdma_chan *ioat_chan, dma_addr_t phys_complete)
579 {
580 	struct ioatdma_device *ioat_dma = ioat_chan->ioat_dma;
581 	struct ioat_ring_ent *desc;
582 	bool seen_current = false;
583 	int idx = ioat_chan->tail, i;
584 	u16 active;
585 
586 	dev_dbg(to_dev(ioat_chan), "%s: head: %#x tail: %#x issued: %#x\n",
587 		__func__, ioat_chan->head, ioat_chan->tail, ioat_chan->issued);
588 
589 	/*
590 	 * At restart of the channel, the completion address and the
591 	 * channel status will be 0 due to starting a new chain. Since
592 	 * it's new chain and the first descriptor "fails", there is
593 	 * nothing to clean up. We do not want to reap the entire submitted
594 	 * chain due to this 0 address value and then BUG.
595 	 */
596 	if (!phys_complete)
597 		return;
598 
599 	active = ioat_ring_active(ioat_chan);
600 	for (i = 0; i < active && !seen_current; i++) {
601 		struct dma_async_tx_descriptor *tx;
602 
603 		prefetch(ioat_get_ring_ent(ioat_chan, idx + i + 1));
604 		desc = ioat_get_ring_ent(ioat_chan, idx + i);
605 		dump_desc_dbg(ioat_chan, desc);
606 
607 		/* set err stat if we are using dwbes */
608 		if (ioat_dma->cap & IOAT_CAP_DWBES)
609 			desc_get_errstat(ioat_chan, desc);
610 
611 		tx = &desc->txd;
612 		if (tx->cookie) {
613 			dma_cookie_complete(tx);
614 			dma_descriptor_unmap(tx);
615 			dmaengine_desc_get_callback_invoke(tx, NULL);
616 			tx->callback = NULL;
617 			tx->callback_result = NULL;
618 		}
619 
620 		if (tx->phys == phys_complete)
621 			seen_current = true;
622 
623 		/* skip extended descriptors */
624 		if (desc_has_ext(desc)) {
625 			BUG_ON(i + 1 >= active);
626 			i++;
627 		}
628 
629 		/* cleanup super extended descriptors */
630 		if (desc->sed) {
631 			ioat_free_sed(ioat_dma, desc->sed);
632 			desc->sed = NULL;
633 		}
634 	}
635 
636 	/* finish all descriptor reads before incrementing tail */
637 	smp_mb();
638 	ioat_chan->tail = idx + i;
639 	/* no active descs have written a completion? */
640 	BUG_ON(active && !seen_current);
641 	ioat_chan->last_completion = phys_complete;
642 
643 	if (active - i == 0) {
644 		dev_dbg(to_dev(ioat_chan), "%s: cancel completion timeout\n",
645 			__func__);
646 		mod_timer(&ioat_chan->timer, jiffies + IDLE_TIMEOUT);
647 	}
648 
649 	/* microsecond delay by sysfs variable  per pending descriptor */
650 	if (ioat_chan->intr_coalesce != ioat_chan->prev_intr_coalesce) {
651 		writew(min((ioat_chan->intr_coalesce * (active - i)),
652 		       IOAT_INTRDELAY_MASK),
653 		       ioat_chan->ioat_dma->reg_base + IOAT_INTRDELAY_OFFSET);
654 		ioat_chan->prev_intr_coalesce = ioat_chan->intr_coalesce;
655 	}
656 }
657 
658 static void ioat_cleanup(struct ioatdma_chan *ioat_chan)
659 {
660 	u64 phys_complete;
661 
662 	spin_lock_bh(&ioat_chan->cleanup_lock);
663 
664 	if (ioat_cleanup_preamble(ioat_chan, &phys_complete))
665 		__cleanup(ioat_chan, phys_complete);
666 
667 	if (is_ioat_halted(*ioat_chan->completion)) {
668 		u32 chanerr = readl(ioat_chan->reg_base + IOAT_CHANERR_OFFSET);
669 
670 		if (chanerr &
671 		    (IOAT_CHANERR_HANDLE_MASK | IOAT_CHANERR_RECOVER_MASK)) {
672 			mod_timer(&ioat_chan->timer, jiffies + IDLE_TIMEOUT);
673 			ioat_eh(ioat_chan);
674 		}
675 	}
676 
677 	spin_unlock_bh(&ioat_chan->cleanup_lock);
678 }
679 
680 void ioat_cleanup_event(unsigned long data)
681 {
682 	struct ioatdma_chan *ioat_chan = to_ioat_chan((void *)data);
683 
684 	ioat_cleanup(ioat_chan);
685 	if (!test_bit(IOAT_RUN, &ioat_chan->state))
686 		return;
687 	writew(IOAT_CHANCTRL_RUN, ioat_chan->reg_base + IOAT_CHANCTRL_OFFSET);
688 }
689 
690 static void ioat_restart_channel(struct ioatdma_chan *ioat_chan)
691 {
692 	u64 phys_complete;
693 
694 	/* set the completion address register again */
695 	writel(lower_32_bits(ioat_chan->completion_dma),
696 	       ioat_chan->reg_base + IOAT_CHANCMP_OFFSET_LOW);
697 	writel(upper_32_bits(ioat_chan->completion_dma),
698 	       ioat_chan->reg_base + IOAT_CHANCMP_OFFSET_HIGH);
699 
700 	ioat_quiesce(ioat_chan, 0);
701 	if (ioat_cleanup_preamble(ioat_chan, &phys_complete))
702 		__cleanup(ioat_chan, phys_complete);
703 
704 	__ioat_restart_chan(ioat_chan);
705 }
706 
707 
708 static void ioat_abort_descs(struct ioatdma_chan *ioat_chan)
709 {
710 	struct ioatdma_device *ioat_dma = ioat_chan->ioat_dma;
711 	struct ioat_ring_ent *desc;
712 	u16 active;
713 	int idx = ioat_chan->tail, i;
714 
715 	/*
716 	 * We assume that the failed descriptor has been processed.
717 	 * Now we are just returning all the remaining submitted
718 	 * descriptors to abort.
719 	 */
720 	active = ioat_ring_active(ioat_chan);
721 
722 	/* we skip the failed descriptor that tail points to */
723 	for (i = 1; i < active; i++) {
724 		struct dma_async_tx_descriptor *tx;
725 
726 		prefetch(ioat_get_ring_ent(ioat_chan, idx + i + 1));
727 		desc = ioat_get_ring_ent(ioat_chan, idx + i);
728 
729 		tx = &desc->txd;
730 		if (tx->cookie) {
731 			struct dmaengine_result res;
732 
733 			dma_cookie_complete(tx);
734 			dma_descriptor_unmap(tx);
735 			res.result = DMA_TRANS_ABORTED;
736 			dmaengine_desc_get_callback_invoke(tx, &res);
737 			tx->callback = NULL;
738 			tx->callback_result = NULL;
739 		}
740 
741 		/* skip extended descriptors */
742 		if (desc_has_ext(desc)) {
743 			WARN_ON(i + 1 >= active);
744 			i++;
745 		}
746 
747 		/* cleanup super extended descriptors */
748 		if (desc->sed) {
749 			ioat_free_sed(ioat_dma, desc->sed);
750 			desc->sed = NULL;
751 		}
752 	}
753 
754 	smp_mb(); /* finish all descriptor reads before incrementing tail */
755 	ioat_chan->tail = idx + active;
756 
757 	desc = ioat_get_ring_ent(ioat_chan, ioat_chan->tail);
758 	ioat_chan->last_completion = *ioat_chan->completion = desc->txd.phys;
759 }
760 
761 static void ioat_eh(struct ioatdma_chan *ioat_chan)
762 {
763 	struct pci_dev *pdev = to_pdev(ioat_chan);
764 	struct ioat_dma_descriptor *hw;
765 	struct dma_async_tx_descriptor *tx;
766 	u64 phys_complete;
767 	struct ioat_ring_ent *desc;
768 	u32 err_handled = 0;
769 	u32 chanerr_int;
770 	u32 chanerr;
771 	bool abort = false;
772 	struct dmaengine_result res;
773 
774 	/* cleanup so tail points to descriptor that caused the error */
775 	if (ioat_cleanup_preamble(ioat_chan, &phys_complete))
776 		__cleanup(ioat_chan, phys_complete);
777 
778 	chanerr = readl(ioat_chan->reg_base + IOAT_CHANERR_OFFSET);
779 	pci_read_config_dword(pdev, IOAT_PCI_CHANERR_INT_OFFSET, &chanerr_int);
780 
781 	dev_dbg(to_dev(ioat_chan), "%s: error = %x:%x\n",
782 		__func__, chanerr, chanerr_int);
783 
784 	desc = ioat_get_ring_ent(ioat_chan, ioat_chan->tail);
785 	hw = desc->hw;
786 	dump_desc_dbg(ioat_chan, desc);
787 
788 	switch (hw->ctl_f.op) {
789 	case IOAT_OP_XOR_VAL:
790 		if (chanerr & IOAT_CHANERR_XOR_P_OR_CRC_ERR) {
791 			*desc->result |= SUM_CHECK_P_RESULT;
792 			err_handled |= IOAT_CHANERR_XOR_P_OR_CRC_ERR;
793 		}
794 		break;
795 	case IOAT_OP_PQ_VAL:
796 	case IOAT_OP_PQ_VAL_16S:
797 		if (chanerr & IOAT_CHANERR_XOR_P_OR_CRC_ERR) {
798 			*desc->result |= SUM_CHECK_P_RESULT;
799 			err_handled |= IOAT_CHANERR_XOR_P_OR_CRC_ERR;
800 		}
801 		if (chanerr & IOAT_CHANERR_XOR_Q_ERR) {
802 			*desc->result |= SUM_CHECK_Q_RESULT;
803 			err_handled |= IOAT_CHANERR_XOR_Q_ERR;
804 		}
805 		break;
806 	}
807 
808 	if (chanerr & IOAT_CHANERR_RECOVER_MASK) {
809 		if (chanerr & IOAT_CHANERR_READ_DATA_ERR) {
810 			res.result = DMA_TRANS_READ_FAILED;
811 			err_handled |= IOAT_CHANERR_READ_DATA_ERR;
812 		} else if (chanerr & IOAT_CHANERR_WRITE_DATA_ERR) {
813 			res.result = DMA_TRANS_WRITE_FAILED;
814 			err_handled |= IOAT_CHANERR_WRITE_DATA_ERR;
815 		}
816 
817 		abort = true;
818 	} else
819 		res.result = DMA_TRANS_NOERROR;
820 
821 	/* fault on unhandled error or spurious halt */
822 	if (chanerr ^ err_handled || chanerr == 0) {
823 		dev_err(to_dev(ioat_chan), "%s: fatal error (%x:%x)\n",
824 			__func__, chanerr, err_handled);
825 		dev_err(to_dev(ioat_chan), "Errors handled:\n");
826 		ioat_print_chanerrs(ioat_chan, err_handled);
827 		dev_err(to_dev(ioat_chan), "Errors not handled:\n");
828 		ioat_print_chanerrs(ioat_chan, (chanerr & ~err_handled));
829 
830 		BUG();
831 	}
832 
833 	/* cleanup the faulty descriptor since we are continuing */
834 	tx = &desc->txd;
835 	if (tx->cookie) {
836 		dma_cookie_complete(tx);
837 		dma_descriptor_unmap(tx);
838 		dmaengine_desc_get_callback_invoke(tx, &res);
839 		tx->callback = NULL;
840 		tx->callback_result = NULL;
841 	}
842 
843 	/* mark faulting descriptor as complete */
844 	*ioat_chan->completion = desc->txd.phys;
845 
846 	spin_lock_bh(&ioat_chan->prep_lock);
847 	/* we need abort all descriptors */
848 	if (abort) {
849 		ioat_abort_descs(ioat_chan);
850 		/* clean up the channel, we could be in weird state */
851 		ioat_reset_hw(ioat_chan);
852 	}
853 
854 	writel(chanerr, ioat_chan->reg_base + IOAT_CHANERR_OFFSET);
855 	pci_write_config_dword(pdev, IOAT_PCI_CHANERR_INT_OFFSET, chanerr_int);
856 
857 	ioat_restart_channel(ioat_chan);
858 	spin_unlock_bh(&ioat_chan->prep_lock);
859 }
860 
861 static void check_active(struct ioatdma_chan *ioat_chan)
862 {
863 	if (ioat_ring_active(ioat_chan)) {
864 		mod_timer(&ioat_chan->timer, jiffies + COMPLETION_TIMEOUT);
865 		return;
866 	}
867 
868 	if (test_and_clear_bit(IOAT_CHAN_ACTIVE, &ioat_chan->state))
869 		mod_timer(&ioat_chan->timer, jiffies + IDLE_TIMEOUT);
870 }
871 
872 static void ioat_reboot_chan(struct ioatdma_chan *ioat_chan)
873 {
874 	spin_lock_bh(&ioat_chan->prep_lock);
875 	set_bit(IOAT_CHAN_DOWN, &ioat_chan->state);
876 	spin_unlock_bh(&ioat_chan->prep_lock);
877 
878 	ioat_abort_descs(ioat_chan);
879 	dev_warn(to_dev(ioat_chan), "Reset channel...\n");
880 	ioat_reset_hw(ioat_chan);
881 	dev_warn(to_dev(ioat_chan), "Restart channel...\n");
882 	ioat_restart_channel(ioat_chan);
883 
884 	spin_lock_bh(&ioat_chan->prep_lock);
885 	clear_bit(IOAT_CHAN_DOWN, &ioat_chan->state);
886 	spin_unlock_bh(&ioat_chan->prep_lock);
887 }
888 
889 void ioat_timer_event(struct timer_list *t)
890 {
891 	struct ioatdma_chan *ioat_chan = from_timer(ioat_chan, t, timer);
892 	dma_addr_t phys_complete;
893 	u64 status;
894 
895 	status = ioat_chansts(ioat_chan);
896 
897 	/* when halted due to errors check for channel
898 	 * programming errors before advancing the completion state
899 	 */
900 	if (is_ioat_halted(status)) {
901 		u32 chanerr;
902 
903 		chanerr = readl(ioat_chan->reg_base + IOAT_CHANERR_OFFSET);
904 		dev_err(to_dev(ioat_chan), "%s: Channel halted (%x)\n",
905 			__func__, chanerr);
906 		dev_err(to_dev(ioat_chan), "Errors:\n");
907 		ioat_print_chanerrs(ioat_chan, chanerr);
908 
909 		if (test_bit(IOAT_RUN, &ioat_chan->state)) {
910 			spin_lock_bh(&ioat_chan->cleanup_lock);
911 			ioat_reboot_chan(ioat_chan);
912 			spin_unlock_bh(&ioat_chan->cleanup_lock);
913 		}
914 
915 		return;
916 	}
917 
918 	spin_lock_bh(&ioat_chan->cleanup_lock);
919 
920 	/* handle the no-actives case */
921 	if (!ioat_ring_active(ioat_chan)) {
922 		spin_lock_bh(&ioat_chan->prep_lock);
923 		check_active(ioat_chan);
924 		spin_unlock_bh(&ioat_chan->prep_lock);
925 		goto unlock_out;
926 	}
927 
928 	/* handle the missed cleanup case */
929 	if (ioat_cleanup_preamble(ioat_chan, &phys_complete)) {
930 		/* timer restarted in ioat_cleanup_preamble
931 		 * and IOAT_COMPLETION_ACK cleared
932 		 */
933 		__cleanup(ioat_chan, phys_complete);
934 		goto unlock_out;
935 	}
936 
937 	/* if we haven't made progress and we have already
938 	 * acknowledged a pending completion once, then be more
939 	 * forceful with a restart
940 	 */
941 	if (test_bit(IOAT_COMPLETION_ACK, &ioat_chan->state)) {
942 		u32 chanerr;
943 
944 		chanerr = readl(ioat_chan->reg_base + IOAT_CHANERR_OFFSET);
945 		dev_err(to_dev(ioat_chan), "CHANSTS: %#Lx CHANERR: %#x\n",
946 			status, chanerr);
947 		dev_err(to_dev(ioat_chan), "Errors:\n");
948 		ioat_print_chanerrs(ioat_chan, chanerr);
949 
950 		dev_dbg(to_dev(ioat_chan), "Active descriptors: %d\n",
951 			ioat_ring_active(ioat_chan));
952 
953 		ioat_reboot_chan(ioat_chan);
954 
955 		goto unlock_out;
956 	}
957 
958 	/* handle missed issue pending case */
959 	if (ioat_ring_pending(ioat_chan)) {
960 		dev_warn(to_dev(ioat_chan),
961 			"Completion timeout with pending descriptors\n");
962 		spin_lock_bh(&ioat_chan->prep_lock);
963 		__ioat_issue_pending(ioat_chan);
964 		spin_unlock_bh(&ioat_chan->prep_lock);
965 	}
966 
967 	set_bit(IOAT_COMPLETION_ACK, &ioat_chan->state);
968 	mod_timer(&ioat_chan->timer, jiffies + COMPLETION_TIMEOUT);
969 unlock_out:
970 	spin_unlock_bh(&ioat_chan->cleanup_lock);
971 }
972 
973 enum dma_status
974 ioat_tx_status(struct dma_chan *c, dma_cookie_t cookie,
975 		struct dma_tx_state *txstate)
976 {
977 	struct ioatdma_chan *ioat_chan = to_ioat_chan(c);
978 	enum dma_status ret;
979 
980 	ret = dma_cookie_status(c, cookie, txstate);
981 	if (ret == DMA_COMPLETE)
982 		return ret;
983 
984 	ioat_cleanup(ioat_chan);
985 
986 	return dma_cookie_status(c, cookie, txstate);
987 }
988 
989 int ioat_reset_hw(struct ioatdma_chan *ioat_chan)
990 {
991 	/* throw away whatever the channel was doing and get it
992 	 * initialized, with ioat3 specific workarounds
993 	 */
994 	struct ioatdma_device *ioat_dma = ioat_chan->ioat_dma;
995 	struct pci_dev *pdev = ioat_dma->pdev;
996 	u32 chanerr;
997 	u16 dev_id;
998 	int err;
999 
1000 	ioat_quiesce(ioat_chan, msecs_to_jiffies(100));
1001 
1002 	chanerr = readl(ioat_chan->reg_base + IOAT_CHANERR_OFFSET);
1003 	writel(chanerr, ioat_chan->reg_base + IOAT_CHANERR_OFFSET);
1004 
1005 	if (ioat_dma->version < IOAT_VER_3_3) {
1006 		/* clear any pending errors */
1007 		err = pci_read_config_dword(pdev,
1008 				IOAT_PCI_CHANERR_INT_OFFSET, &chanerr);
1009 		if (err) {
1010 			dev_err(&pdev->dev,
1011 				"channel error register unreachable\n");
1012 			return err;
1013 		}
1014 		pci_write_config_dword(pdev,
1015 				IOAT_PCI_CHANERR_INT_OFFSET, chanerr);
1016 
1017 		/* Clear DMAUNCERRSTS Cfg-Reg Parity Error status bit
1018 		 * (workaround for spurious config parity error after restart)
1019 		 */
1020 		pci_read_config_word(pdev, IOAT_PCI_DEVICE_ID_OFFSET, &dev_id);
1021 		if (dev_id == PCI_DEVICE_ID_INTEL_IOAT_TBG0) {
1022 			pci_write_config_dword(pdev,
1023 					       IOAT_PCI_DMAUNCERRSTS_OFFSET,
1024 					       0x10);
1025 		}
1026 	}
1027 
1028 	if (is_bwd_ioat(pdev) && (ioat_dma->irq_mode == IOAT_MSIX)) {
1029 		ioat_dma->msixtba0 = readq(ioat_dma->reg_base + 0x1000);
1030 		ioat_dma->msixdata0 = readq(ioat_dma->reg_base + 0x1008);
1031 		ioat_dma->msixpba = readq(ioat_dma->reg_base + 0x1800);
1032 	}
1033 
1034 
1035 	err = ioat_reset_sync(ioat_chan, msecs_to_jiffies(200));
1036 	if (!err) {
1037 		if (is_bwd_ioat(pdev) && (ioat_dma->irq_mode == IOAT_MSIX)) {
1038 			writeq(ioat_dma->msixtba0, ioat_dma->reg_base + 0x1000);
1039 			writeq(ioat_dma->msixdata0, ioat_dma->reg_base + 0x1008);
1040 			writeq(ioat_dma->msixpba, ioat_dma->reg_base + 0x1800);
1041 		}
1042 	}
1043 
1044 	if (err)
1045 		dev_err(&pdev->dev, "Failed to reset: %d\n", err);
1046 
1047 	return err;
1048 }
1049