xref: /openbmc/linux/drivers/dma/ioat/dma.c (revision 842ed298)
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 int completion_timeout = 200;
30 module_param(completion_timeout, int, 0644);
31 MODULE_PARM_DESC(completion_timeout,
32 		"set ioat completion timeout [msec] (default 200 [msec])");
33 static int idle_timeout = 2000;
34 module_param(idle_timeout, int, 0644);
35 MODULE_PARM_DESC(idle_timeout,
36 		"set ioat idel timeout [msec] (default 2000 [msec])");
37 
38 #define IDLE_TIMEOUT msecs_to_jiffies(idle_timeout)
39 #define COMPLETION_TIMEOUT msecs_to_jiffies(completion_timeout)
40 
41 static char *chanerr_str[] = {
42 	"DMA Transfer Source Address Error",
43 	"DMA Transfer Destination Address Error",
44 	"Next Descriptor Address Error",
45 	"Descriptor Error",
46 	"Chan Address Value Error",
47 	"CHANCMD Error",
48 	"Chipset Uncorrectable Data Integrity Error",
49 	"DMA Uncorrectable Data Integrity Error",
50 	"Read Data Error",
51 	"Write Data Error",
52 	"Descriptor Control Error",
53 	"Descriptor Transfer Size Error",
54 	"Completion Address Error",
55 	"Interrupt Configuration Error",
56 	"Super extended descriptor Address Error",
57 	"Unaffiliated Error",
58 	"CRC or XOR P Error",
59 	"XOR Q Error",
60 	"Descriptor Count Error",
61 	"DIF All F detect Error",
62 	"Guard Tag verification Error",
63 	"Application Tag verification Error",
64 	"Reference Tag verification Error",
65 	"Bundle Bit Error",
66 	"Result DIF All F detect Error",
67 	"Result Guard Tag verification Error",
68 	"Result Application Tag verification Error",
69 	"Result Reference Tag verification Error",
70 };
71 
72 static void ioat_eh(struct ioatdma_chan *ioat_chan);
73 
74 static void ioat_print_chanerrs(struct ioatdma_chan *ioat_chan, u32 chanerr)
75 {
76 	int i;
77 
78 	for (i = 0; i < ARRAY_SIZE(chanerr_str); i++) {
79 		if ((chanerr >> i) & 1) {
80 			dev_err(to_dev(ioat_chan), "Err(%d): %s\n",
81 				i, chanerr_str[i]);
82 		}
83 	}
84 }
85 
86 /**
87  * ioat_dma_do_interrupt - handler used for single vector interrupt mode
88  * @irq: interrupt id
89  * @data: interrupt data
90  */
91 irqreturn_t ioat_dma_do_interrupt(int irq, void *data)
92 {
93 	struct ioatdma_device *instance = data;
94 	struct ioatdma_chan *ioat_chan;
95 	unsigned long attnstatus;
96 	int bit;
97 	u8 intrctrl;
98 
99 	intrctrl = readb(instance->reg_base + IOAT_INTRCTRL_OFFSET);
100 
101 	if (!(intrctrl & IOAT_INTRCTRL_MASTER_INT_EN))
102 		return IRQ_NONE;
103 
104 	if (!(intrctrl & IOAT_INTRCTRL_INT_STATUS)) {
105 		writeb(intrctrl, instance->reg_base + IOAT_INTRCTRL_OFFSET);
106 		return IRQ_NONE;
107 	}
108 
109 	attnstatus = readl(instance->reg_base + IOAT_ATTNSTATUS_OFFSET);
110 	for_each_set_bit(bit, &attnstatus, BITS_PER_LONG) {
111 		ioat_chan = ioat_chan_by_index(instance, bit);
112 		if (test_bit(IOAT_RUN, &ioat_chan->state))
113 			tasklet_schedule(&ioat_chan->cleanup_task);
114 	}
115 
116 	writeb(intrctrl, instance->reg_base + IOAT_INTRCTRL_OFFSET);
117 	return IRQ_HANDLED;
118 }
119 
120 /**
121  * ioat_dma_do_interrupt_msix - handler used for vector-per-channel interrupt mode
122  * @irq: interrupt id
123  * @data: interrupt data
124  */
125 irqreturn_t ioat_dma_do_interrupt_msix(int irq, void *data)
126 {
127 	struct ioatdma_chan *ioat_chan = data;
128 
129 	if (test_bit(IOAT_RUN, &ioat_chan->state))
130 		tasklet_schedule(&ioat_chan->cleanup_task);
131 
132 	return IRQ_HANDLED;
133 }
134 
135 void ioat_stop(struct ioatdma_chan *ioat_chan)
136 {
137 	struct ioatdma_device *ioat_dma = ioat_chan->ioat_dma;
138 	struct pci_dev *pdev = ioat_dma->pdev;
139 	int chan_id = chan_num(ioat_chan);
140 	struct msix_entry *msix;
141 
142 	/* 1/ stop irq from firing tasklets
143 	 * 2/ stop the tasklet from re-arming irqs
144 	 */
145 	clear_bit(IOAT_RUN, &ioat_chan->state);
146 
147 	/* flush inflight interrupts */
148 	switch (ioat_dma->irq_mode) {
149 	case IOAT_MSIX:
150 		msix = &ioat_dma->msix_entries[chan_id];
151 		synchronize_irq(msix->vector);
152 		break;
153 	case IOAT_MSI:
154 	case IOAT_INTX:
155 		synchronize_irq(pdev->irq);
156 		break;
157 	default:
158 		break;
159 	}
160 
161 	/* flush inflight timers */
162 	del_timer_sync(&ioat_chan->timer);
163 
164 	/* flush inflight tasklet runs */
165 	tasklet_kill(&ioat_chan->cleanup_task);
166 
167 	/* final cleanup now that everything is quiesced and can't re-arm */
168 	ioat_cleanup_event(&ioat_chan->cleanup_task);
169 }
170 
171 static void __ioat_issue_pending(struct ioatdma_chan *ioat_chan)
172 {
173 	ioat_chan->dmacount += ioat_ring_pending(ioat_chan);
174 	ioat_chan->issued = ioat_chan->head;
175 	writew(ioat_chan->dmacount,
176 	       ioat_chan->reg_base + IOAT_CHAN_DMACOUNT_OFFSET);
177 	dev_dbg(to_dev(ioat_chan),
178 		"%s: head: %#x tail: %#x issued: %#x count: %#x\n",
179 		__func__, ioat_chan->head, ioat_chan->tail,
180 		ioat_chan->issued, ioat_chan->dmacount);
181 }
182 
183 void ioat_issue_pending(struct dma_chan *c)
184 {
185 	struct ioatdma_chan *ioat_chan = to_ioat_chan(c);
186 
187 	if (ioat_ring_pending(ioat_chan)) {
188 		spin_lock_bh(&ioat_chan->prep_lock);
189 		__ioat_issue_pending(ioat_chan);
190 		spin_unlock_bh(&ioat_chan->prep_lock);
191 	}
192 }
193 
194 /**
195  * ioat_update_pending - log pending descriptors
196  * @ioat_chan: ioat+ channel
197  *
198  * Check if the number of unsubmitted descriptors has exceeded the
199  * watermark.  Called with prep_lock held
200  */
201 static void ioat_update_pending(struct ioatdma_chan *ioat_chan)
202 {
203 	if (ioat_ring_pending(ioat_chan) > ioat_pending_level)
204 		__ioat_issue_pending(ioat_chan);
205 }
206 
207 static void __ioat_start_null_desc(struct ioatdma_chan *ioat_chan)
208 {
209 	struct ioat_ring_ent *desc;
210 	struct ioat_dma_descriptor *hw;
211 
212 	if (ioat_ring_space(ioat_chan) < 1) {
213 		dev_err(to_dev(ioat_chan),
214 			"Unable to start null desc - ring full\n");
215 		return;
216 	}
217 
218 	dev_dbg(to_dev(ioat_chan),
219 		"%s: head: %#x tail: %#x issued: %#x\n",
220 		__func__, ioat_chan->head, ioat_chan->tail, ioat_chan->issued);
221 	desc = ioat_get_ring_ent(ioat_chan, ioat_chan->head);
222 
223 	hw = desc->hw;
224 	hw->ctl = 0;
225 	hw->ctl_f.null = 1;
226 	hw->ctl_f.int_en = 1;
227 	hw->ctl_f.compl_write = 1;
228 	/* set size to non-zero value (channel returns error when size is 0) */
229 	hw->size = NULL_DESC_BUFFER_SIZE;
230 	hw->src_addr = 0;
231 	hw->dst_addr = 0;
232 	async_tx_ack(&desc->txd);
233 	ioat_set_chainaddr(ioat_chan, desc->txd.phys);
234 	dump_desc_dbg(ioat_chan, desc);
235 	/* make sure descriptors are written before we submit */
236 	wmb();
237 	ioat_chan->head += 1;
238 	__ioat_issue_pending(ioat_chan);
239 }
240 
241 void ioat_start_null_desc(struct ioatdma_chan *ioat_chan)
242 {
243 	spin_lock_bh(&ioat_chan->prep_lock);
244 	if (!test_bit(IOAT_CHAN_DOWN, &ioat_chan->state))
245 		__ioat_start_null_desc(ioat_chan);
246 	spin_unlock_bh(&ioat_chan->prep_lock);
247 }
248 
249 static void __ioat_restart_chan(struct ioatdma_chan *ioat_chan)
250 {
251 	/* set the tail to be re-issued */
252 	ioat_chan->issued = ioat_chan->tail;
253 	ioat_chan->dmacount = 0;
254 	mod_timer(&ioat_chan->timer, jiffies + COMPLETION_TIMEOUT);
255 
256 	dev_dbg(to_dev(ioat_chan),
257 		"%s: head: %#x tail: %#x issued: %#x count: %#x\n",
258 		__func__, ioat_chan->head, ioat_chan->tail,
259 		ioat_chan->issued, ioat_chan->dmacount);
260 
261 	if (ioat_ring_pending(ioat_chan)) {
262 		struct ioat_ring_ent *desc;
263 
264 		desc = ioat_get_ring_ent(ioat_chan, ioat_chan->tail);
265 		ioat_set_chainaddr(ioat_chan, desc->txd.phys);
266 		__ioat_issue_pending(ioat_chan);
267 	} else
268 		__ioat_start_null_desc(ioat_chan);
269 }
270 
271 static int ioat_quiesce(struct ioatdma_chan *ioat_chan, unsigned long tmo)
272 {
273 	unsigned long end = jiffies + tmo;
274 	int err = 0;
275 	u32 status;
276 
277 	status = ioat_chansts(ioat_chan);
278 	if (is_ioat_active(status) || is_ioat_idle(status))
279 		ioat_suspend(ioat_chan);
280 	while (is_ioat_active(status) || is_ioat_idle(status)) {
281 		if (tmo && time_after(jiffies, end)) {
282 			err = -ETIMEDOUT;
283 			break;
284 		}
285 		status = ioat_chansts(ioat_chan);
286 		cpu_relax();
287 	}
288 
289 	return err;
290 }
291 
292 static int ioat_reset_sync(struct ioatdma_chan *ioat_chan, unsigned long tmo)
293 {
294 	unsigned long end = jiffies + tmo;
295 	int err = 0;
296 
297 	ioat_reset(ioat_chan);
298 	while (ioat_reset_pending(ioat_chan)) {
299 		if (end && time_after(jiffies, end)) {
300 			err = -ETIMEDOUT;
301 			break;
302 		}
303 		cpu_relax();
304 	}
305 
306 	return err;
307 }
308 
309 static dma_cookie_t ioat_tx_submit_unlock(struct dma_async_tx_descriptor *tx)
310 	__releases(&ioat_chan->prep_lock)
311 {
312 	struct dma_chan *c = tx->chan;
313 	struct ioatdma_chan *ioat_chan = to_ioat_chan(c);
314 	dma_cookie_t cookie;
315 
316 	cookie = dma_cookie_assign(tx);
317 	dev_dbg(to_dev(ioat_chan), "%s: cookie: %d\n", __func__, cookie);
318 
319 	if (!test_and_set_bit(IOAT_CHAN_ACTIVE, &ioat_chan->state))
320 		mod_timer(&ioat_chan->timer, jiffies + COMPLETION_TIMEOUT);
321 
322 	/* make descriptor updates visible before advancing ioat->head,
323 	 * this is purposefully not smp_wmb() since we are also
324 	 * publishing the descriptor updates to a dma device
325 	 */
326 	wmb();
327 
328 	ioat_chan->head += ioat_chan->produce;
329 
330 	ioat_update_pending(ioat_chan);
331 	spin_unlock_bh(&ioat_chan->prep_lock);
332 
333 	return cookie;
334 }
335 
336 static struct ioat_ring_ent *
337 ioat_alloc_ring_ent(struct dma_chan *chan, int idx, gfp_t flags)
338 {
339 	struct ioat_dma_descriptor *hw;
340 	struct ioat_ring_ent *desc;
341 	struct ioatdma_chan *ioat_chan = to_ioat_chan(chan);
342 	int chunk;
343 	dma_addr_t phys;
344 	u8 *pos;
345 	off_t offs;
346 
347 	chunk = idx / IOAT_DESCS_PER_CHUNK;
348 	idx &= (IOAT_DESCS_PER_CHUNK - 1);
349 	offs = idx * IOAT_DESC_SZ;
350 	pos = (u8 *)ioat_chan->descs[chunk].virt + offs;
351 	phys = ioat_chan->descs[chunk].hw + offs;
352 	hw = (struct ioat_dma_descriptor *)pos;
353 	memset(hw, 0, sizeof(*hw));
354 
355 	desc = kmem_cache_zalloc(ioat_cache, flags);
356 	if (!desc)
357 		return NULL;
358 
359 	dma_async_tx_descriptor_init(&desc->txd, chan);
360 	desc->txd.tx_submit = ioat_tx_submit_unlock;
361 	desc->hw = hw;
362 	desc->txd.phys = phys;
363 	return desc;
364 }
365 
366 void ioat_free_ring_ent(struct ioat_ring_ent *desc, struct dma_chan *chan)
367 {
368 	kmem_cache_free(ioat_cache, desc);
369 }
370 
371 struct ioat_ring_ent **
372 ioat_alloc_ring(struct dma_chan *c, int order, gfp_t flags)
373 {
374 	struct ioatdma_chan *ioat_chan = to_ioat_chan(c);
375 	struct ioatdma_device *ioat_dma = ioat_chan->ioat_dma;
376 	struct ioat_ring_ent **ring;
377 	int total_descs = 1 << order;
378 	int i, chunks;
379 
380 	/* allocate the array to hold the software ring */
381 	ring = kcalloc(total_descs, sizeof(*ring), flags);
382 	if (!ring)
383 		return NULL;
384 
385 	chunks = (total_descs * IOAT_DESC_SZ) / IOAT_CHUNK_SIZE;
386 	ioat_chan->desc_chunks = chunks;
387 
388 	for (i = 0; i < chunks; i++) {
389 		struct ioat_descs *descs = &ioat_chan->descs[i];
390 
391 		descs->virt = dma_alloc_coherent(to_dev(ioat_chan),
392 					IOAT_CHUNK_SIZE, &descs->hw, flags);
393 		if (!descs->virt) {
394 			int idx;
395 
396 			for (idx = 0; idx < i; idx++) {
397 				descs = &ioat_chan->descs[idx];
398 				dma_free_coherent(to_dev(ioat_chan),
399 						IOAT_CHUNK_SIZE,
400 						descs->virt, descs->hw);
401 				descs->virt = NULL;
402 				descs->hw = 0;
403 			}
404 
405 			ioat_chan->desc_chunks = 0;
406 			kfree(ring);
407 			return NULL;
408 		}
409 	}
410 
411 	for (i = 0; i < total_descs; i++) {
412 		ring[i] = ioat_alloc_ring_ent(c, i, flags);
413 		if (!ring[i]) {
414 			int idx;
415 
416 			while (i--)
417 				ioat_free_ring_ent(ring[i], c);
418 
419 			for (idx = 0; idx < ioat_chan->desc_chunks; idx++) {
420 				dma_free_coherent(to_dev(ioat_chan),
421 						  IOAT_CHUNK_SIZE,
422 						  ioat_chan->descs[idx].virt,
423 						  ioat_chan->descs[idx].hw);
424 				ioat_chan->descs[idx].virt = NULL;
425 				ioat_chan->descs[idx].hw = 0;
426 			}
427 
428 			ioat_chan->desc_chunks = 0;
429 			kfree(ring);
430 			return NULL;
431 		}
432 		set_desc_id(ring[i], i);
433 	}
434 
435 	/* link descs */
436 	for (i = 0; i < total_descs-1; i++) {
437 		struct ioat_ring_ent *next = ring[i+1];
438 		struct ioat_dma_descriptor *hw = ring[i]->hw;
439 
440 		hw->next = next->txd.phys;
441 	}
442 	ring[i]->hw->next = ring[0]->txd.phys;
443 
444 	/* setup descriptor pre-fetching for v3.4 */
445 	if (ioat_dma->cap & IOAT_CAP_DPS) {
446 		u16 drsctl = IOAT_CHAN_DRSZ_2MB | IOAT_CHAN_DRS_EN;
447 
448 		if (chunks == 1)
449 			drsctl |= IOAT_CHAN_DRS_AUTOWRAP;
450 
451 		writew(drsctl, ioat_chan->reg_base + IOAT_CHAN_DRSCTL_OFFSET);
452 
453 	}
454 
455 	return ring;
456 }
457 
458 /**
459  * ioat_check_space_lock - verify space and grab ring producer lock
460  * @ioat_chan: ioat,3 channel (ring) to operate on
461  * @num_descs: allocation length
462  */
463 int ioat_check_space_lock(struct ioatdma_chan *ioat_chan, int num_descs)
464 	__acquires(&ioat_chan->prep_lock)
465 {
466 	spin_lock_bh(&ioat_chan->prep_lock);
467 	/* never allow the last descriptor to be consumed, we need at
468 	 * least one free at all times to allow for on-the-fly ring
469 	 * resizing.
470 	 */
471 	if (likely(ioat_ring_space(ioat_chan) > num_descs)) {
472 		dev_dbg(to_dev(ioat_chan), "%s: num_descs: %d (%x:%x:%x)\n",
473 			__func__, num_descs, ioat_chan->head,
474 			ioat_chan->tail, ioat_chan->issued);
475 		ioat_chan->produce = num_descs;
476 		return 0;  /* with ioat->prep_lock held */
477 	}
478 	spin_unlock_bh(&ioat_chan->prep_lock);
479 
480 	dev_dbg_ratelimited(to_dev(ioat_chan),
481 			    "%s: ring full! num_descs: %d (%x:%x:%x)\n",
482 			    __func__, num_descs, ioat_chan->head,
483 			    ioat_chan->tail, ioat_chan->issued);
484 
485 	/* progress reclaim in the allocation failure case we may be
486 	 * called under bh_disabled so we need to trigger the timer
487 	 * event directly
488 	 */
489 	if (time_is_before_jiffies(ioat_chan->timer.expires)
490 	    && timer_pending(&ioat_chan->timer)) {
491 		mod_timer(&ioat_chan->timer, jiffies + COMPLETION_TIMEOUT);
492 		ioat_timer_event(&ioat_chan->timer);
493 	}
494 
495 	return -ENOMEM;
496 }
497 
498 static bool desc_has_ext(struct ioat_ring_ent *desc)
499 {
500 	struct ioat_dma_descriptor *hw = desc->hw;
501 
502 	if (hw->ctl_f.op == IOAT_OP_XOR ||
503 	    hw->ctl_f.op == IOAT_OP_XOR_VAL) {
504 		struct ioat_xor_descriptor *xor = desc->xor;
505 
506 		if (src_cnt_to_sw(xor->ctl_f.src_cnt) > 5)
507 			return true;
508 	} else if (hw->ctl_f.op == IOAT_OP_PQ ||
509 		   hw->ctl_f.op == IOAT_OP_PQ_VAL) {
510 		struct ioat_pq_descriptor *pq = desc->pq;
511 
512 		if (src_cnt_to_sw(pq->ctl_f.src_cnt) > 3)
513 			return true;
514 	}
515 
516 	return false;
517 }
518 
519 static void
520 ioat_free_sed(struct ioatdma_device *ioat_dma, struct ioat_sed_ent *sed)
521 {
522 	if (!sed)
523 		return;
524 
525 	dma_pool_free(ioat_dma->sed_hw_pool[sed->hw_pool], sed->hw, sed->dma);
526 	kmem_cache_free(ioat_sed_cache, sed);
527 }
528 
529 static u64 ioat_get_current_completion(struct ioatdma_chan *ioat_chan)
530 {
531 	u64 phys_complete;
532 	u64 completion;
533 
534 	completion = *ioat_chan->completion;
535 	phys_complete = ioat_chansts_to_addr(completion);
536 
537 	dev_dbg(to_dev(ioat_chan), "%s: phys_complete: %#llx\n", __func__,
538 		(unsigned long long) phys_complete);
539 
540 	return phys_complete;
541 }
542 
543 static bool ioat_cleanup_preamble(struct ioatdma_chan *ioat_chan,
544 				   u64 *phys_complete)
545 {
546 	*phys_complete = ioat_get_current_completion(ioat_chan);
547 	if (*phys_complete == ioat_chan->last_completion)
548 		return false;
549 
550 	clear_bit(IOAT_COMPLETION_ACK, &ioat_chan->state);
551 	mod_timer(&ioat_chan->timer, jiffies + COMPLETION_TIMEOUT);
552 
553 	return true;
554 }
555 
556 static void
557 desc_get_errstat(struct ioatdma_chan *ioat_chan, struct ioat_ring_ent *desc)
558 {
559 	struct ioat_dma_descriptor *hw = desc->hw;
560 
561 	switch (hw->ctl_f.op) {
562 	case IOAT_OP_PQ_VAL:
563 	case IOAT_OP_PQ_VAL_16S:
564 	{
565 		struct ioat_pq_descriptor *pq = desc->pq;
566 
567 		/* check if there's error written */
568 		if (!pq->dwbes_f.wbes)
569 			return;
570 
571 		/* need to set a chanerr var for checking to clear later */
572 
573 		if (pq->dwbes_f.p_val_err)
574 			*desc->result |= SUM_CHECK_P_RESULT;
575 
576 		if (pq->dwbes_f.q_val_err)
577 			*desc->result |= SUM_CHECK_Q_RESULT;
578 
579 		return;
580 	}
581 	default:
582 		return;
583 	}
584 }
585 
586 /**
587  * __cleanup - reclaim used descriptors
588  * @ioat_chan: channel (ring) to clean
589  * @phys_complete: zeroed (or not) completion address (from status)
590  */
591 static void __cleanup(struct ioatdma_chan *ioat_chan, dma_addr_t phys_complete)
592 {
593 	struct ioatdma_device *ioat_dma = ioat_chan->ioat_dma;
594 	struct ioat_ring_ent *desc;
595 	bool seen_current = false;
596 	int idx = ioat_chan->tail, i;
597 	u16 active;
598 
599 	dev_dbg(to_dev(ioat_chan), "%s: head: %#x tail: %#x issued: %#x\n",
600 		__func__, ioat_chan->head, ioat_chan->tail, ioat_chan->issued);
601 
602 	/*
603 	 * At restart of the channel, the completion address and the
604 	 * channel status will be 0 due to starting a new chain. Since
605 	 * it's new chain and the first descriptor "fails", there is
606 	 * nothing to clean up. We do not want to reap the entire submitted
607 	 * chain due to this 0 address value and then BUG.
608 	 */
609 	if (!phys_complete)
610 		return;
611 
612 	active = ioat_ring_active(ioat_chan);
613 	for (i = 0; i < active && !seen_current; i++) {
614 		struct dma_async_tx_descriptor *tx;
615 
616 		prefetch(ioat_get_ring_ent(ioat_chan, idx + i + 1));
617 		desc = ioat_get_ring_ent(ioat_chan, idx + i);
618 		dump_desc_dbg(ioat_chan, desc);
619 
620 		/* set err stat if we are using dwbes */
621 		if (ioat_dma->cap & IOAT_CAP_DWBES)
622 			desc_get_errstat(ioat_chan, desc);
623 
624 		tx = &desc->txd;
625 		if (tx->cookie) {
626 			dma_cookie_complete(tx);
627 			dma_descriptor_unmap(tx);
628 			dmaengine_desc_get_callback_invoke(tx, NULL);
629 			tx->callback = NULL;
630 			tx->callback_result = NULL;
631 		}
632 
633 		if (tx->phys == phys_complete)
634 			seen_current = true;
635 
636 		/* skip extended descriptors */
637 		if (desc_has_ext(desc)) {
638 			BUG_ON(i + 1 >= active);
639 			i++;
640 		}
641 
642 		/* cleanup super extended descriptors */
643 		if (desc->sed) {
644 			ioat_free_sed(ioat_dma, desc->sed);
645 			desc->sed = NULL;
646 		}
647 	}
648 
649 	/* finish all descriptor reads before incrementing tail */
650 	smp_mb();
651 	ioat_chan->tail = idx + i;
652 	/* no active descs have written a completion? */
653 	BUG_ON(active && !seen_current);
654 	ioat_chan->last_completion = phys_complete;
655 
656 	if (active - i == 0) {
657 		dev_dbg(to_dev(ioat_chan), "%s: cancel completion timeout\n",
658 			__func__);
659 		mod_timer(&ioat_chan->timer, jiffies + IDLE_TIMEOUT);
660 	}
661 
662 	/* microsecond delay by sysfs variable  per pending descriptor */
663 	if (ioat_chan->intr_coalesce != ioat_chan->prev_intr_coalesce) {
664 		writew(min((ioat_chan->intr_coalesce * (active - i)),
665 		       IOAT_INTRDELAY_MASK),
666 		       ioat_chan->ioat_dma->reg_base + IOAT_INTRDELAY_OFFSET);
667 		ioat_chan->prev_intr_coalesce = ioat_chan->intr_coalesce;
668 	}
669 }
670 
671 static void ioat_cleanup(struct ioatdma_chan *ioat_chan)
672 {
673 	u64 phys_complete;
674 
675 	spin_lock_bh(&ioat_chan->cleanup_lock);
676 
677 	if (ioat_cleanup_preamble(ioat_chan, &phys_complete))
678 		__cleanup(ioat_chan, phys_complete);
679 
680 	if (is_ioat_halted(*ioat_chan->completion)) {
681 		u32 chanerr = readl(ioat_chan->reg_base + IOAT_CHANERR_OFFSET);
682 
683 		if (chanerr &
684 		    (IOAT_CHANERR_HANDLE_MASK | IOAT_CHANERR_RECOVER_MASK)) {
685 			mod_timer(&ioat_chan->timer, jiffies + IDLE_TIMEOUT);
686 			ioat_eh(ioat_chan);
687 		}
688 	}
689 
690 	spin_unlock_bh(&ioat_chan->cleanup_lock);
691 }
692 
693 void ioat_cleanup_event(struct tasklet_struct *t)
694 {
695 	struct ioatdma_chan *ioat_chan = from_tasklet(ioat_chan, t, cleanup_task);
696 
697 	ioat_cleanup(ioat_chan);
698 	if (!test_bit(IOAT_RUN, &ioat_chan->state))
699 		return;
700 	writew(IOAT_CHANCTRL_RUN, ioat_chan->reg_base + IOAT_CHANCTRL_OFFSET);
701 }
702 
703 static void ioat_restart_channel(struct ioatdma_chan *ioat_chan)
704 {
705 	u64 phys_complete;
706 
707 	/* set the completion address register again */
708 	writel(lower_32_bits(ioat_chan->completion_dma),
709 	       ioat_chan->reg_base + IOAT_CHANCMP_OFFSET_LOW);
710 	writel(upper_32_bits(ioat_chan->completion_dma),
711 	       ioat_chan->reg_base + IOAT_CHANCMP_OFFSET_HIGH);
712 
713 	ioat_quiesce(ioat_chan, 0);
714 	if (ioat_cleanup_preamble(ioat_chan, &phys_complete))
715 		__cleanup(ioat_chan, phys_complete);
716 
717 	__ioat_restart_chan(ioat_chan);
718 }
719 
720 
721 static void ioat_abort_descs(struct ioatdma_chan *ioat_chan)
722 {
723 	struct ioatdma_device *ioat_dma = ioat_chan->ioat_dma;
724 	struct ioat_ring_ent *desc;
725 	u16 active;
726 	int idx = ioat_chan->tail, i;
727 
728 	/*
729 	 * We assume that the failed descriptor has been processed.
730 	 * Now we are just returning all the remaining submitted
731 	 * descriptors to abort.
732 	 */
733 	active = ioat_ring_active(ioat_chan);
734 
735 	/* we skip the failed descriptor that tail points to */
736 	for (i = 1; i < active; i++) {
737 		struct dma_async_tx_descriptor *tx;
738 
739 		prefetch(ioat_get_ring_ent(ioat_chan, idx + i + 1));
740 		desc = ioat_get_ring_ent(ioat_chan, idx + i);
741 
742 		tx = &desc->txd;
743 		if (tx->cookie) {
744 			struct dmaengine_result res;
745 
746 			dma_cookie_complete(tx);
747 			dma_descriptor_unmap(tx);
748 			res.result = DMA_TRANS_ABORTED;
749 			dmaengine_desc_get_callback_invoke(tx, &res);
750 			tx->callback = NULL;
751 			tx->callback_result = NULL;
752 		}
753 
754 		/* skip extended descriptors */
755 		if (desc_has_ext(desc)) {
756 			WARN_ON(i + 1 >= active);
757 			i++;
758 		}
759 
760 		/* cleanup super extended descriptors */
761 		if (desc->sed) {
762 			ioat_free_sed(ioat_dma, desc->sed);
763 			desc->sed = NULL;
764 		}
765 	}
766 
767 	smp_mb(); /* finish all descriptor reads before incrementing tail */
768 	ioat_chan->tail = idx + active;
769 
770 	desc = ioat_get_ring_ent(ioat_chan, ioat_chan->tail);
771 	ioat_chan->last_completion = *ioat_chan->completion = desc->txd.phys;
772 }
773 
774 static void ioat_eh(struct ioatdma_chan *ioat_chan)
775 {
776 	struct pci_dev *pdev = to_pdev(ioat_chan);
777 	struct ioat_dma_descriptor *hw;
778 	struct dma_async_tx_descriptor *tx;
779 	u64 phys_complete;
780 	struct ioat_ring_ent *desc;
781 	u32 err_handled = 0;
782 	u32 chanerr_int;
783 	u32 chanerr;
784 	bool abort = false;
785 	struct dmaengine_result res;
786 
787 	/* cleanup so tail points to descriptor that caused the error */
788 	if (ioat_cleanup_preamble(ioat_chan, &phys_complete))
789 		__cleanup(ioat_chan, phys_complete);
790 
791 	chanerr = readl(ioat_chan->reg_base + IOAT_CHANERR_OFFSET);
792 	pci_read_config_dword(pdev, IOAT_PCI_CHANERR_INT_OFFSET, &chanerr_int);
793 
794 	dev_dbg(to_dev(ioat_chan), "%s: error = %x:%x\n",
795 		__func__, chanerr, chanerr_int);
796 
797 	desc = ioat_get_ring_ent(ioat_chan, ioat_chan->tail);
798 	hw = desc->hw;
799 	dump_desc_dbg(ioat_chan, desc);
800 
801 	switch (hw->ctl_f.op) {
802 	case IOAT_OP_XOR_VAL:
803 		if (chanerr & IOAT_CHANERR_XOR_P_OR_CRC_ERR) {
804 			*desc->result |= SUM_CHECK_P_RESULT;
805 			err_handled |= IOAT_CHANERR_XOR_P_OR_CRC_ERR;
806 		}
807 		break;
808 	case IOAT_OP_PQ_VAL:
809 	case IOAT_OP_PQ_VAL_16S:
810 		if (chanerr & IOAT_CHANERR_XOR_P_OR_CRC_ERR) {
811 			*desc->result |= SUM_CHECK_P_RESULT;
812 			err_handled |= IOAT_CHANERR_XOR_P_OR_CRC_ERR;
813 		}
814 		if (chanerr & IOAT_CHANERR_XOR_Q_ERR) {
815 			*desc->result |= SUM_CHECK_Q_RESULT;
816 			err_handled |= IOAT_CHANERR_XOR_Q_ERR;
817 		}
818 		break;
819 	}
820 
821 	if (chanerr & IOAT_CHANERR_RECOVER_MASK) {
822 		if (chanerr & IOAT_CHANERR_READ_DATA_ERR) {
823 			res.result = DMA_TRANS_READ_FAILED;
824 			err_handled |= IOAT_CHANERR_READ_DATA_ERR;
825 		} else if (chanerr & IOAT_CHANERR_WRITE_DATA_ERR) {
826 			res.result = DMA_TRANS_WRITE_FAILED;
827 			err_handled |= IOAT_CHANERR_WRITE_DATA_ERR;
828 		}
829 
830 		abort = true;
831 	} else
832 		res.result = DMA_TRANS_NOERROR;
833 
834 	/* fault on unhandled error or spurious halt */
835 	if (chanerr ^ err_handled || chanerr == 0) {
836 		dev_err(to_dev(ioat_chan), "%s: fatal error (%x:%x)\n",
837 			__func__, chanerr, err_handled);
838 		dev_err(to_dev(ioat_chan), "Errors handled:\n");
839 		ioat_print_chanerrs(ioat_chan, err_handled);
840 		dev_err(to_dev(ioat_chan), "Errors not handled:\n");
841 		ioat_print_chanerrs(ioat_chan, (chanerr & ~err_handled));
842 
843 		BUG();
844 	}
845 
846 	/* cleanup the faulty descriptor since we are continuing */
847 	tx = &desc->txd;
848 	if (tx->cookie) {
849 		dma_cookie_complete(tx);
850 		dma_descriptor_unmap(tx);
851 		dmaengine_desc_get_callback_invoke(tx, &res);
852 		tx->callback = NULL;
853 		tx->callback_result = NULL;
854 	}
855 
856 	/* mark faulting descriptor as complete */
857 	*ioat_chan->completion = desc->txd.phys;
858 
859 	spin_lock_bh(&ioat_chan->prep_lock);
860 	/* we need abort all descriptors */
861 	if (abort) {
862 		ioat_abort_descs(ioat_chan);
863 		/* clean up the channel, we could be in weird state */
864 		ioat_reset_hw(ioat_chan);
865 	}
866 
867 	writel(chanerr, ioat_chan->reg_base + IOAT_CHANERR_OFFSET);
868 	pci_write_config_dword(pdev, IOAT_PCI_CHANERR_INT_OFFSET, chanerr_int);
869 
870 	ioat_restart_channel(ioat_chan);
871 	spin_unlock_bh(&ioat_chan->prep_lock);
872 }
873 
874 static void check_active(struct ioatdma_chan *ioat_chan)
875 {
876 	if (ioat_ring_active(ioat_chan)) {
877 		mod_timer(&ioat_chan->timer, jiffies + COMPLETION_TIMEOUT);
878 		return;
879 	}
880 
881 	if (test_and_clear_bit(IOAT_CHAN_ACTIVE, &ioat_chan->state))
882 		mod_timer(&ioat_chan->timer, jiffies + IDLE_TIMEOUT);
883 }
884 
885 static void ioat_reboot_chan(struct ioatdma_chan *ioat_chan)
886 {
887 	spin_lock_bh(&ioat_chan->prep_lock);
888 	set_bit(IOAT_CHAN_DOWN, &ioat_chan->state);
889 	spin_unlock_bh(&ioat_chan->prep_lock);
890 
891 	ioat_abort_descs(ioat_chan);
892 	dev_warn(to_dev(ioat_chan), "Reset channel...\n");
893 	ioat_reset_hw(ioat_chan);
894 	dev_warn(to_dev(ioat_chan), "Restart channel...\n");
895 	ioat_restart_channel(ioat_chan);
896 
897 	spin_lock_bh(&ioat_chan->prep_lock);
898 	clear_bit(IOAT_CHAN_DOWN, &ioat_chan->state);
899 	spin_unlock_bh(&ioat_chan->prep_lock);
900 }
901 
902 void ioat_timer_event(struct timer_list *t)
903 {
904 	struct ioatdma_chan *ioat_chan = from_timer(ioat_chan, t, timer);
905 	dma_addr_t phys_complete;
906 	u64 status;
907 
908 	status = ioat_chansts(ioat_chan);
909 
910 	/* when halted due to errors check for channel
911 	 * programming errors before advancing the completion state
912 	 */
913 	if (is_ioat_halted(status)) {
914 		u32 chanerr;
915 
916 		chanerr = readl(ioat_chan->reg_base + IOAT_CHANERR_OFFSET);
917 		dev_err(to_dev(ioat_chan), "%s: Channel halted (%x)\n",
918 			__func__, chanerr);
919 		dev_err(to_dev(ioat_chan), "Errors:\n");
920 		ioat_print_chanerrs(ioat_chan, chanerr);
921 
922 		if (test_bit(IOAT_RUN, &ioat_chan->state)) {
923 			spin_lock_bh(&ioat_chan->cleanup_lock);
924 			ioat_reboot_chan(ioat_chan);
925 			spin_unlock_bh(&ioat_chan->cleanup_lock);
926 		}
927 
928 		return;
929 	}
930 
931 	spin_lock_bh(&ioat_chan->cleanup_lock);
932 
933 	/* handle the no-actives case */
934 	if (!ioat_ring_active(ioat_chan)) {
935 		spin_lock_bh(&ioat_chan->prep_lock);
936 		check_active(ioat_chan);
937 		spin_unlock_bh(&ioat_chan->prep_lock);
938 		goto unlock_out;
939 	}
940 
941 	/* handle the missed cleanup case */
942 	if (ioat_cleanup_preamble(ioat_chan, &phys_complete)) {
943 		/* timer restarted in ioat_cleanup_preamble
944 		 * and IOAT_COMPLETION_ACK cleared
945 		 */
946 		__cleanup(ioat_chan, phys_complete);
947 		goto unlock_out;
948 	}
949 
950 	/* if we haven't made progress and we have already
951 	 * acknowledged a pending completion once, then be more
952 	 * forceful with a restart
953 	 */
954 	if (test_bit(IOAT_COMPLETION_ACK, &ioat_chan->state)) {
955 		u32 chanerr;
956 
957 		chanerr = readl(ioat_chan->reg_base + IOAT_CHANERR_OFFSET);
958 		dev_err(to_dev(ioat_chan), "CHANSTS: %#Lx CHANERR: %#x\n",
959 			status, chanerr);
960 		dev_err(to_dev(ioat_chan), "Errors:\n");
961 		ioat_print_chanerrs(ioat_chan, chanerr);
962 
963 		dev_dbg(to_dev(ioat_chan), "Active descriptors: %d\n",
964 			ioat_ring_active(ioat_chan));
965 
966 		ioat_reboot_chan(ioat_chan);
967 
968 		goto unlock_out;
969 	}
970 
971 	/* handle missed issue pending case */
972 	if (ioat_ring_pending(ioat_chan)) {
973 		dev_warn(to_dev(ioat_chan),
974 			"Completion timeout with pending descriptors\n");
975 		spin_lock_bh(&ioat_chan->prep_lock);
976 		__ioat_issue_pending(ioat_chan);
977 		spin_unlock_bh(&ioat_chan->prep_lock);
978 	}
979 
980 	set_bit(IOAT_COMPLETION_ACK, &ioat_chan->state);
981 	mod_timer(&ioat_chan->timer, jiffies + COMPLETION_TIMEOUT);
982 unlock_out:
983 	spin_unlock_bh(&ioat_chan->cleanup_lock);
984 }
985 
986 enum dma_status
987 ioat_tx_status(struct dma_chan *c, dma_cookie_t cookie,
988 		struct dma_tx_state *txstate)
989 {
990 	struct ioatdma_chan *ioat_chan = to_ioat_chan(c);
991 	enum dma_status ret;
992 
993 	ret = dma_cookie_status(c, cookie, txstate);
994 	if (ret == DMA_COMPLETE)
995 		return ret;
996 
997 	ioat_cleanup(ioat_chan);
998 
999 	return dma_cookie_status(c, cookie, txstate);
1000 }
1001 
1002 int ioat_reset_hw(struct ioatdma_chan *ioat_chan)
1003 {
1004 	/* throw away whatever the channel was doing and get it
1005 	 * initialized, with ioat3 specific workarounds
1006 	 */
1007 	struct ioatdma_device *ioat_dma = ioat_chan->ioat_dma;
1008 	struct pci_dev *pdev = ioat_dma->pdev;
1009 	u32 chanerr;
1010 	u16 dev_id;
1011 	int err;
1012 
1013 	ioat_quiesce(ioat_chan, msecs_to_jiffies(100));
1014 
1015 	chanerr = readl(ioat_chan->reg_base + IOAT_CHANERR_OFFSET);
1016 	writel(chanerr, ioat_chan->reg_base + IOAT_CHANERR_OFFSET);
1017 
1018 	if (ioat_dma->version < IOAT_VER_3_3) {
1019 		/* clear any pending errors */
1020 		err = pci_read_config_dword(pdev,
1021 				IOAT_PCI_CHANERR_INT_OFFSET, &chanerr);
1022 		if (err) {
1023 			dev_err(&pdev->dev,
1024 				"channel error register unreachable\n");
1025 			return err;
1026 		}
1027 		pci_write_config_dword(pdev,
1028 				IOAT_PCI_CHANERR_INT_OFFSET, chanerr);
1029 
1030 		/* Clear DMAUNCERRSTS Cfg-Reg Parity Error status bit
1031 		 * (workaround for spurious config parity error after restart)
1032 		 */
1033 		pci_read_config_word(pdev, IOAT_PCI_DEVICE_ID_OFFSET, &dev_id);
1034 		if (dev_id == PCI_DEVICE_ID_INTEL_IOAT_TBG0) {
1035 			pci_write_config_dword(pdev,
1036 					       IOAT_PCI_DMAUNCERRSTS_OFFSET,
1037 					       0x10);
1038 		}
1039 	}
1040 
1041 	if (is_bwd_ioat(pdev) && (ioat_dma->irq_mode == IOAT_MSIX)) {
1042 		ioat_dma->msixtba0 = readq(ioat_dma->reg_base + 0x1000);
1043 		ioat_dma->msixdata0 = readq(ioat_dma->reg_base + 0x1008);
1044 		ioat_dma->msixpba = readq(ioat_dma->reg_base + 0x1800);
1045 	}
1046 
1047 
1048 	err = ioat_reset_sync(ioat_chan, msecs_to_jiffies(200));
1049 	if (!err) {
1050 		if (is_bwd_ioat(pdev) && (ioat_dma->irq_mode == IOAT_MSIX)) {
1051 			writeq(ioat_dma->msixtba0, ioat_dma->reg_base + 0x1000);
1052 			writeq(ioat_dma->msixdata0, ioat_dma->reg_base + 0x1008);
1053 			writeq(ioat_dma->msixpba, ioat_dma->reg_base + 0x1800);
1054 		}
1055 	}
1056 
1057 	if (err)
1058 		dev_err(&pdev->dev, "Failed to reset: %d\n", err);
1059 
1060 	return err;
1061 }
1062