xref: /kernel/linux/linux-5.10/drivers/block/rsxx/dma.c (revision 8c2ecf20)
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3* Filename: dma.c
4*
5* Authors: Joshua Morris <josh.h.morris@us.ibm.com>
6*	Philip Kelleher <pjk1939@linux.vnet.ibm.com>
7*
8* (C) Copyright 2013 IBM Corporation
9*/
10
11#include <linux/slab.h>
12#include "rsxx_priv.h"
13
14struct rsxx_dma {
15	struct list_head	 list;
16	u8			 cmd;
17	unsigned int		 laddr;     /* Logical address */
18	struct {
19		u32		 off;
20		u32		 cnt;
21	} sub_page;
22	dma_addr_t		 dma_addr;
23	struct page		 *page;
24	unsigned int		 pg_off;    /* Page Offset */
25	rsxx_dma_cb		 cb;
26	void			 *cb_data;
27};
28
29/* This timeout is used to detect a stalled DMA channel */
30#define DMA_ACTIVITY_TIMEOUT	msecs_to_jiffies(10000)
31
32struct hw_status {
33	u8	status;
34	u8	tag;
35	__le16	count;
36	__le32	_rsvd2;
37	__le64	_rsvd3;
38} __packed;
39
40enum rsxx_dma_status {
41	DMA_SW_ERR    = 0x1,
42	DMA_HW_FAULT  = 0x2,
43	DMA_CANCELLED = 0x4,
44};
45
46struct hw_cmd {
47	u8	command;
48	u8	tag;
49	u8	_rsvd;
50	u8	sub_page; /* Bit[0:2]: 512byte offset */
51			  /* Bit[4:6]: 512byte count */
52	__le32	device_addr;
53	__le64	host_addr;
54} __packed;
55
56enum rsxx_hw_cmd {
57	HW_CMD_BLK_DISCARD	= 0x70,
58	HW_CMD_BLK_WRITE	= 0x80,
59	HW_CMD_BLK_READ		= 0xC0,
60	HW_CMD_BLK_RECON_READ	= 0xE0,
61};
62
63enum rsxx_hw_status {
64	HW_STATUS_CRC		= 0x01,
65	HW_STATUS_HARD_ERR	= 0x02,
66	HW_STATUS_SOFT_ERR	= 0x04,
67	HW_STATUS_FAULT		= 0x08,
68};
69
70static struct kmem_cache *rsxx_dma_pool;
71
72struct dma_tracker {
73	int			next_tag;
74	struct rsxx_dma	*dma;
75};
76
77#define DMA_TRACKER_LIST_SIZE8 (sizeof(struct dma_tracker_list) + \
78		(sizeof(struct dma_tracker) * RSXX_MAX_OUTSTANDING_CMDS))
79
80struct dma_tracker_list {
81	spinlock_t		lock;
82	int			head;
83	struct dma_tracker	list[];
84};
85
86
87/*----------------- Misc Utility Functions -------------------*/
88static unsigned int rsxx_addr8_to_laddr(u64 addr8, struct rsxx_cardinfo *card)
89{
90	unsigned long long tgt_addr8;
91
92	tgt_addr8 = ((addr8 >> card->_stripe.upper_shift) &
93		      card->_stripe.upper_mask) |
94		    ((addr8) & card->_stripe.lower_mask);
95	do_div(tgt_addr8, RSXX_HW_BLK_SIZE);
96	return tgt_addr8;
97}
98
99static unsigned int rsxx_get_dma_tgt(struct rsxx_cardinfo *card, u64 addr8)
100{
101	unsigned int tgt;
102
103	tgt = (addr8 >> card->_stripe.target_shift) & card->_stripe.target_mask;
104
105	return tgt;
106}
107
108void rsxx_dma_queue_reset(struct rsxx_cardinfo *card)
109{
110	/* Reset all DMA Command/Status Queues */
111	iowrite32(DMA_QUEUE_RESET, card->regmap + RESET);
112}
113
114static unsigned int get_dma_size(struct rsxx_dma *dma)
115{
116	if (dma->sub_page.cnt)
117		return dma->sub_page.cnt << 9;
118	else
119		return RSXX_HW_BLK_SIZE;
120}
121
122
123/*----------------- DMA Tracker -------------------*/
124static void set_tracker_dma(struct dma_tracker_list *trackers,
125			    int tag,
126			    struct rsxx_dma *dma)
127{
128	trackers->list[tag].dma = dma;
129}
130
131static struct rsxx_dma *get_tracker_dma(struct dma_tracker_list *trackers,
132					    int tag)
133{
134	return trackers->list[tag].dma;
135}
136
137static int pop_tracker(struct dma_tracker_list *trackers)
138{
139	int tag;
140
141	spin_lock(&trackers->lock);
142	tag = trackers->head;
143	if (tag != -1) {
144		trackers->head = trackers->list[tag].next_tag;
145		trackers->list[tag].next_tag = -1;
146	}
147	spin_unlock(&trackers->lock);
148
149	return tag;
150}
151
152static void push_tracker(struct dma_tracker_list *trackers, int tag)
153{
154	spin_lock(&trackers->lock);
155	trackers->list[tag].next_tag = trackers->head;
156	trackers->head = tag;
157	trackers->list[tag].dma = NULL;
158	spin_unlock(&trackers->lock);
159}
160
161
162/*----------------- Interrupt Coalescing -------------*/
163/*
164 * Interrupt Coalescing Register Format:
165 * Interrupt Timer (64ns units) [15:0]
166 * Interrupt Count [24:16]
167 * Reserved [31:25]
168*/
169#define INTR_COAL_LATENCY_MASK       (0x0000ffff)
170
171#define INTR_COAL_COUNT_SHIFT        16
172#define INTR_COAL_COUNT_BITS         9
173#define INTR_COAL_COUNT_MASK         (((1 << INTR_COAL_COUNT_BITS) - 1) << \
174					INTR_COAL_COUNT_SHIFT)
175#define INTR_COAL_LATENCY_UNITS_NS   64
176
177
178static u32 dma_intr_coal_val(u32 mode, u32 count, u32 latency)
179{
180	u32 latency_units = latency / INTR_COAL_LATENCY_UNITS_NS;
181
182	if (mode == RSXX_INTR_COAL_DISABLED)
183		return 0;
184
185	return ((count << INTR_COAL_COUNT_SHIFT) & INTR_COAL_COUNT_MASK) |
186			(latency_units & INTR_COAL_LATENCY_MASK);
187
188}
189
190static void dma_intr_coal_auto_tune(struct rsxx_cardinfo *card)
191{
192	int i;
193	u32 q_depth = 0;
194	u32 intr_coal;
195
196	if (card->config.data.intr_coal.mode != RSXX_INTR_COAL_AUTO_TUNE ||
197	    unlikely(card->eeh_state))
198		return;
199
200	for (i = 0; i < card->n_targets; i++)
201		q_depth += atomic_read(&card->ctrl[i].stats.hw_q_depth);
202
203	intr_coal = dma_intr_coal_val(card->config.data.intr_coal.mode,
204				      q_depth / 2,
205				      card->config.data.intr_coal.latency);
206	iowrite32(intr_coal, card->regmap + INTR_COAL);
207}
208
209/*----------------- RSXX DMA Handling -------------------*/
210static void rsxx_free_dma(struct rsxx_dma_ctrl *ctrl, struct rsxx_dma *dma)
211{
212	if (dma->cmd != HW_CMD_BLK_DISCARD) {
213		if (!dma_mapping_error(&ctrl->card->dev->dev, dma->dma_addr)) {
214			dma_unmap_page(&ctrl->card->dev->dev, dma->dma_addr,
215				       get_dma_size(dma),
216				       dma->cmd == HW_CMD_BLK_WRITE ?
217						   DMA_TO_DEVICE :
218						   DMA_FROM_DEVICE);
219		}
220	}
221
222	kmem_cache_free(rsxx_dma_pool, dma);
223}
224
225static void rsxx_complete_dma(struct rsxx_dma_ctrl *ctrl,
226				  struct rsxx_dma *dma,
227				  unsigned int status)
228{
229	if (status & DMA_SW_ERR)
230		ctrl->stats.dma_sw_err++;
231	if (status & DMA_HW_FAULT)
232		ctrl->stats.dma_hw_fault++;
233	if (status & DMA_CANCELLED)
234		ctrl->stats.dma_cancelled++;
235
236	if (dma->cb)
237		dma->cb(ctrl->card, dma->cb_data, status ? 1 : 0);
238
239	rsxx_free_dma(ctrl, dma);
240}
241
242int rsxx_cleanup_dma_queue(struct rsxx_dma_ctrl *ctrl,
243			   struct list_head *q, unsigned int done)
244{
245	struct rsxx_dma *dma;
246	struct rsxx_dma *tmp;
247	int cnt = 0;
248
249	list_for_each_entry_safe(dma, tmp, q, list) {
250		list_del(&dma->list);
251		if (done & COMPLETE_DMA)
252			rsxx_complete_dma(ctrl, dma, DMA_CANCELLED);
253		else
254			rsxx_free_dma(ctrl, dma);
255		cnt++;
256	}
257
258	return cnt;
259}
260
261static void rsxx_requeue_dma(struct rsxx_dma_ctrl *ctrl,
262				 struct rsxx_dma *dma)
263{
264	/*
265	 * Requeued DMAs go to the front of the queue so they are issued
266	 * first.
267	 */
268	spin_lock_bh(&ctrl->queue_lock);
269	ctrl->stats.sw_q_depth++;
270	list_add(&dma->list, &ctrl->queue);
271	spin_unlock_bh(&ctrl->queue_lock);
272}
273
274static void rsxx_handle_dma_error(struct rsxx_dma_ctrl *ctrl,
275				      struct rsxx_dma *dma,
276				      u8 hw_st)
277{
278	unsigned int status = 0;
279	int requeue_cmd = 0;
280
281	dev_dbg(CARD_TO_DEV(ctrl->card),
282		"Handling DMA error(cmd x%02x, laddr x%08x st:x%02x)\n",
283		dma->cmd, dma->laddr, hw_st);
284
285	if (hw_st & HW_STATUS_CRC)
286		ctrl->stats.crc_errors++;
287	if (hw_st & HW_STATUS_HARD_ERR)
288		ctrl->stats.hard_errors++;
289	if (hw_st & HW_STATUS_SOFT_ERR)
290		ctrl->stats.soft_errors++;
291
292	switch (dma->cmd) {
293	case HW_CMD_BLK_READ:
294		if (hw_st & (HW_STATUS_CRC | HW_STATUS_HARD_ERR)) {
295			if (ctrl->card->scrub_hard) {
296				dma->cmd = HW_CMD_BLK_RECON_READ;
297				requeue_cmd = 1;
298				ctrl->stats.reads_retried++;
299			} else {
300				status |= DMA_HW_FAULT;
301				ctrl->stats.reads_failed++;
302			}
303		} else if (hw_st & HW_STATUS_FAULT) {
304			status |= DMA_HW_FAULT;
305			ctrl->stats.reads_failed++;
306		}
307
308		break;
309	case HW_CMD_BLK_RECON_READ:
310		if (hw_st & (HW_STATUS_CRC | HW_STATUS_HARD_ERR)) {
311			/* Data could not be reconstructed. */
312			status |= DMA_HW_FAULT;
313			ctrl->stats.reads_failed++;
314		}
315
316		break;
317	case HW_CMD_BLK_WRITE:
318		status |= DMA_HW_FAULT;
319		ctrl->stats.writes_failed++;
320
321		break;
322	case HW_CMD_BLK_DISCARD:
323		status |= DMA_HW_FAULT;
324		ctrl->stats.discards_failed++;
325
326		break;
327	default:
328		dev_err(CARD_TO_DEV(ctrl->card),
329			"Unknown command in DMA!(cmd: x%02x "
330			   "laddr x%08x st: x%02x\n",
331			   dma->cmd, dma->laddr, hw_st);
332		status |= DMA_SW_ERR;
333
334		break;
335	}
336
337	if (requeue_cmd)
338		rsxx_requeue_dma(ctrl, dma);
339	else
340		rsxx_complete_dma(ctrl, dma, status);
341}
342
343static void dma_engine_stalled(struct timer_list *t)
344{
345	struct rsxx_dma_ctrl *ctrl = from_timer(ctrl, t, activity_timer);
346	int cnt;
347
348	if (atomic_read(&ctrl->stats.hw_q_depth) == 0 ||
349	    unlikely(ctrl->card->eeh_state))
350		return;
351
352	if (ctrl->cmd.idx != ioread32(ctrl->regmap + SW_CMD_IDX)) {
353		/*
354		 * The dma engine was stalled because the SW_CMD_IDX write
355		 * was lost. Issue it again to recover.
356		 */
357		dev_warn(CARD_TO_DEV(ctrl->card),
358			"SW_CMD_IDX write was lost, re-writing...\n");
359		iowrite32(ctrl->cmd.idx, ctrl->regmap + SW_CMD_IDX);
360		mod_timer(&ctrl->activity_timer,
361			  jiffies + DMA_ACTIVITY_TIMEOUT);
362	} else {
363		dev_warn(CARD_TO_DEV(ctrl->card),
364			"DMA channel %d has stalled, faulting interface.\n",
365			ctrl->id);
366		ctrl->card->dma_fault = 1;
367
368		/* Clean up the DMA queue */
369		spin_lock(&ctrl->queue_lock);
370		cnt = rsxx_cleanup_dma_queue(ctrl, &ctrl->queue, COMPLETE_DMA);
371		spin_unlock(&ctrl->queue_lock);
372
373		cnt += rsxx_dma_cancel(ctrl);
374
375		if (cnt)
376			dev_info(CARD_TO_DEV(ctrl->card),
377				"Freed %d queued DMAs on channel %d\n",
378				cnt, ctrl->id);
379	}
380}
381
382static void rsxx_issue_dmas(struct rsxx_dma_ctrl *ctrl)
383{
384	struct rsxx_dma *dma;
385	int tag;
386	int cmds_pending = 0;
387	struct hw_cmd *hw_cmd_buf;
388	int dir;
389
390	hw_cmd_buf = ctrl->cmd.buf;
391
392	if (unlikely(ctrl->card->halt) ||
393	    unlikely(ctrl->card->eeh_state))
394		return;
395
396	while (1) {
397		spin_lock_bh(&ctrl->queue_lock);
398		if (list_empty(&ctrl->queue)) {
399			spin_unlock_bh(&ctrl->queue_lock);
400			break;
401		}
402		spin_unlock_bh(&ctrl->queue_lock);
403
404		tag = pop_tracker(ctrl->trackers);
405		if (tag == -1)
406			break;
407
408		spin_lock_bh(&ctrl->queue_lock);
409		dma = list_entry(ctrl->queue.next, struct rsxx_dma, list);
410		list_del(&dma->list);
411		ctrl->stats.sw_q_depth--;
412		spin_unlock_bh(&ctrl->queue_lock);
413
414		/*
415		 * This will catch any DMAs that slipped in right before the
416		 * fault, but was queued after all the other DMAs were
417		 * cancelled.
418		 */
419		if (unlikely(ctrl->card->dma_fault)) {
420			push_tracker(ctrl->trackers, tag);
421			rsxx_complete_dma(ctrl, dma, DMA_CANCELLED);
422			continue;
423		}
424
425		if (dma->cmd != HW_CMD_BLK_DISCARD) {
426			if (dma->cmd == HW_CMD_BLK_WRITE)
427				dir = DMA_TO_DEVICE;
428			else
429				dir = DMA_FROM_DEVICE;
430
431			/*
432			 * The function dma_map_page is placed here because we
433			 * can only, by design, issue up to 255 commands to the
434			 * hardware at one time per DMA channel. So the maximum
435			 * amount of mapped memory would be 255 * 4 channels *
436			 * 4096 Bytes which is less than 2GB, the limit of a x8
437			 * Non-HWWD PCIe slot. This way the dma_map_page
438			 * function should never fail because of a lack of
439			 * mappable memory.
440			 */
441			dma->dma_addr = dma_map_page(&ctrl->card->dev->dev, dma->page,
442					dma->pg_off, dma->sub_page.cnt << 9, dir);
443			if (dma_mapping_error(&ctrl->card->dev->dev, dma->dma_addr)) {
444				push_tracker(ctrl->trackers, tag);
445				rsxx_complete_dma(ctrl, dma, DMA_CANCELLED);
446				continue;
447			}
448		}
449
450		set_tracker_dma(ctrl->trackers, tag, dma);
451		hw_cmd_buf[ctrl->cmd.idx].command  = dma->cmd;
452		hw_cmd_buf[ctrl->cmd.idx].tag      = tag;
453		hw_cmd_buf[ctrl->cmd.idx]._rsvd    = 0;
454		hw_cmd_buf[ctrl->cmd.idx].sub_page =
455					((dma->sub_page.cnt & 0x7) << 4) |
456					 (dma->sub_page.off & 0x7);
457
458		hw_cmd_buf[ctrl->cmd.idx].device_addr =
459					cpu_to_le32(dma->laddr);
460
461		hw_cmd_buf[ctrl->cmd.idx].host_addr =
462					cpu_to_le64(dma->dma_addr);
463
464		dev_dbg(CARD_TO_DEV(ctrl->card),
465			"Issue DMA%d(laddr %d tag %d) to idx %d\n",
466			ctrl->id, dma->laddr, tag, ctrl->cmd.idx);
467
468		ctrl->cmd.idx = (ctrl->cmd.idx + 1) & RSXX_CS_IDX_MASK;
469		cmds_pending++;
470
471		if (dma->cmd == HW_CMD_BLK_WRITE)
472			ctrl->stats.writes_issued++;
473		else if (dma->cmd == HW_CMD_BLK_DISCARD)
474			ctrl->stats.discards_issued++;
475		else
476			ctrl->stats.reads_issued++;
477	}
478
479	/* Let HW know we've queued commands. */
480	if (cmds_pending) {
481		atomic_add(cmds_pending, &ctrl->stats.hw_q_depth);
482		mod_timer(&ctrl->activity_timer,
483			  jiffies + DMA_ACTIVITY_TIMEOUT);
484
485		if (unlikely(ctrl->card->eeh_state)) {
486			del_timer_sync(&ctrl->activity_timer);
487			return;
488		}
489
490		iowrite32(ctrl->cmd.idx, ctrl->regmap + SW_CMD_IDX);
491	}
492}
493
494static void rsxx_dma_done(struct rsxx_dma_ctrl *ctrl)
495{
496	struct rsxx_dma *dma;
497	unsigned long flags;
498	u16 count;
499	u8 status;
500	u8 tag;
501	struct hw_status *hw_st_buf;
502
503	hw_st_buf = ctrl->status.buf;
504
505	if (unlikely(ctrl->card->halt) ||
506	    unlikely(ctrl->card->dma_fault) ||
507	    unlikely(ctrl->card->eeh_state))
508		return;
509
510	count = le16_to_cpu(hw_st_buf[ctrl->status.idx].count);
511
512	while (count == ctrl->e_cnt) {
513		/*
514		 * The read memory-barrier is necessary to keep aggressive
515		 * processors/optimizers (such as the PPC Apple G5) from
516		 * reordering the following status-buffer tag & status read
517		 * *before* the count read on subsequent iterations of the
518		 * loop!
519		 */
520		rmb();
521
522		status = hw_st_buf[ctrl->status.idx].status;
523		tag    = hw_st_buf[ctrl->status.idx].tag;
524
525		dma = get_tracker_dma(ctrl->trackers, tag);
526		if (dma == NULL) {
527			spin_lock_irqsave(&ctrl->card->irq_lock, flags);
528			rsxx_disable_ier(ctrl->card, CR_INTR_DMA_ALL);
529			spin_unlock_irqrestore(&ctrl->card->irq_lock, flags);
530
531			dev_err(CARD_TO_DEV(ctrl->card),
532				"No tracker for tag %d "
533				"(idx %d id %d)\n",
534				tag, ctrl->status.idx, ctrl->id);
535			return;
536		}
537
538		dev_dbg(CARD_TO_DEV(ctrl->card),
539			"Completing DMA%d"
540			"(laddr x%x tag %d st: x%x cnt: x%04x) from idx %d.\n",
541			ctrl->id, dma->laddr, tag, status, count,
542			ctrl->status.idx);
543
544		atomic_dec(&ctrl->stats.hw_q_depth);
545
546		mod_timer(&ctrl->activity_timer,
547			  jiffies + DMA_ACTIVITY_TIMEOUT);
548
549		if (status)
550			rsxx_handle_dma_error(ctrl, dma, status);
551		else
552			rsxx_complete_dma(ctrl, dma, 0);
553
554		push_tracker(ctrl->trackers, tag);
555
556		ctrl->status.idx = (ctrl->status.idx + 1) &
557				   RSXX_CS_IDX_MASK;
558		ctrl->e_cnt++;
559
560		count = le16_to_cpu(hw_st_buf[ctrl->status.idx].count);
561	}
562
563	dma_intr_coal_auto_tune(ctrl->card);
564
565	if (atomic_read(&ctrl->stats.hw_q_depth) == 0)
566		del_timer_sync(&ctrl->activity_timer);
567
568	spin_lock_irqsave(&ctrl->card->irq_lock, flags);
569	rsxx_enable_ier(ctrl->card, CR_INTR_DMA(ctrl->id));
570	spin_unlock_irqrestore(&ctrl->card->irq_lock, flags);
571
572	spin_lock_bh(&ctrl->queue_lock);
573	if (ctrl->stats.sw_q_depth)
574		queue_work(ctrl->issue_wq, &ctrl->issue_dma_work);
575	spin_unlock_bh(&ctrl->queue_lock);
576}
577
578static void rsxx_schedule_issue(struct work_struct *work)
579{
580	struct rsxx_dma_ctrl *ctrl;
581
582	ctrl = container_of(work, struct rsxx_dma_ctrl, issue_dma_work);
583
584	mutex_lock(&ctrl->work_lock);
585	rsxx_issue_dmas(ctrl);
586	mutex_unlock(&ctrl->work_lock);
587}
588
589static void rsxx_schedule_done(struct work_struct *work)
590{
591	struct rsxx_dma_ctrl *ctrl;
592
593	ctrl = container_of(work, struct rsxx_dma_ctrl, dma_done_work);
594
595	mutex_lock(&ctrl->work_lock);
596	rsxx_dma_done(ctrl);
597	mutex_unlock(&ctrl->work_lock);
598}
599
600static blk_status_t rsxx_queue_discard(struct rsxx_cardinfo *card,
601				  struct list_head *q,
602				  unsigned int laddr,
603				  rsxx_dma_cb cb,
604				  void *cb_data)
605{
606	struct rsxx_dma *dma;
607
608	dma = kmem_cache_alloc(rsxx_dma_pool, GFP_KERNEL);
609	if (!dma)
610		return BLK_STS_RESOURCE;
611
612	dma->cmd          = HW_CMD_BLK_DISCARD;
613	dma->laddr        = laddr;
614	dma->dma_addr     = 0;
615	dma->sub_page.off = 0;
616	dma->sub_page.cnt = 0;
617	dma->page         = NULL;
618	dma->pg_off       = 0;
619	dma->cb	          = cb;
620	dma->cb_data      = cb_data;
621
622	dev_dbg(CARD_TO_DEV(card), "Queuing[D] laddr %x\n", dma->laddr);
623
624	list_add_tail(&dma->list, q);
625
626	return 0;
627}
628
629static blk_status_t rsxx_queue_dma(struct rsxx_cardinfo *card,
630			      struct list_head *q,
631			      int dir,
632			      unsigned int dma_off,
633			      unsigned int dma_len,
634			      unsigned int laddr,
635			      struct page *page,
636			      unsigned int pg_off,
637			      rsxx_dma_cb cb,
638			      void *cb_data)
639{
640	struct rsxx_dma *dma;
641
642	dma = kmem_cache_alloc(rsxx_dma_pool, GFP_KERNEL);
643	if (!dma)
644		return BLK_STS_RESOURCE;
645
646	dma->cmd          = dir ? HW_CMD_BLK_WRITE : HW_CMD_BLK_READ;
647	dma->laddr        = laddr;
648	dma->sub_page.off = (dma_off >> 9);
649	dma->sub_page.cnt = (dma_len >> 9);
650	dma->page         = page;
651	dma->pg_off       = pg_off;
652	dma->cb	          = cb;
653	dma->cb_data      = cb_data;
654
655	dev_dbg(CARD_TO_DEV(card),
656		"Queuing[%c] laddr %x off %d cnt %d page %p pg_off %d\n",
657		dir ? 'W' : 'R', dma->laddr, dma->sub_page.off,
658		dma->sub_page.cnt, dma->page, dma->pg_off);
659
660	/* Queue the DMA */
661	list_add_tail(&dma->list, q);
662
663	return 0;
664}
665
666blk_status_t rsxx_dma_queue_bio(struct rsxx_cardinfo *card,
667			   struct bio *bio,
668			   atomic_t *n_dmas,
669			   rsxx_dma_cb cb,
670			   void *cb_data)
671{
672	struct list_head dma_list[RSXX_MAX_TARGETS];
673	struct bio_vec bvec;
674	struct bvec_iter iter;
675	unsigned long long addr8;
676	unsigned int laddr;
677	unsigned int bv_len;
678	unsigned int bv_off;
679	unsigned int dma_off;
680	unsigned int dma_len;
681	int dma_cnt[RSXX_MAX_TARGETS];
682	int tgt;
683	blk_status_t st;
684	int i;
685
686	addr8 = bio->bi_iter.bi_sector << 9; /* sectors are 512 bytes */
687	atomic_set(n_dmas, 0);
688
689	for (i = 0; i < card->n_targets; i++) {
690		INIT_LIST_HEAD(&dma_list[i]);
691		dma_cnt[i] = 0;
692	}
693
694	if (bio_op(bio) == REQ_OP_DISCARD) {
695		bv_len = bio->bi_iter.bi_size;
696
697		while (bv_len > 0) {
698			tgt   = rsxx_get_dma_tgt(card, addr8);
699			laddr = rsxx_addr8_to_laddr(addr8, card);
700
701			st = rsxx_queue_discard(card, &dma_list[tgt], laddr,
702						    cb, cb_data);
703			if (st)
704				goto bvec_err;
705
706			dma_cnt[tgt]++;
707			atomic_inc(n_dmas);
708			addr8  += RSXX_HW_BLK_SIZE;
709			bv_len -= RSXX_HW_BLK_SIZE;
710		}
711	} else {
712		bio_for_each_segment(bvec, bio, iter) {
713			bv_len = bvec.bv_len;
714			bv_off = bvec.bv_offset;
715
716			while (bv_len > 0) {
717				tgt   = rsxx_get_dma_tgt(card, addr8);
718				laddr = rsxx_addr8_to_laddr(addr8, card);
719				dma_off = addr8 & RSXX_HW_BLK_MASK;
720				dma_len = min(bv_len,
721					      RSXX_HW_BLK_SIZE - dma_off);
722
723				st = rsxx_queue_dma(card, &dma_list[tgt],
724							bio_data_dir(bio),
725							dma_off, dma_len,
726							laddr, bvec.bv_page,
727							bv_off, cb, cb_data);
728				if (st)
729					goto bvec_err;
730
731				dma_cnt[tgt]++;
732				atomic_inc(n_dmas);
733				addr8  += dma_len;
734				bv_off += dma_len;
735				bv_len -= dma_len;
736			}
737		}
738	}
739
740	for (i = 0; i < card->n_targets; i++) {
741		if (!list_empty(&dma_list[i])) {
742			spin_lock_bh(&card->ctrl[i].queue_lock);
743			card->ctrl[i].stats.sw_q_depth += dma_cnt[i];
744			list_splice_tail(&dma_list[i], &card->ctrl[i].queue);
745			spin_unlock_bh(&card->ctrl[i].queue_lock);
746
747			queue_work(card->ctrl[i].issue_wq,
748				   &card->ctrl[i].issue_dma_work);
749		}
750	}
751
752	return 0;
753
754bvec_err:
755	for (i = 0; i < card->n_targets; i++)
756		rsxx_cleanup_dma_queue(&card->ctrl[i], &dma_list[i],
757					FREE_DMA);
758	return st;
759}
760
761
762/*----------------- DMA Engine Initialization & Setup -------------------*/
763int rsxx_hw_buffers_init(struct pci_dev *dev, struct rsxx_dma_ctrl *ctrl)
764{
765	ctrl->status.buf = dma_alloc_coherent(&dev->dev, STATUS_BUFFER_SIZE8,
766				&ctrl->status.dma_addr, GFP_KERNEL);
767	ctrl->cmd.buf = dma_alloc_coherent(&dev->dev, COMMAND_BUFFER_SIZE8,
768				&ctrl->cmd.dma_addr, GFP_KERNEL);
769	if (ctrl->status.buf == NULL || ctrl->cmd.buf == NULL)
770		return -ENOMEM;
771
772	memset(ctrl->status.buf, 0xac, STATUS_BUFFER_SIZE8);
773	iowrite32(lower_32_bits(ctrl->status.dma_addr),
774		ctrl->regmap + SB_ADD_LO);
775	iowrite32(upper_32_bits(ctrl->status.dma_addr),
776		ctrl->regmap + SB_ADD_HI);
777
778	memset(ctrl->cmd.buf, 0x83, COMMAND_BUFFER_SIZE8);
779	iowrite32(lower_32_bits(ctrl->cmd.dma_addr), ctrl->regmap + CB_ADD_LO);
780	iowrite32(upper_32_bits(ctrl->cmd.dma_addr), ctrl->regmap + CB_ADD_HI);
781
782	ctrl->status.idx = ioread32(ctrl->regmap + HW_STATUS_CNT);
783	if (ctrl->status.idx > RSXX_MAX_OUTSTANDING_CMDS) {
784		dev_crit(&dev->dev, "Failed reading status cnt x%x\n",
785			ctrl->status.idx);
786		return -EINVAL;
787	}
788	iowrite32(ctrl->status.idx, ctrl->regmap + HW_STATUS_CNT);
789	iowrite32(ctrl->status.idx, ctrl->regmap + SW_STATUS_CNT);
790
791	ctrl->cmd.idx = ioread32(ctrl->regmap + HW_CMD_IDX);
792	if (ctrl->cmd.idx > RSXX_MAX_OUTSTANDING_CMDS) {
793		dev_crit(&dev->dev, "Failed reading cmd cnt x%x\n",
794			ctrl->status.idx);
795		return -EINVAL;
796	}
797	iowrite32(ctrl->cmd.idx, ctrl->regmap + HW_CMD_IDX);
798	iowrite32(ctrl->cmd.idx, ctrl->regmap + SW_CMD_IDX);
799
800	return 0;
801}
802
803static int rsxx_dma_ctrl_init(struct pci_dev *dev,
804				  struct rsxx_dma_ctrl *ctrl)
805{
806	int i;
807	int st;
808
809	memset(&ctrl->stats, 0, sizeof(ctrl->stats));
810
811	ctrl->trackers = vmalloc(DMA_TRACKER_LIST_SIZE8);
812	if (!ctrl->trackers)
813		return -ENOMEM;
814
815	ctrl->trackers->head = 0;
816	for (i = 0; i < RSXX_MAX_OUTSTANDING_CMDS; i++) {
817		ctrl->trackers->list[i].next_tag = i + 1;
818		ctrl->trackers->list[i].dma = NULL;
819	}
820	ctrl->trackers->list[RSXX_MAX_OUTSTANDING_CMDS-1].next_tag = -1;
821	spin_lock_init(&ctrl->trackers->lock);
822
823	spin_lock_init(&ctrl->queue_lock);
824	mutex_init(&ctrl->work_lock);
825	INIT_LIST_HEAD(&ctrl->queue);
826
827	timer_setup(&ctrl->activity_timer, dma_engine_stalled, 0);
828
829	ctrl->issue_wq = alloc_ordered_workqueue(DRIVER_NAME"_issue", 0);
830	if (!ctrl->issue_wq)
831		return -ENOMEM;
832
833	ctrl->done_wq = alloc_ordered_workqueue(DRIVER_NAME"_done", 0);
834	if (!ctrl->done_wq)
835		return -ENOMEM;
836
837	INIT_WORK(&ctrl->issue_dma_work, rsxx_schedule_issue);
838	INIT_WORK(&ctrl->dma_done_work, rsxx_schedule_done);
839
840	st = rsxx_hw_buffers_init(dev, ctrl);
841	if (st)
842		return st;
843
844	return 0;
845}
846
847static int rsxx_dma_stripe_setup(struct rsxx_cardinfo *card,
848			      unsigned int stripe_size8)
849{
850	if (!is_power_of_2(stripe_size8)) {
851		dev_err(CARD_TO_DEV(card),
852			"stripe_size is NOT a power of 2!\n");
853		return -EINVAL;
854	}
855
856	card->_stripe.lower_mask = stripe_size8 - 1;
857
858	card->_stripe.upper_mask  = ~(card->_stripe.lower_mask);
859	card->_stripe.upper_shift = ffs(card->n_targets) - 1;
860
861	card->_stripe.target_mask = card->n_targets - 1;
862	card->_stripe.target_shift = ffs(stripe_size8) - 1;
863
864	dev_dbg(CARD_TO_DEV(card), "_stripe.lower_mask   = x%016llx\n",
865		card->_stripe.lower_mask);
866	dev_dbg(CARD_TO_DEV(card), "_stripe.upper_shift  = x%016llx\n",
867		card->_stripe.upper_shift);
868	dev_dbg(CARD_TO_DEV(card), "_stripe.upper_mask   = x%016llx\n",
869		card->_stripe.upper_mask);
870	dev_dbg(CARD_TO_DEV(card), "_stripe.target_mask  = x%016llx\n",
871		card->_stripe.target_mask);
872	dev_dbg(CARD_TO_DEV(card), "_stripe.target_shift = x%016llx\n",
873		card->_stripe.target_shift);
874
875	return 0;
876}
877
878int rsxx_dma_configure(struct rsxx_cardinfo *card)
879{
880	u32 intr_coal;
881
882	intr_coal = dma_intr_coal_val(card->config.data.intr_coal.mode,
883				      card->config.data.intr_coal.count,
884				      card->config.data.intr_coal.latency);
885	iowrite32(intr_coal, card->regmap + INTR_COAL);
886
887	return rsxx_dma_stripe_setup(card, card->config.data.stripe_size);
888}
889
890int rsxx_dma_setup(struct rsxx_cardinfo *card)
891{
892	unsigned long flags;
893	int st;
894	int i;
895
896	dev_info(CARD_TO_DEV(card),
897		"Initializing %d DMA targets\n",
898		card->n_targets);
899
900	/* Regmap is divided up into 4K chunks. One for each DMA channel */
901	for (i = 0; i < card->n_targets; i++)
902		card->ctrl[i].regmap = card->regmap + (i * 4096);
903
904	card->dma_fault = 0;
905
906	/* Reset the DMA queues */
907	rsxx_dma_queue_reset(card);
908
909	/************* Setup DMA Control *************/
910	for (i = 0; i < card->n_targets; i++) {
911		st = rsxx_dma_ctrl_init(card->dev, &card->ctrl[i]);
912		if (st)
913			goto failed_dma_setup;
914
915		card->ctrl[i].card = card;
916		card->ctrl[i].id = i;
917	}
918
919	card->scrub_hard = 1;
920
921	if (card->config_valid)
922		rsxx_dma_configure(card);
923
924	/* Enable the interrupts after all setup has completed. */
925	for (i = 0; i < card->n_targets; i++) {
926		spin_lock_irqsave(&card->irq_lock, flags);
927		rsxx_enable_ier_and_isr(card, CR_INTR_DMA(i));
928		spin_unlock_irqrestore(&card->irq_lock, flags);
929	}
930
931	return 0;
932
933failed_dma_setup:
934	for (i = 0; i < card->n_targets; i++) {
935		struct rsxx_dma_ctrl *ctrl = &card->ctrl[i];
936
937		if (ctrl->issue_wq) {
938			destroy_workqueue(ctrl->issue_wq);
939			ctrl->issue_wq = NULL;
940		}
941
942		if (ctrl->done_wq) {
943			destroy_workqueue(ctrl->done_wq);
944			ctrl->done_wq = NULL;
945		}
946
947		if (ctrl->trackers)
948			vfree(ctrl->trackers);
949
950		if (ctrl->status.buf)
951			dma_free_coherent(&card->dev->dev, STATUS_BUFFER_SIZE8,
952					  ctrl->status.buf,
953					  ctrl->status.dma_addr);
954		if (ctrl->cmd.buf)
955			dma_free_coherent(&card->dev->dev, COMMAND_BUFFER_SIZE8,
956					  ctrl->cmd.buf, ctrl->cmd.dma_addr);
957	}
958
959	return st;
960}
961
962int rsxx_dma_cancel(struct rsxx_dma_ctrl *ctrl)
963{
964	struct rsxx_dma *dma;
965	int i;
966	int cnt = 0;
967
968	/* Clean up issued DMAs */
969	for (i = 0; i < RSXX_MAX_OUTSTANDING_CMDS; i++) {
970		dma = get_tracker_dma(ctrl->trackers, i);
971		if (dma) {
972			atomic_dec(&ctrl->stats.hw_q_depth);
973			rsxx_complete_dma(ctrl, dma, DMA_CANCELLED);
974			push_tracker(ctrl->trackers, i);
975			cnt++;
976		}
977	}
978
979	return cnt;
980}
981
982void rsxx_dma_destroy(struct rsxx_cardinfo *card)
983{
984	struct rsxx_dma_ctrl *ctrl;
985	int i;
986
987	for (i = 0; i < card->n_targets; i++) {
988		ctrl = &card->ctrl[i];
989
990		if (ctrl->issue_wq) {
991			destroy_workqueue(ctrl->issue_wq);
992			ctrl->issue_wq = NULL;
993		}
994
995		if (ctrl->done_wq) {
996			destroy_workqueue(ctrl->done_wq);
997			ctrl->done_wq = NULL;
998		}
999
1000		if (timer_pending(&ctrl->activity_timer))
1001			del_timer_sync(&ctrl->activity_timer);
1002
1003		/* Clean up the DMA queue */
1004		spin_lock_bh(&ctrl->queue_lock);
1005		rsxx_cleanup_dma_queue(ctrl, &ctrl->queue, COMPLETE_DMA);
1006		spin_unlock_bh(&ctrl->queue_lock);
1007
1008		rsxx_dma_cancel(ctrl);
1009
1010		vfree(ctrl->trackers);
1011
1012		dma_free_coherent(&card->dev->dev, STATUS_BUFFER_SIZE8,
1013				  ctrl->status.buf, ctrl->status.dma_addr);
1014		dma_free_coherent(&card->dev->dev, COMMAND_BUFFER_SIZE8,
1015				  ctrl->cmd.buf, ctrl->cmd.dma_addr);
1016	}
1017}
1018
1019int rsxx_eeh_save_issued_dmas(struct rsxx_cardinfo *card)
1020{
1021	int i;
1022	int j;
1023	int cnt;
1024	struct rsxx_dma *dma;
1025	struct list_head *issued_dmas;
1026
1027	issued_dmas = kcalloc(card->n_targets, sizeof(*issued_dmas),
1028			      GFP_KERNEL);
1029	if (!issued_dmas)
1030		return -ENOMEM;
1031
1032	for (i = 0; i < card->n_targets; i++) {
1033		INIT_LIST_HEAD(&issued_dmas[i]);
1034		cnt = 0;
1035		for (j = 0; j < RSXX_MAX_OUTSTANDING_CMDS; j++) {
1036			dma = get_tracker_dma(card->ctrl[i].trackers, j);
1037			if (dma == NULL)
1038				continue;
1039
1040			if (dma->cmd == HW_CMD_BLK_WRITE)
1041				card->ctrl[i].stats.writes_issued--;
1042			else if (dma->cmd == HW_CMD_BLK_DISCARD)
1043				card->ctrl[i].stats.discards_issued--;
1044			else
1045				card->ctrl[i].stats.reads_issued--;
1046
1047			if (dma->cmd != HW_CMD_BLK_DISCARD) {
1048				dma_unmap_page(&card->dev->dev, dma->dma_addr,
1049					       get_dma_size(dma),
1050					       dma->cmd == HW_CMD_BLK_WRITE ?
1051					       DMA_TO_DEVICE :
1052					       DMA_FROM_DEVICE);
1053			}
1054
1055			list_add_tail(&dma->list, &issued_dmas[i]);
1056			push_tracker(card->ctrl[i].trackers, j);
1057			cnt++;
1058		}
1059
1060		spin_lock_bh(&card->ctrl[i].queue_lock);
1061		list_splice(&issued_dmas[i], &card->ctrl[i].queue);
1062
1063		atomic_sub(cnt, &card->ctrl[i].stats.hw_q_depth);
1064		card->ctrl[i].stats.sw_q_depth += cnt;
1065		card->ctrl[i].e_cnt = 0;
1066		spin_unlock_bh(&card->ctrl[i].queue_lock);
1067	}
1068
1069	kfree(issued_dmas);
1070
1071	return 0;
1072}
1073
1074int rsxx_dma_init(void)
1075{
1076	rsxx_dma_pool = KMEM_CACHE(rsxx_dma, SLAB_HWCACHE_ALIGN);
1077	if (!rsxx_dma_pool)
1078		return -ENOMEM;
1079
1080	return 0;
1081}
1082
1083
1084void rsxx_dma_cleanup(void)
1085{
1086	kmem_cache_destroy(rsxx_dma_pool);
1087}
1088
1089