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dma.c revision 31a70bb4440c963e69ce210389d8119c70b5c39d
1/*
2* Filename: dma.c
3*
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* This program is free software; you can redistribute it and/or
11* modify it under the terms of the GNU General Public License as
12* published by the Free Software Foundation; either version 2 of the
13* License, or (at your option) any later version.
14*
15* This program is distributed in the hope that it will be useful, but
16* WITHOUT ANY WARRANTY; without even the implied warranty of
17* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18* General Public License for more details.
19*
20* You should have received a copy of the GNU General Public License
21* along with this program; if not, write to the Free Software Foundation,
22* Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23*/
24
25#include <linux/slab.h>
26#include "rsxx_priv.h"
27
28struct rsxx_dma {
29	struct list_head	 list;
30	u8			 cmd;
31	unsigned int		 laddr;     /* Logical address */
32	struct {
33		u32		 off;
34		u32		 cnt;
35	} sub_page;
36	dma_addr_t		 dma_addr;
37	struct page		 *page;
38	unsigned int		 pg_off;    /* Page Offset */
39	rsxx_dma_cb		 cb;
40	void			 *cb_data;
41};
42
43/* This timeout is used to detect a stalled DMA channel */
44#define DMA_ACTIVITY_TIMEOUT	msecs_to_jiffies(10000)
45
46struct hw_status {
47	u8	status;
48	u8	tag;
49	__le16	count;
50	__le32	_rsvd2;
51	__le64	_rsvd3;
52} __packed;
53
54enum rsxx_dma_status {
55	DMA_SW_ERR    = 0x1,
56	DMA_HW_FAULT  = 0x2,
57	DMA_CANCELLED = 0x4,
58};
59
60struct hw_cmd {
61	u8	command;
62	u8	tag;
63	u8	_rsvd;
64	u8	sub_page; /* Bit[0:2]: 512byte offset */
65			  /* Bit[4:6]: 512byte count */
66	__le32	device_addr;
67	__le64	host_addr;
68} __packed;
69
70enum rsxx_hw_cmd {
71	HW_CMD_BLK_DISCARD	= 0x70,
72	HW_CMD_BLK_WRITE	= 0x80,
73	HW_CMD_BLK_READ		= 0xC0,
74	HW_CMD_BLK_RECON_READ	= 0xE0,
75};
76
77enum rsxx_hw_status {
78	HW_STATUS_CRC		= 0x01,
79	HW_STATUS_HARD_ERR	= 0x02,
80	HW_STATUS_SOFT_ERR	= 0x04,
81	HW_STATUS_FAULT		= 0x08,
82};
83
84static struct kmem_cache *rsxx_dma_pool;
85
86struct dma_tracker {
87	int			next_tag;
88	struct rsxx_dma	*dma;
89};
90
91#define DMA_TRACKER_LIST_SIZE8 (sizeof(struct dma_tracker_list) + \
92		(sizeof(struct dma_tracker) * RSXX_MAX_OUTSTANDING_CMDS))
93
94struct dma_tracker_list {
95	spinlock_t		lock;
96	int			head;
97	struct dma_tracker	list[0];
98};
99
100
101/*----------------- Misc Utility Functions -------------------*/
102static unsigned int rsxx_addr8_to_laddr(u64 addr8, struct rsxx_cardinfo *card)
103{
104	unsigned long long tgt_addr8;
105
106	tgt_addr8 = ((addr8 >> card->_stripe.upper_shift) &
107		      card->_stripe.upper_mask) |
108		    ((addr8) & card->_stripe.lower_mask);
109	do_div(tgt_addr8, RSXX_HW_BLK_SIZE);
110	return tgt_addr8;
111}
112
113static unsigned int rsxx_get_dma_tgt(struct rsxx_cardinfo *card, u64 addr8)
114{
115	unsigned int tgt;
116
117	tgt = (addr8 >> card->_stripe.target_shift) & card->_stripe.target_mask;
118
119	return tgt;
120}
121
122void rsxx_dma_queue_reset(struct rsxx_cardinfo *card)
123{
124	/* Reset all DMA Command/Status Queues */
125	iowrite32(DMA_QUEUE_RESET, card->regmap + RESET);
126}
127
128static unsigned int get_dma_size(struct rsxx_dma *dma)
129{
130	if (dma->sub_page.cnt)
131		return dma->sub_page.cnt << 9;
132	else
133		return RSXX_HW_BLK_SIZE;
134}
135
136
137/*----------------- DMA Tracker -------------------*/
138static void set_tracker_dma(struct dma_tracker_list *trackers,
139			    int tag,
140			    struct rsxx_dma *dma)
141{
142	trackers->list[tag].dma = dma;
143}
144
145static struct rsxx_dma *get_tracker_dma(struct dma_tracker_list *trackers,
146					    int tag)
147{
148	return trackers->list[tag].dma;
149}
150
151static int pop_tracker(struct dma_tracker_list *trackers)
152{
153	int tag;
154
155	spin_lock(&trackers->lock);
156	tag = trackers->head;
157	if (tag != -1) {
158		trackers->head = trackers->list[tag].next_tag;
159		trackers->list[tag].next_tag = -1;
160	}
161	spin_unlock(&trackers->lock);
162
163	return tag;
164}
165
166static void push_tracker(struct dma_tracker_list *trackers, int tag)
167{
168	spin_lock(&trackers->lock);
169	trackers->list[tag].next_tag = trackers->head;
170	trackers->head = tag;
171	trackers->list[tag].dma = NULL;
172	spin_unlock(&trackers->lock);
173}
174
175
176/*----------------- Interrupt Coalescing -------------*/
177/*
178 * Interrupt Coalescing Register Format:
179 * Interrupt Timer (64ns units) [15:0]
180 * Interrupt Count [24:16]
181 * Reserved [31:25]
182*/
183#define INTR_COAL_LATENCY_MASK       (0x0000ffff)
184
185#define INTR_COAL_COUNT_SHIFT        16
186#define INTR_COAL_COUNT_BITS         9
187#define INTR_COAL_COUNT_MASK         (((1 << INTR_COAL_COUNT_BITS) - 1) << \
188					INTR_COAL_COUNT_SHIFT)
189#define INTR_COAL_LATENCY_UNITS_NS   64
190
191
192static u32 dma_intr_coal_val(u32 mode, u32 count, u32 latency)
193{
194	u32 latency_units = latency / INTR_COAL_LATENCY_UNITS_NS;
195
196	if (mode == RSXX_INTR_COAL_DISABLED)
197		return 0;
198
199	return ((count << INTR_COAL_COUNT_SHIFT) & INTR_COAL_COUNT_MASK) |
200			(latency_units & INTR_COAL_LATENCY_MASK);
201
202}
203
204static void dma_intr_coal_auto_tune(struct rsxx_cardinfo *card)
205{
206	int i;
207	u32 q_depth = 0;
208	u32 intr_coal;
209
210	if (card->config.data.intr_coal.mode != RSXX_INTR_COAL_AUTO_TUNE ||
211	    unlikely(card->eeh_state))
212		return;
213
214	for (i = 0; i < card->n_targets; i++)
215		q_depth += atomic_read(&card->ctrl[i].stats.hw_q_depth);
216
217	intr_coal = dma_intr_coal_val(card->config.data.intr_coal.mode,
218				      q_depth / 2,
219				      card->config.data.intr_coal.latency);
220	iowrite32(intr_coal, card->regmap + INTR_COAL);
221}
222
223/*----------------- RSXX DMA Handling -------------------*/
224static void rsxx_complete_dma(struct rsxx_dma_ctrl *ctrl,
225				  struct rsxx_dma *dma,
226				  unsigned int status)
227{
228	if (status & DMA_SW_ERR)
229		ctrl->stats.dma_sw_err++;
230	if (status & DMA_HW_FAULT)
231		ctrl->stats.dma_hw_fault++;
232	if (status & DMA_CANCELLED)
233		ctrl->stats.dma_cancelled++;
234
235	if (dma->dma_addr)
236		pci_unmap_page(ctrl->card->dev, dma->dma_addr,
237			       get_dma_size(dma),
238			       dma->cmd == HW_CMD_BLK_WRITE ?
239					   PCI_DMA_TODEVICE :
240					   PCI_DMA_FROMDEVICE);
241
242	if (dma->cb)
243		dma->cb(ctrl->card, dma->cb_data, status ? 1 : 0);
244
245	kmem_cache_free(rsxx_dma_pool, dma);
246}
247
248int rsxx_cleanup_dma_queue(struct rsxx_dma_ctrl *ctrl,
249			   struct list_head *q)
250{
251	struct rsxx_dma *dma;
252	struct rsxx_dma *tmp;
253	int cnt = 0;
254
255	list_for_each_entry_safe(dma, tmp, q, list) {
256		list_del(&dma->list);
257		rsxx_complete_dma(ctrl, dma, DMA_CANCELLED);
258		cnt++;
259	}
260
261	return cnt;
262}
263
264static void rsxx_requeue_dma(struct rsxx_dma_ctrl *ctrl,
265				 struct rsxx_dma *dma)
266{
267	/*
268	 * Requeued DMAs go to the front of the queue so they are issued
269	 * first.
270	 */
271	spin_lock_bh(&ctrl->queue_lock);
272	list_add(&dma->list, &ctrl->queue);
273	spin_unlock_bh(&ctrl->queue_lock);
274}
275
276static void rsxx_handle_dma_error(struct rsxx_dma_ctrl *ctrl,
277				      struct rsxx_dma *dma,
278				      u8 hw_st)
279{
280	unsigned int status = 0;
281	int requeue_cmd = 0;
282
283	dev_dbg(CARD_TO_DEV(ctrl->card),
284		"Handling DMA error(cmd x%02x, laddr x%08x st:x%02x)\n",
285		dma->cmd, dma->laddr, hw_st);
286
287	if (hw_st & HW_STATUS_CRC)
288		ctrl->stats.crc_errors++;
289	if (hw_st & HW_STATUS_HARD_ERR)
290		ctrl->stats.hard_errors++;
291	if (hw_st & HW_STATUS_SOFT_ERR)
292		ctrl->stats.soft_errors++;
293
294	switch (dma->cmd) {
295	case HW_CMD_BLK_READ:
296		if (hw_st & (HW_STATUS_CRC | HW_STATUS_HARD_ERR)) {
297			if (ctrl->card->scrub_hard) {
298				dma->cmd = HW_CMD_BLK_RECON_READ;
299				requeue_cmd = 1;
300				ctrl->stats.reads_retried++;
301			} else {
302				status |= DMA_HW_FAULT;
303				ctrl->stats.reads_failed++;
304			}
305		} else if (hw_st & HW_STATUS_FAULT) {
306			status |= DMA_HW_FAULT;
307			ctrl->stats.reads_failed++;
308		}
309
310		break;
311	case HW_CMD_BLK_RECON_READ:
312		if (hw_st & (HW_STATUS_CRC | HW_STATUS_HARD_ERR)) {
313			/* Data could not be reconstructed. */
314			status |= DMA_HW_FAULT;
315			ctrl->stats.reads_failed++;
316		}
317
318		break;
319	case HW_CMD_BLK_WRITE:
320		status |= DMA_HW_FAULT;
321		ctrl->stats.writes_failed++;
322
323		break;
324	case HW_CMD_BLK_DISCARD:
325		status |= DMA_HW_FAULT;
326		ctrl->stats.discards_failed++;
327
328		break;
329	default:
330		dev_err(CARD_TO_DEV(ctrl->card),
331			"Unknown command in DMA!(cmd: x%02x "
332			   "laddr x%08x st: x%02x\n",
333			   dma->cmd, dma->laddr, hw_st);
334		status |= DMA_SW_ERR;
335
336		break;
337	}
338
339	if (requeue_cmd)
340		rsxx_requeue_dma(ctrl, dma);
341	else
342		rsxx_complete_dma(ctrl, dma, status);
343}
344
345static void dma_engine_stalled(unsigned long data)
346{
347	struct rsxx_dma_ctrl *ctrl = (struct rsxx_dma_ctrl *)data;
348	int cnt;
349
350	if (atomic_read(&ctrl->stats.hw_q_depth) == 0 ||
351	    unlikely(ctrl->card->eeh_state))
352		return;
353
354	if (ctrl->cmd.idx != ioread32(ctrl->regmap + SW_CMD_IDX)) {
355		/*
356		 * The dma engine was stalled because the SW_CMD_IDX write
357		 * was lost. Issue it again to recover.
358		 */
359		dev_warn(CARD_TO_DEV(ctrl->card),
360			"SW_CMD_IDX write was lost, re-writing...\n");
361		iowrite32(ctrl->cmd.idx, ctrl->regmap + SW_CMD_IDX);
362		mod_timer(&ctrl->activity_timer,
363			  jiffies + DMA_ACTIVITY_TIMEOUT);
364	} else {
365		dev_warn(CARD_TO_DEV(ctrl->card),
366			"DMA channel %d has stalled, faulting interface.\n",
367			ctrl->id);
368		ctrl->card->dma_fault = 1;
369
370		/* Clean up the DMA queue */
371		spin_lock(&ctrl->queue_lock);
372		cnt = rsxx_cleanup_dma_queue(ctrl, &ctrl->queue);
373		spin_unlock(&ctrl->queue_lock);
374
375		cnt += rsxx_dma_cancel(ctrl);
376
377		if (cnt)
378			dev_info(CARD_TO_DEV(ctrl->card),
379				"Freed %d queued DMAs on channel %d\n",
380				cnt, ctrl->id);
381	}
382}
383
384static void rsxx_issue_dmas(struct rsxx_dma_ctrl *ctrl)
385{
386	struct rsxx_dma *dma;
387	int tag;
388	int cmds_pending = 0;
389	struct hw_cmd *hw_cmd_buf;
390
391	hw_cmd_buf = ctrl->cmd.buf;
392
393	if (unlikely(ctrl->card->halt) ||
394	    unlikely(ctrl->card->eeh_state))
395		return;
396
397	while (1) {
398		spin_lock_bh(&ctrl->queue_lock);
399		if (list_empty(&ctrl->queue)) {
400			spin_unlock_bh(&ctrl->queue_lock);
401			break;
402		}
403		spin_unlock_bh(&ctrl->queue_lock);
404
405		tag = pop_tracker(ctrl->trackers);
406		if (tag == -1)
407			break;
408
409		spin_lock_bh(&ctrl->queue_lock);
410		dma = list_entry(ctrl->queue.next, struct rsxx_dma, list);
411		list_del(&dma->list);
412		ctrl->stats.sw_q_depth--;
413		spin_unlock_bh(&ctrl->queue_lock);
414
415		/*
416		 * This will catch any DMAs that slipped in right before the
417		 * fault, but was queued after all the other DMAs were
418		 * cancelled.
419		 */
420		if (unlikely(ctrl->card->dma_fault)) {
421			push_tracker(ctrl->trackers, tag);
422			rsxx_complete_dma(ctrl, dma, DMA_CANCELLED);
423			continue;
424		}
425
426		set_tracker_dma(ctrl->trackers, tag, dma);
427		hw_cmd_buf[ctrl->cmd.idx].command  = dma->cmd;
428		hw_cmd_buf[ctrl->cmd.idx].tag      = tag;
429		hw_cmd_buf[ctrl->cmd.idx]._rsvd    = 0;
430		hw_cmd_buf[ctrl->cmd.idx].sub_page =
431					((dma->sub_page.cnt & 0x7) << 4) |
432					 (dma->sub_page.off & 0x7);
433
434		hw_cmd_buf[ctrl->cmd.idx].device_addr =
435					cpu_to_le32(dma->laddr);
436
437		hw_cmd_buf[ctrl->cmd.idx].host_addr =
438					cpu_to_le64(dma->dma_addr);
439
440		dev_dbg(CARD_TO_DEV(ctrl->card),
441			"Issue DMA%d(laddr %d tag %d) to idx %d\n",
442			ctrl->id, dma->laddr, tag, ctrl->cmd.idx);
443
444		ctrl->cmd.idx = (ctrl->cmd.idx + 1) & RSXX_CS_IDX_MASK;
445		cmds_pending++;
446
447		if (dma->cmd == HW_CMD_BLK_WRITE)
448			ctrl->stats.writes_issued++;
449		else if (dma->cmd == HW_CMD_BLK_DISCARD)
450			ctrl->stats.discards_issued++;
451		else
452			ctrl->stats.reads_issued++;
453	}
454
455	/* Let HW know we've queued commands. */
456	if (cmds_pending) {
457		atomic_add(cmds_pending, &ctrl->stats.hw_q_depth);
458		mod_timer(&ctrl->activity_timer,
459			  jiffies + DMA_ACTIVITY_TIMEOUT);
460
461		if (unlikely(ctrl->card->eeh_state)) {
462			del_timer_sync(&ctrl->activity_timer);
463			return;
464		}
465
466		iowrite32(ctrl->cmd.idx, ctrl->regmap + SW_CMD_IDX);
467	}
468}
469
470static void rsxx_dma_done(struct rsxx_dma_ctrl *ctrl)
471{
472	struct rsxx_dma *dma;
473	unsigned long flags;
474	u16 count;
475	u8 status;
476	u8 tag;
477	struct hw_status *hw_st_buf;
478
479	hw_st_buf = ctrl->status.buf;
480
481	if (unlikely(ctrl->card->halt) ||
482	    unlikely(ctrl->card->dma_fault) ||
483	    unlikely(ctrl->card->eeh_state))
484		return;
485
486	count = le16_to_cpu(hw_st_buf[ctrl->status.idx].count);
487
488	while (count == ctrl->e_cnt) {
489		/*
490		 * The read memory-barrier is necessary to keep aggressive
491		 * processors/optimizers (such as the PPC Apple G5) from
492		 * reordering the following status-buffer tag & status read
493		 * *before* the count read on subsequent iterations of the
494		 * loop!
495		 */
496		rmb();
497
498		status = hw_st_buf[ctrl->status.idx].status;
499		tag    = hw_st_buf[ctrl->status.idx].tag;
500
501		dma = get_tracker_dma(ctrl->trackers, tag);
502		if (dma == NULL) {
503			spin_lock_irqsave(&ctrl->card->irq_lock, flags);
504			rsxx_disable_ier(ctrl->card, CR_INTR_DMA_ALL);
505			spin_unlock_irqrestore(&ctrl->card->irq_lock, flags);
506
507			dev_err(CARD_TO_DEV(ctrl->card),
508				"No tracker for tag %d "
509				"(idx %d id %d)\n",
510				tag, ctrl->status.idx, ctrl->id);
511			return;
512		}
513
514		dev_dbg(CARD_TO_DEV(ctrl->card),
515			"Completing DMA%d"
516			"(laddr x%x tag %d st: x%x cnt: x%04x) from idx %d.\n",
517			ctrl->id, dma->laddr, tag, status, count,
518			ctrl->status.idx);
519
520		atomic_dec(&ctrl->stats.hw_q_depth);
521
522		mod_timer(&ctrl->activity_timer,
523			  jiffies + DMA_ACTIVITY_TIMEOUT);
524
525		if (status)
526			rsxx_handle_dma_error(ctrl, dma, status);
527		else
528			rsxx_complete_dma(ctrl, dma, 0);
529
530		push_tracker(ctrl->trackers, tag);
531
532		ctrl->status.idx = (ctrl->status.idx + 1) &
533				   RSXX_CS_IDX_MASK;
534		ctrl->e_cnt++;
535
536		count = le16_to_cpu(hw_st_buf[ctrl->status.idx].count);
537	}
538
539	dma_intr_coal_auto_tune(ctrl->card);
540
541	if (atomic_read(&ctrl->stats.hw_q_depth) == 0)
542		del_timer_sync(&ctrl->activity_timer);
543
544	spin_lock_irqsave(&ctrl->card->irq_lock, flags);
545	rsxx_enable_ier(ctrl->card, CR_INTR_DMA(ctrl->id));
546	spin_unlock_irqrestore(&ctrl->card->irq_lock, flags);
547
548	spin_lock_bh(&ctrl->queue_lock);
549	if (ctrl->stats.sw_q_depth)
550		queue_work(ctrl->issue_wq, &ctrl->issue_dma_work);
551	spin_unlock_bh(&ctrl->queue_lock);
552}
553
554static void rsxx_schedule_issue(struct work_struct *work)
555{
556	struct rsxx_dma_ctrl *ctrl;
557
558	ctrl = container_of(work, struct rsxx_dma_ctrl, issue_dma_work);
559
560	mutex_lock(&ctrl->work_lock);
561	rsxx_issue_dmas(ctrl);
562	mutex_unlock(&ctrl->work_lock);
563}
564
565static void rsxx_schedule_done(struct work_struct *work)
566{
567	struct rsxx_dma_ctrl *ctrl;
568
569	ctrl = container_of(work, struct rsxx_dma_ctrl, dma_done_work);
570
571	mutex_lock(&ctrl->work_lock);
572	rsxx_dma_done(ctrl);
573	mutex_unlock(&ctrl->work_lock);
574}
575
576static int rsxx_queue_discard(struct rsxx_cardinfo *card,
577				  struct list_head *q,
578				  unsigned int laddr,
579				  rsxx_dma_cb cb,
580				  void *cb_data)
581{
582	struct rsxx_dma *dma;
583
584	dma = kmem_cache_alloc(rsxx_dma_pool, GFP_KERNEL);
585	if (!dma)
586		return -ENOMEM;
587
588	dma->cmd          = HW_CMD_BLK_DISCARD;
589	dma->laddr        = laddr;
590	dma->dma_addr     = 0;
591	dma->sub_page.off = 0;
592	dma->sub_page.cnt = 0;
593	dma->page         = NULL;
594	dma->pg_off       = 0;
595	dma->cb	          = cb;
596	dma->cb_data      = cb_data;
597
598	dev_dbg(CARD_TO_DEV(card), "Queuing[D] laddr %x\n", dma->laddr);
599
600	list_add_tail(&dma->list, q);
601
602	return 0;
603}
604
605static int rsxx_queue_dma(struct rsxx_cardinfo *card,
606			      struct list_head *q,
607			      int dir,
608			      unsigned int dma_off,
609			      unsigned int dma_len,
610			      unsigned int laddr,
611			      struct page *page,
612			      unsigned int pg_off,
613			      rsxx_dma_cb cb,
614			      void *cb_data)
615{
616	struct rsxx_dma *dma;
617
618	dma = kmem_cache_alloc(rsxx_dma_pool, GFP_KERNEL);
619	if (!dma)
620		return -ENOMEM;
621
622	dma->dma_addr = pci_map_page(card->dev, page, pg_off, dma_len,
623				     dir ? PCI_DMA_TODEVICE :
624				     PCI_DMA_FROMDEVICE);
625	if (!dma->dma_addr) {
626		kmem_cache_free(rsxx_dma_pool, dma);
627		return -ENOMEM;
628	}
629
630	dma->cmd          = dir ? HW_CMD_BLK_WRITE : HW_CMD_BLK_READ;
631	dma->laddr        = laddr;
632	dma->sub_page.off = (dma_off >> 9);
633	dma->sub_page.cnt = (dma_len >> 9);
634	dma->page         = page;
635	dma->pg_off       = pg_off;
636	dma->cb	          = cb;
637	dma->cb_data      = cb_data;
638
639	dev_dbg(CARD_TO_DEV(card),
640		"Queuing[%c] laddr %x off %d cnt %d page %p pg_off %d\n",
641		dir ? 'W' : 'R', dma->laddr, dma->sub_page.off,
642		dma->sub_page.cnt, dma->page, dma->pg_off);
643
644	/* Queue the DMA */
645	list_add_tail(&dma->list, q);
646
647	return 0;
648}
649
650int rsxx_dma_queue_bio(struct rsxx_cardinfo *card,
651			   struct bio *bio,
652			   atomic_t *n_dmas,
653			   rsxx_dma_cb cb,
654			   void *cb_data)
655{
656	struct list_head dma_list[RSXX_MAX_TARGETS];
657	struct bio_vec *bvec;
658	unsigned long long addr8;
659	unsigned int laddr;
660	unsigned int bv_len;
661	unsigned int bv_off;
662	unsigned int dma_off;
663	unsigned int dma_len;
664	int dma_cnt[RSXX_MAX_TARGETS];
665	int tgt;
666	int st;
667	int i;
668
669	addr8 = bio->bi_sector << 9; /* sectors are 512 bytes */
670	atomic_set(n_dmas, 0);
671
672	for (i = 0; i < card->n_targets; i++) {
673		INIT_LIST_HEAD(&dma_list[i]);
674		dma_cnt[i] = 0;
675	}
676
677	if (bio->bi_rw & REQ_DISCARD) {
678		bv_len = bio->bi_size;
679
680		while (bv_len > 0) {
681			tgt   = rsxx_get_dma_tgt(card, addr8);
682			laddr = rsxx_addr8_to_laddr(addr8, card);
683
684			st = rsxx_queue_discard(card, &dma_list[tgt], laddr,
685						    cb, cb_data);
686			if (st)
687				goto bvec_err;
688
689			dma_cnt[tgt]++;
690			atomic_inc(n_dmas);
691			addr8  += RSXX_HW_BLK_SIZE;
692			bv_len -= RSXX_HW_BLK_SIZE;
693		}
694	} else {
695		bio_for_each_segment(bvec, bio, i) {
696			bv_len = bvec->bv_len;
697			bv_off = bvec->bv_offset;
698
699			while (bv_len > 0) {
700				tgt   = rsxx_get_dma_tgt(card, addr8);
701				laddr = rsxx_addr8_to_laddr(addr8, card);
702				dma_off = addr8 & RSXX_HW_BLK_MASK;
703				dma_len = min(bv_len,
704					      RSXX_HW_BLK_SIZE - dma_off);
705
706				st = rsxx_queue_dma(card, &dma_list[tgt],
707							bio_data_dir(bio),
708							dma_off, dma_len,
709							laddr, bvec->bv_page,
710							bv_off, cb, cb_data);
711				if (st)
712					goto bvec_err;
713
714				dma_cnt[tgt]++;
715				atomic_inc(n_dmas);
716				addr8  += dma_len;
717				bv_off += dma_len;
718				bv_len -= dma_len;
719			}
720		}
721	}
722
723	for (i = 0; i < card->n_targets; i++) {
724		if (!list_empty(&dma_list[i])) {
725			spin_lock_bh(&card->ctrl[i].queue_lock);
726			card->ctrl[i].stats.sw_q_depth += dma_cnt[i];
727			list_splice_tail(&dma_list[i], &card->ctrl[i].queue);
728			spin_unlock_bh(&card->ctrl[i].queue_lock);
729
730			queue_work(card->ctrl[i].issue_wq,
731				   &card->ctrl[i].issue_dma_work);
732		}
733	}
734
735	return 0;
736
737bvec_err:
738	for (i = 0; i < card->n_targets; i++) {
739		spin_lock_bh(&card->ctrl[i].queue_lock);
740		rsxx_cleanup_dma_queue(&card->ctrl[i], &dma_list[i]);
741		spin_unlock_bh(&card->ctrl[i].queue_lock);
742	}
743
744	return st;
745}
746
747
748/*----------------- DMA Engine Initialization & Setup -------------------*/
749int rsxx_hw_buffers_init(struct pci_dev *dev, struct rsxx_dma_ctrl *ctrl)
750{
751	ctrl->status.buf = pci_alloc_consistent(dev, STATUS_BUFFER_SIZE8,
752				&ctrl->status.dma_addr);
753	ctrl->cmd.buf = pci_alloc_consistent(dev, COMMAND_BUFFER_SIZE8,
754				&ctrl->cmd.dma_addr);
755	if (ctrl->status.buf == NULL || ctrl->cmd.buf == NULL)
756		return -ENOMEM;
757
758	memset(ctrl->status.buf, 0xac, STATUS_BUFFER_SIZE8);
759	iowrite32(lower_32_bits(ctrl->status.dma_addr),
760		ctrl->regmap + SB_ADD_LO);
761	iowrite32(upper_32_bits(ctrl->status.dma_addr),
762		ctrl->regmap + SB_ADD_HI);
763
764	memset(ctrl->cmd.buf, 0x83, COMMAND_BUFFER_SIZE8);
765	iowrite32(lower_32_bits(ctrl->cmd.dma_addr), ctrl->regmap + CB_ADD_LO);
766	iowrite32(upper_32_bits(ctrl->cmd.dma_addr), ctrl->regmap + CB_ADD_HI);
767
768	ctrl->status.idx = ioread32(ctrl->regmap + HW_STATUS_CNT);
769	if (ctrl->status.idx > RSXX_MAX_OUTSTANDING_CMDS) {
770		dev_crit(&dev->dev, "Failed reading status cnt x%x\n",
771			ctrl->status.idx);
772		return -EINVAL;
773	}
774	iowrite32(ctrl->status.idx, ctrl->regmap + HW_STATUS_CNT);
775	iowrite32(ctrl->status.idx, ctrl->regmap + SW_STATUS_CNT);
776
777	ctrl->cmd.idx = ioread32(ctrl->regmap + HW_CMD_IDX);
778	if (ctrl->cmd.idx > RSXX_MAX_OUTSTANDING_CMDS) {
779		dev_crit(&dev->dev, "Failed reading cmd cnt x%x\n",
780			ctrl->status.idx);
781		return -EINVAL;
782	}
783	iowrite32(ctrl->cmd.idx, ctrl->regmap + HW_CMD_IDX);
784	iowrite32(ctrl->cmd.idx, ctrl->regmap + SW_CMD_IDX);
785
786	return 0;
787}
788
789static int rsxx_dma_ctrl_init(struct pci_dev *dev,
790				  struct rsxx_dma_ctrl *ctrl)
791{
792	int i;
793	int st;
794
795	memset(&ctrl->stats, 0, sizeof(ctrl->stats));
796
797	ctrl->trackers = vmalloc(DMA_TRACKER_LIST_SIZE8);
798	if (!ctrl->trackers)
799		return -ENOMEM;
800
801	ctrl->trackers->head = 0;
802	for (i = 0; i < RSXX_MAX_OUTSTANDING_CMDS; i++) {
803		ctrl->trackers->list[i].next_tag = i + 1;
804		ctrl->trackers->list[i].dma = NULL;
805	}
806	ctrl->trackers->list[RSXX_MAX_OUTSTANDING_CMDS-1].next_tag = -1;
807	spin_lock_init(&ctrl->trackers->lock);
808
809	spin_lock_init(&ctrl->queue_lock);
810	mutex_init(&ctrl->work_lock);
811	INIT_LIST_HEAD(&ctrl->queue);
812
813	setup_timer(&ctrl->activity_timer, dma_engine_stalled,
814					(unsigned long)ctrl);
815
816	ctrl->issue_wq = alloc_ordered_workqueue(DRIVER_NAME"_issue", 0);
817	if (!ctrl->issue_wq)
818		return -ENOMEM;
819
820	ctrl->done_wq = alloc_ordered_workqueue(DRIVER_NAME"_done", 0);
821	if (!ctrl->done_wq)
822		return -ENOMEM;
823
824	INIT_WORK(&ctrl->issue_dma_work, rsxx_schedule_issue);
825	INIT_WORK(&ctrl->dma_done_work, rsxx_schedule_done);
826
827	st = rsxx_hw_buffers_init(dev, ctrl);
828	if (st)
829		return st;
830
831	return 0;
832}
833
834static int rsxx_dma_stripe_setup(struct rsxx_cardinfo *card,
835			      unsigned int stripe_size8)
836{
837	if (!is_power_of_2(stripe_size8)) {
838		dev_err(CARD_TO_DEV(card),
839			"stripe_size is NOT a power of 2!\n");
840		return -EINVAL;
841	}
842
843	card->_stripe.lower_mask = stripe_size8 - 1;
844
845	card->_stripe.upper_mask  = ~(card->_stripe.lower_mask);
846	card->_stripe.upper_shift = ffs(card->n_targets) - 1;
847
848	card->_stripe.target_mask = card->n_targets - 1;
849	card->_stripe.target_shift = ffs(stripe_size8) - 1;
850
851	dev_dbg(CARD_TO_DEV(card), "_stripe.lower_mask   = x%016llx\n",
852		card->_stripe.lower_mask);
853	dev_dbg(CARD_TO_DEV(card), "_stripe.upper_shift  = x%016llx\n",
854		card->_stripe.upper_shift);
855	dev_dbg(CARD_TO_DEV(card), "_stripe.upper_mask   = x%016llx\n",
856		card->_stripe.upper_mask);
857	dev_dbg(CARD_TO_DEV(card), "_stripe.target_mask  = x%016llx\n",
858		card->_stripe.target_mask);
859	dev_dbg(CARD_TO_DEV(card), "_stripe.target_shift = x%016llx\n",
860		card->_stripe.target_shift);
861
862	return 0;
863}
864
865int rsxx_dma_configure(struct rsxx_cardinfo *card)
866{
867	u32 intr_coal;
868
869	intr_coal = dma_intr_coal_val(card->config.data.intr_coal.mode,
870				      card->config.data.intr_coal.count,
871				      card->config.data.intr_coal.latency);
872	iowrite32(intr_coal, card->regmap + INTR_COAL);
873
874	return rsxx_dma_stripe_setup(card, card->config.data.stripe_size);
875}
876
877int rsxx_dma_setup(struct rsxx_cardinfo *card)
878{
879	unsigned long flags;
880	int st;
881	int i;
882
883	dev_info(CARD_TO_DEV(card),
884		"Initializing %d DMA targets\n",
885		card->n_targets);
886
887	/* Regmap is divided up into 4K chunks. One for each DMA channel */
888	for (i = 0; i < card->n_targets; i++)
889		card->ctrl[i].regmap = card->regmap + (i * 4096);
890
891	card->dma_fault = 0;
892
893	/* Reset the DMA queues */
894	rsxx_dma_queue_reset(card);
895
896	/************* Setup DMA Control *************/
897	for (i = 0; i < card->n_targets; i++) {
898		st = rsxx_dma_ctrl_init(card->dev, &card->ctrl[i]);
899		if (st)
900			goto failed_dma_setup;
901
902		card->ctrl[i].card = card;
903		card->ctrl[i].id = i;
904	}
905
906	card->scrub_hard = 1;
907
908	if (card->config_valid)
909		rsxx_dma_configure(card);
910
911	/* Enable the interrupts after all setup has completed. */
912	for (i = 0; i < card->n_targets; i++) {
913		spin_lock_irqsave(&card->irq_lock, flags);
914		rsxx_enable_ier_and_isr(card, CR_INTR_DMA(i));
915		spin_unlock_irqrestore(&card->irq_lock, flags);
916	}
917
918	return 0;
919
920failed_dma_setup:
921	for (i = 0; i < card->n_targets; i++) {
922		struct rsxx_dma_ctrl *ctrl = &card->ctrl[i];
923
924		if (ctrl->issue_wq) {
925			destroy_workqueue(ctrl->issue_wq);
926			ctrl->issue_wq = NULL;
927		}
928
929		if (ctrl->done_wq) {
930			destroy_workqueue(ctrl->done_wq);
931			ctrl->done_wq = NULL;
932		}
933
934		if (ctrl->trackers)
935			vfree(ctrl->trackers);
936
937		if (ctrl->status.buf)
938			pci_free_consistent(card->dev, STATUS_BUFFER_SIZE8,
939					    ctrl->status.buf,
940					    ctrl->status.dma_addr);
941		if (ctrl->cmd.buf)
942			pci_free_consistent(card->dev, COMMAND_BUFFER_SIZE8,
943					    ctrl->cmd.buf, ctrl->cmd.dma_addr);
944	}
945
946	return st;
947}
948
949int rsxx_dma_cancel(struct rsxx_dma_ctrl *ctrl)
950{
951	struct rsxx_dma *dma;
952	int i;
953	int cnt = 0;
954
955	/* Clean up issued DMAs */
956	for (i = 0; i < RSXX_MAX_OUTSTANDING_CMDS; i++) {
957		dma = get_tracker_dma(ctrl->trackers, i);
958		if (dma) {
959			atomic_dec(&ctrl->stats.hw_q_depth);
960			rsxx_complete_dma(ctrl, dma, DMA_CANCELLED);
961			push_tracker(ctrl->trackers, i);
962			cnt++;
963		}
964	}
965
966	return cnt;
967}
968
969void rsxx_dma_destroy(struct rsxx_cardinfo *card)
970{
971	struct rsxx_dma_ctrl *ctrl;
972	int i;
973
974	for (i = 0; i < card->n_targets; i++) {
975		ctrl = &card->ctrl[i];
976
977		if (ctrl->issue_wq) {
978			destroy_workqueue(ctrl->issue_wq);
979			ctrl->issue_wq = NULL;
980		}
981
982		if (ctrl->done_wq) {
983			destroy_workqueue(ctrl->done_wq);
984			ctrl->done_wq = NULL;
985		}
986
987		if (timer_pending(&ctrl->activity_timer))
988			del_timer_sync(&ctrl->activity_timer);
989
990		/* Clean up the DMA queue */
991		spin_lock_bh(&ctrl->queue_lock);
992		rsxx_cleanup_dma_queue(ctrl, &ctrl->queue);
993		spin_unlock_bh(&ctrl->queue_lock);
994
995		rsxx_dma_cancel(ctrl);
996
997		vfree(ctrl->trackers);
998
999		pci_free_consistent(card->dev, STATUS_BUFFER_SIZE8,
1000				    ctrl->status.buf, ctrl->status.dma_addr);
1001		pci_free_consistent(card->dev, COMMAND_BUFFER_SIZE8,
1002				    ctrl->cmd.buf, ctrl->cmd.dma_addr);
1003	}
1004}
1005
1006int rsxx_eeh_save_issued_dmas(struct rsxx_cardinfo *card)
1007{
1008	int i;
1009	int j;
1010	int cnt;
1011	struct rsxx_dma *dma;
1012	struct list_head *issued_dmas;
1013
1014	issued_dmas = kzalloc(sizeof(*issued_dmas) * card->n_targets,
1015			      GFP_KERNEL);
1016	if (!issued_dmas)
1017		return -ENOMEM;
1018
1019	for (i = 0; i < card->n_targets; i++) {
1020		INIT_LIST_HEAD(&issued_dmas[i]);
1021		cnt = 0;
1022		for (j = 0; j < RSXX_MAX_OUTSTANDING_CMDS; j++) {
1023			dma = get_tracker_dma(card->ctrl[i].trackers, j);
1024			if (dma == NULL)
1025				continue;
1026
1027			if (dma->cmd == HW_CMD_BLK_WRITE)
1028				card->ctrl[i].stats.writes_issued--;
1029			else if (dma->cmd == HW_CMD_BLK_DISCARD)
1030				card->ctrl[i].stats.discards_issued--;
1031			else
1032				card->ctrl[i].stats.reads_issued--;
1033
1034			list_add_tail(&dma->list, &issued_dmas[i]);
1035			push_tracker(card->ctrl[i].trackers, j);
1036			cnt++;
1037		}
1038
1039		spin_lock_bh(&card->ctrl[i].queue_lock);
1040		list_splice(&issued_dmas[i], &card->ctrl[i].queue);
1041
1042		atomic_sub(cnt, &card->ctrl[i].stats.hw_q_depth);
1043		card->ctrl[i].stats.sw_q_depth += cnt;
1044		card->ctrl[i].e_cnt = 0;
1045
1046		list_for_each_entry(dma, &card->ctrl[i].queue, list) {
1047			if (dma->dma_addr)
1048				pci_unmap_page(card->dev, dma->dma_addr,
1049					       get_dma_size(dma),
1050					       dma->cmd == HW_CMD_BLK_WRITE ?
1051					       PCI_DMA_TODEVICE :
1052					       PCI_DMA_FROMDEVICE);
1053		}
1054		spin_unlock_bh(&card->ctrl[i].queue_lock);
1055	}
1056
1057	kfree(issued_dmas);
1058
1059	return 0;
1060}
1061
1062int rsxx_eeh_remap_dmas(struct rsxx_cardinfo *card)
1063{
1064	struct rsxx_dma *dma;
1065	int i;
1066
1067	for (i = 0; i < card->n_targets; i++) {
1068		spin_lock_bh(&card->ctrl[i].queue_lock);
1069		list_for_each_entry(dma, &card->ctrl[i].queue, list) {
1070			dma->dma_addr = pci_map_page(card->dev, dma->page,
1071					dma->pg_off, get_dma_size(dma),
1072					dma->cmd == HW_CMD_BLK_WRITE ?
1073					PCI_DMA_TODEVICE :
1074					PCI_DMA_FROMDEVICE);
1075			if (!dma->dma_addr) {
1076				spin_unlock_bh(&card->ctrl[i].queue_lock);
1077				kmem_cache_free(rsxx_dma_pool, dma);
1078				return -ENOMEM;
1079			}
1080		}
1081		spin_unlock_bh(&card->ctrl[i].queue_lock);
1082	}
1083
1084	return 0;
1085}
1086
1087int rsxx_dma_init(void)
1088{
1089	rsxx_dma_pool = KMEM_CACHE(rsxx_dma, SLAB_HWCACHE_ALIGN);
1090	if (!rsxx_dma_pool)
1091		return -ENOMEM;
1092
1093	return 0;
1094}
1095
1096
1097void rsxx_dma_cleanup(void)
1098{
1099	kmem_cache_destroy(rsxx_dma_pool);
1100}
1101
1102