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_free_dma(struct rsxx_dma_ctrl *ctrl, struct rsxx_dma *dma)
225{
226	if (dma->cmd != HW_CMD_BLK_DISCARD) {
227		if (!pci_dma_mapping_error(ctrl->card->dev, dma->dma_addr)) {
228			pci_unmap_page(ctrl->card->dev, dma->dma_addr,
229				       get_dma_size(dma),
230				       dma->cmd == HW_CMD_BLK_WRITE ?
231						   PCI_DMA_TODEVICE :
232						   PCI_DMA_FROMDEVICE);
233		}
234	}
235
236	kmem_cache_free(rsxx_dma_pool, dma);
237}
238
239static void rsxx_complete_dma(struct rsxx_dma_ctrl *ctrl,
240				  struct rsxx_dma *dma,
241				  unsigned int status)
242{
243	if (status & DMA_SW_ERR)
244		ctrl->stats.dma_sw_err++;
245	if (status & DMA_HW_FAULT)
246		ctrl->stats.dma_hw_fault++;
247	if (status & DMA_CANCELLED)
248		ctrl->stats.dma_cancelled++;
249
250	if (dma->cb)
251		dma->cb(ctrl->card, dma->cb_data, status ? 1 : 0);
252
253	rsxx_free_dma(ctrl, dma);
254}
255
256int rsxx_cleanup_dma_queue(struct rsxx_dma_ctrl *ctrl,
257			   struct list_head *q, unsigned int done)
258{
259	struct rsxx_dma *dma;
260	struct rsxx_dma *tmp;
261	int cnt = 0;
262
263	list_for_each_entry_safe(dma, tmp, q, list) {
264		list_del(&dma->list);
265		if (done & COMPLETE_DMA)
266			rsxx_complete_dma(ctrl, dma, DMA_CANCELLED);
267		else
268			rsxx_free_dma(ctrl, dma);
269		cnt++;
270	}
271
272	return cnt;
273}
274
275static void rsxx_requeue_dma(struct rsxx_dma_ctrl *ctrl,
276				 struct rsxx_dma *dma)
277{
278	/*
279	 * Requeued DMAs go to the front of the queue so they are issued
280	 * first.
281	 */
282	spin_lock_bh(&ctrl->queue_lock);
283	ctrl->stats.sw_q_depth++;
284	list_add(&dma->list, &ctrl->queue);
285	spin_unlock_bh(&ctrl->queue_lock);
286}
287
288static void rsxx_handle_dma_error(struct rsxx_dma_ctrl *ctrl,
289				      struct rsxx_dma *dma,
290				      u8 hw_st)
291{
292	unsigned int status = 0;
293	int requeue_cmd = 0;
294
295	dev_dbg(CARD_TO_DEV(ctrl->card),
296		"Handling DMA error(cmd x%02x, laddr x%08x st:x%02x)\n",
297		dma->cmd, dma->laddr, hw_st);
298
299	if (hw_st & HW_STATUS_CRC)
300		ctrl->stats.crc_errors++;
301	if (hw_st & HW_STATUS_HARD_ERR)
302		ctrl->stats.hard_errors++;
303	if (hw_st & HW_STATUS_SOFT_ERR)
304		ctrl->stats.soft_errors++;
305
306	switch (dma->cmd) {
307	case HW_CMD_BLK_READ:
308		if (hw_st & (HW_STATUS_CRC | HW_STATUS_HARD_ERR)) {
309			if (ctrl->card->scrub_hard) {
310				dma->cmd = HW_CMD_BLK_RECON_READ;
311				requeue_cmd = 1;
312				ctrl->stats.reads_retried++;
313			} else {
314				status |= DMA_HW_FAULT;
315				ctrl->stats.reads_failed++;
316			}
317		} else if (hw_st & HW_STATUS_FAULT) {
318			status |= DMA_HW_FAULT;
319			ctrl->stats.reads_failed++;
320		}
321
322		break;
323	case HW_CMD_BLK_RECON_READ:
324		if (hw_st & (HW_STATUS_CRC | HW_STATUS_HARD_ERR)) {
325			/* Data could not be reconstructed. */
326			status |= DMA_HW_FAULT;
327			ctrl->stats.reads_failed++;
328		}
329
330		break;
331	case HW_CMD_BLK_WRITE:
332		status |= DMA_HW_FAULT;
333		ctrl->stats.writes_failed++;
334
335		break;
336	case HW_CMD_BLK_DISCARD:
337		status |= DMA_HW_FAULT;
338		ctrl->stats.discards_failed++;
339
340		break;
341	default:
342		dev_err(CARD_TO_DEV(ctrl->card),
343			"Unknown command in DMA!(cmd: x%02x "
344			   "laddr x%08x st: x%02x\n",
345			   dma->cmd, dma->laddr, hw_st);
346		status |= DMA_SW_ERR;
347
348		break;
349	}
350
351	if (requeue_cmd)
352		rsxx_requeue_dma(ctrl, dma);
353	else
354		rsxx_complete_dma(ctrl, dma, status);
355}
356
357static void dma_engine_stalled(unsigned long data)
358{
359	struct rsxx_dma_ctrl *ctrl = (struct rsxx_dma_ctrl *)data;
360	int cnt;
361
362	if (atomic_read(&ctrl->stats.hw_q_depth) == 0 ||
363	    unlikely(ctrl->card->eeh_state))
364		return;
365
366	if (ctrl->cmd.idx != ioread32(ctrl->regmap + SW_CMD_IDX)) {
367		/*
368		 * The dma engine was stalled because the SW_CMD_IDX write
369		 * was lost. Issue it again to recover.
370		 */
371		dev_warn(CARD_TO_DEV(ctrl->card),
372			"SW_CMD_IDX write was lost, re-writing...\n");
373		iowrite32(ctrl->cmd.idx, ctrl->regmap + SW_CMD_IDX);
374		mod_timer(&ctrl->activity_timer,
375			  jiffies + DMA_ACTIVITY_TIMEOUT);
376	} else {
377		dev_warn(CARD_TO_DEV(ctrl->card),
378			"DMA channel %d has stalled, faulting interface.\n",
379			ctrl->id);
380		ctrl->card->dma_fault = 1;
381
382		/* Clean up the DMA queue */
383		spin_lock(&ctrl->queue_lock);
384		cnt = rsxx_cleanup_dma_queue(ctrl, &ctrl->queue, COMPLETE_DMA);
385		spin_unlock(&ctrl->queue_lock);
386
387		cnt += rsxx_dma_cancel(ctrl);
388
389		if (cnt)
390			dev_info(CARD_TO_DEV(ctrl->card),
391				"Freed %d queued DMAs on channel %d\n",
392				cnt, ctrl->id);
393	}
394}
395
396static void rsxx_issue_dmas(struct rsxx_dma_ctrl *ctrl)
397{
398	struct rsxx_dma *dma;
399	int tag;
400	int cmds_pending = 0;
401	struct hw_cmd *hw_cmd_buf;
402	int dir;
403
404	hw_cmd_buf = ctrl->cmd.buf;
405
406	if (unlikely(ctrl->card->halt) ||
407	    unlikely(ctrl->card->eeh_state))
408		return;
409
410	while (1) {
411		spin_lock_bh(&ctrl->queue_lock);
412		if (list_empty(&ctrl->queue)) {
413			spin_unlock_bh(&ctrl->queue_lock);
414			break;
415		}
416		spin_unlock_bh(&ctrl->queue_lock);
417
418		tag = pop_tracker(ctrl->trackers);
419		if (tag == -1)
420			break;
421
422		spin_lock_bh(&ctrl->queue_lock);
423		dma = list_entry(ctrl->queue.next, struct rsxx_dma, list);
424		list_del(&dma->list);
425		ctrl->stats.sw_q_depth--;
426		spin_unlock_bh(&ctrl->queue_lock);
427
428		/*
429		 * This will catch any DMAs that slipped in right before the
430		 * fault, but was queued after all the other DMAs were
431		 * cancelled.
432		 */
433		if (unlikely(ctrl->card->dma_fault)) {
434			push_tracker(ctrl->trackers, tag);
435			rsxx_complete_dma(ctrl, dma, DMA_CANCELLED);
436			continue;
437		}
438
439		if (dma->cmd != HW_CMD_BLK_DISCARD) {
440			if (dma->cmd == HW_CMD_BLK_WRITE)
441				dir = PCI_DMA_TODEVICE;
442			else
443				dir = PCI_DMA_FROMDEVICE;
444
445			/*
446			 * The function pci_map_page is placed here because we
447			 * can only, by design, issue up to 255 commands to the
448			 * hardware at one time per DMA channel. So the maximum
449			 * amount of mapped memory would be 255 * 4 channels *
450			 * 4096 Bytes which is less than 2GB, the limit of a x8
451			 * Non-HWWD PCIe slot. This way the pci_map_page
452			 * function should never fail because of a lack of
453			 * mappable memory.
454			 */
455			dma->dma_addr = pci_map_page(ctrl->card->dev, dma->page,
456					dma->pg_off, dma->sub_page.cnt << 9, dir);
457			if (pci_dma_mapping_error(ctrl->card->dev, dma->dma_addr)) {
458				push_tracker(ctrl->trackers, tag);
459				rsxx_complete_dma(ctrl, dma, DMA_CANCELLED);
460				continue;
461			}
462		}
463
464		set_tracker_dma(ctrl->trackers, tag, dma);
465		hw_cmd_buf[ctrl->cmd.idx].command  = dma->cmd;
466		hw_cmd_buf[ctrl->cmd.idx].tag      = tag;
467		hw_cmd_buf[ctrl->cmd.idx]._rsvd    = 0;
468		hw_cmd_buf[ctrl->cmd.idx].sub_page =
469					((dma->sub_page.cnt & 0x7) << 4) |
470					 (dma->sub_page.off & 0x7);
471
472		hw_cmd_buf[ctrl->cmd.idx].device_addr =
473					cpu_to_le32(dma->laddr);
474
475		hw_cmd_buf[ctrl->cmd.idx].host_addr =
476					cpu_to_le64(dma->dma_addr);
477
478		dev_dbg(CARD_TO_DEV(ctrl->card),
479			"Issue DMA%d(laddr %d tag %d) to idx %d\n",
480			ctrl->id, dma->laddr, tag, ctrl->cmd.idx);
481
482		ctrl->cmd.idx = (ctrl->cmd.idx + 1) & RSXX_CS_IDX_MASK;
483		cmds_pending++;
484
485		if (dma->cmd == HW_CMD_BLK_WRITE)
486			ctrl->stats.writes_issued++;
487		else if (dma->cmd == HW_CMD_BLK_DISCARD)
488			ctrl->stats.discards_issued++;
489		else
490			ctrl->stats.reads_issued++;
491	}
492
493	/* Let HW know we've queued commands. */
494	if (cmds_pending) {
495		atomic_add(cmds_pending, &ctrl->stats.hw_q_depth);
496		mod_timer(&ctrl->activity_timer,
497			  jiffies + DMA_ACTIVITY_TIMEOUT);
498
499		if (unlikely(ctrl->card->eeh_state)) {
500			del_timer_sync(&ctrl->activity_timer);
501			return;
502		}
503
504		iowrite32(ctrl->cmd.idx, ctrl->regmap + SW_CMD_IDX);
505	}
506}
507
508static void rsxx_dma_done(struct rsxx_dma_ctrl *ctrl)
509{
510	struct rsxx_dma *dma;
511	unsigned long flags;
512	u16 count;
513	u8 status;
514	u8 tag;
515	struct hw_status *hw_st_buf;
516
517	hw_st_buf = ctrl->status.buf;
518
519	if (unlikely(ctrl->card->halt) ||
520	    unlikely(ctrl->card->dma_fault) ||
521	    unlikely(ctrl->card->eeh_state))
522		return;
523
524	count = le16_to_cpu(hw_st_buf[ctrl->status.idx].count);
525
526	while (count == ctrl->e_cnt) {
527		/*
528		 * The read memory-barrier is necessary to keep aggressive
529		 * processors/optimizers (such as the PPC Apple G5) from
530		 * reordering the following status-buffer tag & status read
531		 * *before* the count read on subsequent iterations of the
532		 * loop!
533		 */
534		rmb();
535
536		status = hw_st_buf[ctrl->status.idx].status;
537		tag    = hw_st_buf[ctrl->status.idx].tag;
538
539		dma = get_tracker_dma(ctrl->trackers, tag);
540		if (dma == NULL) {
541			spin_lock_irqsave(&ctrl->card->irq_lock, flags);
542			rsxx_disable_ier(ctrl->card, CR_INTR_DMA_ALL);
543			spin_unlock_irqrestore(&ctrl->card->irq_lock, flags);
544
545			dev_err(CARD_TO_DEV(ctrl->card),
546				"No tracker for tag %d "
547				"(idx %d id %d)\n",
548				tag, ctrl->status.idx, ctrl->id);
549			return;
550		}
551
552		dev_dbg(CARD_TO_DEV(ctrl->card),
553			"Completing DMA%d"
554			"(laddr x%x tag %d st: x%x cnt: x%04x) from idx %d.\n",
555			ctrl->id, dma->laddr, tag, status, count,
556			ctrl->status.idx);
557
558		atomic_dec(&ctrl->stats.hw_q_depth);
559
560		mod_timer(&ctrl->activity_timer,
561			  jiffies + DMA_ACTIVITY_TIMEOUT);
562
563		if (status)
564			rsxx_handle_dma_error(ctrl, dma, status);
565		else
566			rsxx_complete_dma(ctrl, dma, 0);
567
568		push_tracker(ctrl->trackers, tag);
569
570		ctrl->status.idx = (ctrl->status.idx + 1) &
571				   RSXX_CS_IDX_MASK;
572		ctrl->e_cnt++;
573
574		count = le16_to_cpu(hw_st_buf[ctrl->status.idx].count);
575	}
576
577	dma_intr_coal_auto_tune(ctrl->card);
578
579	if (atomic_read(&ctrl->stats.hw_q_depth) == 0)
580		del_timer_sync(&ctrl->activity_timer);
581
582	spin_lock_irqsave(&ctrl->card->irq_lock, flags);
583	rsxx_enable_ier(ctrl->card, CR_INTR_DMA(ctrl->id));
584	spin_unlock_irqrestore(&ctrl->card->irq_lock, flags);
585
586	spin_lock_bh(&ctrl->queue_lock);
587	if (ctrl->stats.sw_q_depth)
588		queue_work(ctrl->issue_wq, &ctrl->issue_dma_work);
589	spin_unlock_bh(&ctrl->queue_lock);
590}
591
592static void rsxx_schedule_issue(struct work_struct *work)
593{
594	struct rsxx_dma_ctrl *ctrl;
595
596	ctrl = container_of(work, struct rsxx_dma_ctrl, issue_dma_work);
597
598	mutex_lock(&ctrl->work_lock);
599	rsxx_issue_dmas(ctrl);
600	mutex_unlock(&ctrl->work_lock);
601}
602
603static void rsxx_schedule_done(struct work_struct *work)
604{
605	struct rsxx_dma_ctrl *ctrl;
606
607	ctrl = container_of(work, struct rsxx_dma_ctrl, dma_done_work);
608
609	mutex_lock(&ctrl->work_lock);
610	rsxx_dma_done(ctrl);
611	mutex_unlock(&ctrl->work_lock);
612}
613
614static int rsxx_queue_discard(struct rsxx_cardinfo *card,
615				  struct list_head *q,
616				  unsigned int laddr,
617				  rsxx_dma_cb cb,
618				  void *cb_data)
619{
620	struct rsxx_dma *dma;
621
622	dma = kmem_cache_alloc(rsxx_dma_pool, GFP_KERNEL);
623	if (!dma)
624		return -ENOMEM;
625
626	dma->cmd          = HW_CMD_BLK_DISCARD;
627	dma->laddr        = laddr;
628	dma->dma_addr     = 0;
629	dma->sub_page.off = 0;
630	dma->sub_page.cnt = 0;
631	dma->page         = NULL;
632	dma->pg_off       = 0;
633	dma->cb	          = cb;
634	dma->cb_data      = cb_data;
635
636	dev_dbg(CARD_TO_DEV(card), "Queuing[D] laddr %x\n", dma->laddr);
637
638	list_add_tail(&dma->list, q);
639
640	return 0;
641}
642
643static int rsxx_queue_dma(struct rsxx_cardinfo *card,
644			      struct list_head *q,
645			      int dir,
646			      unsigned int dma_off,
647			      unsigned int dma_len,
648			      unsigned int laddr,
649			      struct page *page,
650			      unsigned int pg_off,
651			      rsxx_dma_cb cb,
652			      void *cb_data)
653{
654	struct rsxx_dma *dma;
655
656	dma = kmem_cache_alloc(rsxx_dma_pool, GFP_KERNEL);
657	if (!dma)
658		return -ENOMEM;
659
660	dma->cmd          = dir ? HW_CMD_BLK_WRITE : HW_CMD_BLK_READ;
661	dma->laddr        = laddr;
662	dma->sub_page.off = (dma_off >> 9);
663	dma->sub_page.cnt = (dma_len >> 9);
664	dma->page         = page;
665	dma->pg_off       = pg_off;
666	dma->cb	          = cb;
667	dma->cb_data      = cb_data;
668
669	dev_dbg(CARD_TO_DEV(card),
670		"Queuing[%c] laddr %x off %d cnt %d page %p pg_off %d\n",
671		dir ? 'W' : 'R', dma->laddr, dma->sub_page.off,
672		dma->sub_page.cnt, dma->page, dma->pg_off);
673
674	/* Queue the DMA */
675	list_add_tail(&dma->list, q);
676
677	return 0;
678}
679
680int rsxx_dma_queue_bio(struct rsxx_cardinfo *card,
681			   struct bio *bio,
682			   atomic_t *n_dmas,
683			   rsxx_dma_cb cb,
684			   void *cb_data)
685{
686	struct list_head dma_list[RSXX_MAX_TARGETS];
687	struct bio_vec bvec;
688	struct bvec_iter iter;
689	unsigned long long addr8;
690	unsigned int laddr;
691	unsigned int bv_len;
692	unsigned int bv_off;
693	unsigned int dma_off;
694	unsigned int dma_len;
695	int dma_cnt[RSXX_MAX_TARGETS];
696	int tgt;
697	int st;
698	int i;
699
700	addr8 = bio->bi_iter.bi_sector << 9; /* sectors are 512 bytes */
701	atomic_set(n_dmas, 0);
702
703	for (i = 0; i < card->n_targets; i++) {
704		INIT_LIST_HEAD(&dma_list[i]);
705		dma_cnt[i] = 0;
706	}
707
708	if (bio->bi_rw & REQ_DISCARD) {
709		bv_len = bio->bi_iter.bi_size;
710
711		while (bv_len > 0) {
712			tgt   = rsxx_get_dma_tgt(card, addr8);
713			laddr = rsxx_addr8_to_laddr(addr8, card);
714
715			st = rsxx_queue_discard(card, &dma_list[tgt], laddr,
716						    cb, cb_data);
717			if (st)
718				goto bvec_err;
719
720			dma_cnt[tgt]++;
721			atomic_inc(n_dmas);
722			addr8  += RSXX_HW_BLK_SIZE;
723			bv_len -= RSXX_HW_BLK_SIZE;
724		}
725	} else {
726		bio_for_each_segment(bvec, bio, iter) {
727			bv_len = bvec.bv_len;
728			bv_off = bvec.bv_offset;
729
730			while (bv_len > 0) {
731				tgt   = rsxx_get_dma_tgt(card, addr8);
732				laddr = rsxx_addr8_to_laddr(addr8, card);
733				dma_off = addr8 & RSXX_HW_BLK_MASK;
734				dma_len = min(bv_len,
735					      RSXX_HW_BLK_SIZE - dma_off);
736
737				st = rsxx_queue_dma(card, &dma_list[tgt],
738							bio_data_dir(bio),
739							dma_off, dma_len,
740							laddr, bvec.bv_page,
741							bv_off, cb, cb_data);
742				if (st)
743					goto bvec_err;
744
745				dma_cnt[tgt]++;
746				atomic_inc(n_dmas);
747				addr8  += dma_len;
748				bv_off += dma_len;
749				bv_len -= dma_len;
750			}
751		}
752	}
753
754	for (i = 0; i < card->n_targets; i++) {
755		if (!list_empty(&dma_list[i])) {
756			spin_lock_bh(&card->ctrl[i].queue_lock);
757			card->ctrl[i].stats.sw_q_depth += dma_cnt[i];
758			list_splice_tail(&dma_list[i], &card->ctrl[i].queue);
759			spin_unlock_bh(&card->ctrl[i].queue_lock);
760
761			queue_work(card->ctrl[i].issue_wq,
762				   &card->ctrl[i].issue_dma_work);
763		}
764	}
765
766	return 0;
767
768bvec_err:
769	for (i = 0; i < card->n_targets; i++)
770		rsxx_cleanup_dma_queue(&card->ctrl[i], &dma_list[i],
771					FREE_DMA);
772
773	return st;
774}
775
776
777/*----------------- DMA Engine Initialization & Setup -------------------*/
778int rsxx_hw_buffers_init(struct pci_dev *dev, struct rsxx_dma_ctrl *ctrl)
779{
780	ctrl->status.buf = pci_alloc_consistent(dev, STATUS_BUFFER_SIZE8,
781				&ctrl->status.dma_addr);
782	ctrl->cmd.buf = pci_alloc_consistent(dev, COMMAND_BUFFER_SIZE8,
783				&ctrl->cmd.dma_addr);
784	if (ctrl->status.buf == NULL || ctrl->cmd.buf == NULL)
785		return -ENOMEM;
786
787	memset(ctrl->status.buf, 0xac, STATUS_BUFFER_SIZE8);
788	iowrite32(lower_32_bits(ctrl->status.dma_addr),
789		ctrl->regmap + SB_ADD_LO);
790	iowrite32(upper_32_bits(ctrl->status.dma_addr),
791		ctrl->regmap + SB_ADD_HI);
792
793	memset(ctrl->cmd.buf, 0x83, COMMAND_BUFFER_SIZE8);
794	iowrite32(lower_32_bits(ctrl->cmd.dma_addr), ctrl->regmap + CB_ADD_LO);
795	iowrite32(upper_32_bits(ctrl->cmd.dma_addr), ctrl->regmap + CB_ADD_HI);
796
797	ctrl->status.idx = ioread32(ctrl->regmap + HW_STATUS_CNT);
798	if (ctrl->status.idx > RSXX_MAX_OUTSTANDING_CMDS) {
799		dev_crit(&dev->dev, "Failed reading status cnt x%x\n",
800			ctrl->status.idx);
801		return -EINVAL;
802	}
803	iowrite32(ctrl->status.idx, ctrl->regmap + HW_STATUS_CNT);
804	iowrite32(ctrl->status.idx, ctrl->regmap + SW_STATUS_CNT);
805
806	ctrl->cmd.idx = ioread32(ctrl->regmap + HW_CMD_IDX);
807	if (ctrl->cmd.idx > RSXX_MAX_OUTSTANDING_CMDS) {
808		dev_crit(&dev->dev, "Failed reading cmd cnt x%x\n",
809			ctrl->status.idx);
810		return -EINVAL;
811	}
812	iowrite32(ctrl->cmd.idx, ctrl->regmap + HW_CMD_IDX);
813	iowrite32(ctrl->cmd.idx, ctrl->regmap + SW_CMD_IDX);
814
815	return 0;
816}
817
818static int rsxx_dma_ctrl_init(struct pci_dev *dev,
819				  struct rsxx_dma_ctrl *ctrl)
820{
821	int i;
822	int st;
823
824	memset(&ctrl->stats, 0, sizeof(ctrl->stats));
825
826	ctrl->trackers = vmalloc(DMA_TRACKER_LIST_SIZE8);
827	if (!ctrl->trackers)
828		return -ENOMEM;
829
830	ctrl->trackers->head = 0;
831	for (i = 0; i < RSXX_MAX_OUTSTANDING_CMDS; i++) {
832		ctrl->trackers->list[i].next_tag = i + 1;
833		ctrl->trackers->list[i].dma = NULL;
834	}
835	ctrl->trackers->list[RSXX_MAX_OUTSTANDING_CMDS-1].next_tag = -1;
836	spin_lock_init(&ctrl->trackers->lock);
837
838	spin_lock_init(&ctrl->queue_lock);
839	mutex_init(&ctrl->work_lock);
840	INIT_LIST_HEAD(&ctrl->queue);
841
842	setup_timer(&ctrl->activity_timer, dma_engine_stalled,
843					(unsigned long)ctrl);
844
845	ctrl->issue_wq = alloc_ordered_workqueue(DRIVER_NAME"_issue", 0);
846	if (!ctrl->issue_wq)
847		return -ENOMEM;
848
849	ctrl->done_wq = alloc_ordered_workqueue(DRIVER_NAME"_done", 0);
850	if (!ctrl->done_wq)
851		return -ENOMEM;
852
853	INIT_WORK(&ctrl->issue_dma_work, rsxx_schedule_issue);
854	INIT_WORK(&ctrl->dma_done_work, rsxx_schedule_done);
855
856	st = rsxx_hw_buffers_init(dev, ctrl);
857	if (st)
858		return st;
859
860	return 0;
861}
862
863static int rsxx_dma_stripe_setup(struct rsxx_cardinfo *card,
864			      unsigned int stripe_size8)
865{
866	if (!is_power_of_2(stripe_size8)) {
867		dev_err(CARD_TO_DEV(card),
868			"stripe_size is NOT a power of 2!\n");
869		return -EINVAL;
870	}
871
872	card->_stripe.lower_mask = stripe_size8 - 1;
873
874	card->_stripe.upper_mask  = ~(card->_stripe.lower_mask);
875	card->_stripe.upper_shift = ffs(card->n_targets) - 1;
876
877	card->_stripe.target_mask = card->n_targets - 1;
878	card->_stripe.target_shift = ffs(stripe_size8) - 1;
879
880	dev_dbg(CARD_TO_DEV(card), "_stripe.lower_mask   = x%016llx\n",
881		card->_stripe.lower_mask);
882	dev_dbg(CARD_TO_DEV(card), "_stripe.upper_shift  = x%016llx\n",
883		card->_stripe.upper_shift);
884	dev_dbg(CARD_TO_DEV(card), "_stripe.upper_mask   = x%016llx\n",
885		card->_stripe.upper_mask);
886	dev_dbg(CARD_TO_DEV(card), "_stripe.target_mask  = x%016llx\n",
887		card->_stripe.target_mask);
888	dev_dbg(CARD_TO_DEV(card), "_stripe.target_shift = x%016llx\n",
889		card->_stripe.target_shift);
890
891	return 0;
892}
893
894int rsxx_dma_configure(struct rsxx_cardinfo *card)
895{
896	u32 intr_coal;
897
898	intr_coal = dma_intr_coal_val(card->config.data.intr_coal.mode,
899				      card->config.data.intr_coal.count,
900				      card->config.data.intr_coal.latency);
901	iowrite32(intr_coal, card->regmap + INTR_COAL);
902
903	return rsxx_dma_stripe_setup(card, card->config.data.stripe_size);
904}
905
906int rsxx_dma_setup(struct rsxx_cardinfo *card)
907{
908	unsigned long flags;
909	int st;
910	int i;
911
912	dev_info(CARD_TO_DEV(card),
913		"Initializing %d DMA targets\n",
914		card->n_targets);
915
916	/* Regmap is divided up into 4K chunks. One for each DMA channel */
917	for (i = 0; i < card->n_targets; i++)
918		card->ctrl[i].regmap = card->regmap + (i * 4096);
919
920	card->dma_fault = 0;
921
922	/* Reset the DMA queues */
923	rsxx_dma_queue_reset(card);
924
925	/************* Setup DMA Control *************/
926	for (i = 0; i < card->n_targets; i++) {
927		st = rsxx_dma_ctrl_init(card->dev, &card->ctrl[i]);
928		if (st)
929			goto failed_dma_setup;
930
931		card->ctrl[i].card = card;
932		card->ctrl[i].id = i;
933	}
934
935	card->scrub_hard = 1;
936
937	if (card->config_valid)
938		rsxx_dma_configure(card);
939
940	/* Enable the interrupts after all setup has completed. */
941	for (i = 0; i < card->n_targets; i++) {
942		spin_lock_irqsave(&card->irq_lock, flags);
943		rsxx_enable_ier_and_isr(card, CR_INTR_DMA(i));
944		spin_unlock_irqrestore(&card->irq_lock, flags);
945	}
946
947	return 0;
948
949failed_dma_setup:
950	for (i = 0; i < card->n_targets; i++) {
951		struct rsxx_dma_ctrl *ctrl = &card->ctrl[i];
952
953		if (ctrl->issue_wq) {
954			destroy_workqueue(ctrl->issue_wq);
955			ctrl->issue_wq = NULL;
956		}
957
958		if (ctrl->done_wq) {
959			destroy_workqueue(ctrl->done_wq);
960			ctrl->done_wq = NULL;
961		}
962
963		if (ctrl->trackers)
964			vfree(ctrl->trackers);
965
966		if (ctrl->status.buf)
967			pci_free_consistent(card->dev, STATUS_BUFFER_SIZE8,
968					    ctrl->status.buf,
969					    ctrl->status.dma_addr);
970		if (ctrl->cmd.buf)
971			pci_free_consistent(card->dev, COMMAND_BUFFER_SIZE8,
972					    ctrl->cmd.buf, ctrl->cmd.dma_addr);
973	}
974
975	return st;
976}
977
978int rsxx_dma_cancel(struct rsxx_dma_ctrl *ctrl)
979{
980	struct rsxx_dma *dma;
981	int i;
982	int cnt = 0;
983
984	/* Clean up issued DMAs */
985	for (i = 0; i < RSXX_MAX_OUTSTANDING_CMDS; i++) {
986		dma = get_tracker_dma(ctrl->trackers, i);
987		if (dma) {
988			atomic_dec(&ctrl->stats.hw_q_depth);
989			rsxx_complete_dma(ctrl, dma, DMA_CANCELLED);
990			push_tracker(ctrl->trackers, i);
991			cnt++;
992		}
993	}
994
995	return cnt;
996}
997
998void rsxx_dma_destroy(struct rsxx_cardinfo *card)
999{
1000	struct rsxx_dma_ctrl *ctrl;
1001	int i;
1002
1003	for (i = 0; i < card->n_targets; i++) {
1004		ctrl = &card->ctrl[i];
1005
1006		if (ctrl->issue_wq) {
1007			destroy_workqueue(ctrl->issue_wq);
1008			ctrl->issue_wq = NULL;
1009		}
1010
1011		if (ctrl->done_wq) {
1012			destroy_workqueue(ctrl->done_wq);
1013			ctrl->done_wq = NULL;
1014		}
1015
1016		if (timer_pending(&ctrl->activity_timer))
1017			del_timer_sync(&ctrl->activity_timer);
1018
1019		/* Clean up the DMA queue */
1020		spin_lock_bh(&ctrl->queue_lock);
1021		rsxx_cleanup_dma_queue(ctrl, &ctrl->queue, COMPLETE_DMA);
1022		spin_unlock_bh(&ctrl->queue_lock);
1023
1024		rsxx_dma_cancel(ctrl);
1025
1026		vfree(ctrl->trackers);
1027
1028		pci_free_consistent(card->dev, STATUS_BUFFER_SIZE8,
1029				    ctrl->status.buf, ctrl->status.dma_addr);
1030		pci_free_consistent(card->dev, COMMAND_BUFFER_SIZE8,
1031				    ctrl->cmd.buf, ctrl->cmd.dma_addr);
1032	}
1033}
1034
1035int rsxx_eeh_save_issued_dmas(struct rsxx_cardinfo *card)
1036{
1037	int i;
1038	int j;
1039	int cnt;
1040	struct rsxx_dma *dma;
1041	struct list_head *issued_dmas;
1042
1043	issued_dmas = kzalloc(sizeof(*issued_dmas) * card->n_targets,
1044			      GFP_KERNEL);
1045	if (!issued_dmas)
1046		return -ENOMEM;
1047
1048	for (i = 0; i < card->n_targets; i++) {
1049		INIT_LIST_HEAD(&issued_dmas[i]);
1050		cnt = 0;
1051		for (j = 0; j < RSXX_MAX_OUTSTANDING_CMDS; j++) {
1052			dma = get_tracker_dma(card->ctrl[i].trackers, j);
1053			if (dma == NULL)
1054				continue;
1055
1056			if (dma->cmd == HW_CMD_BLK_WRITE)
1057				card->ctrl[i].stats.writes_issued--;
1058			else if (dma->cmd == HW_CMD_BLK_DISCARD)
1059				card->ctrl[i].stats.discards_issued--;
1060			else
1061				card->ctrl[i].stats.reads_issued--;
1062
1063			if (dma->cmd != HW_CMD_BLK_DISCARD) {
1064				pci_unmap_page(card->dev, dma->dma_addr,
1065					       get_dma_size(dma),
1066					       dma->cmd == HW_CMD_BLK_WRITE ?
1067					       PCI_DMA_TODEVICE :
1068					       PCI_DMA_FROMDEVICE);
1069			}
1070
1071			list_add_tail(&dma->list, &issued_dmas[i]);
1072			push_tracker(card->ctrl[i].trackers, j);
1073			cnt++;
1074		}
1075
1076		spin_lock_bh(&card->ctrl[i].queue_lock);
1077		list_splice(&issued_dmas[i], &card->ctrl[i].queue);
1078
1079		atomic_sub(cnt, &card->ctrl[i].stats.hw_q_depth);
1080		card->ctrl[i].stats.sw_q_depth += cnt;
1081		card->ctrl[i].e_cnt = 0;
1082		spin_unlock_bh(&card->ctrl[i].queue_lock);
1083	}
1084
1085	kfree(issued_dmas);
1086
1087	return 0;
1088}
1089
1090int rsxx_dma_init(void)
1091{
1092	rsxx_dma_pool = KMEM_CACHE(rsxx_dma, SLAB_HWCACHE_ALIGN);
1093	if (!rsxx_dma_pool)
1094		return -ENOMEM;
1095
1096	return 0;
1097}
1098
1099
1100void rsxx_dma_cleanup(void)
1101{
1102	kmem_cache_destroy(rsxx_dma_pool);
1103}
1104
1105