[Feature]add MT2731_MP2_MR2_SVN388 baseline version

Change-Id: Ief04314834b31e27effab435d3ca8ba33b499059
diff --git a/src/kernel/linux/v4.14/drivers/block/rsxx/dma.c b/src/kernel/linux/v4.14/drivers/block/rsxx/dma.c
new file mode 100644
index 0000000..6a1b217
--- /dev/null
+++ b/src/kernel/linux/v4.14/drivers/block/rsxx/dma.c
@@ -0,0 +1,1103 @@
+/*
+* Filename: dma.c
+*
+*
+* Authors: Joshua Morris <josh.h.morris@us.ibm.com>
+*	Philip Kelleher <pjk1939@linux.vnet.ibm.com>
+*
+* (C) Copyright 2013 IBM Corporation
+*
+* This program is free software; you can redistribute it and/or
+* modify it under the terms of the GNU General Public License as
+* published by the Free Software Foundation; either version 2 of the
+* License, or (at your option) any later version.
+*
+* This program is distributed in the hope that it will be useful, but
+* WITHOUT ANY WARRANTY; without even the implied warranty of
+* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+* General Public License for more details.
+*
+* You should have received a copy of the GNU General Public License
+* along with this program; if not, write to the Free Software Foundation,
+* Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+*/
+
+#include <linux/slab.h>
+#include "rsxx_priv.h"
+
+struct rsxx_dma {
+	struct list_head	 list;
+	u8			 cmd;
+	unsigned int		 laddr;     /* Logical address */
+	struct {
+		u32		 off;
+		u32		 cnt;
+	} sub_page;
+	dma_addr_t		 dma_addr;
+	struct page		 *page;
+	unsigned int		 pg_off;    /* Page Offset */
+	rsxx_dma_cb		 cb;
+	void			 *cb_data;
+};
+
+/* This timeout is used to detect a stalled DMA channel */
+#define DMA_ACTIVITY_TIMEOUT	msecs_to_jiffies(10000)
+
+struct hw_status {
+	u8	status;
+	u8	tag;
+	__le16	count;
+	__le32	_rsvd2;
+	__le64	_rsvd3;
+} __packed;
+
+enum rsxx_dma_status {
+	DMA_SW_ERR    = 0x1,
+	DMA_HW_FAULT  = 0x2,
+	DMA_CANCELLED = 0x4,
+};
+
+struct hw_cmd {
+	u8	command;
+	u8	tag;
+	u8	_rsvd;
+	u8	sub_page; /* Bit[0:2]: 512byte offset */
+			  /* Bit[4:6]: 512byte count */
+	__le32	device_addr;
+	__le64	host_addr;
+} __packed;
+
+enum rsxx_hw_cmd {
+	HW_CMD_BLK_DISCARD	= 0x70,
+	HW_CMD_BLK_WRITE	= 0x80,
+	HW_CMD_BLK_READ		= 0xC0,
+	HW_CMD_BLK_RECON_READ	= 0xE0,
+};
+
+enum rsxx_hw_status {
+	HW_STATUS_CRC		= 0x01,
+	HW_STATUS_HARD_ERR	= 0x02,
+	HW_STATUS_SOFT_ERR	= 0x04,
+	HW_STATUS_FAULT		= 0x08,
+};
+
+static struct kmem_cache *rsxx_dma_pool;
+
+struct dma_tracker {
+	int			next_tag;
+	struct rsxx_dma	*dma;
+};
+
+#define DMA_TRACKER_LIST_SIZE8 (sizeof(struct dma_tracker_list) + \
+		(sizeof(struct dma_tracker) * RSXX_MAX_OUTSTANDING_CMDS))
+
+struct dma_tracker_list {
+	spinlock_t		lock;
+	int			head;
+	struct dma_tracker	list[0];
+};
+
+
+/*----------------- Misc Utility Functions -------------------*/
+static unsigned int rsxx_addr8_to_laddr(u64 addr8, struct rsxx_cardinfo *card)
+{
+	unsigned long long tgt_addr8;
+
+	tgt_addr8 = ((addr8 >> card->_stripe.upper_shift) &
+		      card->_stripe.upper_mask) |
+		    ((addr8) & card->_stripe.lower_mask);
+	do_div(tgt_addr8, RSXX_HW_BLK_SIZE);
+	return tgt_addr8;
+}
+
+static unsigned int rsxx_get_dma_tgt(struct rsxx_cardinfo *card, u64 addr8)
+{
+	unsigned int tgt;
+
+	tgt = (addr8 >> card->_stripe.target_shift) & card->_stripe.target_mask;
+
+	return tgt;
+}
+
+void rsxx_dma_queue_reset(struct rsxx_cardinfo *card)
+{
+	/* Reset all DMA Command/Status Queues */
+	iowrite32(DMA_QUEUE_RESET, card->regmap + RESET);
+}
+
+static unsigned int get_dma_size(struct rsxx_dma *dma)
+{
+	if (dma->sub_page.cnt)
+		return dma->sub_page.cnt << 9;
+	else
+		return RSXX_HW_BLK_SIZE;
+}
+
+
+/*----------------- DMA Tracker -------------------*/
+static void set_tracker_dma(struct dma_tracker_list *trackers,
+			    int tag,
+			    struct rsxx_dma *dma)
+{
+	trackers->list[tag].dma = dma;
+}
+
+static struct rsxx_dma *get_tracker_dma(struct dma_tracker_list *trackers,
+					    int tag)
+{
+	return trackers->list[tag].dma;
+}
+
+static int pop_tracker(struct dma_tracker_list *trackers)
+{
+	int tag;
+
+	spin_lock(&trackers->lock);
+	tag = trackers->head;
+	if (tag != -1) {
+		trackers->head = trackers->list[tag].next_tag;
+		trackers->list[tag].next_tag = -1;
+	}
+	spin_unlock(&trackers->lock);
+
+	return tag;
+}
+
+static void push_tracker(struct dma_tracker_list *trackers, int tag)
+{
+	spin_lock(&trackers->lock);
+	trackers->list[tag].next_tag = trackers->head;
+	trackers->head = tag;
+	trackers->list[tag].dma = NULL;
+	spin_unlock(&trackers->lock);
+}
+
+
+/*----------------- Interrupt Coalescing -------------*/
+/*
+ * Interrupt Coalescing Register Format:
+ * Interrupt Timer (64ns units) [15:0]
+ * Interrupt Count [24:16]
+ * Reserved [31:25]
+*/
+#define INTR_COAL_LATENCY_MASK       (0x0000ffff)
+
+#define INTR_COAL_COUNT_SHIFT        16
+#define INTR_COAL_COUNT_BITS         9
+#define INTR_COAL_COUNT_MASK         (((1 << INTR_COAL_COUNT_BITS) - 1) << \
+					INTR_COAL_COUNT_SHIFT)
+#define INTR_COAL_LATENCY_UNITS_NS   64
+
+
+static u32 dma_intr_coal_val(u32 mode, u32 count, u32 latency)
+{
+	u32 latency_units = latency / INTR_COAL_LATENCY_UNITS_NS;
+
+	if (mode == RSXX_INTR_COAL_DISABLED)
+		return 0;
+
+	return ((count << INTR_COAL_COUNT_SHIFT) & INTR_COAL_COUNT_MASK) |
+			(latency_units & INTR_COAL_LATENCY_MASK);
+
+}
+
+static void dma_intr_coal_auto_tune(struct rsxx_cardinfo *card)
+{
+	int i;
+	u32 q_depth = 0;
+	u32 intr_coal;
+
+	if (card->config.data.intr_coal.mode != RSXX_INTR_COAL_AUTO_TUNE ||
+	    unlikely(card->eeh_state))
+		return;
+
+	for (i = 0; i < card->n_targets; i++)
+		q_depth += atomic_read(&card->ctrl[i].stats.hw_q_depth);
+
+	intr_coal = dma_intr_coal_val(card->config.data.intr_coal.mode,
+				      q_depth / 2,
+				      card->config.data.intr_coal.latency);
+	iowrite32(intr_coal, card->regmap + INTR_COAL);
+}
+
+/*----------------- RSXX DMA Handling -------------------*/
+static void rsxx_free_dma(struct rsxx_dma_ctrl *ctrl, struct rsxx_dma *dma)
+{
+	if (dma->cmd != HW_CMD_BLK_DISCARD) {
+		if (!pci_dma_mapping_error(ctrl->card->dev, dma->dma_addr)) {
+			pci_unmap_page(ctrl->card->dev, dma->dma_addr,
+				       get_dma_size(dma),
+				       dma->cmd == HW_CMD_BLK_WRITE ?
+						   PCI_DMA_TODEVICE :
+						   PCI_DMA_FROMDEVICE);
+		}
+	}
+
+	kmem_cache_free(rsxx_dma_pool, dma);
+}
+
+static void rsxx_complete_dma(struct rsxx_dma_ctrl *ctrl,
+				  struct rsxx_dma *dma,
+				  unsigned int status)
+{
+	if (status & DMA_SW_ERR)
+		ctrl->stats.dma_sw_err++;
+	if (status & DMA_HW_FAULT)
+		ctrl->stats.dma_hw_fault++;
+	if (status & DMA_CANCELLED)
+		ctrl->stats.dma_cancelled++;
+
+	if (dma->cb)
+		dma->cb(ctrl->card, dma->cb_data, status ? 1 : 0);
+
+	rsxx_free_dma(ctrl, dma);
+}
+
+int rsxx_cleanup_dma_queue(struct rsxx_dma_ctrl *ctrl,
+			   struct list_head *q, unsigned int done)
+{
+	struct rsxx_dma *dma;
+	struct rsxx_dma *tmp;
+	int cnt = 0;
+
+	list_for_each_entry_safe(dma, tmp, q, list) {
+		list_del(&dma->list);
+		if (done & COMPLETE_DMA)
+			rsxx_complete_dma(ctrl, dma, DMA_CANCELLED);
+		else
+			rsxx_free_dma(ctrl, dma);
+		cnt++;
+	}
+
+	return cnt;
+}
+
+static void rsxx_requeue_dma(struct rsxx_dma_ctrl *ctrl,
+				 struct rsxx_dma *dma)
+{
+	/*
+	 * Requeued DMAs go to the front of the queue so they are issued
+	 * first.
+	 */
+	spin_lock_bh(&ctrl->queue_lock);
+	ctrl->stats.sw_q_depth++;
+	list_add(&dma->list, &ctrl->queue);
+	spin_unlock_bh(&ctrl->queue_lock);
+}
+
+static void rsxx_handle_dma_error(struct rsxx_dma_ctrl *ctrl,
+				      struct rsxx_dma *dma,
+				      u8 hw_st)
+{
+	unsigned int status = 0;
+	int requeue_cmd = 0;
+
+	dev_dbg(CARD_TO_DEV(ctrl->card),
+		"Handling DMA error(cmd x%02x, laddr x%08x st:x%02x)\n",
+		dma->cmd, dma->laddr, hw_st);
+
+	if (hw_st & HW_STATUS_CRC)
+		ctrl->stats.crc_errors++;
+	if (hw_st & HW_STATUS_HARD_ERR)
+		ctrl->stats.hard_errors++;
+	if (hw_st & HW_STATUS_SOFT_ERR)
+		ctrl->stats.soft_errors++;
+
+	switch (dma->cmd) {
+	case HW_CMD_BLK_READ:
+		if (hw_st & (HW_STATUS_CRC | HW_STATUS_HARD_ERR)) {
+			if (ctrl->card->scrub_hard) {
+				dma->cmd = HW_CMD_BLK_RECON_READ;
+				requeue_cmd = 1;
+				ctrl->stats.reads_retried++;
+			} else {
+				status |= DMA_HW_FAULT;
+				ctrl->stats.reads_failed++;
+			}
+		} else if (hw_st & HW_STATUS_FAULT) {
+			status |= DMA_HW_FAULT;
+			ctrl->stats.reads_failed++;
+		}
+
+		break;
+	case HW_CMD_BLK_RECON_READ:
+		if (hw_st & (HW_STATUS_CRC | HW_STATUS_HARD_ERR)) {
+			/* Data could not be reconstructed. */
+			status |= DMA_HW_FAULT;
+			ctrl->stats.reads_failed++;
+		}
+
+		break;
+	case HW_CMD_BLK_WRITE:
+		status |= DMA_HW_FAULT;
+		ctrl->stats.writes_failed++;
+
+		break;
+	case HW_CMD_BLK_DISCARD:
+		status |= DMA_HW_FAULT;
+		ctrl->stats.discards_failed++;
+
+		break;
+	default:
+		dev_err(CARD_TO_DEV(ctrl->card),
+			"Unknown command in DMA!(cmd: x%02x "
+			   "laddr x%08x st: x%02x\n",
+			   dma->cmd, dma->laddr, hw_st);
+		status |= DMA_SW_ERR;
+
+		break;
+	}
+
+	if (requeue_cmd)
+		rsxx_requeue_dma(ctrl, dma);
+	else
+		rsxx_complete_dma(ctrl, dma, status);
+}
+
+static void dma_engine_stalled(unsigned long data)
+{
+	struct rsxx_dma_ctrl *ctrl = (struct rsxx_dma_ctrl *)data;
+	int cnt;
+
+	if (atomic_read(&ctrl->stats.hw_q_depth) == 0 ||
+	    unlikely(ctrl->card->eeh_state))
+		return;
+
+	if (ctrl->cmd.idx != ioread32(ctrl->regmap + SW_CMD_IDX)) {
+		/*
+		 * The dma engine was stalled because the SW_CMD_IDX write
+		 * was lost. Issue it again to recover.
+		 */
+		dev_warn(CARD_TO_DEV(ctrl->card),
+			"SW_CMD_IDX write was lost, re-writing...\n");
+		iowrite32(ctrl->cmd.idx, ctrl->regmap + SW_CMD_IDX);
+		mod_timer(&ctrl->activity_timer,
+			  jiffies + DMA_ACTIVITY_TIMEOUT);
+	} else {
+		dev_warn(CARD_TO_DEV(ctrl->card),
+			"DMA channel %d has stalled, faulting interface.\n",
+			ctrl->id);
+		ctrl->card->dma_fault = 1;
+
+		/* Clean up the DMA queue */
+		spin_lock(&ctrl->queue_lock);
+		cnt = rsxx_cleanup_dma_queue(ctrl, &ctrl->queue, COMPLETE_DMA);
+		spin_unlock(&ctrl->queue_lock);
+
+		cnt += rsxx_dma_cancel(ctrl);
+
+		if (cnt)
+			dev_info(CARD_TO_DEV(ctrl->card),
+				"Freed %d queued DMAs on channel %d\n",
+				cnt, ctrl->id);
+	}
+}
+
+static void rsxx_issue_dmas(struct rsxx_dma_ctrl *ctrl)
+{
+	struct rsxx_dma *dma;
+	int tag;
+	int cmds_pending = 0;
+	struct hw_cmd *hw_cmd_buf;
+	int dir;
+
+	hw_cmd_buf = ctrl->cmd.buf;
+
+	if (unlikely(ctrl->card->halt) ||
+	    unlikely(ctrl->card->eeh_state))
+		return;
+
+	while (1) {
+		spin_lock_bh(&ctrl->queue_lock);
+		if (list_empty(&ctrl->queue)) {
+			spin_unlock_bh(&ctrl->queue_lock);
+			break;
+		}
+		spin_unlock_bh(&ctrl->queue_lock);
+
+		tag = pop_tracker(ctrl->trackers);
+		if (tag == -1)
+			break;
+
+		spin_lock_bh(&ctrl->queue_lock);
+		dma = list_entry(ctrl->queue.next, struct rsxx_dma, list);
+		list_del(&dma->list);
+		ctrl->stats.sw_q_depth--;
+		spin_unlock_bh(&ctrl->queue_lock);
+
+		/*
+		 * This will catch any DMAs that slipped in right before the
+		 * fault, but was queued after all the other DMAs were
+		 * cancelled.
+		 */
+		if (unlikely(ctrl->card->dma_fault)) {
+			push_tracker(ctrl->trackers, tag);
+			rsxx_complete_dma(ctrl, dma, DMA_CANCELLED);
+			continue;
+		}
+
+		if (dma->cmd != HW_CMD_BLK_DISCARD) {
+			if (dma->cmd == HW_CMD_BLK_WRITE)
+				dir = PCI_DMA_TODEVICE;
+			else
+				dir = PCI_DMA_FROMDEVICE;
+
+			/*
+			 * The function pci_map_page is placed here because we
+			 * can only, by design, issue up to 255 commands to the
+			 * hardware at one time per DMA channel. So the maximum
+			 * amount of mapped memory would be 255 * 4 channels *
+			 * 4096 Bytes which is less than 2GB, the limit of a x8
+			 * Non-HWWD PCIe slot. This way the pci_map_page
+			 * function should never fail because of a lack of
+			 * mappable memory.
+			 */
+			dma->dma_addr = pci_map_page(ctrl->card->dev, dma->page,
+					dma->pg_off, dma->sub_page.cnt << 9, dir);
+			if (pci_dma_mapping_error(ctrl->card->dev, dma->dma_addr)) {
+				push_tracker(ctrl->trackers, tag);
+				rsxx_complete_dma(ctrl, dma, DMA_CANCELLED);
+				continue;
+			}
+		}
+
+		set_tracker_dma(ctrl->trackers, tag, dma);
+		hw_cmd_buf[ctrl->cmd.idx].command  = dma->cmd;
+		hw_cmd_buf[ctrl->cmd.idx].tag      = tag;
+		hw_cmd_buf[ctrl->cmd.idx]._rsvd    = 0;
+		hw_cmd_buf[ctrl->cmd.idx].sub_page =
+					((dma->sub_page.cnt & 0x7) << 4) |
+					 (dma->sub_page.off & 0x7);
+
+		hw_cmd_buf[ctrl->cmd.idx].device_addr =
+					cpu_to_le32(dma->laddr);
+
+		hw_cmd_buf[ctrl->cmd.idx].host_addr =
+					cpu_to_le64(dma->dma_addr);
+
+		dev_dbg(CARD_TO_DEV(ctrl->card),
+			"Issue DMA%d(laddr %d tag %d) to idx %d\n",
+			ctrl->id, dma->laddr, tag, ctrl->cmd.idx);
+
+		ctrl->cmd.idx = (ctrl->cmd.idx + 1) & RSXX_CS_IDX_MASK;
+		cmds_pending++;
+
+		if (dma->cmd == HW_CMD_BLK_WRITE)
+			ctrl->stats.writes_issued++;
+		else if (dma->cmd == HW_CMD_BLK_DISCARD)
+			ctrl->stats.discards_issued++;
+		else
+			ctrl->stats.reads_issued++;
+	}
+
+	/* Let HW know we've queued commands. */
+	if (cmds_pending) {
+		atomic_add(cmds_pending, &ctrl->stats.hw_q_depth);
+		mod_timer(&ctrl->activity_timer,
+			  jiffies + DMA_ACTIVITY_TIMEOUT);
+
+		if (unlikely(ctrl->card->eeh_state)) {
+			del_timer_sync(&ctrl->activity_timer);
+			return;
+		}
+
+		iowrite32(ctrl->cmd.idx, ctrl->regmap + SW_CMD_IDX);
+	}
+}
+
+static void rsxx_dma_done(struct rsxx_dma_ctrl *ctrl)
+{
+	struct rsxx_dma *dma;
+	unsigned long flags;
+	u16 count;
+	u8 status;
+	u8 tag;
+	struct hw_status *hw_st_buf;
+
+	hw_st_buf = ctrl->status.buf;
+
+	if (unlikely(ctrl->card->halt) ||
+	    unlikely(ctrl->card->dma_fault) ||
+	    unlikely(ctrl->card->eeh_state))
+		return;
+
+	count = le16_to_cpu(hw_st_buf[ctrl->status.idx].count);
+
+	while (count == ctrl->e_cnt) {
+		/*
+		 * The read memory-barrier is necessary to keep aggressive
+		 * processors/optimizers (such as the PPC Apple G5) from
+		 * reordering the following status-buffer tag & status read
+		 * *before* the count read on subsequent iterations of the
+		 * loop!
+		 */
+		rmb();
+
+		status = hw_st_buf[ctrl->status.idx].status;
+		tag    = hw_st_buf[ctrl->status.idx].tag;
+
+		dma = get_tracker_dma(ctrl->trackers, tag);
+		if (dma == NULL) {
+			spin_lock_irqsave(&ctrl->card->irq_lock, flags);
+			rsxx_disable_ier(ctrl->card, CR_INTR_DMA_ALL);
+			spin_unlock_irqrestore(&ctrl->card->irq_lock, flags);
+
+			dev_err(CARD_TO_DEV(ctrl->card),
+				"No tracker for tag %d "
+				"(idx %d id %d)\n",
+				tag, ctrl->status.idx, ctrl->id);
+			return;
+		}
+
+		dev_dbg(CARD_TO_DEV(ctrl->card),
+			"Completing DMA%d"
+			"(laddr x%x tag %d st: x%x cnt: x%04x) from idx %d.\n",
+			ctrl->id, dma->laddr, tag, status, count,
+			ctrl->status.idx);
+
+		atomic_dec(&ctrl->stats.hw_q_depth);
+
+		mod_timer(&ctrl->activity_timer,
+			  jiffies + DMA_ACTIVITY_TIMEOUT);
+
+		if (status)
+			rsxx_handle_dma_error(ctrl, dma, status);
+		else
+			rsxx_complete_dma(ctrl, dma, 0);
+
+		push_tracker(ctrl->trackers, tag);
+
+		ctrl->status.idx = (ctrl->status.idx + 1) &
+				   RSXX_CS_IDX_MASK;
+		ctrl->e_cnt++;
+
+		count = le16_to_cpu(hw_st_buf[ctrl->status.idx].count);
+	}
+
+	dma_intr_coal_auto_tune(ctrl->card);
+
+	if (atomic_read(&ctrl->stats.hw_q_depth) == 0)
+		del_timer_sync(&ctrl->activity_timer);
+
+	spin_lock_irqsave(&ctrl->card->irq_lock, flags);
+	rsxx_enable_ier(ctrl->card, CR_INTR_DMA(ctrl->id));
+	spin_unlock_irqrestore(&ctrl->card->irq_lock, flags);
+
+	spin_lock_bh(&ctrl->queue_lock);
+	if (ctrl->stats.sw_q_depth)
+		queue_work(ctrl->issue_wq, &ctrl->issue_dma_work);
+	spin_unlock_bh(&ctrl->queue_lock);
+}
+
+static void rsxx_schedule_issue(struct work_struct *work)
+{
+	struct rsxx_dma_ctrl *ctrl;
+
+	ctrl = container_of(work, struct rsxx_dma_ctrl, issue_dma_work);
+
+	mutex_lock(&ctrl->work_lock);
+	rsxx_issue_dmas(ctrl);
+	mutex_unlock(&ctrl->work_lock);
+}
+
+static void rsxx_schedule_done(struct work_struct *work)
+{
+	struct rsxx_dma_ctrl *ctrl;
+
+	ctrl = container_of(work, struct rsxx_dma_ctrl, dma_done_work);
+
+	mutex_lock(&ctrl->work_lock);
+	rsxx_dma_done(ctrl);
+	mutex_unlock(&ctrl->work_lock);
+}
+
+static blk_status_t rsxx_queue_discard(struct rsxx_cardinfo *card,
+				  struct list_head *q,
+				  unsigned int laddr,
+				  rsxx_dma_cb cb,
+				  void *cb_data)
+{
+	struct rsxx_dma *dma;
+
+	dma = kmem_cache_alloc(rsxx_dma_pool, GFP_KERNEL);
+	if (!dma)
+		return BLK_STS_RESOURCE;
+
+	dma->cmd          = HW_CMD_BLK_DISCARD;
+	dma->laddr        = laddr;
+	dma->dma_addr     = 0;
+	dma->sub_page.off = 0;
+	dma->sub_page.cnt = 0;
+	dma->page         = NULL;
+	dma->pg_off       = 0;
+	dma->cb	          = cb;
+	dma->cb_data      = cb_data;
+
+	dev_dbg(CARD_TO_DEV(card), "Queuing[D] laddr %x\n", dma->laddr);
+
+	list_add_tail(&dma->list, q);
+
+	return 0;
+}
+
+static blk_status_t rsxx_queue_dma(struct rsxx_cardinfo *card,
+			      struct list_head *q,
+			      int dir,
+			      unsigned int dma_off,
+			      unsigned int dma_len,
+			      unsigned int laddr,
+			      struct page *page,
+			      unsigned int pg_off,
+			      rsxx_dma_cb cb,
+			      void *cb_data)
+{
+	struct rsxx_dma *dma;
+
+	dma = kmem_cache_alloc(rsxx_dma_pool, GFP_KERNEL);
+	if (!dma)
+		return BLK_STS_RESOURCE;
+
+	dma->cmd          = dir ? HW_CMD_BLK_WRITE : HW_CMD_BLK_READ;
+	dma->laddr        = laddr;
+	dma->sub_page.off = (dma_off >> 9);
+	dma->sub_page.cnt = (dma_len >> 9);
+	dma->page         = page;
+	dma->pg_off       = pg_off;
+	dma->cb	          = cb;
+	dma->cb_data      = cb_data;
+
+	dev_dbg(CARD_TO_DEV(card),
+		"Queuing[%c] laddr %x off %d cnt %d page %p pg_off %d\n",
+		dir ? 'W' : 'R', dma->laddr, dma->sub_page.off,
+		dma->sub_page.cnt, dma->page, dma->pg_off);
+
+	/* Queue the DMA */
+	list_add_tail(&dma->list, q);
+
+	return 0;
+}
+
+blk_status_t rsxx_dma_queue_bio(struct rsxx_cardinfo *card,
+			   struct bio *bio,
+			   atomic_t *n_dmas,
+			   rsxx_dma_cb cb,
+			   void *cb_data)
+{
+	struct list_head dma_list[RSXX_MAX_TARGETS];
+	struct bio_vec bvec;
+	struct bvec_iter iter;
+	unsigned long long addr8;
+	unsigned int laddr;
+	unsigned int bv_len;
+	unsigned int bv_off;
+	unsigned int dma_off;
+	unsigned int dma_len;
+	int dma_cnt[RSXX_MAX_TARGETS];
+	int tgt;
+	blk_status_t st;
+	int i;
+
+	addr8 = bio->bi_iter.bi_sector << 9; /* sectors are 512 bytes */
+	atomic_set(n_dmas, 0);
+
+	for (i = 0; i < card->n_targets; i++) {
+		INIT_LIST_HEAD(&dma_list[i]);
+		dma_cnt[i] = 0;
+	}
+
+	if (bio_op(bio) == REQ_OP_DISCARD) {
+		bv_len = bio->bi_iter.bi_size;
+
+		while (bv_len > 0) {
+			tgt   = rsxx_get_dma_tgt(card, addr8);
+			laddr = rsxx_addr8_to_laddr(addr8, card);
+
+			st = rsxx_queue_discard(card, &dma_list[tgt], laddr,
+						    cb, cb_data);
+			if (st)
+				goto bvec_err;
+
+			dma_cnt[tgt]++;
+			atomic_inc(n_dmas);
+			addr8  += RSXX_HW_BLK_SIZE;
+			bv_len -= RSXX_HW_BLK_SIZE;
+		}
+	} else {
+		bio_for_each_segment(bvec, bio, iter) {
+			bv_len = bvec.bv_len;
+			bv_off = bvec.bv_offset;
+
+			while (bv_len > 0) {
+				tgt   = rsxx_get_dma_tgt(card, addr8);
+				laddr = rsxx_addr8_to_laddr(addr8, card);
+				dma_off = addr8 & RSXX_HW_BLK_MASK;
+				dma_len = min(bv_len,
+					      RSXX_HW_BLK_SIZE - dma_off);
+
+				st = rsxx_queue_dma(card, &dma_list[tgt],
+							bio_data_dir(bio),
+							dma_off, dma_len,
+							laddr, bvec.bv_page,
+							bv_off, cb, cb_data);
+				if (st)
+					goto bvec_err;
+
+				dma_cnt[tgt]++;
+				atomic_inc(n_dmas);
+				addr8  += dma_len;
+				bv_off += dma_len;
+				bv_len -= dma_len;
+			}
+		}
+	}
+
+	for (i = 0; i < card->n_targets; i++) {
+		if (!list_empty(&dma_list[i])) {
+			spin_lock_bh(&card->ctrl[i].queue_lock);
+			card->ctrl[i].stats.sw_q_depth += dma_cnt[i];
+			list_splice_tail(&dma_list[i], &card->ctrl[i].queue);
+			spin_unlock_bh(&card->ctrl[i].queue_lock);
+
+			queue_work(card->ctrl[i].issue_wq,
+				   &card->ctrl[i].issue_dma_work);
+		}
+	}
+
+	return 0;
+
+bvec_err:
+	for (i = 0; i < card->n_targets; i++)
+		rsxx_cleanup_dma_queue(&card->ctrl[i], &dma_list[i],
+					FREE_DMA);
+	return st;
+}
+
+
+/*----------------- DMA Engine Initialization & Setup -------------------*/
+int rsxx_hw_buffers_init(struct pci_dev *dev, struct rsxx_dma_ctrl *ctrl)
+{
+	ctrl->status.buf = pci_alloc_consistent(dev, STATUS_BUFFER_SIZE8,
+				&ctrl->status.dma_addr);
+	ctrl->cmd.buf = pci_alloc_consistent(dev, COMMAND_BUFFER_SIZE8,
+				&ctrl->cmd.dma_addr);
+	if (ctrl->status.buf == NULL || ctrl->cmd.buf == NULL)
+		return -ENOMEM;
+
+	memset(ctrl->status.buf, 0xac, STATUS_BUFFER_SIZE8);
+	iowrite32(lower_32_bits(ctrl->status.dma_addr),
+		ctrl->regmap + SB_ADD_LO);
+	iowrite32(upper_32_bits(ctrl->status.dma_addr),
+		ctrl->regmap + SB_ADD_HI);
+
+	memset(ctrl->cmd.buf, 0x83, COMMAND_BUFFER_SIZE8);
+	iowrite32(lower_32_bits(ctrl->cmd.dma_addr), ctrl->regmap + CB_ADD_LO);
+	iowrite32(upper_32_bits(ctrl->cmd.dma_addr), ctrl->regmap + CB_ADD_HI);
+
+	ctrl->status.idx = ioread32(ctrl->regmap + HW_STATUS_CNT);
+	if (ctrl->status.idx > RSXX_MAX_OUTSTANDING_CMDS) {
+		dev_crit(&dev->dev, "Failed reading status cnt x%x\n",
+			ctrl->status.idx);
+		return -EINVAL;
+	}
+	iowrite32(ctrl->status.idx, ctrl->regmap + HW_STATUS_CNT);
+	iowrite32(ctrl->status.idx, ctrl->regmap + SW_STATUS_CNT);
+
+	ctrl->cmd.idx = ioread32(ctrl->regmap + HW_CMD_IDX);
+	if (ctrl->cmd.idx > RSXX_MAX_OUTSTANDING_CMDS) {
+		dev_crit(&dev->dev, "Failed reading cmd cnt x%x\n",
+			ctrl->status.idx);
+		return -EINVAL;
+	}
+	iowrite32(ctrl->cmd.idx, ctrl->regmap + HW_CMD_IDX);
+	iowrite32(ctrl->cmd.idx, ctrl->regmap + SW_CMD_IDX);
+
+	return 0;
+}
+
+static int rsxx_dma_ctrl_init(struct pci_dev *dev,
+				  struct rsxx_dma_ctrl *ctrl)
+{
+	int i;
+	int st;
+
+	memset(&ctrl->stats, 0, sizeof(ctrl->stats));
+
+	ctrl->trackers = vmalloc(DMA_TRACKER_LIST_SIZE8);
+	if (!ctrl->trackers)
+		return -ENOMEM;
+
+	ctrl->trackers->head = 0;
+	for (i = 0; i < RSXX_MAX_OUTSTANDING_CMDS; i++) {
+		ctrl->trackers->list[i].next_tag = i + 1;
+		ctrl->trackers->list[i].dma = NULL;
+	}
+	ctrl->trackers->list[RSXX_MAX_OUTSTANDING_CMDS-1].next_tag = -1;
+	spin_lock_init(&ctrl->trackers->lock);
+
+	spin_lock_init(&ctrl->queue_lock);
+	mutex_init(&ctrl->work_lock);
+	INIT_LIST_HEAD(&ctrl->queue);
+
+	setup_timer(&ctrl->activity_timer, dma_engine_stalled,
+					(unsigned long)ctrl);
+
+	ctrl->issue_wq = alloc_ordered_workqueue(DRIVER_NAME"_issue", 0);
+	if (!ctrl->issue_wq)
+		return -ENOMEM;
+
+	ctrl->done_wq = alloc_ordered_workqueue(DRIVER_NAME"_done", 0);
+	if (!ctrl->done_wq)
+		return -ENOMEM;
+
+	INIT_WORK(&ctrl->issue_dma_work, rsxx_schedule_issue);
+	INIT_WORK(&ctrl->dma_done_work, rsxx_schedule_done);
+
+	st = rsxx_hw_buffers_init(dev, ctrl);
+	if (st)
+		return st;
+
+	return 0;
+}
+
+static int rsxx_dma_stripe_setup(struct rsxx_cardinfo *card,
+			      unsigned int stripe_size8)
+{
+	if (!is_power_of_2(stripe_size8)) {
+		dev_err(CARD_TO_DEV(card),
+			"stripe_size is NOT a power of 2!\n");
+		return -EINVAL;
+	}
+
+	card->_stripe.lower_mask = stripe_size8 - 1;
+
+	card->_stripe.upper_mask  = ~(card->_stripe.lower_mask);
+	card->_stripe.upper_shift = ffs(card->n_targets) - 1;
+
+	card->_stripe.target_mask = card->n_targets - 1;
+	card->_stripe.target_shift = ffs(stripe_size8) - 1;
+
+	dev_dbg(CARD_TO_DEV(card), "_stripe.lower_mask   = x%016llx\n",
+		card->_stripe.lower_mask);
+	dev_dbg(CARD_TO_DEV(card), "_stripe.upper_shift  = x%016llx\n",
+		card->_stripe.upper_shift);
+	dev_dbg(CARD_TO_DEV(card), "_stripe.upper_mask   = x%016llx\n",
+		card->_stripe.upper_mask);
+	dev_dbg(CARD_TO_DEV(card), "_stripe.target_mask  = x%016llx\n",
+		card->_stripe.target_mask);
+	dev_dbg(CARD_TO_DEV(card), "_stripe.target_shift = x%016llx\n",
+		card->_stripe.target_shift);
+
+	return 0;
+}
+
+int rsxx_dma_configure(struct rsxx_cardinfo *card)
+{
+	u32 intr_coal;
+
+	intr_coal = dma_intr_coal_val(card->config.data.intr_coal.mode,
+				      card->config.data.intr_coal.count,
+				      card->config.data.intr_coal.latency);
+	iowrite32(intr_coal, card->regmap + INTR_COAL);
+
+	return rsxx_dma_stripe_setup(card, card->config.data.stripe_size);
+}
+
+int rsxx_dma_setup(struct rsxx_cardinfo *card)
+{
+	unsigned long flags;
+	int st;
+	int i;
+
+	dev_info(CARD_TO_DEV(card),
+		"Initializing %d DMA targets\n",
+		card->n_targets);
+
+	/* Regmap is divided up into 4K chunks. One for each DMA channel */
+	for (i = 0; i < card->n_targets; i++)
+		card->ctrl[i].regmap = card->regmap + (i * 4096);
+
+	card->dma_fault = 0;
+
+	/* Reset the DMA queues */
+	rsxx_dma_queue_reset(card);
+
+	/************* Setup DMA Control *************/
+	for (i = 0; i < card->n_targets; i++) {
+		st = rsxx_dma_ctrl_init(card->dev, &card->ctrl[i]);
+		if (st)
+			goto failed_dma_setup;
+
+		card->ctrl[i].card = card;
+		card->ctrl[i].id = i;
+	}
+
+	card->scrub_hard = 1;
+
+	if (card->config_valid)
+		rsxx_dma_configure(card);
+
+	/* Enable the interrupts after all setup has completed. */
+	for (i = 0; i < card->n_targets; i++) {
+		spin_lock_irqsave(&card->irq_lock, flags);
+		rsxx_enable_ier_and_isr(card, CR_INTR_DMA(i));
+		spin_unlock_irqrestore(&card->irq_lock, flags);
+	}
+
+	return 0;
+
+failed_dma_setup:
+	for (i = 0; i < card->n_targets; i++) {
+		struct rsxx_dma_ctrl *ctrl = &card->ctrl[i];
+
+		if (ctrl->issue_wq) {
+			destroy_workqueue(ctrl->issue_wq);
+			ctrl->issue_wq = NULL;
+		}
+
+		if (ctrl->done_wq) {
+			destroy_workqueue(ctrl->done_wq);
+			ctrl->done_wq = NULL;
+		}
+
+		if (ctrl->trackers)
+			vfree(ctrl->trackers);
+
+		if (ctrl->status.buf)
+			pci_free_consistent(card->dev, STATUS_BUFFER_SIZE8,
+					    ctrl->status.buf,
+					    ctrl->status.dma_addr);
+		if (ctrl->cmd.buf)
+			pci_free_consistent(card->dev, COMMAND_BUFFER_SIZE8,
+					    ctrl->cmd.buf, ctrl->cmd.dma_addr);
+	}
+
+	return st;
+}
+
+int rsxx_dma_cancel(struct rsxx_dma_ctrl *ctrl)
+{
+	struct rsxx_dma *dma;
+	int i;
+	int cnt = 0;
+
+	/* Clean up issued DMAs */
+	for (i = 0; i < RSXX_MAX_OUTSTANDING_CMDS; i++) {
+		dma = get_tracker_dma(ctrl->trackers, i);
+		if (dma) {
+			atomic_dec(&ctrl->stats.hw_q_depth);
+			rsxx_complete_dma(ctrl, dma, DMA_CANCELLED);
+			push_tracker(ctrl->trackers, i);
+			cnt++;
+		}
+	}
+
+	return cnt;
+}
+
+void rsxx_dma_destroy(struct rsxx_cardinfo *card)
+{
+	struct rsxx_dma_ctrl *ctrl;
+	int i;
+
+	for (i = 0; i < card->n_targets; i++) {
+		ctrl = &card->ctrl[i];
+
+		if (ctrl->issue_wq) {
+			destroy_workqueue(ctrl->issue_wq);
+			ctrl->issue_wq = NULL;
+		}
+
+		if (ctrl->done_wq) {
+			destroy_workqueue(ctrl->done_wq);
+			ctrl->done_wq = NULL;
+		}
+
+		if (timer_pending(&ctrl->activity_timer))
+			del_timer_sync(&ctrl->activity_timer);
+
+		/* Clean up the DMA queue */
+		spin_lock_bh(&ctrl->queue_lock);
+		rsxx_cleanup_dma_queue(ctrl, &ctrl->queue, COMPLETE_DMA);
+		spin_unlock_bh(&ctrl->queue_lock);
+
+		rsxx_dma_cancel(ctrl);
+
+		vfree(ctrl->trackers);
+
+		pci_free_consistent(card->dev, STATUS_BUFFER_SIZE8,
+				    ctrl->status.buf, ctrl->status.dma_addr);
+		pci_free_consistent(card->dev, COMMAND_BUFFER_SIZE8,
+				    ctrl->cmd.buf, ctrl->cmd.dma_addr);
+	}
+}
+
+int rsxx_eeh_save_issued_dmas(struct rsxx_cardinfo *card)
+{
+	int i;
+	int j;
+	int cnt;
+	struct rsxx_dma *dma;
+	struct list_head *issued_dmas;
+
+	issued_dmas = kzalloc(sizeof(*issued_dmas) * card->n_targets,
+			      GFP_KERNEL);
+	if (!issued_dmas)
+		return -ENOMEM;
+
+	for (i = 0; i < card->n_targets; i++) {
+		INIT_LIST_HEAD(&issued_dmas[i]);
+		cnt = 0;
+		for (j = 0; j < RSXX_MAX_OUTSTANDING_CMDS; j++) {
+			dma = get_tracker_dma(card->ctrl[i].trackers, j);
+			if (dma == NULL)
+				continue;
+
+			if (dma->cmd == HW_CMD_BLK_WRITE)
+				card->ctrl[i].stats.writes_issued--;
+			else if (dma->cmd == HW_CMD_BLK_DISCARD)
+				card->ctrl[i].stats.discards_issued--;
+			else
+				card->ctrl[i].stats.reads_issued--;
+
+			if (dma->cmd != HW_CMD_BLK_DISCARD) {
+				pci_unmap_page(card->dev, dma->dma_addr,
+					       get_dma_size(dma),
+					       dma->cmd == HW_CMD_BLK_WRITE ?
+					       PCI_DMA_TODEVICE :
+					       PCI_DMA_FROMDEVICE);
+			}
+
+			list_add_tail(&dma->list, &issued_dmas[i]);
+			push_tracker(card->ctrl[i].trackers, j);
+			cnt++;
+		}
+
+		spin_lock_bh(&card->ctrl[i].queue_lock);
+		list_splice(&issued_dmas[i], &card->ctrl[i].queue);
+
+		atomic_sub(cnt, &card->ctrl[i].stats.hw_q_depth);
+		card->ctrl[i].stats.sw_q_depth += cnt;
+		card->ctrl[i].e_cnt = 0;
+		spin_unlock_bh(&card->ctrl[i].queue_lock);
+	}
+
+	kfree(issued_dmas);
+
+	return 0;
+}
+
+int rsxx_dma_init(void)
+{
+	rsxx_dma_pool = KMEM_CACHE(rsxx_dma, SLAB_HWCACHE_ALIGN);
+	if (!rsxx_dma_pool)
+		return -ENOMEM;
+
+	return 0;
+}
+
+
+void rsxx_dma_cleanup(void)
+{
+	kmem_cache_destroy(rsxx_dma_pool);
+}
+