zte's code,first commit

Change-Id: I9a04da59e459a9bc0d67f101f700d9d7dc8d681b
diff --git a/ap/os/linux/linux-3.4.x/drivers/dma/ioat/dma.c b/ap/os/linux/linux-3.4.x/drivers/dma/ioat/dma.c
new file mode 100644
index 0000000..73b2b65
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/drivers/dma/ioat/dma.c
@@ -0,0 +1,1233 @@
+/*
+ * Intel I/OAT DMA Linux driver
+ * Copyright(c) 2004 - 2009 Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * 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.,
+ * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * The full GNU General Public License is included in this distribution in
+ * the file called "COPYING".
+ *
+ */
+
+/*
+ * This driver supports an Intel I/OAT DMA engine, which does asynchronous
+ * copy operations.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/pci.h>
+#include <linux/interrupt.h>
+#include <linux/dmaengine.h>
+#include <linux/delay.h>
+#include <linux/dma-mapping.h>
+#include <linux/workqueue.h>
+#include <linux/prefetch.h>
+#include <linux/i7300_idle.h>
+#include "dma.h"
+#include "registers.h"
+#include "hw.h"
+
+#include "../dmaengine.h"
+
+int ioat_pending_level = 4;
+module_param(ioat_pending_level, int, 0644);
+MODULE_PARM_DESC(ioat_pending_level,
+		 "high-water mark for pushing ioat descriptors (default: 4)");
+
+/* internal functions */
+static void ioat1_cleanup(struct ioat_dma_chan *ioat);
+static void ioat1_dma_start_null_desc(struct ioat_dma_chan *ioat);
+
+/**
+ * ioat_dma_do_interrupt - handler used for single vector interrupt mode
+ * @irq: interrupt id
+ * @data: interrupt data
+ */
+static irqreturn_t ioat_dma_do_interrupt(int irq, void *data)
+{
+	struct ioatdma_device *instance = data;
+	struct ioat_chan_common *chan;
+	unsigned long attnstatus;
+	int bit;
+	u8 intrctrl;
+
+	intrctrl = readb(instance->reg_base + IOAT_INTRCTRL_OFFSET);
+
+	if (!(intrctrl & IOAT_INTRCTRL_MASTER_INT_EN))
+		return IRQ_NONE;
+
+	if (!(intrctrl & IOAT_INTRCTRL_INT_STATUS)) {
+		writeb(intrctrl, instance->reg_base + IOAT_INTRCTRL_OFFSET);
+		return IRQ_NONE;
+	}
+
+	attnstatus = readl(instance->reg_base + IOAT_ATTNSTATUS_OFFSET);
+	for_each_set_bit(bit, &attnstatus, BITS_PER_LONG) {
+		chan = ioat_chan_by_index(instance, bit);
+		tasklet_schedule(&chan->cleanup_task);
+	}
+
+	writeb(intrctrl, instance->reg_base + IOAT_INTRCTRL_OFFSET);
+	return IRQ_HANDLED;
+}
+
+/**
+ * ioat_dma_do_interrupt_msix - handler used for vector-per-channel interrupt mode
+ * @irq: interrupt id
+ * @data: interrupt data
+ */
+static irqreturn_t ioat_dma_do_interrupt_msix(int irq, void *data)
+{
+	struct ioat_chan_common *chan = data;
+
+	tasklet_schedule(&chan->cleanup_task);
+
+	return IRQ_HANDLED;
+}
+
+/* common channel initialization */
+void ioat_init_channel(struct ioatdma_device *device, struct ioat_chan_common *chan, int idx)
+{
+	struct dma_device *dma = &device->common;
+	struct dma_chan *c = &chan->common;
+	unsigned long data = (unsigned long) c;
+
+	chan->device = device;
+	chan->reg_base = device->reg_base + (0x80 * (idx + 1));
+	spin_lock_init(&chan->cleanup_lock);
+	chan->common.device = dma;
+	dma_cookie_init(&chan->common);
+	list_add_tail(&chan->common.device_node, &dma->channels);
+	device->idx[idx] = chan;
+	init_timer(&chan->timer);
+	chan->timer.function = device->timer_fn;
+	chan->timer.data = data;
+	tasklet_init(&chan->cleanup_task, device->cleanup_fn, data);
+	tasklet_disable(&chan->cleanup_task);
+}
+
+/**
+ * ioat1_dma_enumerate_channels - find and initialize the device's channels
+ * @device: the device to be enumerated
+ */
+static int ioat1_enumerate_channels(struct ioatdma_device *device)
+{
+	u8 xfercap_scale;
+	u32 xfercap;
+	int i;
+	struct ioat_dma_chan *ioat;
+	struct device *dev = &device->pdev->dev;
+	struct dma_device *dma = &device->common;
+
+	INIT_LIST_HEAD(&dma->channels);
+	dma->chancnt = readb(device->reg_base + IOAT_CHANCNT_OFFSET);
+	dma->chancnt &= 0x1f; /* bits [4:0] valid */
+	if (dma->chancnt > ARRAY_SIZE(device->idx)) {
+		dev_warn(dev, "(%d) exceeds max supported channels (%zu)\n",
+			 dma->chancnt, ARRAY_SIZE(device->idx));
+		dma->chancnt = ARRAY_SIZE(device->idx);
+	}
+	xfercap_scale = readb(device->reg_base + IOAT_XFERCAP_OFFSET);
+	xfercap_scale &= 0x1f; /* bits [4:0] valid */
+	xfercap = (xfercap_scale == 0 ? -1 : (1UL << xfercap_scale));
+	dev_dbg(dev, "%s: xfercap = %d\n", __func__, xfercap);
+
+#ifdef  CONFIG_I7300_IDLE_IOAT_CHANNEL
+	if (i7300_idle_platform_probe(NULL, NULL, 1) == 0)
+		dma->chancnt--;
+#endif
+	for (i = 0; i < dma->chancnt; i++) {
+		ioat = devm_kzalloc(dev, sizeof(*ioat), GFP_KERNEL);
+		if (!ioat)
+			break;
+
+		ioat_init_channel(device, &ioat->base, i);
+		ioat->xfercap = xfercap;
+		spin_lock_init(&ioat->desc_lock);
+		INIT_LIST_HEAD(&ioat->free_desc);
+		INIT_LIST_HEAD(&ioat->used_desc);
+	}
+	dma->chancnt = i;
+	return i;
+}
+
+/**
+ * ioat_dma_memcpy_issue_pending - push potentially unrecognized appended
+ *                                 descriptors to hw
+ * @chan: DMA channel handle
+ */
+static inline void
+__ioat1_dma_memcpy_issue_pending(struct ioat_dma_chan *ioat)
+{
+	void __iomem *reg_base = ioat->base.reg_base;
+
+	dev_dbg(to_dev(&ioat->base), "%s: pending: %d\n",
+		__func__, ioat->pending);
+	ioat->pending = 0;
+	writeb(IOAT_CHANCMD_APPEND, reg_base + IOAT1_CHANCMD_OFFSET);
+}
+
+static void ioat1_dma_memcpy_issue_pending(struct dma_chan *chan)
+{
+	struct ioat_dma_chan *ioat = to_ioat_chan(chan);
+
+	if (ioat->pending > 0) {
+		spin_lock_bh(&ioat->desc_lock);
+		__ioat1_dma_memcpy_issue_pending(ioat);
+		spin_unlock_bh(&ioat->desc_lock);
+	}
+}
+
+/**
+ * ioat1_reset_channel - restart a channel
+ * @ioat: IOAT DMA channel handle
+ */
+static void ioat1_reset_channel(struct ioat_dma_chan *ioat)
+{
+	struct ioat_chan_common *chan = &ioat->base;
+	void __iomem *reg_base = chan->reg_base;
+	u32 chansts, chanerr;
+
+	dev_warn(to_dev(chan), "reset\n");
+	chanerr = readl(reg_base + IOAT_CHANERR_OFFSET);
+	chansts = *chan->completion & IOAT_CHANSTS_STATUS;
+	if (chanerr) {
+		dev_err(to_dev(chan),
+			"chan%d, CHANSTS = 0x%08x CHANERR = 0x%04x, clearing\n",
+			chan_num(chan), chansts, chanerr);
+		writel(chanerr, reg_base + IOAT_CHANERR_OFFSET);
+	}
+
+	/*
+	 * whack it upside the head with a reset
+	 * and wait for things to settle out.
+	 * force the pending count to a really big negative
+	 * to make sure no one forces an issue_pending
+	 * while we're waiting.
+	 */
+
+	ioat->pending = INT_MIN;
+	writeb(IOAT_CHANCMD_RESET,
+	       reg_base + IOAT_CHANCMD_OFFSET(chan->device->version));
+	set_bit(IOAT_RESET_PENDING, &chan->state);
+	mod_timer(&chan->timer, jiffies + RESET_DELAY);
+}
+
+static dma_cookie_t ioat1_tx_submit(struct dma_async_tx_descriptor *tx)
+{
+	struct dma_chan *c = tx->chan;
+	struct ioat_dma_chan *ioat = to_ioat_chan(c);
+	struct ioat_desc_sw *desc = tx_to_ioat_desc(tx);
+	struct ioat_chan_common *chan = &ioat->base;
+	struct ioat_desc_sw *first;
+	struct ioat_desc_sw *chain_tail;
+	dma_cookie_t cookie;
+
+	spin_lock_bh(&ioat->desc_lock);
+	/* cookie incr and addition to used_list must be atomic */
+	cookie = dma_cookie_assign(tx);
+	dev_dbg(to_dev(&ioat->base), "%s: cookie: %d\n", __func__, cookie);
+
+	/* write address into NextDescriptor field of last desc in chain */
+	first = to_ioat_desc(desc->tx_list.next);
+	chain_tail = to_ioat_desc(ioat->used_desc.prev);
+	/* make descriptor updates globally visible before chaining */
+	wmb();
+	chain_tail->hw->next = first->txd.phys;
+	list_splice_tail_init(&desc->tx_list, &ioat->used_desc);
+	dump_desc_dbg(ioat, chain_tail);
+	dump_desc_dbg(ioat, first);
+
+	if (!test_and_set_bit(IOAT_COMPLETION_PENDING, &chan->state))
+		mod_timer(&chan->timer, jiffies + COMPLETION_TIMEOUT);
+
+	ioat->active += desc->hw->tx_cnt;
+	ioat->pending += desc->hw->tx_cnt;
+	if (ioat->pending >= ioat_pending_level)
+		__ioat1_dma_memcpy_issue_pending(ioat);
+	spin_unlock_bh(&ioat->desc_lock);
+
+	return cookie;
+}
+
+/**
+ * ioat_dma_alloc_descriptor - allocate and return a sw and hw descriptor pair
+ * @ioat: the channel supplying the memory pool for the descriptors
+ * @flags: allocation flags
+ */
+static struct ioat_desc_sw *
+ioat_dma_alloc_descriptor(struct ioat_dma_chan *ioat, gfp_t flags)
+{
+	struct ioat_dma_descriptor *desc;
+	struct ioat_desc_sw *desc_sw;
+	struct ioatdma_device *ioatdma_device;
+	dma_addr_t phys;
+
+	ioatdma_device = ioat->base.device;
+	desc = pci_pool_alloc(ioatdma_device->dma_pool, flags, &phys);
+	if (unlikely(!desc))
+		return NULL;
+
+	desc_sw = kzalloc(sizeof(*desc_sw), flags);
+	if (unlikely(!desc_sw)) {
+		pci_pool_free(ioatdma_device->dma_pool, desc, phys);
+		return NULL;
+	}
+
+	memset(desc, 0, sizeof(*desc));
+
+	INIT_LIST_HEAD(&desc_sw->tx_list);
+	dma_async_tx_descriptor_init(&desc_sw->txd, &ioat->base.common);
+	desc_sw->txd.tx_submit = ioat1_tx_submit;
+	desc_sw->hw = desc;
+	desc_sw->txd.phys = phys;
+	set_desc_id(desc_sw, -1);
+
+	return desc_sw;
+}
+
+static int ioat_initial_desc_count = 256;
+module_param(ioat_initial_desc_count, int, 0644);
+MODULE_PARM_DESC(ioat_initial_desc_count,
+		 "ioat1: initial descriptors per channel (default: 256)");
+/**
+ * ioat1_dma_alloc_chan_resources - returns the number of allocated descriptors
+ * @chan: the channel to be filled out
+ */
+static int ioat1_dma_alloc_chan_resources(struct dma_chan *c)
+{
+	struct ioat_dma_chan *ioat = to_ioat_chan(c);
+	struct ioat_chan_common *chan = &ioat->base;
+	struct ioat_desc_sw *desc;
+	u32 chanerr;
+	int i;
+	LIST_HEAD(tmp_list);
+
+	/* have we already been set up? */
+	if (!list_empty(&ioat->free_desc))
+		return ioat->desccount;
+
+	/* Setup register to interrupt and write completion status on error */
+	writew(IOAT_CHANCTRL_RUN, chan->reg_base + IOAT_CHANCTRL_OFFSET);
+
+	chanerr = readl(chan->reg_base + IOAT_CHANERR_OFFSET);
+	if (chanerr) {
+		dev_err(to_dev(chan), "CHANERR = %x, clearing\n", chanerr);
+		writel(chanerr, chan->reg_base + IOAT_CHANERR_OFFSET);
+	}
+
+	/* Allocate descriptors */
+	for (i = 0; i < ioat_initial_desc_count; i++) {
+		desc = ioat_dma_alloc_descriptor(ioat, GFP_KERNEL);
+		if (!desc) {
+			dev_err(to_dev(chan), "Only %d initial descriptors\n", i);
+			break;
+		}
+		set_desc_id(desc, i);
+		list_add_tail(&desc->node, &tmp_list);
+	}
+	spin_lock_bh(&ioat->desc_lock);
+	ioat->desccount = i;
+	list_splice(&tmp_list, &ioat->free_desc);
+	spin_unlock_bh(&ioat->desc_lock);
+
+	/* allocate a completion writeback area */
+	/* doing 2 32bit writes to mmio since 1 64b write doesn't work */
+	chan->completion = pci_pool_alloc(chan->device->completion_pool,
+					  GFP_KERNEL, &chan->completion_dma);
+	memset(chan->completion, 0, sizeof(*chan->completion));
+	writel(((u64) chan->completion_dma) & 0x00000000FFFFFFFF,
+	       chan->reg_base + IOAT_CHANCMP_OFFSET_LOW);
+	writel(((u64) chan->completion_dma) >> 32,
+	       chan->reg_base + IOAT_CHANCMP_OFFSET_HIGH);
+
+	tasklet_enable(&chan->cleanup_task);
+	ioat1_dma_start_null_desc(ioat);  /* give chain to dma device */
+	dev_dbg(to_dev(chan), "%s: allocated %d descriptors\n",
+		__func__, ioat->desccount);
+	return ioat->desccount;
+}
+
+/**
+ * ioat1_dma_free_chan_resources - release all the descriptors
+ * @chan: the channel to be cleaned
+ */
+static void ioat1_dma_free_chan_resources(struct dma_chan *c)
+{
+	struct ioat_dma_chan *ioat = to_ioat_chan(c);
+	struct ioat_chan_common *chan = &ioat->base;
+	struct ioatdma_device *ioatdma_device = chan->device;
+	struct ioat_desc_sw *desc, *_desc;
+	int in_use_descs = 0;
+
+	/* Before freeing channel resources first check
+	 * if they have been previously allocated for this channel.
+	 */
+	if (ioat->desccount == 0)
+		return;
+
+	tasklet_disable(&chan->cleanup_task);
+	del_timer_sync(&chan->timer);
+	ioat1_cleanup(ioat);
+
+	/* Delay 100ms after reset to allow internal DMA logic to quiesce
+	 * before removing DMA descriptor resources.
+	 */
+	writeb(IOAT_CHANCMD_RESET,
+	       chan->reg_base + IOAT_CHANCMD_OFFSET(chan->device->version));
+	mdelay(100);
+
+	spin_lock_bh(&ioat->desc_lock);
+	list_for_each_entry_safe(desc, _desc, &ioat->used_desc, node) {
+		dev_dbg(to_dev(chan), "%s: freeing %d from used list\n",
+			__func__, desc_id(desc));
+		dump_desc_dbg(ioat, desc);
+		in_use_descs++;
+		list_del(&desc->node);
+		pci_pool_free(ioatdma_device->dma_pool, desc->hw,
+			      desc->txd.phys);
+		kfree(desc);
+	}
+	list_for_each_entry_safe(desc, _desc,
+				 &ioat->free_desc, node) {
+		list_del(&desc->node);
+		pci_pool_free(ioatdma_device->dma_pool, desc->hw,
+			      desc->txd.phys);
+		kfree(desc);
+	}
+	spin_unlock_bh(&ioat->desc_lock);
+
+	pci_pool_free(ioatdma_device->completion_pool,
+		      chan->completion,
+		      chan->completion_dma);
+
+	/* one is ok since we left it on there on purpose */
+	if (in_use_descs > 1)
+		dev_err(to_dev(chan), "Freeing %d in use descriptors!\n",
+			in_use_descs - 1);
+
+	chan->last_completion = 0;
+	chan->completion_dma = 0;
+	ioat->pending = 0;
+	ioat->desccount = 0;
+}
+
+/**
+ * ioat1_dma_get_next_descriptor - return the next available descriptor
+ * @ioat: IOAT DMA channel handle
+ *
+ * Gets the next descriptor from the chain, and must be called with the
+ * channel's desc_lock held.  Allocates more descriptors if the channel
+ * has run out.
+ */
+static struct ioat_desc_sw *
+ioat1_dma_get_next_descriptor(struct ioat_dma_chan *ioat)
+{
+	struct ioat_desc_sw *new;
+
+	if (!list_empty(&ioat->free_desc)) {
+		new = to_ioat_desc(ioat->free_desc.next);
+		list_del(&new->node);
+	} else {
+		/* try to get another desc */
+		new = ioat_dma_alloc_descriptor(ioat, GFP_ATOMIC);
+		if (!new) {
+			dev_err(to_dev(&ioat->base), "alloc failed\n");
+			return NULL;
+		}
+	}
+	dev_dbg(to_dev(&ioat->base), "%s: allocated: %d\n",
+		__func__, desc_id(new));
+	prefetch(new->hw);
+	return new;
+}
+
+static struct dma_async_tx_descriptor *
+ioat1_dma_prep_memcpy(struct dma_chan *c, dma_addr_t dma_dest,
+		      dma_addr_t dma_src, size_t len, unsigned long flags)
+{
+	struct ioat_dma_chan *ioat = to_ioat_chan(c);
+	struct ioat_desc_sw *desc;
+	size_t copy;
+	LIST_HEAD(chain);
+	dma_addr_t src = dma_src;
+	dma_addr_t dest = dma_dest;
+	size_t total_len = len;
+	struct ioat_dma_descriptor *hw = NULL;
+	int tx_cnt = 0;
+
+	spin_lock_bh(&ioat->desc_lock);
+	desc = ioat1_dma_get_next_descriptor(ioat);
+	do {
+		if (!desc)
+			break;
+
+		tx_cnt++;
+		copy = min_t(size_t, len, ioat->xfercap);
+
+		hw = desc->hw;
+		hw->size = copy;
+		hw->ctl = 0;
+		hw->src_addr = src;
+		hw->dst_addr = dest;
+
+		list_add_tail(&desc->node, &chain);
+
+		len -= copy;
+		dest += copy;
+		src += copy;
+		if (len) {
+			struct ioat_desc_sw *next;
+
+			async_tx_ack(&desc->txd);
+			next = ioat1_dma_get_next_descriptor(ioat);
+			hw->next = next ? next->txd.phys : 0;
+			dump_desc_dbg(ioat, desc);
+			desc = next;
+		} else
+			hw->next = 0;
+	} while (len);
+
+	if (!desc) {
+		struct ioat_chan_common *chan = &ioat->base;
+
+		dev_err(to_dev(chan),
+			"chan%d - get_next_desc failed\n", chan_num(chan));
+		list_splice(&chain, &ioat->free_desc);
+		spin_unlock_bh(&ioat->desc_lock);
+		return NULL;
+	}
+	spin_unlock_bh(&ioat->desc_lock);
+
+	desc->txd.flags = flags;
+	desc->len = total_len;
+	list_splice(&chain, &desc->tx_list);
+	hw->ctl_f.int_en = !!(flags & DMA_PREP_INTERRUPT);
+	hw->ctl_f.compl_write = 1;
+	hw->tx_cnt = tx_cnt;
+	dump_desc_dbg(ioat, desc);
+
+	return &desc->txd;
+}
+
+static void ioat1_cleanup_event(unsigned long data)
+{
+	struct ioat_dma_chan *ioat = to_ioat_chan((void *) data);
+
+	ioat1_cleanup(ioat);
+	writew(IOAT_CHANCTRL_RUN, ioat->base.reg_base + IOAT_CHANCTRL_OFFSET);
+}
+
+void ioat_dma_unmap(struct ioat_chan_common *chan, enum dma_ctrl_flags flags,
+		    size_t len, struct ioat_dma_descriptor *hw)
+{
+	struct pci_dev *pdev = chan->device->pdev;
+	size_t offset = len - hw->size;
+
+	if (!(flags & DMA_COMPL_SKIP_DEST_UNMAP))
+		ioat_unmap(pdev, hw->dst_addr - offset, len,
+			   PCI_DMA_FROMDEVICE, flags, 1);
+
+	if (!(flags & DMA_COMPL_SKIP_SRC_UNMAP))
+		ioat_unmap(pdev, hw->src_addr - offset, len,
+			   PCI_DMA_TODEVICE, flags, 0);
+}
+
+dma_addr_t ioat_get_current_completion(struct ioat_chan_common *chan)
+{
+	dma_addr_t phys_complete;
+	u64 completion;
+
+	completion = *chan->completion;
+	phys_complete = ioat_chansts_to_addr(completion);
+
+	dev_dbg(to_dev(chan), "%s: phys_complete: %#llx\n", __func__,
+		(unsigned long long) phys_complete);
+
+	if (is_ioat_halted(completion)) {
+		u32 chanerr = readl(chan->reg_base + IOAT_CHANERR_OFFSET);
+		dev_err(to_dev(chan), "Channel halted, chanerr = %x\n",
+			chanerr);
+
+		/* TODO do something to salvage the situation */
+	}
+
+	return phys_complete;
+}
+
+bool ioat_cleanup_preamble(struct ioat_chan_common *chan,
+			   dma_addr_t *phys_complete)
+{
+	*phys_complete = ioat_get_current_completion(chan);
+	if (*phys_complete == chan->last_completion)
+		return false;
+	clear_bit(IOAT_COMPLETION_ACK, &chan->state);
+	mod_timer(&chan->timer, jiffies + COMPLETION_TIMEOUT);
+
+	return true;
+}
+
+static void __cleanup(struct ioat_dma_chan *ioat, dma_addr_t phys_complete)
+{
+	struct ioat_chan_common *chan = &ioat->base;
+	struct list_head *_desc, *n;
+	struct dma_async_tx_descriptor *tx;
+
+	dev_dbg(to_dev(chan), "%s: phys_complete: %llx\n",
+		 __func__, (unsigned long long) phys_complete);
+	list_for_each_safe(_desc, n, &ioat->used_desc) {
+		struct ioat_desc_sw *desc;
+
+		prefetch(n);
+		desc = list_entry(_desc, typeof(*desc), node);
+		tx = &desc->txd;
+		/*
+		 * Incoming DMA requests may use multiple descriptors,
+		 * due to exceeding xfercap, perhaps. If so, only the
+		 * last one will have a cookie, and require unmapping.
+		 */
+		dump_desc_dbg(ioat, desc);
+		if (tx->cookie) {
+			dma_cookie_complete(tx);
+			ioat_dma_unmap(chan, tx->flags, desc->len, desc->hw);
+			ioat->active -= desc->hw->tx_cnt;
+			if (tx->callback) {
+				tx->callback(tx->callback_param);
+				tx->callback = NULL;
+			}
+		}
+
+		if (tx->phys != phys_complete) {
+			/*
+			 * a completed entry, but not the last, so clean
+			 * up if the client is done with the descriptor
+			 */
+			if (async_tx_test_ack(tx))
+				list_move_tail(&desc->node, &ioat->free_desc);
+		} else {
+			/*
+			 * last used desc. Do not remove, so we can
+			 * append from it.
+			 */
+
+			/* if nothing else is pending, cancel the
+			 * completion timeout
+			 */
+			if (n == &ioat->used_desc) {
+				dev_dbg(to_dev(chan),
+					"%s cancel completion timeout\n",
+					__func__);
+				clear_bit(IOAT_COMPLETION_PENDING, &chan->state);
+			}
+
+			/* TODO check status bits? */
+			break;
+		}
+	}
+
+	chan->last_completion = phys_complete;
+}
+
+/**
+ * ioat1_cleanup - cleanup up finished descriptors
+ * @chan: ioat channel to be cleaned up
+ *
+ * To prevent lock contention we defer cleanup when the locks are
+ * contended with a terminal timeout that forces cleanup and catches
+ * completion notification errors.
+ */
+static void ioat1_cleanup(struct ioat_dma_chan *ioat)
+{
+	struct ioat_chan_common *chan = &ioat->base;
+	dma_addr_t phys_complete;
+
+	prefetch(chan->completion);
+
+	if (!spin_trylock_bh(&chan->cleanup_lock))
+		return;
+
+	if (!ioat_cleanup_preamble(chan, &phys_complete)) {
+		spin_unlock_bh(&chan->cleanup_lock);
+		return;
+	}
+
+	if (!spin_trylock_bh(&ioat->desc_lock)) {
+		spin_unlock_bh(&chan->cleanup_lock);
+		return;
+	}
+
+	__cleanup(ioat, phys_complete);
+
+	spin_unlock_bh(&ioat->desc_lock);
+	spin_unlock_bh(&chan->cleanup_lock);
+}
+
+static void ioat1_timer_event(unsigned long data)
+{
+	struct ioat_dma_chan *ioat = to_ioat_chan((void *) data);
+	struct ioat_chan_common *chan = &ioat->base;
+
+	dev_dbg(to_dev(chan), "%s: state: %lx\n", __func__, chan->state);
+
+	spin_lock_bh(&chan->cleanup_lock);
+	if (test_and_clear_bit(IOAT_RESET_PENDING, &chan->state)) {
+		struct ioat_desc_sw *desc;
+
+		spin_lock_bh(&ioat->desc_lock);
+
+		/* restart active descriptors */
+		desc = to_ioat_desc(ioat->used_desc.prev);
+		ioat_set_chainaddr(ioat, desc->txd.phys);
+		ioat_start(chan);
+
+		ioat->pending = 0;
+		set_bit(IOAT_COMPLETION_PENDING, &chan->state);
+		mod_timer(&chan->timer, jiffies + COMPLETION_TIMEOUT);
+		spin_unlock_bh(&ioat->desc_lock);
+	} else if (test_bit(IOAT_COMPLETION_PENDING, &chan->state)) {
+		dma_addr_t phys_complete;
+
+		spin_lock_bh(&ioat->desc_lock);
+		/* if we haven't made progress and we have already
+		 * acknowledged a pending completion once, then be more
+		 * forceful with a restart
+		 */
+		if (ioat_cleanup_preamble(chan, &phys_complete))
+			__cleanup(ioat, phys_complete);
+		else if (test_bit(IOAT_COMPLETION_ACK, &chan->state))
+			ioat1_reset_channel(ioat);
+		else {
+			u64 status = ioat_chansts(chan);
+
+			/* manually update the last completion address */
+			if (ioat_chansts_to_addr(status) != 0)
+				*chan->completion = status;
+
+			set_bit(IOAT_COMPLETION_ACK, &chan->state);
+			mod_timer(&chan->timer, jiffies + COMPLETION_TIMEOUT);
+		}
+		spin_unlock_bh(&ioat->desc_lock);
+	}
+	spin_unlock_bh(&chan->cleanup_lock);
+}
+
+enum dma_status
+ioat_dma_tx_status(struct dma_chan *c, dma_cookie_t cookie,
+		   struct dma_tx_state *txstate)
+{
+	struct ioat_chan_common *chan = to_chan_common(c);
+	struct ioatdma_device *device = chan->device;
+	enum dma_status ret;
+
+	ret = dma_cookie_status(c, cookie, txstate);
+	if (ret == DMA_SUCCESS)
+		return ret;
+
+	device->cleanup_fn((unsigned long) c);
+
+	return dma_cookie_status(c, cookie, txstate);
+}
+
+static void ioat1_dma_start_null_desc(struct ioat_dma_chan *ioat)
+{
+	struct ioat_chan_common *chan = &ioat->base;
+	struct ioat_desc_sw *desc;
+	struct ioat_dma_descriptor *hw;
+
+	spin_lock_bh(&ioat->desc_lock);
+
+	desc = ioat1_dma_get_next_descriptor(ioat);
+
+	if (!desc) {
+		dev_err(to_dev(chan),
+			"Unable to start null desc - get next desc failed\n");
+		spin_unlock_bh(&ioat->desc_lock);
+		return;
+	}
+
+	hw = desc->hw;
+	hw->ctl = 0;
+	hw->ctl_f.null = 1;
+	hw->ctl_f.int_en = 1;
+	hw->ctl_f.compl_write = 1;
+	/* set size to non-zero value (channel returns error when size is 0) */
+	hw->size = NULL_DESC_BUFFER_SIZE;
+	hw->src_addr = 0;
+	hw->dst_addr = 0;
+	async_tx_ack(&desc->txd);
+	hw->next = 0;
+	list_add_tail(&desc->node, &ioat->used_desc);
+	dump_desc_dbg(ioat, desc);
+
+	ioat_set_chainaddr(ioat, desc->txd.phys);
+	ioat_start(chan);
+	spin_unlock_bh(&ioat->desc_lock);
+}
+
+/*
+ * Perform a IOAT transaction to verify the HW works.
+ */
+#define IOAT_TEST_SIZE 2000
+
+static void __devinit ioat_dma_test_callback(void *dma_async_param)
+{
+	struct completion *cmp = dma_async_param;
+
+	complete(cmp);
+}
+
+/**
+ * ioat_dma_self_test - Perform a IOAT transaction to verify the HW works.
+ * @device: device to be tested
+ */
+int __devinit ioat_dma_self_test(struct ioatdma_device *device)
+{
+	int i;
+	u8 *src;
+	u8 *dest;
+	struct dma_device *dma = &device->common;
+	struct device *dev = &device->pdev->dev;
+	struct dma_chan *dma_chan;
+	struct dma_async_tx_descriptor *tx;
+	dma_addr_t dma_dest, dma_src;
+	dma_cookie_t cookie;
+	int err = 0;
+	struct completion cmp;
+	unsigned long tmo;
+	unsigned long flags;
+
+	src = kzalloc(sizeof(u8) * IOAT_TEST_SIZE, GFP_KERNEL);
+	if (!src)
+		return -ENOMEM;
+	dest = kzalloc(sizeof(u8) * IOAT_TEST_SIZE, GFP_KERNEL);
+	if (!dest) {
+		kfree(src);
+		return -ENOMEM;
+	}
+
+	/* Fill in src buffer */
+	for (i = 0; i < IOAT_TEST_SIZE; i++)
+		src[i] = (u8)i;
+
+	/* Start copy, using first DMA channel */
+	dma_chan = container_of(dma->channels.next, struct dma_chan,
+				device_node);
+	if (dma->device_alloc_chan_resources(dma_chan) < 1) {
+		dev_err(dev, "selftest cannot allocate chan resource\n");
+		err = -ENODEV;
+		goto out;
+	}
+
+	dma_src = dma_map_single(dev, src, IOAT_TEST_SIZE, DMA_TO_DEVICE);
+	dma_dest = dma_map_single(dev, dest, IOAT_TEST_SIZE, DMA_FROM_DEVICE);
+	flags = DMA_COMPL_SRC_UNMAP_SINGLE | DMA_COMPL_DEST_UNMAP_SINGLE |
+		DMA_PREP_INTERRUPT;
+	tx = device->common.device_prep_dma_memcpy(dma_chan, dma_dest, dma_src,
+						   IOAT_TEST_SIZE, flags);
+	if (!tx) {
+		dev_err(dev, "Self-test prep failed, disabling\n");
+		err = -ENODEV;
+		goto free_resources;
+	}
+
+	async_tx_ack(tx);
+	init_completion(&cmp);
+	tx->callback = ioat_dma_test_callback;
+	tx->callback_param = &cmp;
+	cookie = tx->tx_submit(tx);
+	if (cookie < 0) {
+		dev_err(dev, "Self-test setup failed, disabling\n");
+		err = -ENODEV;
+		goto free_resources;
+	}
+	dma->device_issue_pending(dma_chan);
+
+	tmo = wait_for_completion_timeout(&cmp, msecs_to_jiffies(3000));
+
+	if (tmo == 0 ||
+	    dma->device_tx_status(dma_chan, cookie, NULL)
+					!= DMA_SUCCESS) {
+		dev_err(dev, "Self-test copy timed out, disabling\n");
+		err = -ENODEV;
+		goto free_resources;
+	}
+	if (memcmp(src, dest, IOAT_TEST_SIZE)) {
+		dev_err(dev, "Self-test copy failed compare, disabling\n");
+		err = -ENODEV;
+		goto free_resources;
+	}
+
+free_resources:
+	dma->device_free_chan_resources(dma_chan);
+out:
+	kfree(src);
+	kfree(dest);
+	return err;
+}
+
+static char ioat_interrupt_style[32] = "msix";
+module_param_string(ioat_interrupt_style, ioat_interrupt_style,
+		    sizeof(ioat_interrupt_style), 0644);
+MODULE_PARM_DESC(ioat_interrupt_style,
+		 "set ioat interrupt style: msix (default), "
+		 "msix-single-vector, msi, intx)");
+
+/**
+ * ioat_dma_setup_interrupts - setup interrupt handler
+ * @device: ioat device
+ */
+static int ioat_dma_setup_interrupts(struct ioatdma_device *device)
+{
+	struct ioat_chan_common *chan;
+	struct pci_dev *pdev = device->pdev;
+	struct device *dev = &pdev->dev;
+	struct msix_entry *msix;
+	int i, j, msixcnt;
+	int err = -EINVAL;
+	u8 intrctrl = 0;
+
+	if (!strcmp(ioat_interrupt_style, "msix"))
+		goto msix;
+	if (!strcmp(ioat_interrupt_style, "msix-single-vector"))
+		goto msix_single_vector;
+	if (!strcmp(ioat_interrupt_style, "msi"))
+		goto msi;
+	if (!strcmp(ioat_interrupt_style, "intx"))
+		goto intx;
+	dev_err(dev, "invalid ioat_interrupt_style %s\n", ioat_interrupt_style);
+	goto err_no_irq;
+
+msix:
+	/* The number of MSI-X vectors should equal the number of channels */
+	msixcnt = device->common.chancnt;
+	for (i = 0; i < msixcnt; i++)
+		device->msix_entries[i].entry = i;
+
+	err = pci_enable_msix(pdev, device->msix_entries, msixcnt);
+	if (err < 0)
+		goto msi;
+	if (err > 0)
+		goto msix_single_vector;
+
+	for (i = 0; i < msixcnt; i++) {
+		msix = &device->msix_entries[i];
+		chan = ioat_chan_by_index(device, i);
+		err = devm_request_irq(dev, msix->vector,
+				       ioat_dma_do_interrupt_msix, 0,
+				       "ioat-msix", chan);
+		if (err) {
+			for (j = 0; j < i; j++) {
+				msix = &device->msix_entries[j];
+				chan = ioat_chan_by_index(device, j);
+				devm_free_irq(dev, msix->vector, chan);
+			}
+			goto msix_single_vector;
+		}
+	}
+	intrctrl |= IOAT_INTRCTRL_MSIX_VECTOR_CONTROL;
+	goto done;
+
+msix_single_vector:
+	msix = &device->msix_entries[0];
+	msix->entry = 0;
+	err = pci_enable_msix(pdev, device->msix_entries, 1);
+	if (err)
+		goto msi;
+
+	err = devm_request_irq(dev, msix->vector, ioat_dma_do_interrupt, 0,
+			       "ioat-msix", device);
+	if (err) {
+		pci_disable_msix(pdev);
+		goto msi;
+	}
+	goto done;
+
+msi:
+	err = pci_enable_msi(pdev);
+	if (err)
+		goto intx;
+
+	err = devm_request_irq(dev, pdev->irq, ioat_dma_do_interrupt, 0,
+			       "ioat-msi", device);
+	if (err) {
+		pci_disable_msi(pdev);
+		goto intx;
+	}
+	goto done;
+
+intx:
+	err = devm_request_irq(dev, pdev->irq, ioat_dma_do_interrupt,
+			       IRQF_SHARED, "ioat-intx", device);
+	if (err)
+		goto err_no_irq;
+
+done:
+	if (device->intr_quirk)
+		device->intr_quirk(device);
+	intrctrl |= IOAT_INTRCTRL_MASTER_INT_EN;
+	writeb(intrctrl, device->reg_base + IOAT_INTRCTRL_OFFSET);
+	return 0;
+
+err_no_irq:
+	/* Disable all interrupt generation */
+	writeb(0, device->reg_base + IOAT_INTRCTRL_OFFSET);
+	dev_err(dev, "no usable interrupts\n");
+	return err;
+}
+
+static void ioat_disable_interrupts(struct ioatdma_device *device)
+{
+	/* Disable all interrupt generation */
+	writeb(0, device->reg_base + IOAT_INTRCTRL_OFFSET);
+}
+
+int __devinit ioat_probe(struct ioatdma_device *device)
+{
+	int err = -ENODEV;
+	struct dma_device *dma = &device->common;
+	struct pci_dev *pdev = device->pdev;
+	struct device *dev = &pdev->dev;
+
+	/* DMA coherent memory pool for DMA descriptor allocations */
+	device->dma_pool = pci_pool_create("dma_desc_pool", pdev,
+					   sizeof(struct ioat_dma_descriptor),
+					   64, 0);
+	if (!device->dma_pool) {
+		err = -ENOMEM;
+		goto err_dma_pool;
+	}
+
+	device->completion_pool = pci_pool_create("completion_pool", pdev,
+						  sizeof(u64), SMP_CACHE_BYTES,
+						  SMP_CACHE_BYTES);
+
+	if (!device->completion_pool) {
+		err = -ENOMEM;
+		goto err_completion_pool;
+	}
+
+	device->enumerate_channels(device);
+
+	dma_cap_set(DMA_MEMCPY, dma->cap_mask);
+	dma->dev = &pdev->dev;
+
+	if (!dma->chancnt) {
+		dev_err(dev, "channel enumeration error\n");
+		goto err_setup_interrupts;
+	}
+
+	err = ioat_dma_setup_interrupts(device);
+	if (err)
+		goto err_setup_interrupts;
+
+	err = device->self_test(device);
+	if (err)
+		goto err_self_test;
+
+	return 0;
+
+err_self_test:
+	ioat_disable_interrupts(device);
+err_setup_interrupts:
+	pci_pool_destroy(device->completion_pool);
+err_completion_pool:
+	pci_pool_destroy(device->dma_pool);
+err_dma_pool:
+	return err;
+}
+
+int __devinit ioat_register(struct ioatdma_device *device)
+{
+	int err = dma_async_device_register(&device->common);
+
+	if (err) {
+		ioat_disable_interrupts(device);
+		pci_pool_destroy(device->completion_pool);
+		pci_pool_destroy(device->dma_pool);
+	}
+
+	return err;
+}
+
+/* ioat1_intr_quirk - fix up dma ctrl register to enable / disable msi */
+static void ioat1_intr_quirk(struct ioatdma_device *device)
+{
+	struct pci_dev *pdev = device->pdev;
+	u32 dmactrl;
+
+	pci_read_config_dword(pdev, IOAT_PCI_DMACTRL_OFFSET, &dmactrl);
+	if (pdev->msi_enabled)
+		dmactrl |= IOAT_PCI_DMACTRL_MSI_EN;
+	else
+		dmactrl &= ~IOAT_PCI_DMACTRL_MSI_EN;
+	pci_write_config_dword(pdev, IOAT_PCI_DMACTRL_OFFSET, dmactrl);
+}
+
+static ssize_t ring_size_show(struct dma_chan *c, char *page)
+{
+	struct ioat_dma_chan *ioat = to_ioat_chan(c);
+
+	return sprintf(page, "%d\n", ioat->desccount);
+}
+static struct ioat_sysfs_entry ring_size_attr = __ATTR_RO(ring_size);
+
+static ssize_t ring_active_show(struct dma_chan *c, char *page)
+{
+	struct ioat_dma_chan *ioat = to_ioat_chan(c);
+
+	return sprintf(page, "%d\n", ioat->active);
+}
+static struct ioat_sysfs_entry ring_active_attr = __ATTR_RO(ring_active);
+
+static ssize_t cap_show(struct dma_chan *c, char *page)
+{
+	struct dma_device *dma = c->device;
+
+	return sprintf(page, "copy%s%s%s%s%s%s\n",
+		       dma_has_cap(DMA_PQ, dma->cap_mask) ? " pq" : "",
+		       dma_has_cap(DMA_PQ_VAL, dma->cap_mask) ? " pq_val" : "",
+		       dma_has_cap(DMA_XOR, dma->cap_mask) ? " xor" : "",
+		       dma_has_cap(DMA_XOR_VAL, dma->cap_mask) ? " xor_val" : "",
+		       dma_has_cap(DMA_MEMSET, dma->cap_mask)  ? " fill" : "",
+		       dma_has_cap(DMA_INTERRUPT, dma->cap_mask) ? " intr" : "");
+
+}
+struct ioat_sysfs_entry ioat_cap_attr = __ATTR_RO(cap);
+
+static ssize_t version_show(struct dma_chan *c, char *page)
+{
+	struct dma_device *dma = c->device;
+	struct ioatdma_device *device = to_ioatdma_device(dma);
+
+	return sprintf(page, "%d.%d\n",
+		       device->version >> 4, device->version & 0xf);
+}
+struct ioat_sysfs_entry ioat_version_attr = __ATTR_RO(version);
+
+static struct attribute *ioat1_attrs[] = {
+	&ring_size_attr.attr,
+	&ring_active_attr.attr,
+	&ioat_cap_attr.attr,
+	&ioat_version_attr.attr,
+	NULL,
+};
+
+static ssize_t
+ioat_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
+{
+	struct ioat_sysfs_entry *entry;
+	struct ioat_chan_common *chan;
+
+	entry = container_of(attr, struct ioat_sysfs_entry, attr);
+	chan = container_of(kobj, struct ioat_chan_common, kobj);
+
+	if (!entry->show)
+		return -EIO;
+	return entry->show(&chan->common, page);
+}
+
+const struct sysfs_ops ioat_sysfs_ops = {
+	.show	= ioat_attr_show,
+};
+
+static struct kobj_type ioat1_ktype = {
+	.sysfs_ops = &ioat_sysfs_ops,
+	.default_attrs = ioat1_attrs,
+};
+
+void ioat_kobject_add(struct ioatdma_device *device, struct kobj_type *type)
+{
+	struct dma_device *dma = &device->common;
+	struct dma_chan *c;
+
+	list_for_each_entry(c, &dma->channels, device_node) {
+		struct ioat_chan_common *chan = to_chan_common(c);
+		struct kobject *parent = &c->dev->device.kobj;
+		int err;
+
+		err = kobject_init_and_add(&chan->kobj, type, parent, "quickdata");
+		if (err) {
+			dev_warn(to_dev(chan),
+				 "sysfs init error (%d), continuing...\n", err);
+			kobject_put(&chan->kobj);
+			set_bit(IOAT_KOBJ_INIT_FAIL, &chan->state);
+		}
+	}
+}
+
+void ioat_kobject_del(struct ioatdma_device *device)
+{
+	struct dma_device *dma = &device->common;
+	struct dma_chan *c;
+
+	list_for_each_entry(c, &dma->channels, device_node) {
+		struct ioat_chan_common *chan = to_chan_common(c);
+
+		if (!test_bit(IOAT_KOBJ_INIT_FAIL, &chan->state)) {
+			kobject_del(&chan->kobj);
+			kobject_put(&chan->kobj);
+		}
+	}
+}
+
+int __devinit ioat1_dma_probe(struct ioatdma_device *device, int dca)
+{
+	struct pci_dev *pdev = device->pdev;
+	struct dma_device *dma;
+	int err;
+
+	device->intr_quirk = ioat1_intr_quirk;
+	device->enumerate_channels = ioat1_enumerate_channels;
+	device->self_test = ioat_dma_self_test;
+	device->timer_fn = ioat1_timer_event;
+	device->cleanup_fn = ioat1_cleanup_event;
+	dma = &device->common;
+	dma->device_prep_dma_memcpy = ioat1_dma_prep_memcpy;
+	dma->device_issue_pending = ioat1_dma_memcpy_issue_pending;
+	dma->device_alloc_chan_resources = ioat1_dma_alloc_chan_resources;
+	dma->device_free_chan_resources = ioat1_dma_free_chan_resources;
+	dma->device_tx_status = ioat_dma_tx_status;
+
+	err = ioat_probe(device);
+	if (err)
+		return err;
+	ioat_set_tcp_copy_break(4096);
+	err = ioat_register(device);
+	if (err)
+		return err;
+	ioat_kobject_add(device, &ioat1_ktype);
+
+	if (dca)
+		device->dca = ioat_dca_init(pdev, device->reg_base);
+
+	return err;
+}
+
+void __devexit ioat_dma_remove(struct ioatdma_device *device)
+{
+	struct dma_device *dma = &device->common;
+
+	ioat_disable_interrupts(device);
+
+	ioat_kobject_del(device);
+
+	dma_async_device_unregister(dma);
+
+	pci_pool_destroy(device->dma_pool);
+	pci_pool_destroy(device->completion_pool);
+
+	INIT_LIST_HEAD(&dma->channels);
+}