[I/OAT]: Driver for the Intel(R) I/OAT DMA engine

Adds a new ioatdma driver

Signed-off-by: Chris Leech <christopher.leech@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 839 insertions, 0 deletions

diff --git a/drivers/dma/ioatdma.c b/drivers/dma/ioatdma.c
new file mode 100644
index 0000000..11d48b97
--- /dev/null
+++ b/drivers/dma/ioatdma.c
@@ -0,0 +1,839 @@
+/*
+ * Copyright(c) 2004 - 2006 Intel Corporation. All rights reserved.
+ *
+ * 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.
+ *
+ * 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/pci.h>
+#include <linux/interrupt.h>
+#include <linux/dmaengine.h>
+#include <linux/delay.h>
+#include "ioatdma.h"
+#include "ioatdma_io.h"
+#include "ioatdma_registers.h"
+#include "ioatdma_hw.h"
+
+#define to_ioat_chan(chan) container_of(chan, struct ioat_dma_chan, common)
+#define to_ioat_device(dev) container_of(dev, struct ioat_device, common)
+#define to_ioat_desc(lh) container_of(lh, struct ioat_desc_sw, node)
+
+/* internal functions */
+static int __devinit ioat_probe(struct pci_dev *pdev, const struct pci_device_id *ent);
+static void __devexit ioat_remove(struct pci_dev *pdev);
+
+static int enumerate_dma_channels(struct ioat_device *device)
+{
+	u8 xfercap_scale;
+	u32 xfercap;
+	int i;
+	struct ioat_dma_chan *ioat_chan;
+
+	device->common.chancnt = ioatdma_read8(device, IOAT_CHANCNT_OFFSET);
+	xfercap_scale = ioatdma_read8(device, IOAT_XFERCAP_OFFSET);
+	xfercap = (xfercap_scale == 0 ? -1 : (1UL << xfercap_scale));
+
+	for (i = 0; i < device->common.chancnt; i++) {
+		ioat_chan = kzalloc(sizeof(*ioat_chan), GFP_KERNEL);
+		if (!ioat_chan) {
+			device->common.chancnt = i;
+			break;
+		}
+
+		ioat_chan->device = device;
+		ioat_chan->reg_base = device->reg_base + (0x80 * (i + 1));
+		ioat_chan->xfercap = xfercap;
+		spin_lock_init(&ioat_chan->cleanup_lock);
+		spin_lock_init(&ioat_chan->desc_lock);
+		INIT_LIST_HEAD(&ioat_chan->free_desc);
+		INIT_LIST_HEAD(&ioat_chan->used_desc);
+		/* This should be made common somewhere in dmaengine.c */
+		ioat_chan->common.device = &device->common;
+		ioat_chan->common.client = NULL;
+		list_add_tail(&ioat_chan->common.device_node,
+		              &device->common.channels);
+	}
+	return device->common.chancnt;
+}
+
+static struct ioat_desc_sw *ioat_dma_alloc_descriptor(
+	struct ioat_dma_chan *ioat_chan,
+	int flags)
+{
+	struct ioat_dma_descriptor *desc;
+	struct ioat_desc_sw *desc_sw;
+	struct ioat_device *ioat_device;
+	dma_addr_t phys;
+
+	ioat_device = to_ioat_device(ioat_chan->common.device);
+	desc = pci_pool_alloc(ioat_device->dma_pool, flags, &phys);
+	if (unlikely(!desc))
+		return NULL;
+
+	desc_sw = kzalloc(sizeof(*desc_sw), flags);
+	if (unlikely(!desc_sw)) {
+		pci_pool_free(ioat_device->dma_pool, desc, phys);
+		return NULL;
+	}
+
+	memset(desc, 0, sizeof(*desc));
+	desc_sw->hw = desc;
+	desc_sw->phys = phys;
+
+	return desc_sw;
+}
+
+#define INITIAL_IOAT_DESC_COUNT 128
+
+static void ioat_start_null_desc(struct ioat_dma_chan *ioat_chan);
+
+/* returns the actual number of allocated descriptors */
+static int ioat_dma_alloc_chan_resources(struct dma_chan *chan)
+{
+	struct ioat_dma_chan *ioat_chan = to_ioat_chan(chan);
+	struct ioat_desc_sw *desc = NULL;
+	u16 chanctrl;
+	u32 chanerr;
+	int i;
+	LIST_HEAD(tmp_list);
+
+	/*
+	 * In-use bit automatically set by reading chanctrl
+	 * If 0, we got it, if 1, someone else did
+	 */
+	chanctrl = ioatdma_chan_read16(ioat_chan, IOAT_CHANCTRL_OFFSET);
+	if (chanctrl & IOAT_CHANCTRL_CHANNEL_IN_USE)
+		return -EBUSY;
+
+        /* Setup register to interrupt and write completion status on error */
+	chanctrl = IOAT_CHANCTRL_CHANNEL_IN_USE |
+		IOAT_CHANCTRL_ERR_INT_EN |
+		IOAT_CHANCTRL_ANY_ERR_ABORT_EN |
+		IOAT_CHANCTRL_ERR_COMPLETION_EN;
+        ioatdma_chan_write16(ioat_chan, IOAT_CHANCTRL_OFFSET, chanctrl);
+
+	chanerr = ioatdma_chan_read32(ioat_chan, IOAT_CHANERR_OFFSET);
+	if (chanerr) {
+		printk("IOAT: CHANERR = %x, clearing\n", chanerr);
+		ioatdma_chan_write32(ioat_chan, IOAT_CHANERR_OFFSET, chanerr);
+	}
+
+	/* Allocate descriptors */
+	for (i = 0; i < INITIAL_IOAT_DESC_COUNT; i++) {
+		desc = ioat_dma_alloc_descriptor(ioat_chan, GFP_KERNEL);
+		if (!desc) {
+			printk(KERN_ERR "IOAT: Only %d initial descriptors\n", i);
+			break;
+		}
+		list_add_tail(&desc->node, &tmp_list);
+	}
+	spin_lock_bh(&ioat_chan->desc_lock);
+	list_splice(&tmp_list, &ioat_chan->free_desc);
+	spin_unlock_bh(&ioat_chan->desc_lock);
+
+	/* allocate a completion writeback area */
+	/* doing 2 32bit writes to mmio since 1 64b write doesn't work */
+	ioat_chan->completion_virt =
+		pci_pool_alloc(ioat_chan->device->completion_pool,
+		               GFP_KERNEL,
+		               &ioat_chan->completion_addr);
+	memset(ioat_chan->completion_virt, 0,
+	       sizeof(*ioat_chan->completion_virt));
+	ioatdma_chan_write32(ioat_chan, IOAT_CHANCMP_OFFSET_LOW,
+	               ((u64) ioat_chan->completion_addr) & 0x00000000FFFFFFFF);
+	ioatdma_chan_write32(ioat_chan, IOAT_CHANCMP_OFFSET_HIGH,
+	               ((u64) ioat_chan->completion_addr) >> 32);
+
+	ioat_start_null_desc(ioat_chan);
+	return i;
+}
+
+static void ioat_dma_memcpy_cleanup(struct ioat_dma_chan *ioat_chan);
+
+static void ioat_dma_free_chan_resources(struct dma_chan *chan)
+{
+	struct ioat_dma_chan *ioat_chan = to_ioat_chan(chan);
+	struct ioat_device *ioat_device = to_ioat_device(chan->device);
+	struct ioat_desc_sw *desc, *_desc;
+	u16 chanctrl;
+	int in_use_descs = 0;
+
+	ioat_dma_memcpy_cleanup(ioat_chan);
+
+	ioatdma_chan_write8(ioat_chan, IOAT_CHANCMD_OFFSET, IOAT_CHANCMD_RESET);
+
+	spin_lock_bh(&ioat_chan->desc_lock);
+	list_for_each_entry_safe(desc, _desc, &ioat_chan->used_desc, node) {
+		in_use_descs++;
+		list_del(&desc->node);
+		pci_pool_free(ioat_device->dma_pool, desc->hw, desc->phys);
+		kfree(desc);
+	}
+	list_for_each_entry_safe(desc, _desc, &ioat_chan->free_desc, node) {
+		list_del(&desc->node);
+		pci_pool_free(ioat_device->dma_pool, desc->hw, desc->phys);
+		kfree(desc);
+	}
+	spin_unlock_bh(&ioat_chan->desc_lock);
+
+	pci_pool_free(ioat_device->completion_pool,
+	              ioat_chan->completion_virt,
+	              ioat_chan->completion_addr);
+
+	/* one is ok since we left it on there on purpose */
+	if (in_use_descs > 1)
+		printk(KERN_ERR "IOAT: Freeing %d in use descriptors!\n",
+			in_use_descs - 1);
+
+	ioat_chan->last_completion = ioat_chan->completion_addr = 0;
+
+	/* Tell hw the chan is free */
+	chanctrl = ioatdma_chan_read16(ioat_chan, IOAT_CHANCTRL_OFFSET);
+	chanctrl &= ~IOAT_CHANCTRL_CHANNEL_IN_USE;
+	ioatdma_chan_write16(ioat_chan, IOAT_CHANCTRL_OFFSET, chanctrl);
+}
+
+/**
+ * do_ioat_dma_memcpy - actual function that initiates a IOAT DMA transaction
+ * @chan: IOAT DMA channel handle
+ * @dest: DMA destination address
+ * @src: DMA source address
+ * @len: transaction length in bytes
+ */
+
+static dma_cookie_t do_ioat_dma_memcpy(struct ioat_dma_chan *ioat_chan,
+                                       dma_addr_t dest,
+                                       dma_addr_t src,
+                                       size_t len)
+{
+	struct ioat_desc_sw *first;
+	struct ioat_desc_sw *prev;
+	struct ioat_desc_sw *new;
+	dma_cookie_t cookie;
+	LIST_HEAD(new_chain);
+	u32 copy;
+	size_t orig_len;
+	dma_addr_t orig_src, orig_dst;
+	unsigned int desc_count = 0;
+	unsigned int append = 0;
+
+	if (!ioat_chan || !dest || !src)
+		return -EFAULT;
+
+	if (!len)
+		return ioat_chan->common.cookie;
+
+	orig_len = len;
+	orig_src = src;
+	orig_dst = dest;
+
+	first = NULL;
+	prev = NULL;
+
+	spin_lock_bh(&ioat_chan->desc_lock);
+
+	while (len) {
+		if (!list_empty(&ioat_chan->free_desc)) {
+			new = to_ioat_desc(ioat_chan->free_desc.next);
+			list_del(&new->node);
+		} else {
+			/* try to get another desc */
+			new = ioat_dma_alloc_descriptor(ioat_chan, GFP_ATOMIC);
+			/* will this ever happen? */
+			/* TODO add upper limit on these */
+			BUG_ON(!new);
+		}
+
+		copy = min((u32) len, ioat_chan->xfercap);
+
+		new->hw->size = copy;
+		new->hw->ctl = 0;
+		new->hw->src_addr = src;
+		new->hw->dst_addr = dest;
+		new->cookie = 0;
+
+		/* chain together the physical address list for the HW */
+		if (!first)
+			first = new;
+		else
+			prev->hw->next = (u64) new->phys;
+
+		prev = new;
+
+		len  -= copy;
+		dest += copy;
+		src  += copy;
+
+		list_add_tail(&new->node, &new_chain);
+		desc_count++;
+	}
+	new->hw->ctl = IOAT_DMA_DESCRIPTOR_CTL_CP_STS;
+	new->hw->next = 0;
+
+	/* cookie incr and addition to used_list must be atomic */
+
+	cookie = ioat_chan->common.cookie;
+	cookie++;
+	if (cookie < 0)
+		cookie = 1;
+	ioat_chan->common.cookie = new->cookie = cookie;
+
+	pci_unmap_addr_set(new, src, orig_src);
+	pci_unmap_addr_set(new, dst, orig_dst);
+	pci_unmap_len_set(new, src_len, orig_len);
+	pci_unmap_len_set(new, dst_len, orig_len);
+
+	/* write address into NextDescriptor field of last desc in chain */
+	to_ioat_desc(ioat_chan->used_desc.prev)->hw->next = first->phys;
+	list_splice_init(&new_chain, ioat_chan->used_desc.prev);
+
+	ioat_chan->pending += desc_count;
+	if (ioat_chan->pending >= 20) {
+		append = 1;
+		ioat_chan->pending = 0;
+	}
+
+	spin_unlock_bh(&ioat_chan->desc_lock);
+
+	if (append)
+		ioatdma_chan_write8(ioat_chan,
+		                    IOAT_CHANCMD_OFFSET,
+		                    IOAT_CHANCMD_APPEND);
+	return cookie;
+}
+
+/**
+ * ioat_dma_memcpy_buf_to_buf - wrapper that takes src & dest bufs
+ * @chan: IOAT DMA channel handle
+ * @dest: DMA destination address
+ * @src: DMA source address
+ * @len: transaction length in bytes
+ */
+
+static dma_cookie_t ioat_dma_memcpy_buf_to_buf(struct dma_chan *chan,
+                                               void *dest,
+                                               void *src,
+                                               size_t len)
+{
+	dma_addr_t dest_addr;
+	dma_addr_t src_addr;
+	struct ioat_dma_chan *ioat_chan = to_ioat_chan(chan);
+
+	dest_addr = pci_map_single(ioat_chan->device->pdev,
+		dest, len, PCI_DMA_FROMDEVICE);
+	src_addr = pci_map_single(ioat_chan->device->pdev,
+		src, len, PCI_DMA_TODEVICE);
+
+	return do_ioat_dma_memcpy(ioat_chan, dest_addr, src_addr, len);
+}
+
+/**
+ * ioat_dma_memcpy_buf_to_pg - wrapper, copying from a buf to a page
+ * @chan: IOAT DMA channel handle
+ * @page: pointer to the page to copy to
+ * @offset: offset into that page
+ * @src: DMA source address
+ * @len: transaction length in bytes
+ */
+
+static dma_cookie_t ioat_dma_memcpy_buf_to_pg(struct dma_chan *chan,
+                                              struct page *page,
+                                              unsigned int offset,
+                                              void *src,
+                                              size_t len)
+{
+	dma_addr_t dest_addr;
+	dma_addr_t src_addr;
+	struct ioat_dma_chan *ioat_chan = to_ioat_chan(chan);
+
+	dest_addr = pci_map_page(ioat_chan->device->pdev,
+		page, offset, len, PCI_DMA_FROMDEVICE);
+	src_addr = pci_map_single(ioat_chan->device->pdev,
+		src, len, PCI_DMA_TODEVICE);
+
+	return do_ioat_dma_memcpy(ioat_chan, dest_addr, src_addr, len);
+}
+
+/**
+ * ioat_dma_memcpy_pg_to_pg - wrapper, copying between two pages
+ * @chan: IOAT DMA channel handle
+ * @dest_pg: pointer to the page to copy to
+ * @dest_off: offset into that page
+ * @src_pg: pointer to the page to copy from
+ * @src_off: offset into that page
+ * @len: transaction length in bytes. This is guaranteed to not make a copy
+ *	 across a page boundary.
+ */
+
+static dma_cookie_t ioat_dma_memcpy_pg_to_pg(struct dma_chan *chan,
+                                             struct page *dest_pg,
+                                             unsigned int dest_off,
+                                             struct page *src_pg,
+                                             unsigned int src_off,
+                                             size_t len)
+{
+	dma_addr_t dest_addr;
+	dma_addr_t src_addr;
+	struct ioat_dma_chan *ioat_chan = to_ioat_chan(chan);
+
+	dest_addr = pci_map_page(ioat_chan->device->pdev,
+		dest_pg, dest_off, len, PCI_DMA_FROMDEVICE);
+	src_addr = pci_map_page(ioat_chan->device->pdev,
+		src_pg, src_off, len, PCI_DMA_TODEVICE);
+
+	return do_ioat_dma_memcpy(ioat_chan, dest_addr, src_addr, len);
+}
+
+/**
+ * ioat_dma_memcpy_issue_pending - push potentially unrecognoized appended descriptors to hw
+ * @chan: DMA channel handle
+ */
+
+static void ioat_dma_memcpy_issue_pending(struct dma_chan *chan)
+{
+	struct ioat_dma_chan *ioat_chan = to_ioat_chan(chan);
+
+	if (ioat_chan->pending != 0) {
+		ioat_chan->pending = 0;
+		ioatdma_chan_write8(ioat_chan,
+		                    IOAT_CHANCMD_OFFSET,
+		                    IOAT_CHANCMD_APPEND);
+	}
+}
+
+static void ioat_dma_memcpy_cleanup(struct ioat_dma_chan *chan)
+{
+	unsigned long phys_complete;
+	struct ioat_desc_sw *desc, *_desc;
+	dma_cookie_t cookie = 0;
+
+	prefetch(chan->completion_virt);
+
+	if (!spin_trylock(&chan->cleanup_lock))
+		return;
+
+	/* The completion writeback can happen at any time,
+	   so reads by the driver need to be atomic operations
+	   The descriptor physical addresses are limited to 32-bits
+	   when the CPU can only do a 32-bit mov */
+
+#if (BITS_PER_LONG == 64)
+	phys_complete =
+	chan->completion_virt->full & IOAT_CHANSTS_COMPLETED_DESCRIPTOR_ADDR;
+#else
+	phys_complete = chan->completion_virt->low & IOAT_LOW_COMPLETION_MASK;
+#endif
+
+	if ((chan->completion_virt->full & IOAT_CHANSTS_DMA_TRANSFER_STATUS) ==
+		IOAT_CHANSTS_DMA_TRANSFER_STATUS_HALTED) {
+		printk("IOAT: Channel halted, chanerr = %x\n",
+			ioatdma_chan_read32(chan, IOAT_CHANERR_OFFSET));
+
+		/* TODO do something to salvage the situation */
+	}
+
+	if (phys_complete == chan->last_completion) {
+		spin_unlock(&chan->cleanup_lock);
+		return;
+	}
+
+	spin_lock_bh(&chan->desc_lock);
+	list_for_each_entry_safe(desc, _desc, &chan->used_desc, node) {
+
+		/*
+		 * 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.
+		 */
+		if (desc->cookie) {
+			cookie = desc->cookie;
+
+			/* yes we are unmapping both _page and _single alloc'd
+			   regions with unmap_page. Is this *really* that bad?
+			*/
+			pci_unmap_page(chan->device->pdev,
+					pci_unmap_addr(desc, dst),
+					pci_unmap_len(desc, dst_len),
+					PCI_DMA_FROMDEVICE);
+			pci_unmap_page(chan->device->pdev,
+					pci_unmap_addr(desc, src),
+					pci_unmap_len(desc, src_len),
+					PCI_DMA_TODEVICE);
+		}
+
+		if (desc->phys != phys_complete) {
+			/* a completed entry, but not the last, so cleanup */
+			list_del(&desc->node);
+			list_add_tail(&desc->node, &chan->free_desc);
+		} else {
+			/* last used desc. Do not remove, so we can append from
+			   it, but don't look at it next time, either */
+			desc->cookie = 0;
+
+			/* TODO check status bits? */
+			break;
+		}
+	}
+
+	spin_unlock_bh(&chan->desc_lock);
+
+	chan->last_completion = phys_complete;
+	if (cookie != 0)
+		chan->completed_cookie = cookie;
+
+	spin_unlock(&chan->cleanup_lock);
+}
+
+/**
+ * ioat_dma_is_complete - poll the status of a IOAT DMA transaction
+ * @chan: IOAT DMA channel handle
+ * @cookie: DMA transaction identifier
+ */
+
+static enum dma_status ioat_dma_is_complete(struct dma_chan *chan,
+                                            dma_cookie_t cookie,
+                                            dma_cookie_t *done,
+                                            dma_cookie_t *used)
+{
+	struct ioat_dma_chan *ioat_chan = to_ioat_chan(chan);
+	dma_cookie_t last_used;
+	dma_cookie_t last_complete;
+	enum dma_status ret;
+
+	last_used = chan->cookie;
+	last_complete = ioat_chan->completed_cookie;
+
+	if (done)
+		*done= last_complete;
+	if (used)
+		*used = last_used;
+
+	ret = dma_async_is_complete(cookie, last_complete, last_used);
+	if (ret == DMA_SUCCESS)
+		return ret;
+
+	ioat_dma_memcpy_cleanup(ioat_chan);
+
+	last_used = chan->cookie;
+	last_complete = ioat_chan->completed_cookie;
+
+	if (done)
+		*done= last_complete;
+	if (used)
+		*used = last_used;
+
+	return dma_async_is_complete(cookie, last_complete, last_used);
+}
+
+/* PCI API */
+
+static struct pci_device_id ioat_pci_tbl[] = {
+	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_IOAT) },
+	{ 0, }
+};
+
+static struct pci_driver ioat_pci_drv = {
+	.name 	= "ioatdma",
+	.id_table = ioat_pci_tbl,
+	.probe	= ioat_probe,
+	.remove	= __devexit_p(ioat_remove),
+};
+
+static irqreturn_t ioat_do_interrupt(int irq, void *data, struct pt_regs *regs)
+{
+	struct ioat_device *instance = data;
+	unsigned long attnstatus;
+	u8 intrctrl;
+
+	intrctrl = ioatdma_read8(instance, IOAT_INTRCTRL_OFFSET);
+
+	if (!(intrctrl & IOAT_INTRCTRL_MASTER_INT_EN))
+		return IRQ_NONE;
+
+	if (!(intrctrl & IOAT_INTRCTRL_INT_STATUS)) {
+		ioatdma_write8(instance, IOAT_INTRCTRL_OFFSET, intrctrl);
+		return IRQ_NONE;
+	}
+
+	attnstatus = ioatdma_read32(instance, IOAT_ATTNSTATUS_OFFSET);
+
+	printk(KERN_ERR "ioatdma error: interrupt! status %lx\n", attnstatus);
+
+	ioatdma_write8(instance, IOAT_INTRCTRL_OFFSET, intrctrl);
+	return IRQ_HANDLED;
+}
+
+static void ioat_start_null_desc(struct ioat_dma_chan *ioat_chan)
+{
+	struct ioat_desc_sw *desc;
+
+	spin_lock_bh(&ioat_chan->desc_lock);
+
+	if (!list_empty(&ioat_chan->free_desc)) {
+		desc = to_ioat_desc(ioat_chan->free_desc.next);
+		list_del(&desc->node);
+	} else {
+		/* try to get another desc */
+		spin_unlock_bh(&ioat_chan->desc_lock);
+		desc = ioat_dma_alloc_descriptor(ioat_chan, GFP_KERNEL);
+		spin_lock_bh(&ioat_chan->desc_lock);
+		/* will this ever happen? */
+		BUG_ON(!desc);
+	}
+
+	desc->hw->ctl = IOAT_DMA_DESCRIPTOR_NUL;
+	desc->hw->next = 0;
+
+	list_add_tail(&desc->node, &ioat_chan->used_desc);
+	spin_unlock_bh(&ioat_chan->desc_lock);
+
+#if (BITS_PER_LONG == 64)
+	ioatdma_chan_write64(ioat_chan, IOAT_CHAINADDR_OFFSET, desc->phys);
+#else
+	ioatdma_chan_write32(ioat_chan,
+	                     IOAT_CHAINADDR_OFFSET_LOW,
+	                     (u32) desc->phys);
+	ioatdma_chan_write32(ioat_chan, IOAT_CHAINADDR_OFFSET_HIGH, 0);
+#endif
+	ioatdma_chan_write8(ioat_chan, IOAT_CHANCMD_OFFSET, IOAT_CHANCMD_START);
+}
+
+/*
+ * Perform a IOAT transaction to verify the HW works.
+ */
+#define IOAT_TEST_SIZE 2000
+
+static int ioat_self_test(struct ioat_device *device)
+{
+	int i;
+	u8 *src;
+	u8 *dest;
+	struct dma_chan *dma_chan;
+	dma_cookie_t cookie;
+	int err = 0;
+
+	src = kzalloc(sizeof(u8) * IOAT_TEST_SIZE, SLAB_KERNEL);
+	if (!src)
+		return -ENOMEM;
+	dest = kzalloc(sizeof(u8) * IOAT_TEST_SIZE, SLAB_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(device->common.channels.next,
+	                        struct dma_chan,
+	                        device_node);
+	if (ioat_dma_alloc_chan_resources(dma_chan) < 1) {
+		err = -ENODEV;
+		goto out;
+	}
+
+	cookie = ioat_dma_memcpy_buf_to_buf(dma_chan, dest, src, IOAT_TEST_SIZE);
+	ioat_dma_memcpy_issue_pending(dma_chan);
+	msleep(1);
+
+	if (ioat_dma_is_complete(dma_chan, cookie, NULL, NULL) != DMA_SUCCESS) {
+		printk(KERN_ERR "ioatdma: Self-test copy timed out, disabling\n");
+		err = -ENODEV;
+		goto free_resources;
+	}
+	if (memcmp(src, dest, IOAT_TEST_SIZE)) {
+		printk(KERN_ERR "ioatdma: Self-test copy failed compare, disabling\n");
+		err = -ENODEV;
+		goto free_resources;
+	}
+
+free_resources:
+	ioat_dma_free_chan_resources(dma_chan);
+out:
+	kfree(src);
+	kfree(dest);
+	return err;
+}
+
+static int __devinit ioat_probe(struct pci_dev *pdev,
+                                const struct pci_device_id *ent)
+{
+	int err;
+	unsigned long mmio_start, mmio_len;
+	void *reg_base;
+	struct ioat_device *device;
+
+	err = pci_enable_device(pdev);
+	if (err)
+		goto err_enable_device;
+
+	err = pci_set_dma_mask(pdev, DMA_64BIT_MASK);
+	if (err)
+		err = pci_set_dma_mask(pdev, DMA_32BIT_MASK);
+	if (err)
+		goto err_set_dma_mask;
+
+	err = pci_request_regions(pdev, ioat_pci_drv.name);
+	if (err)
+		goto err_request_regions;
+
+	mmio_start = pci_resource_start(pdev, 0);
+	mmio_len = pci_resource_len(pdev, 0);
+
+	reg_base = ioremap(mmio_start, mmio_len);
+	if (!reg_base) {
+		err = -ENOMEM;
+		goto err_ioremap;
+	}
+
+	device = kzalloc(sizeof(*device), GFP_KERNEL);
+	if (!device) {
+		err = -ENOMEM;
+		goto err_kzalloc;
+	}
+
+	/* 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->pdev = pdev;
+	pci_set_drvdata(pdev, device);
+#ifdef CONFIG_PCI_MSI
+	if (pci_enable_msi(pdev) == 0) {
+		device->msi = 1;
+	} else {
+		device->msi = 0;
+	}
+#endif
+	err = request_irq(pdev->irq, &ioat_do_interrupt, SA_SHIRQ, "ioat",
+		device);
+	if (err)
+		goto err_irq;
+
+	device->reg_base = reg_base;
+
+	ioatdma_write8(device, IOAT_INTRCTRL_OFFSET, IOAT_INTRCTRL_MASTER_INT_EN);
+	pci_set_master(pdev);
+
+	INIT_LIST_HEAD(&device->common.channels);
+	enumerate_dma_channels(device);
+
+	device->common.device_alloc_chan_resources = ioat_dma_alloc_chan_resources;
+	device->common.device_free_chan_resources = ioat_dma_free_chan_resources;
+	device->common.device_memcpy_buf_to_buf = ioat_dma_memcpy_buf_to_buf;
+	device->common.device_memcpy_buf_to_pg = ioat_dma_memcpy_buf_to_pg;
+	device->common.device_memcpy_pg_to_pg = ioat_dma_memcpy_pg_to_pg;
+	device->common.device_memcpy_complete = ioat_dma_is_complete;
+	device->common.device_memcpy_issue_pending = ioat_dma_memcpy_issue_pending;
+	printk(KERN_INFO "Intel(R) I/OAT DMA Engine found, %d channels\n",
+		device->common.chancnt);
+
+	err = ioat_self_test(device);
+	if (err)
+		goto err_self_test;
+
+	dma_async_device_register(&device->common);
+
+	return 0;
+
+err_self_test:
+err_irq:
+	pci_pool_destroy(device->completion_pool);
+err_completion_pool:
+	pci_pool_destroy(device->dma_pool);
+err_dma_pool:
+	kfree(device);
+err_kzalloc:
+	iounmap(reg_base);
+err_ioremap:
+	pci_release_regions(pdev);
+err_request_regions:
+err_set_dma_mask:
+	pci_disable_device(pdev);
+err_enable_device:
+	return err;
+}
+
+static void __devexit ioat_remove(struct pci_dev *pdev)
+{
+	struct ioat_device *device;
+	struct dma_chan *chan, *_chan;
+	struct ioat_dma_chan *ioat_chan;
+
+	device = pci_get_drvdata(pdev);
+	dma_async_device_unregister(&device->common);
+
+	free_irq(device->pdev->irq, device);
+#ifdef CONFIG_PCI_MSI
+	if (device->msi)
+		pci_disable_msi(device->pdev);
+#endif
+	pci_pool_destroy(device->dma_pool);
+	pci_pool_destroy(device->completion_pool);
+	iounmap(device->reg_base);
+	pci_release_regions(pdev);
+	pci_disable_device(pdev);
+	list_for_each_entry_safe(chan, _chan, &device->common.channels, device_node) {
+		ioat_chan = to_ioat_chan(chan);
+		list_del(&chan->device_node);
+		kfree(ioat_chan);
+	}
+	kfree(device);
+}
+
+/* MODULE API */
+MODULE_VERSION("1.7");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Intel Corporation");
+
+static int __init ioat_init_module(void)
+{
+	/* it's currently unsafe to unload this module */
+	/* if forced, worst case is that rmmod hangs */
+	if (THIS_MODULE != NULL)
+		THIS_MODULE->unsafe = 1;
+
+	return pci_module_init(&ioat_pci_drv);
+}
+
+module_init(ioat_init_module);
+
+static void __exit ioat_exit_module(void)
+{
+	pci_unregister_driver(&ioat_pci_drv);
+}
+
+module_exit(ioat_exit_module);