ARM: 5648/1: bcmring: add bmcring dma.c

implement dma support for bcmring

Signed-off-by: Leo Chen <leochen@broadcom.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 2321 insertions, 0 deletions

diff --git a/arch/arm/mach-bcmring/dma.c b/arch/arm/mach-bcmring/dma.c
new file mode 100644
index 000000000000..7b20fccb9d4e
--- /dev/null
+++ b/arch/arm/mach-bcmring/dma.c
@@ -0,0 +1,2321 @@
+/*****************************************************************************
+* Copyright 2004 - 2008 Broadcom Corporation.  All rights reserved.
+*
+* Unless you and Broadcom execute a separate written software license
+* agreement governing use of this software, this software is licensed to you
+* under the terms of the GNU General Public License version 2, available at
+* http://www.broadcom.com/licenses/GPLv2.php (the "GPL").
+*
+* Notwithstanding the above, under no circumstances may you combine this
+* software in any way with any other Broadcom software provided under a
+* license other than the GPL, without Broadcom's express prior written
+* consent.
+*****************************************************************************/
+
+/****************************************************************************/
+/**
+*   @file   dma.c
+*
+*   @brief  Implements the DMA interface.
+*/
+/****************************************************************************/
+
+/* ---- Include Files ---------------------------------------------------- */
+
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/dma-mapping.h>
+#include <linux/interrupt.h>
+#include <linux/irqreturn.h>
+#include <linux/proc_fs.h>
+
+#include <mach/timer.h>
+
+#include <linux/mm.h>
+#include <linux/pfn.h>
+#include <asm/atomic.h>
+#include <mach/dma.h>
+
+/* I don't quite understand why dc4 fails when this is set to 1 and DMA is enabled */
+/* especially since dc4 doesn't use kmalloc'd memory. */
+
+#define ALLOW_MAP_OF_KMALLOC_MEMORY 0
+
+/* ---- Public Variables ------------------------------------------------- */
+
+/* ---- Private Constants and Types -------------------------------------- */
+
+#define MAKE_HANDLE(controllerIdx, channelIdx)    (((controllerIdx) << 4) | (channelIdx))
+
+#define CONTROLLER_FROM_HANDLE(handle)    (((handle) >> 4) & 0x0f)
+#define CHANNEL_FROM_HANDLE(handle)       ((handle) & 0x0f)
+
+#define DMA_MAP_DEBUG   0
+
+#if DMA_MAP_DEBUG
+#   define  DMA_MAP_PRINT(fmt, args...)   printk("%s: " fmt, __func__,  ## args)
+#else
+#   define  DMA_MAP_PRINT(fmt, args...)
+#endif
+
+/* ---- Private Variables ------------------------------------------------ */
+
+static DMA_Global_t gDMA;
+static struct proc_dir_entry *gDmaDir;
+
+static atomic_t gDmaStatMemTypeKmalloc = ATOMIC_INIT(0);
+static atomic_t gDmaStatMemTypeVmalloc = ATOMIC_INIT(0);
+static atomic_t gDmaStatMemTypeUser = ATOMIC_INIT(0);
+static atomic_t gDmaStatMemTypeCoherent = ATOMIC_INIT(0);
+
+#include "dma_device.c"
+
+/* ---- Private Function Prototypes -------------------------------------- */
+
+/* ---- Functions  ------------------------------------------------------- */
+
+/****************************************************************************/
+/**
+*   Displays information for /proc/dma/mem-type
+*/
+/****************************************************************************/
+
+static int dma_proc_read_mem_type(char *buf, char **start, off_t offset,
+				  int count, int *eof, void *data)
+{
+	int len = 0;
+
+	len += sprintf(buf + len, "dma_map_mem statistics\n");
+	len +=
+	    sprintf(buf + len, "coherent: %d\n",
+		    atomic_read(&gDmaStatMemTypeCoherent));
+	len +=
+	    sprintf(buf + len, "kmalloc:  %d\n",
+		    atomic_read(&gDmaStatMemTypeKmalloc));
+	len +=
+	    sprintf(buf + len, "vmalloc:  %d\n",
+		    atomic_read(&gDmaStatMemTypeVmalloc));
+	len +=
+	    sprintf(buf + len, "user:     %d\n",
+		    atomic_read(&gDmaStatMemTypeUser));
+
+	return len;
+}
+
+/****************************************************************************/
+/**
+*   Displays information for /proc/dma/channels
+*/
+/****************************************************************************/
+
+static int dma_proc_read_channels(char *buf, char **start, off_t offset,
+				  int count, int *eof, void *data)
+{
+	int controllerIdx;
+	int channelIdx;
+	int limit = count - 200;
+	int len = 0;
+	DMA_Channel_t *channel;
+
+	if (down_interruptible(&gDMA.lock) < 0) {
+		return -ERESTARTSYS;
+	}
+
+	for (controllerIdx = 0; controllerIdx < DMA_NUM_CONTROLLERS;
+	     controllerIdx++) {
+		for (channelIdx = 0; channelIdx < DMA_NUM_CHANNELS;
+		     channelIdx++) {
+			if (len >= limit) {
+				break;
+			}
+
+			channel =
+			    &gDMA.controller[controllerIdx].channel[channelIdx];
+
+			len +=
+			    sprintf(buf + len, "%d:%d ", controllerIdx,
+				    channelIdx);
+
+			if ((channel->flags & DMA_CHANNEL_FLAG_IS_DEDICATED) !=
+			    0) {
+				len +=
+				    sprintf(buf + len, "Dedicated for %s ",
+					    DMA_gDeviceAttribute[channel->
+								 devType].name);
+			} else {
+				len += sprintf(buf + len, "Shared ");
+			}
+
+			if ((channel->flags & DMA_CHANNEL_FLAG_NO_ISR) != 0) {
+				len += sprintf(buf + len, "No ISR ");
+			}
+
+			if ((channel->flags & DMA_CHANNEL_FLAG_LARGE_FIFO) != 0) {
+				len += sprintf(buf + len, "Fifo: 128 ");
+			} else {
+				len += sprintf(buf + len, "Fifo: 64  ");
+			}
+
+			if ((channel->flags & DMA_CHANNEL_FLAG_IN_USE) != 0) {
+				len +=
+				    sprintf(buf + len, "InUse by %s",
+					    DMA_gDeviceAttribute[channel->
+								 devType].name);
+#if (DMA_DEBUG_TRACK_RESERVATION)
+				len +=
+				    sprintf(buf + len, " (%s:%d)",
+					    channel->fileName,
+					    channel->lineNum);
+#endif
+			} else {
+				len += sprintf(buf + len, "Avail ");
+			}
+
+			if (channel->lastDevType != DMA_DEVICE_NONE) {
+				len +=
+				    sprintf(buf + len, "Last use: %s ",
+					    DMA_gDeviceAttribute[channel->
+								 lastDevType].
+					    name);
+			}
+
+			len += sprintf(buf + len, "\n");
+		}
+	}
+	up(&gDMA.lock);
+	*eof = 1;
+
+	return len;
+}
+
+/****************************************************************************/
+/**
+*   Displays information for /proc/dma/devices
+*/
+/****************************************************************************/
+
+static int dma_proc_read_devices(char *buf, char **start, off_t offset,
+				 int count, int *eof, void *data)
+{
+	int limit = count - 200;
+	int len = 0;
+	int devIdx;
+
+	if (down_interruptible(&gDMA.lock) < 0) {
+		return -ERESTARTSYS;
+	}
+
+	for (devIdx = 0; devIdx < DMA_NUM_DEVICE_ENTRIES; devIdx++) {
+		DMA_DeviceAttribute_t *devAttr = &DMA_gDeviceAttribute[devIdx];
+
+		if (devAttr->name == NULL) {
+			continue;
+		}
+
+		if (len >= limit) {
+			break;
+		}
+
+		len += sprintf(buf + len, "%-12s ", devAttr->name);
+
+		if ((devAttr->flags & DMA_DEVICE_FLAG_IS_DEDICATED) != 0) {
+			len +=
+			    sprintf(buf + len, "Dedicated %d:%d ",
+				    devAttr->dedicatedController,
+				    devAttr->dedicatedChannel);
+		} else {
+			len += sprintf(buf + len, "Shared DMA:");
+			if ((devAttr->flags & DMA_DEVICE_FLAG_ON_DMA0) != 0) {
+				len += sprintf(buf + len, "0");
+			}
+			if ((devAttr->flags & DMA_DEVICE_FLAG_ON_DMA1) != 0) {
+				len += sprintf(buf + len, "1");
+			}
+			len += sprintf(buf + len, " ");
+		}
+		if ((devAttr->flags & DMA_DEVICE_FLAG_NO_ISR) != 0) {
+			len += sprintf(buf + len, "NoISR ");
+		}
+		if ((devAttr->flags & DMA_DEVICE_FLAG_ALLOW_LARGE_FIFO) != 0) {
+			len += sprintf(buf + len, "Allow-128 ");
+		}
+
+		len +=
+		    sprintf(buf + len,
+			    "Xfer #: %Lu Ticks: %Lu Bytes: %Lu DescLen: %u\n",
+			    devAttr->numTransfers, devAttr->transferTicks,
+			    devAttr->transferBytes,
+			    devAttr->ring.bytesAllocated);
+
+	}
+
+	up(&gDMA.lock);
+	*eof = 1;
+
+	return len;
+}
+
+/****************************************************************************/
+/**
+*   Determines if a DMA_Device_t is "valid".
+*
+*   @return
+*       TRUE        - dma device is valid
+*       FALSE       - dma device isn't valid
+*/
+/****************************************************************************/
+
+static inline int IsDeviceValid(DMA_Device_t device)
+{
+	return (device >= 0) && (device < DMA_NUM_DEVICE_ENTRIES);
+}
+
+/****************************************************************************/
+/**
+*   Translates a DMA handle into a pointer to a channel.
+*
+*   @return
+*       non-NULL    - pointer to DMA_Channel_t
+*       NULL        - DMA Handle was invalid
+*/
+/****************************************************************************/
+
+static inline DMA_Channel_t *HandleToChannel(DMA_Handle_t handle)
+{
+	int controllerIdx;
+	int channelIdx;
+
+	controllerIdx = CONTROLLER_FROM_HANDLE(handle);
+	channelIdx = CHANNEL_FROM_HANDLE(handle);
+
+	if ((controllerIdx > DMA_NUM_CONTROLLERS)
+	    || (channelIdx > DMA_NUM_CHANNELS)) {
+		return NULL;
+	}
+	return &gDMA.controller[controllerIdx].channel[channelIdx];
+}
+
+/****************************************************************************/
+/**
+*   Interrupt handler which is called to process DMA interrupts.
+*/
+/****************************************************************************/
+
+static irqreturn_t dma_interrupt_handler(int irq, void *dev_id)
+{
+	DMA_Channel_t *channel;
+	DMA_DeviceAttribute_t *devAttr;
+	int irqStatus;
+
+	channel = (DMA_Channel_t *) dev_id;
+
+	/* Figure out why we were called, and knock down the interrupt */
+
+	irqStatus = dmacHw_getInterruptStatus(channel->dmacHwHandle);
+	dmacHw_clearInterrupt(channel->dmacHwHandle);
+
+	if ((channel->devType < 0)
+	    || (channel->devType > DMA_NUM_DEVICE_ENTRIES)) {
+		printk(KERN_ERR "dma_interrupt_handler: Invalid devType: %d\n",
+		       channel->devType);
+		return IRQ_NONE;
+	}
+	devAttr = &DMA_gDeviceAttribute[channel->devType];
+
+	/* Update stats */
+
+	if ((irqStatus & dmacHw_INTERRUPT_STATUS_TRANS) != 0) {
+		devAttr->transferTicks +=
+		    (timer_get_tick_count() - devAttr->transferStartTime);
+	}
+
+	if ((irqStatus & dmacHw_INTERRUPT_STATUS_ERROR) != 0) {
+		printk(KERN_ERR
+		       "dma_interrupt_handler: devType :%d DMA error (%s)\n",
+		       channel->devType, devAttr->name);
+	} else {
+		devAttr->numTransfers++;
+		devAttr->transferBytes += devAttr->numBytes;
+	}
+
+	/* Call any installed handler */
+
+	if (devAttr->devHandler != NULL) {
+		devAttr->devHandler(channel->devType, irqStatus,
+				    devAttr->userData);
+	}
+
+	return IRQ_HANDLED;
+}
+
+/****************************************************************************/
+/**
+*   Allocates memory to hold a descriptor ring. The descriptor ring then
+*   needs to be populated by making one or more calls to
+*   dna_add_descriptors.
+*
+*   The returned descriptor ring will be automatically initialized.
+*
+*   @return
+*       0           Descriptor ring was allocated successfully
+*       -EINVAL     Invalid parameters passed in
+*       -ENOMEM     Unable to allocate memory for the desired number of descriptors.
+*/
+/****************************************************************************/
+
+int dma_alloc_descriptor_ring(DMA_DescriptorRing_t *ring,	/* Descriptor ring to populate */
+			      int numDescriptors	/* Number of descriptors that need to be allocated. */
+    ) {
+	size_t bytesToAlloc = dmacHw_descriptorLen(numDescriptors);
+
+	if ((ring == NULL) || (numDescriptors <= 0)) {
+		return -EINVAL;
+	}
+
+	ring->physAddr = 0;
+	ring->descriptorsAllocated = 0;
+	ring->bytesAllocated = 0;
+
+	ring->virtAddr = dma_alloc_writecombine(NULL,
+						     bytesToAlloc,
+						     &ring->physAddr,
+						     GFP_KERNEL);
+	if (ring->virtAddr == NULL) {
+		return -ENOMEM;
+	}
+
+	ring->bytesAllocated = bytesToAlloc;
+	ring->descriptorsAllocated = numDescriptors;
+
+	return dma_init_descriptor_ring(ring, numDescriptors);
+}
+
+EXPORT_SYMBOL(dma_alloc_descriptor_ring);
+
+/****************************************************************************/
+/**
+*   Releases the memory which was previously allocated for a descriptor ring.
+*/
+/****************************************************************************/
+
+void dma_free_descriptor_ring(DMA_DescriptorRing_t *ring	/* Descriptor to release */
+    ) {
+	if (ring->virtAddr != NULL) {
+		dma_free_writecombine(NULL,
+				      ring->bytesAllocated,
+				      ring->virtAddr, ring->physAddr);
+	}
+
+	ring->bytesAllocated = 0;
+	ring->descriptorsAllocated = 0;
+	ring->virtAddr = NULL;
+	ring->physAddr = 0;
+}
+
+EXPORT_SYMBOL(dma_free_descriptor_ring);
+
+/****************************************************************************/
+/**
+*   Initializes a descriptor ring, so that descriptors can be added to it.
+*   Once a descriptor ring has been allocated, it may be reinitialized for
+*   use with additional/different regions of memory.
+*
+*   Note that if 7 descriptors are allocated, it's perfectly acceptable to
+*   initialize the ring with a smaller number of descriptors. The amount
+*   of memory allocated for the descriptor ring will not be reduced, and
+*   the descriptor ring may be reinitialized later
+*
+*   @return
+*       0           Descriptor ring was initialized successfully
+*       -ENOMEM     The descriptor which was passed in has insufficient space
+*                   to hold the desired number of descriptors.
+*/
+/****************************************************************************/
+
+int dma_init_descriptor_ring(DMA_DescriptorRing_t *ring,	/* Descriptor ring to initialize */
+			     int numDescriptors	/* Number of descriptors to initialize. */
+    ) {
+	if (ring->virtAddr == NULL) {
+		return -EINVAL;
+	}
+	if (dmacHw_initDescriptor(ring->virtAddr,
+				  ring->physAddr,
+				  ring->bytesAllocated, numDescriptors) < 0) {
+		printk(KERN_ERR
+		       "dma_init_descriptor_ring: dmacHw_initDescriptor failed\n");
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+EXPORT_SYMBOL(dma_init_descriptor_ring);
+
+/****************************************************************************/
+/**
+*   Determines the number of descriptors which would be required for a
+*   transfer of the indicated memory region.
+*
+*   This function also needs to know which DMA device this transfer will
+*   be destined for, so that the appropriate DMA configuration can be retrieved.
+*   DMA parameters such as transfer width, and whether this is a memory-to-memory
+*   or memory-to-peripheral, etc can all affect the actual number of descriptors
+*   required.
+*
+*   @return
+*       > 0     Returns the number of descriptors required for the indicated transfer
+*       -ENODEV - Device handed in is invalid.
+*       -EINVAL Invalid parameters
+*       -ENOMEM Memory exhausted
+*/
+/****************************************************************************/
+
+int dma_calculate_descriptor_count(DMA_Device_t device,	/* DMA Device that this will be associated with */
+				   dma_addr_t srcData,	/* Place to get data to write to device */
+				   dma_addr_t dstData,	/* Pointer to device data address */
+				   size_t numBytes	/* Number of bytes to transfer to the device */
+    ) {
+	int numDescriptors;
+	DMA_DeviceAttribute_t *devAttr;
+
+	if (!IsDeviceValid(device)) {
+		return -ENODEV;
+	}
+	devAttr = &DMA_gDeviceAttribute[device];
+
+	numDescriptors = dmacHw_calculateDescriptorCount(&devAttr->config,
+							      (void *)srcData,
+							      (void *)dstData,
+							      numBytes);
+	if (numDescriptors < 0) {
+		printk(KERN_ERR
+		       "dma_calculate_descriptor_count: dmacHw_calculateDescriptorCount failed\n");
+		return -EINVAL;
+	}
+
+	return numDescriptors;
+}
+
+EXPORT_SYMBOL(dma_calculate_descriptor_count);
+
+/****************************************************************************/
+/**
+*   Adds a region of memory to the descriptor ring. Note that it may take
+*   multiple descriptors for each region of memory. It is the callers
+*   responsibility to allocate a sufficiently large descriptor ring.
+*
+*   @return
+*       0       Descriptors were added successfully
+*       -ENODEV Device handed in is invalid.
+*       -EINVAL Invalid parameters
+*       -ENOMEM Memory exhausted
+*/
+/****************************************************************************/
+
+int dma_add_descriptors(DMA_DescriptorRing_t *ring,	/* Descriptor ring to add descriptors to */
+			DMA_Device_t device,	/* DMA Device that descriptors are for */
+			dma_addr_t srcData,	/* Place to get data (memory or device) */
+			dma_addr_t dstData,	/* Place to put data (memory or device) */
+			size_t numBytes	/* Number of bytes to transfer to the device */
+    ) {
+	int rc;
+	DMA_DeviceAttribute_t *devAttr;
+
+	if (!IsDeviceValid(device)) {
+		return -ENODEV;
+	}
+	devAttr = &DMA_gDeviceAttribute[device];
+
+	rc = dmacHw_setDataDescriptor(&devAttr->config,
+				      ring->virtAddr,
+				      (void *)srcData,
+				      (void *)dstData, numBytes);
+	if (rc < 0) {
+		printk(KERN_ERR
+		       "dma_add_descriptors: dmacHw_setDataDescriptor failed with code: %d\n",
+		       rc);
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+EXPORT_SYMBOL(dma_add_descriptors);
+
+/****************************************************************************/
+/**
+*   Sets the descriptor ring associated with a device.
+*
+*   Once set, the descriptor ring will be associated with the device, even
+*   across channel request/free calls. Passing in a NULL descriptor ring
+*   will release any descriptor ring currently associated with the device.
+*
+*   Note: If you call dma_transfer, or one of the other dma_alloc_ functions
+*         the descriptor ring may be released and reallocated.
+*
+*   Note: This function will release the descriptor memory for any current
+*         descriptor ring associated with this device.
+*
+*   @return
+*       0       Descriptors were added successfully
+*       -ENODEV Device handed in is invalid.
+*/
+/****************************************************************************/
+
+int dma_set_device_descriptor_ring(DMA_Device_t device,	/* Device to update the descriptor ring for. */
+				   DMA_DescriptorRing_t *ring	/* Descriptor ring to add descriptors to */
+    ) {
+	DMA_DeviceAttribute_t *devAttr;
+
+	if (!IsDeviceValid(device)) {
+		return -ENODEV;
+	}
+	devAttr = &DMA_gDeviceAttribute[device];
+
+	/* Free the previously allocated descriptor ring */
+
+	dma_free_descriptor_ring(&devAttr->ring);
+
+	if (ring != NULL) {
+		/* Copy in the new one */
+
+		devAttr->ring = *ring;
+	}
+
+	/* Set things up so that if dma_transfer is called then this descriptor */
+	/* ring will get freed. */
+
+	devAttr->prevSrcData = 0;
+	devAttr->prevDstData = 0;
+	devAttr->prevNumBytes = 0;
+
+	return 0;
+}
+
+EXPORT_SYMBOL(dma_set_device_descriptor_ring);
+
+/****************************************************************************/
+/**
+*   Retrieves the descriptor ring associated with a device.
+*
+*   @return
+*       0       Descriptors were added successfully
+*       -ENODEV Device handed in is invalid.
+*/
+/****************************************************************************/
+
+int dma_get_device_descriptor_ring(DMA_Device_t device,	/* Device to retrieve the descriptor ring for. */
+				   DMA_DescriptorRing_t *ring	/* Place to store retrieved ring */
+    ) {
+	DMA_DeviceAttribute_t *devAttr;
+
+	memset(ring, 0, sizeof(*ring));
+
+	if (!IsDeviceValid(device)) {
+		return -ENODEV;
+	}
+	devAttr = &DMA_gDeviceAttribute[device];
+
+	*ring = devAttr->ring;
+
+	return 0;
+}
+
+EXPORT_SYMBOL(dma_get_device_descriptor_ring);
+
+/****************************************************************************/
+/**
+*   Configures a DMA channel.
+*
+*   @return
+*       >= 0    - Initialization was successfull.
+*
+*       -EBUSY  - Device is currently being used.
+*       -ENODEV - Device handed in is invalid.
+*/
+/****************************************************************************/
+
+static int ConfigChannel(DMA_Handle_t handle)
+{
+	DMA_Channel_t *channel;
+	DMA_DeviceAttribute_t *devAttr;
+	int controllerIdx;
+
+	channel = HandleToChannel(handle);
+	if (channel == NULL) {
+		return -ENODEV;
+	}
+	devAttr = &DMA_gDeviceAttribute[channel->devType];
+	controllerIdx = CONTROLLER_FROM_HANDLE(handle);
+
+	if ((devAttr->flags & DMA_DEVICE_FLAG_PORT_PER_DMAC) != 0) {
+		if (devAttr->config.transferType ==
+		    dmacHw_TRANSFER_TYPE_MEM_TO_PERIPHERAL) {
+			devAttr->config.dstPeripheralPort =
+			    devAttr->dmacPort[controllerIdx];
+		} else if (devAttr->config.transferType ==
+			   dmacHw_TRANSFER_TYPE_PERIPHERAL_TO_MEM) {
+			devAttr->config.srcPeripheralPort =
+			    devAttr->dmacPort[controllerIdx];
+		}
+	}
+
+	if (dmacHw_configChannel(channel->dmacHwHandle, &devAttr->config) != 0) {
+		printk(KERN_ERR "ConfigChannel: dmacHw_configChannel failed\n");
+		return -EIO;
+	}
+
+	return 0;
+}
+
+/****************************************************************************/
+/**
+*   Intializes all of the data structures associated with the DMA.
+*   @return
+*       >= 0    - Initialization was successfull.
+*
+*       -EBUSY  - Device is currently being used.
+*       -ENODEV - Device handed in is invalid.
+*/
+/****************************************************************************/
+
+int dma_init(void)
+{
+	int rc = 0;
+	int controllerIdx;
+	int channelIdx;
+	DMA_Device_t devIdx;
+	DMA_Channel_t *channel;
+	DMA_Handle_t dedicatedHandle;
+
+	memset(&gDMA, 0, sizeof(gDMA));
+
+	init_MUTEX_LOCKED(&gDMA.lock);
+	init_waitqueue_head(&gDMA.freeChannelQ);
+
+	/* Initialize the Hardware */
+
+	dmacHw_initDma();
+
+	/* Start off by marking all of the DMA channels as shared. */
+
+	for (controllerIdx = 0; controllerIdx < DMA_NUM_CONTROLLERS;
+	     controllerIdx++) {
+		for (channelIdx = 0; channelIdx < DMA_NUM_CHANNELS;
+		     channelIdx++) {
+			channel =
+			    &gDMA.controller[controllerIdx].channel[channelIdx];
+
+			channel->flags = 0;
+			channel->devType = DMA_DEVICE_NONE;
+			channel->lastDevType = DMA_DEVICE_NONE;
+
+#if (DMA_DEBUG_TRACK_RESERVATION)
+			channel->fileName = "";
+			channel->lineNum = 0;
+#endif
+
+			channel->dmacHwHandle =
+			    dmacHw_getChannelHandle(dmacHw_MAKE_CHANNEL_ID
+						    (controllerIdx,
+						     channelIdx));
+			dmacHw_initChannel(channel->dmacHwHandle);
+		}
+	}
+
+	/* Record any special attributes that channels may have */
+
+	gDMA.controller[0].channel[0].flags |= DMA_CHANNEL_FLAG_LARGE_FIFO;
+	gDMA.controller[0].channel[1].flags |= DMA_CHANNEL_FLAG_LARGE_FIFO;
+	gDMA.controller[1].channel[0].flags |= DMA_CHANNEL_FLAG_LARGE_FIFO;
+	gDMA.controller[1].channel[1].flags |= DMA_CHANNEL_FLAG_LARGE_FIFO;
+
+	/* Now walk through and record the dedicated channels. */
+
+	for (devIdx = 0; devIdx < DMA_NUM_DEVICE_ENTRIES; devIdx++) {
+		DMA_DeviceAttribute_t *devAttr = &DMA_gDeviceAttribute[devIdx];
+
+		if (((devAttr->flags & DMA_DEVICE_FLAG_NO_ISR) != 0)
+		    && ((devAttr->flags & DMA_DEVICE_FLAG_IS_DEDICATED) == 0)) {
+			printk(KERN_ERR
+			       "DMA Device: %s Can only request NO_ISR for dedicated devices\n",
+			       devAttr->name);
+			rc = -EINVAL;
+			goto out;
+		}
+
+		if ((devAttr->flags & DMA_DEVICE_FLAG_IS_DEDICATED) != 0) {
+			/* This is a dedicated device. Mark the channel as being reserved. */
+
+			if (devAttr->dedicatedController >= DMA_NUM_CONTROLLERS) {
+				printk(KERN_ERR
+				       "DMA Device: %s DMA Controller %d is out of range\n",
+				       devAttr->name,
+				       devAttr->dedicatedController);
+				rc = -EINVAL;
+				goto out;
+			}
+
+			if (devAttr->dedicatedChannel >= DMA_NUM_CHANNELS) {
+				printk(KERN_ERR
+				       "DMA Device: %s DMA Channel %d is out of range\n",
+				       devAttr->name,
+				       devAttr->dedicatedChannel);
+				rc = -EINVAL;
+				goto out;
+			}
+
+			dedicatedHandle =
+			    MAKE_HANDLE(devAttr->dedicatedController,
+					devAttr->dedicatedChannel);
+			channel = HandleToChannel(dedicatedHandle);
+
+			if ((channel->flags & DMA_CHANNEL_FLAG_IS_DEDICATED) !=
+			    0) {
+				printk
+				    ("DMA Device: %s attempting to use same DMA Controller:Channel (%d:%d) as %s\n",
+				     devAttr->name,
+				     devAttr->dedicatedController,
+				     devAttr->dedicatedChannel,
+				     DMA_gDeviceAttribute[channel->devType].
+				     name);
+				rc = -EBUSY;
+				goto out;
+			}
+
+			channel->flags |= DMA_CHANNEL_FLAG_IS_DEDICATED;
+			channel->devType = devIdx;
+
+			if (devAttr->flags & DMA_DEVICE_FLAG_NO_ISR) {
+				channel->flags |= DMA_CHANNEL_FLAG_NO_ISR;
+			}
+
+			/* For dedicated channels, we can go ahead and configure the DMA channel now */
+			/* as well. */
+
+			ConfigChannel(dedicatedHandle);
+		}
+	}
+
+	/* Go through and register the interrupt handlers */
+
+	for (controllerIdx = 0; controllerIdx < DMA_NUM_CONTROLLERS;
+	     controllerIdx++) {
+		for (channelIdx = 0; channelIdx < DMA_NUM_CHANNELS;
+		     channelIdx++) {
+			channel =
+			    &gDMA.controller[controllerIdx].channel[channelIdx];
+
+			if ((channel->flags & DMA_CHANNEL_FLAG_NO_ISR) == 0) {
+				snprintf(channel->name, sizeof(channel->name),
+					 "dma %d:%d %s", controllerIdx,
+					 channelIdx,
+					 channel->devType ==
+					 DMA_DEVICE_NONE ? "" :
+					 DMA_gDeviceAttribute[channel->devType].
+					 name);
+
+				rc =
+				     request_irq(IRQ_DMA0C0 +
+						 (controllerIdx *
+						  DMA_NUM_CHANNELS) +
+						 channelIdx,
+						 dma_interrupt_handler,
+						 IRQF_DISABLED, channel->name,
+						 channel);
+				if (rc != 0) {
+					printk(KERN_ERR
+					       "request_irq for IRQ_DMA%dC%d failed\n",
+					       controllerIdx, channelIdx);
+				}
+			}
+		}
+	}
+
+	/* Create /proc/dma/channels and /proc/dma/devices */
+
+	gDmaDir = create_proc_entry("dma", S_IFDIR | S_IRUGO | S_IXUGO, NULL);
+
+	if (gDmaDir == NULL) {
+		printk(KERN_ERR "Unable to create /proc/dma\n");
+	} else {
+		create_proc_read_entry("channels", 0, gDmaDir,
+				       dma_proc_read_channels, NULL);
+		create_proc_read_entry("devices", 0, gDmaDir,
+				       dma_proc_read_devices, NULL);
+		create_proc_read_entry("mem-type", 0, gDmaDir,
+				       dma_proc_read_mem_type, NULL);
+	}
+
+out:
+
+	up(&gDMA.lock);
+
+	return rc;
+}
+
+/****************************************************************************/
+/**
+*   Reserves a channel for use with @a dev. If the device is setup to use
+*   a shared channel, then this function will block until a free channel
+*   becomes available.
+*
+*   @return
+*       >= 0    - A valid DMA Handle.
+*       -EBUSY  - Device is currently being used.
+*       -ENODEV - Device handed in is invalid.
+*/
+/****************************************************************************/
+
+#if (DMA_DEBUG_TRACK_RESERVATION)
+DMA_Handle_t dma_request_channel_dbg
+    (DMA_Device_t dev, const char *fileName, int lineNum)
+#else
+DMA_Handle_t dma_request_channel(DMA_Device_t dev)
+#endif
+{
+	DMA_Handle_t handle;
+	DMA_DeviceAttribute_t *devAttr;
+	DMA_Channel_t *channel;
+	int controllerIdx;
+	int controllerIdx2;
+	int channelIdx;
+
+	if (down_interruptible(&gDMA.lock) < 0) {
+		return -ERESTARTSYS;
+	}
+
+	if ((dev < 0) || (dev >= DMA_NUM_DEVICE_ENTRIES)) {
+		handle = -ENODEV;
+		goto out;
+	}
+	devAttr = &DMA_gDeviceAttribute[dev];
+
+#if (DMA_DEBUG_TRACK_RESERVATION)
+	{
+		char *s;
+
+		s = strrchr(fileName, '/');
+		if (s != NULL) {
+			fileName = s + 1;
+		}
+	}
+#endif
+	if ((devAttr->flags & DMA_DEVICE_FLAG_IN_USE) != 0) {
+		/* This device has already been requested and not been freed */
+
+		printk(KERN_ERR "%s: device %s is already requested\n",
+		       __func__, devAttr->name);
+		handle = -EBUSY;
+		goto out;
+	}
+
+	if ((devAttr->flags & DMA_DEVICE_FLAG_IS_DEDICATED) != 0) {
+		/* This device has a dedicated channel. */
+
+		channel =
+		    &gDMA.controller[devAttr->dedicatedController].
+		    channel[devAttr->dedicatedChannel];
+		if ((channel->flags & DMA_CHANNEL_FLAG_IN_USE) != 0) {
+			handle = -EBUSY;
+			goto out;
+		}
+
+		channel->flags |= DMA_CHANNEL_FLAG_IN_USE;
+		devAttr->flags |= DMA_DEVICE_FLAG_IN_USE;
+
+#if (DMA_DEBUG_TRACK_RESERVATION)
+		channel->fileName = fileName;
+		channel->lineNum = lineNum;
+#endif
+		handle =
+		    MAKE_HANDLE(devAttr->dedicatedController,
+				devAttr->dedicatedChannel);
+		goto out;
+	}
+
+	/* This device needs to use one of the shared channels. */
+
+	handle = DMA_INVALID_HANDLE;
+	while (handle == DMA_INVALID_HANDLE) {
+		/* Scan through the shared channels and see if one is available */
+
+		for (controllerIdx2 = 0; controllerIdx2 < DMA_NUM_CONTROLLERS;
+		     controllerIdx2++) {
+			/* Check to see if we should try on controller 1 first. */
+
+			controllerIdx = controllerIdx2;
+			if ((devAttr->
+			     flags & DMA_DEVICE_FLAG_ALLOC_DMA1_FIRST) != 0) {
+				controllerIdx = 1 - controllerIdx;
+			}
+
+			/* See if the device is available on the controller being tested */
+
+			if ((devAttr->
+			     flags & (DMA_DEVICE_FLAG_ON_DMA0 << controllerIdx))
+			    != 0) {
+				for (channelIdx = 0;
+				     channelIdx < DMA_NUM_CHANNELS;
+				     channelIdx++) {
+					channel =
+					    &gDMA.controller[controllerIdx].
+					    channel[channelIdx];
+
+					if (((channel->
+					      flags &
+					      DMA_CHANNEL_FLAG_IS_DEDICATED) ==
+					     0)
+					    &&
+					    ((channel->
+					      flags & DMA_CHANNEL_FLAG_IN_USE)
+					     == 0)) {
+						if (((channel->
+						      flags &
+						      DMA_CHANNEL_FLAG_LARGE_FIFO)
+						     != 0)
+						    &&
+						    ((devAttr->
+						      flags &
+						      DMA_DEVICE_FLAG_ALLOW_LARGE_FIFO)
+						     == 0)) {
+							/* This channel is a large fifo - don't tie it up */
+							/* with devices that we don't want using it. */
+
+							continue;
+						}
+
+						channel->flags |=
+						    DMA_CHANNEL_FLAG_IN_USE;
+						channel->devType = dev;
+						devAttr->flags |=
+						    DMA_DEVICE_FLAG_IN_USE;
+
+#if (DMA_DEBUG_TRACK_RESERVATION)
+						channel->fileName = fileName;
+						channel->lineNum = lineNum;
+#endif
+						handle =
+						    MAKE_HANDLE(controllerIdx,
+								channelIdx);
+
+						/* Now that we've reserved the channel - we can go ahead and configure it */
+
+						if (ConfigChannel(handle) != 0) {
+							handle = -EIO;
+							printk(KERN_ERR
+							       "dma_request_channel: ConfigChannel failed\n");
+						}
+						goto out;
+					}
+				}
+			}
+		}
+
+		/* No channels are currently available. Let's wait for one to free up. */
+
+		{
+			DEFINE_WAIT(wait);
+
+			prepare_to_wait(&gDMA.freeChannelQ, &wait,
+					TASK_INTERRUPTIBLE);
+			up(&gDMA.lock);
+			schedule();
+			finish_wait(&gDMA.freeChannelQ, &wait);
+
+			if (signal_pending(current)) {
+				/* We don't currently hold gDMA.lock, so we return directly */
+
+				return -ERESTARTSYS;
+			}
+		}
+
+		if (down_interruptible(&gDMA.lock)) {
+			return -ERESTARTSYS;
+		}
+	}
+
+out:
+	up(&gDMA.lock);
+
+	return handle;
+}
+
+/* Create both _dbg and non _dbg functions for modules. */
+
+#if (DMA_DEBUG_TRACK_RESERVATION)
+#undef dma_request_channel
+DMA_Handle_t dma_request_channel(DMA_Device_t dev)
+{
+	return dma_request_channel_dbg(dev, __FILE__, __LINE__);
+}
+
+EXPORT_SYMBOL(dma_request_channel_dbg);
+#endif
+EXPORT_SYMBOL(dma_request_channel);
+
+/****************************************************************************/
+/**
+*   Frees a previously allocated DMA Handle.
+*/
+/****************************************************************************/
+
+int dma_free_channel(DMA_Handle_t handle	/* DMA handle. */
+    ) {
+	int rc = 0;
+	DMA_Channel_t *channel;
+	DMA_DeviceAttribute_t *devAttr;
+
+	if (down_interruptible(&gDMA.lock) < 0) {
+		return -ERESTARTSYS;
+	}
+
+	channel = HandleToChannel(handle);
+	if (channel == NULL) {
+		rc = -EINVAL;
+		goto out;
+	}
+
+	devAttr = &DMA_gDeviceAttribute[channel->devType];
+
+	if ((channel->flags & DMA_CHANNEL_FLAG_IS_DEDICATED) == 0) {
+		channel->lastDevType = channel->devType;
+		channel->devType = DMA_DEVICE_NONE;
+	}
+	channel->flags &= ~DMA_CHANNEL_FLAG_IN_USE;
+	devAttr->flags &= ~DMA_DEVICE_FLAG_IN_USE;
+
+out:
+	up(&gDMA.lock);
+
+	wake_up_interruptible(&gDMA.freeChannelQ);
+
+	return rc;
+}
+
+EXPORT_SYMBOL(dma_free_channel);
+
+/****************************************************************************/
+/**
+*   Determines if a given device has been configured as using a shared
+*   channel.
+*
+*   @return
+*       0           Device uses a dedicated channel
+*       > zero      Device uses a shared channel
+*       < zero      Error code
+*/
+/****************************************************************************/
+
+int dma_device_is_channel_shared(DMA_Device_t device	/* Device to check. */
+    ) {
+	DMA_DeviceAttribute_t *devAttr;
+
+	if (!IsDeviceValid(device)) {
+		return -ENODEV;
+	}
+	devAttr = &DMA_gDeviceAttribute[device];
+
+	return ((devAttr->flags & DMA_DEVICE_FLAG_IS_DEDICATED) == 0);
+}
+
+EXPORT_SYMBOL(dma_device_is_channel_shared);
+
+/****************************************************************************/
+/**
+*   Allocates buffers for the descriptors. This is normally done automatically
+*   but needs to be done explicitly when initiating a dma from interrupt
+*   context.
+*
+*   @return
+*       0       Descriptors were allocated successfully
+*       -EINVAL Invalid device type for this kind of transfer
+*               (i.e. the device is _MEM_TO_DEV and not _DEV_TO_MEM)
+*       -ENOMEM Memory exhausted
+*/
+/****************************************************************************/
+
+int dma_alloc_descriptors(DMA_Handle_t handle,	/* DMA Handle */
+			  dmacHw_TRANSFER_TYPE_e transferType,	/* Type of transfer being performed */
+			  dma_addr_t srcData,	/* Place to get data to write to device */
+			  dma_addr_t dstData,	/* Pointer to device data address */
+			  size_t numBytes	/* Number of bytes to transfer to the device */
+    ) {
+	DMA_Channel_t *channel;
+	DMA_DeviceAttribute_t *devAttr;
+	int numDescriptors;
+	size_t ringBytesRequired;
+	int rc = 0;
+
+	channel = HandleToChannel(handle);
+	if (channel == NULL) {
+		return -ENODEV;
+	}
+
+	devAttr = &DMA_gDeviceAttribute[channel->devType];
+
+	if (devAttr->config.transferType != transferType) {
+		return -EINVAL;
+	}
+
+	/* Figure out how many descriptors we need. */
+
+	/* printk("srcData: 0x%08x dstData: 0x%08x, numBytes: %d\n", */
+	/*        srcData, dstData, numBytes); */
+
+	numDescriptors = dmacHw_calculateDescriptorCount(&devAttr->config,
+							      (void *)srcData,
+							      (void *)dstData,
+							      numBytes);
+	if (numDescriptors < 0) {
+		printk(KERN_ERR "%s: dmacHw_calculateDescriptorCount failed\n",
+		       __func__);
+		return -EINVAL;
+	}
+
+	/* Check to see if we can reuse the existing descriptor ring, or if we need to allocate */
+	/* a new one. */
+
+	ringBytesRequired = dmacHw_descriptorLen(numDescriptors);
+
+	/* printk("ringBytesRequired: %d\n", ringBytesRequired); */
+
+	if (ringBytesRequired > devAttr->ring.bytesAllocated) {
+		/* Make sure that this code path is never taken from interrupt context. */
+		/* It's OK for an interrupt to initiate a DMA transfer, but the descriptor */
+		/* allocation needs to have already been done. */
+
+		might_sleep();
+
+		/* Free the old descriptor ring and allocate a new one. */
+
+		dma_free_descriptor_ring(&devAttr->ring);
+
+		/* And allocate a new one. */
+
+		rc =
+		     dma_alloc_descriptor_ring(&devAttr->ring,
+					       numDescriptors);
+		if (rc < 0) {
+			printk(KERN_ERR
+			       "%s: dma_alloc_descriptor_ring(%d) failed\n",
+			       __func__, numDescriptors);
+			return rc;
+		}
+		/* Setup the descriptor for this transfer */
+
+		if (dmacHw_initDescriptor(devAttr->ring.virtAddr,
+					  devAttr->ring.physAddr,
+					  devAttr->ring.bytesAllocated,
+					  numDescriptors) < 0) {
+			printk(KERN_ERR "%s: dmacHw_initDescriptor failed\n",
+			       __func__);
+			return -EINVAL;
+		}
+	} else {
+		/* We've already got enough ring buffer allocated. All we need to do is reset */
+		/* any control information, just in case the previous DMA was stopped. */
+
+		dmacHw_resetDescriptorControl(devAttr->ring.virtAddr);
+	}
+
+	/* dma_alloc/free both set the prevSrc/DstData to 0. If they happen to be the same */
+	/* as last time, then we don't need to call setDataDescriptor again. */
+
+	if (dmacHw_setDataDescriptor(&devAttr->config,
+				     devAttr->ring.virtAddr,
+				     (void *)srcData,
+				     (void *)dstData, numBytes) < 0) {
+		printk(KERN_ERR "%s: dmacHw_setDataDescriptor failed\n",
+		       __func__);
+		return -EINVAL;
+	}
+
+	/* Remember the critical information for this transfer so that we can eliminate */
+	/* another call to dma_alloc_descriptors if the caller reuses the same buffers */
+
+	devAttr->prevSrcData = srcData;
+	devAttr->prevDstData = dstData;
+	devAttr->prevNumBytes = numBytes;
+
+	return 0;
+}
+
+EXPORT_SYMBOL(dma_alloc_descriptors);
+
+/****************************************************************************/
+/**
+*   Allocates and sets up descriptors for a double buffered circular buffer.
+*
+*   This is primarily intended to be used for things like the ingress samples
+*   from a microphone.
+*
+*   @return
+*       > 0     Number of descriptors actually allocated.
+*       -EINVAL Invalid device type for this kind of transfer
+*               (i.e. the device is _MEM_TO_DEV and not _DEV_TO_MEM)
+*       -ENOMEM Memory exhausted
+*/
+/****************************************************************************/
+
+int dma_alloc_double_dst_descriptors(DMA_Handle_t handle,	/* DMA Handle */
+				     dma_addr_t srcData,	/* Physical address of source data */
+				     dma_addr_t dstData1,	/* Physical address of first destination buffer */
+				     dma_addr_t dstData2,	/* Physical address of second destination buffer */
+				     size_t numBytes	/* Number of bytes in each destination buffer */
+    ) {
+	DMA_Channel_t *channel;
+	DMA_DeviceAttribute_t *devAttr;
+	int numDst1Descriptors;
+	int numDst2Descriptors;
+	int numDescriptors;
+	size_t ringBytesRequired;
+	int rc = 0;
+
+	channel = HandleToChannel(handle);
+	if (channel == NULL) {
+		return -ENODEV;
+	}
+
+	devAttr = &DMA_gDeviceAttribute[channel->devType];
+
+	/* Figure out how many descriptors we need. */
+
+	/* printk("srcData: 0x%08x dstData: 0x%08x, numBytes: %d\n", */
+	/*        srcData, dstData, numBytes); */
+
+	numDst1Descriptors =
+	     dmacHw_calculateDescriptorCount(&devAttr->config, (void *)srcData,
+					     (void *)dstData1, numBytes);
+	if (numDst1Descriptors < 0) {
+		return -EINVAL;
+	}
+	numDst2Descriptors =
+	     dmacHw_calculateDescriptorCount(&devAttr->config, (void *)srcData,
+					     (void *)dstData2, numBytes);
+	if (numDst2Descriptors < 0) {
+		return -EINVAL;
+	}
+	numDescriptors = numDst1Descriptors + numDst2Descriptors;
+	/* printk("numDescriptors: %d\n", numDescriptors); */
+
+	/* Check to see if we can reuse the existing descriptor ring, or if we need to allocate */
+	/* a new one. */
+
+	ringBytesRequired = dmacHw_descriptorLen(numDescriptors);
+
+	/* printk("ringBytesRequired: %d\n", ringBytesRequired); */
+
+	if (ringBytesRequired > devAttr->ring.bytesAllocated) {
+		/* Make sure that this code path is never taken from interrupt context. */
+		/* It's OK for an interrupt to initiate a DMA transfer, but the descriptor */
+		/* allocation needs to have already been done. */
+
+		might_sleep();
+
+		/* Free the old descriptor ring and allocate a new one. */
+
+		dma_free_descriptor_ring(&devAttr->ring);
+
+		/* And allocate a new one. */
+
+		rc =
+		     dma_alloc_descriptor_ring(&devAttr->ring,
+					       numDescriptors);
+		if (rc < 0) {
+			printk(KERN_ERR
+			       "%s: dma_alloc_descriptor_ring(%d) failed\n",
+			       __func__, ringBytesRequired);
+			return rc;
+		}
+	}
+
+	/* Setup the descriptor for this transfer. Since this function is used with */
+	/* CONTINUOUS DMA operations, we need to reinitialize every time, otherwise */
+	/* setDataDescriptor will keep trying to append onto the end. */
+
+	if (dmacHw_initDescriptor(devAttr->ring.virtAddr,
+				  devAttr->ring.physAddr,
+				  devAttr->ring.bytesAllocated,
+				  numDescriptors) < 0) {
+		printk(KERN_ERR "%s: dmacHw_initDescriptor failed\n", __func__);
+		return -EINVAL;
+	}
+
+	/* dma_alloc/free both set the prevSrc/DstData to 0. If they happen to be the same */
+	/* as last time, then we don't need to call setDataDescriptor again. */
+
+	if (dmacHw_setDataDescriptor(&devAttr->config,
+				     devAttr->ring.virtAddr,
+				     (void *)srcData,
+				     (void *)dstData1, numBytes) < 0) {
+		printk(KERN_ERR "%s: dmacHw_setDataDescriptor 1 failed\n",
+		       __func__);
+		return -EINVAL;
+	}
+	if (dmacHw_setDataDescriptor(&devAttr->config,
+				     devAttr->ring.virtAddr,
+				     (void *)srcData,
+				     (void *)dstData2, numBytes) < 0) {
+		printk(KERN_ERR "%s: dmacHw_setDataDescriptor 2 failed\n",
+		       __func__);
+		return -EINVAL;
+	}
+
+	/* You should use dma_start_transfer rather than dma_transfer_xxx so we don't */
+	/* try to make the 'prev' variables right. */
+
+	devAttr->prevSrcData = 0;
+	devAttr->prevDstData = 0;
+	devAttr->prevNumBytes = 0;
+
+	return numDescriptors;
+}
+
+EXPORT_SYMBOL(dma_alloc_double_dst_descriptors);
+
+/****************************************************************************/
+/**
+*   Initiates a transfer when the descriptors have already been setup.
+*
+*   This is a special case, and normally, the dma_transfer_xxx functions should
+*   be used.
+*
+*   @return
+*       0       Transfer was started successfully
+*       -ENODEV Invalid handle
+*/
+/****************************************************************************/
+
+int dma_start_transfer(DMA_Handle_t handle)
+{
+	DMA_Channel_t *channel;
+	DMA_DeviceAttribute_t *devAttr;
+
+	channel = HandleToChannel(handle);
+	if (channel == NULL) {
+		return -ENODEV;
+	}
+	devAttr = &DMA_gDeviceAttribute[channel->devType];
+
+	dmacHw_initiateTransfer(channel->dmacHwHandle, &devAttr->config,
+				devAttr->ring.virtAddr);
+
+	/* Since we got this far, everything went successfully */
+
+	return 0;
+}
+
+EXPORT_SYMBOL(dma_start_transfer);
+
+/****************************************************************************/
+/**
+*   Stops a previously started DMA transfer.
+*
+*   @return
+*       0       Transfer was stopped successfully
+*       -ENODEV Invalid handle
+*/
+/****************************************************************************/
+
+int dma_stop_transfer(DMA_Handle_t handle)
+{
+	DMA_Channel_t *channel;
+
+	channel = HandleToChannel(handle);
+	if (channel == NULL) {
+		return -ENODEV;
+	}
+
+	dmacHw_stopTransfer(channel->dmacHwHandle);
+
+	return 0;
+}
+
+EXPORT_SYMBOL(dma_stop_transfer);
+
+/****************************************************************************/
+/**
+*   Waits for a DMA to complete by polling. This function is only intended
+*   to be used for testing. Interrupts should be used for most DMA operations.
+*/
+/****************************************************************************/
+
+int dma_wait_transfer_done(DMA_Handle_t handle)
+{
+	DMA_Channel_t *channel;
+	dmacHw_TRANSFER_STATUS_e status;
+
+	channel = HandleToChannel(handle);
+	if (channel == NULL) {
+		return -ENODEV;
+	}
+
+	while ((status =
+		dmacHw_transferCompleted(channel->dmacHwHandle)) ==
+	       dmacHw_TRANSFER_STATUS_BUSY) {
+		;
+	}
+
+	if (status == dmacHw_TRANSFER_STATUS_ERROR) {
+		printk(KERN_ERR "%s: DMA transfer failed\n", __func__);
+		return -EIO;
+	}
+	return 0;
+}
+
+EXPORT_SYMBOL(dma_wait_transfer_done);
+
+/****************************************************************************/
+/**
+*   Initiates a DMA, allocating the descriptors as required.
+*
+*   @return
+*       0       Transfer was started successfully
+*       -EINVAL Invalid device type for this kind of transfer
+*               (i.e. the device is _DEV_TO_MEM and not _MEM_TO_DEV)
+*/
+/****************************************************************************/
+
+int dma_transfer(DMA_Handle_t handle,	/* DMA Handle */
+		 dmacHw_TRANSFER_TYPE_e transferType,	/* Type of transfer being performed */
+		 dma_addr_t srcData,	/* Place to get data to write to device */
+		 dma_addr_t dstData,	/* Pointer to device data address */
+		 size_t numBytes	/* Number of bytes to transfer to the device */
+    ) {
+	DMA_Channel_t *channel;
+	DMA_DeviceAttribute_t *devAttr;
+	int rc = 0;
+
+	channel = HandleToChannel(handle);
+	if (channel == NULL) {
+		return -ENODEV;
+	}
+
+	devAttr = &DMA_gDeviceAttribute[channel->devType];
+
+	if (devAttr->config.transferType != transferType) {
+		return -EINVAL;
+	}
+
+	/* We keep track of the information about the previous request for this */
+	/* device, and if the attributes match, then we can use the descriptors we setup */
+	/* the last time, and not have to reinitialize everything. */
+
+	{
+		rc =
+		     dma_alloc_descriptors(handle, transferType, srcData,
+					   dstData, numBytes);
+		if (rc != 0) {
+			return rc;
+		}
+	}
+
+	/* And kick off the transfer */
+
+	devAttr->numBytes = numBytes;
+	devAttr->transferStartTime = timer_get_tick_count();
+
+	dmacHw_initiateTransfer(channel->dmacHwHandle, &devAttr->config,
+				devAttr->ring.virtAddr);
+
+	/* Since we got this far, everything went successfully */
+
+	return 0;
+}
+
+EXPORT_SYMBOL(dma_transfer);
+
+/****************************************************************************/
+/**
+*   Set the callback function which will be called when a transfer completes.
+*   If a NULL callback function is set, then no callback will occur.
+*
+*   @note   @a devHandler will be called from IRQ context.
+*
+*   @return
+*       0       - Success
+*       -ENODEV - Device handed in is invalid.
+*/
+/****************************************************************************/
+
+int dma_set_device_handler(DMA_Device_t dev,	/* Device to set the callback for. */
+			   DMA_DeviceHandler_t devHandler,	/* Function to call when the DMA completes */
+			   void *userData	/* Pointer which will be passed to devHandler. */
+    ) {
+	DMA_DeviceAttribute_t *devAttr;
+	unsigned long flags;
+
+	if (!IsDeviceValid(dev)) {
+		return -ENODEV;
+	}
+	devAttr = &DMA_gDeviceAttribute[dev];
+
+	local_irq_save(flags);
+
+	devAttr->userData = userData;
+	devAttr->devHandler = devHandler;
+
+	local_irq_restore(flags);
+
+	return 0;
+}
+
+EXPORT_SYMBOL(dma_set_device_handler);
+
+/****************************************************************************/
+/**
+*   Initializes a memory mapping structure
+*/
+/****************************************************************************/
+
+int dma_init_mem_map(DMA_MemMap_t *memMap)
+{
+	memset(memMap, 0, sizeof(*memMap));
+
+	init_MUTEX(&memMap->lock);
+
+	return 0;
+}
+
+EXPORT_SYMBOL(dma_init_mem_map);
+
+/****************************************************************************/
+/**
+*   Releases any memory currently being held by a memory mapping structure.
+*/
+/****************************************************************************/
+
+int dma_term_mem_map(DMA_MemMap_t *memMap)
+{
+	down(&memMap->lock);	/* Just being paranoid */
+
+	/* Free up any allocated memory */
+
+	up(&memMap->lock);
+	memset(memMap, 0, sizeof(*memMap));
+
+	return 0;
+}
+
+EXPORT_SYMBOL(dma_term_mem_map);
+
+/****************************************************************************/
+/**
+*   Looks at a memory address and categorizes it.
+*
+*   @return One of the values from the DMA_MemType_t enumeration.
+*/
+/****************************************************************************/
+
+DMA_MemType_t dma_mem_type(void *addr)
+{
+	unsigned long addrVal = (unsigned long)addr;
+
+	if (addrVal >= VMALLOC_END) {
+		/* NOTE: DMA virtual memory space starts at 0xFFxxxxxx */
+
+		/* dma_alloc_xxx pages are physically and virtually contiguous */
+
+		return DMA_MEM_TYPE_DMA;
+	}
+
+	/* Technically, we could add one more classification. Addresses between VMALLOC_END */
+	/* and the beginning of the DMA virtual address could be considered to be I/O space. */
+	/* Right now, nobody cares about this particular classification, so we ignore it. */
+
+	if (is_vmalloc_addr(addr)) {
+		/* Address comes from the vmalloc'd region. Pages are virtually */
+		/* contiguous but NOT physically contiguous */
+
+		return DMA_MEM_TYPE_VMALLOC;
+	}
+
+	if (addrVal >= PAGE_OFFSET) {
+		/* PAGE_OFFSET is typically 0xC0000000 */
+
+		/* kmalloc'd pages are physically contiguous */
+
+		return DMA_MEM_TYPE_KMALLOC;
+	}
+
+	return DMA_MEM_TYPE_USER;
+}
+
+EXPORT_SYMBOL(dma_mem_type);
+
+/****************************************************************************/
+/**
+*   Looks at a memory address and determines if we support DMA'ing to/from
+*   that type of memory.
+*
+*   @return boolean -
+*               return value != 0 means dma supported
+*               return value == 0 means dma not supported
+*/
+/****************************************************************************/
+
+int dma_mem_supports_dma(void *addr)
+{
+	DMA_MemType_t memType = dma_mem_type(addr);
+
+	return (memType == DMA_MEM_TYPE_DMA)
+#if ALLOW_MAP_OF_KMALLOC_MEMORY
+	    || (memType == DMA_MEM_TYPE_KMALLOC)
+#endif
+	    || (memType == DMA_MEM_TYPE_USER);
+}
+
+EXPORT_SYMBOL(dma_mem_supports_dma);
+
+/****************************************************************************/
+/**
+*   Maps in a memory region such that it can be used for performing a DMA.
+*
+*   @return
+*/
+/****************************************************************************/
+
+int dma_map_start(DMA_MemMap_t *memMap,	/* Stores state information about the map */
+		  enum dma_data_direction dir	/* Direction that the mapping will be going */
+    ) {
+	int rc;
+
+	down(&memMap->lock);
+
+	DMA_MAP_PRINT("memMap: %p\n", memMap);
+
+	if (memMap->inUse) {
+		printk(KERN_ERR "%s: memory map %p is already being used\n",
+		       __func__, memMap);
+		rc = -EBUSY;
+		goto out;
+	}
+
+	memMap->inUse = 1;
+	memMap->dir = dir;
+	memMap->numRegionsUsed = 0;
+
+	rc = 0;
+
+out:
+
+	DMA_MAP_PRINT("returning %d", rc);
+
+	up(&memMap->lock);
+
+	return rc;
+}
+
+EXPORT_SYMBOL(dma_map_start);
+
+/****************************************************************************/
+/**
+*   Adds a segment of memory to a memory map. Each segment is both
+*   physically and virtually contiguous.
+*
+*   @return     0 on success, error code otherwise.
+*/
+/****************************************************************************/
+
+static int dma_map_add_segment(DMA_MemMap_t *memMap,	/* Stores state information about the map */
+			       DMA_Region_t *region,	/* Region that the segment belongs to */
+			       void *virtAddr,	/* Virtual address of the segment being added */
+			       dma_addr_t physAddr,	/* Physical address of the segment being added */
+			       size_t numBytes	/* Number of bytes of the segment being added */
+    ) {
+	DMA_Segment_t *segment;
+
+	DMA_MAP_PRINT("memMap:%p va:%p pa:0x%x #:%d\n", memMap, virtAddr,
+		      physAddr, numBytes);
+
+	/* Sanity check */
+
+	if (((unsigned long)virtAddr < (unsigned long)region->virtAddr)
+	    || (((unsigned long)virtAddr + numBytes)) >
+	    ((unsigned long)region->virtAddr + region->numBytes)) {
+		printk(KERN_ERR
+		       "%s: virtAddr %p is outside region @ %p len: %d\n",
+		       __func__, virtAddr, region->virtAddr, region->numBytes);
+		return -EINVAL;
+	}
+
+	if (region->numSegmentsUsed > 0) {
+		/* Check to see if this segment is physically contiguous with the previous one */
+
+		segment = &region->segment[region->numSegmentsUsed - 1];
+
+		if ((segment->physAddr + segment->numBytes) == physAddr) {
+			/* It is - just add on to the end */
+
+			DMA_MAP_PRINT("appending %d bytes to last segment\n",
+				      numBytes);
+
+			segment->numBytes += numBytes;
+
+			return 0;
+		}
+	}
+
+	/* Reallocate to hold more segments, if required. */
+
+	if (region->numSegmentsUsed >= region->numSegmentsAllocated) {
+		DMA_Segment_t *newSegment;
+		size_t oldSize =
+		    region->numSegmentsAllocated * sizeof(*newSegment);
+		int newAlloc = region->numSegmentsAllocated + 4;
+		size_t newSize = newAlloc * sizeof(*newSegment);
+
+		newSegment = kmalloc(newSize, GFP_KERNEL);
+		if (newSegment == NULL) {
+			return -ENOMEM;
+		}
+		memcpy(newSegment, region->segment, oldSize);
+		memset(&((uint8_t *) newSegment)[oldSize], 0,
+		       newSize - oldSize);
+		kfree(region->segment);
+
+		region->numSegmentsAllocated = newAlloc;
+		region->segment = newSegment;
+	}
+
+	segment = &region->segment[region->numSegmentsUsed];
+	region->numSegmentsUsed++;
+
+	segment->virtAddr = virtAddr;
+	segment->physAddr = physAddr;
+	segment->numBytes = numBytes;
+
+	DMA_MAP_PRINT("returning success\n");
+
+	return 0;
+}
+
+/****************************************************************************/
+/**
+*   Adds a region of memory to a memory map. Each region is virtually
+*   contiguous, but not necessarily physically contiguous.
+*
+*   @return     0 on success, error code otherwise.
+*/
+/****************************************************************************/
+
+int dma_map_add_region(DMA_MemMap_t *memMap,	/* Stores state information about the map */
+		       void *mem,	/* Virtual address that we want to get a map of */
+		       size_t numBytes	/* Number of bytes being mapped */
+    ) {
+	unsigned long addr = (unsigned long)mem;
+	unsigned int offset;
+	int rc = 0;
+	DMA_Region_t *region;
+	dma_addr_t physAddr;
+
+	down(&memMap->lock);
+
+	DMA_MAP_PRINT("memMap:%p va:%p #:%d\n", memMap, mem, numBytes);
+
+	if (!memMap->inUse) {
+		printk(KERN_ERR "%s: Make sure you call dma_map_start first\n",
+		       __func__);
+		rc = -EINVAL;
+		goto out;
+	}
+
+	/* Reallocate to hold more regions. */
+
+	if (memMap->numRegionsUsed >= memMap->numRegionsAllocated) {
+		DMA_Region_t *newRegion;
+		size_t oldSize =
+		    memMap->numRegionsAllocated * sizeof(*newRegion);
+		int newAlloc = memMap->numRegionsAllocated + 4;
+		size_t newSize = newAlloc * sizeof(*newRegion);
+
+		newRegion = kmalloc(newSize, GFP_KERNEL);
+		if (newRegion == NULL) {
+			rc = -ENOMEM;
+			goto out;
+		}
+		memcpy(newRegion, memMap->region, oldSize);
+		memset(&((uint8_t *) newRegion)[oldSize], 0, newSize - oldSize);
+
+		kfree(memMap->region);
+
+		memMap->numRegionsAllocated = newAlloc;
+		memMap->region = newRegion;
+	}
+
+	region = &memMap->region[memMap->numRegionsUsed];
+	memMap->numRegionsUsed++;
+
+	offset = addr & ~PAGE_MASK;
+
+	region->memType = dma_mem_type(mem);
+	region->virtAddr = mem;
+	region->numBytes = numBytes;
+	region->numSegmentsUsed = 0;
+	region->numLockedPages = 0;
+	region->lockedPages = NULL;
+
+	switch (region->memType) {
+	case DMA_MEM_TYPE_VMALLOC:
+		{
+			atomic_inc(&gDmaStatMemTypeVmalloc);
+
+			/* printk(KERN_ERR "%s: vmalloc'd pages are not supported\n", __func__); */
+
+			/* vmalloc'd pages are not physically contiguous */
+
+			rc = -EINVAL;
+			break;
+		}
+
+	case DMA_MEM_TYPE_KMALLOC:
+		{
+			atomic_inc(&gDmaStatMemTypeKmalloc);
+
+			/* kmalloc'd pages are physically contiguous, so they'll have exactly */
+			/* one segment */
+
+#if ALLOW_MAP_OF_KMALLOC_MEMORY
+			physAddr =
+			    dma_map_single(NULL, mem, numBytes, memMap->dir);
+			rc = dma_map_add_segment(memMap, region, mem, physAddr,
+						 numBytes);
+#else
+			rc = -EINVAL;
+#endif
+			break;
+		}
+
+	case DMA_MEM_TYPE_DMA:
+		{
+			/* dma_alloc_xxx pages are physically contiguous */
+
+			atomic_inc(&gDmaStatMemTypeCoherent);
+
+			physAddr = (vmalloc_to_pfn(mem) << PAGE_SHIFT) + offset;
+
+			dma_sync_single_for_cpu(NULL, physAddr, numBytes,
+						memMap->dir);
+			rc = dma_map_add_segment(memMap, region, mem, physAddr,
+						 numBytes);
+			break;
+		}
+
+	case DMA_MEM_TYPE_USER:
+		{
+			size_t firstPageOffset;
+			size_t firstPageSize;
+			struct page **pages;
+			struct task_struct *userTask;
+
+			atomic_inc(&gDmaStatMemTypeUser);
+
+#if 1
+			/* If the pages are user pages, then the dma_mem_map_set_user_task function */
+			/* must have been previously called. */
+
+			if (memMap->userTask == NULL) {
+				printk(KERN_ERR
+				       "%s: must call dma_mem_map_set_user_task when using user-mode memory\n",
+				       __func__);
+				return -EINVAL;
+			}
+
+			/* User pages need to be locked. */
+
+			firstPageOffset =
+			    (unsigned long)region->virtAddr & (PAGE_SIZE - 1);
+			firstPageSize = PAGE_SIZE - firstPageOffset;
+
+			region->numLockedPages = (firstPageOffset
+						  + region->numBytes +
+						  PAGE_SIZE - 1) / PAGE_SIZE;
+			pages =
+			    kmalloc(region->numLockedPages *
+				    sizeof(struct page *), GFP_KERNEL);
+
+			if (pages == NULL) {
+				region->numLockedPages = 0;
+				return -ENOMEM;
+			}
+
+			userTask = memMap->userTask;
+
+			down_read(&userTask->mm->mmap_sem);
+			rc = get_user_pages(userTask,	/* task */
+					    userTask->mm,	/* mm */
+					    (unsigned long)region->virtAddr,	/* start */
+					    region->numLockedPages,	/* len */
+					    memMap->dir == DMA_FROM_DEVICE,	/* write */
+					    0,	/* force */
+					    pages,	/* pages (array of pointers to page) */
+					    NULL);	/* vmas */
+			up_read(&userTask->mm->mmap_sem);
+
+			if (rc != region->numLockedPages) {
+				kfree(pages);
+				region->numLockedPages = 0;
+
+				if (rc >= 0) {
+					rc = -EINVAL;
+				}
+			} else {
+				uint8_t *virtAddr = region->virtAddr;
+				size_t bytesRemaining;
+				int pageIdx;
+
+				rc = 0;	/* Since get_user_pages returns +ve number */
+
+				region->lockedPages = pages;
+
+				/* We've locked the user pages. Now we need to walk them and figure */
+				/* out the physical addresses. */
+
+				/* The first page may be partial */
+
+				dma_map_add_segment(memMap,
+						    region,
+						    virtAddr,
+						    PFN_PHYS(page_to_pfn
+							     (pages[0])) +
+						    firstPageOffset,
+						    firstPageSize);
+
+				virtAddr += firstPageSize;
+				bytesRemaining =
+				    region->numBytes - firstPageSize;
+
+				for (pageIdx = 1;
+				     pageIdx < region->numLockedPages;
+				     pageIdx++) {
+					size_t bytesThisPage =
+					    (bytesRemaining >
+					     PAGE_SIZE ? PAGE_SIZE :
+					     bytesRemaining);
+
+					DMA_MAP_PRINT
+					    ("pageIdx:%d pages[pageIdx]=%p pfn=%u phys=%u\n",
+					     pageIdx, pages[pageIdx],
+					     page_to_pfn(pages[pageIdx]),
+					     PFN_PHYS(page_to_pfn
+						      (pages[pageIdx])));
+
+					dma_map_add_segment(memMap,
+							    region,
+							    virtAddr,
+							    PFN_PHYS(page_to_pfn
+								     (pages
+								      [pageIdx])),
+							    bytesThisPage);
+
+					virtAddr += bytesThisPage;
+					bytesRemaining -= bytesThisPage;
+				}
+			}
+#else
+			printk(KERN_ERR
+			       "%s: User mode pages are not yet supported\n",
+			       __func__);
+
+			/* user pages are not physically contiguous */
+
+			rc = -EINVAL;
+#endif
+			break;
+		}
+
+	default:
+		{
+			printk(KERN_ERR "%s: Unsupported memory type: %d\n",
+			       __func__, region->memType);
+
+			rc = -EINVAL;
+			break;
+		}
+	}
+
+	if (rc != 0) {
+		memMap->numRegionsUsed--;
+	}
+
+out:
+
+	DMA_MAP_PRINT("returning %d\n", rc);
+
+	up(&memMap->lock);
+
+	return rc;
+}
+
+EXPORT_SYMBOL(dma_map_add_segment);
+
+/****************************************************************************/
+/**
+*   Maps in a memory region such that it can be used for performing a DMA.
+*
+*   @return     0 on success, error code otherwise.
+*/
+/****************************************************************************/
+
+int dma_map_mem(DMA_MemMap_t *memMap,	/* Stores state information about the map */
+		void *mem,	/* Virtual address that we want to get a map of */
+		size_t numBytes,	/* Number of bytes being mapped */
+		enum dma_data_direction dir	/* Direction that the mapping will be going */
+    ) {
+	int rc;
+
+	rc = dma_map_start(memMap, dir);
+	if (rc == 0) {
+		rc = dma_map_add_region(memMap, mem, numBytes);
+		if (rc < 0) {
+			/* Since the add fails, this function will fail, and the caller won't */
+			/* call unmap, so we need to do it here. */
+
+			dma_unmap(memMap, 0);
+		}
+	}
+
+	return rc;
+}
+
+EXPORT_SYMBOL(dma_map_mem);
+
+/****************************************************************************/
+/**
+*   Setup a descriptor ring for a given memory map.
+*
+*   It is assumed that the descriptor ring has already been initialized, and
+*   this routine will only reallocate a new descriptor ring if the existing
+*   one is too small.
+*
+*   @return     0 on success, error code otherwise.
+*/
+/****************************************************************************/
+
+int dma_map_create_descriptor_ring(DMA_Device_t dev,	/* DMA device (where the ring is stored) */
+				   DMA_MemMap_t *memMap,	/* Memory map that will be used */
+				   dma_addr_t devPhysAddr	/* Physical address of device */
+    ) {
+	int rc;
+	int numDescriptors;
+	DMA_DeviceAttribute_t *devAttr;
+	DMA_Region_t *region;
+	DMA_Segment_t *segment;
+	dma_addr_t srcPhysAddr;
+	dma_addr_t dstPhysAddr;
+	int regionIdx;
+	int segmentIdx;
+
+	devAttr = &DMA_gDeviceAttribute[dev];
+
+	down(&memMap->lock);
+
+	/* Figure out how many descriptors we need */
+
+	numDescriptors = 0;
+	for (regionIdx = 0; regionIdx < memMap->numRegionsUsed; regionIdx++) {
+		region = &memMap->region[regionIdx];
+
+		for (segmentIdx = 0; segmentIdx < region->numSegmentsUsed;
+		     segmentIdx++) {
+			segment = &region->segment[segmentIdx];
+
+			if (memMap->dir == DMA_TO_DEVICE) {
+				srcPhysAddr = segment->physAddr;
+				dstPhysAddr = devPhysAddr;
+			} else {
+				srcPhysAddr = devPhysAddr;
+				dstPhysAddr = segment->physAddr;
+			}
+
+			rc =
+			     dma_calculate_descriptor_count(dev, srcPhysAddr,
+							    dstPhysAddr,
+							    segment->
+							    numBytes);
+			if (rc < 0) {
+				printk(KERN_ERR
+				       "%s: dma_calculate_descriptor_count failed: %d\n",
+				       __func__, rc);
+				goto out;
+			}
+			numDescriptors += rc;
+		}
+	}
+
+	/* Adjust the size of the ring, if it isn't big enough */
+
+	if (numDescriptors > devAttr->ring.descriptorsAllocated) {
+		dma_free_descriptor_ring(&devAttr->ring);
+		rc =
+		     dma_alloc_descriptor_ring(&devAttr->ring,
+					       numDescriptors);
+		if (rc < 0) {
+			printk(KERN_ERR
+			       "%s: dma_alloc_descriptor_ring failed: %d\n",
+			       __func__, rc);
+			goto out;
+		}
+	} else {
+		rc =
+		     dma_init_descriptor_ring(&devAttr->ring,
+					      numDescriptors);
+		if (rc < 0) {
+			printk(KERN_ERR
+			       "%s: dma_init_descriptor_ring failed: %d\n",
+			       __func__, rc);
+			goto out;
+		}
+	}
+
+	/* Populate the descriptors */
+
+	for (regionIdx = 0; regionIdx < memMap->numRegionsUsed; regionIdx++) {
+		region = &memMap->region[regionIdx];
+
+		for (segmentIdx = 0; segmentIdx < region->numSegmentsUsed;
+		     segmentIdx++) {
+			segment = &region->segment[segmentIdx];
+
+			if (memMap->dir == DMA_TO_DEVICE) {
+				srcPhysAddr = segment->physAddr;
+				dstPhysAddr = devPhysAddr;
+			} else {
+				srcPhysAddr = devPhysAddr;
+				dstPhysAddr = segment->physAddr;
+			}
+
+			rc =
+			     dma_add_descriptors(&devAttr->ring, dev,
+						 srcPhysAddr, dstPhysAddr,
+						 segment->numBytes);
+			if (rc < 0) {
+				printk(KERN_ERR
+				       "%s: dma_add_descriptors failed: %d\n",
+				       __func__, rc);
+				goto out;
+			}
+		}
+	}
+
+	rc = 0;
+
+out:
+
+	up(&memMap->lock);
+	return rc;
+}
+
+EXPORT_SYMBOL(dma_map_create_descriptor_ring);
+
+/****************************************************************************/
+/**
+*   Maps in a memory region such that it can be used for performing a DMA.
+*
+*   @return
+*/
+/****************************************************************************/
+
+int dma_unmap(DMA_MemMap_t *memMap,	/* Stores state information about the map */
+	      int dirtied	/* non-zero if any of the pages were modified */
+    ) {
+	int regionIdx;
+	int segmentIdx;
+	DMA_Region_t *region;
+	DMA_Segment_t *segment;
+
+	for (regionIdx = 0; regionIdx < memMap->numRegionsUsed; regionIdx++) {
+		region = &memMap->region[regionIdx];
+
+		for (segmentIdx = 0; segmentIdx < region->numSegmentsUsed;
+		     segmentIdx++) {
+			segment = &region->segment[segmentIdx];
+
+			switch (region->memType) {
+			case DMA_MEM_TYPE_VMALLOC:
+				{
+					printk(KERN_ERR
+					       "%s: vmalloc'd pages are not yet supported\n",
+					       __func__);
+					return -EINVAL;
+				}
+
+			case DMA_MEM_TYPE_KMALLOC:
+				{
+#if ALLOW_MAP_OF_KMALLOC_MEMORY
+					dma_unmap_single(NULL,
+							 segment->physAddr,
+							 segment->numBytes,
+							 memMap->dir);
+#endif
+					break;
+				}
+
+			case DMA_MEM_TYPE_DMA:
+				{
+					dma_sync_single_for_cpu(NULL,
+								segment->
+								physAddr,
+								segment->
+								numBytes,
+								memMap->dir);
+					break;
+				}
+
+			case DMA_MEM_TYPE_USER:
+				{
+					/* Nothing to do here. */
+
+					break;
+				}
+
+			default:
+				{
+					printk(KERN_ERR
+					       "%s: Unsupported memory type: %d\n",
+					       __func__, region->memType);
+					return -EINVAL;
+				}
+			}
+
+			segment->virtAddr = NULL;
+			segment->physAddr = 0;
+			segment->numBytes = 0;
+		}
+
+		if (region->numLockedPages > 0) {
+			int pageIdx;
+
+			/* Some user pages were locked. We need to go and unlock them now. */
+
+			for (pageIdx = 0; pageIdx < region->numLockedPages;
+			     pageIdx++) {
+				struct page *page =
+				    region->lockedPages[pageIdx];
+
+				if (memMap->dir == DMA_FROM_DEVICE) {
+					SetPageDirty(page);
+				}
+				page_cache_release(page);
+			}
+			kfree(region->lockedPages);
+			region->numLockedPages = 0;
+			region->lockedPages = NULL;
+		}
+
+		region->memType = DMA_MEM_TYPE_NONE;
+		region->virtAddr = NULL;
+		region->numBytes = 0;
+		region->numSegmentsUsed = 0;
+	}
+	memMap->userTask = NULL;
+	memMap->numRegionsUsed = 0;
+	memMap->inUse = 0;
+
+	up(&memMap->lock);
+
+	return 0;
+}
+
+EXPORT_SYMBOL(dma_unmap);