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android-kvm / linux / 0fac25908f8e26a27d869f0aa4fad04c3db60dc7 / . / arch / arm / mach-bcmring / dma.c
blob: 0ca00050666aa56cc920bc1f81f0af3196bb234a [file] [log] [blame]
/*****************************************************************************
* 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 <linux/slab.h>
#include <mach/timer.h>
#include <linux/mm.h>
#include <linux/pfn.h>
#include <linux/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 successful.
*
* -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;
}
/****************************************************************************/
/**
* Initializes all of the data structures associated with the DMA.
* @return
* >= 0 - Initialization was successful.
*
* -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));
sema_init(&gDMA.lock, 0);
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 = proc_mkdir("dma", 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));
sema_init(&memMap->lock, 1);
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 rc = 0;
int regionIdx;
int segmentIdx;
DMA_Region_t *region;
DMA_Segment_t *segment;
down(&memMap->lock);
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__);
rc = -EINVAL;
goto out;
}
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);
rc = -EINVAL;
goto out;
}
}
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;
out:
up(&memMap->lock);
return rc;
}
EXPORT_SYMBOL(dma_unmap);