ARM: bcmring: remove unused DMA map code (864e5e36) · Commits · EulixOS / Software / Kernel

arch/arm/mach-bcmring/dma.c

+0 −812

Original line number	Diff line number	Diff line
		@@ -33,17 +33,11 @@

		#include <mach/timer.h>

		#include <linux/mm.h>
		#include <linux/pfn.h>
		#include <linux/atomic.h>
		#include <linux/sched.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 -------------------------------------- */
		@@ -53,58 +47,18 @@
		#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
		@@ -846,8 +800,6 @@ int dma_init(void)
		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:
		@@ -1565,767 +1517,3 @@ int dma_set_device_handler(DMA_Device_t dev, /* Device to set the callback for.
		}

		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 >= CONSISTENT_BASE) {
		/* 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);

arch/arm/mach-bcmring/include/mach/dma.h

+0 −196

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