[linux-2.6-block.git] / drivers / media / video / videobuf-dma-sg.c

/*
 * helper functions for PCI DMA video4linux capture buffers
 *
 * The functions expect the hardware being able to scatter gatter
 * (i.e. the buffers are not linear in physical memory, but fragmented
 * into PAGE_SIZE chunks).  They also assume the driver does not need
 * to touch the video data.
 *
 * (c) 2007 Mauro Carvalho Chehab, <mchehab@infradead.org>
 *
 * Highly based on video-buf written originally by:
 * (c) 2001,02 Gerd Knorr <kraxel@bytesex.org>
 * (c) 2006 Mauro Carvalho Chehab, <mchehab@infradead.org>
 * (c) 2006 Ted Walther and John Sokol
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/slab.h>
#include <linux/interrupt.h>

#include <linux/pci.h>
#include <linux/vmalloc.h>
#include <linux/pagemap.h>
#include <linux/scatterlist.h>
#include <asm/page.h>
#include <asm/pgtable.h>

#include <media/videobuf-dma-sg.h>

#define MAGIC_DMABUF 0x19721112
#define MAGIC_SG_MEM 0x17890714

#define MAGIC_CHECK(is,should)	if (unlikely((is) != (should))) \
	{ printk(KERN_ERR "magic mismatch: %x (expected %x)\n",is,should); BUG(); }

static int debug = 0;
module_param(debug, int, 0644);

MODULE_DESCRIPTION("helper module to manage video4linux pci dma sg buffers");
MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@infradead.org>");
MODULE_LICENSE("GPL");

#define dprintk(level, fmt, arg...)	if (debug >= level) \
	printk(KERN_DEBUG "vbuf-sg: " fmt , ## arg)

/* --------------------------------------------------------------------- */

struct scatterlist*
videobuf_vmalloc_to_sg(unsigned char *virt, int nr_pages)
{
	struct scatterlist *sglist;
	struct page *pg;
	int i;

	sglist = kcalloc(nr_pages, sizeof(struct scatterlist), GFP_KERNEL);
	if (NULL == sglist)
		return NULL;
	sg_init_table(sglist, nr_pages);
	for (i = 0; i < nr_pages; i++, virt += PAGE_SIZE) {
		pg = vmalloc_to_page(virt);
		if (NULL == pg)
			goto err;
		BUG_ON(PageHighMem(pg));
		sg_set_page(&sglist[i], pg, PAGE_SIZE, 0);
	}
	return sglist;

 err:
	kfree(sglist);
	return NULL;
}

struct scatterlist*
videobuf_pages_to_sg(struct page **pages, int nr_pages, int offset)
{
	struct scatterlist *sglist;
	int i = 0;

	if (NULL == pages[0])
		return NULL;
	sglist = kcalloc(nr_pages, sizeof(*sglist), GFP_KERNEL);
	if (NULL == sglist)
		return NULL;
	sg_init_table(sglist, nr_pages);

	if (NULL == pages[0])
		goto nopage;
	if (PageHighMem(pages[0]))
		/* DMA to highmem pages might not work */
		goto highmem;
	sg_set_page(&sglist[0], pages[0], PAGE_SIZE - offset, offset);
	for (i = 1; i < nr_pages; i++) {
		if (NULL == pages[i])
			goto nopage;
		if (PageHighMem(pages[i]))
			goto highmem;
		sg_set_page(&sglist[i], pages[i], PAGE_SIZE, 0);
	}
	return sglist;

 nopage:
	dprintk(2,"sgl: oops - no page\n");
	kfree(sglist);
	return NULL;

 highmem:
	dprintk(2,"sgl: oops - highmem page\n");
	kfree(sglist);
	return NULL;
}

/* --------------------------------------------------------------------- */

struct videobuf_dmabuf *videobuf_to_dma (struct videobuf_buffer *buf)
{
	struct videbuf_pci_sg_memory *mem=buf->priv;
	BUG_ON (!mem);

	MAGIC_CHECK(mem->magic,MAGIC_SG_MEM);

	return &mem->dma;
}

void videobuf_dma_init(struct videobuf_dmabuf *dma)
{
	memset(dma,0,sizeof(*dma));
	dma->magic = MAGIC_DMABUF;
}

static int videobuf_dma_init_user_locked(struct videobuf_dmabuf *dma,
			int direction, unsigned long data, unsigned long size)
{
	unsigned long first,last;
	int err, rw = 0;

	dma->direction = direction;
	switch (dma->direction) {
	case PCI_DMA_FROMDEVICE: rw = READ;  break;
	case PCI_DMA_TODEVICE:   rw = WRITE; break;
	default:                 BUG();
	}

	first = (data          & PAGE_MASK) >> PAGE_SHIFT;
	last  = ((data+size-1) & PAGE_MASK) >> PAGE_SHIFT;
	dma->offset   = data & ~PAGE_MASK;
	dma->nr_pages = last-first+1;
	dma->pages = kmalloc(dma->nr_pages * sizeof(struct page*),
			     GFP_KERNEL);
	if (NULL == dma->pages)
		return -ENOMEM;
	dprintk(1,"init user [0x%lx+0x%lx => %d pages]\n",
		data,size,dma->nr_pages);

	dma->varea = (void *) data;


	err = get_user_pages(current,current->mm,
			     data & PAGE_MASK, dma->nr_pages,
			     rw == READ, 1, /* force */
			     dma->pages, NULL);

	if (err != dma->nr_pages) {
		dma->nr_pages = (err >= 0) ? err : 0;
		dprintk(1,"get_user_pages: err=%d [%d]\n",err,dma->nr_pages);
		return err < 0 ? err : -EINVAL;
	}
	return 0;
}

int videobuf_dma_init_user(struct videobuf_dmabuf *dma, int direction,
			   unsigned long data, unsigned long size)
{
	int ret;
	down_read(&current->mm->mmap_sem);
	ret = videobuf_dma_init_user_locked(dma, direction, data, size);
	up_read(&current->mm->mmap_sem);

	return ret;
}

int videobuf_dma_init_kernel(struct videobuf_dmabuf *dma, int direction,
			     int nr_pages)
{
	dprintk(1,"init kernel [%d pages]\n",nr_pages);
	dma->direction = direction;
	dma->vmalloc = vmalloc_32(nr_pages << PAGE_SHIFT);
	if (NULL == dma->vmalloc) {
		dprintk(1,"vmalloc_32(%d pages) failed\n",nr_pages);
		return -ENOMEM;
	}
	dprintk(1,"vmalloc is at addr 0x%08lx, size=%d\n",
				(unsigned long)dma->vmalloc,
				nr_pages << PAGE_SHIFT);
	memset(dma->vmalloc,0,nr_pages << PAGE_SHIFT);
	dma->nr_pages = nr_pages;
	return 0;
}

int videobuf_dma_init_overlay(struct videobuf_dmabuf *dma, int direction,
			      dma_addr_t addr, int nr_pages)
{
	dprintk(1,"init overlay [%d pages @ bus 0x%lx]\n",
		nr_pages,(unsigned long)addr);
	dma->direction = direction;
	if (0 == addr)
		return -EINVAL;

	dma->bus_addr = addr;
	dma->nr_pages = nr_pages;
	return 0;
}

int videobuf_dma_map(struct videobuf_queue* q,struct videobuf_dmabuf *dma)
{
	void                   *dev=q->dev;

	MAGIC_CHECK(dma->magic,MAGIC_DMABUF);
	BUG_ON(0 == dma->nr_pages);

	if (dma->pages) {
		dma->sglist = videobuf_pages_to_sg(dma->pages, dma->nr_pages,
						   dma->offset);
	}
	if (dma->vmalloc) {
		dma->sglist = videobuf_vmalloc_to_sg
						(dma->vmalloc,dma->nr_pages);
	}
	if (dma->bus_addr) {
		dma->sglist = kmalloc(sizeof(struct scatterlist), GFP_KERNEL);
		if (NULL != dma->sglist) {
			dma->sglen  = 1;
			sg_dma_address(&dma->sglist[0]) = dma->bus_addr & PAGE_MASK;
			dma->sglist[0].offset           = dma->bus_addr & ~PAGE_MASK;
			sg_dma_len(&dma->sglist[0])     = dma->nr_pages * PAGE_SIZE;
		}
	}
	if (NULL == dma->sglist) {
		dprintk(1,"scatterlist is NULL\n");
		return -ENOMEM;
	}
	if (!dma->bus_addr) {
		dma->sglen = pci_map_sg(dev,dma->sglist,
					dma->nr_pages, dma->direction);
		if (0 == dma->sglen) {
			printk(KERN_WARNING
			       "%s: videobuf_map_sg failed\n",__FUNCTION__);
			kfree(dma->sglist);
			dma->sglist = NULL;
			dma->sglen = 0;
			return -EIO;
		}
	}
	return 0;
}

int videobuf_dma_sync(struct videobuf_queue *q,struct videobuf_dmabuf *dma)
{
	void                   *dev=q->dev;

	MAGIC_CHECK(dma->magic,MAGIC_DMABUF);
	BUG_ON(!dma->sglen);

	pci_dma_sync_sg_for_cpu (dev,dma->sglist,dma->nr_pages,dma->direction);
	return 0;
}

int videobuf_dma_unmap(struct videobuf_queue* q,struct videobuf_dmabuf *dma)
{
	void                   *dev=q->dev;

	MAGIC_CHECK(dma->magic,MAGIC_DMABUF);
	if (!dma->sglen)
		return 0;

	pci_unmap_sg (dev,dma->sglist,dma->nr_pages,dma->direction);

	kfree(dma->sglist);
	dma->sglist = NULL;
	dma->sglen = 0;
	return 0;
}

int videobuf_dma_free(struct videobuf_dmabuf *dma)
{
	MAGIC_CHECK(dma->magic,MAGIC_DMABUF);
	BUG_ON(dma->sglen);

	if (dma->pages) {
		int i;
		for (i=0; i < dma->nr_pages; i++)
			page_cache_release(dma->pages[i]);
		kfree(dma->pages);
		dma->pages = NULL;
	}

	vfree(dma->vmalloc);
	dma->vmalloc = NULL;
	dma->varea = NULL;

	if (dma->bus_addr) {
		dma->bus_addr = 0;
	}
	dma->direction = PCI_DMA_NONE;
	return 0;
}

/* --------------------------------------------------------------------- */

int videobuf_pci_dma_map(struct pci_dev *pci,struct videobuf_dmabuf *dma)
{
	struct videobuf_queue q;

	q.dev=pci;

	return (videobuf_dma_map(&q,dma));
}

int videobuf_pci_dma_unmap(struct pci_dev *pci,struct videobuf_dmabuf *dma)
{
	struct videobuf_queue q;

	q.dev=pci;

	return (videobuf_dma_unmap(&q,dma));
}

/* --------------------------------------------------------------------- */

static void
videobuf_vm_open(struct vm_area_struct *vma)
{
	struct videobuf_mapping *map = vma->vm_private_data;

	dprintk(2,"vm_open %p [count=%d,vma=%08lx-%08lx]\n",map,
		map->count,vma->vm_start,vma->vm_end);
	map->count++;
}

static void
videobuf_vm_close(struct vm_area_struct *vma)
{
	struct videobuf_mapping *map = vma->vm_private_data;
	struct videobuf_queue *q = map->q;
	struct videbuf_pci_sg_memory *mem;
	int i;

	dprintk(2,"vm_close %p [count=%d,vma=%08lx-%08lx]\n",map,
		map->count,vma->vm_start,vma->vm_end);

	map->count--;
	if (0 == map->count) {
		dprintk(1,"munmap %p q=%p\n",map,q);
		mutex_lock(&q->vb_lock);
		for (i = 0; i < VIDEO_MAX_FRAME; i++) {
			if (NULL == q->bufs[i])
				continue;
			mem=q->bufs[i]->priv;

			if (!mem)
				continue;

			MAGIC_CHECK(mem->magic,MAGIC_SG_MEM);

			if (q->bufs[i]->map != map)
				continue;
			q->bufs[i]->map   = NULL;
			q->bufs[i]->baddr = 0;
			q->ops->buf_release(q,q->bufs[i]);
		}
		mutex_unlock(&q->vb_lock);
		kfree(map);
	}
	return;
}

/*
 * Get a anonymous page for the mapping.  Make sure we can DMA to that
 * memory location with 32bit PCI devices (i.e. don't use highmem for
 * now ...).  Bounce buffers don't work very well for the data rates
 * video capture has.
 */
static int
videobuf_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
{
	struct page *page;

	dprintk(3,"fault: fault @ %08lx [vma %08lx-%08lx]\n",
		(unsigned long)vmf->virtual_address,vma->vm_start,vma->vm_end);
	page = alloc_page(GFP_USER | __GFP_DMA32);
	if (!page)
		return VM_FAULT_OOM;
	clear_user_page(page_address(page), (unsigned long)vmf->virtual_address,
			page);
	vmf->page = page;
	return 0;
}

static struct vm_operations_struct videobuf_vm_ops =
{
	.open     = videobuf_vm_open,
	.close    = videobuf_vm_close,
	.fault    = videobuf_vm_fault,
};

/* ---------------------------------------------------------------------
 * PCI handlers for the generic methods
 */

/* Allocated area consists on 3 parts:
	struct video_buffer
	struct <driver>_buffer (cx88_buffer, saa7134_buf, ...)
	struct videobuf_pci_sg_memory
 */

static void *__videobuf_alloc(size_t size)
{
	struct videbuf_pci_sg_memory *mem;
	struct videobuf_buffer *vb;

	vb = kzalloc(size+sizeof(*mem),GFP_KERNEL);

	mem = vb->priv = ((char *)vb)+size;
	mem->magic=MAGIC_SG_MEM;

	videobuf_dma_init(&mem->dma);

	dprintk(1,"%s: allocated at %p(%ld+%ld) & %p(%ld)\n",
		__FUNCTION__,vb,(long)sizeof(*vb),(long)size-sizeof(*vb),
		mem,(long)sizeof(*mem));

	return vb;
}

static int __videobuf_iolock (struct videobuf_queue* q,
			      struct videobuf_buffer *vb,
			      struct v4l2_framebuffer *fbuf)
{
	int err,pages;
	dma_addr_t bus;
	struct videbuf_pci_sg_memory *mem=vb->priv;
	BUG_ON(!mem);

	MAGIC_CHECK(mem->magic,MAGIC_SG_MEM);

	switch (vb->memory) {
	case V4L2_MEMORY_MMAP:
	case V4L2_MEMORY_USERPTR:
		if (0 == vb->baddr) {
			/* no userspace addr -- kernel bounce buffer */
			pages = PAGE_ALIGN(vb->size) >> PAGE_SHIFT;
			err = videobuf_dma_init_kernel( &mem->dma,
							PCI_DMA_FROMDEVICE,
							pages );
			if (0 != err)
				return err;
		} else if (vb->memory == V4L2_MEMORY_USERPTR) {
			/* dma directly to userspace */
			err = videobuf_dma_init_user( &mem->dma,
						      PCI_DMA_FROMDEVICE,
						      vb->baddr,vb->bsize );
			if (0 != err)
				return err;
		} else {
			/* NOTE: HACK: videobuf_iolock on V4L2_MEMORY_MMAP
			buffers can only be called from videobuf_qbuf
			we take current->mm->mmap_sem there, to prevent
			locking inversion, so don't take it here */

			err = videobuf_dma_init_user_locked(&mem->dma,
						      PCI_DMA_FROMDEVICE,
						      vb->baddr, vb->bsize);
			if (0 != err)
				return err;
		}
		break;
	case V4L2_MEMORY_OVERLAY:
		if (NULL == fbuf)
			return -EINVAL;
		/* FIXME: need sanity checks for vb->boff */
		/*
		 * Using a double cast to avoid compiler warnings when
		 * building for PAE. Compiler doesn't like direct casting
		 * of a 32 bit ptr to 64 bit integer.
		 */
		bus   = (dma_addr_t)(unsigned long)fbuf->base + vb->boff;
		pages = PAGE_ALIGN(vb->size) >> PAGE_SHIFT;
		err = videobuf_dma_init_overlay(&mem->dma,PCI_DMA_FROMDEVICE,
						bus, pages);
		if (0 != err)
			return err;
		break;
	default:
		BUG();
	}
	err = videobuf_dma_map(q,&mem->dma);
	if (0 != err)
		return err;

	return 0;
}

static int __videobuf_sync(struct videobuf_queue *q,
			   struct videobuf_buffer *buf)
{
	struct videbuf_pci_sg_memory *mem=buf->priv;
	BUG_ON (!mem);
	MAGIC_CHECK(mem->magic,MAGIC_SG_MEM);

	return	videobuf_dma_sync(q,&mem->dma);
}

static int __videobuf_mmap_free(struct videobuf_queue *q)
{
	int i;

	for (i = 0; i < VIDEO_MAX_FRAME; i++) {
		if (q->bufs[i]) {
			if (q->bufs[i]->map)
				return -EBUSY;
		}
	}

	return 0;
}

static int __videobuf_mmap_mapper(struct videobuf_queue *q,
			 struct vm_area_struct *vma)
{
	struct videbuf_pci_sg_memory *mem;
	struct videobuf_mapping *map;
	unsigned int first,last,size,i;
	int retval;

	retval = -EINVAL;
	if (!(vma->vm_flags & VM_WRITE)) {
		dprintk(1,"mmap app bug: PROT_WRITE please\n");
		goto done;
	}
	if (!(vma->vm_flags & VM_SHARED)) {
		dprintk(1,"mmap app bug: MAP_SHARED please\n");
		goto done;
	}

	/* look for first buffer to map */
	for (first = 0; first < VIDEO_MAX_FRAME; first++) {
		if (NULL == q->bufs[first])
			continue;
		mem=q->bufs[first]->priv;
		BUG_ON (!mem);
		MAGIC_CHECK(mem->magic,MAGIC_SG_MEM);

		if (V4L2_MEMORY_MMAP != q->bufs[first]->memory)
			continue;
		if (q->bufs[first]->boff == (vma->vm_pgoff << PAGE_SHIFT))
			break;
	}
	if (VIDEO_MAX_FRAME == first) {
		dprintk(1,"mmap app bug: offset invalid [offset=0x%lx]\n",
			(vma->vm_pgoff << PAGE_SHIFT));
		goto done;
	}

	/* look for last buffer to map */
	for (size = 0, last = first; last < VIDEO_MAX_FRAME; last++) {
		if (NULL == q->bufs[last])
			continue;
		if (V4L2_MEMORY_MMAP != q->bufs[last]->memory)
			continue;
		if (q->bufs[last]->map) {
			retval = -EBUSY;
			goto done;
		}
		size += q->bufs[last]->bsize;
		if (size == (vma->vm_end - vma->vm_start))
			break;
	}
	if (VIDEO_MAX_FRAME == last) {
		dprintk(1,"mmap app bug: size invalid [size=0x%lx]\n",
			(vma->vm_end - vma->vm_start));
		goto done;
	}

	/* create mapping + update buffer list */
	retval = -ENOMEM;
	map = kmalloc(sizeof(struct videobuf_mapping),GFP_KERNEL);
	if (NULL == map)
		goto done;
	for (size = 0, i = first; i <= last; size += q->bufs[i++]->bsize) {
		q->bufs[i]->map   = map;
		q->bufs[i]->baddr = vma->vm_start + size;
	}
	map->count    = 1;
	map->start    = vma->vm_start;
	map->end      = vma->vm_end;
	map->q        = q;
	vma->vm_ops   = &videobuf_vm_ops;
	vma->vm_flags |= VM_DONTEXPAND | VM_RESERVED;
	vma->vm_flags &= ~VM_IO; /* using shared anonymous pages */
	vma->vm_private_data = map;
	dprintk(1,"mmap %p: q=%p %08lx-%08lx pgoff %08lx bufs %d-%d\n",
		map,q,vma->vm_start,vma->vm_end,vma->vm_pgoff,first,last);
	retval = 0;

 done:
	return retval;
}

static int __videobuf_copy_to_user ( struct videobuf_queue *q,
				char __user *data, size_t count,
				int nonblocking )
{
	struct videbuf_pci_sg_memory *mem=q->read_buf->priv;
	BUG_ON (!mem);
	MAGIC_CHECK(mem->magic,MAGIC_SG_MEM);

	/* copy to userspace */
	if (count > q->read_buf->size - q->read_off)
		count = q->read_buf->size - q->read_off;

	if (copy_to_user(data, mem->dma.vmalloc+q->read_off, count))
		return -EFAULT;

	return count;
}

static int __videobuf_copy_stream ( struct videobuf_queue *q,
				char __user *data, size_t count, size_t pos,
				int vbihack, int nonblocking )
{
	unsigned int  *fc;
	struct videbuf_pci_sg_memory *mem=q->read_buf->priv;
	BUG_ON (!mem);
	MAGIC_CHECK(mem->magic,MAGIC_SG_MEM);

	if (vbihack) {
		/* dirty, undocumented hack -- pass the frame counter
			* within the last four bytes of each vbi data block.
			* We need that one to maintain backward compatibility
			* to all vbi decoding software out there ... */
		fc  = (unsigned int*)mem->dma.vmalloc;
		fc += (q->read_buf->size>>2) -1;
		*fc = q->read_buf->field_count >> 1;
		dprintk(1,"vbihack: %d\n",*fc);
	}

	/* copy stuff using the common method */
	count = __videobuf_copy_to_user (q,data,count,nonblocking);

	if ( (count==-EFAULT) && (0 == pos) )
		return -EFAULT;

	return count;
}

static struct videobuf_qtype_ops pci_ops = {
	.magic        = MAGIC_QTYPE_OPS,

	.alloc        = __videobuf_alloc,
	.iolock       = __videobuf_iolock,
	.sync         = __videobuf_sync,
	.mmap_free    = __videobuf_mmap_free,
	.mmap_mapper  = __videobuf_mmap_mapper,
	.video_copy_to_user = __videobuf_copy_to_user,
	.copy_stream  = __videobuf_copy_stream,
};

void *videobuf_pci_alloc (size_t size)
{
	struct videobuf_queue q;

	/* Required to make generic handler to call __videobuf_alloc */
	q.int_ops=&pci_ops;

	q.msize=size;

	return videobuf_alloc (&q);
}

void videobuf_queue_pci_init(struct videobuf_queue* q,
			 struct videobuf_queue_ops *ops,
			 void *dev,
			 spinlock_t *irqlock,
			 enum v4l2_buf_type type,
			 enum v4l2_field field,
			 unsigned int msize,
			 void *priv)
{
	videobuf_queue_core_init(q, ops, dev, irqlock, type, field, msize,
				 priv, &pci_ops);
}

/* --------------------------------------------------------------------- */

EXPORT_SYMBOL_GPL(videobuf_vmalloc_to_sg);

EXPORT_SYMBOL_GPL(videobuf_to_dma);
EXPORT_SYMBOL_GPL(videobuf_dma_init);
EXPORT_SYMBOL_GPL(videobuf_dma_init_user);
EXPORT_SYMBOL_GPL(videobuf_dma_init_kernel);
EXPORT_SYMBOL_GPL(videobuf_dma_init_overlay);
EXPORT_SYMBOL_GPL(videobuf_dma_map);
EXPORT_SYMBOL_GPL(videobuf_dma_sync);
EXPORT_SYMBOL_GPL(videobuf_dma_unmap);
EXPORT_SYMBOL_GPL(videobuf_dma_free);

EXPORT_SYMBOL_GPL(videobuf_pci_dma_map);
EXPORT_SYMBOL_GPL(videobuf_pci_dma_unmap);
EXPORT_SYMBOL_GPL(videobuf_pci_alloc);

EXPORT_SYMBOL_GPL(videobuf_queue_pci_init);

/*
 * Local variables:
 * c-basic-offset: 8
 * End:
 */
Commit	Line	Data
7a7d9a89 MCC	1	/*
	2	* helper functions for PCI DMA video4linux capture buffers
	3	*
	4	* The functions expect the hardware being able to scatter gatter
	5	* (i.e. the buffers are not linear in physical memory, but fragmented
	6	* into PAGE_SIZE chunks). They also assume the driver does not need
	7	* to touch the video data.
	8	*
	9	* (c) 2007 Mauro Carvalho Chehab, <mchehab@infradead.org>
	10	*
	11	* Highly based on video-buf written originally by:
	12	* (c) 2001,02 Gerd Knorr <kraxel@bytesex.org>
	13	* (c) 2006 Mauro Carvalho Chehab, <mchehab@infradead.org>
	14	* (c) 2006 Ted Walther and John Sokol
	15	*
	16	* This program is free software; you can redistribute it and/or modify
	17	* it under the terms of the GNU General Public License as published by
	18	* the Free Software Foundation; either version 2
	19	*/
	20
	21	#include <linux/init.h>
	22	#include <linux/module.h>
	23	#include <linux/moduleparam.h>
	24	#include <linux/slab.h>
	25	#include <linux/interrupt.h>
	26
	27	#include <linux/pci.h>
	28	#include <linux/vmalloc.h>
	29	#include <linux/pagemap.h>
11763609	30	#include <linux/scatterlist.h>
7a7d9a89 MCC	31	#include <asm/page.h>
	32	#include <asm/pgtable.h>
	33
	34	#include <media/videobuf-dma-sg.h>
	35
	36	#define MAGIC_DMABUF 0x19721112
	37	#define MAGIC_SG_MEM 0x17890714
	38
	39	#define MAGIC_CHECK(is,should) if (unlikely((is) != (should))) \
	40	{ printk(KERN_ERR "magic mismatch: %x (expected %x)\n",is,should); BUG(); }
	41
	42	static int debug = 0;
	43	module_param(debug, int, 0644);
	44
	45	MODULE_DESCRIPTION("helper module to manage video4linux pci dma sg buffers");
	46	MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@infradead.org>");
	47	MODULE_LICENSE("GPL");
	48
	49	#define dprintk(level, fmt, arg...) if (debug >= level) \
	50	printk(KERN_DEBUG "vbuf-sg: " fmt , ## arg)
	51
	52	/* --------------------------------------------------------------------- */
	53
	54	struct scatterlist*
	55	videobuf_vmalloc_to_sg(unsigned char *virt, int nr_pages)
	56	{
	57	struct scatterlist *sglist;
	58	struct page *pg;
	59	int i;
	60
	61	sglist = kcalloc(nr_pages, sizeof(struct scatterlist), GFP_KERNEL);
	62	if (NULL == sglist)
	63	return NULL;
45711f1a	64	sg_init_table(sglist, nr_pages);
7a7d9a89 MCC	65	for (i = 0; i < nr_pages; i++, virt += PAGE_SIZE) {
	66	pg = vmalloc_to_page(virt);
	67	if (NULL == pg)
	68	goto err;
	69	BUG_ON(PageHighMem(pg));
642f1490	70	sg_set_page(&sglist[i], pg, PAGE_SIZE, 0);
7a7d9a89 MCC	71	}
	72	return sglist;
	73
	74	err:
	75	kfree(sglist);
	76	return NULL;
	77	}
	78
	79	struct scatterlist*
	80	videobuf_pages_to_sg(struct page **pages, int nr_pages, int offset)
	81	{
	82	struct scatterlist *sglist;
	83	int i = 0;
	84
	85	if (NULL == pages[0])
	86	return NULL;
	87	sglist = kcalloc(nr_pages, sizeof(*sglist), GFP_KERNEL);
	88	if (NULL == sglist)
	89	return NULL;
45711f1a	90	sg_init_table(sglist, nr_pages);
7a7d9a89 MCC	91
	92	if (NULL == pages[0])
	93	goto nopage;
	94	if (PageHighMem(pages[0]))
	95	/* DMA to highmem pages might not work */
	96	goto highmem;
642f1490	97	sg_set_page(&sglist[0], pages[0], PAGE_SIZE - offset, offset);
7a7d9a89 MCC	98	for (i = 1; i < nr_pages; i++) {
	99	if (NULL == pages[i])
	100	goto nopage;
	101	if (PageHighMem(pages[i]))
	102	goto highmem;
642f1490	103	sg_set_page(&sglist[i], pages[i], PAGE_SIZE, 0);
7a7d9a89 MCC	104	}
	105	return sglist;
	106
	107	nopage:
	108	dprintk(2,"sgl: oops - no page\n");
	109	kfree(sglist);
	110	return NULL;
	111
	112	highmem:
	113	dprintk(2,"sgl: oops - highmem page\n");
	114	kfree(sglist);
	115	return NULL;
	116	}
	117
	118	/* --------------------------------------------------------------------- */
	119
	120	struct videobuf_dmabuf videobuf_to_dma (struct videobuf_buffer buf)
	121	{
	122	struct videbuf_pci_sg_memory *mem=buf->priv;
	123	BUG_ON (!mem);
	124
	125	MAGIC_CHECK(mem->magic,MAGIC_SG_MEM);
	126
	127	return &mem->dma;
	128	}
	129
	130	void videobuf_dma_init(struct videobuf_dmabuf *dma)
	131	{
	132	memset(dma,0,sizeof(*dma));
	133	dma->magic = MAGIC_DMABUF;
	134	}
	135
9900132f ML	136	static int videobuf_dma_init_user_locked(struct videobuf_dmabuf *dma,
9900132f ML	137	int direction, unsigned long data, unsigned long size)
7a7d9a89 MCC	138	{
	139	unsigned long first,last;
	140	int err, rw = 0;
	141
	142	dma->direction = direction;
	143	switch (dma->direction) {
	144	case PCI_DMA_FROMDEVICE: rw = READ; break;
	145	case PCI_DMA_TODEVICE: rw = WRITE; break;
	146	default: BUG();
	147	}
	148
	149	first = (data & PAGE_MASK) >> PAGE_SHIFT;
	150	last = ((data+size-1) & PAGE_MASK) >> PAGE_SHIFT;
	151	dma->offset = data & ~PAGE_MASK;
	152	dma->nr_pages = last-first+1;
	153	dma->pages = kmalloc(dma->nr_pages * sizeof(struct page*),
	154	GFP_KERNEL);
	155	if (NULL == dma->pages)
	156	return -ENOMEM;
	157	dprintk(1,"init user [0x%lx+0x%lx => %d pages]\n",
	158	data,size,dma->nr_pages);
	159
	160	dma->varea = (void *) data;
	161
9900132f	162
7a7d9a89 MCC	163	err = get_user_pages(current,current->mm,
	164	data & PAGE_MASK, dma->nr_pages,
	165	rw == READ, 1, /* force */
	166	dma->pages, NULL);
9900132f	167
7a7d9a89 MCC	168	if (err != dma->nr_pages) {
	169	dma->nr_pages = (err >= 0) ? err : 0;
	170	dprintk(1,"get_user_pages: err=%d [%d]\n",err,dma->nr_pages);
	171	return err < 0 ? err : -EINVAL;
	172	}
	173	return 0;
	174	}
	175
9900132f ML	176	int videobuf_dma_init_user(struct videobuf_dmabuf *dma, int direction,
	177	unsigned long data, unsigned long size)
	178	{
	179	int ret;
	180	down_read(&current->mm->mmap_sem);
	181	ret = videobuf_dma_init_user_locked(dma, direction, data, size);
	182	up_read(&current->mm->mmap_sem);
	183
	184	return ret;
	185	}
	186
7a7d9a89 MCC	187	int videobuf_dma_init_kernel(struct videobuf_dmabuf *dma, int direction,
	188	int nr_pages)
	189	{
	190	dprintk(1,"init kernel [%d pages]\n",nr_pages);
	191	dma->direction = direction;
	192	dma->vmalloc = vmalloc_32(nr_pages << PAGE_SHIFT);
	193	if (NULL == dma->vmalloc) {
	194	dprintk(1,"vmalloc_32(%d pages) failed\n",nr_pages);
	195	return -ENOMEM;
	196	}
	197	dprintk(1,"vmalloc is at addr 0x%08lx, size=%d\n",
	198	(unsigned long)dma->vmalloc,
	199	nr_pages << PAGE_SHIFT);
	200	memset(dma->vmalloc,0,nr_pages << PAGE_SHIFT);
	201	dma->nr_pages = nr_pages;
	202	return 0;
	203	}
	204
	205	int videobuf_dma_init_overlay(struct videobuf_dmabuf *dma, int direction,
	206	dma_addr_t addr, int nr_pages)
	207	{
	208	dprintk(1,"init overlay [%d pages @ bus 0x%lx]\n",
	209	nr_pages,(unsigned long)addr);
	210	dma->direction = direction;
	211	if (0 == addr)
	212	return -EINVAL;
	213
	214	dma->bus_addr = addr;
	215	dma->nr_pages = nr_pages;
	216	return 0;
	217	}
	218
	219	int videobuf_dma_map(struct videobuf_queue* q,struct videobuf_dmabuf *dma)
	220	{
	221	void *dev=q->dev;
7a7d9a89 MCC	222
	223	MAGIC_CHECK(dma->magic,MAGIC_DMABUF);
	224	BUG_ON(0 == dma->nr_pages);
	225
	226	if (dma->pages) {
	227	dma->sglist = videobuf_pages_to_sg(dma->pages, dma->nr_pages,
	228	dma->offset);
	229	}
	230	if (dma->vmalloc) {
	231	dma->sglist = videobuf_vmalloc_to_sg
	232	(dma->vmalloc,dma->nr_pages);
	233	}
	234	if (dma->bus_addr) {
	235	dma->sglist = kmalloc(sizeof(struct scatterlist), GFP_KERNEL);
	236	if (NULL != dma->sglist) {
	237	dma->sglen = 1;
	238	sg_dma_address(&dma->sglist[0]) = dma->bus_addr & PAGE_MASK;
	239	dma->sglist[0].offset = dma->bus_addr & ~PAGE_MASK;
	240	sg_dma_len(&dma->sglist[0]) = dma->nr_pages * PAGE_SIZE;
	241	}
	242	}
	243	if (NULL == dma->sglist) {
	244	dprintk(1,"scatterlist is NULL\n");
	245	return -ENOMEM;
	246	}
	247	if (!dma->bus_addr) {
5ddff434	248	dma->sglen = pci_map_sg(dev,dma->sglist,
7a7d9a89	249	dma->nr_pages, dma->direction);
7a7d9a89 MCC	250	if (0 == dma->sglen) {
	251	printk(KERN_WARNING
	252	"%s: videobuf_map_sg failed\n",__FUNCTION__);
	253	kfree(dma->sglist);
	254	dma->sglist = NULL;
	255	dma->sglen = 0;
	256	return -EIO;
	257	}
	258	}
	259	return 0;
	260	}
	261
	262	int videobuf_dma_sync(struct videobuf_queue q,struct videobuf_dmabuf dma)
	263	{
	264	void *dev=q->dev;
7a7d9a89 MCC	265
	266	MAGIC_CHECK(dma->magic,MAGIC_DMABUF);
	267	BUG_ON(!dma->sglen);
	268
5ddff434	269	pci_dma_sync_sg_for_cpu (dev,dma->sglist,dma->nr_pages,dma->direction);
7a7d9a89 MCC	270	return 0;
	271	}
	272
	273	int videobuf_dma_unmap(struct videobuf_queue* q,struct videobuf_dmabuf *dma)
	274	{
	275	void *dev=q->dev;
7a7d9a89 MCC	276
	277	MAGIC_CHECK(dma->magic,MAGIC_DMABUF);
	278	if (!dma->sglen)
	279	return 0;
	280
5ddff434 MCC	281	pci_unmap_sg (dev,dma->sglist,dma->nr_pages,dma->direction);
5ddff434 MCC	282
7a7d9a89 MCC	283	kfree(dma->sglist);
	284	dma->sglist = NULL;
	285	dma->sglen = 0;
	286	return 0;
	287	}
	288
	289	int videobuf_dma_free(struct videobuf_dmabuf *dma)
	290	{
	291	MAGIC_CHECK(dma->magic,MAGIC_DMABUF);
	292	BUG_ON(dma->sglen);
	293
	294	if (dma->pages) {
	295	int i;
	296	for (i=0; i < dma->nr_pages; i++)
	297	page_cache_release(dma->pages[i]);
	298	kfree(dma->pages);
	299	dma->pages = NULL;
	300	}
	301
	302	vfree(dma->vmalloc);
	303	dma->vmalloc = NULL;
	304	dma->varea = NULL;
	305
	306	if (dma->bus_addr) {
	307	dma->bus_addr = 0;
	308	}
	309	dma->direction = PCI_DMA_NONE;
	310	return 0;
	311	}
	312
	313	/* --------------------------------------------------------------------- */
	314
	315	int videobuf_pci_dma_map(struct pci_dev pci,struct videobuf_dmabuf dma)
	316	{
	317	struct videobuf_queue q;
7a7d9a89 MCC	318
7a7d9a89 MCC	319	q.dev=pci;
7a7d9a89 MCC	320
	321	return (videobuf_dma_map(&q,dma));
	322	}
	323
	324	int videobuf_pci_dma_unmap(struct pci_dev pci,struct videobuf_dmabuf dma)
	325	{
	326	struct videobuf_queue q;
7a7d9a89 MCC	327
7a7d9a89 MCC	328	q.dev=pci;
7a7d9a89 MCC	329
	330	return (videobuf_dma_unmap(&q,dma));
	331	}
	332
	333	/* --------------------------------------------------------------------- */
	334
	335	static void
	336	videobuf_vm_open(struct vm_area_struct *vma)
	337	{
	338	struct videobuf_mapping *map = vma->vm_private_data;
	339
	340	dprintk(2,"vm_open %p [count=%d,vma=%08lx-%08lx]\n",map,
	341	map->count,vma->vm_start,vma->vm_end);
	342	map->count++;
	343	}
	344
	345	static void
	346	videobuf_vm_close(struct vm_area_struct *vma)
	347	{
	348	struct videobuf_mapping *map = vma->vm_private_data;
	349	struct videobuf_queue *q = map->q;
	350	struct videbuf_pci_sg_memory *mem;
	351	int i;
	352
	353	dprintk(2,"vm_close %p [count=%d,vma=%08lx-%08lx]\n",map,
	354	map->count,vma->vm_start,vma->vm_end);
	355
	356	map->count--;
	357	if (0 == map->count) {
	358	dprintk(1,"munmap %p q=%p\n",map,q);
64f9477f	359	mutex_lock(&q->vb_lock);
7a7d9a89 MCC	360	for (i = 0; i < VIDEO_MAX_FRAME; i++) {
	361	if (NULL == q->bufs[i])
	362	continue;
	363	mem=q->bufs[i]->priv;
	364
	365	if (!mem)
	366	continue;
	367
	368	MAGIC_CHECK(mem->magic,MAGIC_SG_MEM);
	369
851c0c96	370	if (q->bufs[i]->map != map)
7a7d9a89	371	continue;
851c0c96	372	q->bufs[i]->map = NULL;
7a7d9a89 MCC	373	q->bufs[i]->baddr = 0;
	374	q->ops->buf_release(q,q->bufs[i]);
	375	}
64f9477f	376	mutex_unlock(&q->vb_lock);
7a7d9a89 MCC	377	kfree(map);
	378	}
	379	return;
	380	}
	381
	382	/*
	383	* Get a anonymous page for the mapping. Make sure we can DMA to that
	384	* memory location with 32bit PCI devices (i.e. don't use highmem for
	385	* now ...). Bounce buffers don't work very well for the data rates
	386	* video capture has.
	387	*/
105354a0 NP	388	static int
105354a0 NP	389	videobuf_vm_fault(struct vm_area_struct vma, struct vm_fault vmf)
7a7d9a89 MCC	390	{
	391	struct page *page;
	392
105354a0 NP	393	dprintk(3,"fault: fault @ %08lx [vma %08lx-%08lx]\n",
105354a0 NP	394	(unsigned long)vmf->virtual_address,vma->vm_start,vma->vm_end);
7a7d9a89 MCC	395	page = alloc_page(GFP_USER \| __GFP_DMA32);
7a7d9a89 MCC	396	if (!page)
105354a0	397	return VM_FAULT_OOM;
d172b8bd AM	398	clear_user_page(page_address(page), (unsigned long)vmf->virtual_address,
d172b8bd AM	399	page);
105354a0 NP	400	vmf->page = page;
105354a0 NP	401	return 0;
7a7d9a89 MCC	402	}
	403
	404	static struct vm_operations_struct videobuf_vm_ops =
	405	{
	406	.open = videobuf_vm_open,
	407	.close = videobuf_vm_close,
105354a0	408	.fault = videobuf_vm_fault,
7a7d9a89 MCC	409	};
	410
	411	/* ---------------------------------------------------------------------
	412	* PCI handlers for the generic methods
	413	*/
	414
	415	/* Allocated area consists on 3 parts:
	416	struct video_buffer
	417	struct <driver>_buffer (cx88_buffer, saa7134_buf, ...)
	418	struct videobuf_pci_sg_memory
	419	*/
	420
	421	static void *__videobuf_alloc(size_t size)
	422	{
	423	struct videbuf_pci_sg_memory *mem;
	424	struct videobuf_buffer *vb;
	425
	426	vb = kzalloc(size+sizeof(*mem),GFP_KERNEL);
	427
	428	mem = vb->priv = ((char *)vb)+size;
	429	mem->magic=MAGIC_SG_MEM;
	430
	431	videobuf_dma_init(&mem->dma);
	432
	433	dprintk(1,"%s: allocated at %p(%ld+%ld) & %p(%ld)\n",
	434	__FUNCTION__,vb,(long)sizeof(vb),(long)size-sizeof(vb),
	435	mem,(long)sizeof(*mem));
	436
	437	return vb;
	438	}
	439
	440	static int __videobuf_iolock (struct videobuf_queue* q,
	441	struct videobuf_buffer *vb,
	442	struct v4l2_framebuffer *fbuf)
	443	{
	444	int err,pages;
	445	dma_addr_t bus;
	446	struct videbuf_pci_sg_memory *mem=vb->priv;
	447	BUG_ON(!mem);
	448
	449	MAGIC_CHECK(mem->magic,MAGIC_SG_MEM);
	450
	451	switch (vb->memory) {
	452	case V4L2_MEMORY_MMAP:
	453	case V4L2_MEMORY_USERPTR:
	454	if (0 == vb->baddr) {
	455	/* no userspace addr -- kernel bounce buffer */
	456	pages = PAGE_ALIGN(vb->size) >> PAGE_SHIFT;
	457	err = videobuf_dma_init_kernel( &mem->dma,
	458	PCI_DMA_FROMDEVICE,
	459	pages );
	460	if (0 != err)
	461	return err;
9900132f	462	} else if (vb->memory == V4L2_MEMORY_USERPTR) {
7a7d9a89 MCC	463	/* dma directly to userspace */
	464	err = videobuf_dma_init_user( &mem->dma,
	465	PCI_DMA_FROMDEVICE,
	466	vb->baddr,vb->bsize );
	467	if (0 != err)
	468	return err;
9900132f ML	469	} else {
	470	/* NOTE: HACK: videobuf_iolock on V4L2_MEMORY_MMAP
	471	buffers can only be called from videobuf_qbuf
	472	we take current->mm->mmap_sem there, to prevent
	473	locking inversion, so don't take it here */
	474
	475	err = videobuf_dma_init_user_locked(&mem->dma,
	476	PCI_DMA_FROMDEVICE,
	477	vb->baddr, vb->bsize);
	478	if (0 != err)
	479	return err;
7a7d9a89 MCC	480	}
	481	break;
	482	case V4L2_MEMORY_OVERLAY:
	483	if (NULL == fbuf)
	484	return -EINVAL;
	485	/* FIXME: need sanity checks for vb->boff */
	486	/*
	487	* Using a double cast to avoid compiler warnings when
	488	* building for PAE. Compiler doesn't like direct casting
	489	* of a 32 bit ptr to 64 bit integer.
	490	*/
	491	bus = (dma_addr_t)(unsigned long)fbuf->base + vb->boff;
	492	pages = PAGE_ALIGN(vb->size) >> PAGE_SHIFT;
	493	err = videobuf_dma_init_overlay(&mem->dma,PCI_DMA_FROMDEVICE,
	494	bus, pages);
	495	if (0 != err)
	496	return err;
	497	break;
	498	default:
	499	BUG();
	500	}
	501	err = videobuf_dma_map(q,&mem->dma);
	502	if (0 != err)
	503	return err;
	504
	505	return 0;
	506	}
	507
	508	static int __videobuf_sync(struct videobuf_queue *q,
	509	struct videobuf_buffer *buf)
	510	{
	511	struct videbuf_pci_sg_memory *mem=buf->priv;
	512	BUG_ON (!mem);
	513	MAGIC_CHECK(mem->magic,MAGIC_SG_MEM);
	514
	515	return videobuf_dma_sync(q,&mem->dma);
	516	}
	517
	518	static int __videobuf_mmap_free(struct videobuf_queue *q)
	519	{
	520	int i;
	521
	522	for (i = 0; i < VIDEO_MAX_FRAME; i++) {
	523	if (q->bufs[i]) {
851c0c96	524	if (q->bufs[i]->map)
7a7d9a89 MCC	525	return -EBUSY;
	526	}
	527	}
	528
	529	return 0;
	530	}
	531
	532	static int __videobuf_mmap_mapper(struct videobuf_queue *q,
	533	struct vm_area_struct *vma)
	534	{
	535	struct videbuf_pci_sg_memory *mem;
	536	struct videobuf_mapping *map;
	537	unsigned int first,last,size,i;
	538	int retval;
	539
	540	retval = -EINVAL;
	541	if (!(vma->vm_flags & VM_WRITE)) {
	542	dprintk(1,"mmap app bug: PROT_WRITE please\n");
	543	goto done;
	544	}
	545	if (!(vma->vm_flags & VM_SHARED)) {
	546	dprintk(1,"mmap app bug: MAP_SHARED please\n");
	547	goto done;
	548	}
	549
	550	/* look for first buffer to map */
	551	for (first = 0; first < VIDEO_MAX_FRAME; first++) {
	552	if (NULL == q->bufs[first])
	553	continue;
	554	mem=q->bufs[first]->priv;
	555	BUG_ON (!mem);
	556	MAGIC_CHECK(mem->magic,MAGIC_SG_MEM);
	557
	558	if (V4L2_MEMORY_MMAP != q->bufs[first]->memory)
	559	continue;
	560	if (q->bufs[first]->boff == (vma->vm_pgoff << PAGE_SHIFT))
	561	break;
	562	}
	563	if (VIDEO_MAX_FRAME == first) {
	564	dprintk(1,"mmap app bug: offset invalid [offset=0x%lx]\n",
	565	(vma->vm_pgoff << PAGE_SHIFT));
	566	goto done;
	567	}
	568
	569	/* look for last buffer to map */
	570	for (size = 0, last = first; last < VIDEO_MAX_FRAME; last++) {
	571	if (NULL == q->bufs[last])
	572	continue;
	573	if (V4L2_MEMORY_MMAP != q->bufs[last]->memory)
	574	continue;
851c0c96	575	if (q->bufs[last]->map) {
7a7d9a89 MCC	576	retval = -EBUSY;
	577	goto done;
	578	}
	579	size += q->bufs[last]->bsize;
	580	if (size == (vma->vm_end - vma->vm_start))
	581	break;
	582	}
	583	if (VIDEO_MAX_FRAME == last) {
	584	dprintk(1,"mmap app bug: size invalid [size=0x%lx]\n",
	585	(vma->vm_end - vma->vm_start));
	586	goto done;
	587	}
	588
	589	/* create mapping + update buffer list */
	590	retval = -ENOMEM;
	591	map = kmalloc(sizeof(struct videobuf_mapping),GFP_KERNEL);
	592	if (NULL == map)
	593	goto done;
	594	for (size = 0, i = first; i <= last; size += q->bufs[i++]->bsize) {
851c0c96	595	q->bufs[i]->map = map;
7a7d9a89 MCC	596	q->bufs[i]->baddr = vma->vm_start + size;
	597	}
	598	map->count = 1;
	599	map->start = vma->vm_start;
	600	map->end = vma->vm_end;
	601	map->q = q;
	602	vma->vm_ops = &videobuf_vm_ops;
	603	vma->vm_flags \|= VM_DONTEXPAND \| VM_RESERVED;
	604	vma->vm_flags &= ~VM_IO; /* using shared anonymous pages */
	605	vma->vm_private_data = map;
	606	dprintk(1,"mmap %p: q=%p %08lx-%08lx pgoff %08lx bufs %d-%d\n",
	607	map,q,vma->vm_start,vma->vm_end,vma->vm_pgoff,first,last);
	608	retval = 0;
	609
	610	done:
	611	return retval;
	612	}
	613
7a7d9a89 MCC	614	static int __videobuf_copy_to_user ( struct videobuf_queue *q,
	615	char __user *data, size_t count,
	616	int nonblocking )
	617	{
	618	struct videbuf_pci_sg_memory *mem=q->read_buf->priv;
	619	BUG_ON (!mem);
	620	MAGIC_CHECK(mem->magic,MAGIC_SG_MEM);
	621
	622	/* copy to userspace */
	623	if (count > q->read_buf->size - q->read_off)
	624	count = q->read_buf->size - q->read_off;
	625
	626	if (copy_to_user(data, mem->dma.vmalloc+q->read_off, count))
	627	return -EFAULT;
	628
	629	return count;
	630	}
	631
	632	static int __videobuf_copy_stream ( struct videobuf_queue *q,
	633	char __user *data, size_t count, size_t pos,
	634	int vbihack, int nonblocking )
	635	{
	636	unsigned int *fc;
	637	struct videbuf_pci_sg_memory *mem=q->read_buf->priv;
	638	BUG_ON (!mem);
	639	MAGIC_CHECK(mem->magic,MAGIC_SG_MEM);
	640
	641	if (vbihack) {
	642	/* dirty, undocumented hack -- pass the frame counter
	643	* within the last four bytes of each vbi data block.
	644	* We need that one to maintain backward compatibility
	645	* to all vbi decoding software out there ... */
	646	fc = (unsigned int*)mem->dma.vmalloc;
	647	fc += (q->read_buf->size>>2) -1;
	648	*fc = q->read_buf->field_count >> 1;
	649	dprintk(1,"vbihack: %d\n",*fc);
	650	}
	651
	652	/* copy stuff using the common method */
	653	count = __videobuf_copy_to_user (q,data,count,nonblocking);
	654
	655	if ( (count==-EFAULT) && (0 == pos) )
	656	return -EFAULT;
	657
	658	return count;
	659	}
	660
	661	static struct videobuf_qtype_ops pci_ops = {
	662	.magic = MAGIC_QTYPE_OPS,
	663
	664	.alloc = __videobuf_alloc,
	665	.iolock = __videobuf_iolock,
	666	.sync = __videobuf_sync,
	667	.mmap_free = __videobuf_mmap_free,
	668	.mmap_mapper = __videobuf_mmap_mapper,
13bcd5d0	669	.video_copy_to_user = __videobuf_copy_to_user,
7a7d9a89 MCC	670	.copy_stream = __videobuf_copy_stream,
	671	};
	672
	673	void *videobuf_pci_alloc (size_t size)
	674	{
	675	struct videobuf_queue q;
	676
	677	/* Required to make generic handler to call __videobuf_alloc */
	678	q.int_ops=&pci_ops;
	679
	680	q.msize=size;
	681
	682	return videobuf_alloc (&q);
	683	}
	684
	685	void videobuf_queue_pci_init(struct videobuf_queue* q,
	686	struct videobuf_queue_ops *ops,
	687	void *dev,
	688	spinlock_t *irqlock,
	689	enum v4l2_buf_type type,
	690	enum v4l2_field field,
	691	unsigned int msize,
	692	void *priv)
	693	{
d4cae5a5 MCC	694	videobuf_queue_core_init(q, ops, dev, irqlock, type, field, msize,
d4cae5a5 MCC	695	priv, &pci_ops);
7a7d9a89 MCC	696	}
7a7d9a89 MCC	697
7a7d9a89 MCC	698	/* --------------------------------------------------------------------- */
	699
	700	EXPORT_SYMBOL_GPL(videobuf_vmalloc_to_sg);
	701
	702	EXPORT_SYMBOL_GPL(videobuf_to_dma);
	703	EXPORT_SYMBOL_GPL(videobuf_dma_init);
	704	EXPORT_SYMBOL_GPL(videobuf_dma_init_user);
	705	EXPORT_SYMBOL_GPL(videobuf_dma_init_kernel);
	706	EXPORT_SYMBOL_GPL(videobuf_dma_init_overlay);
	707	EXPORT_SYMBOL_GPL(videobuf_dma_map);
	708	EXPORT_SYMBOL_GPL(videobuf_dma_sync);
	709	EXPORT_SYMBOL_GPL(videobuf_dma_unmap);
	710	EXPORT_SYMBOL_GPL(videobuf_dma_free);
	711
	712	EXPORT_SYMBOL_GPL(videobuf_pci_dma_map);
	713	EXPORT_SYMBOL_GPL(videobuf_pci_dma_unmap);
	714	EXPORT_SYMBOL_GPL(videobuf_pci_alloc);
	715
	716	EXPORT_SYMBOL_GPL(videobuf_queue_pci_init);
7a7d9a89 MCC	717
	718	/*
	719	* Local variables:
	720	* c-basic-offset: 8
	721	* End:
	722	*/