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Commit 968ced78 authored by Mauro Carvalho Chehab's avatar Mauro Carvalho Chehab
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V4L/DVB (7552): videbuf-vmalloc: Corrects mmap code 



There were some bugs on videobuf-vmalloc.

Basically, remap were called with a wrong parameter. Due to that, a later remap
were needed, generating the need of some hacks on videobuf-vmalloc and
videobuf-core.

This patch fixes the remap and removes the hacks.

TODO:

- V4L2_MEMORY_USERPTR is not implemented yet. This method should be
  properly implemented, in order to work with a few userspace applications.

- The driver also doesn't implement V4L2_MEMORY_OVERLAY. This method is used
  only by a few applications, and are becaming obsolete, due to the increment
  of cpu performance. So, most apps prefer to retrieve data to an internal
  buffer, doing some processing like de-interlacing.

Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@infradead.org>
parent fbde31d5

drivers/media/video/videobuf-core.c

+0 −14
Original line number Diff line number Diff line
@@ -91,20 +91,6 @@ int videobuf_iolock(struct videobuf_queue *q, struct videobuf_buffer *vb, 
	MAGIC_CHECK(vb->magic, MAGIC_BUFFER);

	MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);



	/* This is required to avoid OOPS on some cases,

	   since mmap_mapper() method should be called before _iolock.

	   On some cases, the mmap_mapper() is called only after scheduling.

	 */

	if (vb->memory == V4L2_MEMORY_MMAP) {

		wait_event_timeout(vb->done, q->is_mmapped,

				   msecs_to_jiffies(100));

		if (!q->is_mmapped) {

			printk(KERN_ERR

			       "Error: mmap_mapper() never called!\n");

			return -EINVAL;

		}

	}



	return CALL(q, iolock, q, vb, fbuf);

}

drivers/media/video/videobuf-vmalloc.c

+105 −58
Original line number Diff line number Diff line
@@ -124,45 +124,75 @@ static int __videobuf_iolock (struct videobuf_queue* q, 
			      struct videobuf_buffer *vb,

			      struct v4l2_framebuffer *fbuf)

{

	int pages;

	struct videobuf_vmalloc_memory *mem = vb->priv;



	BUG_ON(!mem);



	MAGIC_CHECK(mem->magic, MAGIC_VMAL_MEM);



	pages = PAGE_ALIGN(vb->size) >> PAGE_SHIFT;

	switch (vb->memory) {

	case V4L2_MEMORY_MMAP:

		dprintk(1, "%s memory method MMAP\n", __func__);



	/* Currently, doesn't support V4L2_MEMORY_OVERLAY */

	if ((vb->memory != V4L2_MEMORY_MMAP) &&

				(vb->memory != V4L2_MEMORY_USERPTR) ) {

		printk(KERN_ERR "Method currently unsupported.\n");

		/* All handling should be done by __videobuf_mmap_mapper() */

		if (!mem->vmalloc) {

			printk(KERN_ERR "memory is not alloced/mmapped.\n");

			return -EINVAL;

		}

		break;

	case V4L2_MEMORY_USERPTR:

	{

		int pages = PAGE_ALIGN(vb->size);



		dprintk(1, "%s memory method USERPTR\n", __func__);



#if 1

		if (vb->baddr) {

			printk(KERN_ERR "USERPTR is currently not supported\n");

			return -EINVAL;

		}

#endif



		/* The only USERPTR currently supported is the one needed for

		   read() method.

		 */



	/* FIXME: should be tested with kernel mmap mem */

	mem->vmalloc=vmalloc_user (PAGE_ALIGN(vb->size));

	if (NULL == mem->vmalloc) {

		mem->vmalloc = vmalloc_user(pages);

		if (!mem->vmalloc) {

			printk(KERN_ERR "vmalloc (%d pages) failed\n", pages);

			return -ENOMEM;

		}

		dprintk(1, "vmalloc is at addr %p (%d pages)\n",

			mem->vmalloc, pages);



	dprintk(1,"vmalloc is at addr 0x%08lx, size=%d\n",

				(unsigned long)mem->vmalloc,

				pages << PAGE_SHIFT);

#if 0

		int rc;

		/* Kernel userptr is used also by read() method. In this case,

		   there's no need to remap, since data will be copied to user

		 */

		if (!vb->baddr)

			return 0;



	/* It seems that some kernel versions need to do remap *after*

	   the mmap() call

		/* FIXME: to properly support USERPTR, remap should occur.

		   The code bellow won't work, since mem->vma = NULL

		 */

	if (mem->vma) {

		int retval=remap_vmalloc_range(mem->vma, mem->vmalloc,0);

		kfree(mem->vma);

		mem->vma=NULL;

		if (retval<0) {

			dprintk(1,"mmap app bug: remap_vmalloc_range area %p error %d\n",

				mem->vmalloc,retval);

			return retval;

		/* Try to remap memory */

		rc = remap_vmalloc_range(mem->vma, (void *)vb->baddr, 0);

		if (rc < 0) {

			printk(KERN_ERR "mmap: remap failed with error %d. ", rc);

			return -ENOMEM;

		}

#endif



		break;

	}

	case V4L2_MEMORY_OVERLAY:

	default:

		dprintk(1, "%s memory method OVERLAY/unknown\n", __func__);



		/* Currently, doesn't support V4L2_MEMORY_OVERLAY */

		printk(KERN_ERR "Memory method currently unsupported.\n");

		return -EINVAL;

	}



	return 0;
@@ -178,6 +208,7 @@ static int __videobuf_mmap_free(struct videobuf_queue *q) 
{

	unsigned int i;



	dprintk(1, "%s\n", __func__);

	for (i = 0; i < VIDEO_MAX_FRAME; i++) {

		if (q->bufs[i]) {

			if (q->bufs[i]->map)
@@ -194,9 +225,10 @@ static int __videobuf_mmap_mapper(struct videobuf_queue *q, 
	struct videobuf_vmalloc_memory *mem;

	struct videobuf_mapping *map;

	unsigned int first;

	int retval;

	int retval, pages;

	unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;



	dprintk(1, "%s\n", __func__);

	if (!(vma->vm_flags & VM_WRITE) || !(vma->vm_flags & VM_SHARED))

		return -EINVAL;
@@ -217,38 +249,42 @@ static int __videobuf_mmap_mapper(struct videobuf_queue *q, 
	}



	/* create mapping + update buffer list */

	map = q->bufs[first]->map = kzalloc(sizeof(struct videobuf_mapping),GFP_KERNEL);

	map = kzalloc(sizeof(struct videobuf_mapping), GFP_KERNEL);

	if (NULL == map)

		return -ENOMEM;



	q->bufs[first]->map = map;

	map->start = vma->vm_start;

	map->end   = vma->vm_end;

	map->q     = q;



	q->bufs[first]->baddr = vma->vm_start;



	vma->vm_ops          = &videobuf_vm_ops;

	vma->vm_flags       |= VM_DONTEXPAND | VM_RESERVED;

	vma->vm_private_data = map;



	mem = q->bufs[first]->priv;

	BUG_ON(!mem);

	MAGIC_CHECK(mem->magic, MAGIC_VMAL_MEM);



	pages = PAGE_ALIGN(vma->vm_end - vma->vm_start);

	mem->vmalloc = vmalloc_user(pages);

	if (!mem->vmalloc) {

		printk(KERN_ERR "vmalloc (%d pages) failed\n", pages);

		goto error;

	}

	dprintk(1, "vmalloc is at addr %p (%d pages)\n",

		mem->vmalloc, pages);



	/* Try to remap memory */

	retval = remap_vmalloc_range(vma, mem->vmalloc, 0);

	if (retval < 0) {

		dprintk(1,"mmap: postponing remap_vmalloc_range\n");



		mem->vma=kmalloc(sizeof(*vma),GFP_KERNEL);

		if (!mem->vma) {

			kfree(map);

			q->bufs[first]->map=NULL;

			return -ENOMEM;

		}

		memcpy(mem->vma,vma,sizeof(*vma));

		printk(KERN_ERR "mmap: remap failed with error %d. ", retval);

		vfree(mem->vmalloc);

		goto error;

	}



	vma->vm_ops          = &videobuf_vm_ops;

	vma->vm_flags       |= VM_DONTEXPAND | VM_RESERVED;

	vma->vm_private_data = map;



	dprintk(1,"mmap %p: q=%p %08lx-%08lx (%lx) pgoff %08lx buf %d\n",

		map, q, vma->vm_start, vma->vm_end,

		(long int) q->bufs[first]->bsize,
@@ -256,7 +292,12 @@ static int __videobuf_mmap_mapper(struct videobuf_queue *q, 


	videobuf_vm_open(vma);



	return (0);

	return 0;



error:

	mem = NULL;

	kfree(map);

	return -ENOMEM;

}



static int __videobuf_copy_to_user ( struct videobuf_queue *q,
@@ -348,13 +389,19 @@ EXPORT_SYMBOL_GPL(videobuf_to_vmalloc); 
void videobuf_vmalloc_free (struct videobuf_buffer *buf)

{

	struct videobuf_vmalloc_memory *mem = buf->priv;

	BUG_ON (!mem);



	if (!mem)

		return;



	MAGIC_CHECK(mem->magic, MAGIC_VMAL_MEM);



	vfree(mem->vmalloc);

	mem->vmalloc = NULL;







	/* FIXME: need to do buf->priv = NULL? */



	return;

}

EXPORT_SYMBOL_GPL(videobuf_vmalloc_free);