V4L/DVB (11242): allow v4l2 drivers to provide a get_unmapped_area handler

Shared memory mappings on nommu machines require a get_unmapped_area
file operation that suggests an address for the mapping. This patch
adds a way for v4l2 drivers to provide this callback.

Signed-off-by: Daniel Glöckner <dg@emlix.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This commit is contained in:
Daniel Glöckner 2009-03-26 11:31:08 -03:00 committed by Mauro Carvalho Chehab
parent 8737f66e64
commit c01f1a5a24
2 changed files with 21 additions and 0 deletions

View File

@ -198,6 +198,23 @@ static long v4l2_unlocked_ioctl(struct file *filp,
return vdev->fops->unlocked_ioctl(filp, cmd, arg);
}
#ifdef CONFIG_MMU
#define v4l2_get_unmapped_area NULL
#else
static unsigned long v4l2_get_unmapped_area(struct file *filp,
unsigned long addr, unsigned long len, unsigned long pgoff,
unsigned long flags)
{
struct video_device *vdev = video_devdata(filp);
if (!vdev->fops->get_unmapped_area)
return -ENOSYS;
if (video_is_unregistered(vdev))
return -ENODEV;
return vdev->fops->get_unmapped_area(filp, addr, len, pgoff, flags);
}
#endif
static int v4l2_mmap(struct file *filp, struct vm_area_struct *vm)
{
struct video_device *vdev = video_devdata(filp);
@ -250,6 +267,7 @@ static const struct file_operations v4l2_unlocked_fops = {
.read = v4l2_read,
.write = v4l2_write,
.open = v4l2_open,
.get_unmapped_area = v4l2_get_unmapped_area,
.mmap = v4l2_mmap,
.unlocked_ioctl = v4l2_unlocked_ioctl,
#ifdef CONFIG_COMPAT
@ -265,6 +283,7 @@ static const struct file_operations v4l2_fops = {
.read = v4l2_read,
.write = v4l2_write,
.open = v4l2_open,
.get_unmapped_area = v4l2_get_unmapped_area,
.mmap = v4l2_mmap,
.ioctl = v4l2_ioctl,
#ifdef CONFIG_COMPAT

View File

@ -40,6 +40,8 @@ struct v4l2_file_operations {
unsigned int (*poll) (struct file *, struct poll_table_struct *);
long (*ioctl) (struct file *, unsigned int, unsigned long);
long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
unsigned long (*get_unmapped_area) (struct file *, unsigned long,
unsigned long, unsigned long, unsigned long);
int (*mmap) (struct file *, struct vm_area_struct *);
int (*open) (struct file *);
int (*release) (struct file *);