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@xxxxxxxxx>
---
drivers/media/video/v4l2-dev.c | 19 +++++++++++++++++++
include/media/v4l2-dev.h | 2 ++
2 files changed, 21 insertions(+), 0 deletions(-)
diff --git a/drivers/media/video/v4l2-dev.c b/drivers/media/video/v4l2-dev.c
index 13f87c2..8c84037 100644
--- a/drivers/media/video/v4l2-dev.c
+++ b/drivers/media/video/v4l2-dev.c
@@ -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
diff --git a/include/media/v4l2-dev.h b/include/media/v4l2-dev.h
index e36faab..2058dd4 100644
--- a/include/media/v4l2-dev.h
+++ b/include/media/v4l2-dev.h
@@ -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 *);
--
1.6.2.107.ge47ee
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