diff mbox

[1/4] v4l2: add vb2_get_unmapped_area in vb2 core

Message ID 1315938892-20243-1-git-send-email-scott.jiang.linux@gmail.com (mailing list archive)
State Changes Requested, archived
Headers

Commit Message

Scott Jiang Sept. 13, 2011, 6:34 p.m. UTC 
  no mmu system needs get_unmapped_area file operations to do mmap

Signed-off-by: Scott Jiang <scott.jiang.linux@gmail.com>
---
 drivers/media/video/videobuf2-core.c |   31 +++++++++++++++++++++++++++++++
 include/media/videobuf2-core.h       |    7 +++++++
 2 files changed, 38 insertions(+), 0 deletions(-)

Comments

Guennadi Liakhovetski Sept. 13, 2011, 8:17 a.m. UTC | #1 
On Tue, 13 Sep 2011, Scott Jiang wrote:

> no mmu system needs get_unmapped_area file operations to do mmap
> 
> Signed-off-by: Scott Jiang <scott.jiang.linux@gmail.com>
> ---
>  drivers/media/video/videobuf2-core.c |   31 +++++++++++++++++++++++++++++++
>  include/media/videobuf2-core.h       |    7 +++++++
>  2 files changed, 38 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/media/video/videobuf2-core.c b/drivers/media/video/videobuf2-core.c
> index 3015e60..02a0ec6 100644
> --- a/drivers/media/video/videobuf2-core.c
> +++ b/drivers/media/video/videobuf2-core.c
> @@ -1344,6 +1344,37 @@ int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma)
>  }
>  EXPORT_SYMBOL_GPL(vb2_mmap);
>  
> +#ifndef CONFIG_MMU
> +unsigned long vb2_get_unmapped_area(struct vb2_queue *q,
> +				    unsigned long addr,
> +				    unsigned long len,
> +				    unsigned long pgoff,
> +				    unsigned long flags)
> +{
> +	unsigned long off = pgoff << PAGE_SHIFT;
> +	struct vb2_buffer *vb;
> +	unsigned int buffer, plane;
> +	int ret;
> +
> +	if (q->memory != V4L2_MEMORY_MMAP) {
> +		dprintk(1, "Queue is not currently set up for mmap\n");
> +		return -EINVAL;
> +	}
> +
> +	/*
> +	 * Find the plane corresponding to the offset passed by userspace.
> +	 */
> +	ret = __find_plane_by_offset(q, off, &buffer, &plane);
> +	if (ret)
> +		return ret;
> +
> +	vb = q->bufs[buffer];
> +
> +	return (unsigned long)vb2_plane_vaddr(vb, plane);
> +}
> +EXPORT_SYMBOL_GPL(vb2_get_unmapped_area);

Hm, wouldn't it be better to use vb2_mmap() and provide a dummy .mmap() 
method in videobuf2-dma-contig.c for the NOMMU case?

Thanks
Guennadi

> +#endif
> +
>  static int __vb2_init_fileio(struct vb2_queue *q, int read);
>  static int __vb2_cleanup_fileio(struct vb2_queue *q);
>  
> diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
> index f87472a..5c7b5b4 100644
> --- a/include/media/videobuf2-core.h
> +++ b/include/media/videobuf2-core.h
> @@ -302,6 +302,13 @@ int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type);
>  int vb2_streamoff(struct vb2_queue *q, enum v4l2_buf_type type);
>  
>  int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma);
> +#ifndef CONFIG_MMU
> +unsigned long vb2_get_unmapped_area(struct vb2_queue *q,
> +				    unsigned long addr,
> +				    unsigned long len,
> +				    unsigned long pgoff,
> +				    unsigned long flags);
> +#endif
>  unsigned int vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait);
>  size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count,
>  		loff_t *ppos, int nonblock);
> -- 
> 1.7.0.4
> 
> 

---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/
--
To unsubscribe from this list: send the line "unsubscribe linux-media" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Scott Jiang Sept. 13, 2011, 8:36 a.m. UTC | #2 
>
> Hm, wouldn't it be better to use vb2_mmap() and provide a dummy .mmap()
> method in videobuf2-dma-contig.c for the NOMMU case?
>
these are two different file operations called by mm system.
--
To unsubscribe from this list: send the line "unsubscribe linux-media" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
diff mbox

Patch

diff --git a/drivers/media/video/videobuf2-core.c b/drivers/media/video/videobuf2-core.c
index 3015e60..02a0ec6 100644
--- a/drivers/media/video/videobuf2-core.c
+++ b/drivers/media/video/videobuf2-core.c
@@ -1344,6 +1344,37 @@  int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma)
 }
 EXPORT_SYMBOL_GPL(vb2_mmap);
 
+#ifndef CONFIG_MMU
+unsigned long vb2_get_unmapped_area(struct vb2_queue *q,
+				    unsigned long addr,
+				    unsigned long len,
+				    unsigned long pgoff,
+				    unsigned long flags)
+{
+	unsigned long off = pgoff << PAGE_SHIFT;
+	struct vb2_buffer *vb;
+	unsigned int buffer, plane;
+	int ret;
+
+	if (q->memory != V4L2_MEMORY_MMAP) {
+		dprintk(1, "Queue is not currently set up for mmap\n");
+		return -EINVAL;
+	}
+
+	/*
+	 * Find the plane corresponding to the offset passed by userspace.
+	 */
+	ret = __find_plane_by_offset(q, off, &buffer, &plane);
+	if (ret)
+		return ret;
+
+	vb = q->bufs[buffer];
+
+	return (unsigned long)vb2_plane_vaddr(vb, plane);
+}
+EXPORT_SYMBOL_GPL(vb2_get_unmapped_area);
+#endif
+
 static int __vb2_init_fileio(struct vb2_queue *q, int read);
 static int __vb2_cleanup_fileio(struct vb2_queue *q);
 
diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
index f87472a..5c7b5b4 100644
--- a/include/media/videobuf2-core.h
+++ b/include/media/videobuf2-core.h
@@ -302,6 +302,13 @@  int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type);
 int vb2_streamoff(struct vb2_queue *q, enum v4l2_buf_type type);
 
 int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma);
+#ifndef CONFIG_MMU
+unsigned long vb2_get_unmapped_area(struct vb2_queue *q,
+				    unsigned long addr,
+				    unsigned long len,
+				    unsigned long pgoff,
+				    unsigned long flags);
+#endif
 unsigned int vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait);
 size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count,
 		loff_t *ppos, int nonblock);