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* [PATCH v3] media:uvc_driver: add uvc support on no-mmu arch
@ 2011-04-21  3:17 Bob Liu
  2011-04-21  7:59 ` Daniel Glöckner
  0 siblings, 1 reply; 6+ messages in thread
From: Bob Liu @ 2011-04-21  3:17 UTC (permalink / raw)
  To: linux-media
  Cc: dhowells, linux-uvc-devel, mchehab, hverkuil, laurent.pinchart,
	sakari.ailus, martin_rubli, jarod, tj, arnd, fweisbec, agust,
	gregkh, daniel-gl, vapier, Bob Liu

UVC driver used to have partial no-mmu arch support, but it's removed by
commit c29fcff3daafbf46d64a543c1950bbd206ad8c1c.

This patch added them back and expanded to fully support no-mmu arch, so that
uvc cameras can be used on no-mmu platforms like Blackfin.

Signed-off-by: Bob Liu <lliubbo@gmail.com>
---
 drivers/media/video/uvc/uvc_queue.c |   30 ++++++++++++++++++++++++++++++
 drivers/media/video/uvc/uvc_v4l2.c  |   13 +++++++++++++
 drivers/media/video/uvc/uvcvideo.h  |    6 ++++++
 drivers/media/video/v4l2-dev.c      |   18 ++++++++++++++++++
 include/media/v4l2-dev.h            |    2 ++
 5 files changed, 69 insertions(+), 0 deletions(-)

diff --git a/drivers/media/video/uvc/uvc_queue.c b/drivers/media/video/uvc/uvc_queue.c
index f14581b..448a753 100644
--- a/drivers/media/video/uvc/uvc_queue.c
+++ b/drivers/media/video/uvc/uvc_queue.c
@@ -424,7 +424,11 @@ int uvc_queue_mmap(struct uvc_video_queue *queue, struct vm_area_struct *vma)
 			break;
 	}
 
+#ifdef CONFIG_MMU
 	if (i == queue->count || size != queue->buf_size) {
+#else
+	if (i == queue->count || PAGE_ALIGN(size) != queue->buf_size) {
+#endif
 		ret = -EINVAL;
 		goto done;
 	}
@@ -436,6 +440,7 @@ int uvc_queue_mmap(struct uvc_video_queue *queue, struct vm_area_struct *vma)
 	vma->vm_flags |= VM_IO;
 
 	addr = (unsigned long)queue->mem + buffer->buf.m.offset;
+#ifdef CONFIG_MMU
 	while (size > 0) {
 		page = vmalloc_to_page((void *)addr);
 		if ((ret = vm_insert_page(vma, start, page)) < 0)
@@ -445,6 +450,7 @@ int uvc_queue_mmap(struct uvc_video_queue *queue, struct vm_area_struct *vma)
 		addr += PAGE_SIZE;
 		size -= PAGE_SIZE;
 	}
+#endif
 
 	vma->vm_ops = &uvc_vm_ops;
 	vma->vm_private_data = buffer;
@@ -489,6 +495,30 @@ done:
 }
 
 /*
+ * Get unmapped area.
+ *
+ * NO-MMU arch need this function to make mmap() work correctly.
+ */
+unsigned long uvc_queue_get_unmapped_area(struct uvc_video_queue *queue,
+		unsigned long addr, unsigned long len, unsigned long pgoff)
+{
+	struct uvc_buffer *buffer;
+	unsigned int i;
+	int ret = 0;
+
+	mutex_lock(&queue->mutex);
+	for (i = 0; i < queue->count; ++i) {
+		buffer = &queue->buffer[i];
+		if ((buffer->buf.m.offset >> PAGE_SHIFT) == pgoff)
+			break;
+	}
+	addr = (unsigned long)queue->mem + buffer->buf.m.offset;
+	ret = addr;
+	mutex_unlock(&queue->mutex);
+	return ret;
+}
+
+/*
  * Enable or disable the video buffers queue.
  *
  * The queue must be enabled before starting video acquisition and must be
diff --git a/drivers/media/video/uvc/uvc_v4l2.c b/drivers/media/video/uvc/uvc_v4l2.c
index 9005a8d..9efab61 100644
--- a/drivers/media/video/uvc/uvc_v4l2.c
+++ b/drivers/media/video/uvc/uvc_v4l2.c
@@ -1081,6 +1081,18 @@ static unsigned int uvc_v4l2_poll(struct file *file, poll_table *wait)
 	return uvc_queue_poll(&stream->queue, file, wait);
 }
 
+static unsigned long uvc_v4l2_get_unmapped_area(struct file *file,
+		unsigned long addr, unsigned long len, unsigned long pgoff,
+		unsigned long flags)
+{
+	struct uvc_fh *handle = file->private_data;
+	struct uvc_streaming *stream = handle->stream;
+
+	uvc_trace(UVC_TRACE_CALLS, "uvc_v4l2_get_unmapped_area\n");
+
+	return uvc_queue_get_unmapped_area(&stream->queue, addr, len, pgoff);
+}
+
 const struct v4l2_file_operations uvc_fops = {
 	.owner		= THIS_MODULE,
 	.open		= uvc_v4l2_open,
@@ -1089,5 +1101,6 @@ const struct v4l2_file_operations uvc_fops = {
 	.read		= uvc_v4l2_read,
 	.mmap		= uvc_v4l2_mmap,
 	.poll		= uvc_v4l2_poll,
+	.get_unmapped_area = uvc_v4l2_get_unmapped_area,
 };
 
diff --git a/drivers/media/video/uvc/uvcvideo.h b/drivers/media/video/uvc/uvcvideo.h
index 45f01e7..48a2378 100644
--- a/drivers/media/video/uvc/uvcvideo.h
+++ b/drivers/media/video/uvc/uvcvideo.h
@@ -580,6 +580,12 @@ extern int uvc_queue_mmap(struct uvc_video_queue *queue,
 		struct vm_area_struct *vma);
 extern unsigned int uvc_queue_poll(struct uvc_video_queue *queue,
 		struct file *file, poll_table *wait);
+#ifdef CONFIG_MMU
+#define uvc_queue_get_unmapped_area NULL
+#else
+extern unsigned long uvc_queue_get_unmapped_area(struct uvc_video_queue *queue,
+		unsigned long addr, unsigned long len, unsigned long pgoff);
+#endif
 extern int uvc_queue_allocated(struct uvc_video_queue *queue);
 static inline int uvc_queue_streaming(struct uvc_video_queue *queue)
 {
diff --git a/drivers/media/video/v4l2-dev.c b/drivers/media/video/v4l2-dev.c
index 498e674..221e73f 100644
--- a/drivers/media/video/v4l2-dev.c
+++ b/drivers/media/video/v4l2-dev.c
@@ -368,6 +368,23 @@ static int v4l2_mmap(struct file *filp, struct vm_area_struct *vm)
 	return ret;
 }
 
+#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_registered(vdev))
+		return -ENODEV;
+	return vdev->fops->get_unmapped_area(filp, addr, len, pgoff, flags);
+}
+#endif
+
 /* Override for the open function */
 static int v4l2_open(struct inode *inode, struct file *filp)
 {
@@ -452,6 +469,7 @@ static const struct file_operations v4l2_fops = {
 	.write = v4l2_write,
 	.open = v4l2_open,
 	.mmap = v4l2_mmap,
+	.get_unmapped_area = v4l2_get_unmapped_area,
 	.unlocked_ioctl = v4l2_ioctl,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl = v4l2_compat_ioctl32,
diff --git a/include/media/v4l2-dev.h b/include/media/v4l2-dev.h
index 8266d5a..0616a43 100644
--- a/include/media/v4l2-dev.h
+++ b/include/media/v4l2-dev.h
@@ -63,6 +63,8 @@ struct v4l2_file_operations {
 	long (*ioctl) (struct file *, unsigned int, unsigned long);
 	long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
 	int (*mmap) (struct file *, struct vm_area_struct *);
+	unsigned long (*get_unmapped_area) (struct file *, unsigned long,
+			unsigned long, unsigned long, unsigned long);
 	int (*open) (struct file *);
 	int (*release) (struct file *);
 };
-- 
1.6.3.3


^ permalink raw reply related	[flat|nested] 6+ messages in thread

* Re: [PATCH v3] media:uvc_driver: add uvc support on no-mmu arch
  2011-04-21  3:17 [PATCH v3] media:uvc_driver: add uvc support on no-mmu arch Bob Liu
@ 2011-04-21  7:59 ` Daniel Glöckner
  2011-04-21  8:20   ` Bob Liu
  0 siblings, 1 reply; 6+ messages in thread
From: Daniel Glöckner @ 2011-04-21  7:59 UTC (permalink / raw)
  To: Bob Liu
  Cc: linux-media, dhowells, linux-uvc-devel, mchehab, hverkuil,
	laurent.pinchart, sakari.ailus, martin_rubli, jarod, tj, arnd,
	fweisbec, agust, gregkh, vapier

Hi Bob,

On Thu, Apr 21, 2011 at 11:17:42AM +0800, Bob Liu wrote:
> +#ifdef CONFIG_MMU
>  	if (i == queue->count || size != queue->buf_size) {
> +#else
> +	if (i == queue->count || PAGE_ALIGN(size) != queue->buf_size) {
> +#endif

on mmu systems do_mmap_pgoff contains a len = PAGE_ALIGN(len); line.
If we depend on this behavior, why not do it here as well and get rid
of the #ifdef?

> +unsigned long uvc_queue_get_unmapped_area(struct uvc_video_queue *queue,
> +		unsigned long addr, unsigned long len, unsigned long pgoff)
> +{
> +	struct uvc_buffer *buffer;
> +	unsigned int i;
> +	int ret = 0;

You still didn't change ret to unsigned long.

> +	addr = (unsigned long)queue->mem + buffer->buf.m.offset;
> +	ret = addr;

Why the intermediate step using addr?

> diff --git a/drivers/media/video/v4l2-dev.c b/drivers/media/video/v4l2-dev.c
> index 498e674..221e73f 100644
> --- a/drivers/media/video/v4l2-dev.c
> +++ b/drivers/media/video/v4l2-dev.c
> @@ -368,6 +368,23 @@ static int v4l2_mmap(struct file *filp, struct vm_area_struct *vm)
>  	return ret;
>  }
>  
> +#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_registered(vdev))
> +		return -ENODEV;
> +	return vdev->fops->get_unmapped_area(filp, addr, len, pgoff, flags);
> +}
> +#endif
> +
>  /* Override for the open function */
>  static int v4l2_open(struct inode *inode, struct file *filp)
>  {
> @@ -452,6 +469,7 @@ static const struct file_operations v4l2_fops = {
>  	.write = v4l2_write,
>  	.open = v4l2_open,
>  	.mmap = v4l2_mmap,
> +	.get_unmapped_area = v4l2_get_unmapped_area,
>  	.unlocked_ioctl = v4l2_ioctl,
>  #ifdef CONFIG_COMPAT
>  	.compat_ioctl = v4l2_compat_ioctl32,
> diff --git a/include/media/v4l2-dev.h b/include/media/v4l2-dev.h
> index 8266d5a..0616a43 100644
> --- a/include/media/v4l2-dev.h
> +++ b/include/media/v4l2-dev.h
> @@ -63,6 +63,8 @@ struct v4l2_file_operations {
>  	long (*ioctl) (struct file *, unsigned int, unsigned long);
>  	long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
>  	int (*mmap) (struct file *, struct vm_area_struct *);
> +	unsigned long (*get_unmapped_area) (struct file *, unsigned long,
> +			unsigned long, unsigned long, unsigned long);
>  	int (*open) (struct file *);
>  	int (*release) (struct file *);
>  };

I'd prefer a git revert c29fcff3daafbf46d64a543c1950bbd206ad8c1c for
this block instead of reverting it together with the UVC changes.

  Daniel

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH v3] media:uvc_driver: add uvc support on no-mmu arch
  2011-04-21  7:59 ` Daniel Glöckner
@ 2011-04-21  8:20   ` Bob Liu
  2011-04-21  9:47     ` Daniel Glöckner
  0 siblings, 1 reply; 6+ messages in thread
From: Bob Liu @ 2011-04-21  8:20 UTC (permalink / raw)
  To: Bob Liu, linux-media, dhowells, linux-uvc-devel, mchehab,
	hverkuil, laurent.pinchart, sakari.ailus, martin_rubli, jarod, tj,
	arnd, fweisbec, agust, gregkh, vapier

On Thu, Apr 21, 2011 at 3:59 PM, Daniel Glöckner <daniel-gl@gmx.net> wrote:
> Hi Bob,
>
> On Thu, Apr 21, 2011 at 11:17:42AM +0800, Bob Liu wrote:
>> +#ifdef CONFIG_MMU
>>       if (i == queue->count || size != queue->buf_size) {
>> +#else
>> +     if (i == queue->count || PAGE_ALIGN(size) != queue->buf_size) {
>> +#endif
>
> on mmu systems do_mmap_pgoff contains a len = PAGE_ALIGN(len); line.
> If we depend on this behavior, why not do it here as well and get rid
> of the #ifdef?
>

If do it in do_mmap_pgoff() the whole system will be effected, I am
not sure whether
it's correct and needed for other subsystem.

>> +unsigned long uvc_queue_get_unmapped_area(struct uvc_video_queue *queue,
>> +             unsigned long addr, unsigned long len, unsigned long pgoff)
>> +{
>> +     struct uvc_buffer *buffer;
>> +     unsigned int i;
>> +     int ret = 0;
>
> You still didn't change ret to unsigned long.
>

Oh, Sorry. My fault.

>> +     addr = (unsigned long)queue->mem + buffer->buf.m.offset;
>> +     ret = addr;
>
> Why the intermediate step using addr?
>

If don't return addr, do_mmap_pgoff() will return failure and we can't
setup vma correctly.
See mm/nommu.c line 1386(add = file->f_op->get_unmmapped_area() ).

>> diff --git a/drivers/media/video/v4l2-dev.c b/drivers/media/video/v4l2-dev.c
>> index 498e674..221e73f 100644
>> --- a/drivers/media/video/v4l2-dev.c
>> +++ b/drivers/media/video/v4l2-dev.c
>> @@ -368,6 +368,23 @@ static int v4l2_mmap(struct file *filp, struct vm_area_struct *vm)
>>       return ret;
>>  }
>>
>> +#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_registered(vdev))
>> +             return -ENODEV;
>> +     return vdev->fops->get_unmapped_area(filp, addr, len, pgoff, flags);
>> +}
>> +#endif
>> +
>>  /* Override for the open function */
>>  static int v4l2_open(struct inode *inode, struct file *filp)
>>  {
>> @@ -452,6 +469,7 @@ static const struct file_operations v4l2_fops = {
>>       .write = v4l2_write,
>>       .open = v4l2_open,
>>       .mmap = v4l2_mmap,
>> +     .get_unmapped_area = v4l2_get_unmapped_area,
>>       .unlocked_ioctl = v4l2_ioctl,
>>  #ifdef CONFIG_COMPAT
>>       .compat_ioctl = v4l2_compat_ioctl32,
>> diff --git a/include/media/v4l2-dev.h b/include/media/v4l2-dev.h
>> index 8266d5a..0616a43 100644
>> --- a/include/media/v4l2-dev.h
>> +++ b/include/media/v4l2-dev.h
>> @@ -63,6 +63,8 @@ struct v4l2_file_operations {
>>       long (*ioctl) (struct file *, unsigned int, unsigned long);
>>       long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
>>       int (*mmap) (struct file *, struct vm_area_struct *);
>> +     unsigned long (*get_unmapped_area) (struct file *, unsigned long,
>> +                     unsigned long, unsigned long, unsigned long);
>>       int (*open) (struct file *);
>>       int (*release) (struct file *);
>>  };
>
> I'd prefer a git revert c29fcff3daafbf46d64a543c1950bbd206ad8c1c for
> this block instead of reverting it together with the UVC changes.
>

Okay, I will confirm that and do it.

Thanks a lot for your review.

-- 
Regards,
--Bob

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH v3] media:uvc_driver: add uvc support on no-mmu arch
  2011-04-21  8:20   ` Bob Liu
@ 2011-04-21  9:47     ` Daniel Glöckner
  2011-04-21  9:57       ` Bob Liu
  0 siblings, 1 reply; 6+ messages in thread
From: Daniel Glöckner @ 2011-04-21  9:47 UTC (permalink / raw)
  To: Bob Liu
  Cc: linux-media, dhowells, linux-uvc-devel, mchehab, hverkuil,
	laurent.pinchart, sakari.ailus, martin_rubli, jarod, tj, arnd,
	fweisbec, agust, gregkh, vapier

On Thu, Apr 21, 2011 at 04:20:36PM +0800, Bob Liu wrote:
> > on mmu systems do_mmap_pgoff contains a len = PAGE_ALIGN(len); line.
> > If we depend on this behavior, why not do it here as well and get rid
> > of the #ifdef?
> >
> 
> If do it in do_mmap_pgoff() the whole system will be effected, I am
> not sure whether
> it's correct and needed for other subsystem.

With "here" I was referring to uvc_queue_mmap.

> >> +     addr = (unsigned long)queue->mem + buffer->buf.m.offset;
> >> +     ret = addr;
> >
> > Why the intermediate step using addr?
> >
> 
> If don't return addr, do_mmap_pgoff() will return failure and we can't
> setup vma correctly.
> See mm/nommu.c line 1386(add = file->f_op->get_unmmapped_area() ).

I know, but why not do
	ret = (unsigned long)queue->mem + buffer->buf.m.offset;
instead?

  Daniel

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH v3] media:uvc_driver: add uvc support on no-mmu arch
  2011-04-21  9:47     ` Daniel Glöckner
@ 2011-04-21  9:57       ` Bob Liu
  2011-04-21 10:06         ` Daniel Glöckner
  0 siblings, 1 reply; 6+ messages in thread
From: Bob Liu @ 2011-04-21  9:57 UTC (permalink / raw)
  To: Bob Liu, linux-media, dhowells, linux-uvc-devel, mchehab,
	hverkuil, laurent.pinchart, sakari.ailus, martin_rubli, jarod, tj,
	arnd, fweisbec, agust, gregkh, vapier

On Thu, Apr 21, 2011 at 5:47 PM, Daniel Glöckner <daniel-gl@gmx.net> wrote:
> On Thu, Apr 21, 2011 at 04:20:36PM +0800, Bob Liu wrote:
>> > on mmu systems do_mmap_pgoff contains a len = PAGE_ALIGN(len); line.
>> > If we depend on this behavior, why not do it here as well and get rid
>> > of the #ifdef?
>> >
>>
>> If do it in do_mmap_pgoff() the whole system will be effected, I am
>> not sure whether
>> it's correct and needed for other subsystem.
>
> With "here" I was referring to uvc_queue_mmap.
>

I am sorry, I didn't get your idea. You mean using  PAGE_ALIGN() here for both
mmu and no-mmu arch ?

>> >> +     addr = (unsigned long)queue->mem + buffer->buf.m.offset;
>> >> +     ret = addr;
>> >
>> > Why the intermediate step using addr?
>> >
>>
>> If don't return addr, do_mmap_pgoff() will return failure and we can't
>> setup vma correctly.
>> See mm/nommu.c line 1386(add = file->f_op->get_unmmapped_area() ).
>
> I know, but why not do
>        ret = (unsigned long)queue->mem + buffer->buf.m.offset;
> instead?
>

Okay.
Thanks

-- 
Regards,
--Bob

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH v3] media:uvc_driver: add uvc support on no-mmu arch
  2011-04-21  9:57       ` Bob Liu
@ 2011-04-21 10:06         ` Daniel Glöckner
  0 siblings, 0 replies; 6+ messages in thread
From: Daniel Glöckner @ 2011-04-21 10:06 UTC (permalink / raw)
  To: Bob Liu
  Cc: linux-media, dhowells, linux-uvc-devel, mchehab, hverkuil,
	laurent.pinchart, sakari.ailus, martin_rubli, jarod, tj, arnd,
	fweisbec, agust, gregkh, vapier

On Thu, Apr 21, 2011 at 05:57:31PM +0800, Bob Liu wrote:
> On Thu, Apr 21, 2011 at 5:47 PM, Daniel Glöckner <daniel-gl@gmx.net> wrote:
> > On Thu, Apr 21, 2011 at 04:20:36PM +0800, Bob Liu wrote:
> >> > on mmu systems do_mmap_pgoff contains a len = PAGE_ALIGN(len); line.
> >> > If we depend on this behavior, why not do it here as well and get rid
> >> > of the #ifdef?
> >> >
> >>
> >> If do it in do_mmap_pgoff() the whole system will be effected, I am
> >> not sure whether
> >> it's correct and needed for other subsystem.
> >
> > With "here" I was referring to uvc_queue_mmap.
> >
> 
> I am sorry, I didn't get your idea. You mean using  PAGE_ALIGN() here for both
> mmu and no-mmu arch ?

Yes, rounding size to pages also increases the chance of the following
while loop to end, should mmu do_mmap_pgoff ever have that line removed.

  Daniel

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2011-04-21 10:06 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2011-04-21  3:17 [PATCH v3] media:uvc_driver: add uvc support on no-mmu arch Bob Liu
2011-04-21  7:59 ` Daniel Glöckner
2011-04-21  8:20   ` Bob Liu
2011-04-21  9:47     ` Daniel Glöckner
2011-04-21  9:57       ` Bob Liu
2011-04-21 10:06         ` Daniel Glöckner

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