diff mbox

[v2] media: uvc_driver: add NO-MMU arch support

Message ID BANLkTikGxffMuxWq3P7QxM0213k9oRU4hw@mail.gmail.com (mailing list archive)
State RFC
Headers show

Commit Message

Bob Liu April 20, 2011, 6:02 a.m. UTC
---------- Forwarded message ----------
From: Bob Liu <lliubbo@gmail.com>
Date: Fri, Apr 8, 2011 at 7:16 PM
Subject: [PATCH v2] media: uvc_driver: add NO-MMU arch support
To: linux-kernel@vger.kernel.org
Cc: mchehab@redhat.com, hverkuil@xs4all.nl,
laurent.pinchart@ideasonboard.com,
sakari.ailus@maxwell.research.nokia.com, martin_rubli@logitech.com,
jarod@redhat.com, tj@kernel.org, arnd@arndb.de, fweisbec@gmail.com,
agust@denx.de, gregkh@suse.de, Bob Liu <lliubbo@gmail.com>


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 |   47 +++++++++++++++++++++++++++++++++++
 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, 86 insertions(+), 0 deletions(-)

--
1.6.3.3

Comments

Daniel Glöckner April 20, 2011, 8:59 a.m. UTC | #1
On Wed, Apr 20, 2011 at 02:02:41PM +0800, Bob Liu wrote:
> ---------- Forwarded message ----------

Forwarding broke tabs.

> @@ -445,6 +446,20 @@ int uvc_queue_mmap(struct uvc_video_queue *queue,
> struct vm_area_struct *vma)
>                addr += PAGE_SIZE;
>                size -= PAGE_SIZE;
>        }
> +#else
> +       if (i == queue->count ||
> +                       PAGE_ALIGN(size) != queue->buf_size) {

Why do you need to round up size on nommu?

> +               ret = -EINVAL;
> +               goto done;
> +       }
> +
> +       /* documentation/nommu-mmap.txt */

I don't see where Documentation/nommu-mmap.txt provides any information
on the following line(s).

> +       vma->vm_flags |= VM_IO | VM_MAYSHARE;
> +
> +       addr = (unsigned long)queue->mem + buffer->buf.m.offset;
> +       vma->vm_start = addr;
> +       vma->vm_end = addr +  queue->buf_size;

You don't need to do this here. vm_start and vm_end have already been
modified like this by do_mmap_pgoff after get_unmapped_area had been
called.

> +#endif
> 
>        vma->vm_ops = &uvc_vm_ops;
>        vma->vm_private_data = buffer;
> @@ -489,6 +504,38 @@ 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;

ret should be an unsigned long. You later try to store a pointer in
there.

> +
> +       mutex_lock(&queue->mutex);
> +       for (i = 0; i < queue->count; ++i) {
> +               buffer = &queue->buffer[i];
> +               if ((buffer->buf.m.offset >> PAGE_SHIFT) == pgoff)
> +                       break;
> +       }
> +
> +       if (i == queue->count ||
> +                       PAGE_ALIGN(len) != queue->buf_size) {
> +               ret = -EINVAL;
> +               goto done;
> +       }
> +
> +       addr = (unsigned long)queue->mem + buffer->buf.m.offset;
> +       ret = addr;
> +done:
> +       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

Rest looks good.
Did you change anything in the generic code or is this a plain
git revert c29fcff3daafbf46d64a543c1950bbd206ad8c1c
?

Maybe one can unify the mmu and nommu versions of uvc_queue_mmap by using
remap_vmalloc_range but IMHO the nommu versions of the remap_*_range
functions are broken and should only validate if the source and destination
addresses match.

  Daniel
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Bob Liu April 20, 2011, 10:18 a.m. UTC | #2
On Wed, Apr 20, 2011 at 4:59 PM, Daniel Glöckner <daniel-gl@gmx.net> wrote:
> On Wed, Apr 20, 2011 at 02:02:41PM +0800, Bob Liu wrote:
>> ---------- Forwarded message ----------
>
> Forwarding broke tabs.
>

Hi, Daniel
Thanks for your review, I will make a new patch later.

>> @@ -445,6 +446,20 @@ int uvc_queue_mmap(struct uvc_video_queue *queue,
>> struct vm_area_struct *vma)
>>                addr += PAGE_SIZE;
>>                size -= PAGE_SIZE;
>>        }
>> +#else
>> +       if (i == queue->count ||
>> +                       PAGE_ALIGN(size) != queue->buf_size) {
>
> Why do you need to round up size on nommu?
>

If didn't round up, it always return  -EINVAL.
I don't know why config-mmu doesn't have this problem.

I use luvcview for testing and added some print, you can see that size
always != queue->buf_size.
So we need round up.

root:/> luvcview -f yuv -s 320x240 -i 30
luvcview 0.2.4

SDL information:
  Video driver: fbcon
  Hardware surfaces are available (382k video memory)
Device information:
  Device path:  /dev/video0
Stream settings:
  Frame format: YUYV
  Frame size:   320x240
  Fsaiz e tis  03x2f5800, align size is 0x26000, bufsize is 0x26000

size is 0x25800, align size is 0x26000, bufsize is 0x26000
Unable to map buffer: Invalid argument
 Init v4L2 failed !! exit fatal
root:/>

>> +               ret = -EINVAL;
>> +               goto done;
>> +       }
>> +
>> +       /* documentation/nommu-mmap.txt */
>
> I don't see where Documentation/nommu-mmap.txt provides any information
> on the following line(s).
>

I will rm it, sorry for that.

>> +       vma->vm_flags |= VM_IO | VM_MAYSHARE;
>> +
>> +       addr = (unsigned long)queue->mem + buffer->buf.m.offset;
>> +       vma->vm_start = addr;
>> +       vma->vm_end = addr +  queue->buf_size;
>
> You don't need to do this here. vm_start and vm_end have already been
> modified like this by do_mmap_pgoff after get_unmapped_area had been
> called.
>

will rm also.

>> +#endif
>>
>>        vma->vm_ops = &uvc_vm_ops;
>>        vma->vm_private_data = buffer;
>> @@ -489,6 +504,38 @@ 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;
>
> ret should be an unsigned long. You later try to store a pointer in
> there.
>

okay.

>> +
>> +       mutex_lock(&queue->mutex);
>> +       for (i = 0; i < queue->count; ++i) {
>> +               buffer = &queue->buffer[i];
>> +               if ((buffer->buf.m.offset >> PAGE_SHIFT) == pgoff)
>> +                       break;
>> +       }
>> +
>> +       if (i == queue->count ||
>> +                       PAGE_ALIGN(len) != queue->buf_size) {
>> +               ret = -EINVAL;
>> +               goto done;
>> +       }
>> +
>> +       addr = (unsigned long)queue->mem + buffer->buf.m.offset;
>> +       ret = addr;
>> +done:
>> +       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
>
> Rest looks good.
> Did you change anything in the generic code or is this a plain
> git revert c29fcff3daafbf46d64a543c1950bbd206ad8c1c
> ?
>

It's not a simple revert, I added  uvc_v4l2_get_unmapped_area().

> Maybe one can unify the mmu and nommu versions of uvc_queue_mmap by using
> remap_vmalloc_range but IMHO the nommu versions of the remap_*_range
> functions are broken and should only validate if the source and destination
> addresses match.
>

Maybe we can try in future.
Thanks!
diff mbox

Patch

diff --git a/drivers/media/video/uvc/uvc_queue.c
b/drivers/media/video/uvc/uvc_queue.c
index f14581b..e505afe 100644
--- a/drivers/media/video/uvc/uvc_queue.c
+++ b/drivers/media/video/uvc/uvc_queue.c
@@ -424,6 +424,7 @@  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) {
               ret = -EINVAL;
               goto done;
@@ -445,6 +446,20 @@  int uvc_queue_mmap(struct uvc_video_queue *queue,
struct vm_area_struct *vma)
               addr += PAGE_SIZE;
               size -= PAGE_SIZE;
       }
+#else
+       if (i == queue->count ||
+                       PAGE_ALIGN(size) != queue->buf_size) {
+               ret = -EINVAL;
+               goto done;
+       }
+
+       /* documentation/nommu-mmap.txt */
+       vma->vm_flags |= VM_IO | VM_MAYSHARE;
+
+       addr = (unsigned long)queue->mem + buffer->buf.m.offset;
+       vma->vm_start = addr;
+       vma->vm_end = addr +  queue->buf_size;
+#endif

       vma->vm_ops = &uvc_vm_ops;
       vma->vm_private_data = buffer;
@@ -489,6 +504,38 @@  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;
+       }
+
+       if (i == queue->count ||
+                       PAGE_ALIGN(len) != queue->buf_size) {
+               ret = -EINVAL;
+               goto done;
+       }
+
+       addr = (unsigned long)queue->mem + buffer->buf.m.offset;
+       ret = addr;
+done:
+       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 *);
 };