[PATCH 6/7] media: v4l2-mem2mem: add v4l2_m2m_get_unmapped_area for no-mmu platform

[Dillon Min]

Hi Hans,

On Thu, Jun 17, 2021 at 5:58 PM Hans Verkuil <hverkuil-cisco at xs4all.nl> wrote:
>
> On 20/05/2021 13:05, dillon.minfei at gmail.com wrote:
> > From: Dillon Min <dillon.minfei at gmail.com>
> >
> > For platforms without MMU the m2m provides a helper method
> > v4l2_m2m_get_unmapped_area(), The mmap() routines will call
> > this to get a proposed address for the mapping.
> >
> > More detailed information about get_unmapped_area can be found in
> > Documentation/nommu-mmap.txt
>
> I'm getting checkpatch.pl --strict warnings:
>
> CHECK: Alignment should match open parenthesis
> #31: FILE: drivers/media/v4l2-core/v4l2-mem2mem.c:971:
> +unsigned long v4l2_m2m_get_unmapped_area(struct file *file, unsigned long addr,
> +               unsigned long len, unsigned long pgoff, unsigned long flags)
>
> CHECK: Alignment should match open parenthesis
> #62: FILE: include/media/v4l2-mem2mem.h:500:
> +unsigned long v4l2_m2m_get_unmapped_area(struct file *file, unsigned long addr,
> +               unsigned long len, unsigned long pgoff, unsigned long flags);

Okay, I will add the "--strict" check to my regular patch submission.
Thanks for the reminder.

Best Regards
Dillon

>
> Regards,
>
>         Hans
>
> >
> > Signed-off-by: Dillon Min <dillon.minfei at gmail.com>
> > ---
> >  drivers/media/v4l2-core/v4l2-mem2mem.c | 20 ++++++++++++++++++++
> >  include/media/v4l2-mem2mem.h           |  4 ++++
> >  2 files changed, 24 insertions(+)
> >
> > diff --git a/drivers/media/v4l2-core/v4l2-mem2mem.c b/drivers/media/v4l2-core/v4l2-mem2mem.c
> > index e7f4bf5bc8dd..f82a18ecab2f 100644
> > --- a/drivers/media/v4l2-core/v4l2-mem2mem.c
> > +++ b/drivers/media/v4l2-core/v4l2-mem2mem.c
> > @@ -966,6 +966,26 @@ int v4l2_m2m_mmap(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
> >  }
> >  EXPORT_SYMBOL(v4l2_m2m_mmap);
> >
> > +#ifndef CONFIG_MMU
> > +unsigned long v4l2_m2m_get_unmapped_area(struct file *file, unsigned long addr,
> > +             unsigned long len, unsigned long pgoff, unsigned long flags)
> > +{
> > +     struct v4l2_fh *fh = file->private_data;
> > +     unsigned long offset = pgoff << PAGE_SHIFT;
> > +     struct vb2_queue *vq;
> > +
> > +     if (offset < DST_QUEUE_OFF_BASE) {
> > +             vq = v4l2_m2m_get_src_vq(fh->m2m_ctx);
> > +     } else {
> > +             vq = v4l2_m2m_get_dst_vq(fh->m2m_ctx);
> > +             pgoff -= (DST_QUEUE_OFF_BASE >> PAGE_SHIFT);
> > +     }
> > +
> > +     return vb2_get_unmapped_area(vq, addr, len, pgoff, flags);
> > +}
> > +EXPORT_SYMBOL_GPL(v4l2_m2m_get_unmapped_area);
> > +#endif
> > +
> >  #if defined(CONFIG_MEDIA_CONTROLLER)
> >  void v4l2_m2m_unregister_media_controller(struct v4l2_m2m_dev *m2m_dev)
> >  {
> > diff --git a/include/media/v4l2-mem2mem.h b/include/media/v4l2-mem2mem.h
> > index 5a91b548ecc0..91269227c265 100644
> > --- a/include/media/v4l2-mem2mem.h
> > +++ b/include/media/v4l2-mem2mem.h
> > @@ -495,6 +495,10 @@ __poll_t v4l2_m2m_poll(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
> >  int v4l2_m2m_mmap(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
> >                 struct vm_area_struct *vma);
> >
> > +#ifndef CONFIG_MMU
> > +unsigned long v4l2_m2m_get_unmapped_area(struct file *file, unsigned long addr,
> > +             unsigned long len, unsigned long pgoff, unsigned long flags);
> > +#endif
> >  /**
> >   * v4l2_m2m_init() - initialize per-driver m2m data
> >   *
> >
>