Hi Hans, On Thu, Jun 17, 2021 at 5:58 PM Hans Verkuil <hverkuil-cisco@xxxxxxxxx> wrote: > > On 20/05/2021 13:05, dillon.minfei@xxxxxxxxx wrote: > > From: Dillon Min <dillon.minfei@xxxxxxxxx> > > > > 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@xxxxxxxxx> > > --- > > 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 > > * > > >