Commit 0a08088f authored by Dillon Min's avatar Dillon Min Committed by Mauro Carvalho Chehab
Browse files

media: v4l2-mem2mem: add v4l2_m2m_get_unmapped_area for no-mmu platform 



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

Signed-off-by: default avatarDillon Min <dillon.minfei@gmail.com>
Signed-off-by: default avatarHans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab+huawei@kernel.org>
parent 68dda3e0

drivers/media/v4l2-core/v4l2-mem2mem.c

+21 −0
Original line number Diff line number Diff line
@@ -966,6 +966,27 @@ 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)

{

include/media/v4l2-mem2mem.h

+5 −0
Original line number Diff line number Diff line
@@ -495,6 +495,11 @@ __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

 *