WSL2-Linux-Kernel/drivers/media
Magnus Damm 720b17e759 videobuf-dma-contig: zero copy USERPTR support
Since videobuf-dma-contig is designed to handle physically contiguous
memory, this patch modifies the videobuf-dma-contig code to only accept a
user space pointer to physically contiguous memory.  For now only
VM_PFNMAP vmas are supported, so forget hotplug.

On SuperH Mobile we use this with our sh_mobile_ceu_camera driver together
with various multimedia accelerator blocks that are exported to user space
using UIO.  The UIO kernel code exports physically contiguous memory to
user space and lets the user space application mmap() this memory and pass
a pointer using the USERPTR interface for V4L2 zero copy operation.

With this approach we support zero copy capture, hardware scaling and
various forms of hardware encoding and decoding.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Acked-by: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:40 -07:00
..
common Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2009-04-03 15:24:35 -07:00
dvb trivial: Kconfig: .ko is normally not included in module names 2009-06-12 18:01:50 +02:00
radio V4L/DVB (11675): ivtv/radio: fix V4L2_TUNER_MODE/V4L2_TUNER_SUB confusion 2009-05-09 18:53:16 -03:00
video videobuf-dma-contig: zero copy USERPTR support 2009-06-16 19:47:40 -07:00
Kconfig V4L/DVB (10633): DAB: fix typo 2009-03-30 12:42:49 -03:00
Makefile V4L/DVB (8274): sms1xxx: build cleanup after driver relocation 2008-07-20 07:20:56 -03:00