dont just copy-and-paste stuff.
(compile-tested this time)
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

Convert v4l from nopage to fault.
Remove redundant vma range checks.
Signed-off-by: NNick Piggin <npiggin@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

Most drivers need to set length and offset as well, so may as well fold
those three lines into one.

Add sg_assign_page() for those two locations that only needed to set
the page, where the offset/length is set outside of the function context.
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

Commits

  58b053e4 ("Update arch/ to use sg helpers")
  45711f1a ("[SG] Update drivers to use sg helpers")
  fa05f128 ("Update net/ to use sg helpers")

converted many files to use the scatter gather helpers without ensuring
that the necessary headerfile <linux/scatterlist> is included.  This
happened to work for ia64, powerpc, sparc64 and x86 because they
happened to drag in that file via their <asm/dma-mapping.h>.

On most of the others this probably broke.

Instead of increasing the header file spider web I choose to include
<linux/scatterlist.h> directly into the affectes files.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

Breaks on any target that has copy_to_user() defined as a non-trivial
macro.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In the past, videobuf_queue_init were used to initialize PCI DMA videobuffers.
This patch renames it, to avoid confusion with the previous kernel API, doing:
	s/videobuf_queue_init/void videobuf_queue_core_init/

Also, the operations is now part of the function parameter. The function will
also add a test if this is defined, otherwise producing BUG.
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

Before the videobuf redesign, a procedure for re-using videobuf without PCI
scatter/gather where provided by changing the pci-dependent operations by
other operations.

With the newer approach, those methods are obsolete and can safelly be removed.
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

videobuf_qbuf takes q->lock, and then calls
q->ops->buf_prepare which by design in all drivers calls
videobuf_iolock which calls videobuf_dma_init_user and this
takes current->mm->mmap_sem

on the other hand if user calls mumap from other thread, sys_munmap
takes current->mm->mmap_sem and videobuf_vm_close takes q->lock

Since this can occur only for V4L2_MEMORY_MMAP buffers, take
current->mm->mmap_sem in qbuf, before q->lock, and don't take
current->mm->mmap_sem videobuf_dma_init_user for those buffers
Signed-off-by: NMaxim Levitsky <maximlevitsky@gmail.com>
http://thread.gmane.org/gmane.comp.video.video4linux/34978/focus=34981Reviewed-by: NRicardo Cerqueira <v4l@cerqueira.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>
http://thread.gmane.org/gmane.comp.video.video4linux/34978/focus=34981Reviewed-by: NRicardo Cerqueira <v4l@cerqueira.org>

video-buf currently does two different tasks:

- Manages video buffers with a common code that allows
  implementing all the V4L2 different modes of buffering;

- Controls memory allocations

While the first task is generic, the second were written to support PCI DMA
Scatter/Gather needs. The original approach can't even work for those
video capture hardware that don't support scatter/gather.

I did one approach to make it more generic. While the approach worked
fine for vivi driver, it were not generic enough to handle USB needs.

This patch creates two different modules, one containing the generic
video buffer handling (videobuf-core) and another with PCI DMA S/G.
After this patch, it would be simpler to write an USB video-buf and a
non-SG DMA module.
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>
http://thread.gmane.org/gmane.comp.video.video4linux/34978/focus=34981Reviewed-by: NRicardo Cerqueira <v4l@cerqueira.org>