As pointed by Laurent:
I think min_t(size_t, PAGE_SIZE, size) is the preferred way.
Thanks-to: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
drivers/media/video/videobuf-dma-sg.c: In function ‘videobuf_pages_to_sg’:
drivers/media/video/videobuf-dma-sg.c:119: warning: comparison of distinct pointer types lacks a cast
drivers/media/video/videobuf-dma-sg.c:120: warning: comparison of distinct pointer types lacks a cast
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Add an ext_lock argument to the videobuf init functions. This allows
drivers to pass the vdev->lock pointer (or any other externally held lock)
to videobuf. For now all drivers just pass NULL.
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Currently videobuf uses the vb_lock mutex to lock its data structures.
But this locking will (optionally) move into the v4l2 core, which means
that in that case vb_lock shouldn't be used since the external lock is already
held.
Prepare for this by adding a pointer to such an external mutex and
don't lock if that pointer is set.
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This fixes a nasty memory corruption bug when using userptr I/O.
The function videobuf_pages_to_sg() sets up the scatter-gather list for the
DMA transfer to the userspace pages. The first transfer is setup correctly
(the size is set to PAGE_SIZE - offset), but all other transfers have size
PAGE_SIZE. This is wrong for the last transfer which may be less than PAGE_SIZE.
Most, if not all, drivers will program the boards DMA engine correctly, i.e.
even though the size in the last sg element is wrong, they will do their
own size calculations and make sure the right amount is DMA-ed, and so seemingly
prevent memory corruption.
However, behind the scenes the dynamic DMA mapping support (in lib/swiotlb.c)
may create bounce buffers if the memory pages are not in DMA-able memory.
This happens for example on a 64-bit linux with a board that only supports
32-bit DMA.
These bounce buffers DO use the information in the sg list to determine the
size. So while the DMA engine transfers the correct amount of data, when the
data is 'bounced' back too much is copied, causing buffer overwrites.
The fix is simple: calculate and set the correct size for the last sg list
element.
Signed-off-by: Hans Verkuil <hans.verkuil@tandberg.com>
Cc: stable@kernel.org
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
The videobuf_dmabuf and videobuf_vmalloc_memory fields have a vmalloc
field to store the kernel virtual address of vmalloc'ed buffers. Rename
the field to vaddr.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
The fields are assigned but never used, remove them.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Those functions are only called inside videobuf-dma-sg.c, make them
static.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Instead of creating dirty wrappers around videobuf_dma_map/unmap that
create a dummy videobuf_queue structure, modify videobuf_dma_map/unmap
to take a device pointer argument and use it directly. The
videobuf_sg_dma_map/unmap then become unused and can be removed.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
These functions allocate videobuf_buffer structures only. Renaming in order
to prevent confusion with functions allocating actual video buffer memory.
Rename the functions in videobuf-core.h videobuf-dma-sg.c as well.
Signed-off-by: Pawel Osciak <p.osciak@samsung.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
videobuf_pages_to_sg() and videobuf_vmalloc_to_sg() happen to create
a scatterlist element for every page. However, this is not true for
bus addresses, so other functions shouldn't rely on the length of the
scatter list being equal to nr_pages.
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
While analyzing one of the videobuf patches, I noticed that
videobuf_dma_sync is only used internally inside videobuf-dma-sg.
So, let's remove this function, merging the code at __videobuf_dma_sync()
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
drivers/media/video/videobuf-dma-sg.c: In function ‘__videobuf_mmap_mapper’:
drivers/media/video/videobuf-dma-sg.c:557: warning: ‘size’ may be used uninitialized in this function
The condition where size is floating should never happen, due to the paranoia check,
but a future change at the logic might break it. So, let's just set size to zero and
use it for the paranoia check.
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
mmap_mapper should operate on a buffer, not on a complete queue. So let
the videobuf-core find the correct buffer instead of duplicating that
code in each mmap_mapper implementation.
The dma-sg implementation has backwards compatibility code for handling
the V4L1_COMPAT layer. This code is now under the v4L1_COMPAT config option.
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
The video_copy_to_user and copy_stream ops are almost identical for all
videobuf memtype variants. All that is needed is to use the new vaddr
op and these functions can be moved into the core, ensuring we have just
one single implementation instead of three.
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Rename the .vmalloc op in struct videobuf_qtype_ops to .vaddr. This op returns
the virtual kernel address of a buffer. vaddr is a lot less confusing than
vmalloc since this callback does do any allocations.
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
videobuf_alloc() returned a void *. Change to struct videobuf_buffer *
to get better type checking.
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Remove the mmap_free callback from struct videobuf_qtype_ops.
All implementations of this callback do the same trivial check: return
-EBUSY if any buffer is mmapped. That can also be tested in the
videobuf core.
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
The videobuf_queue_ops function vector is not declared constant, but
there's no need for the videobuf layer to ever change it. Make it const
so that videobuf users can make their operations const without warnings.
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
When the image size (bytesperline*height) is not multiple
of PAGE_SIZE, v4l2 rounded the required buffer size to
be multiple of PAGE_SIZE. This prevented user space
to store images directly into userptr buffers which were
not multiple of PAGE_SIZE. This constraint is removed.
The start address is still assumed to be required
page-aligned, ie., when v4l2 allocates mmap buffers,
the offset between different buffers is page-aligned.
Signed-off-by: Tuukka Toivonen <tuukka.o.toivonen@nokia.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
After m68k's task_thread_info() doesn't refer to current,
it's possible to remove sched.h from interrupt.h and not break m68k!
Many thanks to Heiko Carstens for allowing this.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
* mark struct vm_area_struct::vm_ops as const
* mark vm_ops in AGP code
But leave TTM code alone, something is fishy there with global vm_ops
being used.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
it is better return -ENOMEM than -EIO
Signed-off-by: Figo.zhang <figo1802@gmail.com>
Signed-off-by: Douglas Schilling Landgraf <dougsland@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Change kmalloc()/kfree() to vmalloc()/vfree() for sglist allocation
during videobuf_dma_map() and videobuf_dma_unmap()
High resolution sensors might require too many contiguous pages
to be allocated for sglist by kmalloc() during videobuf_dma_map()
(i.e. 256Kib for 8MP sensor).
In such situations, kmalloc() could face some problem to find the
required free memory. vmalloc() is a safer solution instead, as the
allocated memory does not need to be contiguous.
Signed-off-by: David Cohen <david.cohen@nokia.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Not all architectures provide clear_user_page(), but clear_user_highpage()
is available everywhere at least via the compatibility inline function.
Is this the "trivial patch" that's required for these two drivers?
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
1) Remove a useless initialisation of 'i'
2) Avoid clearing the memory allocated twice (once in 'kcalloc', once
in 'sg_init_table')
3) Remove a test that can never trigger. The function returns NULL in
such a case, so we know that at this point 'pages[0]' != NULL
Signed-off-by: Christophe Jaillet <jaillet.christophe@wanadoo.fr>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
videobuf-dvb were still using a function that were videobuf-dma-sg
dependent. This patch creates a generic handler for this function. This
way, videobuf-dvb can now work with all videobuf implementations.
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
__FUNCTION__ is gcc-specific, use __func__
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Michael Krufky <mkrufky@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
videobuf-dma-sg does not need to depend on PCI. Switch it to using generic
DMA API, convert all affected drivers, relax Kconfig restriction, improve
compile-time type checking, fix some Coding Style violations while at it.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@pengutronix.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
- Static memory is always initialized with 0.
- Replaced in some cases C99 comments for /* */
Signed-off-by: Douglas Schilling Landgraf <dougsland@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
dont just copy-and-paste stuff.
(compile-tested this time)
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
Convert v4l from nopage to fault.
Remove redundant vma range checks.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Mauro 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: Jens Axboe <jens.axboe@oracle.com>
Commits
58b053e4ce ("Update arch/ to use sg helpers")
45711f1af6 ("[SG] Update drivers to use sg helpers")
fa05f1286b ("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: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Breaks on any target that has copy_to_user() defined as a non-trivial
macro.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus 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: Mauro 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: Mauro 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: Maxim Levitsky <maximlevitsky@gmail.com>
http://thread.gmane.org/gmane.comp.video.video4linux/34978/focus=34981
Reviewed-by: Ricardo Cerqueira <v4l@cerqueira.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.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: Mauro Carvalho Chehab <mchehab@infradead.org>
http://thread.gmane.org/gmane.comp.video.video4linux/34978/focus=34981
Reviewed-by: Ricardo Cerqueira <v4l@cerqueira.org>
