The "ni_tio" module contains code to allocate, destroy and operate on a
`struct ni_gpct_device`, which represents a number of counters spread
over one or more blocks (or "chips").  `struct ni_gpct_device` includes
an array member `regs` holding shadow copies of register values.
Unfortunately, this is currently shared by each block of counters so
they interfere with each other.  This is a problem for the "ni_660x"
module, which has 8 counters spread over 2 blocks.  The `regs` storage
needs to be two-dimensional, indexed by block (chip) number and register
number.  (It does not need to be three-dimensional because the registers
for individual counters are intermingled within the block.)

Change the `regs` member to an array pointer that can be indexed like a
two-dimensional array to access the shadow storage for each register in
each block.  Allocate the storage in `ni_gpct_device_construct()` and
free it in `ni_gpct_device_destroy()`.  (`ni_gpct_device_construct()`
can determine the number of blocks from the `num_counters` and
`counters_per_chip` parameters.)

Add new member `num_chips` to hold the number of chips.  Use that to
check that `chip_index` value is in range in the same places that
check the register offset is in range.

Remove the `counters_per_chip` member of `struct ni_gpct_device` as it
is not needed anywhere and could be easily derived from the
`num_counters` and `num_chips` members if required.

Thanks to GitHub user "raabej" (real name unknown) for an initial
implementation of this in the out-of-tree fork of the Comedi drivers.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Add missing break statement in order to prevent the code from falling
through to the default case and return -EINVAL every time.

This bug was found thanks to the ongoing efforts to enable
-Wimplicit-fallthrough.

Fixes: aa94f2888825 ("staging: comedi: ni_660x: tidy up ni_660x_set_pfi_routing()")
Cc: stable@vger.kernel.org
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Removed redunant blank line. Issue found by checkpatch.

Signed-off-by: Sandesh Kenjana Ashok <kas.sandesh@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch is used to remove not necessary braces for single if block.

Signed-off-by: Jitendra Khasdev <jkhasdev@gmail.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

According to the Linux coding guidelines, defines should be written
in uppercase. This patch converts all define-statements in the
ni_pcidio.c file to uppercase, thus matching the coding style of the
kernel.

Signed-off-by: Alexander Schroth <alexander.schroth@fau.de>
Signed-off-by: Marco Ammon <marco.ammon@fau.de>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Fix spelling mistake: "lenghth" -> "length"

Signed-off-by: Matteo Croce <mcroce@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Fixed a coding style issue.

Signed-off-by: William Mitchell Jr <wdmjun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument
of the user address range verification function since we got rid of the
old racy i386-only code to walk page tables by hand.

It existed because the original 80386 would not honor the write protect
bit when in kernel mode, so you had to do COW by hand before doing any
user access.  But we haven't supported that in a long time, and these
days the 'type' argument is a purely historical artifact.

A discussion about extending 'user_access_begin()' to do the range
checking resulted this patch, because there is no way we're going to
move the old VERIFY_xyz interface to that model.  And it's best done at
the end of the merge window when I've done most of my merges, so let's
just get this done once and for all.

This patch was mostly done with a sed-script, with manual fix-ups for
the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form.

There were a couple of notable cases:

 - csky still had the old "verify_area()" name as an alias.

 - the iter_iov code had magical hardcoded knowledge of the actual
   values of VERIFY_{READ,WRITE} (not that they mattered, since nothing
   really used it)

 - microblaze used the type argument for a debug printout

but other than those oddities this should be a total no-op patch.

I tried to fix up all architectures, did fairly extensive grepping for
access_ok() uses, and the changes are trivial, but I may have missed
something.  Any missed conversion should be trivially fixable, though.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Fixed a coding style issue.

Signed-off-by: Amir Mahdi Ghorbanian <indigoomega021@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Changes do_insn*_ioctl functions to allow for data lengths for each
comedi_insn of up to 2^16.  This patch also changes these functions to only
allocate as much memory as is necessary for each comedi_insn, rather than
allocating a fixed-sized scratch space.

In testing some user-space code for the new INSN_DEVICE_CONFIG_GET_ROUTES
facility with some newer hardware, I discovered that do_insn_ioctl and
do_insnlist_ioctl limited the amount of data that can be passed into the
kernel for insn's to a length of 256.  For some newer hardware, the number
of routes can be greater than 1000.  Working around the old limits (256)
would complicate the user-space/kernel interaction.

The new upper limit is reasonable with current memory available and does
not otherwise impact the memory footprint for any current or otherwise
typical configuration.

Signed-off-by: Spencer E. Olson <olsonse@umich.edu>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>