Commit Graph

295112 Commits

Author SHA1 Message Date
Sakari Ailus ce580fe519 [media] v4l: Introduce integer menu controls
Create a new control type called V4L2_CTRL_TYPE_INTEGER_MENU. Integer menu
controls are just like menu controls but the menu items are 64-bit integers
rather than strings.

Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Tested-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2012-04-10 14:49:44 -03:00
Dan Carpenter 3fd7e4341e [media] mxl111sf: remove an unused variable
We don't use this any more after 3be5bb71fb "[media] mxl111sf: fix error
on stream stop in mxl111sf_ep6_streaming_ctrl()" and it makes GCC
complain.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2012-04-09 14:57:20 -03:00
Antti Palosaari 852f0d9d6f [media] af9035: disable frontend0 I2C-gate control
Seems like tuners used for frontend0 are not behind demodulator
I2C-gate thus gate control is not needed. Disable it for sure as
it can cause problems some situations.

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2012-04-09 14:57:14 -03:00
Antti Palosaari b55b4b7a10 [media] af9035: reorganise USB ID and device list
Add and rename "Afatech AF9035 reference design" as a first
device in the list since it sounds logical to keep reference
design IDs on top of the list.

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2012-04-09 14:56:42 -03:00
Antti Palosaari daacd5b27f [media] af9035: minor changes for af9035_fc0011_tuner_callback()
Change function to use same logic than existing functions.
Debugs log writings are done in error case, earlier it was
just returning error code.

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2012-04-09 14:56:20 -03:00
Pierangelo Terzulli dbac01ffbb [media] af9035: add AVerMedia Twinstar (A825) [07ca:0825]
[crope@iki.fi: applied manually since erroneous patch]
Signed-off-by: Pierangelo Terzulli <pierigno@gmail.com>
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2012-04-09 14:55:59 -03:00
Antti Palosaari de7f14fcad [media] af9033: do some minor changes for .get_frontend()
Minor functionality and style changes.

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2012-04-09 14:55:46 -03:00
Gianluca Gennari 0a4df239af [media] af9033: implement get_frontend
Implement the get_frontend function.
The code is derived from the old af9033 driver by Antti Palosaari.

Signed-off-by: Gianluca Gennari <gennarone@gmail.com>
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2012-04-09 14:55:21 -03:00
Antti Palosaari f2b61d0c39 [media] af9035: initial support for IT9135 chip
AF9035 code needed for IT9135 chip support. Needs still small
changes for AF9033 and totally new tuner driver in order to
get that chip version working.

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2012-04-09 14:54:58 -03:00
Michael Büsch a182fd8f79 [media] fc0011: Reduce number of retries
Now that i2c transfers are fixed, 3 retries are enough.

Signed-off-by: Michael Buesch <m@bues.ch>
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2012-04-09 14:54:11 -03:00
Michael Büsch de2bec5e54 [media] af9035: Use usleep_range() in fc0011 support code
Use usleep_range() instead of msleep() to improve power saving opportunities.

Signed-off-by: Michael Buesch <m@bues.ch>
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2012-04-09 14:53:59 -03:00
Michael Büsch c421d5c9d4 [media] fc0011: use usleep_range()
Use usleep_range() instead of msleep() to improve power saving opportunities.

Signed-off-by: Michael Buesch <m@bues.ch>
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2012-04-09 14:53:47 -03:00
Antti Palosaari ad30e91bef [media] af9035: fix and enhance I2C adapter
There was a bug I2C adapter writes and reads one byte too much.
As the most I2C clients has auto-increment register addressing
this leads next register from the target register overwritten by
garbage data.

As a change remove whole register address byte usage and write
data directly to the I2C bus without saying what are register
address bytes to firmware.

Signed-off-by: Antti Palosaari <crope@iki.fi>
Cc: Michael Buesch <m@bues.ch>
Cc: Hans-Frieder Vogt <hfvogt@gmx.net>
Cc: Gianluca Gennari <gennarone@gmail.com>
Tested-by: Michael Buesch <m@bues.ch>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2012-04-09 14:53:30 -03:00
Gianluca Gennari 48bf7e1a9d [media] af9035: use module_usb_driver macro
Let's save a few lines of code using the module_usb_driver macro.

Signed-off-by: Gianluca Gennari <gennarone@gmail.com>
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2012-04-09 14:52:48 -03:00
Gianluca Gennari ce1fe3799c [media] af9035: add support for the tda18218 tuner
Add basic support for the tda18218 tuner and the AVerMedia A835 devices.

Signed-off-by: Gianluca Gennari <gennarone@gmail.com>
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2012-04-09 14:52:34 -03:00
Gianluca Gennari 728827b8d3 [media] af9035: add USB id for 07ca:a867
New USB id for the Avermedia A867 stick (Sky Digital Key with blue led).

Signed-off-by: Gianluca Gennari <gennarone@gmail.com>
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2012-04-09 14:52:00 -03:00
Hans-Frieder Vogt 540fd4ba05 [media] af9035: add Avermedia Volar HD (A867R) support
Support of AVerMedia AVerTV HD Volar, with tuner MxL5007t.

Signed-off-by: Hans-Frieder Vogt <hfvogt@gmx.net>
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2012-04-09 14:51:47 -03:00
Michael Büsch 1083a0f9b8 [media] af9035: Add Afatech USB PIDs
Add some generic Afatech USB PIDs used by "Cabstone" sticks and others.

Signed-off-by: Michael Buesch <m@bues.ch>
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2012-04-09 14:51:08 -03:00
Michael Büsch ffc501f654 [media] af9035: Add fc0011 tuner support
This adds Fitipower fc0011 tuner support to the af9035 driver.

Signed-off-by: Michael Buesch <m@bues.ch>
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2012-04-09 14:50:45 -03:00
Michael Büsch eea977ed63 [media] Add fc0011 tuner driver
This adds support for the Fitipower fc0011 DVB-t tuner.

Signed-off-by: Michael Buesch <m@bues.ch>
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2012-04-09 14:49:32 -03:00
Gianluca Gennari 6ec12988c0 [media] af9035: fix warning
On a 32 bit system:

af9035.c: In function 'af9035_download_firmware':
af9035.c:446:3: warning: format '%lu' expects argument of type 'long unsigned
int', but argument 3 has type 'unsigned int' [-Wformat]

%zu avoids any warning on both 32 and 64 bit systems.

Signed-off-by: Gianluca Gennari <gennarone@gmail.com>
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2012-04-09 14:46:15 -03:00
Michael Büsch b1a9599a0d [media] af9035: Add USB read checksumming
This adds USB message read checksumming to protect against
device and bus errors.
It also adds a read length check to avoid returning garbage from
the buffer, if the device truncated the message.

Signed-off-by: Michael Buesch <m@bues.ch>
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2012-04-09 14:45:37 -03:00
Hans-Frieder Vogt 812fe6d942 [media] af9035: i2c read fix
Enable i2c read requests.

I2C read fix (necessary e.g. for mxl5007t tuner, because it
sends a 2 bytes for a read request, thus msg[0].len != msg[1].len).

Signed-off-by: Hans-Frieder Vogt <hfvogt@gmx.net>
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2012-04-09 14:45:16 -03:00
Antti Palosaari 8e8a5ac763 [media] af9035: add log writing if unsupported Xtal freq is given
Supports currently only 12 MHz Xtals. It is better to print log
and not to attach frontend in that case.

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2012-04-09 14:44:59 -03:00
Antti Palosaari e898ef6272 [media] af9033: implement .read_snr()
Returns values as 0.1 dB resolution as preferred nowadays.
Actual resolution is 1 dB.

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2012-04-09 14:44:45 -03:00
Antti Palosaari 3a871ca270 [media] af9033: correct debug print
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2012-04-09 14:44:12 -03:00
Antti Palosaari 41d44a815a [media] af9035: add missing error check
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2012-04-09 14:43:57 -03:00
Antti Palosaari 77c5ff2d89 [media] af9035: reimplement firmware downloader
Big thanks to Daniel Glöckner <daniel-gl@gmx.net> for
revealing firmware structure on Linux Media mailing
list.

Signed-off-by: Antti Palosaari <crope@iki.fi>
Cc: Daniel Glöckner <daniel-gl@gmx.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2012-04-09 14:43:40 -03:00
Antti Palosaari 5a9abae497 [media] af9035: enhancement for unknown tuner ID handling
* do not attach frontend when tuner is not supported
* fix unkown tuner ID log write format
* add prefix for dvb-usb log writings

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2012-04-09 14:43:01 -03:00
Antti Palosaari 7f882c2e35 [media] Afatech AF9035 DVB USB driver
AF9035 is integrated DVB USB interface and DVB-T demodulator.
Integrated demodulator is AF9033 and its driver is attached
runtime as a own module.

Driver currently supports only one device,
TerraTec Cinergy T Stick [0ccd:0093].

TerraTec Cinergy T Stick is based of Afatech AF9035 +
Infineon TUA 9001 silicon tuner.

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2012-04-09 14:42:19 -03:00
Antti Palosaari 4b64bb268f [media] Afatech AF9033 DVB-T demodulator driver
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2012-04-09 14:33:42 -03:00
Antti Palosaari f9263747b1 [media] Infineon TUA 9001 silicon tuner driver
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2012-04-09 14:31:34 -03:00
Hans de Goede 3f1bfef8e7 pwc: Add support for control events
Since the pwc driver already uses v4l2-device, v4l2-fh, and the control
framework, all that is needed is hooking up event subscription.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2012-04-09 08:28:33 -03:00
Hans Verkuil a875431dfd [media] radio-rtrack2: add missing slab.h
Missed this one, this patch should solve this issue:

http://www.spinics.net/lists/linux-media/msg45880.html

Slab.h was added to all the other isa drivers, but not radio-rtrack2.c.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2012-03-30 16:41:29 -03:00
Hans de Goede 296da3cd14 [media] pwc: poll(): Check that the device has not beem claimed for streaming already
Some apps which use read() start the streaming through a call to poll(),
this means that if another app has already claimed the device for streaming
(through for example a s_fmt, or a reqbufs), that the poll should fail instead
of getting passed through to vb2_poll.

We only check for this when the app is polling for reads, so that ctrl events
still work.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2012-03-27 11:42:04 -03:00
Hans Verkuil 0bf0f713d6 [media] vivi: let vb2_poll handle events
The vb2_poll function now tests for events and sets POLLPRI accordingly.
So there it is no longer necessary to test for it in the vivi driver.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2012-03-27 11:41:56 -03:00
Hans Verkuil 95213ceb1b [media] videobuf2-core: also test for pending events
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Pawel Osciak <pawel@osciak.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2012-03-27 11:41:48 -03:00
Hans Verkuil 0e17e9a9f6 [media] videobuf: only start streaming in poll() if so requested by the poll mask
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2012-03-27 11:41:33 -03:00
Hans Verkuil bf5c7cbb99 [media] videobuf2: only start streaming in poll() if so requested by the poll mask
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Pawel Osciak <pawel@osciak.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2012-03-27 11:41:22 -03:00
Hans Verkuil d0b66fdfd3 [media] ivtv: only start streaming in poll() if polling for input
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Andy Walls <awalls@md.metrocast.net>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2012-03-27 11:36:29 -03:00
Mauro Carvalho Chehab 50953e0640 Merge branch 'poll' into staging/for_v3.4
* poll: (5970 commits)
  poll: add poll_requested_events() and poll_does_not_wait() functions
  crc32: select an algorithm via Kconfig
  crc32: add self-test code for crc32c
  crypto: crc32c should use library implementation
  crc32: bolt on crc32c
  crc32: add note about this patchset to crc32.c
  crc32: optimize loop counter for x86
  crc32: add slice-by-8 algorithm to existing code
  crc32: make CRC_*_BITS definition correspond to actual bit counts
  crc32: fix mixing of endian-specific types
  crc32: miscellaneous cleanups
  crc32: simplify unit test code
  crc32: move long comment about crc32 fundamentals to Documentation/
  crc32: remove two instances of trailing whitespaces
  checkpatch: check for quoted strings broken across lines
  checkpatch: whitespace - add/remove blank lines
  checkpatch: warn on use of yield()
  checkpatch: add --strict tests for braces, comments and casts
  checkpatch: add [] to type extensions
  checkpatch: high precedence operators do not require additional parentheses in #defines
  ...
2012-03-27 11:32:29 -03:00
Hans Verkuil 626cf23660 poll: add poll_requested_events() and poll_does_not_wait() functions
In some cases the poll() implementation in a driver has to do different
things depending on the events the caller wants to poll for.  An example
is when a driver needs to start a DMA engine if the caller polls for
POLLIN, but doesn't want to do that if POLLIN is not requested but instead
only POLLOUT or POLLPRI is requested.  This is something that can happen
in the video4linux subsystem among others.

Unfortunately, the current epoll/poll/select implementation doesn't
provide that information reliably.  The poll_table_struct does have it: it
has a key field with the event mask.  But once a poll() call matches one
or more bits of that mask any following poll() calls are passed a NULL
poll_table pointer.

Also, the eventpoll implementation always left the key field at ~0 instead
of using the requested events mask.

This was changed in eventpoll.c so the key field now contains the actual
events that should be polled for as set by the caller.

The solution to the NULL poll_table pointer is to set the qproc field to
NULL in poll_table once poll() matches the events, not the poll_table
pointer itself.  That way drivers can obtain the mask through a new
poll_requested_events inline.

The poll_table_struct can still be NULL since some kernel code calls it
internally (netfs_state_poll() in ./drivers/staging/pohmelfs/netfs.h).  In
that case poll_requested_events() returns ~0 (i.e.  all events).

Very rarely drivers might want to know whether poll_wait will actually
wait.  If another earlier file descriptor in the set already matched the
events the caller wanted to wait for, then the kernel will return from the
select() call without waiting.  This might be useful information in order
to avoid doing expensive work.

A new helper function poll_does_not_wait() is added that drivers can use
to detect this situation.  This is now used in sock_poll_wait() in
include/net/sock.h.  This was the only place in the kernel that needed
this information.

Drivers should no longer access any of the poll_table internals, but use
the poll_requested_events() and poll_does_not_wait() access functions
instead.  In order to enforce that the poll_table fields are now prepended
with an underscore and a comment was added warning against using them
directly.

This required a change in unix_dgram_poll() in unix/af_unix.c which used
the key field to get the requested events.  It's been replaced by a call
to poll_requested_events().

For qproc it was especially important to change its name since the
behavior of that field changes with this patch since this function pointer
can now be NULL when that wasn't possible in the past.

Any driver accessing the qproc or key fields directly will now fail to compile.

Some notes regarding the correctness of this patch: the driver's poll()
function is called with a 'struct poll_table_struct *wait' argument.  This
pointer may or may not be NULL, drivers can never rely on it being one or
the other as that depends on whether or not an earlier file descriptor in
the select()'s fdset matched the requested events.

There are only three things a driver can do with the wait argument:

1) obtain the key field:

	events = wait ? wait->key : ~0;

   This will still work although it should be replaced with the new
   poll_requested_events() function (which does exactly the same).
   This will now even work better, since wait is no longer set to NULL
   unnecessarily.

2) use the qproc callback. This could be deadly since qproc can now be
   NULL. Renaming qproc should prevent this from happening. There are no
   kernel drivers that actually access this callback directly, BTW.

3) test whether wait == NULL to determine whether poll would return without
   waiting. This is no longer sufficient as the correct test is now
   wait == NULL || wait->_qproc == NULL.

   However, the worst that can happen here is a slight performance hit in
   the case where wait != NULL and wait->_qproc == NULL. In that case the
   driver will assume that poll_wait() will actually add the fd to the set
   of waiting file descriptors. Of course, poll_wait() will not do that
   since it tests for wait->_qproc. This will not break anything, though.

   There is only one place in the whole kernel where this happens
   (sock_poll_wait() in include/net/sock.h) and that code will be replaced
   by a call to poll_does_not_wait() in the next patch.

   Note that even if wait->_qproc != NULL drivers cannot rely on poll_wait()
   actually waiting. The next file descriptor from the set might match the
   event mask and thus any possible waits will never happen.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: Jonathan Corbet <corbet@lwn.net>
Reviewed-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: Davide Libenzi <davidel@xmailserver.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: David Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-23 16:58:38 -07:00
Darrick J. Wong 5cde7656d0 crc32: select an algorithm via Kconfig
Allow the kernel builder to choose a crc32* algorithm for the kernel.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Cc: Bob Pearson <rpearson@systemfabricworks.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-23 16:58:38 -07:00
Darrick J. Wong 577eba9e22 crc32: add self-test code for crc32c
Add self-test code for crc32c.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Cc: Bob Pearson <rpearson@systemfabricworks.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-23 16:58:38 -07:00
Darrick J. Wong 6a0962b22e crypto: crc32c should use library implementation
Since lib/crc32.c now provides crc32c, remove the software implementation
here and call the library function instead.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Bob Pearson <rpearson@systemfabricworks.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-23 16:58:38 -07:00
Darrick J. Wong 46c5801eaf crc32: bolt on crc32c
Reuse the existing crc32 code to stamp out a crc32c implementation.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Bob Pearson <rpearson@systemfabricworks.com>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-23 16:58:38 -07:00
Bob Pearson 78dff41897 crc32: add note about this patchset to crc32.c
Add a comment at the top of crc32.c

[djwong@us.ibm.com: Minor changelog tweaks]
Signed-off-by: Bob Pearson <rpearson@systemfabricworks.com>
Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-23 16:58:38 -07:00
Bob Pearson 0292c497b6 crc32: optimize loop counter for x86
Add two changes that improve the performance of x86 systems

1. replace main loop with incrementing counter this change improves
   the performance of the selftest by about 5-6% on Nehalem CPUs.  The
   apparent reason is that the compiler can use the loop index to perform
   an indexed memory access.  This is reported to make the performance of
   PowerPC CPUs to get worse.

2. replace the rem_len loop with incrementing counter this change
   improves the performance of the selftest, which has more than the usual
   number of occurances, by about 1-2% on x86 CPUs.  In actual work loads
   the length is most often a multiple of 4 bytes and this code does not
   get executed as often if at all.  Again this change is reported to make
   the performance of PowerPC get worse.

[djwong@us.ibm.com: Minor changelog tweaks]
Signed-off-by: Bob Pearson <rpearson@systemfabricworks.com>
Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-23 16:58:37 -07:00
Bob Pearson 324eb0f17d crc32: add slice-by-8 algorithm to existing code
Add slicing-by-8 algorithm to the existing slicing-by-4 algorithm.  This
consists of:

- extend largest BITS size from 32 to 64
- extend tables from tab[4][256] to up to tab[8][256]
- Add code for inner loop.

[djwong@us.ibm.com: Minor changelog tweaks]
Signed-off-by: Bob Pearson <rpearson@systemfabricworks.com>
Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-23 16:58:37 -07:00
Bob Pearson 9a1dbf6a29 crc32: make CRC_*_BITS definition correspond to actual bit counts
crc32.c provides a choice of one of several algorithms for computing the
LSB and LSB versions of the CRC32 checksum based on the parameters
CRC_LE_BITS and CRC_BE_BITS.

In the original version the values 1, 2, 4 and 8 respectively selected
versions of the alrogithm that computed the crc 1, 2, 4 and 32 bits as a
time.

This patch series adds a new version that computes the CRC 64 bits at a
time.  To make things easier to understand the parameter has been
reinterpreted to actually stand for the number of bits processed in each
step of the algorithm so that the old value 8 has been replaced with the
value 32.

This also allows us to add in a widely used crc algorithm that computes
the crc 8 bits at a time called the Sarwate algorithm.

[djwong@us.ibm.com: Minor changelog tweaks]
Signed-off-by: Bob Pearson <rpearson@systemfabricworks.com>
Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-23 16:58:37 -07:00