lib/crc32: Make crc32_be weak for arch override

crc32_le and __crc32c_le can be overridden - extend this to crc32_be.

Signed-off-by: Kevin Bracey <kevin@bracey.fi>
Signed-off-by: Herbert Xu <herber

lib/crc32: Make crc32_be weak for arch override

crc32_le and __crc32c_le can be overridden - extend this to crc32_be.

Signed-off-by: Kevin Bracey <kevin@bracey.fi>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

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lib/crc32: remove unneeded casts

Casts were added in commit 8f243af42ade ("sections: fix const sections
for crc32 table") to cope with the tables not being const. They are no
longer required since c

lib/crc32: remove unneeded casts

Casts were added in commit 8f243af42ade ("sections: fix const sections
for crc32 table") to cope with the tables not being const. They are no
longer required since commit f5e38b9284e1 ("lib: crc32: constify crc32
lookup table").

Signed-off-by: Kevin Bracey <kevin@bracey.fi>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

show more ...

lib/crc32: Make crc32_be weak for arch override

crc32_le and __crc32c_le can be overridden - extend this to crc32_be.

Signed-off-by: Kevin Bracey <kevin@bracey.fi>
Signed-off-by: Herbert Xu <herber

lib/crc32: Make crc32_be weak for arch override

crc32_le and __crc32c_le can be overridden - extend this to crc32_be.

Signed-off-by: Kevin Bracey <kevin@bracey.fi>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

show more ...

lib/crc32: remove unneeded casts

Casts were added in commit 8f243af42ade ("sections: fix const sections
for crc32 table") to cope with the tables not being const. They are no
longer required since c

lib/crc32: remove unneeded casts

Casts were added in commit 8f243af42ade ("sections: fix const sections
for crc32 table") to cope with the tables not being const. They are no
longer required since commit f5e38b9284e1 ("lib: crc32: constify crc32
lookup table").

Signed-off-by: Kevin Bracey <kevin@bracey.fi>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

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lib/crc32.c: fix trivial typo in preprocessor condition

Whether crc32_be needs a lookup table is chosen based on CRC_LE_BITS.
Obviously, the _be function should be governed by the _BE_ define.

This

lib/crc32.c: fix trivial typo in preprocessor condition

Whether crc32_be needs a lookup table is chosen based on CRC_LE_BITS.
Obviously, the _be function should be governed by the _BE_ define.

This probably never pops up as it's hard to come up with a configuration
where CRC_BE_BITS isn't the same as CRC_LE_BITS and as nobody is using
bitwise CRC anyway.

Fixes: 46c5801eaf86 ("crc32: bolt on crc32c")
Signed-off-by: Tobias Jordan <kernel@cdqe.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Krzysztof Kozlowski <krzk@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lkml.kernel.org/r/20200923182122.GA3338@agrajag.zerfleddert.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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docs: move remaining stuff under Documentation/*.txt to Documentation/staging

There are several files that I was unable to find a proper place
for them, and 3 ones that are still in plain old text f

docs: move remaining stuff under Documentation/*.txt to Documentation/staging

There are several files that I was unable to find a proper place
for them, and 3 ones that are still in plain old text format.

Let's place those stuff behind the carpet, as we'd like to keep the
root directory clean.

We can later discuss and move those into better places.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/11bd0d75e65a874f7c276a0aeab0fe13f3376f5f.1592203650.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

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lib/crc32.c: mark crc32_le_base/__crc32c_le_base aliases as __pure

The upcoming GCC 9 release extends the -Wmissing-attributes warnings
(enabled by -Wall) to C and aliases: it warns when particular

lib/crc32.c: mark crc32_le_base/__crc32c_le_base aliases as __pure

The upcoming GCC 9 release extends the -Wmissing-attributes warnings
(enabled by -Wall) to C and aliases: it warns when particular function
attributes are missing in the aliases but not in their target.

In particular, it triggers here because crc32_le_base/__crc32c_le_base
aren't __pure while their target crc32_le/__crc32c_le are.

These aliases are used by architectures as a fallback in accelerated
versions of CRC32. See commit 9784d82db3eb ("lib/crc32: make core crc32()
routines weak so they can be overridden").

Therefore, being fallbacks, it is likely that even if the aliases
were called from C, there wouldn't be any optimizations possible.
Currently, the only user is arm64, which calls this from asm.

Still, marking the aliases as __pure makes sense and is a good idea
for documentation purposes and possible future optimizations,
which also silences the warning.

Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Laura Abbott <labbott@redhat.com>
Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>

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lib/crc32: make core crc32() routines weak so they can be overridden

Allow architectures to drop in accelerated CRC32 routines by making
the crc32_le/__crc32c_le entry points weak, and exposing non-

lib/crc32: make core crc32() routines weak so they can be overridden

Allow architectures to drop in accelerated CRC32 routines by making
the crc32_le/__crc32c_le entry points weak, and exposing non-weak
aliases for them that may be used by the accelerated versions as
fallbacks in case the instructions they rely upon are not available.

Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

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lib/crc: Use consistent naming for CRC-32 polynomials

Header was defining CRCPOLY_LE/BE and CRC32C_POLY_LE but in fact all of
them are CRC-32 polynomials so use consistent naming.

Signed-off-by: Kr

lib/crc: Use consistent naming for CRC-32 polynomials

Header was defining CRCPOLY_LE/BE and CRC32C_POLY_LE but in fact all of
them are CRC-32 polynomials so use consistent naming.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

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lib/crc: Move polynomial definition to separate header

Allow other drivers and parts of kernel to use the same define for
CRC32 polynomial, instead of duplicating it in many places. This code
does

lib/crc: Move polynomial definition to separate header

Allow other drivers and parts of kernel to use the same define for
CRC32 polynomial, instead of duplicating it in many places. This code
does not bring any functional changes, except moving existing code.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

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docs: clean up and add rest of CRC functions to kernel-api.rst

Add the rest of the CRC library functions to kernel-api.

- try to clarify crc32() by adding '@' to a function parameter
- reorder kern

docs: clean up and add rest of CRC functions to kernel-api.rst

Add the rest of the CRC library functions to kernel-api.

- try to clarify crc32() by adding '@' to a function parameter
- reorder kernel-api CRC functions to be less random
- add more CRC functions to kernel-api
- correct the function parameter names in several places

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

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lib: add module support to crc32 tests

Extract the crc32 test code into its own source file, to allow to
compile it either to a loadable module, or builtin into the kernel.

Link: http://lkml.kernel

lib: add module support to crc32 tests

Extract the crc32 test code into its own source file, to allow to
compile it either to a loadable module, or builtin into the kernel.

Link: http://lkml.kernel.org/r/1483470276-10517-1-git-send-email-geert@linux-m68k.org
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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crc32: use ktime_get_ns() for measurement

The crc32 test function measures the elapsed time in nanoseconds, but
uses 'struct timespec' for that. We want to remove timespec from the
kernel for y2038

crc32: use ktime_get_ns() for measurement

The crc32 test function measures the elapsed time in nanoseconds, but
uses 'struct timespec' for that. We want to remove timespec from the
kernel for y2038 compatibility, and ktime_get_ns() also helps make the
code simpler here.

It is also slightly better to use monontonic time, as we are only
interested in the time difference.

Link: http://lkml.kernel.org/r/20160617143932.3289626-1-arnd@arndb.de
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: "David S . Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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lib: crc32: Add some additional __pure annotations

In case they help the compiler.

Signed-off-by: George Spelvin <linux@horizon.com>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-

lib: crc32: Add some additional __pure annotations

In case they help the compiler.

Signed-off-by: George Spelvin <linux@horizon.com>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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lib: crc32: Mark test data __initconst

So it gets discarded after the selftest.

Signed-off-by: George Spelvin <linux@horizon.com>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by:

lib: crc32: Mark test data __initconst

So it gets discarded after the selftest.

Signed-off-by: George Spelvin <linux@horizon.com>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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lib: crc32: Greatly shrink CRC combining code

There's no need for a full 32x32 matrix, when rows before the last are
just shifted copies of the rows after them.

There's still room for improvement (

lib: crc32: Greatly shrink CRC combining code

There's no need for a full 32x32 matrix, when rows before the last are
just shifted copies of the rows after them.

There's still room for improvement (especially on X86 processors with
CRC32 and PCLMUL instructions), but this is a large step in the
right direction [which is in particular useful for its current user,
namely SCTP checksumming over multiple skb frags[] entries, i.e. in
IPVS balancing when other CRC32 offloads are not available].

The internal primitive is now called crc32_generic_shift and takes one
less argument; the XOR with crc2 is done in inline wrappers.

Signed-off-by: George Spelvin <linux@horizon.com>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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lib/crc32.c: remove unnecessary __constant

Use cpu_to_le32 instead of __constant_cpu_to_le32.

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off

lib/crc32.c: remove unnecessary __constant

Use cpu_to_le32 instead of __constant_cpu_to_le32.

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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lib: crc32: reduce number of cases for crc32{, c}_combine

We can safely reduce the number of test cases by a tenth.
There is no particular need to run as many as we're running
now for crc32{,c}_comb

lib: crc32: reduce number of cases for crc32{, c}_combine

We can safely reduce the number of test cases by a tenth.
There is no particular need to run as many as we're running
now for crc32{,c}_combine, that gives us still ~8000 tests
we're doing if people run kernels with crc selftests enabled
which is perfectly fine.

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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lib: crc32: conditionally resched when running testcases

Fengguang reports that when crc32 selftests are running on startup, on
some e.g. 32bit systems, we can get a CPU stall like "INFO: rcu_sched

lib: crc32: conditionally resched when running testcases

Fengguang reports that when crc32 selftests are running on startup, on
some e.g. 32bit systems, we can get a CPU stall like "INFO: rcu_sched
self-detected stall on CPU { 0} (t=2101 jiffies g=4294967081 c=4294967080
q=41)". As this is not intended, add a cond_resched() at the end of a
test case to fix it. Introduced by efba721f63 ("lib: crc32: add test cases
for crc32{, c}_combine routines").

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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lib: crc32: add test cases for crc32{, c}_combine routines

We already have 100 test cases for crcs itself, so split the test
buffer with a-prio known checksums, and test crc of two blocks
against cr

lib: crc32: add test cases for crc32{, c}_combine routines

We already have 100 test cases for crcs itself, so split the test
buffer with a-prio known checksums, and test crc of two blocks
against crc of the whole block for the same results.

Output/result with CONFIG_CRC32_SELFTEST=y:

[ 2.687095] crc32: CRC_LE_BITS = 64, CRC_BE BITS = 64
[ 2.687097] crc32: self tests passed, processed 225944 bytes in 278177 nsec
[ 2.687383] crc32c: CRC_LE_BITS = 64
[ 2.687385] crc32c: self tests passed, processed 225944 bytes in 141708 nsec
[ 7.336771] crc32_combine: 113072 self tests passed
[ 12.050479] crc32c_combine: 113072 self tests passed
[ 17.633089] alg: No test for crc32 (crc32-pclmul)

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>

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lib: crc32: add functionality to combine two crc32{, c}s in GF(2)

This patch adds a combinator to merge two or more crc32{,c}s
into a new one. This is useful for checksum computations of
fragmented

lib: crc32: add functionality to combine two crc32{, c}s in GF(2)

This patch adds a combinator to merge two or more crc32{,c}s
into a new one. This is useful for checksum computations of
fragmented skbs that use crc32/crc32c as checksums.

The arithmetics for combining both in the GF(2) was taken and
slightly modified from zlib. Only passing two crcs is insufficient
as two crcs and the length of the second piece is needed for
merging. The code is made generic, so that only polynomials
need to be passed for crc32_le resp. crc32c_le.

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>

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lib: crc32: clean up spacing in test cases

This is nothing more but a whitepace cleanup, as 80 chars is not a
hard but soft limit, and otherwise makes the test cases array really
look ugly. So fix i

lib: crc32: clean up spacing in test cases

This is nothing more but a whitepace cleanup, as 80 chars is not a
hard but soft limit, and otherwise makes the test cases array really
look ugly. So fix it up.

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>

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lib/crc32: update the comments of crc32_{be,le}_generic()

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-f

lib/crc32: update the comments of crc32_{be,le}_generic()

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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sections: fix const sections for crc32 table

Fix the const sections for the code generated by crc32 table. There's
no ro version of the cacheline aligned section, so we cannot put in
const data wit

sections: fix const sections for crc32 table

Fix the const sections for the code generated by crc32 table. There's
no ro version of the cacheline aligned section, so we cannot put in
const data without a conflict Just don't make the crc tables const for
now.

[ak@linux.intel.com: some fixes and new description]
[akpm@linux-foundation.org: checkpatch fixes]
Signed-off-by: Joe Mario <jmario@redhat.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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lib/crc32.c: fix unused variables warnings

Variables t4, t5, t6 and t7 are only used when CRC_LE_BITS != 32. Fix
the following compilation warnings:

lib/crc32.c: In function 'crc32_body':
lib/

lib/crc32.c: fix unused variables warnings

Variables t4, t5, t6 and t7 are only used when CRC_LE_BITS != 32. Fix
the following compilation warnings:

lib/crc32.c: In function 'crc32_body':
lib/crc32.c:77:55: warning: unused variable 't7'
lib/crc32.c:77:41: warning: unused variable 't6'
lib/crc32.c:77:27: warning: unused variable 't5'
lib/crc32.c:77:13: warning: unused variable 't4'

Signed-off-by: Thiago Rafael Becker <trbecker@trbecker.org>
Cc: "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>

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