Changes in Kconfig

b261d222 - lib/crc: remove CONFIG_LIBCRC32C

Tue, 01 Apr 2025 22:16:00 +0000

lib/crc: remove CONFIG_LIBCRC32CNow that LIBCRC32C does nothing besides select CRC32, make every optionthat selects LIBCRC32C instead select CRC32 directly. Then removeLIBCRC32C.Reviewed-by: Christoph Hellwig Reviewed-by: "Martin K. Petersen" Acked-by: Ard Biesheuvel Link: https://lore.kernel.org/r/20250401221600.24878-8-ebiggers@kernel.orgSigned-off-by: Eric Biggers List of files: /linux-6.15/lib/Kconfig

31ab49a9 - lib/crc: document all the CRC library kconfig options

Tue, 01 Apr 2025 22:15:59 +0000

lib/crc: document all the CRC library kconfig optionsPrevious commits removed all the original CRC kconfig help text, sinceit was oriented towards people configuring the kernel, and the optionsare no longer user-selectable. However, it's still useful for there tobe help text for kernel developers. Add this.Reviewed-by: Christoph Hellwig Reviewed-by: "Martin K. Petersen" Acked-by: Ard Biesheuvel Link: https://lore.kernel.org/r/20250401221600.24878-7-ebiggers@kernel.orgSigned-off-by: Eric Biggers List of files: /linux-6.15/lib/Kconfig

a0d55dd7 - lib/crc: remove unnecessary prompt for CONFIG_CRC_ITU_T

Tue, 01 Apr 2025 22:15:58 +0000

lib/crc: remove unnecessary prompt for CONFIG_CRC_ITU_TAll modules that need CONFIG_CRC_ITU_T already select it, so there is noneed to bother users about the option.Reviewed-by: Christoph Hellwig Reviewed-by: "Martin K. Petersen" Acked-by: Ard Biesheuvel Link: https://lore.kernel.org/r/20250401221600.24878-6-ebiggers@kernel.orgSigned-off-by: Eric Biggers List of files: /linux-6.15/lib/Kconfig

a6d0dbba - lib/crc: remove unnecessary prompt for CONFIG_CRC_T10DIF

Tue, 01 Apr 2025 22:15:57 +0000

lib/crc: remove unnecessary prompt for CONFIG_CRC_T10DIFAll modules that need CONFIG_CRC_T10DIF already select it, so there is noneed to bother users about the option.Reviewed-by: Christoph Hellwig Reviewed-by: "Martin K. Petersen" Acked-by: Ard Biesheuvel Link: https://lore.kernel.org/r/20250401221600.24878-5-ebiggers@kernel.orgSigned-off-by: Eric Biggers List of files: /linux-6.15/lib/Kconfig

2038af8e - lib/crc: remove unnecessary prompt for CONFIG_CRC16

Tue, 01 Apr 2025 22:15:56 +0000

lib/crc: remove unnecessary prompt for CONFIG_CRC16All modules that need CONFIG_CRC16 already select it, so there is noneed to bother users about the option.Reviewed-by: Christoph Hellwig Reviewed-by: "Martin K. Petersen" Acked-by: Ard Biesheuvel Link: https://lore.kernel.org/r/20250401221600.24878-4-ebiggers@kernel.orgSigned-off-by: Eric Biggers List of files: /linux-6.15/lib/Kconfig

7939da26 - lib/crc: remove unnecessary prompt for CONFIG_CRC_CCITT

Tue, 01 Apr 2025 22:15:55 +0000

lib/crc: remove unnecessary prompt for CONFIG_CRC_CCITTAll modules that need CONFIG_CRC_CCITT already select it, so there is noneed to bother users about the option.Reviewed-by: Christoph Hellwig Reviewed-by: "Martin K. Petersen" Acked-by: Ard Biesheuvel Link: https://lore.kernel.org/r/20250401221600.24878-3-ebiggers@kernel.orgSigned-off-by: Eric Biggers List of files: /linux-6.15/lib/Kconfig

9ad19171 - lib/crc: remove unnecessary prompt for CONFIG_CRC32 and drop 'default y'

Tue, 01 Apr 2025 22:15:54 +0000

lib/crc: remove unnecessary prompt for CONFIG_CRC32 and drop 'default y'All modules that need CONFIG_CRC32 already select it, so there is noneed to bother users about the option, nor to default it to y.Reviewed-by: Christoph Hellwig Reviewed-by: "Martin K. Petersen" Acked-by: Ard Biesheuvel Link: https://lore.kernel.org/r/20250401221600.24878-2-ebiggers@kernel.orgSigned-off-by: Eric Biggers List of files: /linux-6.15/lib/Kconfig

981b39dc - lib/crc: remove unnecessary prompt for CONFIG_CRC64

Tue, 04 Mar 2025 23:07:12 +0000

lib/crc: remove unnecessary prompt for CONFIG_CRC64All modules that need CONFIG_CRC64 already select it, so there is noneed to bother users about the option.Acked-by: Ard Biesheuvel Link: https://lore.kernel.org/r/20250304230712.167600-6-ebiggers@kernel.orgSigned-off-by: Eric Biggers List of files: /linux-6.15/lib/Kconfig

dce214db - lib/crc: remove unnecessary prompt for CONFIG_LIBCRC32C

Tue, 04 Mar 2025 23:07:11 +0000

lib/crc: remove unnecessary prompt for CONFIG_LIBCRC32CAll modules that need CONFIG_LIBCRC32C already select it, so there is noneed to bother users about the option.Acked-by: Ard Biesheuvel Link: https://lore.kernel.org/r/20250304230712.167600-5-ebiggers@kernel.orgSigned-off-by: Eric Biggers List of files: /linux-6.15/lib/Kconfig

aa09b322 - lib/crc: remove unnecessary prompt for CONFIG_CRC8

Tue, 04 Mar 2025 23:07:10 +0000

lib/crc: remove unnecessary prompt for CONFIG_CRC8All modules that need CONFIG_CRC8 already select it, so there is no needto bother users about the option.Acked-by: Ard Biesheuvel Link: https://lore.kernel.org/r/20250304230712.167600-4-ebiggers@kernel.orgSigned-off-by: Eric Biggers List of files: /linux-6.15/lib/Kconfig

f5a40fcf - lib/crc: remove unnecessary prompt for CONFIG_CRC7

Tue, 04 Mar 2025 23:07:09 +0000

lib/crc: remove unnecessary prompt for CONFIG_CRC7All modules that need CONFIG_CRC7 already select it, so there is no needto bother users about the option.Acked-by: Ard Biesheuvel Link: https://lore.kernel.org/r/20250304230712.167600-3-ebiggers@kernel.orgSigned-off-by: Eric Biggers List of files: /linux-6.15/lib/Kconfig

7f36255f - lib/crc: remove unnecessary prompt for CONFIG_CRC4

Tue, 04 Mar 2025 23:07:08 +0000

lib/crc: remove unnecessary prompt for CONFIG_CRC4All modules that need CONFIG_CRC4 already select it, so there is no needto bother users about the option.Acked-by: Ard Biesheuvel Link: https://lore.kernel.org/r/20250304230712.167600-2-ebiggers@kernel.orgSigned-off-by: Eric Biggers List of files: /linux-6.15/lib/Kconfig

067bc871 - lib/crc64: add support for arch-optimized implementations

Thu, 30 Jan 2025 03:51:24 +0000

lib/crc64: add support for arch-optimized implementationsAdd support for architecture-optimized implementations of the CRC64library functions, following the approach taken for the CRC32 andCRC-T10DIF library functions.Also take the opportunity to tweak the function prototypes:- Use 'const void *' for the lib entry points (since this is easier for users) but 'const u8 *' for the underlying arch and generic functions (since this is easier for the implementations of these functions).- Don't bother with __pure. It's an unusual optimization that doesn't help properly written code. It's a weird quirk we can do without.Reviewed-by: Ard Biesheuvel Reviewed-by: "Martin K. Petersen" Acked-by: Keith Busch Link: https://lore.kernel.org/r/20250130035130.180676-6-ebiggers@kernel.orgSigned-off-by: Eric Biggers List of files: /linux-6.15/lib/Kconfig

feb541bf - lib/crc64-rocksoft: stop wrapping the crypto API

Thu, 30 Jan 2025 03:51:20 +0000

lib/crc64-rocksoft: stop wrapping the crypto APIFollowing what was done for the CRC32 and CRC-T10DIF library functions,get rid of the pointless use of the crypto API and makecrc64_rocksoft_update() call into the library directly. This is fasterand simpler.Remove crc64_rocksoft() (the version of the function that did not take a'crc' argument) since it is unused.Reviewed-by: Ard Biesheuvel Reviewed-by: "Martin K. Petersen" Acked-by: Keith Busch Link: https://lore.kernel.org/r/20250130035130.180676-2-ebiggers@kernel.orgSigned-off-by: Eric Biggers List of files: /linux-6.15/lib/Kconfig

5e3c1c48 - lib/crc32: remove other generic implementations

Thu, 23 Jan 2025 21:29:04 +0000

lib/crc32: remove other generic implementationsNow that we've standardized on the byte-by-byte implementation of CRC32as the only generic implementation (see previous commit for therationale), remove the code for the other implementations.Tested with crc_kunit.Link: https://lore.kernel.org/r/20250123212904.118683-3-ebiggers@kernel.orgReviewed-by: Ard Biesheuvel Reviewed-by: Martin K. Petersen Signed-off-by: Eric Biggers List of files: /linux-6.15/lib/Kconfig

b0430f39 - lib/crc: simplify the kconfig options for CRC implementations

Thu, 23 Jan 2025 21:29:03 +0000

lib/crc: simplify the kconfig options for CRC implementationsMake the following simplifications to the kconfig options for choosingCRC implementations for CRC32 and CRC_T10DIF:1. Make the option to disable the arch-optimized code be visible only when CONFIG_EXPERT=y.2. Make a single option control the inclusion of the arch-optimized code for all enabled CRC variants.3. Make CRC32_SARWATE (a.k.a. slice-by-1 or byte-by-byte) be the only generic CRC32 implementation.The result is there is now just one option, CRC_OPTIMIZATIONS, which isdefault y and can be disabled only when CONFIG_EXPERT=y.Rationale:1. Enabling the arch-optimized code is nearly always the right choice. However, people trying to build the tiniest kernel possible would find some use in disabling it. Anything we add to CRC32 is de facto unconditional, given that CRC32 gets selected by something in nearly all kernels. And unfortunately enabling the arch CRC code does not eliminate the need to build the generic CRC code into the kernel too, due to CPU feature dependencies. The size of the arch CRC code will also increase slightly over time as more CRC variants get added and more implementations targeting different instruction set extensions get added. Thus, it seems worthwhile to still provide an option to disable it, but it should be considered an expert-level tweak.2. Considering the use case described in (1), there doesn't seem to be sufficient value in making the arch-optimized CRC code be independently configurable for different CRC variants. Note also that multiple variants were already grouped together, e.g. CONFIG_CRC32 actually enables three different variants of CRC32.3. The bit-by-bit implementation is uselessly slow, whereas slice-by-n for n=4 and n=8 use tables that are inconveniently large: 4096 bytes and 8192 bytes respectively, compared to 1024 bytes for n=1. Higher n gives higher instruction-level parallelism, so higher n easily wins on traditional microbenchmarks on most CPUs. However, the larger tables, which are accessed randomly, can be harmful in real-world situations where the dcache may be cold or useful data may need be evicted from the dcache. Meanwhile, today most architectures have much faster CRC32 implementations using dedicated CRC32 instructions or carryless multiplication instructions anyway, which make the generic code obsolete in most cases especially on long messages. Another reason for going with n=1 is that this is already what is used by all the other CRC variants in the kernel. CRC32 was unique in having support for larger tables. But as per the above this can be considered an outdated optimization. The standardization on slice-by-1 a.k.a. CRC32_SARWATE makes much of the code in lib/crc32.c unused. A later patch will clean that up.Link: https://lore.kernel.org/r/20250123212904.118683-2-ebiggers@kernel.orgReviewed-by: Ard Biesheuvel Reviewed-by: Martin K. Petersen Signed-off-by: Eric Biggers List of files: /linux-6.15/lib/Kconfig

87fe0a13 - lib/crc32test: delete obsolete crc32test.c

Mon, 02 Dec 2024 01:20:54 +0000

lib/crc32test: delete obsolete crc32test.cDelete crc32test.c, since it has been superseded by crc_kunit.c.Reviewed-by: Ard Biesheuvel Reviewed-by: Martin K. Petersen Acked-by: Geert Uytterhoeven # m68kCc: Vinicius Peixoto Link: https://lore.kernel.org/r/20241202012056.209768-11-ebiggers@kernel.orgSigned-off-by: Eric Biggers List of files: /linux-6.15/lib/Kconfig

0961c3bc - lib/crc-t10dif: add support for arch overrides

Mon, 02 Dec 2024 01:20:46 +0000

lib/crc-t10dif: add support for arch overridesFollowing what was done for CRC32, add support for architecture-specificoverride of the CRC-T10DIF library. This will allow the CRC-T10DIFlibrary functions to access architecture-optimized code directly.Reviewed-by: Ard Biesheuvel Reviewed-by: Martin K. Petersen Link: https://lore.kernel.org/r/20241202012056.209768-3-ebiggers@kernel.orgSigned-off-by: Eric Biggers List of files: /linux-6.15/lib/Kconfig

be3c45b0 - lib/crc-t10dif: stop wrapping the crypto API

Mon, 02 Dec 2024 01:20:45 +0000

lib/crc-t10dif: stop wrapping the crypto APIIn preparation for making the CRC-T10DIF library directly optimized foreach architecture, like what has been done for CRC32, get rid of theweird layering where crc_t10dif_update() calls into the crypto API.Instead, move crc_t10dif_generic() into the crc-t10dif library module,and make crc_t10dif_update() just call crc_t10dif_generic().Acceleration will be reintroduced via crc_t10dif_arch() in the followingpatches.Reviewed-by: Ard Biesheuvel Reviewed-by: Martin K. Petersen Link: https://lore.kernel.org/r/20241202012056.209768-2-ebiggers@kernel.orgSigned-off-by: Eric Biggers List of files: /linux-6.15/lib/Kconfig

38a9a512 - lib/crc32: make crc32c() go directly to lib

Mon, 02 Dec 2024 01:08:40 +0000

lib/crc32: make crc32c() go directly to libNow that the lower level __crc32c_le() library function is optimized foreach architecture, make crc32c() just call that instead of taking aninefficient and error-prone detour through the shash API.Note: a future cleanup should make crc32c_le() be the actual libraryfunction instead of __crc32c_le(). That will require updating callersof __crc32c_le() to use crc32c_le() instead, and updating callers ofcrc32c_le() that expect a 'const void *' arg to expect 'const u8 *'instead. Similarly, a future cleanup should remove LIBCRC32C by makingeveryone who is selecting it just select CRC32 directly instead.Reviewed-by: Ard Biesheuvel Link: https://lore.kernel.org/r/20241202010844.144356-16-ebiggers@kernel.orgSigned-off-by: Eric Biggers List of files: /linux-6.15/lib/Kconfig