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2025-04-28x86/crc: drop "glue" from filenamesEric Biggers
The use of the term "glue" in filenames is a Crypto API-ism that rarely shows up elsewhere in lib/ or arch/*/lib/. I think adopting it there was a mistake. The library just uses standard functions, so the amount of code that could be considered "glue" is quite small. And while often the C functions just wrap the assembly functions, there are also cases like crc32c_arch() in arch/x86/lib/crc32-glue.c that blur the line by in-lining the actual implementation into the C function. That's not "glue code", but rather the actual code. Therefore, let's drop "glue" from the filenames and instead use e.g. crc32.c instead of crc32-glue.c. Reviewed-by: "Martin K. Petersen" <martin.petersen@oracle.com> Acked-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20250424002038.179114-8-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com>
2025-04-28lib/crc: make the CPU feature static keys __ro_after_initEric Biggers
All of the CRC library's CPU feature static_keys are initialized by initcalls and never change afterwards, so there's no need for them to be in the regular .data section. Put them in .data..ro_after_init instead. Reviewed-by: "Martin K. Petersen" <martin.petersen@oracle.com> Acked-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Heiko Carstens <hca@linux.ibm.com> # s390 Link: https://lore.kernel.org/r/20250413154350.10819-1-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com>
2025-03-10x86/crc32: optimize tail handling for crc32c short inputsEric Biggers
For handling the 0 <= len < sizeof(unsigned long) bytes left at the end, do a 4-2-1 step-down instead of a byte-at-a-time loop. This allows taking advantage of wider CRC instructions. Note that crc32c-3way.S already uses this same optimization too. crc_kunit shows an improvement of about 25% for len=127. Suggested-by: "H. Peter Anvin" <hpa@zytor.com> Acked-by: Uros Bizjak <ubizjak@gmail.com> Link: https://lore.kernel.org/r/20250304213216.108925-1-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com>
2025-02-12x86/crc32: improve crc32c_arch() code generation with clangEric Biggers
crc32c_arch() is affected by https://github.com/llvm/llvm-project/issues/20571 where clang unnecessarily spills the inputs to "rm"-constrained operands to the stack. Replace "rm" with ASM_INPUT_RM which partially works around this by expanding to "r" when the compiler is clang. This results in better code generation with clang, though still not optimal. Link: https://lore.kernel.org/r/20250210210741.471725-1-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com>
2025-02-10x86/crc32: implement crc32_le using new templateEric Biggers
Instantiate crc-pclmul-template.S for crc32_le, and delete the original PCLMULQDQ optimized implementation. This has the following advantages: - Less CRC-variant-specific code. - VPCLMULQDQ support, greatly improving performance on sufficiently long messages on newer CPUs. - A faster reduction from 128 bits to the final CRC. - Support for lengths not a multiple of 16 bytes, improving performance for such lengths. - Support for misaligned buffers, improving performance in such cases. Benchmark results on AMD Ryzen 9 9950X (Zen 5) using crc_kunit: Length Before After ------ ------ ----- 1 427 MB/s 605 MB/s 16 710 MB/s 3631 MB/s 64 704 MB/s 7615 MB/s 127 3610 MB/s 9710 MB/s 128 8759 MB/s 12702 MB/s 200 7083 MB/s 15343 MB/s 256 17284 MB/s 22904 MB/s 511 10919 MB/s 27309 MB/s 512 19849 MB/s 48900 MB/s 1024 21216 MB/s 62630 MB/s 3173 22150 MB/s 72437 MB/s 4096 22496 MB/s 79593 MB/s 16384 22018 MB/s 85106 MB/s Acked-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Keith Busch <kbusch@kernel.org> Reviewed-by: "Martin K. Petersen" <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20250210174540.161705-5-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com>
2025-02-08lib/crc32: remove "_le" from crc32c base and arch functionsEric Biggers
Following the standardization on crc32c() as the lib entry point for the Castagnoli CRC32 instead of the previous mix of crc32c(), crc32c_le(), and __crc32c_le(), make the same change to the underlying base and arch functions that implement it. Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20250208024911.14936-7-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com>
2024-12-01x86/crc32: expose CRC32 functions through libEric Biggers
Move the x86 CRC32 assembly code into the lib directory and wire it up to the library interface. This allows it to be used without going through the crypto API. It remains usable via the crypto API too via the shash algorithms that use the library interface. Thus all the arch-specific "shash" code becomes unnecessary and is removed. Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20241202010844.144356-14-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com>