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author | Linus Torvalds <torvalds@linux-foundation.org> | 2025-07-28 17:43:29 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2025-07-28 17:43:29 -0700 |
commit | a578dd095dfe8b56c167201d9aea43e47d27f807 (patch) | |
tree | 6d4ee6e286b92ebad6d10572af74eb15fd31973f /lib/crc/crc64-main.c | |
parent | 8e736a2eeaf261213b4557778e015699da1e1c8c (diff) | |
parent | 118da22eb6fbd48f896d17411f942399283d600c (diff) |
Merge tag 'crc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux
Pull CRC updates from Eric Biggers:
- Reorganize the architecture-optimized CRC code
It now lives in lib/crc/$(SRCARCH)/ rather than arch/$(SRCARCH)/lib/,
and it is no longer artificially split into separate generic and arch
modules. This allows better inlining and dead code elimination
The generic CRC code is also no longer exported, simplifying the API.
(This mirrors the similar changes to SHA-1 and SHA-2 in lib/crypto/,
which can be found in the "Crypto library updates" pull request)
- Improve crc32c() performance on newer x86_64 CPUs on long messages by
enabling the VPCLMULQDQ optimized code
- Simplify the crypto_shash wrappers for crc32_le() and crc32c()
Register just one shash algorithm for each that uses the (fully
optimized) library functions, instead of unnecessarily providing
direct access to the generic CRC code
- Remove unused and obsolete drivers for hardware CRC engines
- Remove CRC-32 combination functions that are no longer used
- Add kerneldoc for crc32_le(), crc32_be(), and crc32c()
- Convert the crc32() macro to an inline function
* tag 'crc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux: (26 commits)
lib/crc: x86/crc32c: Enable VPCLMULQDQ optimization where beneficial
lib/crc: x86: Reorganize crc-pclmul static_call initialization
lib/crc: crc64: Add include/linux/crc64.h to kernel-api.rst
lib/crc: crc32: Change crc32() from macro to inline function and remove cast
nvmem: layouts: Switch from crc32() to crc32_le()
lib/crc: crc32: Document crc32_le(), crc32_be(), and crc32c()
lib/crc: Explicitly include <linux/export.h>
lib/crc: Remove ARCH_HAS_* kconfig symbols
lib/crc: x86: Migrate optimized CRC code into lib/crc/
lib/crc: sparc: Migrate optimized CRC code into lib/crc/
lib/crc: s390: Migrate optimized CRC code into lib/crc/
lib/crc: riscv: Migrate optimized CRC code into lib/crc/
lib/crc: powerpc: Migrate optimized CRC code into lib/crc/
lib/crc: mips: Migrate optimized CRC code into lib/crc/
lib/crc: loongarch: Migrate optimized CRC code into lib/crc/
lib/crc: arm64: Migrate optimized CRC code into lib/crc/
lib/crc: arm: Migrate optimized CRC code into lib/crc/
lib/crc: Prepare for arch-optimized code in subdirs of lib/crc/
lib/crc: Move files into lib/crc/
lib/crc32: Remove unused combination support
...
Diffstat (limited to 'lib/crc/crc64-main.c')
-rw-r--r-- | lib/crc/crc64-main.c | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/lib/crc/crc64-main.c b/lib/crc/crc64-main.c new file mode 100644 index 000000000000..1337036010fe --- /dev/null +++ b/lib/crc/crc64-main.c @@ -0,0 +1,93 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Normal 64-bit CRC calculation. + * + * This is a basic crc64 implementation following ECMA-182 specification, + * which can be found from, + * https://www.ecma-international.org/publications/standards/Ecma-182.htm + * + * Dr. Ross N. Williams has a great document to introduce the idea of CRC + * algorithm, here the CRC64 code is also inspired by the table-driven + * algorithm and detail example from this paper. This paper can be found + * from, + * http://www.ross.net/crc/download/crc_v3.txt + * + * crc64table[256] is the lookup table of a table-driven 64-bit CRC + * calculation, which is generated by gen_crc64table.c in kernel build + * time. The polynomial of crc64 arithmetic is from ECMA-182 specification + * as well, which is defined as, + * + * x^64 + x^62 + x^57 + x^55 + x^54 + x^53 + x^52 + x^47 + x^46 + x^45 + + * x^40 + x^39 + x^38 + x^37 + x^35 + x^33 + x^32 + x^31 + x^29 + x^27 + + * x^24 + x^23 + x^22 + x^21 + x^19 + x^17 + x^13 + x^12 + x^10 + x^9 + + * x^7 + x^4 + x + 1 + * + * crc64nvmetable[256] uses the CRC64 polynomial from the NVME NVM Command Set + * Specification and uses least-significant-bit first bit order: + * + * x^64 + x^63 + x^61 + x^59 + x^58 + x^56 + x^55 + x^52 + x^49 + x^48 + x^47 + + * x^46 + x^44 + x^41 + x^37 + x^36 + x^34 + x^32 + x^31 + x^28 + x^26 + x^23 + + * x^22 + x^19 + x^16 + x^13 + x^12 + x^10 + x^9 + x^6 + x^4 + x^3 + 1 + * + * Copyright 2018 SUSE Linux. + * Author: Coly Li <colyli@suse.de> + */ + +#include <linux/crc64.h> +#include <linux/export.h> +#include <linux/module.h> +#include <linux/types.h> + +#include "crc64table.h" + +static inline u64 __maybe_unused +crc64_be_generic(u64 crc, const u8 *p, size_t len) +{ + while (len--) + crc = (crc << 8) ^ crc64table[(crc >> 56) ^ *p++]; + return crc; +} + +static inline u64 __maybe_unused +crc64_nvme_generic(u64 crc, const u8 *p, size_t len) +{ + while (len--) + crc = (crc >> 8) ^ crc64nvmetable[(crc & 0xff) ^ *p++]; + return crc; +} + +#ifdef CONFIG_CRC64_ARCH +#include "crc64.h" /* $(SRCARCH)/crc64.h */ +#else +#define crc64_be_arch crc64_be_generic +#define crc64_nvme_arch crc64_nvme_generic +#endif + +u64 crc64_be(u64 crc, const void *p, size_t len) +{ + return crc64_be_arch(crc, p, len); +} +EXPORT_SYMBOL_GPL(crc64_be); + +u64 crc64_nvme(u64 crc, const void *p, size_t len) +{ + return ~crc64_nvme_arch(~crc, p, len); +} +EXPORT_SYMBOL_GPL(crc64_nvme); + +#ifdef crc64_mod_init_arch +static int __init crc64_mod_init(void) +{ + crc64_mod_init_arch(); + return 0; +} +subsys_initcall(crc64_mod_init); + +static void __exit crc64_mod_exit(void) +{ +} +module_exit(crc64_mod_exit); +#endif + +MODULE_DESCRIPTION("CRC64 library functions"); +MODULE_LICENSE("GPL"); |