Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
lib/crc32: expose whether the lib is really optimized at runtime
Make the CRC32 library export a function crc32_optimizations() which
returns flags that indicate which CRC32 functions are actually executing
optimized code at runtime.
This will be used to determine whether the crc32[c]-$arch shash
algorithms should be registered in the crypto API. btrfs could also
start using these flags instead of the hack that it currently uses where
it parses the crypto_shash_driver_name.
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20241202010844.144356-4-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
+35
+10
arch/arm64/lib/crc32-glue.c
+10
arch/arm64/lib/crc32-glue.c
···
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}
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EXPORT_SYMBOL(crc32_be_arch);
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+
u32 crc32_optimizations(void)
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{
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if (alternative_has_cap_likely(ARM64_HAS_CRC32))
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return CRC32_LE_OPTIMIZATION |
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CRC32_BE_OPTIMIZATION |
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CRC32C_OPTIMIZATION;
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return 0;
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}
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EXPORT_SYMBOL(crc32_optimizations);
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+
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MODULE_LICENSE("GPL");
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MODULE_DESCRIPTION("arm64-optimized CRC32 functions");
+10
arch/riscv/lib/crc32-riscv.c
+10
arch/riscv/lib/crc32-riscv.c
···
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}
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EXPORT_SYMBOL(crc32_be_arch);
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+
u32 crc32_optimizations(void)
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{
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if (riscv_has_extension_likely(RISCV_ISA_EXT_ZBC))
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return CRC32_LE_OPTIMIZATION |
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CRC32_BE_OPTIMIZATION |
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CRC32C_OPTIMIZATION;
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return 0;
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}
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EXPORT_SYMBOL(crc32_optimizations);
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+
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MODULE_LICENSE("GPL");
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MODULE_DESCRIPTION("Accelerated CRC32 implementation with Zbc extension");
+15
include/linux/crc32.h
+15
include/linux/crc32.h
···
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return crc32c_le_base(crc, p, len);
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}
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+
/*
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* crc32_optimizations() returns flags that indicate which CRC32 library
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* functions are using architecture-specific optimizations. Unlike
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* IS_ENABLED(CONFIG_CRC32_ARCH) it takes into account the different CRC32
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* variants and also whether any needed CPU features are available at runtime.
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*/
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#define CRC32_LE_OPTIMIZATION BIT(0) /* crc32_le() is optimized */
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#define CRC32_BE_OPTIMIZATION BIT(1) /* crc32_be() is optimized */
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#define CRC32C_OPTIMIZATION BIT(2) /* __crc32c_le() is optimized */
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#if IS_ENABLED(CONFIG_CRC32_ARCH)
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u32 crc32_optimizations(void);
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#else
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static inline u32 crc32_optimizations(void) { return 0; }
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#endif
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+
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/**
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* crc32_le_combine - Combine two crc32 check values into one. For two
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* sequences of bytes, seq1 and seq2 with lengths len1