diff options
| author | Eric Biggers <ebiggers@google.com> | 2024-12-01 17:08:28 -0800 |
|---|---|---|
| committer | Eric Biggers <ebiggers@google.com> | 2024-12-01 17:23:01 -0800 |
| commit | b5ae12e0ee099e4c458f7814f0317f4e2cbf105e (patch) | |
| tree | 2971f631ae4a609aafc5c4e5c932bcd8a6117ab9 | |
| parent | d36cebe03c3ae4ea1fde20cfc797fab8729c3ab5 (diff) | |
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>
| -rw-r--r-- | arch/arm64/lib/crc32-glue.c | 10 | ||||
| -rw-r--r-- | arch/riscv/lib/crc32-riscv.c | 10 | ||||
| -rw-r--r-- | include/linux/crc32.h | 15 |
3 files changed, 35 insertions, 0 deletions
diff --git a/arch/arm64/lib/crc32-glue.c b/arch/arm64/lib/crc32-glue.c index d7f6e1cbf0d2..15c4c9db573e 100644 --- a/arch/arm64/lib/crc32-glue.c +++ b/arch/arm64/lib/crc32-glue.c @@ -85,5 +85,15 @@ u32 __pure crc32_be_arch(u32 crc, const u8 *p, size_t len) } EXPORT_SYMBOL(crc32_be_arch); +u32 crc32_optimizations(void) +{ + if (alternative_has_cap_likely(ARM64_HAS_CRC32)) + return CRC32_LE_OPTIMIZATION | + CRC32_BE_OPTIMIZATION | + CRC32C_OPTIMIZATION; + return 0; +} +EXPORT_SYMBOL(crc32_optimizations); + MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("arm64-optimized CRC32 functions"); diff --git a/arch/riscv/lib/crc32-riscv.c b/arch/riscv/lib/crc32-riscv.c index a3ff7db2a1ce..53d56ab422c7 100644 --- a/arch/riscv/lib/crc32-riscv.c +++ b/arch/riscv/lib/crc32-riscv.c @@ -297,5 +297,15 @@ legacy: } EXPORT_SYMBOL(crc32_be_arch); +u32 crc32_optimizations(void) +{ + if (riscv_has_extension_likely(RISCV_ISA_EXT_ZBC)) + return CRC32_LE_OPTIMIZATION | + CRC32_BE_OPTIMIZATION | + CRC32C_OPTIMIZATION; + return 0; +} +EXPORT_SYMBOL(crc32_optimizations); + MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("Accelerated CRC32 implementation with Zbc extension"); diff --git a/include/linux/crc32.h b/include/linux/crc32.h index 58c632533b08..e9bd40056687 100644 --- a/include/linux/crc32.h +++ b/include/linux/crc32.h @@ -37,6 +37,21 @@ static inline u32 __pure __crc32c_le(u32 crc, const u8 *p, size_t len) return crc32c_le_base(crc, p, len); } +/* + * crc32_optimizations() returns flags that indicate which CRC32 library + * functions are using architecture-specific optimizations. Unlike + * IS_ENABLED(CONFIG_CRC32_ARCH) it takes into account the different CRC32 + * variants and also whether any needed CPU features are available at runtime. + */ +#define CRC32_LE_OPTIMIZATION BIT(0) /* crc32_le() is optimized */ +#define CRC32_BE_OPTIMIZATION BIT(1) /* crc32_be() is optimized */ +#define CRC32C_OPTIMIZATION BIT(2) /* __crc32c_le() is optimized */ +#if IS_ENABLED(CONFIG_CRC32_ARCH) +u32 crc32_optimizations(void); +#else +static inline u32 crc32_optimizations(void) { return 0; } +#endif + /** * crc32_le_combine - Combine two crc32 check values into one. For two * sequences of bytes, seq1 and seq2 with lengths len1 |