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2025-04-28crypto: arm - move library functions to arch/arm/lib/crypto/Eric Biggers
Continue disentangling the crypto library functions from the generic crypto infrastructure by moving the arm BLAKE2s, ChaCha, and Poly1305 library functions into a new directory arch/arm/lib/crypto/ that does not depend on CRYPTO. This mirrors the distinction between crypto/ and lib/crypto/. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2025-04-19crypto: lib/chacha - restore ability to remove modulesEric Biggers
Though the module_exit functions are now no-ops, they should still be defined, since otherwise the modules become unremovable. Fixes: 08820553f33a ("crypto: arm/chacha - remove the redundant skcipher algorithms") Fixes: 8c28abede16c ("crypto: arm64/chacha - remove the skcipher algorithms") Fixes: f7915484c020 ("crypto: powerpc/chacha - remove the skcipher algorithms") Fixes: ceba0eda8313 ("crypto: riscv/chacha - implement library instead of skcipher") Fixes: 632ab0978f08 ("crypto: x86/chacha - remove the skcipher algorithms") Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2025-04-07crypto: arm/chacha - remove the redundant skcipher algorithmsEric Biggers
Since crypto/chacha.c now registers chacha20-$(ARCH), xchacha20-$(ARCH), and xchacha12-$(ARCH) skcipher algorithms that use the architecture's ChaCha and HChaCha library functions, individual architectures no longer need to do the same. Therefore, remove the redundant skcipher algorithms and leave just the library functions. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2025-04-07crypto: chacha - centralize the skcipher wrappers for arch codeEric Biggers
Following the example of the crc32 and crc32c code, make the crypto subsystem register both generic and architecture-optimized chacha20, xchacha20, and xchacha12 skcipher algorithms, all implemented on top of the appropriate library functions. This eliminates the need for every architecture to implement the same skcipher glue code. To register the architecture-optimized skciphers only when architecture-optimized code is actually being used, add a function chacha_is_arch_optimized() and make each arch implement it. Change each architecture's ChaCha module_init function to arch_initcall so that the CPU feature detection is guaranteed to run before chacha_is_arch_optimized() gets called by crypto/chacha.c. In the case of s390, remove the CPU feature based module autoloading, which is no longer needed since the module just gets pulled in via function linkage. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2025-03-21crypto: lib/chacha - remove unused arch-specific init supportEric Biggers
All implementations of chacha_init_arch() just call chacha_init_generic(), so it is pointless. Just delete it, and replace chacha_init() with what was previously chacha_init_generic(). Signed-off-by: Eric Biggers <ebiggers@google.com> Acked-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2021-01-03crypto: arm/chacha-neon - add missing counter incrementArd Biesheuvel
Commit 86cd97ec4b943af3 ("crypto: arm/chacha-neon - optimize for non-block size multiples") refactored the chacha block handling in the glue code in a way that may result in the counter increment to be omitted when calling chacha_block_xor_neon() to process a full block. This violates the skcipher API, which requires that the output IV is suitable for handling more input as long as the preceding input has been presented in round multiples of the block size. Also, the same code is exposed via the chacha library interface whose callers may actually rely on this increment to occur even for final blocks that are smaller than the chacha block size. So increment the counter after calling chacha_block_xor_neon(). Fixes: 86cd97ec4b943af3 ("crypto: arm/chacha-neon - optimize for non-block size multiples") Reported-by: Eric Biggers <ebiggers@kernel.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-11-13crypto: arm/chacha-neon - optimize for non-block size multiplesArd Biesheuvel
The current NEON based ChaCha implementation for ARM is optimized for multiples of 4x the ChaCha block size (64 bytes). This makes sense for block encryption, but given that ChaCha is also often used in the context of networking, it makes sense to consider arbitrary length inputs as well. For example, WireGuard typically uses 1420 byte packets, and performing ChaCha encryption involves 5 invocations of chacha_4block_xor_neon() and 3 invocations of chacha_block_xor_neon(), where the last one also involves a memcpy() using a buffer on the stack to process the final chunk of 1420 % 64 == 12 bytes. Let's optimize for this case as well, by letting chacha_4block_xor_neon() deal with any input size between 64 and 256 bytes, using NEON permutation instructions and overlapping loads and stores. This way, the 140 byte tail of a 1420 byte input buffer can simply be processed in one go. This results in the following performance improvements for 1420 byte blocks, without significant impact on power-of-2 input sizes. (Note that Raspberry Pi is widely used in combination with a 32-bit kernel, even though the core is 64-bit capable) Cortex-A8 (BeagleBone) : 7% Cortex-A15 (Calxeda Midway) : 21% Cortex-A53 (Raspberry Pi 3) : 3% Cortex-A72 (Raspberry Pi 4) : 19% Cc: Eric Biggers <ebiggers@google.com> Cc: "Jason A . Donenfeld" <Jason@zx2c4.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-04-30crypto: arch/lib - limit simd usage to 4k chunksJason A. Donenfeld
The initial Zinc patchset, after some mailing list discussion, contained code to ensure that kernel_fpu_enable would not be kept on for more than a 4k chunk, since it disables preemption. The choice of 4k isn't totally scientific, but it's not a bad guess either, and it's what's used in both the x86 poly1305, blake2s, and nhpoly1305 code already (in the form of PAGE_SIZE, which this commit corrects to be explicitly 4k for the former two). Ard did some back of the envelope calculations and found that at 5 cycles/byte (overestimate) on a 1ghz processor (pretty slow), 4k means we have a maximum preemption disabling of 20us, which Sebastian confirmed was probably a good limit. Unfortunately the chunking appears to have been left out of the final patchset that added the glue code. So, this commit adds it back in. Fixes: 84e03fa39fbe ("crypto: x86/chacha - expose SIMD ChaCha routine as library function") Fixes: b3aad5bad26a ("crypto: arm64/chacha - expose arm64 ChaCha routine as library function") Fixes: a44a3430d71b ("crypto: arm/chacha - expose ARM ChaCha routine as library function") Fixes: d7d7b8535662 ("crypto: x86/poly1305 - wire up faster implementations for kernel") Fixes: f569ca164751 ("crypto: arm64/poly1305 - incorporate OpenSSL/CRYPTOGAMS NEON implementation") Fixes: a6b803b3ddc7 ("crypto: arm/poly1305 - incorporate OpenSSL/CRYPTOGAMS NEON implementation") Fixes: ed0356eda153 ("crypto: blake2s - x86_64 SIMD implementation") Cc: Eric Biggers <ebiggers@google.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: stable@vger.kernel.org Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-01-22crypto: arm/chacha - fix build failured when kernel mode NEON is disabledArd Biesheuvel
When the ARM accelerated ChaCha driver is built as part of a configuration that has kernel mode NEON disabled, we expect the compiler to propagate the build time constant expression IS_ENABLED(CONFIG_KERNEL_MODE_NEON) in a way that eliminates all the cross-object references to the actual NEON routines, which allows the chacha-neon-core.o object to be omitted from the build entirely. Unfortunately, this fails to work as expected in some cases, and we may end up with a build error such as chacha-glue.c:(.text+0xc0): undefined reference to `chacha_4block_xor_neon' caused by the fact that chacha_doneon() has not been eliminated from the object code, even though it will never be called in practice. Let's fix this by adding some IS_ENABLED(CONFIG_KERNEL_MODE_NEON) tests that are not strictly needed from a logical point of view, but should help the compiler infer that the NEON code paths are unreachable in those cases. Fixes: b36d8c09e710c71f ("crypto: arm/chacha - remove dependency on generic ...") Reported-by: Russell King <linux@armlinux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-11-27crypto: arch - conditionalize crypto api in arch glue for lib codeJason A. Donenfeld
For glue code that's used by Zinc, the actual Crypto API functions might not necessarily exist, and don't need to exist either. Before this patch, there are valid build configurations that lead to a unbuildable kernel. This fixes it to conditionalize those symbols on the existence of the proper config entry. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Acked-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-11-17crypto: arm/chacha - expose ARM ChaCha routine as library functionArd Biesheuvel
Expose the accelerated NEON ChaCha routine directly as a symbol export so that users of the ChaCha library API can use it directly. Given that calls into the library API will always go through the routines in this module if it is enabled, switch to static keys to select the optimal implementation available (which may be none at all, in which case we defer to the generic implementation for all invocations). Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-11-17crypto: arm/chacha - remove dependency on generic ChaCha driverArd Biesheuvel
Instead of falling back to the generic ChaCha skcipher driver for non-SIMD cases, use a fast scalar implementation for ARM authored by Eric Biggers. This removes the module dependency on chacha-generic altogether, which also simplifies things when we expose the ChaCha library interface from this module. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>