From: Eric Biggers Date: Wed, 1 Apr 2026 00:05:41 +0000 (-0700) Subject: lib/crypto: arm64/chacha: Remove obsolete chunking logic X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=63fcc765e1a30b7e04d395d7adc440443ae00338;p=thirdparty%2Fkernel%2Flinux.git lib/crypto: arm64/chacha: Remove obsolete chunking logic Since commit aefbab8e77eb ("arm64: fpsimd: Preserve/restore kernel mode NEON at context switch"), kernel-mode NEON sections have been preemptible on arm64. And since commit 7dadeaa6e851 ("sched: Further restrict the preemption modes"), voluntary preemption is no longer supported on arm64 either. Therefore, there's no longer any need to limit the length of kernel-mode NEON sections on arm64. Simplify the ChaCha code accordingly. Reviewed-by: Ard Biesheuvel Link: https://lore.kernel.org/r/20260401000548.133151-3-ebiggers@kernel.org Signed-off-by: Eric Biggers --- diff --git a/lib/crypto/arm64/chacha.h b/lib/crypto/arm64/chacha.h index ca8c6a8b05782..c6f8ddf98e2de 100644 --- a/lib/crypto/arm64/chacha.h +++ b/lib/crypto/arm64/chacha.h @@ -36,9 +36,9 @@ asmlinkage void hchacha_block_neon(const struct chacha_state *state, static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_neon); static void chacha_doneon(struct chacha_state *state, u8 *dst, const u8 *src, - int bytes, int nrounds) + unsigned int bytes, int nrounds) { - while (bytes > 0) { + while (bytes) { int l = min(bytes, CHACHA_BLOCK_SIZE * 5); if (l <= CHACHA_BLOCK_SIZE) { @@ -76,16 +76,8 @@ static void chacha_crypt_arch(struct chacha_state *state, u8 *dst, !crypto_simd_usable()) return chacha_crypt_generic(state, dst, src, bytes, nrounds); - do { - unsigned int todo = min_t(unsigned int, bytes, SZ_4K); - - scoped_ksimd() - chacha_doneon(state, dst, src, todo, nrounds); - - bytes -= todo; - src += todo; - dst += todo; - } while (bytes); + scoped_ksimd() + chacha_doneon(state, dst, src, bytes, nrounds); } #define chacha_mod_init_arch chacha_mod_init_arch