Commit 6d575f11 authored by Eric Biggers's avatar Eric Biggers
Browse files

lib/crypto: arm64/sha3: Remove obsolete chunking logic 



Since commit aefbab8e ("arm64: fpsimd: Preserve/restore kernel mode
NEON at context switch"), kernel-mode NEON sections have been
preemptible on arm64.  And since commit 7dadeaa6 ("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 SHA-3 code accordingly.

Reviewed-by: default avatarArd Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20260401000548.133151-9-ebiggers@kernel.org


Signed-off-by: default avatarEric Biggers <ebiggers@kernel.org>
parent 7116418f

lib/crypto/arm64/sha3-ce-core.S

+3 −5
Original line number Diff line number Diff line
@@ -37,7 +37,7 @@ 
	.endm



	/*

	 * size_t sha3_ce_transform(struct sha3_state *state, const u8 *data,

	 * void sha3_ce_transform(struct sha3_state *state, const u8 *data,

	 *			  size_t nblocks, size_t block_size)

	 *

	 * block_size is assumed to be one of 72 (SHA3-512), 104 (SHA3-384), 136
@@ -185,18 +185,16 @@ SYM_FUNC_START(sha3_ce_transform) 
	eor	 v0.16b,  v0.16b, v31.16b



	cbnz	w8, 3b

	cond_yield 4f, x8, x9

	cbnz	x2, 0b



	/* save state */

4:	st1	{ v0.1d- v3.1d}, [x0], #32

	st1	{ v0.1d- v3.1d}, [x0], #32

	st1	{ v4.1d- v7.1d}, [x0], #32

	st1	{ v8.1d-v11.1d}, [x0], #32

	st1	{v12.1d-v15.1d}, [x0], #32

	st1	{v16.1d-v19.1d}, [x0], #32

	st1	{v20.1d-v23.1d}, [x0], #32

	st1	{v24.1d}, [x0]

	mov	x0, x2

	ret

SYM_FUNC_END(sha3_ce_transform)

lib/crypto/arm64/sha3.h

+4 −11
Original line number Diff line number Diff line
@@ -12,22 +12,15 @@ 


static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_sha3);



asmlinkage size_t sha3_ce_transform(struct sha3_state *state, const u8 *data,

asmlinkage void sha3_ce_transform(struct sha3_state *state, const u8 *data,

				  size_t nblocks, size_t block_size);



static void sha3_absorb_blocks(struct sha3_state *state, const u8 *data,

			       size_t nblocks, size_t block_size)

{

	if (static_branch_likely(&have_sha3) && likely(may_use_simd())) {

		do {

			size_t rem;



		scoped_ksimd()

				rem = sha3_ce_transform(state, data, nblocks,

							block_size);

			data += (nblocks - rem) * block_size;

			nblocks = rem;

		} while (nblocks);

			sha3_ce_transform(state, data, nblocks, block_size);

	} else {

		sha3_absorb_blocks_generic(state, data, nblocks, block_size);

	}