Commit 7116418f authored by Eric Biggers's avatar Eric Biggers
Browse files

lib/crypto: arm64/sha512: 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-512 code accordingly.

Reviewed-by: default avatarArd Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20260401000548.133151-8-ebiggers@kernel.org


Signed-off-by: default avatarEric Biggers <ebiggers@kernel.org>
parent fe1233c2

lib/crypto/arm64/sha512-ce-core.S

+5 −7
Original line number Diff line number Diff line
@@ -93,11 +93,11 @@ 
	.endm



	/*

	 * size_t __sha512_ce_transform(struct sha512_block_state *state,

	 * void sha512_ce_transform(struct sha512_block_state *state,

	 *			    const u8 *data, size_t nblocks);

	 */

	.text

SYM_FUNC_START(__sha512_ce_transform)

SYM_FUNC_START(sha512_ce_transform)

	/* load state */

	ld1		{v8.2d-v11.2d}, [x0]
@@ -186,12 +186,10 @@ CPU_LE( rev64 v19.16b, v19.16b ) 
	add		v10.2d, v10.2d, v2.2d

	add		v11.2d, v11.2d, v3.2d



	cond_yield	3f, x4, x5

	/* handled all input blocks? */

	cbnz		x2, 0b



	/* store new state */

3:	st1		{v8.2d-v11.2d}, [x0]

	mov		x0, x2

	st1		{v8.2d-v11.2d}, [x0]

	ret

SYM_FUNC_END(__sha512_ce_transform)
 
SYM_FUNC_END(sha512_ce_transform)

lib/crypto/arm64/sha512.h

+4 −11
Original line number Diff line number Diff line
@@ -12,7 +12,7 @@ static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_sha512_insns); 


asmlinkage void sha512_block_data_order(struct sha512_block_state *state,

					const u8 *data, size_t nblocks);

asmlinkage size_t __sha512_ce_transform(struct sha512_block_state *state,

asmlinkage void sha512_ce_transform(struct sha512_block_state *state,

				    const u8 *data, size_t nblocks);



static void sha512_blocks(struct sha512_block_state *state,
@@ -20,15 +20,8 @@ static void sha512_blocks(struct sha512_block_state *state, 
{

	if (static_branch_likely(&have_sha512_insns) &&

	    likely(may_use_simd())) {

		do {

			size_t rem;



		scoped_ksimd()

				rem = __sha512_ce_transform(state, data, nblocks);



			data += (nblocks - rem) * SHA512_BLOCK_SIZE;

			nblocks = rem;

		} while (nblocks);

			sha512_ce_transform(state, data, nblocks);

	} else {

		sha512_block_data_order(state, data, nblocks);

	}