Commit fd501713 authored by Eric Biggers's avatar Eric Biggers
Browse files

lib/crypto: arm64/sha1: 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-1 code accordingly.

Reviewed-by: default avatarArd Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20260401000548.133151-6-ebiggers@kernel.org


Signed-off-by: default avatarEric Biggers <ebiggers@kernel.org>
parent dec1061f

lib/crypto/arm64/sha1-ce-core.S

+5 −9
Original line number Diff line number Diff line
@@ -62,10 +62,10 @@ 
	.endm



	/*

	 * size_t __sha1_ce_transform(struct sha1_block_state *state,

	 * void sha1_ce_transform(struct sha1_block_state *state,

	 *			  const u8 *data, size_t nblocks);

	 */

SYM_FUNC_START(__sha1_ce_transform)

SYM_FUNC_START(sha1_ce_transform)

	/* load round constants */

	loadrc		k0.4s, 0x5a827999, w6

	loadrc		k1.4s, 0x6ed9eba1, w6
@@ -116,15 +116,11 @@ CPU_LE( rev32 v11.16b, v11.16b ) 
	add		dgbv.2s, dgbv.2s, dg1v.2s

	add		dgav.4s, dgav.4s, dg0v.4s



	/* return early if voluntary preemption is needed */

	cond_yield	1f, x5, x6



	/* handled all input blocks? */

	cbnz		x2, 0b



	/* store new state */

1:	st1		{dgav.4s}, [x0]

	st1		{dgav.4s}, [x0]

	str		dgb, [x0, #16]

	mov		x0, x2

	ret

SYM_FUNC_END(__sha1_ce_transform)
 
SYM_FUNC_END(sha1_ce_transform)

lib/crypto/arm64/sha1.h

+4 −11
Original line number Diff line number Diff line
@@ -9,22 +9,15 @@ 


static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_ce);



asmlinkage size_t __sha1_ce_transform(struct sha1_block_state *state,

asmlinkage void sha1_ce_transform(struct sha1_block_state *state,

				  const u8 *data, size_t nblocks);



static void sha1_blocks(struct sha1_block_state *state,

			const u8 *data, size_t nblocks)

{

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

		do {

			size_t rem;



		scoped_ksimd()

				rem = __sha1_ce_transform(state, data, nblocks);



			data += (nblocks - rem) * SHA1_BLOCK_SIZE;

			nblocks = rem;

		} while (nblocks);

			sha1_ce_transform(state, data, nblocks);

	} else {

		sha1_blocks_generic(state, data, nblocks);

	}