Commit d82f37ab authored by Ard Biesheuvel's avatar Ard Biesheuvel Committed by Herbert Xu
Browse files

crypto: arm64/sha2-ce - yield NEON after every block of input 



Avoid excessive scheduling delays under a preemptible kernel by
yielding the NEON after every block of input.

Signed-off-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 7df8d164

arch/arm64/crypto/sha2-ce-core.S

+26 −11
Original line number Diff line number Diff line
@@ -79,30 +79,36 @@ 
	 */

	.text

ENTRY(sha2_ce_transform)

	frame_push	3



	mov		x19, x0

	mov		x20, x1

	mov		x21, x2



	/* load round constants */

	adr_l		x8, .Lsha2_rcon

0:	adr_l		x8, .Lsha2_rcon

	ld1		{ v0.4s- v3.4s}, [x8], #64

	ld1		{ v4.4s- v7.4s}, [x8], #64

	ld1		{ v8.4s-v11.4s}, [x8], #64

	ld1		{v12.4s-v15.4s}, [x8]



	/* load state */

	ld1		{dgav.4s, dgbv.4s}, [x0]

	ld1		{dgav.4s, dgbv.4s}, [x19]



	/* load sha256_ce_state::finalize */

	ldr_l		w4, sha256_ce_offsetof_finalize, x4

	ldr		w4, [x0, x4]

	ldr		w4, [x19, x4]



	/* load input */

0:	ld1		{v16.4s-v19.4s}, [x1], #64

	sub		w2, w2, #1

1:	ld1		{v16.4s-v19.4s}, [x20], #64

	sub		w21, w21, #1



CPU_LE(	rev32		v16.16b, v16.16b	)

CPU_LE(	rev32		v17.16b, v17.16b	)

CPU_LE(	rev32		v18.16b, v18.16b	)

CPU_LE(	rev32		v19.16b, v19.16b	)



1:	add		t0.4s, v16.4s, v0.4s

2:	add		t0.4s, v16.4s, v0.4s

	mov		dg0v.16b, dgav.16b

	mov		dg1v.16b, dgbv.16b
@@ -131,16 +137,24 @@ CPU_LE( rev32 v19.16b, v19.16b ) 
	add		dgbv.4s, dgbv.4s, dg1v.4s



	/* handled all input blocks? */

	cbnz		w2, 0b

	cbz		w21, 3f



	if_will_cond_yield_neon

	st1		{dgav.4s, dgbv.4s}, [x19]

	do_cond_yield_neon

	b		0b

	endif_yield_neon



	b		1b



	/*

	 * Final block: add padding and total bit count.

	 * Skip if the input size was not a round multiple of the block size,

	 * the padding is handled by the C code in that case.

	 */

	cbz		x4, 3f

3:	cbz		x4, 4f

	ldr_l		w4, sha256_ce_offsetof_count, x4

	ldr		x4, [x0, x4]

	ldr		x4, [x19, x4]

	movi		v17.2d, #0

	mov		x8, #0x80000000

	movi		v18.2d, #0
@@ -149,9 +163,10 @@ CPU_LE( rev32 v19.16b, v19.16b ) 
	mov		x4, #0

	mov		v19.d[0], xzr

	mov		v19.d[1], x7

	b		1b

	b		2b



	/* store new state */

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

4:	st1		{dgav.4s, dgbv.4s}, [x19]

	frame_pop

	ret

ENDPROC(sha2_ce_transform)