Commit b2eadbf4 authored by Ard Biesheuvel's avatar Ard Biesheuvel Committed by Herbert Xu
Browse files

crypto: arm64/sha2-ce - simplify NEON yield 



Instead of calling into kernel_neon_end() and kernel_neon_begin() (and
potentially into schedule()) from the assembler code when running in
task mode and a reschedule is pending, perform only the preempt count
check in assembler, but simply return early in this case, and let the C
code deal with the consequences.

This reverts commit d82f37ab.

Signed-off-by: default avatarArd Biesheuvel <ardb@kernel.org>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 5a69e1b7

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

+13 −25
Original line number Diff line number Diff line
@@ -76,36 +76,30 @@ 
	 */

	.text

SYM_FUNC_START(sha2_ce_transform)

	frame_push	3



	mov		x19, x0

	mov		x20, x1

	mov		x21, x2



	/* load round constants */

0:	adr_l		x8, .Lsha2_rcon

	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}, [x19]

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



	/* load sha256_ce_state::finalize */

	ldr_l		w4, sha256_ce_offsetof_finalize, x4

	ldr		w4, [x19, x4]

	ldr		w4, [x0, x4]



	/* load input */

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

	sub		w21, w21, #1

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

	sub		w2, w2, #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	)



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

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

	mov		dg0v.16b, dgav.16b

	mov		dg1v.16b, dgbv.16b
@@ -134,24 +128,18 @@ CPU_LE( rev32 v19.16b, v19.16b ) 
	add		dgbv.4s, dgbv.4s, dg1v.4s



	/* handled all input blocks? */

	cbz		w21, 3f



	if_will_cond_yield_neon

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

	do_cond_yield_neon

	cbz		w2, 2f

	cond_yield	3f, x5

	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.

	 */

3:	cbz		x4, 4f

2:	cbz		x4, 3f

	ldr_l		w4, sha256_ce_offsetof_count, x4

	ldr		x4, [x19, x4]

	ldr		x4, [x0, x4]

	movi		v17.2d, #0

	mov		x8, #0x80000000

	movi		v18.2d, #0
@@ -160,10 +148,10 @@ CPU_LE( rev32 v19.16b, v19.16b ) 
	mov		x4, #0

	mov		v19.d[0], xzr

	mov		v19.d[1], x7

	b		2b

	b		1b



	/* store new state */

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

	frame_pop

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

	mov		w0, w2

	ret

SYM_FUNC_END(sha2_ce_transform)

arch/arm64/crypto/sha2-ce-glue.c

+12 −10
Original line number Diff line number Diff line
@@ -30,14 +30,22 @@ struct sha256_ce_state { 
extern const u32 sha256_ce_offsetof_count;

extern const u32 sha256_ce_offsetof_finalize;



asmlinkage void sha2_ce_transform(struct sha256_ce_state *sst, u8 const *src,

asmlinkage int sha2_ce_transform(struct sha256_ce_state *sst, u8 const *src,

				 int blocks);



static void __sha2_ce_transform(struct sha256_state *sst, u8 const *src,

				int blocks)

{

	sha2_ce_transform(container_of(sst, struct sha256_ce_state, sst), src,

			  blocks);

	while (blocks) {

		int rem;



		kernel_neon_begin();

		rem = sha2_ce_transform(container_of(sst, struct sha256_ce_state,

						     sst), src, blocks);

		kernel_neon_end();

		src += (blocks - rem) * SHA256_BLOCK_SIZE;

		blocks = rem;

	}

}



const u32 sha256_ce_offsetof_count = offsetof(struct sha256_ce_state,
@@ -63,9 +71,7 @@ static int sha256_ce_update(struct shash_desc *desc, const u8 *data, 
				__sha256_block_data_order);



	sctx->finalize = 0;

	kernel_neon_begin();

	sha256_base_do_update(desc, data, len, __sha2_ce_transform);

	kernel_neon_end();



	return 0;

}
@@ -90,11 +96,9 @@ static int sha256_ce_finup(struct shash_desc *desc, const u8 *data, 
	 */

	sctx->finalize = finalize;



	kernel_neon_begin();

	sha256_base_do_update(desc, data, len, __sha2_ce_transform);

	if (!finalize)

		sha256_base_do_finalize(desc, __sha2_ce_transform);

	kernel_neon_end();

	return sha256_base_finish(desc, out);

}
@@ -108,9 +112,7 @@ static int sha256_ce_final(struct shash_desc *desc, u8 *out) 
	}



	sctx->finalize = 0;

	kernel_neon_begin();

	sha256_base_do_finalize(desc, __sha2_ce_transform);

	kernel_neon_end();

	return sha256_base_finish(desc, out);

}