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
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+13 −25
Original line number Original line Diff line number Diff line
@@ -76,36 +76,30 @@
	 */
	 */
	.text
	.text
SYM_FUNC_START(sha2_ce_transform)
SYM_FUNC_START(sha2_ce_transform)
	frame_push	3

	mov		x19, x0
	mov		x20, x1
	mov		x21, x2

	/* load round constants */
	/* load round constants */
0:	adr_l		x8, .Lsha2_rcon
	adr_l		x8, .Lsha2_rcon
	ld1		{ v0.4s- v3.4s}, [x8], #64
	ld1		{ v0.4s- v3.4s}, [x8], #64
	ld1		{ v4.4s- v7.4s}, [x8], #64
	ld1		{ v4.4s- v7.4s}, [x8], #64
	ld1		{ v8.4s-v11.4s}, [x8], #64
	ld1		{ v8.4s-v11.4s}, [x8], #64
	ld1		{v12.4s-v15.4s}, [x8]
	ld1		{v12.4s-v15.4s}, [x8]


	/* load state */
	/* load state */
	ld1		{dgav.4s, dgbv.4s}, [x19]
	ld1		{dgav.4s, dgbv.4s}, [x0]


	/* load sha256_ce_state::finalize */
	/* load sha256_ce_state::finalize */
	ldr_l		w4, sha256_ce_offsetof_finalize, x4
	ldr_l		w4, sha256_ce_offsetof_finalize, x4
	ldr		w4, [x19, x4]
	ldr		w4, [x0, x4]


	/* load input */
	/* load input */
1:	ld1		{v16.4s-v19.4s}, [x20], #64
0:	ld1		{v16.4s-v19.4s}, [x1], #64
	sub		w21, w21, #1
	sub		w2, w2, #1


CPU_LE(	rev32		v16.16b, v16.16b	)
CPU_LE(	rev32		v16.16b, v16.16b	)
CPU_LE(	rev32		v17.16b, v17.16b	)
CPU_LE(	rev32		v17.16b, v17.16b	)
CPU_LE(	rev32		v18.16b, v18.16b	)
CPU_LE(	rev32		v18.16b, v18.16b	)
CPU_LE(	rev32		v19.16b, v19.16b	)
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		dg0v.16b, dgav.16b
	mov		dg1v.16b, dgbv.16b
	mov		dg1v.16b, dgbv.16b


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


	/* handled all input blocks? */
	/* handled all input blocks? */
	cbz		w21, 3f
	cbz		w2, 2f

	cond_yield	3f, x5
	if_will_cond_yield_neon
	st1		{dgav.4s, dgbv.4s}, [x19]
	do_cond_yield_neon
	b		0b
	b		0b
	endif_yield_neon

	b		1b


	/*
	/*
	 * Final block: add padding and total bit count.
	 * Final block: add padding and total bit count.
	 * Skip if the input size was not a round multiple of the block size,
	 * 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.
	 * 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_l		w4, sha256_ce_offsetof_count, x4
	ldr		x4, [x19, x4]
	ldr		x4, [x0, x4]
	movi		v17.2d, #0
	movi		v17.2d, #0
	mov		x8, #0x80000000
	mov		x8, #0x80000000
	movi		v18.2d, #0
	movi		v18.2d, #0
@@ -160,10 +148,10 @@ CPU_LE( rev32 v19.16b, v19.16b )
	mov		x4, #0
	mov		x4, #0
	mov		v19.d[0], xzr
	mov		v19.d[0], xzr
	mov		v19.d[1], x7
	mov		v19.d[1], x7
	b		2b
	b		1b


	/* store new state */
	/* store new state */
4:	st1		{dgav.4s, dgbv.4s}, [x19]
3:	st1		{dgav.4s, dgbv.4s}, [x0]
	frame_pop
	mov		w0, w2
	ret
	ret
SYM_FUNC_END(sha2_ce_transform)
SYM_FUNC_END(sha2_ce_transform)
+12 −10
Original line number Original line 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_count;
extern const u32 sha256_ce_offsetof_finalize;
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);
				 int blocks);


static void __sha2_ce_transform(struct sha256_state *sst, u8 const *src,
static void __sha2_ce_transform(struct sha256_state *sst, u8 const *src,
				int blocks)
				int blocks)
{
{
	sha2_ce_transform(container_of(sst, struct sha256_ce_state, sst), src,
	while (blocks) {
			  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,
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);
				__sha256_block_data_order);


	sctx->finalize = 0;
	sctx->finalize = 0;
	kernel_neon_begin();
	sha256_base_do_update(desc, data, len, __sha2_ce_transform);
	sha256_base_do_update(desc, data, len, __sha2_ce_transform);
	kernel_neon_end();


	return 0;
	return 0;
}
}
@@ -90,11 +96,9 @@ static int sha256_ce_finup(struct shash_desc *desc, const u8 *data,
	 */
	 */
	sctx->finalize = finalize;
	sctx->finalize = finalize;


	kernel_neon_begin();
	sha256_base_do_update(desc, data, len, __sha2_ce_transform);
	sha256_base_do_update(desc, data, len, __sha2_ce_transform);
	if (!finalize)
	if (!finalize)
		sha256_base_do_finalize(desc, __sha2_ce_transform);
		sha256_base_do_finalize(desc, __sha2_ce_transform);
	kernel_neon_end();
	return sha256_base_finish(desc, out);
	return sha256_base_finish(desc, out);
}
}


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


	sctx->finalize = 0;
	sctx->finalize = 0;
	kernel_neon_begin();
	sha256_base_do_finalize(desc, __sha2_ce_transform);
	sha256_base_do_finalize(desc, __sha2_ce_transform);
	kernel_neon_end();
	return sha256_base_finish(desc, out);
	return sha256_base_finish(desc, out);
}
}