crypto: arm64/crc32 - add non-SIMD scalar fallback

The arm64 kernel will shortly disallow nested kernel mode NEON, so
add a fallback to scalar C code that can be invoked in that case.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Ard Biesheuvel 2017-07-24 11:28:07 +01:00 committed by Herbert Xu
parent 2dde374e1f
commit 15c7d8f8a2

View File

@ -1,7 +1,7 @@
/*
* Accelerated CRC32(C) using arm64 NEON and Crypto Extensions instructions
*
* Copyright (C) 2016 Linaro Ltd <ard.biesheuvel@linaro.org>
* Copyright (C) 2016 - 2017 Linaro Ltd <ard.biesheuvel@linaro.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
@ -19,6 +19,7 @@
#include <asm/hwcap.h>
#include <asm/neon.h>
#include <asm/simd.h>
#include <asm/unaligned.h>
#define PMULL_MIN_LEN 64L /* minimum size of buffer
@ -105,10 +106,10 @@ static int crc32_pmull_update(struct shash_desc *desc, const u8 *data,
length -= l;
}
if (length >= PMULL_MIN_LEN) {
if (length >= PMULL_MIN_LEN && may_use_simd()) {
l = round_down(length, SCALE_F);
kernel_neon_begin_partial(10);
kernel_neon_begin();
*crc = crc32_pmull_le(data, l, *crc);
kernel_neon_end();
@ -137,10 +138,10 @@ static int crc32c_pmull_update(struct shash_desc *desc, const u8 *data,
length -= l;
}
if (length >= PMULL_MIN_LEN) {
if (length >= PMULL_MIN_LEN && may_use_simd()) {
l = round_down(length, SCALE_F);
kernel_neon_begin_partial(10);
kernel_neon_begin();
*crc = crc32c_pmull_le(data, l, *crc);
kernel_neon_end();