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crypto: algapi - use separate dst and src operands for __crypto_xor()

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In preparation of introducing crypto_xor_cpy(), which will use separate
operands for input and output, modify the __crypto_xor() implementation,
which it will share with the existing crypto_xor(), which provides the
actual functionality when not using the inline version.

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 11:28:03 +01:00 committed by Herbert Xu
parent 9a42e4eed3
commit a7c391f04f
2 changed files with 17 additions and 12 deletions
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25
crypto/algapi.c
View file

@ -975,13 +975,15 @@ void crypto_inc(u8 *a, unsigned int size)
}
EXPORT_SYMBOL_GPL(crypto_inc);
void __crypto_xor(u8 *dst, const u8 *src, unsigned int len)
void __crypto_xor(u8 *dst, const u8 *src1, const u8 *src2, unsigned int len)
{
int relalign = 0;
if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)) {
int size = sizeof(unsigned long);
int d = ((unsigned long)dst ^ (unsigned long)src) & (size - 1);
int d = (((unsigned long)dst ^ (unsigned long)src1) |
((unsigned long)dst ^ (unsigned long)src2)) &
(size - 1);
relalign = d ? 1 << __ffs(d) : size;
@ -992,34 +994,37 @@ void __crypto_xor(u8 *dst, const u8 *src, unsigned int len)
* process the remainder of the input using optimal strides.
*/
while (((unsigned long)dst & (relalign - 1)) && len > 0) {
*dst++ ^= *src++;
*dst++ = *src1++ ^ *src2++;
len--;
}
}
while (IS_ENABLED(CONFIG_64BIT) && len >= 8 && !(relalign & 7)) {
*(u64 *)dst ^= *(u64 *)src;
*(u64 *)dst = *(u64 *)src1 ^ *(u64 *)src2;
dst += 8;
src += 8;
src1 += 8;
src2 += 8;
len -= 8;
}
while (len >= 4 && !(relalign & 3)) {
*(u32 *)dst ^= *(u32 *)src;
*(u32 *)dst = *(u32 *)src1 ^ *(u32 *)src2;
dst += 4;
src += 4;
src1 += 4;
src2 += 4;
len -= 4;
}
while (len >= 2 && !(relalign & 1)) {
*(u16 *)dst ^= *(u16 *)src;
*(u16 *)dst = *(u16 *)src1 ^ *(u16 *)src2;
dst += 2;
src += 2;
src1 += 2;
src2 += 2;
len -= 2;
}
while (len--)
*dst++ ^= *src++;
*dst++ = *src1++ ^ *src2++;
}
EXPORT_SYMBOL_GPL(__crypto_xor);

4
include/crypto/algapi.h
View file

@ -192,7 +192,7 @@ static inline unsigned int crypto_queue_len(struct crypto_queue *queue)
}
void crypto_inc(u8 *a, unsigned int size);
void __crypto_xor(u8 *dst, const u8 *src, unsigned int size);
void __crypto_xor(u8 *dst, const u8 *src1, const u8 *src2, unsigned int size);
static inline void crypto_xor(u8 *dst, const u8 *src, unsigned int size)
{
@ -207,7 +207,7 @@ static inline void crypto_xor(u8 *dst, const u8 *src, unsigned int size)
size -= sizeof(unsigned long);
}
} else {
__crypto_xor(dst, src, size);
__crypto_xor(dst, dst, src, size);
}
}