[PATCH v2] LoongArch/crypto: Clean up useless assignment operations

[PATCH v2] LoongArch/crypto: Clean up useless assignment operations

[WangYuli]

The LoongArch CRC32 hw acceleration is based on
arch/mips/crypto/crc32-mips.c. While the MIPS code supports both
MIPS32 and MIPS64, LA32 lacks the CRC instruction. As a result,
"line len -= sizeof(u32)" is unnecessary.

Removing it can make context code style more unified and improve
code readability.

Suggested-by: Guan Wentao <guanwentao@uniontech.com>
Signed-off-by: WangYuli <wangyuli@uniontech.com>
---
 arch/loongarch/crypto/crc32-loongarch.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/arch/loongarch/crypto/crc32-loongarch.c b/arch/loongarch/crypto/crc32-loongarch.c
index a49e507af38c..3eebea3a7b47 100644
--- a/arch/loongarch/crypto/crc32-loongarch.c
+++ b/arch/loongarch/crypto/crc32-loongarch.c
@@ -44,7 +44,6 @@ static u32 crc32_loongarch_hw(u32 crc_, const u8 *p, unsigned int len)
 
 		CRC32(crc, value, w);
 		p += sizeof(u32);
-		len -= sizeof(u32);
 	}
 
 	if (len & sizeof(u16)) {
@@ -80,7 +79,6 @@ static u32 crc32c_loongarch_hw(u32 crc_, const u8 *p, unsigned int len)
 
 		CRC32C(crc, value, w);
 		p += sizeof(u32);
-		len -= sizeof(u32);
 	}
 
 	if (len & sizeof(u16)) {
-- 
2.43.0

Re: [PATCH v2] LoongArch/crypto: Clean up useless assignment operations

[Herbert Xu]

WangYuli <wangyuli@uniontech.com> wrote:
> The LoongArch CRC32 hw acceleration is based on
> arch/mips/crypto/crc32-mips.c. While the MIPS code supports both
> MIPS32 and MIPS64, LA32 lacks the CRC instruction. As a result,
> "line len -= sizeof(u32)" is unnecessary.
> 
> Removing it can make context code style more unified and improve
> code readability.
> 
> Suggested-by: Guan Wentao <guanwentao@uniontech.com>
> Signed-off-by: WangYuli <wangyuli@uniontech.com>
> ---
> arch/loongarch/crypto/crc32-loongarch.c | 2 --
> 1 file changed, 2 deletions(-)
> 
> diff --git a/arch/loongarch/crypto/crc32-loongarch.c b/arch/loongarch/crypto/crc32-loongarch.c
> index a49e507af38c..3eebea3a7b47 100644
> --- a/arch/loongarch/crypto/crc32-loongarch.c
> +++ b/arch/loongarch/crypto/crc32-loongarch.c
> @@ -44,7 +44,6 @@ static u32 crc32_loongarch_hw(u32 crc_, const u8 *p, unsigned int len)
> 
>                CRC32(crc, value, w);
>                p += sizeof(u32);
> -               len -= sizeof(u32);
>        }

This makes no sense whatsoever.  Please review this patch carefully
before you resubmit.

Thanks,
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

Re: [PATCH v2] LoongArch/crypto: Clean up useless assignment operations

[Herbert Xu]

On Fri, Mar 08, 2024 at 06:19:02PM +0800, Herbert Xu wrote:
>
> > diff --git a/arch/loongarch/crypto/crc32-loongarch.c b/arch/loongarch/crypto/crc32-loongarch.c
> > index a49e507af38c..3eebea3a7b47 100644
> > --- a/arch/loongarch/crypto/crc32-loongarch.c
> > +++ b/arch/loongarch/crypto/crc32-loongarch.c
> > @@ -44,7 +44,6 @@ static u32 crc32_loongarch_hw(u32 crc_, const u8 *p, unsigned int len)
> > 
> >                CRC32(crc, value, w);
> >                p += sizeof(u32);
> > -               len -= sizeof(u32);
> >        }
> 
> This makes no sense whatsoever.  Please review this patch carefully
> before you resubmit.

Nevermind, I see what's going on now.  Your reference to the lack
of a CRC instruction utterly confused me.

The fact that len -= is unnecessary has nothing to do with whether
there is a CRC instruction.

Please modify your patch description so that it is not needlessly
confusing.  You should simply state that len -= is unnecessary
because you only test whether the relevant bit is set in len for
the tail case.

Thanks,
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt