From: Grant Likely <grant.likely@secretlab.ca>
To: "Albrecht Dreß" <albrecht.dress@arcor.de>
Cc: Linux PPC Development <linuxppc-dev@ozlabs.org>
Subject: Re: [PATCH] powerpc: tiny memcpy_(to|from)io optimisation
Date: Thu, 11 Jun 2009 11:30:11 -0600 [thread overview]
Message-ID: <fa686aa40906111030h5cebcbd6xeee76561601cf41a@mail.gmail.com> (raw)
In-Reply-To: <1243454441.3489.1@antares>
On Wed, May 27, 2009 at 2:00 PM, Albrecht Dre=DF<albrecht.dress@arcor.de> w=
rote:
> This trivial patch changes memcpy_(to|from)io as to transfer as many 32-b=
it
> words as possible in 32-bit accesses (in the current solution, the last
> 32-bit word was transferred as 4 byte accesses).
>
> Signed-off-by: Albrecht Dre=DF <albrecht.dress@arcor.de>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
> ---
>
> diff -urpN -X linux-2.6.29.1.orig/Documentation/dontdiff
> linux-2.6.29.1.orig/arch/powerpc/kernel/io.c
> linux-2.6.29.1/arch/powerpc/kernel/io.c
> --- linux-2.6.29.1.orig/arch/powerpc/kernel/io.c =A0 =A0 =A0 =A02009-04-0=
2
> 22:55:27.000000000 +0200
> +++ linux-2.6.29.1/arch/powerpc/kernel/io.c =A0 =A0 2009-05-27
> 11:36:09.000000000 +0200
> @@ -161,7 +161,7 @@ void _memcpy_fromio(void *dest, const vo
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0dest++;
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0n--;
> =A0 =A0 =A0 =A0}
> - =A0 =A0 =A0 while(n > 4) {
> + =A0 =A0 =A0 while(n >=3D 4) {
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0*((u32 *)dest) =3D *((volatile u32 *)vsrc)=
;
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0eieio();
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0vsrc +=3D 4;
> @@ -190,7 +190,7 @@ void _memcpy_toio(volatile void __iomem
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0vdest++;
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0n--;
> =A0 =A0 =A0 =A0}
> - =A0 =A0 =A0 while(n > 4) {
> + =A0 =A0 =A0 while(n >=3D 4) {
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0*((volatile u32 *)vdest) =3D *((volatile u=
32 *)src);
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0src +=3D 4;
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0vdest +=3D 4;
>
> _______________________________________________
> Linuxppc-dev mailing list
> Linuxppc-dev@ozlabs.org
> https://ozlabs.org/mailman/listinfo/linuxppc-dev
>
--=20
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.
next prev parent reply other threads:[~2009-06-11 17:30 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-05-27 20:00 [PATCH] powerpc: tiny memcpy_(to|from)io optimisation Albrecht Dreß
2009-05-28 16:13 ` Joakim Tjernlund
2009-05-28 19:50 ` Albrecht Dreß
2009-05-29 6:31 ` Joakim Tjernlund
2009-05-31 10:11 ` Albrecht Dreß
2009-06-01 6:14 ` Joakim Tjernlund
2009-06-02 18:45 ` Albrecht Dreß
2009-06-02 22:51 ` Benjamin Herrenschmidt
2009-06-03 14:36 ` Kenneth Johansson
2009-06-03 18:35 ` Albrecht Dreß
2009-06-11 17:07 ` Wolfram Sang
2009-06-11 17:30 ` Grant Likely [this message]
2009-06-19 18:42 ` Lorenz Kolb
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