From: Hannes Frederic Sowa <hannes@stressinduktion.org>
To: Tom Herbert <tom@herbertland.com>,
davem@davemloft.net, netdev@vger.kernel.org
Cc: kernel-team@fb.com, tglx@linutronix.de, mingo@redhat.com,
hpa@zytor.com, x86@kernel.org
Subject: Re: [PATCH v2 net-next] net: Implement fast csum_partial for x86_64
Date: Thu, 7 Jan 2016 02:52:04 +0100 [thread overview]
Message-ID: <568DC4C4.2050908@stressinduktion.org> (raw)
In-Reply-To: <1452019261-449449-1-git-send-email-tom@herbertland.com>
Hi Tom,
On 05.01.2016 19:41, Tom Herbert wrote:
> --- /dev/null
> +++ b/arch/x86/lib/csum-partial_64.S
> @@ -0,0 +1,147 @@
> +/* Copyright 2016 Tom Herbert <tom@herbertland.com>
> + *
> + * Checksum partial calculation
> + *
> + * __wsum csum_partial(const void *buff, int len, __wsum sum)
> + *
> + * Computes the checksum of a memory block at buff, length len,
> + * and adds in "sum" (32-bit)
> + *
> + * Returns a 32-bit number suitable for feeding into itself
> + * or csum_tcpudp_magic
> + *
> + * Register usage:
> + * %rdi: argument 1, buff
> + * %rsi: argument 2, length
> + * %rdx: argument 3, add in value
I think you forgot to carry-add-in the %rdx register.
The assembly code replaces do_csum but not csum_partial.
Bye,
Hannes
next prev parent reply other threads:[~2016-01-07 1:52 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-05 18:41 [PATCH v2 net-next] net: Implement fast csum_partial for x86_64 Tom Herbert
2016-01-05 22:18 ` Eric Dumazet
2016-01-06 1:10 ` H. Peter Anvin
2016-01-06 3:02 ` Eric Dumazet
2016-01-06 10:16 ` David Laight
2016-01-06 14:25 ` Eric Dumazet
2016-01-06 14:49 ` David Laight
2016-01-06 15:03 ` Eric Dumazet
2016-01-05 23:35 ` Hannes Frederic Sowa
2016-01-06 3:21 ` Eric Dumazet
2016-01-06 20:05 ` Andi Kleen
2016-01-07 1:52 ` Hannes Frederic Sowa [this message]
2016-01-07 2:36 ` Tom Herbert
2016-01-07 2:43 ` Hannes Frederic Sowa
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