From: Sergei Shtylyov <sergei.shtylyov@cogentembedded•com>
To: Shradha Shah <sshah@solarflare•com>, netdev@vger•kernel.org
Cc: linux-net-drivers@solarflare•com
Subject: Re: [PATCH net v2 1/2] sfc: use 64-bit writes for PIO.
Date: Wed, 28 May 2014 18:48:57 +0400 [thread overview]
Message-ID: <5385F759.8010408@cogentembedded.com> (raw)
In-Reply-To: <5385ABE5.9070406@solarflare.com>
On 05/28/2014 01:27 PM, Shradha Shah wrote:
> From: Jon Cooper <jcooper@solarflare•com>
> Patch to open-code the memory copy routines.
> 32bit writes over the PCI bus causes data corruption.
> Fixes:ee45fd92c739db5b7950163d91dfe5f016af6d24
Same comment as in the patch #2
> orig-hg-hash: 853f313def1e5e9c733f980f2b4e6330a7d063ef
What's this?
> Signed-off-by: Shradha Shah <sshah@solarflare•com>
> ---
> drivers/net/ethernet/sfc/tx.c | 24 +++++++++++++++++++-----
> 1 file changed, 19 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/net/ethernet/sfc/tx.c b/drivers/net/ethernet/sfc/tx.c
> index fa94753..bd6a4b8 100644
> --- a/drivers/net/ethernet/sfc/tx.c
> +++ b/drivers/net/ethernet/sfc/tx.c
> @@ -189,6 +189,20 @@ struct efx_short_copy_buffer {
> u8 buf[L1_CACHE_BYTES];
> };
>
> +/* Copy in explicit 64-bit writes. */
> +static void efx_memcpy_64(void *dest, void *src, size_t len)
> +{
> + uint64_t *src64 = src, *dest64 = dest;
> + size_t i, l64 = len / 8;
> +
> + WARN_ON_ONCE(len % 8 != 0);
> + WARN_ON_ONCE(((u8 *)dest - (u8 *) 0) % 8 != 0);
Be consistent with spaces after a typecast, please.
> + BUILD_BUG_ON(sizeof(uint64_t) != 8);
> +
> + for(i = 0; i < l64; ++i)
> + dest64[i] = src64[i];
> +}
> +
> /* Copy to PIO, respecting that writes to PIO buffers must be dword aligned.
> * Advances piobuf pointer. Leaves additional data in the copy buffer.
> */
[...]
WBR, Sergei
next prev parent reply other threads:[~2014-05-28 14:48 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <cover.1401268725.git.sshah@solarflare.com>
2014-05-28 9:27 ` [PATCH net v2 1/2] sfc: use 64-bit writes for PIO Shradha Shah
2014-05-28 9:32 ` Shradha Shah
2014-05-28 14:48 ` Sergei Shtylyov [this message]
2014-05-28 9:28 ` [PATCH net v2 2/2] sfc: Restrict PIO to 64-bit architectures Shradha Shah
2014-05-28 14:45 ` Sergei Shtylyov
2014-05-28 9:23 [PATCH net v2 0/2] sfc: Restrict PIO for 64bit arch in order to avoid data corruption Shradha Shah
2014-05-28 9:28 ` [PATCH net v2 1/2] sfc: use 64-bit writes for PIO Shradha Shah
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