netdev - Re: [PATCH net v5] sfc: PIO:Restrict to 64bit arch and use 64-bit writes.

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-Id: <20140610.233200.1652605957870754730.davem@davemloft.net>
Date:	Tue, 10 Jun 2014 23:32:00 -0700 (PDT)
From:	David Miller <davem@...emloft.net>
To:	sshah@...arflare.com
Cc:	netdev@...r.kernel.org, linux-net-drivers@...arflare.com
Subject: Re: [PATCH net v5] sfc: PIO:Restrict to 64bit arch and use 64-bit
 writes.

From: Shradha Shah <sshah@...arflare.com>
Date: Fri, 6 Jun 2014 19:24:01 +0100

> +/* Hardware issue requires that only 64-bit naturally aligned writes
> + * are seen by hardware.
> + */
> +#if BITS_PER_LONG == 64
> +/* not strictly necessary to restrict to x86 arch, but done for safety
> + * since unusual write combining behaviour can break PIO.
> + */
> +#ifdef CONFIG_X86_64
>  /* PIO is a win only if write-combining is possible */
>  #ifdef ARCH_HAS_IOREMAP_WC
>  #define EFX_USE_PIO 1
>  #endif
> +#endif
> +#endif

Just restrict this plainly to X86_64, the 64-bit test is completely
redundant.  It's obvious that x86_64 is the only platform you care
about and plan on testing or caring about in any way, so just make
that explicit.

I'm sorry about giving you continually a hard time about this, but
this is really gross, platform specific, ugly hackery going on here
and I'm going to do whatever I can to minimize it's uglyness.

Thank you.
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html