linux-kernel - Re: [PATCH] [POWERPC] Improve (in|out)

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

Message-ID: <4833524C.3040207@freescale.com>
Date:	Tue, 20 May 2008 17:35:56 -0500
From:	Scott Wood <scottwood@...escale.com>
To:	Alan Cox <alan@...rguk.ukuu.org.uk>
CC:	benh@...nel.crashing.org, Trent Piepho <tpiepho@...escale.com>,
	linuxppc-dev@...abs.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] [POWERPC] Improve (in|out)_beXX() asm code

Alan Cox wrote:
>> It looks like we rely on -fno-strict-aliasing to prevent reordering 
>> ordinary memory accesses (such as to DMA descriptors) past the I/O 
> 
> DMA descriptors in main memory are dependant on cache behaviour anyway
> and the dma_* operators should be the ones enforcing the needed behaviour.

What about memory obtained from dma_alloc_coherent()?  We still need a 
sync and a compiler barrier.  The current I/O accessors have the former, 
but not the latter.

-Scott
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/