linux-kernel - RE: [PATCH] fsldma: use PCI Read Multiple command

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: <D7CCA83BB0796C49BC0BB53B6AB1208928CAB2@zch01exm21.fsl.freescale.net>
Date:	Tue, 28 Apr 2009 09:31:08 +0800
From:	"Liu Dave-R63238" <DaveLiu@...escale.com>
To:	"Tabi Timur-B04825" <timur@...escale.com>
Cc:	"Ira Snyder" <iws@...o.caltech.edu>,
	<linux-kernel@...r.kernel.org>, <linuxppc-dev@...abs.org>,
	"Dan Williams" <dan.j.williams@...el.com>,
	"Li Yang-R58472" <LeoLi@...escale.com>
Subject: RE: [PATCH] fsldma: use PCI Read Multiple command

> > You are assuming the PCI memory space is prefetchable( no 
> > side effect) for DMA.
> > Is it possible that DMA is from non-prefetchable memory space?
> 
> This should be a safe assumption for this driver.  Remember, this
> driver just does offload memcpy, from one region to another.  So the
> PCI memory that you are reading from should be just a buffer of data,
> and there should be side-effect of reading it.
> 
> However, I would like to see a comment at the top of the file warning
> people that copying from PCI memory will result in prefetched reads.

How about FIFO RAM case?
--
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/