linux-kernel - Re: dma_alloc_coherent() on PPC32: physical addresses above 2G possible?

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: <20080720124841.0e5e8de0@infradead.org>
Date:	Sun, 20 Jul 2008 12:48:41 -0700
From:	Arjan van de Ven <arjan@...radead.org>
To:	Stefan Richter <stefanr@...6.in-berlin.de>
Cc:	linuxppc-dev@...abs.org, linux-kernel@...r.kernel.org
Subject: Re: dma_alloc_coherent() on PPC32: physical addresses above 2G
 possible?

On Sun, 20 Jul 2008 21:25:51 +0200
Stefan Richter <stefanr@...6.in-berlin.de> wrote:

> Arjan van de Ven wrote:
> > On Sun, 20 Jul 2008 20:36:23 +0200
> > Stefan Richter <stefanr@...6.in-berlin.de> wrote:
> > 
> >> PS:  I don't want to set the DMA mask of this device to
> >> DMA_31BIT_MASK because that would be detrimental to other functions
> >> of the device. It's a TI TSB43AB22A FireWire controller.
> > 
> > Hi,
> > 
> > just want to mention that you can set the coherent mask separately
> > from the generic mask... is that sufficient for your load?
> > (you can even set it just for this allocation..)
> 
> Hmm.  Would that be done this way?
> During probe:
> 
> 	if (chip_is_tsb43ab22a) {
> 		if (dma_supported(dev, DMA_31BIT_MASK))
> 			chip->needs_dma_mask_workaround = 1;
> 		else
> 			chip->needs_some_other_workaround = 1;
> 	}

btw it might be nicer to make this

chip->something_special_mask = DMA_31BIT_MASK;

then you can just use the mask from this struct rather than another
check


-- 
If you want to reach me at my work email, use arjan@...ux.intel.com
For development, discussion and tips for power savings, 
visit http://www.lesswatts.org
--
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/