linux-kernel - 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 for Android: free password hash cracker in your pocket

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

Date:	Sun, 20 Jul 2008 20:36:23 +0200
From:	Stefan Richter <stefanr@...6.in-berlin.de>
To:	linuxppc-dev@...abs.org
CC:	linux-kernel@...r.kernel.org
Subject: dma_alloc_coherent() on PPC32: physical addresses above 2G possible?

Hi all,

I have to implement a workaround for a PCI device which gets into 
trouble if descriptors are located at 32bit addresses, while 31bit 
addresses are fine.  I would like to avoid this workaround on machines 
on which dma_alloc_coherent() won't ever go at memory above 2 GB.

Is defined(CONFIG_PPC32) a safe test for this?  I'm under the impression 
that defined(CONFIG_X86_32) is safe.

Are there any other means to detect when the workaround can be omitted, 
at compile time or at runtime?

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.
-- 
Stefan Richter
-=====-==--- -=== =-=--
http://arcgraph.de/sr/
--
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/