linux-kernel - Re: [PATCH] OMAP: iommu flush page table entries from L1 and L2 cache

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

Date:	Mon, 18 Apr 2011 09:29:33 +0200
From:	Arnd Bergmann <arnd@...db.de>
To:	"Russell King - ARM Linux" <linux@....linux.org.uk>
Cc:	Fernando Guzman Lugo <fernando.lugo@...com>,
	linux-omap@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
	linux-kernel@...r.kernel.org, tony@...mide.com,
	Ramesh Gupta <grgupta@...com>,
	Hari Kanigeri <h-kanigeri2@...com>
Subject: Re: [PATCH] OMAP: iommu flush page table entries from L1 and L2 cache

On Friday 15 April 2011, Russell King - ARM Linux wrote:
> On Thu, Apr 14, 2011 at 04:52:48PM -0500, Fernando Guzman Lugo wrote:
> > From: Ramesh Gupta <grgupta@...com>
> > 
> > This patch is to flush the iommu page table entries from L1 and L2
> > caches using dma_map_single. This also simplifies the implementation
> > by removing the functions  flush_iopgd_range/flush_iopte_range.
> 
> No.  This usage is just wrong.  If you're going to use the DMA API then
> unmap it, otherwise the DMA API debugging will go awol.


It's also completely upside-down: The iommu support should provide interfaces
using the dma-mapping API, not use that API to provide a machine specific
version of the generic interface.

As far as I can tell, nothing actually uses these drivers, maybe we should just
remove them before we get any code in the mainline kernel that depends on it.

	Arnd
--
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/