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From: Santosh Shilimkar <santosh.shilimkar@ti.com>
To: Arnd Bergmann <arnd@arndb.de>, "Anna, Suman" <s-anna@ti.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
	"linux-omap@vger.kernel.org" <linux-omap@vger.kernel.org>,
	"iommu@lists.linux-foundation.org"
	<iommu@lists.linux-foundation.org>,
	Florian Vaussard <florian.vaussard@epfl.ch>,
	"sakari.ailus@iki.fi" <sakari.ailus@iki.fi>,
	Russell King - ARM Linux <linux@arm.linux.org.uk>
Subject: Re: [PATCH 1/5] iommu/omap: Use the cache cleaning API
Date: Fri, 14 Mar 2014 13:59:16 -0400	[thread overview]
Message-ID: <53234374.8010802@ti.com> (raw)
In-Reply-To: <201403141757.48824.arnd@arndb.de>

On Friday 14 March 2014 12:57 PM, Arnd Bergmann wrote:
> On Friday 14 March 2014, Santosh Shilimkar wrote:
>> I remember NAKing this approach in past and my stand remains same.
>> The cache APIs which you are trying to use here are not suppose
>> to be used outside.
>>
>> I think the right way to fix this is to make use of streaming APIs.
>> If needed, IOMMU can have its own dma_ops for special case
>> handling if any.
>>
>> Russell, Arnd might have more ideas.
> 
> I have a bad feeling about using the dma-mapping API within the
> IOMMU code, because that driver is also used to implement the
> dma-mapping API for devices attached to the IOMMU. It's possible
> that it just works.
> 
Thats a good point.

> Is the IOMMU actually designed to have page tables in noncoherent
> memory? I would have expected that the iopt accesses must all be
> done on dma_alloc_coherent() provided memory to guarantee proper
> accesses.
> 
At least the OMAP one seems to use non-coherent memory which will
need CMO.

Regards,
Santosh


  reply	other threads:[~2014-03-14 17:59 UTC|newest]

Thread overview: 41+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-03-08  0:46 [PATCH 0/5] OMAP IOMMU fixes and IOMMU architecture questions Laurent Pinchart
2014-03-08  0:46 ` [PATCH 1/5] iommu/omap: Use the cache cleaning API Laurent Pinchart
     [not found]   ` <1394239574-2389-2-git-send-email-laurent.pinchart-ryLnwIuWjnjg/C1BVhZhaw@public.gmane.org>
2014-03-14  2:47     ` Suman Anna
2014-03-14 16:15       ` Santosh Shilimkar
2014-03-14 16:38         ` Laurent Pinchart
2014-03-14 17:51           ` Santosh Shilimkar
     [not found]             ` <5323418B.90805-l0cyMroinI0@public.gmane.org>
2014-03-15  1:49               ` Suman Anna
2014-03-15 17:54                 ` Santosh Shilimkar
     [not found]                   ` <532493DF.5010409-l0cyMroinI0@public.gmane.org>
2014-03-17 19:16                     ` Suman Anna
2014-03-17 22:56                 ` Laurent Pinchart
2014-03-14 16:57         ` Arnd Bergmann
2014-03-14 17:59           ` Santosh Shilimkar [this message]
     [not found]           ` <201403141757.48824.arnd-r2nGTMty4D4@public.gmane.org>
2014-03-17 23:12             ` Laurent Pinchart
2014-03-18  1:20               ` Suman Anna
2014-03-08  0:46 ` [PATCH 4/5] iommu/omap: Remove comment about supporting single page mappings only Laurent Pinchart
2014-03-08  0:46 ` [PATCH 5/5] iommu/omap: Fix map protection value handling Laurent Pinchart
     [not found]   ` <1394239574-2389-6-git-send-email-laurent.pinchart-ryLnwIuWjnjg/C1BVhZhaw@public.gmane.org>
2014-03-14  0:07     ` Suman Anna
2014-03-14  9:46       ` Laurent Pinchart
2014-03-15  0:16         ` Suman Anna
2014-03-08 11:04 ` [PATCH 0/5] OMAP IOMMU fixes and IOMMU architecture questions Sakari Ailus
2014-03-12 15:26 ` Laurent Pinchart
     [not found] ` <1394239574-2389-1-git-send-email-laurent.pinchart-ryLnwIuWjnjg/C1BVhZhaw@public.gmane.org>
2014-03-08  0:46   ` [PATCH 2/5] iommu/omap: Fix 'no page for' debug message in flush_iotlb_page() Laurent Pinchart
     [not found]     ` <1394239574-2389-3-git-send-email-laurent.pinchart-ryLnwIuWjnjg/C1BVhZhaw@public.gmane.org>
2014-03-13 22:16       ` Suman Anna
2014-03-14  9:50         ` Laurent Pinchart
2014-03-08  0:46   ` [PATCH 3/5] iommu/omap: Flush the TLB only after updating translation table entries Laurent Pinchart
     [not found]     ` <1394239574-2389-4-git-send-email-laurent.pinchart-ryLnwIuWjnjg/C1BVhZhaw@public.gmane.org>
2014-03-13 22:27       ` Suman Anna
     [not found]         ` <532230DA.30302-l0cyMroinI0@public.gmane.org>
2014-03-14  9:58           ` Laurent Pinchart
2014-03-15  0:18             ` Suman Anna
2014-03-14  2:33   ` [PATCH 0/5] OMAP IOMMU fixes and IOMMU architecture questions Suman Anna
2014-03-14 11:00     ` Laurent Pinchart
2014-03-16 21:54       ` Sakari Ailus
     [not found]         ` <20140316215455.GA2108-S+BSfZ9RZZmRSg0ZkenSGLdO1Tsj/99ntUK59QYPAWc@public.gmane.org>
2014-03-17 19:58           ` Suman Anna
2014-03-17 22:44             ` Laurent Pinchart
2014-04-04 12:23               ` Marek Szyprowski
     [not found]                 ` <533EA45D.70002-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
2014-04-08 13:09                   ` Laurent Pinchart
2014-04-04 10:18       ` Joerg Roedel
     [not found]         ` <20140404101811.GR13491-zLv9SwRftAIdnm+yROfE0A@public.gmane.org>
2014-04-08 12:50           ` Laurent Pinchart
2014-04-08 13:43             ` Joerg Roedel
2014-04-08 15:02               ` Laurent Pinchart
2014-04-09 15:08                 ` Joerg Roedel
2014-04-10 23:30                   ` Laurent Pinchart

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