linux-kernel - Questions regarding DMA buffer sharing using IOMMU

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

Date:	Mon, 12 May 2014 15:12:41 +0530
From:	Pintu Kumar <pintu.k@...look.com>
To:	"linux-mm@...ck.org" <linux-mm@...ck.org>,
	"linux-arm-kernel@...ts.infradead.org" 
	<linux-arm-kernel@...ts.infradead.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"linaro-mm-sig@...ts.linaro.org" <linaro-mm-sig@...ts.linaro.org>
Subject: Questions regarding DMA buffer sharing using IOMMU

Hi, 
I have some queries regarding IOMMU and CMA buffer sharing. 
We have an embedded linux device (kernel 3.10, RAM: 256Mb) in which camera and codec supports IOMMU but the display does not support IOMMU. 
Thus for camera capture we are using iommu buffers using ION/DMABUF. But for all display rendering we are using CMA buffers. 
So, the question is how to achieve buffer sharing (zero-copy) between Camera and Display using only IOMMU? 
Currently we are achieving zero-copy using CMA. And we are exploring options to use IOMMU. 
Now we wanted to know which option is better? To use IOMMU or CMA? 
If anybody have come across these design please share your thoughts and results. 

Thank You! 
Regards, 
Pintu

 		 	   		  --
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/