From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Hans J. Koch" Date: Wed, 12 Sep 2012 22:11:16 +0000 Subject: Re: [RFC PATCH 0/2] Add UIO device supporting dynamic memory allocation Message-Id: <20120912221116.GB5097@local> List-Id: References: <1347427785-9767-1-git-send-email-dhobsong@igel.co.jp> In-Reply-To: <1347427785-9767-1-git-send-email-dhobsong@igel.co.jp> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Damian Hobson-Garcia Cc: horms@verge.net.au, magnus.damm@gmail.com, hjk@hansjkoch.de, linux-sh@vger.kernel.org, hdk@igel.co.jp, linux-kernel@vger.kernel.org, Greg Kroah-Hartman On Wed, Sep 12, 2012 at 02:29:43PM +0900, Damian Hobson-Garcia wrote: > Reposting: I realized that this series should have gone out to a broader list. You forgot GregKH, I added him. > My apologies to those who those who will recieve a duplicate post. > > Hello all, > > I've been using this UIO driver for allocation/deallocation > of memory regions through an IOMMU via the dma-mapping API, but > it seems that it would be more generally useful for userspace drivers > to access CMA memory regions. I don't know if it's useful to try to add > this functionality into the core uio driver or not, so for now I've kept > all dynamic memory handling in the specific device driver. > > The number and size of the dynamically allocatable regions is defined > statically in the device platform data, and the actually memory is > allocated and deallocated when the device is opened/closed. > > Details of the dynamically allocated regions are available from sysfs in > exactly the same was as for static regions. The total number of > dynamic and static regions combined cannot exceed MAX_UIO_MAPS. > > Any comments, especially with regard to exposing the dma-mapping API to > userspace in this way, would be greatly appreciated. > > Damian Hobson-Garcia (2): > Add new uio device for dynamic memory allocation > ARM: shmobile: sh7372: Change VPU UIO to uio_dmem_genirq > > arch/arm/mach-shmobile/setup-sh7372.c | 19 +- > drivers/uio/Kconfig | 16 ++ > drivers/uio/Makefile | 1 + > drivers/uio/uio_dmem_genirq.c | 356 +++++++++++++++++++++++++ > include/linux/platform_data/uio_dmem_genirq.h | 26 ++ > 5 files changed, 413 insertions(+), 5 deletions(-) > create mode 100644 drivers/uio/uio_dmem_genirq.c > create mode 100644 include/linux/platform_data/uio_dmem_genirq.h Please add a third patch with a few words for Documentation/DocBook/uio-howto.tmpl since this driver could be useful for other people, too. Otherwise, looks good to me. Thanks, Hans