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Date: Wed, 19 Apr 2017 14:48:08 -0600
From: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
To: Logan Gunthorpe <logang@deltatee.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Dan Williams <dan.j.williams@intel.com>,
	Bjorn Helgaas <helgaas@kernel.org>, Christoph Hellwig <hch@lst.de>,
	Sagi Grimberg <sagi@grimberg.me>,
	"James E.J. Bottomley" <jejb@linux.vnet.ibm.com>,
	"Martin K. Petersen" <martin.petersen@oracle.com>,
	Jens Axboe <axboe@kernel.dk>,
	Steve Wise <swise@opengridcomputing.com>,
	Stephen Bates <sbates@raithlin.com>,
	Max Gurtovoy <maxg@mellanox.com>,
	Keith Busch <keith.busch@intel.com>, linux-pci@vger.kernel.org,
	linux-scsi <linux-scsi@vger.kernel.org>,
	linux-nvme@lists.infradead.org, linux-rdma@vger.kernel.org,
	linux-nvdimm <linux-nvdimm@ml01.01.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Jerome Glisse <jglisse@redhat.com>
Subject: Re: [RFC 0/8] Copy Offload with Peer-to-Peer PCI Memory
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On Wed, Apr 19, 2017 at 01:41:49PM -0600, Logan Gunthorpe wrote:

> > But.. it could point to a GPU and the GPU struct device could have a
> > proxy dma_ops like Dan pointed out.
> 
> Seems a bit awkward to me that in order for the intended use case, you
> have to proxy the dma_ops. I'd probably still suggest throwing a couple
> ops for things like this in the dev_pagemap.

Another option is adding a new 'struct completer_dma_ops *' to struct
device for this use case.

Seems like a waste to expand dev_pagemap when we only need a unique
value per struct device?

Jason