[PATCH] nvme: add wrapper for nvme ctrl register r/w

[zhangweiping@didichuxing.com (weiping zhang)]

On Wed, Jul 12, 2017@02:01:52PM +0200, Johannes Thumshirn wrote:
> On Wed, Jul 12, 2017@01:55:47PM +0200, Christoph Hellwig wrote:
> > Mostly because it's a little shorter and we're only going to get
> > more and more of these calls.  In the end I don't feel strongly
> > and we can just skip the patch for now and reconsider it once
> > we have more register read/write calls.
> 
> I'm in favour of the patch as well. It hides the transport specific
> implementation details quite good.
> 

Thanks all of your suggestions, I just want add a common interface of
register read/write. If someday we change the path of read/write
register, we only need modify nvme_ctrl_reg_xxx than every
ctrl->ops->xxx.