[PATCH V7] nvme-pci: add SGL support

[Keith Busch]

On Fri, Oct 20, 2017 at 03:12:01AM -0700, Christoph Hellwig wrote:
> On Thu, Oct 19, 2017 at 09:48:22AM -0600, Keith Busch wrote:
> > Yeah, I don't have any major concerns. I was hung up on the
> > tagset.cmd_size being smaller when SGL's are used, but it took me a
> > minute to determine that's okay as we were overallocating it before.
> 
> How is it smaller?  The code ensures we use the larger of the two
> calculations:
> 
> 	dev->tagset.cmd_size = nvme_pci_cmd_size(dev, false);
> 	if ((dev->ctrl.sgls & ((1 << 0) | (1 << 1))) && sgl_threshold) {
> 		dev->tagset.cmd_size = max(dev->tagset.cmd_size,
> 				nvme_pci_cmd_size(dev, true));
> 	}

Oops, my mistake.