[PATCH 1/1] nvme: initialize CMB only if supported

[Christoph Hellwig]

On Mon, Jun 29, 2020 at 12:38:53PM +0300, Max Gurtovoy wrote:
> According to the NVMe specification revision 1.4 (CMBS):
> "If set to ‘1’, this bit indicates that the controller supports the
> Controller Memory Buffer, and that addresses supplied by the host are
> permitted to reference the Controller Memory Buffer only if the host has
> enabled the Controller Memory Buffer’s controller memory space. If the
> controller supports the Controller Memory Buffer, this bit shall be set
> to ‘1’."
> 
> Also, while we're here, add more macro definitions related to CMB
> registers added to revision 1.4 of the spec.

Please read my comment on the previous patch that tried this about a
week or two ago.