The head can never overrun the tail since we won't allocate enough command
IDs to let that happen.  The status codes are in sync with the spec.
Signed-off-by: NMatthew Wilcox <matthew.r.wilcox@intel.com>

Signed-off-by: NKrzysztof Wierzbicki <krzysztof.wierzbicki@intel.com>
Signed-off-by: NMatthew Wilcox <willy@linux.intel.com>
Signed-off-by: NMatthew Wilcox <matthew.r.wilcox@intel.com>

Add two reserved registers in the middle of the BAR to match the 1.0
spec plus ECN 0002.

Also rename IMC and ISC to INTMC and INTSC to conform with the spec.
We still don't need to use them :-)
Signed-off-by: NMatthew Wilcox <matthew.r.wilcox@intel.com>

Signed-off-by: NMatthew Wilcox <matthew.r.wilcox@intel.com>

Signed-off-by: NMatthew Wilcox <matthew.r.wilcox@intel.com>

Allow userspace to submit synchronous I/O like the SCSI sg interface does.
Signed-off-by: NMatthew Wilcox <matthew.r.wilcox@intel.com>

Add prp1, prp2 and the metadata prp to the common command, since the
fields are generally used this way.
Signed-off-by: NMatthew Wilcox <matthew.r.wilcox@intel.com>

This driver is for devices that follow the NVM Express standard
Signed-off-by: NMatthew Wilcox <matthew.r.wilcox@intel.com>