gennvm: Generic NVM manager

The implementation for Open-Channel SSDs is divided into media
management and targets. This patch implements a generic media manager
for open-channel SSDs. After a media manager has been initialized,
single or multiple targets can be instantiated with the media managed as
the backend.

Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@fb.com>

drivers/lightnvm/Kconfig

@@ -25,4 +25,11 @@ config NVM_DEBUG
 
 	It is required to create/remove targets without IOCTLs.
 
+config NVM_GENNVM
+	tristate "Generic NVM manager for Open-Channel SSDs"
+	---help---
+	NVM media manager for Open-Channel SSDs that offload management
+	functionality to device, while keeping data placement and garbage
+	collection decisions on the host.
+
 endif # NVM