lightnvm: move device L2P detection to core

A 1.2 device is able to manage the logical to physical mapping
table internally or leave it to the host.

A target only supports one of those approaches, and therefore must
check on initialization. Move this check to core to avoid each target
implement the check.

Signed-off-by: Matias Bjørling <mb@lightnvm.io>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

include/linux/lightnvm.h

@@ -495,9 +495,15 @@ typedef void (nvm_tgt_exit_fn)(void *, bool);
 typedef int (nvm_tgt_sysfs_init_fn)(struct gendisk *);
 typedef void (nvm_tgt_sysfs_exit_fn)(struct gendisk *);
 
+enum {
+	NVM_TGT_F_DEV_L2P = 0,
+	NVM_TGT_F_HOST_L2P = 1 << 0,
+};
+
 struct nvm_tgt_type {
 	const char *name;
 	unsigned int version[3];
+	int flags;
 
 	/* target entry points */
 	nvm_tgt_make_rq_fn *make_rq;