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

drivers/lightnvm/Makefile

@@ -3,3 +3,4 @@
 #
 
 obj-$(CONFIG_NVM)		:= core.o
+obj-$(CONFIG_NVM_GENNVM) 	+= gennvm.o

drivers/lightnvm/gennvm.h

+/*
+ * Copyright: Matias Bjorling <mb@bjorling.me>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ */
+
+#ifndef GENNVM_H_
+#define GENNVM_H_
+
+#include <linux/module.h>
+#include <linux/vmalloc.h>
+
+#include <linux/lightnvm.h>
+
+struct gen_lun {
+	struct nvm_lun vlun;
+
+	int reserved_blocks;
+	/* lun block lists */
+	struct list_head used_list;	/* In-use blocks */
+	struct list_head free_list;	/* Not used blocks i.e. released
+					 * and ready for use
+					 */
+	struct list_head bb_list;	/* Bad blocks. Mutually exclusive with
+					 * free_list and used_list
+					 */
+};
+
+struct gen_nvm {
+	int nr_luns;
+	struct gen_lun *luns;
+};
+
+#define gennvm_for_each_lun(bm, lun, i) \
+		for ((i) = 0, lun = &(bm)->luns[0]; \
+			(i) < (bm)->nr_luns; (i)++, lun = &(bm)->luns[(i)])
+
+#endif /* GENNVM_H_ */