lightnvm: introduce mlc lower page table mappings

NAND MLC memories have both lower and upper pages. When programming,
both of these must be written, before data can be read. However,
these lower and upper pages might not placed at even and odd flash
pages, but can be skipped. Therefore each flash memory has its lower
pages defined, which can then be used when programming and to know when
padding are necessary.

This patch implements the lower page definition in the specification,
and exposes it through a simple lookup table at dev->lptbl.

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

1 files changed, 20 insertions, 0 deletions

diff --git a/include/linux/lightnvm.h b/include/linux/lightnvm.h
index b90d28344e3d..678fd91a1f99 100644
--- a/include/linux/lightnvm.h
+++ b/include/linux/lightnvm.h
@@ -67,6 +67,20 @@ enum {
 	NVM_ID_CAP_CMD_SUSPEND	= 0x2,
 	NVM_ID_CAP_SCRAMBLE	= 0x4,
 	NVM_ID_CAP_ENCRYPT	= 0x8,
+
+	/* Memory types */
+	NVM_ID_FMTYPE_SLC	= 0,
+	NVM_ID_FMTYPE_MLC	= 1,
+};
+
+struct nvm_id_lp_mlc {
+	u16	num_pairs;
+	u8	pairs[886];
+};
+
+struct nvm_id_lp_tbl {
+	__u8	id[8];
+	struct nvm_id_lp_mlc mlc;
 };
 
 struct nvm_id_group {
@@ -89,6 +103,8 @@ struct nvm_id_group {
 	u32	mpos;
 	u32	mccap;
 	u16	cpar;
+
+	struct nvm_id_lp_tbl lptbl;
 };
 
 struct nvm_addr_format {
@@ -297,6 +313,10 @@ struct nvm_dev {
 	int sec_per_blk;
 	int sec_per_lun;
 
+	/* lower page table */
+	int lps_per_blk;
+	int *lptbl;
+
 	unsigned long total_pages;
 	unsigned long total_blocks;
 	int nr_luns;