mtd: rawnand: Move all page cache related fields to a sub-struct

Looking at the field names it's hard to tell what ->data_buf, ->pagebuf
and ->pagebuf_bitflips are for. Clarify that by moving those fields
in a sub-struct named pagecache.
Signed-off-by: Boris Brezillon <bbrezillon@kernel.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Frieder Schrempf <frieder.schrempf@kontron.de>

drivers/mtd/nand/raw/nand_base.c

@@ -459,8 +459,8 @@ static int nand_do_write_oob(struct nand_chip *chip, loff_t to,
 	}
 
 	/* Invalidate the page cache, if we write to the cached page */
-	if (page == chip->pagebuf)
-		chip->pagebuf = -1;
+	if (page == chip->pagecache.page)
+		chip->pagecache.page = -1;
 
 	nand_fill_oob(chip, ops->oobbuf, ops->ooblen, ops);
 
@@ -3173,7 +3173,7 @@ static int nand_do_read_ops(struct nand_chip *chip, loff_t from,
 			use_bufpoi = 0;
 
 		/* Is the current page in the buffer? */
-		if (realpage != chip->pagebuf || oob) {
+		if (realpage != chip->pagecache.page || oob) {
 			bufpoi = use_bufpoi ? chip->data_buf : buf;
 
 			if (use_bufpoi && aligned)
@@ -3199,7 +3199,7 @@ static int nand_do_read_ops(struct nand_chip *chip, loff_t from,
 			if (ret < 0) {
 				if (use_bufpoi)
 					/* Invalidate page cache */
-					chip->pagebuf = -1;
+					chip->pagecache.page = -1;
 				break;
 			}
 
@@ -3208,11 +3208,11 @@ static int nand_do_read_ops(struct nand_chip *chip, loff_t from,
 				if (!NAND_HAS_SUBPAGE_READ(chip) && !oob &&
 				    !(mtd->ecc_stats.failed - ecc_failures) &&
 				    (ops->mode != MTD_OPS_RAW)) {
-					chip->pagebuf = realpage;
-					chip->pagebuf_bitflips = ret;
+					chip->pagecache.page = realpage;
+					chip->pagecache.bitflips = ret;
 				} else {
 					/* Invalidate page cache */
-					chip->pagebuf = -1;
+					chip->pagecache.page = -1;
 				}
 				memcpy(buf, chip->data_buf + col, bytes);
 			}
@@ -3252,7 +3252,7 @@ static int nand_do_read_ops(struct nand_chip *chip, loff_t from,
 			memcpy(buf, chip->data_buf + col, bytes);
 			buf += bytes;
 			max_bitflips = max_t(unsigned int, max_bitflips,
-					     chip->pagebuf_bitflips);
+					     chip->pagecache.bitflips);
 		}
 
 		readlen -= bytes;
@@ -3973,9 +3973,9 @@ static int nand_do_write_ops(struct nand_chip *chip, loff_t to,
 	page = realpage & chip->pagemask;
 
 	/* Invalidate the page cache, when we write to the cached page */
-	if (to <= ((loff_t)chip->pagebuf << chip->page_shift) &&
-	    ((loff_t)chip->pagebuf << chip->page_shift) < (to + ops->len))
-		chip->pagebuf = -1;
+	if (to <= ((loff_t)chip->pagecache.page << chip->page_shift) &&
+	    ((loff_t)chip->pagecache.page << chip->page_shift) < (to + ops->len))
+		chip->pagecache.page = -1;
 
 	/* Don't allow multipage oob writes with offset */
 	if (oob && ops->ooboffs && (ops->ooboffs + ops->ooblen > oobmaxlen)) {
@@ -4196,9 +4196,9 @@ int nand_erase_nand(struct nand_chip *chip, struct erase_info *instr,
 		 * Invalidate the page cache, if we erase the block which
 		 * contains the current cached page.
 		 */
-		if (page <= chip->pagebuf && chip->pagebuf <
+		if (page <= chip->pagecache.page && chip->pagecache.page <
 		    (page + pages_per_block))
-			chip->pagebuf = -1;
+			chip->pagecache.page = -1;
 
 		ret = nand_erase_op(chip, (page & chip->pagemask) >>
 				    (chip->phys_erase_shift - chip->page_shift));
@@ -5782,7 +5782,7 @@ static int nand_scan_tail(struct nand_chip *chip)
 	chip->subpagesize = mtd->writesize >> mtd->subpage_sft;
 
 	/* Invalidate the pagebuffer reference */
-	chip->pagebuf = -1;
+	chip->pagecache.page = -1;
 
 	/* Large page NAND with SOFT_ECC should support subpage reads */
 	switch (ecc->mode) {

include/linux/mtd/rawnand.h

@@ -1007,10 +1007,10 @@ struct nand_legacy {
  * @chipsize:		[INTERN] the size of one chip for multichip arrays
  * @pagemask:		[INTERN] page number mask = number of (pages / chip) - 1
  * @data_buf:		[INTERN] buffer for data, size is (page size + oobsize).
- * @pagebuf:		[INTERN] holds the pagenumber which is currently in
- *			data_buf.
- * @pagebuf_bitflips:	[INTERN] holds the bitflip count for the page which is
- *			currently in data_buf.
+ * @pagecache:		Structure containing page cache related fields
+ * @pagecache.bitflips:	Number of bitflips of the cached page
+ * @pagecache.page:	Page number currently in the cache. -1 means no page is
+ *			currently cached
  * @subpagesize:	[INTERN] holds the subpagesize
  * @id:			[INTERN] holds NAND ID
  * @parameters:		[INTERN] holds generic parameters under an easily
@@ -1060,8 +1060,12 @@ struct nand_chip {
 	uint64_t chipsize;
 	int pagemask;
 	u8 *data_buf;
-	int pagebuf;
-	unsigned int pagebuf_bitflips;
+
+	struct {
+		unsigned int bitflips;
+		int page;
+	} pagecache;
+
 	int subpagesize;
 	uint8_t bits_per_cell;
 	uint16_t ecc_strength_ds;
@@ -1366,7 +1370,7 @@ void nand_deselect_target(struct nand_chip *chip);
  */
 static inline void *nand_get_data_buf(struct nand_chip *chip)
 {
-	chip->pagebuf = -1;
+	chip->pagecache.page = -1;
 
 	return chip->data_buf;
 }