mtd: nand: add 'oob_required' argument to NAND {read,write}_page interfaces

New NAND controllers can perform read/write via HW engines which don't expose
OOB data in their DMA mode. To reflect this, we should rework the nand_chip /
nand_ecc_ctrl interfaces that assume that drivers will always read/write OOB
data in the nand_chip.oob_poi buffer. A better interface includes a boolean
argument that explicitly tells the callee when OOB data is requested by the
calling layer (for reading/writing to/from nand_chip.oob_poi).

This patch adds the 'oob_required' parameter to each relevant {read,write}_page
interface; all 'oob_required' parameters are left unused for now. The next
patch will set the parameter properly in the nand_base.c callers, and follow-up
patches will make use of 'oob_required' in some of the callee functions.

Note that currently, there is no harm in ignoring the 'oob_required' parameter
and *always* utilizing nand_chip.oob_poi, but there can be
performance/complexity/design benefits from avoiding filling oob_poi in the
common case. I will try to implement this for some drivers which can be ported
easily.

Note: I couldn't compile-test all of these easily, as some had ARCH
dependencies.

[dwmw2: Merge later 1/0 vs. true/false cleanup]
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Reviewed-by: Shmulik Ladkani <shmulik.ladkani@gmail.com>
Acked-by: Jiandong Zheng <jdzheng@broadcom.com>
Acked-by: Mike Dunn <mikedunn@newsguy.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

1 files changed, 6 insertions, 6 deletions

diff --git a/drivers/mtd/nand/docg4.c b/drivers/mtd/nand/docg4.c
index 1540de2ad39..1f8485d7500 100644
--- a/drivers/mtd/nand/docg4.c
+++ b/drivers/mtd/nand/docg4.c
@@ -787,13 +787,13 @@ static int read_page(struct mtd_info *mtd, struct nand_chip *nand,
 
 
 static int docg4_read_page_raw(struct mtd_info *mtd, struct nand_chip *nand,
-			       uint8_t *buf, int page)
+			       uint8_t *buf, int oob_required, int page)
 {
 	return read_page(mtd, nand, buf, page, false);
 }
 
 static int docg4_read_page(struct mtd_info *mtd, struct nand_chip *nand,
-			   uint8_t *buf, int page)
+			   uint8_t *buf, int oob_required, int page)
 {
 	return read_page(mtd, nand, buf, page, true);
 }
@@ -953,13 +953,13 @@ static void write_page(struct mtd_info *mtd, struct nand_chip *nand,
 }
 
 static void docg4_write_page_raw(struct mtd_info *mtd, struct nand_chip *nand,
-				 const uint8_t *buf)
+				 const uint8_t *buf, int oob_required)
 {
 	return write_page(mtd, nand, buf, false);
 }
 
 static void docg4_write_page(struct mtd_info *mtd, struct nand_chip *nand,
-			     const uint8_t *buf)
+			     const uint8_t *buf, int oob_required)
 {
 	return write_page(mtd, nand, buf, true);
 }
@@ -1003,7 +1003,7 @@ static int __init read_factory_bbt(struct mtd_info *mtd)
 		return -ENOMEM;
 
 	read_page_prologue(mtd, g4_addr);
-	status = docg4_read_page(mtd, nand, buf, DOCG4_FACTORY_BBT_PAGE);
+	status = docg4_read_page(mtd, nand, buf, 0, DOCG4_FACTORY_BBT_PAGE);
 	if (status)
 		goto exit;
 
@@ -1080,7 +1080,7 @@ static int docg4_block_markbad(struct mtd_info *mtd, loff_t ofs)
 
 	/* write first page of block */
 	write_page_prologue(mtd, g4_addr);
-	docg4_write_page(mtd, nand, buf);
+	docg4_write_page(mtd, nand, buf, 1);
 	ret = pageprog(mtd);
 	if (!ret)
 		mtd->ecc_stats.badblocks++;