[PATCH v3 1/8] mtd: nand: add more helpers in nand.h

[Peter Pan <peterpandong@micron.com>]

This commit adds some helpers in nand.h
    nand_size()
    valid_nand_address()
    valid_nand_oob_ops()
    nand_oob_ops_across_page()
    valid_nand_erase_ops()

Signed-off-by: Peter Pan <peterpandong@micron.com>
---
 include/linux/mtd/nand.h | 59 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 59 insertions(+)

diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h
index c2197b4..4a812e6 100644
--- a/include/linux/mtd/nand.h
+++ b/include/linux/mtd/nand.h
@@ -410,6 +410,65 @@ static inline int nand_neraseblocks(struct nand_device *nand)
 }
 
 /**
+ * nand_size - Get NAND size
+ * @nand: NAND device
+ *
+ * Returns the total size exposed by @nand.
+ */
+static inline u64 nand_size(struct nand_device *nand)
+{
+	return nand->memorg.ndies * nand->memorg.diesize;
+}
+
+static inline bool valid_nand_address(struct nand_device *nand, loff_t addr)
+{
+	return addr < nand_size(nand);
+}
+
+static inline bool valid_nand_oob_ops(struct nand_device *nand, loff_t start,
+				      struct mtd_oob_ops *ops)
+{
+	struct mtd_info *mtd = nand_to_mtd(nand);
+	int ooblen = ops->mode == MTD_OPS_AUTO_OOB ?
+		mtd->oobavail : mtd->oobsize;
+
+	if (ops->ooboffs >= ooblen)
+		return false;
+	if (ops->ooboffs + ops->ooblen >
+	    (nand_len_to_pages(nand, nand_size(nand)) -
+			       nand_offs_to_page(nand, start)) * ooblen)
+		return false;
+
+	return true;
+}
+
+static inline bool nand_oob_ops_across_page(struct nand_device *nand,
+					    struct mtd_oob_ops *ops)
+{
+	struct mtd_info *mtd = nand_to_mtd(nand);
+	int ooblen = ops->mode == MTD_OPS_AUTO_OOB ?
+		     mtd->oobavail : mtd->oobsize;
+
+	return (ops->ooboffs + ops->ooblen) > ooblen;
+}
+
+static inline bool valid_nand_erase_ops(struct nand_device *nand,
+					struct erase_info *einfo)
+{
+	/* check address align on block boundary */
+	if (einfo->addr & (nand_eraseblock_size(nand) - 1))
+		return false;
+	/* check lendth align on block boundary */
+	if (einfo->len & (nand_eraseblock_size(nand) - 1))
+		return false;
+	/* Do not allow erase past end of device */
+	if ((einfo->addr + einfo->len) > nand_size(nand))
+		return false;
+
+	return true;
+}
+
+/**
  * nand_register - Register a NAND device
  * @nand: NAND device
  *
-- 
1.9.1