mtd: Add __nand_calculate_ecc() to NAND ECC functions

Add __nand_calculate_ecc() which does not take struct mtd_info.
The built-in 256/512 software ECC calculation and correction tester
will use it.

Signed-off-by: Akinobu Mita <[e-mail]>
Acked-by: Vimal Singh <[e-mail]>
Signed-off-by: Artem Bityutskiy <[e-mail]>
Signed-off-by: David Woodhouse <[e-mail]>

drivers/mtd/nand/nand_ecc.c

···
 };
 
 /**
- * nand_calculate_ecc - [NAND Interface] Calculate 3-byte ECC for 256/512-byte
+ * __nand_calculate_ecc - [NAND Interface] Calculate 3-byte ECC for 256/512-byte
  *			 block
- * @mtd:	MTD block structure
  * @buf:	input buffer with raw data
+ * @eccsize:	data bytes per ecc step (256 or 512)
  * @code:	output buffer with ECC
  */
-int nand_calculate_ecc(struct mtd_info *mtd, const unsigned char *buf,
+void __nand_calculate_ecc(const unsigned char *buf, unsigned int eccsize,
 		       unsigned char *code)
 {
 	int i;
 	const uint32_t *bp = (uint32_t *)buf;
 	/* 256 or 512 bytes/ecc  */
-	const uint32_t eccsize_mult =
-			(((struct nand_chip *)mtd->priv)->ecc.size) >> 8;
+	const uint32_t eccsize_mult = eccsize >> 8;
 	uint32_t cur;		/* current value in buffer */
 	/* rp0..rp15..rp17 are the various accumulated parities (per byte) */
 	uint32_t rp0, rp1, rp2, rp3, rp4, rp5, rp6, rp7;
···
 		    (invparity[par & 0x55] << 2) |
 		    (invparity[rp17] << 1) |
 		    (invparity[rp16] << 0);
+}
+EXPORT_SYMBOL(__nand_calculate_ecc);
+
+/**
+ * nand_calculate_ecc - [NAND Interface] Calculate 3-byte ECC for 256/512-byte
+ *			 block
+ * @mtd:	MTD block structure
+ * @buf:	input buffer with raw data
+ * @code:	output buffer with ECC
+ */
+int nand_calculate_ecc(struct mtd_info *mtd, const unsigned char *buf,
+		       unsigned char *code)
+{
+	__nand_calculate_ecc(buf,
+			((struct nand_chip *)mtd->priv)->ecc.size, code);
+
 	return 0;
 }
 EXPORT_SYMBOL(nand_calculate_ecc);

include/linux/mtd/nand_ecc.h

···
 struct mtd_info;
 
 /*
- * Calculate 3 byte ECC code for 256 byte block
+ * Calculate 3 byte ECC code for eccsize byte block
+ */
+void __nand_calculate_ecc(const u_char *dat, unsigned int eccsize,
+				u_char *ecc_code);
+
+/*
+ * Calculate 3 byte ECC code for 256/512 byte block
  */
 int nand_calculate_ecc(struct mtd_info *mtd, const u_char *dat, u_char *ecc_code);
 
···
 			unsigned int eccsize);
 
 /*
- * Detect and correct a 1 bit error for 256 byte block
+ * Detect and correct a 1 bit error for 256/512 byte block
  */
 int nand_correct_data(struct mtd_info *mtd, u_char *dat, u_char *read_ecc, u_char *calc_ecc);