spl: fit: nand: fix fit loading in case of bad blocks

The offset at which the image to be loaded from NAND is located is
retrieved from the itb header. The presence of bad blocks in the area
of the NAND where the itb image is located could invalidate the offset
which must therefore be adjusted taking into account the state of the
sectors concerned.

cc: Michael Trimarchi <michael@amarulasolutions.com>
Signed-off-by: NDario Binacchi <dariobin@libero.it>
Reviewed-by: NMichael Trimarchi <michael@amarulasolutions.com>

common/spl/spl_nand.c

@@ -42,8 +42,11 @@ static int spl_nand_load_image(struct spl_image_info *spl_image,
 static ulong spl_nand_fit_read(struct spl_load_info *load, ulong offs,
 			       ulong size, void *dst)
 {
+	ulong sector;
 	int ret;
 
+	sector = *(int *)load->priv;
+	offs = sector + nand_spl_adjust_offset(sector, offs - sector);
 	ret = nand_spl_load_image(offs, size, dst);
 	if (!ret)
 		return size;
@@ -66,7 +69,7 @@ static int spl_nand_load_element(struct spl_image_info *spl_image,
 
 		debug("Found FIT\n");
 		load.dev = NULL;
-		load.priv = NULL;
+		load.priv = &offset;
 		load.filename = NULL;
 		load.bl_len = 1;
 		load.read = spl_nand_fit_read;

drivers/mtd/nand/raw/nand_spl_loaders.c

@@ -41,6 +41,34 @@ int nand_spl_load_image(uint32_t offs, unsigned int size, void *dst)
 	return 0;
 }
 
+/**
+ * nand_spl_adjust_offset - Adjust offset from a starting sector
+ * @sector:	Address of the sector
+ * @offs:	Offset starting from @sector
+ *
+ * If one or more bad blocks are in the address space between @sector
+ * and @sector + @offs, @offs is increased by the NAND block size for
+ * each bad block found.
+ */
+u32 nand_spl_adjust_offset(u32 sector, u32 offs)
+{
+	unsigned int block, lastblock;
+
+	block = sector / CONFIG_SYS_NAND_BLOCK_SIZE;
+	lastblock = (sector + offs) / CONFIG_SYS_NAND_BLOCK_SIZE;
+
+	while (block <= lastblock) {
+		if (nand_is_bad_block(block)) {
+			offs += CONFIG_SYS_NAND_BLOCK_SIZE;
+			lastblock++;
+		}
+
+		block++;
+	}
+
+	return offs;
+}
+
 #ifdef CONFIG_SPL_UBI
 /*
  * Temporary storage for non NAND page aligned and non NAND page sized

include/nand.h

@@ -120,6 +120,7 @@ int nand_unlock(struct mtd_info *mtd, loff_t start, size_t length,
 		int allexcept);
 int nand_get_lock_status(struct mtd_info *mtd, loff_t offset);
 
+u32 nand_spl_adjust_offset(u32 sector, u32 offs);
 int nand_spl_load_image(uint32_t offs, unsigned int size, void *dst);
 int nand_spl_read_block(int block, int offset, int len, void *dst);
 void nand_deselect(void);