mtd: afs: factor footer parsing into the v1 part parsing

This simplifies the code by factoring in the image footer
parsing into the single function parsing the AFSv1 partitions.

Cc: Ryan Harkin <ryan.harkin@linaro.org>
Acked-by: Liviu Dudau <liviu.dudau@arm.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Richard Weinberger <richard@nod.at>

drivers/mtd/parsers/afs.c

@@ -88,63 +88,6 @@ static bool afs_is_v1(struct mtd_info *mtd, u_int off)
 	return (magic == AFSV1_FOOTER_MAGIC);
 }
 
-static int
-afs_read_footer_v1(struct mtd_info *mtd, u_int *img_start, u_int *iis_start,
-		   u_int off, u_int mask)
-{
-	struct footer_v1 fs;
-	u_int ptr = off + mtd->erasesize - sizeof(fs);
-	size_t sz;
-	int ret;
-
-	ret = mtd_read(mtd, ptr, sizeof(fs), &sz, (u_char *)&fs);
-	if (ret >= 0 && sz != sizeof(fs))
-		ret = -EINVAL;
-
-	if (ret < 0) {
-		printk(KERN_ERR "AFS: mtd read failed at 0x%x: %d\n",
-			ptr, ret);
-		return ret;
-	}
-
-	/*
-	 * Does it contain the magic number?
-	 */
-	if (fs.signature != AFSV1_FOOTER_MAGIC)
-		return 0;
-
-	/*
-	 * Check the checksum.
-	 */
-	if (word_sum(&fs, sizeof(fs) / sizeof(u32)) != 0xffffffff)
-		return 0;
-
-	/*
-	 * Don't touch the SIB.
-	 */
-	if (fs.type == 2)
-		return 0;
-
-	*iis_start = fs.image_info_base & mask;
-	*img_start = fs.image_start & mask;
-
-	/*
-	 * Check the image info base.  This can not
-	 * be located after the footer structure.
-	 */
-	if (*iis_start >= ptr)
-		return 0;
-
-	/*
-	 * Check the start of this image.  The image
-	 * data can not be located after this block.
-	 */
-	if (*img_start > off)
-		return 0;
-
-	return 1;
-}
-
 static int
 afs_read_iis_v1(struct mtd_info *mtd, struct image_info_v1 *iis, u_int ptr)
 {
@@ -184,6 +127,7 @@ afs_read_iis_v1(struct mtd_info *mtd, struct image_info_v1 *iis, u_int ptr)
 static int afs_parse_v1_partition(struct mtd_info *mtd,
 				  u_int off, struct mtd_partition *part)
 {
+	struct footer_v1 fs;
 	struct image_info_v1 iis;
 	u_int mask;
 	/*
@@ -192,6 +136,8 @@ static int afs_parse_v1_partition(struct mtd_info *mtd,
 	 */
 	u_int uninitialized_var(iis_ptr);
 	u_int uninitialized_var(img_ptr);
+	u_int ptr;
+	size_t sz;
 	int ret;
 
 	/*
@@ -200,9 +146,43 @@ static int afs_parse_v1_partition(struct mtd_info *mtd,
 	 */
 	mask = mtd->size - 1;
 
-	ret = afs_read_footer_v1(mtd, &img_ptr, &iis_ptr, off, mask);
-	if (ret < 0)
+	ptr = off + mtd->erasesize - sizeof(fs);
+	ret = mtd_read(mtd, ptr, sizeof(fs), &sz, (u_char *)&fs);
+	if (ret >= 0 && sz != sizeof(fs))
+		ret = -EINVAL;
+	if (ret < 0) {
+		printk(KERN_ERR "AFS: mtd read failed at 0x%x: %d\n",
+		       ptr, ret);
 		return ret;
+	}
+	/*
+	 * Check the checksum.
+	 */
+	if (word_sum(&fs, sizeof(fs) / sizeof(u32)) != 0xffffffff)
+		return -EINVAL;
+
+	/*
+	 * Hide the SIB (System Information Block)
+	 */
+	if (fs.type == 2)
+		return 0;
+
+	iis_ptr = fs.image_info_base & mask;
+	img_ptr = fs.image_start & mask;
+
+	/*
+	 * Check the image info base.  This can not
+	 * be located after the footer structure.
+	 */
+	if (iis_ptr >= ptr)
+		return 0;
+
+	/*
+	 * Check the start of this image.  The image
+	 * data can not be located after this block.
+	 */
+	if (img_ptr > off)
+		return 0;
 
 	/* Read the image info block */
 	ret = afs_read_iis_v1(mtd, &iis, iis_ptr);