[PATCH 4/6] mtd: afs: factor footer parsing into the v1 part parsing

Linus Walleij
2019-01-28T13:56:01Z

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>
Cc: Liviu Dudau <liviu.dudau@arm.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
drivers/mtd/parsers/afs.c | 98 ++++++++++++++++-----------------------
1 file changed, 39 insertions(+), 59 deletions(-)

diff --git a/drivers/mtd/parsers/afs.c b/drivers/mtd/parsers/afs.c
index 32ded91ae66c..8ff82a548252 100644
--- a/drivers/mtd/parsers/afs.c
+++ b/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);