[PATCH] mtd: improve calculating partition boundaries when checking for alignment

[Rafał Miłecki]

From: Rafał Miłecki <***@milecki.pl>

When checking for alignment mtd should check absolute offsets. It's
important for subpartitions as it doesn't make sense to check their
relative addresses.

Signed-off-by: Rafał Miłecki <***@milecki.pl>
---
drivers/mtd/mtdpart.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c
index 2b6e53af47da..15197d923ec0 100644
--- a/drivers/mtd/mtdpart.c
+++ b/drivers/mtd/mtdpart.c
@@ -61,6 +61,15 @@ static inline struct mtd_part *mtd_to_part(const struct mtd_info *mtd)
return container_of(mtd, struct mtd_part, mtd);
}

+static uint64_t part_absolute_offset(struct mtd_info *mtd)
+{
+ struct mtd_part *part = mtd_to_part(mtd);
+
+ if (!mtd_is_partition(mtd))
+ return 0;
+
+ return part_absolute_offset(part->parent) + part->offset;
+}

/*
* MTD methods which simply translate the effective address and pass through
@@ -514,7 +523,7 @@ static struct mtd_part *allocate_partition(struct mtd_info *parent,
if (!(slave->mtd.flags & MTD_NO_ERASE))
wr_alignment = slave->mtd.erasesize;

- tmp = slave->offset;
+ tmp = part_absolute_offset(parent) + slave->offset;
remainder = do_div(tmp, wr_alignment);
if ((slave->mtd.flags & MTD_WRITEABLE) && remainder) {
/* Doesn't start on a boundary of major erase size */
@@ -525,7 +534,7 @@ static struct mtd_part *allocate_partition(struct mtd_info *parent,
part->name);
}

- tmp = slave->mtd.size;
+ tmp = part_absolute_offset(parent) + slave->mtd.size;
remainder = do_div(tmp, wr_alignment);
if ((slave->mtd.flags & MTD_WRITEABLE) && remainder) {
slave->mtd.flags &= ~MTD_WRITEABLE;

[Rafał Miłecki]

From: Rafał Miłecki <***@milecki.pl>

When checking for alignment mtd should check absolute offsets. It's
important for subpartitions as it doesn't make sense to check their
relative addresses.

Signed-off-by: Rafał Miłecki <***@milecki.pl>
---
V2: Switch from uint64_t to u64. I got incorrectly inspired by
uint64_t offset;
---
drivers/mtd/mtdpart.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c
index 2b6e53af47da..b6af41b04622 100644
--- a/drivers/mtd/mtdpart.c
+++ b/drivers/mtd/mtdpart.c
@@ -61,6 +61,15 @@ static inline struct mtd_part *mtd_to_part(const struct mtd_info *mtd)
return container_of(mtd, struct mtd_part, mtd);
}

+static u64 part_absolute_offset(struct mtd_info *mtd)
+{
+ struct mtd_part *part = mtd_to_part(mtd);
+
+ if (!mtd_is_partition(mtd))
+ return 0;
+
+ return part_absolute_offset(part->parent) + part->offset;
+}

/*
* MTD methods which simply translate the effective address and pass through
@@ -514,7 +523,7 @@ static struct mtd_part *allocate_partition(struct mtd_info *parent,
if (!(slave->mtd.flags & MTD_NO_ERASE))
wr_alignment = slave->mtd.erasesize;

- tmp = slave->offset;
+ tmp = part_absolute_offset(parent) + slave->offset;
remainder = do_div(tmp, wr_alignment);
if ((slave->mtd.flags & MTD_WRITEABLE) && remainder) {
/* Doesn't start on a boundary of major erase size */
@@ -525,7 +534,7 @@ static struct mtd_part *allocate_partition(struct mtd_info *parent,
part->name);
}

- tmp = slave->mtd.size;
+ tmp = part_absolute_offset(parent) + slave->mtd.size;
remainder = do_div(tmp, wr_alignment);
if ((slave->mtd.flags & MTD_WRITEABLE) && remainder) {
slave->mtd.flags &= ~MTD_WRITEABLE;

[Boris Brezillon]

On Tue, 20 Nov 2018 10:24:09 +0100

Post by Rafał Miłecki
When checking for alignment mtd should check absolute offsets. It's
important for subpartitions as it doesn't make sense to check their
relative addresses.

Queued to mtd/next.

Post by Rafał Miłecki
---
V2: Switch from uint64_t to u64. I got incorrectly inspired by
uint64_t offset;
---
drivers/mtd/mtdpart.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c
index 2b6e53af47da..b6af41b04622 100644
--- a/drivers/mtd/mtdpart.c
+++ b/drivers/mtd/mtdpart.c
@@ -61,6 +61,15 @@ static inline struct mtd_part *mtd_to_part(const struct mtd_info *mtd)
return container_of(mtd, struct mtd_part, mtd);
}
+static u64 part_absolute_offset(struct mtd_info *mtd)
+{
+ struct mtd_part *part = mtd_to_part(mtd);
+
+ if (!mtd_is_partition(mtd))
+ return 0;
+
+ return part_absolute_offset(part->parent) + part->offset;
+}
/*
* MTD methods which simply translate the effective address and pass through
@@ -514,7 +523,7 @@ static struct mtd_part *allocate_partition(struct mtd_info *parent,
if (!(slave->mtd.flags & MTD_NO_ERASE))
wr_alignment = slave->mtd.erasesize;
- tmp = slave->offset;
+ tmp = part_absolute_offset(parent) + slave->offset;
remainder = do_div(tmp, wr_alignment);
if ((slave->mtd.flags & MTD_WRITEABLE) && remainder) {
/* Doesn't start on a boundary of major erase size */
@@ -525,7 +534,7 @@ static struct mtd_part *allocate_partition(struct mtd_info *parent,
part->name);
}
- tmp = slave->mtd.size;
+ tmp = part_absolute_offset(parent) + slave->mtd.size;
remainder = do_div(tmp, wr_alignment);
if ((slave->mtd.flags & MTD_WRITEABLE) && remainder) {
slave->mtd.flags &= ~MTD_WRITEABLE;

[Boris Brezillon]

On Tue, 20 Nov 2018 09:56:12 +0100

Post by Rafał Miłecki
When checking for alignment mtd should check absolute offsets. It's
important for subpartitions as it doesn't make sense to check their
relative addresses.
---
drivers/mtd/mtdpart.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c
index 2b6e53af47da..15197d923ec0 100644
--- a/drivers/mtd/mtdpart.c
+++ b/drivers/mtd/mtdpart.c
@@ -61,6 +61,15 @@ static inline struct mtd_part *mtd_to_part(const struct mtd_info *mtd)
return container_of(mtd, struct mtd_part, mtd);
}
+static uint64_t part_absolute_offset(struct mtd_info *mtd)

^ u64

Looks good otherwise.

Post by Rafał Miłecki
+{
+ struct mtd_part *part = mtd_to_part(mtd);
+
+ if (!mtd_is_partition(mtd))
+ return 0;
+
+ return part_absolute_offset(part->parent) + part->offset;
+}
/*
* MTD methods which simply translate the effective address and pass through
@@ -514,7 +523,7 @@ static struct mtd_part *allocate_partition(struct mtd_info *parent,
if (!(slave->mtd.flags & MTD_NO_ERASE))
wr_alignment = slave->mtd.erasesize;
- tmp = slave->offset;
+ tmp = part_absolute_offset(parent) + slave->offset;
remainder = do_div(tmp, wr_alignment);
if ((slave->mtd.flags & MTD_WRITEABLE) && remainder) {
/* Doesn't start on a boundary of major erase size */
@@ -525,7 +534,7 @@ static struct mtd_part *allocate_partition(struct mtd_info *parent,
part->name);
}
- tmp = slave->mtd.size;
+ tmp = part_absolute_offset(parent) + slave->mtd.size;
remainder = do_div(tmp, wr_alignment);
if ((slave->mtd.flags & MTD_WRITEABLE) && remainder) {
slave->mtd.flags &= ~MTD_WRITEABLE;