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authorDan Ehrenberg <dehrenberg@chromium.org>2015-04-03 01:15:11 +0300
committerBrian Norris <computersforpeace@gmail.com>2015-04-06 03:44:02 +0300
commita62c24d75529118d10c45350c3b75715d52ff574 (patch)
tree6c18ffa557b84ff94dd6dedce302a556766decf7
parent727dc612c46b8f3858537ea23805b3e897cf127e (diff)
downloadlinux-a62c24d75529118d10c45350c3b75715d52ff574.tar.xz
mtd: part: Add sysfs variable for offset of partition
This patch makes a sysfs variable called 'offset' on each partition which contains the offset in bytes from the beginning of the master device that the partition starts. Signed-off-by: Dan Ehrenberg <dehrenberg@chromium.org> Signed-off-by: Brian Norris <computersforpeace@gmail.com>
-rw-r--r--Documentation/ABI/testing/sysfs-class-mtd10
-rw-r--r--drivers/mtd/mtdpart.c29
2 files changed, 39 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-class-mtd b/Documentation/ABI/testing/sysfs-class-mtd
index 76ee192f80a0..3b5c3bca9186 100644
--- a/Documentation/ABI/testing/sysfs-class-mtd
+++ b/Documentation/ABI/testing/sysfs-class-mtd
@@ -222,3 +222,13 @@ Description:
The number of blocks that are marked as reserved, if any, in
this partition. These are typically used to store the in-flash
bad block table (BBT).
+
+What: /sys/class/mtd/mtdX/offset
+Date: March 2015
+KernelVersion: 4.1
+Contact: linux-mtd@lists.infradead.org
+Description:
+ For a partition, the offset of that partition from the start
+ of the master device in bytes. This attribute is absent on
+ main devices, so it can be used to distinguish between
+ partitions and devices that aren't partitions.
diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c
index a19ec5a4e409..be8034086701 100644
--- a/drivers/mtd/mtdpart.c
+++ b/drivers/mtd/mtdpart.c
@@ -554,6 +554,30 @@ out_register:
return slave;
}
+static ssize_t mtd_partition_offset_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct mtd_info *mtd = dev_get_drvdata(dev);
+ struct mtd_part *part = PART(mtd);
+ return snprintf(buf, PAGE_SIZE, "%lld\n", part->offset);
+}
+
+static DEVICE_ATTR(offset, S_IRUGO, mtd_partition_offset_show, NULL);
+
+static const struct attribute *mtd_partition_attrs[] = {
+ &dev_attr_offset.attr,
+ NULL
+};
+
+static int mtd_add_partition_attrs(struct mtd_part *new)
+{
+ int ret = sysfs_create_files(&new->mtd.dev.kobj, mtd_partition_attrs);
+ if (ret)
+ printk(KERN_WARNING
+ "mtd: failed to create partition attrs, err=%d\n", ret);
+ return ret;
+}
+
int mtd_add_partition(struct mtd_info *master, const char *name,
long long offset, long long length)
{
@@ -603,6 +627,8 @@ int mtd_add_partition(struct mtd_info *master, const char *name,
add_mtd_device(&new->mtd);
+ mtd_add_partition_attrs(new);
+
return ret;
err_inv:
mutex_unlock(&mtd_partitions_mutex);
@@ -620,6 +646,8 @@ int mtd_del_partition(struct mtd_info *master, int partno)
list_for_each_entry_safe(slave, next, &mtd_partitions, list)
if ((slave->master == master) &&
(slave->mtd.index == partno)) {
+ sysfs_remove_files(&slave->mtd.dev.kobj,
+ mtd_partition_attrs);
ret = del_mtd_device(&slave->mtd);
if (ret < 0)
break;
@@ -663,6 +691,7 @@ int add_mtd_partitions(struct mtd_info *master,
mutex_unlock(&mtd_partitions_mutex);
add_mtd_device(&slave->mtd);
+ mtd_add_partition_attrs(slave);
cur_offset = slave->offset + slave->mtd.size;
}