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authorDan Ehrenberg <dehrenberg@chromium.org>2015-04-03 01:15:10 +0300
committerBrian Norris <computersforpeace@gmail.com>2015-04-06 03:44:01 +0300
commit727dc612c46b8f3858537ea23805b3e897cf127e (patch)
tree5bcda420d5f0071fc8d8c8c02dc68166256323e7 /drivers/mtd/mtdcore.c
parent9cd5196ed25979a3760f97225aae3e17caf21512 (diff)
downloadlinux-727dc612c46b8f3858537ea23805b3e897cf127e.tar.xz
mtd: part: Create the master device node when partitioned
For many use cases, it helps to have a device node for the entire MTD device as well as device nodes for the individual partitions. For example, this allows querying the entire device's properties. A common idiom is to create an additional partition which spans over the whole device. This patch makes a config option, CONFIG_MTD_PARTITIONED_MASTER, which makes the master partition present even when the device is partitioned. This isn't turned on by default since it presents a backwards-incompatible device numbering. The patch also makes the parent of a partition device be the master, if the config flag is set, now that the master is a full device. Signed-off-by: Dan Ehrenberg <dehrenberg@chromium.org> Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Diffstat (limited to 'drivers/mtd/mtdcore.c')
-rw-r--r--drivers/mtd/mtdcore.c52
1 files changed, 36 insertions, 16 deletions
diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index 11883bd26d9d..d172195fbd15 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -38,6 +38,7 @@
#include <linux/gfp.h>
#include <linux/slab.h>
#include <linux/reboot.h>
+#include <linux/kconfig.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/partitions.h>
@@ -501,6 +502,29 @@ out_error:
return ret;
}
+static int mtd_add_device_partitions(struct mtd_info *mtd,
+ struct mtd_partition *real_parts,
+ int nbparts)
+{
+ int ret;
+
+ if (nbparts == 0 || IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER)) {
+ ret = add_mtd_device(mtd);
+ if (ret == 1)
+ return -ENODEV;
+ }
+
+ if (nbparts > 0) {
+ ret = add_mtd_partitions(mtd, real_parts, nbparts);
+ if (ret && IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER))
+ del_mtd_device(mtd);
+ return ret;
+ }
+
+ return 0;
+}
+
+
/**
* mtd_device_parse_register - parse partitions and register an MTD device.
*
@@ -523,7 +547,8 @@ out_error:
* found this functions tries to fallback to information specified in
* @parts/@nr_parts.
* * If any partitioning info was found, this function registers the found
- * partitions.
+ * partitions. If the MTD_PARTITIONED_MASTER option is set, then the device
+ * as a whole is registered first.
* * If no partitions were found this function just registers the MTD device
* @mtd and exits.
*
@@ -534,27 +559,21 @@ int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types,
const struct mtd_partition *parts,
int nr_parts)
{
- int err;
- struct mtd_partition *real_parts;
+ int ret;
+ struct mtd_partition *real_parts = NULL;
- err = parse_mtd_partitions(mtd, types, &real_parts, parser_data);
- if (err <= 0 && nr_parts && parts) {
+ ret = parse_mtd_partitions(mtd, types, &real_parts, parser_data);
+ if (ret <= 0 && nr_parts && parts) {
real_parts = kmemdup(parts, sizeof(*parts) * nr_parts,
GFP_KERNEL);
if (!real_parts)
- err = -ENOMEM;
+ ret = -ENOMEM;
else
- err = nr_parts;
+ ret = nr_parts;
}
- if (err > 0) {
- err = add_mtd_partitions(mtd, real_parts, err);
- kfree(real_parts);
- } else if (err == 0) {
- err = add_mtd_device(mtd);
- if (err == 1)
- err = -ENODEV;
- }
+ if (ret >= 0)
+ ret = mtd_add_device_partitions(mtd, real_parts, ret);
/*
* FIXME: some drivers unfortunately call this function more than once.
@@ -569,7 +588,8 @@ int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types,
register_reboot_notifier(&mtd->reboot_notifier);
}
- return err;
+ kfree(real_parts);
+ return ret;
}
EXPORT_SYMBOL_GPL(mtd_device_parse_register);