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authorMiquel Raynal <miquel.raynal@bootlin.com>2020-01-14 10:09:52 +0100
committerMiquel Raynal <miquel.raynal@bootlin.com>2020-03-11 14:49:30 +0100
commit46b5889cc2c54bac7d7e727a44d28a298df23cef (patch)
treef3baa809955aa2f4769e3f95e51be986db9a34ee /include/linux/mtd/mtd.h
parent98d54f81e36ba3bf92172791eba5ca5bd813989b (diff)
mtd: implement proper partition handling
Instead of collecting partitions in a flat list, create a hierarchy within the mtd_info structure: use a partitions list to keep track of the partitions of an MTD device (which might be itself a partition of another MTD device), a pointer to the parent device (NULL when the MTD device is the root one, not a partition). By also saving directly in mtd_info the offset of the partition, we can get rid of the mtd_part structure. While at it, be consistent in the naming of the mtd_info structures to ease the understanding of the new hierarchy: these structures are usually called 'mtd', unless there are multiple instances of the same structure. In this case, there is usually a parent/child bound so we will call them 'parent' and 'child'. Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Link: https://lore.kernel.org/linux-mtd/20200114090952.11232-1-miquel.raynal@bootlin.com
Diffstat (limited to 'include/linux/mtd/mtd.h')
-rw-r--r--include/linux/mtd/mtd.h125
1 files changed, 115 insertions, 10 deletions
diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h
index 249e8d9bfbcd..2d1f4a61f4ac 100644
--- a/include/linux/mtd/mtd.h
+++ b/include/linux/mtd/mtd.h
@@ -8,6 +8,7 @@
#include <linux/types.h>
#include <linux/uio.h>
+#include <linux/list.h>
#include <linux/notifier.h>
#include <linux/device.h>
#include <linux/of.h>
@@ -194,10 +195,43 @@ struct mtd_debug_info {
const char *partid;
};
+/**
+ * struct mtd_part - MTD partition specific fields
+ *
+ * @node: list node used to add an MTD partition to the parent partition list
+ * @offset: offset of the partition relatively to the parent offset
+ * @flags: original flags (before the mtdpart logic decided to tweak them based
+ * on flash constraints, like eraseblock/pagesize alignment)
+ *
+ * This struct is embedded in mtd_info and contains partition-specific
+ * properties/fields.
+ */
+struct mtd_part {
+ struct list_head node;
+ u64 offset;
+ u32 flags;
+};
+
+/**
+ * struct mtd_master - MTD master specific fields
+ *
+ * @partitions_lock: lock protecting accesses to the partition list. Protects
+ * not only the master partition list, but also all
+ * sub-partitions.
+ * @suspended: et to 1 when the device is suspended, 0 otherwise
+ *
+ * This struct is embedded in mtd_info and contains master-specific
+ * properties/fields. The master is the root MTD device from the MTD partition
+ * point of view.
+ */
+struct mtd_master {
+ struct mutex partitions_lock;
+ unsigned int suspended : 1;
+};
+
struct mtd_info {
u_char type;
uint32_t flags;
- uint32_t orig_flags; /* Flags as before running mtd checks */
uint64_t size; // Total size of the MTD
/* "Major" erase size for the device. Naïve users may take this
@@ -339,8 +373,52 @@ struct mtd_info {
int usecount;
struct mtd_debug_info dbg;
struct nvmem_device *nvmem;
+
+ /*
+ * Parent device from the MTD partition point of view.
+ *
+ * MTD masters do not have any parent, MTD partitions do. The parent
+ * MTD device can itself be a partition.
+ */
+ struct mtd_info *parent;
+
+ /* List of partitions attached to this MTD device */
+ struct list_head partitions;
+
+ union {
+ struct mtd_part part;
+ struct mtd_master master;
+ };
};
+static inline struct mtd_info *mtd_get_master(struct mtd_info *mtd)
+{
+ while (mtd->parent)
+ mtd = mtd->parent;
+
+ return mtd;
+}
+
+static inline u64 mtd_get_master_ofs(struct mtd_info *mtd, u64 ofs)
+{
+ while (mtd->parent) {
+ ofs += mtd->part.offset;
+ mtd = mtd->parent;
+ }
+
+ return ofs;
+}
+
+static inline bool mtd_is_partition(const struct mtd_info *mtd)
+{
+ return mtd->parent;
+}
+
+static inline bool mtd_has_partitions(const struct mtd_info *mtd)
+{
+ return !list_empty(&mtd->partitions);
+}
+
int mtd_ooblayout_ecc(struct mtd_info *mtd, int section,
struct mtd_oob_region *oobecc);
int mtd_ooblayout_find_eccregion(struct mtd_info *mtd, int eccbyte,
@@ -392,13 +470,16 @@ static inline u32 mtd_oobavail(struct mtd_info *mtd, struct mtd_oob_ops *ops)
static inline int mtd_max_bad_blocks(struct mtd_info *mtd,
loff_t ofs, size_t len)
{
- if (!mtd->_max_bad_blocks)
+ struct mtd_info *master = mtd_get_master(mtd);
+
+ if (!master->_max_bad_blocks)
return -ENOTSUPP;
if (mtd->size < (len + ofs) || ofs < 0)
return -EINVAL;
- return mtd->_max_bad_blocks(mtd, ofs, len);
+ return master->_max_bad_blocks(master, mtd_get_master_ofs(mtd, ofs),
+ len);
}
int mtd_wunit_to_pairing_info(struct mtd_info *mtd, int wunit,
@@ -439,8 +520,10 @@ int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
static inline void mtd_sync(struct mtd_info *mtd)
{
- if (mtd->_sync)
- mtd->_sync(mtd);
+ struct mtd_info *master = mtd_get_master(mtd);
+
+ if (master->_sync)
+ master->_sync(master);
}
int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len);
@@ -452,13 +535,31 @@ int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs);
static inline int mtd_suspend(struct mtd_info *mtd)
{
- return mtd->_suspend ? mtd->_suspend(mtd) : 0;
+ struct mtd_info *master = mtd_get_master(mtd);
+ int ret;
+
+ if (master->master.suspended)
+ return 0;
+
+ ret = master->_suspend ? master->_suspend(master) : 0;
+ if (ret)
+ return ret;
+
+ master->master.suspended = 1;
+ return 0;
}
static inline void mtd_resume(struct mtd_info *mtd)
{
- if (mtd->_resume)
- mtd->_resume(mtd);
+ struct mtd_info *master = mtd_get_master(mtd);
+
+ if (!master->master.suspended)
+ return;
+
+ if (master->_resume)
+ master->_resume(master);
+
+ master->master.suspended = 0;
}
static inline uint32_t mtd_div_by_eb(uint64_t sz, struct mtd_info *mtd)
@@ -538,7 +639,9 @@ static inline loff_t mtd_wunit_to_offset(struct mtd_info *mtd, loff_t base,
static inline int mtd_has_oob(const struct mtd_info *mtd)
{
- return mtd->_read_oob && mtd->_write_oob;
+ struct mtd_info *master = mtd_get_master((struct mtd_info *)mtd);
+
+ return master->_read_oob && master->_write_oob;
}
static inline int mtd_type_is_nand(const struct mtd_info *mtd)
@@ -548,7 +651,9 @@ static inline int mtd_type_is_nand(const struct mtd_info *mtd)
static inline int mtd_can_have_bb(const struct mtd_info *mtd)
{
- return !!mtd->_block_isbad;
+ struct mtd_info *master = mtd_get_master((struct mtd_info *)mtd);
+
+ return !!master->_block_isbad;
}
/* Kernel-side ioctl definitions */