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mtd: Replace static array of devices with an idr structure

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Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
This commit is contained in:
Ben Hutchings 2010-01-29 20:59:42 +00:00 • committed by David Woodhouse
parent 4d1ee80f3a
commit b520e412fa
3 changed files with 74 additions and 76 deletions
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137
drivers/mtd/mtdcore.c
View file

@ -17,6 +17,7 @@
#include <linux/init.h> #include <linux/init.h>
#include <linux/mtd/compatmac.h> #include <linux/mtd/compatmac.h>
#include <linux/proc_fs.h> #include <linux/proc_fs.h>
#include <linux/idr.h>
#include <linux/mtd/mtd.h> #include <linux/mtd/mtd.h>
#include "internal.h" #include "internal.h"
@ -33,13 +34,18 @@ static struct class mtd_class = {
.resume = mtd_cls_resume, .resume = mtd_cls_resume,
}; };
static DEFINE_IDR(mtd_idr);
/* These are exported solely for the purpose of mtd_blkdevs.c. You /* These are exported solely for the purpose of mtd_blkdevs.c. You
should not use them for _anything_ else */ should not use them for _anything_ else */
DEFINE_MUTEX(mtd_table_mutex); DEFINE_MUTEX(mtd_table_mutex);
struct mtd_info *mtd_table[MAX_MTD_DEVICES];
EXPORT_SYMBOL_GPL(mtd_table_mutex); EXPORT_SYMBOL_GPL(mtd_table_mutex);
EXPORT_SYMBOL_GPL(mtd_table);
struct mtd_info *__mtd_next_device(int i)
{
return idr_get_next(&mtd_idr, &i);
}
EXPORT_SYMBOL_GPL(__mtd_next_device);
static LIST_HEAD(mtd_notifiers); static LIST_HEAD(mtd_notifiers);
@ -235,13 +241,13 @@ static struct device_type mtd_devtype = {
* Add a device to the list of MTD devices present in the system, and * Add a device to the list of MTD devices present in the system, and
* notify each currently active MTD 'user' of its arrival. Returns * notify each currently active MTD 'user' of its arrival. Returns
* zero on success or 1 on failure, which currently will only happen * zero on success or 1 on failure, which currently will only happen
* if the number of present devices exceeds MAX_MTD_DEVICES (i.e. 16) * if there is insufficient memory or a sysfs error.
* or there's a sysfs error.
*/ */
int add_mtd_device(struct mtd_info *mtd) int add_mtd_device(struct mtd_info *mtd)
{ {
int i; struct mtd_notifier *not;
int i, error;
if (!mtd->backing_dev_info) { if (!mtd->backing_dev_info) {
switch (mtd->type) { switch (mtd->type) {
@ -260,70 +266,73 @@ int add_mtd_device(struct mtd_info *mtd)
BUG_ON(mtd->writesize == 0); BUG_ON(mtd->writesize == 0);
mutex_lock(&mtd_table_mutex); mutex_lock(&mtd_table_mutex);
for (i=0; i < MAX_MTD_DEVICES; i++) do {
if (!mtd_table[i]) { if (!idr_pre_get(&mtd_idr, GFP_KERNEL))
struct mtd_notifier *not; goto fail_locked;
error = idr_get_new(&mtd_idr, mtd, &i);
} while (error == -EAGAIN);
mtd_table[i] = mtd; if (error)
mtd->index = i; goto fail_locked;
mtd->usecount = 0;
if (is_power_of_2(mtd->erasesize)) mtd->index = i;
mtd->erasesize_shift = ffs(mtd->erasesize) - 1; mtd->usecount = 0;
else
mtd->erasesize_shift = 0;
if (is_power_of_2(mtd->writesize)) if (is_power_of_2(mtd->erasesize))
mtd->writesize_shift = ffs(mtd->writesize) - 1; mtd->erasesize_shift = ffs(mtd->erasesize) - 1;
else else
mtd->writesize_shift = 0; mtd->erasesize_shift = 0;
mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1; if (is_power_of_2(mtd->writesize))
mtd->writesize_mask = (1 << mtd->writesize_shift) - 1; mtd->writesize_shift = ffs(mtd->writesize) - 1;
else
mtd->writesize_shift = 0;
/* Some chips always power up locked. Unlock them now */ mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1;
if ((mtd->flags & MTD_WRITEABLE) mtd->writesize_mask = (1 << mtd->writesize_shift) - 1;
&& (mtd->flags & MTD_POWERUP_LOCK) && mtd->unlock) {
if (mtd->unlock(mtd, 0, mtd->size))
printk(KERN_WARNING
"%s: unlock failed, "
"writes may not work\n",
mtd->name);
}
/* Caller should have set dev.parent to match the /* Some chips always power up locked. Unlock them now */
* physical device. if ((mtd->flags & MTD_WRITEABLE)
*/ && (mtd->flags & MTD_POWERUP_LOCK) && mtd->unlock) {
mtd->dev.type = &mtd_devtype; if (mtd->unlock(mtd, 0, mtd->size))
mtd->dev.class = &mtd_class; printk(KERN_WARNING
mtd->dev.devt = MTD_DEVT(i); "%s: unlock failed, writes may not work\n",
dev_set_name(&mtd->dev, "mtd%d", i); mtd->name);
dev_set_drvdata(&mtd->dev, mtd); }
if (device_register(&mtd->dev) != 0) {
mtd_table[i] = NULL;
break;
}
if (MTD_DEVT(i)) /* Caller should have set dev.parent to match the
device_create(&mtd_class, mtd->dev.parent, * physical device.
MTD_DEVT(i) + 1, */
NULL, "mtd%dro", i); mtd->dev.type = &mtd_devtype;
mtd->dev.class = &mtd_class;
mtd->dev.devt = MTD_DEVT(i);
dev_set_name(&mtd->dev, "mtd%d", i);
dev_set_drvdata(&mtd->dev, mtd);
if (device_register(&mtd->dev) != 0)
goto fail_added;
DEBUG(0, "mtd: Giving out device %d to %s\n",i, mtd->name); if (MTD_DEVT(i))
/* No need to get a refcount on the module containing device_create(&mtd_class, mtd->dev.parent,
the notifier, since we hold the mtd_table_mutex */ MTD_DEVT(i) + 1,
list_for_each_entry(not, &mtd_notifiers, list) NULL, "mtd%dro", i);
not->add(mtd);
mutex_unlock(&mtd_table_mutex); DEBUG(0, "mtd: Giving out device %d to %s\n", i, mtd->name);
/* We _know_ we aren't being removed, because /* No need to get a refcount on the module containing
our caller is still holding us here. So none the notifier, since we hold the mtd_table_mutex */
of this try_ nonsense, and no bitching about it list_for_each_entry(not, &mtd_notifiers, list)
either. :) */ not->add(mtd);
__module_get(THIS_MODULE);
return 0;
}
mutex_unlock(&mtd_table_mutex);
/* We _know_ we aren't being removed, because
our caller is still holding us here. So none
of this try_ nonsense, and no bitching about it
either. :) */
__module_get(THIS_MODULE);
return 0;
fail_added:
idr_remove(&mtd_idr, i);
fail_locked:
mutex_unlock(&mtd_table_mutex); mutex_unlock(&mtd_table_mutex);
return 1; return 1;
} }
@ -344,7 +353,7 @@ int del_mtd_device (struct mtd_info *mtd)
mutex_lock(&mtd_table_mutex); mutex_lock(&mtd_table_mutex);
if (mtd_table[mtd->index] != mtd) { if (idr_find(&mtd_idr, mtd->index) != mtd) {
ret = -ENODEV; ret = -ENODEV;
} else if (mtd->usecount) { } else if (mtd->usecount) {
printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n", printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n",
@ -360,7 +369,7 @@ int del_mtd_device (struct mtd_info *mtd)
list_for_each_entry(not, &mtd_notifiers, list) list_for_each_entry(not, &mtd_notifiers, list)
not->remove(mtd); not->remove(mtd);
mtd_table[mtd->index] = NULL; idr_remove(&mtd_idr, mtd->index);
module_put(THIS_MODULE); module_put(THIS_MODULE);
ret = 0; ret = 0;
@ -448,8 +457,8 @@ struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
break; break;
} }
} }
} else if (num >= 0 && num < MAX_MTD_DEVICES) { } else if (num >= 0) {
ret = mtd_table[num]; ret = idr_find(&mtd_idr, num);
if (mtd && mtd != ret) if (mtd && mtd != ret)
ret = NULL; ret = NULL;
} }

12
drivers/mtd/mtdcore.h
View file

@ -8,17 +8,7 @@
should not use them for _anything_ else */ should not use them for _anything_ else */
extern struct mutex mtd_table_mutex; extern struct mutex mtd_table_mutex;
extern struct mtd_info *mtd_table[MAX_MTD_DEVICES]; extern struct mtd_info *__mtd_next_device(int i);
static inline struct mtd_info *__mtd_next_device(int i)
{
while (i < MAX_MTD_DEVICES) {
if (mtd_table[i])
return mtd_table[i];
i++;
}
return NULL;
}
#define mtd_for_each_device(mtd) \ #define mtd_for_each_device(mtd) \
for ((mtd) = __mtd_next_device(0); \ for ((mtd) = __mtd_next_device(0); \

1
include/linux/mtd/mtd.h
View file

@ -20,7 +20,6 @@
#define MTD_CHAR_MAJOR 90 #define MTD_CHAR_MAJOR 90
#define MTD_BLOCK_MAJOR 31 #define MTD_BLOCK_MAJOR 31
#define MAX_MTD_DEVICES 32
#define MTD_ERASE_PENDING 0x01 #define MTD_ERASE_PENDING 0x01
#define MTD_ERASING 0x02 #define MTD_ERASING 0x02