From b520e412faaaad35641aeedd6059179f9f1b393c Mon Sep 17 00:00:00 2001 From: Ben Hutchings Date: Fri, 29 Jan 2010 20:59:42 +0000 Subject: [PATCH] mtd: Replace static array of devices with an idr structure Signed-off-by: Ben Hutchings Signed-off-by: Artem Bityutskiy Signed-off-by: David Woodhouse --- drivers/mtd/mtdcore.c | 151 +++++++++++++++++++++------------------- drivers/mtd/mtdcore.h | 12 +--- include/linux/mtd/mtd.h | 1 - 3 files changed, 81 insertions(+), 83 deletions(-) diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c index 402d41723c3f..b3b98d1fffc3 100644 --- a/drivers/mtd/mtdcore.c +++ b/drivers/mtd/mtdcore.c @@ -17,6 +17,7 @@ #include #include #include +#include #include #include "internal.h" @@ -33,13 +34,18 @@ static struct class mtd_class = { .resume = mtd_cls_resume, }; +static DEFINE_IDR(mtd_idr); + /* These are exported solely for the purpose of mtd_blkdevs.c. You should not use them for _anything_ else */ DEFINE_MUTEX(mtd_table_mutex); -struct mtd_info *mtd_table[MAX_MTD_DEVICES]; - 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); @@ -235,13 +241,13 @@ static struct device_type mtd_devtype = { * Add a device to the list of MTD devices present in the system, and * notify each currently active MTD 'user' of its arrival. Returns * 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) - * or there's a sysfs error. + * if there is insufficient memory or a sysfs error. */ int add_mtd_device(struct mtd_info *mtd) { - int i; + struct mtd_notifier *not; + int i, error; if (!mtd->backing_dev_info) { switch (mtd->type) { @@ -260,70 +266,73 @@ int add_mtd_device(struct mtd_info *mtd) BUG_ON(mtd->writesize == 0); mutex_lock(&mtd_table_mutex); - for (i=0; i < MAX_MTD_DEVICES; i++) - if (!mtd_table[i]) { - struct mtd_notifier *not; - - mtd_table[i] = mtd; - mtd->index = i; - mtd->usecount = 0; - - if (is_power_of_2(mtd->erasesize)) - mtd->erasesize_shift = ffs(mtd->erasesize) - 1; - else - mtd->erasesize_shift = 0; - - if (is_power_of_2(mtd->writesize)) - mtd->writesize_shift = ffs(mtd->writesize) - 1; - else - mtd->writesize_shift = 0; - - mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1; - mtd->writesize_mask = (1 << mtd->writesize_shift) - 1; - - /* Some chips always power up locked. Unlock them now */ - if ((mtd->flags & MTD_WRITEABLE) - && (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); - } + do { + if (!idr_pre_get(&mtd_idr, GFP_KERNEL)) + goto fail_locked; + error = idr_get_new(&mtd_idr, mtd, &i); + } while (error == -EAGAIN); - /* Caller should have set dev.parent to match the - * physical device. - */ - 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) { - mtd_table[i] = NULL; - break; - } + if (error) + goto fail_locked; - if (MTD_DEVT(i)) - device_create(&mtd_class, mtd->dev.parent, - MTD_DEVT(i) + 1, - NULL, "mtd%dro", i); - - DEBUG(0, "mtd: Giving out device %d to %s\n",i, mtd->name); - /* No need to get a refcount on the module containing - the notifier, since we hold the mtd_table_mutex */ - list_for_each_entry(not, &mtd_notifiers, list) - not->add(mtd); - - 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; - } + mtd->index = i; + mtd->usecount = 0; + + if (is_power_of_2(mtd->erasesize)) + mtd->erasesize_shift = ffs(mtd->erasesize) - 1; + else + mtd->erasesize_shift = 0; + + if (is_power_of_2(mtd->writesize)) + mtd->writesize_shift = ffs(mtd->writesize) - 1; + else + mtd->writesize_shift = 0; + + mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1; + mtd->writesize_mask = (1 << mtd->writesize_shift) - 1; + + /* Some chips always power up locked. Unlock them now */ + if ((mtd->flags & MTD_WRITEABLE) + && (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 + * physical device. + */ + 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; + + if (MTD_DEVT(i)) + device_create(&mtd_class, mtd->dev.parent, + MTD_DEVT(i) + 1, + NULL, "mtd%dro", i); + + DEBUG(0, "mtd: Giving out device %d to %s\n", i, mtd->name); + /* No need to get a refcount on the module containing + the notifier, since we hold the mtd_table_mutex */ + list_for_each_entry(not, &mtd_notifiers, list) + not->add(mtd); + + 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); return 1; } @@ -344,7 +353,7 @@ int del_mtd_device (struct mtd_info *mtd) mutex_lock(&mtd_table_mutex); - if (mtd_table[mtd->index] != mtd) { + if (idr_find(&mtd_idr, mtd->index) != mtd) { ret = -ENODEV; } else if (mtd->usecount) { 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) not->remove(mtd); - mtd_table[mtd->index] = NULL; + idr_remove(&mtd_idr, mtd->index); module_put(THIS_MODULE); ret = 0; @@ -448,8 +457,8 @@ struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num) break; } } - } else if (num >= 0 && num < MAX_MTD_DEVICES) { - ret = mtd_table[num]; + } else if (num >= 0) { + ret = idr_find(&mtd_idr, num); if (mtd && mtd != ret) ret = NULL; } diff --git a/drivers/mtd/mtdcore.h b/drivers/mtd/mtdcore.h index e2f93a300738..6a64fdebc898 100644 --- a/drivers/mtd/mtdcore.h +++ b/drivers/mtd/mtdcore.h @@ -8,17 +8,7 @@ should not use them for _anything_ else */ extern struct mutex mtd_table_mutex; -extern struct mtd_info *mtd_table[MAX_MTD_DEVICES]; - -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; -} +extern struct mtd_info *__mtd_next_device(int i); #define mtd_for_each_device(mtd) \ for ((mtd) = __mtd_next_device(0); \ diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h index 0f32a9b6ff55..ba53ecca107c 100644 --- a/include/linux/mtd/mtd.h +++ b/include/linux/mtd/mtd.h @@ -20,7 +20,6 @@ #define MTD_CHAR_MAJOR 90 #define MTD_BLOCK_MAJOR 31 -#define MAX_MTD_DEVICES 32 #define MTD_ERASE_PENDING 0x01 #define MTD_ERASING 0x02 -- 2.34.1