#include <linux/init.h>
#include <linux/fs.h>
+#include <linux/kdev_t.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/major.h>
#include <linux/errno.h>
#include <linux/module.h>
-#include <linux/smp_lock.h>
#include <linux/seq_file.h>
#include <linux/kobject.h>
#include <linux/cdev.h>
#include <linux/mutex.h>
#include <linux/backing-dev.h>
+#include <linux/tty.h>
-#ifdef CONFIG_KMOD
-#include <linux/kmod.h>
-#endif
#include "internal.h"
/*
* - no readahead or I/O queue unplugging required
*/
struct backing_dev_info directly_mappable_cdev_bdi = {
+ .name = "char",
.capabilities = (
#ifdef CONFIG_MMU
/* permit private copies of the data to be taken */
#endif
/* permit direct mmap, for read, write or exec */
BDI_CAP_MAP_DIRECT |
- BDI_CAP_READ_MAP | BDI_CAP_WRITE_MAP | BDI_CAP_EXEC_MAP),
+ BDI_CAP_READ_MAP | BDI_CAP_WRITE_MAP | BDI_CAP_EXEC_MAP |
+ /* no writeback happens */
+ BDI_CAP_NO_ACCT_AND_WRITEBACK),
};
static struct kobj_map *cdev_map;
unsigned int baseminor;
int minorct;
char name[64];
- struct file_operations *fops;
struct cdev *cdev; /* will die */
} *chrdevs[CHRDEV_MAJOR_HASH_SIZE];
/* index in the above */
-static inline int major_to_index(int major)
+static inline int major_to_index(unsigned major)
{
return major % CHRDEV_MAJOR_HASH_SIZE;
}
cd->major = major;
cd->baseminor = baseminor;
cd->minorct = minorct;
- strncpy(cd->name,name, 64);
+ strlcpy(cd->name, name, sizeof(cd->name));
i = major_to_index(major);
}
/**
- * register_chrdev() - Register a major number for character devices.
+ * __register_chrdev() - create and register a cdev occupying a range of minors
* @major: major device number or 0 for dynamic allocation
+ * @baseminor: first of the requested range of minor numbers
+ * @count: the number of minor numbers required
* @name: name of this range of devices
* @fops: file operations associated with this devices
*
* /dev. It only helps to keep track of the different owners of devices. If
* your module name has only one type of devices it's ok to use e.g. the name
* of the module here.
- *
- * This function registers a range of 256 minor numbers. The first minor number
- * is 0.
*/
-int register_chrdev(unsigned int major, const char *name,
- const struct file_operations *fops)
+int __register_chrdev(unsigned int major, unsigned int baseminor,
+ unsigned int count, const char *name,
+ const struct file_operations *fops)
{
struct char_device_struct *cd;
struct cdev *cdev;
- char *s;
int err = -ENOMEM;
- cd = __register_chrdev_region(major, 0, 256, name);
+ cd = __register_chrdev_region(major, baseminor, count, name);
if (IS_ERR(cd))
return PTR_ERR(cd);
-
+
cdev = cdev_alloc();
if (!cdev)
goto out2;
cdev->owner = fops->owner;
cdev->ops = fops;
kobject_set_name(&cdev->kobj, "%s", name);
- for (s = strchr(kobject_name(&cdev->kobj),'/'); s; s = strchr(s, '/'))
- *s = '!';
-
- err = cdev_add(cdev, MKDEV(cd->major, 0), 256);
+
+ err = cdev_add(cdev, MKDEV(cd->major, baseminor), count);
if (err)
goto out;
out:
kobject_put(&cdev->kobj);
out2:
- kfree(__unregister_chrdev_region(cd->major, 0, 256));
+ kfree(__unregister_chrdev_region(cd->major, baseminor, count));
return err;
}
}
}
-int unregister_chrdev(unsigned int major, const char *name)
+/**
+ * __unregister_chrdev - unregister and destroy a cdev
+ * @major: major device number
+ * @baseminor: first of the range of minor numbers
+ * @count: the number of minor numbers this cdev is occupying
+ * @name: name of this range of devices
+ *
+ * Unregister and destroy the cdev occupying the region described by
+ * @major, @baseminor and @count. This function undoes what
+ * __register_chrdev() did.
+ */
+void __unregister_chrdev(unsigned int major, unsigned int baseminor,
+ unsigned int count, const char *name)
{
struct char_device_struct *cd;
- cd = __unregister_chrdev_region(major, 0, 256);
+
+ cd = __unregister_chrdev_region(major, baseminor, count);
if (cd && cd->cdev)
cdev_del(cd->cdev);
kfree(cd);
- return 0;
}
static DEFINE_SPINLOCK(cdev_lock);
/*
* Called every time a character special file is opened
*/
-int chrdev_open(struct inode * inode, struct file * filp)
+static int chrdev_open(struct inode *inode, struct file *filp)
{
struct cdev *p;
struct cdev *new = NULL;
return -ENXIO;
new = container_of(kobj, struct cdev, kobj);
spin_lock(&cdev_lock);
+ /* Check i_cdev again in case somebody beat us to it while
+ we dropped the lock. */
p = inode->i_cdev;
if (!p) {
inode->i_cdev = p = new;
- inode->i_cindex = idx;
list_add(&inode->i_devices, &p->list);
new = NULL;
} else if (!cdev_get(p))
cdev_put(new);
if (ret)
return ret;
+
+ ret = -ENXIO;
filp->f_op = fops_get(p->ops);
- if (!filp->f_op) {
- cdev_put(p);
- return -ENXIO;
- }
+ if (!filp->f_op)
+ goto out_cdev_put;
+
if (filp->f_op->open) {
- lock_kernel();
- ret = filp->f_op->open(inode,filp);
- unlock_kernel();
+ ret = filp->f_op->open(inode, filp);
+ if (ret)
+ goto out_cdev_put;
}
- if (ret)
- cdev_put(p);
+
+ return 0;
+
+ out_cdev_put:
+ cdev_put(p);
return ret;
}
*/
const struct file_operations def_chr_fops = {
.open = chrdev_open,
+ .llseek = noop_llseek,
};
static struct kobject *exact_match(dev_t dev, int *part, void *data)
{
struct cdev *p = kzalloc(sizeof(struct cdev), GFP_KERNEL);
if (p) {
- p->kobj.ktype = &ktype_cdev_dynamic;
INIT_LIST_HEAD(&p->list);
- kobject_init(&p->kobj);
+ kobject_init(&p->kobj, &ktype_cdev_dynamic);
}
return p;
}
{
memset(cdev, 0, sizeof *cdev);
INIT_LIST_HEAD(&cdev->list);
- cdev->kobj.ktype = &ktype_cdev_default;
- kobject_init(&cdev->kobj);
+ kobject_init(&cdev->kobj, &ktype_cdev_default);
cdev->ops = fops;
}
void __init chrdev_init(void)
{
cdev_map = kobj_map_init(base_probe, &chrdevs_lock);
+ bdi_init(&directly_mappable_cdev_bdi);
}
EXPORT_SYMBOL(cdev_alloc);
EXPORT_SYMBOL(cdev_del);
EXPORT_SYMBOL(cdev_add);
-EXPORT_SYMBOL(register_chrdev);
-EXPORT_SYMBOL(unregister_chrdev);
+EXPORT_SYMBOL(__register_chrdev);
+EXPORT_SYMBOL(__unregister_chrdev);
EXPORT_SYMBOL(directly_mappable_cdev_bdi);
projects / linux-flexiantxendom0-3.2.10.git / blobdiff