72 lines
1.4 KiB
C
72 lines
1.4 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/fs.h>
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#include <linux/init.h>
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#include <linux/proc_fs.h>
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#include <linux/seq_file.h>
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static int devinfo_show(struct seq_file *f, void *v)
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{
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int i = *(loff_t *) v;
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if (i < CHRDEV_MAJOR_MAX) {
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if (i == 0)
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seq_puts(f, "Character devices:\n");
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chrdev_show(f, i);
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}
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#ifdef CONFIG_BLOCK
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else {
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i -= CHRDEV_MAJOR_MAX;
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if (i == 0)
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seq_puts(f, "\nBlock devices:\n");
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blkdev_show(f, i);
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}
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#endif
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return 0;
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}
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static void *devinfo_start(struct seq_file *f, loff_t *pos)
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{
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if (*pos < (BLKDEV_MAJOR_MAX + CHRDEV_MAJOR_MAX))
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return pos;
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return NULL;
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}
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static void *devinfo_next(struct seq_file *f, void *v, loff_t *pos)
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{
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(*pos)++;
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if (*pos >= (BLKDEV_MAJOR_MAX + CHRDEV_MAJOR_MAX))
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return NULL;
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return pos;
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}
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static void devinfo_stop(struct seq_file *f, void *v)
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{
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/* Nothing to do */
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}
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static const struct seq_operations devinfo_ops = {
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.start = devinfo_start,
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.next = devinfo_next,
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.stop = devinfo_stop,
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.show = devinfo_show
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};
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static int devinfo_open(struct inode *inode, struct file *filp)
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{
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return seq_open(filp, &devinfo_ops);
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}
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static const struct file_operations proc_devinfo_operations = {
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.open = devinfo_open,
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.read = seq_read,
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.llseek = seq_lseek,
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.release = seq_release,
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};
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static int __init proc_devices_init(void)
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{
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proc_create("devices", 0, NULL, &proc_devinfo_operations);
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return 0;
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}
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fs_initcall(proc_devices_init);
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