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// SPDX-License-Identifier: GPL-2.0-only
/*
* srm_env.c - Access to SRM environment
* variables through linux' procfs
*
* (C) 2001,2002,2006 by Jan-Benedict Glaw <jbglaw@lug-owl.de>
*
* This driver is a modified version of Erik Mouw's example proc
* interface, so: thank you, Erik! He can be reached via email at
* <J.A.K.Mouw@its.tudelft.nl>. It is based on an idea
* provided by DEC^WCompaq^WIntel's "Jumpstart" CD. They
* included a patch like this as well. Thanks for idea!
*/
#include <linux/kernel.h>
#include <linux/gfp.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <asm/console.h>
#include <linux/uaccess.h>
#include <asm/machvec.h>
#define BASE_DIR "srm_environment" /* Subdir in /proc/ */
#define NAMED_DIR "named_variables" /* Subdir for known variables */
#define NUMBERED_DIR "numbered_variables" /* Subdir for all variables */
#define VERSION "0.0.6" /* Module version */
#define NAME "srm_env" /* Module name */
MODULE_AUTHOR("Jan-Benedict Glaw <jbglaw@lug-owl.de>");
MODULE_DESCRIPTION("Accessing Alpha SRM environment through procfs interface");
MODULE_LICENSE("GPL");
typedef struct _srm_env {
char *name;
unsigned long id;
} srm_env_t;
static struct proc_dir_entry *base_dir;
static struct proc_dir_entry *named_dir;
static struct proc_dir_entry *numbered_dir;
static srm_env_t srm_named_entries[] = {
{ "auto_action", ENV_AUTO_ACTION },
{ "boot_dev", ENV_BOOT_DEV },
{ "bootdef_dev", ENV_BOOTDEF_DEV },
{ "booted_dev", ENV_BOOTED_DEV },
{ "boot_file", ENV_BOOT_FILE },
{ "booted_file", ENV_BOOTED_FILE },
{ "boot_osflags", ENV_BOOT_OSFLAGS },
{ "booted_osflags", ENV_BOOTED_OSFLAGS },
{ "boot_reset", ENV_BOOT_RESET },
{ "dump_dev", ENV_DUMP_DEV },
{ "enable_audit", ENV_ENABLE_AUDIT },
{ "license", ENV_LICENSE },
{ "char_set", ENV_CHAR_SET },
{ "language", ENV_LANGUAGE },
{ "tty_dev", ENV_TTY_DEV },
{ NULL, 0 },
};
static int srm_env_proc_show(struct seq_file *m, void *v)
{
unsigned long ret;
unsigned long id = (unsigned long)m->private;
char *page;
page = (char *)__get_free_page(GFP_USER);
if (!page)
return -ENOMEM;
ret = callback_getenv(id, page, PAGE_SIZE);
if ((ret >> 61) == 0) {
seq_write(m, page, ret);
ret = 0;
} else
ret = -EFAULT;
free_page((unsigned long)page);
return ret;
}
static int srm_env_proc_open(struct inode *inode, struct file *file)
{
return single_open(file, srm_env_proc_show, PDE_DATA(inode));
}
static ssize_t srm_env_proc_write(struct file *file, const char __user *buffer,
size_t count, loff_t *pos)
{
int res;
unsigned long id = (unsigned long)PDE_DATA(file_inode(file));
char *buf = (char *) __get_free_page(GFP_USER);
unsigned long ret1, ret2;
if (!buf)
return -ENOMEM;
res = -EINVAL;
if (count >= PAGE_SIZE)
goto out;
res = -EFAULT;
if (copy_from_user(buf, buffer, count))
goto out;
buf[count] = '\0';
ret1 = callback_setenv(id, buf, count);
if ((ret1 >> 61) == 0) {
do
ret2 = callback_save_env();
while((ret2 >> 61) == 1);
res = (int) ret1;
}
out:
free_page((unsigned long)buf);
return res;
}
static const struct proc_ops srm_env_proc_ops = {
.proc_open = srm_env_proc_open,
.proc_read = seq_read,
.proc_lseek = seq_lseek,
.proc_release = single_release,
.proc_write = srm_env_proc_write,
};
static int __init
srm_env_init(void)
{
srm_env_t *entry;
unsigned long var_num;
/*
* Check system
*/
if (!alpha_using_srm) {
printk(KERN_INFO "%s: This Alpha system doesn't "
"know about SRM (or you've booted "
"SRM->MILO->Linux, which gets "
"misdetected)...\n", __func__);
return -ENODEV;
}
/*
* Create base directory
*/
base_dir = proc_mkdir(BASE_DIR, NULL);
if (!base_dir) {
printk(KERN_ERR "Couldn't create base dir /proc/%s\n",
BASE_DIR);
return -ENOMEM;
}
/*
* Create per-name subdirectory
*/
named_dir = proc_mkdir(NAMED_DIR, base_dir);
if (!named_dir) {
printk(KERN_ERR "Couldn't create dir /proc/%s/%s\n",
BASE_DIR, NAMED_DIR);
goto cleanup;
}
/*
* Create per-number subdirectory
*/
numbered_dir = proc_mkdir(NUMBERED_DIR, base_dir);
if (!numbered_dir) {
printk(KERN_ERR "Couldn't create dir /proc/%s/%s\n",
BASE_DIR, NUMBERED_DIR);
goto cleanup;
}
/*
* Create all named nodes
*/
entry = srm_named_entries;
while (entry->name && entry->id) {
if (!proc_create_data(entry->name, 0644, named_dir,
&srm_env_proc_ops, (void *)entry->id))
goto cleanup;
entry++;
}
/*
* Create all numbered nodes
*/
for (var_num = 0; var_num <= 255; var_num++) {
char name[4];
sprintf(name, "%ld", var_num);
if (!proc_create_data(name, 0644, numbered_dir,
&srm_env_proc_ops, (void *)var_num))
goto cleanup;
}
printk(KERN_INFO "%s: version %s loaded successfully\n", NAME,
VERSION);
return 0;
cleanup:
remove_proc_subtree(BASE_DIR, NULL);
return -ENOMEM;
}
static void __exit
srm_env_exit(void)
{
remove_proc_subtree(BASE_DIR, NULL);
printk(KERN_INFO "%s: unloaded successfully\n", NAME);
}
module_init(srm_env_init);
module_exit(srm_env_exit);
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