diff options
Diffstat (limited to 'arch/alpha/kernel/srm_env.c')
| -rw-r--r-- | arch/alpha/kernel/srm_env.c | 218 |
1 files changed, 218 insertions, 0 deletions
diff --git a/arch/alpha/kernel/srm_env.c b/arch/alpha/kernel/srm_env.c new file mode 100644 index 000000000..217b4dca5 --- /dev/null +++ b/arch/alpha/kernel/srm_env.c @@ -0,0 +1,218 @@ +// 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); |